U.S. Department of the Interior

Bureau of Ocean Energy Management

Gulf of Mexico OCS Region

OCS EIS/EA

BOEM 2015-001

Gulf of Mexico OCS 

Oil and Gas Lease Sales: 2016 and 2017

Central Planning Area Lease Sales 241 and 247

Eastern Planning Area Lease Sale 226

Draft Supplemental Environmental Impact Statement
U.S. Department of the Interior

Bureau of Ocean Energy Management Gulf of Mexico OCS Region

OCS EIS/EA

BOEM 2015-001

Gulf of Mexico OCS 

Oil and Gas Lease Sales: 2016 and 2017

Central Planning Area Lease Sales 241 and 247

Eastern Planning Area Lease Sale 226

Draft Supplemental Environmental Impact Statement

Author

Bureau of Ocean Energy Management

Gulf of Mexico OCS Region

Published by

New Orleans

January 2015



v 

COVER SHEET

Supplemental Environmental Impact Statement 

for 

Proposed Central Planning Area Lease Sales 241 and 247 

and 

Proposed Eastern Planning Area Lease Sale 226

Draft (x) Final ( ) 

Type of Action: Administrative (x) Legislative ( )

Area of Potential Impact: Offshore Marine Environment and Coastal Parishes/Counties of 

Louisiana, Mississippi, Alabama, and Florida

Agency Headquarters’ Contact Region Contacts

U.S. Department of the Interior

Bureau of Ocean Energy Management

Gulf of Mexico OCS Region

(GM 623E)

1201 Elmwood Park Boulevard

New Orleans, LA 70123-2394

Jennifer Bosyk

U.S. Department of the Interior

Bureau of Ocean Energy Management

381 Elden Street (HM 3107)

Herndon, VA 20170-4817

703-787-1843

Tershara Matthews

504-736-2676

Gary D. Goeke

504-736-3233

ABSTRACT

This Supplemental Environmental Impact Statement (EIS) addresses three proposed Gulf of Mexico

Outer Continental Shelf (OCS) oil and gas lease sales: Central Planning Area (CPA) Lease Sales 241 and 

247 and Eastern Planning Area (EPA) Lease Sale 226, as scheduled in the Proposed Final Outer 

Continental Shelf Oil & Gas Leasing Program: 2012-2017 (Five-Year Program) (USDOI, BOEM, 

2012a). 

This Supplemental EIS updates the baseline conditions and potential environmental effects of oil and 

natural gas leasing, exploration, development, and production in the CPA since publication of the Gulf of 

Mexico OCS Oil and Gas Lease Sales: 2012-2017; Western Planning Area Lease Sales 229, 233, 238, 

246, and 248; Central Planning Area Lease Sales 227, 231, 235, 241, and 247, Final Environmental 

Impact Statement (2012-2017 WPA/CPA Multisale EIS) (USDOI, BOEM, 2012b); Gulf of Mexico OCS 

Oil and Gas Lease Sales: 2013-2014; Western Planning Area Lease Sale 233; Central Planning Area 

Lease Sale 231, Final Supplemental Environmental Impact Statement (WPA 233/CPA 231 Supplemental 

EIS) (USDOI, BOEM, 2013a); and Gulf of Mexico OCS Oil and Gas Lease Sales: 2015-2017; Central 

Planning Area Lease Sales 235, 241, and 247, Final Supplemental Environmental Impact Statement 

(CPA 235/241/247 Supplemental EIS) (USDOI, BOEM, 2014). 

This Supplemental EIS also updates the baseline conditions and potential environmental effects of oil 

and natural gas leasing, exploration, development, and production in the EPA since publication of the 

Outer Continental Shelf Oil and Gas Leasing Program: 2012-2017, Final Programmatic Environmental 

Impact Statement (Five-Year Program EIS) (USDOI, BOEM, 2012c) and Gulf of Mexico OCS Oil and 

Gas Lease Sales: 2014 and 2016; Eastern Planning Area Lease Sales 225 and 226, Final Environmental 

Impact Statement (EPA 225/226 EIS) (USDOI, BOEM 2013b); and, due to the close proximity of the

proposed EPA lease sale area to the CPA, incorporates by reference all of the relevant material in the EIS 

and Supplemental EISs that were prepared for the nearby or adjacent CPA and that are referenced above.

This Supplemental EIS analyzes the potential impacts of a CPA proposed action and an EPA

proposed action on sensitive coastal environments, offshore marine resources, and socioeconomic 

resources both onshore and offshore. It is important to note that this Supplemental EIS was prepared 
vi

using the best information that was publicly available at the time the document was prepared. Where 

relevant information on reasonably foreseeable significant adverse impacts is incomplete or unavailable, 

the need for the information was evaluated to determine if it was essential to a reasoned choice among the 

alternatives and if so, was either acquired or in the event it was impossible or exorbitant to acquire the 

information, accepted scientific methodologies were applied in its place.

The proposed actions are considered to be major Federal actions requiring an EIS. This document 

provides the following information in accordance with the National Environmental Policy Act (NEPA)

and its implementing regulations, and it will be used in making decisions on the proposals. This 

document includes the purpose and background of a CPA and EPA proposed action, identification of the 

alternatives, description of the affected environment, and an analysis of the potential environmental 

impacts of a CPA and EPA proposed action, alternatives, and associated activities, including proposed 

mitigating measures and their potential effects. Potential contributions to cumulative impacts resulting 

from activities associated with a CPA and EPA proposed action are also analyzed.

Hypothetical scenarios were developed on the levels of activities, accidental events (such as oil 

spills), and potential impacts that might result if a CPA or EPA proposed action is adopted. Activities 

and disturbances associated with a CPA and EPA proposed action on biological, physical, and 

socioeconomic resources are considered in the analyses.

Additional copies of this Supplemental EIS and the EISs and Supplemental EISs referenced above, 

and the other referenced publications may be obtained from the Bureau of Ocean Energy Management, 

Gulf of Mexico OCS Region, Public Information Office (GM 323A), 1201 Elmwood Park Boulevard, 

New Orleans, Louisiana 70123-2394, by telephone at 504-736-2519 or 1-800-200-GULF, or on the 

Internet at http://www.boem.gov/nepaprocess/. 
Summary vii

SUMMARY

This Supplemental Environmental Impact Statement (EIS) addresses three proposed Federal actions 

that offer for lease an area on the Gulf of Mexico Outer Continental Shelf (OCS) that may contain 

economically recoverable oil and gas resources. Under the Proposed Final Outer Continental Shelf Oil & 

Gas Leasing Program: 2012-2017 (Five-Year Program) (USDOI, BOEM, 2012a), five proposed lease 

sales are scheduled for the Central Planning Area (CPA) and two proposed lease sales are scheduled for 

the Eastern Planning Area (EPA). The remaining two proposed lease sales within the CPA are proposed 

CPA Lease Sales 241 and 247, which are tentatively scheduled to be held in March 2016 and 2017, 

respectively, and the remaining proposed lease sale within the EPA is proposed EPA Lease Sale 226, 

which is tentatively scheduled for March 2016. Federal regulations allow for several related or similar 

proposals to be analyzed in one EIS (40 CFR § 1502.4). Since each lease sale proposal and projected 

activities are very similar, a single Supplemental EIS is being prepared for the two remaining proposed 

CPA lease sales and the one remaining proposed EPA lease sale. At the completion of this Supplemental 

EIS process, a decision will be made on whether or how to proceed with proposed CPA Lease Sale 241. 

It will also support a separate decision regarding proposed EPA Lease Sale 226. A separate National 

Environmental Policy Act (NEPA) review, in a form to be determined by the Bureau of Ocean Energy 

Management (BOEM), will be conducted prior to BOEM’s decision on whether or how to proceed with 

proposed CPA Lease Sale 247. 

This Supplemental EIS updates the baseline conditions and potential environmental effects of oil and 

natural gas leasing, exploration, development, and production in the CPA since publication of Gulf of 

Mexico OCS Oil and Gas Lease Sales: 2012-2017; Western Planning Area Lease Sales 229, 233, 238, 

246, and 248; Central Planning Area Lease Sales 227, 231, 235, 241, and 247, Final Environmental 

Impact Statement (2012-2017 WPA/CPA Multisale EIS) (USDOI, BOEM, 2012b); Gulf of Mexico OCS 

Oil and Gas Lease Sales: 2013-2014; Western Planning Area Lease Sale 233; Central Planning Area 

Lease Sale 231, Final Supplemental Environmental Impact Statement (WPA 233/CPA 231 Supplemental 

EIS) (USDOI, BOEM, 2013a); and Gulf of Mexico OCS Oil and Gas Lease Sales: 2015-2017; Central 

Planning Area Lease Sales 235, 241, and 247, Final Supplemental Environmental Impact Statement

(CPA 235/241/247 Supplemental EIS) (USDOI, BOEM, 2014a). 

This Supplemental EIS also updates the baseline conditions and potential environmental effects of oil 

and natural gas leasing, exploration, development, and production in EPA since publication of the Outer 

Continental Shelf Oil and Gas Leasing Program: 2012-2017, Final Programmatic Environmental Impact 

Statement (Five-Year Program EIS) (USDOI, BOEM, 2012c) and Gulf of Mexico OCS Oil and Gas Lease 

Sales: 2014 and 2016; Eastern Planning Area Lease Sales 225 and 226, Final Environmental Impact 

Statement (EPA 225/226 EIS) (USDOI, BOEM, 2013b). 

This Supplemental EIS analyzes the potential impacts of a CPA and EPA proposed action on 

sensitive coastal environments, offshore marine resources, and socioeconomic resources both onshore and 

offshore. It is important to note that this Supplemental EIS was prepared using the best information that 

was publicly available at the time this document was prepared. Where relevant information on reasonably 

foreseeable significant adverse impacts is incomplete or unavailable, the need for the information was 

evaluated to determine if it was essential to a reasoned choice among the alternatives and if so, it was 

either acquired or in the event it was impossible or exorbitant to acquire the information, accepted 

scientific methodologies were applied in its place.

This summary section provides only a brief overview of the proposed CPA and EPA lease sales, 

alternatives, significant issues, potential environmental and socioeconomic effects, and proposed 

mitigating measures contained in this Supplemental EIS. To obtain the full perspective and context of the 

potential environmental and socioeconomic impacts discussed, it is necessary to read the entire 

Supplemental EIS. Relevant discussions of specific topics can be found in the chapters and appendices of 

this Supplemental EIS as described below.

• Chapter 1, The Proposed Actions, describes the purpose of and need for the 

proposed lease sales, the prelease process, postlease activities, and other OCS oiland gas-related activities.
viii Central and Eastern Planning Areas Supplemental EIS

• Chapter 2, Alternatives Including the Proposed Actions, describes the environmental 

and socioeconomic effects of a proposed CPA and EPA lease sale and alternatives. 

Also discussed are the potential mitigating measures to avoid or minimize impacts.

• Chapter 3, Impact-Producing Factors and Scenario, describes the activities 

associated with a proposed lease sale and the OCS Program, and other foreseeable 

activities that could potentially affect the biological, physical, and socioeconomic 

resources of the Gulf of Mexico.

Chapter 3.1, Impact-Producing Factors and Scenario—Routine Operations, 

describes offshore infrastructure and activities (impact-producing factors) 

associated with a proposed lease sale that could potentially affect the 

biological, physical, and socioeconomic resources of the Gulf of Mexico.

Chapter 3.2, Impact-Producing Factors and Scenario—Accidental Events,

discusses potential accidental events (i.e., oil spills, losses of well control, 

vessel collisions, and spills of chemicals or drilling fluids) that may occur as 

a result of activities associated with a proposed lease sale.

Chapter 3.3, Cumulative Activities Scenario, describes past, present, and 

reasonably foreseeable future human activities, including non-OCS oil- and 

gas-related activities, as well as all OCS oil- and gas-related activities, that 

may affect the biological, physical, and socioeconomic resources of the Gulf 

of Mexico.

• Chapter 4, Description of the Environment and Impact Analysis, describes the 

affected environment and provides analysis of the routine, accidental, and cumulative 

impacts of a CPA proposed action and the alternatives on environmental and 

socioeconomic resources of the Gulf of Mexico.

Chapter 4.1, Proposed Central Planning Area Lease Sales 241 and 247, 

describes the routine, accidental, and cumulative impacts of a CPA proposed 

action and two alternatives to a CPA proposed action on the biological, 

physical, and socioeconomic resources of the Gulf of Mexico.

Chapter 4.2, Proposed Eastern Planning Area Lease Sale 226, describes the 

routine, accidental, and cumulative impacts of the EPA proposed action and 

one alternative to the EPA proposed action on the biological, physical, and 

socioeconomic resources of the Gulf of Mexico.

Chapter 4 also includes Chapter 4.3, Unavoidable Adverse Impacts of the 

Proposed Actions; Chapter 4.4, Irreversible and Irretrievable Commitment 

of Resources; and Chapter 4.5, Relationship Between the Short-term Use of 

Man’s Environment and the Maintenance and Enhancement of Long-Term 

Productivity.

• Chapter 5, Consultation and Coordination, describes the consultation and 

coordination activities with Federal, State, and local agencies and other interested 

parties that occurred during the development of this Supplemental EIS.

• Chapter 6, References Cited, is a list of literature cited throughout this Supplemental 

EIS.

• Chapter 7, Preparers, is a list of names of persons who were primarily responsible 

for preparing and reviewing this Supplemental EIS.

• Chapter 8, Glossary, is a list of definitions of selected terms used in this 

Supplemental EIS.
Summary ix

• Appendix A, Commonly Applied Mitigating Measures, is a list and description of 

standard postlease mitigating measures that may be required by BOEM or BSEE as a 

result of plan and/or permit review processes for the Gulf of Mexico OCS Region.

• Appendix B, Catastrophic Spill Event Analysis, is a technical analysis of a potential 

low-probability catastrophic event to assist BOEM in meeting the Council on 

Environmental Quality’s (CEQ) requirements for evaluating low-probability 

catastrophic events under NEPA. The CEQ regulations address impacts with 

catastrophic consequences in the context of evaluating reasonably foreseeable 

significant adverse effects in an EIS when they address the issue of incomplete or 

unavailable information (40 CFR § 1502.22). For NEPA purposes, “‘[r]easonably 

foreseeable’ impacts include impacts that have catastrophic consequences even if 

their probability of occurrence is low, provided that the analysis of the impacts is 

supported by credible scientific evidence, is not based on pure conjecture, and is 

within the rule of reason” (40 CFR § 1502.22(b)(4)). Therefore, this analysis, which 

is based on credible scientific evidence, identifies the most likely and most 

significant impacts from a high-volume blowout and oil spill that continues for an 

extended period of time. The scenario and impacts discussed in this analysis should 

not be confused with the scenario and impacts anticipated to result from routine 

activities or more reasonably foreseeable accidental events of a CPA proposed action.

• Appendix C, Memorandum of Agreement Between the Bureau of Ocean Energy 

Management and the National Park Service, outlines the responsibilities of BOEM 

and the National Park Service for this Supplemental EIS.

• Keyword Index is a list of descriptive terms and the pages on which they can be 

found in this Supplemental EIS.

Proposed Actions and Alternatives

The following alternatives were included for analysis in this Supplemental EIS.

Alternatives for Proposed Central Planning Area Lease Sales 241 and 247 

Alternative A—The Proposed Action (Preferred Alternative): This alternative would offer for lease 

all unleased blocks within the proposed CPA lease sale area for oil and gas operations (Figure 2-1), with 

the following exceptions:

(1) whole and portions of blocks deferred by the Gulf of Mexico Energy Security Act of 

2006; and

(2) blocks that are adjacent to or beyond the United States’ Exclusive Economic Zone 

in the area known as the northern portion of the Eastern Gap.

The U.S. Department of the Interior (DOI) is conservative throughout the NEPA process and includes 

the total area within the CPA for environmental review even though the leasing of portions of the CPA 

(subareas or blocks) can be deferred during a Five-Year Program. 

The proposed CPA lease sale area encompasses about 63 million acres (ac) of the CPA’s 

66.45 million ac. As of September 2014, approximately 44.2 million ac of the proposed CPA lease sale 

area are currently unleased. This information is updated monthly and can be found on BOEM’s website 

at http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The estimated amount of natural resources 

projected to be developed as a result of a proposed CPA lease sale is 0.460-0.894 billion barrels of oil 

(BBO) and 1.939-3.903 trillion cubic feet (Tcf) of gas (Table 3-1). 

Alternative A has been identified as BOEM’s preferred alternative; however, this does not mean that 

the other alternative may not be selected in the Record of Decision.

Alternative B—Exclude the Blocks Near Biologically Sensitive Topographic Features: This 

alternative would offer for lease all unleased blocks within the proposed CPA lease sale area, as described 
x Central and Eastern Planning Areas Supplemental EIS

for the proposed action (Alternative A), but it would exclude from leasing any unleased blocks subject to 

the Topographic Features Stipulation. The estimated amount of resources projected to be developed is 

0.460-0.894 BBO and 1.939-3.903 Tcf of gas. 

Alternative C—No Action: This alternative is the cancellation of a single proposed CPA lease sale. If 

this alternative is chosen, the opportunity for development of the estimated 0.460-0.894 BBO and 

1.939-3.903 Tcf of gas that could have resulted from a proposed CPA lease sale would be precluded 

during the current 2012-2017 Five-Year Program, but it could again be contemplated as part of a future 

Five-Year Program. Any potential environmental impacts arising out of a proposed CPA lease sale 

would not occur, but activities associated with existing leases in the CPA would continue.

Mitigating Measures

Proposed lease stipulations and other mitigating measures designed to reduce or eliminate 

environmental risks and/or potential multiple-use conflicts between OCS operations and U.S. Department 

of Defense activities may be applied to the chosen alternative. Ten lease stipulations are proposed for a 

CPA proposed lease sale—the Topographic Features Stipulation; the Live Bottom (Pinnacle Trend) 

Stipulation; the Military Areas Stipulation; the Evacuation Stipulation; the Coordination Stipulation; the 

Blocks South of Baldwin County, Alabama, Stipulation; the Protected Species Stipulation; the United 

Nations Convention on the Law of the Sea Royalty Payment Stipulation; the Below Seabed Operations 

Stipulation; and the Stipulation on the Agreement between the United States of America and the United 

Mexican States Concerning Transboundary Hydrocarbon Reservoirs in the Gulf of Mexico. The United 

Nations Convention on the Law of the Sea Royalty Payment Stipulation is applicable to proposed CPA 

lease sales even though it is not an environmental or military stipulation.

Application of lease stipulations will be considered by the Assistant Secretary of the Interior for Land 

and Minerals (ASLM). The inclusion of the stipulations as part of the analysis of a CPA proposed action 

does not ensure that the ASLM will make a decision to apply the stipulations to leases that may result 

from a proposed lease sale, nor does it preclude minor modifications in wording during subsequent steps 

in the prelease process if comments indicate changes are necessary or if conditions warrant. Any lease 

stipulations or mitigating measures to be included in a lease sale will be described in the Final Notice of 

Sale. Mitigating measures in the form of lease stipulations are added to the lease terms and are therefore 

enforceable as part of the lease. In addition, mitigations may be added to plans and/or permits for OCS 

oil- and gas-related activities. For more information on mitigating measures that are added at the 

postlease stage, refer to Appendix A (“Commonly Applied Mitigating Measures”).

Alternatives for Proposed Eastern Planning Area Lease Sale 226

Alternative A (Preferred Alternative)—The Proposed Action: This alternative would offer for lease 

all unleased blocks within the proposed EPA lease sale area for oil and gas operations.

The DOI is conservative throughout the NEPA process and includes the total area within the EPA for 

environmental review even though the leasing of portions of the EPA (subareas or blocks) can be deferred 

during a Five-Year Program.

The proposed EPA lease sale area covers approximately 657,905 ac and includes those blocks 

previously included in the EPA Lease Sales 224 and 225 Area and a triangular-shaped area south of this 

area bordered by the CPA boundary on the west and the Military Mission Line (86o41′ W. longitude) on 

the east. The area is south of eastern Alabama and western Florida; the nearest point of land is 125 miles 

(mi) (201 kilometers [km]) northwest in Louisiana. As of September 2014, approximately 465,200 ac of 

the proposed EPA lease sale area are currently unleased. This information is updated monthly and can be 

found on BOEM’s website at http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The estimated 

amount of natural resources projected to be developed as a result of a proposed EPA lease sale is 

0-0.071 BBO and 0-0.162 Tcf of gas.

Alternative A has been identified as BOEM’s preferred alternative; however, this does not mean that 

the other alternative may not be selected in the Record of Decision.

Alternative B—No Action: This alternative is the cancellation of the proposed EPA lease sale. If this 

alternative is chosen, the opportunity for development of the estimated 0-0.071 BBO and 0-0.162 Tcf of 

gas that could have resulted from the proposed EPA lease sale would be precluded or postponed. Any 

potential environmental impacts resulting from the proposed EPA lease sale would not occur or would be 
Summary xi

postponed to a future lease sale decision. This is also analyzed in the EIS for the Five-Year Program on a 

nationwide programmatic level.

Although for its NEPA analyses in other planning areas BOEM typically analyzes alternatives that 

defer blocks based on the proximity or presence of biologically sensitive features or for other 

programmatic reasons, BOEM has determined that such alternatives are not reasonable in the EPA as 

there are no known blocks to exclude due to proximity to or presence of biologically sensitive features 

and due to the fact that the proposed EPA lease sale area is such a small area for leasing. Scoping did not 

identify any other reasonable alternatives. And finally, other viable alternatives such as the deferral of 

blocks or the delay of the proposed EPA lease sale would essentially result in the same impacts as the No 

Action alternative, and therefore, do not need to be evaluated as separate and distinct alternatives.

Mitigating Measures

Proposed lease stipulations and other mitigating measures designed to reduce or eliminate 

environmental risks and/or potential multiple-use conflicts between OCS operations and U.S. Department 

of Defense activities may be applied to Alternative A. Only 4 of the 10 lease stipulations identified for a 

CPA proposed lease were found to be relevant for the EPA proposed lease sale and are proposed—the 

Protected Species Stipulation, the Military Areas Stipulation, the Evacuation Stipulation, and the 

Coordination Stipulation (refer to Chapter 2.2.2.1). 

Application of lease stipulations will be considered by the ASLM. The inclusion of the stipulations 

as part of the analysis of the EPA proposed action does not ensure that the ASLM will make a decision to 

apply the stipulations to leases that may result from the EPA proposed lease sale nor does it preclude 

minor modifications in wording during subsequent steps in the prelease process if comments indicate 

changes are necessary or if conditions warrant. Any stipulations or mitigation requirements to be 

included in the EPA lease sale will be described in the Final Notice of Sale. Mitigating measures in the 

form of lease stipulations are added to the lease terms and are therefore enforceable as part of the lease. 

In addition, mitigations may be added to plans and/or permits for OCS oil- and gas-related activities. For 

more information on mitigating measures that are added at the postlease stage, refer to Appendix A

(“Commonly Applied Mitigating Measures”).

Scenarios Analyzed

Offshore activities are described in the context of scenarios for a CPA and EPA proposed action 

(Chapter 3.1) and for the OCS Program (Chapter 3.3). BOEM’s Gulf of Mexico OCS Region 

developed these scenarios to provide a framework for detailed analyses of potential impacts of a proposed 

CPA and EPA lease sale. The scenarios are presented as ranges of the amounts of undiscovered, unleased 

hydrocarbon resources estimated to be leased and discovered as a result of a CPA or EPA proposed 

action. The analyses are based on a traditionally employed range of activities (e.g., the installation of 

platforms, wells, and pipelines, and the number of helicopter operations and service-vessel trips) that 

would be needed to develop and produce the amount of resources estimated to be leased.

The cumulative analyses (Chapters 4.1.1 and 4.2.1) consider environmental and socioeconomic 

impacts that may result from the incremental contribution of each CPA and EPA proposed action when 

added to all past, present, and reasonably foreseeable future activities, including non-OCS oil- and gasrelated activities such as import tankering and commercial fishing, as well as all OCS oil- and gas-related 

activities (OCS Program). The OCS Program scenario includes all activities that are projected to occur 

from past, proposed, and future lease sales during the 40-year analysis period (2012-2051). This includes 

projected activity from lease sales that have been held, but for which exploration or development has not 

yet begun or is continuing. In addition to human activities, impacts from natural occurrences, such as 

hurricanes, are analyzed.

Significant Issues

The major issues that frame the environmental analyses in this Supplemental EIS and in the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, CPA 235/241/247 Supplemental 

EIS, and EPA 225/226 EIS are the result of concerns raised during years of scoping for the Gulf of 

Mexico OCS Program. Issues related to OCS oil and gas exploration, development, production, and 

transportation activities include the potential for oil spills, wetlands loss, air emissions, discharges, water 
xii Central and Eastern Planning Areas Supplemental EIS

quality degradation, trash and debris, structure and pipeline emplacement activities, platform removal, 

vessel and helicopter traffic, multiple-use conflicts, support services, population fluctuations, demands on 

public services, land-use planning, impacts to tourism, aesthetic interference, cultural impacts, 

environmental justice, and conflicts with State coastal zone management programs. Environmental 

resources and activities identified during the scoping process that warrant environmental analyses include 

air quality, water quality, coastal barrier beaches and associated dunes, wetlands, seagrass communities, 

live bottoms, topographic features, Sargassum communities, deepwater benthic communities, soft bottom

benthic communities, marine mammals, sea turtles, diamondback terrapins, beach mice, coastal and 

marine birds, Gulf sturgeon, fish resources and essential fish habitat, commercial fisheries, recreational 

fishing, recreational resources, archaeological resources, and socioeconomic conditions. 

Other relevant issues include impacts from the Deepwater Horizon explosion, oil spill, and response;

impacts from past and future hurricanes on environmental and socioeconomic resources; and impacts on 

coastal and offshore infrastructure. During the past few years, both the Gulf Coast States and Gulf of 

Mexico oil and gas activities have been impacted by major hurricanes. The description of the affected 

environment (Chapters 4.1.1 and 4.2.1) includes impacts from these storms on the physical environment, 

biological environment, and socioeconomic activities and on OCS oil- and gas-related infrastructure. 

This Supplemental EIS also considers baseline data in the assessment of impacts from a CPA or EPA 

proposed action on the resources and the environment (Chapters 4.1.1 and 4.2.1). 

Impact Conclusions

The full analyses of the potential impacts of routine activities and accidental events associated with a 

CPA and EPA proposed action and a proposed action’s incremental contribution to the cumulative 

impacts are described in Chapters 4.1.1 and 4.2.1. A summary of the potential impacts from a CPA or 

EPA proposed action on each environmental and socioeconomic resource and the conclusions of the 

analyses can be found below.

Air Quality: Emissions of pollutants into the atmosphere from the routine activities associated with a 

CPA or EPA proposed action are projected to have minimal impacts to onshore air quality because of the 

prevailing atmospheric conditions, emission heights, emission rates, and the distance of these emissions 

from the coastline, and are expected to be well within the National Ambient Air Quality Standards. 

While regulations are in place to reduce the risk of impacts from hydrogen sulfide (H2S) and while no 

H2S-related deaths have occurred on the OCS, accidents involving high concentrations of H2S could result 

in deaths as well as environmental damage. Emissions from routine activities and accidental events 

associated with a CPA or EPA proposed action are not expected to occur at concentrations that would 

change onshore air quality classifications.

Water Quality (Coastal and Offshore Waters): Impacts from routine activities associated with a CPA 

or EPA proposed action would be minimal if all existing regulatory requirements are met. Coastal water 

impacts associated with routine activities include increases in turbidity resulting from pipeline installation 

and navigation canal maintenance, discharges of bilge and ballast water from support vessels, and run-off 

from shore-based facilities. Offshore water impacts associated with routine activities result from the 

discharge of drilling muds and cuttings, produced water, residual chemicals used during workovers, 

structure installation and removal, and pipeline placement. The discharge of drilling muds and cuttings 

causes temporary increased turbidity and changes in sediment composition. The discharge of produced 

water results in increased concentrations of some metals, hydrocarbons, and dissolved solids within an 

area of about 100 meters (m) (328 feet [ft]) adjacent to the point of discharge. Structure installation and 

removal and pipeline placement disturb the sediments and cause increased turbidity. In addition, offshore 

water impacts result from supply and service-vessel bilge and ballast water discharges. The potential 

impacts from accidental events (primarily oil spills) associated with a CPA or EPA proposed action are 

anticipated to be minimal.

Coastal Barrier Beaches and Associated Dunes: Routine activities associated with a CPA or EPA

proposed action, such as increased vessel traffic, maintenance dredging of navigation canals, and pipeline 

installation, would cause negligible impacts. Such impacts would be expected to be restricted to 

temporary and localized disturbances and not deleteriously affect barrier beaches and associated dunes. 

Indirect impacts from routine activities are negligible and indistinguishable from direct impacts of 

onshore activities. The potential impacts from accidental events (primarily oil spills) associated with a 

CPA or EPA proposed action are anticipated to be minimal. Should a spill (other than a low-probability 
Summary xiii

catastrophic spill, which is not part of a CPA proposed action and not likely expected) contact a barrier 

beach, oiling is expected to be light and sand removal during cleanup activities minimized. No significant 

long-term impacts to the physical shape and structure of barrier beaches and associated dunes are 

expected to occur as a result of a CPA or EPA proposed action.

Wetlands: Routine activities associated with a CPA or EPA proposed action are expected to be small, 

localized, and temporary due to the small length of projected onshore pipelines, the minimal contribution 

to the need for maintenance dredging, the disposal of OCS wastes, and the mitigating measures that 

would be used to further reduce these impacts. Indirect impacts from wake erosion and saltwater 

intrusion are expected to result in low impacts that are indistinguishable from direct impacts from inshore 

activities. The potential impacts from accidental events (primarily oil spills) are anticipated to be 

minimal. Overall, impacts to wetland habitats from an oil spill associated with activities related to a CPA 

or EPA proposed action would be expected to be small and temporary because of the nature of the 

wetland system, regulations, and specific cleanup techniques.

Seagrass Communities: Turbidity impacts from pipeline installation and maintenance dredging 

associated with a CPA or EPA proposed action would be temporary and localized. The increment of 

impacts from service-vessel transit associated with a CPA or EPA proposed action would be minimal. 

Should an oil spill occur near a seagrass community, impacts from the spill and cleanup would be 

considered short term in duration and minor in scope. Close monitoring and restrictions on the use of 

bottom-disturbing equipment to clean up the spill would be needed to avoid or minimize those impacts.

Live Bottoms (Pinnacle Trend and Low Relief): The combination of its depth (200-400 ft; 60-120 m), 

separation from sources of impacts as mandated by the Live Bottom (Pinnacle Trend) Stipulation and 

through site-specific seafloor reviews of proposed activity, and a community adapted to sedimentation

makes damage to the ecosystem unlikely from routine activities associated with a CPA or EPA proposed 

action. In the unlikely event that oil from a subsurface spill would reach the biota of these communities, 

the effects would be primarily sublethal for adult sessile biota, and there would be limited incidences of 

mortality.

Topographic Features: The routine activities associated with a CPA or EPA proposed action that 

would impact topographic feature communities include anchoring, infrastructure and pipeline 

emplacement, infrastructure removal, drilling discharges, and produced-water discharges. However, 

adherence to the proposed Topographic Features Stipulation would make damage to the ecosystem 

unlikely. Contact with accidentally spilled oil would cause lethal and sublethal effects in benthic 

organisms, but the oiling of benthic organisms is not likely because of the small area of the banks, the 

scattered occurrence of spills, the depth of the features, and because the proposed Topographic Features 

Stipulation, if applied, would keep subsurface sources of spills away from the immediate vicinity of 

topographic features.

Sargassum Communities: The impacts that are associated with a CPA or EPA proposed action are 

expected to have only minor effects to a small portion of the Sargassum community as a whole. Limited 

portions of the Sargassum community could suffer mortality if it contacts spilled oil or cleanup activities. 

The Sargassum community lives in pelagic waters with generally high water quality and would be 

resilient to the minor effects predicted. It has a yearly cycle that promotes quick recovery from impacts. 

No measurable impacts are expected to the overall population of the Sargassum community from a CPA 

or EPA proposed action.

Chemosynthetic and Nonchemosynthetic Deepwater Benthic Communities: Chemosynthetic and 

nonchemosynthetic communities are susceptible to physical impacts from structure placement, anchoring, 

and pipeline installation associated with a CPA or EPA proposed action. However, the policy 

requirements described in Notice to Lessees and Operators (NTL) 2009-G40 greatly reduce the risk of 

these physical impacts by clarifying the measures that must be taken to ensure avoidance of potential 

chemosynthetic communities and, by consequence, avoidance of other hard bottom communities. Even in 

situations where substantial burial of typical benthic infaunal communities occurred, recolonization by 

populations from widespread, neighboring, soft bottom substrate would be expected over a relatively 

short period of time for all size ranges of organisms. Potential accidental events associated with a CPA or 

EPA proposed action are expected to cause little damage to the ecological function or biological 

productivity of the widespread, low-density chemosynthetic communities and the widespread, typical, 

deep-sea benthic communities.

Soft Bottom Benthic Communities: The routine activities associated with a CPA or EPA proposed 

action that would impact soft bottoms generally occur within a few hundred meters of platforms, and the 
xiv Central and Eastern Planning Areas Supplemental EIS

greatest impacts are seen close to the platform communities. Although localized impacts to 

comparatively small areas of the soft bottom benthic communities would occur, the impacts would be on 

a relatively small area of the seafloor compared with the overall area of the seafloor of the CPA 

(268,922 km2

; 103,831 mi2). A CPA or EPA proposed action is not expected to adversely impact the 

entire soft bottom environment because the local impacted areas are extremely small compared with the 

entire seafloor of the Gulf of Mexico and because the soft bottom benthic communities are ubiquitous 

throughout the Gulf of Mexico. 

Marine Mammals: Routine events related to a CPA or EPA proposed action are not expected to have 

adverse effects on the size and productivity of any marine mammal species or population in the northern 

Gulf of Mexico. Impacts from vessel traffic, structure removals, and seismic activity could negatively 

impact marine mammals by increasing noise levels, as well as having the potential to harm or harass 

marine mammal species. These activities, when mitigated as required by BOEM and the National Marine 

Fisheries Service, are not expected to have long-term impacts on the size and productivity of any marine 

mammal species or population. Characteristics of impacts from accidental events depend on chronic or 

acute exposure from accidental events resulting in harassment, harm, or mortality to marine mammals, 

while exposure to dispersed hydrocarbons is likely to result in sublethal impacts.

Sea Turtles: Routine activities resulting from a CPA or EPA proposed action have the potential to 

harm sea turtles, although this potential is unlikely to rise to a level of significance due to the activity 

already present in the Gulf of Mexico and due to mitigating measures that are in place. Accidental events 

associated with a CPA or EPA proposed action have the potential to impact small to large numbers of sea 

turtles. Populations of sea turtles in the northern Gulf of Mexico may be exposed to residuals of oils 

spilled as a result of a CPA or EPA proposed action during their lifetimes. While chronic or acute 

exposure from accidental events may result in the harassment, harm, or mortality to sea turtles, in the 

most likely scenarios, exposure to hydrocarbons persisting in the sea following the dispersal of an oil 

slick are expected to most often result in sublethal impacts (e.g., decreased health and/or reproductive 

fitness and increased vulnerability to disease) to sea turtles. The incremental contribution of a CPA or 

EPA proposed action would not be likely to result in a significant incremental impact on sea turtles within 

the CPA or EPA; in comparison, non-OCS energy-related activities, such as overexploitation, commercial 

fishing, and pollution, have historically proved to be a greater threat to the sea turtle species.

Diamondback Terrapins: The routine activities of a CPA or EPA proposed action are unlikely to 

have significant adverse effects on the size and recovery of terrapin species or populations in the Gulf of 

Mexico. Impacts on diamondback terrapins from smaller accidental events are likely to affect individual 

diamondback terrapins in the spill area, but they are unlikely to rise to the level of population effects (or 

significance) given the probable size and scope of such spills. Due to the distance of most terrapin habitat 

from offshore OCS energy-related activities, impacts associated with activities occurring as a result of a 

CPA or EPA proposed action are not expected to impact terrapins or their habitat. The incremental effect 

of a CPA or EPA proposed action on diamondback terrapin populations is not expected to be significant 

when compared with historic and current non-OCS energy-related activities, such as habitat loss, 

overharvesting, crabbing, and fishing.

Beach Mice: An impact from the consumption of beach trash and debris associated with a CPA or 

EPA proposed action on the Alabama, Choctawhatchee, St. Andrew, and Perdido Key beach mice is 

possible but unlikely. While potential spills that could result from a CPA or EPA proposed action are not 

expected to contact beach mice or their habitats, large-scale oiling of beach mice could result in 

extinction, and, if all personnel are not thoroughly trained, oil-spill response and cleanup activities could 

have a significant impact to the beach mice and their habitat.

Coastal and Marine Birds: The majority of impacts resulting from routine activities associated with a 

CPA or EPA proposed action on threatened and endangered and nonthreatened and nonendangered avian 

species are expected to be adverse, but not significant. These impacts include behavioral effects, 

exposure to or intake of OCS oil- and gas-related contaminants and discarded debris, disturbance-related 

impacts, and displacement of birds from habitats that are destroyed, altered, or fragmented, making these 

areas otherwise unavailable. Impacts from potential oil spills associated with a CPA or EPA proposed 

action and the effects related to oil-spill cleanup are expected to be adverse, but not significant. Oil spills, 

irrespective of size, can result in some mortality as well as sublethal, chronic short- and long-term effects, 

in addition to potential impacts to food resources. The effect of cumulative activities on coastal and 

marine birds is expected to result in discernible changes to avian species’ composition, distribution, and 

abundance. The incremental contribution of a CPA or EPA proposed action to cumulative impacts is 
Summary xv

expected to be adverse, but not significant, because it may seriously alter avian species’ composition and 

abundance due to reductions in the overall carrying capacity of disturbed habitats, and possibly to the 

availability, abundance, and distribution of preferred food resources.

Gulf Sturgeon: Routine activities associated with a CPA or EPA proposed action, such as the 

installation of pipelines, maintenance dredging, potential vessel strikes, and nonpoint-source runoff from 

onshore facilities, would cause negligible impacts and would not deleteriously affect Gulf sturgeon. 

Indirect impacts from routine activities to inshore habitats are negligible and indistinguishable from direct 

impacts of inshore activities and are further reduced through mitigations and regulations. The potential 

impacts from accidental events, mainly oil spills associated with a CPA or EPA proposed action, are 

anticipated to be minimal. Because of the floating nature of oil, reduced toxicity through weathering 

(offshore dispersant treatment), and the small tidal range of the Gulf of Mexico, oil spills alone would 

typically have very little impact on benthic feeders such as the Gulf sturgeon. The incremental 

contribution of a CPA or EPA proposed action to the cumulative impact is negligible.

Fish Resources and Essential Fish Habitat: Fish resources and essential fish habitat could be 

impacted by coastal environmental degradation potentially caused by canal dredging, increases in 

infrastructure, and inshore spills and marine environmental degradation possibly caused by pipeline 

trenching, offshore discharges, and offshore spills. Impacts of routine dredging and discharges are 

localized in time and space and are regulated by Federal and State agencies through permitting processes; 

therefore, there would be minimal impact to fish resources and essential fish habitat from these routine 

activities associated with a CPA or EPA proposed action. Accidental events that could impact fish 

resources and essential fish habitat include blowouts and oil or chemical spills. If a spill were to occur as 

a result of a CPA or EPA proposed action and if it was proximate to mobile fishes, the impacts of the spill 

would depend on multiple factors, including the amount spilled, the areal extent of the spill, the distance 

of the spill from particular essential fish habitats (e.g., nursery habitats), and the type and toxicity of oil 

spilled. Much of the sensitive essential fish habitat would have decreased effects from oil spills because 

of the depths many are found and because of the distance that these low-probability spills would occur 

from many of the essential fish habitats (due to stipulations, NTLs, etc.). If there is an effect of an oil 

spill on fish resources in the Gulf of Mexico, it is expected to cause a minimal decrease in standing stocks 

of any population. This is because most spill events would be localized, therefore affecting a small 

portion of fish populations.

Commercial Fisheries: Routine activities in the CPA and EPA, such as seismic surveys and pipeline 

trenching, would cause negligible impacts and would not deleteriously affect commercial fishing 

activities. Indirect impacts from routine activities to inshore habitats are negligible and indistinguishable 

from direct impacts of inshore activities on commercial fisheries. The potential impacts from accidental 

events, such as a well blowout or an oil spill, associated with a CPA or EPA proposed action are 

anticipated to be minimal. Commercial fishermen are anticipated to avoid the area of a well blowout or 

an oil spill. Large spills may impact commercial fisheries by area closures. The extent of impact depends 

on the areal extent and length of the closure. The impact of spills on catch or value of catch would 

depend on the volume and location (i.e., distance from shore) of the spill, as well as the physical 

properties of the oil spilled.

Recreational Fishing: There could be minor and short-term, space-use conflicts with recreational 

fishermen during the initial phases of a CPA or EPA proposed action. A CPA or EPA proposed action 

could also lead to low-level environmental degradation of fish habitat, which would also negatively 

impact recreational fishing activity. However, these minor negative effects would be offset by the 

beneficial role that oil platforms serve as artificial reefs for fish populations. An oil spill would likely 

lead to recreational fishing closures in the vicinity of the oil spill. Except for a low-probability 

catastrophic spill, which is not part of a CPA or EPA proposed action and not likely expected (e.g., the 

Deepwater Horizon oil spill), oil spills should not affect recreational fishing to a large degree due to the 

likely availability of substitute fishing sites in neighboring regions.

Recreational Resources: Routine OCS oil- and gas-related activities can cause minor disturbances to 

recreational resources, particularly beaches, through increased levels of noise, debris, and rig visibility. 

The oil spills most likely to result from a CPA or EPA proposed action would be small, of short duration, 

and not likely to impact Gulf Coast recreational resources. Should an oil spill occur and contact a beach 

area or other recreational resource, it would cause some disruption during the impact and cleanup phases 

of the spill. However, except for a low-probability catastrophic spill, which is not part of a CPA or EPA
xvi Central and Eastern Planning Areas Supplemental EIS

proposed action and not likely expected (e.g., the Deepwater Horizon oil spill), these effects are likely to 

be small in scale and of short duration.

Archaeological Resources (Historic and Prehistoric): The greatest potential impact to an 

archaeological resource as a result of routine activities associated with a CPA or EPA proposed action 

would result from direct contact between an offshore activity (e.g., platform installation, drilling rig 

emplacement, structure removal or site clearance operation, and dredging or pipeline project) and a 

historic or prehistoric site. The archaeological survey and archaeological clearance of sites, where 

required prior to an operator beginning OCS oil- and gas-related activities on a lease, are expected to be 

highly effective at identifying possible offshore archaeological sites; however, should such contact occur, 

there would be localized damage to or loss of significant and/or unique archaeological information. It is 

expected that coastal archaeological resources would be protected through the review and approval 

processes of the various Federal, State, and local agencies involved in permitting onshore activities.

It is not very likely that a large oil spill would occur and contact coastal prehistoric or historic 

archaeological sites from accidental events associated with a CPA or EPA proposed action. Should a spill 

contact a prehistoric archaeological site, damage might include loss of radiocarbon-dating potential, direct 

impact from oil-spill cleanup equipment, and/or looting resulting in the irreversible loss of unique or 

significant archaeological information. The major effect from an oil-spill impact on coastal historic 

archaeological sites would be visual contamination, which, while reversible, could result in additional 

impacts to fragile cultural materials from the cleaning process.

Land Use and Coastal Infrastructure: A CPA or EPA proposed action would not require additional 

coastal infrastructure, with the exception of possibly one new gas processing facility and one new pipeline 

landfall, and it would not alter the current land use of the analysis area. The existing oil and gas 

infrastructure is expected to be sufficient to handle development associated with a CPA and EPA 

proposed action. There may be some expansion at current facilities, but the land in the analysis area is 

sufficient to handle such development. There is also sufficient land to construct a new gas processing 

plant in the analysis area, should it be needed. Accidental events such as oil or chemical spills, blowouts, 

and vessel collisions would have no effects on land use. Coastal or nearshore spills, as well as vessel 

collisions, could have short-term adverse effects on coastal infrastructure, requiring cleanup of any oil or 

chemicals spilled.

Demographics: A CPA or EPA proposed action is projected to minimally affect the demography of 

the analysis area. Population impacts from a CPA or EPA proposed action are projected to be minimal 

(<1% of total population) for any economic impact area in the Gulf of Mexico region. The baseline 

population patterns and distributions, as projected and described in Chapters 4.1.1.23.2 and 4.2.1.22.2, 

are expected to remain unchanged as a result of a CPA or EPA proposed action. The increase in 

employment is expected to be met primarily with the existing population and available labor force, with 

the exception of some in-migration (from elsewhere within or outside the U.S.), which is projected to 

move into focal areas such as Port Fourchon. Accidental events associated with a CPA or EPA proposed 

action, such as oil or chemical spills, blowouts, and vessel collisions, would likely have no effects on the 

demographic characteristics of the Gulf coastal communities.

Economic Factors: A CPA or EPA proposed action is expected to generate a <1 percent increase in 

employment in any of the coastal subareas, even when the net employment impacts from accidental 

events are included. Most of the employment related to a CPA or EPA proposed action is expected to 

occur in Louisiana and Texas. The demand would be met primarily with the existing population and 

labor force.

Environmental Justice: Environmental justice implications arise indirectly from onshore activities 

conducted in support of OCS oil and gas exploration, development, and production. Because the onshore 

infrastructure support system for the OCS oil- and gas-related industry (and its associated labor force) is 

highly developed, widespread, and has operated for decades within a heterogeneous Gulf of Mexico 

population, a CPA or EPA proposed action is not expected to have disproportionately high or adverse 

environmental or health effects on minority or low-income people. A CPA or EPA proposed action 

would help to maintain ongoing levels of activity, which may or may not result in the expansion of 

existing infrastructure. For a detailed discussion of scenario projections and the potential for expansion at 

existing facilities and/or construction of new facilities, refer to Chapter 3.1.2. 
Table of Contents xvii

TABLE OF CONTENTS

Page

SUMMARY................................................................................................................................................vii

LIST OF FIGURES ................................................................................................................................. xxiii

LIST OF TABLES.................................................................................................................................... xxv

ABBREVIATIONS AND ACRONYMS ...............................................................................................xxvii

CONVERSION CHART .........................................................................................................................xxxi

1. THE PROPOSED ACTIONS .............................................................................................................. 1-3

1.1. Purpose of and Need for the Proposed Actions ....................................................................... 1-3

1.2. Description of the Proposed Actions ....................................................................................... 1-5

1.3. Regulatory Framework ............................................................................................................ 1-6

1.3.1. Recent BOEM/BSEE Rule Changes......................................................................... 1-8

1.3.1.1. Recent and Ongoing Regulatory Reform and GovernmentSponsored Research ................................................................................. 1-8

1.3.1.2. Recent and Ongoing Industry Reform and Research ............................. 1-10

1.4. Prelease Process..................................................................................................................... 1-10

1.5. Postlease Activities................................................................................................................ 1-13

1.6. Other OCS Oil- and Gas-Related Activities .......................................................................... 1-14

2. ALTERNATIVES INCLUDING THE PROPOSED ACTIONS ........................................................ 2-3

2.1. Supplemental EIS NEPA Analysis.......................................................................................... 2-3

2.2. Alternatives, Mitigating Measures, and Issues ........................................................................ 2-3

2.2.1. Alternatives ............................................................................................................... 2-3

2.2.1.1. Alternatives for Proposed Central Planning Area Lease Sales 

241 and 247.............................................................................................. 2-4

2.2.1.2. Alternatives for Proposed Eastern Planning Area Lease Sale 226........... 2-5

2.2.2. Mitigating Measures.................................................................................................. 2-6

2.2.2.1. Proposed Mitigating Measures Analyzed ................................................ 2-6

2.2.2.2. Existing Mitigating Measures.................................................................. 2-7

2.2.3. Issues......................................................................................................................... 2-8

2.2.3.1. Issues to be Analyzed............................................................................... 2-8

2.2.3.2. Issues Considered but Not Analyzed ....................................................... 2-9

2.3. Proposed Central Planning Area Lease Sales 241 and 247...................................................... 2-9

2.3.1. Alternative A—The Proposed Action ....................................................................... 2-9

2.3.1.1. Description............................................................................................... 2-9

2.3.1.2. Summary of Impacts.............................................................................. 2-10

2.3.1.3. Mitigating Measures .............................................................................. 2-11

2.3.1.3.1. Topographic Features Stipulation ....................................... 2-11

2.3.1.3.2. Live Bottom (Pinnacle Trend) Stipulation .......................... 2-12

2.3.1.3.3. Military Areas Stipulation................................................... 2-12

2.3.1.3.4. Evacuation Stipulation ........................................................ 2-12

2.3.1.3.5. Coordination Stipulation ..................................................... 2-13
xviii Central and Eastern Planning Areas Supplemental EIS

2.3.1.3.6. Blocks South of Baldwin County, Alabama, 

Stipulation ........................................................................... 2-13

2.3.1.3.7. Protected Species Stipulation .............................................. 2-13

2.3.1.3.8. United Nations Convention on the Law of the Sea 

Royalty Payment Stipulation............................................... 2-13

2.3.1.3.9. Below Seabed Operations Stipulation................................. 2-13

2.3.1.3.10. Stipulation on the Agreement between the United 

States of America and the United Mexican States 

Concerning Transboundary Hydrocarbon Reservoirs 

in the Gulf of Mexico .......................................................... 2-13

2.3.2. Alternative B—Exclude the Unleased Blocks Near the Biologically 

Sensitive Topographic Features .............................................................................. 2-14

2.3.2.1. Description............................................................................................. 2-14

2.3.2.2. Summary of Impacts.............................................................................. 2-14

2.3.3. Alternative C—No Action....................................................................................... 2-14

2.3.3.1. Description............................................................................................. 2-14

2.3.3.2. Summary of Impacts.............................................................................. 2-15

2.4. Proposed Eastern Planning Area Lease Sale 226................................................................... 2-15

2.4.1. Alternative A—The Proposed Action ..................................................................... 2-15

2.4.1.1. Description............................................................................................. 2-15

2.4.1.2. Summary of Impacts.............................................................................. 2-15

2.4.1.3. Mitigating Measures .............................................................................. 2-17

2.4.1.3.1. Protected Species Stipulation .............................................. 2-17

2.4.1.3.2. Military Areas Stipulation................................................... 2-17

2.4.1.3.3. Evacuation Stipulation ........................................................ 2-17

2.4.1.3.4. Coordination Stipulation ..................................................... 2-18

2.4.2. Alternative B—No Action....................................................................................... 2-18

2.4.2.1. Description............................................................................................. 2-18

2.4.2.2. Summary of Impacts .............................................................................. 2-18

3. IMPACT-PRODUCING FACTORS AND SCENARIO .................................................................... 3-3

3.1. Impact-Producing Factors and Scenario—Routine Operations............................................... 3-3

3.1.1. Offshore Impact-Producing Factors and Scenario .................................................... 3-3

3.1.1.1. Resource Estimates and Timetables......................................................... 3-4

3.1.1.1.1. Proposed Actions................................................................... 3-4

3.1.1.1.2. OCS Program ........................................................................ 3-5

3.1.1.2. Exploration and Delineation .................................................................... 3-6

3.1.1.2.1. Seismic Surveying Operations .............................................. 3-6

3.1.1.2.2. Exploration and Delineation Plans and Drilling.................... 3-7

3.1.1.3. Development and Production................................................................... 3-8

3.1.1.4. Operational Waste Discharged Offshore................................................ 3-11

3.1.1.5. Air Emissions......................................................................................... 3-12

3.1.1.6. Noise ...................................................................................................... 3-12

3.1.1.7. Major Sources of Oil Inputs in the Gulf of Mexico ............................... 3-13

3.1.1.8. Offshore Transport................................................................................. 3-13

3.1.1.9 Safety Issues........................................................................................... 3-14

3.1.1.10. Decommissioning and Removal Operations.......................................... 3-14

3.1.2. Coastal Impact-Producing Factors and Scenario..................................................... 3-14

3.1.2.1. Coastal Infrastructure ............................................................................. 3-14

3.1.2.2. Discharges and Wastes........................................................................... 3-16
Table of Contents xix 

3.2. Impact-Producing Factors and Scenario—Accidental Events ............................................... 3-17

3.2.1. Oil Spills .................................................................................................................. 3-17

3.2.1.1. Spill Prevention ...................................................................................... 3-17

3.2.1.2. Past OCS Spills ...................................................................................... 3-17

3.2.1.3. Characteristics of OCS Oil ..................................................................... 3-18

3.2.1.4. Overview of Spill Risk Analysis ............................................................ 3-19

3.2.1.5. Risk Analysis for Offshore Spills 1,000 bbl ........................................ 3-19

3.2.1.6. Risk Analysis for Offshore Spills <1,000 bbl ........................................ 3-20

3.2.1.7. Risk Analysis for Coastal Spills ............................................................. 3-21

3.2.1.8. Risk Analysis by Resource ..................................................................... 3-21

3.2.1.9. Spill Response ........................................................................................ 3-22

3.2.2. Losses of Well Control ............................................................................................ 3-26

3.2.3. Pipeline Failures ...................................................................................................... 3-27

3.2.4. Vessel Collisions ..................................................................................................... 3-27 

3.2.5. Chemical and Drilling-Fluid Spills ......................................................................... 3-27 

3.3. Cumulative Activities Scenario ............................................................................................. 3-28

3.3.1. OCS Program .......................................................................................................... 3-28

3.3.2. State Oil and Gas Activity ....................................................................................... 3-29

3.3.3. Other Major Factors Influencing Offshore Environments ...................................... 3-30

3.3.3.1. Dredged Material Disposal .................................................................... 3-30

3.3.3.2. OCS Sand Borrowing ............................................................................. 3-31

3.3.3.3. Marine Transportation ............................................................................ 3-32

3.3.3.4. Military Activities .................................................................................. 3-32

3.3.3.5. Artificial Reefs and Rigs-to-Reefs Development ................................... 3-33

3.3.3.6. Offshore Liquefied Natural Gas Projects and Deepwater Ports ............. 3-34

3.3.3.7. Development of Gas Hydrates ............................................................... 3-34

3.3.3.8. Renewable Energy and Alternative Use ................................................. 3-34

3.3.4. Other Major Factors Influencing Coastal Environments ......................................... 3-36

3.3.4.1. Sea-Level Rise and Subsidence ............................................................. 3-36

3.3.4.2. Mississippi River Hydromodification .................................................... 3-36

3.3.4.3. Maintenance Dredging and Federal Channels ....................................... 3-36

3.3.4.4. Coastal Restoration Programs ................................................................ 3-37

3.3.5. Natural Events and Processes .................................................................................. 3-39

3.3.6. Non-OCS Oil- and Gas-Related Oil Spills .............................................................. 3-40

4. DESCRIPTION OF THE ENVIRONMENT AND IMPACT ANALYSIS ........................................ 4-3

4.1. Proposed Central Planning Area Lease Sales 241 and 247 ...................................................... 4-3

4.1.1. Alternative A—The Proposed Action ....................................................................... 4-9

4.1.1.1. Air Quality ............................................................................................... 4-9

4.1.1.2. Water Quality ......................................................................................... 4-12

4.1.1.2.1. Coastal Waters ..................................................................... 4-12

4.1.1.2.2. Offshore Waters .................................................................. 4-15

4.1.1.3. Coastal Barrier Beaches and Associated Dunes ..................................... 4-18

4.1.1.4. Wetlands ................................................................................................. 4-22

4.1.1.5. Seagrass Communities ........................................................................... 4-26

4.1.1.6. Live Bottoms (Pinnacle Trend and Low Relief) .................................... 4-29

4.1.1.7. Topographic Features ............................................................................. 4-32

4.1.1.8. Sargassum Communities ........................................................................ 4-36

4.1.1.9. Chemosynthetic Deepwater Benthic Communities ................................ 4-40

4.1.1.10. Nonchemosynthetic Deepwater Benthic Communities .......................... 4-44
xx Central and Eastern Planning Areas Supplemental EIS

4.1.1.11. Soft Bottom Benthic Communities ........................................................ 4-48

4.1.1.12. Marine Mammals ................................................................................... 4-51

4.1.1.13. Sea Turtles .............................................................................................. 4-56

4.1.1.14. Diamondback Terrapins ......................................................................... 4-60

4.1.1.15. Beach Mice ............................................................................................ 4-63

4.1.1.16. Coastal and Marine Birds ....................................................................... 4-66

4.1.1.17. Gulf Sturgeon ......................................................................................... 4-70

4.1.1.18. Fish Resources and Essential Fish Habitat ............................................. 4-72

4.1.1.19. Commercial Fisheries............................................................................. 4-76

4.1.1.20. Recreational Fishing............................................................................... 4-80

4.1.1.21. Recreational Resources .......................................................................... 4-83

4.1.1.22. Archaeological Resources ...................................................................... 4-86

4.1.1.22.1. Historic Archaeological Resources ..................................... 4-86

4.1.1.22.2. Prehistoric Archaeological Resources ................................. 4-89

4.1.1.23. Human Resources and Land Use ........................................................... 4-92

4.1.1.23.1. Land Use and Coastal Infrastructure ................................... 4-92

4.1.1.23.2. Demographics ...................................................................... 4-98

4.1.1.23.3. Economic Factors .............................................................. 4-100

4.1.1.23.4. Environmental Justice ....................................................... 4-103

4.1.1.24. Species Considered due to U.S. Fish and Wildlife Service 

Concerns ............................................................................................... 4-108

4.1.2. Alternative B—Exclude the Unleased Blocks Near Biologically Sensitive 

Topographic Features ............................................................................................ 4-111

4.1.3. Alternative C—No Action ..................................................................................... 4-113

4.2. Proposed Eastern Planning Area Lease Sale 226 ................................................................. 4-115

4.2.1. Alternative A—The Proposed Action ................................................................... 4-119

4.2.1.1. Air Quality ........................................................................................... 4-119

4.2.1.2 Water Quality ....................................................................................... 4-122

4.2.1.2.1. Coastal Waters ................................................................... 4-122

4.2.1.2.2. Offshore Waters ................................................................ 4-125

4.2.1.3. Coastal Barrier Beaches and Associated Dunes ................................... 4-128

4.2.1.4. Wetlands ............................................................................................... 4-132

4.2.1.5. Seagrass Communities ......................................................................... 4-136

4.2.1.6. Live Bottoms (Pinnacle Trend and Low Relief) .................................. 4-139

4.2.1.7. Topographic Features ........................................................................... 4-141

4.2.1.8. Sargassum Communities ...................................................................... 4-144

4.2.1.9. Chemosynthetic Deepwater Benthic Communities .............................. 4-148

4.2.1.10. Nonchemosynthetic Deepwater Benthic Communities ........................ 4-152

4.2.1.11. Soft Bottom Benthic Communities ...................................................... 4-157

4.2.1.12. Marine Mammals ................................................................................. 4-160

4.2.1.13. Sea Turtles ............................................................................................ 4-165

4.2.1.14. Diamondback Terrapins ....................................................................... 4-169

4.2.1.15. Beach Mice .......................................................................................... 4-173

4.2.1.16. Coastal and Marine Birds ..................................................................... 4-176

4.2.1.17. Fish Resources and Essential Fish Habitat (includes Gulf 

sturgeon) ............................................................................................... 4-179

4.2.1.18. Commercial Fisheries........................................................................... 4-184

4.2.1.19. Recreational Fishing............................................................................. 4-188

4.2.1.20. Recreational Resources ........................................................................ 4-191
Table of Contents xxi

4.2.1.21. Archaeological Resources.................................................................... 4-193

4.2.1.21.1. Historic Archaeological Resources................................... 4-193

4.2.1.21.2. Prehistoric Archaeological Resources............................... 4-196

4.2.1.22. Human Resources and Land Use ......................................................... 4-199

4.2.1.22.1. Land Use and Coastal Infrastructure ................................. 4-199

4.2.1.22.2. Demographics.................................................................... 4-205

4.2.1.22.3. Economic Factors.............................................................. 4-207

4.2.1.22.4. Environmental Justice ....................................................... 4-210

4.2.1.23. Species Considered due to U.S. Fish and Wildlife Concerns .............. 4-216

4.2.2. Alternative B—No Action..................................................................................... 4-219

4.3. Unavoidable Adverse Impacts of the Proposed Actions...................................................... 4-221

4.4. Irreversible and Irretrievable Commitment of Resources.................................................... 4-223

4.5. Relationship between the Short-term Use of Man’s Environment and the 

Maintenance and Enhancement of Long-term Productivity ................................................ 4-224

5. CONSULTATION AND COORDINATION ..................................................................................... 5-3

5.1. Development of the Proposed Actions..................................................................................... 5-3

5.2. Call for Information and Notice of Intent to Prepare a Supplemental EIS .............................. 5-3

5.3. Development of the Draft Supplemental EIS........................................................................... 5-3

5.3.1. Summary of Comments Received in Response to the Calls for Information............ 5-4

5.3.2. Summary of Scoping Comments............................................................................... 5-4

5.3.3. Additional Scoping Opportunities............................................................................. 5-6

5.3.4. Cooperating Agency.................................................................................................. 5-7

5.4. Distribution of the Draft Supplemental EIS for Review and Comment .................................. 5-7

5.5. Coastal Zone Management Act.............................................................................................. 5-11

5.6. Endangered Species Act......................................................................................................... 5-11

5.7. Magnuson-Stevens Fishery Conservation and Management Act .......................................... 5-12

5.8. National Historic Preservation Act ........................................................................................ 5-12

5.9. Government-to-Government.................................................................................................. 5-13

6. REFERENCES CITED........................................................................................................................ 6-3

7. PREPARERS ....................................................................................................................................... 7-3

8. GLOSSARY ........................................................................................................................................ 8-3

FIGURES......................................................................................................................................... Figures-3 

TABLES ........................................................................................................................................... Tables-3 

APPENDIX A. COMMONLY APPLIED MITIGATING MEASURES.............................................. A-3 

APPENDIX B. CATASTROPHIC SPILL EVENT ANALYSIS: HIGH-VOLUME, EXTENDEDDURATION OIL SPILL RESULTING FROM LOSS OF WELL CONTROL ON 

THE GULF OF MEXICO OUTER CONTINENTAL SHELF .................................. B-iii

APPENDIX C. MEMORANDUM OF AGREEMENT BETWEEN THE BUREAU OF

OCEAN ENERGY MANAGEMENT AND THE NATIONAL PARK 

SERVICE ..................................................................................................................... C-3 

KEYWORD INDEX................................................................................................................... Keywords-3 

List of Figures xxiii

LIST OF FIGURES

Page

Figure 1-1. Gulf of Mexico Planning Areas, Proposed CPA and EPA Lease Sale Areas, and 

Locations of Major Cities. .........................................................................................Figures-3

Figure 2-1. Location of Proposed Stipulations and Deferrals.......................................................Figures-4

Figure 2-2. Military Warning Areas and Eglin Water Test Areas in the Gulf of Mexico. ...........Figures-5

Figure 3-1. Offshore Subareas in the Gulf of Mexico. ................................................................. Figures-6

Figure 4-1. Location of Live Bottom Features and Stipulation Blocks on the Mississippi, 

Alabama, and Florida Continental Shelf....................................................................Figures-7

Figure 4-2. OCS Leasing Activity Near the Gulf Islands National Seashore...............................Figures-8

Figure 4-3. Photograph of the View from Petit Bois Island Looking South. ...............................Figures-9

Figure 4-4. Federal OCS Lease Blocks Subject to the Gulf Island National Seashore 

Information to Lessees. ............................................................................................Figures-10

List of Tables xxv

LIST OF TABLES

Page

Table 3-1. Projected Oil and Gas in the Gulf of Mexico OCS..................................................... Tables-3

Table 3-2. Offshore Scenario Information Related to a Typical Lease Sale in the 

Central Planning Area................................................................................................. Tables-4

Table 3-3. Offshore Scenario Information Related to a Typical Sale in the Eastern 

Planning Area for the Years 2012-2051...................................................................... Tables-5

Table 3-4. Offshore Scenario Information Related to OCS Program Activities in the 

Gulf of Mexico (WPA, CPA, and EPA) for 2012-2051 ............................................. Tables-6

Table 3-5. Offshore Scenario Information Related to OCS Program Activities in the 

Central Planning Area for 2012-2051......................................................................... Tables-7

Table 3-6. Offshore Scenario Information Related to OCS Program Activities in the 

Eastern Planning Area for the Years 2012-2051......................................................... Tables-8

Table 3-7. Annual Volume of Produced Water Discharged by Depth (millions of bbl)..............Tables-8

Table 3-8. Properties and Persistence by Oil Component Group................................................. Tables-9

Table 4-1. Unusual Mortality Event Cetacean Data for the Northern Gulf of Mexico ..............Tables-10

Table 4-2. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2011 ...................Tables-11

Table 4-3. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2012..................Tables-18

Table 4-4. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2013...................Tables-26

Table 4-5. Angler Trips in the Gulf of Mexico by Location and Mode from 2008 

through 2013 ............................................................................................................. Tables-36

Table 4-6. Fish Species Caught by Recreational Anglers from 2008 through 2013 ..................Tables-38

Table 4-7. Economic Impact of Recreational Fishing in the Gulf of Mexico in 2012 ...............Tables-39

Table 4-8. Employment in the Leisure/Hospitality Industry in Selected Geographic 

Regions ..................................................................................................................... Tables-40

Table 4-9. Baseline Population Projections (in thousands) by Economic Impact Area .............Tables-41

Table 4-10. Baseline Employment Projections (in thousands) by Economic Impact Area..........Tables-43

Table 4-11. Demographic and Employment Baseline Projections for Economic Impact 

Area AL-1 ................................................................................................................. Tables-45

Table 4-12. Demographic and Employment Baseline Projections for Economic Impact 

Area FL-1 .................................................................................................................. Tables-48

Table 4-13. Demographic and Employment Baseline Projections for Economic Impact 

Area FL-2 .................................................................................................................. Tables-51

Table 4-14. Demographic and Employment Baseline Projections for Economic Impact 

Area FL-3 .................................................................................................................. Tables-54

Table 4-15. Demographic and Employment Baseline Projections for Economic Impact 

Area FL-4 .................................................................................................................. Tables-57

Table 4-16. Demographic and Employment Baseline Projections for Economic Impact 

Area LA-1 ................................................................................................................. Tables-60

Table 4-17. Demographic and Employment Baseline Projections for Economic Impact 

Area LA-2 ................................................................................................................. Tables-63
xxvi Central and Eastern Planning Areas Supplemental EIS

Table 4-18. Demographic and Employment Baseline Projections for Economic Impact 

Area LA-3 ................................................................................................................. Tables-66

Table 4-19. Demographic and Employment Baseline Projections for Economic Impact 

Area LA-4 ................................................................................................................. Tables-69

Table 4-20. Demographic and Employment Baseline Projections for Economic Impact 

Area MS-1 ................................................................................................................. Tables-72

Table 4-21. Demographic and Employment Baseline Projections for Economic Impact 

Area TX-1 ................................................................................................................. Tables-75

Table 4-22. Demographic and Employment Baseline Projections for Economic Impact 

Area TX-2 ................................................................................................................. Tables-78

Table 4-23. Demographic and Employment Baseline Projections for Economic Impact 

Area TX-3 ................................................................................................................. Tables-81

Table 4-24. Sales Volumes, Sales Values, and Revenues............................................................ Tables-84
Abbreviations and Acronyms xxvii

ABBREVIATIONS AND ACRONYMS

°C degree Celsius

°F degree Fahrenheit

μg microgram 

2012-2017 WPA/CPA Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017;

Multisale EIS Western Planning Area Lease Sales 229, 233, 238, 246, and 248; 

Central Planning Area Lease Sales 227, 231, 235, 241, and 247; 

Final Environmental Impact Statement; Volumes I-III 

2D two-dimensional

3D three-dimensional

ac acre

ACP Area Contingency Plan

Agreement Agreement between the United States of America and the United

Mexican States Concerning Transboundary Hydrocarbon Reservoirs 

in the Gulf of Mexico

AL Alabama

API American Petroleum Institute

Area ID Area Identification

ASLM Assistant Secretary of the Interior for Land and Minerals

B.P. before present

bbl barrel

BBO billion barrels of oil

BOEM Bureau of Ocean Energy Management

BOEMRE Bureau of Ocean Energy Management, Regulation and Enforcement

BOP blowout preventer

BP British Petroleum

BSEE Bureau of Safety and Environmental Enforcement

BTEX benzene, ethylbenzene, toluene, and xylene

Call Call for Information

CD Consistency Determination

CEQ Council on Environmental Quality

CEWAF water-accommodated fractions plus COREXIT 9500

CFR Code of Federal Regulations

CG Coast Guard (also: USCG)

CH4 methane

CIAP Coastal Impact Assistance Program

cm centimeter

CMP Coastal Management Program 

CO carbon monoxide

CO2 carbon dioxide

COE Corps of Engineers (U.S. Army)

CPA Central Planning Area

CPA 235/241/247 Gulf of Mexico OCS Oil and Gas Lease Sales: 2015-2017;

Supplemental EIS Central Planning Area Lease Sales 235, 241, and 247;

Final Supplemental Environmental Impact Statement

CSA Continental Shelf Associates

CWPPRA Coastal Wetlands Planning, Protection and Restoration Act

CZM Coastal Zone Management

CZMA Coastal Zone Management Act

DOC Department of Commerce (U.S.) (also: USDOC)

DOCD development operations coordination document

DOD Department of Defense (U.S.) (also: USDOD)

DOE Department of Energy (U.S.) (also: USDOE)

DOI Department of the Interior (U.S.) (also: USDOI)
xxviii Central and Eastern Planning Areas Supplemental EIS

DP dynamically positioned

DPS Distinct Population Segment

e.g. for example

EA environmental assessment

EFH essential fish habitat

EIA Economic Impact Area

EIS environmental impact statement

EP exploration plan

EPA Eastern Planning Area

EPA 225/226 EIS Gulf of Mexico OCS Oil and Gas Lease Sales: 2014 and 2016; 

 Eastern Planning Area Lease Sales 225 and 226; 

Final Environmental Impact Statement

ERMA Environmental Response Management Application

ESA Endangered Species Act of 1973

ESI Environmental Sensitivity Index

et al. and others

et seq. and the following

EWTA Eglin Water Test Area

Five-Year Program Proposed Final Outer Continental Shelf Oil & Gas Leasing Program: 

 2012-2017

Five-Year Program EIS Outer Continental Shelf Oil and Gas Leasing Program: 2012-2017, 

 Final Programmatic Environmental Impact Statement

FL Florida

FPSO floating production, storage, and offloading system

FR Federal Register

ft feet

FWS Fish and Wildlife Service

FY fiscal year

g gram 

G&G geological and geophysical

GMFMC Gulf of Mexico Fishery Management Council

GOM Gulf of Mexico

GPS global positioning system 

GUIS Gulf Islands National Seashore 

H2S hydrogen sulfide

ha hectare

HWCG Helix Well Containment Group

i.e. specifically

in inch

IUCN International Union for the Conservation of Nature

km kilometer

L liter

LA Louisiana

LC50 lethal concentration, 50% mortality

LCA Louisiana Coastal Area

LNG liquefied natural gas

m meter

m/sec meters/second

MAFLA Mississippi, Alabama, and Florida

MARAD U.S. Department of Transportation, Maritime Administration

Mcf thousand cubic feet

mi mile

mm millimeter

MMbbl million barrels

MMPA Marine Mammal Protection Act of 1972

MMS Minerals Management Service
Abbreviations and Acronyms xxix

MOA Memorandum of Agreement

MODU mobile offshore drilling unit

MS Mississippi

MWCC Marine Well Containment Company

N. north

N2O nitrous oxide

NAAQS National Ambient Air Quality Standards

NASA National Aeronautics and Space Administration

NCP National Contingency Plan

NEPA National Environmental Policy Act

NGL natural gas liquid

NMFS National Marine Fisheries Service

nmi nautical-mile

NO2 nitrogen dioxide

NOA Notice of Availability

NOAA National Oceanic and Atmospheric Administration

NOI Notice of Intent to Prepare an EIS

NOS Notice of Sale

NOx nitrogen oxides

NPDES National Pollutant and Discharge Elimination System

NPS National Park Service

NRC National Research Council

NRDA Natural Resource Damage Assessment

NTL Notice to Lessees and Operators

O3 ozone

OBC ocean bottom cables

OCS Outer Continental Shelf

OCSLA Outer Continental Shelf Lands Act

ODMDS ocean dredged-material disposal site

OSAT Operational Science Advisory Team

OSHA Occupational Safety and Health Administration

OSRA Oil Spill Risk Analysis

OSRP oil-spill response plans

OSV offshore supply/service vessels

P.L. Public Law

PAH polycyclic aromatic hydrocarbons

PBR potential biological removal

PM10 particulate matter less than or equal to 10 μm 

PM2.5 particulate matter less than or equal to 2.5 μm 

ppb parts per billion

ppm parts per million

PSBF potentially sensitive biological feature

PSD Prevention of Significant Deterioration

RESTORE Act Resources and Ecosystems Sustainability, Tourist Opportunities, and Revived 

 Economies of the Gulf Coast States Act of 2012

ROD Record of Decision

ROV remotely operated vehicle

RRT Regional Response Team

S. south

SAV submerged aquatic vegetation

SBF synthetic-based fluid

SBM synthetic-based mud

SCAT Shoreline Cleanup and Assessment Team

sec second

Secretary Secretary of the Interior

SIL Significant Impact Level
xxx Central and Eastern Planning Areas Supplemental EIS

SMART Special Monitoring of Applied Response Technologies

SO2 sulphur dioxide

SOx sulphur oxides

sp. species

spp. multiple species

Stat. Statute

STOF-THPO Seminole Tribe of Florida-Tribal Historic Preservation Officer

TA&R Technology Assessment and Research Program

Tcf trillion cubic feet

TPH total petroleum hydrocarbon

Trustee Council Natural Resource Damage Assessment Trustee Council

TX Texas

U.S. United States

U.S.C. United States Code

UME unusual mortality event

USCG U.S. Coast Guard (also: CG)

USDHS U.S. Department of Homeland Security

USDOC U.S. Department of Commerce (also: DOC)

USDOE U.S. Department of Energy (also: DOE)

USDOI U.S. Department of the Interior (also: DOI)

USDOT U.S. Department of Transportation (also: DOT)

USEPA U.S. Environmental Protection Agency

USGS United States Geological Survey (also: GS)

VGP Vessel General Permit

VOC volatile organic compound

VSP vertical seismic profiling

W. west

WAF water-accommodated fractions

WPA Western Planning Area

WPA 233/CPA 231 Gulf of Mexico OCS Oil and Gas Lease Sales: 2013-2014; 

Supplemental EIS Western Planning Area Lease Sale 233; Central Planning Area 

Lease Sale 231, Final Supplemental Environmental Impact Statement

WPA 238/246/248 Gulf of Mexico OCS Oil and Gas Lease Sales: 2014-2016; 

Supplemental EIS Western Planning Area Lease Sales 238, 246, and 248; 

Final Environmental Impact Statement

WSF water soluble fraction

yd yard

yr year
Conversion Chart xxxi

CONVERSION CHART

To convert from To Multiply by

centimeter (cm) inch (in) 0.3937

millimeter (mm) inch (in) 0.03937

meter (m) foot (ft) 3.281

meter2 (m2) foot2 (ft2) 10.76

meter2 (m2) yard2 (yd2) 1.196

meter2 (m2) acre (ac) 0.0002471

meter3 (m3) foot3 (ft3) 35.31

meter3 (m3) yard3 (yd3) 1.308

kilometer (km) mile (mi) 0.6214

kilometer2 (km2) mile2 (mi2) 0.3861

hectare (ha) acre (ac) 2.47

liter (L) gallons (gal) 0.2642

degree Celsius (°C) degree Fahrenheit (°F) °F = (1.8 x °C) + 32

1 barrel (bbl) = 42 gal = 158.9 L = approximately 0.1428 metric tons

1 nautical mile (nmi) = 1.15 mi (1.85 km) or 6,076 ft (1,852 m)

tonnes = 1 long ton or 2,240 pounds

CHAPTER 1 

THE PROPOSED ACTIONS

The Proposed Actions 1-3 

1. THE PROPOSED ACTIONS

1.1. PURPOSE OF AND NEED FOR THE PROPOSED ACTIONS

The proposed Federal actions addressed in this Supplemental Environmental Impact Statement (EIS) 

are to offer for lease certain Outer Continental Shelf (OCS) blocks located in the Central Planning Area 

(CPA) and Eastern Planning Area (EPA) of the Gulf of Mexico (GOM) (Figure 1-1). Under the 

Proposed Final Outer Continental Shelf Oil & Gas Leasing Program: 2012-2017 (Five-Year Program) 

(USDOI, BOEM, 2012a), proposed CPA Lease Sales 241 and 247 are tentatively scheduled to be held in 

March 2016 and 2017, respectively, and proposed EPA Lease Sale 226 is tentatively scheduled to be held 

in March 2016. The 2012-2017 WPA/CPA Multisale EIS notes that two proposed Gulf of Mexico lease 

sales may be held each year during the Five-Year Program—one in the WPA and one in the CPA. The 

EPA 225/226 EIS notes that two proposed EPA lease sales may be held, one in 2014 and one in 2016.

The purpose of the proposed Federal actions is to offer for lease those areas that may contain 

economically recoverable oil and gas resources in accordance with the Outer Continental Shelf Lands Act 

(OCSLA) of 1953 (67 Stat. 462), as amended (43 U.S.C. §§ 1331 et seq.). The proposed CPA and EPA 

lease sales will provide qualified bidders the opportunity to bid upon and lease acreage in the Gulf of 

Mexico OCS in order to explore, develop, and produce oil and natural gas. Under the OCSLA, for each 

potential lease sale in the Five-Year Program, the Bureau of Ocean Energy Management (BOEM) makes 

individual decisions on whether and how to proceed with a proposed lease sale. Although the analyses 

cover more than one proposed lease sale in the CPA, this Supplemental EIS will be used by BOEM to 

support a decision only for proposed CPA Lease Sale 241 and proposed EPA Lease Sale 226. An 

additional National Environmental Policy Act (NEPA) review, as appropriate, will be prepared prior to an 

individual lease sale decision on proposed CPA Lease Sale 247 to address any newly available significant 

information relevant to that proposed action (refer to Chapter 2.1). This NEPA review will tier from and 

incorporate by reference the analyses from previous EISs and Supplement EISs. 

The need for the proposed actions is to further the orderly development of OCS resources. The Gulf 

of Mexico constitutes one of the world’s major oil- and gas-producing areas and has proved a steady and 

reliable source of crude oil and natural gas for more than 50 years. Oil serves as the feedstock for liquid 

hydrocarbon products, including gasoline, aviation and diesel fuel, and various petrochemicals. Oil from 

the CPA and EPA would help reduce the Nation’s need for oil imports and lessen the dependence on 

foreign oil. The U.S. consumed 18.9 million barrels (MMbbl) of oil per day (USDOE, Energy 

Information Administration, 2014a) and 25.68 trillion cubic feet (Tcf) of natural gas per day (USDOE, 

Energy Information Administration, 2014b) in 2013. The Energy Information Administration projects the 

total U.S. consumption of liquid fuels, including fossil fuels and biofuels, to fall slightly from 

19.03 MMbbl per day in 2013 to 18.73 MMbbl by 2040 (USDOE, Energy Information Administration, 

2014c). The Energy Information Administration also projects the total U.S. consumption of natural gas to 

rise from 25.68 Tcf to 31.48 Tcf by 2040 (USDOE, Energy Information Administration, 2014b). The 

U.S. net imports of natural gas accounted for 1.34 percent of our total natural gas consumption in 2013 

and are projected to decrease to 0.04 percent by 2017 (USDOE, Energy Information Administration, 

2014b). Altogether, net imports of crude oil and petroleum products (imports minus exports) accounted 

for 34 percent of our total petroleum consumption in 2013 and are projected to decrease to 32 percent by 

2040 (USDOE, Energy Information Administration, 2014d). The U.S. crude oil imports stood at 

7.7 MMbbl per day in 2013, and the petroleum product imports were 2.1 MMbbl per day in 2013 

(USDOE, Energy Information Administration, 2014e). Exports totaled 2.9 MMbbl per day in 2013, 

mainly in the form of distillate fuel oil, petroleum coke, and residual fuel oil (USDOE, Energy 

Information Administration, 2014f). The net exports of natural gas are projected to be 0.66 percent in 

2018 and rise to 5.78 percent in 2040 (USDOE, Energy Information Administration, 2014b). In 2013, the 

Nation’s biggest supplier of crude oil and petroleum-product imports was Canada (32%), with countries 

in the Persian Gulf being the second largest source (21%) (USDOE, Energy Information Administration, 

2014e). In 2013, the Nation’s biggest supplier of natural gas was Canada (97%), with Trinidad being the 

second largest source (2.4%) (USDOE, Energy Information Administration, 2014g). Oil produced from 

the CPA and EPA would also reduce the environmental risks associated with transoceanic oil tankering 

from sources overseas. Natural gas is not easily transported, making domestic production especially 
1-4 Central and Eastern Planning Areas Supplemental EIS

desirable. The need for domestic natural gas reserves is also based upon its use as an environmentally 

preferable alternative to oil for generating electricity.

The Secretary of the Interior (Secretary) has designated BOEM as the administrative agency 

responsible for the mineral leasing of submerged OCS lands and for the supervision of most offshore 

operations after lease issuance. BOEM is responsible for managing development of the Nation’s offshore 

resources in an environmentally and economically responsible way. The functions of BOEM include 

leasing, exploration and development, plan administration, environmental studies, NEPA analysis, 

resource evaluation, economic analysis, and the renewable energy program. The Bureau of Safety and 

Environmental Enforcement (BSEE) is responsible for enforcing safety and environmental regulations. 

The functions of BSEE include all field operations, including permitting and research, inspections, 

offshore regulatory programs, oil-spill response, and training and environmental compliance functions.

Other Pertinent Environmental Reviews or Documentation

This Supplemental EIS supplements and incorporates by reference all of the relevant analyses from

the EISs and Supplemental EISs listed below.

Proposed CPA Lease Sales 241 and 247 

• July 2012 – Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017; Western 

Planning Area Lease Sales 229, 233, 238, 246, and 248; Central Planning Area 

Lease Sales 227, 231, 235, 241, and 247, Final Environmental Impact Statement 

(2012-2017 WPA/CPA Multisale EIS) (USDOI, BOEM, 2012b) 

• April 2013 – Gulf of Mexico OCS Oil and Gas Lease Sales: 2013-2014; Western 

Planning Area Lease Sale 233; Central Planning Area Lease Sale 231, Final 

Supplemental Environmental Impact Statement (WPA 233/CPA 231 Supplemental 

EIS) (USDOI, BOEM, 2013a) 

• September 2014 – Gulf of Mexico OCS Oil and Gas Lease Sales: 2015-2017; 

Central Planning Area Lease Sales 235, 241, and 247, Final Supplemental 

Environmental Impact Statement (CPA 235/241/247 Supplemental EIS) (USDOI, 

BOEM, 2014a) 

Proposed EPA Lease Sale 226 

• July 2012 – Outer Continental Shelf Oil and Gas Leasing Program: 2012-2017, 

Final Programmatic Environmental Impact Statement (Five-Year Program EIS) 

(USDOI, BOEM, 2012a) 

• October 2013 – Gulf of Mexico OCS Oil and Gas Lease Sales: 2014 and 2016; 

Eastern Planning Area Lease Sales 225 and 226, Final Environmental Impact 

Statement (EPA 225/226 EIS) (USDOI, BOEM, 2013b) 

The NEPA documents listed above are part of the Five-Year Program, and their relationship (tiering

and supplementing) and timing with their respective proposed actions (lease sales) are illustrated in the 

figure below.
The Proposed Actions 1-5 

Each subsequent Supplemental EIS, regardless of the planning area, updates the potential 

environmental effects of oil and natural gas leasing, exploration, development, and production in the 

GOM in Chapters 4.1 and 4.2, and updates the cumulative impacts from the most recent Supplemental 

EIS. Within each specific planning area, the baseline conditions for that planning area are updated to 

reflect the most recent technical and scientific information available. 

This Supplemental EIS focuses on updating the baseline conditions and potential environmental 

effects of oil and natural gas leasing, exploration, development, and production in the CPA and EPA since 

publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS for the CPA and since publication of the Five-Year Program EIS and EPA 

225/226 EIS for the EPA. 

This Supplemental EIS analyzes the potential impacts of each proposed action in the CPA and EPA

on the marine, coastal, and human environments. This Supplemental EIS will also assist decisionmakers 

in making informed, future decisions regarding the approval of operations, as well as leasing. At the 

completion of the NEPA process, a decision will be made only for proposed CPA Lease Sale 241 and 

proposed EPA Lease Sale 226. A separate NEPA review, in a form to be determined by BOEM, will be 

conducted prior to BOEM’s decision on whether or how to proceed with proposed CPA Lease Sale 247. 

The analysis in this Supplemental EIS also focuses on the potential environmental effects of oil and 

natural gas leasing, exploration, development, and production in the areas identified through the Area 

Identification (Area ID) procedure as the proposed lease sale areas. In addition to the No Action 

alternative (i.e., cancel a proposed lease sale), other alternatives are considered for the proposed CPA

lease sales, such as deferring certain areas from the proposed lease sales. 

1.2. DESCRIPTION OF THE PROPOSED ACTIONS

The proposed actions are the next two oil and gas lease sales in the CPA and the one remaining oil 

and gas lease sale in the EPA, as scheduled in the Five-Year Program. Proposed CPA Lease Sale 241 and 

proposed EPA Lease Sale 226 are tentatively scheduled to be held in March 2016, and proposed CPA 

Lease Sale 247 is tentatively scheduled to be held in 2017. Federal regulations allow for several related 
1-6 Central and Eastern Planning Areas Supplemental EIS

or similar proposals to be analyzed in one EIS (40 CFR § 1502.4). Since the proposed CPA and EPA 

lease sales are in the same general area and since their projected activities are very similar, BOEM has 

decided to prepare a combined Supplemental EIS for proposed CPA Lease Sales 241 and 247 and 

proposed EPA Lease Sale 226. The analyses contained within this Supplemental EIS examine impacts 

from a single, typical CPA and EPA lease sale. The findings of these analyses can be applied individually 

to each of the proposed lease sales, i.e., proposed CPA Lease Sales 241 and 247 and proposed EPA Lease 

Sale 226. While the impact analyses can be applied to each proposed lease sale, this Supplemental EIS 

supports a decision document for only proposed CPA Lease Sale 241 and proposed EPA Lease Sale 226. 

The proposed CPA lease sale area encompasses about 63 million acres (ac) of the total CPA area of 

66.45 million ac. This area begins 3 nautical miles (nmi) (3.5 miles [mi]; 5.6 kilometers [km]) offshore 

Louisiana, Mississippi, and Alabama, and extends seaward to the limits of the United States’ jurisdiction 

over the continental shelf (often referred to as the Exclusive Economic Zone) in water depths up to 

approximately 3,346 meters (m) (10,978 feet [ft]) (Figure 1-1). As of September 2014, approximately 

44.2 million ac of the proposed CPA lease sale area are unleased. This information is updated monthly 

and can be found on BOEM’s website at http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. 

The estimated amount of resources projected to be developed as a result of a single, typical CPA lease 

sale (i.e., proposed CPA Lease Sale 241) is 0.460-0.894 billion barrels of oil (BBO) and 1.939-3.903 

trillion cubic feet (Tcf) of gas. A proposed CPA lease sale includes proposed lease stipulations designed 

to reduce environmental risks; these stipulations are discussed in Chapter 2.3.1.3 of this Supplemental 

EIS and in Chapter 2.4.1.3 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 

Supplemental EIS.

The proposed EPA lease sale area covers approximately 657,905 ac and includes those blocks 

previously included in the EPA Lease Sales 224 and 225 Area and a triangular-shaped area south of this 

area bordered by the CPA boundary on the west and the Military Mission Line (86o41'W. longitude) on 

the east. The area is south of eastern Alabama and western Florida; the nearest point of land is 125 mi 

(201 km) northwest in Louisiana. As of September 2014, approximately 465,200 ac of the proposed EPA 

lease sale area are currently unleased. This information is updated monthly and can be found on BOEM’s 

website at http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The estimated amount of 

resources projected to be developed as a result of the proposed EPA lease sale is 0-0.071 BBO and 0-

0.162 Tcf of gas. The proposed EPA lease sale includes proposed lease stipulations designed to reduce 

environmental risks; these stipulations are discussed in Chapter 2.4.1.3 of this Supplemental EIS and in 

Chapter 2.3.1.3 of the EPA 225/226 EIS.

1.3. REGULATORY FRAMEWORK

Federal laws mandate the OCS leasing program (e.g., OCSLA) and the environmental review process 

(e.g., NEPA). Several Federal regulations establish specific consultation and coordination processes with 

Federal, State, and local agencies (e.g., Coastal Zone Management Act, Endangered Species Act, the 

Magnuson-Stevens Fishery Conservation and Management Act, and the Marine Mammal Protection Act). 

In addition, the OCS leasing process and all activities and operations on the OCS must comply with other 

applicable Federal, State, and local laws and regulations. A detailed list of the major, applicable Federal 

laws, regulations, and Executive Orders are listed below.

Regulation, Law, and Executive Order Citation

Outer Continental Shelf Lands Act 43 U.S.C. §§ 1331 et seq.

National Environmental Policy Act of 1969 42 U.S.C. §§ 4321-4347

40 CFR parts 1500-1508

Coastal Zone Management Act of 1972 16 U.S.C. §§ 1451 et seq.

15 CFR part 930

Endangered Species Act of 1973 16 U.S.C. §§ 1531 et seq.

Magnuson-Stevens Fishery Conservation and Management Act 16 U.S.C. §§ 1251 et seq.

Essential Fish Habitat Consultation (in 1996 reauthorization of the 

Magnuson-Stevens Fishery Conservation and Management Act)

P.L. 94-265

16 U.S.C. §§ 1801-1891

50 CFR part 600 subpart K
The Proposed Actions 1-7 

Marine Mammal Protection Act 16 U.S.C. §§ 1361 et seq.

Clean Air Act 42 U.S.C. §§ 7401 et seq.

40 CFR part 55

Clean Water Act 33 U.S.C. §§ 1251 et seq.

Harmful Algal Bloom and Hypoxia Research and Control Act P.L. 105-383

Oil Pollution Act of 1990 33 U.S.C. §§ 2701 et seq.

Executive Order 12777

Comprehensive Environmental Response, Compensation, and 

Liability Act of 1980 42 U.S.C. §§ 9601 et seq. 

Resource Conservation and Recovery Act 42 U.S.C. §§ 6901 et seq.

Marine Plastic Pollution Research and Control Act 33 U.S.C. §§ 1901 et seq.

National Fishing Enhancement Act of 1984 33 U.S.C. §§ 2601 et seq.

Fishermen’s Contingency Fund 43 U.S.C. §§ 1841-1846

Ports and Waterways Safety Act of 1972 33 U.S.C. §§ 1223 et seq.

Marine and Estuarine Protection Acts 33 U.S.C. §§ 1401 et seq. 

Marine Protection, Research, and Sanctuaries Act of 1972 P.L. 92-532

National Estuarine Research Reserves 16 U.S.C. § 1461, Section 315

National Estuary Program P.L. 100-4 

Coastal Barrier Resources Act 16 U.S.C. §§ 3501 et seq.

National Historic Preservation Act 16 U.S.C. §§ 470 et seq.

Rivers and Harbors Act of 1899 33 U.S.C. §§ 401 et seq.

Occupational Safety and Health Act of 1970 29 U.S.C. §§ 651 et seq.

Energy Policy Act of 2005 P.L. 109-58

Gulf of Mexico Energy Security Act of 2006 P.L. 109-432

Marine Debris Research, Prevention, and Reduction Act P.L. 109-449

American Indian Religious Freedom Act of 1978 P.L. 95-341

42 U.S.C. §§ 1996 and 1996a

Migratory Bird Treaty Act of 1918 16 U.S.C. §§ 703 et seq.

Submerged Lands Act of 1953 43 U.S.C. §§ 1301 et seq.

49 U.S.C. § 44718: Structures Interfering with Air Commerce 49 U.S.C. § 44718

Marking of Obstructions 14 U.S.C. § 86

Wilderness Act of 1964

P.L. 88-577

16 U.S.C. §§ 1131-1136

78 Stat. 890

Toxic Substances Control Act

P.L. 94-469

15 U.S.C. §§ 2601-2697

Stat. 2003

Bald Eagle Protection Act of 1940 P.L. 86-70

16 U.S.C. §§ 668-668d

Executive Order 11988: Floodplain Management 42 FR 26951 (1977); amended by 

Executive Order 12148 (7/20/79)

Executive Order 11990: Protection of Wetlands 42 FR 26961 (1977); amended by 

Executive Order 12608 (9/9/87)

Executive Order 12114: Environmental Effects Abroad 44 FR 1957 (1979)

Executive Order 12898: Environmental Justice 59 FR 5517 (1994)

Executive Order 13007: Indian Sacred Sites 61 FR 26771-26772 (1996)

Executive Order 13089: Coral Reef Protection 63 FR 32701-32703 (1998)
1-8 Central and Eastern Planning Areas Supplemental EIS

Executive Order 13175: Consultation and Coordination with Indian 

Tribal Governments 65 FR 67249-67252 (2000)

Executive Order 13186: Responsibilities of Federal Agencies to 

Protect Migratory Birds 66 FR 3853 (2001)

1.3.1. Recent BOEM/BSEE Rule Changes

In light of the 2010 Deepwater Horizon explosion, oil spill, and response, the Federal Government, 

along with industry, increased their rules and safety measures related to oil-spill prevention, containment, 

and response. Additionally, the Federal Government and industry have increased their research and 

reform in response to the Deepwater Horizon explosion, oil spill, and response through governmentfunded research, industry-funded research, and joint partnerships. These joint partnerships are often 

between government agencies, industry, and nongovernmental organizations. For more information about 

the recent BOEM/BSEE rule changes prior to this Supplemental EIS, refer to Chapters 1.3 and 1.5 of the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, CPA 235/241/247 

Supplemental EIS, and EPA 225/226 EIS. 

1.3.1.1. Recent and Ongoing Regulatory Reform and Government-Sponsored 

Research

BOEM and BSEE have instituted regulatory reforms responsive to many of the recommendations 

expressed in the various reports prepared following the Deepwater Horizon explosion, oil spill, and 

response. To date, regulatory reform has occurred through both prescriptive and performance-based 

regulation and guidance, as well as OCS safety and environmental protection requirements, as described 

in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and the EPA 225/226 

EIS. The reforms strengthen the requirements for all aspects of OCS operations. Ongoing reform and 

research endeavors to improve workplace safety and to strengthen oil-spill prevention planning, 

containment, and response are described in detail in Chapter 1.3.1.2 of the 2012-2017 WPA/CPA 

Multisale EIS and Chapter 1.3.2.3 of the EPA 225/226 EIS, with updated information in Chapter 1.3.2.2 

of the WPA 233/CPA 231 Supplemental EIS and Chapter 1.3.1.1 of the CPA 235/241/241 Supplemental 

EIS. Since publication of the CPA 235/241/247 Supplemental EIS, no substantive rule changes have 

been implemented that would affect potential environmental impacts from OCS oil- and gas-related 

activities in the Gulf of Mexico. However, new and modified Notices to Lessees (NTLs) and other 

policies applicable to OCS oil and gas operations in the Gulf of Mexico are summarized below.

NTL 2014-BOEM-G04, “Military Warning and Water Test Areas” 

This NTL is issued pursuant to 30 CFR § 550.103 and provides links to the addresses and telephone 

numbers of the individual command headquarters for the military warning and water test areas in the Gulf 

of Mexico (GOM). This NTL updates BOEM’s contact information and replaces NTL 2009-G06.

NTL 2014-JOINT-G01, “Drilling Windows, Eastern Planning Area, Gulf of Mexico” 

This NTL supersedes NTL 2012-BOEM-G01 on this subject. It provides a new schedule for the 

drilling window program and a website address for a map that shows the areas covered by the drilling 

window program.

NTL 2014-BOEM-G05, “Extension of Prior Notices to Lessees”

This NTL relates to the following two NTLs:

• NTL 2008-G04, effective April 1, 2008, which provides guidance on the information 

requirements for OCS plans required by 30 CFR part 550, subpart B; and

• NTL 2008-G05, effective April 1, 2008, which describes the shallow hazards 

program, which was designed to ensure that exploration, development, production, 
The Proposed Actions 1-9 

and transportation operations are conducted with a minimum risk to human life and 

the environment.

These two NTLs were extended on April 1, 2013, until the end of calendar year 2013 (NTL 2013-

G02), on January 1, 2014, until June 30, 2014 (NTL 2014-G03), and are hereby being extended again in 

their current form until December 31, 2014, unless one or both of them are replaced earlier.

BSEE Proposed Changes to 30 CFR part 250 subpart H – Oil and Gas Production Safety 

Systems

This regulatory action will ensure that the regulations are keeping pace with industry’s recent 

technological advancements, which often rely on the use of equipment that is located on the seabed. 

These new technologies are more complex than those that were traditionally used for shallow-water 

drilling on shelf areas, where safety equipment was traditionally placed on the rig itself rather than on the 

seafloor. With the shift to deeper water in the past decade, more specialized requirements and regulations 

are required for these newer and emerging safety technologies.

Gulf of Mexico Environmental Studies Program

BOEM’s Environmental Studies Program develops, conducts, and oversees world-class scientific 

research specifically to inform policy decisions regarding development of OCS energy and mineral 

resources. Research covers physical oceanography, atmospheric sciences, biology, protected species, 

social sciences and economics, submerged cultural resources, and environmental fates and effects. 

BOEM is a leading contributor to the growing body of scientific knowledge about the Nation’s marine 

and coastal environment. Studies published by the Environmental Studies Program, Gulf of Mexico OCS 

Region, since publication of the CPA 235/241/247 Supplemental EIS are shown in the table below. For a 

list of studies published by the Environmental Studies Program, Gulf of Mexico OCS Region, prior to 

those listed below (i.e., 2006-2013), refer to Appendix E of the CPA 235/241/247 Supplemental EIS.

Publications of the Environmental Studies Program, Gulf of Mexico OCS Region, 

Since Publication of the CPA 235/241/247 Supplemental EIS

Study Number Title

BOEM 2013-011110 Archaeological Analysis of Submerged Sites on the Gulf of Mexico Outer Continental 

Shelf

BOEM 2013-214

BOEM 2013-215

Long-Term Monitoring at the East and West Flower Gardens Banks National Marine 

Sanctuary, 2009-2010

Volume I: Technical Report

Volume II: Appendices

BOEM 2014-607

Forcing Functions Governing Salt Transports in Coastal Navigation Canals and 

Connectivity to Surrounding Wetland Landscapes in South Louisiana Using Houma 

Navigation Canal as a Surrogate

BOEM 2014-608 Characterization and Potential Impacts of Noise Producing Construction and 

Operation Activities on the Outer Continental Shelf: Data Synthesis

BOEM 2014-650

BOEM 2014-651

Investigations of Chemosynthetic Communities on the Lower Continental Slope of the 

Gulf of Mexico

Volume I: Final Report

Volume II: Appendix

BOEM 2014-657 Onshore Oil and Gas Infrastructure to Support Development in the Mid-Atlantic OCS 

Region
1-10 Central and Eastern Planning Areas Supplemental EIS

1.3.1.2. Recent and Ongoing Industry Reform and Research

Since the publication of the WPA 233/CPA 231 Supplemental EIS, CPA 235/241/247 Supplemental 

EIS, and EPA 225/226 EIS, the oil and gas industry and engineering trade groups have continued to 

prepare new standards and develop best practices for the safe and environmentally responsible 

development of OCS oil and gas. As an example, the American Petroleum Institute (API) has produced 

several Recommended Practices and Standards that have become part of State and Federal regulations. In 

July 2014, API completed Recommended Practice 17W, “Recommended Practice for Subsea Capping 

Stacks” (API, 2014a). This recommended practice covers the design, fabrication, and operation of new 

subsea capping stacks, and it can be used to improve existing equipment. The API’s Recommended 

Practices and technical information can be found on their website (API, 2014b). 

1.4. PRELEASE PROCESS

Scoping for this Supplemental EIS was conducted in accordance with the Council on Environmental 

Quality’s (CEQ) guidelines on implementing NEPA. Scoping provides those with an interest in the OCS 

Program an opportunity to provide comments on the proposed actions. In addition, scoping provides 

BOEM an opportunity to update the Gulf of Mexico OCS Region’s environmental and socioeconomic 

information base. BOEM conducted early coordination with appropriate Federal and State agencies, 

Tribal Nations, nongovernmental organizations, and other concerned parties to discuss and coordinate the 

prelease process for proposed CPA Lease Sales 241 and 247, proposed EPA Lease Sale 226, and for this 

Supplemental EIS. While scoping is an ongoing process, it officially commenced on June 20, 2014, with 

the publication of the Notice of Intent to Prepare an EIS (NOI) in the Federal Register (2014a). 

Additional public notices were distributed via local newspapers, the U.S. Postal Service, and the Internet. 

A 30-day comment period was provided; it closed on July 21, 2014. Federal, State, and local 

governments, along with other interested parties, were invited to send written comments to the Gulf of 

Mexico OCS Region on the scope of this Supplemental EIS. Comments were received in response to the 

NOI from Federal, State, and local government agencies; interest groups; industry; businesses; and the 

general public on the scope of this Supplemental EIS, significant issues that should be addressed, 

alternatives that should be considered, and mitigating measures. All scoping comments received were 

considered in the preparation of the Draft Supplemental EIS. The comments are summarized in 

Chapter 5.3, “Development of the Draft Supplemental EIS.”

In addition to BOEM’s consideration of scoping comments received for this Supplemental EIS, this 

document tiers from and incorporates by reference all of the relevant scoping comments and responses to 

the comments from the 2012-2017 WPA/CPA Multisale EIS (USDOI, BOEM, 2012b), WPA 233/CPA 

231 Supplemental EIS (USDOI, BOEM, 2013a), CPA 235/241/247 Supplemental EIS (USDOI, BOEM, 

2014a), and EPA 225/226 EIS (USDOI, BOEM, 2013b). A summary of scoping comments incorporated 

by reference can be found in Chapter 5.3, “Development of the Draft Supplemental EIS,” of the those 

NEPA documents. 

At the beginning of each Five-Year Program, the Gulf of Mexico OCS Region releases an Area 

Identification (Area ID) for each planning area, defining the proposed lease sale areas. On June 20, 2011, 

BOEM released its Area ID decision for the CPA and WPA lease sale areas. On August 29, 2012, 

BOEM released its Area ID decision for the EPA lease sale area. The Area ID is an administrative 

prelease step that describes the geographical area of the proposed actions (proposed lease sale areas) and 

identifies the alternatives, mitigating measures, and issues to be analyzed in the appropriate NEPA

document. As mandated by NEPA, this Supplemental EIS analyzes the potential impacts of the CPA and 

EPA proposed actions on the marine, coastal, and human environments.

BOEM will mail copies of this Draft Supplemental EIS for review and comment to Federal, State, 

and local government agencies; Tribal Nations; industry; nongovernmental organizations; the general 

public; and local libraries. To initiate the public review and comment period on this Draft Supplemental 

EIS, BOEM will publish a Notice of Availability (NOA) in the Federal Register. In addition, public 

notices will be mailed with this Draft Supplemental EIS and will be placed on BOEM’s website at http://

www.boem.gov/nepaprocess/. 

A consistency review will be performed in accordance with the Coastal Zone Management Act 

(CZMA), and a Consistency Determination (CD) will be prepared for each affected State prior to each 

proposed CPA lease sale and the proposed EPA lease sale. To prepare the CDs, BOEM reviews each 
The Proposed Actions 1-11

State’s Coastal Management Program (CMP) and analyzes the potential impacts as outlined in this 

Supplemental EIS, new information, and applicable studies as they pertain to the enforceable policies of 

each CMP. Based on the analyses, BOEM’s Gulf of Mexico OCS Region’s Regional Director makes an 

assessment of consistency, which is then sent to the States of Louisiana, Mississippi, Alabama, and 

Florida for CPA and EPA lease sales. If a State disagrees with the Bureau of Ocean Energy 

Management’s CDs, the State is required to do the following under the CZMA: (1) indicate how 

BOEM’s presale proposal is inconsistent with its CMP; (2) suggest alternative measures to bring 

BOEM’s proposal into consistency with their CMP; or (3) describe the need for additional information 

that would allow a determination of consistency. Unlike the consistency process for specific OCS plans 

and permits, there is not a procedure for administrative appeal to the Secretary of Commerce for a Federal 

CD for presale activities. In the event of a disagreement between a Federal agency and the State’s CMP 

regarding consistency of the proposed lease sales, either BOEM or the State may request mediation. The 

regulations provide for an opportunity to resolve any differences with the State, but the CZMA allows 

BOEM to proceed with a proposed lease sale despite any unresolved disagreements if the Federal agency 

clearly describes in writing how the activity is consistent to the maximum extent practicable with the 

State’s CMP. 

Prior to proposed CPA Lease Sale 241 and proposed EPA Lease Sale 226, which are tentatively 

scheduled for March 2016, BOEM will publish the Final Supplemental EIS, which must be available for 

public review for 30 days. To initiate public review, BOEM will publish an NOA in the Federal 

Register. BOEM will send copies of the Final Supplemental EIS to Federal, State, and local agencies; 

Tribal Nations; industry; nongovernmental organizations; the general public; and local libraries. In 

addition, public notices will be mailed with the Final Supplemental EIS and will be placed on BOEM’s 

website at http://www.boem.gov/nepaprocess/. At the completion of this Supplemental EIS process, a 

decision will be made for proposed CPA Lease Sale 241 and proposed EPA Lease Sale 226. A separate 

NEPA review will be conducted prior to proposed CPA Lease Sale 247.

The Final Supplemental EIS is not a decision document. A Decision Memorandum will be prepared 

by the Assistant Secretary of the Interior for Land and Minerals Management (ASLM) for the decision on 

whether to hold each lease sale (i.e., one each for proposed CPA Lease Sales 241 and 247 and proposed 

EPA Lease Sale 226). A NEPA Record of Decision (ROD) will memorialize the decision and will 

identify BOEM’s preferred alternative for each lease sale, as well as the environmentally preferable 

alternative, if different. The ROD will summarize the proposed action and the alternatives evaluated in 

this Supplemental EIS, the information considered in reaching the decision, and the adopted mitigations. 

A Proposed Notice of Sale (NOS) will become available to the public 4-5 months prior to each 

proposed lease sale. A notice announcing the availability of the Proposed NOS appears in the Federal 

Register, initiating a 60-day comment period. Comments received will be analyzed during preparation of 

the decision documents that are the basis for the Final NOS, including lease sale configuration and terms 

and conditions.

If the ASLM decides to hold a proposed lease sale, a Final NOS will be published in its entirety in the 

Federal Register at least 30 days prior to the lease sale date, as required by the OCSLA.

Measures to Enhance Transparency and Effectiveness in the Leasing and Tiering Process

The following discussion is from the Five-Year Program EIS and has been incorporated into this 

Supplemental EIS for information purposes.

BOEM realizes that each region is different in terms of mineral resources and dependent economies, 

the relative state of infrastructure and support industries, and the sensitivity of ecosystems, environmental 

resources, and communities; and that a leasing strategy needs to be sensitive to those differences, but also 

that it must be consistent with OCSLA principles. BOEM envisions a phased OCSLA process that 

minimizes multiple-use and environmental conflicts to the extent possible during the Five-Year Program 

implementation, that makes lease sale decisions in the context of the best available information, and that 

discloses clear reasons for those decisions, even in the face of uncertainty. This vision is consistent with 

the National Ocean Policy Implementation Plan and related Marine Planning initiatives, all of which 

provide a complementary framework for space-use conflict considerations.

BOEM is committing to several process enhancements to ensure transparency during the phased 

OCSLA and tiered NEPA processes of this Five-Year Program. Although specific approaches to 
1-12 Central and Eastern Planning Areas Supplemental EIS

implementation may be tailored to the different needs of the Regions and their stakeholders, BOEM is 

determined to improve the effectiveness of the tiering process (40 CFR § 1508.28) through the following: 

• Alternative and Mitigation Tracking Table. BOEM has established an alternative 

and mitigation tracking table to provide increased visibility into the consideration of 

recommendations for deferrals, mitigations, and alternatives at different stages of the 

leasing process. Beginning with the Five-Year Program EIS, the table tracks the 

lineage and treatment of suggestions for spatial exclusions, temporal deferrals, and/or 

mitigation from the Five-Year Program to the lease sale phase and on to the plan 

phase. This table allows commenters to see how and at what stage of the process 

their concerns are being considered. BOEM will maintain a table that will be 

updated as deferral requests are considered at the lease sale and plan stages and as 

new requests are made. The alternative and mitigation tracking table has been placed 

on BOEM’s website at http://www.boem.gov/5-year/2012-2017/Tracking-Table/. A 

link to the table will be provided in the lease sale documents and in the annual report, 

which is discussed below.

• Strengthening the Prelease Sale Process. BOEM is taking a number of steps to 

enhance opportunities for members of the public to comment and provide new 

information in the prelease sale planning process. Historically, the Call for 

Information (Call), which is the first step in the Prelease Sale Process, has generally 

asked for industry to nominate specific blocks or descriptions of areas within the 

Five-Year Program area for which they have the most interest. The NOI requests 

comments from other Federal, State, and local governments, nongovernmental 

organizations, and the general public on issues that should be addressed and 

alternatives that should be considered in the NEPA documents that will be prepared 

for the action.

• Annual Progress Report. BOEM will publish an annual progress report on the 

approved Five-Year Program that includes an opportunity for stakeholders and the 

public to comment on the Five-Year Program’s implementation. Under Section 18(e) 

of the OCSLA, the Secretary must review annually the approved Five-Year Program. 

Historically, this has been an internal review process that reported to the Secretary 

any information or events that might result in a revision to the Five-Year Program. If 

the revision is considered significant under the OCSLA, the Five-Year Program can 

only be revised and reapproved by following the same Section 18 steps used to 

originally develop the Program. However, once the Section 18 process has been 

initiated for the next Five-Year Program, the annual review is subsumed in that 

process, as the same substantive and procedural requirements are being addressed.

The findings of this progress report may lead the Secretary to revise the Five-Year 

Program by reducing the size of, delaying, or canceling scheduled lease sales. If the 

desired revisions are considered significant, such as including new areas for 

consideration or more lease sales in areas already included, the entire Section 18 

process must be followed, in essence resulting in the preparation of a new Program.

• Systematic Planning. BOEM is committed to engaging in systematic planning 

opportunities that foster improved governmental coordination, communication, and 

information exchange. As the only agency authorized to grant renewable energy, 

marine mineral, and oil and gas leases on the OCS, the Bureau of Ocean Energy 

Management has been assigned the Federal co-lead, along with the U.S. Coast Guard, 

for systematic regional planning efforts in the Mid-Atlantic. Additionally, BOEM 

will participate on Regional Planning Bodies in the Northeast, Mid-Atlantic, and 

West Coast as the DOI lead. In the Gulf of Mexico OCS Region, BOEM 

representatives will assist the U.S. Fish and Wildlife Service (FWS), the DOI 

regional lead, with various working group activities. This will facilitate data and 

information availability, provide research of new technologies, and identify conflict 
The Proposed Actions 1-13

resolution and avoidance strategies. BOEM anticipates that its Marine Planning 

engagement will enhance regulatory efficiency through improved coordination and 

collaboration, and, in the long term, enhance the stewardship of ocean and coastal 

resources.

These strategies will allow BOEM to not only address the activities that take place under the 

2012-2017 Five-Year Program but also to lay the groundwork for decisions that will be faced in 

subsequent Five-Year Programs. BOEM will improve efforts to gather information while enhancing 

opportunities for stakeholders and other interested parties to participate in and be engaged in the 

decisionmaking process. The initiation of studies and long-term planning will facilitate future decisions 

by ensuring that the best information is available when making leasing decisions on the approved 

program and before the development of future OCS Programs.

1.5. POSTLEASE ACTIVITIES

BOEM and BSEE are responsible for managing, regulating, and monitoring oil and natural gas 

exploration, development, and production operations on the Federal OCS to promote the orderly 

development of mineral resources and to prevent harm or damage to, or waste of, any natural resource, 

any life or property, or the marine, coastal, or human environment. Regulations for oil, gas, and sulphur 

lease operations are specified in 30 CFR parts 250, 550, 551 (except those aspects that pertain to drilling), 

and 554.

Measures to minimize potential impacts are an integral part of the OCS Program. These measures are 

implemented through lease stipulations, operating regulations, and project-specific requirements or 

approval conditions. Notices to Lessees and Operators (NTLs) provide clarifications and additional 

information on some of these measures. Mitigating measures address concerns such as endangered and 

threatened species, geologic and manmade hazards, military warning and ordnance disposal areas, 

archaeological sites, air quality, oil-spill response planning, chemosynthetic communities, artificial reefs, 

operations in hydrogen sulfide (H2S) prone areas, and shunting of drill effluents in the vicinity of 

biologically sensitive features. Refer to Appendix A (“Commonly Applied Mitigating Measures”) for 

more information on the mitigations that BOEM and BSEE apply to permits.

BOEM issues NTLs to provide clarification, description, or interpretation of a regulation; to provide 

guidelines on the implementation of a special lease stipulation or regional requirement; or to convey 

administrative information. A detailed listing of the current Gulf of Mexico OCS Region NTLs is 

available through BOEM’s Gulf of Mexico OCS Region’s website at http://boem.gov/Regulations/

Notices-Letters-and-Information-to-Lessees-and-Operators.aspx or through the Region’s Public 

Information Office at 504-736-2519 or 1-800-200-GULF.

Formal plans must be submitted to BOEM for review and approval before any project-specific 

activities, except for ancillary activities (such as geological and geophysical [G&G] activities or studies 

that model potential oil and hazardous substance spills), can begin on a lease. Conditions of approval, 

which are mechanisms to control or mitigate potential safety or environmental problems associated with 

proposed operations, must be met before the activities can be approved by BOEM or BSEE. Conditions 

of approval are based on BOEM’s technical and environmental evaluations of the proposed operations. 

Comments from Federal and State agencies (as applicable) are also considered in establishing conditions. 

Conditions may be applied to any OCS plan, permit, right-of-use of easement, or pipeline right-of-way 

grant.

Some BOEM-identified mitigating measures are implemented through cooperative agreements or 

coordination with the oil and gas industry and Federal and State agencies. These measures include the 

National Marine Fisheries Service’s (NMFS’s) Observer Program to protect marine mammals and sea 

turtles when OCS structures are removed using explosives, labeling of operational supplies to track 

sources of accidental debris loss, development of methods of pipeline landfall to eliminate impacts to 

barrier beaches, and semiannual beach cleanup events.

Refer to Chapter 1.5 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental 

EIS, CPA 235/241/247 Supplemental EIS, and EPA 225/226 EIS for descriptions of postlease activities 

including G&G surveys; exploration and development plans; permits and applications; inspection and 

enforcement; pollution prevention, oil-spill response plans, and financial responsibility; air emissions; 

flaring and venting; hydrogen sulfide contingency plans; archaeological resources regulation; coastal zone 
1-14 Central and Eastern Planning Areas Supplemental EIS

management consistency review and appeals for plans; best available and safest technologies, including at 

production facilities; personnel training and education; structure removal and site clearance; marine 

protected species NTLs; and the Rigs-to-Reefs program.

1.6. OTHER OCS OIL- AND GAS-RELATED ACTIVITIES

BOEM and BSEE have programs and activities that are OCS oil- and gas-related but not specific to 

the oil and gas leasing process or to the management of exploration, development, and production 

activities. These programs include environmental and technical studies, cooperative agreements with 

other Federal and State agencies for NEPA work, joint jurisdiction over cooperative efforts, inspection 

activities, OCS sand borrowing, and regulatory enforcement. BOEM also participates in industry 

research efforts and forums. Chapter 1.6 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, CPA 235/241/247 Supplemental EIS, and EPA 225/226 EIS contains descriptions of 

the other OCS oil- and gas-related activities, including the Environmental Studies Program, Technology 

Assessment and Research Program, and interagency agreements.
CHAPTER 2 

ALTERNATIVES INCLUDING THE PROPOSED ACTIONS

Alternatives Including the Proposed Actions 2-3 

2. ALTERNATIVES INCLUDING THE PROPOSED ACTIONS

This Supplemental EIS addresses three proposed Federal actions: proposed oil and gas Lease Sales 

241 and 247 in the CPA and proposed Lease Sale 226 in the EPA of the Gulf of Mexico OCS

(Figure 1-1), as scheduled in the Five-Year Program (USDOI, BOEM, 2012a). The proposed actions 

(proposed lease sales) assume compliance with applicable regulations and lease stipulations in place at the 

time a ROD is signed for each proposed action.

2.1. SUPPLEMENTAL EIS NEPA ANALYSIS

Since proposed CPA Lease Sales 241 and 247 and proposed EPA Lease Sale 226 and their projected 

activities are very similar, this Supplemental EIS encompasses the three proposed lease sales as 

authorized under 40 CFR § 1502.4, which allows related or similar proposals to be analyzed in one EIS. 

In addition, one Area ID was prepared for the proposed CPA lease sale area and another Area ID was 

prepared for the EPA lease sale area. The Multisale EIS approach is intended to focus the NEPA/EIS 

process on the differences between the proposed lease sales and on new issues and information. It also 

lessens duplication and saves agency resources. At the completion of the NEPA process for this 

Supplemental EIS, a decision will be made on whether or how to hold proposed CPA Lease Sale 241 

and/or proposed EPA Lease Sale 226. An additional NEPA review will be conducted in the year prior to 

proposed CPA Lease Sale 247 to address any relevant significant new information. This additional 

NEPA review could take the form of a determination of NEPA adequacy, an environmental assessment, 

or if BOEM deems necessary, a supplemental EIS. Informal and formal consultation with other Federal 

agencies, the affected States, Tribal Nations, nongovernmental organizations, and the public will be 

carried out to assist in the determination of whether or not the information and analysis contained in this 

Supplemental EIS is still valid. Specifically, information requests will be issued soliciting input on 

proposed CPA Lease Sale 247.

2.2. ALTERNATIVES, MITIGATING MEASURES, AND ISSUES

2.2.1. Alternatives

The alternatives to be considered for proposed CPA Lease Sales 241 and 247 are detailed in Chapter 

2.3 below and in Chapter 2.4 for proposed EPA Lease Sale 226. These suggested alternatives have been 

derived from both the historical comments submitted to BOEM and the EIS-specific scoping performed 

for this analysis.

Through our scoping efforts for this Supplemental EIS and previous EISs and Supplemental EISs, 

numerous issues and topics were identified for consideration. During the scoping period for the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, CPA 235/241/247 Supplemental 

EIS, and EPA 225/226 EIS, a number of alternatives or deferral options were suggested and examined for 

inclusion in Chapter 2.2.1 of each of those NEPA documents. Those alternative and deferral options were 

also reexamined during the preparation of this Supplemental EIS. These suggestions included additional 

deferrals, policy changes, and suggestions beyond the scope of this Supplemental EIS. BOEM has not 

identified any new significant information that changes its conclusions in the NEPA documents 

mentioned above or that indicates that the proposed alternatives or deferral options are not appropriate for 

further in-depth analysis. The justifications for not carrying those suggestions through detailed analyses 

in this Supplemental EIS are the same as those used in the previously mentioned NEPA documents. 

The analyses of environmental impacts from the proposed alternatives summarized in Chapter 

2.3.1.2 below and described in detail in Chapter 4.1.1 are based on the development scenario, which is a 

set of assumptions and estimates on the amounts, locations, and timing for OCS oil and gas exploration, 

development, and production operations and facilities, both offshore and onshore. A detailed discussion 

of the development scenario and major related impact-producing factors is included in Chapter 3. 
2-4 Central and Eastern Planning Areas Supplemental EIS

2.2.1.1. Alternatives for Proposed Central Planning Area Lease Sales 241 and 247

Alternative A—The Proposed Action (Preferred Alternative): This alternative would offer for lease 

all unleased blocks within the proposed CPA lease sale area for oil and gas operations (Figure 2-1), with 

the following exceptions: 

(1) whole and portions of blocks deferred by the Gulf of Mexico Energy Security Act of 

2006; and

(2) blocks that are adjacent to or beyond the United States’ Exclusive Economic Zone 

in the area known as the northern portion of the Eastern Gap.

The DOI is conservative throughout the NEPA process and includes the total area within the CPA for 

environmental review even though the leasing of portions of the CPA (subareas or blocks) can be deferred 

during a Five-Year Program.

The proposed CPA lease sale area encompasses about 63 million ac of the total CPA area of 

66.45 million ac. As of September 2014, approximately 44.2 million ac of the proposed CPA lease sale 

area are unleased. This information is updated monthly and can be found on BOEM’s website at

http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The estimated amount of resources projected 

to be developed as a result of a proposed CPA lease sale is 0.460-0.894 BBO and 1.939-3.903 Tcf of gas 

(Table 3-1). 

Alternative B—Exclude the Unleased Blocks Near Biologically Sensitive Topographic Features: This 

alternative would offer for lease all unleased blocks within the proposed CPA lease sale area, as described 

for the proposed action (Alternative A), but it would exclude from leasing any unleased blocks subject to 

the Topographic Features Stipulation. The estimated amount of resources projected to be developed is 

0.460-0.894 BBO and 1.939-3.903 Tcf of gas (refer to Chapter 2.3.2 for further details).

Alternative C—No Action: This alternative is the cancellation of a proposed CPA lease sale. If this 

alternative is chosen, the opportunity for development of the estimated 0.460-0.894 BBO and 

1.939-3.903 Tcf of gas that could have resulted from a proposed CPA lease sale would be postponed

during the current 2012-2017 Five-Year Program, but it could again be contemplated as part of a future 

Five-Year Program. Any potential environmental impacts arising out of a proposed CPA lease sale

would not occur, but activities associated with existing leases in the CPA would continue. This

alternative is also analyzed in the EIS for the Five-Year Program on a nationwide programmatic level.

Alternatives and Deferrals Considered but Not Analyzed in Detail

Chapter 2.2.1.2 of the 2012-2017 WPA/CPA Multisale EIS includes a detailed description of 

alternatives considered but not analyzed in this Supplemental EIS, including the following: exclude deep 

water and limit leasing to shallow waters; delay leasing until drilling safety is improved; do not allow 

drilling in areas with strong ocean currents such as the Loop Current; delay leasing until the state of the

Gulf of Mexico environmental baseline is known; and identify and protect sensitive ecosystems. The 

justifications for not engaging in detailed analysis of these alternatives and deferrals in this Supplemental 

EIS are the same as those used in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS, and BOEM has identified no new 

information that changes these conclusions.

During scoping for this Supplemental EIS, the National Park Service requested that BOEM develop 

an alternative that excludes unleased blocks within 15 mi (24 km) of the Gulf Island National Seashore to 

fully address the National Park Service’s concerns described in detail under their specific comments in

Chapter 5.3.2. This would specifically affect lease blocks in the CPA’s Mobile Area, i.e., Mobile Blocks 

810-825, 854-869, and 899-913.

As noted in Chapter 1.1, the purpose of the proposed Federal actions is to offer for lease those areas 

that may contain economically recoverable oil and gas resources in accordance with the Outer Continental 

Shelf Lands Act (OCSLA) of 1953 (67 Stat. 462), as amended (43 U.S.C. §§ 1331 et seq.). The OCSLA 

provided the congressional mandate for BOEM to make “available for expeditious and orderly 

development, subject to environmental safeguards, in a manner which is consistent with the maintenance 

of competition and other national needs” the lands of the Federal OCS. The proposed CPA and EPA 

lease sales will provide qualified bidders the opportunity to bid upon and lease acreage in the Gulf of 
Alternatives Including the Proposed Actions 2-5 

Mexico OCS in order to explore, develop, and produce oil and natural gas. The need for the proposed 

actions is to further the orderly development of OCS resources. BOEM and its predecessors have made 

concerted efforts to identify and protect sensitive resources and habitats in the Gulf of Mexico since 1973 

(nearly 4 decades). Over that time period, the Environmental Studies Program in the Gulf of Mexico 

OCS Region has spent over $250 million on completed studies of physical, biological, and socioeconomic 

resources. Over time, using adaptive management practices, this Agency has proactively developed a 

suite of mitigating measures that are applied at the prelease or postlease phases of the oil and gas 

program. These mitigating measures serve to avoid and protect fixed biologically and culturally sensitive 

features such as topographic features, pinnacles, live bottoms, chemosynthetic communities, deepwater

corals, and historic shipwrecks on the coast, shelf, slope, and in deep water (e.g., Topographic Features 

Stipulation, Live Bottom (Pinnacle Trend) Stipulation, NTL 2009-G39, NTL 2009-G40, and NTL 

2005-G07). Protective measures are also in place to mitigate the potential impacts from seismic 

activities, marine debris, vessel traffic, structure-removal activities, and vessel traffic to mobile resources 

such as marine mammals and sea turtles (e.g., NTL 2007-G02, NTL 2007-G03, NTL 2007-G04, NTL 

2010-G05, NTL 2012-BSEE-G01, NTL 2012-JOINT-G01, and NTL 2012-JOINT-G02). Protective 

measures are also in place to mitigate the potential impacts to the Gulf Islands National Seashore (Gulf 

Islands National Seashore Information to Lessees and Operators [ITL]). 

Because of the extensive environmental protection measures already implemented by BOEM and 

BSEE, the ability to identify and protect sensitive environmental and cultural resources (including coastal 

areas) on an ongoing basis, the recently established ITL for the subject area, and the reasonably 

unforeseeable purchase of leases that could not be mitigated using subsea and other technologies, this 

alternative was not analyzed in detail in this Supplemental EIS.

2.2.1.2. Alternatives for Proposed Eastern Planning Area Lease Sale 226

Alternative A—The Proposed Action (Preferred Alternative): This alternative would offer for lease 

all unleased blocks within the proposed EPA lease sale area for oil and gas operations (Figure 2-1). 

The DOI is conservative throughout the NEPA process and includes the total area within the EPA for 

environmental review even though the leasing of portions of the EPA (subareas or blocks) can be deferred 

during a Five-Year Program.

The proposed EPA lease sale area covers approximately 657,905 ac and includes those blocks 

previously included in the EPA Lease Sales 224 and 225 Area and a triangular-shaped area south of this 

area bordered by the CPA boundary on the west and the Military Mission Line (86o41′ W. longitude) on 

the east. The area is south of eastern Alabama and western Florida; the nearest point of land is 125 mi 

(201 km) northwest in Louisiana. As of September 2014, approximately 465,200 ac of the proposed EPA 

lease sale area are currently unleased. This information is updated monthly and can be found on BOEM’s 

website at http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The estimated amount of natural 

resources projected to be developed as a result of a proposed EPA lease sale is 0-0.071 BBO and 

0-0.162 Tcf of gas.

Alternative B—No Action: This alternative is the cancellation of the proposed EPA lease sale. If this 

alternative is chosen, the opportunity for development of the estimated 0-0.071 BBO and 0-0.162 Tcf of 

gas that could have resulted from the proposed EPA lease sale would be precluded. Any potential 

environmental impacts resulting from the proposed EPA lease sale would not occur or would be 

postponed to a future lease sale decision. This is also analyzed in the EIS for the Five-Year Program on a 

nationwide programmatic level.

Although for its NEPA analyses in other planning areas BOEM typically analyzes alternatives that 

defer blocks based on the proximity or presence of biologically sensitive features or for other 

programmatic reasons, BOEM has determined that such alternatives are not reasonable in the EPA as 

there are no known blocks to exclude due to proximity to or presence of biologically sensitive features 

and due to the fact that the EPA proposed action area is such a small area for leasing. Scoping did not 

identify any other reasonable alternatives. And finally, other viable alternatives such as the deferral of 

blocks or the delay of the proposed EPA lease sale would essentially result in the same impacts as the 

No Action alternative, and therefore, do not need to be evaluated as separate and distinct alternatives.
2-6 Central and Eastern Planning Areas Supplemental EIS

Alternatives and Deferrals Considered but Not Analyzed in Detail

Chapter 2.9 of the Five-Year Program EIS (USDOI, BOEM, 2012a) includes a description of 

alternatives considered but not analyzed in this Supplemental EIS or in the EPA 225/226 EIS, including 

the following: expand the oil and gas leasing program to include more or all OCS planning areas beyond 

those identified in the NOI; hold multiple sales in some OCS planning areas; delay leasing until further 

data regarding oil-spill response and drilling safety is improved; delay leasing until the state of the Gulf of 

Mexico’s environmental baseline is known; develop alternative/renewable energy sources as a complete 

or partial substitute for oil and gas leasing on the OCS; add spatial exclusions and temporal deferrals; 

reduce the lease sale sizes to smaller than areawide; and defer deepwater leasing. The justifications for 

not carrying these alternatives and deferrals through detailed analyses in this Supplemental EIS are the 

same as those used in the Five-Year Program EIS and EPA 225/226 EIS, and BOEM has identified no 

new information that changes these conclusions.

BOEM received a public comment during the EPA 225/226 EIS’s scoping period (refer to Chapter 

5.3.1 of the EPA 225/226 EIS, Center for Biological Diversity letter, comment 2) stating that the EPA 

225/226 EIS should consider an alternative of removing the EPA from the Five-Year Program and 

canceling proposed EPA Lease Sales 225 and 226. This requested alternative would remove the EPA 

from the Five-Year Program due to the fact “the area is directly adjacent to an area subject to 

Congressional moratorium from oil and gas leasing and any spills would directly and negatively impact 

the area under moratorium and frustrate the aim of OCSLA to ‘balance the potential for environmental 

damage with the potential for the discovery of oil and gas’ 43 U.S.C. § 1344(a)(3).” The requested 

alternative is functionally equivalent to and would result in the same environmental impacts as 

Alternative B (No Action). Therefore, the requested alternative was not analyzed as a separate and 

distinct alternative.

2.2.2. Mitigating Measures

The NEPA process is intended to help public officials make decisions that are based on an 

understanding of environmental consequences and to take actions that protect, restore, and enhance the 

environment. Agencies are required to identify and include in the alternative chosen relevant and 

reasonable mitigating measures and lease stipulations that could improve the action. The CEQ 

regulations (40 CFR § 1508.20) define mitigation as follows: 

• Avoidance—Avoiding an impact altogether by not taking a certain action or part of 

an action.

• Minimization—Minimizing impacts by limiting the intensity or magnitude of the 

action and its implementation.

• Restoration—Rectifying the impact by repairing, rehabilitating, or restoring the 

affected environment.

• Maintenance—Reducing or eliminating the impact over time by preservation and 

maintenance operations during the life of the action.

• Compensation—Compensating for the impact by replacing or providing substitute 

resources or environments.

2.2.2.1. Proposed Mitigating Measures Analyzed

The potential lease stipulations and mitigating measures included for analysis in this Supplemental 

EIS were developed as a result of numerous scoping efforts for the continuing OCS Program in the Gulf 

of Mexico. Ten lease stipulations (described in Chapter 2.4.1.3 of the 2012-2017 WPA/CPA Multisale 

EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 2.3.1.3 of the CPA 235/241/247 

Supplemental EIS) are proposed for CPA Lease Sales 241 and 247—the Topographic Features 

Stipulation; the Live Bottom (Pinnacle Trend) Stipulation; the Military Areas Stipulation; the Evacuation 

Stipulation; the Coordination Stipulation; the Blocks South of Baldwin County, Alabama, Stipulation; the 

Protected Species Stipulation; the United Nations Convention on the Law of the Sea Royalty Payment 
Alternatives Including the Proposed Actions 2-7 

Stipulation; the Below Seabed Operations Stipulation; and the Stipulation on the Agreement between the 

United States of America and the United Mexican States Concerning Transboundary Hydrocarbon 

Reservoirs in the Gulf of Mexico. The United Nations Convention on the Law of the Sea Royalty 

Payment Stipulation is applicable to a proposed CPA lease sale even though it is not an environmental or 

military stipulation. Four of these 10 lease stipulations (described in Chapter 2.3.1.3 of the EPA 225/226 

EIS with detailed descriptions in Chapter 2.3.1.3 of the 2012-2017 WPA/CPA Multisale EIS) are 

proposed for EPA Lease Sale 226—the Protected Species Stipulation, the Military Areas Stipulation, the 

Evacuation Stipulation, and the Coordination Stipulation. Due to the location and small size of the 

proposed EPA lease sale area and lack of known topographic features and live bottoms, the other six 

stipulations were not deemed relevant to the EPA proposed lease sale.

These measures will be considered for adoption by the ASLM, under authority delegated by the 

Secretary of the Interior. The analysis of any stipulations for Alternative A does not ensure that the 

ASLM will make a decision to apply the stipulations to leases that may result from a proposed CPA or 

EPA lease sale nor does it preclude minor modifications in wording during subsequent steps in the 

prelease process if comments indicate changes are necessary or if conditions change.

Any lease stipulations or mitigating measures to be included in a lease sale will be described in the 

ROD for that lease sale. Mitigating measures in the form of lease stipulations are added to the lease terms 

and are therefore enforceable as part of the lease. In addition, each exploration and development plan, as 

well as any pipeline applications that result from a lease sale, will undergo a NEPA review, and additional 

project-specific mitigations will be applied as conditions of plan approval. The BSEE has the authority to 

monitor and enforce these conditions and, under 30 CFR part 250 subpart N, may seek remedies and 

penalties from any operator that fails to comply with those conditions, stipulations, and mitigating 

measures.

2.2.2.2. Existing Mitigating Measures

Mitigating measures have been proposed, identified, evaluated, or developed through previous 

BOEM lease sale NEPA review and analysis. Many of these mitigating measures have been adopted and 

incorporated into regulations and/or guidelines governing OCS oil and gas exploration, development, and 

production activities. All plans for OCS oil- and gas-related activities (e.g., exploration and development 

plans, pipeline applications, and structure-removal applications) go through rigorous BOEM review and 

approval to ensure compliance with established laws and regulations. Existing mitigating measures must 

be incorporated and documented in plans submitted to BOEM. Operational compliance of the mitigating 

measures is enforced through BSEE’s onsite inspection program.

Mitigating measures are a standard part of BOEM’s program to ensure that the operations are always 

conducted in an environmentally sound manner (with an emphasis on minimizing any adverse impact of 

routine operations on the environment). For example, certain measures ensure site clearance, and survey 

procedures are carried out to determine potential snags to commercial fishing gear and to avoid 

archaeological sites and biologically sensitive areas such as pinnacles, topographic features, and 

chemosynthetic communities. In addition, all BOEM-regulated activities and operations must comply 

with the requirements of other agencies having jurisdiction. Refer to Chapter 5 for more information on 

applicable consultation and coordination requirements.

Some BOEM-identified mitigating measures are incorporated into OCS operations through 

cooperative agreements or efforts with industry and State and Federal agencies. These mitigating 

measures include mandating compliance with NMFS’s Observer Program to protect marine mammals and 

sea turtles during the use of explosives for structure removal, labeling operational supplies to track 

possible sources of debris or equipment loss, developing methods of pipeline landfall to eliminate impacts 

to beaches or wetlands, and requiring beach cleanup events. 

Site-specific mitigating measures are also applied by BOEM during plan and permit reviews. BOEM 

realized that many of these site-specific mitigations were recurring and developed a list of “standard” 

mitigations. There are currently over 120 standard mitigations. The wording of a standard mitigation is 

developed by BOEM in advance and may be applied whenever conditions warrant. Standard mitigation 

text is revised as often as is necessary (e.g., to reflect changes in regulatory citations, agency/personnel 

contact numbers, and internal policy). Site-specific mitigation “categories” include the following: air 

quality; archaeological resources; artificial reef material; chemosynthetic communities; Flower Garden 

Banks; topographic features; hard bottom/pinnacles, military warning areas and Eglin water test areas; 
2-8 Central and Eastern Planning Areas Supplemental EIS

hydrogen sulfide; drilling hazards; remotely operated vehicle surveys; geophysical survey reviews; and 

general safety concerns. Site-specific mitigation “types” include the following: advisories; conditions of 

approval; hazard survey reviews; inspection requirements; notifications; post-approval submittals; and 

safety precautions. In addition to standard mitigations, BOEM may apply nonrecurring mitigating 

measures that are developed on a case-by-case basis. Refer to Appendix A (“Commonly Applied 

Mitigating Measures”) for more information on the mitigations that BOEM and BSEE apply to permits.

BOEM is continually revising applicable mitigations to allow the Gulf of Mexico OCS Region to 

more easily and routinely track mitigation compliance and effectiveness. A primary focus of this effort is 

requiring post-approval submittal of information within a specified timeframe or after a triggering event 

(e.g., end of operations reports for plans, construction reports for pipelines, and removal reports for 

structure removals).

2.2.3. Issues

Issues are defined in CEQ Guidance as the principal “effects” that an EIS should evaluate in-depth. 

Selection of environmental and socioeconomic issues to be analyzed was based on the following criteria:

• the issue is identified in CEQ regulations as subject to evaluation;

• the relevant resource/activity was identified through agency expertise, through the 

scoping process, or from comments on past EISs;

• the resource/activity may be vulnerable to one or more of the impact-producing 

factors associated with the OCS Program;

• a reasonable probability of an interaction between the resource/activity and impactproducing factor should exist; or

• the information that indicates a need to evaluate the potential impacts to a 

resource/activity has become available.

2.2.3.1. Issues to be Analyzed

Chapter 2.2.3.1 of the 2012-2017 WPA/CPA Multisale EIS and EPA 225/226 EIS address the issues 

related to potential impact-producing factors and the environmental and socioeconomic resources and 

activities that could be affected by OCS oil and gas exploration, development, production, and 

transportation activities (i.e., accidental events; drilling fluids and cuttings; visual and aesthetic 

interference; air emissions; water quality degradation and other wastes; structure and pipeline 

emplacement; platform removals; OCS oil- and gas-related support services, activities, and infrastructure; 

and regional cultures and socioeconomics). Chapters 4.1.1 and 4.2.1 of this Supplemental EIS, Chapter 

4.2.1 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, and Chapter 

4.1.1 of the CPA 235/241/247 Supplemental EIS and EPA 225/226 EIS describe the resources and 

activities that could be affected by the impact-producing factors listed above and include the following 

resource topics:
Alternatives Including the Proposed Actions 2-9 

— Air Quality

— Archaeological Resources (Historic and 

Prehistoric)

— Beach Mice

— Coastal Barrier Beaches and Associated 

Dunes

— Coastal and Marine Birds

— Commercial Fisheries

— Deepwater Benthic Communities 

(Chemosynthetic and 

Nonchemosynthetic)

— Diamondback Terrapins

— Fish Resources and Essential Fish 

Habitat

— Gulf Sturgeon

— Human Resources and Land Use 

(Land Use and Coastal 

Infrastructure, Demographics, 

Economic Factors, and 

Environmental Justice)

— Live Bottoms (Pinnacle Trend and 

Low Relief)

— Marine Mammals

— Recreational Fishing

— Recreational Resources

— Sargassum Communities

— Sea Turtles

— Seagrass Communities

— Soft Bottom Benthic Communities

— Topographic Features

— Water Quality (Coastal and Offshore)

— Wetlands

2.2.3.2. Issues Considered but Not Analyzed

As previously noted, the CEQ regulations for implementing NEPA instruct agencies to adopt an early 

process (termed “scoping”) for determining the scope of issues to be addressed and for identifying 

significant issues related to a proposed action. As part of this scoping process, agencies shall identify and 

eliminate from detailed study the issues that are not significant to a CPA or EPA proposed action or that 

have been covered by prior environmental review. No additional issues were identified during scoping 

that are not addressed in this Supplemental EIS. Comments received during scoping are summarized in 

Chapter 5.3. 

2.3. PROPOSED CENTRAL PLANNING AREA LEASE SALES 241 AND 247

2.3.1. Alternative A—The Proposed Action

2.3.1.1. Description

Alternative A would offer for lease all unleased blocks within the proposed CPA lease sale area for oil 

and gas operations (Figure 2-1), with the following exceptions: 

(1) whole and portions of blocks deferred by the Gulf of Mexico Energy Security Act of 

2006; and

(2) blocks that are adjacent to or beyond the United States Exclusive Economic Zone in 

the area known as the northern portion of the Eastern Gap.

The DOI is conservative throughout the NEPA process and includes the total area within the CPA for 

environmental review even though the leasing of portions of the CPA (subareas or blocks) can be deferred 

during a Five-Year Program.

The proposed CPA lease sale area encompasses about 63 million ac of the total CPA area of 

66.45 million ac. As of September 2014, approximately 44.2 million ac of the proposed CPA lease sale 

area are currently unleased. This information is updated monthly and can be found on BOEM’s website 

at http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The estimated amount of resources 

projected to be developed as a result of a proposed CPA lease sale is 0.460-0.894 BBO and 

1.939-3.903 Tcf of gas (Table 3-1). 

The analyses of impacts summarized below and described in detail in Chapter 4.1.1 are based on the 

development scenario, which is a set of assumptions and estimates on the amounts, locations, and timing 

for OCS oil and gas exploration, development, and production operations and facilities, both offshore and 

onshore. A detailed discussion of the development scenario and major related impact-producing factors is 

included in Chapter 3. 
2-10 Central and Eastern Planning Areas Supplemental EIS

Alternative A has been identified as BOEM’s preferred alternative; however, this does not mean that 

another alternative may not be selected in the Record of Decision.

2.3.1.2. Summary of Impacts

A search by BOEM’s subject-matter experts was conducted for each resource to consider new 

information made available since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS and to consider new information on the 

Deepwater Horizon explosion, oil spill, and response. It must also be emphasized that, in arriving at the 

overall conclusions for certain environmental resources (e.g., coastal and marine birds, fisheries, and 

wetlands), the conclusions are not based on impacts to individuals, small groups of animals, or small 

areas of habitat, but on impacts to the resources/populations as a whole. Any new information discovered 

was analyzed by BOEM’s subject-matter experts to determine if the impact conclusions presented in 

those NEPA documents were altered as a result of the new information.

For the following resources, BOEM’s subject-matter experts determined through literature searches 

and communications with other agencies and academia that there was no new information made available 

since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS that was relevant to potential impacts from a CPA proposed action. 

Therefore, the impact conclusions for these resources remain the same as those that were presented in

those NEPA documents. These impact conclusions are presented in Chapter 4.1.1 of this Supplemental 

EIS. For ease of review, the individual chapter numbers for each resource are provided in the following 

list.

• Diamondback Terrapin (Chapter 4.1.1.14) 

• Gulf Sturgeon (Chapter 4.1.1.17) 

• Archaeological Resources (Prehistoric) (Chapter 4.1.1.22.2) 

• Species Considered due to U.S. Fish and Wildlife Service Concerns (Chapter 

4.1.1.24) 

For the following resources, BOEM’s subject-matter experts determined through literature searches 

and communications with other agencies and academia that there was new information made available 

since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS that was relevant to potential impacts from a CPA proposed action. 

BOEM’s subject-matter experts have reexamined the analyses for these resources based on new 

information made available; however, none of the new information was deemed significant in that it did 

not alter the impact conclusions presented in those NEPA documents. These impact conclusions are 

presented in Chapter 4.1.1. For ease of review, the individual chapter numbers for each resource are 

provided in the following list.

• Air Quality (Chapter 4.1.1.1) 

• Water Quality (Coastal and Offshore) (Chapters 4.1.1.2.1 and 4.1.2.2, respectively) 

• Coastal Barrier Beaches and Associated Dunes (Chapter 4.1.1.3) 

• Wetlands (Chapter 4.1.1.4) 

• Seagrass Communities (Chapter 4.1.1.5) 

• Live Bottoms (Chapter 4.1.1.6) 

• Topographic Features (Chapter 4.1.1.7) 

• Sargassum Communities (Chapter 4.1.1.8) 

• Chemosynthetic Deepwater Benthic Communities (Chapter 4.1.1.9) 

• Nonchemosynthetic Deepwater Benthic Communities (Chapter 4.1.1.10) 
Alternatives Including the Proposed Actions 2-11

• Soft Bottom Benthic Communities (Chapter 4.1.1.11) 

• Marine Mammals (Chapter 4.1.1.12) 

• Sea Turtles (Chapter 4.1.1.13) 

• Beach Mice (Chapter 4.1.1.15) 

• Coastal and Marine Birds (Chapter 4.1.1.16) 

• Fish Resources and Essential Fish Habitat (Chapter 4.1.1.18) 

• Commercial Fisheries (Chapter 4.1.1.19) 

• Recreational Fishing (Chapter 4.1.1.20) 

• Recreational Resources (Chapter 4.1.1.21) 

• Archaeological Resources (Historic) (Chapter 4.1.1.22.1) 

• Human Resources and Land Use (Land Use and Coastal Infrastructure, 

Demographics, Economic Factors, and Environmental Justice) (Chapters 4.1.1.23.1, 

4.1.1.23.2, 4.1.1.23.3, and 4.1.1.23.4, respectively) 

Ultimately, no new significant information was discovered that would alter the impact conclusions for 

any of the resources analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS. The analyses and potential impacts detailed 

in those NEPA documents remain valid and, as such, apply for proposed CPA Lease Sales 241 and 247. 

In accordance with CEQ guidelines to provide decisionmakers with a robust environmental analysis, 

Appendix B (“Catastrophic Spill Event Analysis”) provides an analysis of the potential impacts of a lowprobability catastrophic oil spill, which is not part of a CPA proposed action and not likely expected, to 

the environmental and cultural resources and the socioeconomic conditions analyzed in Chapter 4.1.1. 

2.3.1.3. Mitigating Measures

The following lease stipulations may be applied to a CPA proposed action and the EPA proposed 

action as mitigating measures. If the decision is to hold a lease sale, the lease stipulations applicable to 

the sale will be announced in the Notice of Sale and Record of Decision.

2.3.1.3.1. Topographic Features Stipulation

The topographic features located in the CPA provide habitat for hard bottom communities of high 

biomass and diversity (Chapter 4.1.1.7). These communities could be severely and adversely impacted 

by oil and gas activities resulting from a CPA proposed action if such activities took place on blocks that 

are within the boundaries of a topographic feature, a No Activity Zone surrounding a topographic feature, 

or a shunting zone (1,000-Meter, 1-Mile, 3-Mile, and/or 4-Mile) surrounding a topographic feature 

without the Topographic Features Stipulation and if such activities were not mitigated. The DOI has 

recognized this problem for some years and, since 1973, has made lease stipulations a part of leases on or 

near these biotic communities so that impacts from nearby oil and gas activities were mitigated to the 

greatest extent possible. This stipulation would not prevent the recovery of oil and gas resources but 

would serve to protect valuable and sensitive biological resources from routine OCS oil- and gas-related 

activity by distancing bottom-disturbing activity (e.g., anchors, chains, cables, and wire ropes) 152 m 

(500 ft) from the No Activity Zone that surrounds topographic features and by requiring that drill muds 

and cuttings be shunted to the seafloor if a well is within a shunting zone (1,000-Meter, 1-Mile, 3-Mile, 

and/or 4-Mile) surrounding a topographic feature. 

The Topographic Features Stipulation was formulated based on consultation with various Federal 

agencies and comments solicited from the States, industry, environmental organizations, and academic 

representatives. BOEM and the National Oceanic and Atmospheric Administration (NOAA) also 

co-sponsor an ongoing long-term monitoring program at the Flower Garden Banks in order to determine 

if continued offshore oil- and gas-related activity in the GOM has impacted the reef habitat of these 
2-12 Central and Eastern Planning Areas Supplemental EIS

features. The Topographic Features Stipulation has been updated over time, using years of scientific 

information collected since the stipulation was first proposed. This information includes numerous 

Agency-funded studies of topographic features in the GOM; numerous stipulation-imposed, industryfunded monitoring reports; and the National Research Council (NRC) report entitled Drilling Discharges 

in the Marine Environment (1983). This stipulation protects these biotic communities from routine oil 

and gas activities resulting from a CPA proposed action, while allowing the development of nearby oil 

and gas resources. This stipulation would not prevent adverse effects of an accident such as a large 

blowout on a nearby oil or gas operation from impacting these biotic communities; however, it would 

distance the activity at least 152 m (500 ft) from the No Activity Zone surrounding topographic features, 

reducing the possibility of physical oiling. The location of the blocks affected by the Topographic 

Features Stipulation is shown on Figure 2-1. A more detailed discussion and definition of this stipulation 

and its effectiveness are found in Chapter 2.4.1.3.1 of the 2012-2017 WPA/CPA Multisale EIS.

2.3.1.3.2. Live Bottom (Pinnacle Trend) Stipulation

The Live Bottom (Pinnacle Trend) Stipulation covers the pinnacle trend area of the proposed CPA 

lease sale area. A small portion of the northeastern proposed CPA lease sale area is characterized by a 

pinnacle trend, which is classified as a live bottom under the stipulation. The pinnacles are a series of 

topographic irregularities with variable biotal coverage, which provide structural habitat for a variety of 

pelagic fish. The pinnacles in the region could be impacted from physical damage of unrestricted oil and 

gas activities, as noted in Chapter 4.1.1.6. The Live Bottom (Pinnacle Trend) Stipulation would protect 

live bottoms (Pinnacle Trend features) from routine OCS oil- and gas-related activity by distancing 

bottom-disturbing activity (e.g., anchors, chains, cables, and wire ropes) 30 m (100 ft) from hard 

bottoms/pinnacles. The Live Bottom (Pinnacle Trend) Stipulation is intended to protect the pinnacle 

trend and the associated hard bottom communities from damage and, at the same time, provide for 

recovery of potential oil and gas resources. The location of the pinnacle trend areas of the proposed CPA 

lease sale area is shown on Figure 2-1. A more detailed discussion and definition of this stipulation and 

its effectiveness are found in Chapter 2.4.1.3.2 of the 2012-2017 WPA/CPA Multisale EIS.

2.3.1.3.3. Military Areas Stipulation

The Military Areas Stipulation has been applied to all blocks leased in military areas since 1977, and 

it reduces the potential impacts, particularly in regards to safety. However, this stipulation does not 

reduce or eliminate the actual physical presence of oil and gas operations in areas where military 

operations are conducted. The stipulation contains a “hold harmless” clause (holding the U.S. 

Government harmless in case of an accident involving military operations) and requires lessees to 

coordinate their activities with appropriate local military contacts. Figure 2-2 shows the military warning 

areas in the Gulf of Mexico. A more detailed discussion and definition of this stipulation and its 

effectiveness are found in Chapter 2.3.1.3.2 of the 2012-2017 WPA/CPA Multisale EIS.

2.3.1.3.4. Evacuation Stipulation

The Evacuation Stipulation would be a part of any lease in the easternmost portion of the proposed 

CPA lease sale area resulting from a CPA proposed action, i.e., Lease Sales 241 and 247. This stipulation 

would provide for evacuation of personnel and shut-in of operations during any events conducted by the 

military that could pose a danger to ongoing oil and gas operations. It is expected that the invocation of 

these evacuation requirements will be extremely rare.

It is expected that these measures will serve to eliminate dangerous conflicts between oil and gas 

operations and military operations. Continued close coordination between BSEE and the military may 

result in improvements in the wording and implementation of these stipulations.

An evacuation stipulation has been applied to all blocks leased in this area since 2001. A more 

detailed discussion and definition of this stipulation and its effectiveness are found in Chapter 2.4.1.3.4 of 

the 2012-2017 WPA/CPA Multisale EIS.
Alternatives Including the Proposed Actions 2-13

2.3.1.3.5. Coordination Stipulation

The Coordination Stipulation would be a part of any lease in the easternmost portion of the proposed 

CPA lease sale area resulting from a CPA proposed action, i.e., Lease Sales 241 and 247. This stipulation 

would provide for review of pending oil and gas operations by military authorities and could result in 

delaying oil and gas operations if military activities have been scheduled in the area that may put the oil 

and gas operations and personnel at risk.

A coordination stipulation has been applied to all blocks leased in this area since 2001. A more 

detailed discussion and definition of this stipulation and its effectiveness are found in Chapter 2.4.1.3.5 of 

the 2012-2017 WPA/CPA Multisale EIS.

2.3.1.3.6. Blocks South of Baldwin County, Alabama, Stipulation

The Blocks South of Baldwin County, Alabama, Stipulation will be included only on leases on blocks 

south of and within 15 mi (24 km) of Baldwin County, Alabama. The stipulation specifies requirements 

for consultation that lessees must follow when developing plans for fixed structures. The stipulation has 

been continually adopted in annual CPA lease sales since 1999. It has been considered satisfactorily 

responsive to the concern of the Governor of Alabama and was adopted in each of the CPA lease sales in 

the 2002-2007 and 2007-2012 Five-Year Programs. A more detailed discussion and definition of this 

stipulation and its effectiveness are found in Chapter 2.4.1.3.6 of the 2012-2017 WPA/CPA Multisale 

EIS.

2.3.1.3.7. Protected Species Stipulation

The Protected Species Stipulation has been applied to all blocks leased in the GOM since December 

2001. This stipulation was developed in consultation with the Department of Commerce, National 

Oceanic and Atmospheric Administration, NMFS and the Department of the Interior, FWS in accordance 

with Section 7 of the Endangered Species Act, and it is designed to minimize or avoid potential adverse 

impacts to federally protected species. A more detailed discussion and definition of this stipulation and 

its effectiveness are found in Chapter 2.3.1.3.3 of the 2012-2017 WPA/CPA Multisale EIS.

2.3.1.3.8. United Nations Convention on the Law of the Sea Royalty Payment

Stipulation

The United Nations Convention on the Law of the Sea Royalty Payment Stipulation applies to blocks 

or portions of blocks beyond the U.S. Exclusive Economic Zone (generally greater than 200 nmi [230 mi; 

370 km] from the U.S. coastline). Leases on these blocks may be subject to special royalty payments 

under the provisions of the 1982 United Nations Convention on the Law of the Sea Royalty Payment

(consistent with Article 82), if the U.S. becomes a party to the Convention prior to or during the life of the 

lease. A more detailed discussion and definition of this stipulation and its effectiveness are found in 

Chapter 2.3.1.3.4 of the 2012-2017 WPA/CPA Multisale EIS.

2.3.1.3.9. Below Seabed Operations Stipulation

The Below Seabed Operations Stipulation language is intended to be lease sale-specific language and 

would incorporate maps of the blocks that may be affected. This stipulation can be found in Chapter 

2.4.1.3.9 of the 2012-2017 WPA/CPA Multisale EIS.

2.3.1.3.10. Stipulation on the Agreement between the United States of America and the 

United Mexican States Concerning Transboundary Hydrocarbon Reservoirs 

in the Gulf of Mexico

The “Agreement Between the United States of America and the United Mexican States Concerning 

Transboundary Hydrocarbon Reservoirs in the Gulf of Mexico” has now entered into force, making it 

possible for U.S. lessees to enter into voluntary agreements with a licensee of the United Mexican States 

to develop transboundary reservoirs. The stipulation has been applied to blocks or portions of blocks 

located wholly or partially within the 3 statute miles (4.8 km) of the maritime or continental shelf 
2-14 Central and Eastern Planning Areas Supplemental EIS

boundary with Mexico. The stipulation incorporates by reference the Agreement and notifies lessees that, 

among other things, activities in this boundary area will be subject to the Agreement and that approval of 

plans, permits, and unitization agreements will be conditioned upon compliance with the terms of the 

Agreement. For more information, refer to the Agreement itself, which is available on BOEM’s website 

at http://www.boem.gov/BOEM-Newsroom/Library/Publications/Agreement-between-the-United-Statesand-Mexico-Concerning-Transboundary-Hydrocarbon-Reservoirs-in-the-Gulf-of-Mexico.aspx. 

2.3.2. Alternative B—Exclude the Unleased Blocks Near the Biologically 

Sensitive Topographic Features

2.3.2.1. Description

Alternative B differs from Alternative A by not offering the blocks that are potentially subject to the 

proposed Topographic Features Stipulation (Chapter 2.4.1.3.1 of the 2012-2017 WPA/CPA Multisale EIS 

and Figure 2-1 of this Supplemental EIS). All other assumptions (including the 9 other potential 

mitigating measures and the 1 stipulation) and estimates are the same as for Alternative A. The estimated 

amount of resources projected to be developed is 0.460-0.894 BBO and 1.939-3.903 Tcf of gas.

2.3.2.2. Summary of Impacts

The analyses of impacts summarized in Chapter 2.3.1.2 and described in detail in Chapter 4.1.1 are 

based on the development scenario, which is a set of assumptions and estimates on the amounts, 

locations, and timing for OCS oil and gas exploration, development, and production operations and 

facilities, both offshore and onshore. A detailed discussion of the development scenario and major related 

impact-producing factors is included in Chapter 3. 

The difference between the potential impacts described for Alternative A and those under 

Alternative B is that under Alternative B no OCS oil- and gas-related activity would take place in the 

blocks subject to the Topographic Features Stipulation (Figure 2-1). The number of blocks that would 

not be offered under Alternative B represents only a small percentage of the total number of blocks to be 

offered under Alternative A; therefore, it is assumed that the levels of activity for Alternative B would be 

similar to those projected for a CPA proposed action. As a result, the impacts expected to result from 

Alternative B would be very similar to those described under a CPA proposed action (Chapter 4.1.1). 

Regional impact levels for all resources, except for the topographic features, would be similar to those 

described under a CPA proposed action. This alternative, if adopted, would prevent any OCS oil- and 

gas-related activity whatsoever in the affected blocks; thus, it would eliminate any potential direct 

impacts to the biota of those blocks from OCS oil- and gas-related activities, which otherwise would be 

conducted within the blocks.

2.3.3. Alternative C—No Action

2.3.3.1. Description

Alternative C is the cancellation of a proposed CPA lease sale. If this alternative is chosen, the 

opportunity for development of the estimated 0.460-0.894 BBO and 1.939-3.903 Tcf of gas that could 

have resulted from a proposed CPA lease sale would be precluded or postponed to a future CPA lease 

sale. Any potential environmental impacts arising out of a proposed CPA lease sale would not occur, but 

activities associated with existing leases in the CPA would continue. The No Action alternative, 

therefore, encompasses the same potential impacts as a decision to delay the leasing of unleased blocks in 

the CPA to a later scheduled lease sale under the Five-Year Program, when another decision on whether 

to hold that future lease sale would be made. Because delay of a proposed CPA lease sale would yield 

essentially the same results as the No Action alternative (i.e., most impacts related to Alternative A would 

not occur), delay of a proposed CPA lease sale was not considered as a separate alternative under this 

Supplemental EIS.
Alternatives Including the Proposed Actions 2-15

2.3.3.2. Summary of Impacts

Canceling a proposed CPA lease sale would eliminate the effects described for Alternative A 

(Chapter 4.1.3). The incremental contribution of a proposed lease sale to the cumulative effects would 

also be foregone, but the effects from other activities, including other previous OCS lease sales, would 

remain. Moreover, if a proposed CPA lease sale was canceled, the resulting development of oil and gas 

could be reevaluated under a future proposed lease sale. Therefore, the overall level of OCS oil- and gasrelated activity in the CPA would only be reduced by a small percentage, if any, and the cancellation of a 

proposed CPA lease sale would not significantly change the environmental impacts of overall OCS oiland gas-related activity in the short term at least. However, the cancellation of a proposed CPA lease sale 

could result in direct economic impacts to the individual companies. Revenues collected by the Federal 

Government (and thus revenue disbursements to the States) also would be adversely affected.

If a proposed CPA lease sale was canceled, then other sources of energy could potentially be 

substituted for the lost production. Principal substitutes would be additional imports, conservation, 

additional domestic production, and switching to other fuels. These alternatives, except conservation, 

have significant negative environmental impacts of their own. For example, the tankering of fuels from 

alternate sources over longer distances may have significant potential negative impacts, including the 

increased risk of spills in the Gulf of Mexico.

2.4. PROPOSED EASTERN PLANNING AREA LEASE SALE 226

2.4.1. Alternative A—The Proposed Action

2.4.1.1. Description

Alternative A would offer for lease all unleased blocks within the proposed EPA lease sale area for 

oil and gas operations.

The DOI is conservative throughout the NEPA process and includes the total area within the EPA for 

environmental review even though the leasing of portions of the EPA (subareas or blocks) can be deferred 

during a Five-Year Program.

The proposed EPA lease sale area covers approximately 657,905 ac and includes those blocks 

previously included in the EPA Lease Sales 224 and 225 Area and a triangular-shaped area south of this 

area bordered by the CPA boundary on the west and the Military Mission Line (86o41′ W. longitude) on 

the east. The area is south of eastern Alabama and western Florida; the nearest point of land is 125 mi 

(201 km) northwest in Louisiana. As of September 2014, approximately 465,200 ac of the proposed EPA 

lease sale area are currently unleased. This information is updated monthly and can be found on BOEM’s 

website at http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The estimated amount of natural 

resources projected to be developed as a result of the proposed EPA lease sale is 0-0.071 BBO and 

0-0.162 Tcf of gas.

The analyses of impacts summarized below and described in detail in Chapter 4.2.1 are based on the 

development scenario, which is a set of assumptions and estimates on the amounts, locations, and timing 

for OCS oil and gas exploration, development, and production operations and facilities, both offshore and 

onshore. A detailed discussion of the development scenario and major related impact-producing factors is 

included in Chapter 3. 

Alternative A has been identified as BOEM’s preferred alternative; however, this does not mean that 

the other alternative may not be selected in the Record of Decision.

2.4.1.2. Summary of Impacts

A search by BOEM’s subject-matter experts was conducted for each resource to consider new 

information made available since publication of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS and to consider 

new information on the Deepwater Horizon explosion, oil spill, and response. It must also be emphasized 

that, in arriving at the overall conclusions for certain environmental resources (e.g., coastal and marine 

birds, fisheries, and wetlands), the conclusions are not based on the impacts to individuals, small groups 

of animals, or small areas of habitat, but on the impacts to the resources/populations as a whole. Any new 

information discovered was analyzed by BOEM’s subject-matter experts to determine if the impact 
2-16 Central and Eastern Planning Areas Supplemental EIS

conclusions presented in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS were altered as a result of the new 

information.

For the following resources, BOEM’s subject-matter experts determined through literature searches 

and communications with other agencies and academia that there was no new information made available 

since publication of the EPA 225/225 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS that was relevant to potential impacts from 

the EPA proposed action. Therefore, the impact conclusions for these resources remain the same as those 

that were presented in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS. These impact conclusions are presented in 

Chapter 4.2.1 of this Supplemental EIS. For ease of review, the individual chapter numbers for each 

resource are provided in the following list.

• Diamondback Terrapin (Chapter 4.2.1.14) 

• Archaeological Resources (Prehistoric) (Chapter 4.2.1.21.2) 

• Species Considered due to U.S. Fish and Wildlife Service Concerns (Chapter 

4.2.1.23) 

For the following resources, BOEM’s subject-matter experts determined through literature searches 

and communications with other agencies and academia that there was new information made available 

since publication of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS that was relevant to potential impacts from 

the EPA proposed action. BOEM’s subject-matter experts have reexamined the analyses for these 

resources based on new information made available; however, none of the new information was deemed 

significant in that it did not alter the impact conclusions presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS. These impact conclusions are presented in Chapter 4.2.1. For ease of review, the individual 

chapter numbers for each resource are provided in the following list.

• Air Quality (Chapter 4.2.1.1) 

• Water Quality (Coastal and Offshore) (Chapters 4.1.1.2.1 and 4.1.2.2, respectively)

• Coastal Barrier Beaches and Associated Dunes (Chapter 4.2.1.3) 

• Wetlands (Chapter 4.2.1.4) 

• Seagrass Communities (Chapter 4.2.1.5) 

• Live Bottoms (Chapter 4.2.1.6) 

• Topographic Features (Chapter 4.2.1.7) 

• Sargassum Communities (Chapter 4.2.1.8) 

• Chemosynthetic Deepwater Benthic Communities (Chapter 4.2.1.9) 

• Nonchemosynthetic Deepwater Benthic Communities (Chapter 4.2.1.10) 

• Soft Bottom Benthic Communities (Chapter 4.2.1.11) 

• Marine Mammals (Chapter 4.2.1.12) 

• Sea Turtles (Chapter 4.2.1.13) 

• Beach Mice (Chapter 4.2.1.15) 

• Coastal and Marine Birds (Chapter 4.2.1.16) 
Alternatives Including the Proposed Actions 2-17

• Fish Resources and Essential Fish Habitat (includes Gulf sturgeon) (Chapter 

4.2.1.17) 

• Commercial Fisheries (Chapter 4.2.1.18) 

• Recreational Fishing (Chapter 4.2.1.19) 

• Recreational Resources (Chapter 4.2.1.20) 

• Archaeological Resources (Historic) (Chapter 4.2.1.21.1) 

• Human Resources and Land Use (Land Use and Coastal Infrastructure, 

Demographics, Economic Factors, and Environmental Justice) (Chapters 4.2.1.22.1, 

4.2.1.22.2, 4.2.1.22.3, and 4.2.1.22.4, respectively)

Ultimately, no new significant information was discovered that would alter the impact conclusions for 

any of the resources analyzed in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. The analyses and potential 

impacts detailed in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS remain valid and, as such, apply for 

proposed EPA Lease Sale 226. 

In accordance with CEQ guidelines to provide decisionmakers with a robust environmental analysis, 

Appendix B (“Catastrophic Spill Event Analysis”) provides an analysis of the potential impacts of a lowprobability catastrophic oil spill, which is not part of the EPA proposed action and not likely expected, to 

the environmental and cultural resources and the socioeconomic conditions analyzed in Chapter 4.2.1. 

2.4.1.3. Mitigating Measures

The following lease stipulations may be applied to the proposed actions as mitigating measures. If 

the decision is to hold a lease sale, the lease stipulations applicable to the sale will be announced in the 

Notice of Sale and a Record of Decision.

2.4.1.3.1. Protected Species Stipulation

The Protected Species Stipulation has been applied to all blocks leased in the Gulf of Mexico since 

2001. This stipulation was developed in consultation with the Department of Commerce, National 

Oceanic and Atmospheric Administration, NMFS and the Department of the Interior, FWS in accordance 

with Section 7 of the Endangered Species Act, and it is designed to minimize or avoid potential adverse 

impacts to federally protected species. A more detailed discussion and definition of this stipulation and 

its effectiveness are found in Chapter 2.4.1.3.7 of the 2012-2017 WPA/CPA Multisale EIS; Chapter 

2.3.1.3.1 of the EPA 225/226 EIS also discussed this stipulation. 

2.4.1.3.2. Military Areas Stipulation

The Military Areas Stipulation has been applied to all blocks leased in military areas since 1977 and 

reduces or avoids potential conflicts of use and impacts, particularly in regards to safety; but, it does not 

reduce or eliminate the actual physical presence of oil and gas operations in areas where military 

operations are conducted. The stipulation contains a “hold harmless” clause (holding the U.S. 

Government harmless in case of an accident involving military operations) and requires lessees to 

coordinate their activities with appropriate local military contacts. Figure 2-2 shows the military warning 

areas in the Gulf of Mexico. A more detailed discussion and definition of this stipulation and its 

effectiveness are found in Chapter 2.3.1.3.2 of the EPA 225/226 EIS and Chapter 2.4.1.3.3 of the 

2012-2017 WPA/CPA Multisale EIS.

2.4.1.3.3. Evacuation Stipulation

The Evacuation Stipulation has been included on all blocks leased in this area since 2001. The 

Evacuation Stipulation is designed to protect the lives and welfare of offshore oil and gas personnel. Oil 

and gas activities have the potential to occasionally interfere with specific requirements and operating 
2-18 Central and Eastern Planning Areas Supplemental EIS

parameters for the lessee’s activities in accordance with the military stipulation clauses contained herein. 

If it is determined that the operations will result in interference with scheduled military missions in such a 

manner as to possibly jeopardize the national defense or to pose unacceptable risks to life and property, 

then a temporary suspension of operations and the evacuation of personnel may be necessary. A more 

detailed discussion and definition of this stipulation and its effectiveness are found in Chapter 2.3.1.3.3 of 

the EPA 225/226 EIS and Chapter 2.4.1.3.4 of the 2012-2017 WPA/CPA Multisale EIS.

2.4.1.3.4. Coordination Stipulation

The Coordination Stipulation has been included on all blocks leased in this area since 2001. The 

Coordination Stipulation is designed to increase communication and cooperation between military 

authorities and offshore oil and gas operators. Specific requirements and operating parameters are 

established for the lessee’s activities in accordance with the military stipulation clauses. For instance, if it 

is determined that the operations will result in interference with scheduled military missions in such a 

manner as to possibly jeopardize the national defense or to pose unacceptable risks to life and property, 

then certain measures become activated and the oil and gas operations may be curtailed in the interest of 

national defense. A more detailed discussion and definition of this stipulation and its effectiveness are 

found in Chapter 2.3.1.3.4 of the EPA 225/226 EIS and Chapter 2.4.1.3.5 of the 2012-2017 WPA/CPA 

Multisale EIS.

2.4.2. Alternative B—No Action

2.4.2.1. Description

Alternative B is the cancellation of the proposed EPA lease sale. If this alternative is chosen, the 

opportunity for development of the estimated 0-0.071 BBO and 0-0.162 Tcf of gas that could have 

resulted from the proposed EPA lease sale would be precluded or postponed. Any potential 

environmental impacts resulting from the proposed EPA lease sale would not occur. This is also analyzed 

in the EIS for the Five-Year Program on a nationwide programmatic level.

2.4.2.2. Summary of Impacts

Canceling the proposed EPA lease sale would eliminate the effects described for Alternative A 

(Chapter 4.2.2). The incremental contribution of the proposed lease sale to the cumulative effects would 

also be avoided, but effects from other activities, including other OCS lease sales, would remain.

If the proposed EPA lease sale (e.g., Lease Sale 226) would be canceled, under the OCS Lands Act 

BOEM would be required to consider any proposed lease sales remaining in the current Five-Year 

Program, if applicable, or proposed as part of a future Five-Year Program. Therefore, a decision to cancel 

the lease sale will not alter future decision points for lease sales in the EPA, as required by OCSLA. The 

decision point is at the individual proposed action or lease sale stage. Selection of the No Action 

alternative for a single proposed action, i.e., proposed Lease Sale 226, would result in avoiding the 

drilling of 3-12 exploration wells, the drilling of up to 17 development and production wells, the 

installation of up to 82 km (51 mi) of pipeline, 144-17,000 service-vessel trips, up to 27 helicopter trips, 

and the recovery of 0-0.071 BBO and 0-0.162 Tcf of gas over a 40-year period. By selecting the No 

Action alternative those potential impacts related to proposed Lease Sale 226 would be avoided; however, 

please be advised that a decision to cancel a single proposed lease sale would not preclude activity related 

to past lease sales nor decisions on future lease sales. Should the No Action alternative be selected, in the 

interim, industry may explore and develop their existing portfolio of lease holds subject to the terms of

those leases and any conditions of approval for plans or permits. Individual or a series of decisions on 

lease sales in a given planning area may influence industry’s decisionmaking or strategy to develop 

existing leases. In this context, the No Action alternative does not explicitly presume an identical 

proposal or one only delayed into the future. As noted above, under the OCS Lands Act, BOEM would 

be required to consider any proposed lease sales remaining in the current Five-Year Program, if 

applicable, or proposed as part of a future Five-Year Program. As such, each lease sale will have its own 

decision point.

The cancellation of the proposed EPA lease sale would not significantly change the environmental 

impacts of overall OCS oil- and gas-related activity. However, the cancellation of the proposed EPA 
Alternatives Including the Proposed Actions 2-19

lease sale may result in direct economic impacts to the individual companies. Revenues collected by the 

Federal Government (and thus revenue disbursements to the States) would be adversely affected also.

Other sources of energy may substitute for the lost production. Principal substitutes would be 

additional imports, conservation, additional domestic production, and switching to other fuels. These 

alternatives, except conservation, have negative environmental impacts of their own. In particular, import 

tankering of alternative supplies of oil and gas increases the potential risk for oil spills in the Gulf of 

Mexico.

CHAPTER 3 

IMPACT-PRODUCING FACTORS AND SCENARIO

Impact-Producing Factors and Scenario 3-3 

3. IMPACT-PRODUCING FACTORS AND SCENARIO

3.1. IMPACT-PRODUCING FACTORS AND SCENARIO—ROUTINE OPERATIONS

3.1.1. Offshore Impact-Producing Factors and Scenario

Chapter 3.1.1 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, 

and CPA 235/241/247 Supplemental EIS describes the offshore infrastructure and activities (impactproducing factors) associated with a CPA proposed action (i.e., a typical lease sale) within the CPA that 

could potentially affect the biological, physical, and socioeconomic resources of the Gulf of Mexico.

Chapter 3.1.1 of the EPA 225/226 EIS describes the offshore infrastructure and activities (impactproducing factors) associated with an EPA proposed action (i.e., a typical lease sale) within the EPA that 

could potentially affect the biological, physical, and socioeconomic resources of the Gulf of Mexico.

In addition, these chapters describe the OCS Program’s cumulative activity scenario resulting from 

past and future lease sales in the WPA, CPA, and EPA that could potentially affect biological, physical, 

and socioeconomic resources within the Gulf of Mexico. Note that offshore and onshore impactproducing factors and scenarios associated with WPA proposed actions, i.e., typical lease sales that would 

result from the proposed actions within the WPA, as well as OCS Program activity resulting from past 

and future leases sales in the WPA, have been disclosed in the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and WPA 238/246/248 Supplemental EIS. 

Offshore is defined here as the OCS portion of the GOM that begins 10 mi (16 km) offshore Florida; 

3 nmi (3.45 mi; 5.56 km) offshore Louisiana, Mississippi, and Alabama; and 3 marine leagues (9 nmi; 

10.36 mi; 16.67 km) offshore Texas. The OCS extends seaward to the limits of the United States’ 

jurisdiction over the continental shelf in water depths up to approximately 3,346 m (10,978 ft), which 

comprises the Exclusive Economic Zone (Figure 1-1). Coastal infrastructure and activities associated 

with a CPA or EPA proposed action are described in Chapter 3.1.2. 

BOEM projects that the overwhelming majority of the oil and natural gas fields discovered as a result 

of a CPA or EPA proposed action will reach the end of their economic life within a time span of 40 years 

following a lease sale. Therefore, activity levels are not projected beyond 40 years for this document. 

Although unusual cases exist where activity on a lease may continue beyond 40 years, BOEM’s forecasts 

indicate that most significant activities associated with exploration, development, production, and 

abandonment of leases in the GOM occur well within the 40-year analysis period. For the cumulative 

case analysis, total OCS Program exploration and development activities are also forecast over a 40-year 

period. For modeling purposes and quantitative OCS Program activity analyses, a 40-year analysis period 

is also used. Exploration and development activity forecasts become increasingly more uncertain as the 

length of time of the forecast increases and the number of influencing factors increases.

BOEM uses a series of spreadsheet-based, data analysis tools to develop the forecasts of oil and gas 

exploration, discovery, development, and production activity for a CPA or EPA proposed action and OCS 

Program scenarios presented in this Supplemental EIS. Our analyses incorporate all relevant historical 

activity and infrastructure data, and our resulting forecasts are analyzed and compared with actual 

historical data to ensure that historical precedent and recent trends are reflected in each activity forecast.

BOEM is confident that our analysis methodology, with adjustments and refinements based on recent 

activity levels, adequately projects Gulf of Mexico OCS oil- and gas-related activities in both the short 

term and the long term for the Supplemental EIS analyses.

The CPA and EPA proposed actions and the Gulfwide OCS Program scenarios are based on the 

following factors:

• resource estimates developed by BOEM;

• recent trends in the amount and location of leasing, exploration, and development 

activity;

• estimates of undiscovered, unleased, economically recoverable oil and gas resources 

in each water-depth category and each planning area;

• existing offshore and onshore oil and/or gas infrastructure; 
3-4 Central and Eastern Planning Areas Supplemental EIS

• published data and information;

• industry information; and

• oil and gas technologies, and the economic considerations and environmental 

constraints of these technologies.

The proposed lease sales under the 2012-2017 Five-Year Program within the Gulf of Mexico OCS are 

EPA Lease Sales 225 and 226; WPA Lease Sales 229, 233, 238, 246, and 248; and CPA Lease Sales 227, 

231, 235, 241, and 247. In the CPA, a typical lease sale each represents 3-4 percent of the OCS Program 

activities expected in the CPA from 2012 through 2051 based on barrels of oil equivalent (BOE) resource 

estimates and 3 percent of the total OCS Program (WPA, CPA, and EPA) from 2012 through 2051. In 

general, a proposed lease sale in the proposed EPA lease sale area represents less than 1 percent of the 

total resource estimates in the Gulfwide OCS Program, but it represents 34 percent of the resource 

estimates in the proposed EPA lease sale area alone based on barrels of oil equivalent. 

Specific projections of activities associated with a CPA or an EPA proposed action (a typical lease

sale) are discussed in the following scenario sections. The potential impacts of the projected activities 

associated with a proposed “typical” lease sale are considered in the environmental analysis section 

(Chapter 4.1.1). 

The OCS Program scenario includes all activities that are projected to occur from past, proposed, and 

future lease sales during the analysis period. This includes projected activity from lease sales that have 

been held, including the most recent CPA Lease Sale 231 and EPA Lease Sale 225 (March 2013), but for 

which exploration or development has either not yet begun or is continuing. Activities that take place 

beyond the analysis timeframe as a result of future lease sales are not included in this analysis. The 

impacts of activities associated with the OCS Program on biological, physical, and socioeconomic 

resources are analyzed in the cumulative environmental analysis sections (Chapters 4.1.1 and 4.2.1). 

3.1.1.1. Resource Estimates and Timetables

The CPA proposed action and cumulative case have not changed since last analyzed for the CPA 

235/241/247 Supplemental EIS, and the EPA proposed action and cumulative case have not changed 

since last analyzed for the EPA 225/226 EIS. BOEM has not identified any new information or change in 

circumstances since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS or EPA 225/226 EIS that would change the 

estimates and timetables.

3.1.1.1.1. Proposed Actions 

The proposed action scenarios are used to assess the potential impacts of a proposed typical lease 

sale. The resource estimates for a proposed action are based on two factors: (1) the conditional estimates 

of undiscovered, unleased, conventionally recoverable oil and gas resources in the proposed lease sale 

area; and (2) estimates of the portion or percentage of these resources assumed to be leased, discovered, 

developed, and produced as a result of a proposed action. Due to the inherent uncertainties associated 

with an assessment of undiscovered resources, probabilistic techniques were employed and the results 

were reported as a range of values corresponding to different probabilities of occurrence. The estimates 

of the portion of the resources assumed to be leased, discovered, developed, and produced as a result of a 

proposed action are based upon logical sequences of events that incorporate past experience, current 

conditions, and foreseeable development strategies. Historical databases and information derived from oil 

and gas exploration and development activities are available to BOEM and were used extensively in the 

development of these scenarios. The undiscovered, unleased, conventionally recoverable resource 

estimates for a proposed action are expressed as ranges, from low to high. This range provides a 

reasonable expectation of anticipated oil and gas production from a typical lease sale held as a result of a 

proposed action based on an actual range of historic observations.

Table 3-1 presents the projected oil and gas production for a typical lease sale and cumulatively for 

the OCS Program (between 2012 and 2051) based on planning areas. Tables 3-2 and 3-3 provide a 

summary of the major scenario elements of the proposed actions, a typical lease sale, and some of the 

related impact-producing factors for a CPA and an EPA proposed action, respectively. To analyze 
Impact-Producing Factors and Scenario 3-5 

impact-producing factors for the proposed actions and the OCS Program, the proposed lease sale areas 

were divided into an offshore subarea based upon ranges in water depth. Figure 3-1 depicts the location 

of the offshore subareas. The water-depth range reflects the technological requirements and related 

physical and economic impacts as a consequence of the oil and gas potential, exploration and 

development activities, and lease terms unique to each water-depth range. Estimates of resources and 

facilities are distributed into each of the subareas.

Proposed Action Scenario (CPA Typical Lease Sale): The estimated amounts of resources projected 

to be leased, discovered, developed, and produced as a result of a typical proposed CPA lease sale are 

0.460-0.894 BBO and 1.939-3.903 Tcf of gas.

Proposed Action Scenario (EPA Typical Lease Sale): The estimated amounts of resources projected 

to be leased, discovered, developed, and produced as a result of a typical proposed EPA lease sale are 

0-0.071 BBO and 0-0.162 Tcf of gas.

The impact-producing factors, affected environment, and environmental consequences related to a 

WPA proposed typical lease sale has been disclosed and addressed in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and WPA 238/246/248 Supplemental EIS. 

The numbers of exploration and delineation wells, production platforms, and development wells 

projected to develop and produce the estimated resources for a CPA or an EPA proposed action are given 

in Tables 3-2 and 3-3, respectively. These tables show the distribution of these factors by the offshore 

subarea in the proposed lease sale areas. Tables 3-2 and 3-3 also include estimates of the major impactproducing factors related to the projected levels of exploration, development, and production activity.

Exploratory drilling activity typically takes place over an 8-year period, beginning within 1 year after 

the lease sale. Development activity takes place over a 39-year period, beginning with the installation of 

the first production platform and ending with the drilling of the last development wells. Production of oil 

and gas begins by the third year after the lease sale and continues to the 40th year (and in some limited 

cases beyond). 

3.1.1.1.2. OCS Program

OCS Program Cumulative Scenario (WPA, CPA, and EPA): Projected reserve/resource production 

for the OCS Program is 18.335-25.640 BBO and 75.886-111.627 Tcf of gas and represents anticipated 

production from lands currently under lease plus anticipated production from future lease sales over the 

40-year analysis period. The OCS Program cumulative scenario includes WPA, CPA, and EPA 

production estimates. Table 3-4 presents all anticipated production from lands currently under lease in 

the WPA, CPA, and EPA plus all anticipated production from future total OCS Program (WPA, CPA, 

and EPA) lease sales over the 40-year analysis period.

WPA Cumulative Scenario: Projected reserve/resource production for the OCS Program in the WPA 

(2.510-3.696 BBO and 12.539-18.434 Tcf of gas) represents all anticipated production from lands 

currently under lease in the WPA plus all anticipated production from future WPA lease sales over the 

40-year analysis period. Projected production represents approximately 14 percent of the oil and 

17 percent of the gas of the total Gulfwide OCS Program. The impact-producing factors, affected 

environment, and environmental consequences related to the WPA cumulative OCS Program activities 

have been disclosed and addressed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and WPA 238/246/248 Supplemental EIS. The WPA cumulative scenario is included 

in this Supplemental EIS in the context of the OCS Program, as the OCS Program covers all three 

panning areas.

CPA Cumulative Scenario: Projected reserve/resource production for the OCS Program in the CPA 

(15.825-21.733 BBO and 63.347-92.691 Tcf of gas) represents all anticipated production from lands 

currently under lease in the CPA plus all anticipated production from future CPA lease sales over the 

40-year analysis period. Projected production represents approximately 85-86 percent of the oil and 

83 percent of the gas of the total Gulfwide OCS Program. Table 3-5 presents projections of the major 

activities and impact-producing factors related to future cumulative OCS Program activities in the CPA 

over the 40-year analysis period. The impact-producing factors, affected environment, and environmental 

consequences related to the CPA cumulative OCS Program activities have been disclosed and addressed 

in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS. 
3-6 Central and Eastern Planning Areas Supplemental EIS

EPA Cumulative Scenario: Projected reserve/resource production for the OCS Program in the EPA 

(0-0.211 BBO and 0-0.502 Tcf of gas) represents all anticipated production from lands currently under 

lease in the EPA plus all anticipated production from future EPA lease sales over the 40-year analysis 

period. Projected production represents approximately less than 1 percent of the oil and gas of the total 

Gulfwide OCS Program. Table 3-6 presents projections of the major activities and impact-producing 

factors related to future cumulative OCS Program activities in the EPA over the 40-year analysis period. 

The impact-producing factors, affected environment, and environmental consequences related to the EPA 

cumulative OCS Program activities have been disclosed and addressed in the EPA 225/226 EIS.

3.1.1.2. Exploration and Delineation

3.1.1.2.1. Seismic Surveying Operations

Prelease surveys are comprised of seismic work performed on or off leased areas, focused most 

commonly (but not always) on deeper targets and collectively authorized under BOEM’s geological and 

geophysical permitting process. Postlease, high-resolution seismic surveys collect data on surficial or 

near-surface geology used to identify potential shallow geologic hazards for engineering and site planning 

for bottom-founded structures. Noise associated with OCS oil and gas development results from seismic 

surveys, the operation of fixed structures such as offshore platforms and drilling rigs, and helicopter and 

service-vessel traffic.

Noise sources related to a CPA proposed action are discussed in Chapter 3.1.1.6 of this 

Supplemental EIS and Chapter 3.1.1.6 of the 2012-2017 WPA/CPA Multisale EIS.

Noise sources related to an EPA proposed action are discussed in Chapter 3.1.1.6 of this 

Supplemental EIS and Chapter 3.1.1.6 of the EPA 225/226 EIS and 2012-2017 WPA/CPA Multisale EIS.

CPA or EPA Proposed Action Scenario (Typical Lease Sale): Because of the cyclic nature in the 

acquisition of seismic surveys, a prelease seismic survey would be attributable to lease sales held up to 7-

9 years after the survey was completed. Based on an amalgam of historical trends in G&G permitting and 

industry input, BOEM projects that proposed lease sales within the WPA, CPA, and EPA would result in 

29,197 OCS blocks surveyed by 2D and 3D deep seismic operations for the years 2012-2017. This

breaks down per planning area as follows: WPA ~7,300 blocks; CPA ~21,314 blocks; and EPA ~583 

blocks. (Note that the number of blocks could include multiple surveys on a single block that would then 

be counted as a unique block survey each time.) For postlease sale seismic surveys, information obtained 

from high-resolution seismic contractors operating in the GOM project that the proposed actions would 

result in about 50 vertical seismic profiling (VSP) operations and 629 high-resolution surveys covering 

approximately 226,400 line miles (364,420 km) of near-surface and shallow penetration seismic for the 

years 2012-2017.

Chapter 3.1.1.2.1 of the 2012-2017 WPA/CPA Multisale EIS describes in detail ocean-bottom 

surveys related to a CPA proposed action.

Chapter 3.1.1.2.1 of the EPA 225/226 EIS describes in detail ocean-bottom surveys related to an EPA 

proposed action.

OCS Program Cumulative Scenario (WPA, CPA, and EPA): Seismic surveys are projected to follow 

the same trend as exploration activities, which peaked in 2008-2010, will steadily decline until 2027, and 

will remain relatively steady throughout the second half of the 40-year analysis period. It is important to 

note that the cycling of G&G data acquisition is not driven by the 40-year life cycle of productive leasing, 

but instead it will trend to respond to new production or potential new production driven by new 

technology. Consequently, some areas will be resurveyed in 2-year cycles, while other areas, considered 

nonproductive, may not be surveyed for 20 years or more.

Assuming that acoustic-sourced seismic will remain the dominant exploration tool used by industry in 

the future and that a number of surveyed blocks will be resurveyed several more times, BOEM makes the 

following projections. During the first 5 years (2012-2017) of the 40-year analysis period (2012-2051), 

BOEM projects the following annual activities: 50 VSP operations; 226,400 lines miles (364,420 km) 

surveyed by high-resolution seismic; and 29,197 blocks surveyed by deep seismic, including areas that 

will be resurveyed. Expanding this analysis to the first 20 years (2012-2032), the annual projections 

would be 60 VSP operations, 400,000 mi (740,800 km) surveyed by high-resolution seismic, and 

33,000 blocks of 2D/3D deep seismic (60% in the CPA, 10% in the EPA, and 30% in the WPA). During 

the second half of the 40-year analysis period, the annual projection would be approximately 40 VSP 
Impact-Producing Factors and Scenario 3-7 

operations, 240,000 mi (444,480 km) surveyed by high-resolution seismic, and 15,000-20,000 blocks 

surveyed by deep seismic annually (50% in the CPA, 20% in the EPA, and 30% in the WPA). 

3.1.1.2.2. Exploration and Delineation Plans and Drilling

Chapter 3.1.1.2.2 of the 2012-2017 WPA/CPA Multisale EIS describes in detail exploration and 

delineation plans and drilling related to a CPA proposed action.

Chapter 3.1.1.2.2 of the EPA 225/226 EIS describes in detail exploration and delineation plans and 

drilling related to an EPA proposed action.

Oil and gas operators use drilling terms that represent stages in the discovery and exploitation of 

hydrocarbon resources. An exploration well generally refers to the first well drilled on a prospective 

geologic structure to confirm that a resource exists and to validate how much resource can be expected. If 

a resource is discovered in quantities that appear economically viable, one or more follow-up delineation 

wells help define the amount of resource or the extent of the reservoir. Following a discovery, an 

operator will often temporarily plug and abandon a discovery well to allow time for a development 

scenario to be generated and for equipment to be built or procured.

In the GOM, exploration and delineation wells are typically drilled with mobile offshore drilling units 

(MODUs), e.g., jack-up rigs, semisubmersible rigs, submersible rigs, platform rigs, or drill ships. NonMODUs, such as inland barges, are also used. The type of rig chosen to drill a prospect depends 

primarily on water depth. Because the water-depth ranges for each type of drilling rig overlap to a 

degree, other factors such as availability and daily rates play a large role when an operator decides upon 

the type of rig to contract. The depth ranges for exploration rigs used in this analysis for Gulf of Mexico 

MODUs are indicated below.

MODU or Drilling Rig Type Water Depth Range

Jack-up, submersible, and inland barges ≤100 m (328 ft)

Semisubmersible and platform rig 100-3,000 m (328-9,843 ft)

Drillship ≥600 m (1,969 ft)

Historically, drilling rig availability has been a limiting factor for activity in the GOM and is assumed 

to be a limiting factor for activity projected as a result of a proposed lease sale. Drilling activities may 

also be constrained by the availability of rig crews, shore-based facilities, risers, and other equipment.

The scenario for a proposed action assumes that an average exploration well will require 30-120 

(mean of 60) days to drill. The actual time required for each well depends on a variety of factors, 

including the depth of the prospect’s potential target zone, the complexity of the well design, and the 

directional offset of the wellbore needed to reach a particular zone. This scenario assumes that the 

average exploration or delineation well depth will be approximately 4,572-7,010 m (15,000-23,000 ft) 

below the mudline.

Some delineation wells may be drilled using a sidetrack technique. In sidetracking a well, a portion 

of the existing wellbore is plugged back to a specific depth, directional drilling equipment is installed, and 

a new wellbore is drilled to a different geologic location. The lessee may use this technology to better 

understand their prospect and to plan future wells. Use of this technology may also reduce the time and 

exploration expenditures needed to help evaluate the prospective horizons on a new prospect.

The cost of an average exploration well can be $40-$150 million or more, without certainty that 

objectives can be reached. Some recent ultra-deepwater exploration wells (>6,000-ft [1,829-m] water 

depth) in the GOM have been reported to cost upwards of $200 million. The actual cost for each well 

depends on a variety of factors, including the depth of the prospect’s potential target zone, the complexity 

of the well design, and the directional offset of the wellbore needed to reach a particular zone.

Subpart D of BSEE’s regulations (30 CFR part 250) specifies requirements for drilling activities. 

Refer to Chapter 1.3.1 of this Supplemental EIS, Chapter 1.3.1 and Table 1-2 of the 2012-2017 

WPA/CPA Multisale EIS, Chapter 1.3.2 of the WPA 233/CPA 231 Supplemental EIS, and Chapter 1.3.1 

of the CPA 235/241/247 Supplemental EIS, which provide a summary of new and updated safety 

requirements related to a CPA proposed action. 
3-8 Central and Eastern Planning Areas Supplemental EIS

Refer to Chapter 1.3.1 of this Supplemental EIS, Chapter 1.3.1 and Table 1-2 of the 2012-2017 

WPA/CPA Multisale EIS, and Chapter 1.3.1 of the EPA 225/226 EIS for a summary of new and updated 

safety requirements related to an EPA proposed action.

CPA Proposed Action Scenario (Typical Lease Sale): BOEM estimates that 168-329 exploration and 

delineation wells would be drilled as a result of a CPA proposed action. Table 3-2 shows the estimated 

range of exploration and delineation wells by water-depth range. Greater than 50 percent of the projected 

wells for a CPA proposed action is expected to be on the continental shelf (0-200 m [0-656 ft] water 

depth). 

CPA Cumulative Scenario: BOEM estimates that 5,270-8,110 exploration and delineation wells 

would be drilled as a result of all cumulative OCS Program activities in the CPA (Table 3-5). 

EPA Proposed Action Scenario (Typical Lease Sale): BOEM estimates that 3-12 exploration and 

delineation wells would be drilled as a result of the EPA proposed action (Table 3-3). 

EPA Cumulative Scenario: BOEM estimates that 10-27 exploration and delineation wells would be 

drilled as a result of all cumulative OCS Program activities in the EPA (Table 3-6). 

OCS Program Cumulative Scenario (WPA, CPA, and EPA): BOEM estimates that 6,910-9,827 

exploration and delineation wells would be drilled in the WPA, CPA, and EPA as a result of all past OCS 

lease sales and projected activity for future lease sales associated with this Five-Year Program. Tables 

3-4 through and 3-6 show the estimated range of exploration and delineation wells by water-depth range

for the OCS Program activities (WPA, CPA, and EPA), the OCS Program activities in the CPA, and OCS 

Program activities in the EPA, respectively. Of these wells, approximately 55 percent are expected to be 

on the continental shelf (0-200 m [0-656 ft] water depth) and approximately 45 percent are expected in 

intermediate water-depth ranges and deeper (>200 m; 656 ft). Note that the offshore and onshore impactproducing factors, affected environment, and environmental consequences related to the WPA cumulative

OCS Program activities have been disclosed and are addressed in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and WPA 238/246/248 WPA Supplemental EIS.

3.1.1.3. Development and Production

Development and Production Drilling

Chapter 3.1.1.3.1 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 3.1.1.3 of the WPA 

233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS describe in detail development 

and production drilling, and development operations and coordination documents (DOCDs) related to a 

CPA proposed action. 

Chapter 3.1.1.3.1 of the EPA 225/226 EIS and 2012-2017 WPA/CPA Multisale EIS describes in 

detail development and production drilling and DOCDs related to an EPA proposed action.

Delineation and production wells are sometimes collectively termed development wells. A 

development well is designed to extract resources from a known hydrocarbon reservoir. After a 

discovery, the operator must decide whether or not to complete the well without delay, to delay 

completion with the rig on station so that additional tests may be conducted, or to temporarily abandon 

the well site and move the rig off station to a new location and drill another well. Sometimes an operator 

will decide to drill a series of development wells, move off location, and then return with a rig to 

complete all the wells at one time. If an exploration well is clearly a dry hole, the operator permanently 

abandons the well without delay.

When the decision is made to complete the well, a new stage of activity begins. Completing a well 

involves preparing the well for production. BOEM estimates that approximately 90 percent of 

development wells will become producing wells. The typical process includes setting and cementing the 

production casing, installing some downhole production equipment, perforating the casing and 

surrounding cement, treating the formation, setting a gravel pack (if needed), and installing production 

tubing. One form of formation treatment is known as “induced hydraulic fracturing,” commonly referred 

to as “fracking.” Induced hydraulic fracturing is a process used to fracture a reservoir rock formation 

using pressurized liquid. The technique is used to increase flow rate and maximize production. The 

pressurized fluid is typically a mixture of water, well treatment chemicals and a mechanical agent or 

proppant. The mechanical agents, such as sand, manmade ceramics, or small microspheres (tiny glass 

beads), are designed to keep open the induced hydraulic fractures that are created by the pressurized 

fluids so they can perform as conduits to assist the flow of hydrocarbons from the reservoir formation to 
Impact-Producing Factors and Scenario 3-9 

the wellbore. Well treatment chemicals are commonly used to improve well productivity. For example, 

acidizing a reservoir to dissolve cementing agents and improve fluid flow is the most common well 

treatment in the GOM. In contrast to the large-scale induced hydraulic fracturing procedures used in 

onshore oil and gas operations for low-permeability “tight gas,” “tight oil,” “shale gas,” and “coal gas” 

reservoirs, induced hydraulic fracturing treatments carried out on the OCS in the GOM are small-scale by 

comparison and most commonly used for high-permeability formations to repair formation damage 

caused during drilling operations. Since damage to the formation caused by drilling operations does not 

extend for large distances away from the reservoir-borehole interface, the fracturing induced by the 

procedure is also designed to remain in close proximity to the borehole, extending distances of only a few 

feet to 40 or 60 ft (12 or 18 m) from the borehole, rarely extending for more than 100 ft (30 m) from the 

borehole. After a production test determines the desired production rate to avoid damaging the reservoir, 

the well is ready to go online and produce.

The DOCD is the chief planning document that lays out an operator’s specific intentions for 

development. The range of postlease development plans is discussed in Chapter 1.5. BOEM estimates 

that approximately 82 percent of development wells would become producing wells.

CPA Proposed Action Scenario (Typical Lease Sale): It is estimated that 215-417 development and 

production wells will be drilled as a result of a CPA proposed action. Table 3-2 shows the estimated 

range of development and production wells by water-depth subarea. The percentage of projected oil wells 

within the CPA is more evenly distributed throughout the water-depth ranges, with the greatest number of 

wells being forecasted for water depths >2,400 m (7,874 ft), whereas 66-75 percent of the gas wells are 

projected to be drilled on the continental shelf (0-200 m [0-656 ft] water depth).

CPA Cumulative Scenario: BOEM estimates that 7,080-10,020 development and production wells 

would be drilled as a result of all cumulative OCS Program activities in the CPA (Table 3-5). 

EPA Proposed Action Scenario (Typical Lease Sale): BOEM estimates that 0-17 development and 

production wells would be drilled as a result of an EPA proposed action (Table 3-3). 

EPA Cumulative Scenario: BOEM estimates that 0-40 development and production wells would be 

drilled as a result of all cumulative OCS Program activities in the EPA (Table 3-6). 

OCS Program Cumulative Scenario (WPA, CPA, and EPA): It is estimated that 8,530-12,180 

development and production wells would be drilled in the WPA, CPA, and EPA as a result of the 

proposed lease sales and all OCS oil- and gas-related activity associated with previous lease sales. 

Tables 3-4 through 3-6 show the estimated range of development wells by water depth. 

Note that the impact-producing factors, affected environment, and environmental consequences 

related to the WPA cumulative OCS Program activities have been disclosed and addressed in the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and WPA 238/246/248 

Supplemental EIS. 

Infrastructure Emplacement/Structure Installation and Commissioning Activities

Chapter 3.1.1.3.2 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 3.1.1.3 of the WPA 

233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS describe in detail infrastructure

emplacement/structure installation and commissioning activities related to a CPA proposed action.

Chapter 3.1.1.3.2 of the EPA 225/226 EIS and 2012-2017 WPA/CPA Multisale EIS describes in 

detail infrastructure emplacement/structure installation and commissioning activities related to an EPA 

proposed action.

Bottom-founded or floating structures may be placed over development wells to facilitate production 

from a prospect. These structures provide the means to access and control the wells. They serve as a 

staging area to process and treat produced hydrocarbons from the wells, initiate export of the produced 

hydrocarbons, conduct additional drilling or reservoir stimulation, conduct workover activities, and carry 

out eventual abandonment procedures. There is a range of offshore infrastructure installed for 

hydrocarbon production. Among these are pipelines, fixed and floating platforms, caissons, well 

protectors, casing, wellheads, and conductors.

CPA Proposed Action Scenario (Typical Lease Sale): It is estimated that 35-67 production structures 

will be installed as a result of a CPA proposed action. Table 3-2 shows the projected number of structure 

installations for a CPA proposed action by water-depth range. About 80 percent of all the production 

structures installed for a CPA proposed action are projected to be on the continental shelf (0-60 m; 

0-197 ft).
3-10 Central and Eastern Planning Areas Supplemental EIS

CPA Cumulative Scenario: BOEM estimates that 1,180-1,640 production structures would be 

installed as a result of all cumulative OCS Program activities in the CPA (Table 3-5). 

EPA Proposed Action Scenario (Typical Lease Sale): It is estimated that 0-1 production structures 

would be installed as a result of an EPA proposed action (Table 3-3). 

EPA Cumulative Scenario: BOEM estimates that 0-2 production structures would be installed as a 

result of all cumulative OCS Program activities in the EPA (Table 3-6). 

OCS Program Cumulative Scenario (WPA, CPA, and EPA): It is estimated that 1,435-2,026 

production structures would be installed in the WPA, and CPA, and EPA as a result of the proposed lease 

sales and all OCS oil- and gas-related activity associated with previous lease sales. Table 3-4, 3-5, and 

3-6 show the projected number of structure installations by water-depth range for the OCS. 

Note that the impact-producing factors, affected environment, and environmental consequences 

related to the WPA cumulative OCS Program activities have been disclosed and addressed in the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and WPA 238/246/248 

Supplemental EIS.

Bottom Area Disturbance

Chapter 3.1.1.3.2.1 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 3.1.1.3 of the WPA 

233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS describe in detail infrastructure

emplacement/structure installation and commissioning activities related to a CPA proposed action.

Chapter 3.1.1.3.2.1 of the EPA 225/226 EIS and 2012-2017 WPA/CPA Multisale EIS describes in 

detail bottom area disturbances related to an EPA proposed action. 

Structures emplaced or anchored on the OCS to facilitate oil and gas exploration and production 

include drilling rigs or MODUs (i.e., jack-ups, semisubmersibles, and drillships), pipelines, and fixed 

surface, floating, and subsea production systems. For a CPA proposed action, these are discussed in 

Chapter 3.1.1.3 of this Supplemental EIS, Chapters 3.1.1.3.1 and 3.1.1.3.2 of the 2012-2017 WPA/CPA 

Multisale EIS, and Chapter 3.1.1.3 of the WPA 233/CPA 231 Supplemental EIS and CPA 235/241/247 

Supplemental EIS. For an EPA proposed action, these are discussed in Chapter 3.1.1.3 of this 

Supplemental EIS and Chapters 3.1.1.3.1 and 3.1.1.3.2 of the EPA 225/226 EIS. The emplacement or 

removal of these structures disturbs small areas of the sea bottom beneath or adjacent to the structure. If 

mooring lines of steel, chain, or synthetic polymer are anchored to the sea bottom, areas around the 

structure can also be directly affected by their emplacement. This disturbance includes physical 

compaction or crushing beneath the structure or mooring lines and the resuspension and settlement of 

sediment caused by the activities of emplacement. Movement of floating types of facilities will also 

cause the movement of the mooring lines in its array. Small areas of the sea bottom will be affected by 

this kind of movement. Impacts from bottom disturbance are of concern near sensitive areas such as 

topographic features, pinnacles, low-relief live bottom features, chemosynthetic communities, highdensity biological communities in water depths ≥400 m (1,312 ft), and archaeological sites.

Sediment Displacement

Chapter 3.1.1.3.2.2 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 3.1.1.3 of the WPA 

233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS describe in detail sediment 

displacement related to a CPA proposed action.

Chapters 3.1.1.3.2.2 of the EPA 225/226 EIS describes in detail sediment displacement related to an 

EPA proposed action. 

Displaced sediments are those that have been physically moved “in bulk.” Displaced sediments will 

cover or bury an area of the seafloor, while resuspended sediments will cause an increase in turbidity of 

the adjacent water column. Resuspended sediments eventually settle, covering the surrounding seafloor. 

Resuspended sediments may include entrained heavy metals or hydrocarbons.

Infrastructure Presence

Chapter 3.1.1.3.3 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 3.1.1.3 of the WPA 

233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS describe in detail impactproducing factors due to infrastructure presence related to a CPA proposed action.
Impact-Producing Factors and Scenario 3-11

Chapter 3.1.1.3.3 of the EPA 225/226 EIS describes in detail impact-producing factors due to 

infrastructure presence related to an EPA proposed action. 

The installation and maintenance of infrastructure may include, but is not limited to, the following:

• anchoring;

• offshore production systems;

• space-use requirements (deployment of survey equipment or bottom-founded 

production equipment);

• aesthetic quality (presence and visibility of equipment, vessels, and air traffic); and

• workovers and abandonments.

3.1.1.4. Operational Waste Discharged Offshore

For a CPA proposed action, Chapter 3.1.1.4 of the 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental, and CPA 235/241/247 Supplemental EIS describes in detail the impactproducing factors due to operational wastes discharged offshore and provides summaries as well as 

detailed updated information on more recent, stricter regulations regarding vessel discharges. 

For an EPA proposed action, Chapter 3.1.1.4 of the EPA 225/226 EIS describes in detail the impactproducing factors due to operational wastes discharged offshore and provides summaries as well as 

detailed updated information on more recent, stricter regulations regarding vessel discharges. 

Operational wastes discharged offshore include the following:

• drilling muds and cuttings;

• produced waters; 

• well treatment, workover, and completion fluids;

• production solids and equipment;

• bilge, ballast, and fire water;

• cooling water;

• deck drainage;

• treated domestic and sanitary wastes; 

• minor discharges; 

• vessel operational discharges; and

• distillation and reverse osmosis brine.

BOEM maintains records of the volume of water produced from each block on the OCS and its 

disposition―injected on lease, injected off lease, transferred off lease, or discharged overboard. The 

amount discharged overboard for the years 2000-2013 is summarized by water depth in Table 3-7, with 

new data provided for the year 2013. The total volume for all water depths during this 13-year period 

ranged from 489.0 to 648.2 MMbbl, with the largest contribution (68-88%) coming from operations on 

the shelf. The total volume of produced water generally decreased after 2004, reflecting an overall 

decrease in contributions from operations on the shelf. The contribution of produced water from 

operations in deep water (>400 m [1,312 ft] water depth) and ultra-deepwater (>1,600 m [5,249 ft] water 

depth) production has been increasing. From 2000 to 2013, the contribution from these operations (deep 

and ultra-deepwater together) increased from 6 percent (37.8 MMbbl) to 28 percent (142.8 MMbbl) of the 

total produced-water volume (calculated from data in Table 3-7). The updated annual amounts and depth 

distributions of produced water discharged by depth are within the range of or similar to data presented in 

the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 
3-12 Central and Eastern Planning Areas Supplemental EIS

Supplemental EIS for a CPA proposed action and the EPA 225/226 EIS for an EPA proposed action. 

Thus, this new information did not change the validity of the operational wastes discussions previously 

presented. 

3.1.1.5. Air Emissions

In 1990, pursuant to Section 328 of the Clean Air Act Amendments and following consultation with 

the Commandant of the U.S. Coast Guard (USCG) and the Secretary of the Interior, the U.S. 

Environmental Protection Agency (USEPA) assumed air quality responsibility for the OCS waters in the 

GOM east of longitude 87.5o W., and this Agency retained National Ambient Air Quality Standards 

(NAAQS) air quality jurisdiction for OCS operations west of the same longitude in the GOM. Air quality 

regulations are under a comprehensive review in 2014 to replace obsolete provisions and to ensure that 

updates in regulations are following improvements in scientific and technological information.

There are many air emissions sources related to OCS oil and gas exploration, development, and 

production in the GOM. During the exploration stage, most OCS emissions are from non-platform 

sources and include combustion from the equipment used on a drilling rig or from fuel usage of a support 

vessel. During the production stage, most emissions are from platform emission sources and include 

boilers, diesel engines, combustion flares, fugitives, glycol dehydrators, natural gas engines, turbines, 

pneumatic pumps, pressure/level controllers, storage tanks, cold vents, and others. During the 

development stage, most OCS emissions are from non-platform emissions and include fuel usage of 

support or survey vessels to lay pipelines, install facilities, or map geologic formations and seismic 

properties.

Pollutants released by OCS oil- and gas-related sources include the NAAQS pollutants carbon 

monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), and sulfur dioxide (SO2). Pollutants also 

released by OCS sources (NOx and volatile organic compounds [VOC]) are precursors to ozone, which is 

formed by photochemical reactions in the atmosphere and is another NAAQS pollutant. Lastly, OCS oiland gas-related sources release greenhouse gas emissions, such as carbon dioxide (CO2), methane (CH4), 

and nitrous oxide (N2O).

The Year 2008 Gulfwide Emissions Inventory Study (Wilson et al., 2010) indicates that, for calendar 

year 2008, OCS oil and gas production platforms and non-platform sources emit the majority of criteria 

pollutants and greenhouse gases in the GOM on the OCS, with the exception of PM and SO2 (primarily 

emitted from commercial marine vessels) and N2O (from biological sources). The OCS oil and gas 

production platform and non-platform sources account for 93 percent of the total CO emissions, 

74 percent of NOx emissions, 76 percent of VOC emissions, 99 percent of the CH4 emissions, and 

84 percent of the CO2 emissions. Natural gas engines on platforms represented the largest CO emission 

source, accounting for 60 percent of the total estimated CO emissions; support vessels were the highest 

emitters of NOx, accounting for 35 percent of the total estimated emissions. Oil and natural gas 

production platform vents and fugitive sources account for the highest percentage of VOC and CH4

emissions. Support vessels (29% of total emissions), production platform natural gas turbines (15% of 

total emissions), and drilling rigs (12% of total emissions) emit the majority of the CO2 emissions. An 

update to Wilson et al. (2010), which is currently in progress, is built upon previous studies to develop a 

base year 2011 air pollution emissions inventory for all OCS oil and gas production-related sources in 

GOM. This study combines the most recent emissions factors released by the USEPA and the updated 

estimations methods to develop a comprehensive criteria pollutant and greenhouse gases emissions 

inventory.

3.1.1.6. Noise

Noise associated with OCS oil and gas development results from seismic surveys, the installation of 

structures, the operation of fixed structures such as offshore platforms and drilling rigs, the 

decommissioning and removal of structures, and helicopter and service-vessel traffic. Noise generated 

from these activities can be transmitted through both air and water, and may be long-lived or temporary. 

Offshore drilling and production involve various activities that produce a composite underwater noise 

field. The intensity level and frequency of the noise emissions are highly variable, both between and 

among the various industry sources. Noise from proposed OCS oil- and gas-related activities may affect 

resources near the activities. Whether a sound is or is not detected by marine organisms depends both on 
Impact-Producing Factors and Scenario 3-13

the acoustic properties of the source (spectral characteristics, intensity, and transmission patterns) and the 

sensitivity of the hearing system in the marine organism. Extreme levels of noise can cause harassment, 

physical damage, or death to an exposed animal and, in limited circumstances, can cause “take” of marine 

mammals under the Marine Mammal Protection Act or endangered and threatened species as defined in 

the Endangered Species Act. Source levels well above hearing thresholds can damage hearing or induce 

behavioral changes (Richardson et al., 1995).

Chapter 3.1.1.6 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, 

and CPA 235/241/247 Supplemental EIS describes in detail noise-related impact-producing factors 

associated with OCS oil and gas development for a CPA proposed action.

Chapter 3.1.1.6 of the EPA 225/226 EIS describes in detail noise-related impact-producing factors 

associated with OCS oil and gas development for an EPA proposed action. 

3.1.1.7. Major Sources of Oil Inputs in the Gulf of Mexico

Petroleum hydrocarbons can enter the GOM from a wide variety of sources. The major sources of oil 

inputs in the GOM are natural seepage, permitted produced-water discharges, land-based discharges, and 

accidental spills. Numerical estimates of the contributions for these sources to the GOM coastal and 

offshore waters are shown in Tables 3-8 and 3-9 of the 2012-2017 WPA/CPA Multisale EIS for a CPA 

proposed action and Tables 3-6 and 3-7 of the EPA 225/226 EIS for an EPA proposed action. Chapter 

3.1.1.7 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS describes in detail major sources of oil inputs in the Gulf of Mexico, 

including natural seepage, produced water, land-based discharges, and spills for a CPA proposed action. 

Chapter 3.1.1.7 of the EPA 225/226 EIS described in detail major sources of oil inputs in the Gulf of 

Mexico, including natural seepage, produced water, land-based discharges, and spills for an EPA 

proposed action.

Chapter 3.1.1.7.4 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, 

and CPA 235/241/247 Supplemental EIS for a CPA proposed action and Chapter 3.1.1.7.4 of the EPA 

225/226 EIS for an EPA proposed action also provide the following information related to oil spills: 

• trends in reported spill volumes and numbers;

• projections of future spill events;

• OCS oil- and gas-related offshore oil spills; 

• non-OCS oil- and gas-related offshore spills; 

• OCS oil- and gas-related coastal spills; 

• non-OCS oil- and gas-related coastal spills; and

• other sources of oil.

From 1991 through 2011, non-tank vessels accounted for 75.4 percent of the number of spills that 

occurred in U.S. waters (USDHS, CG, 2012). Historically, tank vessels (ships and barges) accounted for 

most of the volume spilled in U.S. waters. However, since passage of the Oil Pollution Act of 1990, the 

distribution of spill volumes has shifted away from tank vessel sources. For example, at the national level 

for the years 1999 through 2011, 29 percent of the volume of oil spilled came from tank vessels (e.g., 

ships/barges) compared with 41 percent from facilities and other non-vessels (the Macondo well was not 

included). Furthermore, in 2010, the largest oil spill in U.S. waters emanated from the exploratory 

Macondo oil well in the Gulf of Mexico. However, with the exception of rare but extreme incidents such 

as the Deepwater Horizon oil spill, the overall number and volume of spills in U.S. waters has been on a 

steady downward trend since 1973. In fact, 2010, the year of the largest recorded spill in U.S. waters, 

was followed by a record low annual volume of 210,270 gallons in 2011 (USDHS, CG, 2012).

3.1.1.8. Offshore Transport

Offshore transport includes both movements of oil and gas products as well as the transportation of 

equipment and personnel. These include pipelines (installation and maintenance, and landfalls), barges, 
3-14 Central and Eastern Planning Areas Supplemental EIS

oil tankers, and projections related to floating production, storage, and offloading systems, service 

vessels, and helicopter trips.

Chapter 3.1.1.8 of the 2012-2017 WPA/CPA Multisale EIS and CPA 235/241/247 Supplemental EIS 

describes in detail the sources of offshore transport and proposed action scenarios for a CPA proposed 

action.

Chapter 3.1.1.8 of the EPA 225/226 EIS describes in detail the sources of offshore transport and 

proposed action scenarios for an EPA proposed action.

3.1.1.9 Safety Issues

Safety issues related to OCS oil and gas development include the presence of hydrogen sulfide and 

sulfurous petroleum and shallow hazards. These safety issues are described in detail for a CPA proposed 

action in Chapters 3.1.1.9.1 and 3.1.1.9.2 of the 2012-2017 WPA/CPA Multisale EIS. Safety issues are 

described in detail for an EPA proposed action in Chapter 3.1.1.9 of the EPA 225/226 EIS. 

In addition, technologies continue to evolve to meet the technical, environmental, and economic 

challenges of deepwater development. For the CPA proposed action, these new and unusual technologies 

are described in Chapter 3.1.1.9.3 of the 2012-2017 WPA/CPA Multisale EIS. For an EPA proposed 

action, the new and unusual technologies are described in Chapter 3.1.1.9.3 of the EPA 225/226 EIS. 

3.1.1.10.Decommissioning and Removal Operations

During exploration, development, and production operations, the seafloor around activity sites within 

a proposed lease sale area becomes the repository of temporary and permanent equipment and structures. 

In compliance with Section 22 of BOEM’s Oil and Gas Lease Form (BOEM-2005) and BSEE regulations 

(30 CFR §§ 250.1710 et seq.—Permanently Plugging Wells and 30 CFR §§ 250.1725 et seq.—Removing 

Platforms and Other Facilities), lessees are required to remove all seafloor obstructions from their leases 

within 1 year of lease termination or relinquishment. These regulations require lessees to sever bottomfounded structures and their related components at least 5 m (15 ft) below the mudline to ensure that 

nothing would be exposed that could interfere with future lessees and other activities in the area. The 

structures are generally grouped into two main categories depending upon their relationship either to the 

platform/facility (e.g., piles, jackets, caissons, templates, mooring devises, etc.) or to the well (e.g., 

wellheads, casings, casing stubs, etc.).

Decommissioning and removal operations, including a CPA proposed action and OCS Program 

scenarios, are described in detail in Chapter 3.1.1.10 of the 2012-2017 WPA/CPA Multisale EIS. 

Decommissioning and removal operations, including an EPA proposed action and OCS Program 

scenarios, are described in detail in Chapter 3.1.1.10 of the EPA 225/226 EIS.

3.1.2. Coastal Impact-Producing Factors and Scenario

3.1.2.1. Coastal Infrastructure

A full description of coastal impact-producing factors and scenario is presented in Chapter 3.1.2 of 

the 2012-2017 WPA/CPA Multisale EIS, WPA/CPA 233/231 Supplemental EIS, and CPA 235/241/247

Supplemental EIS for a CPA proposed action and Chapter 3.1.2 of the EPA 225/226 EIS for an EPA 

proposed action. No new significant information was discovered that would alter impact conclusions 

based upon these operations. 

The WPA 233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS provide a 

summary and updated information on OCS oil- and gas-related coastal infrastructure types for a CPA 

proposed action. Information covered includes the following:

• service bases; 

• helicopter hubs;

• platform fabrication yards;

• shipbuilding and shipyards;
Impact-Producing Factors and Scenario 3-15

• pipecoating facilities and yards;

• refineries; 

• gas processing plants; 

• liquefied natural gas facilities; 

• pipeline shore facilities, barge terminals, and tanker port areas; 

• coastal pipelines; 

• coastal barging; and

• navigation channels.

This OCS oil- and gas-related infrastructure has been developed over many decades, and it is an 

extensive and mature system that provides support for offshore activities. The expansive presence of this 

coastal infrastructure is the result of long-term industry offshore and onshore trends and is not subject to 

rapid fluctuations. The routine activities of built infrastructure associated with a CPA proposed action or 

an EPA proposed action are regulated by Federal and State agencies through permitting processes, routine 

inspections, and a structured enforcement regime. Permit requirements largely mitigate any air and water 

quality impacts that can result from these activities.

A detailed description of the baseline affected environment for land use and coastal infrastructure in 

the CPA is provided in Chapter 4.2.1.23.1.1 of the 2012-2017 WPA/CPA Multisale EIS, and updated 

information is provided in Chapter 4.1.1.23.1 of this Supplemental EIS, Chapter 4.2.1.23.1 of the WPA 

233/CPA 231 Supplemental EIS, and Chapter 4.1.1.23.1 of the CPA 235/241/247 Supplemental EIS. 

Chapter 3.1.1.3.2 of the 2012-2017 WPA/CPA Multisale EIS describes in detail offshore infrastructure 

emplacement/structure installation and commissioning activities related to a CPA proposed action.

A detailed description of the baseline affected environment for land use and coastal infrastructure in 

the EPA is provided in Chapter 4.1.1.22.1 of the EPA 225/226 EIS, and updated information is provided 

in Chapter 4.2.1.23.1 of this Supplemental EIS. Chapter 3.1.1.3.2 of the EPA 225/226 EIS describes in 

detail offshore infrastructure emplacement/structure installation and commissioning activities related to 

an EPA proposed action.

BOEM projects no new coastal infrastructure with the exception of up to one new pipeline landfall 

and up to one new gas processing facility as a result of an individual proposed action. While offshore 

projects may add additional miles of pipeline to transport product, it is not likely that these projects would 

transport natural gas or crude oil directly onshore, but rather interconnect with existing systems. Because 

of unconventional onshore shale plays, the United States is transitioning from being a net importer of 

1.5 Tcf of natural gas in 2012 to a net exporter of 5.8 Tcf in 2040. The U.S. Energy Information 

Administration predicts that the newest changes in natural gas consumption will be in transportation and 

natural gas exported as liquefied natural gas (LNG). The profitability of natural gas as a transportation 

fuel or as LNG for export will depend primarily on the price differential between crude oil and natural gas 

(USDOE, Energy Information Administration, 2014h). In 2014, New Orleans-based Harvey Gulf 

International Marine broke ground on a Port Fourchon-based LNG terminal. The first of its kind in the 

United States, the LNG facility will provide LNG fuel to the growing supply of hybrid LNG-operated 

vessels servicing the OCS as well as over-the-road vehicles fueled by LNG (Workboat.com, 2014a). 

BOEM will continue to monitor future development of this new coastal infrastructure category (LNG 

bunkering facility), but this one proposed plan would not be expected to, on its own, represent a 

significant development or change in land use. 

Chapters 4.1.1.20.1 and 4.2.1.23.1 describe shipbuilding and shipyards in the analysis areas. In the 

GOM region, there is a direct correlation between oil and gas activities and the demand or opportunities 

for expanding shipbuilding and offshore support vessels. There are 137 shipyards in the analysis area, 

with the highest concentration in Louisiana at 64; there are 32 in Texas, 9 in Mississippi, 18 in Alabama, 

and 14 in Florida (Dismukes, 2011). No new facilities are expected to be constructed as a result of a CPA

or EPA proposed action. There is more than an adequate supply of shipyard resources in the GOM. No 

new facilities are expected to be constructed in support of OCS Program activities. Some shipyards may 

close, be bought out, or merge over the 2012-2051 period, resulting in fewer active yards in the analysis 

area.
3-16 Central and Eastern Planning Areas Supplemental EIS

Navigation channels undergo maintenance dredging that is essential for sustaining proper water 

depths to allow ships to move safely through the waterways to ports, services bases, and terminal 

facilities. In the northern GOM, the existing system of navigation channels is projected to be adequate to 

allow proper accommodation for vessel traffic that will occur as a result of a single CPA or EPA proposed 

action. The Gulf-to-port channels and the Gulf Intracoastal Waterway that support prospective OCS ports 

are maintained by regular dredging and are generally sufficiently deep and wide to handle OCS oil- and 

gas-related traffic (refer to Table 3-7 of the CPA 235/241/247 Supplemental EIS for a CPA proposed 

action and Table 3-12 of the EPA 225/226 Supplemental EIS for an EPA proposed action). BOEM 

projects that no new navigation channels will be authorized and constructed during the years 2012-2051 

as a direct result of the OCS Program.

The U.S. Energy Information Administration updates national energy projections annually, including 

refinery capacity. A crude oil refinery is a group of industrial facilities that turns crude oil and other 

inputs into finished petroleum products. A refinery’s capacity refers to the maximum amount of crude oil 

designed to flow into the distillation unit of a refinery, also known as the crude unit. In BOEM’s

identified Economic Impact Areas (EIAs), most of the refineries are located in Texas (18) and Louisiana 

(15) (Table 3-13 of the 2012-2017 WPA/CPA Multisale EIS and Table 3-11 of the EPA 225/226 EIS). 

As a whole, Texas has 27 operable refineries, with an operating capacity of over 5.1 MMbbl/day, which is 

over 28 percent of the total U.S. capacity. Louisiana follows closely behind Texas, with 19 operable 

refineries, with an operational capacity of over 3.27 MMbbl/day, which is 18 percent of the total U.S. 

capacity. Mississippi and Alabama each have three refineries and Florida has none (USDOE, Energy 

Information Administration, 2013i). The estimated amounts of crude oil projected to be leased, 

discovered, developed, and produced as a result of a typical proposed CPA lease sale are between 

0.460 and 0.894. BBO (Table 3-1), which would require only 0.7 percent of the current combined Texas 

and Louisiana refinery capacity over the 40-year planning period. The estimated amounts of crude oil 

projected to be leased, discovered, developed, and produced as a result of a typical proposed EPA lease 

sale are between 0 and 0.071 BBO (Table 3-1), which would require only 0.05 percent of the current 

combined Texas and Louisiana refinery capacity over the 40-year planning period. No new facilities are 

expected to be constructed as a result of a CPA or EPA proposed action. For many years financial, 

environmental, and legal considerations have made it unlikely that new refineries will be built in the 

United States, and this is expected to continue. Therefore, expansions at existing refineries, rather than 

new refinery construction, will eventually increase total U.S. refining capacity over the 2012-2051 period.

3.1.2.2. Discharges and Wastes

Chapter 3.1.2.2 of the 2012-2017 WPA/CPA Multisale EIS describes in detail coastal discharges and 

wastes, and Chapter 3.1.2.2 of the WPA 233/CPA 231 Supplemental EIS and CPA 235/241/247

Supplemental EIS provides a summary and update to coastal discharges and wastes for a CPA proposed 

action. Chapter 3.1.2.2 of the EPA 225/226 EIS provides a summary and update to coastal discharges and 

wastes for an EPA proposed action. Information covered includes the following:

• disposal and storage for offshore operational wastes; 

• onshore facility discharges; 

• coastal service-vessel discharges; 

• offshore wastes disposed onshore; and

• beach trash and debris.

The USEPA, through general permits issued by the USEPA Region with jurisdictional oversight, 

regulates all waste streams generated from offshore oil and gas activities. The USEPA Region 6 has 

jurisdiction over the CPA off the Louisiana coast and all of the WPA. The USEPA Region 4 has 

jurisdiction over the eastern portion of the GOM, including all of the EPA and part of the CPA off the 

coasts of Alabama and Mississippi. Each region has promulgated general permits for discharges that 

incorporate the 1993 effluent guidelines as a minimum. In some instances, a site-specific permit is 

required. The USEPA also regulates vessel discharges with the Vessel General Permit (VGP), which is a 

Clean Water Act National Pollutant Discharge Elimination System (NPDES) permit that authorizes, on a 
Impact-Producing Factors and Scenario 3-17

nationwide basis, discharges incidental to the normal operation of nonmilitary and nonrecreational vessels 

greater than or equal to 79 ft (24 m) in length. On March 28, 2013, the USEPA reissued the 2008 VGP 

for another 5 years; the reissued permit, the 2013 VGP, now contains numeric ballast water discharge 

limits for most vessels. The VGP also contains more stringent effluent limits for oil-to-sea interfaces and 

exhaust gas scrubber washwater (USEPA, 2013). The VGP, geographically, covers inland waters out to 

3 mi (5 km) and applies to vessels acting as a means of transportation. If the vessel is moored to a rig 

generating an amount of water that is greater than what it takes for the normal operation of a vessel, the 

VGP would not apply to brine production.

The BSEE policy regarding marine debris prevention is outlined in NTL 2012-BSEE-G01, “Marine 

Trash and Debris Awareness and Elimination.” The NTL instructs OCS operators to post informational 

placards that outline the legal consequences and potential ecological harms of discharging marine debris. 

The NTL also states that OCS workers should complete annual marine debris prevention training and 

instructs operators to develop a certification process for the completion of this training by their workers. 

These various laws, regulations, and the aforementioned NTL will likely minimize the discharge of 

marine debris from OCS operations.

For a CPA or EPA proposed action, existing onshore facilities would continue to be used to dispose 

of wastes generated offshore. However, no new disposal facilities are expected to be licensed as a direct 

result of a CPA or EPA proposed action. There is no current expectation for new onshore waste disposal

facilities to be authorized and constructed during the 2012-2051 period as a direct result of the OCS 

Program. If needed, existing facilities may undergo expansion, but no new disposal facilities are 

expected.

3.2. IMPACT-PRODUCING FACTORS AND SCENARIO—ACCIDENTAL EVENTS

3.2.1. Oil Spills

Oil spills are unplanned accidental events, and historical data provide the most relevant data for use in 

predicting future oil-spill frequency and volume in the GOM on a programmatic level. The following 

chapters discuss spill prevention and spill response, and analyze the risk of spills that could occur as a 

result of activities associated with a CPA or EPA proposed action. Public input through public scoping 

meetings, Federal and State agencies’ input through consultation and coordination, and industry and 

nongovernmental organizations input indicate that oil spills are perceived to be a major issue, especially 

in the wake of the Deepwater Horizon oil spill. The following chapters analyze the risk of spills that 

could occur as a result of a typical CPA or EPA proposed action, as well as information on the number 

and sizes of spills from non-OCS sources. Refer to Appendix B for the “Catastrophic Spill Event 

Analysis.”

3.2.1.1. Spill Prevention

Over the years, BOEM has established comprehensive pollution-prevention requirements that include 

redundant safety systems, as well as inspection and testing requirements to confirm that these devices are 

working properly (Chapter 1.5). Until the Deepwater Horizon oil spill, an overall reduction in spill 

volume occurred during the previous 40 years, while oil production generally increased. A 

characterization of spill rates, average and median volumes from 1995 to 2009 compared with 1996-2010, 

which includes the Deepwater Horizon oil spill, is provided in Update of Occurrence Rates for Offshore 

Oil Spills (Anderson et al., 2012). BOEM attributes this improvement to its operational requirements, 

ongoing efforts by the oil and gas industry to enhance safety and pollution prevention, and the evolution 

and improvement of offshore technology. 

3.2.1.2. Past OCS Spills

The BSEE spill-event database includes records of past spills from activities that are regulated by 

BOEM and BSEE. These data include oil spills >1 bbl that occurred in Federal waters from OCS 

facilities and pipeline operations. Spills from facilities include spills from drilling rigs, drillships, and 

storage, processing, or production platforms that occurred during OCS drilling, development, and 

production operations. Spills from pipeline operations are those that have occurred on the OCS and are 
3-18 Central and Eastern Planning Areas Supplemental EIS

directly attributable to the transportation of OCS oil. Anderson et al. (2012) was utilized in the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS for a CPA proposed action, and in the EPA 225/226 EIS for an EPA proposed action to 

characterize spill rates and to provide analysis for average and median volumes. The Anderson et al. 

(2012) analysis examined spill data for the period 1964 to 2010, including the Deepwater Horizon oil 

spill.

A search of BSEE’s oil-spill database (USDOI, BSEE, 2013) was performed to assess new spill 

information during the 2011-2013 period and to provide an update to the Anderson et al. (2012) analysis. 

During the period 2011 to 2013, there were 46 spills from OCS oil- and gas-related activities of 

<1,000 bbl in size. The breakdown of the 46 spills <1,000 bbl that occurred from 2011 to 2013 from OCS 

oil- and gas-related activities into size classes is as follows: 28 spills of 1-4 bbl; 6 spills of 5-9 bbl; 

10 spills of 10-49 bbl; 1 spill of 50-99 bbl; 1 spill of 100-999 bbl; and 0 spills of ≥1,000 bbl. The 

combined total of oil spilled in these 46 events was 857 bbl. The BSEE database (USDOI, BSEE, 2013) 

indicated that there were two spills (one in 2011 and one in 2012) that were between 50 and 500 bbl in 

size, both of which occurred in the CPA. The spill in 2011 equaled 67 bbl and was the result of 

equipment failure from a platform leak located in Garden Banks Block 72. The spill in 2012 was 

estimated at 480 bbl and resulted from an explosion on a platform located in West Delta Block 32. There 

have been zero spills >50 bbl since the 480-bbl spill in 2012. In summary, two spills >50 bbl occurred 

during the period 2011 to 2013. This is an outcome that is well within the range of spills estimated to 

occur in Table 3-12 of the 2012-2017 WPA/CPA Multisale EIS and Table 3-10 of the EPA 225/226 EIS, 

which provide an estimate of the number and size of spills likely to occur as a result of a CPA or EPA 

proposed action over a 40-year time period. Thus, the additional information provided by the review of 

BSEE’s oil-spill database (USDOI, BSEE 2013a) did not change the validity of the scenario previously 

presented. 

The majority of the 2011-2013 spills are attributed to OCS oil- and gas-related platforms/rigs, 

followed by vessels, and lastly by OCS oil- and gas related pipelines. These data were compared with the 

estimated number and size of spills presented in Table 3-12 of the 2012-2017 WPA/CPA Multisale EIS 

and Table 3-10 of the EPA 225/226 EIS, and it was found that the new spill data were well within the 

spill numbers estimated in the previous documents. The new data also concurred with the previous 

finding that the most likely source of a spill would be from platforms, rigs, or vessels. Thus, a review of 

recent information does not change the risk analyses for spills <1,000 bbl previously provided in the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, CPA 235/241/247 

Supplemental EIS, and EPA 225/226 EIS. As estimated in Table 3-12 of the 2012-2017 WPA/CPA 

Multisale EIS and Table 3-10 of the EPA 225/226 EIS, no spills have occurred in the ≥1,000-bbl size 

class since the Deepwater Horizon oil spill in 2010.

3.2.1.3. Characteristics of OCS Oil

The physical and chemical properties of oil greatly affect its transport and its ultimate fate in the 

environment and determine the following: how oil will behave on the water surface (surface spills) or in 

the water column and sediments (subsea spills); the persistence of the slick on the water; the type and 

speed of weathering processes; the degree and mechanisms of toxicity; the effectiveness of containment 

and recovery equipment; and the ultimate fate of the spill residues. Crude oils are a natural mixture of 

hundreds of different compounds, with liquid hydrocarbons accounting for up to 98 percent of the total 

composition. The chemical composition of crude oil can vary significantly from different producing 

areas; thus, the exact composition of oil being produced in OCS waters varies throughout the Gulf. The 

American Petroleum Institute gravity (API gravity) is a measure of the relative density of oil compared 

with water and is expressed in degrees (°). Oils with an API gravity <10 are heavier and typically sink, 

whereas oils with an API gravity >10 are lighter and typically float. Following an oil spill, the 

composition of the released oil can change substantially due to weathering processes such as evaporation, 

emulsification, dissolution, and oxidation. More details on the properties and persistence of different 

types of oils are provided in Table 3-8. 

Extensive laboratory testing has been performed on various oils from the GOM to determine their 

physical and chemical characteristics. For example, numerous oils collected from the GOM (U.S. waters) 

are included in Environment Canada’s (2013) oil properties database. The database provides details of an 

oil’s chemical composition including hydrocarbon groups (i.e., saturates, aromatics, resins, and 
Impact-Producing Factors and Scenario 3-19

asphaltenes), VOCs (such as benzene, toluene, ethylbenzene, and xylene), sulfur content, biomarkers, and 

metals. The database also includes API gravities, of which GOM oils are in the range, of 15° to 60°. 

Since the Deepwater Horizon oil spill, new data have been collected from the approximately 

450 deepwater exploration plans (EPs) and DOCDs that were submitted to BOEM/BSEE. These data are 

available through BOEM’s Exploration and Development Plans Online Query (refer to USDOI, BOEM, 

2014b). Statistics on these API gravities result in a similar range (16° to 58°) as previously reported, with 

a mean value of 36°. These new data corroborate the information previously presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS for a CPA proposed action and in the EPA 225/226 EIS for an EPA proposed action.

3.2.1.4. Overview of Spill Risk Analysis

There are many factors that BOEM evaluates to determine the risk of impact occurring from an oil 

spill, including likely spill sources, likely spill locations, likely spill sizes, the likelihood and frequency of 

occurrence for different size spills, timeframes for the persistence of spilled oil, volumes of oil removed 

due to weathering and cleanup, and the likelihood of transport by wind and waves resulting in contact to 

specified environmental features. Sensitivity of the environmental resources and potential effects are 

addressed in the analyses for the specific resources of concern (Chapter 4.1.1). BOEM uses data on past 

OCS production and spills, along with estimates of future production, to evaluate the risk of future spills. 

Additionally, BOEM uses a numerical model to calculate the likely trajectory of spills (i.e., transport 

pathways) and analyzes historical data of occurrence rates for oil spills (refer to Anderson et al., 2012) to 

make projections of future oil-spill frequency and size. A more detailed description of the spill risk 

analysis and the trajectory model, called OSRA (oil-spill risk analysis) model, were provided in Chapter 3 

of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS for a CPA proposed action, and in Chapter 3 of the EPA 225/226 EIS for 

an EPA proposed action, as well as in the Ji et al. (2012) OSRA report. Appendix C of the CPA 

235/241/247 Supplemental EIS also contains the OSRA model’s catastrophic spill event results to 

estimate the risks associated with a possible future low-probability catastrophic or high-volume, longduration oil spill.

The OSRA model’s results and estimated spill size/frequency tables as presented and discussed in the 

2012-2017 WPA/CPA Multisale EIS for a CPA proposed action and in the EPA 225/226 EIS for an EPA 

proposed action remain applicable because the basic assumptions inherent in the model and calculations 

are still valid. The latest analysis available for the characterization of spill rates and for average and 

median volumes (Anderson et al., 2012) inputted into the model is still valid because the more recent 

small OCS spills (2011-2013) were within spill scenario estimates developed using the past data. In 

addition, the physical forcing (e.g., ocean currents and wind fields) and environmental resources input 

(e.g., locations and seasonality of various biological resources) to the OSRA model are still representative 

of our current state of knowledge regarding both ocean modeling and potential environmental resources at 

risk. Numerous efforts are underway since the Deepwater Horizon oil spill to further improve trajectory 

modeling in the Gulf of Mexico, including several BOEM environmental studies (e.g., refer to Section 4.2 

in Ji et al., 2013). However, the results of these new research activities are not yet available or fully 

tested for incorporation into BOEM’s oil-spill risk analysis. Thus, new information did not change the 

results of previous spill risk analyses provided in the 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS for a CPA proposed action and 

in the EPA 225/226 EIS for the EPA proposed action.

The following discussions provide separate risk information for offshore and coastal spills that may 

result from a CPA or EPA proposed action. This analysis is divided into discussions of offshore spills 

≥1,000 bbl, offshore spills <1,000 bbl, and coastal spills of any spill volume. Only spills ≥1,000 bbl are 

addressed using OSRA because smaller spills typically do not persist long enough to be simulated by 

trajectory modeling.

3.2.1.5. Risk Analysis for Offshore Spills ≥1,000 bbl

Chapter 3.2.1.5 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 3.2.1.4 of the EPA 225/226 

EIS addressed the risk of spills ≥1,000 bbl that could occur from accidents associated with activities 

resulting from a CPA or EPA proposed action, respectively. The risk analyses included the following:
3-20 Central and Eastern Planning Areas Supplemental EIS

• estimated number of offshore spills ≥1,000 bbl and probability of occurrence;

• most likely source of offshore spills ≥1,000 bbl;

• most likely size of an offshore spill ≥1,000 bbl;

• fate of offshore spills ≥1,000 bbl;

• transport of spills ≥1,000 bbl by winds and currents;

• length of coastline affected by offshore spills ≥1,000 bbl; and

• likelihood of an offshore spill ≥1,000 bbl occurring and contacting modeled locations 

of environmental resources.

Specifically, Table 3-19 of the 2012-2017 WPA/CPA Multisale EIS estimated for a CPA proposed 

action that the mean number of spills ≥1,000 bbl was estimated at ≤1 spill (mean equal to 0.5-1.0), and 

Table 3-21 of the EPA 225/226 EIS estimated for an EPA proposed action that the mean number of spills 

was estimated at <1 spill (mean equal to 0-0.1) from both OCS oil- and gas-related platforms and 

pipelines. Because no spills ≥1,000 bbl in size have occurred during 2011-2013, use of Anderson et al. 

(2012) remains applicable and up to date for characterizing spill rates and average and median spill 

volumes in this Supplemental EIS. In terms of weathering, fate, and transport of oil spills in the Gulf of 

Mexico, a variety of ongoing studies are providing more insights in the aftermath of the Deepwater

Horizon oil spill. For example, recent studies have provided further evidence that the diverse microbial 

communities in both the water column (e.g., Mason et al., 2012) and sediments (Kimes et al., 2013) of the 

GOM can play an active role in metabolizing and bioremediating crude oil from offshore spills. Further 

research is also being conducted regarding what impact chemical dispersant application may have on this 

biodegradation process. Other research on oil fates suggests that marine snow formation in the aftermath 

of a large oil-spill event (such as the Deepwater Horizon oil spill) may play a key role in the fate of 

surface oil (e.g., Passow et al., 2012). However, many of the important recent findings related to the 

quantitative modeling of fate and transport of large oil spills in the Gulf of Mexico are part of the ongoing 

Natural Resource Damage Assessment (NRDA) process and have not yet been publicly released. Thus, a 

review of recent information does not change the quantitative risk analyses for spills ≥1,000 bbl 

previously provided in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, 

and CPA 235/241/247 Supplemental EIS for a CPA proposed action and in the EPA 225/226 EIS for an 

EPA proposed action.

3.2.1.6. Risk Analysis for Offshore Spills <1,000 bbl

Chapter 3.2.1.6 of the 2012-2017 WPA/CPA Multisale EIS addressed the risk of spills <1,000 bbl 

resulting from a CPA proposed action and Chapter 3.2.1.5 of the EPA 225/226 EIS addressed the risk of

spills <1,000 bbl resulting from an EPA proposed action. Analysis of historical data shows that most 

offshore OCS oil spills fall within this category, with the majority of spills falling within the significantly 

smaller range of ≤1 bbl (Anderson et al., 2012). Although spills of ≤1 bbl amount to 96 percent of all 

OCS oil- and gas-related spill occurrences, they have contributed very little to the total volume of oil 

spilled. The risk analyses addressed in Chapter 3.2.1.6 of the 2012-2017 WPA/CPA Multisale EIS for a 

CPA proposed action and in Chapter 3.2.1.5 of the EPA 225/226 EIS for an EPA proposed action 

included the following:

• estimated number of offshore spills <1,000 bbl and total volume of oil spilled;

• most likely source and type of offshore spills <1,000 bbl;

• most likely size of offshore spills <1,000 bbl;

• persistence, spreading, and weathering of offshore oil spills <1,000 bbl;
Impact-Producing Factors and Scenario 3-21

• transport of spills <1,000 bbl by winds and currents; and

• likelihood of an offshore spill <1,000 bbl occurring and contacting modeled locations 

of environmental resources.

A search of BSEE’s oil-spill database (USDOI, BSEE, 2013) was performed to assess new spill 

information during 2011-2013, a period that was not analyzed in Anderson et al. (2012). During 2011-

2013, there were 46 spills from OCS oil- and gas-related activities of <1,000 bbl in size, totaling 857 bbl 

overall. The breakdown of these spills into size classes is provided in Chapter 3.2.1.2. As noted above, 

the 2011-2013 spill data were compared with the estimated number and sizes of spills presented in Table 

3-12 of the 2012-2017 WPA/CPA Multisale EIS and Table 3-10 of the EPA 225/226 EIS, and they were 

found to be well within the spill numbers estimated in the previous documents. The new data also 

supported previous findings that the most likely source of a spill of <1,000 bbl would be from platforms, 

rigs, or vessels. Thus, a review of recent information does not change the risk analyses for spills 

<1,000 bbl previously provided in Chapter 3.2.1.6 of the 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS for a CPA proposed action and 

in Chapter 3.2.1.7 of the EPA 225/226 EIS for an EPA proposed action.

3.2.1.7. Risk Analysis for Coastal Spills 

Spills in coastal waters could occur at storage or processing facilities supporting the OCS oil and gas 

industry or from the transportation of OCS-produced oil through State offshore waters and along 

navigation channels, rivers, and through coastal bays. BOEM projects that almost all (>99%) oil 

produced as a result of a CPA or EPA proposed action will be brought ashore via pipelines to oil pipeline 

shore bases, stored at these facilities, and eventually transferred via pipeline or barge to Gulf coastal 

refineries. Because oil is commingled at shore bases and cannot be directly attributed to a particular lease 

sale, this analysis of coastal spills addresses spills that could occur prior to the oil arriving at the initial 

shoreline facility. It is also possible that non-OCS oil may be commingled with OCS oil at these facilities 

or during subsequent secondary transport. Chapter 3.2.1.7 of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS for a CPA proposed 

action and Chapter 3.2.1.6 of the EPA 225/226 EIS for an EPA proposed action describe in detail the 

estimated number and most likely sizes of coastal spills and the likelihood of coastal spill contact.

The number and most likely spill sizes to occur in coastal waters in the future are expected to 

resemble the patterns that have occurred in the past as long as the level of hydrocarbon use and transport 

activities remains the same. As discussed in Chapter 3.2.1.7 of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, CPA 235/241/247 Supplemental EIS for a CPA proposed action 

and in Chapter 3.2.1.6 of the EPA 225/226 EIS for an EPA proposed action, estimates of future coastal 

spills for this analysis are based on the number and location of historical coastal spills reported to the 

USCG. Consequently, in the GOM region, Louisiana and Texas are predicted to be the states most likely 

to have a spill ≥1,000 bbl occur in coastal waters based upon historical USCG data.

3.2.1.8. Risk Analysis by Resource

BOEM previously analyzed the risk to resources from oil spills and oil slicks that could occur as a 

result of a CPA proposed action in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS and as a result of an EPA proposed action in 

the EPA 225/226 EIS. The risk results were based on BOEM’s estimates of likely spill locations, 

sources, sizes, frequency of occurrence, physical fates of different types of oil slicks, and probable 

transport that were described in more detail in specific spill scenarios. For offshore spills ≥1,000 bbl, 

combined probabilities were calculated using the OSRA model, which includes both the likelihood of a 

spill from a CPA or EPA proposed action occurring and the likelihood of the oil slick reaching areas 

where known environmental resources exist. For a CPA proposed action, the analysis of the likelihood of 

direct exposure and interaction of a resource with an oil slick and the sensitivity of a resource to the oil is 

provided under each resource category in Chapter 4.1.1 of this Supplemental EIS and was provided in 

Chapter 4.1.2 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, 

Chapter 4.1.1 of the CPA 235/241/247 Supplemental EIS, and Chapter 3.2.1.8 and Figures 3-8 through 

3-28 of the 2012-2017 WPA/CPA Multisale EIS. For an EPA proposed action, the analysis of the 
3-22 Central and Eastern Planning Areas Supplemental EIS

likelihood of direct exposure and interaction of a resource with an oil slick and the sensitivity of a 

resource to the oil is provided under each resource category in Chapter 4.1.2 of this Supplemental EIS 

and was provided in Chapter 4.1.1 of the EPA 225/226 EIS.

3.2.1.9. Spill Response

For a CPA proposed action, Chapter 3.2.1.9 of the 2012-2017 WPA/CPA Multisale EIS describes in 

detail issues related to spill response, including BOEM’s spill-response requirements and initiatives, 

offshore response, containment, and cleanup technology; and onshore response and cleanup. For the EPA 

proposed action, Chapter 3.2.1.8 of the EPA 225/226 EIS describes analogous information.

As a result of the Oil Pollution Act of 1990 and the reorganization of the Bureau of Ocean Energy 

Management, Regulation and Enforcement into BOEM and BSEE, BSEE was tasked with a number of 

oil-spill response duties and planning requirements. The following requirements are implemented 

according to BSEE’s regulations at 30 CFR parts 250 and 254:

• requires immediate notification for spills >1 bbl—all spills require notification to 

USCG, and BSEE receives notification from the USCG of all spills ≥1 bbl;

• conducts investigations to determine the cause of a spill;

• assesses civil and criminal penalties, if needed;

• oversees spill source control and abatement operations by industry;

• sets requirements and reviews and approves oil spill response plans (OSRPs) for 

offshore facilities;

• conducts unannounced drills to ensure compliance with OSRPs; 

• requires operators to ensure that their spill-response operating and management 

teams receive appropriate spill-response training;

• conducts inspections of oil-spill response equipment;

• requires industry to show financial responsibility to respond to possible spills; and

• provides research leadership to improve the capabilities for detecting and responding 

to an oil spill in the marine environment.

BOEM also has regulatory requirements addressing site-specific OSRPs and spill-response 

information. In accordance with BOEM’s regulations at 30 CFR §§ 550.219 and 550.250, operators are 

required to provide BOEM an OSRP that is prepared in accordance with 30 CFR part 254 subpart B with 

their proposed exploration, development, or production plan for the facilities that they will use to conduct 

their activities; or to alternatively reference their approved regional OSRP by providing the following 

information: 

• a discussion of the approved OSRP;

• the location of the primary oil-spill equipment base and staging area;

• the name of the oil-spill equipment removal organization(s) for both equipment and 

personnel;

• the calculated volume of a facilities’ worst-case discharge scenario in accordance 

with 30 CFR § 254.26(a) and a comparison of the worst-case discharge scenario in 

the approved regional OSRP with the worst-case discharge calculated for these 

proposed activities;

• a description of the worst-case discharge scenario to include the trajectory 

information, potentially impacted resources, and a detailed discussion of the spill 

response proposed to the worst-case discharge in accordance with 30 CFR §§ 
Impact-Producing Factors and Scenario 3-23

254(b)-(d). The spill-response discussion is required to include a description of the 

response equipment, personnel, and support equipment to be called out and the time 

required for the equipment to be procured, transported, and deployed at a spill site.

All OSRPs are reviewed and approved by BSEE, whether submitted with a BOEM-associated plan or 

directly to BSEE in accordance with 30 CFR part 254. Hence, BOEM relies heavily upon BSEE’s 

expertise to ensure that the OSRP complies with all pertinent laws and regulations and demonstrates the 

ability of an operator to respond to a worst-case discharge. Site-specific OSRPs are required to be 

submitted to BOEM with a proposed exploration, development, or production plan, and BOEM’s 

regulations require that an operator must have an approved OSRP prior to BOEM’s approval of an 

operator-submitted exploration, development, or production plan. BOEM also requests that BSEE review 

these site-specific OSRPs. In contrast, BSEE’s regulations at 30 CFR § 254.2 state only that an OSRP 

must be submitted to BSEE for approval before a facility may be used. The BSEE, therefore, interprets 

their regulations to link the approval of OSRPs to the application for permit to drill submitted to BSEE as 

opposed to the exploration, development, or production plans submitted at a much earlier time to BOEM.

The NTLs and guidance documents have been issued that clarify additional oil-spill requirements 

since the occurrence of the Deepwater Horizon explosion, oil spill, and response. The spill responserelated NTLs issued prior to 2012 and the guidance documents issued by BOEM and BSEE are described 

in detail in Chapter 3.2.1.9 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental 

EIS, and CPA 235/241/247 Supplemental EIS for a CPA proposed action and in Chapter 3.2.1.8 of the 

EPA 225/226 EIS for an EPA proposed action.

NTL 2012-BSEE-N06, “Guidance to Owners and Offshore Facilities Seaward of the Coast 

Line Concerning Regional Oil Spill Response Plans”

This NTL provides clarification, guidance, and information concerning the preparation and submittal 

of a regional OSRP for owners and operators of oil handling, storage, or transportation facilities, 

including pipelines located seaward of the coastline. A regional OSRP is defined as a spill response plan 

covering multiple facilities or leases of an owner, or operator, or their affiliates, which are located in the 

same BSEE region. Site-specific OSRPs submitted with BOEM exploration, development, or production 

plans can either be prepared using the 30 CFR part 254 regulations or the guidance outlined in NTL 2012-

BSEE-N06.

Some of the clarifications and encouraged practices identified in NTL 2012-BSEE-N06 are based 

upon lessons learned from the Deepwater Horizon oil-spill response. This NTL indicates that BSEE’s 

review of OSRPs will also be based, in part, upon information obtained during the Deepwater Horizon

oil-spill response. For example, during the Deepwater Horizon oil-spill response it was discovered that 

the total estimated de-rated recovery capacity for all equipment listed in the OSRP overestimated the 

amount of oil that could be removed from the water. The NTL 2012-BSEE-N06 therefore states that the 

OSRP should be developed considering (1) a fully developed response strategy that includes the 

identification of the available dedicated recovery equipment as well as the actual operating characteristics 

of the systems associated with each skimmer and (2) the use of new technology and response systems that 

will increase the effectiveness of mechanical recovery tactics.

The NTL is designed to encourage owners and operators of offshore facilities to include innovative 

offshore oil-spill response techniques, particularly for a continuous high-rate spill. The NTL 2012-BSEEN06 includes requirements for the submittal of information regarding subsea containment equipment and 

subsea dispersant application, among other provisions. This NTL also encourages the inclusion of 

options that will improve spill-response capabilities such as

• using remote-sensing techniques as a tool for safe night operations to increase oilspill detection and to improve thickness determinations for ascertaining the 

effectiveness of response strategies;

• increasing spill-response operational time by reducing transit times to disposal 

locations and decontamination equipment;
3-24 Central and Eastern Planning Areas Supplemental EIS

• identifying sources for supplies and materials, such as fire boom and dispersants, that 

can support a response to an uncontrolled spill lasting longer than 30 days or for the 

duration of the spill response; and

• the use and specification of primary and secondary communications technology and 

software for coordinating and directing spill-response operations systems and/or 

providing a common operating picture to all spill management and response 

personnel, including the Federal On-Scene Coordinator and participating Federal and 

State government officials.

NTL 2013-BSEE-N02, “Significant Change to Oil Spill Response Plan Worst Case 

Discharge Scenario”

The BSEE issued this NTL to clarify what BSEE considers a significant change in a worst-case 

discharge scenario, which requires that an OSRP revision be submitted. The guidance issued by this NTL 

states that a significant change in worst-case discharge may occur when calculating a new worst-case 

discharge based upon the following:

• the addition of a new facility installation or well;

• a modification to an existing facility; or

• a change in any assumptions and calculations used to determine the prior estimated 

worst-case discharge.

The NTL 2013-BSEE-N02 identifies the process an owner or operator of a facility should utilize to 

determine whether the new worst-case discharge represents a significant change. The BSEE considers a 

change in worst-case discharge as significant and thus requires a revision when the process identifies the 

need for additional onshore or offshore response equipment beyond what is included in an approved 

OSRP. Although information to make this determination is submitted to BOEM and forwarded to BSEE 

with a proposed exploration, development, or production plan, pursuant to NTL 2013-BSEE-N02, the 

15-day timeframe for notification of a significant change will be enforced by BSEE as beginning no later 

than the date that the operator submitted an Application for Permit to Drill to BSEE, which occurs after 

BOEM must take action on a proposed exploration, development, or production plan.

Typically, for OSRP revisions, once BSEE approves an OSRP, it must be reviewed at least every 

2 years, and modifications must be submitted in accordance with 30 CFR § 254.30(a). If no 

modifications are deemed necessary, the owner or operator must inform BSEE in writing that there are no 

changes. The BSEE will only review and approve revised or biennially modified OSRP submittals that 

are provided by an operator to BSEE if one of the four conditions requiring a revision to the OSRP within 

15 days is met (30 CFR 254. 30(b)). These four conditions include the following: 

• a change that significantly reduces operator response capabilities;

• a significant change occurs in the worst-case discharge or in the type of oil being 

handled, stored, or transported at a facility;

• a change in the names or capabilities of the oil-spill removal organizations cited in 

the plan; or

• significant change to the area contingency plan.

NTL 2012-BSEE-N07, “Oil Discharge Written Follow-up Reports”

The BSEE issued this NTL to address the oil discharge reports (30 CFR § 254.46(b)(2)) that are 

required to be submitted by a responsible party to BSEE for spills >1 bbl within 15 days after a spill has 

been stopped or ceased. The responsible party is encouraged to report cause, location, volume, remedial 

action taken, sea state, meteorological conditions, and the size and appearance of the slick.
Impact-Producing Factors and Scenario 3-25

Mechanical Cleanup

As previously indicated, BSEE oversees a research program to improve the capabilities for detecting 

and responding to an oil spill in the marine environment. One of BSEE’s recently completed research 

projects suggested an alternative to improve the present regulatory requirements at 30 CFR § 254.44 for 

determining the effective daily recovery capacity of spill-response skimming equipment. This suggested 

alternative would consider the encounter rate of a skimming system with spilled oil instead of the 

presently used derated pump capacity of a skimmer. This project was undertaken because the Deepwater

Horizon oil-spill response highlighted that the existing regulation may not be an effective or accurate 

planning standard and predictor of oil-spill response equipment recovery capacity. The project was 

completed in 2012 and the National Academy of Sciences completed a peer review in 2013. The BSEE is 

currently determining if any significant revisions to the report or to BSEE’s oil-spill program are 

appropriate based upon the National Academy of Sciences’ review (USDOI, BSEE, 2014a). The USCG 

has indicated that the guidance generated by this research is applicable for offshore use but that a separate 

standard would still need to be developed for nearshore response capability determinations.

There have been some changes to the spill-response equipment staging locations previously reported 

in the 2012-2017 WPA/CPA Multisale EIS and EPA 225/226 EIS. Due to these changes, it is expected 

that the oil-spill response equipment needed to respond to an offshore spill in a proposed lease sale area 

could be called out from one or more of the following oil-spill equipment base locations: New Iberia, 

Belle Chasse, Baton Rouge, Sulphur, Morgan City, Port Fourchon, Harvey, Leeville, Fort Jackson, 

Venice, Grand Isle, or Lake Charles, Louisiana; La Porte, Corpus Christi, Port Arthur, Aransas Pass, 

Ingleside, Galveston, or Houston, Texas; Pascagoula or Kiln, Mississippi; Mobile or Bayou La Batre, 

Alabama; and/or Panama City, Pensacola, Tampa, or Miami, Florida (Clean Gulf Associates, 2014; 

Marine Spill Response Corporation, 2014; National Response Corporation, 2014).

Dispersants

The State of Florida’s Department of Environmental Protection submitted a letter dated May 5, 2011, 

to the USEPA Region IV, Regional Response Team in which the State of Florida withdrew all State 

waters (9 nmi [10 mi; 17 km] off the coast of Florida in the Gulf of Mexico) from the Green Zone (or 

approved area) for dispersant preapproval as outlined within the “Region IV Dispersant Use Policy in 

Ocean and Coastal Waters.” The State indicated in the letter that this change was requested due to the 

enormous changes that have occurred in communication and response technologies since the preapproval 

was first agreed to in 1996. The State indicated that they felt that the “Region IV Dispersant Use Policy 

in Ocean and Coastal Waters” document needed to be updated to reflect technological advances and 

lessons learned during the response to the Deepwater Horizon oil spill (State of Florida, Dept. of 

Environmental Protection, 2011).

The USEPA updated the National Contingency Plan (NCP) product schedule in 2014. The 2014 NCP 

Product Schedule lists the following types of products that are authorized for use on oil discharges: 

• dispersants; 

• surface washing agents;

• surface collecting agents;

• bioremediation agents; and

• miscellaneous oil-spill control agents.

The USEPA has also published an NCP Product Schedule Notebook in February 2014 that presents 

the manufacturer’s summary information that describes (1) the conditions under which each of the 

products is recommended for use, (2) handling and worker precautions, (3) storage information, 

(4) recommended application procedures, (5) physical properties, (6) toxicity information, and 

(7) effectiveness information (USEPA, 2014).

Due to the unprecedented volume of dispersants applied for an extended period of time in situations 

not previously envisioned or incorporated in existing dispersant use plans during the Deepwater Horizon

oil-spill response, the National Response Team (NRT) has developed a guidance document for 
3-26 Central and Eastern Planning Areas Supplemental EIS

monitoring atypical dispersant operations entitled Environmental Monitoring for Atypical Dispersant 

Operations: Including Guidance for Subsea Application and Prolonged Surface Application,” which was 

approved on May 30, 2013. The subsea guidance generally applies to the subsurface ocean environment 

and focuses on operations in waters below 300 m (984 ft). The surface application guidance supplements 

and complements the existing protocols as outlined within the existing Special Monitoring of Applied 

Response Technologies (SMART) monitoring program where the duration of the application of 

dispersants on discharged oil extends beyond 96 hours from the time of the first application (NRT, 2013). 

This guidance is provided to the Regional Response Teams by the NRT to enhance existing SMART 

protocols and to ensure that their planning and response activities will be consistent with national policy.

Shoreline Cleanup Countermeasures

In addition, the USCG has worked diligently to improve coastal oil-spill response since the 

Deepwater Horizon oil spill by replacing the One Gulf Plan with separate Area Contingency Plans 

(ACPs) for each coastal USCG sector. The ACPs cover subregional geographic areas and represent the 

third tier of the National Response Planning System mandated by the Oil Pollution Act of 1990. The 

ACPs are a focal point of response planning. The Gulf of Mexico OCS Region’s ACPs also include 

separate Geographic Response Plans, which are developed jointly with local, State, and other Federal 

entities to better focus spill-response tactics and priorities. These Geographic Response Plans contain the 

resources initially identified for protection during a spill, response priorities, procedures, and appropriate 

spill-response countermeasures.

3.2.2. Losses of Well Control

A blowout preventer (BOP) is a device with a complex of choke lines and hydraulic rams mounted 

atop a wellhead designed to close the wellbore with a sharp horizontal motion that may cut through or 

pinch shut casing and sever tool strings. The BOPs were invented in the early 1920’s and have been 

instrumental in ending dangerous, costly, and environmentally damaging oil blowouts on land and in 

water. The BOPs have been required for OCS oil and gas operations from the time offshore drilling 

began in the late 1940’s.

The BOPs are actuated as a last resort upon imminent threat to the integrity of the well or the surface 

rig. For a cased well, which is the typical well configuration, the hydraulic ram of a BOP may be closed 

if oil or gas from an underground zone enters the wellbore to destabilize the well. By closing a BOP, 

usually by redundant surface-operated and hydraulic actuators, the drilling crew can prevent explosive 

pressure release and allow control of the well to be regained by balancing the pressure exerted by a 

column of drilling mud with formation fluids or gases from below. Chapter 3.2.1.9.2 of the 2012-2017 

WPA/CPA Multisale EIS for a CPA proposed action and Chapter 3.2.2 of the EPA 225/226 EIS for an 

EPA proposed action provide information on subsea well containment that could be utilized if a loss of 

well control occurred and resulted in a loss of fluids.

All losses of well control must be reported to BSEE. The BSEE clarified its procedure for loss of 

well control incident reporting in NTL 2010-N05, “Increased Safety Measures for Energy Development 

on the OCS,” which became effective on June 8, 2010. The BSEE Drilling Safety Rule (Federal 

Register, 2012a) became effective on October 22, 2012. This rule implements certain additional safety 

measures recommended in NTL 2010-N05 by incorporating the recommendations contained in the DOI 

report titled Increased Safety Measures for Energy Development on the Outer Continental Shelf (Safety 

Measures Report) (USDOI, 2010) and the Deepwater Horizon Joint Investigation Team report (USDOI, 

BOEMRE and USDHS, CG, Joint Investigation Team, 2013). The BSEE amended the drilling, wellcompletion, well-workover, and decommissioning regulations related to well control, including subsea 

and surface blowout preventers, well casing and cementing, secondary intervention, unplanned 

disconnects, recordkeeping, and well plugging. The Drilling Safety Rule also enhanced the description 

and classification of well-control barriers, defined testing requirements for cement, clarified requirements 

for the installation of dual mechanical barriers, and extended requirements for BOPs and well-control 

fluids to well-completions, workovers, and decommissioning operations. Operators are required to 

document any loss of well-control event, even if temporary, and the cause of the event, and they are 

required to furnish that information by mail or email to the addressee indicated in the NTL. The operator 

does not have to provide information on kicks that were controlled, but the operator should include the 
Impact-Producing Factors and Scenario 3-27

release of fluids through a flow diverter (a conduit used to direct fluid flowing from a well away from the 

drilling rig).

The current definition for loss of well control is as follows:

• uncontrolled flow of formation or other fluids (the flow may be to an exposed

formation [an underground blowout] or at the surface [a surface blowout]);

• uncontrolled flow through a diverter; and/or

• uncontrolled flow resulting from a failure of surface equipment or procedures.

A loss of well control can occur during any phase of development, i.e., exploratory drilling, 

development drilling, well completion, production, or workover operations. A loss of well control can 

occur when improperly balanced well pressure results in sudden, uncontrolled releases of fluids from a 

wellhead or wellbore (PCCI Marine and Environmental Engineering, 1999; Neal Adams Firefighters, 

Inc., 1991). From 2007 to 2013, of the 41 loss of well-control events reported in the GOM, 22 (54%) 

resulted in loss of fluids at the surface or underground (USDOI, BSEE, 2014b). In addition to spills, the 

loss of well control can resuspend and disperse bottom sediments. Historically, since 1971, most OCS 

blowouts have resulted in the release of gas, while blowouts resulting in the release of oil have been rare.

3.2.3. Pipeline Failures

The potential mechanisms for damage to OCS pipeline infrastructure include mass sediment 

movements and mudslides that can exhume or push the pipelines into another location, impacts from 

anchor drops or boat collisions, and accidental excavation or breaching because the exact whereabouts of 

a pipeline is uncertain. Pipeline failures could also be by rig/platform and pipeline activities supporting a

CPA or EPA proposed action. Chapter 3.2.3 of the 2012-2017 WPA/CPA Multisale EIS describes 

previous incidents of OCS oil- and gas-related pipeline failures related to a CPA proposed action. 

Chapter 3.2.3 of the EPA 225/226 EIS describes previous incidents of OCS oil- and gas-related pipeline 

failures related to an EPA proposed action. 

Any one of the mechanisms listed above could cause an OCS oil- and gas-related oil spill ≥1,000 bbl. 

Any resulting spill size would be limited by the size of the pipeline and the ability of an operator to 

quickly shut off flow from the source. The median spill size estimated from a pipeline failure is 2,200 bbl 

(Table 3-12 of the 2012-2017 WPA/CPA Multisale EIS). For both a CPA and EPA proposed action, up 

to one spill of this size is estimated to occur during the 40-year analysis period.

3.2.4. Vessel Collisions

The BSEE revised operator incident reporting requirements in a final rule effective July 17, 2006 

(Federal Register, 2006). The incident reporting rule more clearly defines what incidents must be 

reported, broadens the scope to include incidents that have the potential to be serious, and requires the 

reporting of standard information for both oral and written reports. As part of the incident reporting rule, 

BSEE’s regulations at 30 CFR § 250.188(a)(6) require an operator to report all collisions that result in 

property or equipment damage greater than $25,000. “Collision” is defined as the act of a moving vessel 

(including an aircraft) striking another vessel or striking a stationary vessel or object (e.g., a boat striking 

a drilling rig or platform). Chapter 3.2.3 of the 2012-2017 WPA/CPA Multisale EIS provides data related 

to vessel collisions and discusses methods of prevention and avoidance of vessel collisions related to a 

CPA proposed action. Chapter 3.2.3 of the EPA 225/226 EIS provides data related to vessel collisions 

and discusses methods of prevention and avoidance of vessel collisions related to an EPA proposed 

action.

3.2.5. Chemical and Drilling-Fluid Spills

Chapter 3.2.5 of the 2012-2017 WPA/CPA Multisale EIS for a CPA proposed action and Chapter 

3.2.5 of the EPA 225/226 EIS for an EPA proposed action describe OCS oil- and gas-related chemical 

and synthetic-based fluid spills. Below is a brief summary of that information.
3-28 Central and Eastern Planning Areas Supplemental EIS

Chemicals are stored and used to condition drill muds during production and in well completions, 

stimulation, and workover procedures. The most common chemicals spilled are methanol, ethylene 

glycol, and zinc bromide. Methanol and ethylene glycol may be used as a treatment to prevent the 

formation of gas hydrates while zinc bromide may be used in completion fluids. Completion fluids are 

used in the largest quantity and constitute the largest volume of accidental releases. Completion fluids 

consist of brines made from seawater mixed with calcium chloride, calcium bromide, and/or zinc 

bromide. A study of chemical spills from OCS oil- and gas-related activities determined that only two 

chemicals could potentially impact the marine environment—zinc bromide and ammonium chloride 

(Boehm et al., 2001). Both of these chemicals are used for well treatment or completion and, therefore, 

are not in continuous use. Most other chemicals are either nontoxic or used in small quantities. There are 

some differences in the operational needs for chemicals in deepwater versus shallow-water operations. 

Higher volumes of treatment chemicals (e.g., defoamers and hydrate inhibitors) are used in deepwater 

environments due to the conditions encountered there (Boehm et al., 2001).

Synthetic-based fluids (SBFs) or synthetic-based muds (SBMs) have been used since the mid 1990’s. 

In deepwater drilling, SBFs are preferred over water-based muds because of the SBF’s superior 

performance properties. The synthetic oils used in SBFs are relatively nontoxic to the marine 

environment and have the potential to biodegrade. However, it should be noted that SBFs are not 

permitted to be discharged into the marine environment; only cuttings wetted with SBF may be 

discharged after the majority of synthetic fluid has been removed. For further discussion on this topic, 

refer to Chapter 3.1.1.4.1 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 3.1.1.4.1 of the EPA 

225/226 EIS. Accidental riser disconnects could result in the release of large quantities of drilling fluids 

and are of particular concern when SBFs are in use. The BSEE previously tracked spill incidents of 

≥1 bbl in size for chemical and synthetic-based fluids resulting from OCS oil- and gas-related activities, 

and BSEE has historically produced counts and summaries for spills ≥50 bbl. Refer to Chapter 3.2.5 of 

the CPA 235/241/247 Supplemental EIS for the most recent information on BSEE’s counts and 

summaries for spills ≥50 bbl.

3.3. CUMULATIVE ACTIVITIES SCENARIO

The preceding sections of Chapter 3 discuss the impact-producing factors and scenario for routine 

activities and accidental events associated with a CPA or EPA proposed action that could potentially 

impact the physical, environmental, and socioeconomic resources that are analyzed in this Supplemental 

EIS. This chapter presents a summary of other factors that may cumulatively impact those resources. For 

a more complete and detailed discussion of topics related to cumulative activities related to a CPA 

proposed action, refer to Chapter 3.3 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by reference. 

For a more complete and detailed discussion of topics related to cumulative activities related to an EPA 

proposed action, refer to Chapter 3.3 of the EPA 225/226 EIS and 2012-2017 WPA/CPA Multisale EIS, 

which are hereby incorporated by reference.

3.3.1. OCS Program

The OCS Program’s cumulative scenario includes all activities that are projected to occur from past, 

proposed, and future lease sales during the 40-year activity period. Projected reserve/resource production 

for the OCS Program (Table 3-1) is 18.34-25.64 BBO and 75.886-111.627 Tcf of gas. Tables 3-3 

through 3-6 present projections of the major activities and impact-producing factors related to future 

Gulfwide OCS Program activities.

The level of OCS oil- and gas-related activity is connected to oil prices, resource potential, cost of 

development, and rig availability rather than just the amount of acreage leased. The impacts of activities 

associated with the OCS Program on biological, physical, and socioeconomic resources are analyzed in 

the cumulative impacts analysis sections of Chapter 4.1.1 of this Supplemental EIS, Chapter 4.2.1 of the 

2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, and Chapter 4.1.1 of the 

CPA 235/241/247 Supplemental EIS for a CPA proposed action and in Chapter 4.2.1 of this 

Supplemental EIS and Chapter 4.1.1 of the EPA 225/226 EIS for an EPA proposed action. 

Note that the impact-producing factors, affected environment, and environmental consequences 

related to the WPA cumulative OCS Program activities have been disclosed and addressed in the 2012-
Impact-Producing Factors and Scenario 3-29

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and WPA 238/246/248 

Supplemental EIS.

3.3.2. State Oil and Gas Activity

All five Gulf Coast States have had some historical oil and gas exploration activity and, with the 

exception of Florida and Mississippi, currently produce oil and gas in State waters. The coastal 

infrastructure that supports the OCS Program also supports State oil and gas activities.

State oil and gas infrastructure consists of the wells that extract hydrocarbon resources, facilities that 

produce and treat the raw product, pipelines that transport the product to refineries and gas facilities for 

further processing, and additional pipelines that transport finished product to points of storage and final 

consumption. The type and size of infrastructure that supports production depends upon the size, type, 

and location of the producing field, the time of development, and the life cycle stage of operations. 

Chapter 3.3.2 of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS provide a reference for relevant historical information on State 

leasing programs for a CPA proposed action. Chapter 3.3.2 of the EPA 225/226 EIS and 2012-2017 

WPA/CPA Multisale EIS provides a reference for relevant historical information on State leasing 

programs for an EPA proposed action. The most recent lease sale information for Texas and Louisiana 

has been updated below.

Texas 

The most recent oil and gas lease sale occurred on July 1, 2014. Thirteen parcels containing more 

than 21,520 ac of State lands were offered for oil and gas leasing in the offshore area by Texas State 

University Lands (State of Texas, General Lands Office, 2014). BOEM expects that Texas will conduct 

regular oil and gas lease sales during the 40-year cumulative activities scenario for OCS oil- and gasrelated activity, although the lease sale’s regularity could differ from current practices.

Louisiana

The most recent oil and gas lease sale occurred on April 12, 2014. Forty-four leases containing more 

than 29,698 ac were offered for oil and gas leasing by the Office of Mineral Resources on behalf of the 

State Mineral Board for Louisiana. The April 12, 2014, State lease sale offered no leases in offshore 

areas. During the 2013-2014 Fiscal Year, 99 offshore leases containing more than 164,154 ac were 

offered; of these, only 28 leases were awarded. BOEM expects that Louisiana will conduct regular oil 

and gas lease sales during the 40-year cumulative activities scenario for OCS oil- and gas-related activity, 

although the lease sale’s regularity could differ from current practices (State of Louisiana, Dept. of 

Natural Resources, 2014).

Mississippi

Per conversations with the Mississippi Development Authority (2012), BOEM expects Mississippi to 

institute a lease sale program in the near future and to begin leasing in State waters during the 40-year 

cumulative activities scenario for OCS oil- and gas-related activity analyzed in this Supplemental EIS. 

Recent efforts to open Mississippi State waters for seismic and leasing activities have been challenged in 

court (Davis, 2014).

Alabama 

Alabama has no established schedule of lease sales. The limited number of blocks in State waters has 

resulted in the State not holding regularly scheduled lease sales. The last lease sale was held in 1997. 

BOEM does not expect Alabama to institute a lease sale program in the near future, although there is at 

least a possibility of a lease sale in State waters during the 40-year cumulative activities scenario for OCS 

oil- and gas-related activity following a proposed action (Mobile Area Chamber of Commerce, 2011).
3-30 Central and Eastern Planning Areas Supplemental EIS

Florida

BOEM does not expect Florida to institute a lease sale program in the near future, although it is 

possible that a change in policy could lead to leasing on the OCS or in State waters during the 40-year 

cumulative activities scenario for OCS oil- and gas-related activity analyzed in this Supplemental EIS. 

For more information, refer to Chapter 3.3.2 of the 2012-2017 WPA/CPA Multisale EIS.

Pipeline Infrastructure

A mature pipeline network exists in the GOM to transport oil and gas produced on the OCS to shore 

(Chapter 4.1.1.23.1 for a CPA proposed action and Chapter 4.2.1.22.1 for an EPA proposed action). 

The network carries oil and gas onshore and inland to refineries and terminals, and a network of pipelines

distributes finished products such as diesel fuel or gasoline to and between refineries and processing 

facilities onshore (Peele et al., 2002, Figure 4.1). Expansion of this network is projected to be primarily 

small-diameter pipelines to increase the interconnectivity of the existing network and a few major 

interstate pipeline expansions. Any new larger-diameter pipelines would likely be constructed to support 

onshore and offshore LNG terminals. Refer to Chapter 3.3.2 of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS for information on 

pipeline infrastructure activities within the State waters of Texas, Louisiana, Mississippi, and Alabama in 

relation to a CPA proposed action. Refer to Chapter 3.3.2 of the EPA 225/226 EIS and 2012-2017 

WPA/CPA Multisale EIS for information on pipeline infrastructure activities within the State waters of 

Texas, Louisiana, Mississippi, and Alabama in relation to an EPA proposed action. 

3.3.3. Other Major Factors Influencing Offshore Environments

Other influencing factors occur in the offshore areas of the Gulf Coast States while OCS oil- and gasrelated activity takes place at the same time. Some of these factors are (1) dredged material disposal, 

(2) OCS sand borrowing, (3) marine transportation, (4) military activities, (5) artificial reefs and rigs-toreefs development, (6) offshore LNG projects, (7) development of gas hydrates, and (8) renewable energy

and alternative use.

Cumulative impacts to biological, physical, and socioeconomic resources from these types of 

non-OCS oil- and gas-related activities are analyzed in the cumulative impacts analysis sections in

Chapters 4.1.1 and 4.2.1 of this Supplemental EIS, Chapter 4.2.1 of the 2012-2017 WPA/CPA Multisale 

EIS, and Chapter 4.1.1 of the EPA 225/226 EIS.

3.3.3.1. Dredged Material Disposal

Dredged material is described at 33 CFR part 324 as any material excavated or dredged from 

navigable waters of the United States. Materials from maintenance dredging are primarily disposed of 

offshore on existing dredged-material disposal banks and in ocean dredged-material disposal sites 

(ODMDSs), which are regulated by USEPA. Additional dredged-material disposal areas for maintenance 

or new-project dredging are developed as needed and must be evaluated and permitted by COE and 

relevant State agencies prior to construction.

If funds are available, dredged materials disposed offshore are available for potential beneficial uses 

to restore and create habitat, beach nourishment projects, and industrial and commercial development—a 

use called the beneficial use of dredge materials program by COE (Chapter 3.3.4.3). Virtually all ocean 

dumping that occurs today is maintenance dredging of sediments from the bottom of channels and 

waterbodies in order to maintain adequate channel depth for navigation and berthing. There are four 

small ODMDSs offshore Louisiana and Mississippi along open-water stretches of the main Gulf 

Intracoastal Waterway between Louisiana and Mississippi: in Louisiana ODMDS 66 (1,593 ac; 645 ha); 

and in Mississippi ODMDSs 65A (1,962 ac; 794 ha), 65B (815 ac; 330 ha), and 65C (176 ac; 71 ha) (U.S. 

Dept. of the Army, COE, 2008, Table 1). Dredged materials from the Gulf Intracoastal Waterway are 

sidecast at these ODMDS locations. The ODMDSs utilized by COE in the cumulative activities area 

include those shown in Table 3-30 of the 2012-2017 WPA/CPA Multisale EIS.

There are two primary Federal environmental statutes governing dredge material disposal. The 

Marine Protection, Research, and Sanctuaries Act (also called the Ocean Dumping Act) governs 

transportation for the purpose of disposal into ocean waters. Section 404 of the Clean Water Act governs 
Impact-Producing Factors and Scenario 3-31

the discharge of dredged or fill material into U.S. coastal and inland waters. The USEPA and COE are 

jointly responsible for the management and monitoring of ocean disposal sites. The responsibilities are 

divided as follows: (1) COE issues permits under the Clean Water Act and the Marine Protection, 

Research, and Sanctuaries Act; (2) USEPA has lead for establishing environmental guidelines/criteria that 

must be met to receive a permit under either statute; (3) permits for ODMDS disposal are subject to 

USEPA review and concurrence; and (4) USEPA is responsible for identifying recommended ODMDSs. 

The COE’s Ocean Disposal Database reports the amount of dredged material disposed in ODMDSs 

by district (U.S. Dept. of the Army, COE, 2010, Table 1). Table 3-9 of the CPA 235/241/247 

Supplemental EIS (for a CPA proposed action) and Table 3-27 of the EPA 225/226 EIS (for an EPA 

proposed action) show the quantities of dredged materials disposed of in ODMDSs between 2005 and 

2010 by the Mobile and New Orleans Districts.

The New Orleans District dredges an average annual 78 million yd3 (59,635,279 m3

). Current figures 

estimate that approximately 38 percent (or 30 million yd3 [22,936,646 m3

]) of that average is available for 

the beneficial use of dredge materials program (U.S. Dept. of the Army, COE, 2013). The remaining 

62 percent of the total material dredged yearly by COE’s New Orleans District is disposed of at 

placement areas regulated under Section 404 of the Clean Water Act, at ODMDSs, or it is stored in 

temporary staging areas located inland (e.g., the Pass a Loutre Hopper Dredge Disposal Site at the head of 

the Mississippi River’s main “birdfoot” distributary channel system).

Cumulative Activities Scenario: BOEM anticipates that, over the next 40 years, the amount of 

dredged material disposed at ODMDSs will fluctuate generally within the trends established by the COE 

district offices. Over the last 5 years, the New Orleans District has averaged about 21.7 million yd3

(16.6 million m3

) of material dredged per year disposed at ODMDSs, while the Mobile District is about 

one-quarter of that quantity, or 4.5 million yd3 (refer to Table 3-9 of the CPA 235/241/247 Supplemental 

EIS for a CPA proposed action and Table 3-27 of the EPA 225/226 EIS for an EPA proposed action). 

Quantities disposed at ODMDSs may decrease as more beneficial uses of dredged material onshore are 

identified and evaluated. For a more complete and detailed discussion of dredged material disposal 

activities, refer to Chapter 3.3.3.1 of the 2012-2017 WPA/CPA Multisale EIS and CPA 235/241/247 

Supplemental EIS for a CPA proposed action and Chapter 3.3.3.1 of the EPA 225/226 EIS for an EPA 

proposed action, which are hereby incorporated by reference.

3.3.3.2. OCS Sand Borrowing

If OCS sand is desired for coastal restoration or beach nourishment, BOEM uses the following two 

types of lease conveyances: a noncompetitive negotiated agreement that can only be used for obtaining 

sand and gravel for public works projects funded in part or whole by a Federal, State, or local government 

agency; and a competitive lease sale in which any qualified person may submit a bid. BOEM has issued 

43 noncompetitive negotiated agreements, but it has never held a competitive lease sale for OCS sand and 

gravel resources. BOEM’s Marine Minerals Program continues to focus on identifying sand resources for 

coastal restoration, investigating the environmental implications of using those resources, and processing 

noncompetitive use requests. BOEM is expected to issue one new lease in Louisiana for the Deepwater

Horizon NRDA Whiskey Island Restoration Project in Terrebonne Parish using sand from Ship Shoal 

Block 88. In March 2014, BOEM issued a lease for Phase Two of the Caminada Headland Restoration 

Project in Lafourche and Jefferson Parishes in Louisiana using sand from South Pelto Blocks 13 and 14. 

BOEM has outlined its responsibility as steward of significant sand resources on the OCS in NTL 2009-

G04, which states: “If it is determined that significant OCS sediment resources may be impacted by a 

proposed activity, the MMS GOMR may require you to undertake measures deemed economically, 

environmentally, and technically feasible to protect the resources to the maximum extent practicable. 

Measures may include modification of operations and monitoring of pipeline locations after installation.” 

This NTL also provides guidance for the avoidance and protection of significant OCS sediment resources 

essential to coastal restoration initiatives in BOEM’s Gulf of Mexico OCS Region. Over the next 

40 years, increased use of OCS sand for Louisiana restoration projects is likely. Currently, no Texas 

restoration projects have been specifically identified. For more information on OCS sand borrowing, 

refer to Chapter 3.3.3.2 of the 2012-2017 WPA/CPA Multisale EIS and CPA 235/241/247 Supplemental 

EIS for a CPA proposed Action and Chapter 3.3.3.2 of the EPA 225/226 EIS for an EPA proposed action. 
3-32 Central and Eastern Planning Areas Supplemental EIS

3.3.3.3. Marine Transportation

Under current conditions, freight and cruise ship passenger marine transportation within the analyzed 

area should continue to grow at a modest rate or remain relatively unchanged based on historical freight 

traffic statistics under current conditions. In 2011, the Port of Houston was the second largest port in the 

United States, while the Port of New Orleans was the sixth largest port. Tankers carrying mostly 

petrochemicals account for about 60 percent of the vessel calls in the Gulf of Mexico. Dry-bulk vessels 

including bulk vessels, bulk containerships, cement carriers, ore carriers, and wood-chip carriers 

accounted for another 17 percent of the vessel calls. The Gulf supports a popular cruise industry. In 

2011, there were 149 cruise ship departures from Galveston, 139 cruise ship departures from New 

Orleans, and 199 cruise ship departures from Tampa (USDOT, MARAD, 2012). 

Total port use in the U.S. is increasing as a whole, and total port use within the GOM is also 

increasing. Gulf of Mexico port use represents approximately 32 percent of total U.S. port use. Trends 

for Gulf of Mexico port use relative to total U.S. port use show an approximate 3 percent average increase

of Gulf of Mexico port use over the last decade from 17,673 in 2002 to 22,989 in 2011 (USDOT, 

MARAD, 2013) (Table 3-10 of the CPA 235/241/247 Supplemental EIS and Table 3-28 of the EPA 

225/226 EIS). Table 3-2 presents the estimated number of vessel trips that would occur as a result of a 

CPA proposed action. Annual OCS oil- and gas-related vessel traffic due to a typical CPA or EPA

proposed action represents a small proportion (<1% and <0.1%, respectively) of the total vessel traffic in 

the GOM (Chapter 3.1.1.8 of this Supplemental EIS and Chapter 3.1.1.8.4 of the 2012-2017 WPA/CPA 

Multisale EIS for a CPA proposed action, and Chapter 3.1.1.8 of this Supplemental EIS and Chapter 

3.1.1.8.2 of the EPA 225/226 EIS for an EPA proposed action). Annual OCS oil- and gas-related vessel 

traffic due to cumulative OCS oil- and gas-related activity represents between 9 and 12 percent of the 

total traffic in the GOM.

Cumulative Activities Scenario: It is expected that the usage of GOM ports will continue to increase 

by approximately 3 percent annually over the next 40 years. As such, it is anticipated that port calls by all 

ship types will be bounded annually by a lower limit of current use and an upper limit of approximately 

85,000 vessel port calls. 

3.3.3.4. Military Activities

A standard military warning areas stipulation has been applied to all blocks leased in military areas in 

the GOM since 1977. The air space over the GOM is used by the U.S. Department of Defense (DOD) for 

conducting various military operations. Twelve military warning areas and six Eglin Water Test Areas

(EWTAs) are located within the Gulf of Mexico (Figure 2-1). These military warning areas and EWTAs 

are multiple-use areas where military operations and oil and gas development have coexisted without 

conflict for many years. Several military stipulations are planned for leases issued within identified 

military areas.

CPA Activities Scenario: Six designated military areas and three EWTAs that are used for military 

operations lie wholly or partially within the CPA (Figure 2-1). The military warning areas within the 

CPA total approximately 13.3 million ac (about 23% of the total acreage of the CPA). The EWTAs 

within the CPA total approximately 7 million ac (about 12% of the total acreage of the CPA). Chapter 

3.3.3.4 of the 2012-2017 WPA/CPA Multisale EIS describes military activities within the OCS.

EPA Activities Scenario: The EPA has 64,563,679 total acres; approximately 43,217,494 ac are in 

EWTAs and approximately 15,670,911 ac are in military warning areas. The EWTAs and military 

warning areas account for 91 percent of the acreage in the EPA. The proposed EPA lease sale area is not 

within any of the military warning areas; however, the entire proposed EPA lease sale area (657,905 ac) is 

within EWTA boundaries. For a more complete and detailed discussion of military activities, refer to 

Chapter 3.3.3.4 of the EPA 225/226 EIS and 2012-2017 WPA/CPA Multisale EIS, which are hereby 

incorporated by reference.

In addition to the previously noted standard Military Areas Stipulation, the EWTAs will require the 

following special stipulations:

• Evacuation Stipulation: Lessee is required to evacuate, upon receipt of a directive 

from BOEM’s Regional Director, all personnel from structures on the lease. Lessee 
Impact-Producing Factors and Scenario 3-33

must also shut-in and secure all wells and other equipment, including pipelines, on 

the lease.

• Coordination Stipulation: Lessee is required to consult with the appropriate military 

command headquarters regarding the location, density, and the planned periods of 

operation of surface structures on the lease, and to maximize exploration while 

minimizing conflicts with DOD activities prior to approval of an exploration plan by 

BOEM’s Regional Director.

Cumulative Activities Scenario: BOEM anticipates that, over the next 40 years, the military use areas 

currently designated in the CPA, EPA, and WPA will remain the same and that none of them would be 

released for nonmilitary use. Over the cumulative activities scenario, BOEM expects to continue to 

require military coordination stipulations in these areas. The intensity of the military’s use of these areas, 

or the type of activities conducted in them, is anticipated to fluctuate with the military mission needs.

3.3.3.5. Artificial Reefs and Rigs-to-Reefs Development

A full description of artificial reefs and Rigs-to-Reefs operations is presented in the 2012-2017 

WPA/CPA Multisale EIS for a CPA proposed action and in the EPA 225/226 EIS for an EPA proposed 

action.. No new significant information was discovered that would alter impact conclusions based upon 

these operations. The following is a summary; for more details, refer to Chapter 3.1.1.10 of this 

Supplemental EIS and Chapter 3.1.1.10 of the 2012-2017 WPA/CPA Multisale for a CPA proposed 

action and to Chapter 3.1.1.10 of this Supplemental EIS and Chapter 3.1.1.10 of the EPA 225/226 EIS 

for an EPA proposed action. 

Artificial reefs have been used along the coastline of the U.S. since the early 19th century. Stone 

(1974) documented that the use of obsolete materials to create artificial reefs has provided valuable 

habitat for numerous species of fish in areas devoid of natural hard bottom. Some studies have indicated 

that artificial reefs in marine waters not only attract fish but, in some instances, may also enhance the 

production of fish (Stone et al., 1979; Carr and Hixon, 1997; Dance et al., 2011). All of the five Gulf 

Coast States—Texas, Louisiana, Mississippi, Alabama, and Florida—have established State artificial reef 

programs and plans. These programs are guided by the National Artificial Reef Plan, a requirement of the 

National Fishing Enhancement Act of 1984. The lead agencies responsible for guiding and regulating 

artificial reef development are NOAA and the COE.

Offshore oil and gas platforms have been contributing hard substrate to the GOM since the first 

platform was installed in 1942. However, the Outer Continental Shelf Lands Act (OCSLA) and 

implementing regulations establish decommissioning obligations, including the removal of platforms. 

The Rigs-to-Reefs Policy provides a means by which lessees may request a waiver to the removal 

requirement. Although BSEE supports and encourages the reuse of obsolete oil and gas structures as 

artificial reefs, lessees must meet specific requirements for a departure to be granted. In recent years, 

approximately 12 percent of the platforms decommissioned from the Gulf OCS have been used in 

authorized artificial reef programs (USDOI, BSEE, 2014c). Scientific and public interest in the ecology 

of offshore structures and the potential benefits of contributing substantial quantities of hard substrate to a 

predominantly soft bottom environment may lead to increased emphasis on the creation of artificial reefs 

through the Rigs-to-Reefs Policy. At present, Texas, Louisiana, Alabama, and Mississippi participate in 

the Rigs-to-Reefs Program. 

WPA, CPA, and EPA Proposed Actions Scenario (Typical Lease Sale): The number of platform 

removals projected for a WPA, CPA, or EPA proposed action is 14-22, 32-61, and 0-1, respectively 

(Tables 3-2 and 3-3 of this Supplemental EIS for a CPA or EPA proposed action, respectively, and Table 

3-2 of the 2012-2017 WPA/CPA Multisale EIS for a WPA proposed action). The number of platforms 

anticipated to be part of the Rigs-to-Reefs Program as a result of a WPA, CPA, or EPA proposed action is 

approximately 10 percent of the projected removals, or 1-2 in the WPA, 3-7 in the CPA, and up to 1 in the 

EPA. 

OCS Program Scenario: Over the course of the 40-year cumulative activities scenario for the OCS 

Program (2012-2051), BOEM projects that a total of 1,279-1,837 platforms will be removed (Table 3-4). 

If approximately 10 percent of these structures are accepted into the Rigs-to-Reefs Program, there may be 

as many as 128-184 additional artificial reefs installed in the WPA, CPA, and EPA.
3-34 Central and Eastern Planning Areas Supplemental EIS

3.3.3.6. Offshore Liquefied Natural Gas Projects and Deepwater Ports

There are currently no LNG terminals operating on the OCS in the Gulf of Mexico. The following 

provides updates to the status of LNG projects and deepwater ports in the GOM as provided in Chapter 

3.3.3.6 of the 2012-2017 WPA/CPA Multisale EIS and CPA 235/241/247 Supplemental EIS for a CPA 

proposed action and Chapter 3.3.3.6 of the EPA 225/226 EIS for an EPA proposed action (USDOT, 

MARAD, 2014). 

Florida

Port Dolphin. On March 29, 2007, Port Dolphin Energy LLC filed an application with the Maritime 

Administration to construct a deepwater port located in Federal waters approximately 28 mi (45 km) 

offshore of Tampa, Florida. The applicant is a wholly owned subsidiary of Höegh LNG. The proposed 

port will consist of two Submerged Turret Loading (STL) buoys similar to those used in the Northeast 

Gateway and Neptune projects. On October 26, 2009, the Maritime Administration issued a Record of 

Decision approving, with conditions, the Port Dolphin Energy Deepwater Port License application, and 

on April 19, 2010, the official license was issued. Port Dolphin is currently working with the relevant 

Federal and State of Florida agencies to obtain the required authorizations and permits for construction 

and operation of the facility. Due to market considerations and commercial potential of the project, Port 

Dolphin requested on October 17, 2014, that the Commission extend the deadline until December 31, 

2018, for constructing and placing into operation the facilities authorized by the December 3, 2009, 

Federal Energy Regulatory Commission Certificate (Port Dolphin Energy, 2014). 

3.3.3.7. Development of Gas Hydrates

Chapter 3.3.3.7 of the 2012-2017 WPA/CPA Multisale EIS and CPA 235/241/247 Supplemental EIS 

for a CPA proposed action and Chapter 3.3.3.7 of the EPA 225/226 EIS for an EPA proposed action

describe the development of gas hydrates in detail. BOEM still anticipates that, within 40 years, it is 

likely that the first U.S. domestic production from hydrates may occur in Alaska. Gas obtained from 

onshore hydrates in Alaska will either support local oil and gas field operations or be available for 

commercial sale if and when a gas pipeline is constructed to the lower 48 states. However, Moridis et al. 

(2008) stated that one should not discount the possibility that the first U.S. domestic production of gas 

hydrates could occur in the GOM. Despite the substantially increased complexity and cost of offshore 

operations, there is a mature network of available pipeline capacity and easier access to markets in the 

Gulf of Mexico.

3.3.3.8. Renewable Energy and Alternative Use

On August 8, 2005, President George W. Bush signed the Energy Policy Act (EPAct) into law. 

Section 388 (a) of EPAct amended Section 8 of the OCSLA (43 U.S.C. § 1337) to authorize DOI to grant 

leases, easements, or rights-of-way on the OCS for the development and support of energy resources 

other than oil and gas and to allow for alternate uses of existing structures on OCS lands.

A final programmatic EIS for the OCS renewable energy program was published by this Agency in 

October 2007 (USDOI, MMS, 2007a) and a Record of Decision was published in the Federal Register on 

January 10, 2008 (Federal Register, 2008). The Act authorized this Agency to develop a comprehensive 

program and regulations to implement the new authority. Final rules for BOEM’s renewable energy 

program were published on April 29, 2009, as 30 CFR part 285 (Federal Register, 2009).

The two primary categories of renewable energy that have the potential for development in the coastal 

and OCS waters of the U.S. are (1) wind turbines and (2) marine hydrokinetic systems. The first and 

most technologically mature renewable energy is wind energy, a popular source of clean and renewable 

energy that has been in use for centuries. The DOE released a strategic plan for creating an offshore wind 

industry in the U.S. (USDOE, 2011). In this plan, DOE determined that offshore wind energy can help 

the Nation reduce its greenhouse gas emissions, diversify its energy supply, provide cost-competitive 

electricity to key coastal regions, and stimulate economic revitalization of key sectors of the economy. 

However, if the Nation is to realize these benefits, key barriers to the development and deployment of 

offshore wind technology must be overcome, including the relatively high cost of energy, technical 

challenges surrounding installation and grid interconnection, and the permitting processes governing 
Impact-Producing Factors and Scenario 3-35

deployment in both Federal and State waters. There are two critical objectives to realize the strategic 

plan’s goals: (1) reduce the cost of offshore wind energy; and (2) reduce the timeline for deploying 

offshore wind energy (USDOE, 2011, page 2). Since April 29, 2009, when the regulations governing 

renewable energy on the OCS were published, no wind park developments have been proposed in OCS 

waters of the GOM; however, there have been proposals in Texas coastal waters.

In Fiscal Year 2010, the U.S. Department of Energy instituted the Offshore Wind Innovation and 

Demonstration (OSWInD) initiative to consolidate and expand its efforts to promote and accelerate 

responsible commercial offshore wind development in the U.S. In 2012, the U.S. Department of Energy’s 

Wind Program announced nationwide Federal funding in three major categories: technology 

development; market acceleration; and advanced technology demonstration. The Wind Program is 

working with BOEM to advance a national strategy for offshore wind research and development 

(Navigant Consulting, Inc., 2013). According to the report, there is a potential of 594 gigawatts of 

potential wind energy available in the GOM. Offshore wind could create approximately 20.7 direct jobs 

per annual megawatt (or 20,700 jobs per annual gigawatt) installed in U.S. waters. Texas received 

$4 million to produce three demonstration turbines in State waters (refer to the below).

The second category of offshore renewable energy is marine hydrokinetic systems, which are in a 

more developmental stage relative to wind turbines. The marine hydrokinetic systems consist of devices 

capable of capturing energy from ocean waves and currents. There has been no interest expressed in 

wave or current technologies in the GOM because the conditions necessary for their deployment are not 

suitable to the Gulf. The marine hydrokinetic current technologies are actively being considered for the 

east coast of Florida where the Gulf Stream provides a strong and continuous source of energy to turn 

underwater turbines.

The EPAct clarifies the Secretary’s authority to allow the existing oil and gas structures on OCS lands 

to remain in place after production activities have ceased and to transfer liability and extend the life of 

these facilities for non-oil and gas purposes, such as research, renewable energy production, aquaculture, 

etc., before being removed. With approximately 1,900 bottom-founded platform structures located in 

OCS waters, the GOM would seem to have some potential for the reuse of these facilities. Although 

BOEM has had conversations with developers about conceptual ideas for alternative use projects, no 

developer has stepped forward with an application to actualize one.

Cumulative Activities Scenario: BOEM expects that, over the next 40 years, a limited number of 

alternative use projects will be proposed in the WPA. It is also likely that these alternative use projects 

will consist of wind energy projects based on the current development of that technology. BOEM’s 

expectation is based on the fact that known projects are being proposed in Texas State waters Likewise, 

the potential alternative use projects could consist of a combination of integrated existing GOM 

infrastructure with new-built facilities.

Renewable Energy Projects in Texas State Waters

Chapter 3.3.3.8 of the 2012-2017 WPA/CPA Multisale EIS describes renewable energy and 

alternative use programs of Texas in detail. Below are updates to the status of the previously reported 

projects. 

Project Name

Proposed 

Capacity 

(megawatts) 

Number of 

Turbines Status Notes

Target 

Completion 

Date

Galveston Offshore 

Wind (Coastal Point 

Energy)

150 55-75

Has lease from Texas General Land 

Office. Announced intention to install 

a 750-kilowatt test turbine.

2018

Baryonyx Rio Grande 

Wind Farms (North 

and South)

1,000 100-200

Received lease from Texas General 

Land Office in 2009. The COE 

environmental studies are underway. 

Received DOE Wind Program grant to 

produce 3 demonstration turbines by 

2017.

2019

Navigant Consulting, Inc., 2013. 
3-36 Central and Eastern Planning Areas Supplemental EIS

3.3.4. Other Major Factors Influencing Coastal Environments

3.3.4.1. Sea-Level Rise and Subsidence

Given the results from the National Assessment of Coastal Vulnerability to Sea Level Rise, BOEM 

anticipates that, over the next 40 years, the northern GOM will likely experience a minimum relative sealevel rise of 55.2 millimeters (2.17 inches) and a maximum relative sea-level rise of 384 millimeters 

(15.1 inches) (Pendleton et al., 2010). Sea-level rise and subsidence together have the potential to affect 

many important areas, including the OCS oil and gas industry, oil and gas infrastructure, waterborne 

commerce, commercial fishery landings, and important habitat for biological resources (State of 

Louisiana, Coastal Protection and Restoration Authority, 2012a). Chapter 3.3.4.1 of the 2012-2017 

WPA/CPA Multisale EIS and CPA 235/241/247 Supplemental EIS for a CPA proposed action and 

Chapter 3.3.4.1 of the EPA 225/226 EIS for an EPA proposed action describes sea-level rise and 

subsidence in detail. Programmatic aspects of climate change relative to the environmental baseline for 

the Gulf of Mexico OCS Program are discussed in Appendix G.3 of the 2012-2017 WPA/CPA Multisale 

EIS.

3.3.4.2. Mississippi River Hydromodification

Hydromodifying interventions include construction of (1) levees along the river and distributary 

channel systems, (2) upstream dams and flood control structures that impound sediment and meter the 

river flow rate, and (3) channelized canals with earthen or armored banks. Once the natural processes that 

act to add sediment to the delta platform to keep it emergent are shut down, subsidence begins to outpace 

deposition of sediment. BOEM anticipates that, over the next 40 years, there might be minor sediment 

additions resulting from new and continuing freshwater diversion projects managed by the COE. Chapter 

3.3.4.2 of the 2012-2017 WPA/CPA Multisale EIS and CPA 235/241/247 Supplemental EIS for a CPA 

proposed action and Chapter 3.3.4.2 of the EPA 225/226 EIS for an EPA proposed action describe 

Mississippi River hydromodification in detail. 

3.3.4.3. Maintenance Dredging and Federal Channels

The Gulf Intracoastal Waterway is the main Federal channel in Florida. The Gulf Intracoastal 

Waterway is a shallow-draft navigation channel constructed to provide a domestic connection between 

Gulf ports after the discovery of oil in East Texas in the early 1900’s and to serve the growing need for 

the interstate transport of steel and other manufacturing materials. It extends approximately 1,400 mi 

(2,253 km) along the Gulf Coast from St. Marks, south of Tallahassee, in northwestern Florida to 

Brownsville, Texas. The length of the Gulf Intracoastal Waterway along the Florida coast is 

approximately 186 mi (300 km), along Alabama approximately 50 mi (80 km), along Mississippi 

approximately 70 mi (112 km), along Louisiana approximately 990 mi (1,600 km), and from the Sabine 

River through Texas to the Mexican Border 428 mi (690 km) (Good et al., 1995), which does not include 

the length of subsidiary channels included in the COE’s maintenance programs. Maintenance dredging is 

performed by the COE on an as-needed basis along the Gulf Intracoastal Waterway and the subsidiary 

channels that directly or indirectly connect to it or open water. Typically, COE schedules surveys every 

2 years for each navigation channel under its responsibility in order to maintain channel depth to specified 

standards.

The Tampa Bay Estuary Program and the COE have developed a long-term plan for maintenance 

dredging and use of dredged material (Tampa Bay Estuary Program, 2012). Dredging to maintain the 

Tampa Bay shipping channel and other nautical channels generates about a million cubic yards of 

material each year (Tampa Bay Estuary Program, 2012), almost all of which has been deposited on two 

manmade spoil islands or is used onshore for other beneficial uses, rather than deposited offshore in 

ODMDSs. The existing capacity for onshore beneficial use is currently at its limit in the Tampa Bay area 

(Tampa Bay Estuary Program, 2012), indicating that increased disposal in ODMDSs can be expected for 

dredged materials.

For a more complete and detailed discussion of maintenance dredging and Federal channels, refer to 

Chapter 3.3.4.3 of the 2012-2017 WPA/CPA Multisale EIS and CPA 235/241/247 Supplemental EIS for 

a CPA proposed action and Chapter 3.3.3.7 of the EPA 225/226 EIS for an EPA proposed action. For 

more information on coastal restoration programs, refer to Chapter 3.3.4.4 of this Supplemental EIS and 
Impact-Producing Factors and Scenario 3-37

Chapter 3.4.4.4 of the 2012-2017 WPA/CPA Multisale EIS for a CPA proposed action and Chapter 

3.3.4.4 of the EPA 225/226 EIS for an EPA proposed action. 

3.3.4.4. Coastal Restoration Programs

The Mississippi Delta sits atop a pile of Mesozoic and Tertiary-aged sediments up to 7.5 mi (12.2 km) 

thick at the coast, and it may be as much as 60,000 ft (18,288 m) or 11.4 mi (18.3 km) thick offshore 

(Gagliano, 1999). Five major lobes are generally recognized within about the uppermost 50 m (164 ft) of 

sediments (Britsch and Dunbar, 1993; Frazier, 1967, Figure 1). The oldest lobe contains peat deposits 

dated as 7,240 years old (Frazier, 1967, page 296). The youngest delta lobe of the Mississippi Delta is the 

Plaquemines-Balize lobe that has been active since the St. Bernard lobe was abandoned about 1,000 years 

ago. The lower Mississippi River has shifted its course to the Gulf of Mexico every thousand years or so, 

seeking the most direct path to the sea while building a new deltaic lobe. Older lobes were abandoned to 

erosion and subsidence as the sediment supply was shut off. Because of the dynamics of delta building 

and abandonment, the Louisiana Coastal Area (LCA) (U.S. Dept. of the Army, COE, 2004) experiences 

relatively high rates of subsidence relative to more stable coastal areas eastward and westward.

The first systematic program authorized for coastal restoration in the LCA was the 1990 Coastal 

Wetlands Planning, Protection and Restoration Act (CWPPRA), otherwise known as the “Breaux Act.” 

Individual CWPPRA projects are designed to protect and restore between 10 and 10,000 ac (4 and 

4,047 ha), require an average of 5 years to transition from approval to construction, and are funded to 

operate for 20 years (U.S. Government Accountability Office, 2007), which is a typical expectation for 

project effectiveness (Campbell et al., 2005).

The 1990 CWPPRA introduced an ongoing program of relatively small projects to partially restore 

the coastal ecosystem. As the magnitude of Louisiana’s coastal landlosses and ecosystem degradation 

became more apparent, so too appeared the need for a more systematic approach to integrate smaller 

projects with larger projects to restore natural geomorphic structures and processes. Projects have ranged 

from small demonstration projects to projects that cost over $50 million. The Coast 2050 Report 

(Louisiana Dept. of Natural Resources, 1998) combined previous restoration planning efforts with new 

initiatives from private citizens, local governments, State and Federal agency personnel, and the scientific 

community to converge on a shared vision to sustain the coastal ecosystem. The LCA Ecosystem 

Restoration Study (U.S. Dept. of the Army, COE, 2004) built upon the Coast 2050 Report. The LCA’s 

restoration strategies generally fell into one of the following categories: (1) freshwater diversion; 

(2) marsh management; (3) hydrologic restoration; (4) sediment diversion; (5) vegetative planting; 

(6) beneficial use of dredge material; (7) barrier island restoration; (8) sediment/nutrient trapping; and 

(9) shoreline protection, as well as other types of projects (Louisiana Coastal Wetlands Conservation and 

Restoration Task Force, 2006, Table 1). 

Following Hurricanes Katrina and Rita in 2005, an earlier emphasis on coastal or ecosystem 

restoration of the LCA was reordered to at least add an equal emphasis on hurricane flood protection. 

The Department of Defense Appropriations Act of 2006 authorized COE to develop a comprehensive 

hurricane protection analysis to present a full range of flood control, coastal restoration, and hurricane 

protection measures for south Louisiana (U.S. Dept. of the Army, COE, 2009a). The Appropriations Act 

required Louisiana to create a State organization to sponsor the hurricane protection and restoration 

projects that resulted. The State legislature established the Coastal Protection and Restoration Authority 

and charged it with coordinating the efforts of local, State, and Federal agencies to achieve long-term, 

integrated flood control and wetland restoration. The Coastal Protection and Restoration Authority 

produced a comprehensive master plan for a sustainable coast (State of Louisiana, Coastal Protection and 

Restoration Authority, 2007) as their vision of an integrated program of what had been separate areas of 

activity—flood protection and coastal restoration. The Coastal Protection and Restoration Authority’s 

Annual Plans prioritize the types of projects undertaken each fiscal year. It is not entirely clear how 

coordination between the State and Federal authorities is undertaken in order to develop the range of 

projects selected for the State’s Coastal Protection and Restoration Authority’s Annual Plan and COE’s 

plan (U.S. Dept. of the Army, COE, 2009b). 

As of May 2013, COE reported 196 authorized CWPPRA projects, 99 of which have been 

constructed. Another 20 projects are under construction, 34 are in the engineering and design phase, and

43 have been deauthorized or transferred to another program. Over 81,000 “anticipated total acres” 

(32,780 ha) have been projected from constructed projects and 60 not yet completed as of mid-2013 are 
3-38 Central and Eastern Planning Areas Supplemental EIS

reported to result in 33,297 anticipated total acres (13,474 ha) (LaCoast.gov, 2013). Of the 99 completed 

projects listed on LaCoast.gov (2013), more than half were one of three categories types: shoreline 

protection projects (29 projects); hydrolic restoration projects (24 projects); and marsh creation projects

(16 projects). 

Louisiana’s Coastal Protection & Restoration Authority released a Final Coastal Master Plan in 2012. 

The objectives of the plan focus on flood protection, harnessing natural processes, supporting coastal 

habitats, sustaining cultural heritage, and promoting a working coast (State of Louisiana, Coastal 

Protection and Restoration Authority, 2012a). 

There is no simple way to anticipate what projects under the protection of the State’s Coastal 

Protection and Restoration Authority are admitted to its Annual Plan and completed. There is also no 

simple way to anticipate what projects are undertaken for COE’s comprehensive range of flood control, 

coastal restoration, and hurricane protection measures for the LCA, which will feed into the Coastal 

Protection and Restoration Authority’s Annual Plan for authorization, and there is no simple way to 

anticipate which ones will be ultimately completed. Because these projects are chosen on the basis of 

annual appropriations, there is no simple way to establish projections for land added or preserved over the 

cumulative activities scenario.

Coastal Impact Assistance Program

The Energy Policy Act of 2005 was signed into law by President George W. Bush on August 8, 2005. 

Section 384 of EPAct amended Section 31 of the OCSLA (43 U.S.C. § 1356(a)) to establish the Coastal 

Impact Assistance Program (CIAP). The authority and responsibility for the management of CIAP is 

vested in the Secretary of the Interior; the Secretary delegated this authority and responsibility to 

BOEM’s predecessor up until September 30, 2011. In 2011, it was announced that FWS would take over 

administration of CIAP effective October 1, 2011, since the program aligns with FWS’s conservation 

mission and similar grant programs run by FWS. The eligibility requirements for States, coastal political 

subdivisions, and fundable projects remain largely the same after the transfer.

The CIAP provides Federal grant funds derived from Federal offshore lease revenues to oil-producing 

states for conservation, protection, or restoration of coastal areas. This includes wetlands; mitigation of 

damage to fish, wildlife, or natural resources; planning assistance and the administrative costs of 

complying with these objectives; implementation of a federally approved marine, coastal, or 

comprehensive conservation management plan; and mitigation of the impact of OCS oil- and gas-related 

activities through the funding of onshore infrastructure projects and public service needs. Under Section 

384 of EPAct, the Secretary of the Interior was directed to disburse $250 million for each of the Fiscal 

Years 2007 through 2010 to eligible OCS oil- and gas-producing States and coastal political subdivisions.

Eligible CIAP States Eligible CIAP Coastal Political Subdivisions 

Alabama Baldwin and Mobile Counties

Alaska Municipality of Anchorage and Bristol Bay, Kenai Peninsula, Kodiak Island, Lake 

and Peninsula, Matanuska-Susitna, North Slope, and Northwest Arctic Boroughs

California

Alameda, Contra Costa, Los Angeles, Marin, Monterey, Napa, Orange, San Diego, 

San Francisco, San Luis Obispo, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, 

Solano, Sonoma, and Ventura Counties

Louisiana

Assumption, Calcasieu, Cameron, Iberia, Jefferson, Lafourche, Livingston, Orleans, 

Plaquemines, St. Bernard, St. Charles, St. James, St. John the Baptist, St. Martin, 

St. Mary, St. Tammany, Tangipahoa, Terrebonne, and Vermilion Parishes

Mississippi Hancock, Harrison, and Jackson Counties

Texas

Aransas, Brazoria, Calhoun, Cameron, Chambers, Galveston, Harris, Jackson, 

Jefferson, Kenedy, Kleberg, Matagorda, Nueces, Orange, Refugio, San Patricio, 

Victoria, and Willacy Counties
Impact-Producing Factors and Scenario 3-39

Natural Resource Damage Assessment Trustee Council

The Oil Pollution Act, as provided in 33 U.S.C. § 2706, allowed the designation of certain Federal 

agencies, States, and Indian Nations—collectively known as the Natural Resource Damage Assessment 

Trustee Council (Trustee Council). The Trustee Council is authorized to act on behalf of the public to 

(1) assess natural resource injuries resulting from a discharge of oil or the substantial threat of a discharge 

and response activities and (2) develop and implement a plan(s) for restoration of those injured resources 

(USDOI, 2012). With respect to NRDA for the Deepwater Horizon explosion and oil spill, a list of 

trustees can be found at http://www.gulfspillrestoration.noaa.gov/about-us/co-trustees/. On 

September 27, 2010, the Trustee Council submitted documentation supporting their determination of 

jurisdiction and their intent to conduct restoration planning. Executive Order 13554, signed on October 5, 

2010, recognized the role of the Trustee Council under the Oil Pollution Act and required that the Gulf 

Coast Ecosystem Restoration Task Force support the NRDA process by referring potential ecosystem 

restoration actions to the Trustee Council for consideration. Specifically, Executive Order 13554 

recognized the importance of carefully coordinating the work of the Task Force with the Trustee Council, 

“whose members have statutory responsibility to assess natural resource damages from the Deepwater 

Horizon Oil Spill, to restore trust resources, and seek compensation for lost use of those trust resources” 

(The White House, 2012). The Trustee Council is currently in the early restoration phase, and their data 

collection and analysis are ongoing (USDOI, 2012).

Gulf Coast Ecosystem Restoration Council

The Gulf Coast Ecosystem Restoration Task Force (refer to Chapter 3.3.4.4 of the 2012-2017 

WPA/CPA Multisale EIS for a CPA proposed action and Chapter 3.3.4.4 of the EPA 225/226 EIS for an 

EPA proposed action) was terminated in December 2012, following release of Executive Order 13626 in 

September 2012, affirming the Federal Government’s Gulf Coast ecosystem restoration efforts in light of 

the recent passage of the RESTORE Act (Resources and Ecosystems Sustainability, Tourist Opportunities 

and Revived Economies of the Gulf Coast States Act of 2012). The RESTORE Act established a 

mechanism for providing funding to the Gulf region to restore ecosystems and rebuild local economies 

damaged by the Deepwater Horizon oil spill. Additionally, the RESTORE Act established the Gulf 

Restoration Council, an independent entity charged with developing a comprehensive plan for ecosystem 

restoration in the Gulf Coast (Comprehensive Plan), as well as any future revisions to the Comprehensive 

Plan. This Council replaced the Gulf Coast Ecosystem Restoration Task Force in December 2012.

Among its other duties, the Gulf Restoration Council is tasked with identifying projects 

and programs aimed at restoring and protecting the natural resources and ecosystems of 

the Gulf Coast region, to be funded from a portion of the Trust Fund; establishing such 

other advisory committees as may be necessary to assist the Gulf Restoration Council, 

including a scientific advisory committee and a committee to advise the Gulf Restoration 

Council on public policy issues; gathering information relevant to Gulf Coast restoration, 

including through research, modeling, and monitoring; and providing an annual report to 

the Congress on implementation progress. Consistent with the RESTORE Act, the 

Comprehensive Plan developed by the Gulf Restoration Council will include provisions 

necessary to fully incorporate the Strategy, projects, and programs recommended by the 

Task Force (The White House, 2012).

3.3.5. Natural Events and Processes

Chapter 3.3.5 of the 2012-2017 WPA/CPA Multisale EIS describes in detail natural events and 

processes in the GOM related to a CPA proposed action, including physical oceanography and hurricanes. 

Chapter 3.3.5 of the EPA 225/226 EIS describes in detail natural events and processes in the GOM related 

to an EPA proposed action, including physical oceanography and hurricanes.

Since 2009, most of the extreme atmospheric events in the GOM have been categorized as tropical 

storms with strong winds, heavy rain, and storm surges causing coastal flooding. However, on 

August 28, 2012, Hurricane Isaac made landfall in southeastern Louisiana as a Category 1 hurricane. 

While there were no reports of moderate or extensive damage to offshore oil or gas infrastructure in the 

GOM, Hurricane Isaac did result in the suspension of small amounts of tarballs and some oil from 
3-40 Central and Eastern Planning Areas Supplemental EIS

sediments (Mulabagal et al., 2013). In addition, Mitra et al. (2009) evaluated the extent to which 

Hurricanes Katrina and Rita in 2005 dispersed and resuspended sediments in marshes and in the shallow 

and deep shelf of the Gulf of Mexico. This conforms with predictions in the 2012-2017 WPA/CPA 

Multisale EIS and EPA 225/226 EIS analyses and is discussed more fully in Chapter 4.1.1.2.1 of this 

Supplemental EIS.

3.3.6. Non-OCS Oil- and Gas-Related Oil Spills

Oil spills related to non-OCS oil- and gas-related activities such as State oil and gas activity or vessel 

collisions (including tankering, barging, or State oil and gas vessels) can result in the contamination of 

offshore or coastal environments. The Oil Pollution Act of 1990 strengthens planning and prevention 

activities in waters by (1) providing for the establishment of spill contingency plans for all areas of the 

U.S., (2) mandating the development of response plans for individual tank vessels and certain facilities for 

responding to a worst-case discharge or a substantial threat of such a discharge, and (3) providing 

requirements for spill-removal equipment and periodic inspections. Oil spills associated with a CPA

proposed action are discussed in Chapter 3.2.1 of this Supplemental EIS and Chapter 3.2.1 of the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247

Supplemental EIS for a CPA proposed action. Oil spills associated with an EPA proposed action are 

discussed in Chapter 3.2.1 of this Supplemental EIS and Chapter 3.2.1 of the EPA 225/226 EIS. For 

more information on the Oil Spill Pollution Act of 1990 and other response requirements and initiatives

regarding oil spills, refer to Chapter 3.2.1.9 of this Supplemental EIS and Chapter 3.2.1.9 of the 2012-

2017 WPA/CPA Multisale EIS for a CPA proposed action and Chapter 3.2.1.8 of the EPA 225/226 EIS 

for an EPA proposed action. Spills from tankers involve the spillage of crude oil, whereas barge spills 

involve spills of both crude oil and other petroleum products. Anderson et al. (2012) noted that tanker 

spill rates have continued to have a substantial decline since 2000. Most likely, tanker spills have

declined due to major regulatory changes in the early 1990’s that substantially eliminated the use of 

single-hull tankers by requiring double hulls or their equivalent (Anderson et al., 2012). A majority of 

spills from tankers occurred in coastal areas (37 spills) verses offshore (16 spills) between 1974 and 2008. 

Barge spill rates for the last 15 years (1994 through 2008) declined dramatically as compared with the 

entire time period of available data (1974 through 2008), especially for crude oil barges and for both spill 

sizes ≥1,000 bbl and >10,000 bbl (Anderson et al., 2012). From 1974 through 2008, 197 petroleum spills 

≥1,000 bbl (28 of which were crude oil spills) occurred from barges in U.S. coastal, offshore, and inland 

waters (including U.S. territorial waters). Because the data available on barge transport in U.S. waters do 

not differentiate between inland and coastal/offshore transport, inland transport was included.
CHAPTER 4 

DESCRIPTION OF THE ENVIRONMENT

AND IMPACT ANALYSIS

Description of the Environment and Impact Analysis 4-3 

4. DESCRIPTION OF THE ENVIRONMENT AND IMPACT ANALYSIS

Since proposed CPA Lease Sales 241 and 247 and proposed EPA Lease Sale 226 are in the same 

general area and their projected activities are very similar, BOEM has decided to prepared this single

Supplemental EIS that encompasses the three proposed lease sales as authorized under 40 CFR § 1502.4, 

which allows related or similar proposals to be analyzed in one EIS.

The impacts of 10 WPA and CPA lease sales were analyzed in the Gulf of Mexico OCS Oil and Gas 

Lease Sales: 2012-2017; Western Planning Area Lease Sales 229, 233, 238, 246, and 248; Central 

Planning Area Lease Sales 227, 231, 235, 241, and 247, Final Environmental Impact Statement (2012-

2017 WPA/CPA Multisale EIS) (USDOI, BOEM, 2012b), and this analysis was updated in the Gulf of 

Mexico OCS Oil and Gas Lease Sales: 2013-2014; Western Planning Area Lease Sale 233; Central 

Planning Area Lease Sale 231, Final Supplemental Environmental Impact Statement (WPA 233/CPA 231 

Supplemental EIS) (USDOI, BOEM, 2013a) and Central Planning Area Lease Sales 235, 241, and 247, 

Final Supplemental Environmental Impact Statement (CPA 235/241/247 Supplemental EIS) (USDOI, 

BOEM, 2014a). An analysis of the routine, accidental, and cumulative impacts of a CPA proposed action 

on the environmental, socioeconomic, and cultural resources of the GOM can be found in Chapter 4.2.1 

of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, and Chapter 4.1.1 

of the CPA 235/241/247 Supplemental EIS. The 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS are hereby incorporated by reference.

The impacts of two EPA lease sales were analyzed in the Outer Continental Shelf Oil and Gas 

Leasing Program: 2012-2017, Final Programmatic Environmental Impact Statement (Five-Year 

Program EIS) (USDOI, BOEM, 2012a) and Gulf of Mexico OCS Oil and Gas Lease Sales: 2014 and 

2016, Eastern Planning Area Lease Sales 225 and 226 (EPA 225/226 EIS) (USDOI, BOEM, 2013b). An 

analysis of the routine, accidental, and cumulative impacts of the EPA proposed action on the 

environmental, socioeconomic, and cultural resources of the GOM can be found in Chapter 4.1.1 of the 

EPA 225/226 EIS. The Five-Year Program EIS and EPA 225/226 EIS are hereby incorporated by 

reference.

The purpose of this Supplemental EIS is to determine if there are significant new circumstances or 

information bearing on the proposed actions or their impacts, as stated in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, CPA 235/241/247 Supplemental EIS, and EPA 

225/226 EIS, and, if so, to disclose those changes and conclusions. This includes all relevant new 

information available since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, CPA 235/241/247 Supplemental EIS, and EPA 225/226 EIS. This Supplemental EIS 

analyzes the potential impacts of a CPA proposed action (Chapter 4.1.1) and EPA proposed action 

(Chapter 4.2.1) on the sensitive coastal environments, offshore marine resources, onshore and offshore 

socioeconomic resources, and cultural resources.

4.1. PROPOSED CENTRAL PLANNING AREA LEASE SALES 241 AND 247

Proposed CPA Lease Sales 241 and 247 are tentatively scheduled to be held in March 2016 and 2017, 

respectively. The proposed CPA lease sale area encompasses about 63 million ac of the total CPA area of 

66.45 million ac. This area begins 3 nmi (3.5 mi; 5.6 km) offshore Louisiana, Mississippi, and Alabama, 

and extends seaward to the limits of the United States’ jurisdiction (often the Exclusive Economic Zone) 

in water depths up to approximately 3,346 m (10,978 ft) (Figure 1-1). As of September 2014, 

approximately 44.2 million ac of the proposed CPA lease sale area are currently unleased. This 

information is updated monthly and can be found on BOEM’s website at http://www.boem.gov/Gulf-ofMexico-Region-Lease-Map/. A CPA proposed action would offer for lease all unleased blocks within the 

proposed CPA lease sale area for oil and gas operations (Figure 2-1), with the following exceptions:

(1) whole and portions of blocks deferred by the Gulf of Mexico Energy Security Act of 

2006; and

(2) blocks that are adjacent to or beyond the United States’ Exclusive Economic Zone 

in the area known as the northern portion of the Eastern Gap.
4-4 Central and Eastern Planning Areas Supplemental EIS

The DOI is conservative throughout the NEPA process and includes the total area within the CPA for 

environmental review even though the leasing of portions of the CPA (subareas or blocks) can be deferred 

during a Five-Year Program.

Chapter 4.1.1 presents a brief summary of the baseline data for the physical, biological, and 

socioeconomic resources that would potentially be affected by a CPA proposed action or the alternatives. 

For additional information on the baseline data for the physical, biological, and socioeconomic resources 

that would potentially be affected by a CPA proposed action or the alternatives, refer to Chapter 4.2.1 of 

the 2012-2017 WPA/CPA Multisale EIS and to updated information provided in Chapter 4.2.1 of the 

WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1 of the WPA 235/241/247 Supplemental EIS.

Chapter 4.1.1 also presents analyses of the potential impacts of routine events, accidental events, and 

cumulative activities associated with a CPA proposed action or the alternatives on these resources. 

Baseline data are considered in the assessment of impacts from proposed CPA Lease Sales 241 and 247 

on these resources. In addition, Appendix B (“Catastrophic Spill Event Analysis”) serves as a 

complement to this chapter and provides additional analysis of the potential impacts of a low-probability 

catastrophic spill, which is not part of a CPA proposed action and not likely expected, to the 

environmental and cultural resources and the socioeconomic conditions analyzed below.

The Deepwater Horizon explosion off the Louisiana coast resulted in the largest oil spill in U.S. 

history. An event such as this has the potential to adversely affect multiple resources over a large area. 

The level of adverse effect depends on many factors, including the sensitivity of the resource as well as 

the sensitivity of the environment in which the resource is located. All effects may not initially be seen 

and some could take years to fully develop. The following analyses of impacts from the Deepwater 

Horizon explosion, oil spill, and response on the physical, biological, and socioeconomic resources are 

based on post-Deepwater Horizon credible scientific information that was publicly available at the time 

this document was prepared. This credible scientific information was applied using accepted 

methodologies, including numerical modeling of data and scientific writing methods to convey the 

information of BOEM’s subject-matter experts’ technical knowledge and experience. However, the 

Trustee Council of the NRDA for the Deepwater Horizon oil spill continues to study, measure, and 

interpret impacts arising out of that spill. Because the NRDA information has not yet been made 

available to BOEM or the general public, there are thus instances in which BOEM is faced with 

incomplete or unavailable information that may be relevant to evaluating reasonably foreseeable 

significant adverse impacts on the human environment. While incomplete or unavailable information 

could conceivably result in potential future shifts in baseline conditions of habitats that could affect 

BOEM’s decisionmaking, BOEM has determined that there is sufficient basis to proceed with this 

Supplemental EIS while operating on the basis of the most current available data and expertise of 

BOEM’s subject-matter experts.

Chapter 4.1.1 and Appendix B provide a summary of existing credible scientific evidence related to 

this issue and BOEM’s evaluation of potential impacts based upon theoretical approaches or research 

methods generally accepted in the scientific community. Despite the unavailability of complete 

information from the NRDA process, BOEM has determined that it can make an informed decision even 

without this incomplete or unavailable information because BOEM utilizes the best available 

scientifically credible information in its decisionmaking process and because, although BOEM cannot 

speculate as to the results of ongoing NRDA studies, BOEM experts can apply other scientifically 

credible information using accepted theoretical approaches and research methods, such as information on 

related or surrogate species. Moreover, BOEM will continue to monitor these resources for effects 

caused by the Deepwater Horizon explosion, oil spill, and response, and will ensure that future BOEM 

environmental reviews take into account any new information that may emerge. 

Chapter 3.2.1 of this Supplemental EIS provides a brief summary of the information on accidental 

spills that could result from all operations conducted under the OCS Program, as well as information on 

the number and sizes of spills from non-OCS sources. Table 3-12 of the 2012-2017 WPA/CPA Multisale 

EIS provides the number of spills ≥1,000 bbl and <1,000 bbl estimated to occur as a result of a CPA 

proposed action. BOEM estimates that the mean number of spills ≥1,000 bbl for a CPA proposed action 

is <1-1 spill. Table 3-12 of the 2012-2017 WPA/CPA Multisale EIS provides spill rates for several spillsize categories. Chapter 3.2.1.8 and Figures 3-8 through 3-28 of the 2012-2017 WPA/CPA Multisale EIS

describe the probabilities of a spill ≥1,000 bbl occurring and contacting modeled environmental 

resources. For additional information on accidental spills that could result from all operations conducted 

under the OCS Program, as well as information on the number and sizes of spills from non-OCS sources, 
Description of the Environment and Impact Analysis 4-5 

refer to Chapter 3.2.1 of this Supplemental EIS and Chapter 3.2.1 of the 2012-2017 WPA/CPA Multisale 

EIS and CPA 235/241/247 Supplemental EIS.

Analytical Approach

The analyses of potential effects to the wide variety of physical, environmental, and socioeconomic 

resources in the vast area of the GOM and adjacent coastal areas is very complex. Specialized education, 

experience, and technical knowledge are required, as well as familiarity with the numerous impactproducing factors associated with oil and gas activities and other activities that can cause cumulative 

impacts in the area. Knowledge and practical working experience of major environmental laws and 

regulations such as NEPA, the Clean Water Act, Clean Air Act, Coastal Zone Management Act (CZMA), 

Endangered Species Act (ESA), Marine Mammal Protection Act (MMPA), the Magnuson-Stevens 

Fishery Conservation and Management Act, and others are also required.

In order to accomplish this task, BOEM has assembled a multidisciplinary staff with hundreds of 

years of collective experience. The vast majority of this staff has advanced degrees with a high level of 

knowledge related to the particular resources discussed in this chapter. This staff prepares the input to 

BOEM’s lease sale EISs and a variety of subsequent postlease NEPA reviews, and they are also involved 

with ESA, essential fish habitat (EFH), and CZMA consultations. In addition, this same staff is also 

directly involved with the development of studies conducted by BOEM’s Environmental Studies

Program. The results of these studies feed directly into our NEPA analyses.

For this Supplemental EIS, BOEM developed a set of assumptions and a scenario, and described the 

impact-producing factors that could occur from routine oil and gas activities, as well as accidental events. 

These assumptions, scenario, and factors are summarized in Chapter 3 of this Supplemental EIS and are 

discussed in detail in Chapter 3 of the 2012-2017 WPA/CPA Multisale EIS. On the basis of these 

assumptions, scenario, and factors, BOEM’s multidisciplinary staff applies its knowledge and experience 

to analyze the potential effects that could arise out of proposed CPA Lease Sales 241 and 247.

For most resources, the conclusions developed by BOEM’s subject-matter experts regarding the 

potential effects of proposed CPA Lease Sales 241 and 247 are necessarily qualitative in nature; however, 

these conclusions are based on the expert opinion and judgment of highly trained subject-matter experts. 

BOEM’s staff approaches this effort in good faith utilizing credible scientific information including, but 

not limited to, information available since the Deepwater Horizon explosion, oil spill, and response, and 

applying this information using accepted methodologies, including numerical modeling of data and 

scientific writing methods to convey the information of the subject-matter experts’ technical knowledge 

and experience. It must also be emphasized that, in arriving at the overall conclusions for certain 

environmental resources (e.g., coastal and marine birds, fisheries, and wetlands), the conclusions are not 

based on impacts to individuals, small groups of animals, or small areas of habitat, but on impacts to the 

resources/populations as a whole. Where relevant information on reasonably foreseeable significant 

adverse impacts is incomplete or unavailable, the need for the information was evaluated to determine if it 

was essential to a reasoned choice among the alternatives. If BOEM’s subject-matter experts determined 

that the incomplete or unavailable information was essential, BOEM made good faith efforts to acquire 

the information. In the event that BOEM was unable to obtain essential information due to either 

impossibility or exorbitant cost, BOEM applied accepted scientific methodologies in place of that 

information. This approach is described in the next subsection on “Incomplete or Unavailable 

Information.”

Over the years, BOEM has developed a suite of lease stipulations and mitigating measures to 

eliminate or ameliorate potential environmental effects. In many instances, these lease stipulations and 

mitigating measures were developed in coordination with other natural resource agencies such as NMFS 

and FWS.

Throughout its effort to prepare this Supplemental EIS, BOEM has made painstaking efforts to 

comply with the spirit and intent of NEPA, to avoid being arbitrary and capricious in its analyses of 

potential environmental effects, and to use adaptive management to respond to new developments related 

to the OCS Program.
4-6 Central and Eastern Planning Areas Supplemental EIS

Incomplete or Unavailable Information

In the following analyses of physical, environmental, and socioeconomic resources, BOEM identifies 

situations in which its analysis contains incomplete or unavailable information. The major area where 

BOEM is faced with incomplete or unavailable information is in relation to the Deepwater Horizon

explosion, oil spill, and response. Information related to the explosion, oil spill, and response is still 

being collected, interpreted, and analyzed by a myriad of Federal and State agencies. With respect to 

some of this information, including much of the data related to the NRDA process, those in charge of 

analyzing impacts from the spill have not yet shared their data and findings with BOEM or made this 

information publicly available. Therefore, in situations in which BOEM’s subject-matter experts were 

faced with incomplete or unavailable information, the subject-matter experts for each resource utilized the 

most recent publicly available, scientifically credible information from other sources to support the 

conclusions contained in this Supplemental EIS. This information is identified and summarized in 

Chapter 4.1.1 of this Supplemental EIS and is discussed in detail for each resource in Chapter 4.2.1 of 

the 2012-2017 WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1 of the WPA 

233/CPA 231 Supplemental EIS and Chapter 4.1.1 of the CPA 235/241/247 Supplemental EIS. In certain 

circumstances, identified and described in more detail in Chapter 4.1.1 of this Supplemental EIS, 

BOEM’s subject-matter experts were required to utilize accepted methodologies to extrapolate 

conclusions from existing or new information and to make reasoned estimates and developed conclusions 

regarding the current CPA baseline for resource categories and expected impacts from a CPA proposed 

action given any baseline changes. For reasons described below, there are no changes to the conclusions 

presented in the 2012-2017 WPA\CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS.

It is important to note that, barring another catastrophic oil spill, which is a low-probability accidental 

event, the adverse impacts associated with a proposed CPA lease sale are small, even in light of the 

Deepwater Horizon explosion, oil spill, and response. This is because of draft lease sale stipulations and 

because of BOEM’s and other Federal and State entities’ mitigating measures. BOEM also imposes sitespecific mitigations that become conditions of plan or permit approval at the postlease stage. 

Collectively, these measures further reduce the likelihood of adverse impacts. 

For the following resources, as with the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS, the subject-matter experts determined that 

there is incomplete or unavailable information that is relevant to reasonably foreseeable significant 

adverse impacts; however, it is not essential to a reasoned choice among alternatives.

• Physical Resources in the CPA: Physical resources (i.e., water quality and air 

quality) within the CPA are likely not continuing to be affected to any discernible 

degree by the Deepwater Horizon explosion, oil spill, and response, based on the best 

available information, including recent sampling data. Although unable to speculate 

as to the results of ongoing NRDA studies, BOEM has determined that the 

incomplete or unavailable information is not essential to a reasoned choice among 

alternatives because BOEM utilizes the best available scientifically credible 

information in its decisionmaking process. Much of the information related to the 

Deepwater Horizon explosion, oil spill, and response may not be available for some 

time, regardless of the costs necessary to obtain this information, as there are 

numerous task forces and interagency groups involved in the production of the 

information. It is not expected that these data would become publicly available in the 

near term, and certainly not within the timeline contemplated in the NEPA analysis 

of this Supplemental EIS.

• Nonmobile Biological Resources within the CPA: Coastal and offshore biological 

and benthic habitats (i.e., barrier beaches, wetlands, seagrasses, soft bottom benthic 

communities, topographic features, and chemosynthetic and nonchemosynthetic 

communities) and nonmobile benthic species that would be expected to spend their 

entire life cycle in the CPA were likely not affected to any discernible degree by the 

Deepwater Horizon explosion, oil spill, and response, based on the best available 

information, including recent sampling data. Similarly to the analysis of physical 
Description of the Environment and Impact Analysis 4-7 

resources in the CPA described in the preceding paragraph, although unable to 

speculate as to the results of ongoing NRDA studies, BOEM has determined that the 

incomplete or unavailable information regarding nonmobile biological resources is 

not essential to a reasoned choice among alternatives because BOEM utilizes the best 

available scientifically credible information in its decisionmaking process.

• Mobile Biological Resources within or Migrating through the CPA: Certain mobile 

biological resources (i.e., birds, fish, marine mammals, and sea turtles) having ranges 

and/or habitats that may include different areas in the GOM may have individually 

been affected by exposure to oil and/or spill-response activities, provided they were 

in the vicinity of the Deepwater Horizon explosion, oil spill, and response during 

spill conditions. Precise information on the impacts on mobile biological resources 

within or migrating through the CPA is therefore not known, and it is not expected 

that these data would become publicly available within the timeline contemplated in 

the NEPA analysis of this Supplemental EIS. Although unable to speculate as to the 

results of ongoing NRDA studies, BOEM has determined that the incomplete or 

unavailable information is not essential to a reasoned choice among the alternatives 

because the adverse impacts from routine activities associated with a CPA proposed 

action are expected to be small, even in light of how baseline conditions may have 

been changed by the Deepwater Horizon explosion, oil spill, and response. 

Moreover, based on the scientifically credible information that was available and 

applied in Chapter 4.1.1, such as peer-reviewed journals and government reports, 

this incomplete or unavailable information is not essential to a reasoned choice 

among the alternatives because the subject-matter experts for this Supplemental EIS 

have already evaluated the probability and severity of these potential impacts and 

because this incomplete or unavailable information is not essential to understand 

every particular mechanism by which these significant impacts could occur. With 

regard to future potentially low-probability catastrophic spills, any incomplete or 

unavailable information regarding the nature of a very large spill would not be 

essential to a reasoned choice among the alternatives. This is because a catastrophic 

spill and its impacts are not “expected” as a result of a CPA proposed action since 

such a spill remains a low-probability event, particularly in light of improved safety 

and oil-spill-response requirements that have been put in place since the spill.

• Endangered and Threatened Species: BOEM reinitiated consultation with NMFS 

and FWS in light of new information that may become available on these species and 

in light of effects from the Deepwater Horizon explosion, oil spill, and response. 

Pending the completion of the reinitiated ESA section 7 consultation, BOEM has 

prepared an ESA section 7(d) determination (50 CFR § 402.09). Section 7(d) of the 

ESA requires that, after initiation or reinitiation of consultation under section 7(a)(2), 

the Federal agency “shall not make any irreversible or irretrievable commitment of 

resources with respect to the agency action which has the effect of foreclosing the 

formulation or implementation of any reasonable and prudent alternative measures 

which would not violate” section 7(a)(2). BOEM has determined that a CPA 

proposed action during the reinitiated section 7 consultation period is consistent with 

the requirements of ESA section 7(d) because (1) approving and/or conducting a 

proposed CPA lease sale will not foreclose the formulation or implementation of any 

Reasonable and Prudent Alternative measures that may be necessary to avoid 

jeopardy (or the likely destruction or adverse modification of critical habitat) and 

(2) the Secretary of the Interior retains the discretion under OCSLA to deny, suspend, 

or rescind plans and permits authorized under OCSLA at any time, as necessary to 

avoid jeopardy. Lease sales alone do not constitute an irreversible and irretrievable 

commitment of resources. In addition, the results of consultation and any additional 

relevant information on endangered and threatened species can be employed during 

postlease activities to ensure that Reasonable and Prudent Alternative measures are 

not foreclosed. BOEM and BSEE have developed an interim coordination program 

with NMFS and FWS for individual consultations on postlease activities requiring 
4-8 Central and Eastern Planning Areas Supplemental EIS

permits or plan approvals while formal consultation and development of a new 

Biological Opinion is ongoing.

• Natural Resource Damage Assessment (NRDA) Data: In response to the Deepwater

Horizon explosion, oil spill, and response, a major NRDA is underway to assess 

impacts to all natural resources in the GOM that may have been impacted by the 

resulting spill from the Macondo well, as well as impacts from the spill-response 

operations. The NRDA is mandated by the Oil Pollution Act of 1990. The U.S. 

Department of the Interior is a co-Trustee in the NRDA process, and BOEM is a 

cooperating agency on a Programmatic EIS being prepared as part of the NEPA

analysis for NRDA. However, the NRDA process is being led by the NRDA 

Trustees, which include NOAA and DOI (FWS and the National Park Service), but 

not BOEM. BOEM is listed as an affected party for NRDA purposes. At this time, 

limited data compiled in the NRDA process have been made publicly available. 

Because limited data have been made publicly available, most NRDA datasets are not 

available for BOEM to use in its NEPA analyses. BOEM acknowledges that the 

ability to obtain and use the NRDA data in its NEPA analyses could be relevant to 

reasonably foreseeable significant adverse impacts; however, the NRDA data are not 

essential to a reasoned choice among the alternatives. Impacts identified through the 

NRDA process would likely be the same under any alternative and obtaining these 

data would not help inform the decisionmaker on a reasoned choice among those 

alternatives. This is because, as discussed above, the adverse impacts associated with 

a proposed CPA lease sale are small, even in light of how baseline conditions in the 

CPA may have been changed by the Deepwater Horizon explosion, oil spill, and 

response. The impacts are expected to be small because of BOEM’s lease sale 

stipulations and mitigating measures, site-specific mitigations that become conditions 

of plan or permit approval at the postlease stage, and mitigations required by other 

State and Federal agencies. Even if the NRDA data were essential to a reasoned 

choice among the alternatives, it is not publicly available and much of the data may 

not become available for many years. The NEPA allows for decisions to be made

based on available scientifically credible information (peer-reviewed journals and 

studies, government reports, etc.) applied using accepted methodologies where the 

incomplete information cannot be obtained or the cost of obtaining it is exorbitant. 

The NRDA process is ongoing and there is no timeline on when this information will 

be released. It is not within BOEM’s authority to obtain this information. Cost is not 

an issue in obtaining the information, regardless of whether the cost would be 

exorbitant or not. Instead, the limitations on the NRDA process, including statutory 

requirements under the Oil Pollution Act of 1990, are the determining factors on the 

availability of this information. In light of the fact that the NRDA data may not be 

available for years, BOEM has used accepted scientific methodologies to evaluate 

each resource, as described in this chapter. Since the spill, BOEM’s Gulf of Mexico 

OCS Region’s Environmental Studies Program has continually modified its Studies 

Plan to reflect the Agency’s current information needs for studies that address 

impacts and recovery from the oil spill. The scientific studies conducted by the 

Environmental Studies Program provide some of the data that BOEM relies on in 

making decisions in this Supplemental EIS. BOEM’s proposed studies attempt to 

avoid duplication of study efforts while striving to fill information gaps where 

NRDA studies may not address particular resources and their impacts from the oil 

spill.

• Socioeconomic and Cultural Resources: Incomplete or unavailable information 

related to socioeconomic and cultural impacts (i.e., commercial and recreational 

fishing, recreational resources, archaeological resources, land use and coastal 

infrastructure, demographics, economic factors, and environmental justice) may be 

relevant to reasonably foreseeable adverse impacts on these resources. Although 

unable to speculate as to the results of ongoing NRDA studies, BOEM has 

determined that the incomplete or unavailable information would not be essential to a 
Description of the Environment and Impact Analysis 4-9 

reasoned choice among alternatives because BOEM utilizes the best available 

scientifically credible information in its decisionmaking process.

This chapter has thoroughly examined the existing credible scientific evidence that is relevant to 

evaluating the reasonably foreseeable significant adverse impacts of the proposed CPA lease sales on the 

human environment. The subject-matter experts that prepared this Supplemental EIS conducted a diligent 

search for pertinent new information, and BOEM’s evaluation of such impacts is based upon theoretical 

approaches or research methods generally accepted in the scientific community. All reasonably 

foreseeable impacts were considered, including impacts that could have catastrophic consequences, even 

if their probability of occurrence is low (Appendix B). Throughout this chapter, where information was 

incomplete or unavailable, BOEM complied with its obligations under NEPA to determine if the 

information was relevant to reasonably foreseeable significant adverse impacts; if so, whether it was 

essential to a reasoned choice among alternatives; and, if it is essential, whether it can be obtained and 

whether the cost of obtaining the information is exorbitant, as well as whether generally accepted 

scientific methodologies can be applied in its place (40 CFR § 1502.22).

4.1.1. Alternative A—The Proposed Action

4.1.1.1. Air Quality

BOEM has reexamined the analysis for air quality presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented below. No new significant information was discovered that would alter 

the impact conclusion for air quality presented in those NEPA documents. The analysis and potential 

impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.1 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.1 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.1 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The following routine activities associated with a CPA proposed action would potentially affect air 

quality: platform construction and emplacement; platform operations; drilling activities; flaring; seismicsurvey and support-vessel operations; pipeline laying and burial operations; evaporation of volatile 

petroleum hydrocarbons during transfers; and fugitive emissions. The impact analysis is based on four 

parameters—emission rates, surface winds, atmospheric stability, and mixing height. Emissions of 

pollutants into the atmosphere from the activities associated with the CPA proposed action are projected 

to have minimal effects on onshore air quality because of the prevailing atmospheric conditions, emission 

rates and mixing heights, and the resulting pollutant concentrations.

The accidental release of hydrocarbons related to a CPA proposed action would result in the emission 

of air pollutants. The OCS oil- and gas-related accidents could include the release of oil, condensate, 

natural gas, and chemicals used offshore, or pollutants from the burning of these products. The air 

pollutants include criteria NAAQS pollutants, volatile and semi-volatile organic compounds, H2S, and 

methane. If a fire was associated with the accidental event, it would produce a broad array of pollutants, 

including NAAQS-regulated primary pollutants, nitrogen dioxide (NO2), carbon monoxide (CO), sulphur 

dioxide (SO2), volatile organic compounds (VOCs), particulate matter less than or equal to 10 μm (PM10), 

and particulate matter less than or equal to 2.5 μm (PM2.5). Response activities to an accidental event that 

could impact air quality include in-situ burning, the use of flares to burn gas and oil, and the use of 

dispersants applied from aircraft. Measurements taken during an in-situ burning show that a major 

portion of compounds was consumed in the burn (Fingas et al., 1995), and it was found that, during the 

burn, the pollutants were measured only at background levels; therefore, pollutant concentrations would 

be expected to be within the NAAQS. Accidents involving high concentrations of H2S could result in 
4-10 Central and Eastern Planning Areas Supplemental EIS

deaths as well as environmental damage. Regulations and NTLs include safeguards and protective 

measures, which are in place to protect workers from H2S releases. Other emissions of pollutants into the 

atmosphere from accidental events as a result of a CPA proposed action are not projected to have 

significant impacts on onshore air quality because of the prevailing atmospheric conditions, emissions 

height, emission rates, and the distance of these emissions from the coastline.

Cumulative Impacts

The cumulative analysis considers OCS oil- and gas-related and non-OCS oil- and gas-related 

activities that could occur and adversely affect onshore air quality from OCS oil- and gas-related sources 

during the 40-year analysis period. The OCS oil- and gas-related activities that could impact air quality 

include the following: platform construction and emplacement; platform operations; drilling activities; 

flaring; seismic-survey and support-vessel operations; pipeline laying and burial operations; evaporation 

of volatile petroleum hydrocarbons during transfers; fugitive emissions; the release of oil, condensate, 

natural gas, and chemicals used offshore, or pollutants from the burning of these products; blowouts; a 

low-probability catastrophic spill, which is not part of a CPA proposed action and not likely expected

(refer to Appendix B for more details); and fires. Emissions of pollutants into the atmosphere from 

activities associated with the OCS Program are not projected to have significant effects on onshore air 

quality because of the prevailing atmospheric conditions, emission rates and heights, and the resulting 

pollutant concentrations, which result in dilution of the emissions offshore before they reach the 

shoreline. In the CPA, the impacts of the OCS oil- and gas-related emissions on the onshore air quality 

are annual NO2 (0.4μ/m3

) and 24-hour PM2.5 (0.3μ/m3) in the Class I area, which exceed the USEPA’s 

Significant Impact Levels (SILs) for annual NO2 (0.1μ/m3

) and 24-hour PM2.5 (0.07μ/m3) in the Class I 

area. However, onshore impacts on air quality from emissions from OCS oil- and gas-related activities 

are estimated to be within the Prevention of Significant Deterioration (PSD) Class II allowable 

increments. The background concentration and impact concentration are below the NAAQS. The only 

potential exception is for ozone, where there may be some minimal contribution to ozone at the shoreline.

Non-OCS oil- and gas-related activity includes both marine and onshore industries and activities that 

are unrelated to oil and gas exploration and production. The non-OCS oil- and gas-related activities in the 

cumulative scenario that could potentially impact onshore air quality include the following: State oil and 

gas programs; other major offshore but non-OCS oil- and gas-related factors influencing offshore 

environments (such as sand borrowing and transportation); onshore non-OCS oil- and gas-related 

activities such as emissions from industry (including major stationary sources, e.g., power plants, 

petroleum refineries and chemical plants) and mobile sources (cars/trucks) related to human activities; 

onshore non-OCS oil- and gas-related sources unrelated to human activities such as forest fires; accidental 

releases from an oil spill; accidental releases of hydrogen sulfide; and natural events (e.g., hurricanes). 

The non-OCS oil- and gas-related activity on the water that would most likely contribute to cumulative 

impacts to air quality would be the marine shipping or transportation industry. Industrial activity in the 

industrial areas of Louisiana, Mississippi, and Alabama and emissions from cars in areas with high 

populations are the onshore sources that would contribute to the cumulative impact to air quality. These 

offshore and onshore emissions sources generate greater amounts of pollutants than OCS oil- and gasrelated activities. Human populations reside near these same industries because they offer employment, 

and therefore humans encounter more air contaminants as a result of non-OCS oil- and gas-related 

activities than they do from the OCS Program. These non-OCS oil- and gas-related sources would 

represent the majority of the cumulative emissions that are present at onshore locations.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS

A search of State and Federal databases, including updates to regulations, was conducted to determine 

the availability of recent information. It has been discovered that Birmingham, Alabama, is no longer in 

nonattainment for any NAAQS criteria pollutant.

The search revealed new information on the hydrofracking of oil onshore and intercontinental sources 

of fine particles in the atmosphere since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. This information is pertinent 
Description of the Environment and Impact Analysis 4-11

to this Supplemental EIS because it details new information on non-OCS oil- and gas-related impacts to 

the environment.

New information indicates that intercontinental dust transport may have impacts on air quality. For 

example, dust from Central America has been found in the Texas atmosphere. Fine particulates (PM2.5), 

such as ammonium sulfate, can be suspended in the atmosphere and can impair visibility and adversely 

affect human health. Once in the atmosphere, these fine particulates can be transported for long 

distances. It has been observed that a substantial amount of the fine particulates observed in Texas comes 

from Mexico and Central America, and enters into the United States across Texas’ southern border. As a 

result, it reduces the visibility at Big Bend and Guadalupe Mountains National Parks, both Class I 

(pristine with respect to visibility) areas. The results of air dispersion modeling indicate that as much as 

half of the visibility impairment (occurring on 20% of the most visibility impaired days) at Big Bend 

comes from international transport (Texas Commission on Environmental Quality, 2014). These results 

indicate that an increase in visibility impairment in Texas is likely due to international transport of dust 

rather than OCS oil- and gas-related emission sources. The trade winds have an east-to-west direction 

and the concentration of PM2.5 in Texas is lower than at the source of origin. Because of the long 

distances that can be covered, intercontinental dust may affect other regions of the Gulf Coast, including 

those of the CPA.

New information indicates that hydrofracking of oil may also cause potential health and 

environmental effects. Some of the pollutants released by hydrofracking include benzene, toluene, xylene 

and ethyl benzene (BTEX); particulate matter and dust; ground-level ozone; nitrogen oxides; carbon 

monoxide; formaldehyde; and metals contained in diesel fuel combustion. These pollutants can travel in 

the atmosphere. The exposure to these chemicals could cause short-term effects to human health and the 

environment (Climate Science Watch, 2014). This information indicates that hydrofracking may result in 

more impacts to human health and the environment onshore than offshore OCS oil- and gas-related 

activities. The Offshore and Coastal Dispersion modeling results, which are discussed in Appendix A of 

the CPA 235/241/247 Supplemental EIS and which are incorporated by reference here, indicate that 

typical operations on the OCS do not generate pollutants in an amount that would significantly impact or 

significantly contribute to air quality degradation and that the same applies to emissions that are generated 

from isolated events (e.g., accidents, which are temporary sources).

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. However, as discussed in this Supplemental EIS and in Chapter 4.2.1.1 of the 

2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, and Chapter 4.1.1.1 of 

the CPA 235/241/247 Supplemental EIS, BOEM has identified unavailable information regarding air 

quality impacts related to the Deepwater Horizon explosion, oil spill, and response in the CPA. This 

information cannot be obtained because the means to obtain it are not known. This unavailable 

information may be relevant to adverse effects because air emissions could have reached land or 

dispersed throughout the WPA/CPA before the oil-spill response was activated. BOEM utilized relevant 

analysis such as air emissions measurements taken by Federal agencies to determine air impacts. For 

example, a large number of air emissions measurements were obtained and released to the public by 

USEPA, the National Oceanic and Atmospheric Administration, and other agencies, indicating that air 

emissions impacts tended to be minor and below USEPA’s health-based standards. And, since there are 

no continuing sources of air pollution related to the Deepwater Horizon explosion, oil spill, and response, 

BOEM would not expect any additional measurements or information to alter the conclusions from 

currently existing data.

In addition, as noted in Appendix A of the CPA 235/241/247 Supplemental EIS, there are a number 

of competing methods and available models for estimating and tracking potential air emissions and 

impacts. Each of these methods and models has inherent limitations, particularly with regard to the 

offshore environment in which a CPA proposed action would take place. BOEM’s Offshore and Coastal 

Dispersion Model, which was used for this environmental impact assessment (Appendix A of the CPA 

235/241/247 Supplemental EIS), has limitations such that it is a short-range dispersion model and it does 

not involve the reactive chemical. In acknowledgement of these limitations, BOEM’s subject-matter 
4-12 Central and Eastern Planning Areas Supplemental EIS

experts, using their best professional judgment and experience, have developed conservative assumptions 

and modeling parameters so as to ensure that the impact conclusions herein are reasonable and not 

underestimated (refer to Appendix A of the CPA 235/241/247 Supplemental EIS for the modeling

analysis). The modeling that was conducted was overly conservative. All of the emissions during 1 year 

for the entire CPA, which would actually be dispersed throughout the CPA, were modeled as if they 

originated in a single block, i.e., Mississippi Canyon Block 856. This block was selected because it 

represented a location where the water is deep enough that a dynamically positioned drillship would be 

used and where hydrocarbons are probably present. Although there are limitations in air quality 

modeling, the evidence currently available and that was used to develop conservative assumptions 

supports past analyses and does not indicate severe adverse impacts to air quality.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing the relevant analysis and formulating the conclusions presented here. Although there is 

incomplete or unavailable information, the evidence currently available supports past analyses and does 

not indicate reasonably foreseeable significant adverse impacts. Therefore, BOEM has determined that 

this information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for air quality presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented above. No new significant information was discovered that would alter 

the impact conclusion for air quality presented in those NEPA documents because of the available 

scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. Emissions of pollutants into the atmosphere from the routine activities and accidental events 

associated with the CPA proposed action are projected to have minimal impacts to onshore air quality, 

and emissions of pollutants into the atmosphere from activities associated with the OCS Program are also 

not projected to have significant effects on onshore air quality. The non-OCS oil- and gas-related 

emission sources of intercontinental origin and the hydrofracking of oil may have the potential to impact 

onshore air quality and human health. However, the new information does not alter previous impact 

conclusions for air quality. The analysis and potential impacts discussed in the previously mentioned 

NEPA documents still apply for proposed CPA Lease Sales 241 and 247.

4.1.1.2. Water Quality

4.1.1.2.1. Coastal Waters

BOEM has reexamined the analysis for coastal water quality presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA Lease Sales 235/241/247 Supplemental 

EIS based on the additional information presented below. No new significant information was discovered 

that would alter the impact conclusion for coastal water quality presented in those NEPA documents. The 

analysis and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 

and 247.

Coastal waters within the CPA, as defined by BOEM, include all the bays and estuaries from the 

Louisiana/Texas State border to the Alabama/Florida State border. A detailed description of the affected 

environment and the full analyses of the potential impacts of routine activities, accidental events, and 

cumulative impacts associated with a CPA proposed action are presented in Chapter 4.2.1.2.1 of the 

2012-2017 WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.2.1 of the WPA 

233/CPA 231 Supplemental EIS and Chapter 4.1.1.2.1 of the CPA 235/241/247 Supplemental EIS. The 

following information is a summary of the resource description and impact analysis incorporated from 

those NEPA documents. Any new information that has become available since those documents were 

published is presented below.

Impacts of Routine Activities and Accidental Events

The routine activities associated with a CPA proposed action that would impact coastal water quality

include the following:
Description of the Environment and Impact Analysis 4-13

• discharges during drilling of exploration and development wells;

• structure installation and removal;

• discharges during production;

• installation of pipelines; 

• workovers of wells,

• maintenance dredging of existing navigational canals;

• service-vessel discharges; and

• nonpoint-source runoff from platforms and OCS Program-related vessels.

The primary impacting sources to water quality in coastal waters from oil and gas exploration and 

production activities are point-source and storm-water discharges from support facilities, vessel 

discharges, and nonpoint-source runoff. These activities are not only highly regulated but also localized 

and temporary in nature. The impacts to coastal water quality from routine activities associated with the 

CPA proposed actions should be minimal because of the distance to shore of most routine activities, 

USEPA and USCG regulations that restrict discharges, and few, if any, new pipeline landfalls or onshore 

facilities that would be constructed.

Accidental events resulting from a CPA proposed action, including oil spills and blowouts, have the 

potential to alter and degrade coastal waters through the increase of petroleum hydrocarbons and their 

various transformation/degradation products in the water.

Accidental events associated with a CPA proposed action that could impact coastal water quality

include spills of oil and refined hydrocarbons, releases of natural gas, spills of chemicals or drilling fluids, 

loss of well control, pipeline failures, collisions, or other malfunctions that would result in such spills. In 

the case of an accidental event, it is likely that response efforts would reduce the amount of oil. Although 

response efforts may decrease the amount of oil in the environment, the response efforts may also impact 

the environment. Increased vessel traffic, hydromodification (e.g., dredging, berm building, boom 

deployment, etc.), and the addition of dispersants and methanol to the marine environment in an effort to 

contain, mitigate, or clean up the oil may also tax the environment. Chapter 3.2.1.9 provides further 

discussion of oil-spill response considerations. A major hurricane can affect OCS oil- and gas-related 

activities and result in a greater number of coastal oil and chemical spill events with increased spill 

volume and oil-spill response times.

In addition to response efforts, natural processes can physically, chemically, and biologically degrade 

oil over time. For coastal spills, two additional factors that must be considered are the shallowness of the 

area and the proximity of the spill to shore. Chemicals used in the oil and gas industry are not a 

significant risk in the event of a spill because they are either nontoxic, are used in minor quantities, or are 

only used on a noncontinuous basis. Spills from collisions are not expected to be significant because 

collisions occur infrequently.

Cumulative Impacts

Coastal waters are vulnerable to impacts from OCS oil- and gas-related activities including erosion 

and runoff, sediment disturbance and turbidity, vessel discharges, and accidental releases of oil, gas, or 

chemicals. Increased turbidity and discharge from a CPA proposed action would be temporary in nature 

and minimized by regulations and mitigation. Since a catastrophic OCS Program-related accident would 

be rare and not expected to occur in coastal waters, the impact of accidental spills is expected to be small. 

A low-probability catastrophic spill, which is not part of a CPA proposed action and not likely expected,

is discussed in Appendix B. 

Coastal waters are vulnerable to impacts from non-OCS oil- and gas-related activities or activities not 

related to a CPA proposed action or the OCS Program, including State oil and gas activities, alternative 

energy activities, alternate use programs for platforms (e.g., aquaculture), sand borrowing, the activities 

of other Federal agencies (including the military), natural events or processes, and activities related to the 

direct or indirect use of land and waterways by the human population. These activities may result in 
4-14 Central and Eastern Planning Areas Supplemental EIS

erosion and runoff, sediment disturbance and turbidity, vessel discharges, and accidental releases of oil, 

gas, or chemicals.

The impacts resulting from a CPA proposed action are a small addition to the cumulative impacts on 

the coastal waters of the Gulf of Mexico because non-OCS oil- and gas-related activities, including vessel 

traffic, erosion, and nonpoint source runoff, are cumulatively responsible for a majority of coastal water

impacts. The incremental contribution of the routine activities and accidental events associated with a 

CPA proposed action to the cumulative impacts on coastal water quality is not expected to be significant 

for the reasons identified above.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

Various Internet sources were examined and literature searches conducted in order to assess the 

availability of new information regarding the water quality and sediment quality in coastal waters that 

may be pertinent to a CPA proposed action. The searches included, but were not limited to, Google, 

Google Scholar, several USEPA websites, and the NOAA Central Library Deepwater Horizon: A 

Preliminary Bibliography of Published Research and Expert Commentary website. New information was 

found on the affected environment after the Deepwater Horizon explosion, oil spill, and response. The 

following summary discusses new research regarding the distribution of hydrocarbons from the 

Deepwater Horizon release and biological degradation processes that have been found in the presence of 

the hydrocarbons.

Liu and Liu (2013) investigated bacterial communities present in oil mousses collected from impacted 

salt marshes during the Deepwater Horizon explosion, oil spill, and response. Vibrio bacteria, a human 

pathogen, represented 57 percent of the community, suggesting that this indigenous genus is particularly 

responsive to weathered oil in the salt marshes (for more information on salt marshes, refer to Chapter 

4.1.1.4). Tao et al. (2011) found high numbers of Vibrio vulnificus in surface residual balls (also called 

tarballs) composed of weathered oil from the Deepwater Horizon oil spill. A study by Stephens et al. 

(2013) found that levels of Vibrio vulnificus were higher after the Deepwater Horizon explosion, oil spill, 

and response. They state that vibrios are found naturally in the marine environment and prefer brackish 

water (e.g., 5-10 parts per thousand salinity for Vibrio vulnificus and 17-23 parts per thousand salinity for 

Vibrio parahaemolyticus). However, a study by Smith et al. (2012) found that Vibrio parahaemolyticus

did not grow on or oxidize naphthalene or phenanthrene, and a degradation product of naphthalene was 

found to inhibit growth.

Sammarco et al. (2013) examined the geographic extent of petroleum hydrocarbon contamination in 

sediment and seawater during and after the Deepwater Horizon explosion, oil spill, and response. 

Concentrations of total petroleum hydrocarbon (TPH), polycyclic aromatic hydrocarbons (PAHs), and 

12 compound classes (subsets of PAHs) were examined in samples from these media. Sediment TPH, 

PAHs, and all compound classes peaked near Pensacola, Florida, and Galveston, Texas. Seawater TPH 

peaked off Pensacola, Florida, and all compound classes peaked in seawater off the Mississippi River in 

Louisiana and Galveston. Wilson et al. (2014) critiqued the paper by Sammarco et al. (2013), focusing on 

matters including sampling strategy and methods, analytical methods, and data analysis; Sammarco et al. 

(2014) subsequently responded to the critique. None of the comments from Wilson et al. (2014) changed 

the Sammarco et al. (2013) conclusions regarding petroleum distribution. As further evidence of the 

petroleum distribution observed by Sammarco et al. (2013), tar mats continue to wash up on beaches off 

Pensacola, Florida. As of June 26, 2014, up to 1,526 pounds of tar material (i.e., oil, sand, shell, and 

water mixture) had been collected at Fort Pickens beach on Santa Rosa Island, Florida; this was 

performed with USCG oversight and was documented in the Pensacola News Journal (2014a). As of 

July 16, 2014, the total amount of tar material recovered had increased to 1,738 pounds (Murphy, official 

communication, 2014).

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.2.1 of the 2012-
Description of the Environment and Impact Analysis 4-15

2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.2.1 of the 

CPA 235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information that 

may be relevant to reasonably foreseeable impacts on coastal water quality. Much of this information 

relates to the Deepwater Horizon explosion, oil spill, and response and is continuing to be collected and 

developed through the NRDA process. BOEM used reasonably accepted scientific methodologies to 

extrapolate from existing information in completing this analysis and formulating the conclusions 

presented here. Given the available data on coastal sediments and water quality that have been released 

and evaluated, as described above and in Chapter 4.2.1.2.1 of the 2012-2017 WPA/CPA Multisale EIS 

and WPA 233/CPA 231 Supplemental EIS, and as noted in Chapter 4.1.1.2.1 of the CPA 235/241/247 

Supplemental EIS, water and sediment quality within the CPA were likely not affected to any discernible 

degree by the Deepwater Horizon explosion, oil spill, and response. Therefore, BOEM believes that this 

incomplete or unavailable information is not essential to a reasoned choice among alternatives for the 

reasons stated herein and in the previously mentioned NEPA documents.

Summary and Conclusion

BOEM has reexamined the analysis for coastal waters presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for coastal waters presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.2.2. Offshore Waters

Offshore waters within the CPA, as defined by BOEM, include Louisiana, Mississippi, and Alabama 

offshore waters and Federal OCS waters, which includes everything outside any barrier islands to the 

Exclusive Economic Zone.

BOEM has reexamined the analysis for offshore water quality presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for offshore water quality presented in those NEPA documents. The analysis 

and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 

247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.2.2 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.2.2 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.2.2 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The routine activities associated with a CPA proposed action that would impact offshore water 

quality include the following:

• discharges during drilling of exploration and development wells;

• structure installation and removal;

• discharges during production;

• installation of pipelines; 

• workovers of wells;
4-16 Central and Eastern Planning Areas Supplemental EIS

• maintenance dredging of existing navigational canals;

• service-vessel discharges; and

• nonpoint-source runoff from platforms and OCS Program-related vessels.

During exploratory activities, the primary impacting sources to offshore water quality are discharges

of drilling fluids and cuttings. During platform installation and removal activities, the primary impacting 

sources to water quality are sediment disturbance and temporarily increased turbidity. Impacting 

discharges during production activities are produced water and supply-vessel discharges. Regulations are 

in place to limit the toxicity of the discharge components, the levels of incidental contaminants in these 

discharges, and, in some cases, the discharge rates and discharge locations. Pipeline installation can also 

affect water quality by sediment disturbance and increased turbidity. Service-vessel discharges might 

include water with an oil concentration of approximately 15 ppm as established by USEPA regulatory 

standards. Any disturbance of the seafloor would increase turbidity in the surrounding water, but the 

increased turbidity should be temporary and restricted to the area near the disturbance. There are multiple 

Federal regulations and permit requirements that would decrease the magnitude of these activities. 

Impacts to offshore waters from routine activities associated with a CPA proposed action should be 

minimal as long as regulatory requirements are followed.

Accidental events associated with a CPA proposed action that could impact offshore water quality

include spills of oil and refined hydrocarbons, releases of natural gas and condensate, spills of chemicals 

or drilling fluids, loss of well control, pipeline failures, collisions, or other malfunctions that would result 

in such spills. Spills from collisions are not expected to be significant. Overall, since major losses of 

well control and blowouts are rare events, the potential impacts to offshore water quality are not expected 

to be significant except in the rare case of a catastrophic event. Although response efforts may decrease 

the amount of oil in the environment, the response efforts may also impact the environment through, for 

example, increased vessel traffic and the application of dispersants. Natural degradation processes will 

also decrease the amount of spilled oil over time. Chemicals used in the oil and gas industry are not a 

significant risk for a spill because they are either nontoxic, are used in minor quantities, or are only used 

on a noncontinuous basis.

Cumulative Impacts

Offshore waters are vulnerable to impacts from cumulative OCS oil- and gas-related activities 

including erosion and runoff, sediment disturbance and turbidity, vessel discharges, discharges from 

exploration and production activities, and accidental releases of oil, gas, or chemicals. Routine activities 

that increase turbidity and discharges are temporary in nature and are regulated; therefore, these activities 

would not have a lasting adverse impact on water quality. In the case of a low-probability catastrophic

event, degradation processes in both surface and subsurface waters would decrease the amount of spilled 

oil over time through natural processes that can physically, chemically, and biologically degrade oil 

(NRC, 2003).

Offshore waters are also vulnerable to impacts from activities not related to a CPA proposed action or 

the OCS Program, including State oil and gas activities, alternative uses of platforms (e.g., aquaculture),

sand borrowing, renewable energy activities, the activities of other Federal agencies (including the 

military), natural events or processes, and activities related to the direct or indirect use of land and 

waterways by the human population(e.g., urbanization, agricultural practices, coastal industry, and 

municipal wastes). These activities may result in erosion and runoff, sediment disturbance and turbidity, 

vessel discharges, natural releases of oil and gas (e.g., seeps), and accidental releases of oil, gas, or 

chemicals. Although some of these impacts are likely to affect coastal areas to a greater degree than 

offshore waters, coastal pollutants that are transported away from shore would also affect offshore 

environments.

The impacts resulting from a CPA proposed action are a small addition to the cumulative impacts on 

the offshore waters of the Gulf, when compared with inputs from natural hydrocarbon inputs (seeps), 

coastal factors (such as erosion and runoff), and other non-OCS oil- and gas-related industrial discharges. 

The incremental contribution of the routine activities and accidental discharges associated with a CPA 

proposed action to the cumulative impacts on offshore water quality is not expected to be significant.
Description of the Environment and Impact Analysis 4-17

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

Various Internet sources were examined and literature searches conducted in order to assess the 

availability of new information regarding the water quality and sediment quality in offshore waters that 

may be pertinent to the CPA. The searches included, but were not limited to, Google, Google Scholar, 

several USEPA websites, and the NOAA Central Library Deepwater Horizon: A Preliminary 

Bibliography of Published Research and Expert Commentary website. New information was found in 

relation to the affected offshore environment following the Deepwater Horizon explosion, oil spill, and 

response and oil degradation. Several researchers reported on biodegradation and photodegradation 

processes of crude oil related to the Deepwater Horizon explosion, oil spill, and response. The CPA and 

EPA contain natural seeps at the seafloor that contribute oil and gas to the offshore marine environment. 

Therefore, the new research discussed below pertaining to hydrocarbon degradation processes applies to 

both the CPA and EPA.

A Deepwater Horizon oil spill dataset, including extensive chemical analyses of sediment and water, 

is available online through NOAA (USDOC, NOAA, 2013a). The dataset as a whole is not fully 

interpreted or discussed in context to the condition of the Gulf of Mexico, but since the data are the work 

of other Federal agencies, State environmental management agencies, and British Petroleum and its 

contractors that has been compiled by NOAA, at least some of the data was discussed in the Inter-Agency 

Joint Analysis Group reports as well as the OSAT reports discussed in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. BOEM 

expects these data to be considered by the scientific community and further incorporated into additional 

reports and published in peer-reviewed literature in the future.

Liu et al. (2014) evaluated impacts of the Deepwater Horizon explosion, oil spill, and response on 

concentrations of petroleum hydrocarbons in surface water near the release. Concentrations of total 

dissolved n-alkanes in surface water were more than an order of magnitude higher in May 2010 than in 

August 2010 or May 2011, indicating that the contamination was due to the release. In contrast, evennumbered n-alkanes dominated the dissolved fraction in the May 2011 samples, but they were generally 

not prevalent in the suspended particulate fraction. The authors concluded that the dissolved evennumbered n-alkanes originated from bacteria or were transported to the sample location from elsewhere. 

Concentrations of PAHs in suspended particles were on average 5 times higher in the May 2010 sample 

than in the May 2011 sample. The results taken together indicate that surface waters of the sampling area 

in May 2010 were contaminated by the oil spill and that rapid weathering and/or physical dilution quickly 

reduced hydrocarbon levels by August 2010. Zhou et al. (2013) investigated the photochemical and 

biological degradation of crude oil from the Deepwater Horizon explosion, oil spill, and response under 

controlled laboratory conditions. Naphthalene, phenanthrene, fluoranthene, and chrysene, in order from 

lower to higher molecular weight, were the most dominant PAHs in the samples. Photochemical 

degradation caused a large decline in the aromatic fraction of oil, a preferential loss of low molecular 

weight alkanes and PAHs, and decreased degradation indexes such as n-C17/pristine ratio. Biodegradation 

of these compounds was also observed in the absence of light.

Yang et al. (2014) evaluated bacterial populations in the water column during and after the 

Deepwater Horizon explosion, oil spill, and response. They found that the bacterial community was 

temporarily dominated in May 2010 by Oceanospirillales responding to oil in the water column. By 

October 2010, this bacterial bloom had been replaced by a diversified bacterial community that resembled 

its predecessor prior to the release. However, even after the deep hydrocarbon plume was no longer 

detectable in the wellhead area in October 2010, small populations of Oceanospirillales remained.

As discussed in Chapter 4.2.1.2.1.4 of the 2012-2017 WPA/CPA Multisale EIS, nutrients carried in 

waters of the Louisiana and Texas rivers contribute to seasonal formation of hypoxic zones on the 

Louisiana and Texas shelf. On June 24, 2014, NOAA and its partners announced they predict an average 

“dead zone” for the Gulf of Mexico. The NOAA-supported modeling has forecasted the 2014 hypoxic 

zone to cover an area ranging from 4,633 to 5,708 square miles (12,000 to 14,785 square kilometers). 

The models rely on nutrient loading estimates from the USGS (Gulf of Mexico Alliance, 2014). By 

comparison, the 2013 dead zone measured 5,840 square miles (15,126 square kilometers) (USDOC, 

NOAA, 2013b). 
4-18 Central and Eastern Planning Areas Supplemental EIS

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.2.2 of the 2012-

2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.2.2 of the 

CPA 235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information that 

may be relevant to reasonably foreseeable impacts on offshore water quality. Much of this information 

relates to the Deepwater Horizon explosion, oil spill, and response and is continuing to be collected and 

developed through the NRDA process.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions. Given the available data on offshore sediments 

and water quality that have been released and evaluated most recently in Chapter 4.1.1.2.2 of the CPA 

235/241/247 Supplemental EIS, as well as in Chapter 4.2.1.2.2 of the 2012-2017 WPA/CPA Multisale 

EIS and WPA 233/CPA 231 Supplemental EIS, BOEM believes that this incomplete or unavailable 

information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for offshore waters presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for offshore waters presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.3. Coastal Barrier Beaches and Associated Dunes

BOEM has reexamined the analysis for coastal barrier beaches and associated dunes presented in the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for coastal barrier beaches and associated dunes 

presented in those NEPA documents. The analysis and potential impacts discussed in those documents 

still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.3 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.3 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.3 of the CPA

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors of a CPA proposed action on coastal barrier beaches

and associated dunes include pipeline emplacements, use of navigation channels by vessel traffic, 

dredging, and the use and construction of support infrastructure. Effects to coastal barrier beaches and 

associated dunes from pipeline emplacements, navigation channel use and dredging, and construction or 

continued use of infrastructure in support of a CPA proposed action are expected to be restricted to 

temporary and localized disturbances. The expected 0-1 pipeline landfalls projected in support of a CPA 

proposed action are not expected to cause significant impacts to barrier beaches because of the use of 

nonintrusive installation methods and regulations. Impacts could be reduced or eliminated through 

modern techniques such as horizontal, directional (trenchless) drilling to avoid damages to these sensitive 

wetland habitats. Any new processing facilities would not be expected to be constructed on barrier 

beaches. A CPA proposed action may contribute to the continued use of gas processing facilities that
Description of the Environment and Impact Analysis 4-19

already exist. Existing pipelines, in particular those that are parallel and landward of beaches and that had 

been placed on barrier islands using older techniques that left canals or shore protection structures, have 

caused and could continue to cause barrier beaches to narrow and breach.

Maintenance dredging of barrier inlets and bar channels is expected to occur, which, when combined 

with channel jetties, generally causes minor and localized impacts on adjacent barrier beaches downdrift 

of the channel. Dredging activities in these channels are permitted, regulated, and coordinated by the 

COE with the appropriate State and Federal resource agencies. Impacts from these operations are 

minimal due to requirements for the beneficial use of the dredged material for wetland and beach 

construction and restoration. Permit requirements further mitigate dredged material placement in 

approved disposal areas by requiring the dredged material to be placed in such a manner that it neither 

disrupts hydrology nor changes elevation in the surrounding marsh. Because these impacts occur whether 

a CPA proposed action is implemented or not, a CPA proposed action would account for a small 

percentage of these impacts.

Routine activities associated with a CPA proposed action are not expected to adversely alter barrier 

beach configurations much beyond existing, ongoing impacts in localized areas downdrift of artificially 

jettied and maintained channels. Strategic placement of dredged material from channel maintenance, 

channel deepening, and related actions can mitigate adverse impacts upon those localized areas.

Accidental disturbances resulting from a CPA proposed action, including oil spills and blowouts, 

have the potential to impact coastal barrier beaches and associated dunes of the CPA. The main 

accidental impact-producing factors that would affect coastal barrier beaches and associated dunes are oil 

spills and cleanup activities.

The potential impacts from oil spills to barrier islands seaward of the barrier-dune system are 

discussed below, while the potential impacts from spills that occur landward of the barrier-dune system

are considered in the wetlands analysis (refer to Chapter 4.1.1.4). Due to the proximity of inshore spills 

(i.e., spills in a river, bay, or estuary) to barrier islands and beaches, inshore spills pose the greatest threat 

because of their concentration and lack of weathering by the time they hit the shore and because 

dispersants are not utilized in inshore waters due to the negative effects on the shallow-water coastal 

habitats. Such spills may result from either vessel collisions that release fuel and lubricants or from 

pipelines that rupture. Impacts of a nearshore spill would likely be considered short term in duration and 

minor in scope because the size of such a spill is projected to be small. When limited to just oil- and gasrelated spill sources such as platforms, pipelines, MODUs, and support vessels, Louisiana, Texas, 

Mississippi, and Alabama would have a total of 130-170, 5-10, 3-5, and about 2 spills <1,000 bbl/yr, 

respectively. Louisiana and Texas are the states most likely to have a spill ≥1,000 bbl occur in coastal 

waters (refer to Chapter 3.2.1.7.1 of the 2012-2017 WPA/CPA Multisale EIS). The distribution of spill 

sizes is likely to be similar to those identified in Anderson et al. (2012) for OCS spills. Ninety-six percent 

of spills are <1 bbl (average size = 0.05 bbl) and 98 percent of spills are <10 bbl (average size for spills 

1-9 bbl = 3 bbl). For more information on spill sizes, refer to Chapter 3.2.1.7.1 of the 2012-2017 

WPA/CPA Multisale EIS.

For offshore spills, the spill may be larger but the oil would likely be lessened in toxicity when it 

reaches the coastal environments due to the distance from shore, increased weathering, and the possible 

use of dispersant. Equipment and personnel used in cleanup efforts can generate the greatest direct 

impacts to an area, such as the disturbance of beach and foredune sands through foot traffic and 

mechanized cleanup equipment (e.g., sifters), dispersal of oil deeper into sands and sediments, and foot 

traffic in marshes impacting the distribution of oils and marsh vegetation. Close monitoring and 

restrictions on the use of bottom-disturbing equipment would be needed to avoid or minimize those 

impacts. The cleanup impacts of these spills could result in a short-term (up to 2 years) adjustment in 

beach profiles and configurations during cleanup operations. Beach profiles could be altered in various 

ways when oil is removed from beaches: by hand, using tools such as shovels and rakes; and by heavy 

equipment such as backhoes and graders. Holes may be dug to remove tarballs, and beaches may be 

graded, changing the shape of the beaches. Sand may be lost from the beach as it is removed along with 

oil and tar. Crab burrows and other habitat may be altered, and park visitors may observe an altered 

landscape compared with the natural beach observed previously. Some impact as a result of physical 

contact to lower areas of sand dunes is expected. These contacts would not result in significant 

destabilization of the dunes. The long-term stressors to barrier beach communities caused by the physical 

effects and chemical toxicity of an oil spill may lead to decreased primary production, plant dieback, and 

further erosion, particularly if oil is carried onto dunes by hurricanes. 
4-20 Central and Eastern Planning Areas Supplemental EIS

Currently available information suggests that impacts on barrier islands and beaches from accidental 

impacts associated with a CPA proposed action would be minimal. Should a spill other than a lowprobability catastrophic spill contact a barrier beach, oiling is expected to be light and sand removal 

during cleanup activities minimized. No significant long-term impacts to the physical shape and structure 

of barrier beaches and associated dunes are expected to occur as a result of a CPA proposed action. 

Therefore, a CPA proposed action would not pose a significant increase in risk to barrier island or beach 

resources.

Cumulative Impacts

The OCS oil- and gas-related impact-producing factors that could have cumulative impacts include 

dredging, construction and expansion of navigational canals and port facilities, pipeline 

emplacement/landfalls, vessel traffic, oil spills, and oil-spill response and cleanup activities. Under the 

cumulative scenario, up to one OCS oil- and gas-related pipeline landfall is projected. This pipeline is 

expected to be installed using modern techniques, which cause little to no impacts to the barrier islands 

and beaches. Impacts from existing infrastructure could continue to cause barrier beaches to narrow and 

breach. The impacts of oil spills from OCS oil- and gas-related sources to the Louisiana, Mississippi, and 

Alabama coast should not result in long-term alteration of landforms if the beaches are cleaned using 

techniques that do not significantly remove sand from the beach or dunes. Barrier beaches in the region 

around Lafourche, Cameron, Plaquemines, and St. Bernard Parishes in Louisiana have the greatest risks 

of sustaining impacts from oil-spill landfalls because of the high concentrations of oil production near that 

coast and the high volume of oil transported by ships in that area. Oil spills as a result of a lowprobability catastrophic spill, which is not part of a CPA proposed action and not likely expected, are 

discussed in Appendix B. 

Non-OCS oil- and gas-related impacts include non-OCS oil- and gas-related vessel traffic, beach 

protection and stabilization projects, sea-level rise, subsidence, development and urbanization, tourism, 

recreational activities, and the potential for nearshore salinity modifications (such as preparation of salt 

domes for oil storage). In addition, oil spills and oil-spill response and cleanup activities can originate 

from non-OCS oil- and gas-related activities, i.e., international tankers. River channelization, sediment 

deprivation, tropical and extra-tropical storm activity, sea-level rise, and rapid submergence have resulted 

in erosion of most of the barrier and shoreline landforms along the Louisiana coast. Storm-induced 

changes in hydrology have, in some cases, changed the current regime responsible for stabilizing the 

barrier islands. Some beach stabilization projects are considered by coastal geomorphologists and 

engineers to accelerate coastal erosion. The beneficial use of maintenance dredged materials and other 

restoration techniques could be required to mitigate some of these impacts. Recreational use of some 

barrier beaches in the CPA is intense due to their accessibility by roads. These activities can cause 

changes to the beach landscapes. There are ongoing restoration efforts to minimize damages to beaches 

from both natural and human impacts.

Coastal barrier beaches have experienced severe adverse cumulative impacts from natural processes 

and human activities. Natural processes are generally considered the major contributor to these impacts, 

whereas human activities cause severe local impacts and accelerate the natural processes that deteriorate 

coastal barriers. Human activities that have caused the greatest adverse impacts are river channelization 

and damming, pipeline canals, navigation channel stabilization and maintenance, and beach stabilization 

structures. Deterioration of Gulf barrier beaches is expected to continue in the future. Federal, State, and 

county/parish governments have made efforts to restore or protect the sensitive and vulnerable barrier 

islands and mainland beaches.

A CPA proposed action is not expected to adversely alter barrier beach configurations significantly. 

A CPA proposed action is not expected to increase the probabilities of oil spills beyond the current 

estimates. Strategic placement of dredged material from channel maintenance, channel deepening, and 

related actions can mitigate adverse impacts upon those localized areas. Compared with other impacting 

factors on coastal barrier beaches and dunes, the incremental contribution of a CPA proposed action to the 

cumulative impacts to these resources is expected to be small.
Description of the Environment and Impact Analysis 4-21

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search was conducted for information published on barrier beaches and dunes, and various Internet 

sources were examined to determine any recent information regarding barrier beaches and dunes. 

Sources investigated include BOEM; the U.S. Department of the Interior, Geological Survey (USGS); 

National Wetlands Research Center; the USGS Gulf of Mexico Integrated Science Data Information 

Management System; Gulf of Mexico Alliance; State environmental agencies; USEPA; and coastal 

universities. Other websites from scientific publication databases (including Science Direct, Elsevier, the 

NOAA Central Library National Oceanographic Data Center, and JSTOR) were checked for new 

information using general Internet searches based on major themes. Most new and pertinent information 

has been the result of Deepwater Horizon-related research, and these studies have provided insight into 

many aspects of the spill and its effects as it relates to beach and dune environments.

Urbano et al. (2013) examined small surface residue balls (also called tarballs) of oil on Fourchon 

Beach and Elmer’s Island, Louisiana, and found that the position with respect to the tidal zone affected 

the rate of biodegradation, with the most efficient degradation occurring in the Fourchon supratidal 

samples and in some intertidal small residual balls. Elango et al. (2014) followed up on that study and 

found that biodegradation of small residual balls continued over a 19-month period, while submerged oil 

mat samples did not demonstrate biodegradation. Newton et al. (2013) sampled beach sands at seven 

Gulf Coast beaches and found that, while individual beaches had unique bacterial communities, oil 

contamination increased the variability in community composition. Daylander et al. (2014) evaluated 

mobility and redistribution patterns of tarballs. They found that, under calm conditions, small residual 

balls are unlikely to move alongshore, but that mobility and transport was likely during storms and that 

inlets probably serve as traps for small residual balls. Snyder et al. (2014) sampled tissues of Coquina 

clams (Donax, spp.) to monitor PAH levels in Florida beaches. The clams had higher levels of PAHs 

relative to the sand, the levels were highly variable, and fell below levels of detection within 2 years after 

oil landed on the beaches.

These studies serve to expand our understanding of the baseline environment following the

Deepwater Horizon explosion, oil spill, and response. They also provide information about the 

continuing impacts in the years following oil contamination of beaches.

Another recent study has investigated the impacts of non-OCS oil- and gas-related activity, such as 

reduced ecological resilience observed as sandy beach ecosystems are squeezed between fortifications 

and increasing sea levels (Berry et al., 2013). They found that hard-engineered options such as 

revetments, groins, seawalls, and breakwaters, and soft-engineered options such as sand and vegetation 

and beach nourishment and ecosystem engineering impede sand transport and storage systems and 

prevent retreat from advancing seas. This study helps to provide a context for the threats to beaches from 

sources other than OCS oil- and gas-related activities.

While the recent research has provided new information regarding impacts to coastal beaches and 

dunes from oil spills, this new information does not change the conclusions of the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS because 

such a low-probability catastrophic event is unlikely to occur and because BOEM has already considered 

the potential irreversible effects to coastal beaches and dunes in Appendix B of this Supplemental EIS.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.3 of the 2012-2017 

WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.3 of the CPA 

235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information regarding 

coastal barrier beaches and associated dunes in the CPA. This information cannot reasonably be obtained 

because the long-term effects may not yet be detectable and the overall costs in time and money to 

determine this are exorbitant. This incomplete or unavailable information may be relevant to reasonably 

foreseeable significant adverse effects because recent events such as the Deepwater Horizon explosion, 

oil spill, and response may have caused changes to baseline conditions for coastal beaches and associated 
4-22 Central and Eastern Planning Areas Supplemental EIS

dunes of the Gulf of Mexico. A large body of information regarding impacts of the Deepwater Horizon

explosion, oil spill, and response upon coastal barrier beaches and associated dunes is being developed 

through the NRDA process, but it is not yet available. There are also unknowns regarding the future 

restoration efforts being planned, such as what projects will ultimately be constructed and how successful 

they may be. In addition, the future rates of relative sea-level rise are not known with certainty 

(Intergovernmental Panel on Climate Change, 2013), and thus, the resulting impacts to coastal barrier 

beaches and associated dunes are unknown.

BOEM has determined that the information is not essential to a reasoned choice among alternatives 

because the CPA is an active oil and gas region with ongoing exploration, drilling, and production 

activities. In addition, non-OCS energy-related factors will continue to occur in the CPA irrespective of a 

CPA proposed action (i.e., development, urbanization, recreational activities, etc.). The potential for 

effects from changes to the affected environment (post-Deepwater Horizon), routine activities, accidental 

spills (including low-probability catastrophic spills), and cumulative impacts remains whether or not the 

No Action or an Action alternative is chosen under this Supplemental EIS. Impacts on coastal barrier 

beaches and associated dunes from either smaller accidental events or low-probability catastrophic spills 

would remain the same.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from existing information in completing this analysis and formulating the conclusions presented here. 

For example, the following studies were analyzed with regards to coastal barrier beaches and dunes: 

Urbano et al. (2013); Elango et al. (2014); Newton et al. (2013); Daylander et al. (2014); Snyder et al. 

(2014); and Berry et al. (2013). The results of these recent studies of coastal barrier beaches and dunes 

indicate that the extent of impacts resulting from a low-probability catastrophic oil spill could be 

extensive but that the oil would be degraded over time. However, a low-probability catastrophic oil spill 

is not much more likely with a proposed CPA lease sale than without, given the existing level of OCS oiland gas-related activities and the small incremental increase in the activity that is expected from a 

proposed CPA lease sale. Therefore, none of these sources reveal reasonably foreseeable significantly 

greater adverse impacts, whether or not the No Action or an Action alternative is chosen under this 

Supplemental EIS.

Summary and Conclusion

BOEM has reexamined the analysis for coastal barrier beaches and associated dunes presented in the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for coastal barrier beaches and associated dunes 

presented in those NEPA documents because of the available scientifically credible evidence in this 

analysis and based upon accepted scientific methods and approaches. The analysis and potential impacts 

discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

4.1.1.4. Wetlands

BOEM has reexamined the analysis for wetlands presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented below. No new significant information was discovered that would alter 

the impact conclusion for wetlands presented in those NEPA documents. The analysis and potential 

impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.4 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.4 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.4 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.
Description of the Environment and Impact Analysis 4-23

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on wetlands along the coast adjacent to the CPA 

include pipeline emplacement, construction, and maintenance; navigation channel use (vessel traffic) and 

maintenance dredging; disposal of OCS oil- and gas-related wastes; and use and construction of support 

infrastructure in coastal areas. Other potential impacts that are indirectly associated with OCS oil- and 

gas-related activities are wake erosion resulting from navigational traffic; levee construction that prevents 

necessary sedimentary processes; saltwater intrusion that changes the hydrology, leading to unfavorable 

conditions for wetland vegetation; and vulnerability to storm damage from eroded wetlands. It is 

expected that impacts of pipelines would be reduced or eliminated through mitigation, such as horizontal, 

directional (trenchless) drilling techniques to avoid damages to these sensitive wetland habitats. Although 

maintenance dredging of navigation channels and canals in the CPA is expected to occur, a CPA 

proposed action is expected to contribute minimally to the need for this dredging. Alternative dredgedmaterial disposal methods can be used to enhance and create wetlands. Secondary impacts to wetlands 

from a CPA proposed action would result from OCS oil- and gas-related vessel traffic, contributing to the 

erosion and widening of navigation channels and canals. Overall, the impacts to wetlands from routine 

activities associated with a CPA proposed action are expected to be low due to the small length of 

projected onshore pipelines, the minimal contribution to the need for maintenance dredging, and the 

mitigating measures that would be used to further reduce these impacts.

Accidental disturbances resulting from a CPA proposed action, mainly oil spills, have the potential to 

cause plant mortality and permanent loss of wetlands of the CPA. Offshore oil spills resulting from a 

CPA proposed action would have a low probability of contacting and damaging wetlands along the Gulf

Coast, except in the case of a low-probability catastrophic spill, which is not part of a CPA proposed 

action and not likely expected (refer to Appendix B). This is because of the distance of the spill to the 

coast, the likely weathered condition of oil (through evaporation, dilution, and biodegradation) should it 

reach the coast, and because wetlands are generally protected by barrier islands, peninsulas, sand spits, 

and in some cases by currents. However, because the protective capacity of barrier islands has been 

reduced due to land lost in hurricanes and anthropogenic factors, there is a greater potential for the oiling 

of coastal wetlands during an accidental event. The causes of coastal and offshore oil spills are 

summarized in Chapters 3.1.1.7 and 3.3.5.2. Although the probability of occurrence is low, the greatest 

threat from an oil spill to wetland habitat is from a spill as a result of an inland or nearshore vessel 

accident or pipeline rupture. Wetlands in the northern Gulf of Mexico are in moderate- to high-energy 

environments; therefore, sediment transport and tidal stirring should reduce the chances for oil persisting 

in the event that these areas are oiled. While a resulting slick may cause impacts to wetland habitat and 

surrounding seagrass communities, the equipment, chemical treatments, and personnel used for cleanup 

can generate the greatest impacts to the area. Associated foot traffic may work oil farther into the 

sediment than would otherwise occur. Close monitoring and restrictions on the use of bottom-disturbing 

equipment would be needed to avoid or minimize those impacts. In addition, an assessment of the area 

covered, oil type, and plant composition of the wetland oiled should be made prior to choosing 

remediation treatment. These treatments could include mechanical and chemical techniques with onsite 

technicians. Overall, impacts to wetland habitats from an oil spill associated with activities related to a 

CPA proposed action would be expected to be low and temporary because of the nature of the system, 

regulations, and specific cleanup techniques.

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors related to a CPA proposed 

action, prior and future OCS lease sales in the Gulf of Mexico, and non-OCS oil- and gas-related 

activities such as State oil and gas activities, other governmental and private projects and activities, and 

natural processes that may affect wetlands. Several OCS oil- and gas-related cumulative impactproducing factors could potentially impact wetland resources, including the following: oil spills and 

cleanup activity; OCS oil- and gas-related vessel traffic; construction of OCS oil- and gas-related 

infrastructure and support structure (including pipelines); and waste disposal. 

The primary impact-producing factors attributable to a CPA proposed action are pipeline landfalls, 

canal widening, and maintenance dredging of navigation canals because they result in land loss. 

However, modern construction techniques and regulations reduce impacts to wetlands as a result of these 
4-24 Central and Eastern Planning Areas Supplemental EIS

activities. In addition, because the increase in pipelines, dredging, and vessel traffic from a CPA 

proposed action are predicted to be minimal, impacts related to these factors are also expected to be 

minimal. The possibility of physical oiling of wetlands from a CPA proposed action as a result of an oil 

spill originating in OCS waters is minimal compared with an oil spill that is closer to the wetlands and 

that could occur in State waters or in rivers, bays, or estuaries. The effects from a spill have the highest 

probability of occurring in Lafourche, Cameron, Plaquemines, and St. Bernard Parishes in Louisiana. 

These are the primary areas where oil produced in the CPA is transported and distributed. If any oil spills 

occur in rivers, bays, or estuaries from pipelines or vessels, they will likely be small and at service bases

or other support facilities, and these small-scale local spills would not be expected to severely affect 

wetlands. Accidental spills as a result of a low-probability catastrophic spill, which is not part of a CPA 

proposed action and not likely expected, may have impacts on wetlands. Low-probability catastrophic 

events are discussed in Appendix B. 

Non-OCS oil- and gas-related cumulative impact-producing factors that could potentially impact 

wetland resources include the following: State oil and gas activities; non-OCS oil- and gas-related vessel 

traffic; coastal infrastructure and development; maintenance of navigation canals; natural processes 

(including hurricane and tropical storms); and sea-level rise. Non-OCS oil- and gas-related impacts from 

residential, commercial, agricultural, and silvicultural (forest expansion) developments are expected to 

continue in coastal regions around the Gulf of Mexico. Wetlands are most vulnerable to oil spills that 

may occur in State waters or in rivers, bays, or estuaries, the impacts of which would be primarily 

localized in nature. Many such spills are from non-OCS oil- and gas-related sources, such as State oil and 

gas activities, which can include vessel collisions, pipeline breaks, and shore-based transfer, refining, and 

production facilities. Insignificant adverse impacts on wetlands from maintenance dredging are expected 

because the large majority of the material would be placed in existing disposal areas or used beneficially 

for marsh restoration or creation. Hurricanes and tropical storms can cause extensive damage to 

wetlands, including conversion of large acreages of wetlands to open water. Marine vegetation deposited 

by storms can rest on wetland plants, resulting in mortality. One benefit of storms is that they can be 

capable of delivering sediment from offshore or interior bays into wetland areas, partially offsetting 

erosion. Sea-level rise can impact coastal wetlands by the drowning of plants. Relative sea-level rise, 

which includes local factors such as subsidence, can increase salinity and flooding, resulting in reduced 

productivity of wetland plants (Spalding and Hester, 2007).

Development pressures in the coastal regions of Louisiana, Mississippi, Alabama, and Florida have 

caused the destruction of large areas of wetlands. In coastal Louisiana, the most destructive 

developments have been the inland oil and gas industry projects, which have resulted in the dredging of 

huge numbers of access channels. Agricultural, residential, and commercial developments have caused 

the most destruction of wetlands in Mississippi, Alabama, and Florida. In Florida, recreational and tourist 

developments have been particularly destructive. Groundwater extraction, vessel traffic, the drainage of 

wetland soils, and the construction of buildings, roads, and levees have also caused the loss of wetlands. 

The cumulative effects of human and natural activities in the coastal area have severely degraded the 

deltaic processes and have shifted the coastal area from a condition of net land building to one of net land 

loss. Therefore, wetland loss is expected to continue.

A CPA proposed action represents a small (<5%) portion of the OCS oil- and gas-related impacts that 

will occur over the 40-year analysis period. Impacts associated with a CPA proposed action are a 

minimal part of the overall OCS oil- and gas-related impacts. The incremental contribution of a CPA 

proposed action to the cumulative impacts to coastal wetlands is minimal compared with the impacts 

associated with non-OCS oil- and gas-related activities in the Gulf of Mexico.

New Information Available Since the Publication of 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search was conducted for information published on northern Gulf of Mexico wetland communities, 

and various Internet sources were examined to determine any recent information regarding these 

communities. Sources investigated include BOEM, the USGS National Wetlands Research Center, the 

USGS Gulf of Mexico Integrated Science Data Information Management System, Gulf of Mexico 

Alliance, State environmental agencies, USEPA, and coastal universities. Other websites from scientific 

publication databases (including Science Direct, Elsevier, the NOAA Central Library National 
Description of the Environment and Impact Analysis 4-25

Oceanographic Data Center, and JSTOR) were checked for new information using general Internet 

searches based on major themes.

Numerous studies have been published regarding impacts of the Deepwater Horizon explosion, oil 

spill, and response. Zengel et al. (2014) compared treatment options for oiled marshes in Barataria Bay, 

Louisiana, 3 years after the initial oiling. They found mechanical treatment (including vegetation raking, 

cutting, and using “squeegees” to skim thick oil mousse from the marsh surface), coupled with the 

planting of Spartina alterniflora, resulted in improved habitat recovery, compared with no treatment and 

mechanical treatment alone. Judy et al. (2014) studied impacts of oil from the Deepwater Horizon oil 

spill on Phragmites australis and found strong resistance to negative impacts when oil was applied to 

shoots alone, and greater impacts when oil was applied to the soil or with repeated shoot oiling. Sublethal 

effects were observed from application of oil to the soil, but mortality was not observed. This study 

indicates that Phragmites australis may have experienced greater impacts from oiled soil than oiled 

shoots alone as a result of the Deepwater Horizon explosion, oil spill, and response.

Michel and Rutherford (2014) reviewed 32 oil spills and field experiments and found that, in many 

cases, recovery of marshes occurred within 1-2 growing seasons, even without treatment. Recovery was 

shortest for spills in a warm climate, light to heavy oiling of the vegetation only (not the marsh surface), 

medium crude oils, and less intensive treatment. They also offered treatment recommendations for spills 

based on several related criteria.

Liu and Liu (2013) investigated bacterial communities present in oil mousses collected from impacted 

salt marshes during the Deepwater Horizon explosion, oil spill, and response. Vibrio bacteria, a human 

pathogen, represented 57 percent of the community, suggesting that this indigenous genus is particularly 

responsive to weathering oil in the salt marshes.

Khanna et al. (2013) used Advanced Visible Infrared Imaging Spectrometer (AVIRIS) data from 

Barataria Bay, Louisiana, in September 2010 and August 2011 to map oil contamination and examine the 

impacts to vegetation. They found that vegetation stress was restricted to the tidal zone, extending 14 m 

(46 ft) inland from the shoreline in 2010, with the highest stress at the shoreline, and decreasing with 

distance from the water. They also found varying degrees of revegetation in 2011, with the poorest 

recovery adjacent to shorelines, which is where oil stress was the highest. This study showed salt marsh 

recovery the year following the Deepwater Horizon explosion, oil spill, and response, with the slowest 

recovery in the most heavily oiled areas.

Moody et al. (2013) compared the utilization of salt-marsh habitats by transient and resident nekton 

before and after the Deepwater Horizon explosion, oil spill, and response. They did not find significant 

differences in recruitment of marsh-associated nekton in coastal Alabama following the spill, and they 

found little evidence for severe acute or persistent oil-induced impacts.

Other recent research focused on issues other than oil-spill impacts. Staszak and Armitage (2013) 

evaluated the results of salt marsh restoration projects in Galveston Bay, Texas. They found that the 

restored areas had relatively high ecological value and contributed to the integrity of the regional wetland

landscape.

Glick et al. (2013) investigated the potential impact of current and accelerating sea-level rise rates on 

key coastal wetland habitats in southeastern Louisiana, using the Sea Level Affecting Marshes Model. 

Results indicate a range of potential wetland losses from 9 to 24 percent of the 2007 wetland area by 

2100, depending on whether the lowest or highest sea-level-rise scenario was used. Cypress-tupelo 

swamp is projected to be heavily impacted by permanent flooding, thereby affecting regeneration.

Howard et al. (2014) investigated the impact of 3D seismic surveys in the coastal marshes of 

Louisiana. They found that effects from activities related to the 3D seismic surveys, including reduced 

vegetative height, reduced vegetative cover, did not persist beyond three months, and that marshes were 

resilient to the impacts of 3D seismic exploration.

While the recent research has provided much new information regarding impacts to wetlands from oil 

spills, this new information does not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS 

because a catastrophic event is unlikely to occur and because BOEM has already considered the potential 

irreversible effects to marshes, such as erosion and permanent loss, in Appendix B (Chapter B.3.1.4) of 

this Supplemental EIS.
4-26 Central and Eastern Planning Areas Supplemental EIS

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined the new information does not 

change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental 

EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or unavailable 

information. As identified in the resource analyses in this Supplemental EIS, as well as in the previously 

mentioned NEPA documents, BOEM has identified incomplete or unavailable information regarding 

wetlands in the CPA. This incomplete or unavailable information may be relevant to reasonably 

foreseeable significant adverse effects because recent events such as the Deepwater Horizon explosion, 

oil spill, and response may have caused changes to baseline conditions for coastal wetlands of the Gulf of 

Mexico. A large body of information regarding impacts of the Deepwater Horizon explosion, oil spill, 

and response upon coastal wetlands is being developed through the NRDA process, but this information 

is not yet available. Other unknowns are future benefits from restoration projects and future impacts of 

sea-level rise.

BOEM has determined that the information is not essential to a reasoned choice among alternatives 

because the CPA is an active oil and gas region with ongoing exploration, drilling, and production 

activities. In addition, non-OCS energy-related factors will continue to occur in the CPA irrespective of a 

CPA proposed action (i.e., commercial development, subsidence, hurricanes, etc.). The potential for 

effects from changes to the affected environment (post-Deepwater Horizon), routine activities, accidental 

spills (including low-probability catastrophic spills), and cumulative impacts remains whether or not the 

No Action or an Action alternative is chosen under this Supplemental EIS. Impacts on wetlands from 

either smaller accidental events or low-probability catastrophic events will remain the same.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from existing information in completing this analysis and formulating the conclusions presented here. 

For example, the following studies were analyzed with regards to wetlands: Zengel et al. (2014); Judy 

et al. (2014); Michel and Rutherford (2014); Liu and Liu (2013); Khanna et al. (2013); Moody et al. 

(2013); Staszak and Armitage (2013); Glick et al. (2013); and Howard et al. (2014). The results of these 

recent studies of wetlands indicate that the extent of impacts resulting from a catastrophic oil spill could 

be extensive but that the oil would be degraded over time. While marsh vegetation can recover in some 

areas, conversion of some marsh to open water is likely due to plant mortality and erosion. However, a 

low-probability catastrophic oil spill is not much more likely with a proposed CPA lease sale than 

without, given the existing level of OCS oil- and gas-related activities and the small incremental increase 

in that activity expected from a proposed CPA lease sale. Therefore, none of these sources reveal 

reasonably foreseeable significantly greater adverse impacts whether or not the No Action or an Action 

alternative is chosen under this Supplemental EIS.

Summary and Conclusion

BOEM has reexamined the analysis for wetlands presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented above. No new significant information was discovered that would alter 

the impact conclusion for wetlands presented in those NEPA documents because of the available 

scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.5. Seagrass Communities

BOEM has reexamined the analysis for seagrass communities presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new information was discovered that would alter the 

impact conclusion for seagrass communities presented in those NEPA documents. The analysis and 

potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 247. 

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.5 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.5 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.5 of the CPA 
Description of the Environment and Impact Analysis 4-27

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on seagrass communities of the CPA are the 

construction of pipelines, canals, navigation channels, and onshore facilities; maintenance dredging; and 

vessel traffic (e.g., propeller scars). The previous routine OCS oil- and gas-related activities in the CPA 

that may impact seagrasses are not expected to significantly increase as a result of a CPA proposed action 

because minimal action-associated nearshore activities and infrastructure are expected. There is only one 

potential pipeline landfall and only a minor increase in OCS vessel traffic (<1%) projected as a result of a 

CPA proposed action (Chapter 3.1.1.8). Any work in and around submerged aquatic vegetation, 

especially seagrasses, is highly regulated by multiple State and Federal programs; as such, considerable 

mitigation is expected to reduce the undesirable effects on submerged vegetation beds. This includes the 

rerouting of pipelines, avoidance of vegetated communities, use of turbidity curtains, or use of directional 

boring techniques. Local programs decrease the occurrence of prop scarring in grass beds; however, 

channels utilized by OCS oil- and gas-related vessels are typically away from exposed submerged 

vegetation beds. Because of these requirements and implemented programs, along with the beneficial 

effects of natural flushing (e.g., from winds and currents), any potential effects from routine OCS oil- and 

gas-related activities on submerged vegetation in the CPA are expected to be short term, localized, and 

not significantly adverse.

Accidental disturbances resulting from a CPA proposed action, including oil spills and blowouts, 

have the potential to change community structure, decrease growth rates, cause death, or cause a decline 

in ecological services by seagrass communities of the CPA. Accidental events possible with a CPA 

proposed action that could adversely affect submerged vegetation beds include nearshore and inshore 

spills connected with the transport and storage of oil. The greatest possibility of a spill is from a vessel 

accident or pipeline rupture; however, because pipelines can be shut off, ships carry limited amounts of 

oil, and response vessels can more easily access nearshore areas, it is expected that the resulting spill 

would be smaller and shorter than an uncontrolled offshore spill or blowout, resulting in short-term and 

localized impacts. Additionally, extreme tides and/or wind events are the only time that submerged 

aquatic vegetation is typically exposed to the air-water interface where most oil would be floating. As 

such, seagrasses are not expected to come in direct contact with surface oil; however, if oil did come in 

contact with seagrasses, the results could range from the sloughing of epiphytes to death. Offshore oil 

spills that occur in a CPA proposed action area are less likely to contact seagrass communities than are 

inshore spills. If the temporal and spatial duration of the spill is large enough, an offshore spill could 

affect submerged vegetation communities. However, the oil would be substantially more weathered and 

spills would be outside the barrier islands, peninsulas, sand spits, and currents that protect most seagrass 

beds (refer to Chapter 3.2.1.5.4 of the 2012-2017 WPA/CPA Multisale EIS). Cleanup efforts in response 

to a spill can also negatively impact submerged aquatic vegetation. Close monitoring and restrictions on 

the use of bottom-disturbing equipment and vessel operations in and around submerged aquatic 

vegetation would be needed to avoid or minimize those impacts. The floating nature of nondispersed 

crude oil, the regional microtidal range, the dynamic climate with mild temperatures, and the amount of 

microorganisms that consume oil would alleviate prolonged effects on submerged vegetation 

communities. It has been shown that short-term effects from an offshore spill could have little impact on 

specific seagrass communities. Fodrie and Heck (2011) found that, after the Deepwater Horizon oil spill, 

there were few immediate or catastrophic changes in seagrass-based nekton communities in Alabama, 

Florida, and Louisiana seagrass communities. Also, safety and spill-prevention technologies are expected 

to continue to improve and will decrease detrimental effects to submerged vegetation from an accidental 

event related to a CPA proposed action. Overall, impacts to submerged vegetation from an accidental 

event related to a CPA proposed action are expected to be minimal due to the distance of most activities 

from the submerged vegetation beds and because the likelihood of an accidental event of size, location, 

and duration reaching submerged vegetation beds remains small.
4-28 Central and Eastern Planning Areas Supplemental EIS

Cumulative Impacts 

The cumulative OCS oil- and gas-related activities that present the greatest threat of impacts to 

submerged vegetation communities are dredging, oil spills, and pipeline installation. In general, a CPA 

proposed action would cause a minor incremental contribution to impacts on submerged vegetation from 

related dredging, pipeline installations, and oil spills. Of those mentioned, dredging generates the greatest 

overall risk to submerged vegetation by uprooting and burying plants, decreasing oxygen in the water, 

and reducing water clarity in an area. A low-probability catastrophic spill, which is not part of a CPA

proposed action and not likely expected, could also impact seagrass communities. Further, non-OCS oiland gas-related dredging and vessel traffic, boat scarring, changes in salinity and nutrient inputs (Waycott 

et al., 2009; Orth et al., 2006), changes to natural flow regimes from constructed structures, and storm 

events could continue to cause direct damage to seagrass beds by physical destruction, increased turbidity 

and burial of plants, and reduction in favorable environmental conditions for seagrass bed growth. 

However, the incremental contribution of stress from a CPA proposed action to submerged vegetation is 

reduced by the implementation of proposed lease stipulations, mitigating measures currently in place, and 

the small probability of an oil spill.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of various printed and Internet sources was conducted for any recent information published 

regarding coastal submerged vegetation. Sources investigated include BOEM, the National Oceanic and 

Atmospheric Administration, the USGS National Wetlands Research Center, the USGS Gulf of Mexico 

Integrated Science Data Information Management System, Seagrass Watch, Gulf of Mexico Alliance, 

State environmental agencies, USEPA, and coastal universities. Other websites from scientific 

publication databases (including Science Direct, SCIRUS, Google Scholar, Elsevier, Pro Quest, and 

JSTOR) were checked for new information using general Internet searches based on major themes.

New information available that is relevant to a CPA proposed action includes information related to 

responses of seagrass species that were potentially exposed to Macondo oil. Moody et al. (2013) found 

that recruitment of many species of invertebrates in an Alabama marsh was not negatively impacted by 

the Macondo oil spill. Although focused on the marsh, this study is important because many of the 

species found in the marsh are also found in the seagrass. Dubansky et al. (2013) did note that exposure 

to Macondo-related sediments that were contaminated with PAHs resulted in Gulf killifish having multitissue molecular, genomic, and developmental responses. The presence of these effects suggests that oil 

exposure may result in population-level effects; however, a population-level effect may be lethal or 

sublethal. Given that animals were recovered at the same locations in both years suggests that any lethal 

effects on animals may have been mitigated by subsequent cohorts, despite the presence of sublethal 

effects. Gulf killifish are a cosmopolitan, but nonmigratory species, and effects due to a spill would be 

expected to have an impact that was limited to the local population exposed to the spill rather than the 

population as a whole. As such, the overall impact would be positively correlated with the size of the 

spill.

None of the new or available information examined here provides evidence that would result in a 

change of BOEM’s impact conclusions for seagrasses resulting from a CPA proposed action.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS are still valid because no new information on seagrass communities pertinent to a CPA 

proposed action has become available since those NEPA documents were published. As discussed in this 

Supplemental EIS and in the previously mentioned EISs and Supplemental EISs, BOEM has identified 

unavailable information regarding seagrass communities in the CPA. This information cannot reasonably 

be obtained because the long-term effects may not yet be detectable and the overall costs in time and 

money to determine this are exorbitant. This unavailable information may be relevant to adverse effects 

because much of the data related to research and monitoring of the Deepwater Horizon explosion, oil 
Description of the Environment and Impact Analysis 4-29

spill, and response has yet to be completed and made publicly available. Other unavailable information 

may be related to university-related research that has yet to be published as a thesis or a dissertation.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from existing information in completing this analysis and formulating the conclusions presented here. 

For example, Fodrie and Heck (2011) did not sample all of the seagrasses across the northern GOM, but 

they sampled enough locations where OCS oil- and gas-related resource development occurs to allow for 

a general conclusion that changes within seagrass beds are not related to OCS oil- and gas-related 

development or the Deepwater Horizon oil spill. Gab-Alla (2000), Nievales (2009), and Mauseth et al. 

(2001) each showed that, historically, oil spills in other parts of the world have had little long-term 

negative impact on seagrass environments. Overall, none of the new sources or sources referenced in the 

previously mentioned EIS or Supplemental EISs reveal any reasonably foreseeable significant adverse 

impacts as a result of a CPA proposed action. The lack of impact to seagrasses is because seagrasses are 

a benthic organism that is spatially separated from floating oil. If oil does impact seagrasses, it would be 

along the shallow, shoreward margins or at the leaf tips that can be at the air-water interface at times. 

These leaf tips are generally older leaves that have undergone a considerable amount of senescence and 

are routinely discarded by the plant as they age. Oil found in seagrasses is often found as tarballs that 

typically do not result in large-scale effects. Therefore, BOEM has determined that the information is not 

essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for seagrass communities presented in 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for seagrass communities presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.6. Live Bottoms (Pinnacle Trend and Low Relief) 

BOEM has reexamined the analysis for live bottoms presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on additional 

information presented below. No new significant information was discovered that would alter the impact 

conclusion for live bottoms presented in those NEPA documents. The analysis and potential impacts 

discussed in those documents still apply for proposed CPA Lease Sales 241 and 247. 

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.6 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.6 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.6 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on live bottoms of the CPA are seafloor-disturbing 

activities (e.g., anchoring, infrastructure emplacement, and infrastructure removal), waste discharge (e.g., 

produced waters and drilling muds), resuspension of sediments (e.g., drill cuttings and pipeline burial), 

and explosive severance activities. These impact-producing factors have the potential to damage live 

bottom habitats and disrupt associated communities. Potential impacts as a result of seafloor-disturbing 

activities are mitigated through avoidance. The proposed Live Bottom (Pinnacle Trend) Stipulation

would protect features by requiring all bottom-disturbing activity be distanced at least 30 m (100 ft) from 

pinnacles. In addition, case-by-case reviews of permit applications allow BOEM to identify and protect 

live bottoms that occur outside identified live bottom low-relief blocks. A Live Bottom (Low Relief) 

Stipulation may also be applied to leases in live bottom low-relief blocks with water depths of 100 m 

(328 ft) or less in the EPA and northeast corner of the CPA; however, no blocks subject to the Live 
4-30 Central and Eastern Planning Areas Supplemental EIS

Bottom (Low Relief) Stipulation will be offered for lease in the proposed CPA lease sale. Measures 

distancing wells and structures from live bottom features would also reduce the potential for other impactproducing factors to adversely affect live bottom organisms. Impacts would be expected to be negligible.

Waste discharges from routine OCS oil- and gas-related operations may cause localized increases in 

turbidity or be moderately toxic to marine organisms at the point of discharge, potentially impacting 

benthos near drill sites. However, waste discharges rapidly disperse and would have little or no 

measurable effect on organisms inhabiting live bottoms distanced 30 m (100 ft) or more from the 

discharge point. Drilling muds and cuttings may be diluted 100 times at a distance of 10 m (33 ft) from 

the source, and up to 1,000 times more diluted at a distance of 100 m (328 ft) from the discharge point 

(Neff, 2005). Deposition of drilling muds and cuttings near the Pinnacle Trend and low-relief areas, 

distanced 30 m (100 ft) or more from OCS oil- and gas-related activities, would not greatly impact the 

biota of the live bottoms because the communities associated with live bottom features in the CPA are 

adapted to turbid (nepheloid) conditions and high sedimentation rates associated with the outflow of the 

Mississippi River (Gittings et al., 1992). Similarly, structure removal, pipeline burial, and other activities 

that resuspend sediment have the potential to impact communities associated with live bottoms if not 

sufficiently distanced from these features. The proposed Live Bottom (Pinnacle Trend) Stipulation and 

BOEM’s case-by-case reviews would prevent these activities from occurring within 30 m (100 ft) of any 

live bottom, mitigating potential impacts.

The use of explosive severance methods during decommissioning activities has the potential to 

impact live bottoms and associated fauna. The BSEE Interim Policy Document 2013-07, “Rigs-to-Reefs

Policy,” specifies the use of explosive severance methods “will not be approved if analysis determines 

they will cause harm to established artificial reef sites and/or natural biological/topographic features, such 

as the Flower Garden Banks and Pinnacles.” This policy, coupled with the distancing requirement and 

case-by-case reviews to identify and protect sensitive habitat, will minimize any potential for live bottoms 

to be adversely impacted by decommissioning operations.

Accidental disturbances resulting from a CPA proposed action, including oil spills and blowouts, 

have the potential to damage live bottom habitats and disrupt associated communities. Live bottom 

features represent a small fraction of the continental shelf area in the CPA. The proposed Live Bottom 

(Pinnacle Trend) Stipulation (Chapter 2.3.1.3.2) and case-by-case reviews of permit applications would 

distance activities that could result in oil spills and blowouts at least 30 m (100 ft) from the features, 

mitigating most of the potential impacts. In a subsurface spill or blowout situation, it would be expected 

that the majority of released oil would rise to the surface and that the most heavily oiled sediments would 

likely be deposited before reaching live bottom features. A subsurface plume may impact sessile biota of 

live bottom features. Impacts may include loss of habitat, biodiversity, and live coverage; change in 

community structure; and reduced reproductive success. Distancing OCS oil- and gas-related activities 

from these features would allow for oil to mix with the surrounding water and become less concentrated, 

thus reducing toxicity to live bottom organisms.

Surface oil spills also have the potential to impact live bottom features. Some pinnacle features rise 

to within 40 m (130 ft) of the sea surface, while many others have much less relief or are in deeper 

waters. The distance to the sea surface serves to buffer these features from surface spills. Any oil that 

might contact pinnacle features would probably be at low concentrations because the expected mixing 

depth in the water column is less than the peak of the tallest pinnacles. Outside the designated Live 

Bottom (Low Relief) blocks, low-relief features are typically found at depths sufficiently deep to prevent 

surface spills from severely impacting sensitive habitat. Oil becomes diluted as it physically mixes with 

the surrounding water and moves into the water column. Any oil that might be driven to a depth of 10 m 

(33 ft) or more is expected to be diluted to such a degree that any effects to these features would be minor. 

Any features in water shallower than 10 m (33 ft) would be located far from the source of activities in a 

CPA proposed action. Therefore, concentrated oil is not expected to reach live bottom features, and any 

impacts from diluted oil would be sublethal.

Suspended sediment and oil adhered to sediment in the water column as a result of a blowout may 

impact benthic organisms. However, because OCS oil- and gas-related activities would be distanced at 

least 30 m (100 ft) from live bottom features, the heaviest sediment concentrations would be expected to 

fall out of suspension and disperse before sensitive features could be severely impacted. Live bottom 

organisms of the CPA are located within the influence of the Mississippi River plume and have adapted to 

turbid (nepheloid) conditions and high sedimentation rates associated with the outflow of the Mississippi 
Description of the Environment and Impact Analysis 4-31

River (Gittings et al., 1992). Many organisms also have the ability to rid themselves of sediment through 

ciliary action and mucus shedding.

In summary, the proposed Live Bottom (Pinnacle Trend) Stipulation and case-by-case reviews of 

permit applications would, through avoidance, mitigate potential impacts to live bottom communities as a 

result of routine activities and accidental disturbances. In addition, because no Live Bottom (Low Relief) 

blocks are included in a CPA proposed action, most live bottom features are distanced from oil-producing 

activity. In the unlikely event that oil from a spill reached the biota of a live bottom, the effects would be 

primarily sublethal and impacts would be at the community level. However, in such an event, if oil 

impacted a live bottom community at lethal concentrations, coral recovery could take in excess of 

10 years (Fucik et al., 1984). Overall impacts as a result of routine activities and accidental disturbances 

would be expected to be minor.

Cumulative Impacts

The cumulative analysis considers impacts resulting from ongoing routine oil and gas operations, as 

well as those resulting from past and future OCS leasing. These impacts include seafloor-disturbances 

(e.g., anchoring, structure emplacement, and structure removal), waste discharge (e.g., drilling muds, 

cuttings, and effluent), and accidental disturbances (e.g., blowouts and oil spills). Potential non-OCS oiland gas-related factors include vessel anchoring, import tankering, storms, and commercial fishing.

The OCS oil- and gas-related seafloor-disturbing activities represent the greatest threat to live 

bottoms. Potential impacts may be avoided through the continued application of the proposed Live 

Bottom (Pinnacle Trend) Stipulation and case-by-case review of permit applications for the presence of 

live bottom habitat and mitigation of potential impacts. This stipulation would avoid mechanical damage 

to live bottom habitat by prohibiting bottom-disturbing activities from occurring within 30 m (100 ft) of 

live bottoms. The 30 m (100 ft) buffer would also diminish the potential for adverse impacts resulting 

from operational discharges, due to the highly localized and temporary effect of such discharges. The 

USEPA’s discharge regulations and permits further reduce the potential for discharge-related impacts.

The majority of oil released below the sea surface rises and should not physically contact organisms 

on live bottoms. In the unlikely event that oil from a subsurface spill would reach the biota of a live 

bottom, the effects would be primarily sublethal. In the very unlikely event that oil from a subsurface 

spill reached an area containing coral cover in lethal concentrations, the recovery period could exceed 

10 years (Fucik et al., 1984). In the event that a live bottom suffers severe mechanical damage (e.g., 

vessel collision), recovery could take decades depending on the extent of the damage. Because these 

events are rare, the potential for impacts is considered low. For information on impacts resulting from a 

catastrophic spill, refer to Appendix B. 

Non-OCS oil- and gas-related activities (e.g., anchoring, trawling, and vessel collisions) can damage 

live bottoms, resulting in impacts similar to those described above. Commercial fishing activities may 

dislodge or damage organisms inhabiting live bottoms if lines or trawls are dragged across the live bottom 

surface or become entangled. Natural events of sufficient magnitude (e.g., hurricanes or earthquakes) 

may also cause severe impacts. Recreational SCUBA diving, fishing, and discharges or spills from 

tankering of imported oil may also have adverse impacts on live bottoms. Overall, the incremental 

contribution of a CPA proposed action to the cumulative impact is negligible.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources and scientific journals was conducted to determine the 

availability of recent information (including ACS Publications, BioOne, EBSCO, Elsevier, the Gulf of 

Mexico Fishery Management Council website, JSTOR, NMFS databases, NOAA Gulf Spill Restoration 

Publications website, PLoS ONE, Science Direct, and SeaGrant website). This search revealed new 

information relevant to an analysis of the potential impacts of OCS oil- and gas-related activities on live 

bottom benthic communities.

Investigations of deepwater corals following the Deepwater Horizon oil spill and response suggest 

visually observable impacts may be limited to communities within 25 km (16 mi) of the well site (White 

et al., 2012; Hsing et al., 2013; and Fisher et al., 2014). Substantial impacts to corals have not been 

documented north of the well. The only affected corals identified by White et al. (2012) are located 
4-32 Central and Eastern Planning Areas Supplemental EIS

11 km (7 mi) southwest of the well site, and the two impacted communities discovered by Fisher et al. 

(2014) are located 6 km (4 mi) south and 22 km (14 mi) southeast of the well. Within each affected 

community, impacts were patchy and coral response to exposure varied. The colony identified by White 

et al. (2012) was surveyed five times over a 17-month period to document the temporal progression of 

coral response to acute oil exposure (Hsing et al., 2013). During the study period, corals exhibited a 

dramatic decrease in observable impacts, indicating resiliency to acute oil exposure (Hsing et al., 2013) 

and possibly recovery.

The limited geographic extent of impacts from subsurface oil exposure documented by White et al. 

(2012), Hsing et al. (2013), and Fisher et al. (2014) suggests that oil from the Deepwater Horizon oil spill

may not have impacted corals inhabiting the Pinnacle Trend or live bottom (low relief) habitats. The 

Pinnacle Trend feature nearest the well is approximately 60 km (37 mi) to the north, and the highest 

concentration of Pinnacle features is 100 km (62 mi) to the northeast. In addition, research into the 

potential impacts to fishes that potentially use or inhabit waters adjacent to the Pinnacles suggest that 

many species may not have been severely impacted (Fodrie and Heck, 2011; Moody et al., 2013; Rooker, 

2013; Incardona et al., 2014; Mager et al., 2014). For additional information, refer to Chapters 4.1.1.18 

and 4.1.1.19 of this Supplemental EIS and Chapters 4.2.1.18 and 4.2.1.19 of the CPA 235/241/247 

Supplemental EIS. Therefore, BOEM finds that, as more information has become available, the research 

supports the analyses in anticipating localized, temporary impacts.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS, as well as in the previously mentioned 

NEPA documents, BOEM has identified incomplete or unavailable information related to live bottoms in 

the CPA. The potential impacts to organisms associated with live bottoms (Pinnacle Trend and low 

relief) as a result of the Deepwater Horizon oil spill and response have not been specifically addressed in 

the current literature. However, available information on species and habitats similar to those associated 

with the Pinnacle Trend and low relief live bottoms provides sufficient basis from which to extrapolate 

potential impacts; it is reasonable to assume that similar responses may be expected. Data collected in the 

vicinity of the Pinnacle Trend features is under development through the NRDA process and may be 

relevant to an analysis of live bottom (Pinnacle Trend and low relief) habitat in the CPA. However, 

analysis of these data may take years to complete and the outcome cannot be predicted. Although the 

body of available information is incomplete and long-term effects cannot yet be known, evidence does not 

suggest that assemblages associated with live bottom (Pinnacle Trend and low relief) habitat sustained 

severe adverse impacts. BOEM has determined that the incomplete or unavailable information is not 

essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for live bottoms presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented above. No new significant information was discovered that would alter 

the impact conclusion for live bottoms presented in those NEPA documents because of the available 

scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.7. Topographic Features

BOEM has reexamined the analysis for topographic features presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for topographic features presented in those NEPA documents. The analysis 
Description of the Environment and Impact Analysis 4-33

and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 

247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.7 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.7 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.7 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Topographic features are hard bottom habitats and are rare compared with the ubiquitous soft bottoms

in the GOM (Parker et al., 1983). These features can be upthrusts of rock due to an uplift of the 

underlying salt (diapirs) or the remnants of fossilized shorelines. These topographic highs, or subsea 

banks, provide an island of hard substrate in a virtual ocean of soft bottoms. Wherever rock protrudes up 

into the water column, reef organisms may thrive. The type of organisms inhabiting a reef is determined 

by environmental conditions. There are 37 protected topographic features in the GOM: 21 in the WPA 

and 16 in the CPA.

Because of the recognized importance of the topographic features, BOEM proposes attaching the 

Topographic Features Stipulation to OCS oil and gas leases within Topographic Feature Stipulation 

blocks. When applied, this mitigation would prevent most of the potential impacts on topographic 

features from bottom-disturbing activities (structure removal and emplacement) and operational 

discharges associated with a CPA proposed action through avoidance. In addition, it would distance 

topographic features from possible accidental events. The mitigation would require that bottomdisturbing activities be located at least 152 m (500 ft) from a topographic feature’s No Activity Zone and 

that drill cuttings and fluids from wells within designated shunting zones must be shunted to the seafloor, 

although shunting requirements can vary among features.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on topographic features of the CPA could include 

bottom-disturbing activities such as anchoring, infrastructure emplacement or removal, and drillingeffluent and produced-water discharges. These factors could result in crushing and smothering of 

sensitive organisms and exposure to concentrated discharges. If the Topographic Features Stipulation is 

applied, it will minimize the potential impacts to the topographic features by distancing bottom-disturbing 

activities from the sensitive habitat. The distancing eliminates the possibility of anchors, pipelines, and 

structures being placed on top of the features, and structure removal activity will be distanced enough to 

minimize impacts to topographic features. If any contaminants reach topographic features, the 

contaminants would be diluted from their original concentration, and impacts that may occur should be 

minimal. In addition to the mitigations, discharges or activities that could harm topographic features are 

regulated by other agencies, including discharge permit restrictions from USEPA and essential fish 

habitat restrictions from NOAA. Furthermore, the high-energy environment and prevailing water currents 

associated with topographic features would help protect the features by enabling rapid turnover of the 

water column.

Adverse effects from accidental disturbances resulting from a CPA proposed action could include 

surface and subsurface oil spills and blowouts. Each has the potential to disrupt and alter the 

environmental, commercial, recreational, and aesthetic values of topographic features of the CPA through 

oiling and sedimentation. The proposed Topographic Features Stipulation would assist in preventing 

most of the possible accidental impacts on topographic feature communities by increasing the distance of 

such events from the topographic features. It is expected that the majority of subsurface oil released 

during an accidental event would rise rapidly to the surface and that the most heavily oiled sediments in 

the water column would likely be deposited on the seafloor before reaching the topographic features. In 

the event that diluted oil from a subsurface spill did reach the biota of a topographic feature, the effects 

would be primarily sublethal and impacts would be at the community level. Any turbidity, sedimentation, 

and oil adsorbed to sediment particles would also be at low concentrations by the time the topographic 

features were reached, likely resulting in primarily sublethal impacts. Impacts from a surface oil spill on 

topographic features are also lessened by the distance of the spill to the features, the depth of the features, 
4-34 Central and Eastern Planning Areas Supplemental EIS

and the prevailing water currents that sweep around the features. For information on impacts resulting 

from events outside the scope of routine activities and accidental events, refer to Appendix B. 

Cumulative Impacts

The cumulative impact from routine OCS oil- and gas-related operations includes effects resulting 

from a CPA proposed action, as well as those resulting from past and future OCS leasing. These 

operations include anchoring, structure emplacement, muds and cuttings discharge, effluent discharge, 

blowouts, oil spills, and structure removal. Without mitigation, these factors could result in crushing and 

smothering of organisms on topographic features or exposure to concentrated discharges or oil. Lowprobability catastrophic spills in the vicinity of one of these features could also potentially cause damage 

to benthic biota (refer to Appendix B for more details). Impacts from OCS oil- and gas-related activities 

would be mitigated by the continued application of the proposed Topographic Features Stipulation, 

precluding physical damage caused by oil and gas leaseholders by establishing a buffer around the 

features. As such, little impact would be incurred by the biota of the topographic features as a result of 

OCS oil- and gas-related activities. The USEPA’s discharge regulations and permits would further 

reduce discharge-related impacts.

Potential non-OCS oil- and gas-related factors include vessel anchoring, SCUBA diving, treasurehunting activities, import tankering, heavy storms and hurricanes, the collapse of the tops of the 

topographic features due to dissolution of the underlying salt structure, and fishing activities. Many of 

these non-OCS oil- and gas-related factors may result in physical damage to organisms that colonize 

topographic features. For example, treasure hunting activities in the 1980’s resulted in several large 

cavities being dug on one of the topographic features that has yet to recover. Anchoring can result in the 

destruction of hard corals due to the ability of anchor lines to cut through the coral heads. Anchoring can 

also result in the tearing of soft corals from the seafloor during anchor removal or the movement of the 

anchoring line through the water column. Because corals and other benthic fauna are slow growing, 

physical disturbance represents the greatest threat to the organisms that colonize topographic features.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources (e.g., the NOAA Gulf Spill Restoration Publications website, 

the Environmental Response Management Application [ERMA] Gulf Response website; NOAA’s 

Deepwater Horizon Archive Publications and Factsheets; the Gulf of Mexico Sea Grant Deepwater 

Horizon Oil Spill Research and Monitoring Activities Database; RestoreTheGulf.gov website, and the 

Deepwater Horizon Oil Spill Portal) and public search engines to search published journal articles, 

Federal documents, and research reports was conducted to determine the availability of recent information 

on topographic features. The search revealed new information on the affected environment that is 

pertinent to this Supplemental EIS.

Newly published research related to the corals found a high degree of population connectivity among 

the Flower Garden Banks and other coral reefs in the Florida Reef Tract and the Caribbean (GoodbodyGringley, 2011; Serrano, 2013). Genetic similarities for shallow-water Montastraea cavernosa

populations suggest that the Flower Gardens may be an important larval source and/or that there is an 

unidentified source providing larvae throughout the region. Differences among populations in appearance 

are phenotypic rather than genetic (Goodbody-Gringley, 2011; Serrano, 2013). As such, if further 

research determines that the Flower Gardens Banks are a larval source for the Florida Reef Tract, then 

these source corals may be more important to the ecology of the Gulf of Mexico at the landscape scale 

than previously suggested. The Flower Garden Banks are located in the WPA, but it demonstrates that 

the topographic structures located all along the shelf edge in the CPA can be connected at the landscape 

and basin scale.

For the Flower Gardens, BOEM has published a study in conjunction with the Flower Garden Banks

National Marine Sanctuary that monitored multiple species of vertebrates and invertebrates found on the 

topographic structures (Johnston et al., 2013). They found that the reefs are among the healthiest in the 

GOM with relatively high coral cover but relatively low species diversity. They also state that the reefs 

have maintained this status throughout a time period when OCS oil and gas development has occurred in 
Description of the Environment and Impact Analysis 4-35

nearby blocks, suggesting that the Topographic Features Stipulation does successfully mitigate against 

impacts due to routine activities and accidental events.

Additionally, Nash et al. (2013) reviewed the species diversity at the topographic features located off 

the southern Texas coast and found that each of these banks exhibited a high degree of diversity but that 

research on these features has not been updated in decades. They also noted that Southern Bank was a 

good surrogate for understanding trends in biodiversity among the other banks in the region and that it 

could be used as a sentinel site to detect landscape-scale changes. They also suggest that these reefs may 

have a high degree of connectivity with the Tuxpan Reef System in Mexico, emphasizing the role of 

topographic features on regional ecological processes.

At Stetson Bank, a topographic feature in the WPA, DeBose et al. (2012) found that the feature has 

undergone two shifts in population structure since 1999. The result is that the community has changed 

from a coral-sponge community to an algal-dominated community. The exact causes of the shifts are 

undetermined, but it is suggested that the increased hurricane activity in 2005 and a regionwide coral 

bleaching event may have been threshold events preventing recovery of the coral-sponge community. 

This study does not implicate development of any OCS oil and gas resources as a potential cause of the 

community shifts. Although this site is in the WPA, the conditions that affect the bank are found 

throughout the Gulf of Mexico.

With respect to the actual concentration of PAHs in the samples of oil from the Macondo well 

collected during the NRDA process, questions have been raised about the sampling methodology used 

during the NRDA sampling cruises. Sammarco et al. (2013) criticized the technique of using Niskin 

bottles to collect at discrete positions within the water column in favor of techniques that collected or 

filtered larger quantities of water using other sampling media. Their results suggest that PAH 

concentrations may be more prevalent and more concentrated than reported by NRDA. The only 

topographic feature they sampled was in the CPA (Sackett Bank), but if exposure was higher there, the 

possibility exists that exposure to other topographic features throughout the Gulf of Mexico may have 

been greater than previously thought. 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. Working in deep marine systems is complex and requires substantial resources, 

and as such, research on these features has been limited. Thus, there is a substantial amount of 

information that remains unknown about these features. All analyses discussed in this Supplemental EIS 

and in Chapter 4.2.1.7 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental 

EIS, and Chapter 4.1.1.7 of the CPA 235/241/247 Supplemental EIS are based on incomplete 

information. Because topographic features are not unique to the CPA, information collected throughout 

the GOM has been used in this analysis. For example, our understanding of the possible impacts of 

surface oil spills to topographic features in the GOM was determined by combining research on the depth 

and concentration of physical mixing of surface oil with the known depths of CPA topographic features. 

These results suggest that, although oil measurements were not collected at every feature under every 

condition, topographic features exist at depths deeper than lethal concentrations of oil would be expected 

(Lange, 1985; McAuliffe et al., 1975 and 1981a; Tkalich and Chan, 2002; Rezak et al., 1983; Wyers 

et al., 1986) unless dispersants are used. Additionally, continuous monitoring of the Flower Garden 

Banks since the 1970’s for impacts related to OCS development suggests that BOEM’s topographic 

features stipulations may achieve the stated objective of minimizing damage to topographic features from 

OCS oil- and gas-related activities (refer to Johnston et al., 2013, and references therein). At the Flower 

Garden Banks, corals have flourished while OCS development has occurred, and in some cases, activities 

have taken place just outside the mitigation zone. Since corals are generally considered to be more fragile 

than most other organisms found in the CPA, it is reasonable to conclude that topographic features in the 

CPA with more resilient organisms than the Flower Garden Banks have not negatively impacted other 

topographic structures in the GOM.

With respect to unavailable information in relation to the Deepwater Horizon explosion, oil, spill, and 

response, the majority of this information cannot be obtained because it has not been released. Relevant 

data on the status of topographic features may take years to acquire and analyze. This unavailable 
4-36 Central and Eastern Planning Areas Supplemental EIS

information may be relevant to adverse effects because the Deepwater Horizon explosion, oil spill, and 

response may have caused changes to baseline conditions for topographic features in the Gulf of Mexico. 

While outstanding reports are not expected to reveal reasonable foreseeably significant effects, BOEM 

nonetheless determined that additional information could not be timely acquired and incorporated within 

the timeline contemplated in the NEPA analysis of this Supplemental EIS. For example, if sampling 

techniques show that oil concentration were greater at Sackett Bank in the CPA (Sammarco, 2013), then it 

is possible that more oil reached other topographic features in the CPA than previously reported. 

However, until this information is made available, it is impossible to make this determination.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from available information in completing this analysis and formulating the conclusions presented here. 

Although the body of available information is incomplete, the evidence currently available supports past 

analyses and does not indicate severe adverse impacts to topographic features. Therefore, BOEM has 

determined that the incomplete or unavailable information is not essential to a reasoned choice among 

alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for topographic features presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on

the additional information provided above. No new significant information was discovered that would 

alter the impact conclusion for topographic features presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis of potential impacts discussed in those documents still applies for the proposed 

CPA Lease Sales 241 and 247. It is concluded that the CPA proposed action would have a negligible or 

minor impact on the topographic features of the CPA.

4.1.1.8. Sargassum Communities

BOEM has reexamined the analysis for Sargassum communities presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented below. No new significant information was discovered 

that would alter the impact conclusion for Sargassum and Sargassum communities presented in those 

NEPA documents. The analysis and potential impacts discussed in those documents still apply for 

proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.8 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.8 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.8 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Sargassum is one of the most ecologically important brown algal genera found in the pelagic 

environment of tropical and subtropical regions of the world. The pelagic complex in the GOM is mainly 

comprised of S. natans and S. fluitans (Lee and Moser, 1998; Stoner, 1983; Littler and Littler, 2000). 

Both species of Sargassum live immediately below the water surface and are fully adapted to a pelagic 

existence (Lee and Moser, 1998). These floating plants may be up to a few meters in length and may be 

found floating alone or in larger rafts or mats that support communities of fish and a variety of other 

marine organisms. The distribution, size, and abundance of Sargassum mats varies depending on 

environmental and physiochemical factors such as temperature, salinity, and dissolved oxygen.

Impacts of Routine Activities and Accidental Events

Impact-producing factors associated with routine events for a CPA proposed action that could affect 

Sargassum communities may include the following: (1) drilling discharges (i.e., muds and cuttings); 

(2) produced water and well treatment chemicals; (3) operational discharges (i.e., deck drainage, sanitary 

and domestic water, and bilge and ballast water); and (4) physical disturbance from vessel traffic and the 

presence of exploration and production structures (i.e., rigs, platforms, and MODUs). Considering 
Description of the Environment and Impact Analysis 4-37 

Sargassum’s widespread distribution and occurrence in the upper water column near the sea surface, it 

may be contacted by routine discharges from oil and gas operations; however, the quantity and volume of 

these discharges is relatively small compared with the surface area of pelagic waters of the CPA 

(268,922 km2

; 103,831 mi2). Therefore, contact through routine activities would only occur for a small 

portion of the Sargassum population and associated communities. Because these discharges are highly 

regulated to control toxicity and because they would continue to be diluted in the Gulf water, reducing 

concentrations of any toxic component, produced-water impacts on Sargassum communities would be 

minimal.

The impingement by service vessels, working platforms, and drillships would contact only a very 

small portion of the Sargassum population. For algae coming in contact with OCS oil- and gas-related 

equipment, most should remain unharmed as they are pushed out of the way, but a small percentage of 

algae may be physically destroyed via propellers or stranded and subsequently become desiccated. For 

animals, the smaller organisms could be stranded with the algae or be destroyed by the equipment. 

Larger animals that often associate with Sargassum could avoid contact with most equipment. Because 

the distribution of Sargassum is dependent on many factors, the result is that the distribution is 

unpredictable and haphazard. As such, impacts to Sargassum communities associated with a CPA 

proposed action are expected to have a negligible or minor effect on the small portion of the Sargassum

community that could be contacted. Additionally, Sargassum and many of the associated species have 

adapted a rapid growing lifestyle to allow for rapid recovery from negative impacts. No measurable 

impacts are expected to the overall population of the Sargassum community.

Potential impact-producing factors associated with accidental events for a CPA proposed action that 

could affect Sargassum and its associated communities include (1) spills (i.e., surface oil, fuel spills, and 

underwater well blowouts), (2) spill-response activities, and (3) chemical spills. These impacting factors 

would have varied effects depending on the intensity of the spill and the presence of Sargassum in the 

area of the spill. All types of spills, including surface oil and fuel spills, underwater well blowouts, and 

chemical spills, could potentially contact Sargassum communities. The quantity and volume of most of 

these spills would be relatively small compared with the surface waters of the CPA (268,922 km2

; 

103,831 mi2

). Therefore, most spills would only contact a small portion of the Sargassum complex. 

Accidental spills would be diluted by Gulf water and, therefore, concentrations of toxic components that 

could potentially contaminate or kill Sargassum tissues or the associated community would also be 

reduced in this scenario. Any Sargassum that did come in contact with large concentrations of oil would 

eventually sink and advect oil bound to the algae to the seafloor. Presumably, any vessel contact during 

response activities to Sargassum would be to capture algae that are dead or dying due to contact with oil 

released during a spill, as such, response vessels would not impact the algae more than they are already 

impacted by the oil. The impacts to Sargassum associated with a CPA proposed action are expected to 

have only minor effects to a small portion of the Sargassum community. In the case of a very large spill, 

the consequences would be death of a large number of algae across a geographically large area in the 

northern Gulf of Mexico. However, the Sargassum community complex lives in pelagic waters with 

generally high water quality and is expected to show good resilience to the predicted effects of spills. It 

has a yearly growth cycle that promotes quick recovery from impacts and that would be expected to 

restore typical population levels in 1-2 growing seasons. For information on the impacts resulting from 

events outside the scope of routine activities and accidental events, refer to Appendix B. 

Cumulative Impacts

Cumulative impacts from OCS oil- and gas-related operations include effects resulting from a CPA 

proposed action, as well as those resulting from past and future OCS leasing. These operations include 

drilling discharges, produced water and well treatment chemicals, operational discharges, accidental 

spills, and physical disturbance from OCS oil- and gas-related vessels and structures. Potential non-OCS 

oil- and gas-related factors include hurricanes, water quality, and non-OCS oil- and gas-related vessel 

traffic. 

The OCS oil- and gas-related vessels transiting the GOM pass through Sargassum mats, producing 

slight impacts to the Sargassum community by breaking up clumps/mats or physically destroying the 

algae. Turbulence from wakes and direct damage from propellers on vessels servicing OCS oil- and gasrelated activities could affect Sargassum by breaking up mats or destroying strands. However, the 

amount of damage that vessels could inflict on a Sargassum mat would be minimized because of 
4-38 Central and Eastern Planning Areas Supplemental EIS

Sargassum’s temporary and seasonal nature. When present, Sargassum mats are naturally loose knit with 

the ability to break apart and re-form. Any vessel-related damage would likely be seen in the community 

of organisms inhabiting these mats, which may be killed when being struck by a vessel. Sea turtles and 

small fishes that reside in (rather than below) Sargassum mats would be most susceptible to this type of 

damage. However, the foot print of any vessel in the CPA is small compared with the distribution of 

Sargassum, and its transitory life history minimizes the possibility that any mat or the inhabitants are 

routinely affected. None of these would have more than minor localized effects to the affected mats as 

these mats routinely break up and move across extensive areas. The OCS oil- and gas-related structures 

can alter the movement of Sargassum mats and entrap small quantities of the algae. Because the 

proposed activity is not expected to substantially increase (if any) the number of OCS oil- and gas-related 

vessels, it is likely that OCS oil- and gas-related activities will only have a minimum and local effect on 

the Sargassum community.

Accidental spills could contribute to the cumulative impacts of OCS oil- and gas-related activities if 

an accidental spill was exceptionally large, located in the “nursery” area where Sargassum resides in the 

western GOM, and was during a time of the year when the standing stock is restricted to the “nursery” 

area (e.g., late winter and spring) (Gower and King 2011). The probability of this happening temporally 

and spatially is extremely low (refer to Appendix B). Given the life history of Sargassum, recovery of 

the algae could occur relatively rapidly; however, during the recovery period, animals that rely on 

Sargassum to move around the Gulf or use Sargassum for refuge would be severely impacted due to the 

loss of habitat or a method of transportation. Cumulative impacts would be most pronounced for animals 

that rely exclusively on Sargassum and have low reproduction rates or have larvae that only disperse 

locally. Any spill that was noncatastrophic would likely only result in localized and short-term adverse 

impacts that would contribute little to the overall cumulative effect of a CPA proposed action.

Potential non-OCS oil- and gas-related factors include hurricanes, water quality, and non-OCS oiland gas-related vessel traffic. Hurricanes are major natural sources of impacts that affect Sargassum. 

The energy associated with these storms can break up mats, destroy strands, and displace animals; 

however, the life history and the widespread distribution of Sargassum communities minimize the 

probability that any given storm will have any lasting population-level effects. Violent surface turbulence 

caused by these storms would dislocate many of the organisms living on and in the Sargassum. Some of 

the organisms (those that cannot swim or swim only weakly) such as nudibranchs (sea slugs), shrimp, 

Sargassum fish (Histrio histrio), and pipefish (Syngnathus spp.) would become separated from the algae. 

Without cover, many would fall prey to fish after a storm; others may sink to the seafloor and die. Some 

epifauna, such as hydroids, living on the algae may suffer physical damage or be broken off. Hurricanes 

can also drive Sargassum into waters less conducive for growth and can strand large quantities on 

beaches. In addition, Sargassum communities may be susceptible to nonpoint-source pollution from 

land-based runoffs carrying pollutants and excessive nutrients, especially in nearshore areas. The results 

could be a basinwide reduction in Sargassum biomass. Turbulence from wakes, direct damage from 

propellers, impingement on non-OCS oil- and gas-related vessels (i.e., commercial shipping, fishing 

activity, and pleasure boating) could also affect Sargassum by breaking up mats, destroying algae, or 

stranding algae. However, the amount of damage that vessels could inflict on a Sargassum mat would be 

minimized because of Sargassum’s transitory nature. Any vessel-related damage would likely be seen in 

the community of organisms inhabiting these mats, which may be killed by being struck by a vessel. Sea 

turtles and small fishes that reside in (rather than below) Sargassum mats would be most susceptible to 

this type of damage.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources (e.g., the NOAA Gulf Spill Restoration Publications website, 

NOAA’s Environmental Response Management Application [ERMA] Gulf Response website, NOAA’s 

Deepwater Horizon Archive Publications and Factsheets, the Gulf of Mexico Sea Grant Deepwater 

Horizon Oil Spill Research and Monitoring Activities Database, RestoreTheGulf.gov website, and the 

Deepwater Horizon Oil Spill Portal) and public search engines to search published journal articles, 

Federal documents, and research reports was conducted to determine the availability of recent information 

on Sargassum communities. The search revealed new information on nursery areas for Sargassum, 

Sargassum’s suitability as habitat for other organisms, and impacts related to oil and dispersant exposure.
Description of the Environment and Impact Analysis 4-39

One of the primary publications relevant to this Supplemental EIS is the identification of the 

northwest Gulf of Mexico and the area near the mouth of the Amazon River as “nursery areas” for 

Sargassum in the Sargasso Sea. Estimates suggest that between 0.6 and 6 million metric tons of 

Sargassum are present annually in the Gulf of Mexico, with an additional 100 million metric tons 

exported to the Atlantic basin (Gower and King, 2008; Gower and King, 2011; Gower et al., 2013). This 

highlights the importance of the GOM in the global transport of Sargassum and that, even if there is a 

catastrophic spill in the GOM at the right place and time to severely impact Sargassum populations, the 

GOM is not the only source for the Sargasso Sea.

In addition, Rooker et al. (2012) quantified the use of Sargassum by billfishes in the Gulf of Mexico 

and concluded that the Sargassum biomass was not a suitable habitat for most juvenile billfishes because 

it can concentrate predators. As such, small-scale losses of Sargassum may not negatively impact billfish 

populations because billfish that settle in Sargassum may have a naturally low survival rate due to the fact 

that Sargassum also concentrates animals that prey on billfish of this size.

Powers et al. (2013) suggest that exposure to oil and/or dispersants can result in direct, sublethal, and 

indirect effects to Sargassum, resulting in death or a decrease in Sargassum-related ecosystem services. 

Therefore, if Sargassum is exposed to oil at the surface, it is expected that some of the algae material will 

die back or no longer provide a suitable habitat for other organisms. Their results were variable with 

respect to the amount of time or the rate it took for the algae to die back or succumb. Under normal 

conditions in the GOM, both species of Sargassum co-exist and conditions would never be identical to 

those in a laboratory. Ultimately, damage may occur to Sargassum if it is exposed to oil or dispersant; 

however, the effects would be localized and variable.

Finally, NMFS recently designated Sargassum as a critical habitat for loggerhead turtles (Caretta 

caretta) in the Gulf of Mexico and northwest Atlantic Ocean (Federal Register, 2014b). In the GOM, this 

includes all Sargassum between the 10-m (33-ft) depth contour and the outer boundary of the Exclusive 

Economic Zone. This designation could impact the commercial harvest of Sargassum; however, to our 

knowledge, the commercial harvest of Sargassum does not occur in the GOM. Additionally, NMFS does 

not expect that this designation would add any risk factors or add any conservation measures by BOEM 

because sea turtles and their required habitats are already adequately protected through the ESA Section 7 

process. For more information, refer to Chapter 4.1.1.13. 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.8 of the 2012-2017 

WPA/CPA Multisale EIS and WPA 233/CPA 231Supplemental EIS and Chapter 4.1.1.7 of the CPA 

235/241/247 Supplemental EIS, BOEM has identified unavailable information regarding Sargassum and 

Sargassum communities in the CPA. This incomplete or unavailable information includes information on 

the effects of in-situ oil exposure and the movement patterns of Sargassum. BOEM used existing 

information and reasonably accepted scientific methodologies to extrapolate in completing this analysis. 

BOEM has determined that there are few foreseeable significant adverse impacts to the Sargassum 

population associated with routine or accidental OCS oil- and gas-related events using publications such 

as Gower and King (2011), Gower et al. (2013), and Powers et al. (2013). Gower and King (2011) and 

Gower et al. (2013) suggest that Sargassum is continually present in the west-central GOM and that it 

moves in a general west to east pattern during the growing season; however, movements at a finer 

temporal or spatial scale are more difficult to predict. Liu et al. (2014) noted that the toxicity or the 

presence of oil across the surface waters of the GOM was also variable at any given time, suggesting that 

it is difficult to predict the effects of coming in contact with surface oil. Additionally, Lindo-Atichati 

(2012) suggested that patterns of larval fish in the surface currents in the northern GOM were not 

consistent spatially or temporally and that they were highly dependent on mesoscale current structures 

like the Loop Current and associated eddies. Combined, these studies suggest that, as Sargassum is 

passively moved in the surface waters, its presence at any given location or at any given time is difficult 

to predict, especially as the population grows exponentially during the growing season. Powers et al. 

(2013) also suggests that there were adverse effects to Sargassum under the proper conditions, but the 

spatial or temporal extent of those effects remain unknown. It is expected that for routine activities or 
4-40 Central and Eastern Planning Areas Supplemental EIS

accidental events the probability of enough Sargassum coming in contact with oil and dying as a result of 

this contact are low given that oil and Sargassum are each controlled by surface currents in differential 

manners. Ultimately, the cosmopolitan nature across the northern GOM and the reproductive capabilities 

of Sargassum provide a life history that is resilient towards localized or short-term deleterious effects, 

such as those expected to be associated with routine OCS oil- and gas-related activities and 

noncatastrophic oil or chemical spills. Therefore, BOEM has determined that the incomplete information 

on Sargassum is not essential to a reasoned choice among alternatives and that the information used in 

lieu of the missing information is acceptable for this analysis.

BOEM recognizes that the incomplete information, with respect to possible impacts to Sargassum in 

the CPA as a result of the Deepwater Horizon explosion, oil spill, and response, may be relevant to the 

evaluation of impacts. Because of this, BOEM’s subject-matter experts have used available scientifically 

credible evidence in this analysis and applied it using accepted scientific methods and approaches to 

extrapolate in completing this analysis. Sargassum communities within the CPA were affected by the 

Deepwater Horizon explosion, oil spill, and response; however, because the spill did not occur near an 

area where Sargassum persists year round, abundance recovered rapidly. Powers et al. (2013) 

documented a four-fold increase in Sargassum in the north-central GOM in the years following the spill. 

Additional information related to other possible adverse impacts of the Deepwater Horizon explosion, oil 

spill, and response to Sargassum communities in the CPA cannot be obtained during the timeline 

contemplated in the NEPA analysis of this Supplemental EIS because data related to research and 

monitoring related to the Deepwater Horizon explosion, oil spill, and response has yet to be completed 

and made publicly available. Therefore, BOEM has determined that the information is not essential to a 

reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for Sargassum communities presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for Sargassum communities presented in those NEPA documents

because of the available scientifically credible evidence in this analysis and based upon accepted 

scientific methods and approaches. The analysis and potential impacts discussed in those documents still 

apply for proposed CPA Lease Sales 241 and 247.

4.1.1.9. Chemosynthetic Deepwater Benthic Communities

BOEM has reexamined the analysis for chemosynthetic deepwater benthic communities presented in 

the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for chemosynthetic deepwater benthic 

communities presented in those previous NEPA documents. The analysis and potential impacts discussed 

in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.9 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.9 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.9 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on chemosynthetic deepwater benthic communities of 

the CPA are bottom-disturbing activities associated with anchoring, structure emplacement, pipelaying, 

structure removal, and discharges of drill cuttings, muds, and produced water. The application of 

avoidance criteria for chemosynthetic communities provided as guidance in NTL 2009-G40, “Deepwater

Benthic Communities,” precludes the placement of a well within 610 m (2,000 ft) of any suspected site of 

a chemosynthetic community. Considerable mechanical damage could be inflicted upon deepwater 
Description of the Environment and Impact Analysis 4-41

chemosynthetic communities by routine OCS oil- and gas-related drilling activities associated with a CPA 

proposed action if mitigations are not applied to permits.

Bottom-disturbing activities associated with anchoring, structure emplacement, pipelaying, and 

structure removal cause localized bottom disturbances and disruption of benthic communities in the 

immediate area. Routine discharge of drill cuttings with associated muds can also affect the seafloor. 

Without mitigating measures, these activities could result in smothering by the suspension of sediments or 

the crushing of organisms residing in these communities. The risk of these physical impacts is greatly 

reduced by requiring the avoidance of potential chemosynthetic communities. Discharges of produced 

waters on the sea surface, chemical spills, and deck runoff would be diluted in surface waters, having no 

effect on seafloor habitats. Impacts from bottom-disturbing activities directly on chemosynthetic 

communities are expected to be extremely rare because of the application of required protective measures 

as described by NTL 2009-G40. Information included in required hazards surveys for OCS oil- and gasrelated activities depicts areas that could potentially harbor chemosynthetic communities. This allows 

BOEM to require avoidance of any areas that are conducive to chemosynthetic growth. If a high-density 

community is subjected to direct impacts by bottom-disturbing activities, potentially severe or 

catastrophic impacts could occur due to raking of the sea bottom by anchors and anchor chains, and 

partial or complete burial by muds and cuttings. The severity of such an impact is such that there would

be incremental losses of productivity, reproduction, community relationships, and overall ecological 

functions of the local community, and incremental damage to ecological relationships with the 

surrounding benthos.

Routine activities of a CPA proposed action are expected to cause no damage to the ecological 

function or biological productivity of chemosynthetic communities. Widely scattered, high-density 

chemosynthetic communities would not be expected to experience impacts from routine OCS oil- and 

gas-related activities in deep water because the impacts would be limited by the required avoidance 

criteria. Impacts on chemosynthetic communities from routine activities associated with a CPA proposed 

action would be minimal to none.

Accidental disturbances from a CPA proposed action, including subsea oil spills and blowouts, have 

the potential to result in impacts on chemosynthetic communities of the CPA. Accidental events that 

could impact chemosynthetic communities are primarily limited to seafloor blowouts. A blowout at the 

seafloor could create a crater and could resuspend and disperse large quantities of bottom sediments. 

Chemosynthetic communities could be susceptible to physical impacts, including smothering, from a 

blowout depending on bottom-current conditions. The avoidance criteria described above reduces the risk 

of these physical impacts by requiring a buffer of 610 m (2,000 ft) from wells. The avoidance required 

would protect sensitive communities from heavy sedimentation, with only light sediment components 

able to reach the communities in small quantities.

Studies indicate that periods as long as hundreds of years are required to reestablish a seep 

community once it has disappeared (depending on the community type) (Powell, 1995; Fisher, 1995). 

There is evidence that substantial impacts on these communities could permanently prevent 

reestablishment (Fisher, 1995), particularly if hard substrate required for recolonization is buried by 

resuspended sediments from a blowout. Because widely scattered, high-density chemosynthetic 

communities would be located at more than 610 m (2,000 ft) away from a blowout due to mitigating 

measures, potential accidental impacts from a CPA proposed action are expected to cause little damage to 

ecological or biological function of these communities.

If dispersants are applied to an oil spill or if oil is ejected under high pressure, oil would mix into the 

water column, be carried by underwater currents, and eventually contact the seafloor in some form, either 

concentrated (near the source) or decayed (farther from the source), where it may impact patches of 

chemosynthetic community habitat in its path. As with sediments, the farther the dispersed oil travels, the 

more diluted the oil will become as it mixes with surrounding water.

There is some reason to believe the presence of oil would have a limited effect on chemosynthetic 

organisms because these communities live among oil and gas seeps; however, natural seepage is very 

constant and at very low rates as compared with the potential volume of oil released from a blowout or 

pipeline rupture. In addition, organisms inhabit certain niches within the gradients found at oil seeps, 

choosing locations with enough hydrocarbons to sustain their metabolism but not enough to be toxic. All 

seep organisms also require unrestricted access to oxygenated water at the same time as exposure to 

hydrocarbon energy sources. Oil plumes that contact the seafloor before degrading could potentially 
4-42 Central and Eastern Planning Areas Supplemental EIS

affect sensitive benthic communities if they happen to encounter such a habitat in a localized area. The 

coating of organisms could cause mortality or sublethal effect.

Accidental impacts associated with a CPA proposed action would likely result in only minimal 

impacts to chemosynthetic communities with adherence to the proposed biological stipulation and the 

guidance provided in NTL 2009-G40.

Cumulative Impacts

Cumulative factors considered to impact the chemosynthetic communities of the Gulf of Mexico 

include both OCS oil- and gas-related and non-OCS oil- and gas-related activities. Cumulative OCS oiland gas-related impacts to deepwater communities in the Gulf of Mexico are considered negligible 

because of the application of the proposed mitigation. The most serious, impact-producing factor 

threatening chemosynthetic communities is physical disturbance of the seafloor, which could destroy the 

organisms of these communities. Such disturbance would most likely come from those OCS oil- and gasrelated activities associated with pipelaying, anchoring, structure emplacement, and seafloor blowouts. 

Drilling discharges and resuspended sediments have a potential to cause minor, mostly sublethal impacts 

to chemosynthetic communities, but substantial sediment accumulations could result in more serious 

impacts. Possible catastrophic oil spills (Appendix B) due to seafloor blowouts have the potential to 

devastate localized deepwater benthic habitats. This could occur in the case of a low-probability 

catastrophic spill combined with the application of dispersant or high-pressure ejection of oil, producing 

the potential to cause devastating effects on local patches of habitat in the path of subsea plumes where 

they physically contact the seafloor. The possible impacts, however, will be localized due to the 

directional movement of oil plumes by the water currents and because the sensitive habitats have a 

scattered, patchy distribution. Oil plumes that remain in the water column for longer periods would 

disperse and decay, having only minimal effect. However, these events are rare and would only affect a 

small portion of the sensitive benthic habitat in the Gulf of Mexico.

The non-OCS oil- and gas-related impact-producing factors include activities such as commercial 

fishing, trawling, storm impacts, and climate change. Fishing and trawling could potentially crush, 

topple, and remove chemosynthetic communities in the path of the gear. Because of the water depths 

where chemosynthetic communities live (>300 m; 984 ft) and because of the low density of potentially 

commercially valuable fishery species, these activities are not expected to substantially impact deepwater

benthic communities. However, if trawling were to occur over a chemosynthetic community, the 

community may be devastated. Regionwide and even global impacts from CO2 build-up and proposed 

methods to sequester carbon in the deep sea (e.g., ocean fertilization) are not expected to have major 

impacts to deepwater habitats in the near future. This is because changes to water temperature and pH 

from the CO2 would not reach extremes at the water depths where chemosynthetic communities occur. 

Overall, non-OCS oil- and gas-related activities are not expected to greatly impact chemosynthetic

communities, and the incremental contribution of a CPA proposed action to cumulative impacts is 

expected to be negligible to minor due to the proposed mitigation. 

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A broad Internet search for relevant new information and scientific journal articles made available 

since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

the CPA 235/241/247 Supplemental EIS was conducted using a publicly available search engine. The 

websites for Federal and State agencies, as well as other organizations, were reviewed for newly released 

information. Sources investigated include NOAA’s Ocean Exploration website, the Gulf of Mexico 

Alliance, the U.S. Environmental Protection Agency, USGS, and coastal universities.

Becker et al. (2013) studied stable isotope compositions of macrofaunal communities from shallow 

and deep sites. Tissue from shrimp and vestimentiferan tubeworm analysis showed that seep animals 

derive a greater proportion of their nutrition from seeps (and less from the surface) at greater depths. This 

study is relevant as it contributes to BOEM’s understanding of how these communities grow. No new 

studies that are relevant to deepwater chemosynthetic communities and that would impact those analyses 

or conclusions have been made available since publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS.
Description of the Environment and Impact Analysis 4-43

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in those NEPA documents, there remains incomplete or 

unavailable information on the effects of the Deepwater Horizon explosion, oil spill, and response on 

chemosynthetic communities that could potentially be relevant to reasonably foreseeable significant 

adverse impacts. Ongoing research projects funded by NOAA and the National Science Foundation are 

investigating these impacts. This information cannot reasonably be obtained because the long-term 

effects may not yet be detectable and the means to obtain it are unknown. This unavailable information 

may be relevant to adverse effects because it could provide an example of adverse impacts directly caused 

by the blowout of a well.

Existing information suggests that chemosynthetic communities did not experience significant 

adverse impacts from the Deepwater Horizon explosion, oil spill, and response. Numerous cruises using 

research ships, submersibles, and drift cameras investigated the seafloor in the area surrounding the well 

site (USDOC, NOAA, 2011a and 2011b). Damage to chemosynthetic communities in the vicinity of the 

Macondo well has not been reported to date (Shedd, official communication, 2014). Therefore, it has not 

been demonstrated that even a catastrophic oil spill would have significant adverse impacts or change the 

baseline for chemosynthetic communities in the Gulf of Mexico. Even if this incomplete or unavailable 

information becomes available and ultimately demonstrates that such communities in the vicinity of the 

Macondo well have been severely impacted by the Deepwater Horizon explosion, oil spill, and response, 

BOEM has determined that the information is not essential to a reasoned choice among alternatives 

because it is clear that widespread impacts did not occur, or some indication of these impacts would have 

been revealed by the numerous studies to date. Even if some impacts did occur, chemosynthetic 

communities are found throughout the Gulf and are in patchy distributions, thus minimizing the 

proportion that would be likely to be impacted by any single event.

BOEM has also identified incomplete or unavailable information regarding the abundance and 

distribution of chemosynthetic communities in the GOM. Current understanding of the relationship 

between reflectivity of the seafloor and occurrence of potential habitat for chemosynthetic communities is 

used by BOEM to assess whether such communities occur in the vicinity of proposed OCS oil- and gasrelated activities. Similarly, side-scan sonar data are also used to determine the presence of likely habitat. 

These and other data are used to implement distance requirements to protect these communities. 

Incomplete or unavailable information could change our understanding of what signatures from such data 

sources indicate. Development of improved data or methods could help in determining where 

chemosynthetic communities occur. Such information could be used by BOEM to reduce impacts to 

these communities. Available scientifically credible information has been applied by BOEM’s subjectmatter experts using accepted scientific methodologies. The confirmed presence of chemosynthetic 

communities in areas predicted to have likely habitat via reflectivity or side-scan sonar data indicates that 

BOEM is currently able to effectively protect these communities from OCS oil- and gas-related activities. 

Therefore, BOEM has determined that the information is not essential to a reasoned choice among 

alternatives because existing information has shown that current methods provide for an appropriate 

means for protecting these communities.

Summary and Conclusion

BOEM has reexamined the analysis for chemosynthetic communities presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS, with the understanding that no new significant information on chemosynthetic communities has 

become available since the publication of those NEPA documents. Therefore, no new significant 

information was discovered that would alter the impact conclusion for chemosynthetic communities 

presented in those NEPA documents because of the available scientifically credible evidence in this 

analysis and based upon accepted scientific methods and approaches. The analysis and potential impacts 

discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.
4-44 Central and Eastern Planning Areas Supplemental EIS

4.1.1.10. Nonchemosynthetic Deepwater Benthic Communities

BOEM has reexamined the analysis for nonchemosynthetic deepwater benthic communities presented 

in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information presented below. No new significant 

information was discovered that would alter the impact conclusion for nonchemosynthetic deepwater

benthic communities presented in those NEPA documents. The analysis and potential impacts discussed 

in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine events, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.10 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.10 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.10 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on nonchemosynthetic deepwater benthic 

communities of the CPA are bottom-disturbing activities associated with anchoring, structure 

emplacement, pipelaying, structure removal, and discharges of drill cuttings, muds, and produced water. 

The application of avoidance criteria for deepwater benthic communities provided as guidance in NTL 

2009-G40, “Deepwater Benthic Communities,” precludes the placement of a well within 610 m (2,000 ft) 

of any suspected site of a deepwater benthic community. Considerable mechanical damage could be 

inflicted upon sensitive nonchemosynthetic deepwater benthic communities by routine OCS drilling 

activities associated with a CPA proposed action if mitigations are not applied to permits. Deepwater live 

bottom communities, primarily structured by the coral Lophelia pertusa, are the nonchemosynthetic 

deepwater benthic communities that would be sensitive to impacts from OCS oil- and gas-related 

activities.

Bottom-disturbing activities associated with anchoring, structure emplacement, pipelaying, and 

structure removal cause localized bottom disturbances and disruption of benthic communities in the 

localized areas. If a sensitive community is subjected to direct impacts by bottom-disturbing activities, 

potentially severe or catastrophic impacts could occur due to raking of the sea bottom by anchors and 

anchor chains and partial or complete burial by muds and cuttings. The severity of such an impact is such 

that there would be incremental losses of productivity, reproduction, community relationships, and overall 

ecological functions of the local community, and incremental damage to ecological relationships with the 

surrounding benthos. Should this occur, it could result in recovery times in the order of decades or more 

with the possibility of the community never recovering (Food and Agriculture Organization of the United 

Nations, 2008; Jones, 1992; Probert et al., 1997). However, impacts from bottom-disturbing activities 

directly on deepwater coral communities are expected to be rare because of the application of required 

protective measures as guidance provided in NTL 2009-G40, “Deepwater Benthic Communities.”

Routine discharge of drill cuttings with associated muds can also affect the seafloor. In deep water, 

as opposed to shallower areas on the continental shelf, discharges of drilling fluids and cuttings at the sea 

surface are spread across broad areas of the seafloor and are generally distributed in thinner 

accumulations. A deepwater effects study funded by this Agency included determinations of the extent of 

muds and cuttings accumulations in approximately 1,000 m (3,281 ft) of water (CSA, 2006). 

Geophysical and chemical measurements indicated that a layer of cuttings and muds several centimeters 

thick was deposited within a 500-m (1,640-ft) radius of well sites. This suggests that the required 

2,000-ft (610-m) distance would protect deepwater benthic communities from impacts. Discharges of 

produced waters on the sea surface, chemical spills, and deck runoff would be diluted in surface waters, 

having no effect on seafloor habitats.

Routine activities associated with a CPA proposed action are not expected to cause damage to the 

ecological function or biological productivity of sensitive nonchemosynthetic deepwater benthic 

communities (deep coral reefs) due to the consistent application of BOEM’s protection guidance provided 

in NTL 2009-G40. Information included in required hazards surveys for OCS oil- and gas-related 

activities depicts areas that could potentially harbor nonchemosynthetic communities. This allows 
Description of the Environment and Impact Analysis 4-45

BOEM to require avoidance of any areas that are conducive to the growth of sensitive hard bottom 

communities. The same geophysical conditions associated with the potential presence of chemosynthetic 

communities also results in the potential occurrence of hard carbonate substrate and other associated, 

nonchemosynthetic deepwater benthic communities. Because of the required avoidance criteria, these 

communities are generally avoided in exploration and development planning and in bottom-disturbing 

activities. Impacts on sensitive deepwater communities from routine activities associated with a CPA 

proposed action would be minimal to none.

Accidental disturbances resulting from a CPA proposed action, including oil spills and blowouts, 

have the potential to result in impacts to nonchemosynthetic deepwater benthic communities of the CPA. 

Accidental events that could impact nonchemosynthetic deepwater benthic communities are primarily 

limited to seafloor blowouts. A blowout at the seafloor could create a crater and could resuspend and 

disperse large quantities of bottom sediments. This would destroy any organisms located nearby via 

burial or modification of narrow habitat quality requirements. Substantial impacts on these communities 

could permanently prevent reestablishment, particularly if hard substrate required for recolonization is 

buried by resuspended sediments from a blowout. Physical disturbance or destruction of a limited area of 

benthos or to a limited number of megafauna organisms (e.g., brittle stars, sea pens, and crabs) would not 

result in a major impact to the deepwater benthos ecosystem as a whole or even in relation to a small area 

of the seabed within a lease block. The application of avoidance criteria for deepwater coral communities 

as guidance described in NTL 2009-G40 precludes the placement of a well within 610 m (2,000 ft) of any 

suspected site of a deepwater coral community, therefore distancing the community from sedimentation 

resulting from a possible blowout.

Accidental impacts due to oil spills caused by blowouts associated with a CPA proposed action would 

likely result in only minimal impacts to nonchemosynthetic communities with adherence to the required 

avoidance measures. A blowout could result in a low-probability catastrophic spill (Appendix B), which 

is not part of a CPA proposed action and not likely expected, but the distance requirements would tend to 

lessen but not necessarily eliminate the impacts. A large subsea spill combined with the application of 

dispersant or high-pressure ejection of oil could mix oil into the water column, resulting in a subsea 

plume. Such a plume could potentially cause devastating effects on local patches of habitat in its path 

where it physically contacts the seafloor. If such an event were to occur, it could take decades to 

reestablish the nonchemosynthetic community in that location. The possible impacts, however, would be 

localized due to the directional movement of an oil plume by the water currents and because the sensitive 

habitats have a scattered, patchy distribution. As with sediments, the farther the dispersed oil travels, the 

more diluted it would become as it mixes with the surrounding water, and bacteria would degrade the oil 

over time (and distance). Oil plumes that remain in the water column for longer periods would disperse 

and decay, having only a minimal effect.

Cumulative Impacts

Cumulative factors considered to impact the deepwater benthic communities (>300 m; 984 ft) of the 

Gulf of Mexico include both OCS oil- and gas-related and non-OCS oil- and gas-related activities. The 

OCS oil- and gas-related activities associated with pipelaying, anchoring, structure emplacement, drilling 

discharges, and seafloor blowouts have the potential to impact nonchemosynthetic deepwater benthic 

communities. The most serious, impact-producing factor threatening nonchemosynthetic communities is 

physical disturbance of the seafloor, which could destroy the organisms of these communities. Such 

disturbance would most likely come from those OCS oil- and gas-related activities associated with 

pipelaying, anchoring, and structure emplacement. Anchoring and pipeline and structure emplacement 

have the potential to crush deepwater benthic communities. Drilling discharges and resuspended 

sediments have the potential to cause minor, mostly sublethal impacts to nonchemosynthetic 

communities, but substantial accumulations could result in more serious impacts. Possible effects of an 

oil spill could be no discernible effect (for well-dispersed oil undergoing biodegradation), lack of growth, 

interruption of reproductive cycles, loss of gamete viability, tissue damage, death of affected organisms, 

and a reduction in the areas of distribution of species, depending on the amount and duration of 

contamination. Major impacts to localized benthic habitat are possible in the event of a low-probability 

catastrophic blowout on the seafloor (refer to Appendix B for more details). However, a low-probability 

catastrophic spill is not part of a CPA proposed action and not likely expected to occur. Therefore, 

cumulative impacts to deepwater communities in the Gulf of Mexico are considered negligible because of 
4-46 Central and Eastern Planning Areas Supplemental EIS

the application of the avoidance criteria described in NTL 2009-G40, which distances bottom-disturbing

activities from sensitive habitats.

Non-OCS oil- and gas-related activities include fishing and trawling at a relatively small scale; largescale factors include storm impacts and climate change, CO2 build-up, and proposed methods to sequester 

carbon in the deep sea. Among the activities unrelated to the OCS Program (non-OCS oil and gas 

impact-producing factors), fishing and trawling represent the greatest possible threat to 

nonchemosynthetic communities and associated fish communities as a result of habitat destruction and 

overfishing (Kaiser, 2004). The impacts on deepwater fisheries in the GOM associated with deepwater 

coral habitat as a result of trawling activity are unknown, but because of the water depths (>300 m; 

984 ft) and the low density of potentially commercially valuable fishery species in areas associated with 

these communities, fishing and trawling are not expected to severely impact deepwater benthic 

communities. Regionwide and even global impacts from climate change, CO2 build-up, and proposed 

methods to sequester carbon in the deep sea (e.g., ocean fertilization) are not expected to have major 

impacts to deepwater habitats in the near future. More distant scenarios could include severe impacts. 

Storms generally cause little to no impacts at the depths (>300 m; 984 ft) that nonchemosynthetic 

communities occur. A storm could potentially cause some type of accident that could then cause 

secondary impacts, such as shipwrecks that could crush nonchemosynthetic communities, but such 

occurrences would be rare. State oil and gas activities are not expected to impact deepwater benthic 

communities due to the great distance between such activities and water depths of >300 m (984 ft).

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A broad Internet search for relevant new information was conducted using a publicly available search 

engine. Internet websites visited included four Federal agencies (USEPA, the U.S. Geological Survey, 

NOAA [including Deepwater Horizon Bibliography], and BOEM), five coastal universities or 

universities with coastal divisions (University of Louisiana at Lafayette, Louisiana State University, 

Texas A&M University, University of Texas at Austin Marine Science Institute College of Natural 

Sciences, and Florida State University), several various stakeholders (Sierra Club, National Fish and 

Wildlife Foundation, Nature Conservancy, Gulf of Mexico Alliance, and Gulf of Mexico Program), and 

Louisiana Universities Marine Consortium (“Effects of Offshore Oil and Gas Development: A Current 

Awareness Bibliography”). Where applicable, websites of subdivisions of many of these agencies, 

universities, and stakeholders were also searched. Environmental journal articles were also located online 

using four search engines (JSTOR, EBSCO, Google Advanced Scholar Search, and Google Advanced 

Book Search). Three of the search engines collectively searched all of the ecology journals of six major 

publishers (John Wiley and Sons, Springer, Elsevier Science, Taylor and Francis Group, Cambridge 

University Press, and Oxford University Press). New information was found on habitat preferences for 

deepwater corals, as well as information on impacts from sedimentation and oil exposure.

Additional research has indicated that, if a well is located too close to deepwater coral habitat, 

damage may occur to the corals. Experiments with sediment and cold-water corals affirm possible lethal 

or sublethal impacts of anthropogenic sedimentation from drill cuttings (Allers et al., 2013). Branching 

coral varieties (e.g., Lophelia pertusa) have a structure that creates low-energy microenvironments inside 

the thickets, where experiments suggest the occurrence of lethal or sublethal impacts of drill cuttings 

occurs (Allers et al., 2013). These studies reaffirm the necessity for distancing wells from deepwater 

coral habitats so that the corals are protected from the accumulation of drill cuttings.

A new study has investigated the association of deepwater corals with oil seeps from the seafloor 

(Quattrini et al., 2013), documenting depth and seep activity as the most significant contributing factors 

on realized niches of these corals. This research indicates that such an adaptation could result in 

resilience after exposure to oil from a blowout. Quattrini et al. (2013) also found that broken shells and 

coral rubble within soft bottom environments can provide sufficient substrate for settlement and growth of 

Callogorgia spp. (common octocorals). This new information is important because it shows that some 

deepwater corals may attach to broken shells or rubble scattered within otherwise soft bottom 

environments, and could fail to be protected under BOEM’s policy because small patches of substrate do 

not always show up on surveys conducted to find probable deepwater coral habitat.

While the recent research has provided new information regarding impacts to nonchemosynthetic 

communities from oil spills, this new information does not change the conclusions of the 2012-2017 
Description of the Environment and Impact Analysis 4-47

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS because such a low-probability catastrophic event is unlikely to occur.

Incomplete or Unavailable Information 

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplement EIS and in Chapter 4.2.1.10 of the 2012-2017 

WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.10 of the CPA 

235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information for impacts 

related to the location of deepwater corals in the Gulf of Mexico, toxicity of oil to deepwater corals, 

impacts on deepwater fish communities due to impacts on nonchemosynthetic deepwater benthic 

communities, and impacts from the Deepwater Horizon explosion, oil spill, and response on 

nonchemosynthetic deepwater benthic communities that may be relevant to reasonably foreseeable 

significant adverse impacts.

At present, the best available information does not provide data for a complete understanding of these 

four data gaps. BOEM used reasonably accepted scientific methodologies to extrapolate from existing 

information in completing this analysis and formulating the conclusions presented here. BOEM’s 

database of known deepwater benthic communities is incomplete. This database is used when deepwater 

exploration and development plans are reviewed to ensure that deepwater corals are not impacted by OCS 

oil- and gas-related activities. In order to fill this data gap, BOEM’s subject-matter experts identify 

probable habitat for deepwater corals using a database of 3D seismic data, which provides the locations of 

28,000 features that could represent such communities, in conjunction with side-scan sonar data and sitespecific, high-resolution surveys to identify sensitive habitat and communities. BOEM’s database of 

3D seismic anomalies is well suited to the identification of general areas in which favorable coral habitat 

may occur and is sufficient in assisting BOEM in identifying areas that should be avoided for OCS oiland gas-related activities. However, these surveys may not be sufficiently high resolution for the 

identification of small, scattered hard substrate, as discussed by Quattrini et al. (2013). Small patches of 

shell and rubble substrate are commonly observed in soft bottom habitat near active and inactive seep 

sites, which frequently occur in areas targeted for OCS oil- and gas-related activities. If data are sparse or 

indicate additional detail is warranted, this data gap may be additionally filled by site-specific video or 

photographic surveys to obtain this information. Despite these procedures, some communities scattered 

throughout predominantly soft bottom habitat may still be impacted if seafloor surveys do not suggest 

deepwater coral habitat is present. However, BOEM has determined that the incomplete information is 

not essential to a reasoned choice among alternatives because BOEM reviews plans on a case-by-case 

basis to reduce the possibility of impacting deepwater coral habitat.

Information on the toxic impacts of oil on deepwater corals is unavailable. An investigation of 

several deepwater octocorals and their association with oil seeps indicated that one species was found in 

association with oil seeps. The results of this study indicate that this coral could “possess mechanisms for 

dealing with natural levels of exposure to hydrocarbons” (Quattrini et al., 2013). Such an adaptation 

could result in resilience after exposure to oil from a blowout. It is possible that, if this coral may be 

tolerant of oil exposure, there may be others as well; however, that information is not known at this time. 

BOEM has determined that the unavailable information on the tolerance of deepwater corals to oil 

exposure is not essential to a reasoned choice among alternatives because BOEM requires that OCS oiland gas-related activities are sufficiently distanced from wells and because exposure from accidental 

events is unlikely.

Harm to nonchemosynthetic deepwater benthic communities as a result of bottom trawling would 

have an uncertain impact on deepwater bottom fisheries. In place of unavailable information on 

commercial fishing impacts on deepwater fisheries in areas of deepwater coral habitat, existing 

information on commercial fishing activity in the deep GOM shows that, unlike other areas in the Atlantic 

Ocean and in Europe, bottom-fishing and trawling efforts in the deeper water of the CPA are currently 

minimal, and areas where royal red shrimp are obtained are in soft bottom communities (CSA, 2002). 

The primary Gulf grounds are restricted to the upper continental slope off the Mississippi Delta (off 

Mississippi and Alabama) (CSA, 2002). Grounds there are blue-black terrigenous silt and greenish mud, 

and any known hard bottom (potential nonchemosynthetic communities) would not be trawled (CSA, 
4-48 Central and Eastern Planning Areas Supplemental EIS

2002). The monetary value of seafood is not worth the expense and trouble of deepwater trawling, except 

to a few fishermen (CSA, 2002). The minimal fishery and minimal areal extent of potential 

nonchemosynthetic communities that are inside the outer boundaries of the fishery indicate that the 

footprint of the fishery would not likely overlap with the footprint of an impacted deepwater benthic 

community. Also, nonchemosynthetic communities are widely distributed in the Gulf of Mexico, mostly 

outside the narrowly distributed area of royal red shrimp grounds. Therefore, impacts on such 

communities as a whole are expected to be negligible. In conclusion, available information consistent 

with acceptable scientific reasoning shows that commercial fishing impacts on nonchemosynthetic 

deepwater benthic communities are expected to cause only negligible impacts.

BOEM has determined that the information is not essential to a reasoned choice among alternatives 

because nonchemosynthetic deepwater benthic communities are found throughout the Gulf of Mexico and 

are in patchy distributions, minimizing the number that would be likely to be impacted by any single 

event. Available scientifically credible information has been applied by BOEM’s subject-matter experts 

using accepted scientific methodologies. Existing information indicates that, even though one or more 

coral communities in the vicinity of the Macondo well was impacted by the largest oil spill in the history 

of the Gulf of Mexico, the impact to coral communities of the GOM, in terms of the proportion of all such 

communities that was affected, was relatively minor.

Summary and Conclusion

BOEM has reexamined the analysis for nonchemosynthetic deepwater benthic communities presented 

in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information presented above. The potential for 

effects from changes to the affected environment (post-Deepwater Horizon), routine activities, accidental 

spills (including low-probability catastrophic spills), and cumulative impacts remains whether or not the 

No Action or an Action alternative is chosen under this Supplemental EIS. Impacts on 

nonchemosynthetic deepwater benthic communities from either smaller accidental events or lowprobability catastrophic events will remain the same. No new significant information was discovered that 

would alter the impact conclusion for nonchemosynthetic communities presented in those previously

mentioned NEPA documents because of the available scientifically credible evidence in this analysis and 

based upon accepted scientific methods and approaches. The analysis and potential impacts discussed in 

those documents still apply for proposed CPA Lease Sales 241 and 247.

4.1.1.11. Soft Bottom Benthic Communities

BOEM has reexamined the analysis for soft bottom benthic communities presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

based on the additional information presented below. No new significant information was discovered that 

would alter the impact conclusion for soft bottom benthic communities presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247. 

A detailed description of soft bottom benthic communities and the full analyses of the potential 

impacts of routine activities, accidental events, and cumulative impacts associated with a CPA proposed 

action are presented in Chapter 4.2.1.11 of the 2012-2017 WPA/CPA Multisale EIS. Updated 

information is provided in Chapter 4.2.1.11 of the WPA 233/CPA 231 Supplemental EIS and Chapter 

4.1.1.11 of the CPA 235/241/247 Supplemental EIS. The following information is a summary of the 

resource description and impact analysis incorporated from those NEPA documents. Any new 

information that has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors include seafloor disturbances (e.g., anchoring, 

trenching, infrastructure emplacement, and infrastructure removal, waste discharge (e.g., drilling muds 

and cuttings from oil and gas operations), and resuspension of sediments (e.g., pipeline burial and 

decommissioning operations). Disturbances of soft bottom benthic communities cause localized 

disruptions to benthic community composition and an alteration in food sources for some large 

invertebrate and finfish species. Analysis of these routine activities has identified only localized and 
Description of the Environment and Impact Analysis 4-49

short-term impacts to soft bottom benthic communities. Any activity that may affect the soft bottom 

communities would only impact a small portion of the overall area of the seafloor of the Gulf of Mexico. 

Because the soft bottom substrate is ubiquitous throughout the Gulf of Mexico, there are no lease 

stipulations to avoid these communities; however, other routine practices restrict detrimental activities 

that could cause undue harm to benthic habitats (e.g., discharge restrictions, debris regulations, and 

NPDES permits).

Accidental disturbances to soft bottom benthic communities can result from oil spills or blowouts

associated with OCS oil- and gas-related activities. Because of the proportionately small area that OCS 

oil- and gas-related activities occupy on the seafloor, only a very small portion of Gulf of Mexico soft 

bottom benthic communities would experience impacts as a result of blowouts and oil spills. The greatest 

impacts would likely occur closest to the source of the spill, and impacts would rapidly decrease with 

increased distance from the source. Contact with spilled oil outside the vicinity of the event would likely 

cause sublethal to negligible effects to benthic invertebrates and finfishes. Oil deposited on sediment 

communities could result in changes to local community structure. The organic enrichment of impacted 

sediments may result in altered sediment communities as bacteria degrade deposited organic matter. This 

response can lead to hypoxic conditions and a series of altered community structures until the organic 

matter is depleted and surface sediments return to an oxygenated state (Neff, 2005). Although an oil spill 

may have some detrimental impacts, especially closest to the occurrence of the spill, the impacts may be 

no greater than natural fluctuations (Clark, 1982), and impacts would affect a relatively small portion of 

the seafloor.

Cumulative Impacts

The cumulative analysis considers impacts resulting from ongoing routine oil and gas operations, as 

well as those resulting from past and future OCS leasing. These impacts include seafloor disturbances, 

waste discharge, and resuspension of sediments. Potential non-OCS oil- and gas-related disturbances 

include storms, sand mining, trawling, State oil and gas activities, and hypoxia.

Although OCS oil- and gas-related activities may have locally devastating impacts, impacted 

communities are repopulated relatively quickly and the cumulative effect on the overall seafloor and 

benthic communities would be negligible. Long-term OCS oil- and gas-related activities are not expected 

to adversely impact the entire soft bottom environment of the GOM because the locally impacted areas 

are small in comparison with the entire area of the GOM. For information on impacts resulting from 

events outside the scope of routine activities and accidental events, refer to Appendix B. 

Non-OCS oil- and gas-related disturbances are likely to impact the soft bottom communities more 

frequently than do OCS oil- and gas-related activities. In some areas, soft bottom benthic communities 

remain in an early successional stage due to the frequency of natural and anthropogenic disturbances. 

The incremental contribution of a CPA proposed action to the cumulative impact is expected to be minor.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

BOEM has examined newly available information for findings that may impact analyses of routine 

activities, accidental events, and cumulative impacts of OCS oil- and gas-related activities and potentially 

alter previous conclusions. A search of Internet information sources and scientific journals was 

conducted to determine the availability of recent information (including ACS Publications, BioOne, 

EBSCO, Elsevier, the Gulf of Mexico Fishery Management Council’s website, JSTOR, NMFS’s 

databases, NOAA Gulf Spill Restoration Publications website, PLoS ONE, Science Direct, and SeaGrant 

website). This search revealed that new information relevant to an analysis of the potential impacts of 

OCS oil- and gas-related activities on soft bottom benthic communities has been published.

New studies suggest that community structure of microbial communities can be influenced by the 

presence of oil, the weathered state of oil, and the chemical composition of oil (Kimes et al., 2013; Liu 

and Liu, 2013; Mason et al., 2014). These studies also document shifts in community structure as the 

environment transitions from aerobic to anaerobic, such as may occur as a result of excessive aerobic 

biodegradation of hydrocarbons. Data also suggest that PAHs are more persistent in the deep-sea 

sediments and that degradation of these molecules may occur at a reduced rate when compared with other 

hydrocarbons (Kimes et al., 2013; Mason et al., 2014). The consequences of the slow breakdown of 
4-50 Central and Eastern Planning Areas Supplemental EIS

PAHs on sediment communities remain unknown; however, these studies suggest that the microbial 

community exhibits a high degree of community resiliency and may revert to a structure similar to prespill conditions once the PAHs are consumed. These findings support previous impact analyses because 

they indicate that lower-order soft bottom benthic communities’ structure may transition rapidly when 

exposed to changing environmental conditions, demonstrating significant resiliency. Based on the new 

information presented here and earlier analyses indicating that only a small portion of the GOM seafloor 

and associated benthic organisms would be impacted by oil exposure, BOEM concludes that populationlevel responses are not realistically expected.

An investigation of niche divergence among octocorals of the genus Callogorgia documented depth 

and the presence of hydrocarbon seep activity as the most significant contributing factors on niche 

preference (Quattrini et al., 2013). The study also noted that “flat or even concave surfaces with 

broken/dead shells or coral rubble” provided sufficient substrate for settlement and growth of these corals 

(Quattrini et al., 2013). This new information is important because small patches of shell and rubble 

substrate are commonly observed in soft bottom habitat near active and inactive seep sites, which 

frequently occur in areas targeted for OCS oil- and gas-related activities. Shell and coral rubble were not 

previously considered suitable substrate for coral settlement when potential impacts to deepwater coral 

habitat were analyzed. These study results may provide information for BOEM’s site-specific reviews of 

postlease OCS oil- and gas-related activities, enhancing BOEM’s ability to identify and protect 

potentially sensitive habitat and deepwater benthic communities within predominantly soft bottom 

habitat. In a second study, Allers et al. (2013) reported that the coral species Lophelia pertusa, if not 

completely buried by sediment, is capable of surviving episodic sedimentation from suspended sediment 

loads comparable to those expected from anthropogenic activities, such as intermittent drilling discharges. 

As with the previous study, this information is important for its potential to inform analyses and influence 

policy concerning the protection of sensitive communities located in the vicinity of OCS oil- and gasrelated activities within predominantly soft bottom habitat. For additional information on deepwater 

corals, refer to Chapter 4.1.1.10. 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS are still valid because no new significant information on soft bottom benthic 

communities has been published since those NEPA documents were published; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.11 of 

the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.11 

of the CPA 235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information 

regarding the distribution and abundance of deepwater corals in areas of predominantly soft bottom 

habitat, the long-term effects of persistent PAHs (Kimes et al., 2013; Liu and Liu, 2013; Mason et al., 

2014), and the long-term effects of episodic sedimentation events (Allers et al., 2013; Kimes et al., 2013; 

Liu and Liu, 2013; Mason et al., 2014).

Although the distribution and abundance of deepwater corals in areas of predominantly soft bottom

habitat is not known, BOEM uses reasonably accepted scientific methodologies to extrapolate from 

existing information when locating communities and suitable substrates potentially impacted by proposed 

OCS oil- and gas-related activities. Data produced using several seafloor survey methods are analyzed to 

identify potential deepwater coral habitat. Refer to Chapter 4.1.1.10 for more detail on deepwater corals. 

BOEM has determined that the incomplete information is not essential to a reasoned choice among 

alternatives because BOEM reviews plans and surveys on a case-by-case basis to reduce the possibility of 

impacting deepwater coral habitat.

The cumulative impacts of OCS oil and gas exploration and development may result in locally 

significant impacts to soft bottom benthic communities. However, soft bottom communities are abundant 

throughout the GOM and the area of the seafloor impacted by OCS oil- and gas-related activities is very 

small in comparison with the overall area of soft bottom habitat in the GOM. Analysis of available 

information did not identify any reasonably foreseeable impacts extending beyond localized responses to 

persistent PAHs or sedimentation events among soft bottom inhabitants (Kimes et al., 2013; Liu and Liu, 

2013; Mason et al., 2014). Although additional information regarding impacts to soft bottom benthic 

communities and potential changes in baseline conditions may be in development, research to date does 
Description of the Environment and Impact Analysis 4-51

not suggest Gulfwide impacts should be expected. Relevant data regarding the status and function of soft 

bottom benthic communities directly impacted by OCS oil- and gas-related activity, including that being 

developed through the NRDA process, may take years to acquire and analyze and cannot be obtained 

within the timeline contemplated in the NEPA analysis of this Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing the analysis of impacts to soft bottom benthic communities and subsequent recovery. The 

new information summarized above indicates microbial communities transition rapidly when exposed to 

changing environmental conditions and demonstrate significant resiliency (Kimes et al., 2013; Liu and 

Liu, 2013; Mason et al., 2014). Although the body of available information is incomplete and long-term 

effects cannot yet be known, the evidence currently available supports past analyses and does not indicate 

severe adverse impacts to the soft bottom benthic communities of the CPA or entire GOM as a result of 

OCS oil- and gas-related activities. Therefore, BOEM has determined that the incomplete information is 

not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for soft bottom benthic communities presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for soft bottom benthic communities presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed CPA Lease Sales 241 and 247.

4.1.1.12. Marine Mammals

BOEM has reexamined the analysis for marine mammals presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for marine mammals presented in those NEPA documents. The analysis and 

potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.12 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.12 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.12 of CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Operators must adhere to certain NTLs while conducting OCS oil- and gas-related activities in order 

to reduce impacts to marine mammals. The operator’s reaffirmed compliance with NTL 2012-JOINTG01 (“Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”) and NTL 2012-BSEEG01 (“Marine Trash and Debris Awareness and Elimination”), as well as the limited scope, timing, and 

geographic location of a CPA proposed action, would result in negligible effects from the proposed 

drilling activities on marine mammals. In addition, NTL 2012-JOINT-G02, “Implementation of Seismic 

Survey Mitigation Measures and Protected Species Observer Program,” minimizes the potential of harm 

from seismic operations to marine mammals. These mitigations include onboard observers, airgun shutdowns for whales in the exclusion zone, ramp-up procedures, and the use of a minimum sound source.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on marine mammals of the CPA are the degradation of 

water quality from operational discharges; noise generated by aircraft, vessels, operating platforms, and 

drillships; vessel traffic; explosive structure removals; seismic surveys; and marine debris from service 

vessels and OCS oil- and gas-related facilities. Some routine activities related to a CPA proposed action 

have the potential to have adverse, but not significant, impacts to marine mammal populations in the Gulf 

of Mexico. Impacts from vessel traffic, structure removals, and seismic activity could negatively impact 

marine mammals by increasing noise levels as well as having the potential to harm or harass marine 
4-52 Central and Eastern Planning Areas Supplemental EIS

mammal species. These activities, when mitigated as required by BOEM and NMFS, are not expected to 

have long-term impacts on the size and productivity of any marine mammal species or population. 

Mitigations reduce the risk of harassing or harming marine mammal species. Other routine activities such 

as aircraft activity, drilling and production noise, discharges, and marine debris are expected to have 

negligible effects.

Accidental disturbances resulting from a CPA proposed action, including oil spills, blowouts and 

spill-response activities, have the potential to have adverse, but not significant impacts on marine 

mammals of the CPA. Characteristics of impacts (i.e., acute vs. chronic impacts) depend on the 

magnitude, frequency, location, and date of accidents; characteristics of spilled oil; spill-response 

capabilities and timing; and various meteorological and hydrological factors. Oil spills may cause 

chronic (long-term lethal or sublethal oil-related injuries) and acute (spill-related deaths occurring during 

a spill) effects on marine mammals. Long-term effects include decreases in prey availability and 

abundance because of increased mortality rates, change in age-class population structure because certain 

year-classes were impacted more by oil, decreased reproductive rate, and increased rate of disease or 

neurological problems from exposure to oil (Harvey and Dahlheim, 1994). The effects of cleanup 

activities are unknown, but increased human presence (e.g., vessels) could add to changes in marine 

mammal behavior and/or distribution, thereby additionally stressing animals and perhaps making them 

more vulnerable to various physiologic and toxic effects.

Even after an oil spill is stopped, oiling or deaths of marine mammals could still occur due to oil and 

dispersants persisting in the water, past marine mammal and oil or dispersant interactions, and ingestion 

of contaminated prey. The animals’ exposure to hydrocarbons persisting in the sea may result in 

sublethal impacts (e.g., decreased health, reproductive fitness, and longevity; and increased vulnerability 

to disease) and some soft tissue irritation, respiratory stress from inhalation of toxic fumes, food reduction 

or contamination, direct ingestion of oil and/or tar, and temporary displacement from preferred habitats.

Cumulative Impacts

The cumulative impact from oil and gas operations includes effects resulting from a CPA proposed 

action, as well as those resulting from past and future OCS leasing. These impact-producing factors 

include ingestion and entanglement in marine debris; contaminant spills and spill-response activities; 

vessel strikes; and noise from numerous sources (i.e., platforms, drillships, helicopters, vessels, etc.), 

seismic surveys, and explosive structure removals. Potential non-OCS oil- and gas-related factors include 

vessel traffic and related noise (including from commercial shipping and research vessels), State oil and 

gas activities, military operations, commercial fishing, pollution, scientific research, and natural 

phenomena. Groups such as the military (U.S. Navy and USCG) and other Federal agencies (USEPA, the 

Corps of Engineers, and NMFS), dredges, commercial fishermen, and recreational boaters operate vessels 

and aircraft that can contribute to the ambient noise in the GOM. Noise in the ocean has become a 

worldwide topic of concern, particularly in the last two decades. Noises originate from a broad range of 

sources, both natural and anthropogenic (Richardson et al., 1995). Virtually all of the marine mammal

species in the GOM have been exposed to OCS industrial noise due to the rapid advance into GOM deep 

oceanic waters by the oil and gas industry in recent years; whereas, 20 years ago, the confinement of 

industry to shallower coastal and continental shelf waters generally only exposed two species of marine 

mammals (the bottlenose dolphin and the Atlantic spotted dolphin) to industry activities and the related 

sounds. Most marine mammal species in the GOM, and particularly the deepwater mammals, rely on 

echolocation for basic and vital life processes including feeding, navigation, and conspecific and mate 

communication. Noise levels that interfere with these basic marine mammal capabilities could have 

impacts on individuals and populations. The OCS oil and gas industry’s operations contribute noise to 

the marine environment from several different operations. It is believed that some of the industry-related 

noise is at lower frequencies than is detectable or in the sensitivity range of most of the GOM marine 

mammal species (Southall et al., 2007). Examples of some industry-related noise sources are summarized 

in the 2013 G&G Survey Techniques Information sheet (USDOI, BOEM, 2013c) and are described in 

greater detail in Chapter 3 of the Atlantic OCS Proposed Geological and Geophysical Activities: MidAtlantic and South Atlantic Planning Areas, Final Programmatic Environmental Impact Statement

(USDOI, BOEM, 2014c). 

Cumulative impacts on marine mammals are expected to result in a number of chronic and sporadic 

sublethal effects (i.e., behavioral effects and nonfatal exposure to or intake of OCS oil- and gas-related 
Description of the Environment and Impact Analysis 4-53

contaminants or discarded debris) that may stress and/or weaken individuals of a local group or 

population and predispose them to infection from natural or anthropogenic sources (Harvey and 

Dahlheim, 1994). Disturbance (noise from vessel traffic and drilling operations) and/or exposure to 

sublethal levels of toxins and anthropogenic contaminants may stress animals, weaken their immune 

systems, and make them more vulnerable to parasites and diseases that normally would not be fatal 

(Harvey and Dahlheim, 1994). Cumulative noise can potentially cause masking effects that may prevent 

an individual from detecting another individual’s calls or interfere with navigation ability (Hatch et al., 

2014; Merchant et al., 2014; Southall et al., 2007). Available information regarding industry-related and 

other anthropogenic sound effects on marine mammals are mainly qualitative descriptions, but a 

committee was convened in 2010 to advance a method for systematic evaluation (Streever et al., 2012). 

Streever et al. (2012) identified typical anthropogenic sources during autumn bowhead whale migration in 

the Alaskan Beaufort Sea (i.e., production, seismic data acquisition, and vessel traffic), used available 

empirical data for bowhead behavior inputs, and conducted a modelled sea trial using simplified 

assumptions to collect acoustic data for individual virtual animals. Empirical data (i.e., bowhead 

behavioral response to sound and migration patterns) provided relevant and necessary inputs for the 

model, ambient noise was not considered, and overall, the committee offered documentation and guidance 

for future work (Streever et al., 2012). Baseline soundscape is not well-documented for the GOM, and 

marine mammal behavioral data related to sound effects are not available for all species. These and other

factors are essential for modelling inputs and for predicting effects of sound on marine mammals. BOEM

continues to make efforts to gain a more thorough understanding of the potential effects of sound on 

marine mammals. The net result of any disturbance will depend upon the size and percentage of the 

population likely to be affected, the ecological importance of the disturbed area, the environmental and 

biological parameters that influence an animal’s sensitivity to disturbance and stress, or the 

accommodation time in response to prolonged disturbance (Hatch et al., 2008; Geraci and St. Aubin, 

1980).

The effects of a CPA proposed action, when viewed in light of the effects associated with other past, 

present, and reasonably foreseeable future activities, may result in impacts to marine mammals when 

compared with before the Deepwater Horizon explosion, oil spill, and response; however, the magnitude 

of those effects cannot yet be determined. This is because the long-term effects may not yet be 

detectable. A large body of information regarding impacts of the Deepwater Horizon explosion, oil spill, 

and response on marine mammals is being developed through the NRDA process, but it is not yet 

available. Nonetheless, as mentioned earlier, operators are required to follow all applicable lease 

stipulations and regulations, as clarified by NTLs (i.e., NTL 2012-JOINT-G01, NTL 2012-BSEE-G01, 

and NTL 2012-JOINT-G02), to minimize these potential interactions and impacts. Even when taking into 

consideration the potential effects of the Deepwater Horizon explosion, oil spill, and response and the 

minimization of impacts through lease stipulations and regulations, no significant cumulative impacts to 

marine mammals would be expected as a result of the proposed activities when added to the impacts of 

past, present, or reasonably foreseeable oil and gas development in the area, as well as other ongoing 

activities in the area.

Non-OCS oil- and gas-related activities that may affect marine mammal populations include vessel 

traffic and related noise (including from commercial shipping and research vessels), State oil and gas 

activities, military operations, commercial fishing, pollution, scientific research, and natural phenomena. 

Groups such as the military (U.S. Navy and USCG) and other Federal agencies (USEPA, the Corps of 

Engineers, and NMFS), dredges, commercial fishermen, and recreational boaters operate vessels and 

aircraft that can contribute to the ambient noise in the GOM. Pollution in the ocean comes from many 

point and nonpoint sources. The drainage of the Mississippi River results in massive amounts of 

chemicals and other pollutants being constantly discharged into the GOM. Tropical storms and 

hurricanes are normal occurrences in the GOM and along the coast. Generally, the impacts have been

localized and infrequent. The actual impacts of these storms on the animals in the GOM, and the listed 

species and critical habitat in particular, have not yet been determined and, for the most part, may remain 

very difficult to quantify.

An unusual mortality event (UME) is defined under the Marine Mammal Protection Act as “a 

stranding that is unexpected; involves a significant die-off of any marine mammal population; and 

demands immediate response.” Infections, biotoxins, human interactions, and malnutrition are considered 

causes of UMEs. A UME for bottlenose dolphins occurred off the coast of Texas in 2011-2012 when 

126 dolphins were stranded. While there is no known cause for the strandings, preliminary findings 
4-54 Central and Eastern Planning Areas Supplemental EIS

include infected lungs, poor body condition, discoloration of the teeth, and substance in the stomach in 

four of the animals (USDOC, NMFS, 2014a). Further, a UME for the entire northern GOM began in 

February 2010 and has continued through 2014. However, this UME is defined by the Florida panhandle 

west to the Louisiana-Texas border (USDOC, NMFS, 2014b). The relationship of these UMEs to the 

Deepwater Horizon explosion, oil spill, and response remains unclear (refer to the “Incomplete or 

Unavailable Information” section below).

Within the GOM, there is a long-standing and well-developed OCS Program (more than 50 years); 

there are no data to suggest that activities from the preexisting OCS Program are significantly impacting 

marine mammal populations. The incremental contribution of a CPA proposed action to the cumulative 

impact is expected to be negligible. There are existing leases in the CPA with either ongoing or the 

potential for oil and gas exploration, drilling, and production activities. In addition, the potential for nonOCS oil- and gas-related activities discussed herein will continue to occur in the CPA irrespective of a 

CPA proposed action. The potential for effects from changes to the affected environment (postDeepwater Horizon), routine activities, accidental spills, low-probability catastrophic spills (which are 

discussed in Appendix B and which are not part of a CPA proposed action and not likely expected), and 

cumulative effects remains whether or not the No Action or an Action alternative is chosen under this 

Supplemental EIS. Impacts on marine mammals from either smaller accidental events or low-probability 

catastrophic events would remain the same. Therefore, in light of a CPA proposed action and its impacts, 

the incremental effect of a CPA proposed action on marine mammal populations is not expected to be 

significant when compared with non-OCS energy-related activities.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources (NOAA’s websites and the RestoreTheGulf.gov website), as 

well as recently published journal articles, was conducted to determine the availability of recent 

information on marine mammals. 

On December 13, 2010, NMFS declared a UME for cetaceans (whales and dolphins) in the Gulf of 

Mexico. Evidence of the UME was first noted by NMFS as early as February 2010, before the 

Deepwater Horizon explosion, oil spill, and response. As of November 16, 2014, a total of 

1,283 cetaceans (6% stranded alive and 94% stranded dead) have stranded since the start of the UME, 

with a vast majority of these strandings between Franklin County, Florida, and the Louisiana/Texas 

border (Table 4-1). In addition to investigating all other potential causes, scientists are investigating what 

role Brucella plays in the northern Gulf of Mexico UME. As of October 28, 2014, 54 out of 177 dolphins 

tested were positive or suspected positive for Brucella. More detail on the UME can be found on 

NMFS’s website (USDOC, NMFS, 2014c). It is unclear at this time whether the increase in strandings is 

related partially, wholly, or not at all to the Deepwater Horizon explosion, oil spill, and response.

The 21 species of cetaceans that occur in the GOM are identified in the most recent NMFS annual 

Stock Assessment Report (Waring et al., 2014). Most of the information on GOM species was updated in 

the 2012 Stock Assessment Report; however, the 2013 Stock Assessment Report updated population 

abundance estimates for the Gulf of Mexico oceanic stock of bottlenose dolphins (5,806) and for Risso’s 

dolphins (2,442) found in waters from the 200-m (656-ft) isobath to the seaward extent of the U.S. 

Exclusive Economic Zone during a 2009 oceanic survey (Waring et al., 2014). During 2010, Waring 

et al. (2014) found that 221 bottlenose dolphins were considered to be part of the UME and most are 

assumed to belong to one of the coastal stocks or to bay, sound, and estuary stocks; however, it is possible 

that part of the UME belonged to the continental shelf or oceanic stocks. In 2010-2011, Risso’s dolphins 

were not considered part of the UME (Waring et al., 2014). 

A study recently published from the NRDA process began evaluating the possible effects of the 

Deepwater Horizon explosion, oil spill, and response on Barataria Bay bottlenose dolphins, which 

received some degree of prolonged and heavy oiling, and compared them with bottlenose dolphins 

located in Sarasota Bay where no oil was observed. Bottlenose dolphins in Barataria Bay exhibited an 

elevated occurrence of overall poor health and prevalence of poor body condition, disease, and 

abnormalities as compared with Sarasota bottlenose dolphins and dolphins from other U.S. coastal sites 

(Schwacke et al., 2013). While this information may ultimately be useful in expanding the available 

knowledge on baseline environmental conditions following the Deepwater Horizon explosion, oil spill, 
Description of the Environment and Impact Analysis 4-55

and response, it remains difficult to draw specific conclusions regarding the current overall bottlenose 

dolphin population in the GOM.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions presented in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS, as well as in the previously mentioned 

NEPA documents, BOEM has identified incomplete information for impacts on marine mammals from 

the Deepwater Horizon explosion, oil spill, and response. The final determinations on damages to marine 

mammal resources from the Deepwater Horizon explosion, oil spill, and response will ultimately be made 

through the NRDA process. The Deepwater Horizon explosion, oil spill, and response will ultimately 

allow a better understanding of any realized effects from a low-probability catastrophic spill, which is not 

part of a CPA proposed action and not likely expected. However, even with recent publications such as 

Schwacke et al. (2013), the best available information on impacts to marine mammals does not yet 

provide a complete understanding of the effects of the oil spill and active response/cleanup activities from 

the Deepwater Horizon explosion, oil spill, and response on marine mammals as a whole in the GOM and 

whether these impacts reach a population level. As identified above, unavailable information, such as the 

anthropogenic impacts following an oil-spill response and the population variation due to naturally 

occurring events such as hurricanes and UMEs, provides challenges in understanding the baseline 

conditions and changes within marine mammal populations. As also previously discussed, the actual 

impacts of tropical storms and hurricanes on the GOM, and on the listed species and critical habitat in 

particular, have not yet been determined and, ultimately, the impacts may remain very difficult to 

quantify. However, BOEM used existing information and reasonably accepted scientific methodologies 

to extrapolate from available information in completing this analysis.

BOEM concludes that the unavailable information from these events may be relevant but not 

necessarily essential to reasonably foreseeable significant adverse impacts to marine mammals. In some 

specific cases, such as with bottlenose dolphins as noted above, the unavailable information may also be 

relevant to a reasoned choice among the alternatives based on the discussion below. The cost of obtaining 

data on the effects from the UME and/or Deepwater Horizon explosion, oil spill, and response are 

exorbitant, duplicative of efforts already being undertaken as part of the UME and NRDA, and would 

likewise take years to acquire and analyze through the existing NRDA and UME processes. The NMFS 

has jurisdiction for the investigation of marine mammal strandings and has only released raw data on 

stranding numbers to date. Therefore, it is not possible for BOEM to obtain this information within the 

timeline contemplated in the NEPA analysis of this Supplemental EIS, regardless of the cost or resources 

needed. In light of the incomplete or unavailable information, BOEM’s subject-matter experts have used 

available scientifically credible evidence, such as the scientific research evaluated in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS, as well as new information such as the Schwacke et al. (2013) paper, in this analysis and have 

applied it using accepted scientific methods and approaches. Analyses relevant to the UME and 

Deepwater Horizon explosion, oil spill, and response discussion identify that localized 

populations/species in the CPA are unlikely to have been affected with the majority of oil-spill effect data 

derived from the Exxon Valdez and limited exposure treatments (i.e., Waring et al., 2011; Geraci, 1990; 

St. Aubin and Lounsbury, 1990). Wider ranging species may have been exposed to the Deepwater 

Horizon oil spill but are unlikely to have experienced population-level effects due to their wide-ranging 

distributions and behavior (i.e., Davis et al., 2000; Jochens et al., 2008). Further, impacts from the 

Deepwater Horizon explosion, oil spill, and response may be difficult or impossible to discern from other 

factors. For example, even 20 years after the Exxon Valdez spill, long-term impacts to marine mammal 

populations were still being investigated (Matkin et al., 2008). Therefore, it is not possible for BOEM to 

obtain this information within the timeline contemplated in the NEPA analysis of this Supplemental EIS, 

regardless of the cost or resources needed. In light of the incomplete or unavailable information, 

BOEM’s subject-matter experts have used available scientifically credible evidence in this analysis and 

applied it using accepted scientific methods and approaches. Nevertheless, a complete understanding of 

the missing information is not essential to a reasoned choice among alternatives for this Supplemental EIS 

(including the No Action and Action alternatives) for the three main reasons listed below.
4-56 Central and Eastern Planning Areas Supplemental EIS

(1) The CPA is an active oil and gas region with ongoing (or the potential for) 

exploration, drilling, and production activities. In addition, non-OCS oil- and gasrelated activities will continue to occur in the CPA irrespective of a CPA proposed 

action (i.e., fishing, military activities, and scientific research). The potential for 

effects from changes to the affected environment (post-Deepwater Horizon), routine 

activities, accidental spills (including low-probability catastrophic spills), and 

cumulative effects remains whether or not the No Action or an Action alternative is 

chosen under this Supplemental EIS. Impacts on marine mammals from either 

smaller accidental events or low-probability catastrophic events will remain the 

same.

(2) Some marine mammal populations in the CPA do not generally travel throughout 

areas affected by spilled oil from the Deepwater Horizon explosion, and they would 

not be subject to a changed baseline or cumulative effects from the Deepwater 

Horizon explosion, oil spill, and response (e.g., coastal bottlenose dolphins that are 

resident in the EPA). Other marine mammals, such as Bryde’s whales 

(Balaenoptera edeni) and West Indian manatees (Trichechus manatus), although not 

likely affected by the Deepwater Horizon explosion, oil spill, and response, also do 

not typically occur in the proposed CPA lease sale area. 

(3) Other wide-ranging populations of marine mammals that may occur in the GOM 

and within areas affected by the spill are unlikely to have experienced populationlevel effects from the Deepwater Horizon explosion, oil spill, and response given 

their wide-ranging distribution and behaviors.

Summary and Conclusion

BOEM has reexamined the analysis for marine mammals presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for marine mammals presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.13. Sea Turtles

BOEM has reexamined the analysis for sea turtles presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231, and CPA 235/241/247 Supplemental EIS based on the additional information 

presented below. No new significant information was discovered that would alter the impact conclusion 

for sea turtles in those NEPA documents. The analysis and potential impacts discussed in those 

documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the routine events, 

accidental events, and cumulative impacts associated with a CPA proposed action are presented in 

Chapter 4.2.1.13 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is provided in 

Chapter 4.2.1.13 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.13 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

In order to minimize potential interactions and impacts to sea turtles, operators are required to follow 

all applicable lease stipulations and regulations, as clarified by NTLs. The operator’s reaffirmed 

compliance with NTL 2012-JOINT-G01 (“Vessel-Strike Avoidance and Injured/Dead Protected Species 

Reporting”) and NTL 2012-BSEE-G01 (“Marine Trash and Debris Awareness Elimination”), as well as 

the limited scope, timing, and geographic location of a CPA proposed action, would result in negligible 

effects from a CPA proposed action on sea turtles. In addition, NTL 2012-JOINT-G02, “Implementation 

of Seismic Survey Mitigation Measures and Protected Species Observer Program,” minimizes the 
Description of the Environment and Impact Analysis 4-57

potential of harm from seismic operations to sea turtles and marine mammals; these mitigations include 

onboard observers, airgun shut-downs for whales in the exclusion zone, ramp-up procedures, the use of a 

minimum sound source, and delayed use of explosives when sea turtles or marine mammals are observed 

in the exclusion zone.

Impacts of Routine Activities and Accidental Events

The routine activities associated with proposed CPA Lease Sales 241 and 247 that could potentially 

affect sea turtles include the following: the degradation of water quality resulting from operational 

discharges; noise generated by helicopter and vessel traffic, platforms, drill ships, and seismic 

exploration; noise and impact from explosive structure removals; vessel strikes; and marine debris 

generated by service vessels and OCS oil- and gas-related facilities. Noise disturbance and/or exposure to 

sublethal levels of toxins and anthropogenic contaminants may stress animals, weaken their immune 

systems, and make them more vulnerable to parasites and diseases that normally would not be fatal during 

their life cycle. Because of the mitigations (e.g., BOEM and BSEE proposed compliance with NTLs) as 

described in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS and as summarized below, routine activities (e.g., operational discharges, 

noise, vessel traffic, and marine debris) related to a CPA proposed action are not expected to have longterm adverse effects on the size and productivity of any sea turtle species or populations in the northern 

Gulf of Mexico. With the mitigations, few deaths are expected from chance collisions with OCS oil- and 

gas-related service vessels, ingestion of plastic material, and pathogens. To minimize impacts to sea 

turtles and marine mammals from explosive structure removal, the use of explosives is delayed when sea 

turtles or marine mammals are observed in the exclusion zone. In addition, the best available scientific 

information indicates that sea turtles do not rely on acoustics; therefore, vessel noise and related activities 

(drilling, seismic exploration, and explosive structure removals) would have limited effects. Most routine 

OCS oil- and gas-related activities are expected to have sublethal effects that are not expected to rise to 

the level of significance.

Accidental events including marine debris generated by service vessels and OCS oil- and gas-related 

facilities, blowouts, oil spills, contaminant spills, and spill-response activities may be associated with a 

CPA proposed action. The major impact-producing factors resulting from the accidental activities 

associated with a CPA proposed action that may affect loggerhead, Kemp’s ridley, hawksbill, green, and 

leatherback turtles include accidental blowouts, oil spills, and spill-response activities that have the 

potential to impact small to large numbers of sea turtles in the GOM, depending on the magnitude and 

frequency of accidents, the ability to respond to accidents, the location and time of year the accidents 

occur, and various meteorological and hydrological factors. Impacts from smaller accidental events may 

affect individual sea turtles in the area, but impacts are unlikely to rise to the level of population effects 

(or significance) given the size and scope of such spills. Population-level impacts are not anticipated 

based on the best available information. Further, the potential remains for smaller accidental spills to 

occur in a CPA proposed action area, regardless of any alternative selected under this Supplemental EIS, 

given that it is an active oil and gas region with either ongoing or the potential for exploration, drilling, 

and production activities.

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors of OCS oil- and gas-related 

impacts along with non-OCS oil- and gas-related impacts of other commercial, military, recreational, 

offshore, and coastal activities that may occur and adversely affect sea turtles in the same general area of 

a CPA proposed action. The major impact-producing factors resulting from cumulative OCS oil- and gasrelated activities associated with a CPA proposed action that may affect loggerhead, Kemp’s ridley, 

hawksbill, green, and leatherback turtles and their habitats include marine debris, contaminant spills and 

spill-response activities, vessel strikes, noise, seismic surveys, and explosive structure removals. Lease 

stipulations and regulations, as clarified by NTLs, are in place to reduce vessel strike mortalities, impacts 

from marine trash and debris, and seismic surveys. The cumulative impact of these ongoing OCS oil- and 

gas-related activities on sea turtles may result in a number of chronic and sporadic sublethal effects (i.e., 

behavioral effects and nonfatal exposure to or intake of OCS oil- and gas-related contaminants or 

discarded debris) because these activities may stress and/or weaken individuals of a local group or 
4-58 Central and Eastern Planning Areas Supplemental EIS

population and may predispose them to infection from natural or anthropogenic sources. However, these 

effects are not expected to impact the GOM sea turtle population as a whole. As discussed in 

Appendix B, a low-probability catastrophic spill, which is not part of a CPA proposed action and not 

likely expected to occur, could have population-level effects on sea turtles. The net result of any 

disturbance depends upon the size and percentage of the population likely to be affected, the ecological 

importance of the disturbed area, the environmental and biological parameters that influence an animal’s 

sensitivity to disturbance and stress, or the accommodation time in response to prolonged disturbance 

(Geraci and St. Aubin, 1980).

Non-OCS oil- and gas-related activities that may affect sea turtle populations include vessel noise and 

strikes (including commercial shipping, recreational, and research vessels), State drilling operations, 

military operations, commercial and recreational fishing, pollution, historic overexploitation, coastal 

infrastructure and habitat loss, dredging, pathogens, increased runoff, and natural phenomena. Effects 

from these activities could result in physiological stress, reduced reproductive success, weakened immune 

systems, or mortality of individuals.

The effects of a CPA proposed action, when viewed in light of the effects associated with other past, 

present, and reasonably foreseeable future activities, may result in more significant impacts to sea turtles

as compared with effects before the Deepwater Horizon explosion, oil spill, and response; however, the 

magnitude of those effects cannot yet be determined. Applicable lease stipulations and regulations, as 

clarified by NTLs such as those discussed above, would minimize impacts. Even when taking into 

consideration the potential effects of the Deepwater Horizon explosion, oil spill, and response and the 

minimization of impacts through lease stipulations and regulations, no significant cumulative impacts to 

sea turtles would be expected as a result of the proposed exploration activities when added to the impacts 

of past, present, or reasonably foreseeable oil and gas development in the area, as well as other ongoing 

activities in the area.

No significant cumulative impacts to sea turtles would be expected as a result of a CPA proposed 

action. The potential for impacts is mainly focused on the individual, and population-level impacts are 

not anticipated. The effects of a CPA proposed action, when viewed in light of the effects associated with 

other past, present, and reasonably foreseeable future OCS oil- and gas-related activities, may result in 

greater impacts to sea turtles than before the Deepwater Horizon explosion, oil spill, and response; 

however, the magnitude of those effects cannot yet be determined. However, the incremental 

contribution of a CPA proposed action would not be likely to result in a significant incremental impact on 

sea turtles within the CPA; in comparison, non-OCS oil- and gas-related activities, such as 

overexploitation, commercial fishing, and pollution, have historically proved to be a greater threat to sea 

turtles.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search was conducted for information published on sea turtles, and various Internet sources were 

examined to determine any recent information regarding sea turtles. Sources investigated included, but 

were not limited to, journals and scientific articles, Google, Google Scholar, and other Federal and State 

natural resource management agency websites. All new relevant information was incorporated into the 

analysis below.

On April 17, 2014, NMFS published the proposed rule, “Taking of Marine Mammals Incidental to 

Commercial Fishing Operations; Bottlenose Dolphin Take Reduction Plan; Sea Turtle Conservation; 

Modification to Fishing Activities” (Federal Register, 2014c). The comment period ended on June 2, 

2014. On July 10, 2014, NOAA published a final rule for “Endangered and Threatened Species: Critical 

Habitat for the Northwest Atlantic Ocean Loggerhead Sea Turtle Distinct Population Segment (DPS) and 

Determination Regarding Critical Habitat for the North Pacific Ocean Loggerhead DPS” (Federal 

Register, 2014b). In the GOM, this includes all Sargassum between the 10-m (33-ft) depth contour and 

the outer boundary of the Exclusive Economic Zone. This designation could impact the commercial 

harvest of Sargassum; however, to our knowledge, the commercial harvest of Sargassum does not occur 

in the GOM. Additionally, NMFS does not expect that this designation would add any risk factors or any 

conservation measures by BOEM because sea turtles and their required habitats are already adequately 

protected through the ESA Section 7 process. Within the GOM, there is a long-standing and welldeveloped OCS Program (more than 50 years); there are no data to suggest that activities from the 
Description of the Environment and Impact Analysis 4-59

preexisting OCS Program are significantly impacting sea turtle populations within these designated 

critical habitats. Therefore, in light of a CPA proposed action and its impacts, the incremental effect on 

sea turtle critical habitat is not expected to be significant when compared with non-OCS energy-related 

activities. 

Since January 1, 2011, a notable increase in sea turtle strandings has occurred in the northern GOM, 

primarily in Mississippi. While turtle strandings in this region typically increase in the spring, the recent 

increase is a cause for concern. The Sea Turtle Stranding and Salvage Network is monitoring and 

investigating this increase. The network is part of the NOAA/FWS National Marine Mammal Health and 

Stranding Response Program and encompasses the coastal areas of the 18 states from Maine through 

Texas. There are many possible reasons for the increase in strandings in the northern GOM, both natural 

and human caused (USDOC, NMFS, 2014d). These sea turtle species include loggerhead, green, Kemp’s 

ridley, leatherback, hawksbill, and unidentified. Since the beginning (2011) ` adjacent to a CPA proposed 

action, NMFS has identified 203 strandings in Alabama, 473 strandings in Louisiana, 641 strandings in 

Mississippi, and 1,219 strandings in Texas (upper Texas coast—Zone 18) as of the last available update 

through August 25, 2013 (USDOC, NMFS, 2014e). In 2013, the State of Florida’s Fish and Wildlife 

Conservation Commission reported 1,886 stranded sea turtles throughout Florida (Foley, 2014). Of those, 

466 strandings occurred in counties on the west coast of Florida, excluding Monroe and Dade Counties. 

Strandings for previous years in western Florida are similar to 2013, with 410 strandings in 2012 and 

467 strandings in 2011(Tables 4-2 through 4-4). In 2014, 235 cold-stunned sea turtles were rescued in 

the panhandle in January from two separate cold weather events (Foley, 2014) and, as of November 21, 

2014, stranding data are not yet released for 2014. 

In 2013, loggerhead sea turtle nest counts on Florida’s beaches were lower than 2012 numbers, 

totaling 77,975 nests (9,952 west coast). As of November 21, 2014, nesting raw data for 2014 are 

unavailable and are expected to be available in 2015 (State of Florida, Fish and Wildlife Conservation 

Commission, 2014a). . However, some of the 2014 data totals have been plotted (State of Florida, Fish 

and Wildlife Conservation Commission, 2014b). Even with a slight decline in nesting, 2012 and 2013 

saw high loggerhead nest counts in comparison to the previous decade. In 2014, there was an increase in 

nesting from the previous year in peninsular Florida for loggerheads. Green sea turtle nest counts have 

increased approximately one hundredfold from 1989 to 2013, from 267 nests in 1989 to 25,553 (207 west 

coast) nests in 2013 on Florida index beaches. The nest count for 2014 was similar to that of the previous 

decade, other than the steep peak seen in 2013 (State of Florida, Fish and Wildlife Conservation 

Commission, 2014a and 2014b). No leatherback nests were recorded on the west coast of Florida in 2013 

(State of Florida, Fish and Wildlife Conservation Commission, 2014a). Similar to the nest counts for 

green turtles, leatherback nest counts have been increasing exponentially on Florida index beaches (State 

of Florida, Fish and Wildlife Conservation Commission, 2014b) and reached their highest numbers in 

2014 (State of Florida, Fish and Wildlife Conservation Commission, 2014b). A total of 82 nests were 

discovered in 2013 along the Alabama Gulf Coast (Share the Beach, 2014). Texas’ coastline had a 

documented 153 Kemp’s ridley, 13 loggerhead, and 15 green sea turtle nests in 2013 (USDOI, NPS, 

2014; Shaver, official communication, 2014). Nesting surveys are not conducted in Mississippi or 

Louisiana due to logistical and funding limitations, although intermittent observations indicated that some 

does occur (USDOI, FWS, official communication, 2012). 

The new information presented in this chapter provides additional details on the baseline affected 

environment for sea turtles, and it does not change BOEM’s conclusions about the potential effects of a 

CPA proposed action on sea turtles.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or

unavailable information. As discussed above, as well as in the 2012-2017 WPA/CPA Multisale EIS,

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, BOEM has identified 

incomplete information regarding impacts of the Deepwater Horizon explosion, oil spill, and response on 

sea turtles in the CPA. BOEM used existing information and reasonably accepted scientific

methodologies to extrapolate from available information in completing the relevant analysis of potential 

oil exposure impacts to sea turtles using studies investigating evidence of oil and impacts stemming from 
4-60 Central and Eastern Planning Areas Supplemental EIS

exposure to oil (Witham, 1978; Vargo et al., 1986; Lutz and Lutcavage, 1989; Lutcavage et al., 1995; 

Plotkin and Amos, 1988). In addition, BOEM used information published on sea turtle nests and 

strandings to draw conclusions about sea turtle populations following the Deepwater Horizon explosion, 

oil spill, and response (USDOC, NMFS, 2014d and 2014e; Foley, 2014; State of Florida, Fish and 

Wildlife Conservation Commission, 2014a, and 2014b; Share the Beach, 2014). Unavailable information 

on the effects to sea turtles from the Deepwater Horizon explosion, oil spill, and response (and thus 

changes to the sea turtle baseline in the affected environment) makes an understanding of the cumulative 

effects less clear. A large body of information is being developed though the NRDA process, but it is not 

yet available. Relevant data on the status of sea turtle populations after the Deepwater Horizon explosion, 

oil spill, and response and increased sea turtle GOM strandings may take years to acquire and analyze, 

and impacts from the Deepwater Horizon explosion, oil spill, and response may be difficult or impossible 

to discern from other factors. BOEM used existing information and reasonably accepted scientific 

methodologies to extrapolate from available information on sea turtle nests and strandings in completing 

the relevant analysis of sea turtle populations. None of these sources reveal reasonably foreseeable 

significant adverse impacts. Therefore, BOEM concludes that the unavailable information from these 

events may be relevant to foreseeable significant adverse impacts to sea turtles because the full extent of 

impacts on sea turtles is not known, but BOEM has determined that the information is not essential to a 

reasoned choice among alternatives for this Supplemental EIS.

Nevertheless, there are existing leases in the CPA with either ongoing or the potential for exploration, 

drilling, and production activities. In addition, non-OCS oil- and gas-related activities will continue to 

occur in the CPA irrespective of a CPA proposed action (i.e., fishing, military activities, and scientific 

research). The potential for effects from changes to the affected environment (post-Deepwater Horizon

explosion, oil spill, and response), routine activities, accidental spills (including low-probability 

catastrophic spills), and cumulative effects remains whether or not the No Action or an Action alternative 

is chosen under this Supplemental EIS. All wide-ranging populations of sea turtles that may occur in the 

CPA and within areas affected by the spill are unlikely to have experienced population-level effects from 

the Deepwater Horizon explosion, oil spill, and response given their wide-ranging distribution and 

behaviors.

Summary and Conclusion

BOEM has reexamined the analysis for sea turtles presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented above. No new significant information was discovered that would alter 

the impact conclusion for sea turtles presented in those NEPA documents because of the available 

scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.14. Diamondback Terrapins

BOEM has reexamined the analysis for the diamondback terrapin (Malaclemys terrapin littoralis) and 

Mississippi diamondback terrapin (Malaclemys terrapin pileata) (referred to as diamondback terrapins in 

this document) presented in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental 

EIS, and CPA 235/241/247 Supplemental EIS based on the additional information presented below. No 

new significant information was discovered that would alter the impact conclusion for diamondback 

terrapins in those NEPA documents. The analysis and potential impacts discussed in those documents 

still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action is 

presented in Chapter 4.2.1.14 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.14 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.14 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.
Description of the Environment and Impact Analysis 4-61

The global conservation status rank of diamondback terrapins is apparently secure—uncommon but 

not rare; some cause for long-term concern due to declines or other factors. The subspecies conservation 

status ranks range from imperiled (mangrove diamondback terrapin), vulnerable (Mississippi 

diamondback terrapin), and apparently secure (Florida east coast terrapin and ornate diamondback 

terrapin) (NatureServe 2014). “Species of concern” is an informal term that refers to those species that 

might be in need of concentrated conservation actions. Species of concern receive no legal protection 

above those already afforded the species under other laws, and the use of the term does not necessarily 

mean that the species will eventually be proposed for listing as a threatened or endangered species. At the 

present time, the diamondback terrapin is neither a listed species nor a candidate for listing under the 

Endangered Species Act.

Impacts of Routine Activities and Accidental Events

The following routine activities associated with proposed CPA Lease Sales 241 and 247 could 

potentially affect diamondback terrapins: ingestion of beach trash and debris generated by service vessels 

and OCS oil- and gas-related facilities; direct injury from vessel traffic (boat propellers); and indirect 

injury from loss of habitat due to coastal marsh erosion associated with vessel traffic (refer to Chapters 

4.1.1.3 and 3.3.4.3 of this Supplemental EIS and Chapters 4.1.1.3 and 3.3.4.3 of the CPA 235/241/247 

Supplemental EIS). Erosion to marshes can be indirectly attributed to OCS service traffic and onshore 

development, but it is expected to cause little to no damage to the physical integrity, species diversity, or 

biological productivity of terrapin habitat. Adverse impacts due to routine activities resulting from a CPA 

proposed action are possible but unlikely. Because of the greatly improved handling of waste and trash 

by industry and because of the annual awareness training required by the marine debris mitigations, the 

plastics in the ocean are decreasing and the devastating effects on offshore and coastal marine life are 

minimized. Collisions with OCS vessel traffic are minimized by NTL 2012-JOINT-G01, “Vessel Strike 

Avoidance and Injured/Dead Protected Species Reporting,” which provides guidelines on monitoring 

procedures related to vessel strike avoidance measures. Due to the distance from shore, most impacts are 

not expected to reach terrapins or their habitat. Impacts that may occur from routine activities of a CPA 

proposed action are unlikely to have significant adverse effects on the size and recovery of any terrapin 

species or population in the Gulf of Mexico because most routine, OCS oil- and gas-related activities are 

expected to have sublethal effects. Sublethal effects such as behavioral effects, nonfatal exposure to or 

intake of OCS oil- and gas-related contaminants, or discarded debris may stress and/or weaken 

individuals of a local group or population and predispose them to infection from natural or anthropogenic 

sources. These effects are not expected to rise to the level of significance to the populations.

Impact-producing factors associated with accidental events that may be associated with a CPA 

proposed action that could affect diamondback terrapins include offshore and coastal oil spills and spillresponse activities. Behavioral effects and nonfatal exposure to or intake of OCS oil- and gas-related 

contaminants may stress and/or weaken individuals of a local group or population and predispose them to 

infection from natural or anthropogenic sources. Even after the oil is no longer visible, terrapins may still 

be exposed while they forage in the salt marshes lining the edges of estuaries where oil may have 

accumulated under the sediments and within the food chain (Burger, 1994; Roosenburg et al., 1999). 

Reproductive success may be reduced if nests are disturbed or destroyed by cleanup efforts. Hatching 

success studies at various oiled nesting sites of the northern diamondback terrapin suggest that spills may 

result in a reduction in nest size and increased mortality of spring emergers at the oiled sites (Wood and 

Hales, 2001). However, research on the PAH exposure and toxicology of eggs in the vicinity of a spill 

site found no correlation to substrate PAHs when compared with egg toxicology. The level of PAHs 

found in the eggs may be the result of maternal transfer and represent the exposure level of the nesting 

female rather than environmental exposure to PAHs from oil at the site of the nest (Holliday et al., 2008). 

Impacts on diamondback terrapins from smaller accidental events are likely to affect individual 

diamondback terrapins in the spill area, but they are unlikely to rise to the level of population effects (or a 

level of significance) given the probable size and scope of such spills. Further, the potential remains for 

smaller accidental spills to occur in a CPA proposed action area, regardless of any alternative selected 

under this Supplemental EIS, given that it is an active oil and gas region with either ongoing or the 

potential for exploration, drilling, and production activities.
4-62 Central and Eastern Planning Areas Supplemental EIS

Cumulative Impacts

The major OCS oil- and gas-related impact-producing factors that may affect the diamondback 

terrapin include (1) vessel traffic, (2) exposure or intake of OCS oil- and gas-related contaminants or 

debris, and (3) oil spills and spill response. To mitigate the potential impacts from OCS oil- and gasrelated activities, operators are required to follow all applicable lease stipulations and regulations, as 

clarified by NTLs, to minimize these potential interactions and impacts. The operator’s reaffirmed 

compliance with NTL 2012-BSEE-G01 (“Marine Trash and Debris Awareness and Elimination”) and 

NTL 2012-JOINT-G01 (“Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”), as 

well as the limited scope, timing, and geographic location of a CPA proposed action, would result in 

minimal effects from the proposed drilling activities on diamondback terrapins. Most spills related to a 

CPA proposed action, as well as low-probability catastrophic spills, which are not part of a CPA proposed 

action and not likely expected (refer to Appendix B for more information), as well as oil spills stemming 

from tankering and prior and future lease sales, are not expected to contact terrapins or their habitats. 

Most routine and accidental OCS oil- and gas-related activities are expected to have sublethal effects, 

such as behavioral effects, that are not expected to rise to the level of significance to the populations as a 

whole. Therefore, the incremental contribution of a CPA proposed action to cumulative impacts on 

terrapins is expected to be minimal.

Activities posing the greatest potential harm to terrapins are non-OCS oil- and gas-related factors, 

including habitat destruction, overharvesting and crab pot fishing, vessel traffic and road mortality, nest 

depredation, State oil- and gas-related activity, and natural processes. Spending most of their lives within 

their limited home ranges at the aquatic-terrestrial boundary in estuaries, terrapins are susceptible to 

habitat destruction (i.e., urban development, subsidence/sea-level rise, direct oil contact from non-OCS 

oil- and gas-related leasing program activities, and associated cleanup efforts). Habitat destruction, road 

construction, nest depredation, and drowning in crab traps are the most recent threats to diamondback 

terrapins. In the 1800’s, populations declined due to overharvesting for meat (Hogan, 2003). Tropical 

storms, hurricanes, and beach erosion threaten their preferred nesting habitats. Characteristics of terrapin

life history render this species especially vulnerable to overharvesting and habitat loss. These 

characteristics include low reproductive rates, low survivorship, limited population movements, and nest 

site fidelity year after year. Inshore oil spills from non-OCS oil- and gas-related sources are potential 

threats to the terrapins’ brackish coastal marsh habitat.

The incremental contribution of a CPA proposed action is expected to be minimal compared with 

non-OCS oil- and gas-related activities. The major impact-producing factors resulting from the 

cumulative activities associated with a CPA proposed action that may affect diamondback terrapins

include oil spills and spill-response activities, alteration and reduction of habitat, and consumption of 

trash and debris. Overall, within the CPA, there is a long-standing and well-developed OCS Program 

(more than 50 years); there are no data to suggest that activities from the preexisting OCS Program are 

significantly impacting diamondback terrapin populations. Due to the extended distance from shore, 

impacts associated with activities occurring in the OCS Program are not expected to impact terrapins or 

their habitat. Non-OCS oil- and gas-related activities will continue to occur in the CPA irrespective of a 

proposed CPA lease sale (i.e., crabbing, fishing, military activities, scientific research, and shoreline 

development). Therefore, in light of the above analysis of a CPA proposed action and its impacts, the 

incremental effect of a CPA proposed action on diamondback terrapin populations is not expected to be 

significant when compared with historic and current non-OCS oil- and gas-related activities, such as 

habitat loss, overharvesting, crabbing, and fishing.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources (NOAA’s and FWS’s websites, and the RestoreTheGulf.gov 

website), as well as recently published journal articles, was conducted to determine the availability of 

recent information on diamondback terrapins. The search revealed no new information pertinent to this 

Supplemental EIS. No new information was found at this time that would alter the overall conclusions of 

the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS that impacts on diamondback terrapins associated with a CPA proposed action are 

expected to be minimal.
Description of the Environment and Impact Analysis 4-63

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from 

previous documents are still valid because no new information on diamondback terrapins pertinent to the 

proposed action has become available since publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is 

still incomplete or unavailable information on possible impacts to diamondback terrapins as a result of the 

Deepwater Horizon explosion, oil spill, and response.

Diamondback terrapins within the CPA were likely not affected to any discernible degree by the 

Deepwater Horizon explosion, oil spill, and response, based on the best available information and the 

distance of terrapin habitat from the Macondo well. However, BOEM has identified incomplete 

information regarding impacts of the Deepwater Horizon explosion, oil spill, and response on 

diamondback terrapin in the CPA because little information about Deepwater Horizon explosion, oil spill, 

and response has been released as of the publication of this Supplemental EIS. Through NRDA, ongoing 

research and analysis of the presence of contaminants in terrapin eggs following the Deepwater Horizon

oil spill is being conducted (USDOC, NOAA, 2012), but the results are not yet available. Relevant data 

on the status of diamondback terrapin populations after the Deepwater Horizon explosion, oil spill, and 

response may take years to acquire and analyze, and impacts may be difficult or impossible to discern 

from other factors. This incomplete information may be relevant to evaluating adverse effects because

the full extent of potential impacts on terrapins is not known. In place of the missing information, BOEM 

used existing information and reasonably accepted scientific methodologies to extrapolate from available 

information in completing the relevant analysis, such as studies investigating the evidence of oil and 

impacts stemming from exposure to oil (Burger, 1994; Roosenburg et al., 1999; Holliday et al., 2008; 

Wood and Hales, 2001). The results of these studies indicate impacts resulting from the Deepwater 

Horizon oil spill have been largely indistinguishable from natural fluctuations or variability due to other 

anthropogenic activities. Although the body of available information is incomplete and long-term effects 

cannot yet be known, past analyses are not indicative of significant population-level responses. BOEM 

has determined that the information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for diamondback terrapins presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS. No new significant information was discovered that would alter the impact conclusion for 

diamondback terrapin presented in those NEPA documents because of the available scientifically credible 

evidence in this analysis and based upon accepted scientific methods and approaches. The analysis and 

potential impacts discussed in those documents still apply for the proposed CPA Lease Sales 241 and 247.

4.1.1.15. Beach Mice

BOEM has reexamined the analysis for beach mice presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented below. No new significant information was discovered that would alter 

the conclusion for beach mice presented in those NEPA documents. The analysis and potential impacts 

discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.15 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.15 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.15 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.

Impact of Routine Activities and Accidental Events

The potential routine impact-producing factors that may affect beach mice are beach trash and debris, 

and efforts undertaken for the removal of marine debris or for restoration. An impact from the routine 
4-64 Central and Eastern Planning Areas Supplemental EIS

activities associated with a CPA proposed action on the Alabama (Peromyscus polionotus ammobates), 

Choctawhatchee (P. p. allophrys), St. Andrew (P. p. peninularis), Perdido Key (P. p. trissyllepsis), and 

Santa Rosa (P. p. leucocephalus) beach mice is possible but unlikely. Impacts may result from 

consumption of or entanglement in beach trash and debris. Because a CPA proposed action would 

deposit only a small portion of the total debris that would reach the habitat, the impacts would be 

minimal. Any coastal discharges into marine water would not affect beach mice because they drink only 

fresh water. Boat traffic would have no impact on beach mice because they live above high tide. 

Helicopter traffic is expected to occur only well to the west of beach mouse habitat (the nearest existing 

helicopter hub in Theodore, Alabama; refer to Chapter 3.1.2.1.2. of the 2012-2017 WPA/CPA Multisale 

EIS). Coastal and nearshore construction projects (e.g., those producing OCS oil- and gas-related 

supporting structures and facilities and those involving OCS oil- and gas-related activities such as 

navigation channel dredging) are not expected to have impacts on beach mice because their critical 

habitat is protected.

The major impact-producing factors resulting from accidental events associated with a CPA proposed 

action that may affect beach mice include offshore and coastal oil spills, and spill-response activities. The 

oiling of beach mice could result in local extinction. An accidental spill occurring and contacting the 

shoreline is unlikely and the area of viable habitat is broad relative to the area potentially contacted by a 

spill (Figure 3-11 of the 2012-2017 WPA/CPA Multisale EIS). To contact beach mouse habitat oil would 

have to wash over the foredunes to beach mouse habitat in a storm surge. A review of the available 

information shows that impacts on beach mice from accidental impacts associated with a CPA proposed 

action would be minimal.

Cumulative Impacts

Cumulative activities have the potential to harm or reduce the abundance of beach mice. The OCS 

oil- and gas-related activities include oil spills and the consumption of and entanglement in beach trash

and debris. Non-OCS oil- and gas-related impacts include oil spills; beach development that alters, 

fragments, or reduces habitat; hurricanes; and tropical storms. Most spills related to a CPA proposed 

action and prior and future lease sales are not expected to contact beach mice or their habitats because the 

species lives above the intertidal zone where contact is less likely. Destruction of the remaining beach 

mouse habitat due to a low-probability catastrophic spill and cleanup activities, which is not part of a 

CPA proposed action and not likely expected, would increase the threat of extinction. Impacts on beach 

mice from a catastrophic spill are discussed in Appendix B. 

Cumulative impacts could potentially deplete some beach mice populations to unsustainable levels. 

Within the last 20-30 years, the combination of habitat loss due to beachfront development, the isolation 

of remaining beach mouse habitat areas and populations, and the destruction of remaining habitat by 

tropical storms and hurricanes have increased the threat of extinction of several subspecies of beach mice. 

Impacts from OCS oil- and gas-related activities could come from trash and debris, and efforts to remove 

them, as well as oil spills and cleanup operations. However, the expected incremental contribution of a 

CPA proposed action to the cumulative impacts is negligible.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources including published journal articles was conducted to 

determine the availability of recent information on coastal and marine birds. Websites visited included 

four for Federal agencies (U.S. Fish and Wildlife Service, U.S. Environmental Protection Agency, U.S. 

Geological Survey, and the Bureau of Ocean Energy Management), five for State agencies (Alabama 

Department of Conservation and Natural Resources, Alabama Department of Environmental 

Management, Alabama Wildlife and Freshwater Fisheries Division, State of Florida Department of 

Environmental Protection, and State of Florida’s Fish and Wildlife Conservation Commission, two for 

universities (Florida State University and University of Florida), several for various stakeholders (Sierra 

Club, National Fish and Wildlife Foundation, Nature Conservancy, Gulf of Mexico Alliance, Gulf of 

Mexico Program, Gulf Coast Ecosystem Task Force, and Gulf Coast Ecosystem Restoration Council), 

NOAA Central Library’s Deepwater Horizon Bibliography (Belter, 2014), and LUMCON Library’s the 

“Effects of Offshore Oil and Gas Development: A Current Awareness Bibliography” (Conover, 2004). 
Description of the Environment and Impact Analysis 4-65

Where applicable, websites of subdivisions of many of these organizations were also consulted. 

Environmental journal articles were also located online using four search engines (JSTOR, EBSCO, 

Google Advanced Scholar Search, and Google Advanced Book Search). Three of the search engines 

collectively searched all of the ecology journals of six major publishers (John Wiley and Sons, Springer, 

Elsevier Science, Taylor and Francis Group, Cambridge University Press, and Oxford University Press).

A search was conducted for information related to the cumulative impacts of non-OCS oil- and gasrelated activities on beach mice. This search included the information about the frequency and height of 

storm-related surges, the impact of a hurricane on dune habitats, the probabilities of extinction, how 

hurricanes alter predation risk, the role of interspecific competition, the importance of swale and dune 

vegetation, and the behavioral ecology of beach mice.

Although not specific to beach mice, recent analyses have reexamined the frequency of hurricanes

that impact beach mouse habitat (Blake and Gibney, 2011) and modeled expected storm surges with 

hurricanes (Chen et al., 2008). This information is important because it provides insight into the 

frequency and potential of flooding of beach mouse habitat. If this happens to coincide with an oil spill, a 

storm surge would be the primary pathway by which large amounts of oil could be transported into beach 

mouse habitat. For example, if a hurricane similar to Hurricanes Ivan or Katrina were to coincide in time 

and space with an oil spill, it can be expected that the storm surge would carry oil into all beach mouse 

habitat that is 2.5 m (8.2 ft) above sea level (Chen et al., 2008).

Tertiary dunes in Alabama beach mouse habitat were observed at as much as 10 m (33 ft) above mean 

sea level (Boyd et al., 2004).

Hurricane Georges (in 1998) did not change tertiary dunes and scrub in Alabama beach mouse

habitat; it only slightly changed secondary dunes and scoured beaches and breached primary dunes (Boyd 

et al., 2004).

Conroy and Runge (2008) used a state-of-the-art robust population viability analysis with trapping 

grid data from 1994 through 2006 to model extinction probabilities for the Alabama beach mouse. The 

probabilities of extinction with standard errors (SE) were 0.01 (SE = 0.08) over the next 10 years, 

0.05 (SE = 0.23) over the next 20 years, 0.17 (SE = 0.38) over the next 50 years, 0.25 (SE = 0.43) over 

the next 100 years, and 0.31 (SE = 0.46) over the next 200 years,

Additionally, Wilkinson et al. (2013) found a positive relationship between the amount of hurricanerelated habitat fragmentation in an area and the ability of mice to avoid predation. This is important 

because habitat fragmentation above a threshold could lead to a nonlinear increase in the cumulative 

impacts on beach mice. From an ecological standpoint, Falcy and Danielson (2013) found that 

competition between the Alabama beach mouse and the hispid cotton rat (Sigmodon hispidus) has 

minimal effect, suggesting that intraspecific competition among rats may not be important when 

determining cumulative impacts.

Finally, Lynn (2014) and Yanchis (2014) provide new details of threats to beach mouse habitat that 

may influence the cumulative impact analysis. The main threat to beach mice is coastal development, 

including residential and commercial buildings, nonnative landscaping, nonnative predators (i.e., dogs 

and cats), and excessive lighting.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, BOEM 

has identified incomplete information regarding beach mice in the CPA. This incomplete information 

may be relevant to an evaluation of adverse effects because it provides any change in the baseline 

environmental conditions for beach mouse populations in the affected environment from the Deepwater

Horizon oil spill and response, exacerbating any impacts from a CPA proposed action. Relevant data on 

the status of beach mice after the Deepwater Horizon explosion, oil spill, and response may take years to 

acquire and analyze. Much of these data are being developed through the NRDA process, which may 

take years to complete. It is not possible for BOEM to obtain this information and incorporate it into this 

analysis within the timeline contemplated in the NEPA analysis of this Supplemental EIS, regardless of 

the costs or resources needed. Current studies are investigating the effects of the Deepwater Horizon
4-66 Central and Eastern Planning Areas Supplemental EIS

explosion, oil spill, and response activities on beach mice and their habitat (Frater, official 

communication, 2014). The time when the studies’ results will be released is unclear; therefore, BOEM 

cannot commit to waiting for this new information to become available to incorporate it into this 

Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. The following is an example of 

extrapolations made from data summarized from OSAT-2 (2011) that BOEM used in the stead of 

unavailable and incomplete information. Assessment of the efficacy of shoreline cleanup in supratidal 

Alabama beach mouse habitat showed 60 percent “no oil observed,” 37 percent “light-very light oiling,” 

and 3 percent “moderate-heavy oiling.” Much of the supratidal habitat of the Perdido Key and 

Choctawhatchee beach mice showed “no oil observed.” The supratidal habitat of the St. Andrew beach 

mouse was not affected by the Deepwater Horizon oil spill and response. A “toxicity reference value” is 

developed by USEPA for low (2-3 ring) and high (4-7 ring) molecular weight PAHs. Two scenarios for 

the PAH oral uptake by Alabama beach mouse were reported: 10 percent contribution and a worst-case 

100 percent contribution of small tarballs to the overall ingesting of soil. The estimated daily dose of 

PAHs from oral uptake following the Deepwater Horizon oil spill and response did not exceed the 

toxicity reference value for low molecular weight PAHs in the Alabama beach mouse.

The following is another example of extrapolations made from data summarized from Frater (official 

communication, 2011) that BOEM used in the stead of unavailable or incomplete information. Known 

occupied habitat has been trampled, denuded, and eroded. Reasonable estimates of the amount of beach 

mouse habitat that has been damaged, altered, or destroyed varies from 1 to 50 ac throughout the range of 

the five Gulf Coast subspecies (4 of which are federally protected). Preliminary data suggest that impacts 

to beach mouse habitat was very minor. The impacts to beach mouse habitat during the Deepwater

Horizon response probably have not caused significant impacts to the population levels of beach mice. 

The habitat that was damaged was primarily young dunes. The damage may restrict population expansion 

and recovery for a few years, but anticipated restoration activities will probably offset this impact in the 

near future.

Any additional NRDA information obtained from the Deepwater Horizon oil spill and response is 

unlikely to be so significant as to change the assessed impact level. In summary, BOEM has determined 

that the information is not essential to a reasoned choice of alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for beach mice presented in the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, based on the 

additional information presented above. No new significant information was discovered that would alter 

the impact conclusion for beach mice presented in those NEPA documents because of the available 

scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.16. Coastal and Marine Birds

BOEM has reexamined the analysis for coastal and marine birds presented in the 2012-2017 

WPA/CPA Multisale EIS., WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on additional information presented below. No new significant information was discovered 

that would alter the impact conclusion for coastal and marine birds presented in those NEPA documents. 

The analysis and potential impacts discussed in those documents still apply for proposed CPA Lease 

Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.1.1.16 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.16 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.16 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.
Description of the Environment and Impact Analysis 4-67

Impacts of Routine Activities and Accidental Events

The majority of the effects resulting from the routine activities of a CPA proposed action (Tables 3-2 

through 3-4) on threatened or endangered (Table 4-1 of the WPA 233/CPA 231 Supplemental EIS) and 

nonthreatened and nonendangered coastal and marine birds are expected to be sublethal, primarily 

disturbance-related effects (Chapter 4.2.1.16.2 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 

4.2.1.16 of the WPA 233/CPA 231 Supplemental EIS). Major potential impact-producing factors 

resulting from routine activities for marine birds in the offshore environment include the following:

• habitat loss and fragmentation (Fahrig, 1997 and 1998);

• behavioral effects primarily due to disturbance from OCS oil- and gas-related 

helicopter and service-vessel traffic and associated noise (Habib et al., 2007; Bayne 

et al., 2008);

• mortality due to exposure and intake of OCS oil- and gas-related contaminants, e.g., 

drilling discharges and produced waters (Wiese et al., 2001; Fraser et al., 2006) and 

discarded debris (Robards et al., 1995; Pierce et al., 2004);

• sublethal, chronic effects from air emissions (Newman, 1979; Newman and 

Schreiber, 1988); and

• mortality and energetic costs associated with structure presence and associated light 

(Russell, 2005; Montevecchi, 2006).

A detailed impact analysis of the routine activities associated with proposed CPA Lease Sales 241 

and 247 on coastal and marine birds can be found in Chapter 4.2.1.16.2 of the 2012-2017 WPA/CPA 

Multisale EIS, and updated information is provided in Chapter 4.2.1.16 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.16 of the CPA 235/241/247 Supplemental EIS.

Overall, impacts to avian species from routine activities are expected to be adverse but not significant. 

Impacts from routine impacts are more likely to be sublethal to moderate numbers of birds and 

infrequently lethal. Mortality is expected to be distributed among many populations with no substantial 

mortality for any one population.

Impact-producing factors from accidents include oil spills, regardless of size and despite oil-spill 

cleanup activities, including the release of rehabilitated birds. Information regarding a CPA proposed 

action and oil-spill information can be found in Table 3-22 of the 2012-2017 WPA/CPA Multisale EIS.

Oil-spill impacts on birds from a CPA proposed action are expected to be adverse but not significant, 

given the number and relatively small size of spills expected over the 40-year life of a CPA proposed 

action (Table 3-12 of the 2012-2017 WPA/CPA Multisale EIS). Impacts of oil-spill cleanup from a CPA 

proposed action are also expected to be adverse, but not significant, but may be negligible depending on 

the scope and scale of efforts. Significant impacts to coastal and marine birds could result in the event of 

a low-probability catastrophic spill, depending on the timing, location, and size of the spill. For 

additional information on a low-probability catastrophic spill, refer to Appendix B. 

Cumulative Impacts

The cumulative analysis considers impact-producing factors that may adversely affect populations of 

threatened and endangered avian species, as well as nonthreatened and nonendangered species, related to 

OCS oil- and gas-related and non-OCS oil- and gas-related activities. Several OCS oil- and gas-related 

impact-producing factors could potentially affect coastal and marine birds, including the following:

• air pollution;

• pollution of coastal and offshore waters resulting from OCS oil- and gas-related 

activities, including platform and pipeline oil spills, produced waters, and any spillresponse activities;

• structure presence and lighting (e.g., OCS platforms); 
4-68 Central and Eastern Planning Areas Supplemental EIS

• aircraft and vessel traffic and oil-spill cleanup associated noise; 

• maintenance and use of navigation waterways;

• habitat loss, fragmentation, and alteration from coastal facility and OCS oil- and gasrelated support structure construction;

• OCS pipeline landfalls; and

• trash and debris.

A detailed discussion of catastrophic OCS oil- and gas-related events can be found in Appendix B. 

In addition to the factors listed above, there are several non-OCS oil- and gas-related impactproducing factors that could potentially impact coastal and marine birds. These factors include the 

following: air pollution; habitat loss, alteration, and fragmentation associated with commercial and 

residential construction and industrial growth; water pollution including State or tanker oil- and gasrelated spills and any spill-response activities and pollution of coastal waters resulting from municipal, 

industrial, and agricultural runoff and discharge; aircraft and vessel (including military) activities and 

noise; nonconsumptive and consumptive recreation; maintenance and use of navigation waterways; 

collisions with anthropogenic structures; predation; diseases; climate change and related impacts; impacts 

from storms and floods; fisheries interactions; and trash and debris.

The incremental contribution of a CPA proposed action to the cumulative impact is considered 

adverse but not significant because the effects of the most probable impacts, such as lease sale-related 

operational discharges and helicopters and service-vessel noise and traffic, are expected to be sublethal; 

and some displacement of local individuals or flocks may occur to other habitat, if available. In general, 

the net effect of habitat loss from oil spills, OCS oil- and gas-related pipeline landfalls, and maintenance 

and use of navigation waterways, as well as habitat loss and modification resulting from coastal facility 

construction and development, will probably reduce the overall carrying capacity of the disturbed 

habitat(s). That is, impacted habitats may result in reductions to both species composition (fewer species) 

and abundance (lower numbers) as compared with what the area supported historically. These would be 

the most serious cumulative impacts on birds. In conclusion, the incremental contribution of a CPA 

proposed action to the cumulative impact is considered adverse but not significant when compared with 

the impacts of some of the reasonably foreseeable non-OCS oil- and gas-related factors.

New Information Available Since the Publication of 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources including published journal articles was conducted to 

determine the availability of recent information on coastal and marine birds. Websites visited included 

5 for Federal agencies (U.S. Environmental Protection Agency, U.S. Geological Survey, National 

Oceanographic and Atmospheric Administration, U.S. Fish and Wildlife Service, and the Bureau of 

Ocean Energy Management), 12 for State agencies (Texas Commission on Environmental Quality; Texas 

Parks and Wildlife Department; Louisiana Department of Wildlife and Fisheries; Louisiana Department 

of Natural Resources; Louisiana Department of Environmental Quality; Mississippi Department of 

Environmental Quality; Mississippi Department of Wildlife, Fisheries, and Parks; Alabama Department 

of Conservation and Natural Resources; Alabama Department of Environmental Management; Alabama 

Wildlife and Freshwater Fisheries Division; State of Florida Department of Environmental Protection; 

and State of Florida’s Fish and Wildlife Conservation Commission), 5 for universities (University of 

Louisiana at Lafayette, Louisiana State University, Texas A&M University, University of Texas at Austin 

Marine Science Institute College of Natural Sciences, and Florida State University), several for various 

stakeholders (Sierra Club, National Fish and Wildlife Foundation, Nature Conservancy, Gulf of Mexico 

Alliance, Gulf of Mexico Program, Barataria-Terrebonne National Estuary Program, National Audubon 

Society, Gulf Coast Ecosystem Task Force, and Gulf Coast Ecosystem Restoration Council), NOAA 

Central Library’s Deepwater Horizon Bibliography (Belter, 2014), and LUMCON Library’s the “Effects 

of Offshore Oil and Gas Development: A Current Awareness Bibliography” (Conover, 2004). Where 

applicable, websites of subdivisions of many of these organizations were also consulted. Environmental 

journal articles were also located online using four search engines (JSTOR, EBSCO, Google Advanced 
Description of the Environment and Impact Analysis 4-69 

Scholar Search, and Google Advanced Book Search). Three of the search engines collectively searched 

all of the ecology journals of six major publishers (John Wiley and Sons, Springer, Elsevier Science, 

Taylor and Francis Group, Cambridge University Press, and Oxford University Press). The search 

revealed new information on cumulative impacts (large-scale impacts on bird mortality) that is pertinent 

to this Supplemental EIS.

An estimated range of national annual mortality from collision with vehicles is 62-275 million birds 

per year (Loss et al., 2014a). An estimate of national annual mortality from collision with buildings is 

599 million birds per year (Loss et al., 2014b). Finally, an estimate of annual mortality from predation by 

free-ranging domestic cats is 1.4-3.7 billion birds per year (Loss et al., 2013). For collisions with 

buildings and cat predation, these numbers are within the ranges previously reported in Table 4-7 of the 

2012-2017 WPA/CPA Multisale EIS; for collision with vehicles, the numbers previously reported in 

Table 4-7 of the 2012-2017 WPA/CPA Multisale EIS are within the range of numbers reported here. 

Severity levels of cumulative impacts from these anthropogenic sources or mortality is expected to be 

significant. These severity levels were not explicitly stated in the 2012-2017 WPA/CPA Multisale EIS. 

The mortality estimates are nationwide and not just for the CPA of the northern Gulf of Mexico, where 

impacts would be much less. The previous estimates of mortality from these impacts are unreliable. Loss 

et al. (2014b) provide unprecedented state-of-the-art science (Machtans, 2014).

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, BOEM 

has identified incomplete information regarding coastal and marine birds in the CPA. This incomplete 

information may be relevant to the evaluation of adverse effects because it provides any change in the 

baseline environmental conditions for bird populations in the affected environment from the Deepwater

Horizon oil spill, exacerbating any impacts from a CPA proposed action. Much of these data are being 

developed through the NRDA process, which may take years to complete. This information cannot be 

obtained because it may take years to acquire and analyze through the NRDA process, producing a 

reliable, model-based estimate of mortality that accounts for detection-related issues (Flint et al., 1999; 

Byrd et al., 2009). The information cannot be released due to ongoing NRDA litigation and, even after it 

is released, the impacts of the oil spill may be difficult or impossible to discern from other factors. It is 

not possible for BOEM to obtain this information and incorporate it into this analysis within the timeline 

contemplated by the NEPA analysis of this Supplemental EIS regardless of the costs or resources needed. 

At present, the best available information does not provide a complete understanding of the effects of the 

spilled oil or the recovery potential for the most impacted species (Tables 4-8, 4-12, and 4-13 of the 2012-

2017 WPA/CPA Multisale EIS and Table 4-2 of the WPA 233/CPA 231 Supplemental EIS). 

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here (refer to Table 4-2 of the WPA 

233/CPA 231 Supplemental EIS). A mortality estimate, given the total number of dead birds collected 

(7,258 birds) through May 12, 2011, and given a recovery rate from the literature (0%), is 725,800 birds. 

These existing data do not reveal reasonably foreseeable significant adverse impacts. The mortality 

estimate of 725,800 birds would be a small increment of what is anticipated from non-OCS oil- and gasrelated factors such as habitat loss, collisions with non-OCS oil- and gas-related structures, disease, and 

other anthropogenic factors, which may result in billions of bird deaths per year (as shown in Table 4-7 of 

the 2012-2017 WPA/CPA Multisale EIS). Any additional (NRDA) information obtained from the 

Deepwater Horizon oil spill and response is unlikely to be so significant as to change the relative 

importance of non-OCS oil- and gas-related factors to bird populations, which is demonstrated in Table 

4-7 of the 2012-2017 WPA/CPA Multisale EIS and Table 4-2 of the WPA 233/CPA 231 Supplemental 

EIS. In summary, BOEM has determined that the incomplete information is not essential to a reasoned 

choice among alternatives.
4-70 Central and Eastern Planning Areas Supplemental EIS

Summary and Conclusion

BOEM has reexamined the analysis for coastal and marine birds presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for coastal and marine birds presented in those NEPA documents

because of the available scientifically credible evidence in this analysis and based upon accepted 

scientific methods and approaches. The analysis and potential impacts discussed in those documents still 

apply for proposed CPA Lease Sales 241 and 247.

4.1.1.17. Gulf Sturgeon

BOEM has reexamined the analysis for Gulf sturgeon presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for Gulf sturgeon presented in those NEPA documents. The analysis and 

potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.17 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.17 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.17 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

Potential routine impacts to the threatened Gulf sturgeon (Acipenser oxyrinchus desotoi) and their 

designated critical habitat from routine activities associated with a CPA proposed action may occur from 

drilling and produced-water discharges, degradation of estuarine and marine water quality from 

infrastructure, dredging activities, vessel traffic, pipeline installation, and explosive platform removal. 

Designated Gulf sturgeon critical habitat is confined to State waters, and navigation channels are exempt 

from the critical habitat status. Most activities related to a CPA proposed action would occur in Federal 

waters (i.e., structure placement, drilling, removal, etc.). Though critical habitat may be impacted directly 

or indirectly, such impacts are expected to be negligible due to the distance of Gulf sturgeon habitat and 

life cycles from most activities related to a CPA proposed action.

Potential accidental impacts on Gulf sturgeon and the designated critical habitat may occur primarily 

from oil spills. Unusually low tidal events, increased wave energy, or the use of oil dispersants increases 

the risk of impact with bottom-feeding and bottom-dwelling fauna. For this reason, dispersants are not 

expected to be used with coastal spills. Winds, currents, and outflow from the Mississippi River would 

also diminish the volume of a slick. The spreading of the slick would reduce the oil concentrations that 

would potentially impact the coastal Gulf sturgeon critical habitat. The potential risk to sturgeon would 

result from either direct contact with oil spills (or the potential PAHs introduced through the spill), 

exposure through their diet or, in some cases, long-term exposure to produced water or water associated 

with extraction processes. If there is contact with spilled oil, it could have detrimental physiological 

effects on an individual Gulf sturgeon. Due to the distance of the activity from shore and Gulf sturgeon 

critical habitat, there is a minimal risk of any oil coming in contact with Gulf sturgeon from an offshore 

spill.

Cumulative Impacts

The cumulative impact from routine oil and gas operations includes oil spills. Potential non-OCS oiland gas-related impact-producing factors considered in this analysis include natural catastrophes, fishing, 

and other factors that can result in changes to habitats.

Gulf sturgeon could be impacted by oil spills resulting from a CPA proposed action. The effects on 

Gulf sturgeon from contact with spilled oil would be sublethal (Berg, 2006). Other potential impacts may 

occur from drilling and produced-water discharges, bottom degradation of estuarine and marine water 
Description of the Environment and Impact Analysis 4-71

quality by nonpoint runoff from estuarine OCS oil- and gas-related facilities, vessel traffic, pipeline 

installation, and explosive removal of structures. However, these impacts are expected to have negligible 

effects on Gulf sturgeon and their designated critical habitat, and will not be discussed as part of the 

cumulative impacts analysis.

For a low-probability catastrophic spill, the proximity, type of oil, weather conditions, as well as the 

amount and location (distance offshore and water depth) of the dispersant treatment, may contribute to the 

severity of the spill’s impact to the sturgeon and its habitat (for more information regarding a lowprobability catastrophic spill, refer to Appendix B). 

The Gulf sturgeon and its critical habitat can be cumulatively impacted by non-OCS oil- and gasrelated activities including natural catastrophes, commercial fishing, State oil and gas activities, and other 

factors that can result in habitat changes. Recent climate trends and projections indicate more frequent 

and higher intensity storms, flooding, droughts, coastal erosion, and rising sea levels (Parry et al., 2007), 

all of which could impact Gulf sturgeon critical habitat, spawning areas and life history stages. Other 

naturally occurring events that can impact Gulf sturgeon may increase, such as the 1999 and 2005 red 

tides in Choctawhatchee Bay that resulted in sturgeon deaths (USDOI, FWS, 2000; State of Florida, Dept. 

of Environmental Protection, 2012) or El Niño/La Niña events, which can cause fish to extend their range 

(USDOC, NOAA, 2013c). Deaths of adult sturgeon and potential habitat alterations are expected to occur

from commercial fishing. Non-OCS oil- and gas-related accidental spills can happen, such as the 2008 

industrial spill in the Pearl River in Louisiana that resulted in the mortality of juvenile and adult Gulf 

sturgeon (Kimmel and Constant, 2011) and the February 2013 spill of wastewater from a water pollution 

control plant into the Withlacoochee River in Georgia (Schaefer, 2013). While these events have 

happened recently and there is ongoing monitoring of the impacted areas, it is unknown how the related 

mortalities affect the Gulf sturgeon population. Upstream urbanization and commercial or residential 

development can adversely affect the water quality downstream and therefore can have potential 

cumulative impacts to Gulf sturgeon.

A CPA proposed action would not require dredging near natal rivers used as migratory routes to 

upstream spawning areas. While there could be a need for maintenance dredging not directly related to 

OCS oil- and gas-related activities in the nearshore waters, juvenile or adult sturgeon using these areas 

have the ability to avoid the regulated dredging activity.

On August 8, 2013, a notice of issuance of permits was published in the Federal Register for take of 

Gulf sturgeon for scientific research (Federal Register, 2013). Substantial damage to Gulf sturgeon 

critical habitat is expected from natural catastrophes and inshore alteration activities, such as dam 

building or maintenance dredging. As a result, it is expected that the Gulf sturgeon would experience a 

decline in population sizes and a displacement from their current distribution that would last more than 

one generation.

The incremental contribution of a CPA proposed action to the cumulative impacts on Gulf sturgeon is 

expected to be negligible. This is because the effect of contact between lease sale-specific oil spills and 

Gulf sturgeon is expected to be sublethal, and regulations and mitigations decrease impacts from routine 

events. Other non-OCS oil- and gas-related activities, including storms and anthropogenic factors on 

habitat, are expected to result in more incremental and cumulative impacts to this species. Non-OCS oiland gas-related impacts are seen as the primary cumulative impacts on Gulf sturgeon, compared with a 

CPA proposed action, even in light of incomplete or unavailable information.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search was conducted for published journal articles on Gulf sturgeon, and various Internet websites 

(Federal Register, FWS, National Marine Fisheries Service, USGS, and Gulf Coast State Natural 

Resources websites) were examined to determine any recent information regarding this species.

The search revealed no new information on Gulf sturgeon and its critical habitat that is pertinent to 

this Supplemental EIS and that does not change the conclusions of the 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. 

The NRDA team has completed an assessment plan for nearshore resources following the Deepwater

Horizon explosion, oil spill, and response. The goals set forth are to characterize the extent and 

distribution of nearshore sediment oiling, to model exposure of organisms in the water column and 

benthos to hydrocarbons in nearshore sediments, and to evaluate and quantify injury to nearshore benthic 
4-72 Central and Eastern Planning Areas Supplemental EIS

organisms (USDOC, NOAA, 2012a). Workplans for this assessment can be found on NOAA’s website 

(USDOC, NOAA, 2013d). Analyses of available data are unavailable.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the lack of new information 

does not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. This incomplete information may be relevant to adverse effects because the 

PAH toxicity to similar fish (shortnose sturgeon, salmonids) varies substantially, although conclusions of 

the impacts of PAHs on fish are often generalized due to the difficulty in testing any specific chemical 

(Berg, 2006). The final determinations on damages to Gulf sturgeon resources from the Deepwater

Horizon explosion, oil spill, and response will ultimately be made through the NRDA process. The 

Deepwater Horizon explosion, oil spill, and response will ultimately allow a better understanding of any 

realized effects from a low-probability catastrophic spill, which is not part of a CPA proposed action and 

not likely expected. This information cannot be obtained because the means to obtain it are not known 

and because related information already in development has not been released from the NRDA process.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. For example, studies such as 

Malins et al. (1985), O’Conner and Huggett (1988), Fabacher et al. (1991), Varanasi et al. (1992), 

Bateman and Brim (1994), Baumann et al. (1996), Matthiessen and Sumpter (1998), and Berg (2006) 

indicated no reasonably foreseeable significant adverse impacts from oil. For example, in the rare event 

that Gulf sturgeon have contact with oil, this could cause sublethal effects, including causing the fish to 

temporarily migrate from the affected area, irritation of gill epithelium, an increase of liver function in a 

few adults, and possibly interference with reproductive activity. The juvenile and subadult Gulf sturgeon, 

at a minimum, seasonally use the nearshore coastal waters and could potentially be at risk from both 

coastal and offshore spills. Due to the distance of the proposed activity from shore and the Gulf sturgeon 

critical habitat, there is a minimal risk of any oil coming in contact with Gulf sturgeon from an offshore 

spill. Indeed, there is little risk of most routine activities impacting Gulf sturgeon for the same reasons. 

Therefore, BOEM has determined that the information is not essential to a reasoned choice among 

alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for Gulf sturgeon presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information provided above. No new significant information was discovered that would 

alter the impact conclusion for these Gulf sturgeon presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.18. Fish Resources and Essential Fish Habitat

BOEM has reexamined the analysis for fish resources and essential fish habitat (EFH) presented in 

the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for fish resources and EFH presented in those 

NEPA documents. The analysis and potential impacts discussed in those documents still apply for 

proposed CPA Lease Sales 241 and 247. 

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.18 and Appendix D of the 2012-2017 WPA/CPA Multisale EIS. Updated 

information is provided in Chapter 4.2.1.18 of the WPA 233/CPA 231 Supplemental EIS and Chapter 

4.1.1.18 of the CPA 235/241/247 Supplemental EIS. Also, EFH is discussed in the following chapters of 

this Supplemental EIS: water quality (Chapter 4.1.1.2); wetlands (Chapter 4.1.1.4); seagrass 

communities (Chapter 4.1.1.5); live bottoms (Chapter 4.1.1.6); topographic features (Chapter 4.1.1.7); 
Description of the Environment and Impact Analysis 4-73

Sargassum communities (Chapter 4.1.1.8); chemosynthetic deepwater benthic communities (Chapter 

4.1.1.9); nonchemosynthetic deepwater benthic communities (Chapter 4.1.1.10); and soft bottom benthic 

communities (Chapter 4.1.1.11). The following information is a summary of the resource description 

and impact analysis incorporated from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS. Any new information that has become 

available since those documents were published is presented below.

The Gulf of Mexico supports a great diversity of fish. The distribution of fish species is related to 

variable ecological factors that include salinity, primary productivity, and bottom type. These factors 

differ widely across the Gulf of Mexico and between the inshore and offshore waters. Characteristic fish 

resources are associated with the various environments and are not randomly distributed.

Impacts of Routine Activities and Accidental Events

Effects on fish resources and EFH from routine activities associated with a CPA proposed action 

could result from coastal and marine environmental degradation as a result of construction activities (i.e., 

from onshore facilities to well-site construction activities, including board roads, ring levees, and 

impoundments), pipeline trenching, offshore discharges of drilling muds and produced waters, anchor and 

anchor chain placement, and structure emplacement and removal. Since the majority of fish species 

within the CPA are estuary dependent, any modification of the coastal environment resulting from a CPA 

proposed action has the potential to adversely affect EFH and fish resources through the loss of nursery 

habitat or functional impairment of existing habitat through decreased water quality (Chambers, 1992; 

Stroud, 1992). Although the potential exists, it is expected that any possible coastal and marine 

environmental degradation from a CPA proposed action would have little effect on fish resources or EFH.

With a CPA proposed action, BOEM projects no new coastal infrastructure with the exception of a 

potential new pipeline landfall and a potential new gas processing facility. Although the installation of 

pipelines has the potential to temporarily resuspend sediment in localized areas, this is expected to have a 

negligible impact. Depending on the sediment characteristics, sediment load, and duration of exposure, 

impacts to commercially valuable species within a sediment plume can vary. Responses range in severity 

from no effect to mortality, but mobile species can avoid severe effects by limiting exposure. Sessile 

organisms and those with limited mobility may be exposed for longer durations, leading to increasingly 

severe impacts (e.g., increased respiratory rates, reduced feeding, and mortality). Regulations, 

mitigations, and practices reduce the undesirable effects on coastal habitats from dredging and other 

construction activities; permit requirements should ensure that pipeline routes avoid sensitive coastal 

habitat types. At the expected level of impact, the resultant influence on fish resources would be short 

term and localized, affecting only small portions of fish populations and selected areas of EFH. As a 

result, there would be little disturbance to fish resources or EFH.

The primary impacting sources to water quality in coastal waters are point-source and storm-water 

discharges from support facilities, vessel discharges, and nonpoint-source runoff. These activities are not 

only highly regulated but also localized and temporary in nature. The impacts to coastal water quality 

from routine activities associated with a CPA proposed action should be minimal because of the distance 

to shore of most routine activities and USEPA regulations that restrict discharges. Offshore water quality 

is affected temporarily and in a limited area by the discharge of produced water and the overboard 

discharge of drill muds. Maintenance dredging and canal widening in inshore areas causes only the 

temporary suspension of sediments. Negative impacts from most of these routine operations would 

require a short time for fish resources to recover. This is because of multiple life history and 

environmental factors such as fecundity or year-class recruitment through oceanographic circulation.

Offshore, many of the EFHs are protected under the stipulations and regulations currently in place. 

Without these measures, there could be major negative impacts to topographic features and live bottoms. 

However, with routine impact-producing factors mitigated by BOEM through the Topographic Feature 

Stipulation and the Live Bottom (Pinnacle Trend and Low Relief) Stipulations, negative impacts are 

expected to be avoided. These stipulations establish a No Activity Zone around BOEM-protected 

topographic features, such as the Flower Gardens Banks, and NTL 2009-G39 and NTL 2009-G40 advise 

operators of BOEM’s distancing requirements for bottom-disturbing activity from identified seafloor 

features (i.e., live bottoms, Pinnacles, topographic features, potentially sensitive biological features, and 

features capable of supporting high-density deepwater benthic communities). Additionally, hard substrate 

habitat provided by structure installation in areas where natural hard bottom is rare will tend to increase 
4-74 Central and Eastern Planning Areas Supplemental EIS

fish populations or attract fish populations. The removal of these structures will eliminate that habitat, 

except when decommissioned platforms are used as artificial reef material. This practice is expected to 

increase over time. A more detailed discussion of decommissioning and the impacts of these activities on 

marine fishes can be found in Chapters 3.1.1.10 and 4.1.1.19, respectively.

For these reasons, as well as the fact that Gulf of Mexico fish stocks have retained both diversity and 

relatively stable biomass throughout the years of offshore development and other disturbances, a CPA 

proposed action is expected to result in a minimal decrease in fish resources and/or standing stocks or in 

EFH.

Accidental disturbances resulting from a CPA proposed action, including oil or chemical spills and 

blowouts, have the potential to adversely affect fish resources and EFH within the CPA. If oil or 

chemical spills due to a CPA proposed action were to occur in open waters of the OCS proximate to 

mobile adult finfish, the effects would likely be nonfatal and the extent of damage would be reduced 

because adult fish have the ability to move away from a spill, to metabolize hydrocarbons, and to excrete 

both metabolites and parent compounds. Weathered crude oil has been shown in laboratory experiments 

and field research to cause a range of sublethal effects, including malformation, genetic damage, and 

physiological impairment in different life history stages of different fish species (Carls et al., 1999; 

Whitehead et al., 2011). Oil can be lethal to fish, especially in larval and egg stages, since early life 

stages of animals are usually more sensitive to environmental stress than adults (Moore and Dwyer, 1974) 

and are unable to avoid spills, putting early development stages at greater risk. Therefore, fish 

populations would primarily be affected if oil reaches the coastal and estuarine areas because many 

species reside in estuaries for at least part of their life cycle or are dependent on the nutrients exported 

from the estuaries to the shelf region. However, pelagic species may also be affected. Offshore spawning 

and nursery habitat supports several valuable species that could likewise be impacted by widespread 

contamination of the epipelagic region. However, due to natural variability in spawning success, 

recruitment, oceanographic conditions, and other factors, it is difficult to attribute specific causes to shortterm shifts in stocks, and research to date has been inconclusive with respect to the individual 

contributions of the many factors impacting these fishes because of natural variability in spawning 

success, recruitment, oceanographic conditions, and other factors (Rijnsdorp et al., 2009; Atlantic Bluefin 

Tuna Status Review Team, 2011; Rooker et al., 2013). The probability of a spill impacting these nursery 

habitats is low. Much of the coastal northern Gulf of Mexico is a moderate- to high-energy environment; 

therefore, sediment transport and tidal stratification should reduce the chances for oil persisting in these 

areas if they are oiled. The extent to which a spill could impact offshore spawning and nursery habitat is 

highly dependent upon the time of year of the event.

The effect of oil spills that may be associated with a CPA proposed action on fish resources is 

expected to cause a minimal decrease in standing stocks of any population because most spill events 

would be small in scale and localized. Historically, there have been no oil spills of any size in the Gulf of 

Mexico that have had a long-term impact on fishery populations. Although many potential effects of the 

Deepwater Horizon explosion, oil spill, and response have been alleged, the actual effects are largely 

unknown and likely to remain so for several years, until more research is completed and the analyses 

become available. Recent analysis of early stage survival of fish species inhabiting seagrass nursery 

habitat from Chandeleur Islands, Louisiana, to St. Joseph Bay, Florida, pre- and post-Deepwater Horizon

oil spill show that immediate catastrophic losses of 2010 cohorts were largely avoided and that no shifts 

in species composition occurred following the spill (Fodrie and Heck, 2011). Analysis of the effects of a 

low-probability catastrophic oil spill can be found in Appendix B. The fish populations of the Gulf of 

Mexico have repeatedly proven to be resilient to large, annually occurring areas of hypoxic conditions, 

major hurricanes, and oil spills. Accidental events from a CPA proposed action are not expected to 

significantly affect fish populations or EFH in the Gulf of Mexico.

Cumulative Impacts

There are widespread anthropogenic and natural factors that impact EFH and fish populations in the 

GOM. These include OCS oil- and gas-related and non-OCS oil- and gas-related factors. The OCS oiland-gas activities that could impact fish resources and EFH include construction, pipeline and structure 

emplacement, anchor and anchor chain placement, drilling and produced-water discharges, structure 

removal, and oil spills. The routine OCS oil- and gas-related activities have the potential to impacts fish 

and degrade EFH, but they would probably only have a minimal effect on fish resources and EFH because 
Description of the Environment and Impact Analysis 4-75

of the regulations, mitigations, and permit reviews that are applied for OCS oil- and gas-related activity. 

Oil spills, although considered rare events, can affect seagrass beds through physical oiling and 

destruction from oil spill cleanup. Low-probability catastrophic spills, which are not part of a CPA

proposed action and not likely expected, similar to the Deepwater Horizon explosion and oil spill are 

analyzed in Appendix B. Overall, the incremental contribution of OCS oil- and gas-related effects to fish 

populations and EFH is minor due to regulations, mitigations, and permit reviews.

Non-OCS oil- and gas-related factors that can impact fisheries and EFH include State oil and gas 

activity, inshore pollutants, dredging, coastal development, human population expansion, commercial and 

recreational fishing, overfishing, and natural phenomena. Inshore inputs of pollutants to estuaries from 

runoff and industry are contributors to wetland loss and degradation of water quality. Fish are known to 

avoid any area of adverse water quality, such as hypoxia (Wannamaker and Rice, 2000; Craig and 

Bosman, 2013). Canal dredging primarily accommodates commercial, residential, and recreational 

development, and increased population and commercial pressures on the Gulf Coast are also causing the 

expansion of ports and marinas. Resource management agencies, both State and Federal, set restrictions 

and issue permits in an effort to mitigate the effects of development projects and industry activities. The 

Federal and State governments are also funding research and coastal restoration projects; however, it may 

take decades of monitoring to ascertain the feasibility and the long-term effectiveness of these coastal 

restoration efforts.

Overfishing (including bycatch) has contributed to population effects seen with GOM fishes. The 

Magnuson-Stevens Fishery Conservation and Management Act and its amendments address sustainable 

fisheries and set guidelines for protecting marine resources and habitat from fishing- and nonfishingrelated activities. Under this Act, fisheries management plans, including limits on catch and fishing 

seasons, are developed and proposed by the regional fisheries management councils for approval and 

implementation by NMFS. State agencies regulate inshore fishing seasons and limits.

Some natural phenomena can impact fish resources and EFHs. Nearshore habitat can be affected 

through events such as severe storms and floods. These events can accelerate wetland loss or damage 

oyster reef habitat. Offshore resources such as biologically sensitive underwater features may be 

damaged or buried by events like storms or turbidity flows, potentially affecting fish resources. 

Additionally, variability in spawning success and juvenile survival directly affect Gulf of Mexico fish 

populations. These natural phenomena are all continual, integral elements of the ecosystem, and impacts 

attributed to these events are often exacerbated by anthropogenic activities.

While all of these events and activities cause some sort of effect on the different EFHs and fish 

resources, many anthropogenic inputs, including a CPA proposed action, are now monitored, regulated, 

and mitigated by the permitting agency or State. A CPA proposed action would add a minimal amount to 

the overall cumulative effects.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of Internet information sources and scientific journals was conducted to determine the 

availability of recent information (including NMFS’s databases, the Gulf of Mexico Fishery Management 

Council’s website, Science Direct, EBSCO, Elsevier, PLoS ONE, JSTOR, and BioOne). This search 

revealed new information relevant, but not essential, to an analysis of the potential impacts of OCS oiland gas-related activities on fish resources and EFH. The following studies investigated the impacts of 

acute hydrocarbon exposure on larval and juvenile life stages of species, which helped in this analysis. A 

recent study of the effects of oil on embryonic and larval pelagic fishes (Incardona et al., 2014) 

documented results consistent with earlier research and supports conclusions reached by previous BOEM 

analyses. Researchers observed that PAHs accumulate more rapidly in smaller eggs due to an increased 

surface-to-volume ratio, resulting in lower threshold concentrations required to induce adverse effects. 

Another study that examined crude oil exposure on embryonic and juvenile dolphinfish (Corphaena 

hippurus) was Mager et al. (2014); they suggested that sensitivity to acute oil exposure decreases with 

increasing developmental stage.

These studies serve to expand our understanding of the potential impacts an oil spill may have on 

valuable marine species and reaffirm the conclusions reached in the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. Therefore, the analysis 
4-76 Central and Eastern Planning Areas Supplemental EIS

and potential impacts discussed in those NEPA documents still apply for proposed CPA Lease Sales 241 

and 247.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from previous documents; nevertheless, there is still incomplete or unavailable 

information. As discussed in this Supplemental EIS and in Chapter 4.2.1.18 of the 2012-2017 WPA/CPA 

Multisale EIS and WPA 233/CPA 231 Supplemental EIS, Chapter 4.1.1.18 of the CPA 235/241/247 

Supplemental EIS, BOEM has identified incomplete information regarding impacts of the Deepwater

Horizon explosion, oil spill, and response or other oil exposure on fish resources and EFH in the CPA. 

This incomplete information may be relevant to evaluating adverse effects because the full extent of the 

potential impacts on fish resources and EFH are not known. Relevant data on fish resources and EFH 

after the Deepwater Horizon explosion, oil spill, and response may take years to acquire and analyze. 

Much of these data are being developed through the NRDA process, which may take years to complete. 

Therefore, it is not possible for BOEM to obtain this information within the timeline contemplated in the 

NEPA analysis of this Supplemental EIS, regardless of the cost or resources needed. This information 

cannot be obtained because the overall costs are exorbitant.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. The following studies 

investigating evidence of oil and impacts stemming from exposure to oil among pelagic fishes, coastal 

fishes, and marsh-associated nekton were utilized to reach the decision at this time: Atlantic Bluefin 

Tuna Status Review Team (2011); Fodrie and Heck (2011); Soniat et al. (2011); Carmichael et al. (2012); 

Moody et al. (2013); and Rooker et al. (2013). The results of these recent studies of fish resources

(species and communities) indicate that impacts resulting from the Deepwater Horizon oil spill have been 

largely indistinguishable from natural fluctuations or variability due to other anthropogenic activities. 

Although the body of available information is incomplete and the long-term effects cannot yet be known, 

the evidence currently available supports past analyses and are not indicative of significant populationlevel responses. Additional information on commercially and recreationally valuable species can be 

found in Chapters 4.1.1.19 and 4.1.1.20. 

Summary and Conclusion

BOEM has reexamined the analysis for fish resources and EFH presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for the fish resources and EFH presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed CPA Lease Sales 241 and 247.

4.1.1.19. Commercial Fisheries

BOEM has reexamined the analysis for commercial fisheries presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/ CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for commercial fisheries presented in those NEPA documents. The analysis 

and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 

247. 

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.19 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in the WPA 233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS. The 

following information is a summary of the resource description and impact analysis incorporated from 

those NEPA documents. Any new information that has become available since those documents were 

published is presented below.
Description of the Environment and Impact Analysis 4-77

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors include seafloor disturbing activities (e.g., pipeline 

installation, infrastructure emplacement, and dredging); waste discharge (e.g., drilling muds, cuttings, and 

produced waters); explosive severance operations (decommissioning and structure removal); and spaceuse conflicts (e.g., seismic surveys and structure emplacement). Some of these factors have the potential 

to indirectly impact commercial fisheries through degradation or loss of habitat. Healthy fish stocks 

depend on EFH, which is defined in the Sustainable Fisheries Act as “those waters and substrate 

necessary to fish for spawning, breeding, feeding, and/or growth to maturity.” Since the majority of 

commercially harvested species within the CPA are estuary-dependent, coastal environmental degradation 

resulting from a CPA proposed action has the potential to adversely affect EFH and commercially 

valuable fishes. However, analysis of routine OCS oil- and gas-related activities, such as pipeline 

trenching, maintenance dredging, canal construction, and OCS discharge of drilling muds and produced 

water, has identified only short-term localized disturbances that minimally impact commercially valuable 

fish species and associated EFH. Resuspended sediments and offshore discharges settle or dissipate 

rapidly, limiting both the area affected and the duration of the effect. Additionally, regulations, 

mitigations, and current practices reduce the undesirable effects of construction and operational activities 

on coastal and offshore habitats. At the expected level of impact, the resultant influence on fish resources

would be indistinguishable from natural fluctuations and other anthropogenic influences.

Fish mortality as a result of decommissioning operations is an example of OCS oil- and gas-related 

activities directly impacting fishes. However, a study of structure removals employing explosive 

severance methods found that associated mortality for three commercially important fishes did not 

significantly alter projected stocks (Gitschlag et al., 2000). To account for inherent variations in species 

composition and abundance among platforms (e.g., Stanley and Wilson, 1997; Gitschlag et al., 2000; 

Stanley and Wilson, 2000; Wilson et al., 2003), mortality estimates were doubled and stock estimates 

were recalculated. Although the study was limited and cannot be directly applied to all species or 

habitats, it is reasonable to assume that other commercially important fishes would respond similarly. At 

the projected rate of removal, these activities are not expected to have a substantial negative impact on 

stocks of commercially important fishes or, by extension, the associated fisheries. 

Space-use conflicts could result directly from OCS oil- and gas-related activities that restrict or 

prevent other users from accessing OCS resources. For example, seismic surveys and structure 

emplacement represent short-term and semi-permanent obstructions, respectively. Although studies have 

shown air guns can produce behavioral responses in fishes, possibly even resulting in species- or gearspecific effects on catch rate (Popper and Hastings, 2009; Fewtrell and McCauley, 2012; Løkkeborg 

et al., 2012), there is insufficient data to consistently predict responses and important variables, such as 

the duration of exposure and repeated exposure, have not been fully addressed. The OCS structures 

present a minor space-use conflict when compared with the area available for commercial fishing. In 

addition, the current paradigm posits these structures act as both fish-attracting and production-enhancing 

devices, depending upon the species (Carr and Hixon, 1997; Gallaway et al., 2009; Shipp and Bortone, 

2009). The resultant assemblages frequently include commercially valuable fishes, such as tunas 

(Thunnus spp.), red snapper (Lutjanus campechanus) and wahoo (Acanthocybium solanderi). Therefore, 

OCS structures may either enhance or obstruct commercial fishing, depending upon gear type (e.g., 

hydraulic reel, greenstick, trawl, and long-line) and target species. For more information, refer to 

Chapters 4.1.1.18 and 4.1.1.20. 

Accidental events that could impact commercial fisheries are very limited. Oil spills on the OCS that 

are >1 bbl due to a CPA proposed action are highly unlikely (Table 3-12 of the 2012-2017 WPA/CPA 

Multisale EIS). If oil spills due to a CPA proposed action were to occur in open waters of the OCS 

proximate to mobile adult finfish, the effects would likely be nonfatal, and the extent of damage would be 

reduced because adult fish have the ability to avoid adverse water conditions. This behavioral mechanism 

allows mobile fishes to move away from the source of the hydrocarbons, thereby minimizing exposure. 

However, larval and juvenile life stages are typically more vulnerable than adults and would be expected 

to suffer significant adverse effects as a result of acute oil exposure. Species-specific response, duration 

of exposure, and hydrocarbon concentration are critical factors in determining short- and long-term 

effects, but BOEM conservatively assumes larval and juvenile fishes exposed to oil in close proximity to 

the point of accidental release would be expected to experience mortality. The probability of an offshore 

spill impacting nearshore environments is low, and spilled oil would generally be volatilized or dispersed 
4-78 Central and Eastern Planning Areas Supplemental EIS

by currents in the offshore environment prior to impacting inshore nursery habitat. Overall, the 

commercial fish and shellfish populations have remained healthy in the Gulf of Mexico despite ongoing 

anthropogenic and natural disturbances.

Cumulative Impacts

The cumulative analysis considers activities that have occurred, are currently occurring, and could 

occur and adversely affect commercial fisheries by harming fishes and affecting landings, or the value of 

those landings, for the years 2012-2051. These activities include the effects of the OCS Program

(proposed action and prior and future OCS lease sales) resulting from pipeline installation, channel 

dredging, waste discharge, decommissioning operations, seismic surveys, and structure emplacement. In 

recent years, decommissioning operations have exceeded structure emplacements, resulting in a decrease 

in the total number of OCS platforms. BOEM expects this trend to continue throughout the OCS 

Program years, further reducing the potential for impacts to commercial fisheries through space-use 

conflicts. Although the decommissioning process frequently employs explosive severance methods, 

which result in localized mortality of fishes, the cumulative impact to commercially valuable stocks is 

expected to be indistinguishable from natural fluctuations and the effects of commercial and recreational 

fishing activity. For information on impacts resulting from catastrophic spills, refer to Appendix B. 

Non-OCS oil- and gas-related factors include State oil and gas activity, coastal development, natural 

phenomena, and commercial and recreational fishing. Although some OCS oil- and gas-related activities 

contribute incrementally to the degradation and loss of wetland habitat (Chapter 4.1.1.4), the cumulative 

impact is small in comparison with the combined effect of State oil and gas development; coastal 

commercial, residential, and agricultural development; levees; river channelization; and episodic natural 

phenomena. The cumulative direct impact to commercial fisheries through a reduction in resources 

(fishable area and fish stocks) is negligible.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

BOEM has examined newly available information for findings that may impact the analyses of 

routine activities, accidental events, and cumulative impacts and that may potentially alter previous 

conclusions. A search of Internet information sources and scientific journals was conducted to determine 

the availability of recent information (including NMFS’s databases, the NOAA Gulf Spill Restoration 

Publications website, the Gulf of Mexico Fishery Management Council website, Science Direct, EBSCO, 

Elsevier, PLoS ONE, JSTOR, and BioOne). This search revealed new information relevant, but not 

essential, to an analysis of the potential impacts of OCS oil- and gas-related activities on commercial 

fisheries. 

The following studies investigated the impacts of acute hydrocarbon exposure on larval and juvenile 

life stages of species that may be used to extrapolate potential effects to species of commercial interest. 

An investigation of the impacts of acute exposure to crude oil and dispersed oil on larval and juvenile 

spotted seatrout (Cynoscion nebulosus) found that short-term growth was reduced during exposure 

(Brewton et al., 2013). Juveniles recovered to the average total length of their cohort after 4 weeks of 

depuration, suggesting that the observed effects of acute exposure may not be long term and could be a 

result of higher metabolic costs associated with exposure to sublethal concentrations of crude oil and 

dispersed oil (Brewton et al., 2013). Similarly, Anderson et al. (2014) assessed the effects of acute 

exposure to crude oil water-accommodated fraction (WAF) treatments and dispersed oil treatments on 

juvenile Harris mud crabs (Rhithropanopeus harrisii). The majority of juvenile crab mortalities occurred 

within the initial 24 hours of exposure to chemically enhanced (dispersed) water-accommodated fraction 

(CEWAF) treatments; one crab exposed to WAFs died. Surviving subjects of all treatments exhibited no 

long-term effects and there was no significant difference in post-exposure survival. These results indicate 

that chemical dispersion of oil may significantly increase the toxicity to juvenile Harris mud crabs 

(Anderson et al., 2014).

These studies serve to expand our understanding of the potential impacts an oil spill may have on 

valuable marine species and reaffirm conclusions reached in previous analyses. As previously noted, 

adult fish have the ability to avoid adverse water conditions and are expected to experience reduced 

exposure due to their mobility and avoidance response. Larval and juvenile life stages are generally more 
Description of the Environment and Impact Analysis 4-79

vulnerable, but studies such as the ones above suggest some species may be more tolerant of exposure 

than others. Furthermore, these results suggest that, should unweathered oil impact critical nursery 

habitat, the effects of sublethal acute exposure for some species and life stages may be short term. The 

potential impact short-term effects may have on juvenile survival and recruitment is not known. Past 

research (Myers and Cadigan, 1993; Levin and Stuntz, 2005) suggests that larval and juvenile survival 

rates strongly influence offshore adult populations, and a new model developed by Baker et al. (2014) 

indicates that the survival of juvenile white shrimp (Litopenaeus setiferus) may factor more strongly than 

fishing pressure into population size.

A recent study of the effects of oil on embryonic and larval pelagic fishes (Incardona et al., 2014) 

documents results consistent with earlier research and supports conclusions reached by previous BOEM 

analyses. Researchers observed that PAHs accumulate more rapidly in smaller eggs due to an increased 

surface-to-volume ratio, resulting in lower threshold concentrations required to induce adverse effects. A 

second study, also consistent with earlier research and further supporting conclusions reached by previous 

BOEM analyses, exposed embryonic and juvenile dolphinfish (Corphaena hippurus) to crude oil WAF 

treatments for 48 hours and 24 hours, respectively (Mager et al., 2014). Embryos grown out to a juvenile 

stage demonstrated a 37 percent reduction in mean critical swimming speed. By comparison, juveniles 

raised under hatchery conditions to an age of ~31 days and assessed immediately following a 24-hour 

exposure to a WAF 30 times more concentrated than was used to treat embryos, experienced a 22 percent 

reduction in mean critical swimming speed (Mager et al., 2014). These findings support earlier research 

and suggest that sensitivity to acute oil exposure decreases with increasing developmental stages (Mager 

et al., 2014).

Detailed information on species found in the Gulf of Mexico, or closely related to those found in the 

GOM, continues to be developed and serves as a baseline for determining potential impacts. Given that 

morphological defects, reduced cardiac efficiency, and decreased swimming performance may result in 

reduced feeding success and increased susceptibility to predation, it may be assumed that early life stage 

acute exposure to oil results in decreased survival to maturity. However, without knowing the extent to 

which spawning overlapped spatially and temporally with waters contaminated by the 2010 Deepwater

Horizon oil spill, it is difficult to estimate the potential impacts to pelagic species. The value of the data 

summarized above could be further enhanced if analyzed in the presence of additional details (e.g., oil 

volatilization rates, species’ spatial and temporal spawning distributions, duration of exposure, and 

persistence of effects resulting from acute oil exposure) that would support the decisionmaking process. 

In the absence of additional information, BOEM has conservatively assumed near 100 percent mortality 

among exposed embryonic fishes. This position aligns with the NMFS status review team report in 

assuming a maximal reduction of 20 percent to the bluefin tuna 2010 cohort as a result of the Deepwater 

Horizon oil spill and estimating a less than 4 percent reduction in future spawning biomass (Atlantic 

Bluefin Tuna Status Review Team, 2011; USDOC, NMFS, 2013). Estimates for oil-related dolphinfish 

mortality as a result of the Deepwater Horizon oil spill were not available at the time of publication of 

this Supplemental EIS.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS, as well as in the previously mentioned 

NEPA documents, BOEM has identified incomplete or unavailable information regarding impacts related 

to explosive structure removal, seismic surveys, acute oil exposure, and chronic oil exposure. Fish 

mortality resulting from explosive structure removal has not been fully studied across a wide range of 

water depths and environmental conditions. However, as stated in the summary above, existing 

information (e.g., Gitschlag et al., 2000) is sufficient for the purpose of analyzing potential impacts of 

anticipated decommissioning activities. Specific responses by fishes to seismic survey activities cannot 

be predicted and are unknowable due to the many possible interactions among variables (e.g., species, 

environmental conditions, exposure history and duration, spawning status, presence of prey or predators, 

etc.) that could influence the response to sound. However, available information (Popper and Hastings, 

2009; Fewtrell and McCauley, 2012; Løkkeborg et al., 2012) is sufficient, within the context of historical 

landings and with knowledge of anticipated survey frequency and distribution, to extrapolate an overall 
4-80 Central and Eastern Planning Areas Supplemental EIS

expectation of negligible impact to commercial fisheries. Information on the potential for juvenile 

survival to be impacted by acute exposure to oil remains incomplete (Brewton et al., 2013; Anderson 

et al., 2014); however, recent studies suggest that fishes recruited near the time of the Deepwater Horizon

explosion, oil spill, and response may not have suffered catastrophic losses (Fodrie and Heck, 2011; 

Atlantic Bluefin Tuna Status Review Team, 2011; Rooker et al., 2013). As such, it is reasonable to 

extrapolate that short-term effects of the oil spill did not severely impact recruitment. In the long-term, 

the effects of acute or chronic exposures to oil remain unknown. This information cannot reasonably be 

obtained because the long-term effects may not yet be detectable and the overall costs in time and money 

to determine this are exorbitant. BOEM recognizes that the incomplete information with respect to longterm effects may be relevant to the evaluation of impacts on commercial fisheries. 

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. Although the body of available 

information is incomplete and long-term effects cannot yet be known, the evidence currently available 

supports past analyses and does not indicate severe adverse impacts to commercial fisheries. Therefore, 

BOEM has determined that the incomplete information is not essential to a reasoned choice among 

alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for commercial fisheries presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for commercial fisheries presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.20. Recreational Fishing

BOEM has reexamined the analysis for recreational fishing presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for recreational fishing presented in those NEPA documents. The analyses 

and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 

247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.20 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.20 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.20 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

Activities during the initial phases of a CPA proposed action, such as seismic surveying operations 

and other forms of vessel traffic, may lead to some space-use conflicts with recreational fishermen. 

Vessel traffic during subsequent infrastructure emplacement and production operations could also lead to 

some space-use conflicts with recreational fishing activities. The OCS oil- and gas-related activities 

could also affect the aesthetics of fishing in a particular location, which could dissuade anglers from 

fishing in specific locations. Some activities arising from proposed CPA Lease Sales 241 and 247, such 

as construction activities and discharges of muds and produced water, may also lead to low-level 

environmental degradation of fish habitat (Chapter 4.1.1.18), which would negatively impact 

recreational fishing activity. However, these minor negative effects would likely be outweighed by the 

beneficial addition of hard substrate and complex habitat provided by oil and gas infrastructure. The level 

of participation in any particular State Rigs-to-Reefs program will be an important determinant of the 

long-term impact of a CPA proposed action on recreational fishing activity. As structures are scheduled 
Description of the Environment and Impact Analysis 4-81

for decommissioning, a higher level of participation may benefit fishermen through the retention of 

complex habitat and potentially enhanced production for some recreationally desirable species, as 

opposed to structure removals (particularly those that use explosives) that can negatively impact the 

recreational activity that depends on any particular platform.

Oil spills can arise from accidents with respect to vessels, pipelines, drilling operations, or production 

operations. An oil spill would likely lead to recreational fishing closures in the vicinity of the oil spill. 

Small-scale spills should not affect recreational fishing to a large degree due to the likely availability of 

substitute fishing sites in neighboring regions. The longer-term effects of an oil spill will be determined 

by its effects on fish populations (Chapter 4.1.1.18), as well as by its effects on people and firms that 

support recreational fishing activity. Some of these effects will be similar to the effects on species that 

are important to commercial fishing activity, which are discussed in Chapter 4.1.1.19. 

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors related to OCS oil and gas 

along with non-OCS oil- and gas-related impacts that may occur and adversely affect recreational fishing

in the same general area of a CPA proposed action. A proposed CPA lease sale will contribute to the 

impacts of the broader OCS Program. This includes the space-use impacts arising from vessel traffic and 

construction operations, as well as the low-level environmental degradation to fish habitats that could 

occur. A proposed CPA lease sale will also incrementally add to the probabilities of oil spills, which 

could affect recreational fishing activity in the short term. Low-probability catastrophic oil spills, which 

are not part of a CPA proposed action and not likely expected, could also impacts recreational fishing and 

are described in Appendix B. A proposed CPA lease sale could also have positive impacts to 

recreational fishing activity since OCS oil and gas platforms often serve as reefs for fish populations, 

although removals of these platforms could have negative impacts on recreational fishing activity. 

However, these negative effects would be partially offset if some platforms are maintained through Rigsto-Reefs programs.

Recreational fishing activity could also be influenced by a number of non-OCS oil- and gas-related 

factors, such as commercial, military, recreational, and industrial activities; natural processes; wetlands

loss; hypoxia events; fish kills; water quality degradation; fisheries management plans; hurricanes; State 

oil and gas activities; State artificial reef programs; tourism (refer to Chapter 4.1.1.21); and other 

economic factors (refer to Chapter 4.1.1.23.3). Many of these impacts will be determined by the 

cumulative impacts to fish populations, which are discussed in Chapter 4.1.1.18. However, recreational 

fishing activity is driven by unique economic and tourism trends (refer to Chapters 4.1.1.21 and 

4.1.1.23.3). It can also be influenced by the quality of fishing grounds, such as wetland areas, which can 

be degraded by hurricanes. Military activities, recreational vessel traffic, and other forms of vessel traffic 

could also cause space-use conflicts with recreational fishermen. However, it is likely that Fisheries 

Management Plans of the Federal and State governments would serve to keep overall recreational fishing 

activity reasonably stable through time.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

BOEM examined a variety of Internet sources, as well as known data providers, for new information 

regarding the impacts of a CPA proposed action on recreational fishing. Some new information sources 

related to fish populations and commercial fishing activity are discussed in Chapters 4.1.1.18 and 

4.1.1.19. The primary new data source specific to recreational fishing is an annual update to data 

provided by NMFS (USDOC, NMFS, 2014f), which clarifies the affected environment for recreational 

fishing. This data source provides data on both the species caught and the amount of angler effort in any 

particular year, which clarifies the affected environment for recreational fishing. Table 4-5 presents data 

on the number of angler trips taken in Louisiana, Mississippi, Alabama, and West Florida from 2008 to 

2013. In 2013, there were 15.9 million angler trips in West Florida, 4.6 million angler trips in Louisiana, 

2.9 million angler trips in Alabama, and 1.8 million angler trips in Mississippi. Compared with 2012 

effort levels, angler effort increased in Alabama, Louisiana, and West Florida while angler effort 

decreased in Mississippi. Table 4-5 also breaks down these trips by location and mode. The three 

geographic locations for each state are inland, State ocean waters, and Federal ocean waters. The three 
4-82 Central and Eastern Planning Areas Supplemental EIS

modes of fishing are shore fishing, charter fishing, and private/rental fishing. For the Gulf as a whole, all 

forms of ocean-based fishing in State and Federal waters were higher in 2013 than in 2012. Shore inland 

and private/rental inland fishing decreased in 2013 when compared with 2012, while charter inland 

fishing increased.

Panel A of Table 4-6 presents data on the most commonly landed species by recreational fishermen 

in Louisiana, Mississippi, and Alabama combined from 2008 to 2013. Panel B of Table 4-6 presents data 

on the most commonly landed species by recreational fishermen in West Florida from 2008 to 2013. In 

both regions, landings in 2013 for most species were roughly consistent with landings observed in prior 

years. However, in both regions, there were fairly large increases in landings of black drum (Pogonias 

cromis), dolphins (Coryphaena hippurus), red snapper (Lutjanus campechanus), and Spanish mackerel 

(Scomberomorus maculatus). There were decreases in landings of sand seatrout (Cynoscion arenarius) in 

both regions.

The NMFS has also released its Fisheries Economics of the U.S. 2014 report (USDOC, NMFS, 

2014g). This report presents various data regarding the economic significance of recreational fishing in 

the Gulf of Mexico, which clarifies the affected environment for recreational fishing. Table 4-7 presents 

data from this report on expenditures, sales, value added, and employment in each Gulf Coast State in 

2012. The largest economic impacts from recreational fishing occurred in West Florida. Louisiana and 

Texas had the next largest impacts, followed by Alabama and Mississippi.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplement EIS, as well as in the previously mentioned 

NEPA documents, BOEM has identified incomplete or unavailable information related to recreational 

fishing. This incomplete information may be relevant to evaluating adverse effects because the full 

extents of potential impacts on recreational species are not known. This information relates to the 

ultimate impacts of the Deepwater Horizon explosion, oil spill, and response on fish populations that 

support recreational fishing activity. This information is relevant because it would allow BOEM to more 

accurately estimate the scales of recreational fishing activity in future time periods. Much of this 

information is being developed through the NRDA process, and this information has not yet been 

released. There is also uncertainty regarding the extent to which recreational fishing is dependent upon 

OCS oil and gas platforms. BOEM is planning to undertake a study project to examine this issue, 

although the results from this study project will not be released within the timeline contemplated in the 

NEPA analysis of this Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. For example, BOEM has used 

data on recreational fishing activity provided by NMFS, which allowed BOEM to examine trends in 

recreational fishing over time. BOEM does not expect the missing information to significantly change its 

estimates of the impacts of the OCS Program on recreational fishing activity because BOEM still has 

enough baseline data to reasonably estimate impacts. Therefore, BOEM has determined that the 

incomplete or unavailable information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for recreational fishing presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235, 241, and 247 Supplemental EIS 

based on the additional information presented above. No new significant information was discovered that 

would alter the impact conclusion for recreational fishing presented in those NEPA documents because of 

the available scientifically credible evidence in this analysis and based upon accepted scientific methods 

and approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.
Description of the Environment and Impact Analysis 4-83

4.1.1.21. Recreational Resources

BOEM has reexamined the analysis for recreational resources presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for recreational resources presented in those NEPA documents. The analysis 

and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 

247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.21 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.21 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.21 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

Routine OCS oil- and gas-related activities in the CPA can cause various disturbances to recreational 

resources. For example, marine debris can noticeably affect the aesthetic value of coastal areas, 

particularly beaches. Many mitigating measures have been adopted and incorporated into regulations 

and/or guidelines governing OCS oil and gas exploration, development, and production activities. 

Regulations and NTLs include safeguards and protective measures, which are in place to reduce impacts 

of marine trash and debris from oil and gas activities. Vessel noise and the visibility of OCS oil and gas 

infrastructure can also conflict with some recreational activities. Similarly, vessel traffic can cause spaceuse conflicts with recreational activities. The OCS oil- and gas-related activities can also change the 

composition of local economies through changes in employment, land use, and demand for activities 

related to recreation and tourism. The presence of OCS oil and gas platforms can enhance some 

recreational activities such as fishing and diving, although the long-term impacts of platforms depend on 

the nature of the decommissioning of the platform. However, the small scale of a CPA proposed action 

relative to the scale of the existing oil and gas industry suggests that these potential impacts on 

recreational resources are likely to be minimal.

Accidental events that could result from a CPA proposed action will be small, of short duration, and 

not likely to impact Gulf Coast recreational resources. Should an oil spill occur and contact a beach area 

or other recreational resource, it will cause some disruption during the impact and cleanup phases of the 

spill. Beaches, nature parks, and wetland areas could be impacted during these phases of a spill. These 

disruptions could also have impacts on firms and consumers that depend on the use of these resources. 

Media coverage and public perception regarding the extent of the oil damage can also influence the 

ultimate economic impacts of the spill. The economic impacts of a spill would be mitigated to some 

extent if a legal damage claims process were to be implemented subsequent to an oil spill. However, all 

of these effects would likely be small in scale and of short duration. However, a catastrophic oil spill 

would likely have larger impacts on recreational resources; these impacts are discussed in Appendix B. 

This assessment is based on historical leasing patterns, as well as the subsequent review process called for 

in BOEM’s Information to Lessees and Operators regarding the Gulf Islands National Seashore, both of 

which are discussed below.

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors related to OCS oil and gas 

along with non-OCS oil- and gas-related impacts of other commercial, military, offshore, and coastal 

activities, and natural processes that may occur and adversely affect recreational resources in the same 

general area of a CPA proposed action.

A CPA proposed action would contribute to the aesthetic impacts and space-use conflicts that arise 

due to the broader OCS Program. This includes impacts from vessel traffic, marine debris, and the 

presence or absence of OCS oil- and gas-related infrastructure. Vessel traffic can cause space-use 

conflicts with recreational activities such as boating. Marine debris can degrade the recreational value of 

resources such as beaches. The presence or absence of OCS oil- and gas-related infrastructure could 
4-84 Central and Eastern Planning Areas Supplemental EIS

impact activities such as recreational fishing or diving. Oil spills could also contribute to the overall 

degradation of beach and wetland-based recreational resources. Most accidental spills are not likely to 

impact Gulf Coast recreational resources because they are expected to be small and of short duration. If 

oil resulting from a spill were to contact a beach area or other recreational resource, disruption could 

occur from oiling and oil cleanup. However, these effects are also likely to be small in scale and of short 

duration. The impacts of a low-probability catastrophic oil spill, which is not part of a CPA proposed 

action and not likely expected, on recreational resources are discussed in Appendix B. 

Recreational resources along the Gulf Coast can also be impacted by non-OCS oil- and gas-related 

aesthetic and space-use conflicts, as well as a variety of other factors, such as coastal erosion, beach 

disruptions, and economic factors. However, the incremental contribution of a CPA proposed action is 

expected to be minimal in light of all OCS oil- and gas-related and non-OCS oil- and gas-related 

activities. This is because of the small scale of a CPA proposed action, as well as the fact that most 

impacts to recreational resources will be temporary.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

BOEM conducted a search of Internet sources and of known data providers for new information 

regarding recreational resources. The Bureau of Labor Statistics has released preliminary data regarding 

the scale of employment in various industries in Gulf Coast States in 2013 (U.S. Department of Labor, 

Bureau of Labor Statistics, 2014). Table 4-8 presents data on the levels of employment in leisure and 

hospitality industries in various Economic Impact Areas (EIAs) and coastal areas. Leisure and hospitality 

employment was higher in 2013 than in any year from 2008 through 2012 in all EIAs and coastal areas. 

This is likely primarily due to the gradual improvement in overall economic conditions since the most 

recent economic recession.

Cullinane-Thomas et al. (2014) provide estimates of the number of visitors, amount of spending, 

number of jobs, and amount of income in 2012 supported by each national park along the Gulf Coast. 

The number of visitors and the amount of visitor spending supported by parks along the Gulf Coast are as 

follows: Padre Island National Seashore (Texas) (573,855 visitors; $22,815,000); Jean Lafitte National 

Historical Park and Preserve (Louisiana) (419,964 visitors; $22,584,000); Gulf Islands National Seashore 

(Mississippi and Florida) (4,973,462 visitors; $199,385,000); De Soto National Memorial (Florida) 

(432,981 visitors; $23,299,000); Big Cypress National Preserve (Florida) (882,570 visitors; $64,229,000); 

Everglades National Park (Florida) (1,141,906 visitors; $102,765,000); and Dry Tortugas National Park

(Florida) (60,550 visitors; $3,211,000).

During scoping for this Supplemental EIS, the National Park Service’s (NPS) Southeast Region 

Office requested that the Supplemental EIS analyze the degradation of aesthetics and the wilderness 

character of Horn and Petit Bois Islands since they were designated as having wilderness status in 1978 

through the establishment of the Gulf Islands Wilderness Area. BOEM addressed these issues in the 

WPA 233/CPA 231 Supplemental EIS, from which this Supplemental EIS tiers. In particular, BOEM 

agrees that visitor experiences on Horn and Petit Bois Islands are sensitive to disruptions to the 

wilderness experiences on these islands. However, the OCS structures arising from the proposed actions 

are likely to be sufficiently far from these islands to make these impacts minimal. This assessment is 

based on historical leasing patterns, as well as the subsequent review process called for in BOEM’s 

Information to Lessees and Operators regarding the Gulf Islands National Seashore (GUIS), both of 

which are discussed below. In addition, the proposed actions would likely only minimally contribute to 

the existing disturbances from OCS and non-OCS sources.

To be more specific, there are currently 11 producing platform complexes (fixed platforms and 

caissons) within 7-15 mi (11-24 km) of GUIS offshore the States of Louisiana, Mississippi, and Alabama

(Figure 4-2). Some OCS platforms are visible on the horizon. Numerous OCS structures and wells have 

existed within 3-7 mi (5-11 km) of Petit Bois Island over the years. Many of these platforms have been 

removed and only three structures are currently within 7-10 mi (11-16 km) of Petit Bois Island, which is a 

designated wilderness area (Figure 4-3). 

The NPS additionally voiced specific concerns regarding the visual and noise impacts of OCS oiland gas-related activities. The NPS cited White (2014), which provides data on baseline noise levels at 

Horn and Petit Bois Islands relative to Fort Pickens (which is a nonwilderness, higher human use area) in 

the Florida District of the GUIS. This study found that Horn and Petit Bois Islands have lower overall 
Description of the Environment and Impact Analysis 4-85

levels of extrinsic noise than Fort Pickens. Horn and Petit Bois Islands have higher measures of 

watercraft noise and lower levels of aircraft noise than Fort Pickens. This study also found that Horn and 

Petit Bois Islands have higher levels of noise at night than during the day, while Fort Pickens has more 

noise during the day than at night.

The NPS also voiced concerns regarding the night lighting of OCS structures. The NPS provided 

BOEM with baseline data regarding the overall scales of natural and anthropogenic light at Horn and Petit 

Bois Island. These data found that the anthropogenic light ratio is 537 percent higher than baseline 

conditions at Horn Island and 510 percent higher than baseline conditions at Petit Bois Island.

To address the NPS’s concerns, BOEM developed ITL that provides for NPS consultation on a 

lessee’s plans, as appropriate, and began adding the ITL to the Notices of Sale for proposed CPA lease 

sales beginning with CPA Lease Sale 231. The ITL states the following:

(q) Gulf Islands National Seashore. Potential bidders are hereby notified that postlease 

plans submitted by lessees of whole and partial lease blocks located within the first 

12 miles of Federal waters near the Gulf Islands National Seashore (State of Mississippi 

Barrier Island Chain Map – see page 12 of these ITLs) may be subject to additional 

review in order to minimize visual impacts from development operations on these blocks. 

BOEM will review and make decisions on a lessee’s plans for these blocks in accordance 

with applicable Federal law and regulations, and BOEM policies, to determine if visual 

impacts are expected to cause serious harm and if any additional mitigative action is 

required. Mitigations may include, but are not limited to, requested changes in location, 

modifications to design or direction of proposed structures, pursuing joint use of existing 

structures on neighboring blocks, changes in color design, or other plan modifications. 

BOEM may consult with the State of Mississippi and/or the State of Alabama and with 

the National Park Service, Southeast Regional Office, during such reviews as appropriate.

The following whole and partial blocks, are specifically identified for this ITL: 

Chandeleur Area – 1; Mobile – 765-767, 778, 779, 809-823, 853-867, 897-910, 942-954, 

987-997; and Viosca Knoll – 24-27. (Refer to Figure 4-4.)

Even without the presence of oil and gas activities in State waters and on the Federal OCS, there is 

substantial vessel traffic in this area due to the presence of federally designated shipping safety fairways 

and anchorage areas to provide unobstructed approaches for vessels using U.S. ports (33 CFR part 166). 

These visual impacts would remain ongoing and unaffected by the proposed actions. 

New data regarding the extent of shoreline oiling arising from the Deepwater Horizon oil spill has 

become available (USDOC, NOAA, 2014). These data show that the majority of the shoreline of 

Louisiana has been cleaned. However, some areas, particularly areas near Chandeleur Sound and 

Barataria Bay, still had areas of oiled shoreline (these data were as of March 25, 2014). This has lessened 

the opportunities for beach visitation, fishing, and nature viewing in these areas (Drapkin, 2014). Finally, 

Ocean Conservancy (2014) provides data regarding the levels of marine debris found on the coastlines of 

various states in 2013, which clarifies the affected environment for recreational resources. The most trash

was found along the coastline of Florida, followed by Texas, Alabama, Mississippi, and Louisiana.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. This incomplete information may be relevant to evaluating 

adverse effects because the full extent of potential impacts on recreational resources is not known. This 

information relates to quantifying measures of recreation and tourism along the Gulf Coast, as well as 

information relating to the impacts of the Deepwater Horizon explosion, oil spill, and response on 

recreational resources. These information sources assist in assessing the baseline environment for 

recreational resources. BOEM has funded a study that is attempting to improve its information regarding 

these issues, although the study is not yet complete.
4-86 Central and Eastern Planning Areas Supplemental EIS

In light of the incomplete or unavailable information, BOEM used existing data sources and standard 

methods to estimate the impacts of a CPA proposed action on recreational resources. For example, 

BOEM used data from the Bureau of Labor Statistics using broader industry categories to estimate the 

scale of recreation-related activities in recent years. These data provide sufficient baseline information 

from which to estimate the impacts of the OCS Program, particularly since the available data suggest that 

most recreational areas have recovered from the impacts of the Deepwater Horizon explosion, oil spill, 

and response. Therefore, BOEM has determined that the incomplete or unavailable information is not 

essential to a reasoned choice among alternatives.

There is also incomplete and unavailable information regarding some site-specific aspects of the 

potential visual impacts of OCS structures. In particular, NPS requested that BOEM conduct a visual 

impact analysis of various potential structures at each specific location within Horn and Petit Bois Island. 

While BOEM will consider this, and while this information may be relevant in order to more precisely 

estimate visual impacts, BOEM has determined that this information is not essential to a reasoned choice 

among alternatives. This is because the broad determinants of visual impacts, such as the distance, 

brightness, size, and overall location of potential structures, are known. In addition, BOEM has used 

generally accepted scientific principles, including incorporating the data, mapping, research, and 

photographic evidence discussed above, to estimate the potential visual impacts of OCS structures that 

may arise from the proposed actions. Finally, these site-specific issues would be addressed at later stages 

of BOEM’s review process, particularly in light of the ITL discussed above. BOEM’s review process 

will appropriately consider the visual impacts a specific proposed structure in light of safety issues and 

other regulatory requirements.

Summary and Conclusion

BOEM has reexamined the analysis for recreational resources presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for recreational resources presented in those NEPA documents because the 

new information was roughly consistent with prior expectations. The analysis and potential impacts 

discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

4.1.1.22. Archaeological Resources

4.1.1.22.1. Historic Archaeological Resources

BOEM has reexamined the analysis for historic archaeological resources presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented below. No new significant information was discovered 

that would alter the impact conclusion for historic archaeological resources presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

Historic archaeological resources on the OCS consist of historic shipwrecks and a single historic 

lighthouse, the Ship Shoal Light. A historic shipwreck is defined as a submerged or buried vessel or its 

associated components, at least 50 years old, that has foundered, stranded, or wrecked, and that is 

currently lying on or embedded in the seafloor. Ships are known to have traversed the waters of the CPA 

as early as Captain Alonso Alverez de Piñeda’s expedition in 1519.

A detailed description of the affected environments and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.22.1 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.22.1 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.22.1 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were prepared is presented below.
Description of the Environment and Impact Analysis 4-87

Impacts of Routine Activities and Accidental Events

Routine impact-producing factors associated with a CPA proposed action that could affect historic 

archaeological resources include direct physical contact with a shipwreck site; the placement of drilling 

rigs and production systems on the seafloor; pile driving associated with platform emplacement; dredging 

of new channels, as well as maintenance dredging of existing channels; anchoring activities; pipeline 

installation and maintenance; post-decommissioning platform removal and trawling clearance; and the 

masking from geophysical sensors of archaeological resources from industry-related debris.

The greatest potential impact to an archaeological resource as a result of a CPA proposed action 

would result from direct contact between an offshore activity (e.g., platform installation, drilling rig 

emplacement, and dredging or pipeline project) and a historic site because of incomplete knowledge of 

the location of these sites in the Gulf. The risk of contact to archaeological resources is greater in 

instances where archaeological survey data are inadequate or unavailable. Such an event could result in 

the disturbance or destruction of important archaeological information. Archaeological surveys provide 

the necessary information to develop avoidance strategies that reduce the potential for impacts on 

archaeological resources.

Damage to archaeological resources from offshore oil and gas activity can be minimized by 

conducting archaeological surveys before seabed disturbance occurs. Archaeological surveys, where 

required prior to an operator beginning OCS oil- and gas-related activities on a lease, are expected to be 

effective at identifying possible archaeological sites. The technical requirements of the archaeological 

resource reports are detailed in NTL 2005-G07, “Archaeological Resource Surveys and Reports.” Under 

30 CFR § 550.194(c) lessees are required to immediately halt operations and notify BOEM’s Regional 

Director of the discovery of any potential archaeological resources. Under 30 CFR § 250.194(c) and 

30 CFR § 250.1010(c), lessees are also required to immediately halt operations and notify BSEE’s 

Regional Director of the discovery of any potential archaeological resources.

Except for the projection of up to one new gas processing facility and up to one new pipeline landfall, 

a CPA proposed action would require no new oil and gas coastal infrastructure. It is expected that 

archaeological resources would be protected through the review and approval processes of the various 

Federal, State, and local agencies involved in permitting onshore activities.

Impacts to documented (which currently exist only onshore) and undocumented (potentially on and 

offshore) historic archaeological resources could occur as a result of an accidental oil spill and the 

associated cleanup operations. Detailed risk analyses of offshore oil spills ranging from <1,000 bbl to 

≥1,000 bbl and coastal spills associated with a CPA proposed action are provided in Chapters 3.2.1.5, 

3.2.1.6, and 3.2.1.7. When oil is spilled in offshore areas, much of the oil volatilizes or is dispersed by 

currents, so it has a low probability of contacting coastal areas. However, should a spill contact a historic 

archaeological site (including submerged sites), damage might include contamination of materials, direct 

impact from oil-spill cleanup equipment, and/or looting. An additional major effect from an oil spill 

could be viewshed pollution of a historic coastal site, such as a fort or lighthouse. Although such effects 

may be temporary and reversible, cleaning oil from historic structures can be a complex, time-consuming, 

and expensive process, and the use of dispersants may result in long-term chemical contamination of 

submerged cultural heritage sites (e.g., Chin and Church, 2010). It is expected, however, that any spill 

cleanup operations would be considered a Federal undertaking for the purposes of Section 106 of the 

National Historic Preservation Act and would be conducted in such a way as to minimize impacts to 

historic archaeological resources.

Cumulative Impacts

Several OCS oil- and gas-related cumulative impact-producing factors could potentially impact 

historic archaeological resources, including the following: (1) OCS Program routine and accidental 

impacts; (2) artificial rigs-to-reefs development; and (3) renewable energy and alternative use 

conversions. Historic archaeological resources on the OCS are vulnerable to OCS oil- and gas-related 

cumulative impact-producing factors due to the associated bottom-disturbing activities. An impact could 

result from direct physical contact between historic shipwrecks located on the OCS and OCS Program oil 

and gas activities (i.e., pipeline and platform installations, drilling rig emplacement and operation, site 

decommissioning, rigs-to-reefs development, dredging, and anchoring activities). Permitting OCS oiland gas-related development prior to requiring archaeological surveys has been documented to have 
4-88 Central and Eastern Planning Areas Supplemental EIS

impacted wrecks containing significant or unique historic information. Impacts may be reduced when 

preconstruction surveys are required by BOEM or the permitting agency prior to these activities. Impacts 

to historic resources may still occur in areas where a remote-sensing survey fails to resolve the location of 

partially or completely buried resources or when no pre-disturbance survey is required. Impacts to 

documented (which currently exist only onshore) and undocumented (potentially on and offshore) historic 

archaeological resources could occur as a result of an accidental oil spill and the associated cleanup 

operations; however, the potential for spills is low, the effects would generally be localized, and the 

cleanup efforts would be regulated. Low-probability catastrophic spills, which are not part of a CPA 

proposed action and not likely expected, are discussed in Appendix B. 

Non-OCS oil- and gas-related cumulative impact-producing factors that could potentially impact 

historic archaeological resources include the following: (1) State oil and gas activity; (2) offshore LNG 

projects; (3) new channel dredging and maintenance dredging; (4) State renewable energy and alternative 

use conversions; (5) State artificial reefs and rigs-to-reefs development; (6) commercial fishing; (7) sport 

diving and commercial treasure hunting; and (8) natural processes, including wave action and hurricanes. 

As with the OCS oil- and gas-related cumulative impact-producing factors, risks from the above non-OCS 

oil- and gas-related cumulative impact-producing factors are related to their associated bottom-disturbing 

activities. An impact could result from direct physical contact between historic shipwrecks and Staterelated oil and gas activities, sand borrowing, renewable energy activities, LNG facility construction, 

artificial reef creation, new channel dredging, and maintenance dredging. With the exception of 

maintenance-dredging, preconstruction surveys may be required for these activities. Impacts to historic 

archaeological resources may still occur in areas where a remote-sensing survey fails to resolve the 

location of partially or completely buried resources or when no pre-disturbance survey is required.

The effects of the various impact-producing factors discussed in this analysis have likely resulted in 

the localized loss of significant or unique historic archaeological information. In the case of factors 

related to OCS Program activities within the cumulative activity area, it is reasonable to assume that most 

impacts would have occurred where development occurred prior to any archaeological survey 

requirements. The incremental contribution of a CPA proposed action is expected to be very small due to 

the efficacy of remote-sensing surveys and archaeological reports where required. Future OCS Program 

activities and the bottom-disturbing activities permitted by BOEM and other agencies may require 

preconstruction archaeological surveys that, when completed, are highly effective in identifying bottom 

anomalies that could be avoided or investigated before bottom-disturbing activities begin. When surveys 

are not required, it is impossible to anticipate what might be embedded in or lying directly on the seafloor, 

and impacts to these sites are likely to be major in scale. Despite diligence in site-clearance survey 

reviews, there is still the possibility of an unanticipated interaction between bottom-disturbing activity 

(e.g., rig emplacement, pipeline trenching, anchoring, and other ancillary activities) and a historic 

shipwreck.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

Various Internet sources were examined to assess recent information regarding impacts to 

archaeological resources or potential new threats to archaeological resources that may be pertinent to the 

CPA. These Internet sources included online indexes to periodical literature, such as JSTOR (http://

www.jstor.org/), the National Technical Information Service’s National Technical Reports Library 

(https://ntrlr3.ntis.gov), and ScienceDirect (http://www.sciencedirect.com/). In addition, BOEM has 

conducted scientific research in the GOM. The research has identified new information on shipwrecks 

that is pertinent to this Supplemental EIS.

In July 2013 and April 2014, BOEM participated in a multi-agency investigation of three earlynineteenth century shipwrecks located in the CPA (USDOI, BOEM, 2014d). Preliminary analysis of the 

data indicates that these wooden-hulled sailing vessels share similarities in hull construction 

characteristics and artifact assemblages. Additionally, these shipwrecks are located within 4 nmi (5 mi; 

7 km) of each other, suggesting that they may have been sailing together in convoy when they were 

caught and sunk by a violent storm. Regardless of whether these vessels were sailing together or on 

separate voyages, their discovery supports BOEM’s previous analysis that there is a high probability of 

historic shipwrecks being located in deepwater areas of the CPA along historic trading routes (Pearson 

et al., 2003; Lugo-Fernandez et al., 2007).
Description of the Environment and Impact Analysis 4-89

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231, Supplemental EIS, and CPA 235/241/247 

Supplemental EIS are still valid. No new significant information has been identified since those NEPA

documents were published that would alter those documents’ conclusions on impacts to historic 

archaeological resources from a CPA proposed action. Nevertheless, there is still incomplete or 

unavailable information regarding the location of historic archaeological resources in the CPA. This 

information cannot be obtained because the overall costs of obtaining a survey of the entire CPA are 

exorbitant. This incomplete information may be relevant to adverse effects because the locations and 

integrity of many historic archaeological resources remain unknown. Nevertheless, this incomplete 

information is not likely to be available within the timeline contemplated in the NEPA analysis of this 

Supplemental EIS. It would take several years before data confirming the presence (or lack thereof) of 

historic archaeological resources, and the status of each, could be investigated, analyzed, and compiled. 

Historic archaeological sites within the CPA region have the potential to be buried, embedded in, or 

laying on the seafloor. The CPA covers an area of 66,446,351 ac and ranges in water depths from an 

estimated 3 to 3,475 m (10 to 11,401 ft). It includes highly variable bathymetric and geophysical 

regimes, which differentially affect the ease and ability to identify, ground truth, and evaluate historic 

archaeological sites. This fact, combined with the scope of the acreage within the CPA, results in the 

aforementioned exorbitant costs and time factors.

BOEM used reasonably accepted scientific theories on archaeological site potential in the Gulf of 

Mexico to extrapolate from existing survey data in completing the relevant analysis and formulating the 

conclusions presented here. In addition, future site-specific, remote-sensing surveys of the seafloor are 

required when deemed appropriate to establish the presence of potential resources (NTL 2005-G07). The 

results of these surveys are reviewed in tandem with credible scientific evidence from previously 

identified sites, regional sedimentology, and physical oceanography that is relevant to evaluating the 

adverse impacts on historic resources that are a part of the human environment. The required surveys are 

analyzed by industry and BOEM archaeologists prior to the authorization of any new or significant 

bottom-disturbing impacts and, if necessary, avoidance of potential archaeological resources is 

prescribed. Archaeological surveys are expected to be highly effective in identifying resources to allow 

for the protection of the resource during OCS oil- and gas-related activities. A CPA proposed action is 

not a reasonably foreseeable significant impact because BOEM’s evaluation of such impacts is based 

upon pre-disturbance and site-specific surveys, the results of which BOEM uses to require substantial 

avoidance of any potential historic resource that could be impacted by the proposed activity. Therefore, 

BOEM has determined that the information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for historic archaeological resources presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS. No new significant information was discovered that would alter the impact conclusion for historic 

archaeological resources presented in those NEPA documents because of the available scientifically 

credible evidence in this analysis and based upon accepted scientific methods and approaches. The 

analysis and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 

and 247.

4.1.1.22.2. Prehistoric Archaeological Resources

BOEM has reexamined the analysis for prehistoric archaeological resources presented in the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for prehistoric archaeological resources presented 

in those NEPA documents. The analysis and potential impacts discussed in those documents still apply 

for proposed CPA Lease Sales 241 and 247.

Prehistoric archaeological resources are any material remains of human life or activities associated 

with the earliest inhabitants of the Gulf Coast, predating European discovery and exploration of the area. 

Available evidence suggests that the first Americans arrived on the Gulf Coast as much as 12,000 years 
4-90 Central and Eastern Planning Areas Supplemental EIS

B.P. (before present) during a time when the continental shelf was exposed above sea level and open to 

habitation (Pearson et al., 1986). Prehistoric archaeological sites are thought to be preserved shoreward 

of the 45-m (148-ft) bathymetric contour, where the Gulf of Mexico continental shelf was subaerially 

exposed during the Late Pleistocene.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.22.2 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.22.2 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.22.2 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were prepared is presented below.

Impacts of Routine Activities and Accidental Events

Routine impact-producing factors associated with a CPA proposed action that could affect prehistoric 

archaeological resources include direct physical contact associated with the placement of drilling rigs and 

production systems on the seafloor; pile driving associated with platform emplacement; dredging of new 

channels, as well as maintenance dredging of existing channels; anchoring activities; pipeline installation 

and maintenance; and post-decommissioning platform removal and trawling clearance. This direct 

physical contact with a site could destroy fragile artifacts or site features and could disturb artifact 

provenance and site stratigraphy. The result would be the loss of archaeological data on prehistoric 

migrations, settlement patterns, subsistence strategies, and archaeological contexts for North America, 

Central America, South America, and the Caribbean.

Archaeological survey and archaeological clearance of sites, where required prior to an operator 

beginning oil and gas activities on a lease, are expected to be somewhat effective at identifying 

submerged landforms that could support archaeological sites. The NTL 2005-G07 suggests a 300-m 

(984-ft) line spacing for remote-sensing surveys of leases within areas having a high potential for 

prehistoric sites. While surveys, where required, provide a reduction in the potential for a damaging 

interaction between an impact-producing factor and a prehistoric archaeological site, there is a possibility 

of an OCS oil- and gas-related activity contacting an archaeological site because of an insufficiently 

dense survey grid. Should such contact occur, there would be damage to or loss of significant and/unique 

archaeological information. The risk of contact to archaeological resources is greater in instances where 

archaeological survey data are inadequate or unavailable. Archaeological surveys provide the necessary 

information to develop avoidance strategies that reduce the potential for impacts on archaeological 

resources.

Except for the projection of up to one new gas processing facility and up to one new pipeline landfall, 

a CPA proposed action would require no new oil and gas coastal infrastructure. It is expected that the 

protection of archaeological resources would be maximized through the review and approval processes of 

the various Federal, State, and local agencies involved in permitting onshore activities.

Impacts to documented (which currently exist only onshore) and undocumented (potentially on and 

offshore) prehistoric archaeological resources could occur as a result of an accidental oil spill and the 

associated cleanup operations. Oil spills resulting from a well blowout in the CPA and related spillresponse activities have the potential to impact cultural resources near the spill site and landfall areas. 

Detailed risk analyses of offshore oil spills ranging from <1,000 bbl to ≥1,000 bbl and coastal spills that 

may be associated with a CPA proposed action is provided in Chapters 3.2.1.5, 3.2.1.6, and 3.2.1.7 of 

this Supplemental EIS and Chapters 3.2.1.5, 3.2.1.6, and 3.2.1.7 of the 2012-2017 WPA/CPA Multisale 

EIS. Should a spill contact a prehistoric archaeological site, damage might include loss of radiocarbondating potential, direct impact from oil-spill cleanup equipment, and/or looting. Previously unrecorded 

sites could be impacted by oil-spill cleanup operations on beaches. However, when oil is spilled in 

offshore areas, much of the oil volatilizes or is dispersed by currents, so it has a low probability of 

contacting coastal and barrier island prehistoric sites as a result of a CPA proposed action. A CPA 

proposed action, therefore, is not expected to result in impacts to prehistoric archaeological sites due to an 

accidental oil spill.
Description of the Environment and Impact Analysis 4-91

Cumulative Impacts

The OCS oil- and gas-related activities that could impact prehistoric archaeological sites located on 

the OCS through contact include pipeline and platform installations, drilling rig emplacement and 

operation, site decommissioning, rigs-to-reefs development, dredging, and anchoring activities. 

Preconstruction surveys may be required by BOEM or the lead permitting agency prior to these activities. 

Impacts to prehistoric resources may still occur in areas where a remote-sensing survey fails to resolve the 

location of partially or completely buried resources or when no pre-disturbance survey is required. 

Development onshore as a result of a CPA proposed action could result in the direct physical contact 

between a prehistoric site and pipeline trenching. It is assumed that archaeological investigations prior to 

construction will serve to mitigate these potential impacts. Oil spills have the potential to impact coastal 

prehistoric sites directly or indirectly by physical impacts caused by oil-spill cleanup operations. The 

number and most likely spill sizes to occur in coastal waters in the future are expected to resemble the 

patterns that have occurred in the past, as long as the level of oil- and gas-related commercial and 

recreational activities remain the same. Low-probability catastrophic spills, which are not part of the 

proposed action and not likely expected, could also contact coastal prehistoric sites, and the effects of a 

spill that size would likely result in longer-lasting impacts that take longer to mitigate. Accidental spills 

as a result of a low-probability catastrophic spill are discussed in Appendix B. 

Non-OCS oil- and gas-related cumulative impact-producing factors that could potentially impact 

prehistoric archaeological resources including the following: (1) State oil and gas activity; (2) new 

channel dredging and maintenance dredging; (3) State renewable energy and alternative use conversions; 

(4) State artificial reefs and rigs-to-reefs development; (5) OCS sand borrowing; (6) offshore LNG 

projects; (7) commercial fishing; and (8) natural processes, including wave action and hurricanes. These 

impact-producing factors all create associated bottom disturbances that may threaten prehistoric 

archaeological resources. An impact could result from contact between prehistoric resources and 

permitted activities such as State oil and gas activities, renewable energy activities, artificial reef creation, 

new channel dredging, and maintenance dredging. With the exception of maintenance dredging, 

preconstruction surveys may be required for these activities. Impacts to prehistoric resources may still 

occur in areas where a remote-sensing survey fails to resolve the location of partially or completely buried 

resources or when no pre-disturbance survey is required. Oil and gas program wells, structures, and 

pipelines existing entirely in State waters are not under the jurisdiction of BOEM with respect to the 

archaeological resource protection requirements of the National Historic Preservation Act and would be 

the responsibility of the State and the permitting Federal agency. Prehistoric sites in shallow waters and 

on coastal beaches are exposed to the destructive effects of wave action and scouring currents. Overall, 

loss of data from prehistoric sites has probably occurred, and will continue to occur, in the northeastern 

Gulf of Mexico from the effects of tropical storms.

The effects of the various impact-producing factors discussed in this analysis have likely resulted in 

localized losses of significant or unique prehistoric archaeological information. In the case of factors 

related to OCS Program activities in the cumulative activity area, it is reasonable to assume that most 

impacts have occurred in areas where surveys have not been required in the past or have been acquired at 

insufficient transect spacing. The incremental contribution of a CPA proposed action is expected to be 

very small due to the efficacy of the required remote-sensing survey and concomitant archaeological 

report and clearance.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

Various Internet sources were examined to assess recent information regarding impacts to 

archaeological resources or potential new threats to archaeological resources that may be pertinent to the 

CPA. These Internet sources included various online indexes to periodical literature such as JSTOR 

(http://www.jstor.org/), the National Technical Information Service’s National Technical Reports Library 

(https://ntrlr3.ntis.gov), and ScienceDirect (http://www.sciencedirect.com/). 

This search did not identify any new information that would be pertinent to the analysis of the 

potential impacts of OCS oil- and gas-related activities on prehistoric archaeological resources. 
4-92 Central and Eastern Planning Areas Supplemental EIS

Incomplete or Unavailable Information 

Even after evaluating the information above, BOEM has determined that the conclusions from the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231, Supplemental EIS, and CPA 235/241/247 

Supplemental EIS are still valid because no new information on prehistoric archaeological resources from 

a CPA proposed action has become available since those documents were published; nevertheless, there is 

still incomplete or unavailable information on the location of prehistoric archaeological resources in the 

CPA.

This incomplete information may be relevant to adverse effects because the locations and integrity of 

prehistoric archaeological resources on the OCS remain unknown. Nevertheless, this incomplete 

information is not likely to be available within the timeline contemplated within the NEPA analysis of 

this Supplemental EIS. It would take many years before data confirming the presence of prehistoric 

archaeological resources in a given location, and the status of each, could be investigated, analyzed, and 

compiled. Most prehistoric sites within the CPA region are likely deeply buried, resulting in the largest 

portion of the aforementioned exorbitant costs and time factors. An extensive study funded by the 

National Park Service in 1977 in the CPA estimated that prehistoric period sites could be buried on the 

OCS under as much as 200 m (656 ft) of sediment in western portions of the CPA and 107 m (351 ft) of 

sediment in eastern portions of the CPA (Coastal Environments, Inc., 1977).

BOEM used reasonably accepted scientific methodologies to extrapolate from existing survey data in 

completing the relevant analysis and formulating the conclusions presented here. In addition, new sitespecific, remote-sensing surveys of the seafloor are required when deemed appropriate to establish the 

presence of potential resources. The results of these surveys are reviewed in tandem with credible 

scientific evidence from previously identified terrestrial sites, regional sedimentology, and physical 

oceanography that is relevant to evaluating the adverse impacts on landforms that may preserve 

prehistoric resources that are a part of the human environment. The required surveys are analyzed by 

archaeologists prior to any new or significant bottom-disturbing impacts being authorized and avoidance 

of potential resources prescribed. Archaeological surveys, where required, are expected to be highly 

effective in identifying resources to allow for the protection of the resource during OCS oil- and gasrelated activities. A CPA proposed action is not a reasonably foreseeable significant impact because 

BOEM’s evaluation of such impacts is based upon pre-disturbance and site-specific survey, the results of 

which BOEM uses to require substantial avoidance of any potential prehistoric resource that could be 

impacted by the proposed activity. Therefore, BOEM has determined that the information is not essential 

to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for prehistoric archaeological resources presented in the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for prehistoric archaeological resources presented 

in those NEPA documents because of the available scientifically credible evidence in this analysis and 

based upon accepted scientific methods and approaches. The analysis and potential impacts discussed in 

those documents still apply for proposed CPA Lease Sales 241 and 247.

4.1.1.23. Human Resources and Land Use

4.1.1.23.1. Land Use and Coastal Infrastructure

BOEM has reexamined the analysis for land use and coastal infrastructure presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS, based on the additional information presented below. No new significant information was 

discovered that would alter the impact conclusion for land use and coastal infrastructure presented in 

those NEPA documents. The analysis and potential impacts detailed in those documents still apply for 

proposed CPA Lease Sales 241 and 247.

A detailed description of the affect environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.23 of the 2012-2017 WPA/CPA Multisale EIS, and updated information is 
Description of the Environment and Impact Analysis 4-93

provided in Chapter 4.2.1.23 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.23 of the 

CPA 235/241/247 Supplemental EIS. The following is a summary of the resource description and impact 

analysis incorporated from those NEPA documents. Any new information that has become available 

since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

Routine impact-producing factors associated with a CPA proposed action that could affect land use

and coastal infrastructure include the fluctuation of offshore supply vessel (OSV) day rates, the dredging 

of navigation channels, and the expansion of gas processing facilities, pipeline landfalls, service bases, 

and waste disposal facilities. The impacts of routine activities associated with a CPA proposed action are 

expected to remain consistent with historic activity levels. The OCS oil- and gas-related infrastructure 

has developed over many decades and is an extensive and mature system that provides support for 

offshore activities. The expansive presence of this coastal infrastructure is the result of long-term 

industry trends, and it is not subject to rapid fluctuations.

Routine activities relating to the OCS Program are expected to minimally affect the current land use

of the analysis area because most subareas have strong industrial bases and designated industrial parks 

with existing infrastructure and facilities to accommodate future growth in oil and gas businesses. Since 

the supporting infrastructure is mature and not subject to rapid fluctuations and because BOEM only 

projects up to one new gas processing facility and up to one new pipeline landfall for a CPA proposed 

action, the impacts of routine activities associated with a CPA proposed action are expected to remain at 

historic activity levels (Dismukes, official communication, 2013). There may be a new increased demand 

for waste disposal services as a result of a CPA proposed action; however, the effects on land use and 

infrastructure would be limited, would occur on lands designated for such purposes, and would have 

minimal impacts to land use and coastal infrastructure. Because the projected addition to infrastructure is 

near zero, the routine activities associated with a CPA proposed action would have little effect on land use 

and existing coastal infrastructure, and there would be minimal impacts from any expansion of existing 

infrastructure. BOEM anticipates that there would be maintenance dredging of navigation channels, 

provided funding is appropriated, in support of routine activity at services bases as a result of a CPA 

proposed action. In regard to land use and infrastructure, it does not appear that there would be adverse 

impacts from routine activities associated with a CPA proposed action.

Accidental events associated with a CPA proposed action that could affect land use and coastal 

infrastructure include, but are not limited to, oil spills, vessel collisions, and chemical/drilling-fluid spills. 

Accidental events associated with a CPA proposed action would occur at differing levels of severity, 

based in part on the location and size of event. Depending on where an accidental event occurs, it is 

expected that the oil-spill response equipment needed to respond to an offshore spill as a result of a 

proposed CPA lease sale could be called out from one or more of the following oil-spill equipment base 

locations: New Iberia, Belle Chasse, Baton Rouge, Sulphur, Morgan City, Port Fourchon, Harvey, 

Leeville, Fort Jackson, Venice, Grand Isle, or Lake Charles, Louisiana; La Porte, Corpus Christi, Port 

Arthur, Aransas Pass, Ingleside, Galveston, or Houston, Texas; Kiln or Pascagoula, Mississippi; Mobile 

or Bayou La Batre, Alabama; Panama City, Pensacola, Tampa, or Miami, Florida; and/or Ponce or San 

Juan, Puerto Rico (Clean Gulf Associates, 2014; Marine Spill Response Corporation, 2014; National 

Response Corporation, 2014).

Cumulative Impacts

The cumulative analysis considers both existing land use patterns and the effects of impact-producing 

factors from OCS oil- and gas-related and non-OCS oil- and gas-related activities. Impact-producing 

factors associated with OCS oil- and gas-related activities that could affect land use and coastal 

infrastructure include gas processing facilities, pipeline landfalls, service bases, navigation channels, 

waste disposal facilities, oil spills, vessel collisions, and chemical/drilling-fluid spills. Any service base 

expansion in the cumulative case would be limited, would occur on lands designated for such purposes, 

and would have minimal effects on land use and infrastructure. Therefore, the incremental contribution 

of a CPA proposed action to the cumulative impacts on land use and coastal infrastructure is also 

expected to be minor.
4-94 Central and Eastern Planning Areas Supplemental EIS

The non-OCS oil- and gas-related factors that can contribute substantially to the baseline conditions 

as well as impact coastal infrastructure and land use consist of the following:

• prior, current, and future State oil and gas lease sales;

• other onshore fossil fuel exploration and production activities;

• petrochemical and manufacturing activities;

• housing and other residential developments;

• the development of private and publicly owned recreational facilities;

• the construction and maintenance of industrial facilities and transportation systems;

• urbanization;

• city planning and zoning;

• changes to public facilities such as water, sewer, educational, and health facilities;

• changes to military bases and reserves;

• changes in population density;

• changes in State and Federal land use regulations;

• changes in non-OCS oil- and gas-related demands for water transportation systems 

and ports;

• macro- and microeconomic trends;

• coastal landloss and subsidence; and

• natural processes.

The OCS Gulf of Mexico leasing program exists within a highly industrialized and economically 

diverse coastal region, which is itself the aggregate of past and present community, government, and 

business actions. How land has been traditionally used or will be used in the future is determined 

irrespective of a CPA proposed action. Coastal infrastructure associated with the OCS oil and gas 

industry is also utilized by State leased and privately owned oil and gas interests, as well as other 

industries. State oil and gas activities and associated impacts will occur based on State leasing programs, 

geologic plays, economic trends, and local regulatory regimes. The OCS oil- and gas-related support 

activities occur within a context of a well-established populated coastal region, which is home to a diverse 

and robust economy. Many local and national industries, such as agricultural and industrial interests, 

utilize the same transportation systems and ports used by the OCS oil and gas industry. The OCS oil- and 

gas-related demands on land use are typically relegated to coastal or inland waterway industrial zones and 

represent a small fraction of how existing residential, recreational, agricultural, military, and industrial 

uses utilize and impact land use and coastal infrastructure. Because the vast majority of coastal 

infrastructure supports OCS and State offshore and land-based oil and gas production, as well as other 

land-based industrial uses, the coastal infrastructure supporting a CPA proposed action represents only a 

small portion of the coastal land use and infrastructure throughout the CPA and Gulf of Mexico, and 

because this is a shared resource, the incremental contribution of a CPA proposed action is expected to 

have minimal impact overall.

Land use categories are tied to existing infrastructure and historic uses, and for the purpose of this 

analysis include the Economic Research Service’s land use inventory categories, which include the 

following: land-based oil and gas activities; agriculture; forest, parks, and special use areas; urban areas; 

miscellaneous areas; and inland navigable waterways and ports. Land use patterns vary greatly by region, 

reflecting differences in soils, climate, topography, and patterns of population settlement. Changes in 

land use will largely depend upon local zoning and economic trends. Of the over 400,000 mi2

(1,035,995 km2

) comprising these coastal states, 18 percent of the total land area is covered in cropland. 

Texas and Mississippi have the highest percentages of cropland, with 20 percent and 19 percent of each 
Description of the Environment and Impact Analysis 4-95

respective State’s total land being used for cropland. Louisiana’s highway network is the 32nd largest in 

the Nation, with the State highway system the 11th largest. The network is comprised of over 60,000 mi 

(96,561 km) and more than 13,000 bridges under the jurisdiction of Federal, State, and local governments 

and entities. The 27.4 percent of highway network centerline mileage that are State-owned places 

Louisiana 10th nationally, while the 30 percent of total highway network lane mileage that are Stateowned places Louisiana 11th (State of Louisiana, Dept. of Transportation and Development, 2011). Five 

interstate highways converge in Alabama, allowing goods to be shipped to major markets. The I-22 is 

planned to be completed by 2014, making this the sixth interstate in Alabama (Economic Development 

Partnership of Alabama, 2013).

The Ports of South Louisiana and Houston rank 12th and 13th, respectively, in total trade for all world 

ports and 1st and 2nd, respectively, for American ports (American Association of Port Authorities, 2011). 

With direct access to the Mississippi River and its system of inland rivers, the Port of South Louisiana 

averages 223 million metric tons per year. In Louisiana, there are 2,823 mi (4,543 km) of inland 

waterways (State of Louisiana, Dept. of Transportation and Development, 2011). Alabama’s water 

corridors connect to over 15,000 mi (24,140 km) of inland waterways in 23 states (Economic 

Development Partnership of Alabama, 2013). Meanwhile, OCS oil- and gas-related coastal infrastructure

and land use represent only an incremental contribution to total land use, and the cumulative impacts as a 

result of a CPA proposed action and the OCS Program as a whole on land use and coastal infrastructure 

are also expected to be minor. This short summary of land uses and land use categories and coastal 

infrastructure is by no means comprehensive, but it should illustrate that OCS oil- and gas-related coastal 

land use and infrastructure comprises only a percentage of the total land use and allows us a bird’s eye 

view of the program within the context of other impact-producing factors.

The proposed CPA lease sales would mostly maintain ongoing activity levels associated with the 

current OCS Program. Industry would essentially maintain its current usage of infrastructure according to 

the proposed lease sale schedule. Macroeconomic shifts, such as a change in commodity prices or an 

economic upturn or downturn, will also determine future utilization of this infrastructure.

A CPA proposed action would minimally affect the current land use within the analysis area because 

most subareas have strong industrial bases and designated industrial parks with enough capacity to 

accommodate the future growth that OCS oil- and gas-related businesses would demand. Coastal land 

use and infrastructure along the Gulf Coast can also be impacted by non-OCS oil- and gas-related 

conflicts, as well as a variety of other factors, such as coastal erosion and economic factors. However, the 

incremental contribution of a CPA proposed action is expected to be minimal in light of all OCS oil- and 

gas-related and non-OCS oil- and gas-related activities.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

Additional research was conducted to investigate the availability of recent information affecting land 

use and coastal infrastructure since publication of the 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. Various Internet sources 

were examined, including the websites of numerous Federal and State agencies (USDHS, Federal 

Emergency Management Agency; USDOC, Bureau of the Census; USDOC, NOAA; U.S. Department of 

Energy, Energy Information Administration; U.S. Department of Transportation, Maritime 

Administration; USDOI, FWS; RestoreTheGulf.gov website; Deepwater Horizon Oil Spill Portal; 

USEPA; Louisiana Department of Environmental Quality; Louisiana Recovery Authority; Louisiana 

Office of Community Development; Mississippi Department of Environmental Quality; Alabama 

Department of Environmental Management; and the State of Florida Department of Environmental 

Protection). Further information was sought from other organizations, recently published journal articles, 

and trade publications such as The Greater Lafourche Port Commission, LA1 Coalition, The Oil Drum, 

Rigzone, Oil and Gas Journal, Offshore Magazine, Reuters, TOLLROADS News, and The Energy 

Journal. 

A new U.S. Department of Energy, Energy Information Administration report found that Federal 

waters in the Gulf of Mexico in 2013 accounted for 69 percent of all the crude oil produced on land and 

water owned by the Federal Government (USDOE, Energy Information Administration, 2014j). The 

Energy Information Administration did note that offshore GOM oil production declined from 584 bbl in 

2010 to 447 MMbbl in 2013. Anticipated growth, however, is still fueling investment in infrastructure
4-96 Central and Eastern Planning Areas Supplemental EIS

and supporting industries. Reuters recently reported that offshore drilling is fueling investments for the 

handful of helicopter operators that shuttle oil workers to and from remote rigs. Barclays estimates that 

300 new helicopters will be needed to meet the demand (Gopinath, 2014). There are 115 OCS oil- and 

gas-related heliports across southern Louisiana. Mississippi and Alabama only host four helicopter hubs 

each (Gopinath, 2014).

The recent combination of horizontal drilling and hydraulic fracturing technologies has enabled landbased oil and gas companies to economically recover a much larger share of domestic shale resources 

than previously possible. Domestic shale oil and gas have helped make the U.S. a global growth leader in 

crude oil production capacity growth and the largest natural gas producer (IHS Global Inc., 2014). The 

majority of new offshore infrastructure investments will support new development areas such as the 

Bakken and Eagle Ford production regions, which have not been historically large production regions. 

As a result of the current shale market, much of the infrastructure that processes OCS- and land-based oil 

and gas will likely experience investment and growth to accommodate the current boom. IHS Global Inc. 

projects that, between 2014 and 2020, an average of greater than $80 billion will be invested annually in 

U.S. midstream and downstream petroleum. Of that, $41.5 billion will be distributed within the 

southeastern region, which includes Texas, Louisiana, Alabama, Mississippi, and Florida, As of 

September 2011, over 70 mi (113 km) of interstate pipeline have gone into service to transport Marcellus 

Shale basin gas, 319 mi (513 km) of interstate pipeline are approved and under construction, 116 mi 

(187 km) are pending, and almost 5,000 mi (8,047 km) of potential projects have been announced. 

Natural gas liquid (NGL) pipelines, which serve as the key connecter between the gas processing plants 

and the large NGL fractionating hubs, have increased investment. Investment decisions have been made 

to also expand two already very large refineries, i.e., Marathon Petroleum in Garyville, Louisiana, and 

Motiva in Port Arthur, Texas. But the demand for refined petroleum products has actually decreased, and 

since 2010, calculated, nonsustaining capital investment in refining has decreased from $7.4 billion in 

2010 to just under $3 billion in 2013.

Since 2009, U.S. domestic total natural gas storage has increased by 500 billion cubic feet to a total 

storage capacity of 9,100 billion cubic feet. As a result, IHS Global Inc.’s analysis projects that over 

18,000 mi (28,968 km) of major crude oil pipelines will be constructed, expanded, reversed, or converted 

from natural gas or other pipeline service. This major corridor will be a continuous line of several 

different systems running horizontally from West Texas to refineries in Texas and along the Louisiana 

Gulf Coast, with production from Eagle Ford on ramping to the Texas longitudinal corridor (IHS Global 

Inc., 2013, page 28). IHS Global Inc. forecasts cumulative investment in U.S. crude oil pipelines of 

$37.8 billion between 2014 and 2025, with the majority being invested during the first 6 years of the 

forecast period. Crude oil movements by rail have increased from less than 50,000 bbl per day in 2010 to 

800,000 bbl per day in 2013, driving capital investment in rail tracks, rail loading and unloading facilities, 

and tank cars used in the transportation of crude oil. The investment in rail and marine logistics for 

transporting crude oil and NGLs has increased from less than $0.5 billion in 2010 to over $5 billion in 

2013 (IHS Global Inc., 2013, page 18). Several of the LNG export projects now under development are 

likely to be completed. The Federal Energy Regulatory Commission authorized a second LNG export 

project in Cameron Parish, Louisiana, which will liquefy and export domestically produced natural gas 

from its existing LNG import terminal. The Federal Energy Regulatory Commission also authorized 

pipeline and compression facilities in Cameron, Calcasieu, and Beauregard Parishes, Louisiana, to supply 

the Cameron LNG facility with domestically produced gas (Federal Energy Regulatory Commission, 

2014).

In July 2014, a subsidiary of Chinese chemical manufacturer Shandong Yuhuang Chemical Co. 

announced that they plan to build a methanol manufacturing complex on the Mississippi River in 

St. James Parish (Sayre, 2014). The OCS oil- and gas-related businesses will likely utilize infrastructure

and transportation corridors that it shares in common with onshore producers. But to reiterate, onshore 

domestic shale oil and gas has driven and will continue to drive much of the infrastructure additions and 

expansions that impact coastal land use. The dynamics of fossil fuel exploration and production are 

driven by micro- and macroeconomics, local and Federal regulations, technological advances, and 

geopolitics, among other trends and forces. Because the OCS oil and gas leasing program is a tightly 

scheduled and regulated industry, its anticipated utilization of coastal land and infrastructure is anticipated 

to stay within average parameters. None of this new significant information would alter the impact 

conclusion for land use and coastal infrastructure presented in 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS because the new 
Description of the Environment and Impact Analysis 4-97

information was roughly consistent with prior expectations. The analysis and potential impacts discussed 

in those NEPA documents still apply for proposed CPA Lease Sales 241 and 247.

Incomplete or Unavailable Information 

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.23.1 of the 2012-

2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.1 of the 

CPA 235/241/247 Supplemental EIS, BOEM has identified incomplete information regarding the 

potential impacts of coastal landloss on land use and coastal infrastructure. This incomplete information 

may be relevant to adverse effects because a comprehensive understanding of the potential impacts of 

coastal landloss on coastal infrastructure and land use remains unknown. It is not completely known how 

current subsidence and erosion are impacting industry or whether industry is making plans to mitigate 

current or future impacts. This information cannot reasonably be obtained because the overall costs in 

time and money to collect data on the varying impacts of coastal landloss to different firms are exorbitant. 

BOEM has proposed a study to evaluate these potential effects by surveying industry on current impacts 

and potential adaptation strategies, but at the time of publication of this Supplemental EIS, it is unfunded, 

and it would take several years before data could be available. Nevertheless, this incomplete information 

is not likely to be available within the timeline contemplated in the NEPA analysis of this Supplemental 

EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. For example, BOEM knows 

that, in the case of coastal ports for instance, dredged material from navigation slips are used to fill in 

property and mitigation habitat areas for wildlife and to act as a barrier to protect ports from storm surges 

(Volz, 2013). While coastal infrastructure is subject to the impacts of coastal landloss and routine tropical 

storm activity, there is still considerable investment to expand, improve, and protect existing 

infrastructure. In June 2013, Governor Bobby Jindal of Louisiana signed Senate Bill 122, which 

modified the Investor Tax Credit and the Import-Export Tax Credit. The new credits now include 

projects like warehousing and storage, port operations, marine cargo handling, ship building and repairs, 

and oil- and gas-related activities (State of Louisiana, Office of the Governor, 2013). Additionally, the 

decision criteria for the State of Louisiana’s 5-year coastal restoration planning document places a higher 

value on collections of risk reduction and restoration projects that improve coastal conditions for oil- and 

gas-related infrastructure and increase the resilience of coastal communities that support the industry. 

The criterion also puts a higher value on projects that benefit the navigation industry and places a lower 

value on projects that impede navigation (State of Louisiana, Coastal Protection and Restoration 

Authority, 2012b). Therefore, coastal restoration efforts will be focused on those land use areas with a 

higher concentration of OCS coastal infrastructure. While not completely known, current and future 

industry adaptation plans for coastal landloss are not essential to a reasoned choice among alternatives for 

this Supplemental EIS (including the No Action and an Action alternative).

Like any industrial infrastructure improvements, future adaptations will likely occur on an as-needed 

basis or as new technologies become available. Therefore, BOEM has determined that the information is 

not essential to a reasoned choice among alternatives. BOEM will continue to monitor industry and its 

infrastructure footprint over time to document short- and long-term impacts of continued landloss. For a 

more detailed discussion on deltaic landloss, refer to Chapter 4.1.1.4. 

Summary and Conclusion

BOEM has reexamined the analysis for land use and coastal infrastructure presented in the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for land use and coastal infrastructure presented in those NEPA

documents because the new information was roughly consistent with prior expectations. The analysis and 

potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.
4-98 Central and Eastern Planning Areas Supplemental EIS

4.1.1.23.2. Demographics

BOEM has reexamined the analysis for demographics presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for demographics presented in those NEPA documents. The analysis and 

potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected and the full analyses of the potential impacts of routine 

activities, accidental events, and cumulative events associated with a CPA proposed action are presented 

in Chapter 4.2.1.23.3 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is provided in 

Chapter 4.2.1.23.3 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.3 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis presented in those NEPA documents. Any new information that has become available 

since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

In general, impact-producing factors that cause employment impacts, such as exploration and 

delineation activities, development and production activities, and coastal infrastructure development, can 

have some impacts on the demographic characteristics of a particular area. However, routine activities 

associated with a CPA proposed action are projected to minimally affect the demography of the analysis 

area. The projected impacts to population arising from a proposed CPA lease sale are calculated by 

multiplying the employment estimates from the mathematical model MAG-PLAN by an estimate of the 

number of members in a typical family. The projected population increases arising from a proposed CPA 

lease sale are then divided by the population forecasts in Woods and Poole, Inc. (2014), which yields the 

percentage impacts to population of a proposed CPA lease sale. Population impacts from a CPA 

proposed action are projected to be minimal (<1% of the total population) for all EIAs in the Gulf of 

Mexico region.

Accidental events associated with a CPA proposed action, such as low- to moderate-scale oil or 

chemical spills, blowouts, and vessel collisions, would likely have no effects on the long-term 

demographic characteristics of the Gulf coastal communities. This is because accidental events typically 

cause only short-term population movements as individuals seek employment related to the event or have 

their existing employment displaced during the event.

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors related to OCS oil- and 

gas-related activities along with non-OCS oil- and gas-related impact-producing factors. The OCS oiland gas-related factors that could impact the demographics of any area consist of routine activities and 

accidental events arising from prior, current, and future OCS lease sales, including impact-producing 

factors that cause employment impacts (i.e., exploration and delineation activities, development and 

production activities, and coastal infrastructure development) as well as oil spills, blowouts, and vessel 

collisions. The impacts to population arising from a CPA proposed action are projected to be minimal 

(<1% of the total population) for any EIA in the Gulf of Mexico region based on the employment 

estimates from the mathematical model MAG-PLAN for low-case and high-case scenarios for OCS oiland gas-related activities. Accidental events should not have long-term effects on the demographic 

characteristics of the Gulf coastal communities because population movements from such events are 

typically short-term. For a detailed discussion of the employment and demographic impacts of a lowprobability catastrophic spill, which is not part of a CPA proposed action and not likely expected, refer to 

Appendix B. 

There are numerous non-OCS oil- and gas-related factors that could impact demographics, including 

fluctuations in workforce, net migration, relative income, oil and gas activity in State waters, offshore 

LNG activity, trends in tourism activities (refer to Chapter 4.1.1.21), and other economic factors (refer to 

Chapter 4.1.1.23.3). Common approaches in analyzing cumulative effects begin by assembling a list of 

other projects and actions that will likely be associated with a CPA proposed action. However, no such 

list of future projects and actions could be assembled that would be sufficiently current and 

comprehensive to support a cumulative analysis for all 132 of the coastal counties and parishes in the 
Description of the Environment and Impact Analysis 4-99

analysis area over a 40-year period. Instead, this analysis uses the economic and demographic projections 

from Woods & Poole Economics, Inc. (2014) as a reasonable approximation to define the contributions of 

other likely projects, actions, and trends to the cumulative case.

A CPA proposed action would contribute to the population impacts arising from the overall OCS 

Program. The EIAs TX-3, TX-1, LA-2, and LA-3 are projected to have some increases in the levels of 

their populations as a result of an increase in demand for OCS labor from both a CPA proposed action 

and the overall OCS Program. A CPA proposed action is projected to have an incremental contribution of 

less than 1 percent to the population level in any of the EIAs, in comparison with other factors influencing 

population growth, such as the status of the overall economy, fluctuations in workforce, net migration, 

health trends, and changes in income. Given both the low levels of population growth and industrial 

expansion associated with a CPA proposed action, it is expected that the baseline age and racial 

distribution patterns will continue through the analysis period.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

BOEM conducted a search of Internet resources and known data sources related to demographics. 

The primary source of new information is Woods & Poole Economics, Inc. (2014), which is an annual 

update of the data that were used in the CPA 235/241/247 Supplemental EIS. Woods & Poole 

Economics, Inc. (2014) provides projections of economic and demographic variables at the county/parish 

level. Table 4-9 provides projections of the evolution of the total population in all EIAs in future years, 

while Table 4-10 provides projections of the evolution of total employment in the same areas. These 

projections assume the continuation of existing social, economic, and technological trends at the time of 

the forecast. In 2013, the total Gulf Coast population was 25.51 million. In 2013, the EIAs with the 

largest populations were TX-3 (6.54 million), FL-4 (6.43 million), and FL-3 (3.77 million). The EIAs 

with the smallest populations were LA-1 (353,510), MS-1 (493,860), and LA-2 (603,940). For all EIAs 

combined, it is expected that the total population will grow at a 1.27 percent rate between 2014 and 2055. 

The fastest population growth is expected in TX-3 (1.65%), TX-1 (1.46%), and FL-3 (1.28%); the slowest 

population growth is expected in LA-4 (0.45%) and MS-1 (0.62%). Tables 4-11 through 4-23 provide 

projections of employment, income, wealth, business patterns, and racial composition for individual 

EIAs. In general, the projections of these variables have not changed noticeably from the projections in 

the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS.

Austin et al. (2014a and 2014b) are two volumes of a recently completed study of the social impacts 

of the Deepwater Horizon oil spill. This study employed an ethnographic methodology that entailed 

analyzing data sources, examining various sources of descriptive information, and conducting field 

interviews with people in Louisiana, Mississippi, and Alabama. This study documents the complex and 

varied impacts of the Deepwater Horizon oil spill during the 20 months subsequent to the spill. This 

study found that the impacts of the spill on a particular community depended on a number of factors, such 

as its proximity to the spill, economic structure, social and political dynamics, organizational structure for 

dealing with disasters, and ability to adapt to the structures of the oil cleanup and damage claims 

processes. This study also provides background information regarding the demographic structures of 

certain communities.

Incomplete or Unavailable Information 

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.23.2 of the 2012-

2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.2 of the 

CPA 235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information related 

to demographics in the CPA. This incomplete information may be relevant to evaluating adverse effects 

because the full extent of potential impacts on demographics is not known. This incomplete or 

unavailable information relates to translating employment impacts of OCS oil- and gas-related activities 

into estimated population impacts. This information cannot be obtained at this time due to data 
4-100 Central and Eastern Planning Areas Supplemental EIS

limitations and the complexity of methodologies needed to accurately estimate population impacts arising 

from OCS oil- and gas-related activities. BOEM plans to initiate a study project to analyze population 

impacts more fully, although this potential study project will not be completed within the timeline 

contemplated in the NEPA analysis of this Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions here. For example, BOEM used data from 

Woods & Poole Economics, Inc. (2014), which provides projections of the evolution of the total 

population in all EIAs in future years. These projections assume the continuation of existing social, 

economic, and technological trends at the time of the forecast. This incomplete or unavailable 

information is unlikely to significantly impact BOEM’s estimates of the impacts of OCS lease sales on 

demographics, in part because these impacts are fairly limited. In addition, increases in population arising 

from lease sales are generally positive, not adverse, impacts. Therefore, BOEM has determined that the 

incomplete or unavailable information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for demographics presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for demographics presented in those NEPA documents because the new 

Woods and Poole Economics, Inc. data did not change much from what was presented in those documents

because of the available scientifically credible evidence in this analysis and based upon accepted 

scientific methods and approaches. The analysis and potential impacts in those documents still apply for 

proposed CPA Lease Sales 241and 247.

4.1.1.23.3. Economic Factors

BOEM has reexamined the analysis for economic factors presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for economic factors presented in those NEPA documents. The analysis and 

potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts on 

economic factors from routine activities, accidental events, and cumulative events associated with a CPA 

proposed action are presented in Chapter 4.2.1.23.3 of the 2012-2017 WPA/CPA Multisale EIS. Updated 

information is provided in Chapter 4.2.1.23.3 of the WPA 233/CPA 231 Supplemental EIS and Chapter 

4.1.1.23.3 of the CPA 235/241/247 Supplemental EIS. The following is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new information that 

has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

As a result of proposed CPA Lease Sales 241 and 247, there would be only minor economic changes 

in the Texas, Louisiana, Mississippi, Alabama, and Florida EIAs. This is because the demand would be 

met primarily with the existing population and labor force. Most of the employment related to proposed 

CPA Lease Sales 241 and 247 is expected to occur in Texas (primarily in the EIA TX-3) and in the 

coastal areas of Louisiana. A CPA proposed action, irrespective of whether one analyzes the high-case or 

low-case production scenario, would not cause employment effects >1 percent in any EIA along the Gulf 

Coast.

Accidental events associated with a CPA proposed action, such as an oil spill, can cause a number of 

disruptions to local economies. Many of these effects are due to industries that depend on damaged 

resources. However, the impacts of an oil spill can be somewhat broader if companies further along 

industry supply chains are affected. These effects depend on issues such as the duration, methods, and 

logistics of the cleanup operations and the responses of policymakers to a spill. However, the impacts of 

small- to medium-sized spills should be localized and temporary.
Description of the Environment and Impact Analysis 4-101

Cumulative Impacts

The cumulative analysis considers the effects of OCS oil- and gas-related impact-producing factors 

along with non-OCS oil- and gas-related impact-producing factors that may occur and adversely affect 

economic factors in the same general area of a CPA proposed action. BOEM uses the model 

MAG-PLAN to determine the direct, indirect, and induced employment arising from a particular scenario 

for oil and gas exploration and development activities (i.e., drilling, platform installations, and structure 

removals). A CPA proposed action would not cause employment effects >1 percent in any EIA along the 

Gulf Coast. Oil spills can cause a number of disruptions to local economies; however, small- to mediumsized spills should have localized, temporary impacts. A low-probability catastrophic spill, which is not 

part of a CPA proposed action and not likely expected, would have more noticeable impacts to the 

economy. However, the likelihood of another spill of this scale is quite low. A detailed analysis of a 

low-probability catastrophic spill can be found in Appendix B. 

Non-OCS oil- and gas-related impact-producing factors that can affect economic trends in economic 

areas in the Gulf of Mexico region include commercial, military, recreation/tourism (refer to Chapter 

4.1.1.21), and numerous other offshore and coastal activities. To estimate the cumulative impacts to 

economic factors from non-OCS oil- and gas-related impact-producing factors, BOEM employs the 

economic and demographic projections from Woods & Poole Economics, Inc. (2014). These projections 

are based on local, regional, and national trend data, as well as likely changes to local, regional, and 

national economic and demographic conditions. Therefore, the projections include employment

associated with the continuation of current patterns in OCS oil- and gas-related leasing activity, as well as 

the continuation of trends in other industries important to the region. For example, these forecasts include 

the contributions of State oil and gas activities, renewable energy activities, coastal land use, and tourismrelated activities. The cumulative impacts of a CPA proposed action would be determined by the 

expected path of the economy and by the expected progression of the OCS oil and gas industry in 

upcoming years. The expected path of the overall economy is projected using the data provided by 

Woods and Poole Economics, Inc. (2014). The expected economic impacts of the OCS oil and gas 

industry in upcoming years are estimated using the mathematical model MAG-PLAN. The cumulative 

impacts of a CPA proposed action to the economies along the Gulf Coast are expected to be relatively 

small.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/ 241/247 Supplemental EIS 

BOEM conducted a search of Internet sources and known data sources regarding economic factors. 

Table 4-24 presents updated data from The Office of Natural Resources Revenue (2014) regarding sales 

volumes, sales values, and government revenues received from Federal offshore energy activities in the 

Gulf of Mexico. Panel A of Table 4-24 presents annual data regarding the quantities of royalty-bearing 

and nonroyalty-bearing sales volumes for natural gas, NGLs, and oil. In FY 2013, royalty-bearing natural 

gas sales continued on a long-term downward trend, falling from 1.12 billion Mcf (thousand cubic feet) in 

FY 2012 to 970 million Mcf in FY 2013. Sales volumes of royalty-bearing NGLs also continued on a 

steady downward trend in FY 2013, although sales volumes of nonroyalty-bearing NGLs increased in 

FY 2013 compared with FY 2012. Sales volumes of royalty-bearing oil increased in FY 2013, while 

sales volumes of nonroyalty-bearing oil decreased. Panel B of Table 4-24 presents the sales values of 

gas, NGLs, and oil produced in Federal areas in the Gulf of Mexico. Sales values of oil and natural gas 

increased, while sales values of NGLs decreased. The increase in the sales value of natural gas reflects 

the higher average price for natural gas in FY 2013 compared with FY 2012. Panel C of Table 4-24

presents the Federal Government revenues received from offshore energy activities in the Gulf of Mexico. 

The Federal Government received $8.86 billion in revenue from energy sales and from OCS oil and gas 

lease sales that occurred during FY 2013, which was larger than any amount received since FY 2008. 

This increased revenue reflects the higher energy prices that prevailed in FY 2013, as well as the large 

amount of bonus bid revenue received from offshore oil and gas lease sales.

The U.S. Department of Energy’s Energy Information Administration has released its 2014 Annual 

Energy Outlook (USDOE, Energy Information Administration, 2014k). This report provides forecasts 

regarding a wide variety of issues related to energy markets. For example, this report provides forecasts 

of the levels of oil and gas production and prices that will occur in Gulf offshore waters in future years. 
4-102 Central and Eastern Planning Areas Supplemental EIS

In its reference scenario, this report forecasts that, from 2012 through 2040, Gulf offshore oil production 

will decrease at an average annual rate of 2.7 percent rate in shallow waters and will increase at an 

average rate of 1.6 percent in deepwater areas. This report forecasts that, from 2012 through 2040, Gulf 

offshore natural gas production will decrease at an average annual rate of 1.2 percent in shallow waters 

and will increase at an average rate of 2.7 percent in deepwater areas. This report forecasts that oil prices 

will slightly decrease through 2017 before gradually increasing in subsequent years. Natural gas prices 

are forecasted to gradually increase in future years from the very low prices observed in recent years. 

This report also notes the uncertainties associated with these forecasts and presents results for various 

scenarios that make different assumptions regarding energy prices, regulatory changes, and the path of the 

overall economy.

A report conducted by Smith (2014) provides an overview of the status of the oil and gas industries, 

with an emphasis on the status of Louisiana’s energy industry. This report describes how the large-scale 

development of onshore shale oil and gas activities will impact the competitive environment for offshore 

oil and gas activities. The report forecasts that nearshore natural gas production will continue to decline 

but that this decline will be partially offset by higher energy production in certain deepwater areas. This 

report also describes how the low price of natural gas is diverting development and production activities 

from extracting natural gas to extracting oil and NGLs.

New reports have become available regarding certain industries that are involved with offshore oil 

and gas activities. Beaubouef (2014a) reports that drilling activity has slightly declined in recent months, 

in part due to rising costs. For example, there were about 1,921 months of backlogged contract drilling 

work in May 2014 compared with 2,017 months of work in December 2013. Workboat.com (2014b) 

reports that day rates for four of the five classes of supply boats, as well as for both of the two classes of 

crew boats, increased from April 2013 to April 2014. IHS Petrodata (2014) reports that, in July 2014, 

79 of 88 marketed drilling rigs were under contract; 77 of 81 drilling rigs were under contract in July 

2013. Finally, Beaubouef (2014b) discusses a number of recent field discoveries and expanded 

developments of existing fields, which should help to support future oil and gas development and 

production activities.

Austin et al. (2014a and 2014b) are two volumes of a recently completed study of the social impacts 

of the Deepwater Horizon oil spill. This study employed an ethnographic methodology that entailed 

analyzing data sources, examining various sources of descriptive information, and conducting field 

interviews with people in Louisiana, Mississippi, and Alabama. This study documents the complex and 

varied impacts of the Deepwater Horizon oil spill during the 20 months subsequent to the spill. This 

study found that the impacts of the spill on a particular community depended on a number of factors, such 

as its proximity to the spill, its economic structure, its social and political dynamics, its organizational 

structure for dealing with disasters, and its ability to adapt to the structures of the oil cleanup and damage 

claims processes. This study also provides background information regarding the economic structures of 

certain communities.

The impacts of a proposed CPA lease sale and the OCS Program should be viewed in the context of 

overall economic conditions. In Table 4-10, data from Woods and Poole Economics, Inc. (2014) is used 

to generate forecasts of overall employment in all EIAs during the life of activities that would arise from a 

proposed CPA lease sale; these employment forecasts assume the continued progression of offshore oil 

and gas exploration and development activities. From 2014 to 2055, the fastest employment growth is 

expected in EIA TX 3 (1.89%), TX-1 (1.73%), and FL-4 (1.64%); the slowest employment growth is 

expected in EIA MS-1 (0.84%) and LA-4 (0.95%). The growth forecasts from Woods and Poole 

Economics, Inc. (2014) show slight increases in the growth forecasts compared with the 2013 data in all 

EIAs except FL-2, whose forecasted employment growth slightly decreased compared with the 2013 data. 

Woods and Poole Economics, Inc. (2014) is also used to forecast various demographic variables; refer to 

Chapter 4.1.1.23.2 for more information regarding demographics. In general, the projections of these 

variables have not changed noticeably from the projections in the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/ Supplemental EIS.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 
Description of the Environment and Impact Analysis 4-103

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.2.1.23.3 of the 2012-

2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.3 of the 

CPA 235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information related 

to the potential impacts of CPA lease sales on economic factors. This information primarily relates to the 

onshore geographic distributions of economic impacts arising from the OCS Program, which would allow 

BOEM to better estimate routine and cumulative impacts. This information is difficult to obtain since 

most data sources do not adequately differentiate between onshore and offshore oil and gas activities.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing the relevant analysis and formulating the conclusions presented here. In particular, BOEM 

used the most recent version of MAG-PLAN to estimate the impacts of a CPA proposed action and the 

OCS Program. In addition, BOEM is planning to launch a study project to explore new avenues for 

improving BOEM’s information regarding onshore distributions, although this project will take time and 

funding to pursue. However, any new information regarding onshore distributions of economic impacts 

is unlikely to significantly change BOEM’s estimates of the impacts of the OCS Program. In addition, 

the economic impacts arising from the OCS Program are generally positive, not adverse. Therefore, 

BOEM has determined that the incomplete or unavailable information is not essential to a reasoned 

choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for economic factors presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for economic factors presented those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

CPA Lease Sales 241 and 247.

4.1.1.23.4. Environmental Justice

BOEM has reexamined the analysis for environmental justice presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented below. No new significant information was discovered that would 

alter the impact conclusion for environmental justice presented in those NEPA documents. The analyses 

and potential impacts discussed in those documents still apply for proposed CPA Lease Sales 241 and 

247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.23.4 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in Chapter 4.2.1.23.4 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.4 of the 

CPA 235/241/247 Supplemental EIS. The following information is a summary of the resource 

description and impact analysis incorporated from those NEPA documents. Any new significant 

information that has become available since those documents were published is presented below.

The oil and gas industry and its associated support sectors are interlinked and widely distributed along 

the Gulf Coast. Offshore OCS oil- and gas-related industry operations within the CPA may utilize 

onshore facilities located within the WPA, CPA, or both planning areas. This analysis focuses on 

potential disproportionate impacts to minority and low-income populations living onshore. BOEM 

conducts a county-level analysis to determine the concentration of minority and low-income populations 

located in the same counties/parishes as oil- and gas-related onshore coastal infrastructure (refer to 

Chapter 4.2.1.23.4.1 and Figures 4-26 through 4-35 of the 2012-2017 WPA/CPA Multisale EIS).

During the NEPA process, BOEM provides opportunities for public input, which includes minority 

and low-income populations Some of the numerous avenues for public outreach employed by BOEM 

include the following: specific types of notices that are (1) mailed to public libraries, interest groups, 

industry, the general public, local, State, and Federal agencies, and Tribal Nations; (2) published in local 

newspapers; (3) posted on the Internet; and (4) published in the Federal Register. These notices reflect 

the stages of the NEPA process and include the Notice of Intent to Prepare an EIS (NOI), the Call for 
4-104 Central and Eastern Planning Areas Supplemental EIS

Information (Call), and Notice of Availability (NOA) for the Draft Supplemental EIS. A series of 

specified time periods after the NOI, Call, and NOA allow for public comments, all of which are 

considered and addressed. The formal scoping process is initiated by the NOI and Call, and public 

scoping meetings are held in several geographically separate cities to allow for public discussion and 

questions, and to identify all stakeholders’ concerns. All public comments and responses to comments 

are published in the Draft and Final Supplemental EISs. A detailed discussion of the complete scoping 

process can be found in Chapter 1.4. Public comments and responses to comments can be found in 

Chapter 5.3.1. 

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors associated with a proposed CPA action that could 

affect environmental justice include the following: possible infrastructure changes or expansions 

including fabrication yards, support bases, and onshore disposal sites for offshore waste; increased 

commuter and truck traffic; and employment changes and immigration. Given the existing extensive and 

widespread support system for the OCS oil- and gas-related industry and its associated labor force, the 

effects of routine operations related to a CPA proposed action are expected to be widely distributed and to 

have little impact because a CPA proposed action would not significantly change the already existing 

conditions, such as traffic or the amount of infrastructure. Impacts related to routine operations are 

expected to be primarily economic in nature and to have a limited but positive effect because a CPA 

proposed action would contribute to the sustainability of the current industry, related support services, and 

associated employment, especially in Louisiana where an extensive concentration of OCS oil- and gasrelated infrastructure is located, e.g., Port Fourchon in Lafourche Parish. BOEM’s county-level analysis 

determined that there are limited concentrations of minority and low-income population adjacent to OCS 

oil- and gas-related coastal infrastructure. The routine operations associated with a CPA proposed action 

are not expected to have a disproportionate negative effect on these populations. Rather, a CPA proposed 

action would contribute to the maintenance of current OCS oil- and gas-related activity and employment 

levels, resulting in some beneficial direct and indirect effects to low-income and minority populations.

Accidental disturbances resulting from a CPA proposed action, including oil spills, vessel collision, 

blowouts, and chemical/ drilling fluids spills, have the potential to impact minority and low-income

populations through direct exposure to oil, dispersants, degreasers, and other chemicals that can affect 

human health; decreased access to natural resources due to environmental damages, fisheries closures, or 

wildlife contamination; and proximity to onshore disposal sites used in support of oil and chemical spill 

cleanup efforts. Oil, chemical, and drilling fluid spills may be associated with exploration, production, or 

transportation activities that result from a CPA proposed action. Low-income and minority populations 

might be more sensitive to spills in coastal waters than are the general population because of their 

potentially higher dietary reliance on wild coastal resources, reliance on these resources for other 

subsistence purposes such as sharing and bartering, limited flexibility in substituting wild resources with 

purchased ones, and likelihood of participating in cleanup efforts and other mitigating activities.

Little is known about subsistence along the Gulf Coast, and BOEM is currently funding a study to 

better document subsistence in the region.

As studies of past oil spills have highlighted, different cultural groups can possess varying capacities 

to cope with these types of events (Palinkas et al., 1992). Some minority and/or low-income groups may 

be more reliant on natural resources and/or less equipped to substitute contaminated or inaccessible 

natural resources with private market offerings than higher income level and/or nonminority groups. 

Because lower-income and/or minority populations may live near and may be directly involved with spill 

cleanup efforts, the vectors of exposure can be higher for them than for the general population, increasing 

the potential risks of long-term health effects. However, small-scale accidental oil spills, vessel collision, 

blowouts, and chemical/drilling fluids spills are not likely to be of sufficient size or duration to have 

adverse and disproportionate long-term effects for minority and low-income populations in the analysis 

area.

Cumulative Impacts

The cumulative analysis considers impacts that may result from a CPA proposed action within the 

context of OCS oil- and gas-related and non-OCS oil- and gas-related impact-producing factors for 
Description of the Environment and Impact Analysis 4-105

environmental justice. The OCS oil- and gas-related impact-producing factors include OCS leasing, 

exploration, development, and production activities and the accidental events arising from these OCS oiland gas-related activities. Non-OCS oil- and gas-related impact-producing factors include all human 

activities and natural events and processes. The context in which people may find themselves and how 

that context affects their ability to respond to an additional change in the socioeconomic or physical 

environment is the heart of an environmental justice analysis.

The OCS oil- and gas-related impact-producing factors include the OCS Program, which includes 

OCS oil and gas leasing, exploration, development, and production activities that could result in potential 

infrastructure changes/expansions, including fabrication yards, support bases, and onshore disposal sites 

for offshore waste; increased commuter and truck traffic; and employment changes and immigration, as 

well as accidental events arising from these OCS oil- and gas-related activities, such as oil spills, vessel 

collisions, chemical/drilling-fluid spills, and the resultant cleanup that may temporarily impact lowincome populations who may experience direct exposure to contaminants through subsistence and 

cleanup operations. However, this exposure is expected to be small scale and short term and not result in 

disproportionate long-term effects. A detailed analysis of a low-probability catastrophic event, such as 

the Deepwater Horizon explosion, oil spill, and response, can be found in Appendix B. In general, the 

cumulative OCS oil- and gas-related effects are expected to be economic, widely distributed, and to have 

a limited but positive effect on low-income and minority populations. In Louisiana, these positive 

economic effects are expected to be greater because of the existence of an extensive and widespread 

support system for OCS oil- and gas-related activities and associated labor force, especially in Lafourche 

Parish, Louisiana, where Port Fourchon is located. Given the existing distribution of the OCS oil and gas 

industry and the limited concentrations of minority and low-income populations near oil and gas 

infrastructure, based on county-level analysis, a CPA proposed action and the cumulative OCS Program 

are not expected to have disproportionate high/adverse environmental or health effects on minority or 

low-income populations.

Non-OCS oil- and gas-related cumulative effects cover a wide range of potential impact-producing 

factors, including all human activities and natural events and processes that are not related to OCS oiland gas-related activities in Federal waters. Some of the human activities that may disproportionately 

affect low-income and minority populations include, but are not limited to, the following: urbanization; 

pollution (air, light, noise, garbage dumping, and contaminated runoff); commercial/residential/

agricultural development; zoning ordinances; community development strategies (multi-purpose and 

single-use); expansions to the Federal, State and local highway systems; expansions to regional port 

facilities; military activities; demographic shifts (in-migration and out-migration); economic shifts on the 

national, State and local levels (job creation and job losses); educational systems (quality, availability, 

expansions or contractions); family support systems (availability, proximity and quality of mental health 

services, foster care, charity hospital systems, addictive disorders rehabilitation centers, family planning 

services, early learning programs, etc.); governmental functions (municipal waterworks systems, sewage 

systems, tax structures, revenue collection, law enforcement, fire protection, traffic control, voting 

processes, legislative processes, court procedures and processes, real estate property assessments, 

construction permits, environmental protection services, land-use permits, etc.); contraction or expansion 

of the tourism industry; financial system (banking and investment services); State renewable energy

activities; river channelization; dredging of waterways; State oil and gas activity; existing infrastructure

associated with downstream activities such as petrochemical processing; and public health issues.

While human activities are extensive and nearly all-encompassing, there are a substantial number of 

natural events and processes that may be classified as non-OCS oil- and gas-related cumulative effects 

that may disproportionally affect low-income and minority populations including: oyster reef 

degradation; saltwater intrusion; sedimentation of rivers; sediment deprivation; barrier island migration 

and erosion; fish kills; red tide; beach strandings; coastal erosion/subsidence; sea-level rise; and coastal 

storms. Both human-induced and natural factors, unrelated to OCS oil- and gas-related activities, could 

affect minority and low-income populations through exposure to high levels of pollution, job loss, 

reduced social services, adverse infrastructure siting, decreased tourism, public health issues, 

displacement, and increased risk of adverse impacts from storm surge, reduced opportunities for 

subsistence activities, and vulnerability of coastal communities to name a few. For a detailed discussion 

of these non-OCS oil- and gas-related cumulative effects on low income and minority populations, refer 

to Chapter 4.1.1.23.4 of the CPA 235/241/247 Supplemental EIS.
4-106 Central and Eastern Planning Areas Supplemental EIS

To summarize, the cumulative effects of a CPA proposed action on minority and low-income

populations would be concentrated in coastal areas, and particularly in Louisiana. Most OCS Program 

effects are expected to make a positive contribution to minority and low-income populations by helping to 

maintain current employment levels and contributing to economic stimulation. The contribution of the 

cumulative OCS Program to the cumulative impacts of all factors affecting environmental justice is 

expected to be minor; therefore, the incremental contribution of a CPA proposed action to the cumulative 

impacts would also be minor. State offshore leasing programs have similar, although more limited, 

effects due to their smaller scale. Cumulative effects from onshore infrastructure, including waste 

facilities, are also expected to be minor because existing infrastructure is regulated, because little new 

infrastructure is expected to result in the cumulative case, and because any new infrastructure will be 

subject to relevant permitting requirements. While all human activities and natural events and processes 

also may raise environmental justice issues, the cumulative consequences to environmental justice cannot 

be determined. The enormity of such a task i.e., the time, labor, and funds that would be necessary to 

assess and analyze the entirety of non-OCS oil- and gas-related factors’ impacts, would not be cost 

effective or even possible to accomplish. When added to existing State and Federal leasing programs, the 

associated onshore infrastructure, onshore and offshore OCS oil- and gas-related activities and all of the 

non-OCS oil- and gas-related impacting factors, a single proposed CPA lease sale would make miniscule 

contributions to the cumulative effects on minority and low-income populations.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of various information sources and trade publications (U.S. Department of Health and 

Human Services, National Institutes of Health; USEPA; USDOC, Bureau of the Census and Bureau of 

Labor Statistics; U.S. Department of Homeland Security, Federal Emergency Management Agency; 

RestoreTheGulf.gov website; Deepwater Horizon Claims Center; Deepwater Horizon Oil Spill Portal; 

Louisiana Department of Environmental Quality; Mississippi Department of Environmental Quality; 

Alabama Department of Environmental Management; State of Florida Department of Environmental 

Protection; Louisiana Recovery Authority; Louisiana Office of Community Development; The Greater 

Lafourche Port Commission; LA1 Coalition; Reuters; Rigzone; Oil and Gas Journal; and The Oil Drum), 

as well as recently published journal articles, was conducted to determine the availability of recent 

information on environmental justice. The search revealed the following new information on claims and 

human health impacts from the Deepwater Horizon explosion, oil spill, and response. This information is 

important because it expands our knowledge of the baseline environment following the Deepwater 

Horizon explosion, oil spill, and response.

The remaining Deepwater Horizon medical claims that were on appeal before the U.S. Court of 

Appeals for the Fifth Circuit were dismissed on February 11, 2014, and the effective date of the 

Deepwater Horizon Medical Benefits Settlement is February 12, 2014 (Deepwater Horizon CourtSupervised Settlement Program 2014). An Advisory regarding the Economics & Property Damages 

Settlement was issued. Even though the deadline to file claims in the Seafood Compensation Program 

was January 22, 2013, the Claims Administrator developed a “Procedure for Handling Untimely Seafood 

Claims,” which will allow the submittal of late claims with deadline extension requests. The procedure is 

located in the “Alerts” section of the Deepwater Horizon economic settlement website (Deepwater 

Horizon Claims Center, 2013). 

The Deepwater Horizon Research Consortia, headed by the National Institute for Environmental 

Health Sciences, developed university-community partnerships to address health effects resulting from 

the Deepwater Horizon explosion, oil spill, and response. The intent is that the Consortia’s research 

findings will inform community preparedness and disaster response, thereby limiting disaster-related 

health impacts, e.g., exposure to contaminants, emotional distress, and diet changes (National Institute of 

Environmental Health Sciences, 2014a). The funding allocation of $25.2 million is being spread across 

the Gulf region to fund numerous studies through several universities, covering several kinds of research 

topics. A few examples include the following: oil-spill impacts to the health of women and their 

children; Gulf resilience and women’s health; oil-spill impacts on pregnant women; seafood safety; 

individual, family, and community resilience along the Gulf Coast; social capital and resilience; and 

community/individual network building (Louisiana State University Health Sciences Center, School of 
Description of the Environment and Impact Analysis 4-107

Public Health, 2014; Tulane University, 2014; Center for Gulf Coast Environmental Health, 2014; 

University of Florida, 2014; Weiss, 2014).

The National Institute of Environmental Health Sciences’ ongoing GuLF Study (“Gulf Long-term 

Follow-up Study”) has completed Phase 1 and has started Phase 2 as of April 2014. Of the 33,000 

participants, preliminary findings from the first health exam indicated that cleanup workers were about 

30 percent more likely to report moderate to severe depression, anxiety, and stress than participants who 

did no cleanup work. Researchers stated that it is unclear whether these mental health impacts were the 

result of exposure to spilled oil and/or dispersants or some other factor of the oil-spill experience and its 

aftermath. Cleanup workers also reported more physical symptoms, such as coughing, wheezing, and 

shortness of breath, than did those who were not cleanup workers. Some of the workers still reported 

these symptoms 3 years after the spill. However, it is too early to determine if cleanup exposures will 

lead to chronic diseases such as cancer or lung disease. Researchers stressed the importance of 

participants continuing in the 10-year study so that any potential long-term health impacts may be 

discovered (National Institute of Environmental Health Sciences, 2014b).

A new study published in April 2014, The Coastal Index: The Problem and Possibility of Our Coast, 

developed new indicators to measure progress toward sustainability in southeast Louisiana (Hobor et al., 

2014). Population shifts in coastal areas were tracked, and the study analyzed whether water management 

activities may diversify the regional economy toward a more positive trajectory. The study establishes a 

baseline from which social change may be measured in the future. As many people have been moving 

farther from the coast to avoid landloss, flooding, and coastal subsidence, low-income populations have 

not been able to relocate as readily, especially in areas such as Theriot and Dulac, Louisiana, where the 

poverty rates are over 40 percent. The study suggests that increases in water management activities such 

as diversions, hydraulic restoration, marsh creation, and barrier island restoration will produce positive 

economic benefits that will affect everyone, including low-income and minority populations (Hobor et al., 

2014).

A recently released BOEM-funded study, Offshore Oil and Deepwater Horizon: Social Effects on 

Gulf Coast Communities—Volume I: Methodology, Timeline, Context, and Communities; and Volume II: 

Key Economic Sectors, NGOs, and Ethnic Groups (Austin et al., 2014a and 2014b), researched the social 

impacts of the Deepwater Horizon from April 2010 through December 2012. The study sought to 

accurately describe and document how the Deepwater Horizon explosion, oil spill, and response was 

experienced and understood by the people it affected most directly as the events surrounding the spill 

unfolded. An ethnographic approach with several field workers in Louisiana, Mississippi, and Alabama 

coastal communities, the study did not attempt to quantify economic losses. The study found that the spill 

affected many different groups of people and individuals across the Gulf region. The economic effects 

were felt in the offshore oil and gas industry, commercial and recreational fishing industries, and tourism

industries, as well as oil and gas support sector services and other businesses from caterers to retail outlets 

and restaurants. Local and State governments and nongovernmental and community-based organizations 

were affected by the loss of revenues and by the need to respond to the economic needs of the people in 

the region. Programs such as BP’s Vessels of Opportunity and claims processes, aiming to mitigate 

negative economic conditions, had mixed results, with positive impacts distributed in a seemingly random 

manner through the communities. The ability of individuals and communities to secure resources 

depended on their political and legal status. The disaster did not generate the sorts of volunteer 

opportunities that follow hurricanes. With disasters such as hurricanes, the allocation of funds for social 

services is outlined explicitly in the Stafford Act, establishing a mechanism to help nonprofit 

organizations respond as needed, but there is no provision for social services to help people recover under 

the Oil Pollution Act of 1990. Environmental justice-focused nongovernmental organizations (NGOs) 

found that funding resources after the spill were scarce because the spill was not designated a Federal 

disaster. The failure to declare this event a Federal disaster exacerbated its effects. People who would 

have normally donated funds to NGOs were not donating because they viewed it as BP’s responsibility to 

fund the recovery (Austin et al., 2014a and 2014b).

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 
4-108 Central and Eastern Planning Areas Supplemental EIS

unavailable information. As discussed in this Supplemental EIS, as well as in the previously mentioned 

NEPA documents, BOEM has identified unavailable information regarding the impacts of the Deepwater

Horizon explosion, oil spill, and response related to environmental justice. This information cannot be 

obtained because long-term health impact studies, subsistence studies, and the NRDA process are 

ongoing, and data from these efforts will be unavailable and unobtainable until the studies and NRDA 

process are complete. In order to fill this data gap, BOEM used existing information and reasonably 

accepted scientific methodologies to extrapolate from available information in completing the relevant 

analysis including limited information that has been released after the Deepwater Horizon explosion, oil 

spill, and response and studies of past oil spills, which indicate that a low-probability, catastrophic oil 

spill, which is not part of a CPA proposed action and not likely expected, may have significant adverse 

impacts on lower-income and minority communities. Long-term effects are unknown at this time, but so 

far there has been little concrete evidence thathealth or subsistence effects have occurred (Brown et al., 

2011; Dickey, 2012; King and Gibbons, 2011; Middlebrook et al., 2012; U.S. Dept. of Labor, 

Occupational Safety and Health Administration, 2010a and 2010b), although there is some dispute in the 

scientific community about proper risk assessment standards in seafood contamination research (RotkinEllman et al., 2012; Rotkin-Ellman and Soloman, 2012). In addition, some studies have shown that 

different cultural groups can possess varying levels of coping capacities (Palinkas, 1992), and impacts to 

social cohesion, including increased distrust in government and other institutions, contributed to 

community anxiety (Tuler et al., 2009). Also, because lower-income and/or minority populations may 

live near and be involved directly with spill cleanup efforts, the vectors of exposure can be higher for 

them than for the general population, increasing the potential risks of long-term health effects. Therefore, 

because long-term health and subsistence impacts and to low-income and minority populations are 

unknown, this information may be relevant to the evaluation of impacts from the Deepwater Horizon

explosion, oil spill, and response to environmental justice. However, a subsistence study and long-term 

health studies are pending and will not be available within the timeline contemplated in the NEPA 

analysis of this Supplemental EIS. BOEM will continue to seek additional information as it becomes 

available and bases the previous analysis on the best information currently available. Although long-term 

health or subsistence impacts to minority and low-income populations may be relevant to this analysis, 

BOEM has determined that the incomplete information is not essential to a reasoned choice among 

alternatives based on the information discussed above.

Summary and Conclusion

BOEM has reexamined the analysis for environmental justice presented in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on 

the additional information presented above. No new significant information was discovered that would 

alter the impact conclusion for environmental justice presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts in those documents still apply for proposed CPA Lease 

Sales 241 and 247.

4.1.1.24. Species Considered due to U.S. Fish and Wildlife Service Concerns

BOEM has reexamined the analysis for species considered due to FWS concerns presented in the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for species considered due to FWS concerns

presented in those NEPA documents. The analysis and potential impacts discussed in those documents 

still apply for proposed CPA Lease Sales 241 and 247.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with a CPA proposed action are 

presented in Chapter 4.2.1.24 of the 2012-2017 WPA/CPA Multisale EIS. Updated information is 

provided in the WPA 233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS. The 

following information is a summary of the resource description and impact analysis incorporated from 

those NEPA documents. Any new information that has become available since those documents were 

published is presented below.
Description of the Environment and Impact Analysis 4-109

The species considered are the Louisiana black bear (Ursus americanus luteolus), gopher tortoise 

(Gopherus polyphemus), Alabama red-belly turtle (Pseudemys alabamensis), ringed map turtle 

(Graptemys oculifera), black pine snake (Pituophis melanoleucus lodingi), yellow-blotched map turtle 

(Graptemys flavimaculata), eastern indigo snake (Drymarchon corais couperi), Mississippi gopher frog 

(Rana capito sevosa), frosted flatwoods salamander (Ambystoma cingulatum), reticulated flatwoods 

salamander (Ambystoma bishopi), pallid sturgeon (Scaphirhynchus albus), pearl darter (Percina aurora), 

inflated heelsplitter (Potamilus inflatus), Louisiana quillwort (Isoetes louisianensis), and telephus spurge 

(Euphorbia telephioides). Some species considered due to FWS concerns are discussed in other chapters 

of this Supplemental EIS. The conclusions for the following species can be found in their respective 

chapters: West Indian manatee (Chapter 4.2.1.12); green, hawksbill, Kemp’s ridley, leatherback, and 

loggerhead sea turtles (Chapter 4.2.1.13); and red knot (Calidris canutus rufa), piping plover, whooping 

crane, and mountain plover (Chapter 4.2.1.16). 

Impacts of Routine Activities and Accidental Events

Adverse impacts due to routine activities resulting from a CPA proposed action such as operational 

discharges, noise, and marine debris are possible but unlikely. Lethal effects could occur from ingestion 

of released plastic materials from OCS oil- and gas-related vessels and facilities. However, there have 

been no reports to date on such incidences. Because of the mitigations that may be implemented 

(Chapter 2.3.1.3), routine activities (e.g., operational discharges, noise, and marine debris) related to a 

CPA proposed action are not expected to have long-term adverse effects on the size and productivity of 

any of these species or populations in the Gulf of Mexico. Greatly improved handling of waste and trash

by industry and annual awareness training required by the marine debris mitigations are reducing the 

amount of plastics in the ocean, and therefore minimizing the devastating effects on offshore and coastal 

marine life. The routine activities of a CPA proposed action are unlikely to have significant adverse 

effects on the size and recovery of any of the above-mentioned species or populations in the GOM due to 

the distance of most activities, the heavy regulation of infrastructure and pipelines, and permitting and 

siting requirements.

Accidental blowouts, oil spills, and spill-response activities resulting from a CPA proposed action 

have the potential to impact small to large areas in the Gulf of Mexico with physical oiling and habitat 

destruction. The severity of impacts depends on the magnitude and frequency of accidents, the ability to 

respond to accidents, the location and date of accidents, and various meteorological and hydrological 

factors (including tropical storms). Adverse impacts due to accidental events are also likely to be 

minimal because the habitats utilized by the species considered are far from OCS oil- and gas-related 

activities and are inland. Therefore, a CPA proposed action would be expected to have little or no effect 

on these species of concern.

Cumulative Impacts

The cumulative analysis considers activities that have occurred, are currently occurring, and could 

occur and adversely affect species considered due to FWS concerns. The OCS oil- and gas-related 

activities that could impact species considered due to FWS concerns include operational discharges, 

noise, marine debris, blowouts, oil spills, and spill response activities. Routine activities are not 

anticipated to impact these species because of the mitigations and regulations implemented by BOEM, 

and accidental events are expected to be minimal to these species because the habitats utilized by the 

species considered are far from OCS oil- and gas-related activities and are inland. A low-probability 

catastrophic spill, which is not part of a CPA proposed action and not likely expected, could impact 

species considered due to FWS concerns and is discussed in Appendix B. 

Non-OCS oil- and gas-related activities that could impact species considered due to FWS concerns

include State oil and gas activities, other governmental and private projects and activities, hurricanes, and 

natural processes and events that may occur and that adversely affect wetland habitat. Non-OCS oil- and 

gas-related activities posing the greatest potential harm to species considered due to FWS concerns are 

factors such as habitat loss and ecological competition. These factors have historically proved to be of 

greater threat to these species of concern. Impacts may also occur to these species if a hurricane passes 

over an oil spill or causes spills itself. However, at this time, there is no known record of a hurricane 

crossing the path of a large oil spill; the impacts of such have yet to be determined. The experience from 
4-110 Central and Eastern Planning Areas Supplemental EIS

Hurricanes Katrina and Rita in 2005 was that the oil released during the storms widely dispersed as far as 

the surge reached, reducing impacts from concentrated oil exposure (USDOC, NOAA, 2010).

Non-OCS oil- and gas-related activities have a greater potential to impact species considered due to 

FWS concerns than OCS oil- and gas-related activities, especially those factors that contribute to habitat 

loss. Because these species rely on terrestrial habitats to carry out their life-history functions at a 

considerable distance from the GOM, the activities of a CPA proposed action are unlikely to have 

significant adverse effects on the size and recovery of any of the above populations. Therefore, the 

incremental contribution of a CPA proposed action would not be likely to result in a significant 

incremental impact on these species within the CPA.

New Information Available Since Publication of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS 

A search of information sources (FWS’s websites), as well as recently published journal articles was

conducted to determine the availability of recent information on species considered due to FWS concerns. 

The search revealed no new information pertinent to this Supplemental EIS.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the lack of new information 

does not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in Chapter 4.2.1.24 of the 2012-2017 WPA/CPA Multisale EIS 

and WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.24 of the CPA 235/241/247 Supplemental 

EIS, BOEM has identified incomplete information on the impacts to species considered due to FWS 

concerns as a result of the Deepwater Horizon explosion, oil spill, and response because little data have 

been released to the public. As data continue to be gathered and impact assessments completed, a better 

characterization of the full scope of impacts to populations in the GOM from the Deepwater Horizon

explosion, oil spill, and response will be available. Relevant data on the status of populations after the 

Deepwater Horizon explosion, oil spill, and response may take years to acquire and analyze, and impacts 

from the Deepwater Horizon explosion, oil spill, and response may be difficult or impossible to discern 

from other factors. Therefore, it is not possible for BOEM to obtain this information within the timeline 

contemplated in the NEPA analysis of this Supplemental EIS, regardless of the cost or resources needed. 

In light of the incomplete or unavailable information, BOEM’s subject-matter experts have extrapolated 

from available scientifically credible evidence in this analysis. Based on life histories of these species 

and the fact that they live inland, BOEM has determined that these species within the CPA were not 

affected to any discernible degree by the Deepwater Horizon explosion, oil spill, and response. Although 

the body of available information is incomplete, the information extrapolated from life history of the 

species and distance of the Macondo well from their habitats was sufficient to draw reasonable 

conclusions that they should not have been impacted by the Deepwater Horizon explosion, oil spill, and 

response; therefore, BOEM has determined that the incomplete information is not essential to a reasoned 

choice among alternatives.

Summary and Conclusion

There is a long-standing and well-developed OCS Program of more than 50 years within the CPA, 

and there are no data to suggest that activities from the preexisting OCS Program are significantly 

impacting the above-mentioned species populations; therefore, a CPA proposed action would be expected 

to have little or no effect on the above-mentioned species. Because of the mitigations that may be 

implemented, routine activities (e.g., operational discharges, noise, and marine debris) related to a CPA 

proposed action are not expected to have long-term adverse effects on the size and productivity of any of 

these species or populations in the GOM. Lethal effects could occur from ingestion of accidentally 

released plastic materials from OCS oil- and gas-related and non-OCS oil- and gas-related vessels and 

facilities. However, there have been no reports to date on such incidences. BOEM employs several 

measures (e.g., marine debris mitigations) to reduce the potential impacts to any animal from routine 

activities associated with a CPA proposed action. Accidental blowouts, oil spills, and spill response 
Description of the Environment and Impact Analysis 4-111

activities resulting from a CPA proposed action have the potential to impact small to large areas in the 

GOM, depending on the magnitude and frequency of accidents, the ability to respond to accidents, the 

location and date of accidents, and various meteorological and hydrological factors (including tropical 

storms). The incremental contribution of a CPA proposed action would not be likely to result in a 

significant incremental impact on the above-mentioned species within the CPA; in comparison, non-OCS 

oil- and gas-related activities, such as habitat loss and competition, have historically proven to be a 

greater threat to the above-mentioned species.

BOEM has reexamined the analysis for species considered due to FWS concerns presented in the 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for species considered due to FWS concerns 

presented in those NEPA documents. The analysis and potential impacts discussed in those documents 

still apply for proposed CPA Lease Sales 241 and 247.

4.1.2. Alternative B—Exclude the Unleased Blocks Near Biologically Sensitive 

Topographic Features

Description of the Alternative

Alternative B differs from Alternative A (the Proposed Action) by not offering blocks that are 

possibly affected by the proposed Topographic Features Stipulation (Chapter 2.3.1.3.1 of this 

Supplemental EIS and Chapter 2.4.1.3.1 of the 2012-2017 WPA/CPA Multisale EIS). All of the 

assumptions (including the nine other potential mitigating measures) and estimates are the same as for the 

proposed action (Alternative A). A description of Alternative A is presented in Chapter 2.3.1.1. There 

are 207 blocks (962,470 ac) in the CPA in which the Topographic Features Stipulation may be applied 

(Figure 2-1). The currently unleased blocks with these features would not be available for lease under 

Alternative B during this proposed lease sale. The number of unleased blocks that would not be offered 

under Alternative B represents only a small percentage of the total number of blocks to be offered under 

Alternative A; therefore, it is assumed that the levels of activity for Alternative B would be essentially the 

same as those projected for a CPA proposed action (refer to Chapter 2.3.2 for further details). The 

estimated amount of resources projected to be developed under Alternative B is within the same scenario 

range as for Alternative A, i.e., 0.116-0.200 BBO and 0.538-0.938 Tcf of gas.

All of the assumptions, including the nine other potential stipulations (i.e., the Live Bottom

Stipulation; Military Areas Stipulation; Evacuation Stipulation; Coordination Stipulation; Blocks South of 

Baldwin County, Alabama, Stipulation; Protected Species Stipulation; United Nations Convention on the 

Law of the Sea Royalty Payment Stipulation; Below Seabed Operations Stipulation; and the Stipulation 

on the Agreement between the United States of America and the United Mexican States Concerning 

Transboundary Hydrocarbon Reservoirs in the Gulf of Mexico, as described in Chapter 2.2.1.3), are the 

same as for a CPA proposed action (Alternative A). A description of Alternative A is presented in 

Chapter 2.3.1.1. The Topographic Features Stipulation would not be applied with Alternative B because 

the blocks that could be affected by the Topographic Features Stipulation would not be offered for lease.

Because the incremental contribution of Alternative A (the Proposed Action) to the cumulative 

impacts on topographic features is expected to be slight and because negative impacts should be restricted 

by the implementation of the Topographic Features Stipulation and site-specific mitigations, the depths of 

the features, and water currents in the topographic feature area, Alternative A is not expected to result in 

adverse impacts greater than Alternative B. Therefore, since both Alternatives A and B minimize the 

potential for adverse impacts to Topographic Features, but since Alternative A better meets the purpose 

and need by providing a greater level of flexibility when considering oil and gas exploration, 

development, and production activities, Alternative A is BOEM’s preferred alternative.

Effects of the Alternative

The following analyses are based on the scenario for a CPA proposed action (Alternative A). The 

scenario provides assumptions and estimates on the amounts, locations, and timing for OCS oil- and gasrelated exploration, development, and production operations and facilities, both offshore and onshore. 

These are estimates only and not predictions of what would happen as a result of holding proposed CPA 
4-112 Central and Eastern Planning Areas Supplemental EIS

Lease Sales 241 and 247. A detailed discussion of the scenario and related impact-producing factors is 

presented in Chapter 3.1 of this Supplemental EIS and in Chapter 3.1 of the 2012-2017 WPA/CPA 

Multisale EIS, and updated information is provided in Chapter 3.1 of the WPA 233/CPA 231 

Supplemental EIS and CPA 235/241/247 Supplemental EIS.

The analyses of impacts to the various resources under Alternative B are very similar to those for 

Alternative A. The reader should refer to the appropriate discussions under Alternative A for additional 

and more detailed information regarding impact-producing factors and their expected effects on the 

various resources. Impacts under Alternative B are expected to be the same as a CPA proposed action 

(Chapter 4.1.1) for the following resources:

— Air Quality

— Water Quality

— Coastal Barrier Beaches and Associated 

Dunes

— Wetlands

— Seagrass Communities

— Live Bottoms (Pinnacle Trend and 

Low Relief) 

— Sargassum Communities

— Chemosynthetic and Nonchemosynthetic 

Deepwater Benthic Communities

— Soft Bottom Benthic Communities

— Marine Mammals

— Sea Turtles

— Diamondback Terrapins

— Beach Mice

— Coastal and Marine Birds

— Gulf Sturgeon

— Fish Resources and Essential Fish 

Habitat

— Commercial Fisheries

— Recreational Fishing

— Recreational Resources

— Archaeological Resources

— Human Resources and Land Use

The impacts to some Gulf of Mexico resources under Alternative B would be slightly different from 

the impacts expected under a CPA proposed action (Alternative A). These impacts are described below.

Impacts on Topographic Features

The sources and severity in impacts associated with this alternative are those lease sale-related 

activities discussed for a CPA proposed action. The potential impact-producing factors to the topographic 

features of the CPA are anchoring and structure emplacement, effluent discharge, blowouts, oil spills, and 

structure removal. A more detailed discussion of these potential impact-producing factors and the 

appropriate mitigating measures are presented in Chapter 2.3.1.3.1 of this Supplemental EIS and Chapter 

2.4.1.3.1 of the 2012-2017 WPA/CPA Multisale EIS.

Impacts of Routine Activities and Accidental Events

Of the 16 topographic features in the CPA, 15 are located within water depths less than 200 m 

(656 ft). Geyer Bank is located in water depths of 190-210 m (623-689 ft). These features occupy a very 

small portion of the entire area. Of the potential impact-producing factors that may affect the topographic 

features, anchoring, structure emplacement, and structure removal would be eliminated by the adoption of 

this alternative. Effluent discharge and blowouts would not be a threat to the topographic features 

because blocks near enough to the banks for these events to have an impact on the biota of the banks 

would have been excluded from leasing under this alternative. Thus, the only impact-producing factor 

remaining from operations in blocks included in this alternative (i.e., those blocks not excluded by this 

alternative) is an oil spill. The potential impacts from oil spills are summarized below and are discussed 

further in Chapter 3.2.1 of this Supplemental EIS and Chapter 3.2.1 of the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS.

A subsurface spill would have no effect on a biologically sensitive feature unless the oil or its 

dissolved components comes into direct contact with the habitat. Oil from a subsurface spill is expected 

to rise to the sea surface, based on the specific gravity of Gulf of Mexico oil. An exception to this could 

occur if oil is released at the seafloor under high pressure, having the effect of atomizing the oil into 

micro-droplets that have very little buoyancy. Under these conditions, a subsea oil plume could form and 

travel laterally with the prevailing currents. This can also happen if chemical dispersants are used 

underwater, forming a plume. If a subsea oil plume does form, the oil is expected to be swept clear of the 
Description of the Environment and Impact Analysis 4-113

banks because prevailing currents travel around the banks rather than over them (Rezak et al., 1983). As 

the oil travels in the water column, it will become diluted from its original concentration. Transient 

concentrations of oil below 20 ppm are not expected to result in lasting harm to a coral reef (Shigenaka, 

2001). The fact that the topographic features are widely dispersed in the CPA, combined with the random 

nature of spill events, would serve to limit the likelihood of a spill occurring near a topographic feature. 

In addition, the exclusion of blocks adjacent to topographic features from a proposed CPA lease sale 

would further distance potential spills from the habitat. Chapter 4.2.1.7 of the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS discusses 

the risk of spills interacting with topographic features in more detail. The currents that move around the 

banks would likely steer any spilled oil around the banks rather than directly upon them, lessening impact 

severity. In the unlikely event that oil from a subsurface spill would reach the biota of a topographic 

feature, the effects would be primarily sublethal for most of the adult sessile biota. Lethal effects would 

probably be limited to a few coral colonies (CSA, 1992 and 1994). If oil from a subsurface spill 

contacted a coral-covered area, the areal extent of coral mortality would be limited, but long-lasting 

sublethal effects may be incurred by organisms surviving the initial effects of a spill (Jackson et al., 

1989). Stress resulting from the oiling of reef coral colonies could affect their resilience to natural 

disturbances (e.g., elevated water temperature and diseases) and may hamper their ability to reproduce. A 

complete recovery of such an affected area could take in excess of 10 years.

Cumulative Impacts

With the exception of the topographic features, the cumulative impacts of Alternative B on the 

environmental and socioeconomic resources of the CPA would be identical to Alternative A. The 

incremental contribution of a CPA proposed action to the cumulative impacts on topographic features is 

expected to be slight, and negative impacts should be restricted by the implementation of the Topographic 

Features Stipulation and site-specific mitigations, the depths of the features, and water currents in the 

topographic feature area.

Summary and Conclusion

Alternative B, if adopted, would prevent any OCS oil- and gas-related activity whatsoever in the 

blocks containing topographic features and their surrounding protective zones ; thus, it would eliminate 

any potential direct impacts to the biota of those blocks from routine oil- and gas-related activities within 

the blocks. In the unlikely event that oil from a subsurface spill contacts the biota of a topographic 

feature, the effects would be localized and primarily sublethal for most of the adult sessile biota. Some 

lethal effects would probably occur upon oil contact to coral colonies.

Environmental impacts of Alternative B would be almost indistinguishable from Alternative A with 

the Topographic Features Stipulation in place. There would be an economic impact to the extent that 

economic returns from the excluded lease blocks would not be realized.

4.1.3. Alternative C—No Action 

Description of the Alternative

Alternative C is the cancellation of a proposed CPA lease sale. If this alternative is chosen, the 

opportunity for development of the estimated 0.460-0.894 BBO and 1.939-3.903 Tcf of gas that could 

have resulted from a proposed CPA lease sale would be precluded during the current 2012-2017 FiveYear Program, but it could again be contemplated as part of a future Five-Year Program. The No Action 

alternative encompasses the same potential impacts as a decision to delay a proposed CPA lease sale to a 

later scheduled lease sale under the Five-Year Program, when another decision on whether to hold that 

future lease sale is made. Delay of a proposed CPA lease sale was not considered as a separate alternative 

from Alternative C because the potential impacts are the same, namely that most impacts related to 

Alternative A would not occur as described below. Any potential environmental impacts resulting from a 

proposed CPA lease sale would not occur or would be postponed to a future lease sale decision. This 

alternative is also analyzed in the EIS for the 2012-2017 Five-Year Program on a nationwide 

programmatic level.
4-114 Central and Eastern Planning Areas Supplemental EIS

Effects of the Alternative

This Agency published a report that examined previous exploration and development activity 

scenarios (USDOI, MMS, 2007b). This Agency compared forecasted activity with the actual activity 

from 14 WPA and 14 CPA lease sales. The report shows that many lease sales contribute to the present 

level of OCS oil- and gas-related activity, and any single lease sale accounts for only a small percentage 

of the total OCS oil- and gas-related activities. In 2006, leases from 92 different sales contributed to Gulf 

of Mexico production. An average WPA lease sale contributed to 3 percent of oil production and 

3 percent of gas production in the WPA, while an average CPA lease sale contributed to 2 percent of oil 

production and 2 percent of gas production in the CPA. In 2006, leases from 15 different sales 

contributed to the installation of production structures in the Gulf of Mexico. An average WPA lease sale 

contributed to 6 percent of the installation of production structures in the WPA, while an average CPA 

lease sale contributed to 6 percent of the installation of production structures in the CPA. In 2006, leases 

from 70 different sales contributed to wells drilled in the Gulf of Mexico. An average WPA lease sale 

contributed to 6 percent of the wells drilled in the WPA, while an average CPA lease sale contributed to 

4 percent of the wells drilled in the CPA.

As in the past, a proposed CPA lease sale would contribute to maintaining the present level of OCS 

oil- and gas-related activity in the Gulf of Mexico. Exploration and development activity, including 

service-vessel trips, helicopter trips, and construction that would result from a proposed CPA lease sale 

would replace activity resulting from existing leases that have reached, or are near the end of, their 

economic life.

In the short term, however, it is important to note that activities under previous lease sales would 

continue in the Gulf of Mexico, including exploration, development, production, and decommissioning

activities. As a decision on a proposed CPA lease sale will not affect those preexisting leases and 

activities related to them, there may still be environmental impacts occurring in the Gulf in the short term, 

even if a proposed CPA lease sale is cancelled.

Environmental Impacts

If a proposed CPA lease sale would be cancelled, the resulting development of oil and gas would 

most likely be postponed to a future lease sale; therefore, the overall level of OCS oil- and gas-related 

activity in the CPA would only be reduced by a small percentage, if any. Therefore, the cancellation of a 

proposed CPA lease sale would not significantly change the environmental impacts of overall OCS oiland gas-related activity in the long term. The environmental impacts expected to result from a CPA 

proposed action, which are described above, would not occur in the short term, but they would likely be 

postponed to any future lease sale.

Economic Impacts 

Although environmental impacts may be reduced or postponed by cancelling a proposed CPA lease 

sale, the economic impacts of cancelling the scheduled lease sale should be given consideration. Chapter 

4.2.1.23.3 of the 2012-2017 WPA/CPA Multisale EIS, Chapter 4.2.1.23.3 of the WPA 233/CPA 231 

Supplemental EIS, and Chapter 4.1.1.23.3 of the CPA 235/241/247 Supplemental EIS discuss the 

potential economic impacts of a CPA proposed action. In the event that a proposed CPA lease sale is 

cancelled or postponed, there may be impacts to employment along the Gulf Coast, but these are not 

expected to be significant (e.g., less than 1% of total employment) or long term given the existing OCS 

infrastructure. 

Federal, State, and local governments would also have to forgo the revenue that would have been 

received from a proposed CPA lease sale. There could be minor impacts on global energy prices from 

cancelling a proposed CPA lease sale, along with minor changes in energy consumption patterns that 

would result from these price changes.

Other factors may minimize or exacerbate the economic impacts of cancelling a proposed CPA lease 

sale. For example, the longer-term economic impacts of cancelling a CPA proposed lease sale could be 

minimized if they were offset by a larger lease sale at a later date. The economic impacts may be 

exacerbated if additional lease sales are cancelled. The OCS industry is dependent on high capital 

investment costs and there may be long lags between the lease sale and the majority of production 

activities. Therefore, firms’ investment and spending decisions are dependent on their confidence that the 
Description of the Environment and Impact Analysis 4-115

OCS Program will be maintained in the future. In addition, while firms in the OCS industry are generally 

likely to be able to weather the cancellation of a single lease sale, the cancellation of multiple lease sales 

could lead to broader damage to firms and workers in the industry or decisions to operate in areas other 

than the Gulf. These economic impacts would be particularly damaging to the coastal counties and 

parishes in Texas and Louisiana for which the OCS industry as a whole is an important component of 

their economies.

Summary and Conclusion

Cancelling a proposed CPA lease sale would eliminate the effects described for Alternative A 

(Chapter 4.1.1); however, any single lease sale in the CPA accounts for only a small percentage of the 

total OCS oil- and gas-related activities in the GOM. If a proposed CPA lease sale would be cancelled, 

the resulting development of oil and gas would most likely be postponed to a future lease sale; therefore, 

the overall level of OCS oil- and gas-related activity in the CPA would only be reduced by a small 

percentage, if any. Therefore, the cancellation of a proposed CPA lease sale would not significantly 

change the environmental impacts of overall OCS oil- and gas-related activity in the long term.

Federal, State, and local governments would have to forgo the revenue that would have been received 

from a proposed CPA lease sale. There could be minor impacts on global energy prices from cancelling a 

proposed CPA lease sale, along with minor changes in energy consumption patterns that would result 

from these price changes. Other factors may minimize or exacerbate the economic impacts of cancelling 

a proposed CPA lease sale.

4.2. PROPOSED EASTERN PLANNING AREA LEASE SALE 226

Proposed EPA Lease Sale 226 is tentatively scheduled to be held in March 2016. The proposed EPA 

lease sale area covers approximately 657,905 ac and includes those blocks previously included in the EPA 

Lease Sales 224 and 225 Area and a triangular-shaped area south of this area bordered by the CPA 

boundary on the west and the Military Mission Line (86o41′ W. longitude) on the east. The area is south 

of eastern Alabama and western Florida; the nearest point of land is 125 mi (201 km) northwest in 

Louisiana. As of September 2014, approximately 465,200 ac of the proposed EPA lease sale area are 

currently unleased. This information is updated monthly and can be found on BOEM’s website at

http://www.boem.gov/Gulf-of-Mexico-Region-Lease-Map/. The EPA proposed action would offer for 

lease all unleased blocks within the proposed EPA lease sale area for oil and gas operations (Figure 1-1). 

The DOI is conservative throughout the NEPA process and includes the total area within the EPA for 

environmental review even though the leasing of portions of the EPA (subareas or blocks) can be deferred 

during a Five-Year Program.

Chapter 4.2.1 presents a brief summary of the baseline data for the physical, biological, and 

socioeconomic resources that would potentially be affected by the EPA proposed action or the alternative. 

For additional information on the baseline data for the physical, biological, and socioeconomic resources 

that would potentially be affected by the EPA proposed action or the alternative, refer to Chapter 4.1 of 

the EPA 225/226 EIS.

Chapter 4.2.1 also presents analyses of the potential impacts of routine events, accidental events, and 

cumulative activities associated with the EPA proposed action or the alternative on these resources. 

Baseline data are considered in the assessment of impacts from proposed EPA Lease Sale 226 on these 

resources. In addition, Appendix B (“Catastrophic Spill Event Analysis”) serves as a complement to this 

chapter and provides additional analysis of the potential impacts of a low-probability catastrophic oil 

spill, which is not part of the EPA proposed action and not likely expected, to the environmental and 

cultural resources and the socioeconomic conditions analyzed below.

The Deepwater Horizon explosion off the Louisiana coast resulted in the largest oil spill in U.S. 

history. An event such as this has the potential to adversely affect multiple resources over a large area. 

The level of adverse effect depends on many factors, including the sensitivity of the resource as well as 

the sensitivity of the environment in which the resource is located. All effects may not initially be seen 

and some could take years to fully develop. The following analyses of impacts from the Deepwater 

Horizon explosion, oil spill, and response on the physical, biological, and socioeconomic resources are 

based on post-Deepwater Horizon credible scientific information that was publicly available at the time 

this document was prepared. This credible scientific information was applied using accepted 
4-116 Central and Eastern Planning Areas Supplemental EIS

methodologies, including numerical modeling of data and scientific writing methods to convey the 

information of BOEM’s subject-matter experts’ technical knowledge and experience. However, the 

Trustee Council of the NRDA for the Deepwater Horizon oil spill continues to study, measure, and 

interpret impacts arising out of that spill. Because the NRDA information has not yet been made 

available to BOEM or the general public, there are thus instances in which BOEM is faced with 

incomplete or unavailable information that may be relevant to evaluating reasonably foreseeable 

significant adverse impacts on the human environment. While incomplete or unavailable information 

could conceivably result in potential future shifts in baseline conditions of habitats that could affect 

BOEM’s decisionmaking, BOEM has determined that there is sufficient basis to proceed with this 

Supplemental EIS while operating on the basis of the most current available data and expertise of 

BOEM’s subject-matter experts.

Chapter 4.2.1 and Appendix B provide a summary of existing credible scientific evidence related to 

this issue and BOEM’s evaluation of potential impacts based upon theoretical approaches or research 

methods generally accepted in the scientific community. Despite the unavailability of complete 

information from the NRDA process, BOEM has determined that it can make an informed decision even 

without this incomplete or unavailable information because BOEM utilizes the best available 

scientifically credible information in its decisionmaking process and because, although BOEM cannot 

speculate as to the results of ongoing NRDA studies, BOEM experts can apply other scientifically 

credible information using accepted theoretical approaches and research methods, such as information on 

related or surrogate species. Moreover, BOEM will continue to monitor these resources for effects 

caused by the Deepwater Horizon explosion, oil spill, and response, and will ensure that future BOEM 

environmental reviews take into account any new information that may emerge. 

Chapter 3.2.1 of this Supplemental EIS provides a brief summary of the information on accidental 

spills that could result from all operations conducted under the OCS Program, as well as information on 

the number and sizes of spills from non-OCS sources. Table 3-10 of the EPA 225/226 EIS provides the 

number of spills ≥1,000 bbl and <1,000 bbl estimated to occur as a result of the EPA proposed action. 

BOEM estimates that the mean number of spills ≥1,000 bbl for the EPA proposed action is <1 spill. 

Table 3-10 of the EPA 225/226 EIS provides spill rates for several spill-size categories. Chapter 3.2.1.7 

and Figures 3-8 through 3-23 of the EPA 225/226 EIS describe the probabilities of a spill ≥1,000 bbl 

occurring and contacting modeled environmental resources. For additional information on accidental 

spills that could result from all operations conducted under the OCS Program, as well as information on 

the number and sizes of spills from non-OCS sources, refer to Chapter 3.2.1 of this Supplemental EIS 

and Chapter 3.2.1 of the EPA 225/226 EIS.

Analytical Approach

The analyses of potential effects to the wide variety of physical, environmental, and socioeconomic 

resources in the vast area of the GOM and adjacent coastal areas is very complex. Specialized education, 

experience, and technical knowledge are required, as well as familiarity with the numerous impactproducing factors associated with oil and gas activities and other activities that can cause cumulative 

impacts in the area. Knowledge and practical working experience of major environmental laws and 

regulations such as NEPA, the Clean Water Act, Clean Air Act, Coastal Zone Management Act (CZMA), 

Endangered Species Act (ESA), Marine Mammal Protection Act (MMPA), the Magnuson-Stevens 

Fishery Conservation and Management Act, and others are also required.

In order to accomplish this task, BOEM has assembled a multidisciplinary staff with hundreds of 

years of collective experience. The vast majority of this staff has advanced degrees with a high level of 

knowledge related to the particular resources discussed in this chapter. This staff prepares the input to 

BOEM’s lease sale EISs and a variety of subsequent postlease NEPA reviews, and they are also involved 

with ESA, essential fish habitat (EFH), and CZMA consultations. In addition, this same staff is also 

directly involved with the development of studies conducted by BOEM’s Environmental Studies 

Program. The results of these studies feed directly into our NEPA analyses.

For this Supplemental EIS, BOEM developed a set of assumptions and a scenario, and described the 

impact-producing factors that could occur from routine oil and gas activities, as well as accidental events. 

These assumptions, scenario, and factors are summarized in Chapter 3 of this Supplemental EIS and are 

discussed in detail in Chapter 3 of the EPA 225/226 EIS. On the basis of these assumptions, scenario, 
Description of the Environment and Impact Analysis 4-117

and factors, BOEM’s multidisciplinary staff applies its knowledge and experience to analyze the potential 

effects that could arise out of proposed EPA Lease Sale 226.

For most resources, the conclusions developed by BOEM’s subject-matter experts regarding the 

potential effects of proposed EPA Lease Sale 226 are necessarily qualitative in nature; however, these 

conclusions are based on the expert opinion and judgment of highly trained subject-matter experts. 

BOEM’s staff approaches this effort in good faith utilizing credible scientific information including, but 

not limited to, information available since the Deepwater Horizon explosion, oil spill, and response, and 

applying this information using accepted methodologies, including numerical modeling of data and 

scientific writing methods to convey the information of the subject-matter experts’ technical knowledge 

and experience. It must also be emphasized that, in arriving at the overall conclusions for certain 

environmental resources (e.g., coastal and marine birds, fisheries, and wetlands), the conclusions are not 

based on impacts to individuals, small groups of animals, or small areas of habitat, but on impacts to the 

resources/populations as a whole. Where relevant information on reasonably foreseeable significant 

adverse impacts is incomplete or unavailable, the need for the information was evaluated to determine if it 

was essential to a reasoned choice among the alternatives. If BOEM’s subject-matter experts determined 

that the incomplete or unavailable information was essential, BOEM made good faith efforts to acquire 

the information. In the event that BOEM was unable to obtain essential information due to either 

impossibility or exorbitant cost, BOEM applied accepted scientific methodologies in place of that 

information. This approach is described in the next subsection on “Incomplete or Unavailable 

Information.”

Over the years, BOEM has developed a suite of lease stipulations and mitigating measures to 

eliminate or ameliorate potential environmental effects. In many instances, these lease stipulations and 

mitigating measures were developed in coordination with other natural resource agencies such as NMFS 

and FWS.

Throughout its effort to prepare this Supplemental EIS, BOEM has made painstaking efforts to 

comply with the spirit and intent of NEPA, to avoid being arbitrary and capricious in its analyses of 

potential environmental effects, and to use adaptive management to respond to new developments related 

to the OCS Program.

Incomplete or Unavailable Information

In the following analyses of physical, environmental, and socioeconomic resources, BOEM identifies 

situations in which its analysis contains incomplete or unavailable information. The major area where 

BOEM is faced with incomplete or unavailable information is in relation to the Deepwater Horizon

explosion, oil spill, and response. Information related to the explosion, oil spill, and response is still 

being collected, interpreted, and analyzed by a myriad of Federal and State agencies. With respect to 

some of this information, including much of the data related to the NRDA process, those in charge of 

analyzing impacts from the spill have not yet shared their data and findings with BOEM or made this 

information publicly available. Therefore, in situations in which BOEM’s subject-matter experts were 

faced with incomplete or unavailable information, the subject-matter experts for each resource utilized the 

most recent publicly available, scientifically credible information from other sources to support the 

conclusions contained in this Supplemental EIS. This information is identified and summarized in 

Chapter 4.2.1 of this Supplemental EIS and is discussed in detail for each resource in Chapter 4.1 of the 

EPA 225/226 EIS. In certain circumstances, identified and described in more detail in Chapter 4.2.1 of 

this Supplemental EIS, BOEM’s subject-matter experts were required to utilize accepted methodologies 

to extrapolate conclusions from existing or new information and to make reasoned estimates and 

developed conclusions regarding the current CPA baseline for resource categories and expected impacts 

from a CPA proposed action given any baseline changes. For reasons described below, there are no 

changes to the conclusions presented in the EPA 225/226 EIS.

It is important to note that, barring another catastrophic oil spill, which is a low-probability accidental 

event, the adverse impacts associated with a proposed EPA lease sale are small, even in light of the 

Deepwater Horizon explosion, oil spill, and response. This is because of draft lease sale stipulations and 

because of BOEM’s and other Federal and State entities’ mitigating measures. BOEM also imposes sitespecific mitigations that become conditions of plan or permit approval at the postlease stage. 

Collectively, these measures further reduce the likelihood of adverse impacts.
4-118 Central and Eastern Planning Areas Supplemental EIS

For the following resources, as with the EPA 225/226 EIS, the subject-matter experts determined that 

there is incomplete or unavailable information that is relevant to reasonably foreseeable significant 

adverse impacts; however, it is not essential to a reasoned choice among alternatives.

• Air Quality (Chapter 4.2.1.1) 

• Water Quality (Coastal and Offshore) (Chapters 4.2.1.2.1 and 4.2.1.2.2,

respectively)

• Coastal Barrier Beaches and Associated Dunes (Chapter 4.2.1.3) 

• Wetlands (Chapter 4.2.1.4) 

• Sargassum Communities (Chapter 4.2.1.8) 

• Chemosynthetic Deepwater Benthic Communities (Chapter 4.2.1.9)

• Nonchemosynthetic Deepwater Benthic Communities (Chapter 4.2.1.10)

• Soft Bottom Benthic Communities (Chapter 4.2.1.11) 

• Beach Mice (Chapter 4.2.1.15) 

• Commercial Fisheries (Chapter 4.2.1.18) 

• Recreational Fishing (Chapter 4.2.1.19) 

• Recreational Resources (Chapter 4.2.1.20) 

• Archaeological Resources (Historic and Prehistoric) (Chapters 4.2.1.21.1 and 

4.2.1.21.2, respectively)

• Human Resources and Land Use (Land Use and Coastal Infrastructure, 

Demographics, and Economic Factors) (Chapters 4.2.1.22.1, 4.2.1.22.2, and 

4.2.1.22.3, respectively)

• Species Considered due to U.S. Fish and Wildlife Service Concerns (Chapter 

4.2.1.23) 

For the following resources, BOEM’s subject-matter experts determined that there is incomplete or 

unavailable information that is relevant to reasonably foreseeable significant adverse impacts and may be 

essential to a reasoned choice among alternatives, for the reasons described in the chapters identified 

below. BOEM’s subject-matter experts determined that, in many instances, the cost of obtaining the 

information was exorbitant or that, regardless of cost, it could not be obtained within the timeline 

contemplated in the NEPA analysis of this Supplemental EIS. In place of the incomplete or unavailable 

information, BOEM’s subject-matter experts used what scientifically credible information was available 

and applied it using accepted scientific methodologies.

• Seagrass Communities (Chapter 4.2.1.5) 

• Live Bottoms (Pinnacle Trend and Low Relief) (Chapters 4.2.1.6) 

• Topographic Features (Chapter 4.2.1.7) 

• Marine Mammals (Chapter 4.2.1.12) 

• Sea Turtles (Chapter 4.2.1.13) 

• Diamondback Terrapins (Chapter 4.2.1.14) 

• Coastal and Marine Birds (Chapter 4.2.1.16) 

• Fish Resources and Essential Fish Habitat (includes Gulf sturgeon) (Chapter 

4.2.1.17) 
Description of the Environment and Impact Analysis 4-119

• Human Resources and Land Uses (Environmental Justice) (Chapter 4.2.1.22.4) 

This chapter has thoroughly examined the existing credible scientific evidence that is relevant to 

evaluating the reasonably foreseeable significant adverse impacts of the proposed EPA lease sale area on 

the human environment. The subject-matter experts that prepared this Supplemental EIS conducted a 

diligent search for pertinent new information, and BOEM’s evaluation of such impacts is based upon 

theoretical approaches or research methods generally accepted in the scientific community. All 

reasonably foreseeable impacts were considered, including impacts that could have catastrophic

consequences, even if their probability of occurrence is low (Appendix B). Throughout this chapter, 

where information was incomplete or unavailable, BOEM complied with its obligations under NEPA to 

determine if the information was relevant to reasonably foreseeable significant adverse impacts; if so, 

whether it was essential to a reasoned choice among alternatives; and, if it is essential, whether it can be 

obtained and whether the cost of obtaining the information is exorbitant, as well as whether generally 

accepted scientific methodologies can be applied in its place (40 CFR § 1502.22).

4.2.1. Alternative A—The Proposed Action

4.2.1.1. Air Quality

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for air quality presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for air quality presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.1 of the EPA 225/226 EIS and Chapter 4.2.1.1 of the 2012-2017 WPA/CPA 

Multisale EIS. As noted in Chapter 4.1.1.1 of the EPA 225/226 EIS, OCS oil and gas operations west of 

87.5o W. longitude fall under BOEM’s jurisdiction for purposes of the Clean Air Act. The OCS waters 

east of 87.5o W. longitude are under the jurisdiction of USEPA. The proposed EPA lease sale area falls 

east of 87.5o W. longitude, where jurisdiction is assigned to USEPA. Updated information is provided in 

Chapter 4.2.1.1 of the WPA 233/CPA 231 Supplemental EIS and Chapters 4.1.1.1 of the CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The following routine activities associated with the EPA proposed action would potentially affect air 

quality: platform construction and emplacement; platform operations; drilling activities; flaring; seismicsurvey and support-vessel operations; pipeline laying and burial operations; evaporation of volatile 

petroleum hydrocarbons during transfers; and fugitive emissions. These activities could result in 

emissions that are released to the atmosphere and then influenced by meteorology on air quality. This 

impact analysis is based on four parameters—emission rates, surface winds, atmospheric stability, and 

mixing height (refer to Appendix G of the EPA 225/226 EIS for details on air quality modeling). 

Emissions of pollutants into the atmosphere from the activities associated with the EPA proposed action 

are projected to have minimal effects on onshore air quality because of the distance from shore where the 

emissions are released and dilution before they reach shore, as well as the prevailing atmospheric 

conditions; emission rates and mixing heights; and the resulting pollutant concentrations.
4-120 Central and Eastern Planning Areas Supplemental EIS

Accidental events that may cause impacts to air quality include the release of oil, condensate, natural 

gas, chemicals used offshore, or pollutants from the burning of these products, as well as blowouts and 

fires. The accidental release of hydrocarbons related to the EPA proposed action may result in the 

emission of air pollutants. The air pollutants include criteria NAAQS pollutants, volatile and semivolatile organic compounds, H2S, and methane. If a fire was associated with the accidental event, it could 

produce a broad array of pollutants, including NAAQS-regulated primary pollutants, NO2, CO, SO2, 

VOC, PM10, and PM2.5. Response activities to an accidental event that could impact air quality include 

in-situ burning, the use of flares to burn gas and oil, and the use of dispersants applied from aircraft. 

Measurements taken during an in-situ burning show that a major portion of compounds was consumed in 

the burn (Fingas et al., 1995), and it was found that, during the burn, the pollutants were measured only at 

background levels; therefore, pollutant concentrations would be expected to be within the NAAQS. 

These response activities are temporary in nature and occur offshore; therefore, there are little expected 

impacts from these actions to onshore air quality. Accidents involving high concentrations of H2S could 

result in human deaths as well as environmental damage. Regulations and NTLs mandate safeguards and 

protective measures, which are in place to protect workers from H2S releases. Overall, since blowouts 

and fires are rare events and are of short duration, the potential impacts to air quality are not expected to 

be significant.

Cumulative Impacts

The cumulative analysis considers OCS oil- and gas-related and non-OCS oil- and gas-related 

activities that could occur and adversely affect onshore air quality from OCS oil- and gas-related sources 

during the 40-year analysis period. The OCS oil- and gas-related activities that could impact air quality 

include the following: platform construction and emplacement; platform operations; drilling activities; 

flaring; seismic-survey and support-vessel operations; pipeline laying and burial operations; evaporation 

of volatile petroleum hydrocarbons during transfers; fugitive emissions; the release of oil, condensate, 

natural gas, and chemicals used offshore, or pollutants from the burning of these products; blowouts; a 

low-probability catastrophic spill, which is not part of the EPA proposed action and not likely expected

(refer to Appendix B for more details); and fires. Emissions of pollutants into the atmosphere from 

activities associated with the OCS Program are not projected to have significant effects on onshore air 

quality because of the prevailing atmospheric conditions, emission rates and heights, and the resulting 

pollutant concentrations, which result in dilution of the emissions offshore before they reach the 

shoreline. In the EPA, the impacts of the OCS oil- and gas-related emissions on the onshore air quality 

are below the USEPA’s Significant Impact Levels (SILs) and BOEM’s Significance Levels, and they are 

well below the NAAQS. However, onshore impacts on air quality from emissions from OCS oil- and 

gas-related activities are estimated to be within the Prevention of Significant Deterioration (PSD) Class II 

allowable increments. The only potential exception is for ozone, where there may be some minimal 

contribution to ozone at the shoreline.

Non-OCS oil- and gas-related activity includes both marine and onshore industries and activities that 

are unrelated to oil and gas exploration and production. The non-OCS oil- and gas-related activities in the 

cumulative scenario that could potentially impact onshore air quality include the following: State oil and 

gas programs; other major offshore but non-OCS oil- and gas-related factors influencing offshore 

environments (such as sand borrowing and transportation); onshore non-OCS oil- and gas-related 

activities such as emissions from industry (including major stationary sources, e.g., power plants, 

petroleum refineries and chemical plants) and mobile sources (cars/trucks) related to human activities; 

onshore non-OCS oil- and gas-related sources unrelated to human activities such as forest fires; accidental 

releases from an oil spill; accidental releases of hydrogen sulfide; and natural events (e.g., hurricanes). 

The non-OCS oil- and gas-related activity on the water that would most likely contribute to cumulative 

impacts to air quality would be the marine shipping or transportation industry. Industrial activity in the 

industrial areas of the Gulf region and emissions from cars in areas with high populations are the onshore 

sources that would contribute to the cumulative impact to air quality. These offshore and onshore 

emissions sources generate greater amounts of pollutants than OCS oil- and gas-related activities. Human 

populations reside near these same industries because they offer employment, and therefore humans 

encounter more air contaminants as a result of non-OCS oil- and gas-related activities than they do from 

the OCS Program. These non-OCS oil- and gas-related sources would represent the majority of the 

cumulative emissions that are present at onshore locations.
Description of the Environment and Impact Analysis 4-121

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of State and Federal databases, including updates to regulations, was conducted to determine 

the availability of recent information. It has been discovered that Birmingham, Alabama, is no longer in 

nonattainment for any NAAQS criteria pollutant. The search revealed new information on the 

hydrofracking of oil onshore and intercontinental sources of fine particles in the atmosphere since 

publication of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS. This information is pertinent to this 

Supplemental EIS because it details new information on non-OCS oil- and gas-related impacts to the 

environment.

New information indicates that intercontinental dust transport may have impacts on air quality. For 

example, dust from Central America has been found in the Texas atmosphere. Fine particulates (PM2.5), 

such as ammonium sulfate, can be suspended in the atmosphere and can impair visibility and adversely 

affect human health. Once in the atmosphere, these fine particulates can be transported for long 

distances. It has been observed that a substantial amount of the fine particulates observed in Texas comes 

from Mexico and Central America, and enters into the United States across Texas’ southern border. As a 

result, it reduces the visibility at Big Bend and Guadalupe Mountains National Parks, both Class I 

(pristine with respect to visibility) areas. The results of air dispersion modeling indicate that as much as 

half of the visibility impairment (occurring on 20% of the most visibility impaired days) at Big Bend 

comes from international transport (Texas Commission on Environmental Quality, 2014). These results 

indicate that an increase in visibility impairment in Texas is likely due to international transport of dust 

rather than OCS oil- and gas-related emission sources. The trade winds have an east-to-west direction 

and the concentration of PM2.5 in Texas is lower than at the source of origin. Because of the long 

distances that can be covered, intercontinental dust may affect other regions of the Gulf Coast, including 

those of the EPA.

New information indicates that hydrofracking of oil may also cause potential health and 

environmental effects. Some of the pollutants released by hydrofracking include benzene, toluene, xylene 

and ethyl benzene (BTEX); particulate matter and dust; ground-level ozone; nitrogen oxides; carbon 

monoxide; formaldehyde; and metals contained in diesel fuel combustion. These pollutants can travel in 

the atmosphere. The exposure to these chemicals could cause short-term effects to human health and the 

environment (Climate Science Watch, 2014). This information indicates that hydrofracking may result in 

more impacts to human health and the environment onshore than offshore OCS oil- and gas-related 

activities.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined the new information does not 

change conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. However, as discussed in this 

Supplemental EIS and in Chapter 4.1.1.1 of the EPA 225/226 EIS, Chapter 4.2.1.1 of the 2012-2017 

WPA/CPA Multisale EIS and WPA 233/CPA231 Supplemental EIS, and Chapter 4.1.1.1 of the CPA 

235/241/247 Supplemental EIS, BOEM has identified incomplete or unavailable information regarding 

air impacts from the Deepwater Horizon explosion, oil spill, and response in the EPA, as well as 

limitations resulting from air quality modeling.

Although final summary information and reports on air quality impacts from the Deepwater Horizon

explosion, oil spill, and response may be forthcoming, the final and conclusive information is not 

available at this time and will not be available within the timeline contemplated in the NEPA analysis of 

this Supplemental EIS. This unavailable information may be relevant to adverse effects and possible 

long-term effects because air emissions could have reached land or dispersed throughout the EPA before 

oil-spill response was activated. BOEM used reasonably accepted scientific methodologies to extrapolate 

from available information on air quality measurements taken by Federal agencies in completing the 

relevant analysis to determine air impacts (USEPA, 2010; de Gouw et al., 2011). Limited data released to 

the public and obtained from USEPA, the National Oceanic and Atmospheric Administration, and other 

agencies indicated that air impacts tended to be minor and below USEPA’s health-based standards. Data 
4-122 Central and Eastern Planning Areas Supplemental EIS

obtained from USEPA, the National Oceanic and Atmospheric Administration, and other agencies do not 

reveal reasonably foreseeable significant adverse impacts, and because there are no continuing sources of 

air pollution related to the Deepwater Horizon explosion, oil spill, and response, BOEM would not expect 

any additional measurements or information to alter the conclusions from currently existing data. 

Therefore, BOEM has determined that the information is not essential to a reasoned choice among 

alternatives.

In addition, as noted in Appendix G of the EPA 225/226 EIS, there are a number of competing 

methods and available models for estimating and tracking potential air emissions and impacts. Each of 

these methods and models has inherent limitations, particularly with regard to the offshore environment in 

which the EPA proposed action would take place. BOEM’s Offshore and Coastal Dispersion Model, 

which was used for this environmental impact assessment (Appendix G of the EPA 225/226 EIS), has 

limitations such that it is a short-range dispersion model and it does not involve the reactive chemical. In 

acknowledgement of these limitations, BOEM’s subject-matter experts, using their best professional 

judgment and experience, have developed conservative assumptions and modeling parameters so as to 

ensure that the impact conclusions herein are reasonable and not underestimated (refer to Appendix G of 

the EPA 225/226 EIS for the modeling analysis). The modeling that was conducted was overly 

conservative. All of the emissions during 1 year for the entire EPA, which would actually be dispersed 

throughout the EPA, were modeled as if they originated in a single block, i.e., De Soto Canyon Block 

548. This block was selected because it represented a location where the water is deep enough that a 

dynamically positioned drillship would be used and where hydrocarbons are probably present. Although 

there are limitations in air quality modeling, the evidence currently available and that was used to develop 

conservative assumptions supports past analyses and does not indicate severe adverse impacts to air 

quality.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing the relevant analysis and formulating the conclusions presented here. Although there is 

incomplete or unavailable information, the evidence currently available supports past analyses and does 

not indicate reasonably foreseeable significant adverse impacts. Therefore, BOEM has determined that 

this information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for air quality presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for air quality presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. Emissions of pollutants into the atmosphere from the routine activities and accidental events

associated with the EPA proposed action are projected to have minimal impacts to onshore air quality, 

and emissions of pollutants into the atmosphere from activities associated with the OCS Program are also

not projected to have significant effects on onshore air quality. The non-OCS oil- and gas-related 

emission sources of intercontinental origin and the hydrofracking of oil may have the potential to impact 

onshore air quality and human health. However, the new information does not alter previous impact 

conclusions for air quality. The analysis and potential impacts discussed in the previously mentioned 

NEPA documents still apply for proposed EPA Lease Sale 226.

4.2.1.2 Water Quality

4.2.1.2.1. Coastal Waters

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for coastal water quality presented in the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 
Description of the Environment and Impact Analysis 4-123

was discovered that would alter the impact conclusion for coastal water quality presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

Coastal waters within the EPA, as defined by BOEM, include all the bays and estuaries from the 

Alabama/Florida State border along the west coast of Florida. A detailed description of the affected 

environment and the full analyses of the potential impacts of routine activities, accidental events, and 

cumulative impacts associated with the EPA proposed action are presented in Chapter 4.1.1.2.1 of the 

EPA 225/226 EIS and Chapter 4.2.1.2.1 of the 2012-2017 WPA/CPA Multisale EIS. Updated 

information is provided in Chapter 4.1.1.2.1 of the WPA 233/CPA 231 Supplemental EIS and CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The routine activities associated with the EPA proposed action that would impact coastal water 

quality include the following:

• discharges during drilling of exploration and development wells;

• structure installation and removal;

• discharges during production;

• installation of pipelines; 

• workovers of wells,

• maintenance dredging of existing navigational canals;

• service-vessel discharges; and

• nonpoint-source runoff from platforms and OCS Program-related vessels.

The primary impacting sources to water quality in coastal waters from oil and gas exploration and 

production activities are point-source and storm-water discharges from support facilities, vessel 

discharges, and nonpoint-source runoff. These activities are not only highly regulated but also localized 

and temporary in nature. The impacts to coastal water quality from routine activities associated with the 

EPA proposed action should be minimal because of the distance to shore of most routine activities, 

USEPA and USCG regulations that restrict discharges, and few, if any, new pipeline landfalls or onshore 

facilities that would be constructed.

Accidental events resulting from the EPA proposed action, including oil spills and blowouts, have the 

potential to alter and degrade coastal waters through the increase of petroleum hydrocarbons and their 

various transformation/degradation products in the water.

Accidental events associated with the EPA proposed action that could impact coastal water quality

include spills of oil and refined hydrocarbons, releases of natural gas, spills of chemicals or drilling fluids, 

loss of well control, pipeline failures, collisions, or other malfunctions that would result in such spills. In 

the case of an accidental event, it is likely that response efforts would reduce the amount of oil. Although 

response efforts may decrease the amount of oil in the environment, the response efforts may also impact 

the environment. Increased vessel traffic, hydromodification (e.g., dredging, berm building, boom 

deployment, etc.), and the addition of dispersants and methanol to the marine environment in an effort to 

contain, mitigate, or clean up the oil may also tax the environment. Chapter 3.2.1.9 provides further 

discussion of oil-spill response considerations. A major hurricane can affect OCS oil- and gas-related 

activities and result in a greater number of coastal oil and chemical spill events with increased spill 

volume and oil-spill response times.

In addition to response efforts, natural processes can physically, chemically, and biologically degrade 

oil over time. For coastal spills, two additional factors that must be considered are the shallowness of the 

area and the proximity of the spill to shore. Chemicals used in the oil and gas industry are not a 

significant risk in the event of a spill because they are either nontoxic, are used in minor quantities, or are 
4-124 Central and Eastern Planning Areas Supplemental EIS

only used on a noncontinuous basis. Spills from collisions are not expected to be significant because 

collisions occur infrequently.

Cumulative Impacts

Coastal waters are vulnerable to impacts from OCS oil- and gas-related activities including erosion 

and runoff, sediment disturbance and turbidity, vessel discharges, and accidental releases of oil, gas, or 

chemicals. Increased turbidity and discharge from the EPA proposed action would be temporary in nature 

and minimized by regulations and mitigation. Since a catastrophic OCS Program-related accident, though 

not part of the EPA proposed action and not likely expected, would be rare and not expected to occur in 

coastal waters, the impact of accidental spills is expected to be small. A low-probability catastrophic 

spill, which is not part of the EPA proposed action and not likely expected, is discussed in Appendix B. 

Coastal waters are vulnerable to impacts from non-OCS oil- and gas-related activities or activities not 

related to the EPA proposed action or the OCS Program, including State oil and gas activities, alternative 

energy activities, alternate use programs for platforms (e.g., aquaculture), sand borrowing, the activities 

of other Federal agencies (including the military), natural events or processes, and activities related to the 

direct or indirect use of land and waterways by the human population. These activities may result in 

erosion and runoff, sediment disturbance and turbidity, vessel discharges, and accidental releases of oil, 

gas, or chemicals.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

Various Internet sources were examined and literature searches conducted in order to assess the 

availability of new information regarding the water quality and sediment quality in coastal waters that 

may be pertinent to the EPA proposed action. The searches included, but were not limited to, Google, 

Google Scholar, several USEPA websites, and the NOAA Central Library Deepwater Horizon: A 

Preliminary Bibliography of Published Research and Expert Commentary website. New information was 

found on the affected environment after the Deepwater Horizon explosion, oil spill, and response. The 

following summary discusses new research regarding the distribution of hydrocarbons from the 

Deepwater Horizon release and biological degradation processes that have been found in the presence of 

the hydrocarbons.

Liu and Liu (2013) investigated bacterial communities present in oil mousses collected from impacted 

salt marshes during the Deepwater Horizon explosion, oil spill, and response. Vibrio bacteria, a human 

pathogen, represented 57 percent of the community, suggesting that this indigenous genus is particularly 

responsive to weathered oil in the salt marshes (for more information on salt marshes, refer to Chapter 

4.1.1.4). Tao et al. (2011) found high numbers of Vibrio vulnificus in surface residual balls (also called 

tarballs) composed of weathered oil from the Deepwater Horizon oil spill. A study by Stephens et al. 

(2013) found that levels of Vibrio vulnificus were higher after the Deepwater Horizon explosion, oil spill, 

and response. They state that vibrios are found naturally in the marine environment and prefer brackish 

water (e.g., 5-10 parts per thousand salinity for Vibrio vulnificus and 17-23 parts per thousand salinity for 

Vibrio parahaemolyticus). However, a study by Smith et al. (2012) found that Vibrio parahaemolyticus

did not grow on or oxidize naphthalene or phenanthrene, and a degradation product of naphthalene was 

found to inhibit growth.

Sammarco et al. (2013) examined the geographic extent of petroleum hydrocarbon contamination in 

sediment and seawater during and after the Deepwater Horizon explosion, oil spill, and response. 

Concentrations of TPH, PAHs, and 12 compound classes (subsets of PAHs) were examined in samples 

from these media. Sediment TPH, PAHs, and all compound classes peaked near Pensacola, Florida, and 

Galveston, Texas. Seawater TPH peaked off Pensacola, Florida, and all compound classes peaked in 

seawater off the Mississippi River in Louisiana and Galveston. Wilson et al. (2014) critiqued the paper 

by Sammarco et al. (2013), focusing on matters including sampling strategy and methods, analytical 

methods, and data analysis; Sammarco et al. (2014) subsequently responded to the critique. None of the 

comments from Wilson et al. (2014) changed the Sammarco et al. (2013) conclusions regarding 

petroleum distribution. As further evidence of the petroleum distribution observed by Sammarco et al. 

(2013), tar mats continue to wash up on beaches off Pensacola, Florida. As of June 26, 2014, up to 
Description of the Environment and Impact Analysis 4-125

1,526 pounds of tar material (i.e., oil, sand, shell, and water mixture) had been collected at Fort Pickens 

beach on Santa Rosa Island, Florida; this was performed with USCG oversight and was documented in 

the Pensacola News Journal (2014a). As of July 16, 2014, the total amount of tar material recovered had 

increased to 1,738 pounds (Murphy, 2014, official communication). 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.1.2.1 of 

the EPA 225/226 EIS, Chapter 4.2.1.2.1 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 

231 Supplemental EIS, and Chapter 4.1.1.2.1 of the CPA 235/241/247 Supplemental EIS, BOEM has 

identified incomplete or unavailable information that may be relevant to reasonably foreseeable impacts 

on coastal water quality. Much of this information relates to the Deepwater Horizon explosion, oil spill, 

and response and is continuing to be collected and developed through the NRDA process. BOEM used 

reasonably accepted scientific methodologies to extrapolate from existing information in completing this 

analysis and formulating the conclusions presented here. Given the available data on coastal sediments 

and water quality that have been released and evaluated, as described in Chapter 4.1.1.2.1 of the EPA 

225/226 EIS, Chapter 4.2.1.2.1 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 

Supplemental EIS, and Chapter 4.1.1.2.1 of the CPA 235/241/247 Supplemental EIS, water and sediment 

quality within the EPA were likely not affected to any discernible degree by the Deepwater Horizon

explosion, oil spill, and response, and due to the close proximity, the water and sediment quality within 

the EPA were likely not affected to any discernible degree. Therefore, BOEM believes that this 

incomplete or unavailable information is not essential to a reasoned choice among alternatives for the 

reasons stated herein and in the previously mentioned NEPA documents.

Summary and Conclusion

BOEM has reexamined the analysis for coastal waters presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for coastal waters presented in those NEPA documents because of 

the available scientifically credible evidence in this analysis and based upon accepted scientific methods 

and approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

4.2.1.2.2. Offshore Waters

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for offshore water quality presented in the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for offshore water quality presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226. 

Offshore waters within the EPA, as defined by BOEM, include all the bays and estuaries from the 

Alabama/Florida State border along the west coast of Florida. A detailed description of the affected 

environment and the full analyses of the potential impacts of routine activities, accidental events, and 

cumulative impacts associated with the EPA proposed action are presented in Chapter 4.1.1.2.2 of the 

EPA 225/226 EIS and Chapter 4.2.1.2.2 of the 2012-2017 WPA/CPA Multisale EIS. Updated 

information is provided in Chapter 4.2.1.2.2 of the WPA 233/CPA 231 Supplemental EIS and Chapter 

4.1.1.2.2 of the CPA 235/241/247 Supplemental EIS. The following information is a summary of the 
4-126 Central and Eastern Planning Areas Supplemental EIS

resource description incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The routine activities associated with the EPA proposed action that would impact offshore water 

quality include the following: discharges during drilling of exploration and development wells; structure 

installation and removal; discharges during production; installation of pipelines; workovers of wells; 

maintenance dredging of existing navigational canals; service vessel discharges; and nonpoint-source 

runoff. 

During exploratory activities, the primary impacting sources to offshore water quality are discharges

of drilling fluids and cuttings. During platform installation and removal activities, the primary impacting 

sources to water quality are sediment disturbance and temporarily increased turbidity. Impacting 

discharges during production activities are produced water and supply-vessel discharges. Regulations are 

in place to limit the toxicity of the discharge components, the levels of incidental contaminants in these 

discharges, and, in some cases, the discharge rates and discharge locations. Pipeline installation can also 

affect water quality by sediment disturbance and increased turbidity. Service-vessel discharges might 

include water with an oil concentration of approximately 15 ppm as established by USEPA regulatory 

standards. Any disturbance of the seafloor would increase turbidity in the surrounding water, but the 

increased turbidity should be temporary and restricted to the area near the disturbance. There are multiple 

Federal regulations and permit requirements that would decrease the magnitude of these activities. 

Impacts to offshore waters from routine activities associated with the EPA proposed action should be 

minimal as long as regulatory requirements are followed.

Accidental events associated with the EPA proposed action that could impact offshore water quality

include spills of oil and refined hydrocarbons, releases of natural gas and condensate, spills of chemicals 

or drilling fluids, loss of well control, pipeline failures, collisions, or other malfunctions that would result 

in such spills. Spills from collisions are not expected to be significant. Overall, since major losses of 

well control and blowouts are rare events, the potential impacts to offshore water quality are not expected 

to be significant except in the rare case of a catastrophic event. Although response efforts may decrease 

the amount of oil in the environment, the response efforts may also impact the environment through, for 

example, increased vessel traffic and the application of dispersants. Natural degradation processes will 

also decrease the amount of spilled oil over time. Chemicals used in the oil and gas industry are not a 

significant risk for a spill because they are either nontoxic, are used in minor quantities, or are only used 

on a noncontinuous basis.

Cumulative Impacts

Offshore waters are vulnerable to impacts from cumulative OCS oil- and gas-related activities 

including erosion and runoff, sediment disturbance and turbidity, vessel discharges, discharges from 

exploration and production activities, and accidental releases of oil, gas, or chemicals. Routine activities 

that increase turbidity and discharges are temporary in nature and are regulated; therefore, these activities 

would not have a lasting adverse impact on water quality. In the case of a large-scale spill event, 

degradation processes in both surface and subsurface waters would decrease the amount of spilled oil 

over time through natural processes that can physically, chemically, and biologically degrade oil (NRC, 

2003). A low-probability catastrophic spill, which is not part of the EPA proposed action and not likely 

expected, is discussed in Appendix B. The impacts resulting from the EPA proposed action are a small 

addition to the cumulative impacts on the offshore waters of the Gulf.

Offshore waters are also vulnerable to impacts from activities not related to the EPA proposed action 

or the OCS Program, including State oil and gas activities, alternative uses of platforms (e.g., 

aquaculture), sand borrowing, renewable energy activities, the activities of other Federal agencies 

(including the military), natural events or processes, and activities related to the direct or indirect use of 

land and waterways by the human population(e.g., urbanization, agricultural practices, coastal industry, 

and municipal wastes). These activities may result in erosion and runoff, sediment disturbance and 

turbidity, vessel discharges, natural releases of oil and gas (e.g., seeps), and accidental releases of oil, gas, 

or chemicals. Although some of these impacts are likely to affect coastal areas to a greater degree than 
Description of the Environment and Impact Analysis 4-127

offshore waters, coastal pollutants that are transported away from shore would also affect offshore 

environments.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

Various Internet sources were examined and literature searches conducted in order to assess the 

availability of new information regarding the water quality and sediment quality in offshore waters that 

may be pertinent to the EPA. The searches included, but were not limited to, Google, Google Scholar, 

several USEPA websites, and the NOAA Central Library Deepwater Horizon: A Preliminary 

Bibliography of Published Research and Expert Commentary website. New information was found in 

relation to the affected offshore environment following the Deepwater Horizon explosion, oil spill, and 

response and oil degradation. Several researchers reported on biodegradation and photodegradation 

processes of crude oil related to the Deepwater Horizon explosion, oil spill, and response. However, the 

CPA and EPA contain natural seeps at the seafloor that contribute oil and gas to the offshore marine 

environment. Therefore, the new research discussed below pertaining to hydrocarbon degradation 

processes applies to both the CPA and EPA.

A Deepwater Horizon oil spill dataset, including extensive chemical analyses of sediment and water, 

is available online through NOAA (USDOC, NOAA, 2013a). The dataset as a whole is not fully 

interpreted or discussed in context to the condition of the Gulf of Mexico, but since the data are the work 

of other Federal agencies, State environmental management agencies, and British Petroleum and its 

contractors that has been compiled by NOAA, at least some of the data was discussed in the Inter-Agency 

Joint Analysis Group reports as well as the OSAT reports discussed in the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. BOEM 

expects these data to be considered by the scientific community and further incorporated into additional 

reports and published in peer-reviewed literature in the future.

Liu et al. (2014) evaluated impacts of the Deepwater Horizon explosion, oil spill, and response on 

concentrations of petroleum hydrocarbons in surface water near the release. Concentrations of total 

dissolved n-alkanes in surface water were more than an order of magnitude higher in May 2010 than in 

August 2010 or May 2011, indicating that the contamination was due to the release. In contrast, evennumbered n-alkanes dominated the dissolved fraction in the May 2011 samples, but they were generally 

not prevalent in the suspended particulate fraction. The authors concluded that the dissolved evennumbered n-alkanes originated from bacteria or were transported to the sample location from elsewhere. 

Concentrations of PAHs in suspended particles were on average 5 times higher in the May 2010 sample 

than in the May 2011 sample. The results taken together indicate that surface waters of the sampling area 

in May 2010 were contaminated by the oil spill and that rapid weathering and/or physical dilution quickly 

reduced hydrocarbon levels by August 2010.

Zhou et al. (2013) investigated the photochemical and biological degradation of crude oil from the 

Deepwater Horizon explosion, oil spill, and response under controlled laboratory conditions. 

Naphthalene, phenanthrene, fluoranthene, and chrysene, in order from lower to higher molecular weight, 

were the most dominant PAHs in the samples. Photochemical degradation caused a large decline in the 

aromatic fraction of oil, a preferential loss of low molecular weight alkanes and PAHs, and decreased 

degradation indexes such as n-C17/pristine ratio. Biodegradation of these compounds was also observed 

in the absence of light.

Yang et al. (2014) evaluated bacterial populations in the water column during and after the 

Deepwater Horizon explosion, oil spill, and response. They found that the bacterial community was 

temporarily dominated in May 2010 by Oceanospirillales responding to oil in the water column. By 

October 2010, this bacterial bloom had been replaced by a diversified bacterial community that resembled 

its predecessor prior to the release. However, even after the deep hydrocarbon plume was no longer 

detectable in the wellhead area in October 2010, small populations of Oceanospirillales remained.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 
4-128 Central and Eastern Planning Areas Supplemental EIS

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.1.2.2 of 

the EPA 225/226 EIS, Chapter 4.2.1.2.2 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 

231 Supplemental EIS, and Chapter 4.1.1.2.2 of the CPA 235/241/247 Supplemental EIS, BOEM has 

identified incomplete or unavailable information that may be relevant to reasonably foreseeable impacts 

on offshore water quality. Much of this information relates to the Deepwater Horizon explosion, oil spill, 

and response and is continuing to be collected and developed through the NRDA process. BOEM used 

reasonably accepted scientific methodologies to extrapolate from existing information in completing this 

analysis and formulating the conclusions. Given the available data on offshore sediments and water 

quality that have been released and evaluated most recently in Chapter 4.1.1.2.2 of the CPA 235/241/247 

Supplemental EIS as well as in Chapter 4.1.1.2.2 of the EPA 225/226 EIS and Chapter 4.2.1.2.2 of the 

2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, BOEM believes that 

this incomplete or unavailable information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for offshore waters presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for offshore waters presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.3. Coastal Barrier Beaches and Associated Dunes

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for coastal barrier beaches and associated dunes presented 

in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS,

and CPA 235/241/247 Supplemental EIS based on the additional information presented below. No new 

significant information was discovered that would alter the impact conclusion for coastal barrier beaches 

and associated dunes presented in those NEPA documents. The analysis and potential impacts discussed 

in those documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.3 of the EPA 225/226 EIS and Chapter 4.2.1.3 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.3 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.3 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on coastal barrier beaches and associated dunes of the 

EPA include pipeline emplacements, use of navigation channels by vessel traffic, dredging, and the use 

and construction of support infrastructure. Effects to coastal barrier beaches and associated dunes from 

pipeline emplacements, navigation channel use and dredging, and construction or continued use of 

infrastructure in support of the EPA proposed action are expected to be restricted to temporary and 

localized disturbances. The projected 0-1 pipeline landfalls projected in support of the EPA proposed 

action are not expected to cause significant impacts to barrier beaches because of the use of nonintrusive 

installation methods and regulations. Impacts could be reduced or eliminated through modern techniques 

such as horizontal, directional (trenchless) drilling to avoid damages to these sensitive wetland habitats. 
Description of the Environment and Impact Analysis 4-129

Any new processing facilities would not be expected to be constructed on barrier beaches. The EPA 

proposed action may contribute to the continued use of gas processing facilities that already exist. 

Existing pipelines, in particular those that are parallel and landward of beaches and that had been placed 

on barrier islands using older techniques that left canals or shore protection structures, have caused and 

could continue to cause barrier beaches to narrow and breach.

Maintenance dredging of barrier inlets and bar channels is expected to occur, which, when combined 

with channel jetties, generally causes minor and localized impacts on adjacent barrier beaches downdrift 

of the channel. Updated navigational channels that support the OCS Program are listed in Tables 3-12 

and 3-13 of the CPA 235/241/247 Supplemental EIS. Dredging activities in these channels are permitted, 

regulated, and coordinated by the COE with the appropriate State and Federal resource agencies. Impacts 

from these operations are minimal due to requirements for the beneficial use of the dredged material for 

wetland and beach construction and restoration. Permit requirements further mitigate dredged material 

placement in approved disposal areas by requiring the dredged material to be placed in such a manner that 

it neither disrupts hydrology nor changes elevation in the surrounding marsh. Because these impacts 

occur whether the EPA proposed action is implemented or not, the EPA proposed action would account 

for a small percentage of these impacts.

Routine activities associated with the EPA proposed action are not expected to adversely alter barrier 

beach configurations much beyond existing, ongoing impacts in localized areas downdrift of artificially 

jettied and maintained channels. Strategic placement of dredged material from channel maintenance, 

channel deepening, and related actions can mitigate adverse impacts upon those localized areas.

Accidental disturbances resulting from the EPA proposed action, including oil spills and blowouts, 

have the potential to impact coastal barrier beaches and associated dunes of the EPA. The main 

accidental impact-producing factors that would affect coastal barrier beaches and associated dunes are oil 

spills and cleanup activities.

The potential impacts from oil spills to barrier islands seaward of the barrier-dune system are 

discussed below, while the potential impacts from spills that occur landward of the barrier-dune system 

are considered in the wetlands analysis (refer to Chapter 4.2.1.4). Due to the proximity of inshore spills 

to barrier islands and beaches, inshore spills pose the greatest threat because of their concentration and 

lack of weathering by the time they hit the shore and because dispersants are not utilized in inshore waters 

due to the negative effects on the shallow-water coastal habitats. Such spills may result from either vessel 

collisions that release fuel and lubricants or from pipelines that rupture. Impacts of a nearshore spill 

would likely be considered short term in duration and minor in scope because the size of such a spill is 

projected to be small. When limited to just oil- and gas-related spill sources such as platforms, pipelines, 

MODUs, and support vessels, Louisiana, Texas, Mississippi, and Alabama would have a total of 130-170, 

5-10, 3-5, and about 2 spills <1,000 bbl/yr, respectively. Louisiana and Texas are the states most likely to 

have a spill ≥1,000 bbl occur in coastal waters (refer to Chapter 3.2.1.7.1 of the 2012-2017 WPA/CPA 

Multisale EIS). The distribution of spill sizes is likely to be similar to those identified in Anderson et al. 

(2012) for OCS spills. Ninety-six percent of spills are <1 bbl (average size = 0.05 bbl) and 98 percent of 

spills are <10 bbl (average size for spills 1-9 bbl = 3 bbl). For more information on spill sizes, refer to 

Chapter 3.2.1.7.1 of the 2012-2017 WPA/CPA Multisale EIS.

For offshore spills, the spill may be larger but the oil would likely be lessened in toxicity when it 

reaches the coastal environments due to the distance from shore (the nearest shoreline to the proposed 

activity is 125 mi [201 km]), increased weathering, and the possible use of dispersant. Equipment and 

personnel used in cleanup efforts can generate the greatest direct impacts to an area, such as the 

disturbance of beach and foredune sands through foot traffic and mechanized cleanup equipment (e.g., 

sifters), dispersal of oil deeper into sands and sediments, and foot traffic in marshes impacting the 

distribution of oils and marsh vegetation. Close monitoring and restrictions on the use of bottomdisturbing equipment would be needed to avoid or minimize those impacts. The cleanup impacts of these 

spills could result in a short-term (up to 2 years) adjustment in beach profiles and configurations during 

cleanup operations. Some impact as a result of physical contact to lower areas of sand dunes is expected. 

These contacts would not result in significant destabilization of the dunes. The long-term stressors to 

barrier beach communities caused by the physical effects and chemical toxicity of an oil spill may lead to 

decreased primary production, plant dieback, and further erosion, particularly if oil is carried onto dunes 

by hurricanes. 

Currently available information suggests that impacts on barrier islands and beaches from accidental 

impacts associated with the EPA proposed action would be minimal. Should a spill other than a low-
4-130 Central and Eastern Planning Areas Supplemental EIS

probability catastrophic spill contact a barrier beach, oiling is expected to be light and sand removal 

during cleanup activities minimized. No significant long-term impacts to the physical shape and structure 

of barrier beaches and associated dunes are expected to occur as a result of the EPA proposed action. 

Therefore, the EPA proposed action would not pose a significant increase in risk to barrier island or beach 

resources.

Cumulative Impacts

The OCS oil- and gas-related impact-producing factors that could have cumulative impacts include 

dredging, construction and expansion of navigational canals and port facilities, pipeline 

emplacement/landfalls, vessel traffic, oil spills, and oil-spill response and cleanup activities. These 

pipelines are expected to be installed using modern techniques, which cause little to no impacts to the 

barrier islands and beaches. Impacts from existing infrastructure could continue to cause barrier beaches 

to narrow and breach. The impacts of oil spills from OCS oil- and gas-related sources to the Louisiana, 

Mississippi, and Alabama coast should not result in long-term alteration of landforms if the beaches are 

cleaned using techniques that do not significantly remove sand from the beach or dunes. Barrier beaches 

in the region around Lafourche, Cameron, Plaquemines, and St. Bernard Parishes in Louisiana have the 

greatest risks of sustaining impacts from oil-spill landfalls because of the high concentrations of oil 

production near that coast and the high volume of oil transported by ships in that area. Oil spills as a 

result of a low-probability catastrophic spill, which is not part of the EPA proposed action and not likely 

expected, are discussed in Appendix B. 

Non-OCS oil- and gas-related impacts include non-OCS oil- and gas-related vessel traffic, beach 

protection and stabilization projects, sea-level rise, subsidence, development and urbanization, tourism, 

recreational activities, and the potential for nearshore salinity modifications (such as preparation of salt 

domes for oil storage). In addition, oil spills and oil-spill response and cleanup activities can originate 

from non-OCS oil- and gas-related activities, i.e., international tankers. River channelization, sediment 

deprivation, tropical and extra-tropical storm activity, sea-level rise, and rapid submergence have resulted 

in erosion of most of the barrier and shoreline landforms along the Louisiana coast. Storm-induced 

changes in hydrology have, in some cases, changed the current regime responsible for stabilizing the 

barrier islands. Some beach stabilization projects are considered by coastal geomorphologists and 

engineers to accelerate coastal erosion. The beneficial use of maintenance dredged materials and other 

restoration techniques could be required to mitigate some of these impacts. Recreational use of some 

barrier beaches in the EPA is intense due to their accessibility by roads. These activities can cause 

changes to the beach landscapes. There are ongoing restoration efforts to minimize damages to beaches 

from both natural and human impacts.

Coastal barrier beaches have experienced severe adverse cumulative impacts from natural processes 

and human activities. Natural processes are generally considered the major contributor to these impacts, 

whereas human activities cause severe local impacts and accelerate the natural processes that deteriorate 

coastal barriers. Human activities that have caused the greatest adverse impacts are river channelization 

and damming, pipeline canals, navigation channel stabilization and maintenance, and beach stabilization 

structures. Deterioration of Gulf barrier beaches is expected to continue in the future. Federal, State, and 

county/parish governments have made efforts to restore or protect the sensitive and vulnerable barrier 

islands and mainland beaches.

The EPA proposed action is not expected to adversely alter barrier beach configurations significantly. 

The EPA proposed action is not expected to increase the probabilities of oil spills beyond the current 

estimates. Strategic placement of dredged material from channel maintenance, channel deepening, and 

related actions can mitigate adverse impacts upon those localized areas. Compared with other impacting 

factors on coastal barrier beaches and dunes, the incremental contribution of the EPA proposed action to 

the cumulative impacts to these resources is expected to be small.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search was conducted for information published on barrier beaches and dunes, and various sources 

were examined to determine any recent information regarding barrier beaches and dunes. Sources 
Description of the Environment and Impact Analysis 4-131

investigated include BOEM; the U.S. Department of the Interior, Geological Survey (USGS); National 

Wetlands Research Center; the USGS Gulf of Mexico Integrated Science Data Information Management 

System; Gulf of Mexico Alliance; State environmental agencies; USEPA; and coastal universities. Other 

websites from scientific publication databases (including Science Direct, Elsevier, the NOAA Central 

Library National Oceanographic Data Center, and JSTOR) were checked for new information using 

general Internet searches based on major themes. Most new and pertinent information has been the result 

of Deepwater Horizon-related research, and these studies have provided insight into many aspects of the 

spill and its effects as it relates to beach and dune environments.

Urbano et al. (2013) examined small surface residue balls (also called tarballs) of oil on Fourchon 

Beach and Elmer’s Island, Louisiana, and found that the position with respect to the tidal zone affected 

the rate of biodegradation, with the most efficient degradation occurring in the Fourchon supratidal 

samples and in some intertidal small residual balls. Elango et al. (2014) followed up on that study and 

found that biodegradation of small residual balls continued over a 19-month period, while submerged oil 

mat samples did not demonstrate biodegradation. Newton et al. (2013) sampled beach sands at seven 

Gulf Coast beaches and found that, while individual beaches had unique bacterial communities, oil 

contamination increased the variability in community composition. Daylander et al. (2014) evaluated 

mobility and redistribution patterns of surface residual balls. They found that, under calm conditions, 

small residual balls are unlikely to move alongshore, but that mobility and transport was likely during 

storms and that inlets probably serve as traps for small residual balls. Snyder et al. (2014) sampled 

tissues of Coquina clams (Donax, spp.) to monitor PAH levels in Florida beaches. The clams had higher 

levels of PAHs relative to the sand, the levels were highly variable, and fell below levels of detection 

within 2 years after oil landed on the beaches.

These studies serve to expand our understanding of the baseline environment following the

Deepwater Horizon explosion, oil spill, and response. They also provide information about the potential 

for continuing impacts in the years following oil contamination of beaches from buried oil. 

Another recent study has investigated the impacts of non-OCS oil- and gas-related activity, such as 

reduced ecological resilience observed as sandy beach ecosystems are squeezed between fortifications 

and increasing sea levels (Berry et al., 2013). They found that hard-engineered options such as 

revetments, groins, seawalls, and breakwaters and soft-engineered options such as sand and vegetation 

and beach nourishment and ecosystem engineering impede sand transport and storage systems and 

prevent retreat from advancing seas. This study helps to provide a context for the threats to beaches from 

sources other than OCS oil- and gas-related activities.

While the recent research has provided new information regarding impacts to coastal beaches and 

dunes from oil spills, this new information does not change the conclusions of the 2012-2017 WPA/CPA 

Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS because 

such a low-probability catastrophic event is unlikely to occur and because BOEM has already considered 

the potential irreversible effects to coastal beaches and dunes in Appendix B. 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247; nevertheless, there is still incomplete or unavailable 

information. As discussed in this Supplemental EIS and in Chapter 4.1.1.3 of the EPA 225/226 EIS, 

Chapter 4.2.1.3 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, 

and Chapter 4.1.1.3 of the CPA 235/241/247 Supplemental EIS, BOEM has identified incomplete or 

unavailable information regarding coastal barrier beaches and associated dunes in the EPA. This 

information cannot reasonably be obtained because the long-term effects may not yet be detectable and 

the overall costs in time and money to determine this are exorbitant. This incomplete or unavailable 

information may be relevant to reasonably foreseeable significant adverse effects because recent events 

such as the Deepwater Horizon explosion, oil spill, and response may have caused changes to baseline 

conditions for coastal beaches and associated dunes of the Gulf of Mexico. A large body of information 

regarding impacts of the Deepwater Horizon explosion, oil spill, and response upon coastal barrier 

beaches and associated dunes is being developed through the NRDA process, but it is not yet available. 

There are also unknowns regarding the future restoration efforts being planned, such as what projects will 

ultimately be constructed and how successful they may be. In addition, the future rates of relative sea-
4-132 Central and Eastern Planning Areas Supplemental EIS

level rise are not known with certainty (Intergovernmental Panel on Climate Change, 2013), and thus, the 

resulting impacts to coastal barrier beaches and associated dunes are unknown.

BOEM has determined that the information is not essential to a reasoned choice among alternatives 

because the CPA, which is adjacent to the area of the proposed EPA lease sale, is an active oil and gas 

region with ongoing exploration, drilling, and production activities. In addition, non-OCS energy-related 

factors will continue to occur in the EPA irrespective of the EPA proposed action (i.e., development, 

urbanization, recreational activities, etc.). The potential for effects from changes to the affected 

environment (post-Deepwater Horizon), routine activities, accidental spills (including low-probability 

catastrophic spills), and cumulative impacts remains whether or not the No Action or Action alternative is 

chosen under this Supplemental EIS. Impacts on coastal barrier beaches and associated dunes from either 

smaller accidental events or low-probability catastrophic spills will remain the same.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from existing information in completing this analysis and formulating the conclusions presented here. 

For example, the following studies were analyzed with regards to coastal barrier beaches and dunes: 

Urbano et al. (2013); Elango et al. (2014); Newton et al. (2013); Daylander et al. (2014); Snyder et al. 

(2014); and Berry et al. (2013). The results of these recent studies of coastal barrier beaches and dunes 

indicate that the extent of impacts resulting from a low-probability catastrophic oil spill could be 

extensive, but that the oil would be degraded over time. However, a low-probability catastrophic spill is 

not much more likely with the proposed EPA lease sale than without, given the existing level of OCS oiland gas-related activities and the small incremental increase in the activity that is expected from the 

proposed EPA lease sale. Therefore, none of these sources reveal reasonably foreseeable significantly 

greater adverse impacts, whether or not the No Action or Action alternative is chosen under this 

Supplemental EIS.

Summary and Conclusion

BOEM has reexamined the analysis for coastal barrier beaches and associated dunes presented in the 

EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS based on the additional information presented above. No new 

significant information was discovered that would alter the impact conclusions for coastal barrier beaches 

and associated dunes presented in those NEPA documents because of the available scientifically credible 

evidence in this analysis and based upon accepted scientific methods and approaches. The analysis and 

potential impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

4.2.1.4. Wetlands

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for wetlands presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for wetlands communities presented in those 

NEPA documents. The analysis and potential impacts discussed in those documents still apply for 

proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full impact analysis of the potential 

impacts of routine activities, accidental events, and cumulative impacts associated with the EPA proposed 

action is presented in Chapter 4.1.1.4 of the EPA 225/226 EIS and Chapter 4.2.1.4 of the 2012-2017 

WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.4 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.4 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new significant information that has become available since those documents were 

published is presented below.
Description of the Environment and Impact Analysis 4-133

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on wetlands along the coast adjacent to the EPA 

include pipeline emplacement, construction, and maintenance; navigation channel use (vessel traffic) and 

maintenance dredging; disposal of OCS oil- and gas-related wastes; and use and construction of support 

infrastructure in coastal areas. Other potential impacts that are indirectly associated with OCS oil- and 

gas-related activities are wake erosion resulting from navigational traffic, levee construction that prevents 

necessary sedimentary processes, saltwater intrusion that changes the hydrology leading to unfavorable 

conditions for wetland vegetation, and vulnerability to storm damage from eroded wetlands. It is 

expected that impacts of pipelines would be reduced or eliminated through mitigation, such as horizontal, 

directional (trenchless) drilling techniques to avoid damages to these sensitive wetland habitats. Although 

maintenance dredging of navigation channels and canals in the EPA is expected to occur, the EPA 

proposed action is expected to contribute minimally to the need for this dredging. Alternative dredgedmaterial disposal methods can be used to enhance and create wetlands. Secondary impacts to wetlands 

from the EPA proposed action would result from OCS oil- and gas-related vessel traffic, contributing to 

the erosion and widening of navigation channels and canals. Overall, the impacts to wetlands from 

routine activities associated with the EPA proposed action are expected to be low due to the small length 

of projected onshore pipelines, the minimal contribution to the need for maintenance dredging, and the 

mitigating measures that would be used to further reduce these impacts.

Accidental disturbances resulting from the EPA proposed action, mainly oil spills, have the potential 

to cause plant mortality and permanent loss of wetlands of the EPA. Offshore oil spills resulting from the 

EPA proposed action would have a low probability of contacting and damaging wetlands along the Gulf 

Coast, except in the case of a low-probability catastrophic spill, which is not part of the EPA proposed 

action and not likely expected (refer to Appendix B). This is because of the distance of the spill to the 

coast (the nearest shoreline to the proposed activity is 125 mi [201 km]), the likely weathered condition of 

oil (through evaporation, dilution, and biodegradation) should it reach the coast, and because wetlands are 

generally protected by barrier islands, peninsulas, sand spits, and in some cases by currents. However, 

because the protective capacity of barrier islands has been reduced due to land lost in hurricanes and 

anthropogenic factors, there is a greater potential for the oiling of coastal wetlands during an accidental 

event. The causes of coastal and offshore oil spills are summarized in Chapters 3.1.1.7 and 3.3.5.2. 

Although the probability of occurrence is low, the greatest threat from an oil spill to wetland habitat is 

from a spill as a result of an inland or nearshore vessel accident or pipeline rupture. Wetlands in the 

northern Gulf of Mexico are in moderate- to high-energy environments; therefore, sediment transport and 

tidal stirring should reduce the chances for oil persisting in the event that these areas are oiled. While a 

resulting slick may cause minor impacts to wetland habitat and surrounding seagrass communities, the 

equipment, chemical treatments, and personnel used for cleanup can generate the greatest impacts to the 

area. Associated foot traffic may work oil farther into the sediment than would otherwise occur. Close 

monitoring and restrictions on the use of bottom-disturbing equipment would be needed to avoid or 

minimize those impacts. In addition, an assessment of the area covered, oil type, and plant composition 

of the wetland oiled should be made prior to choosing remediation treatment. These treatments could 

include mechanical and chemical techniques with onsite technicians. Overall, impacts to wetland habitats 

from an oil spill associated with activities related to the EPA proposed action would be expected to be 

low and temporary because of the nature of the system, regulations, and specific cleanup techniques.

Cumulative Impacts

The primary impact-producing factors attributable to the EPA proposed action are pipeline landfalls, 

canal widening, and maintenance dredging of navigation canals because they result in land loss. 

However, modern construction techniques and regulations reduce impacts to wetlands as a result of these 

activities. In addition, because the increase in pipelines, dredging, and vessel traffic from the EPA 

proposed action are predicted to be minimal, impacts related to these factors are also expected to be 

minimal. The possibility of the physical oiling of wetlands from the EPA proposed action as a result of 

an oil spill originating in OCS waters is minimal compared with an oil spill that is closer to the wetlands 

and that could occur in State waters or in rivers, bays, or estuaries. The effects from a spill have the 

highest probability of occurring in Lafourche, Cameron, Plaquemines, and St. Bernard Parishes in 

Louisiana. These are the primary areas where oil produced in the CPA is transported and distributed. If 
4-134 Central and Eastern Planning Areas Supplemental EIS

any oil spills occur in rivers, bays, or estuaries from pipelines or vessels, they will likely be small and at 

service bases or other support facilities, and these small-scale local spills would not be expected to 

severely affect wetlands. Accidental spills as a result of a low-probability catastrophic event, which is not 

part of the EPA proposed action and not likely expected, may have impacts on wetlands. Low-probability 

catastrophic events are discussed in Appendix B. 

Non-OCS oil- and gas-related cumulative impact-producing factors that could potentially impact 

wetland resources include the following: State oil and gas activities; non-OCS oil- and gas-related vessel 

traffic; coastal infrastructure and development; maintenance of navigation canals; natural processes 

(including hurricane and tropical storms); and sea-level rise. Non-OCS oil- and gas-related impacts from 

residential, commercial, agricultural, and silvicultural (forest expansion) developments are expected to 

continue in coastal regions around the Gulf of Mexico. Wetlands are most vulnerable to oil spills that 

may occur in State waters or in rivers, bays, or estuaries, the impacts of which would be primarily 

localized in nature. Many such spills are from non-OCS oil- and gas-related sources, such as State oil and 

gas activities, which can include vessel collisions, pipeline breaks, and shore-based transfer, refining, and 

production facilities. Insignificant adverse impacts upon wetlands from maintenance dredging are 

expected because the large majority of the material would be placed in existing disposal areas or used 

beneficially for marsh restoration or creation. Hurricanes and tropical storms can cause extensive damage 

to wetlands, including conversion of large acreages of wetlands to open water. Marine vegetation 

deposited by storms can rest on wetland plants, resulting in mortality. One benefit of storms is that they 

can be capable of delivering sediment from offshore or interior bays into wetland areas, partially 

offsetting erosion. Sea-level rise can impact coastal wetlands by the drowning of plants. Relative sealevel rise, which includes local factors such as subsidence, can increase salinity and flooding, resulting in 

reduced productivity of wetland plants (Spalding and Hester, 2007).

Development pressures in the coastal regions of Louisiana, Mississippi, Alabama, and Florida have 

caused the destruction of large areas of wetlands. In coastal Louisiana, the most destructive 

developments have been the inland oil and gas industry projects, which have resulted in the dredging of 

huge numbers of access channels. Agricultural, residential, and commercial developments have caused 

the most destruction of wetlands in Mississippi, Alabama, and Florida. In Florida, recreational and tourist 

developments have been particularly destructive. Groundwater extraction, vessel traffic, the drainage of 

wetland soils, and the construction of buildings, roads, and levees have also caused the loss of wetlands. 

The cumulative effects of human and natural activities in the coastal area have severely degraded the 

deltaic processes and have shifted the coastal area from a condition of net land building to one of net land 

loss. Therefore, wetland loss is expected to continue.

The EPA proposed action represents a very small portion of the OCS oil- and gas-related impacts that 

will occur over the 40-year analysis period. Impacts associated with the EPA proposed action are a 

minimal part of the overall OCS oil- and gas-related impacts. The incremental contribution of the EPA 

proposed action to the cumulative impacts to coastal wetlands is minimal compared with the impacts 

associated with non-OCS oil- and gas-related activities in the Gulf of Mexico.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search was conducted for information published on northern Gulf of Mexico wetland communities, 

and various Internet sources were examined to determine any recent information regarding these 

communities. Sources investigated include BOEM, the USGS National Wetlands Research Center, the 

USGS Gulf of Mexico Integrated Science Data Information Management System, Gulf of Mexico 

Alliance, State environmental agencies, USEPA, and coastal universities. Other websites from scientific 

publication databases (including Science Direct, Elsevier, the NOAA Central Library National 

Oceanographic Data Center, and JSTOR) were checked for new information using general Internet 

searches based on major themes.

Numerous studies have been published regarding impacts of the Deepwater Horizon explosion, oil 

spill, and response. Zengel et al. (2014) compared treatment options for oiled marshes in Barataria Bay, 

Louisiana, 3 years after the initial oiling. They found mechanical treatment (including vegetation raking, 

cutting, and using “squeegees” to skim thick oil mousse from the marsh surface), coupled with the 

planting of Spartina alterniflora, resulted in improved habitat recovery, compared with no treatment and 
Description of the Environment and Impact Analysis 4-135

mechanical treatment alone. Judy et al. (2014) studied impacts of oil from the Deepwater Horizon oil 

spill on Phragmites australis and found strong resistance to negative impacts when oil was applied to 

shoots alone and greater impacts when oil was applied to the soil or with repeated shoot oiling. Sublethal 

effects were observed from the application of oil to the soil, but mortality was not observed. This study 

indicates that Phragmites australis may have experienced greater impacts from oiled soil than oiled 

shoots alone as a result of the Deepwater Horizon explosion, oil spill, and response.

Michel and Rutherford (2014) reviewed 32 oil spills and field experiments and found that, in many 

cases, recovery of marshes occurred within 1-2 growing seasons, even without treatment. Recovery was 

shortest for spills in a warm climate, light to heavy oiling of the vegetation only (not the marsh surface), 

medium crude oils, and less intensive treatment. They (2014) offered treatment recommendations for 

spills based on several related criteria.

Liu and Liu (2013) investigated bacterial communities present in oil mousses collected from impacted 

salt marshes during the Deepwater Horizon explosion, oil spill, and response. Vibrio bacteria, a human 

pathogen, represented 57 percent of the community, suggesting that this indigenous genus is particularly 

responsive to weathering oil in the salt marshes.

Khanna et al. (2013) used Advanced Visible Infrared Imaging Spectrometer (AVIRIS) data from 

Barataria Bay, Louisiana, in September 2010 and August 2011 to map oil contamination and examine the 

impacts to vegetation. They found that vegetation stress was restricted to the tidal zone, extending 14 m 

(46 ft) inland from the shoreline in 2010, with the highest stress at the shoreline, and decreasing with 

distance from the water. They also found varying degrees of revegetation in 2011, with the poorest 

recovery adjacent to shorelines, which is where oil stress was the highest. This study showed salt marsh 

recovery the year following the Deepwater Horizon explosion, oil spill, and response, with the slowest 

recovery in the most heavily oiled areas.

Moody et al. (2013) compared the utilization of salt-marsh habitats by transient and resident nekton 

before and after the Deepwater Horizon explosion, oil spill, and response. They did not find significant 

differences in the recruitment of marsh-associated nekton in coastal Alabama following the spill, and they 

found little evidence for severe acute or persistent oil-induced impacts.

Other recent research focused on issues other than oil-spill impacts. Staszak and Armitage (2013) 

evaluated the results of salt marsh restoration projects in Galveston Bay, Texas. They found that the 

restored areas had relatively high ecological value and contributed to the integrity of the regional wetland

landscape.

Glick et al. (2013) investigated the potential impact of current and accelerating sea-level rise rates on 

key coastal wetland habitats in southeastern Louisiana, using the Sea Level Affecting Marshes Model. 

Results indicate a range of potential wetland losses from 9 to 24 percent of the 2007 wetland area by 

2100, depending on whether the lowest or highest sea-level-rise scenario was used. Cypress-tupelo 

swamp is projected to be heavily impacted by permanent flooding, thereby affecting regeneration.

Howard et al. (2014) investigated the impact of 3D seismic surveys in coastal marshes of Louisiana. 

They found that effects from activities related to the 3D seismic surveys, including reduced vegetative 

height and reduced vegetative cover, did not persist beyond 3 months and that marshes were resilient to 

the impacts of 3D seismic exploration.

While the recent research has provided much new information regarding impacts to wetlands from oil 

spills, this new information does not change the conclusions of the 2012-2017 WPA/CPA Multisale EIS, 

WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS because a catastrophic

event is unlikely to occur and because BOEM has already considered the potential irreversible effects to 

marshes (such as erosion and permanent loss) in Appendix B (Chapter B.3.1.4). 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As identified in the resource analyses in this Supplemental EIS, in Chapter 

4.2.1.4 of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, and WPA 233/CPA 231 

Supplemental EIS, and in Chapter 4.1.1.4 of the CPA 235/241/247 Supplemental EIS, BOEM has 

identified incomplete or unavailable information regarding wetlands in the EPA. This incomplete or 

unavailable information may be relevant to reasonably foreseeable significant adverse effects because 
4-136 Central and Eastern Planning Areas Supplemental EIS

recent events such as the Deepwater Horizon explosion, oil spill, and response may have caused changes 

to baseline conditions for coastal wetlands of the Gulf of Mexico. A large body of information regarding 

impacts of the Deepwater Horizon explosion, oil spill, and response upon coastal wetlands is being 

developed through the NRDA process, but this information is not yet available. Other unknowns are 

future benefits from restoration projects and future sea-level rise.

BOEM has determined that the information is not essential to a reasoned choice among alternatives 

because the CPA, which is adjacent to the area of the proposed EPA lease sale area, is an active oil and 

gas region with ongoing exploration, drilling, and production activities. In addition, non-OCS energyrelated factors will continue to occur in the CPA irrespective of the EPA proposed action (i.e., 

commercial development, subsidence, hurricanes, etc.). The potential for effects from changes to the 

affected environment (post-Deepwater Horizon), routine activities, accidental spills (including lowprobability catastrophic spills), and cumulative impacts remains whether or not the No Action or Action 

alternative is chosen under this Supplemental EIS. Impacts on wetlands from either smaller accidental 

events or low-probability catastrophic events will remain the same.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from existing information in completing this analysis and formulating the conclusions presented here. 

For example, the following studies were analyzed with regards to wetlands: Zengel et al. (2014); Judy 

et al. (2014); Michel and Rutherford (2014); Liu and Liu (2013); Khanna et al. (2013); Moody et al. 

(2013); Staszak and Armitage (2013); Glick et al. (2013); and Howard et al. (2014). The results of these 

recent studies of wetlands indicate that the extent of impacts resulting from a catastrophic oil spill could 

be extensive but that the oil would be degraded over time. While marsh vegetation can recover in some 

areas, conversion of some marsh to open water is likely due to plant mortality and erosion. However, a 

low-probability catastrophic oil spill is not much more likely with the proposed EPA lease sale than 

without, given the existing level of OCS oil- and gas-related activities and the small incremental increase 

in that activity expected from the proposed EPA lease sale. Therefore, none of these sources reveal 

reasonably foreseeable significantly greater adverse impacts whether or not the No Action or Action 

alternative is chosen under this Supplemental EIS.

Summary and Conclusion

BOEM has reexamined the analysis for wetlands presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for wetlands presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

4.2.1.5. Seagrass Communities

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for seagrass communities presented in the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new information was 

discovered that would alter the impact conclusion for seagrass communities presented in those NEPA

documents. The analysis and potential impacts discussed in those NEPA documents still apply for 

proposed EPA Lease Sale 226. 

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.5 of the EPA 225/226 EIS and Chapter 4.2.1.5 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.5 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.5 of the CPA 235/241/247 Supplemental EIS. The following 
Description of the Environment and Impact Analysis 4-137

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on seagrass communities of the EPA are the 

construction of pipelines, canals, navigation channels, and onshore facilities; maintenance dredging; and 

vessel traffic (e.g., propeller scars). There is only one potential pipeline landfall and only a minor 

increase in vessel traffic projected as a result of the EPA proposed action. Any work in and around 

submerged aquatic vegetation, especially seagrasses, is highly regulated by multiple State and Federal 

programs; as such, considerable mitigation is expected to reduce the undesirable effects on submerged 

vegetation beds. This includes the rerouting of pipelines, avoidance of vegetated communities, use of 

turbidity curtains, or use of directional boring techniques. Local programs decrease the occurrence of 

prop scarring in grass beds; however, channels utilized by OCS oil- and gas-related vessels are typically 

away from exposed submerged vegetation beds. Because of these requirements and implemented 

programs, along with the beneficial effects of natural flushing (e.g., from winds and currents), any 

potential effects from routine OCS oil- and gas-related activities on submerged vegetation in the EPA are 

expected to be short term, localized, and not significantly adverse.

Accidental disturbances resulting from the EPA proposed action, including oil spills and blowouts, 

have the potential to change community structure by decreasing growth rates, death, or causing a decline 

in ecological services by seagrass communities of the EPA. The greatest possibility of a spill is from a 

vessel accident or pipeline rupture; however, these activities would still be a long distance from many 

EPA submerged vegetation communities. As such, seagrasses are not expected to come in direct contact 

with surface oil; however, if oil did come in contact with seagrasses, the results could range from the 

sloughing of epiphytes to death. Offshore oil spills that occur in the EPA proposed action area are less 

likely to contact seagrass communities than are inshore spills because the EPA proposed action is 

approximately 125 mi (201 km) away. It has been shown that short-term effects from an offshore spill 

could have little impact on specific seagrass communities. Fodrie and Heck (2011) found that, after the 

Deepwater Horizon oil spill, there were few immediate or catastrophic changes in seagrass-based nekton 

communities in Alabama, Florida, and Louisiana seagrass communities. Impacts to submerged 

vegetation from an accidental event related to the EPA proposed action are expected to be minimal due to 

the great distance of most activities from the submerged vegetation beds and because the likelihood of an 

accidental event of size, location, and duration reaching submerged vegetation beds remains small.

Cumulative Impacts

The cumulative OCS oil- and gas-related activities that present the greatest threat of impacts to 

submerged vegetation communities are dredging, oil spills, and pipeline installation. In general, the EPA 

proposed action would cause a minor incremental contribution to impacts on submerged vegetation from 

related dredging, pipeline installations, and oil spills. Of those mentioned, dredging generates the greatest 

overall risk to submerged vegetation by uprooting and burying plants, decreasing oxygen in the water, 

and reducing water clarity in an area. A low-probability catastrophic spill, which is not part of the EPA 

proposed action and not likely expected, could also impact seagrass communities. Further, non-OCS oiland gas-related dredging and vessel traffic, boat scarring, changes in salinity and nutrient inputs (Waycott 

et al., 2009; Orth et al., 2006), changes to natural flow regimes from constructed structures, and storm 

events could continue to cause direct damage to seagrass beds by physical destruction, increased turbidity 

and burial of plants, and reduction in favorable environmental conditions for seagrass bed growth. 

However, the incremental contribution of stress from the EPA proposed action to submerged vegetation is 

reduced by the implementation of proposed lease stipulations, mitigating measures currently in place, and 

the small probability of an oil spill.
4-138 Central and Eastern Planning Areas Supplemental EIS

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of various printed and Internet sources was conducted for any recent information published 

regarding coastal submerged vegetation. Sources investigated include BOEM, the National Oceanic and 

Atmospheric Administration, the USGS National Wetlands Research Center, the USGS Gulf of Mexico 

Integrated Science Data Information Management System, Seagrass Watch, Gulf of Mexico Alliance, 

State environmental agencies, USEPA, and coastal universities. Other websites from scientific 

publication databases (including Science Direct, SCIRUS, Google Scholar, Elsevier, Pro Quest, and 

JSTOR) were checked for new information using general Internet searches based on major themes.

New information available that is relevant to the EPA proposed action includes information related to 

responses of seagrass species that were potentially exposed to Macondo oil. Moody et al. (2013) found 

that recruitment of many species of invertebrates in an Alabama marsh was not negatively impacted by 

the Macondo oil spill. Although focused on the marsh, this study is important because many of the 

species found in the marsh are also found in the seagrass. Dubansky et al. (2013) did note that exposure 

to Macondo-related sediments that were contaminated with PAHs resulted in Gulf killifish having multitissue molecular, genomic, and developmental responses. The presence of these effects suggests that oil 

exposure may result in population-level effects; however, a population-level effect may be lethal or 

sublethal. Given that animals were recovered at the same locations in both years suggests that any lethal 

effects on animals may have been mitigated by subsequent cohorts, despite the presence of sublethal 

effects. Gulf killifish are a cosmopolitan, but nonmigratory species, and effects due to a spill would be 

expected to have an impact that was limited to the local population exposed to the spill rather than the 

population as a whole. As such, the overall impact would be positively correlated with the size of the 

spill.

None of the new or available information examined here provides evidence that would result in a 

change of BOEM’s impact conclusions for seagrasses resulting from the EPA proposed action.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from the 

EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS are still valid because no new information on seagrass communities

pertinent to the EPA proposed action has become available since those NEPA documents were published. 

As discussed in this Supplemental EIS and in the previously mentioned EISs and Supplemental EISs, 

BOEM has identified unavailable information regarding seagrass communities in the EPA. This 

information cannot reasonably be obtained because the long-term effects may not yet be detectable and 

the overall costs in time and money to determine this are exorbitant. This unavailable information may be 

relevant to adverse effects because much of the data related to research and monitoring of the Deepwater

Horizon explosion, oil spill, and response has yet to be completed and made publicly available. Other 

unavailable information may be related to university-related research that has yet to be published as a 

thesis or a dissertation.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from existing information in completing this analysis and formulating the conclusions presented here. 

For example, Fodrie and Heck (2011) did not sample all of the seagrasses across the northern GOM, but 

they sampled enough locations where OCS oil- and gas-related resource development occurs to allow for 

a general conclusion that changes within seagrass beds are not related to OCS oil- and gas-related 

development or the Deepwater Horizon oil spill. Gab-Alla (2000), Nievales (2009), and Mauseth et al. 

(2001) each showed that, historically, oil spills in other parts of the world have had little long-term 

negative impact on seagrass environments. Overall, none of the new sources or sources referenced in 

previously mentioned EISs and Supplemental EISs reveal any reasonably foreseeable significant adverse 

impacts as a result of the EPA proposed action. The lack of impact to seagrasses is because seagrasses 

are a benthic organism that is spatially separated from floating oil. If oil does impact seagrasses it would 

be along the shallow, shoreward margins or at the leaf tips that can be at the air-water interface at times. 

These leaf tips are generally older leaves that have undergone a considerable amount of senesce and are 

routinely discarded by the plant as they age. Oil found in seagrasses is often found as tarballs that 
Description of the Environment and Impact Analysis 4-139

typically do not result in large-scale effects. Therefore, BOEM has determined that the information is not 

essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for seagrass communities presented in EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for seagrass communities presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.6. Live Bottoms (Pinnacle Trend and Low Relief) 

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and the CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for live bottoms presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for live bottoms presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.6 of the EPA 225/226 EIS and Chapter 4.2.1.6 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in the WPA 233/CPA 231 Supplemental EIS and CPA 

235/241/247 Supplemental EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

The blocks with known live bottom features nearest the proposed EPA lease sale area are located in 

the CPA and are more than 120 km (75 mi) away (Figure 4-1). The proposed EPA lease sale area is 

greater than 120 km (75 mi) away from typical shallow-water (less than 200 m [656 ft]) live bottom 

communities that could exist in the EPA. Potential routine impact-producing factors such as seafloor 

disturbances (e.g., anchoring, infrastructure emplacement, and infrastructure removal), waste discharge 

(e.g., produced waters and drilling muds), resuspension of sediments (e.g., drill cuttings and pipeline 

burial), and explosive severance activities are not expected to have an impact on live bottom resources at 

such a distance.

Accidental disturbances resulting from the EPA proposed action, including oil spills and blowouts, 

have the potential to damage live bottom habitats and disrupt associated communities. However, because 

of the distance from live bottom features, only large spills would have the potential to impact live bottom 

habitat.

In the event of an accidental release, the majority of the oil is expected to rise to the sea surface. 

Lighter compounds in oil rapidly evaporate, while other compounds may dissolve in the seawater, 

become emulsified, or adsorb to sediment particles and fall to the seafloor. Small oil droplets formed by a 

subsurface oil spill ejected under high pressure may become entrained in the water column and remain 

neutrally buoyant. Dispersed oil in the water column may flocculate with particulate matter and fall to the 

seafloor, generating increased sedimentation. Biodegradation of oil compounds would occur throughout 

the water column and continue at the seafloor. Any oil reaching a live bottom feature as a result of the 

EPA proposed action would be expected to be well-dispersed and weathered, generating only a slight 
4-140 Central and Eastern Planning Areas Supplemental EIS

increase in sedimentation. Any potential impact to sessile inhabitants of a live bottom feature as a result 

of an accidental disturbance from the EPA proposed action is expected to be negligible.

Cumulative Impacts

The cumulative analysis considers impacts resulting from ongoing routine oil and gas operations, as 

well as those resulting from past and future OCS leasing. These impacts include seafloor disturbances 

(e.g., anchoring, structure emplacement, and structure removal), waste discharge (e.g., drilling muds, 

cuttings, and effluent), and accidental disturbances (e.g., blowouts and oil spills). Potential non-OCS oiland gas-related factors include vessel anchoring, import tankering, storms, and commercial fishing.

The OCS oil- and gas-related seafloor-disturbing activities represent the greatest threat to live 

bottoms. Potential impacts may be avoided through the continued application of the proposed Live 

Bottom (Pinnacle Trend) Stipulation and case-by-case review of permit applications for the presence of 

live bottom habitat and mitigation of potential impacts. This stipulation would avoid mechanical damage 

to live bottom habitat by prohibiting bottom-disturbing activities from occurring within 30 m (100 ft) of 

live bottoms. The 30-m (100-ft) buffer would also diminish the potential for adverse impacts resulting 

from operational discharges, due to the highly localized and temporary effect of such discharges. The 

USEPA’s discharge regulations and permits further reduce the potential for discharge-related impacts.

The majority of oil released below the sea surface rises and should not physically contact organisms 

on live bottoms. In the unlikely event that oil from a subsurface spill would reach the biota of a live 

bottom, the effects would be primarily sublethal. In the very unlikely event that oil from a subsurface 

spill reached an area containing coral cover in lethal concentrations, the recovery period could exceed 10 

years (Fucik et al., 1984). In the event that a live bottom suffers severe mechanical damage (e.g., vessel 

collision), recovery could take decades depending on the extent of the damage. Because these events are 

rare, the potential for impacts is considered low. For information on impacts resulting from catastrophic 

spills, refer to Appendix B. 

Non-OCS oil- and gas-related activities (e.g., anchoring, trawling, and vessel collisions) can damage 

live bottoms, resulting in impacts similar to those described above. Commercial fishing activities may 

dislodge or damage organisms inhabiting live bottoms if lines or trawls are dragged across the live bottom 

surface or become entangled. Natural events of sufficient magnitude (e.g., hurricanes or earthquakes) 

may also cause severe impacts. Recreational SCUBA diving, fishing, and discharges or spills from 

tankering of imported oil may also have adverse impacts on live bottoms. Overall, the incremental 

contribution of the EPA proposed action to the cumulative impact is negligible.

While there are potential non-OCS impacts to low relief live bottoms in the EPA, there is not an OCS 

incremental impact in the EPA; therefore, there is no cumulative impact as a result of OCS activities in 

the EPA.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources and scientific journals was conducted to determine the 

availability of recent information (including ACS Publications, BioOne, EBSCO, Elsevier, the Gulf of 

Mexico Fishery Management Council’s website, JSTOR, NMFS’s databases, NOAA Gulf Spill 

Restoration Publications website, PLoS ONE, Science Direct, and SeaGrant website). This search 

revealed new information relevant to an analysis of the potential impacts of OCS oil- and gas-related 

activities on live bottom benthic communities.

Investigations of deepwater corals following the Deepwater Horizon oil spill and response suggest 

visually observable impacts may be limited to communities within 25 km (16 mi) of the well site (White 

et al., 2012; Hsing et al., 2013; and Fisher et al., 2014). Substantial impacts to corals have not been 

documented north of the well. The only affected corals identified by White et al. (2012) are located 

11 km (7 mi) southwest of the well site, and the two impacted communities discovered by Fisher et al. 

(2014) are located 6 km (4 mi) south and 22 km (14 mi) southeast of the well. Within each affected 

community, impacts were patchy and coral response to exposure varied. The colony identified by White 

et al. (2012) was surveyed five times over a 17-month period to document the temporal progression of 

coral response to acute oil exposure (Hsing et al., 2013). During the study period, corals exhibited a 
Description of the Environment and Impact Analysis 4-141

dramatic decrease in observable impacts, indicating resiliency to acute oil exposure (Hsing et al., 2013) 

and possibly recovery.

The limited geographic extent of impacts from subsurface oil exposure documented by White at al. 

(2012), Hsing et al. (2013), and Fisher et al. (2014) suggests that oil from the Deepwater Horizon oil spill

may not have impacted corals inhabiting the Pinnacle Trend or live bottom (low relief) habitats. The 

Pinnacle Trend feature nearest the well is approximately 60 km (37 mi) to the north and the highest 

concentration of Pinnacle features is 100 km (62 mi) to the northeast. In addition, research into the

potential impacts to fishes that potentially use or inhabit waters adjacent to the Pinnacles suggest that 

many species may not have been severely impacted (Fodrie and Heck, 2011; Moody et al., 2013; Rooker, 

2013; Incardona et al., 2014; Mager et al., 2014). For additional information, refer to Chapters 4.2.1.17 

and 4.2.1.18 of this Supplemental EIS and Chapters 4.2.1.18 and 4.2.1.19 of the CPA 235/241/247 

Supplemental EIS. Therefore, BOEM finds that, as more information has become available, the research

supports the analyses in anticipating localized, temporary impacts.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS, as well as in the 

previously mentioned NEPA documents, BOEM has identified incomplete or unavailable information 

related to live bottoms in the EPA. Potential impacts to organisms associated with live bottoms (Pinnacle 

Trend and low relief) as a result of the Deepwater Horizon oil spill and response have not been 

specifically addressed in the current literature. However, available information on species and habitats 

similar to those associated with the Pinnacle Trend and low relief live bottoms provides sufficient basis 

from which to extrapolate potential impacts; it is reasonable to assume that similar responses may be 

expected. Data collected in the vicinity of the Pinnacle Trend features is under development through the 

NRDA process and may be relevant to an analysis of live bottom (Pinnacle Trend and low relief) habitat 

in the EPA. However, analysis of these data may take years to complete and the outcome cannot be 

predicted. Although the body of available information is incomplete and long-term effects cannot yet be 

known, evidence does not suggest that assemblages associated with live bottom (Pinnacle Trend and low 

relief) habitat sustained severe adverse impacts. BOEM has determined that the incomplete or 

unavailable information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for live bottoms presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the information presented above. No new significant information was discovered that 

would alter the impact conclusion for live bottoms presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

4.2.1.7. Topographic Features

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. No new significant information was discovered that would alter the impact conclusion for 

topographic features presented in those NEPA documents. The analysis and potential impacts discussed 

in those documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.7 of the EPA 225/226 EIS and Chapter 4.2.1.7 of the 2012-2017 WPA/CPA 
4-142 Central and Eastern Planning Areas Supplemental EIS

Multisale EIS. Updated information is provided in Chapter 4.2.1.12 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.12 of CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Topographic features are hard bottom habitats and are rare compared with the ubiquitous soft bottoms

in the GOM (Parker et al., 1983). These features can be upthrusts of rock due to an uplift of the 

underlying salt (diapirs) or the remnants of fossilized shorelines. These topographic highs, or subsea 

banks, provide an island of hard substrate in a virtual ocean of soft bottoms. Wherever rock protrudes up 

into the water column, reef organisms may thrive. The type of organisms inhabiting a reef is determined 

by environmental conditions. There are 37 protected topographic features in the GOM: 21 in the WPA 

and 16 in the CPA, all of which are distanced approximately 155 mi (250 km) or greater from the EPA 

proposed action. 

Impacts of Routine Activities and Accidental Events

There are no protected topographic features in the proposed EPA lease sale area; however, the 

potential routine impact-producing factors in the EPA have a minuscule chance of impacting the 

topographic features of the CPA. Potential impacts include drilling-effluent and produced-water 

discharges. These factors could result in exposure to concentrated discharges if the discharge is of a high 

enough concentration to not be diluted after travelling approximately 155 mi (250 km). This is unlikely 

since discharges that could harm topographic features are regulated by other agencies, including discharge 

permit restrictions from USEPA and essential fish habitat restrictions from NOAA. Furthermore, the 

high-energy environment and prevailing water currents associated with topographic features would help 

protect the features by enabling rapid mixing and dilution.

Although highly unlikely, adverse effects from accidental disturbances resulting from the EPA 

proposed action could include surface and subsurface oil spills. If spills travels approximately 155 mi 

(250 km), each spill has the potential to disrupt and alter the environmental, commercial, recreational, and 

aesthetic values of topographic features of the CPA through oiling; however, a typical surface spill would 

most likely not be large enough to travel to the nearest topographic feature, and if it did, the oil would be 

diluted and weathered. It is expected that the majority of subsurface oil released during an accidental 

event would rise rapidly to the surface and that the most heavily oiled sediments in the water column 

would likely be deposited on the seafloor well before reaching the topographic features. In the unlikely 

event that diluted oil from a subsurface spill did reach the biota of a topographic feature, the effects would 

be primarily sublethal because the oil would be highly weathered and highly diluted. Any impacts would 

be at the local level, affecting only communities of organisms. For information on impacts resulting from 

events outside the scope of routine activities and accidental events, refer to Appendix B. 

Cumulative Impacts

The cumulative impacts from routine OCS oil and gas operations include effects resulting from the 

EPA proposed action, as well as those resulting from past and future OCS leasing. These operations 

include anchoring, structure emplacement, muds and cuttings discharge, effluent discharge, blowouts, oil 

spills, and structure removal. Because of the distance between the proposed EPA lease sale area and the 

nearest topographic feature, none of the routine or accidental impacts associated with this proposed action 

would add to the cumulative effect of future OCS leasing on topographic features. Impacts around the 

features from OCS oil- and gas-related activities would be mitigated by the continued application of the 

proposed Topographic Features Stipulation, precluding physical damage caused by oil and gas 

leaseholders by establishing a buffer around the features. As such, little impact would be incurred by the 

biota of the topographic features as a result of any OCS oil- and gas-related activities. The USEPA 

discharge regulations and permits would further reduce discharge-related impacts.

Potential non-OCS oil- and gas-related factors include vessel anchoring, SCUBA diving, treasurehunting activities, import tankering, heavy storms and hurricanes, the collapse of the tops of the 

topographic features due to dissolution of the underlying salt structure, and fishing activities. Many of 

these non-OCS oil- and gas-related factors may result in physical damage to organisms that colonize 

topographic features. For example, treasure hunting activities in the 1980’s resulted in several large 
Description of the Environment and Impact Analysis 4-143

cavities being dug on one of the topographic features that has yet to recover. Anchoring can result in the 

destruction of hard corals due to the ability of anchor lines to cut through the coral heads. Anchoring can 

also result in the tearing of soft corals from the seafloor during anchor removal or the movement of the 

anchoring line through the water column. Because corals and other benthic fauna are slow growing, 

physical disturbance represents the greatest threat to the organisms that colonize topographic features.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources (e.g., the NOAA Gulf Spill Restoration Publications website, 

the Environmental Response Management Application [ERMA] Gulf Response website; NOAA’s 

Deepwater Horizon Archive Publications and Factsheets; the Gulf of Mexico Sea Grant Deepwater 

Horizon Oil Spill Research and Monitoring Activities Database; RestoreTheGulf.gov website, and the 

Deepwater Horizon Oil Spill Portal) and public search engines to search published journal articles, 

Federal documents, and research reports was conducted to determine the availability of recent information 

on topographic features. The search revealed new information on the affected environment that is 

pertinent to this Supplemental EIS.

Newly published research related to the corals found a high degree of population connectivity among 

the Flower Garden Banks and other coral reefs in the Florida Reef Tract and the Caribbean (GoodbodyGringley, 2011; Serrano, 2013). Genetic similarities for shallow-water Montastraea cavernosa

populations suggest that the Flower Gardens may be an important larval source and/or that there is an 

unidentified source providing larvae throughout the region. Differences among populations in appearance 

are phenotypic rather than genetic (Goodbody-Gringley, 2011; Serrano, 2013). As such, if further 

research determines that the Flower Gardens Banks are a larval source for the Florida Reef Tract, then 

these source corals may be more important to the ecology of the Gulf of Mexico at the landscape scale 

than previously suggested. The Flower Garden Banks are located in the WPA, but it demonstrates that 

the topographic structures located all along the shelf edge can be connected at the landscape and basin 

scale to reefs in the EPA.

Nash et al. (2013) reviewed the species diversity at the topographic features located off the southern 

Texas coast and found that each of these banks exhibited a high degree of diversity but that research on 

these features has not been updated in decades. They also noted that Southern Bank was a good surrogate 

for understanding trends in biodiversity among the other banks in the region and could be used as a 

sentinel site to detect landscape-scale changes. They also suggest that these reefs may have a high degree 

of connectivity with the Tuxpan Reef System in Mexican waters. This research highlights the potential 

role of topographic features on landscape-scale ecological processes. As such, topographic features could 

influence environments within the proposed EPA lease sale area.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. However, working in deep marine systems is complex and 

requires substantial resources; as such, research on these features has been limited. Thus, there is a 

substantial amount of information that remains unknown about these features. All analyses discussed in 

this Supplemental EIS and in Chapter 4.1.1.7 of the EPA 225/226 EIS, Chapter 4.2.1.7 of the 2012-2017 

WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, and Chapter 4.1.1.7 of the CPA 

235/241/247 Supplemental EIS are all based on incomplete information. Because there are no 

topographic features in the EPA, information collected throughout the GOM has been used in this 

analysis. For example, our understanding of the possible impacts of surface oil spills to topographic 

features in the GOM was determined by combining research on the depth and concentration of physical 

mixing of surface oil with the known depths of topographic features. These results suggest that, although 

oil measurements were not collected at every feature under every condition, topographic features exist at 

depths deeper than lethal concentrations of oil would be expected (Lange, 1985; McAuliffe et al., 1975 

and 1981a; Tkalich and Chan, 2002; Rezak et al., 1983; Wyers et al., 1986) unless dispersants are used. 
4-144 Central and Eastern Planning Areas Supplemental EIS

With respect to unavailable information in relation to the Deepwater Horizon explosion, oil, spill, and 

response, the majority of this information cannot be obtained because it has not been released. Relevant 

data on the status of topographic features may take years to acquire and analyze. This unavailable 

information may be relevant to adverse effects because the Deepwater Horizon explosion, oil spill, and 

response may have caused changes to baseline conditions for topographic features in the Gulf of Mexico. 

While outstanding reports are not expected to reveal reasonable foreseeably significant effects, BOEM 

nonetheless determined that additional information could not be timely acquired and incorporated within 

the timeline contemplated in the NEPA analysis of this Supplemental EIS. For example, if sampling 

techniques show that oil concentration were greater at Sackett Bank in the CPA (Sammarco, 2013), then it 

is possible that more oil reached other topographic features in the CPA than previously reported. 

However, until this information is made available, it is impossible to make this determination.

BOEM used existing information and reasonably accepted scientific methodologies to extrapolate 

from available information in completing this analysis and formulating the conclusions presented here. 

Although the body of available information is incomplete, the evidence currently available supports past 

analyses and does not indicate severe adverse impacts to topographic features. Therefore, BOEM has

determined that the incomplete or unavailable information is not essential to a reasoned choice among 

alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for topographic features presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for topographic features presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226. It is concluded that the EPA proposed action 

would have a negligible impact on the topographic features of the CPA.

4.2.1.8. Sargassum Communities

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. No new significant information was discovered that would alter the impact conclusion for 

Sargassum communities presented in those NEPA documents. The analysis and potential impacts 

discussed in those documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action is 

presented in Chapter 4.1.1.8 of the EPA 225/226 EIS and Chapter 4.2.1.8 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.8 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.8 of CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Sargassum is one of the most ecologically important brown algal genera found in the pelagic 

environment of tropical and subtropical regions of the world. The pelagic complex in the GOM is 

comprised of S. natans and S. fluitans (Lee and Moser, 1998; Stoner, 1983; Littler and Littler, 2000). 

Both species of Sargassum live immediately below the water surface and are fully adapted to a pelagic 

existence (Lee and Moser, 1998). These floating algae may be up to a few meters in length and may be 

found floating alone or in larger rafts or mats that support communities of fish and a variety of other 

marine organisms. The distribution, size, and abundance of Sargassum mats varies depending on 

environmental and physiochemical factors such as temperature, salinity, and dissolved oxygen. 

Generally, Sargassum is only seasonally abundant in the EPA during the warmer months. During the 
Description of the Environment and Impact Analysis 4-145

growing season, Sargassum moves from the western Gulf and into the eastern Gulf where it is entrained 

by the Loop Current and later the Gulf Stream Current and then transported into the Sargasso Sea in the 

Atlantic Ocean (Gower et al., 2006, Gower and King, 2008). Contained within the matrix of Sargassum

exists a community of vertebrates and invertebrates that may exist permanently or temporarily as these 

algae move throughout the Gulf of Mexico and into the Atlantic Ocean.

Impacts of Routine Activities and Accidental Events

Potential impact-producing factors associated with routine events for an EPA proposed action that 

could affect Sargassum communities may include the following: (1) drilling discharges (i.e., muds and 

cuttings); (2) produced water and well treatment chemicals; (3) operational discharges (i.e., deck 

drainage, sanitary and domestic water, and bilge and ballast water); and (4) physical disturbance from 

vessel traffic and the presence of exploration and production structures (i.e., rigs, platforms, and 

MODUs). Considering Sargassum’s widespread distribution and occurrence in the upper water column 

near the sea surface, it may be contacted by routine discharges from oil and gas operations; however, the 

quantity and volume of these discharges is relatively small compared with the surface area of pelagic 

waters of the CPA (268,922 km2

; 103,831 mi2). Therefore, contact through routine activities would only 

occur for a small portion of the Sargassum population and associated communities. Because these 

discharges are highly regulated to control toxicity and because they would continue to be diluted in Gulf 

water, produced-water impacts on Sargassum communities would be minimal.

The impingement by service vessels, working platforms, and drillships would contact only a very 

small portion of the Sargassum population. For those algae coming in contact with OCS oil- and gasrelated equipment, most should remain unharmed as they are pushed out of the way, but a small 

percentage of algae may be physically destroyed via propellers or stranded and subsequently become 

desiccated. For animals, the smaller organisms could be stranded with the plant or be destroyed by the 

equipment. Larger animals that often associate with Sargassum could avoid contact with most 

equipment. Because the distribution of Sargassum is dependent on many factors, the result is that the 

distribution is unpredictable and haphazard. As such, impacts to Sargassum communities associated with 

the EPA proposed action are expected to have a negligible effect on the small portion of the Sargassum

community that could be contacted. Additionally, Sargassum and many of the associated species have 

adapted a lifestyle that facilitates rapid growth, allowing for rapid recovery from negative impacts. No 

measurable impacts are expected to the overall population of the Sargassum community.

Potential impact-producing factors associated with accidental events for the EPA proposed action that 

could affect Sargassum and its associated communities include (1) spills (i.e., surface oil, fuel spills, and 

underwater well blowouts), (2) spill-response activities, and (3) chemical spills. These impacting factors 

would have varied effects depending on the intensity of the spill and the presence of Sargassum in the 

area of the spill. All types of spills, including surface oil and fuel spills, underwater well blowouts, and 

chemical spills, could potentially contact Sargassum communities if the algae are present. The quantity 

and volume of most of these spills would be relatively small compared with the surface waters of the EPA 

(2,662 km2

) and the CPA (268,922 km2; 103,831 mi2). Therefore, most spills would only contact a small 

portion of the Sargassum complex. Accidental spills would be diluted by Gulf water and, therefore, 

concentrations of toxic components that could potentially contaminate or kill Sargassum tissues or the 

associated community would also be reduced in this scenario. Any Sargassum that did come in contact 

with large concentrations of oil would eventually sink and advect oil bound to the plant to the seafloor. 

Vessel contact during response activities to Sargassum would be to capture algae that are dead or dying 

due to contact with oil; as such, response vessels would not impact the algae more than they are already 

impacted by the oil. The impacts to Sargassum that are associated with the EPA proposed action are 

expected to have only minor effects to a small portion of the Sargassum community. In the case of a very 

large spill, the Sargassum algae community could result in the death of a large number of algae across a 

geographically large area in the northern Gulf of Mexico. The Sargassum community lives in pelagic 

waters with generally high water quality and is expected to show good resilience to the predicted effects 

of spills. It has a yearly growth cycle that promotes quick recovery from impacts and that would be 

expected to restore typical population levels in 1-2 growing seasons. For information on the impacts 

resulting from events outside the scope of routine activities and accidental events, refer to Appendix B. 
4-146 Central and Eastern Planning Areas Supplemental EIS

Cumulative Impacts

Cumulative impacts from OCS oil- and gas-related operations include effects resulting from the EPA 

proposed action, as well as those resulting from past and future OCS leasing. These operations include 

drilling discharges, produced water and well treatment chemicals, operational discharges, accidental 

spills, and physical disturbance from OCS oil- and gas-related vessels and structures.

The OCS oil- and gas-related vessels transiting the GOM pass through Sargassum mats, producing 

slight impacts to the Sargassum community by breaking up clumps/mats or physically destroying the 

plant. Turbulence from wakes and direct damage from propellers on vessels servicing OCS oil- and gasrelated activities could affect Sargassum by breaking up mats or destroying strands. However, the 

amount of damage that vessels could inflict on a Sargassum mat would be minimized because of

Sargassum’s temporary and seasonal nature. When present, Sargassum mats are naturally loose knit with 

the ability to break apart and reform. Any vessel-related damage would likely be seen in the community 

of organisms inhabiting these mats, which may be killed when being struck by a vessel. Sea turtles and 

small fishes that reside in (rather than below) Sargassum mats would be most susceptible to this type of 

damage. However, the foot print of any vessel in the CPA is small compared with the distribution of 

Sargassum, and its transitory life history minimizes the possibility that any mat or the inhabitants are 

routinely affected. None of these would have more than minor localized effects to the affected mats as 

these mats routinely break up and move across extensive areas. The OCS oil- and gas-related structures 

can alter the movement of Sargassum mats and entrap small quantities of the algae. Because the 

proposed activity is not expected to substantially increase (if any) the number of OCS oil- and gas-related 

vessels, it is likely that OCS oil- and gas-related activities will only have a minimum and local effect on 

the Sargassum community.

Accidental spills could contribute to the cumulative impacts of OCS oil- and gas-related activities if 

an accidental spill was catastrophic, located in the “nursery” area where Sargassum resides in the western 

GOM, and was during a time of the year when the standing stock is restricted to the “nursery” area (e.g., 

late winter and spring) (Gower and King, 2011). The probability of this happening temporally and 

spatially is extremely low (refer to Appendix B). Given the life history of Sargassum, recovery of the 

algae could occur relatively rapidly; however, during the recovery period, animals that rely on Sargassum

to move around the Gulf or use Sargassum for refuge would be severely impacted due to the loss of 

habitat or a method of transportation. Cumulative impacts would be most pronounced for animals that 

rely exclusively on Sargassum and have low reproduction rates or have larvae that only disperse locally. 

Any spill that was noncatastrophic would likely only result in localized and short-term adverse impacts 

that would contribute little to the overall cumulative effect of the EPA proposed action.

Potential non-OCS oil- and gas-related factors include hurricanes, water quality, and non-OCS oiland gas-related vessel traffic. Hurricanes are major natural sources of impacts that affect Sargassum. 

The energy associated with these storms can break up mats, destroy strands, and displace animals; 

however, the life history and the widespread distribution of Sargassum communities minimizes the 

probability that any given storm will have any lasting population-level effects. Violent surface turbulence 

caused by these storms would dislocate many of the organisms living on and in the Sargassum. Some of 

the organisms (those that cannot swim or swim only weakly) such as nudibranchs (sea slugs), shrimp, 

Sargassum fish (Histrio histrio), and pipefish (Syngnathus spp.) would become separated from the algae. 

Without cover, many would fall prey to fish after a storm; others may sink to the seafloor and die. Some 

epifauna, such as hydroids, living on the algae may suffer physical damage or be broken off. Hurricanes 

can also drive Sargassum into waters less conducive for growth and can strand large quantities on 

beaches. In addition, Sargassum communities may be susceptible to nonpoint-source pollution from 

land-based runoffs carrying pollutants and excessive nutrients, especially in nearshore areas. The results 

could be a basinwide reduction in Sargassum biomass. Turbulence from wakes, direct damage from 

propellers, impingement on non-OCS oil- and gas-related vessels (i.e., commercial shipping, fishing 

activity, and pleasure boating) could also affect Sargassum by breaking up mats, destroying plants, or 

stranding plants. However, the amount of damage that vessels could inflict on a Sargassum mat would be 

minimized because of Sargassum’s transitory nature. Any vessel-related damage would likely be seen in 

the community of organisms inhabiting these mats, which may be killed by being struck by a vessel. Sea 

turtles and small fishes that reside in (rather than below) Sargassum mats would be most susceptible to 

this type of damage.
Description of the Environment and Impact Analysis 4-147

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources (e.g., the NOAA Gulf Spill Restoration Publications website, 

NOAA’s Environmental Response Management Application [ERMA] Gulf Response website, NOAA’s 

Deepwater Horizon Archive Publications and Factsheets, the Gulf of Mexico Sea Grant Deepwater 

Horizon Oil Spill Research and Monitoring Activities Database, RestoreTheGulf.gov website, and the 

Deepwater Horizon Oil Spill Portal) and public search engines to search published journal articles, 

Federal documents, and research reports was conducted to determine the availability of recent information 

on Sargassum communities. The search revealed new information on nursery areas for Sargassum, 

Sargassum’s suitability as habitat for other organisms, and impacts related to oil and dispersant exposure.

One of the primary publications relevant to this Supplemental EIS is the identification of the 

northwest Gulf of Mexico and the area near the mouth of the Amazon River as “nursery areas” for 

Sargassum in the Sargasso Sea. Estimates suggest that between 0.6 and 6 million metric tons of 

Sargassum are present annually in the Gulf of Mexico, with an additional 100 million metric tons 

exported to the Atlantic basin (Gower and King, 2008; Gower and King, 2011; Gower et al., 2013). This 

highlights the importance of the GOM in the global transport of Sargassum and that, even if there is a 

catastrophic spill in the GOM at the right place and time to severely impact Sargassum populations, the 

GOM is not the only source for the Sargasso Sea.

In addition, Rooker et al. (2012) quantified the use of Sargassum by billfishes in the Gulf of Mexico 

and concluded that the Sargassum biomass was not a suitable habitat for most juvenile billfishes because 

it can concentrate predators. As such, small-scale losses of Sargassum may not negatively impact billfish 

populations because billfish that settle in Sargassum may have a naturally low survival rate due to the fact 

that Sargassum also concentrates animals that prey on billfish of this size.

Powers et al. (2013) suggest that exposure to oil and/or dispersants can result in direct, sublethal, and 

indirect effects to Sargassum, resulting in death or a decrease in Sargassum-related ecosystem services. 

Therefore, if Sargassum is exposed to oil at the surface, it is expected that some of the plant material will 

die back or no longer provide a suitable habitat for other organisms. Their results were variable with 

respect to the amount of time or the rate it took for the plant to die back or succumb. Under normal 

conditions in the GOM, both species of Sargassum co-exist and conditions would never be identical to 

those in a laboratory. Ultimately, damage may occur to Sargassum if it is exposed to oil or dispersant; 

however, the effects would be localized and variable.

Finally, NMFS recently designated Sargassum as a critical habitat for loggerhead turtles (Caretta 

caretta) in the Gulf of Mexico and northwest Atlantic Ocean (Federal Register, 2014b). In the GOM, this 

includes all Sargassum between the 10-m (33-ft) depth contour and the outer boundary of the Exclusive 

Economic Zone. This designation could impact the commercial harvest of Sargassum; however, to our 

knowledge, the commercial harvest of Sargassum does not occur in the GOM. Additionally, NMFS does 

not expect that this designation would add any risk factors or add any conservation measures by BOEM 

because sea turtles and their required habitats are already adequately protected through the ESA Section 7 

process.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.1.8 of 

the EPA 225/226 EIS, Chapter 4.2.1.8 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 

231 Supplemental EIS, and Chapter 4.1.1.7 of the CPA 235/241/247 Supplemental EIS, BOEM has 

identified unavailable information regarding Sargassum in the EPA. This incomplete or unavailable 

information includes information on the effects of in-situ oil exposure and the movement patterns of 

Sargassum. BOEM used existing information and reasonably accepted scientific methodologies to 

extrapolate in completing this analysis. BOEM has determined that there are few foreseeable significant 

adverse impacts to the Sargassum population associated with routine or accidental OCS oil- and gasrelated events using publications like Gower and King (2011), Gower et al. (2013), and Powers et al. 
4-148 Central and Eastern Planning Areas Supplemental EIS

(2013). Gower and King (2011) and Gower et al. (2013) suggest that Sargassum is continually present in 

the west-central GOM and that it moves in a general west to east pattern during the growing season; 

however, movements at a finer temporal or spatial scale are more difficult to predict. Liu et al. (2014) 

noted that the toxicity or the presence of oil across the surface waters of the GOM was also variable at 

any given time, suggesting that it is difficult to predict the effects of coming in contact with surface oil. 

Additionally, Lindo-Atichati (2012) suggested that patterns of larval fish in the surface currents in the 

northern GOM were not consistent spatially or temporally and that they were highly dependent on 

mesoscale current structures like the Loop Current and associated eddies. Combined, these studies 

suggest that, as Sargassum is passively moved in the surface waters, its presence at any given location or 

at given any time is difficult to predict, especially as the population grows exponentially during the 

growing season. Powers et al. (2013) also suggest that there were adverse effects to Sargassum under the 

proper conditions, but the spatial or temporal extent of those effects remain unknown. It is expected that 

for routine activities or accidental events, the probability of enough Sargassum coming in contact with oil 

and dying as a result of this contact are low given that oil and Sargassum are each controlled by surface 

currents in differential manners. Ultimately, the cosmopolitan nature across the northern GOM and the 

reproductive capabilities of Sargassum provide a life history that is resilient towards localized or shortterm deleterious effects, such as those expected to be associated with routine OCS oil- and gas-related 

activities and noncatastrophic oil or chemical spills. Therefore, BOEM has determined that the 

incomplete information on Sargassum is not essential to a reasoned choice among alternatives and that 

the information used in lieu of the missing information is acceptable for this analysis.

BOEM recognizes that the incomplete information with respect to possible impacts to Sargassum in 

the EPA/CPA as a result of the Deepwater Horizon explosion, oil spill, and response may be relevant to 

the evaluation of impacts. Because of this, BOEM’s subject-matter experts have used available 

scientifically credible evidence in this analysis and applied it using accepted scientific methods and 

approaches to extrapolate in completing this analysis. Sargassum communities within the EPA/CPA 

were affected by the Deepwater Horizon explosion, oil spill, and response; however, because the spill did 

not occur near an area where Sargassum persists year round, abundance recovered rapidly. Powers et al. 

(2013) documented a four-fold increase in Sargassum in the north-central GOM in the years following the 

spill. Additional information related to other possible adverse impacts of the Deepwater Horizon

explosion, oil spill, and response to Sargassum communities in the EPA/CPA cannot be obtained during 

the timeline contemplated in the NEPA analysis of this Supplemental EIS because data related to research 

and monitoring related to the Deepwater Horizon explosion, oil spill, and response has yet to be 

completed and made publicly available. Therefore, BOEM has determined that the information is not 

essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for Sargassum communities presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for Sargassum communities presented in those 

NEPA documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.9. Chemosynthetic Deepwater Benthic Communities

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. No new significant information was discovered that would alter the impact conclusion for 

chemosynthetic communities presented in those NEPA documents. The analysis and potential impacts 

discussed in those documents still apply for proposed EPA Lease Sale 226.
Description of the Environment and Impact Analysis 4-149

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action is 

presented in Chapter 4.1.1.9 of the EPA 225/226 EIS and Chapter 4.2.1.9 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.9 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.9 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analyses incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Deepwater chemosynthetic communities in the proposed EPA lease sale area are not expected to 

differ from those in the adjacent CPA. There are presently no known sites in the proposed EPA lease sale 

area, though there is still some potential that they could occur in the EPA. The deep water provides a 

very stable environment, especially in the depths found for the proposed EPA lease sale area (>800 m; 

2,625 ft), and there are no notable environmental differences between the proposed EPA lease sale area 

and the adjacent CPA.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on chemosynthetic deepwater benthic communities of 

the EPA are bottom-disturbing activities associated with anchoring, structure emplacement, pipelaying, 

structure removal, and discharges of drill cuttings, muds, and produced water. The application of 

avoidance criteria for chemosynthetic communities provided as guidance in NTL 2009-G40, “Deepwater

Benthic Communities,” precludes the placement of a well within 610 m (2,000 ft) of any suspected site of 

a chemosynthetic community. Considerable mechanical damage could be inflicted upon deepwater 

chemosynthetic communities by routine OCS oil- and gas-related drilling activities associated with the 

EPA proposed action if mitigations are not applied to permits.

Bottom-disturbing activities associated with anchoring, structure emplacement, pipelaying, and 

structure removal cause localized bottom disturbances and disruption of benthic communities in the 

immediate area. Routine discharge of drill cuttings with associated muds can also affect the seafloor. 

Without mitigating measures, these activities could result in smothering by the suspension of sediments or 

the crushing of organisms residing in these communities. The risks of these physical impacts are greatly 

reduced by requiring the avoidance of potential chemosynthetic communities. Discharges of produced 

waters on the sea surface, chemical spills, and deck runoff would be diluted in surface waters, having no 

effect on seafloor habitats. Impacts from bottom-disturbing activities directly on chemosynthetic 

communities are expected to be extremely rare because of the application of required protective measures 

as described by NTL 2009-G40. Information included in required hazards surveys for oil and gas 

activities depicts areas that could potentially harbor chemosynthetic communities. This allows BOEM to 

require avoidance of any areas that are conducive to chemosynthetic growth. If a high-density 

community is subjected to direct impacts by bottom-disturbing activities, potentially severe or 

catastrophic impacts could occur due to raking of the sea bottom by anchors and anchor chains, and 

partial or complete burial by muds and cuttings. The severity of such an impact is such that there would 

be incremental losses of productivity, reproduction, community relationships, and overall ecological 

functions of the local community, and incremental damage to ecological relationships with the 

surrounding benthos.

Routine activities of the EPA proposed action are expected to cause no damage to the ecological 

function or biological productivity of chemosynthetic communities. Widely scattered, high-density 

chemosynthetic communities would not be expected to experience impacts from routine OCS oil- and 

gas-related activities in deep water because the impacts would be limited by avoidance criteria. Impacts 

on chemosynthetic communities from routine activities associated with the EPA proposed action would 

be minimal to none.

Accidental disturbances from the EPA proposed action, including oil spills and blowouts, have the 

potential to result in impacts on chemosynthetic communities of the CPA. Accidental events that could 

impact chemosynthetic communities are primarily limited to seafloor blowouts. A blowout at the seafloor 

could create a crater and could resuspend and disperse large quantities of bottom sediments. 

Chemosynthetic communities could be susceptible to physical impacts, including smothering, from a 

blowout depending on bottom-current conditions. The avoidance criteria described above reduces the risk 

of these physical impacts by requiring a buffer of 610 m (2,000 ft) from wells. The avoidance required 
4-150 Central and Eastern Planning Areas Supplemental EIS

would protect sensitive communities from heavy sedimentation, with only light sediment components 

able to reach the communities in small quantities.

Studies indicate that periods as long as hundreds of years are required to reestablish a seep 

community once it has disappeared (depending on the community type) (Powell, 1995; Fisher, 1995). 

There is evidence that substantial impacts on these communities could permanently prevent 

reestablishment (Fisher, 1995), particularly if hard substrate required for recolonization is buried by 

resuspended sediments from a blowout. However, when substrate remains available, chemosynthetic 

communities may reappear relatively quickly once the process begins, as in the case of a mussel 

community (Powell, 1995; Fisher, 1995). Because widely scattered, high-density chemosynthetic 

communities would be located at more than 610 m (2,000 ft) away from a blowout due to mitigating 

measures, potential accidental impacts from the EPA proposed action are expected to cause little damage 

to ecological or biological function of these communities.

If dispersants are applied to an oil spill, or if oil is ejected under high pressure, oil would mix into the 

water column, be carried by underwater currents, and eventually contact the seafloor in some form, either 

concentrated (near the source) or decayed (farther from the source), where it may impact patches of 

chemosynthetic community habitat in its path. As with sediments, the farther the dispersed oil travels, the 

more diluted the oil will become as it mixes with surrounding water.

There is some reason to believe the presence of oil would have a limited effect on chemosynthetic 

organisms because these communities live among oil and gas seeps; however, natural seepage is very 

constant and at very low rates as compared with the potential volume of oil released from a blowout or 

pipeline rupture. In addition, organisms inhabit certain niches within the gradients found at oil seeps, 

choosing locations with enough hydrocarbons to sustain their metabolism but not enough to be toxic. All 

seep organisms also require unrestricted access to oxygenated water at the same time as exposure to 

hydrocarbon energy sources. Oil plumes that contact the seafloor before degrading could potentially 

affect sensitive benthic communities if they happen to encounter such a habitat in a localized area.

Accidental impacts associated with the EPA proposed action would likely result in only minimal 

impacts to chemosynthetic communities with adherence to the proposed biological stipulation and the 

guidance provided in NTL 2009-G40.

Cumulative Impacts

Cumulative factors considered to impact the chemosynthetic communities of the Gulf of Mexico 

include both OCS oil- and gas-related and non-OCS oil- and gas-related activities. Cumulative OCS oiland gas-related impacts to deepwater communities in the Gulf of Mexico are considered negligible 

because of the application of the proposed mitigation. The most serious, impact-producing factor 

threatening chemosynthetic communities is physical disturbance of the seafloor, which could destroy the 

organisms of these communities. Such disturbance would most likely come from those OCS oil- and gasrelated activities associated with pipelaying, anchoring, structure emplacement, and seafloor blowouts. 

Drilling discharges and resuspended sediments have a potential to cause minor, mostly sublethal impacts 

to chemosynthetic communities, but substantial sediment accumulations could result in more serious 

impacts. Possible catastrophic oil spills (Appendix B) due to seafloor blowouts have the potential to 

devastate localized deepwater benthic habitats. This could occur in the case of a low-probability 

catastrophic spill combined with the application of dispersant or high-pressure ejection of oil, producing 

the potential to cause devastating effects on local patches of habitat in the path of subsea plumes where 

they physically contact the seafloor. The possible impacts, however, would be localized due to the 

directional movement of oil plumes by the water currents and because the sensitive habitats have a 

scattered, patchy distribution. Oil plumes that remain in the water column for longer periods would 

disperse and decay, having only minimal effect. However, these events are rare and would only affect a 

small portion of the sensitive benthic habitat in the Gulf of Mexico.

The non-OCS oil- and gas-related impact-producing factors include activities such as commercial 

fishing, trawling, storm impacts, and climate change. Fishing and trawling could potentially crush, 

topple, and remove chemosynthetic communities in the path of the gear. Because of the water depths 

where chemosynthetic communities live (>300 m; 984 ft) and because of the low density of potentially 

commercially valuable fishery species, these activities are not expected to substantially impact deepwater

benthic communities. However, if trawling were to occur over a chemosynthetic community, the 

community may be devastated. Regionwide and even global impacts from CO2 build-up and proposed 
Description of the Environment and Impact Analysis 4-151

methods to sequester carbon in the deep sea (e.g., ocean fertilization) are not expected to have major 

impacts to deepwater habitats in the near future. This is because changes to water temperature and pH 

from the CO2 would not reach extremes at the water depths where chemosynthetic communities occur. 

Overall, non-OCS oil- and gas-related activities are not expected to impact chemosynthetic communities, 

and the incremental contribution of the EPA proposed action to cumulative impacts is expected to be 

negligible to minor due to the proposed mitigation. 

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A broad Internet search for relevant new information and scientific journal articles made available 

since publication of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS was conducted using a publicly available 

search engine. The websites for Federal and State agencies, as well as other organizations, were reviewed 

for newly released information. Sources investigated include NOAA’s Ocean Exploration website, the 

Gulf of Mexico Alliance, the U.S. Environmental Protection Agency, USGS, and coastal universities.

Becker et al. (2013) studied stable isotope compositions of macrofaunal communities from shallow 

and deep sites. Tissue from shrimp and vestimentiferan tubeworm analysis showed that seep animals 

derive a greater proportion of their nutrition from seeps (and less from the surface) at greater depths. This 

study is relevant as it contributes to BOEM’s understanding of how these communities grow. No new 

studies that are relevant to deepwater chemosynthetic communities and that would impact those analyses 

or conclusions have been made available since publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined the new information does not 

change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in those NEPA documents, there remains incomplete or 

unavailable information on the effects of the Deepwater Horizon explosion, oil spill, and response on 

chemosynthetic communities that could potentially be relevant to reasonably foreseeable significant 

adverse impacts. Ongoing research projects funded by NOAA and the National Science Foundation are 

investigating these impacts. This information cannot reasonably be obtained because the long-term 

effects may not yet be detectable and the means to obtain it are unknown. This unavailable information 

may be relevant to adverse effects because it could provide an example of adverse impacts directly caused 

by the blowout of a well.

Existing information suggests that chemosynthetic communities did not experience significant 

adverse impacts from the Deepwater Horizon explosion, oil spill, and response. Numerous cruises using 

research ships, submersibles, and drift cameras investigated the seafloor in the area surrounding the well 

site (USDOC, NOAA, 2011a and 2011b). Damage to chemosynthetic communities in the vicinity of the 

Macondo well has not been reported to date (Shedd, official communication, 2014). Therefore, it has not 

been demonstrated that even a catastrophic oil spill would have significant adverse impacts or change the 

baseline for chemosynthetic communities in the Gulf of Mexico. Even though incomplete or unavailable 

information may eventually demonstrate that such communities in the vicinity of the Macondo well have 

been severely impacted by the Deepwater Horizon explosion, oil spill, and response, BOEM has 

determined that the information is not essential to a reasoned choice among alternatives because it is clear 

that vast impacts did not occur, or some indication of the impacts would have been revealed by the 

numerous studies. Even if some impacts did occur, chemosynthetic communities are found throughout 

the Gulf and are in patchy distributions, thus minimizing the proportion that would be likely to be 

impacted by any single event.

BOEM has also identified incomplete or unavailable information regarding the abundance and 

distribution of chemosynthetic communities in the GOM. Current understanding of the relationship 

between reflectivity of the seafloor and occurrence of potential habitat for chemosynthetic communities is 
4-152 Central and Eastern Planning Areas Supplemental EIS

used by BOEM to assess whether such communities occur in the vicinity of proposed OCS oil- and gasrelated activities. Similarly, side-scan sonar data are also used to determine the presence of likely habitat. 

These and other data are used to implement distance requirements to protect these communities. 

Incomplete or unavailable information could change our understanding of what signatures from such data 

sources indicate. Development of improved data or methods could help in determining where 

chemosynthetic communities occur. Such information could be used by BOEM to reduce impacts to 

these communities. Available scientifically credible information has been applied by BOEM’s subjectmatter experts using accepted scientific methodologies. The confirmed presence of chemosynthetic 

communities in areas predicted to have likely habitat via reflectivity or side-scan sonar data indicates that 

BOEM is currently able to effectively protect these communities from OCS oil- and gas-related activities. 

Therefore, BOEM has determined that the information is not essential to a reasoned choice among 

alternatives because existing information has shown that current methods provide for an appropriate 

means for protecting these communities.

Summary and Conclusion

BOEM has reexamined the analysis for chemosynthetic communities presented in the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS, with the understanding that no new significant information on chemosynthetic 

communities has become available since publication of those NEPA documents because of the available 

scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. Therefore, no new significant information was discovered that would alter the impact 

conclusion for chemosynthetic communities presented in those NEPA documents. The analysis and 

potential impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

4.2.1.10. Nonchemosynthetic Deepwater Benthic Communities

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for nonchemosynthetic deepwater benthic communities

presented in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the additional information 

presented below. No new significant information was discovered that would alter the impact conclusion 

for nonchemosynthetic communities presented in those NEPA documents. The analysis and potential 

impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine events, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.10 of the EPA 225/226 EIS and Chapter 4.2.1.10 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.10 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.10 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Nonchemosynthetic deepwater benthic communities in the proposed EPA lease sale area are not 

expected to differ from those in the adjacent CPA. Deepwater benthic communities, primarily structured 

by the coral Lophelia pertusa, are the nonchemosynthetic deepwater benthic communities that would be 

sensitive to impacts from OCS oil- and gas-related activities. The deep water provides a very stable 

environment, especially in the depths found for the proposed EPA lease sale area (>800 m; 2,625 ft), and 

there are no notable environmental differences between the proposed EPA lease sale area and the adjacent 

CPA.
Description of the Environment and Impact Analysis 4-153

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on nonchemosynthetic deepwater benthic 

communities of the EPA are bottom-disturbing activities associated with anchoring, structure 

emplacement, pipelaying, structure removal, and discharges of drill cuttings, muds, and produced water. 

The application of avoidance criteria for deepwater benthic communities provided as guidance in NTL 

2009-G40, “Deepwater Benthic Communities,” precludes the placement of a well within 610 m (2,000 ft) 

of any suspected site of a deepwater benthic community. Considerable mechanical damage could be 

inflicted upon sensitive nonchemosynthetic deepwater benthic communities by routine OCS drilling 

activities associated with the EPA proposed action if mitigations are not applied to permits. Deepwater 

live bottom communities, primarily structured by the coral Lophelia pertusa, are the nonchemosynthetic 

deepwater benthic communities that would be sensitive to impacts from OCS oil- and gas-related 

activities.

Bottom-disturbing activities associated with anchoring, structure emplacement, pipelaying, and 

structure removal cause localized bottom disturbances and disruption of benthic communities in the 

localized areas. If a sensitive community is subjected to direct impacts by bottom-disturbing activities, 

potentially severe or catastrophic impacts could occur due to raking of the sea bottom by anchors and 

anchor chains and partial or complete burial by muds and cuttings. The severity of such an impact is such 

that there would be incremental losses of productivity, reproduction, community relationships, and overall 

ecological functions of the local community, and incremental damage to ecological relationships with the 

surrounding benthos. Should this occur, it could result in recovery times in the order of decades or more 

with the possibility of the community never recovering (Food and Agriculture Organization of the United 

Nations, 2008; Jones, 1992; Probert et al., 1997). However, impacts from bottom-disturbing activities 

directly on deepwater coral communities are expected to be rare because of the application of required 

protective measures as guidance provided in NTL 2009-G40, “Deepwater Benthic Communities.”

Routine discharge of drill cuttings with associated muds can also affect the seafloor. In deep water, 

as opposed to shallower areas on the continental shelf, discharges of drilling fluids and cuttings at the sea 

surface are spread across broad areas of the seafloor and are generally distributed in thinner 

accumulations. A deepwater effects study funded by this Agency included determinations of the extent of 

muds and cuttings accumulations in approximately 1,000 m (3,281 ft) of water (CSA, 2006). 

Geophysical and chemical measurements indicated that a layer of cuttings and muds several centimeters 

thick was deposited within a 500-m (1,640-ft) radius of well sites. This suggests that the required 

2,000-ft (610-m) distance would protect deepwater benthic communities from impacts. Discharges of 

produced waters on the sea surface, chemical spills, and deck runoff would be diluted in surface waters, 

having no effect on seafloor habitats.

Routine activities associated with the EPA proposed action are not expected to cause damage to the 

ecological function or biological productivity of sensitive nonchemosynthetic deepwater benthic 

communities (deep coral reefs) due to the consistent application of BOEM’s protection guidance provided 

in NTL 2009-G40. Information included in required hazards surveys for OCS oil- and gas-related 

activities depicts areas that could potentially harbor nonchemosynthetic communities. This allows 

BOEM to require avoidance of any areas that are conducive to the growth of sensitive hard bottom 

communities. The same geophysical conditions associated with the potential presence of chemosynthetic 

communities also results in the potential occurrence of hard carbonate substrate and other associated, 

nonchemosynthetic deepwater benthic communities. Because of the required avoidance criteria, these 

communities are generally avoided in exploration and development planning and in bottom-disturbing 

activities. Impacts on sensitive deepwater communities from routine activities associated with the EPA 

proposed action would be minimal to none.

Accidental disturbances resulting from the EPA proposed action, including oil spills and blowouts, 

have the potential to result in impacts to nonchemosynthetic deepwater benthic communities of the EPA. 

Accidental events that could impact nonchemosynthetic deepwater benthic communities are primarily 

limited to seafloor blowouts. A blowout at the seafloor could create a crater and could resuspend and 

disperse large quantities of bottom sediments. This would destroy any organisms located nearby via 

burial or modification of narrow habitat quality requirements. Substantial impacts on these communities 

could permanently prevent reestablishment, particularly if hard substrate required for recolonization is 

buried by resuspended sediments from a blowout. Physical disturbance or destruction of a limited area of 

benthos or to a limited number of megafauna organisms (e.g., brittle stars, sea pens, and crabs) would not 
4-154 Central and Eastern Planning Areas Supplemental EIS

result in a major impact to the deepwater benthos ecosystem as a whole or even in relation to a small area 

of the seabed within a lease block. The application of avoidance criteria for deepwater coral communities 

as guidance provided in NTL 2009-G40 precludes the placement of a well within 610 m (2,000 ft) of any 

suspected site of a deepwater coral community, therefore distancing the community from sedimentation 

resulting from a possible blowout.

Accidental impacts due to oil spills caused by blowouts associated with the EPA proposed action 

would likely result in only minimal impacts to nonchemosynthetic deepwater benthic communities with 

adherence to the required avoidance measures. A blowout could result in a low-probability catastrophic 

spill (Appendix B), which is not part of the EPA proposed action and not likely expected, but the 

distance requirements would tend to lessen but not necessarily eliminate the impacts. A large subsea 

spill, combined with the application of dispersant or high-pressure ejection of oil, could mix oil into the 

water column, resulting in a subsea plume. Such a plume could potentially cause devastating effects on 

local patches of habitat in its path where it physically contacts the seafloor. If such an event were to 

occur, it could take decades to reestablish the nonchemosynthetic community in that location. The 

possible impacts, however, would be localized due to the directional movement of an oil plume by the 

water currents and because the sensitive habitats have a scattered, patchy distribution. As with sediments, 

the farther the dispersed oil travels, the more diluted it would become as it mixes with the surrounding 

water, and bacteria would degrade the oil over time (and distance). Oil plumes that remain in the water 

column for longer periods would disperse and decay, having only minimal effect.

Cumulative Impacts

Cumulative factors considered to impact the deepwater benthic communities (>300 m; 984 ft) of the 

Gulf of Mexico include both OCS oil- and gas-related and non-OCS oil- and gas-related activities. The 

OCS oil- and gas-related activities associated with pipelaying, anchoring, structure emplacement, drilling 

discharges, and seafloor blowouts have the potential to impact nonchemosynthetic deepwater benthic 

communities. The most serious, impact-producing factor threatening nonchemosynthetic communities is 

physical disturbance of the seafloor, which could destroy the organisms of these communities. Such 

disturbance would most likely come from those OCS oil- and gas-related activities associated with 

pipelaying, anchoring, and structure emplacement. Anchoring and pipeline and structure emplacement 

have the potential to crush deepwater benthic communities. Drilling discharges and resuspended 

sediments have a potential to cause minor, mostly sublethal impacts to nonchemosynthetic communities, 

but substantial accumulations could result in more serious impacts. Possible effects of an oil spill could 

be no discernible effect (for well-dispersed oil undergoing biodegradation), lack of growth, interruption of 

reproductive cycles, loss of gamete viability, tissue damage, death of affected organisms, and a reduction 

in the areas of distribution of species, depending on the amount and duration of contamination. Major 

impacts to localized benthic habitat are possible in the event of a low-probability catastrophic blowout on 

the seafloor (refer to Appendix B for more details). However, a low-probability catastrophic oil spill is 

not part of the EPA proposed action and not likely expected to occur. Therefore, cumulative impacts to 

deepwater communities in the Gulf of Mexico are considered negligible because of the application of the 

avoidance criteria described in NTL 2009-G40, which distances bottom-disturbing activities from 

sensitive habitats.

Non-OCS oil- and gas-related activities include fishing and trawling at a relatively small scale; largescale factors include storm impacts and climate change, CO2 build-up, and proposed methods to sequester 

carbon in the deep sea. Among the activities unrelated to the OCS Program (non-OCS oil and gas 

impact-producing factors), fishing and trawling represent the greatest possible threat to 

nonchemosynthetic communities and associated fish communities as a result of habitat destruction and 

overfishing (Kaiser, 2004). The impacts on deepwater fisheries in the GOM associated with deepwater 

coral habitat as a result of trawling activity are unknown, but because of the water depths (>300 m; 

984 ft) and the low density of potentially commercially valuable fishery species in areas associated with 

these communities, fishing and trawling are not expected to severely impact deepwater benthic 

communities. Regionwide and even global impacts from climate change, CO2 build-up, and proposed 

methods to sequester carbon in the deep sea (e.g., ocean fertilization) are not expected to have major 

impacts to deepwater habitats in the near future. More distant scenarios could include severe impacts. 

Storms generally cause little to no impacts at the depths (>300 m; 984 ft) that nonchemosynthetic 

communities occur. A storm could potentially cause some type of accident that could then cause 
Description of the Environment and Impact Analysis 4-155

secondary impacts, such as shipwrecks that could crush nonchemosynthetic communities, but such 

occurrences would be rare. State oil and gas activities are not expected to impact deepwater benthic 

communities due to the great distance between such activities and water depths of >300 m (984 ft).

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A broad Internet search for relevant new information was conducted using a publicly available search 

engine. Internet websites visited included four Federal agencies (USEPA, U.S. Geological Survey, 

NOAA [including Deepwater Horizon Bibliography], and BOEM), five coastal universities or 

universities with coastal divisions (University of Louisiana at Lafayette, Louisiana State University, 

Texas A&M University, University of Texas at Austin Marine Science Institute College of Natural 

Sciences, and Florida State University), several various stakeholders (Sierra Club, National Fish and 

Wildlife Foundation, Nature Conservancy, Gulf of Mexico Alliance, and Gulf of Mexico Program), and 

Louisiana Universities Marine Consortium (“Effects of Offshore Oil and Gas Development: A Current 

Awareness Bibliography”). Where applicable, websites of subdivisions of many of these agencies, 

universities, and stakeholders were also searched. Environmental journal articles were also located online 

using four search engines (JSTOR, EBSCO, Google Advanced Scholar Search, and Google Advanced 

Book Search). Three of the search engines collectively searched all of the ecology journals of six major 

publishers (John Wiley and Sons, Springer, Elsevier Science, Taylor and Francis Group, Cambridge 

University Press, and Oxford University Press). New information was found on habitat preferences for 

deepwater corals, as well as information on impacts from sedimentation and oil exposure.

Additional research has indicated that, if a well is located too close to deepwater coral habitat, 

damage may occur to the corals. Experiments with sediment and cold-water corals affirm possible lethal 

or sublethal impacts of anthropogenic sedimentation from drill cuttings (Allers et al., 2013). Branching 

coral varieties (e.g., Lophelia pertusa) have a structure that creates low-energy microenvironments inside 

the thickets, where experiments suggest the occurrence of lethal or sublethal impacts of drill cuttings 

occurs (Allers et al., 2013). These studies reaffirm the necessity for distancing wells from deepwater 

coral habitats so that the corals are protected from the accumulation of drill cuttings.

A new study has investigated the association of deepwater corals with oil seeps from the seafloor 

(Quattrini et al., 2013), documenting depth and seep activity as the most significant contributing factors 

on realized niches of these corals This research indicates that such an adaptation could result in resilience 

after exposure to oil from a blowout. Quattrini et al. (2013) also found that broken shells and coral rubble 

within soft bottom environments can provide sufficient substrate for settlement and growth of 

Callogorgia spp. (common octocorals). This new information is important because it shows that some 

deepwater corals may attach to broken shells or rubble scattered within otherwise soft bottom 

environments and could fail to be protected under BOEM’s policy because small patches of substrate do 

not always show up on surveys conducted to find probable deepwater coral habitat.

While the recent research has provided new information regarding impacts to nonchemosynthetic 

communities from oil spills, this new information does not change the conclusions of the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS because such a low-probability catastrophic event is unlikely to occur.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still incomplete or 

unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.1.10 of the EPA 

225/226 EIS, Chapter 4.2.1.10 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 231 

Supplemental EIS, and Chapter 4.1.1.10 of the CPA 235/241/247 Supplemental EIS, there remains 

incomplete or unavailable information on the effects of the Deepwater Horizon explosion, oil spill, and 

response on nonchemosynthetic deepwater benthic communities that may be relevant to reasonably 

foreseeable significant adverse impacts.
4-156 Central and Eastern Planning Areas Supplemental EIS

At present, the best available information does not provide data for a complete understanding of these 

four data gaps. BOEM used reasonably accepted scientific methodologies to extrapolate from existing 

information in completing this analysis and formulating the conclusions presented here. BOEM’s 

database of known deepwater benthic communities is incomplete. This database is used when deepwater 

exploration and development plans are reviewed to ensure that deepwater corals are not impacted by OCS 

oil- and gas-related activities. In order to fill this data gap, BOEM’s subject-matter experts identify 

probable habitat for deepwater corals using a database of 3D seismic data, which provides the locations of 

28,000 features that could represent such communities, in conjunction with side-scan sonar data and sitespecific, high-resolution surveys to identify sensitive habitat and communities. BOEM’s database of 3D 

seismic anomalies is well suited to the identification of general areas in which favorable coral habitat may 

occur and is sufficient in assisting BOEM in identifying areas that should be avoided for OCS oil- and 

gas-related activities. However, these surveys may not be sufficiently high resolution for the 

identification of small, scattered hard substrate, as discussed by Quattrini et al. (2013). Small patches of 

shell and rubble substrate are commonly observed in soft bottom habitat near active and inactive seep 

sites, which frequently occur in areas targeted for OCS oil- and gas-related activities. If data are sparse or 

indicate additional detail is warranted, this data gap may be additionally filled by site-specific video or 

photographic surveys to obtain this information. Despite these procedures, some communities scattered 

throughout predominantly soft bottom habitat may still be impacted if seafloor surveys do not suggest 

deepwater coral habitat is present. However, BOEM has determined that the incomplete information is 

not essential to a reasoned choice among alternatives because BOEM reviews plans on a case-by-case 

basis to reduce the possibility of impacting deepwater coral habitat.

Information on the toxic impacts of oil on deepwater corals is unavailable. An investigation of 

several deepwater octocorals and their association with oil seeps indicated that one species was found in 

association with oil seeps. The results of this study indicate that this coral could “possess mechanisms for 

dealing with natural levels of exposure to hydrocarbons” (Quattrini et al., 2013). Such an adaptation 

could result in resilience after exposure to oil from a blowout. It is possible that, if this coral may be 

tolerant of oil exposure, there may be others as well; however, that information is not known at this time. 

BOEM has determined that the incomplete information on the tolerance of deepwater corals to oil 

exposure is not essential to a reasoned choice among alternatives because BOEM requires that OCS oiland gas-related activities are sufficiently distanced from wells and because exposure from accidental 

events is unlikely.

Harm to nonchemosynthetic deepwater benthic communities as a result of bottom trawling would 

have an uncertain impact on deepwater bottom fisheries. In place of unavailable information on 

commercial fishing impacts on deepwater fisheries in areas of deepwater coral habitat, existing 

information on commercial fishing activity in the deep GOM shows that, unlike other areas in the Atlantic 

Ocean and in Europe, bottom-fishing and trawling efforts in the deeper water of the EPA are currently 

minimal, and areas where royal red shrimp are obtained are in soft bottom communities (CSA, 2002). 

The primary Gulf grounds are restricted to the upper continental slope off the Mississippi Delta (off 

Mississippi and Alabama) (CSA, 2002). Grounds there are blue-black terrigenous silt and greenish mud, 

and any known hard bottom (potential nonchemosynthetic communities) would not be trawled (CSA, 

2002). The monetary value of seafood is not worth the expense and trouble of deepwater trawling except 

to a few fishermen (CSA, 2002). The minimal fishery and minimal areal extent of potential 

nonchemosynthetic communities that are inside the outer boundaries of the fishery indicate that the 

footprint of the fishery would not likely overlap with the footprint of an impacted deepwater benthic 

community. Also, nonchemosynthetic communities are widely distributed in the Gulf of Mexico, mostly 

outside the narrowly distributed area of royal red shrimp grounds. Therefore, impacts on such 

communities as a whole are expected to be negligible. In conclusion, available information consistent 

with acceptable scientific reasoning shows that commercial fishing impacts on nonchemosynthetic 

deepwater benthic communities are expected to cause only negligible impacts.

BOEM has determined that the information is not essential to a reasoned choice among alternatives 

because nonchemosynthetic deepwater benthic communities are found throughout the Gulf and are in 

patchy distributions, minimizing the number that would be likely to be impacted by any single event. 

Available scientifically credible information has been applied by BOEM’s subject-matter experts using 

accepted scientific methodologies. Existing information indicates that, even though one or more coral

communities in the vicinity of the Macondo well was impacted by the largest oil spill in the history of the 
Description of the Environment and Impact Analysis 4-157

Gulf of Mexico, the impact to coral communities of the GOM, in terms of the proportion of all such 

communities that was affected, was relatively minor.

Summary and Conclusion

BOEM has reexamined the analysis for nonchemosynthetic deepwater benthic communities presented 

in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, 

and CPA 235/241/247 Supplemental EIS based on the additional information presented above. The 

potential for effects from changes to the affected environment (post-Deepwater Horizon explosion, oil 

spill and response), routine activities, accidental events, and cumulative impacts remains whether or not 

the No Action or Action alternative is chosen under this Supplemental EIS. Impacts on 

nonchemosynthetic deepwater benthic communities from either smaller accidental events or lowprobability catastrophic events will remain the same. No new significant information was discovered that 

would alter the impact conclusion for nonchemosynthetic communities presented in the previously 

mentioned NEPA documents because of the available scientifically credible evidence in this analysis and 

based upon accepted scientific methods and approaches. The analysis and potential impacts discussed in 

those documents still apply for proposed EPA Lease Sale 226.

4.2.1.11. Soft Bottom Benthic Communities

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for soft bottom benthic communities presented in the EPA 

225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information presented below. No new significant 

information was discovered that would alter the impact conclusion for soft bottom benthic communities 

presented in those NEPA documents. The analysis and potential impacts discussed in those documents 

EIS still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action is 

presented in Chapter 4.1.1.11 and of the EPA 225/226 EIS and Chapter 4.2.1.11 of the 2012-2017 

WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.11 of the WPA 233/CPA 

231 Supplemental EIS and Chapter 4.1.1.11 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors include seafloor disturbances (e.g., anchoring, 

trenching, infrastructure emplacement, and infrastructure removal), waste discharge (e.g., drilling muds 

and cuttings from oil and gas operations), and resuspension of sediments (e.g., pipeline burial and 

decommissioning operations). Disturbances of soft bottom benthic communities cause localized 

disruptions to benthic community composition and an alteration in food sources for some large 

invertebrate and finfish species. Analysis of these routine activities has identified only localized and 

short-term impacts to soft bottom benthic communities. Any activity that may affect the soft bottom 

communities would only impact a small portion of the overall area of the seafloor of the Gulf of Mexico. 

Because the soft bottom substrate is ubiquitous throughout the Gulf of Mexico, there are no lease 

stipulations to avoid these communities; however, other routine practices restrict detrimental activities 

that could cause undue harm to benthic habitats (e.g., discharge restrictions, debris regulations, and 

NPDES permits).

Accidental disturbances to soft bottom benthic communities can result from oil spills or blowouts

associated with OCS oil- and gas-related activities. Because of the proportionately small area that OCS 

oil- and gas-related activities occupy on the seafloor, only a very small portion of Gulf of Mexico soft 
4-158 Central and Eastern Planning Areas Supplemental EIS

bottom benthic communities would experience impacts as a result of blowouts and oil spills. The greatest 

impacts would likely occur closest to the source of the spill, and impacts would rapidly decrease with 

increased distance from the source. Contact with spilled oil outside the vicinity of the event would likely 

cause sublethal to negligible effects to benthic invertebrates and finfishes. Oil deposited on sediment 

communities could result in changes to local community structure. The organic enrichment of impacted 

sediments may result in altered sediment communities as bacteria degrade deposited organic matter. This 

response can lead to hypoxic conditions and a series of altered community structures until the organic 

matter is depleted and surface sediments return to an oxygenated state (Neff, 2005). Although an oil spill 

may have some detrimental impacts, especially closest to the occurrence of the spill, the impacts may be 

no greater than natural fluctuations (Clark, 1982), and impacts would affect a relatively small portion of 

the seafloor.

Cumulative Impacts

The cumulative analysis considers impacts resulting from ongoing routine oil and gas operations, as 

well as those resulting from past and future OCS leasing. These impacts include seafloor disturbances, 

waste discharge, and resuspension of sediments. Potential non-OCS oil- and gas-related disturbances 

include storms, sand mining, trawling, State oil and gas activities, and hypoxia.

Although OCS oil- and gas-related activities may have locally devastating impacts, impacted 

communities are repopulated relatively quickly and the cumulative effect on the overall seafloor and 

benthic communities would be negligible. Long-term OCS oil- and gas-related activities are not expected 

to adversely impact the entire soft bottom environment of the GOM because the locally impacted areas 

are small in comparison with the entire area of the GOM. For information on impacts resulting from 

events outside the scope of routine activities and accidental events, refer to Appendix B. 

Non-OCS oil- and gas-related disturbances are likely to impact the soft bottom communities more 

frequently than do OCS oil- and gas-related activities. In some areas, soft bottom benthic communities 

remain in an early successional stage due to the frequency of natural and anthropogenic disturbances. 

The incremental contribution of the EPA proposed action to the cumulative impact is expected to be 

minor.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

BOEM has examined newly available information for findings that may impact analyses of routine 

activities, accidental events, and cumulative impacts of OCS oil- and gas-related activities and potentially 

alter previous conclusions. A search of Internet information sources and scientific journals was 

conducted to determine the availability of recent information (including ACS Publications, BioOne, 

EBSCO, Elsevier, the Gulf of Mexico Fishery Management Council website, JSTOR, NMFS databases, 

NOAA Gulf Spill Restoration Publications website, PLoS ONE, Science Direct, and SeaGrant website). 

This search revealed that new information relevant to an analysis of the potential impacts of OCS oil- and 

gas-related activities on soft bottom benthic communities has been published.

New studies suggest that community structure of microbial communities can be influenced by the 

presence of oil, the weathered state of oil, and the chemical composition of oil (Kimes et al., 2013; Liu 

and Liu, 2013; Mason et al., 2014). These studies also document shifts in community structure as the 

environment transitions from aerobic to anaerobic, such as may occur as a result of excessive aerobic 

biodegradation of hydrocarbons. Data also suggest PAHs are more persistent in the deep-sea sediments 

and that degradation of these molecules may occur at a reduced rate when compared with other 

hydrocarbons (Kimes et al., 2013; Mason et al., 2014). The consequences of the slow breakdown of 

PAHs on sediment communities remain unknown; however, these studies suggest that the microbial 

community exhibits a high degree of community resiliency and may revert to a structure similar to prespill conditions once the PAHs are consumed. These findings support previous impact analyses because 

they indicate that lower-order soft bottom benthic communities’ structure may transition rapidly when 

exposed to changing environmental conditions, demonstrating significant resiliency. Based on the new 

information presented here and earlier analyses indicating that only a small portion of the GOM seafloor 
Description of the Environment and Impact Analysis 4-159

and associated benthic organisms would be impacted by oil exposure, BOEM concludes that populationlevel responses are not realistically expected.

An investigation of niche divergence among octocorals of the genus Callogorgia documented depth 

and the presence of hydrocarbon seep activity as the most significant contributing factors on niche 

preference (Quattrini et al., 2013). The study also noted that “flat or even concave surfaces with 

broken/dead shells or coral rubble” provided sufficient substrate for settlement and growth of these corals 

(Quattrini et al., 2013). This new information is important because small patches of shell and rubble 

substrate are commonly observed in soft bottom habitat near active and inactive seep sites, which 

frequently occur in areas targeted for OCS oil- and gas-related activities. Shell and coral rubble were not 

previously considered suitable substrate for coral settlement when potential impacts to deepwater coral 

habitat were analyzed. These study results may provide information for BOEM’s site-specific reviews of 

postlease OCS oil- and gas-related activities, enhancing BOEM’s ability to identify and protect 

potentially sensitive habitat and deepwater benthic communities within predominantly soft bottom 

habitat. In a second study, Allers et al. (2013) reported that the coral species Lophelia pertusa, if not 

completely buried by sediment, is capable of surviving episodic sedimentation from suspended sediment 

loads comparable to those expected from anthropogenic activities, such as intermittent drilling discharges. 

As with the previous study, this information is important for its potential to inform analyses and influence 

policy concerning the protection of sensitive communities located in the vicinity of OCS oil- and gasrelated activities within predominantly soft bottom habitat. For additional information on deepwater 

corals, refer to Chapter 4.1.1.10. 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from the 

EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231, Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS are still valid because no new significant information on soft bottom

benthic communities has become available since publication of those NEPA documents; nevertheless, 

there is still incomplete or unavailable information. As discussed in this Supplemental EIS and in 

Chapter 4.1.1.11 of the EPA 225.226 EIS, Chapter 4.2.1.11 of the 2012-2017 WPA/CPA Multisale EIS 

and WPA 233/CPA 231, Supplemental EIS, and Chapter 4.1.1.11 of the CPA 235/241/247 Supplemental 

EIS, BOEM has identified incomplete or unavailable information regarding the distribution and 

abundance of deepwater corals in areas of predominantly soft bottom habitat, the long-term effects of 

persistent PAHs (Kimes et al., 2013; Liu and Liu, 2013; Mason et al., 2014), and the long-term effects of 

episodic sedimentation events (Allers et al., 2013; Kimes et al., 2013; Liu and Liu, 2013;Mason et al., 

2014).

Although the distribution and abundance of deepwater corals in areas of predominantly soft bottom

habitat is not known, BOEM uses reasonably accepted scientific methodologies to extrapolate from 

existing information when locating communities and suitable substrates potentially impacted by proposed 

OCS oil- and gas-related activities. Data produced using several seafloor survey methods are analyzed to 

identify potential deepwater coral habitat. Refer to Chapter 4.2.1.10 for more detail on deepwater corals. 

BOEM has determined that the incomplete information is not essential to a reasoned choice among 

alternatives because BOEM reviews plans and surveys on a case-by-case basis to reduce the possibility of 

impacting deepwater coral habitat.

The cumulative impacts of OCS oil and gas exploration and development may result in locally 

significant impacts to soft bottom benthic communities. However, soft bottom communities are abundant 

throughout the GOM and the area of the seafloor impacted by OCS oil- and gas-related activities is very 

small in comparison with the overall area of soft bottom habitat in the GOM. Analysis of available 

information did not identify any reasonably foreseeable impacts extending beyond localized responses to 

persistent PAHs or sedimentation events among soft bottom inhabitants (Kimes et al., 2013; Liu and Liu, 

2013; Mason et al., 2014). Soft bottom benthic communities within the EPA were likely not affected to 

any discernible degree by the Deepwater Horizon explosion, oil spill, and response because of the EPA’s 

distance from the Macondo well. Although information on possible impacts to soft bottom benthic 

communities in the EPA may be relevant to the baseline conditions of the affected environment, 

incomplete information and other relevant data regarding the status and function of soft bottom benthic 

communities, including that being developed through the NRDA process, may take years to acquire and 
4-160 Central and Eastern Planning Areas Supplemental EIS

analyze and cannot be obtained within the timeline contemplated in the NEPA analysis of this 

Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing the analysis of impacts to soft bottom benthic communities and subsequent recovery. The 

new information summarized above indicates microbial communities transition rapidly when exposed to 

changing environmental conditions and demonstrate significant resiliency (Kimes et al., 2013; Liu and 

Liu, 2013; Mason et al., 2014). Although the body of available information is incomplete and long-term 

effects cannot yet be known, the evidence currently available supports past analyses and does not indicate 

severe adverse impacts to the soft bottom benthic communities of the EPA or entire GOM as a result of 

OCS oil- and gas-related activities. Therefore, BOEM has determined that the incomplete information is 

not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for soft bottom benthic communities presented in the EPA 

225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information provided above. No new significant 

information was discovered that would alter the impact conclusion for soft bottom benthic communities 

presented in those NEPA documents because of the available scientifically credible evidence in this 

analysis and based upon accepted scientific methods and approaches. The analysis and potential impacts 

discussed in those documents still apply for proposed EPA Lease Sale 226.

4.2.1.12. Marine Mammals

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for marine mammals presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for marine mammals presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.12 of the EPA 225/226 EIS and Chapter 4.2.1.12 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.12 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.12 of CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Operators must adhere to certain NTLs while conducting OCS oil- and gas-related activities in order 

to reduce impacts to marine mammals. The operator’s reaffirmed compliance with NTL 2012-JOINTG01 (“Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”) and NTL 2012-BSEEG01 (“Marine Trash and Debris Awareness and Elimination”), as well as the limited scope, timing, and 

geographic location of the EPA proposed action, would result in negligible effects from the proposed 

drilling activities on marine mammals. In addition, NTL 2012-JOINT-G02, “Implementation of Seismic 

Survey Mitigation Measures and Protected Species Observer Program,” minimizes the potential of harm 

from seismic operations to marine mammals. These mitigations include onboard observers, airgun shutdowns for whales in the exclusion zone, ramp-up procedures, and the use of a minimum sound source.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on marine mammals of the EPA are the degradation of 

water quality from operational discharges; noise generated by aircraft, vessels, operating platforms, and 
Description of the Environment and Impact Analysis 4-161

drillships; vessel traffic; explosive structure removals; seismic surveys; and marine debris from service 

vessels and OCS oil- and gas-related facilities. Some routine activities related to the EPA proposed 

action have the potential to have adverse, but not significant, impacts to marine mammal populations in 

the Gulf of Mexico. Impacts from vessel traffic, structure removals, and seismic activity could negatively 

impact marine mammals by increasing noise levels as well as having the potential to harm or harass 

marine mammal species. These activities, when mitigated as required by BOEM and NMFS, are not 

expected to have long-term impacts on the size and productivity of any marine mammal species or 

population. Mitigations reduce the risk of harassing or harming marine mammal species. Other routine 

activities such as aircraft activity, drilling and production noise, discharges, and marine debris are 

expected to have negligible effects.

Accidental disturbances resulting from the EPA proposed action, including oil spills, blowouts, and 

spill-response activities, have the potential to have adverse, but not significant impacts, on marine 

mammals of the EPA. Characteristics of impacts (i.e., acute vs. chronic impacts) depend on the 

magnitude, frequency, location, and date of accidents; characteristics of spilled oil; spill-response 

capabilities and timing; and various meteorological and hydrological factors. Oil spills may cause 

chronic (long-term lethal or sublethal oil-related injuries) and acute (spill-related deaths occurring during 

a spill) effects on marine mammals. Long-term effects include decreases in prey availability and 

abundance because of increased mortality rates, change in age-class population structure because certain 

year-classes were impacted more by oil, decreased reproductive rate, and increased rate of disease or 

neurological problems from exposure to oil (Harvey and Dahlheim, 1994). The effects of cleanup 

activities are unknown, but increased human presence (e.g., vessels) could add to changes in marine 

mammal behavior and/or distribution, thereby additionally stressing animals and perhaps making them 

more vulnerable to various physiologic and toxic effects.

Even after the spill is stopped, oiling or deaths of marine mammals would still occur due to oil and 

dispersants persisting in the water, past marine mammal and oil or dispersant interactions, and ingestion 

of contaminated prey. The animals’ exposure to hydrocarbons persisting in the sea may result in 

sublethal impacts (e.g., decreased health, reproductive fitness, and longevity; and increased vulnerability 

to disease) and some soft tissue irritation, respiratory stress from inhalation of toxic fumes, food reduction 

or contamination, direct ingestion of oil and/or tar, and temporary displacement from preferred habitats.

The cumulative impact from oil and gas operations includes effects resulting from the EPA proposed 

action, as well as those resulting from past and future OCS leasing. These impact-producing factors 

include ingestion and entanglement in marine debris; contaminant spills and spill-response activities; 

vessel strikes; and noise from numerous sources, seismic surveys, and explosive structure removals. 

Potential non-OCS oil- and gas-related factors include vessel traffic and related noise (including from 

commercial shipping and research vessels), State oil and gas activities, military operations, commercial 

fishing, pollution, scientific research, and natural phenomena. Groups such as the military (U.S. Navy 

and USCG) and other Federal agencies (USEPA, the Corps of Engineers, and NMFS), dredges, 

commercial fishermen, and recreational boaters operate vessels and aircraft that can contribute to the 

ambient noise in the GOM.

Noise in the ocean has become a worldwide topic of concern, particularly in the last two decades. 

Noises originate from a broad range of sources, both natural and anthropogenic (Richardson et al., 1995). 

Virtually all of the marine mammal species in the GOM have been exposed to OCS industrial noise due 

to the rapid advance into GOM deep oceanic waters by the oil and gas industry in recent years; whereas, 

20 years ago, the confinement of industry to shallower coastal and continental shelf waters generally only 

exposed two species of marine mammals (the bottlenose dolphin and the Atlantic spotted dolphin) to 

industry activities and the related sounds. Most marine mammal species in the GOM, and particularly the 

deepwater mammals, rely on echolocation for basic and vital life processes including feeding, navigation, 

and conspecific and mate communication. Noise levels that interfere with these basic marine mammal 

capabilities could have impacts on individuals and populations. The OCS oil and gas industry’s 

operations contribute noise to the marine environment from several different operations. It is believed 

that some of the industry-related noise is at lower frequencies than is detectable or in the sensitivity range 

of most of the GOM marine mammal species (Southall et al., 2007). 
4-162 Central and Eastern Planning Areas Supplemental EIS

Cumulative Impacts

Cumulative impacts on marine mammals are expected to result in a number of chronic and sporadic 

sublethal effects (i.e., behavioral effects and nonfatal exposure to or intake of OCS oil- and gas-related 

contaminants or discarded debris) that may stress and/or weaken individuals of a local group or 

population and predispose them to infection from natural or anthropogenic sources (Harvey and 

Dahlheim, 1994). Disturbance (noise from vessel traffic and drilling operations) and/or exposure to 

sublethal levels of toxins and anthropogenic contaminants may stress animals, weaken their immune 

systems, and make them more vulnerable to parasites and diseases that normally would not be fatal 

(Harvey and Dahlheim, 1994). Cumulative noise can potentially cause masking effects that may prevent 

an individual from detecting another individual’s calls or interfere with navigation ability (Hatch et al., 

2014; Merchant et al., 2014; Southall et al., 2007). Available information regarding industry-related and 

other anthropogenic sound effects on marine mammals are mainly qualitative descriptions, but a 

committee was convened in 2010 to advance a method for systematic evaluation (Streever et al., 2012). 

Streever et al. (2012) identified typical anthropogenic sources during autumn bowhead whale migration in 

the Alaskan Beaufort Sea (i.e., production, seismic data acquisition, and vessel traffic), used available 

empirical data for bowhead behavior inputs, and conducted a modelled sea trial using simplified 

assumptions to collect acoustic data for individual virtual animals. Empirical data (i.e., bowhead 

behavioral response to sound and migration patterns) provided relevant and necessary inputs for the 

model, ambient noise was not considered, and overall, the committee offered documentation and guidance 

for future work (Streever et al., 2012). Baseline soundscape is not well-documented for the GOM, and 

marine mammal behavioral data related to sound effects are not available for all species. These and other 

factors are essential for modelling inputs and for predicting effects of sound on marine mammals. BOEM 

continues to make efforts to gain a more thorough understanding of the potential effects of sound on 

marine mammals. The net result of any disturbance will depend upon the size and percentage of the 

population likely to be affected, the ecological importance of the disturbed area, the environmental and 

biological parameters that influence an animal’s sensitivity to disturbance and stress, or the 

accommodation time in response to prolonged disturbance (Hatch et al., 2008; Geraci and St. Aubin, 

1980).

The effects of the EPA proposed action, when viewed in light of the effects associated with other 

past, present, and reasonably foreseeable future activities, may result in impacts to marine mammals when 

compared with before the Deepwater Horizon explosion, oil spill, and response; however, the magnitude 

of those effects cannot yet be determined. Nonetheless, operators are required to follow all applicable 

lease stipulations and regulations, as clarified by NTLs (NTL 2012-JOINT-G01, NTL 2012-BSEE-G01, 

and NTL 2012-JOINT-G02), to minimize these potential interactions and impacts. Even when taking into 

consideration the potential effects of the Deepwater Horizon explosion, oil spill, and response and the 

minimization of impacts through lease stipulations and regulations, no significant cumulative impacts to 

marine mammals would be expected as a result of the proposed activities when added to the impacts of 

past, present, or reasonably foreseeable oil and gas development in the area, as well as other ongoing 

activities in the area.

Non-OCS oil- and gas-related activities that may affect marine mammal populations include vessel 

traffic and related noise (including from commercial shipping and research vessels), State oil and gas 

activities, military operations, commercial fishing, pollution, scientific research, and natural phenomena. 

Groups such as the military (U.S. Navy and USCG) and other Federal agencies (USEPA, the Corps of 

Engineers, and NMFS), dredges, commercial fishermen, and recreational boaters operate vessels and 

aircraft that can contribute to the ambient noise in the GOM. Pollution in the ocean comes from many 

point and nonpoint sources. The drainage of the Mississippi River results in massive amounts of 

chemicals and other pollutants being constantly discharged into the GOM. Tropical storms and 

hurricanes are normal occurrences in the GOM and along the coast. Generally, the impacts have been 

localized and infrequent. The actual impacts of these storms on the animals in the GOM, and the listed 

species and critical habitat in particular, have not yet been determined and, for the most part, may remain 

very difficult to quantify.

An unusual mortality event (UME) is defined under the Marine Mammal Protection act as “a 

stranding that is unexpected; involves a significant die-off of any marine mammal population; and 

demands immediate response.” Infections, biotoxins, human interactions, and malnutrition are considered 

causes of UMEs. A UME for bottlenose dolphins occurred off the coast of Texas in 2011-2012 when 
Description of the Environment and Impact Analysis 4-163

126 dolphins were stranded. While there is no known cause for the strandings, preliminary findings 

include infected lungs, poor body condition, discoloration of the teeth, and substance in the stomach in 

four of the animals (USDOC, NMFS, 2014a). Further, a UME for the entire northern GOM began in 

February 2010 and has continued through 2014. However, this UME is defined by the Florida panhandle 

west to the Louisiana-Texas border (USDOC, NMFS, 2014b). The relationship of these UMEs to the 

Deepwater Horizon explosion, oil spill, and response remains unclear (refer to the “Incomplete or 

Unavailable Information” section below).

Within the GOM, there is a long-standing and well-developed OCS Program (more than 50 years); 

there are no data to suggest that activities from the preexisting OCS Program are significantly impacting 

marine mammal populations. The incremental contribution of the EPA proposed action to the cumulative 

impact is expected to be negligible. There are existing leases in the EPA, so there is potential for 

exploration, drilling, and production activities. In addition, the potential for non-OCS oil- and gas-related 

activities discussed herein will continue to occur in the EPA irrespective of the EPA proposed action. 

The potential for effects from changes to the affected environment (post-Deepwater Horizon ), routine 

activities, accidental spills, low-probability catastrophic spills (which are discussed in Appendix B and 

which are not part of the EPA proposed action and not likely expected), and cumulative effects remains 

whether or not the No Action or Action alternative is chosen under this Supplemental EIS. Impacts on 

marine mammals from either smaller accidental events or low-probability catastrophic events would 

remain the same.

Therefore, in light of the EPA proposed action and its impacts, the incremental effect of the EPA 

proposed action on marine mammal populations is not expected to be significant when compared with 

non-OCS oil- and gas-related activities.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources (NOAA’s websites and the RestoreTheGulf.gov website), as 

well as recently published journal articles, was conducted to determine the availability of recent 

information on marine mammals. 

On December 13, 2010, NMFS declared a UME for cetaceans (whales and dolphins) in the Gulf of 

Mexico. Evidence of the UME was first noted by NMFS as early as February 2010, before the 

Deepwater Horizon explosion, oil spill, and response. As of November 16, 2014, a total of 

1,283 cetaceans (6% stranded alive and 94% stranded dead) have stranded since the start of the UME, 

with a vast majority of these strandings between Franklin County, Florida, and the Louisiana/Texas 

border (Table 4-1). In addition to investigating all other potential causes, scientists are investigating what 

role Brucella plays in the northern Gulf of Mexico UME. As of October 28, 2014, 54 out of 177 dolphins 

tested were positive or suspected positive for Brucella. More detail on the UME can be found on 

NMFS’s website (USDOC, NMFS, 2014c). It is unclear at this time whether the increase in strandings is 

related partially, wholly, or not at all to the Deepwater Horizon explosion, oil spill, and response.

The 21 species of cetaceans that occur in the GOM are identified in the most recent NMFS annual 

Stock Assessment Report (Waring et al., 2014). Most of the information on GOM species was updated in 

the 2012 Stock Assessment Report; however, the 2013 Stock Assessment Report updated population 

abundance estimates for the Gulf of Mexico oceanic stock of bottlenose dolphins (5,806) and for Risso’s 

dolphins (2,442) found in waters from the 200-m (656-ft) isobath to the seaward extent of the U.S. 

Exclusive Economic Zone during a 2009 oceanic survey (Waring et al., 2014). During 2010, Waring 

et al. (2014) found that 221 bottlenose dolphins were considered to be part of the UME and most are 

assumed to belong to one of the coastal stocks or to bay, sound, and estuary stocks; however, it is possible 

that part of the UME belonged to the continental shelf or oceanic stocks. In 2010-2011, Risso’s dolphins 

were not considered part of the UME (Waring et al., 2014). 

A study recently published from the NRDA process began evaluating the possible effects of the 

Deepwater Horizon explosion, oil spill, and response on Barataria Bay bottlenose dolphins, which 

received some degree of prolonged and heavy oiling, and compared them with bottlenose dolphins 

located in Sarasota Bay where no oil was observed. Bottlenose dolphins in Barataria Bay exhibited an 

elevated occurrence of overall poor health and prevalence of poor body condition, disease, and 

abnormalities as compared with Sarasota bottlenose dolphins and dolphins from other U.S. coastal sites 
4-164 Central and Eastern Planning Areas Supplemental EIS

(Schwacke et al., 2013). While this information may ultimately be useful in expanding the available 

knowledge on baseline environmental conditions following the Deepwater Horizon explosion, oil spill, 

and response, it remains difficult to draw specific conclusions regarding the current overall bottlenose 

dolphin population in the GOM.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions presented in the Five-Year Program EIS, EPA 225/226 EIS, and WPA 

233/CPA 231 Supplemental EIS; nevertheless, there is still incomplete or unavailable information. As 

discussed in this Supplemental EIS, as well as in the previously mentioned NEPA documents, BOEM has 

identified incomplete information for impacts on marine mammals from the Deepwater Horizon

explosion, oil spill, and response. The final determinations on damages to marine mammal resources 

from the Deepwater Horizon explosion, oil spill, and response will ultimately be made through the 

NRDA process. The Deepwater Horizon explosion, oil spill, and response will ultimately allow a better 

understanding of any realized effects from a low-probability catastrophic spill, which is not part of the 

EPA proposed action and not likely expected. However, even with recent publications such as Schwacke 

et al. (2013), the best available information on impacts to marine mammals does not yet provide a 

complete understanding of the effects of the oil spill and active response/cleanup activities from the 

Deepwater Horizon explosion, oil spill, and response on marine mammals as a whole in the GOM and 

whether these impacts reach a population level. As identified above, unavailable information such as the 

anthropogenic impacts following an oil-spill response and the population variation due to naturally 

occurring events such as hurricanes and UMEs, provides challenges in understanding the baseline 

conditions and changes within marine mammal populations. As also discussed earlier, the actual impacts 

of tropical storms and hurricanes on the GOM, and on the listed species and critical habitat in particular, 

have not yet been determined and, ultimately, the impacts may remain very difficult to quantify. 

However, BOEM used existing information and reasonably accepted scientific methodologies to 

extrapolate from available information in completing this analysis.

BOEM concludes that the unavailable information from these events may be relevant but not 

necessarily essential to reasonably foreseeable significant adverse impacts to marine mammals from the 

Deepwater Horizon explosion, oil spill, and response. In some specific cases, such as with bottlenose 

dolphins as noted above, the unavailable information may also be relevant to a reasoned choice among the 

alternatives based on the discussion below. The cost of obtaining data on the effects from the UME

and/or Deepwater Horizon explosion, oil spill, and response are exorbitant, duplicative of efforts already 

being undertaken as part of the UME and NRDA, and would likewise take years to acquire and analyze 

through the existing NRDA and UME processes. The NMFS has jurisdiction for the investigation of 

marine mammal strandings and has only released raw data on stranding numbers to date. Therefore, it is 

not possible for BOEM to obtain this information within the timeline contemplated in the NEPA analysis 

of this Supplemental EIS, regardless of the cost or resources needed. In light of the incomplete or 

unavailable information, BOEM’s subject-matter experts have used available scientifically credible 

evidence, such as the scientific research evaluated in the EPA 225/226 EIS and 2012-2017 WPA/CPA 

Multisale EIS as well as new information such as the Schwacke et al. (2013) paper, in this analysis and 

applied it using accepted scientific methods and approaches. Analyses relevant to the UME and 

Deepwater Horizon explosion, oil spill, and response discussion identify that localized 

populations/species in the EPA are unlikely to have been affected with the majority of oil-spill effect data 

derived from the Exxon Valdez and limited exposure treatments (i.e., Waring et al., 2011; Geraci, 1990; 

St. Aubin and Lounsbury, 1990). Wider ranging species may have been exposed to the Deepwater 

Horizon oil spill but are unlikely to have experienced population-level effects due to their wide-ranging 

distributions and behavior (i.e., Davis et al., 2000; Jochens et al., 2008). Further, impacts from the 

Deepwater Horizon explosion, oil spill, and response may be difficult or impossible to discern from other 

factors. For example, even 20 years after the Exxon Valdez spill, long-term impacts to marine mammal 

populations were still being investigated (Matkin et al., 2008). Therefore, it is not possible for BOEM to 

obtain this information within the timeline contemplated in the NEPA analysis of this Supplemental EIS, 

regardless of the cost or resources needed. In light of the incomplete or unavailable information, 

BOEM’s subject-matter experts have used available scientifically credible evidence in this analysis and 

applied it using accepted scientific methods and approaches. Nevertheless, a complete understanding of 
Description of the Environment and Impact Analysis 4-165

the missing information is not essential to a reasoned choice among alternatives for this Supplemental EIS 

(including the No Action and Action alternatives) for the three main reasons listed below.

(1) The CPA, which is adjacent to the proposed EPA lease sale area, is an active oil and 

gas region with ongoing (or the potential for) exploration, drilling, and production 

activities. In addition, non-OCS oil- and gas-related activities will continue to occur 

in the CPA and EPA irrespective of the EPA proposed action (i.e., fishing, military 

activities, and scientific research). The potential for effects from changes to the 

affected environment (post-Deepwater Horizon), routine activities, accidental spills 

(including low-probability catastrophic spills), and cumulative effects remains 

whether or not the No Action or Action alternative is chosen under this 

Supplemental EIS. Impacts on marine mammals from either smaller accidental 

events or low-probability catastrophic events will remain the same.

(2) Some marine mammal populations in the EPA do not generally travel throughout 

areas affected by spilled oil from the Deepwater Horizon explosion, and they would 

not be subject to a changed baseline or cumulative effects from the Deepwater 

Horizon explosion, oil spill, and response (e.g., coastal bottlenose dolphins that are 

resident in the EPA). Other marine mammals, such as Bryde’s whales 

(Balaenoptera edeni) and West Indian manatees (Trichechus manatus), although not 

likely affected by the Deepwater Horizon explosion, oil spill, and response, also do 

not typically occur in the proposed EPA lease sale area. 

(3) Other wide-ranging populations of marine mammals that may occur in the GOM 

and within areas affected by the spill are unlikely to have experienced populationlevel effects from the Deepwater Horizon explosion, oil spill, and response given 

their wide-ranging distribution and behaviors.

Summary and Conclusion

BOEM has reexamined the analysis for marine mammals presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS, based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for marine mammals presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.13. Sea Turtles

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for sea turtles presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for sea turtles in those NEPA documents. The 

analysis and potential impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential routine 

activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.13 of the EPA 225/226 EIS and Chapter 4.2.1.13 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.13 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.13 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA
4-166 Central and Eastern Planning Areas Supplemental EIS

documents. Any new information that has become available since those documents were published is 

presented below.

In order to minimize potential interactions and impacts to sea turtles, operators are required to follow 

all applicable lease stipulations and regulations, as clarified by NTLs. The operator’s reaffirmed 

compliance with NTL 2012-JOINT-G01 (“Vessel-Strike Avoidance and Injured/Dead Protected Species 

Reporting”) and NTL 2012-BSEE-G01 (“Marine Trash and Debris Awareness Elimination”), as well as 

the limited scope, timing, and geographic location of the EPA proposed action, would result in negligible 

effects from the EPA proposed action on sea turtles. In addition, NTL 2012-JOINT-G02, 

“Implementation of Seismic Survey Mitigation Measures and Protected Species Observer Program,” 

minimizes the potential of harm from seismic operations to sea turtles and marine mammals; these 

mitigations include onboard observers, airgun shut-downs for whales in the exclusion zone, ramp-up 

procedures, the use of a minimum sound source, and delayed use of explosives when sea turtles or marine 

mammals are observed in the exclusion zone.

Impacts of Routine Activities and Accidental Events

The routine activities associated with proposed EPA Lease Sale 226 that could potentially affect sea 

turtles include the following: the degradation of water quality resulting from operational discharges; 

noise generated by helicopter and vessel traffic, platforms, drill ships, and seismic exploration; noise and 

impact from explosive structure removals; vessel strikes; and marine debris generated by service vessels 

and OCS oil- and gas-related facilities. Noise disturbance and/or exposure to sublethal levels of toxins 

and anthropogenic contaminants may stress animals, weaken their immune systems, and make them more 

vulnerable to parasites and diseases that normally would not be fatal during their life cycle. Because of 

the mitigations (e.g., BOEM and BSEE proposed compliance with NTLs) as described in the in the 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS and as summarized below, routine activities (e.g., operational discharges, noise, vessel 

traffic, and marine debris) related to the EPA proposed action are not expected to have long-term adverse 

effects on the size and productivity of any sea turtle species or populations in the northern Gulf of 

Mexico. With the mitigations, few deaths are expected from chance collisions with OCS oil- and gasrelated service vessels, ingestion of plastic material, and pathogens. To minimize impacts to sea turtles 

and marine mammals from explosive structure removal, the use of explosives is delayed when turtles or 

marine mammals are observed in the exclusion zone. In addition, the best available scientific information 

indicates that sea turtles do not rely on acoustics; therefore, vessel noise and related activities (drilling, 

seismic exploration, and explosive structure removals) would have limited effect. Most routine OCS oiland gas-related activities are expected to have sublethal effects that are not expected to rise to the level of 

significance.

Accidental events including marine debris generated by service vessels and OCS oil- and gas-related 

facilities, blowouts, oil spills, contaminant spills, and spill-response activities may be associated with the 

EPA proposed action. The major impact-producing factors resulting from the accidental activities 

associated with the EPA proposed action that may affect loggerhead, Kemp’s ridley, hawksbill, green, 

and leatherback turtles include accidental blowouts, oil spills, and spill-response activities that have the 

potential to impact small to large numbers of sea turtles in the GOM, depending on the magnitude and 

frequency of accidents, the ability to respond to accidents, the location and time of year the accidents 

occur, and various meteorological and hydrological factors. Impacts from smaller accidental events may 

affect individual sea turtles in the area, but impacts are unlikely to rise to the level of population effects 

(or significance) given the size and scope of such spills. Population-level impacts are not anticipated 

based on the best available information. Further, the potential remains for smaller accidental spills to 

occur in the EPA proposed action area, regardless of any alternative selected under this Supplemental 

EIS, given that the CPA, which is adjacent to the proposed EPA lease sale area, is an active oil and gas 

region with either ongoing or the potential for exploration, drilling, and production activities.

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors of OCS oil and gas-related 

impacts along with non-OCS oil- and gas-related impacts of other commercial, military, recreational, 

offshore, and coastal activities that may occur and adversely affect sea turtles in the same general area of 
Description of the Environment and Impact Analysis 4-167

the EPA proposed action. The major impact-producing factors resulting from cumulative OCS oil- and 

gas-related activities associated with the EPA proposed action that may affect loggerhead, Kemp’s 

Ridley, hawksbill, green, and leatherback turtles and their habitats include marine debris, contaminant 

spills and spill-response activities, vessel strikes, noise, seismic surveys, and explosive structure 

removals. Lease stipulations and regulations, as clarified by NTLs, are in place to reduce vessel strike 

mortalities, impacts from marine trash and debris, and seismic surveys. The cumulative impact of these 

ongoing OCS oil- and gas-related activities on sea turtles may result in a number of chronic and sporadic 

sublethal effects (i.e., behavioral effects and nonfatal exposure to or intake of OCS oil- and gas-related 

contaminants or discarded debris) because these activities may stress and/or weaken individuals of a local 

group or population and may predispose them to infection from natural or anthropogenic sources. 

However, these effects are not expected to impact the GOM sea turtle population as a whole. As 

discussed in Appendix B, a low-probability catastrophic spill, which is not part of the EPA proposed 

action and not likely expected to occur, could have population-level effects on sea turtles. The net result 

of any disturbance depends upon the size and percentage of the population likely to be affected, the 

ecological importance of the disturbed area, the environmental and biological parameters that influence an 

animal’s sensitivity to disturbance and stress, or the accommodation time in response to prolonged 

disturbance (Geraci and St. Aubin, 1980).

Non-OCS oil- and gas-related activities that may affect sea turtle populations include vessel noise and 

strikes (including commercial shipping, recreational, and research vessels), State drilling operations, 

military operations, commercial and recreational fishing, pollution, historic overexploitation, coastal 

infrastructure and habitat loss, dredging, pathogens, increased runoff, and natural phenomena. Effects 

from these activities could result in physiological stress, reduced reproductive success, weakened immune 

systems, or mortality of individuals.

The effects of the EPA proposed action, when viewed in light of the effects associated with other 

past, present, and reasonably foreseeable future OCS oil- and gas-related activities, may result in greater 

impacts to sea turtles than before the Deepwater Horizon explosion, oil spill, and response; however, the 

magnitude of those effects cannot yet be determined. Applicable lease stipulations and regulations, as 

clarified by NTLs such as those discussed above, would minimize impacts. Limited scope, timing, and 

geographic location of the EPA proposed action would further minimize impacts and result in negligible 

effects from the proposed drilling activities on sea turtles.

No significant cumulative impacts to sea turtles would be expected as a result of the EPA proposed 

action. The potential for impacts is mainly focused on the individual; population-level impacts are not 

anticipated. Even when taking into consideration the potential effects of the Deepwater Horizon

explosion, oil spill, and response and the minimization of impacts through lease stipulations and 

regulations, no significant cumulative impacts to sea turtles would be expected as a result of the proposed 

exploration activities when added to the impacts of past, present, or reasonably foreseeable oil and gas 

development in the area, as well as other ongoing activities in the area. However, the incremental 

contribution of the EPA proposed action would not be likely to result in a significant incremental impact 

on sea turtles within the EPA; in comparison, non-OCS oil- and gas-related activities, such as 

overexploitation, commercial fishing, and pollution, have historically proved to be a greater threat to sea 

turtles.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search was conducted for information published on sea turtles, and various Internet sources were 

examined to determine any recent information regarding sea turtles. Sources investigated included, but 

were not limited to, journals and scientific articles, Google, Google Scholar, and other Federal and State 

natural resource management agency websites. All new relevant information was incorporated into the 

analysis below.

On April 17, 2014, NMFS published the proposed rule, “Taking of Marine Mammals Incidental to 

Commercial Fishing Operations; Bottlenose Dolphin Take Reduction Plan; Sea Turtle Conservation; 

Modification to Fishing Activities” (Federal Register, 2014c). The comment period ended on June 2, 

2014. On July 10, 2014, NOAA published a final rule for “Endangered and Threatened Species: Critical

Habitat for the Northwest Atlantic Ocean Loggerhead Sea Turtle Distinct Population Segment (DPS) and 
4-168 Central and Eastern Planning Areas Supplemental EIS

Determination Regarding Critical Habitat for the North Pacific Ocean Loggerhead DPS” (Federal 

Register, 2014b). In the GOM, this includes all Sargassum between the 10-m (33-ft) depth contour and 

the outer boundary of the Exclusive Economic Zone. This designation could impact the commercial 

harvest of Sargassum; however, to our knowledge, the commercial harvest of Sargassum does not occur

in the GOM. Additionally, NMFS does not expect that this designation would add any risk factors or any 

conservation measures by BOEM because sea turtles and their required habitats are already adequately 

protected through the ESA Section 7 process. Within the GOM, there is a long-standing and welldeveloped OCS Program (more than 50 years); there are no data to suggest that activities from the 

preexisting OCS Program are significantly impacting sea turtle populations within these designated 

critical habitats. Therefore, in light of the EPA proposed action and its impacts, the incremental effect on 

sea turtle critical habitat is not expected to be significant when compared with non-OCS energy-related 

activities.

Since January 1, 2011, a notable increase in sea turtle strandings has occurred in the northern GOM, 

primarily in Mississippi. While turtle strandings in this region typically increase in the spring, the recent 

increase is a cause for concern. The Sea Turtle Stranding and Salvage Network is monitoring and 

investigating this increase. The network is part of the NOAA/FWS National Marine Mammal Health and 

Stranding Response Program and encompasses the coastal areas of the 18 states from Maine through 

Texas. There are many possible reasons for the increase in strandings in the northern GOM, both natural 

and human caused (USDOC, NMFS, 2014d). These sea turtle species include loggerhead, green, Kemp’s 

ridley, leatherback, hawksbill, and unidentified.

Since the beginning (2011) of the monitoring in states adjacent to a CPA proposed action, NMFS has 

identified 203 strandings in Alabama, 473 strandings in Louisiana, 641 strandings in Mississippi, and 

1,219 strandings in Texas (upper Texas coast—Zone 18) as of the last available update through 

August 25, 2013 (USDOC, NMFS, 2014e). In 2013, the State of Florida’s Fish and Wildlife 

Conservation Commission reported 1,886 stranded sea turtles throughout Florida. Of those, 

466 strandings occurred in counties on the west coast of Florida, excluding Monroe and Dade Counties. 

Strandings for previous years in western Florida are similar to 2013, with 410 strandings in 2012 and 

467 strandings in 2011(Tables 4-2 through 4-4). In 2014, 235 cold-stunned sea turtles were rescued in 

the panhandle in January from two separate cold weather events (Foley, 2014) and, as of November 21, 

2014, stranding data are not yet released for 2014. 

In 2013, loggerhead sea turtle nest counts on Florida’s beaches were lower than 2012 numbers, 

totaling 77,975 nests (9,952 west coast). As of November 21, 2014, nesting raw data for 2014 are 

unavailable and are expected to be available in 2015. However, some of the 2014 data totals have been 

plotted (State of Florida, Fish and Wildlife Conservation Commission, 2014b). Even with a slight decline 

in nesting, 2012 and 2013 saw high loggerhead nest counts in comparison to the previous decade. In 

2014, there was an increase in nesting from the previous year in peninsular Florida for loggerheads. 

Green sea turtle nest counts have increased approximately one hundredfold from 1989 to 2013, from 

267 nests in 1989 to 25,553 (207 west coast) nests in 2013 on Florida index beaches. The nest count for 

2014 was similar to that of the previous decade, other than the steep peak seen in 2013 (State of Florida, 

Fish and Wildlife Conservation Commission, 2014a and 2014b). No leatherback nests were recorded on 

the west coast of Florida in 2013 (State of Florida, Fish and Wildlife Conservation Commission, 2014a). 

Similar to the nest counts for green turtles, leatherback nest counts have been increasing exponentially on 

Florida index beaches (State of Florida, Fish and Wildlife Conservation Commission, 2014b) and reached 

their highest numbers in 2014 (State of Florida, Fish and Wildlife Conservation Commission, 2014b). A 

total of 82 nests were discovered in 2013 along the Alabama Gulf Coast (Share the Beach, 2014). Texas’ 

coastline had a documented 153 Kemp’s ridley, 13 loggerhead, and 15 green sea turtle nests in 2013

(USDOI, NPS, 2014; Shaver, official communication, 2014). Nesting surveys are not conducted in 

Mississippi or Louisiana due to logistical and funding limitations, although intermittent observations 

indicated that some does occur (USDOI, FWS, official communication, 2012). 

The new information presented in this chapter provides additional details on the baseline affected 

environment for sea turtles, and it does not change BOEM’s conclusions about the potential effects of the 

EPA proposed action on sea turtles.
Description of the Environment and Impact Analysis 4-169

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed above, as well as in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS, BOEM has identified incomplete information regarding impacts of the Deepwater

Horizon explosion, oil spill, and response on sea turtles in the EPA. BOEM used existing information 

and reasonably accepted scientific methodologies to extrapolate from available information in completing 

the relevant analysis of potential oil exposure impacts to sea turtles using studies investigating evidence 

of oil and impacts stemming from exposure to oil (Witham, 1978; Vargo et al., 1986; Lutz and Lutcavage, 

1989; Lutcavage et al., 1995; Plotkin and Amos, 1988). In addition, BOEM used information published 

on sea turtle nests and strandings to draw conclusions about sea turtle populations following the 

Deepwater Horizon explosion, oil spill, and response (USDOC, NMFS, 2014d and 2014e; Foley, 2014; 

State of Florida, Fish and Wildlife Conservation Commission, 2014a and 2014b; Share the Beach, 2014). 

Unavailable information on the effects to sea turtles from the Deepwater Horizon explosion, oil spill, and 

response (and thus changes to the sea turtle baseline in the affected environment) makes an understanding 

of the cumulative effects less clear. A large body of information is being developed though the NRDA 

process, but it is not yet available. Relevant data on the status of sea turtle populations after the 

Deepwater Horizon explosion, oil spill, and response and increased sea turtle GOM strandings may take 

years to acquire and analyze, and impacts from the Deepwater Horizon explosion, oil spill, and response 

may be difficult or impossible to discern from other factors. BOEM used existing information and 

reasonably accepted scientific methodologies to extrapolate from available information on sea turtle nests 

and strandings in completing the relevant analysis of sea turtle populations. None of these sources reveal 

reasonably foreseeable significant adverse impacts. Therefore, BOEM concludes that the unavailable 

information from these events may be relevant to foreseeable significant adverse impacts to sea turtles

because the full extent of impacts on sea turtles is not known, but BOEM has determined that the 

information is not essential to a reasoned choice among alternatives for this Supplemental EIS.

Nevertheless, there are existing leases in the EPA with either ongoing or the potential for exploration, 

drilling, and production activities. In addition, non-OCS oil- and gas-related activities will continue to 

occur in the EPA irrespective of the EPA proposed action (i.e., fishing, military activities, and scientific 

research). The potential for effects from changes to the affected environment (post-Deepwater Horizon

explosion, oil spill, and response), routine activities, accidental spills (including low-probability 

catastrophic spills), and cumulative effects remains whether or not the No Action or Action alternative is 

chosen under this Supplemental EIS. All wide-ranging populations of sea turtles that may occur in the 

EPA and within areas affected by the spill are unlikely to have experienced population-level effects from 

the Deepwater Horizon explosion, oil spill, and response given their wide-ranging distribution and 

behaviors.

Summary and Conclusion

BOEM has reexamined the analysis for sea turtles presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for sea turtles presented in those NEPA documents because of the 

available scientifically credible evidence in this analysis and based upon accepted scientific methods and 

approaches. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

4.2.1.14. Diamondback Terrapins

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 
4-170 Central and Eastern Planning Areas Supplemental EIS

reference. BOEM has reexamined the analysis for the four diamondback terrapin subspecies that occur in 

the EPA and within Florida; the Florida east coast terrapin (Malaclemys terrapin tequesta), mangrove

diamondback terrapin (Malaclemys terrapin rhizophorarum), ornate diamondback terrapin (Malaclemys 

terrapin macrospilota), and the Mississippi diamondback terrapin (Malaclemys terrapin pileata) (Butler 

et al., 2006) (referred to as diamondback terrapins in this Supplemental EIS) presented in the EPA 

225/226 EIS. Due to the close proximity to the CPA and WPA, BOEM also reexamined the 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented below. No new significant information was discovered 

that would alter the impact conclusion for diamondback terrapins presented in those NEPA documents. 

The analysis and potential impacts discussed in those documents still apply for proposed EPA Lease Sale 

226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.14 of the EPA 225/226 EIS and Chapter 4.2.1.14 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.14 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.14 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

The global conservation status rank of diamondback terrapins is apparently secure—uncommon but 

not rare; some cause for long-term concern due to declines or other factors. The subspecies conservation 

status ranks range from imperiled (mangrove diamondback terrapin), vulnerable (Mississippi 

diamondback terrapin), and apparently secure (Florida east coast terrapin and ornate diamondback 

terrapin) (NatureServe 2014). “Species of concern” is an informal term that refers to those species that 

might be in need of concentrated conservation actions. Species of concern receive no legal protection 

above those already afforded the species under other laws, and the use of the term does not necessarily 

mean that the species will eventually be proposed for listing as a threatened or endangered species. At the 

present time, the diamondback terrapin is neither a listed species nor a candidate for listing under the 

Endangered Species Act.

Impacts of Routine Activities and Accidental Events

The following routine activities associated with proposed EPA Lease Sale 226 could potentially affect 

diamondback terrapins: ingestion of beach trash and debris generated by service vessels and OCS oiland gas-related facilities; direct injury from vessel traffic (boat propellers); and indirect injury from loss 

of habitat due to coastal marsh erosion associated with vessel traffic (refer to Chapters 4.1.1.3 and

Chapter 3.3.4.3 of this Supplemental EIS and Chapters 4.1.1.3 and 3.3.4.3 of the CPA 235/241/247 

Supplemental EIS). Erosion to marshes can be indirectly attributed to OCS service traffic and onshore 

development, but it is expected to cause little to no damage to the physical integrity, species diversity, or 

biological productivity of terrapin habitat. Adverse impacts due to routine activities resulting from the 

EPA proposed action are possible but unlikely. Because of the greatly improved handling of waste and 

trash by industry and because of the annual awareness training required by the marine debris mitigations, 

the plastics in the ocean are decreasing and the devastating effects on offshore and coastal marine life are 

minimized. Collisions with OCS vessel traffic are minimized by NTL 2012-JOINT-G01,“Vessel Strike 

Avoidance and Injured/Dead Protected Species Reporting,” which provides guidelines on monitoring 

procedures related to vessel strike avoidance measures. Due to the distance from shore, most impacts are 

not expected to reach terrapins or their habitat. Impacts that may occur from routine activities of the EPA 

proposed action are unlikely to have significant adverse effects on the size and recovery of any terrapin 

species or population in the Gulf of Mexico because most routine, OCS oil- and gas-related activities are 

expected to have sublethal effects. Sublethal effects such as behavioral effects, nonfatal exposure to or 

intake of OCS oil- and gas-related contaminants, or discarded debris may stress and/or weaken 

individuals of a local group or population and predispose them to infection from natural or anthropogenic 

sources. These effects are not expected to rise to the level of significance to the populations.

Impact-producing factors associated with accidental events that may be associated with the EPA 

proposed action that could affect diamondback terrapins include offshore and coastal oil spills and spillresponse activities. Behavioral effects and nonfatal exposure to or intake of OCS oil- and gas-related 
Description of the Environment and Impact Analysis 4-171

contaminants may stress and/or weaken individuals of a local group or population and predispose them to 

infection from natural or anthropogenic sources. Even after the oil is no longer visible, terrapins may still 

be exposed while they forage in the salt marshes lining the edges of estuaries where oil may have 

accumulated under the sediments and within the food chain (Burger, 1994; Roosenburg et al., 1999). 

Reproductive success may be reduced if nests are disturbed or destroyed by cleanup efforts. Hatching 

success studies at various oiled nesting sites of the northern diamondback terrapin suggest that spills may 

result in a reduction in nest size and increased mortality of spring emergers at the oiled sites (Wood and 

Hales, 2001). However, research on the PAH exposure and toxicology of eggs in the vicinity of a spill 

site found no correlation to substrate PAHs when compared with egg toxicology. The level of PAHs 

found in the eggs may be the result of maternal transfer and represent the exposure level of the nesting 

female rather than environmental exposure to PAHs from oil at the site of the nest (Holliday et al., 2008). 

Impacts on diamondback terrapins from smaller accidental events are likely to affect individual 

diamondback terrapins in the spill area, but they are unlikely to rise to the level of population effects (or a 

level of significance) given the probable size and scope of such spills. Further, the potential remains for 

smaller accidental spills to occur in the EPA proposed action area, regardless of any alternative selected 

under this Supplemental EIS, given that the CPA, which is adjacent to the proposed EPA lease sale area, 

is an active oil and gas region with either ongoing or the potential for exploration, drilling, and production 

activities.

Cumulative Impacts

The major OCS oil- and gas-related impact-producing factors that may affect the diamondback 

terrapin include (1) vessel traffic, (2) exposure or intake of OCS oil- and gas-related contaminant or 

debris, and (3) oil spills and spill response. To mitigate the potential impacts from OCS oil- and gasrelated activities, operators are required to follow all applicable lease stipulations and regulations, as 

clarified by NTLs, to minimize these potential interactions and impacts. The operator’s reaffirmed 

compliance with NTL 2012-BSEE-G01 (“Marine Trash and Debris Awareness and Elimination”) and 

NTL 2012-JOINT-G01 (“Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”), as 

well as the limited scope, timing, and geographic location of the EPA proposed action, would result in 

minimal effects from the proposed drilling activities on diamondback terrapins. Most spills related to the 

EPA proposed action, as well as low-probability catastrophic spills, which are not part of the EPA 

proposed action and not likely expected (refer to Appendix B for more information), as well as oil spills 

stemming from tankering and prior and future lease sales, are not expected to contact terrapins or their 

habitats. Most routine and accidental OCS oil- and gas-related activities are expected to have sublethal 

effects, such as behavioral effects, that are not expected to rise to the level of significance to the 

populations as a whole. Therefore, the incremental contribution of the EPA proposed action to 

cumulative impacts on terrapins is expected to be minimal.

Activities posing the greatest potential harm to terrapins are non-OCS oil- and gas-related factors, 

including habitat destruction, overharvesting and crab pot fishing, vessel traffic and road mortality, nest 

depredation, State oil- and gas-related activity, and natural processes. Spending most of their lives within 

their limited home ranges at the aquatic-terrestrial boundary in estuaries, terrapins are susceptible to 

habitat destruction (i.e., urban development, subsidence/sea-level rise, direct oil contact from non-OCS 

oil- and gas-related leasing program activities, and associated cleanup efforts). Habitat destruction, road 

construction, nest depredation, and drowning in crab traps are the most recent threats to diamondback 

terrapins. In the 1800’s, populations declined due to overharvesting for meat (Hogan, 2003). Tropical 

storms, hurricanes, and beach erosion threaten their preferred nesting habitats. Characteristics of terrapin 

life history render this species especially vulnerable to overharvesting and habitat loss. These 

characteristics include low reproductive rates, low survivorship, limited population movements, and nest 

site fidelity year after year. Inshore oil spills from non-OCS oil- and gas-related sources are potential 

threats to the terrapins’ brackish coastal marsh habitat.

The incremental contribution of the EPA proposed action is expected to be minimal compared with 

non-OCS oil- and gas-related activities. The major impact-producing factors resulting from the 

cumulative activities associated with the EPA proposed action that may affect diamondback terrapins

include oil spills and spill-response activities, alteration and reduction of habitat, and consumption of 

trash and debris. The OCS Program is quite limited in the EPA when compared with the CPA, but overall 

it is long-standing (more than 50 years); also, there are no data to suggest that activities from the 
4-172 Central and Eastern Planning Areas Supplemental EIS

preexisting OCS Program are having a significant cumulative impact on diamondback terrapin 

populations in the EPA. Due to the extended distance from shore, impacts associated with activities 

occurring in the OCS Program are not expected to impact terrapins or their habitat. Non-OCS oil- and 

gas-related activities will continue to occur in the EPA irrespective of the proposed EPA lease sale (i.e., 

crabbing, fishing, military activities, scientific research, and shoreline development). Therefore, in light 

of the above analysis of the EPA proposed action and its impacts, the incremental effect of the EPA 

proposed action on diamondback terrapin populations is not expected to be significant when compared 

with historic and current non-OCS oil- and gas-related activities, such as habitat loss, overharvesting, 

crabbing, and fishing.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources (NOAA’s and FWS’s websites, and the RestoreTheGulf.gov 

website), as well as recently published journal articles, was conducted to determine the availability of 

recent information on diamondback terrapins. The search revealed no new information pertinent to this 

Supplemental EIS. No new information was found at this time that would alter the overall conclusions of 

the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS that impacts on diamondback terrapins associated with the EPA 

proposed action are expected to be minimal.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from 

previous documents are still valid because no new information on diamondback terrapins pertinent to the 

EPA proposed action has become available since publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235,241, and 247 

Supplemental EIS; nevertheless, there is still incomplete or unavailable information on possible impacts 

to diamondback terrapins as a result of the Deepwater Horizon explosion, oil spill, and response.

Diamondback terrapins within the EPA were likely not affected to any discernible degree by the 

Deepwater Horizon explosion, oil spill, and response, based on the best available information and the 

distance of terrapin habitat from the Macondo well. However, BOEM has identified incomplete 

information regarding impacts of the Deepwater Horizon explosion, oil spill, and response on 

diamondback terrapins in the EPA because little information about the Deepwater Horizon explosion, oil 

spill, and response has been released as of the publication of this Supplemental EIS. Through NRDA, 

ongoing research and analysis of the presence of contaminants in terrapin eggs following the Deepwater 

Horizon oil spill is being conducted (USDOC, NOAA, 2012), but the results are not yet available. 

Relevant data on the status of diamondback terrapin populations after the Deepwater Horizon explosion, 

oil spill, and response may take years to acquire and analyze, and impacts may be difficult or impossible 

to discern from other factors. This incomplete information may be relevant to evaluating adverse effects 

because the full extent of potential impacts on terrapins is not known. In place of the missing 

information, BOEM used existing information and reasonably accepted scientific methodologies to 

extrapolate from available information in completing the relevant analysis, such as studies investigating 

the evidence of oil and impacts stemming from exposure to oil (Burger, 1994; Roosenburg et al., 1999; 

Holliday et al., 2008, Wood and Hales, 2001). The results of these studies indicate impacts resulting from 

the Deepwater Horizon oil spill have been largely indistinguishable from natural fluctuations or

variability due to other anthropogenic activities. Although the body of available information is 

incomplete and long-term effects cannot yet be known, past analyses are not indicative of significant 

population-level responses. BOEM has determined that the information is not essential to a reasoned 

choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for diamondback terrapins presented in the EPA 225/226, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 
Description of the Environment and Impact Analysis 4-173

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for diamondback terrapin in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for the proposed EPA Lease Sale 226.

4.2.1.15. Beach Mice

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for beach mice presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for beach mice presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.15 of the EPA 225/226 EIS and Chapter 4.2.1.15 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in, Chapter 4.2.1.15 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.15 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Impact of Routine Activities and Accidental Events

The potential routine impact-producing factors that may affect beach mice are beach trash and debris, 

and efforts undertaken for the removal of marine debris or for restoration. An impact from the routine 

activities associated with the EPA proposed action on the Alabama (Peromyscus polionotus ammobates), 

Choctawhatchee (P. p. allophrys), St. Andrew (P. p. peninularis), Perdido Key (P. p. trissyllepsis), and 

Santa Rosa (P. p. leucocephalus) beach mice is possible but unlikely. Impact may result from 

consumption of or entanglement in beach trash and debris. Because the EPA proposed action would 

deposit only a small portion of the total debris that would reach the habitat, the impacts would be 

minimal. Any coastal discharges into marine water would not affect beach mice because they drink only 

fresh water. Boat traffic would have no impact on beach mice because they live above high tide. 

Helicopter traffic is expected to occur only well to the west of beach mouse habitat (the nearest existing 

helicopter hub in Theodore, Alabama; refer to Chapter 3.1.2.1.2. of the 2012-2017 WPA/CPA Multisale 

EIS). Coastal and nearshore construction projects (e.g., those producing OCS oil- and gas-related 

supporting structures and facilities and those involving OCS oil- and gas-related activities such as 

navigation channel dredging) are not expected to have impacts on beach mice because their critical 

habitat is protected.

The major impact-producing factors resulting from accidental events associated with the EPA 

proposed action that may affect beach mice include offshore and coastal oil spills, and spill-response 

activities. The oiling of beach mice could result in local extinction. A small spill or a large spill 

(>1,000 bbl) both occurring and contacting the shoreline is unlikely because the nearest shoreline to the 

proposed activity is 125 mi (201 km) away and the area of viable habitat is broad relative to the area 

potentially contacted by a small or large spill (Figure 3-10 of the EPA 225/226 EIS). To contact beach 

mouse habitat, oil would have to wash over the foredunes into beach mouse habitat in a storm surge. A 

review of the available information shows that impacts on beach mice from accidental impacts associated 

with the EPA proposed action would be minimal.
4-174 Central and Eastern Planning Areas Supplemental EIS

Cumulative Impacts

Cumulative activities have the potential to harm or reduce the abundance of beach mice. The OCS 

oil-and gas-related activities include oil spills and the consumption of and entanglement in beach trash

and debris. Non-OCS oil- and gas-related impacts include oil spills, beach development that alters or 

reduces habitat, predation, competition, ingestion of and entanglement in beach trash and debris, 

hurricanes, and tropical storms. Most spills related to the EPA proposed action and prior and future lease 

sales are not expected to contact beach mice or their habitats because the species lives above the intertidal 

zone where contact is less likely. Destruction of the remaining beach mouse habitat due to a lowprobability catastrophic spill and cleanup activities, which is not part of the EPA proposed action and not 

likely expected, would increase the threat of extinction, but the potential for a catastrophic spill that 

would substantially affect beach mice habitat is low. Impacts on beach mice from a low-probability 

catastrophic spill, which is not part of the EPA proposed action and not likely expected, are discussed in 

Appendix B. Unlike impacts from routine activities and accidental events, the cumulative impact of a 

catastrophic spill could affect the southeastern (Peromyscus polionotus niveiventris) and Anastasia Island 

(P. p. phasma) beach mice on the east coast of Florida.

Cumulative impacts could potentially deplete some beach mice populations to unsustainable levels. 

Within the last 20-30 years, the combination of habitat loss due to beachfront development, the isolation 

of the remaining beach mouse habitat areas and populations, and the destruction of the remaining habitat 

by tropical storms and hurricanes have increased the threat of extinction of several subspecies of beach 

mice. Impacts from OCS oil- and gas-related activities could come from trash and debris, and efforts to 

remove them, as well as from oil spills and cleanup operations. The expected incremental contribution of 

the EPA proposed action to the cumulative impacts is negligible.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources including published journal articles was conducted to 

determine the availability of recent information on coastal and marine birds. Websites visited included 

four for Federal agencies (U.S. Fish and Wildlife Service, U.S. Environmental Protection Agency, U.S. 

Geological Survey, and the Bureau of Ocean Energy Management), five for State agencies (Alabama 

Department of Conservation and Natural Resources, Alabama Department of Environmental 

Management, Alabama Wildlife and Freshwater Fisheries Division, State of Florida Department of 

Environmental Protection, and State of Florida’s Fish and Wildlife Conservation Commission, two for 

universities (Florida State University and University of Florida), several for various stakeholders (Sierra 

Club, National Fish and Wildlife Foundation, Nature Conservancy, Gulf of Mexico Alliance, Gulf of 

Mexico Program, Gulf Coast Ecosystem Task Force, and Gulf Coast Ecosystem Restoration Council), 

NOAA Central Library’s Deepwater Horizon Bibliography (Belter, 2014), and LUMCON Library’s the 

“Effects of Offshore Oil and Gas Development: A Current Awareness Bibliography” (Conover, 2004). 

Where applicable, websites of subdivisions of many of these organizations were also consulted. 

Environmental journal articles were also located online using four search engines (JSTOR, EBSCO, 

Google Advanced Scholar Search, and Google Advanced Book Search). Three of the search engines 

collectively searched all of the ecology journals of six major publishers (John Wiley and Sons, Springer, 

Elsevier Science, Taylor and Francis Group, Cambridge University Press, and Oxford University Press).

A search was conducted for information related to the cumulative impacts of non-OCS oil- and gasrelated activities on beach mice. This search included the information about the frequency and height of 

storm-related surges, the impact of a hurricane on dune habitats, probabilities of extinction, how 

hurricanes alter predation risk, the role of interspecific competition, the importance of swale and dune 

vegetation, and the behavioral ecology of beach mice.

Although not specific to beach mice, recent analyses have reexamined the frequency of hurricanes

that impact beach mouse habitat (Blake and Gibney, 2011) and modeled expected storm surges with 

hurricanes (Chen et al., 2008). This information is important because it provides insight into the 

frequency and potential of flooding of beach mouse habitat. If this happens to coincide with an oil spill, a 

storm surge would be the primary pathway by which large amounts of oil could be transported into beach 

mouse habitat. For example, if a hurricane similar to Hurricanes Ivan or Katrina were to coincide in time 
Description of the Environment and Impact Analysis 4-175

and space with an oil spill, it can be expected that the storm surge would carry oil into all beach mouse 

habitat that is 2.5 m (8.2 ft) above sea level (Chen et al., 2008).

Tertiary dunes in the Alabama beach mouse habitat were observed at as much as 10 m (33 ft) above 

mean sea level (Boyd et al., 2004).

Hurricane Georges (in 1998) did not change tertiary dunes and scrub in the Alabama beach mouse

habitat; it only slightly changed secondary dunes and scoured beaches and breached primary dunes (Boyd 

et al., 2004).

Conroy and Runge (2008) used a state-of-the-art robust population viability analysis with trapping 

grid data from 1994 through 2006 to model extinction probabilities for the Alabama beach mouse. The 

probabilities of extinction with standard errors (SE) were 0.01 (SE = 0.08) over the next 10 years, 

0.05 (SE = 0.23) over the next 20 years, 0.17 (SE = 0.38) over the next 50 years, 0.25 (SE = 0.43) over 

the next 100 years, and 0.31 (SE = 0.46) over the next 200 years.

Additionally, Wilkinson et al. (2013) found a positive relationship between the amount of hurricanerelated habitat fragmentation in an area and the ability of mice to avoid predation. This is important 

because habitat fragmentation above a threshold could lead to a nonlinear increase in the cumulative 

impacts on beach mice. From an ecological standpoint, Falcy and Danielson (2013) found that 

competition between the Alabama beach mouse and the hispid cotton rat (Sigmodon hispidus) has 

minimal effect, suggesting that intraspecific competition among rats may not be important when 

determining cumulative impacts.

Finally, Lynn (2014) and Yanchis (2014) provide new details of threats to beach mouse habitat that 

may influence the cumulative impact analysis. The main threat to beach mice is coastal development, 

including residential and commercial buildings, nonnative landscaping, nonnative predators (i.e., dogs 

and cats), and excessive lighting.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in the previously 

mentioned NEPA documents, BOEM has identified incomplete information regarding beach mice in the 

EPA. This incomplete information may be relevant to the evaluation of adverse effects because it 

provides any change in the baseline environmental conditions for beach mouse populations in the affected 

environment from the Deepwater Horizon oil spill and response, exacerbating any impacts from the EPA 

proposed action. Relevant data on the status of beach mice after the Deepwater Horizon explosion, oil 

spill, and response may take years to acquire and analyze. Much of these data are being developed 

through the NRDA process, which may take years to complete. It is not possible for BOEM to obtain this 

information and incorporate it into this analysis within the timeline contemplated in the NEPA analysis of 

this Supplemental EIS, regardless of the costs or resources needed. Current studies are investigating the 

effects of the Deepwater Horizon explosion, oil spill, and response activities on beach mice and their 

habitat (Frater, official communication, 2014). The time when the studies’ results will be released is 

unclear; therefore, BOEM cannot commit to waiting for this new information to become available to 

incorporate it into this Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. The following is an example of 

extrapolation made from data summarized from OSAT-2 (2011) that BOEM used in the stead of 

unavailable and incomplete information. Assessment of the efficacy of shoreline cleanup in supratidal 

Alabama beach mouse habitat showed 60 percent “no oil observed,” 37 percent “light-very light oiling,” 

and 3 percent “moderate-heavy oiling.” Much of the supratidal habitat of the Perdido Key and 

Choctawhatchee beach mice showed “no oil observed.” The supratidal habitat of the St. Andrew beach 

mouse was not affected by the Deepwater Horizon oil spill and response. A “toxicity reference value” is 

developed by USEPA for low (2-3 ring) and high (4-7 ring) molecular weight PAHs. Two scenarios for 

PAH oral uptake by the Alabama beach mouse were reported: 10 percent contribution and a worst-case 

100 percent contribution of small tarballs to the overall ingesting of soil. The estimated daily dose of 

PAHs from oral uptake following the Deepwater Horizon oil spill and response did not exceed the 

toxicity reference value for low molecular weight PAHs in the Alabama beach mouse.
4-176 Central and Eastern Planning Areas Supplemental EIS

The following is another example of extrapolation made from data summarized from Frater (official 

communication, 2011) that BOEM used in the stead of unavailable or incomplete information. Known 

occupied habitat has been trampled, denuded, and eroded. Reasonable estimates of the amount of beach 

mouse habitat that has been damaged, altered, or destroyed varies from 1 to 50 ac throughout the range of 

the five Gulf Coast subspecies (4 of which are federally protected). Preliminary data suggest that impacts 

to beach mouse habitat was very minor. The impacts to beach mouse habitat during the Deepwater

Horizon response probably have not caused significant impacts to the population levels of beach mice. 

The habitat that was damaged was primarily young dunes. The damage may restrict population expansion 

and recovery for a few years, but anticipated restoration activities will probably offset this impact in the 

near future.

Any additional NRDA information obtained from the Deepwater Horizon oil spill and response is 

unlikely to be so significant as to change the assessed impact level. In summary, BOEM has determined 

that the information is not essential to a reasoned choice of alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for beach mice presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS, based on the additional information presented above. No new significant information was 

discovered that would alter the impact conclusion for beach mice presented in those NEPA documents

because of the available scientifically credible evidence in this analysis and based upon accepted 

scientific methods and approaches. The analysis and potential impacts discussed in those documents still 

apply for proposed EPA Lease Sale 226.

4.2.1.16. Coastal and Marine Birds

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by reference. 

BOEM has reexamined the analysis for coastal and marine birds presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for coastal and marine birds presented in those 

NEPA documents. The analysis and potential impacts discussed in those documents still apply for 

proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.16 of the EPA 225/226 EIS and Chapter 4.2.1.16 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.16 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.16 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Impacts of Routine Activities and Accidental Events

The majority of the effects resulting from the routine activities of a CPA proposed action (Tables 3-2 

through 3-4) on threatened or endangered (Table 4-1 of the WPA 233/CPA 231 Supplemental EIS) and 

nonthreatened and nonendangered coastal and marine birds are expected to be sublethal, primarily 

disturbance-related effects (Chapter 4.2.1.16.2 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 

4.2.1.16 of the WPA 233/CPA 231 Supplemental EIS). Major potential impact-producing factors 

resulting from routine activities for marine birds in the offshore environment include the following:
Description of the Environment and Impact Analysis 4-177

• habitat loss and fragmentation (Fahrig, 1997 and 1998);

• behavioral effects primarily due to disturbance from OCS oil- and gas-related 

helicopter and service-vessel traffic and associated noise (Habib et al., 2007; Bayne 

et al., 2008);

• mortality due to exposure and intake of OCS oil- and gas-related contaminants, e.g., 

drilling discharges and produced waters (Wiese et al., 2001; Fraser et al., 2006) and 

discarded debris (Robards et al., 1995; Pierce et al., 2004);

• sublethal, chronic effects from air emissions (Newman, 1979; Newman and 

Schreiber, 1988); and

• mortality and energetic costs associated with structure presence and associated light 

(Russell, 2005; Montevecchi, 2006).

A detailed impact analysis of the routine activities associated with proposed EPA Lease Sale 226 on 

coastal and marine birds can be found in Chapter 4.1.1.16.2 of the EPA 225/226 EIS and Chapter 

4.2.1.16.2 of the 2012-2017 WPA/CPA Multisale EIS, and updated information is provided in Chapter 

4.2.1.16 of the WPA 233/CPA 231 Supplemental EIS and CPA 235/241/247 Supplemental EIS.

Overall, impacts to avian species from routine activities are expected to be adverse but not significant. 

Impacts from routine impacts are more likely to be sublethal to moderate numbers of birds and 

infrequently lethal. Mortality is expected to be distributed among many populations with no substantial 

mortality for any one population.

Impact-producing factors from accidents include oil spills, regardless of size and despite oil-spill 

cleanup activities, including the release of rehabilitated birds. Information regarding the EPA proposed 

action and oil-spill information can be found in Tables 3-10, 3-15, and 3-16 of the EPA 225/226 EIS.

Oil-spill impacts on birds from the EPA proposed action are expected to be adverse but not 

significant, given the number and relatively small size of spills expected over the 40-year life of the EPA 

proposed action (Table 3-12 of the 2012-2017 WPA/CPA Multisale EIS). Impacts of oil-spill cleanup 

from the EPA proposed action are also expected to be adverse, but not significant, but may be negligible 

depending on the scope and scale of efforts. Significant impacts to coastal and marine birds could result 

in the event of a low-probability catastrophic spill, depending on the timing, location, and size of the spill. 

For additional information on a low-probability catastrophic spill, refer to Appendix B. 

Cumulative Impacts

The cumulative analysis considers impact-producing factors that may adversely affect populations of 

threatened and endangered avian species, as well as nonthreatened and nonendangered species, related to 

OCS oil- and gas-related and non-OCS oil- and gas-related activities. Several OCS oil- and gas-related 

impact-producing factors could potentially affect coastal and marine birds, including the following:

• air pollution;

• pollution of coastal and offshore waters resulting from OCS oil- and gas-related 

activities, including platform and pipeline oil spills, produced waters, and any spillresponse activities;

• structure presence and lighting (e.g., OCS platforms);

• aircraft and vessel traffic and oil-spill cleanup associated noise; 

• maintenance and use of navigation waterways;

• habitat loss, fragmentation, and alteration from coastal facility and OCS support 

structure construction;

• OCS pipeline landfalls; and

• trash and debris.
4-178 Central and Eastern Planning Areas Supplemental EIS

A detailed discussion of catastrophic OCS oil- and gas-related events can be found in Appendix B. 

In addition to the factors listed above, there are several non-OCS oil- and gas-related impactproducing factors that could potentially impact coastal and marine birds. These factors include the 

following: air pollution; habitat loss, alteration, and fragmentation associated with commercial and 

residential construction and industrial growth; water pollution including State or tanker oil- and gasrelated spills and any spill-response activities and pollution of coastal waters resulting from municipal, 

industrial, and agricultural runoff and discharge; aircraft and vessel (including military) activities and 

noise; nonconsumptive and consumptive recreation; maintenance and use of navigation waterways; 

collisions with anthropogenic structures; predation; diseases; climate change and related impacts; impacts 

from storms and floods; fisheries interactions; and trash and debris.

The incremental contribution of the EPA proposed action to the cumulative impact is considered 

adverse but not significant because the effects of the most probable impacts, such as lease sale-related 

operational discharges and helicopters and service-vessel noise and traffic, are expected to be sublethal; 

and some displacement of local individuals or flocks may occur to other habitat, if available. In general, 

the net effect of habitat loss from oil spills, OCS oil- and gas-related pipeline landfalls, and maintenance 

and use of navigation waterways, as well as habitat loss and modification resulting from coastal facility 

construction and development, will probably reduce the overall carrying capacity of the disturbed 

habitat(s). That is, impacted habitats may result in reductions to both species composition (fewer species) 

and abundance (lower numbers) as compared with what the area supported historically. These would be 

the most serious cumulative impacts on birds. In conclusion, the incremental contribution of the EPA 

proposed action to the cumulative impact is considered adverse but not significant when compared with 

the impacts of some of the reasonably foreseeable non-OCS oil- and gas-related factors. 

New Information Available Since the Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources including published journal articles was conducted to 

determine the availability of recent information on coastal and marine birds. Websites visited included 5 

for Federal agencies (U.S. Environmental Protection Agency, U.S. Geological Survey, National 

Oceanographic and Atmospheric Administration, U.S. Fish and Wildlife Service, and the Bureau of 

Ocean Energy Management); 10 for State agencies (Louisiana Department of Wildlife and Fisheries; 

Louisiana Department of Natural Resources; Louisiana Department of Environmental Quality; 

Mississippi Department of Environmental Quality; Mississippi Department of Wildlife, Fisheries, and 

Parks; Alabama Department of Conservation and Natural Resources; Alabama Department of 

Environmental Management; Alabama Wildlife and Freshwater Fisheries Division; State of Florida 

Department of Environmental Protection; and State of Florida’s Fish and Wildlife Conservation 

Commission), 3 for universities (University of Louisiana at Lafayette, Louisiana State University, and 

Florida State University), several for various stakeholders (Sierra Club, National Fish and Wildlife 

Foundation, Nature Conservancy, Gulf of Mexico Alliance, Gulf of Mexico Program, National Audubon 

Society, Gulf Coast Ecosystem Task Force, and Gulf Coast Ecosystem Restoration Council), NOAA 

Central Library’s Deepwater Horizon Bibliography (Belter, 2014), and LUMCON Library’s the “Effects 

of Offshore Oil and Gas Development: A Current Awareness Bibliography” (Conover, 2004). Where 

applicable, websites of subdivisions of many of these organizations were also consulted. Environmental 

journal articles were also located online using four search engines (JSTOR, EBSCO, Google Advanced 

Scholar Search, and Google Advanced Book Search). Three of the search engines collectively searched 

all of the ecology journals of six major publishers (John Wiley and Sons, Springer, Elsevier Science, 

Taylor and Francis Group, Cambridge University Press, and Oxford University Press). The search 

revealed new information on cumulative impacts (large-scale impacts on bird mortality) that is pertinent 

to this Supplemental EIS.

An estimated range of national annual mortality from collision with vehicles is 62-275 million birds 

per year (Loss et al., 2014a). An estimate of national annual mortality from collision with buildings is 

599 million birds per year (Loss et al., 2014b). Finally, an estimate of annual mortality from predation by 

free-ranging domestic cats is 1.4-3.7 billion birds per year (Loss et al., 2013). For collisions with 

buildings and cat predation, these numbers are within the ranges previously reported in Table 4-7 of the 

2012-2017 WPA/CPA Multisale EIS; for collision with vehicles, the numbers previously reported in 
Description of the Environment and Impact Analysis 4-179

Table 4-7 of the 2012-2017 WPA/CPA Multisale EIS are within the range of numbers reported here. 

Severity levels of cumulative impacts from these anthropogenic sources of mortality are expected to be 

significant. These severity levels were not explicitly stated in the 2012-2017 WPA/CPA Multisale EIS. 

The mortality estimates are nationwide and not just for the EPA of the northern Gulf of Mexico, where 

impacts would be much less. The previous estimates of mortality from these impacts are unreliable. Loss 

et al. (2014b) provide unprecedented state-of-the-art science (Machtans, 2014).

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in the previously 

mentioned NEPA documents, BOEM has identified incomplete information regarding coastal and marine 

birds in the EPA. This incomplete information may be relevant to the evaluation of adverse effects 

because it provides any change in the baseline environmental conditions for bird populations in the 

affected environment from the Deepwater Horizon oil spill, exacerbating any impacts from the EPA 

proposed action. Much of these data are being developed through the NRDA process, which may take 

years to complete. This information cannot be obtained because it may take years to acquire and analyze 

through the NRDA process, producing a reliable, model-based estimate of mortality that accounts for 

detection-related issues (Flint et al., 1999; Byrd et al., 2009). The information cannot be released due to 

ongoing NRDA litigation and, even after it is released, the impacts of the oil spill may be difficult or 

impossible to discern from other factors. It is not possible for BOEM to obtain this information and 

incorporate it into this analysis within the timeline contemplated by the NEPA analysis of this 

Supplemental EIS regardless of the costs or resources needed. At present, the best available information 

does not provide a complete understanding of the effects of the spilled oil or the recovery potential for the 

most impacted species (Tables 4-8, 4-12, and 4-13 of the 2012-2017 WPA/CPA Multisale EIS and Table 

4-2 of the WPA 233/CPA 231 Supplemental EIS). 

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here (refer to Table 4-2 of the WPA 

233/CPA 231 Supplemental EIS). A mortality estimate, given the total number of dead birds collected 

(7,258 birds) through May 12, 2011 and given a recovery rate from the literature (0%), is 725,800 birds. 

These existing data do not reveal reasonably foreseeable significant adverse impacts. The mortality 

estimate of 725,800 birds would be a small increment of what is anticipated from non-OCS oil- and gasrelated factors such as habitat loss, collisions with non-OCS oil- and gas-related structures, disease, and 

other anthropogenic factors, which may result in billions of bird deaths per year (as shown in Table 4-7 of 

the 2012-2017 WPA/CPA Multisale EIS). Any additional (NRDA) information obtained from the 

Deepwater Horizon oil spill and response is unlikely to be so significant as to change the relative 

importance of non-OCS oil- and gas-related factors to bird populations, which is demonstrated in Table 

4-7 of the 2012-2017 WPA/CPA Multisale EIS and Table 4-2 of the WPA 233/CPA 231 Supplemental 

EIS. In summary, BOEM has determined that the incomplete information is not essential to a reasoned 

choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for coastal and marine birds presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for coastal and marine birds presented in those 

NEPA documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.17. Fish Resources and Essential Fish Habitat (includes Gulf sturgeon) 

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 
4-180 Central and Eastern Planning Areas Supplemental EIS

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for fish resources and EFH presented in the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for fish resources and EFH presented in those 

NEPA documents. The analysis and potential impacts discussed in those documents still apply for 

proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine events, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.17 and Appendix D of the EPA 225/226 EIS and Chapter 4.2.1.18 and 

Appendix D of the 2012-2017 WPA/CPA Multisale EIS. Updated information is provided in Chapter 

4.2.1.18 of the WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.18 of the CPA 235/241/247 

Supplemental EIS. Also, EFH is discussed in the following chapters of this Supplemental EIS: water 

quality (Chapter 4.2.1.2); wetlands (Chapter 4.2.1.4); seagrass communities (Chapter 4.2.1.5); live 

bottoms (Chapter 4.2.1.6); topographic features (Chapter 4.2.1.7); Sargassum communities (Chapter 

4.2.1.8); chemosynthetic deepwater benthic communities (Chapter 4.2.1.9); nonchemosynthetic 

deepwater benthic communities (Chapter 4.2.1.10); and soft bottom benthic communities (Chapter 

4.2.1.11). The following information is a summary of the resource description and impact analysis 

incorporated from those NEPA documents. Any new or relevant information that has become available 

since those documents were published is presented below.

The Gulf of Mexico supports a great diversity of fish. The distribution of fish species is related to 

variable ecological factors that include salinity, primary productivity, and bottom type. These factors 

differ widely across the Gulf of Mexico and between the inshore and offshore waters. Characteristic fish 

resources are associated with the various environments and are not randomly distributed.

There are two ESA-protected fish species in the EPA; both are inshore or nearshore inhabitants. The 

first is the Gulf sturgeon (Acipenser oxyrinchus desotoi). The NMFS and FWS listed the Gulf sturgeon as 

a threatened species on September 30, 1991. Critical habitat for this species is limited to coastal bays and 

rivers on the Gulf Coast from the Pearl and Bogue Chitto Rivers in the Pontchartrain Basin, Louisiana, to 

Apalachicola Bay, Florida. The EPA proposed action is located in the De Soto Canyon and Walker Ridge 

leasing areas of the Gulf of Mexico, approximately ~201 km (~125 mi) south of the northern Gulf Coast 

and not within any habitat known to be inhabited by the Gulf sturgeon. For more information regarding 

Gulf sturgeon, refer to Chapter 4.1.1.17. The other ESA-protected fish species is the smalltooth sawfish

(Pristis pectinata), which is listed as endangered. The EPA proposed action is ~523 km (~325 mi) west 

of the area of the known species range.

Impacts of Routine Activities and Accidental Events

Effects on fish resources and EFH from routine activities associated with the EPA proposed action 

could result from coastal and marine environmental degradation as a result of construction activities (i.e., 

from onshore facilities to well-site construction activities, including board roads, ring levees, and 

impoundments), pipeline trenching, offshore discharges of drilling muds and produced waters, anchor and 

anchor chain placement, and structure installations and removals. Since the majority of fish species 

within the EPA are estuary dependent, any modification of the coastal environment resulting from the 

EPA proposed action has the potential to adversely affect EFH and fish resources through the loss of 

nursery habitat or functional impairment of existing habitat through decreased water quality (Chambers, 

1992; Stroud, 1992). Although the potential exists, it is expected that any possible coastal and marine 

environmental degradation from the EPA proposed action would have little effect on fish resources or 

EFH.

With the EPA proposed action, BOEM projects no new coastal infrastructure with the exception of a 

potential new pipeline landfall and a potential new gas processing facility. Although the installation of 

pipelines has the potential to temporarily resuspend sediment in localized areas, this is expected to have a 

negligible impact. Depending on the sediment characteristics, sediment load, and duration of exposure, 

impacts to commercially valuable species within a sediment plume can vary. Responses range in severity 

from no effect to mortality, but mobile species can avoid severe effects by limiting exposure. Sessile 
Description of the Environment and Impact Analysis 4-181

organisms and those with limited mobility may be exposed for longer durations, leading to increasingly 

severe impacts (e.g., increased respiratory rates, reduced feeding, and mortality). Regulations, 

mitigations, and practices reduce the undesirable effects on coastal habitats from dredging and other 

construction activities; permit requirements should ensure that pipeline routes avoid sensitive coastal 

habitat types. At the expected level of impact, the resultant influence on fish resources would be short 

term and localized, affecting only small portions of fish populations and selected areas of EFH. As a 

result, there would be little disturbance to fish resources or EFH.

The primary impacting sources to water quality in coastal waters are point-source and storm-water 

discharges from support facilities, vessel discharges, and nonpoint-source runoff. These activities are not 

only highly regulated but also localized and temporary in nature. The impacts to coastal water quality 

from routine activities associated with the EPA proposed action should be minimal because of the 

distance to shore of most routine activities and USEPA regulations that restrict discharges. Offshore 

water quality is affected temporarily and in a limited area by the discharge of produced water and the 

overboard discharge of drill muds. Maintenance dredging and canal widening in inshore areas causes 

only the temporary suspension of sediments. Negative impacts from most of these routine operations 

would require a short time for fish resources to recover. This is because of multiple life history and 

environmental factors such as fecundity or year-class recruitment through oceanographic circulation.

Offshore, many of the EFHs are protected under the stipulations and regulations currently in place. 

Without these measures, there could be major negative impacts to topographic features and live bottoms. 

However, with routine impact-producing factors mitigated by BOEM through the Topographic Feature 

Stipulation and the Live Bottom (Pinnacle Trend and Low Relief) Stipulations, negative impacts are 

expected to be avoided. These stipulations establish a No Activity Zone around BOEM-protected 

topographic features, such as the Flower Gardens Banks, and NTL 2009-G39 and NTL 2009-G40 advise 

operators of BOEM’s distancing requirements for bottom-disturbing activity from identified seafloor 

features (i.e., live bottoms, Pinnacles, topographic features, potentially sensitive biological features, and 

features capable of supporting high-density deepwater benthic communities). Additionally, hard substrate 

habitat provided by structure installation in areas where natural hard bottom is rare will tend to increase 

fish populations or attract fish populations. The removal of these structures will eliminate that habitat, 

except when decommissioned platforms are used as artificial reef material. This practice is expected to 

increase over time.

For the reasons discussed above, as well as the fact that Gulf of Mexico fish stocks have retained both 

diversity and relatively stable biomass throughout the years of offshore development and other 

disturbances, the EPA proposed action is expected to result in a minimal decrease in fish resources and/or 

standing stocks or in EFH. Further, due to regulations, mitigations, and the distance of routine activities 

from known Gulf sturgeon habitats, impacts from routine activities of the EPA proposed action would be 

expected to have negligible effects on Gulf sturgeon and smalltooth sawfish and their designated critical 

habitat.

Accidental disturbances resulting from the EPA proposed action, including oil or chemical spills and 

blowouts, have the potential to adversely affect fish resources and EFH within the EPA. If oil or 

chemical spills due to the EPA proposed action were to occur in open waters of the OCS proximate to 

mobile adult finfish, the effects would likely be nonfatal, and the extent of damage would be reduced 

because adult fish have the ability to move away from a spill, to metabolize hydrocarbons, and to excrete 

both metabolites and parent compounds. Weathered crude oil has been shown in laboratory experiments 

and field research to cause a range of sublethal effects, including malformation, genetic damage, and 

physiological impairment in different life history stages of different fish species (Carls et al., 1999; 

Whitehead et al., 2011). Oil can be lethal to fish, especially in larval and egg stages, since early life 

stages of animals are usually more sensitive to environmental stress than adults (Moore and Dwyer, 1974) 

and are unable to avoid spills, putting early development stages at greater risk. Therefore, fish 

populations would primarily be affected if oil reaches the coastal and estuarine areas because many 

species reside in estuaries for at least part of their life cycle or are dependent on the nutrients exported 

from the estuaries to the shelf region. However, pelagic species may also be affected. Offshore spawning 

and nursery habitat supports several valuable species that could likewise be impacted by widespread 

contamination of the epipelagic region. It is difficult to attribute specific causes to short-term shifts in 

stocks, and research to date has been inconclusive with respect to the individual contributions of the many 

factors impacting these fishes because of natural variability in spawning success, recruitment, 

oceanographic conditions, and other factors (Rijnsdorp et al., 2009; Atlantic Bluefin Tuna Status Review 
4-182 Central and Eastern Planning Areas Supplemental EIS

Team, 2011; Rooker et al., 2013). The probability of a spill impacting these nursery habitats is low. 

Much of the coastal northern Gulf of Mexico is a moderate- to high-energy environment; therefore, 

sediment transport and tidal stratification should reduce the chances for oil persisting in these areas if they 

are oiled. The extent to which a spill could impact offshore spawning and nursery habitat is highly 

dependent upon the time of year of the event.

The effect of oil spills that may be associated with the EPA proposed action on fish resources is 

expected to cause a minimal decrease in standing stocks of any population because most spill events 

would be small in scale and localized. Historically, there have been no oil spills of any size in the Gulf of 

Mexico that have had a long-term impact on fishery populations. Although many potential effects of the 

Deepwater Horizon explosion, oil spill, and response have been alleged, the actual effects are largely 

unknown and likely to remain so for several years, until more research is completed and the analyses 

become available. Recent analysis of early stage survival of fish species inhabiting seagrass nursery 

habitat from Chandeleur Islands, Louisiana, to St. Joseph Bay, Florida, pre- and post-Deepwater Horizon

oil spill show that immediate catastrophic losses of 2010 cohorts were largely avoided and that no shifts 

in species composition occurred following the spill (Fodrie and Heck, 2011). Analysis of the effects of a 

low-probability catastrophic oil spill can be found in Appendix B. The fish populations of the Gulf of 

Mexico have repeatedly proven to be resilient to large, annually occurring areas of hypoxic conditions, 

major hurricanes, and oil spills. Accidental events from the EPA proposed action are not expected to 

significantly affect fish populations or EFH in the Gulf of Mexico.

Protected Nearshore Fish Species

Potential routine impacts on Gulf sturgeon and smalltooth sawfish and their designated critical habitat 

may occur from drilling and produced-water discharges, bottom degradation of estuarine and marine 

water quality by nonpoint runoff from estuarine OCS oil- and gas-related facilities, vessel traffic, and 

pipeline installation. Because of the permitted discharge limits mandated and enforced in the Federal and 

State regulatory process, the dilution and low toxicity of this pollution is expected to result in a negligible 

impact of the EPA proposed action on Gulf sturgeon and smalltooth sawfish. The Gulf sturgeon’s 

characteristics of bottom-feeding and general avoidance of disturbance make the probability of vessel 

strike extremely remote.

Due to the distance of the activity from shore and the Gulf sturgeon and smalltooth sawfish critical 

habitat, there is a minimal risk of any oil coming in contact with Gulf sturgeon and smalltooth sawfish 

from an offshore spill. 

Cumulative Impacts

There are widespread anthropogenic and natural factors that impact EFH and fish populations in the 

GOM. These include OCS oil- and gas-related and non-OCS oil- and gas-related factors. The OCS oiland gas-related activities that could impact fish resources and EFH include construction, pipeline and 

structure emplacement, anchor and anchor chain placement, drilling and produced water discharges, 

structure removal, and oil spills. The routine OCS oil- and gas-related activities have the potential to 

impact fish and degrade EFH, but they could only have a minimal effect on fish resources and EFH 

because of the regulations, mitigations, and permit reviews that are applied for OCS oil- and gas-related 

activity. Oil spills, although considered rare events, can affect seagrass beds through physical oiling and 

destruction from oil spill cleanup. Low-probability catastrophic spills, which are not part of the EPA 

proposed action and not likely expected, similar to the Deepwater Horizon explosion and oil spill are 

analyzed in Appendix B. Overall, the incremental contribution of OCS oil- and gas-related effects to fish 

populations and EFH is small due to regulations, mitigations, and permit reviews.

Non-OCS oil- and gas-related factors that can impact fisheries and EFH include State oil and gas 

activity, inshore pollutants, dredging, coastal development, human population expansion, commercial and 

recreational fishing, overfishing, and natural phenomena. Inshore inputs of pollutants to estuaries from 

runoff and industry are contributors to wetland loss and degradation of water quality. Fish are known to 

avoid any area of adverse water quality, such as hypoxia (Wannamaker and Rice, 2000; Craig and 

Bosman, 2013). Canal dredging primarily accommodates commercial, residential, and recreational 

development, and increased population and commercial pressures on the Gulf Coast are also causing the 

expansion of ports and marinas. Resource management agencies, both State and Federal, set restrictions 
Description of the Environment and Impact Analysis 4-183

and issue permits in an effort to mitigate the effects of development projects and industry activities. The 

Federal and State governments are also funding research and coastal restoration projects; however, it may 

take decades of monitoring to ascertain the feasibility and the long-term effectiveness of these coastal 

restoration efforts.

Overfishing (including bycatch) has contributed to population effects seen with GOM fishes. The 

Magnuson-Stevens Fishery Conservation and Management Act and its amendments address sustainable 

fisheries and set guidelines for protecting marine resources and habitat from fishing- and nonfishingrelated activities. Under this Act, fisheries management plans, including limits on catch and fishing 

seasons, are developed and proposed by the regional fisheries management councils for approval and 

implementation by NMFS. State agencies regulate inshore fishing seasons and limits.

Some natural phenomena can impact fish resources and EFHs. Nearshore habitat can be affected 

through events such as severe storms and floods. These events can accelerate wetland loss or damage 

oyster reef habitat. Offshore resources such as biologically sensitive underwater features may be 

damaged or buried by events like storms or turbidity flows, potentially affecting fish resources. 

Additionally, variability in spawning success and juvenile survival directly affect Gulf of Mexico fish 

populations. These natural phenomena are all continual, integral elements of the ecosystem, and impacts 

attributed to these events are often exacerbated by anthropogenic activities.

While all of these events and activities cause some sort of effect on the different EFHs and fish 

resources, many anthropogenic inputs, including the EPA proposed action, are now monitored, regulated, 

and mitigated by the permitting agency or State. The EPA proposed action would add a minimal amount 

to the overall cumulative effects.

Protected Nearshore Fish Species

The Gulf sturgeon and smalltooth sawfish and their critical habitats can be cumulatively impacted by 

OCS oil- and gas-related activities such as dredging, oil spills, natural catastrophes, and other factors that 

can result in changes to habitats. The EPA proposed action would not require dredging near natal rivers 

used as migratory routes to upstream spawning areas. While there could be a need for maintenance 

dredging in the nearshore waters, juvenile or adult sturgeon using these areas have the ability to avoid the 

regulated dredging activity. Because of the low probability of an offshore oil spill from the EPA 

proposed action occurring and contacting Gulf sturgeon and smalltooth sawfish critical habitat, Gulf 

sturgeon and smalltooth sawfish contact with oil is expected to be minimal.

Substantial damage to Gulf sturgeon and smalltooth sawfish critical habitats is expected from nonOCS oil- and gas-related activities such as inshore alteration activities (e.g., dredging, dams, and salinity 

shifts) and natural catastrophes. As a result, it is expected that the Gulf sturgeon and smalltooth sawfish 

would experience a decline in population sizes and a displacement from their current distribution that 

would last more than one generation.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources and scientific journals was conducted to determine the 

availability of recent information (including NMFS’s databases, the Gulf of Mexico Fishery Management 

Council’s website, Science Direct, EBSCO, Elsevier, PLoS ONE, JSTOR, and BioOne). This search 

revealed new information relevant, but not essential, to an analysis of the potential impacts of OCS oiland gas-related activities on fish resources and EFH. The following studies investigated the impacts of 

acute hydrocarbon exposure on larval and juvenile life stages of species, which helped in this analysis. A 

recent study of the effects of oil on embryonic and larval pelagic fishes (Incardona et al., 2014) 

documented results consistent with earlier research and supports conclusions reached by previous BOEM 

analyses. Researchers observed that PAHs accumulate more rapidly in smaller eggs due to an increased 

surface-to-volume ratio, resulting in lower threshold concentrations required to induce adverse effects. 

Another study that examined crude oil exposure on embryonic and juvenile dolphinfish (Corphaena 

hippurus) was Mager et al. (2014); they suggested that sensitivity to acute oil exposure decreases with 

increasing developmental stage.
4-184 Central and Eastern Planning Areas Supplemental EIS

These studies serve to expand our understanding of the potential impacts an oil spill may have on 

valuable marine species and reaffirm the conclusions reached in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS. Therefore, the analysis and potential impacts discussed in those NEPA documents still apply for 

proposed EPA Lease Sale 226.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.1.17 of 

the EPA 225/226 EIS, Chapter 4.2.1.18 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 

231 Supplemental EIS, and Chapter 4.1.1.18 of the CPA 235/241/247 Supplemental EIS, BOEM has 

identified incomplete information regarding impacts of the Deepwater Horizon explosion, oil spill, and 

response or other oil exposure on fish resources and EFH in the EPA. This incomplete information may 

be relevant to evaluating adverse effects because the full extent of the potential impacts on fish resources 

and EFH are not known. Relevant data on fish resources and EFH after the Deepwater Horizon 

explosion, oil spill, and response may take years to acquire and analyze. Much of these data are being 

developed through the NRDA process, which may take years to complete. Therefore, it is not possible for 

BOEM to obtain this information within the timeline contemplated in the NEPA analysis of this 

Supplemental EIS, regardless of the cost or resources needed. This information cannot be obtained 

because the overall costs are exorbitant.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. The following studies 

investigating evidence of oil and impacts stemming from exposure to oil among pelagic fishes, coastal 

fishes, and marsh-associated nekton were utilized to reach the decision at this time: Atlantic Bluefin 

Tuna Status Review Team (2011); Fodrie and Heck (2011); Soniat et al. (2011); Carmichael et al. (2012); 

Moody et al. (2013); and Rooker et al. (2013). The results of these recent studies of fish resources

(species and communities) indicate that impacts resulting from the Deepwater Horizon oil spill have been 

largely indistinguishable from natural fluctuations or variability due to other anthropogenic activities. 

Although the body of available information is incomplete and long-term effects cannot yet be known, the 

evidence currently available supports past analyses and are not indicative of significant population-level 

responses. Additional information on commercially and recreationally valuable species can be found in 

Chapters 4.2.1.18 and 4.2.1.19. 

Summary and Conclusion

BOEM has reexamined the analysis for fish resources and EFH presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for the fish resources and EFH presented in those 

NEPA documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.18. Commercial Fisheries

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for commercial fisheries presented in the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for commercial fisheries presented in those NEPA
Description of the Environment and Impact Analysis 4-185

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

The portion of the EPA being considered for the EPA proposed action is in deep water

(approximately 800 m [2,625 ft] deep or greater) and, for the purpose of commercial fisheries, is used 

primarily by fishermen targeting pelagic fishes. The affected environment is outside the direct influence 

of several impact-producing factors that may impact shallow, coastal waters, and does not support many 

of the commercial species that may be associated with those shallower waters.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.18 and Appendix D of the EPA 225/226 EIS and Chapter 4.2.1.19 of the 2012-

2017 WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.19 of the WPA 

233/CPA 231 Supplemental EIS and Chapter 4.1.1.19 of CPA 235/241/247 Supplemental EIS. The 

following information is a summary of the resource description and impact analysis incorporated from 

those NEPA documents. Any new information that has become available since those documents were 

published is presented below.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors include waste discharge (e.g., drilling muds, cuttings, 

and produced waters) and space-use conflicts (e.g., seismic surveys and structure emplacement). 

Discharge of drilling muds, cuttings, and produced waters has the potential to indirectly impact 

commercial fisheries through degradation of habitat. Healthy fish stocks depend on EFH, which is 

defined in the Sustainable Fisheries Act as “those waters and substrate necessary to fish for spawning, 

breeding, feeding, and/or growth to maturity.” The species commercially harvested within the portion of 

the EPA being considered for the proposed action and adjacent EPA and CPA waters are pelagic fishes, 

and degradation of these waters as a result of the EPA proposed action has the potential to adversely 

affect EFH and commercial fisheries. However, analysis of routine OCS oil- and gas-related activities, 

such as OCS waste discharge, has identified only short-term localized disturbances that minimally impact 

commercially valuable fish species and associated EFH. Offshore discharges settle or dissipate rapidly, 

limiting both the area affected and the duration of the effect. Additionally, regulations, mitigations, and 

current practices reduce the undesirable effects of construction and operational activities on offshore 

habitats. At the expected level of impact, the resultant influence on fish resources would be negligible.

Space-use conflicts could result directly from OCS oil- and gas-related activities that restrict or 

prevent other users from accessing OCS resources. For example, seismic surveys and structure 

emplacement represent short-term and semi-permanent obstructions, respectively. Although studies have 

shown air guns can produce behavioral responses in fishes, possibly even resulting in species- or gearspecific effects on catch rate (Popper and Hastings, 2009; Fewtrell and McCauley, 2012; Lokkeborg 

et al., 2012), there is insufficient data to consistently predict responses and important variables, such as 

the duration of exposure and repeated exposure, have not been fully addressed. The OCS structures 

present a minor space-use conflict when compared with the area available for commercial fishing. In 

addition, the current paradigm posits these structures act as both fish-attracting and production-enhancing 

devices, depending upon the species (Carr and Hixon, 1997; Gallaway et al., 2009; Shipp and Bortone, 

2009). The resultant assemblages frequently include commercially valuable fishes, such as tunas 

(Thunnus spp.), red snapper (Lutjanus campechanus) and wahoo (Acanthocybium solanderi). Therefore, 

OCS structures may either enhance or obstruct commercial fishing, depending upon gear type (e.g., 

hydraulic reel, greenstick, trawl, and long-line) and target species. For more information, refer to 

Chapters 4.2.1.17 and 4.2.1.20. 

Accidental events that could impact commercial fisheries are very limited. Oil spills on the OCS that 

are >1 bbl due to the EPA proposed action are highly unlikely (Table 3-10 of the EPA 225/226 EIS). If 

oil spills due to the EPA proposed action were to occur in open waters of the OCS proximate to mobile 

adult finfish, the effects would likely be nonfatal, and the extent of damage would be reduced because 

adult fish have the ability to avoid adverse water conditions. This behavioral mechanism allows mobile 

fishes to move away from the source of the hydrocarbons, thereby minimizing exposure. However, larval 

and juvenile life stages are typically more vulnerable than adults and would be expected to suffer 

significant adverse effects as a result of acute oil exposure. Species-specific response, duration of 

exposure, and hydrocarbon concentration are critical factors in determining short- and long-term effects, 
4-186 Central and Eastern Planning Areas Supplemental EIS

but BOEM conservatively assumes larval and juvenile fishes exposed to oil in close proximity to the 

point of accidental release would be expected to experience mortality. The probability of an offshore spill 

impacting nearshore environments is low, and spilled oil would generally be volatilized or dispersed by 

currents in the offshore environment prior to impacting inshore habitat.

Cumulative Impacts

The cumulative analysis considers activities that have occurred, are currently occurring, and could 

occur and adversely affect commercial fisheries by harming fishes and affecting landings, or the value of 

those landings, for the years 2012-2051. These activities include the effects of the OCS Program 

(proposed action and prior and future OCS lease sales) resulting from pipeline installation, channel 

dredging, waste discharge, decommissioning operations, seismic surveys, and structure emplacement. In 

recent years, decommissioning operations have exceeded structure emplacements, resulting in a decrease 

in the total number of OCS platforms. BOEM expects this trend to continue throughout the OCS 

Program years, further reducing the potential for impacts to commercial fisheries through space-use 

conflicts. Although the decommissioning process frequently employs explosive severance methods, 

which result in localized mortality of fishes, the cumulative impact to commercially valuable stocks is 

expected to be indistinguishable from natural fluctuations and the effects of commercial and recreational 

fishing activity. For information on impacts resulting from catastrophic spills, refer to Appendix B. 

Non-OCS oil- and gas-related factors include State oil and gas activity, coastal development, natural 

phenomena, and commercial and recreational fishing. Although some OCS oil- and gas-related activities 

contribute incrementally to the degradation and loss of wetland habitat (Chapter 4.1.1.4), the cumulative 

impact is small in comparison with the combined effect of State oil and gas development; coastal 

commercial, residential, and agricultural development; levees; river channelization; and episodic natural 

phenomena. The cumulative direct impact to commercial fisheries through a reduction in resources 

(fishable area and fish stocks) is negligible.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

BOEM has examined newly available information for findings that may impact the analyses of 

routine activities, accidental events, and cumulative impacts and that may potentially alter previous 

conclusions. A search of Internet information sources and scientific journals was conducted to determine 

the availability of recent information (including NMFS’s databases, the NOAA Gulf Spill Restoration 

Publications website, the Gulf of Mexico Fishery Management Council website, Science Direct, EBSCO, 

Elsevier, PLoS ONE, JSTOR, and BioOne). This search revealed new information relevant, but not 

essential, to an analysis of the potential impacts of OCS oil- and gas-related activities on commercial 

fisheries. 

The following studies investigated the impacts of acute hydrocarbon exposure on larval and juvenile 

life stages of species that may be used to extrapolate potential effects to species of commercial interest. 

An investigation of the impacts of acute exposure to crude oil and dispersed oil on larval and juvenile 

spotted seatrout (Cynoscion nebulosus) found that short-term growth was reduced during exposure 

(Brewton et al., 2013). Juveniles recovered to the average total length of their cohort after 4 weeks of 

depuration, suggesting that the observed effects of acute exposure may not be long term and could be a 

result of higher metabolic costs associated with exposure to sublethal concentrations of crude oil and 

dispersed oil (Brewton et al., 2013). Similarly, Anderson et al. (2014) assessed the effects of acute 

exposure to crude oil WAF treatments and dispersed oil treatments on juvenile Harris mud crabs 

(Rhithropanopeus harrisii). The majority of juvenile crab mortalities occurred within the initial 24 hours 

of exposure to CEWAF treatments; only one of the crabs exposed to WAFs died. Surviving subjects of 

all treatments exhibited no long-term effects and there was no significant difference in post-exposure 

survival. These results indicate that chemical dispersion of oil may significantly increase the toxicity to 

juvenile Harris mud crabs (Anderson et al., 2014).

These studies serve to expand our understanding of the potential impacts an oil spill may have on 

valuable marine species and reaffirm conclusions reached in previous analyses. As previously noted, 

adult fish have the ability to avoid adverse water conditions and are expected to experience reduced 
Description of the Environment and Impact Analysis 4-187

exposure due to their mobility and avoidance response. Larval and juvenile life stages are generally more 

vulnerable, but studies such as the ones above suggest some species may be more tolerant of exposure 

than others. Furthermore, these results suggest that, should unweathered oil impact critical nursery 

habitat, the effects of sublethal acute exposure for some species and life stages may be short term. The 

potential impact that short-term effects may have on juvenile survival and recruitment is not known. Past 

research (Myers and Cadigan, 1993; Levin and Stuntz, 2005) suggests that larval and juvenile survival 

rates strongly influence offshore adult populations, and a new model developed by Baker et al. (2014) 

indicates that the survival of juvenile white shrimp (Litopenaeus setiferus) may factor more strongly than 

fishing pressure into population size.

A recent study of the effects of oil on embryonic and larval pelagic fishes (Incardona et al., 2014) 

documents results consistent with earlier research and supports conclusions reached by previous BOEM 

analyses. Researchers observed that PAHs accumulate more rapidly in smaller eggs due to an increased 

surface-to-volume ratio, resulting in lower threshold concentrations required to induce adverse effects. A 

second study, also consistent with earlier research and further supporting conclusions reached by previous 

BOEM analyses, exposed embryonic and juvenile dolphinfish (Corphaena hippurus) to crude oil WAF 

treatments for 48 hours and 24 hours, respectively (Mager et al., 2014). Embryos grown out to a juvenile 

stage demonstrated a 37 percent reduction in mean critical swimming speed. By comparison, juveniles 

raised under hatchery conditions to an age of ~31 days and assessed immediately following a 24-hour 

exposure to a WAF 30 times more concentrated than was used to treat embryos, experienced a 22 percent 

reduction in mean critical swimming speed (Mager et al., 2014). These findings support earlier research 

and suggest that sensitivity to acute oil exposure decreases with increasing developmental stages (Mager 

et al., 2014).

Detailed information on species found in the Gulf of Mexico, or closely related to those found in the 

GOM, continues to be developed and serves as a baseline for determining potential impacts. Given that 

morphological defects, reduced cardiac efficiency, and decreased swimming performance may result in 

reduced feeding success and increased susceptibility to predation, it may be assumed that early life stage 

acute exposure to oil results in decreased survival to maturity. However, without knowing the extent to 

which spawning overlapped spatially and temporally with waters contaminated by the 2010 Deepwater

Horizon oil spill, it is difficult to estimate the potential impacts to pelagic species. The value of the data 

summarized above could be further enhanced if analyzed in the presence of additional details (e.g., oil 

volatilization rates, species’ spatial and temporal spawning distributions, duration of exposure, and 

persistence of effects resulting from acute oil exposure) that would support the decisionmaking process. 

In the absence of additional information, BOEM has conservatively assumed near 100 percent mortality 

among exposed embryonic fishes. This position aligns with the NMFS status review team report in 

assuming a maximal reduction of 20 percent to the bluefin tuna 2010 cohort as a result of the Deepwater 

Horizon oil spill and estimating a less than 4 percent reduction in future spawning biomass (Atlantic 

Bluefin Tuna Status Review Team, 2011; USDOC, NMFS, 2013). Estimates for oil-related dolphinfish 

mortality as a result of the Deepwater Horizon oil spill were not available at the time of publication of 

this Supplemental EIS.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS, as well as in the 

previously mentioned NEPA documents, BOEM has identified incomplete or unavailable information 

regarding impacts related to explosive structure removal, seismic surveys, acute oil exposure, and chronic 

oil exposure. Fish mortality resulting from explosive structure removal has not been fully studied across 

a wide range of water depths and environmental conditions. However, as stated in the summary above, 

existing information (e.g., Gitschlag et al., 2000) is sufficient for the purpose of analyzing potential 

impacts of anticipated decommissioning activities. Specific responses by fishes to seismic survey 

activities cannot be predicted and are unknowable due to the many possible interactions among variables 

(e.g., species, environmental conditions, exposure history and duration, spawning status, presence of prey 

or predators, etc.) that could influence the response to sound. However, available information (Popper 

and Hastings, 2009; Fewtrell and McCauley, 2012; Lokkeborg et al., 2012) is sufficient, within the 
4-188 Central and Eastern Planning Areas Supplemental EIS

context of historical landings and with knowledge of anticipated survey frequency and distribution, to 

extrapolate an overall expectation of negligible impact to commercial fisheries. Information on the 

potential impacts to embryonic pelagic fishes is incomplete; however, recent studies suggest that fishes 

recruited near the time of the Deepwater Horizon explosion, oil spill, and response may not have suffered 

catastrophic losses (Fodrie and Heck, 2011; Atlantic Bluefin Tuna Status Review Team, 2011; USDOC, 

NMFS, 2013; Rooker et al., 2013). As such, it is reasonable to extrapolate that short-term effects of the 

oil spill did not severely impact recruitment. In the long term, the effects of acute or chronic exposures to 

oil remain unknown. This information cannot reasonably be obtained because the long-term effects may 

not yet be detectable and the overall costs in time and money to determine this are exorbitant. BOEM 

recognizes that the incomplete information with respect to long-term effects may be relevant to the 

evaluation of impacts on commercial fisheries. 

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. Although the body of available 

information is incomplete and long-term effects cannot yet be known, the evidence currently available 

supports past analyses and does not indicate severe adverse impacts to commercial fisheries. Therefore, 

BOEM has determined that the incomplete information is not essential to a reasoned choice among 

alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for commercial fisheries presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information provided above. No new significant information 

was discovered that would alter the impact conclusion for commercial fisheries presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.19. Recreational Fishing

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for recreation fishing presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for recreational fishing presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.19 of the EPA 225/226 EIS and Chapter 4.2.1.20 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.20 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.20 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Impacts of Routine Activities and Accidental Events

Activities during the initial phases of the EPA proposed action, such as seismic surveying operations 

and other forms of vessel traffic, may lead to some space-use conflicts with recreational fishermen. 

Vessel traffic during subsequent infrastructure emplacement and production operations could also lead to 

some space-use conflicts with recreational fishing activities. The OCS oil- and gas-related activities 

could also affect the aesthetics of fishing in a particular location, which could dissuade anglers from 
Description of the Environment and Impact Analysis 4-189

fishing in specific locations. Some activities that may arise from proposed EPA Lease Sale 226, such as 

construction activities and discharges of produced water, may also lead to low-level environmental 

degradation of fish habitat (Chapter 4.2.1.17), which would negatively impact recreational fishing 

activity. The level of participation in any particular State Rigs-to-Reefs program will be an important 

determinant of the long-term impact of the EPA proposed action on recreational fishing activity. As 

structures are scheduled for decommissioning, a higher level of participation may benefit fishermen 

through the retention of complex habitat and potentially enhanced production for some recreationally 

desirable species, as opposed to structure removals (particularly those that use explosives) that can 

negatively impact the recreational activity that depends on any particular platform. However, given the 

far distance of the EPA proposed action from shore, as well as the small scale of the EPA proposed 

action, these effects on recreational fishing activity will be minimal.

Oil spills can arise from accidents with respect to vessels, pipelines, drilling operations, or production 

operations. An oil spill would likely lead to recreational fishing closures in the vicinity of the oil spill. 

Small-scale spills should not affect recreational fishing to a large degree due to the likely availability of 

substitute fishing sites in neighboring regions. The longer-term effects of an oil spill will be determined 

by its effects on fish populations (Chapter 4.2.1.17), as well as by its effects on people and firms that 

support recreational fishing activity. Some of these effects will be similar to effects on species that are 

important to commercial fishing activity, which are discussed in Chapter 4.1.1.18. 

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors related to OCS oil and gas 

along with non-OCS oil- and gas-related impacts that may occur and adversely affect recreational fishing

in the same general area of the EPA proposed action. The proposed EPA lease sale will contribute to the 

impacts of the broader OCS Program. This includes the space-use impacts arising from vessel traffic and 

construction operations, as well as the low-level environmental degradation to fish habitats that could 

occur. However, there are only minimal levels of existing OCS oil- and gas-related activities in the area 

of the proposed EPA lease sale. The proposed EPA lease sale will also incrementally add to the 

probabilities of oil spills, which could affect recreational fishing activity in the short term. Lowprobability catastrophic oil spills, which are not part of the EPA proposed action and not likely expected, 

could also impact recreational fishing and are described in Appendix B. The proposed EPA lease sale 

could also have positive impacts to recreational fishing activity since OCS platforms often serve as reefs 

for fish populations, although removals of these platforms could have negative impacts on recreational 

fishing activity. However, the deepwater depths in the area of the EPA proposed action would limit the 

reef functions of OCS oil- and gas-related structures. However, these negative effects would be partially 

offset if some platforms are maintained through Rigs-to-Reefs programs. However, given the far distance 

of the EPA proposed action from shore, as well as the small scale of the EPA proposed action, these 

effects on recreational fishing activity will be minimal.

Recreational fishing activity could also be influenced by a number of non-OCS oil- and gas-related 

factors, such as commercial, military, recreational and industrial activities; natural processes; wetlands

loss; hypoxia events; fish kills; water quality degradation; fisheries management plans; hurricanes; State 

oil and gas activities; State artificial reef programs; tourism (refer to Chapter 4.2.1.20); and other 

economic factors (refer to Chapter 4.2.1.22.3). Many of these impacts will be determined by the 

cumulative impacts to fish populations, which are discussed in Chapter 4.2.1.17. However, recreational 

fishing activity is driven by unique tourism and economic trends (refer to Chapters 4.2.1.20 and 

4.2.1.22.3). It can also be influenced by the quality of fishing grounds, such as wetland areas, which can 

be degraded by hurricanes. Military activities, recreational vessel traffic, and other forms of vessel traffic 

could also cause space-use conflicts with recreational fishermen. However, it is likely that Fisheries 

Management Plans of the Federal and State governments would serve to keep overall recreational fishing 

activity reasonably stable through time.
4-190 Central and Eastern Planning Areas Supplemental EIS

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

BOEM examined a variety of Internet sources, as well as known data providers, for new information 

regarding the impacts of the EPA proposed action on recreational fishing. Some new information sources 

related to fish populations and to commercial fishing activity are discussed in Chapters 4.2.1.17 and 

4.2.1.18. The primary new data source specific to recreational fishing is an annual update to data 

provided by NMFS (USDOC, NMFS, 2014f), which clarifies the affected environment for recreational 

fishing. This data source provides data on both the species caught and the amount of angler effort in any 

particular year. Table 4-5 presents data on the number of angler trips taken in Louisiana, Mississippi, 

Alabama, and West Florida from 2008 to 2013. In 2013, there were 15.9 million angler trips in West 

Florida, 4.6 million angler trips in Louisiana, 2.9 million angler trips in Alabama, and 1.8 million angler 

trips in Mississippi. Compared with 2012 effort levels, angler effort increased in Alabama, Louisiana, 

and West Florida while angler effort decreased in Mississippi. Table 4-5 also breaks down these trips by 

location and mode. The three geographic locations for each state are inland, State ocean waters, and 

Federal ocean waters. The three modes of fishing are shore fishing, charter fishing, and private/rental 

fishing. For the Gulf as a whole, all forms of ocean-based fishing in State and Federal waters were higher 

in 2013 than in 2012. Shore inland and private/rental inland fishing decreased in 2013 when compared 

with 2012, while charter inland fishing increased.

Panel A of Table 4-6 presents data on the most commonly landed species by recreational fishermen 

in Louisiana, Mississippi, and Alabama combined from 2008 to 2013. Panel B of Table 4-6 presents data 

on the most commonly landed species by recreational fishermen in West Florida from 2008 to 2013. In 

both regions, landings in 2013 for most species were roughly consistent with landings observed in prior 

years. However, in both regions, there were fairly large increases in landings of black drum (Pogonias 

cromis), dolphins (Coryphaena hippurus), red snapper (Lutjanus campechanus) and Spanish mackerel 

(Scomberomorus maculatus). There were decreases in landings of sand seatrout (Cynoscion arenarius) in 

both regions.

The NMFS has also released its Fisheries Economics of the U.S. 2014 report (USDOC, NMFS, 

2014g). This report presents various data regarding the economic significance of recreational fishing in 

the Gulf of Mexico, which clarifies the affected environment for recreational fishing. Table 4-7 presents 

data from this report on expenditures, sales, value added, and employment in each Gulf Coast State in 

2012. The largest economic impacts from recreational fishing occurred in West Florida. Louisiana and 

Texas had the next largest impacts, followed by Alabama and Mississippi.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS, as well as in the 

previously mentioned NEPA documents, BOEM has identified incomplete or unavailable information 

related to recreational fishing. This incomplete information may be relevant to evaluating adverse effects 

because the full extents of potential impacts on recreational species are not known. This information 

relates to the ultimate impacts of the Deepwater Horizon explosion, oil spill, and response on fish 

populations that support recreational fishing activity. This information is relevant because it would allow 

BOEM to more accurately estimate the scales of recreational fishing activity in future time periods. 

Much of this information is being developed through the NRDA process, and this information has not yet 

been released. There is also uncertainty regarding the extent to which recreational fishing is dependent 

upon OCS oil and gas platforms. BOEM is planning to undertake a study project to examine this issue, 

although the results from this study project will not be released within the timeline contemplated in the 

NEPA analysis of this Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. For example, BOEM has used 

data on recreational fishing activity provided by NMFS, which allowed BOEM to examine trends in 

recreational fishing over time. BOEM does not expect the missing information to significantly change its 
Description of the Environment and Impact Analysis 4-191

estimates of the impacts of the OCS Program on recreational fishing activity because BOEM still has 

enough baseline data to reasonably estimate impacts. Therefore, BOEM has determined that the 

incomplete or unavailable information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for recreational fishing presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for recreational fishing presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.20. Recreational Resources

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for recreational resources presented in the EPA 225/226 

EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented below. No new significant information 

was discovered that would alter the impact conclusion for recreational resources presented in those NEPA

documents. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associate with the EPA proposed action are 

presented in Chapter 4.1.1.20 of the EPA 225/226 EIS and Chapter 4.2.1.21 of the 2012-2017 WPA/CPA 

Multisale. Updated information is provided in Chapter 4.2.1.21 of the WPA 233/CPA 231 Supplemental 

EIS and Chapter 4.1.1.21 of the CPA 235/241/247 Supplemental EIS. The following information is a 

summary of the resource description and impact analysis incorporated from those NEPA documents. Any 

new information that has become available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

Routine OCS oil- and gas-related activities in the EPA can cause various disturbances to recreational 

resources. For example, marine debris can noticeably affect the aesthetic value of coastal areas, 

particularly beaches. Vessel noise and the visibility of OCS oil- and gas-related infrastructure can also 

conflict with some recreational activities. Similarly, vessel traffic can cause space-use conflicts with 

recreational activities. The OCS oil- and gas-related activities can also change the composition of local 

economies through changes in employment, land use, and demand for activities related to recreation and 

tourism. The presence of OCS oil and gas platforms can enhance some recreational activities such as 

fishing and diving, although the long-term impacts of platforms depend on the nature of the 

decommissioning of the platform. However, the small scale of the EPA proposed action and the far 

distance from shore of the EPA proposed action suggest that these potential impacts on recreational 

resources are likely to be minimal.

Accidental events that could result from the EPA proposed action will be small, of short duration, and 

not likely to impact Gulf Coast recreational resources. Should an oil spill occur and contact a beach area 

or other recreational resource, it will cause some disruption during the impact and cleanup phases of the 

spill. Beaches, nature parks, and wetland areas could be impacted during these phases of a spill. These 

disruptions could also have impacts on firms and consumers that depend on the use of these resources. 

Media coverage and public perception regarding the extent of oil damage can also influence the ultimate 

economic impacts of the spill. The economic impacts of a spill would be mitigated to some extent if a 

legal damage claims process were to be implemented subsequent to an oil spill. However, all of these 

effects would likely be small in scale and of short duration.
4-192 Central and Eastern Planning Areas Supplemental EIS

Cumulative Impacts

The EPA proposed action would contribute to a number of aesthetic, space-use, oil spill, and 

infrastructure emplacement and removal impacts arising from existing and future oil and gas programs. 

Recreational resources along the Gulf Coast can also be impacted by non-OCS oil- and gas-related 

aesthetic and space-use conflicts, as well as a variety of other factors, such as coastal erosion, beach 

disruptions, and economic factors. However, the incremental contribution of the EPA proposed action is 

expected to be minimal in light of all OCS oil- and gas-related and non-OCS oil- and gas-related 

activities. This is because of the small scale of the EPA proposed action, as well as the far distance from 

shore of the EPA proposed action.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

BOEM conducted a search of Internet sources and of known data providers for new information 

regarding recreational resources. The Bureau of Labor Statistics has released preliminary data regarding 

the scale of employment in various industries in Gulf Coast States in 2013 (U.S. Department of Labor, 

Bureau of Labor Statistics, 2014). Table 4-8 presents data on the levels of employment in leisure and 

hospitality industries in various EIAs and coastal areas. Leisure and hospitality employment was higher 

in 2013 than in any year from 2008 through 2012 in all EIAs and coastal areas. This is likely primarily 

due to the gradual improvement in overall economic conditions since the most recent economic recession.

Cullinane-Thomas et al. (2014) provide estimates of the number of visitors, amount of spending, 

number of jobs, and amount of income in 2012 supported by each national park along the Gulf Coast. 

The number of visitors and the amount of visitor spending supported by parks along the Gulf Coast are as 

follows: Padre Island National Seashore (Texas) (573,855 visitors; $22,815,000); Jean Lafitte National 

Historical Park and Preserve (Louisiana) (419,964 visitors; $22,584,000); Gulf Islands National Seashore 

(Mississippi and Florida) (4,973,462 visitors; $199,385,000); De Soto National Memorial (Florida) 

(432,981 visitors; $23,299,000); Big Cypress National Preserve (Florida) (882,570 visitors; $64,229,000); 

Everglades National Park (Florida) (1,141,906 visitors; $102,765,000); and Dry Tortugas National Park 

(Florida) (60,550 visitors; $3,211,000).

New data regarding the extent of shoreline oiling arising from the Deepwater Horizon oil spill has 

become available (USDOC, NOAA, 2014). These data show that the majority of the shoreline of 

Louisiana has been cleaned. However, some areas, particularly areas near Chandeleur Sound and 

Barataria Bay, still had areas of oiled shoreline (these data were as of March 25, 2014). This has lessened 

the opportunities for beach visitation, fishing, and nature viewing in these areas (Drapkin, 2014). Finally, 

Ocean Conservancy (2014) provides data regarding the levels of marine debris found on the coastlines of 

various states in 2013, which clarifies the affected environment for recreational resources. The most trash

was found along the coastline of Florida, followed by Texas, Alabama, Mississippi, and Louisiana.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. This incomplete information may be relevant to evaluating 

adverse effects because the full extent of potential impacts on recreational resources is not known. This 

information relates to quantifying measures of recreation and tourism along the Gulf Coast, as well as 

information relating to the impacts of the Deepwater Horizon explosion, oil spill, and response on 

recreational resources. These information sources assist in assessing the baseline environment for 

recreational resources. BOEM has funded a study that is attempting to improve its information regarding 

these issues, although the study is not yet complete.

In light of the incomplete or unavailable information, BOEM used existing data sources and standard 

methods to estimate the impacts of the EPA proposed action on recreational resources. For example, 

BOEM used data from the Bureau of Labor Statistics using broader industry categories to estimate the 

scale of recreation-related activities in recent years. These data provide sufficient baseline information 
Description of the Environment and Impact Analysis 4-193

from which to estimate the impacts of the OCS Program, particularly since the available data suggest that 

most recreational areas have recovered from the impacts of the Deepwater Horizon explosion, oil spill, 

and response. Therefore, BOEM has determined that the incomplete or unavailable information is not 

essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for recreational resources presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information

was discovered that would alter the impact conclusion for recreational resources presented in those NEPA

documents because the new information was roughly consistent with prior expectations. The analysis and 

potential impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

4.2.1.21. Archaeological Resources

4.2.1.21.1. Historic Archaeological Resources

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for historic archaeological resources presented in the EPA 

225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information presented below. No significant new 

information was discovered that would alter the impact conclusion for historic archaeological resources 

presented in those NEPA documents. The analysis and potential impacts discussed in those documents 

still apply for proposed EPA Lease Sale 226. 

Historic archaeological resources on the OCS consist of historic shipwrecks and a single historic 

lighthouse, the Ship Shoal Light. A historic shipwreck is defined as a submerged or buried vessel or its 

associated components, at least 50 years old, that has foundered, stranded, or wrecked and that is 

currently lying on or embedded in the seafloor. Recent research on historic shipping routes suggests that 

the ultra-deepwater area of the Gulf of Mexico, between 25o and 27.5o N. latitude, was located along the 

historic Spanish trade route, which therefore increases the probability that a historic shipwreck could be 

located in this area (Lugo-Fernandez et al., 2007). This route runs through the EPA proposed-action area. 

A study to conduct archival research on these historic shipping routes was completed in 2010 (Krivor 

et al., 2011) and concluded that both Spanish and French vessels were lost in the 16th, 17th, and 18th

centuries while transiting the route between Vera Cruz, New Orleans, and Havana.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented Chapter 4.1.1.21.1 of the EPA 225/226 EIS and Chapter 4.2.1.22.1 of the 2012-2017 

WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.22.1 of the WPA 233/CPA 

231 Supplemental EIS and Chapter 4.1.1.22.1 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

Impacts of Routine Activities and Accidental Events

Routine impact-producing factors associated with the EPA proposed action that could affect historical 

archaeological resources include direct physical contact with a shipwreck site; the placement of drilling 

rigs and production systems on the seafloor; pile driving associated with platform emplacement; pipeline 

placement; dredging of new channels, as well as maintenance dredging of existing channels; anchoring 

activities; pipeline installation; post-decommissioning trawling clearance; and the masking from 

geophysical sensors of archaeological resources from industry-related debris.
4-194 Central and Eastern Planning Areas Supplemental EIS

The greatest potential impact to an archaeological resource as a result of the EPA proposed action 

would result from direct contact between an offshore activity (i.e., platform installation, drilling rig 

emplacement, and dredging or pipeline project) and a historic site because of incomplete knowledge of 

the location of these sites in the Gulf. The risk of contact to archaeological resources is greater in 

instances where archaeological survey data are inadequate or unavailable. Such an event could result in 

the disturbance or destruction of important archaeological information. Archaeological surveys provide 

the necessary information to develop avoidance strategies that reduce the potential for impacts on 

archaeological resources.

Damage to archaeological resources from offshore oil and gas activity can be minimized by 

conducting archaeological surveys before seabed disturbance occurs. Archaeological surveys, where 

required prior to an operator beginning OCS oil- and gas-related activities on a lease, are expected to be 

effective at identifying possible archaeological sites. The technical requirements of the archaeological 

resource reports are detailed in NTL 2005-G07, “Archaeological Resource Surveys and Reports.” Under

30 CFR § 550.194(c) lessees are required to immediately halt operations and notify BOEM’s Regional 

Director of the discovery of any potential archaeological resources. Under 30 CFR § 250.194(c) and 

30 CFR § 250.1010(c), lessees are also required to immediately halt operations and notify BSEE’s 

Regional Director of the discovery of any potential archaeological resources.

Except for the projected 0-1 new gas processing facilities and 0-1 new pipeline landfalls, the EPA 

proposed action would require no new oil and gas coastal infrastructure. It is expected that archaeological 

resources would be protected through the review and approval processes of the various Federal, State, and 

local agencies involved in permitting onshore activities.

Impacts to documented (which currently exist only onshore) and undocumented (potentially on and 

offshore) historic archaeological resources could occur as a result of an accidental oil spill and the 

associated cleanup operations. Detailed risk analyses of offshore oil spills ranging from <1,000 bbl to 

≥1,000 bbl and coastal spills associated with the EPA proposed action are provided in Chapters 3.2.1.5, 

3.2.1.6, and 3.2.1.7. When oil is spilled in offshore areas, much of the oil volatilizes or is dispersed by 

currents, so it has a low probability of contacting coastal areas. However, should a spill contact a historic 

archaeological site (including submerged sites), damage might include contamination of materials, direct 

impact from oil-spill cleanup equipment, and/or looting. An additional major effect from an oil spill 

could be viewshed pollution of a historic coastal site, such as a fort or lighthouse. Although such effects 

may be temporary and reversible, cleaning oil from historic structures can be a complex, time-consuming, 

and expensive process, and the use of dispersants may result in long-term chemical contamination of 

submerged cultural heritage sites (e.g., Chin and Church, 2010). It is expected, however, that any spill 

cleanup operations would be considered a Federal undertaking for the purposes of Section 106 of the 

National Historic Preservation Act and would be conducted in such a way as to minimize impacts to 

historic archaeological resources.

Cumulative Impacts

Several OCS oil- and gas-related cumulative impact-producing factors could potentially impact 

historic archaeological resources, including the following: (1) OCS Program routine and accidental 

impacts; (2) artificial rigs-to-reefs development; and (3) renewable energy and alternative use 

conversions. Historic archaeological resources on the OCS are vulnerable to the above OCS oil- and gasrelated cumulative impact-producing factors due to the associated bottom-disturbing activities. An 

impact could result from direct physical contact between historic shipwrecks located on the OCS and 

OCS Program oil and gas activities (i.e., pipeline and platform installations, drilling rig emplacement and 

operation, site decommissioning, rigs-to-reefs development, dredging, and anchoring activities). 

Permitting OCS oil- and gas-related development prior to requiring archaeological surveys has been 

documented to have impacted wrecks containing significant or unique historic information. Impacts may 

be reduced when preconstruction surveys are required by BOEM or the permitting agency prior to these 

activities. Impacts to historic resources may still occur in areas where a remote-sensing survey fails to 

resolve the location of partially or completely buried resources or when no pre-disturbance survey is 

required.

Impacts to documented (which currently exist only onshore) and undocumented (which currently 

exist only onshore) historic archaeological resources could occur as a result of an accidental oil spill and 

the associated cleanup operations; however, the potential for spills is low, the effects would generally be 
Description of the Environment and Impact Analysis 4-195

localized, and the cleanup efforts would be regulated. Low-probability catastrophic spills, which are not 

part of the EPA proposed action and not likely expected, are discussed in Appendix B. 

Non-OCS oil- and gas-related cumulative impact-producing factors that could potentially impact 

historic archaeological resources include the following: (1) State oil and gas activity; (2) offshore LNG 

projects; (3) new channel dredging and maintenance dredging; (4) State renewable energy and alternative 

use conversions; (5) State artificial reefs and rigs-to-reefs development; (6) commercial fishing; (7) sport 

diving and commercial treasure hunting; and (8) natural processes, including wave action and hurricanes. 

As with the OCS oil- and gas-related cumulative impact-producing factors, risks from the above non-OCS 

oil- and gas-related cumulative impact-producing factors are related to their associated bottom-disturbing 

activities. An impact could result from direct physical contact between historic shipwrecks and Staterelated oil and gas activities, sand borrowing, renewable energy activities, LNG facility construction, 

artificial reef creation, new channel dredging, and maintenance dredging. With the exception of 

maintenance dredging, preconstruction surveys may be required for these activities. Impacts to historic 

resources may still occur in areas where a remote-sensing survey fails to resolve the location of partially 

or completely buried resources or when no pre-disturbance survey is required.

The effects of the various impact-producing factors discussed in this analysis have likely resulted in 

the localized loss of significant or unique historic archaeological information. In the case of factors 

related to OCS Program activities of the past within the cumulative activity area, it is reasonable to 

assume that most impacts would have occurred prior to 1973 (the date of initial archaeological survey and 

site-clearance requirements). The incremental contribution of the EPA proposed action is expected to be 

very small due to the efficacy of remote-sensing surveys and archaeological reports, where required. 

Future OCS Program activities and the bottom-disturbing activities permitted by BOEM and other 

agencies may require preconstruction archaeological surveys that, when completed, are highly effective in 

identifying bottom anomalies that could be avoided or investigated before bottom-disturbing activities 

begin. When surveys are not required, it is impossible to anticipate what might be imbedded in or lying 

directly on the seafloor, and impacts to these sites are likely to be major in scale. Despite diligence in 

site-clearance survey reviews, there is still the possibility of an unanticipated interaction between a 

bottom-disturbing activity (i.e., rig emplacement, pipeline trenching, anchoring, and other ancillary 

activities) and a historic shipwreck.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

Various Internet sources were examined to assess recent information regarding impacts to 

archaeological resources or potential new threats to archaeological resources that may be pertinent to the 

EPA. These Internet sources included various online indexes to periodical literature, such as JSTOR 

(http://www.jstor.org/), the National Technical Information Service’s National Technical Reports Library 

(https://ntrlr3.ntis.gov), and ScienceDirect (http://www.sciencedirect.com/). In addition, BOEM has 

conducted scientific research in the GOM. The research has identified new information on shipwrecks 

that is pertinent to this Supplemental EIS.

In July 2013 and April 2014, BOEM participated in a multi-agency investigation of three earlynineteenth century shipwrecks located in the CPA (USDOI, BOEM, 2014d). Preliminary analysis of the 

data indicates that these wooden-hulled sailing vessels share similarities in hull construction 

characteristics and artifact assemblages. Additionally, these shipwrecks are located within 4 nmi (5 mi; 

7 km) of each other, suggesting that they may have been sailing together in convoy when they were 

caught and sunk by a violent storm. Regardless of whether these vessels were sailing together or on 

separate voyages, their discovery supports BOEM’s previous analysis that there is a high probability of 

historic shipwrecks being located in deepwater areas of the Gulf along historic trading routes (Pearson 

et al., 2003; Lugo-Fernandez et al., 2007).

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from the 

EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231, Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS are still valid because no new information on historic archaeological 
4-196 Central and Eastern Planning Areas Supplemental EIS

resources from the EPA proposed action has become available since those documents were published; 

nevertheless, there is still incomplete or unavailable information regarding the location of historic 

archaeological resources in the EPA. This information cannot be obtained because the overall costs of 

obtaining a survey of the entire EPA are exorbitant. This incomplete information may be relevant to 

adverse effects because the locations and integrity of many historic archaeological resources remain 

unknown. Nevertheless, this incomplete information is not likely to be available within the timeline 

contemplated in the NEPA analysis for this Supplemental EIS. It would take several years before data 

confirming the presence (or lack thereof) of historic archaeological resources, and the status of each, 

could be investigated, analyzed, and compiled. Historic archaeological sites within the EPA region have 

the potential to be buried, embedded in, or laying on the seafloor. The proposed EPA lease sale area 

covers an area of 657,905 ac and ranges in water depths from an estimated 800 to >2,400 m (2,624 to 

>11,401 ft). It includes highly variable bathymetric and geophysical regimes, which differentially affect 

the ease and ability to identify, ground truth, and evaluate historic archaeological sites. This fact, 

combined with the scope of the acreage within the EPA, results in the aforementioned exorbitant costs 

and time factors.

BOEM used reasonably accepted scientific theories on archaeological site potential in the Gulf of 

Mexico to extrapolate from existing survey data in completing the relevant analysis and formulating the 

conclusions presented here. In addition, future site-specific remote-sensing surveys of the seafloor are 

required when deemed appropriate to establish the presence of potential resources (NTL 2005-G07). The 

results of these surveys are reviewed in tandem with credible scientific evidence from previously 

identified sites, regional sedimentology, and physical oceanography that is relevant to evaluating the 

adverse impacts on historic resources that are a part of the human environment. The required surveys are 

analyzed by industry and BOEM archaeologists prior to the authorization of any new or significant 

bottom-disturbing impacts and, if necessary, avoidance of potential archaeological resources is 

prescribed. Archaeological surveys are expected to be highly effective in identifying resources to allow 

for the protection of the resource during OCS oil- and gas-related activities. The EPA proposed action is 

not a reasonably foreseeable significant impact because BOEM’s evaluation of such impacts is based 

upon pre-disturbance and site-specific surveys, the results of which BOEM uses to require substantial 

avoidance of any potential historic resource that could be impacted by the proposed activity. Therefore, 

BOEM has determined that the information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for historic archaeological resources presented in the EPA 

225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information presented above. No new significant 

information was discovered that would alter the impact conclusion for historic archaeological resources 

presented in those NEPA documents because of the available scientifically credible evidence in this 

analysis and based upon accepted scientific methods and approaches. The analysis and potential impacts 

discussed in those documents still apply for the proposed EPA Lease Sale 226.

4.2.1.21.2. Prehistoric Archaeological Resources

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for prehistoric archaeological resources presented in the 

EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS based on the additional information presented below. No new 

significant information was discovered that would alter the impact conclusion for prehistoric 

archaeological resources presented in those NEPA documents. The analysis and potential impacts 

discussed in those documents still apply for proposed EPA Lease Sale 226. 

Prehistoric archaeological resources are any material remains of human life or activities associated 

with the earliest inhabitants of the Gulf Coast, predating European discovery and exploration of the area. 
Description of the Environment and Impact Analysis 4-197

Available evidence suggests that the first Americans arrived on the Gulf Coast as much as 12,000 years 

B.P. during a time when the continental shelf was exposed above sea level and open to habitation 

(Pearson et al., 1986). Prehistoric archaeological sites are thought to be preserved shoreward of the 45-m 

(148-ft) bathymetric contour, where the Gulf of Mexico continental shelf was subaerially exposed during 

the Late Pleistocene. No area of the proposed EPA lease sale area is within this bathymetric range.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.21.2 of the EPA 225/226 EIS and Chapter 4.2.1.22.2 of the 2012-2017 

WPA/CPA Multisale EIS. The following information is a summary of the resource description and 

impact analysis incorporated from those NEPA documents. Any new information that has become 

available since those documents were published is presented below.

Impacts of Routine Activities and Accidental Events

Water depths in the proposed EPA lease sale area considerably exceed the 60-m (197-ft) depth 

contour that is generally accepted as the seaward limit of the subaerially exposed land mass that would 

have been available for human habitation when people migrated into the Gulf region around 12,000 B.P. 

As a result, prehistoric sites would not be expected to be affected by routine offshore development.

Onshore development as a result of the EPA proposed action could result in direct physical contact 

between construction of new facilities or a pipeline landfall and a previously unidentified prehistoric site. 

Direct physical contact with a prehistoric site could destroy fragile artifacts or site features and could 

disturb the site context. The result would be the loss of information on the prehistory of North America 

and the Gulf Coast region. There is up to one new gas processing facility and up to one new pipeline 

landfall expected as a result of the EPA proposed action. Furthermore, any facility or pipeline 

constructed is subject to coastal use requirements and must receive approval from the pertinent Federal 

agency, State agency, county/parish, and/or community involved. The protection of archaeological 

resources in these cases is expected to be achieved through the various approval processes involved. 

There should, therefore, be no impact to onshore prehistoric sites from onshore development related to the 

EPA proposed action.

Impacts to a prehistoric archaeological resource could occur as a result of an accidental oil spill. A 

major effect from an oil-spill impact would be contamination of a prehistoric coastal site, such as a shell 

midden, disturbance as a result of cleanup activities, or looting from the location of the site becoming 

known after an oil spill.

Other impacts that remain unknown at this time include the effect that the oiling of archaeological 

resources would have on the ability to conduct future chemical and observational analysis on the artifact 

assemblage. Currently, it is unknown to what extent the release of hydrocarbons or of dispersant would 

impede the analysis that may help interpret and understand archaeological resources.

An oil spill occurring and contacting an archaeological resource is unlikely, given that oil released 

tends to rise quickly to the surface where it can be cleaned up and that the average size of any spill would 

be small.

Cumulative Impacts

The OCS oil- and gas-related activities that could impact prehistoric archaeological sites located on 

the OCS through contact include pipeline and platform installations, drilling rig emplacement and 

operation, site decommissioning, rigs-to-reefs development, dredging, and anchoring activities. 

Preconstruction surveys may be required by BOEM or the lead permitting agency prior to these activities. 

Impacts to prehistoric resources may still occur in areas where a remote-sensing survey fails to resolve the 

location of partially or completely buried resources or when no pre-disturbance survey is required. 

Development onshore as a result of the EPA proposed action could result in the direct physical contact 

between a prehistoric site and pipeline trenching. It is assumed that archaeological investigations prior to 

construction will serve to mitigate these potential impacts. Oil spills have the potential to impact coastal 

prehistoric sites directly or indirectly by physical impacts caused by oil-spill cleanup operations. The 

number and most likely spill sizes to occur in coastal waters in the future are expected to resemble the 

patterns that have occurred in the past, as long as the level of oil- and gas-related commercial and 

recreational activities remain the same. Low-probability catastrophic spills, which are not part of the 
4-198 Central and Eastern Planning Areas Supplemental EIS

EPA proposed action and not likely expected, could also contact coastal prehistoric sites, and the effects 

of a spill that size would likely result in longer-lasting impacts that take longer to mitigate. Accidental 

spills as a result of a low-probability catastrophic spill are discussed in Appendix B. 

Non-OCS oil- and gas-related cumulative impact-producing factors that could potentially impact 

prehistoric archaeological resources including the following: (1) State oil and gas activity; (2) new 

channel dredging and maintenance dredging; (3) State renewable energy and alternative use conversions; 

(4) State artificial reefs and rigs-to-reefs development; (5) OCS sand borrowing; (6) offshore LNG 

projects; (7) commercial fishing; and (8) natural processes, including wave action and hurricanes. These 

impact-producing factors all create associated bottom disturbances that may threaten prehistoric 

archaeological resources. An impact could result from contact between prehistoric resources and 

permitted activities such as State oil and gas activities, renewable energy activities, artificial reef creation, 

new channel dredging, and maintenance dredging. With the exception of maintenance dredging, 

preconstruction surveys may be required for these activities. Impacts to prehistoric resources may still 

occur in areas where a remote-sensing survey fails to resolve the location of partially or completely buried 

resources or when no pre-disturbance survey is required. Oil and gas program wells, structures, and 

pipelines existing entirely in State waters are not under the jurisdiction of BOEM with respect to the 

archaeological resource protection requirements of the National Historic Preservation Act and would be 

the responsibility of the State and the permitting Federal agency. Prehistoric sites in shallow waters and 

on coastal beaches are exposed to the destructive effects of wave action and scouring currents. Overall, 

loss of data from prehistoric sites has probably occurred, and will continue to occur, in the northeastern 

Gulf of Mexico from the effects of tropical storms.

Onshore and nearshore maintenance dredging in support of activities resulting from the EPA 

proposed action has the potential to impact prehistoric resources. Impacts from maintenance dredging 

can be attributed proportionally to the users of the navigation channels. BOEM estimates that, under the 

EPA proposed action, <1 percent of the ship traffic is related to OCS use. Therefore, the impact to 

archaeological sites directly attributable to traffic and maintenance dredging as a result of the OCS 

Program is negligible. Additionally, any such maintenance activities are subject to coastal use 

requirements and must receive approval from the pertinent Federal agency, State agency, county/parish, 

and/or community involved. The protection of archaeological resources in these cases is expected to be 

achieved through the various approval processes involved. There should, therefore, be no impact to 

onshore prehistoric sites from maintenance dredging related to the EPA proposed action.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

Various Internet sources were examined to assess recent information regarding impacts to 

archaeological resources or potential new threats to archaeological resources that may be pertinent to the 

EPA. These Internet sources included various online indexes to periodical literature such as JSTOR 

(http://www.jstor.org/), the National Technical Information Service’s National Technical Reports Library 

(https://ntrlr3.ntis.gov), and ScienceDirect (http://www.sciencedirect.com/). 

This search did not identify any new information that would be pertinent to the analysis of the 

potential impacts of OCS oil- and gas-related activities on prehistoric archaeological resources. 

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the conclusions from the 

EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231, Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS are still valid because no new information on prehistoric 

archaeological resources from the EPA proposed action has become available since those documents were 

published; nevertheless, there is still incomplete or unavailable information on the location of prehistoric 

archaeological resources in the CPA. This incomplete information may be relevant to adverse effects 

because the locations and integrity of many prehistoric archaeological resources remain unknown. 

Nevertheless, this incomplete information is not likely to be available within the timeline contemplated in 

the NEPA analysis of this Supplemental EIS. It would take many years before data confirming the 

presence of prehistoric archaeological resources in a given location, and the status of each, could be 
Description of the Environment and Impact Analysis 4-199

investigated, analyzed, and compiled. Most prehistoric sites within the EPA region are likely deeply 

buried, resulting in the largest portion of the aforementioned exorbitant costs and time factors. An 

extensive study funded by the National Park Service in 1977 in the CPA estimated that prehistoric period 

sites could be buried on the OCS under as much as 200 m (656 ft) of sediment in western portions of the 

CPA and 107 m (351 ft) of sediment in eastern portions of the CPA (Coastal Environments, Inc., 1977).

BOEM used reasonably accepted scientific methodologies to extrapolate from existing survey data in 

completing the relevant analysis and formulating the conclusions presented here. In addition, new sitespecific, remote-sensing surveys of the seafloor are required when deemed appropriate to establish the 

presence of potential resources. The results of these surveys are reviewed in tandem with credible 

scientific evidence from previously identified sites, regional sedimentology, and physical oceanography

that is relevant to evaluating the adverse impacts on prehistoric resources that are a part of the human 

environment. The required surveys are analyzed by archaeologists prior to any new or significant bottomdisturbing impacts being authorized and avoidance of potential resources prescribed. Archaeological 

surveys, where required, are expected to be highly effective in identifying resources to allow for the 

protection of the resource during OCS oil- and gas-related activities. The EPA proposed action is not a 

reasonably foreseeable significant impact because BOEM’s evaluation of such impacts is based upon predisturbance and site-specific survey, the results of which BOEM uses to require substantial avoidance of 

any potential prehistoric resource that could be impacted by the proposed activity. Therefore, BOEM has 

determined that the information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for prehistoric archaeological resources presented in the EPA 

225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231, Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information presented above. No new significant 

information was discovered that would alter the impact conclusion for prehistoric archaeological 

resources presented in those NEPA documents because of the available scientifically credible evidence in 

this analysis and based upon accepted scientific methods and approaches. The analysis and potential 

impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

4.2.1.22. Human Resources and Land Use

4.2.1.22.1. Land Use and Coastal Infrastructure

Though this Supplemental EIS pertains to the EPA proposed action, the EPA is not significantly 

different from the adjacent CPA lease blocks with regard to socioeconomic impacts to land use and 

onshore coastal infrastructure. The EPA proposed action would be on a smaller scale than a CPA 

proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by reference. 

BOEM has examined the analysis for land use and onshore coastal infrastructure presented in the EPA 

225/226 Multisale EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS based on the additional information presented below. No new 

significant information was discovered that would alter the impact conclusion for land use and coastal 

infrastructure presented in those NEPA documents. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226. 

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.22.1 of the EPA 225/226 EIS and Chapter 4.2.1.23.1 of the 2012-2017 

WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.23.1 of the WPA 233/CPA 

231 Supplemental EIS and Chapter 4.1.1.23.1 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description incorporated from those NEPA documents. Any 

new information that has become available since those documents were published is presented below.

Impacts from Routine Activities and Accidental Events

Routine impact-producing factors associated with the EPA proposed action that could affect land use

and coastal infrastructure include the fluctuation of OSV day rates, the dredging of navigation channels, 
4-200 Central and Eastern Planning Areas Supplemental EIS

and the expansion of gas processing facilities, pipeline landfalls, service bases, and waste disposal

facilities. The impacts of routine events associated with the EPA proposed action are expected to remain 

consistent with historic activity levels. The OCS oil- and gas-related infrastructure has developed over 

many decades and is an extensive and mature system that provides support for offshore activities. The 

expansive presence of this coastal infrastructure is the result of long-term industry trends, and it is not 

subject to rapid fluctuations.

For the EPA proposed action, the primary region of geographic influence is coastal Louisiana, 

Mississippi, and Alabama. Oil- and gas-related activities are quite limited in the Florida area. Routine 

activities relating to the OCS Program are expected to minimally affect the current land use of the 

analysis area because most subareas have strong industrial bases and designated industrial parks with 

existing infrastructure and facilities to accommodate the future growth of oil and gas businesses. Since 

the supporting infrastructure is mature and not subject to rapid fluctuations and because BOEM only 

projects up to one new gas processing facility and up to one new pipeline landfall for the EPA proposed 

action, the impacts of routine activities associated with the EPA proposed action are expected to remain at 

historic activity levels (Dismukes, official communication, 2013). There may be a new increased demand 

for waste disposal services as a result of the EPA proposed action; however, the effects on land use and 

infrastructure would be limited, would occur on lands designated for such purposes, and would have 

minimal impacts to land use and coastal infrastructure. Because the projected addition to infrastructure is 

near zero, the routine activities associated with the EPA proposed action would have little effect on land 

use and existing coastal infrastructure, and there would be minimal impacts from any expansion of 

existing infrastructure. BOEM anticipates that there would be maintenance dredging of navigation 

channels, provided funding is appropriated, in support of routine activity at services bases as a result of 

the EPA proposed action. In regard to land use and infrastructure, it does not appear that there would be 

adverse impacts from routine activities associated with the EPA proposed action.

Accidental events (impact-producing factors) associated with the EPA proposed action that could 

affect land use and coastal infrastructure include, but are not limited to, oil spills, vessel collisions, and 

chemical/drilling-fluid spills. Accidental events associated with the EPA proposed action would occur at 

differing levels of severity, based in part on the location and size of event. Depending on where an 

accidental event occurs, it is expected that the oil-spill response equipment needed to respond to an 

offshore spill as a result of the EPA proposed action could be called out from one or more of the 

following oil-spill equipment base locations: New Iberia, Belle Chasse, Baton Rouge, Sulphur, Morgan 

City, Port Fourchon, Harvey, Leeville, Fort Jackson, Venice, Grand Isle, or Lake Charles, Louisiana; 

La Porte, Corpus Christi, Port Arthur, Aransas Pass, Ingleside, Galveston, or Houston, Texas; Kiln or 

Pascagoula, Mississippi; Mobile or Bayou La Batre, Alabama; Panama City, Pensacola, Tampa, or 

Miami, Florida; and/or Ponce or San Juan, Puerto Rico (Clean Gulf Associates, 2014; Marine Spill 

Response Corporation, 2014; National Response Corporation, 2014).

Cumulative Impacts

The cumulative analysis considers both existing land use patterns and the effects of impact-producing 

factors from OCS oil- and gas-related and non-OCS oil- and gas-related activities. Impact-producing 

factors associated with OCS oil- and gas-related activities that could affect land use and coastal 

infrastructure include gas processing facilities, pipeline landfalls, service bases, navigation channels, 

waste disposal facilities, oil spills, vessel collisions, and chemical/drilling-fluid spills. Any service base 

expansion in the cumulative case would be limited, would occur on lands designated for such purposes, 

and would have minimal effects on land use and infrastructure. Therefore, the incremental contribution 

of the EPA proposed action to the cumulative impacts on land use and coastal infrastructure is also 

expected to be minor.

The non-OCS oil- and gas-related factors that can contribute substantially to the baseline conditions 

as well as impact coastal infrastructure and land use and consist of the following:

• prior, current, and future State oil and gas lease sales;

• other onshore fossil fuel exploration and production activities;

• petrochemical and manufacturing activities;
Description of the Environment and Impact Analysis 4-201

• housing and other residential developments;

• the development of private and publicly owned recreational facilities;

• the construction and maintenance of industrial facilities and transportation systems;

• urbanization;

• city planning and zoning;

• changes to public facilities such as water, sewer, educational, and health facilities;

• changes to military bases and reserves;

• changes in population density;

• changes in State and Federal land use regulations;

• changes in non-OCS oil- and gas-related demands for water transportation systems 

and ports;

• macro- and microeconomic trends;

• coastal landloss and subsidence; and

• natural processes.

The OCS Gulf of Mexico leasing program exists within a highly industrialized and economically 

diverse coastal region, which is itself the aggregate of past and present community, government, and 

business actions. Again, for the EPA proposed action, the primary region of geographic influence is 

coastal Louisiana, Mississippi, and Alabama. Oil- and gas-related activities are limited in the EPA 

compared with the CPA and WPA. How land has been traditionally used or will be used in the future is 

determined irrespective of the EPA proposed action. Coastal infrastructure associated with the OCS oil 

and gas industry is also utilized by State leased and privately owned oil and gas interests, as well as other 

industries. State oil and gas activities and associated impacts will occur based on State leasing programs, 

geologic plays, economic trends, and local regulatory regimes. The OCS oil- and gas-related support 

activities occur within a context of a well-established populated coastal region, which is home to a diverse 

and robust economy. Many local and national industries, such as agricultural and industrial interests, 

utilize the same transportation systems and ports used by the OCS oil and gas industry. The OCS oil- and 

gas-related demands on land use are typically relegated to coastal or inland waterway industrial zones and 

represent a small fraction of how existing residential, recreational, agricultural, military, and industrial 

uses utilize and impact land use and coastal infrastructure. Because the vast majority of coastal 

infrastructure supports OCS and State offshore and land-based oil and gas production, as well as other 

land-based industrial uses, the coastal infrastructure supporting the EPA proposed action represents only a 

small portion of the coastal land use and infrastructure throughout the CPA and Gulf of Mexico, and 

because this is a shared resource, the incremental contribution of the EPA proposed action is expected to 

have minimal impact overall.

Land use categories are tied to existing infrastructure and historic uses, and for the purpose of this

analysis include the Economic Research Service’s land use inventory categories, which include the 

following: land-based oil and gas activities; agriculture; forests, parks, and special use areas; urban areas; 

miscellaneous areas; and inland navigable waterways and ports. Land use patterns vary greatly by region, 

reflecting differences in soils, climate, topography, and patterns of population settlement. Changes in 

land use will largely depend upon local zoning and economic trends. The future of non-OCS oil- and gasrelated land use and infrastructure will largely be determined by economic drivers that influence where 

people settle or re-locate. In Louisiana, for instance, people are moving away from coastal parishes 

because of coastal landloss, while in Florida, more people are moving to coastal counties, contributing to 

a 20-percent population rate increase since 1990 (Smith, 2005). Of the over 400,000 mi2

 (1,035,995 km2) 

comprising these coastal states including Texas, 18 percent of the total land area is covered in cropland. 

Texas and Mississippi have the highest percentages of cropland, with 20 percent and 19 percent of each 

respective State’s total land being used for cropland. Louisiana’s highway network is the 32nd largest in 

the Nation, with the State highway system the 11th largest. The network is comprised of over 60,000 mi 
4-202 Central and Eastern Planning Areas Supplemental EIS

(96,561 km) and more than 13,000 bridges under the jurisdiction of Federal, State, and local governments 

and entities. The 27.4 percent of highway network centerline mileage that are State-owned places 

Louisiana 10th nationally, while the 30 percent of total highway network lane mileage that are Stateowned places Louisiana 11th (State of Louisiana, Dept. of Transportation and Development, 2011). Five 

interstate highways converge in Alabama, allowing goods to be shipped to major markets. The I-22 is 

planned to be completed by 2014, making this the sixth interstate in Alabama (Economic Development 

Partnership of Alabama, 2013).

There is a substantial amount of domestic waterborne commerce in the analysis area and also some 

foreign maritime traffic. For the year 2009, eight of the leading 25 U.S. ports ranked by total trade 

tonnage are located in Louisiana, Mississippi, Alabama, and Florida (American Association of Port 

Authorities, 2009). The Ports of South Louisiana and Houston rank 12th and 13th, respectively, in total 

trade for all world ports and 1st and 2nd, respectively, for American ports (American Association of Port 

Authorities, 2011). With direct access to the Mississippi River and its system of inland rivers, the Port of 

South Louisiana averages 223 million metric tons per year. In Louisiana, there are 2,823 mi (4,543 km) 

of inland waterways (State of Louisiana, Dept. of Transportation and Development, 2011). Alabama’s 

water corridors connect to over 15,000 mi (24,140 km) of inland waterways in 23 states (Economic 

Development Partnership of Alabama, 2013). In the EPA, the vast majority of shipyards are located in 

Louisiana (64), followed by Alabama (18), Florida (14), and Mississippi (9). While the Gulf Coast 

shipbuilding region covers an area between south Texas and the tip of Florida, most shipbuilding facilities 

are concentrated in a 200-mi (322-km) area between New Orleans and Mobile. Meanwhile OCS oil- and 

gas-related coastal infrastructure and land use represent only an incremental contribution to total land use, 

and the cumulative impacts as a result of the EPA proposed action and the OCS Program as a whole on 

land use and coastal infrastructure are also expected to be minor. This short summary of land uses and 

land use categories is by no means comprehensive, but it should illustrate that OCS coastal land use and 

infrastructure comprises only a percentage of the total land use and allows us a bird’s eye view of the 

program within context of other impact-producing factors.

The proposed EPA lease sale would mostly maintain ongoing activity levels associated with the 

current OCS Program. Industry would essentially maintain its current usage of infrastructure according to 

the proposed lease sale schedule. Macroeconomic shifts, such as a change in commodity prices or an 

economic upturn or downturn, will also determine future utilization of this infrastructure.

The EPA proposed action would minimally affect the current land use within the analysis area 

because most subareas have strong industrial bases and designated industrial parks with enough capacity 

to accommodate the future growth that OCS oil- and gas-related businesses would demand. Coastal land 

use and infrastructure along the Gulf Coast can also be impacted by non-OCS oil- and gas-related 

conflicts, as well as a variety of other factors, such as coastal erosion and economic factors. However, the 

incremental contribution of the EPA proposed action is expected to be minimal in light of all OCS oiland gas-related and non-OCS oil- and gas-related activities.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

Additional research was conducted to investigate the availability of recent information affecting land 

use and coastal infrastructure since publication of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale 

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS. Various Internet 

sources were examined, including the websites of numerous Federal and State agencies (USDHS, Federal 

Emergency Management Agency; USDOC, Bureau of the Census; USDOC, NOAA; U.S. Department of 

Energy, Energy Information Administration; U.S. Department of Transportation, Maritime 

Administration; USDOI, FWS; RestoreTheGulf.gov website; Deepwater Horizon Oil Spill Portal; 

USEPA; Louisiana Department of Environmental Quality; Louisiana Recovery Authority; Louisiana 

Office of Community Development; Mississippi Department of Environmental Quality; Alabama 

Department of Environmental Management; and the State of Florida Department of Environmental 

Protection). Further information was sought from other organizations, recently published journal articles, 

and trade publications such as The Greater Lafourche Port Commission, LA1 Coalition, The Oil Drum, 

Reuters, Rigzone, Oil and Gas Journal, Offshore Magazine, Reuters, TOLLROADS News, and The 

Energy Journal. 
Description of the Environment and Impact Analysis 4-203 

A new U.S. Department of Energy, Energy Information Administration report found that Federal 

waters in the Gulf of Mexico in 2013 accounted for 69 percent of all the crude oil produced on land and 

water owned by the Federal Government (USDOE, Energy Information Administration, 2014j). The 

Energy Information Administration did note that offshore GOM oil production declined from 584 bbl in 

2010 to 447 MMbbl in 2013. Anticipated growth, however, is still fueling investment in infrastructure

and supporting industries. Reuters recently reported that offshore drilling is fueling investments for the 

handful of helicopter operators that shuttle oil workers to and from remote rigs. Barclays estimates that 

300 new helicopters will be needed to meet the demand (Gopinath, 2014). There are 115 OCS oil- and 

gas-related heliports across southern Louisiana. Mississippi and Alabama only host four helicopter hubs 

each (Gopinath, 2014). There are no actively utilized OCS oil- and gas-related heliports in Florida, but 

the infrastructure exists should the demand arise.

The recent combination of horizontal drilling and hydraulic fracturing technologies has enabled landbased oil and gas companies to economically recover a much larger share of domestic shale resources 

than previously possible. Domestic shale oil and gas have helped make the U.S. a global growth leader in 

crude oil production capacity growth and the largest natural gas producer (IHS Global Inc., 2014). The 

majority of new offshore infrastructure investments will support new development areas such as the 

Bakken and Eagle Ford production regions, which have not been historically large production regions. 

As a result of the current shale market, much of the infrastructure that processes OCS- and land-based oil 

and gas will likely experience investment and growth to accommodate the current boom. IHS Global Inc. 

projects that, between 2014 and 2020, an average of greater than $80 billion will be invested annually in 

U.S. midstream and downstream petroleum. Of that, $41.5 billion will be distributed within the 

southeastern region, which includes Texas, Louisiana, Alabama, Mississippi, and Florida. As of 

September 2011, over 70 mi (113 km) of interstate pipeline have gone into service to transport Marcellus 

Shale basin gas, 319 mi (513 km) of interstate pipeline are approved and under construction, 116 mi 

(187 km) are pending, and almost 5,000 mi (8,047 km) of potential projects have been announced. The 

NGL pipelines, which serve as the key connecter between the gas processing plants and the large NGL 

fractionating hubs, have increased investment. Investment decisions have been made to also expand two 

already very large refineries, i.e., Marathon Petroleum in Garyville, Louisiana, and Motiva in Port Arthur, 

Texas. But the demand for refined petroleum products has actually decreased and since 2010, calculated, 

nonsustaining capital investment in refining has decreased from $7.4 billion in 2010 to just under 

$3 billion in 2013.

Since 2009, U.S. domestic total natural gas storage has increased by 500 billion cubic feet to a total 

storage capacity of 9,100 billion cubic feet. As a result, the IHS Global Inc. analysis projects that over 

18,000 mi (28,968 km) of major crude oil pipelines will be constructed, expanded, reversed, or converted 

from natural gas or other pipeline service. This major corridor will be a continuous line of several 

different systems running horizontally from West Texas to refineries in Texas and Louisiana Gulf Coast, 

with production from Eagle Ford on ramping the Texas longitudinal corridor (IHS Global Inc., 2013, 

page 28). IHS Global Inc. forecasts cumulative investment in U.S. crude oil pipelines of $37.8 billion 

between 2014 and 2025, with the majority being invested during the first 6 years of the forecast period. 

Crude oil movements by rail have increased from less than 50,000 bbl per day in 2010 to 800,000 bbl per 

day in 2013, driving capital investment in rail tracks, rail loading and unloading facilities, and tank cars 

used in the transportation of crude oil. The investment in rail and marine logistics for transporting crude 

oil and NGLs has increased from less than $0.5 billion in 2010 to over $5 billion in 2013 (IHS Global 

Inc., 2013, page 18). Several of the LNG export projects now under development are likely to be 

completed. The Federal Energy Regulatory Commission authorized a second LNG export project in 

Cameron Parish, Louisiana, which will liquefy and export domestically produced natural gas from its 

existing LNG import terminal. The Federal Energy Regulatory Commission also authorized pipeline and 

compression facilities in Cameron, Calcasieu, and Beauregard Parishes, Louisiana, to supply the Cameron 

LNG facility with domestically produced gas (Federal Energy Regulatory Commission, 2014).

The OCS oil- and gas-related businesses would likely utilize infrastructure and transportation 

corridors that it shares in common with onshore producers. But to reiterate, onshore domestic shale oil 

and gas has driven and continue to drive much of the infrastructure additions and expansions that impact 

coastal land use. The dynamics of fossil fuel exploration and production are driven by micro- and 

macroeconomics, local and Federal regulations, technological advances, and geopolitics, among other 

trends and forces. Because the OCS oil and gas leasing program is a tightly scheduled and regulated 

industry, its anticipated utilization of coastal land and infrastructure is anticipated to stay within average 
4-204 Central and Eastern Planning Areas Supplemental EIS

parameters. None of this new significant information would alter the impact conclusion for land use and 

coastal infrastructure presented in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS because the new information 

was roughly consistent with prior expectations. The analysis and potential impacts discussed in those 

NEPA documents still apply for proposed EPA Lease Sale 226.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.1.22.1 

of the EPA 225/226 EIS, Chapter 4.2.1.23.1 of the 2012-2017 WPA/CPA Multisale EIS and WPA 

233/CPA 231 Supplemental EIS, and Chapter 4.1.1.23.1 of the CPA 235/241/247 Supplemental EIS, 

BOEM has identified incomplete information regarding the potential impacts of coastal landloss on land 

use and coastal infrastructure. This incomplete information may be relevant to adverse effects because a 

comprehensive understanding of the potential impacts of coastal landloss on coastal infrastructure and 

land use remains unknown. It is not completely known how current subsidence and erosion are impacting 

industry or whether industry is making plans to mitigate current or future impacts. This information 

cannot reasonably be obtained because the overall costs in time and money to collect data on the varying 

impacts of coastal landloss to different firms are exorbitant. BOEM has proposed a study to evaluate 

these potential effects by surveying industry on current impacts and potential adaptation strategies, but at 

the time of publication of this Supplemental EIS, it is unfunded, and it would take several years before 

data could be available. Nevertheless, this incomplete information is not likely to be available within the 

timeline contemplated in the NEPA analysis of this Supplemental EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions presented here. For example, BOEM knows 

that, in the case of coastal ports for instance, dredged material from navigation slips are used to fill in 

property and mitigation habitat areas for wildlife and to act as a barrier to protect ports from storm surges 

(Volz, 2013). While coastal infrastructure is subject to the impacts of coastal landloss and routine tropical 

storm activity, there is still considerable investment to expand, improve, and protect existing 

infrastructure. In June 2013, Governor Bobby Jindal of Louisiana signed Senate Bill 122, which 

modified the Investor Tax Credit and the Import-Export Tax Credit. The new credits now include 

projects like warehousing and storage, port operations, marine cargo handling, ship building and repairs, 

and oil- and gas-related activities (State of Louisiana, Office of Governor, 2013). Additionally, the 

decision criteria for the State of Louisiana’s 5-year coastal restoration planning document places a higher 

value on collections of risk reduction and restoration projects that improve coastal conditions for oil- and 

gas-related infrastructure and increase the resilience of coastal communities that support the industry. 

The criterion also puts a higher value on projects that benefit the navigation industry and places a lower 

value on projects that impede navigation (State of Louisiana, Coastal Protection and Restoration 

Authority, 2012b). Therefore, coastal restoration efforts will be focused on those land use areas with a 

higher concentration of OCS coastal infrastructure. While not completely known, current and future 

industry adaptation plans for coastal landloss are not essential to a reasoned choice among alternatives for 

this Supplemental EIS (including the No Action and an Action alternative).

Like any industrial infrastructure improvements, future adaptations will likely occur on an as-needed 

basis or as new technologies become available. Therefore, BOEM has determined that the information is 

not essential to a reasoned choice among alternatives. BOEM will continue to monitor industry and its 

infrastructure footprint over time to document short- and long-term impacts of continued landloss. For a 

more detailed discussion on deltaic landloss, refer to Chapter 4.1.1.4. 

Summary and Conclusion 

BOEM has reexamined the analysis for land use and coastal infrastructure presented in the EPA 

225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS based on the additional information presented above. No new significant 

information was discovered that would alter the impact conclusion for land use and coastal infrastructure 
Description of the Environment and Impact Analysis 4-205

presented in those NEPA documents because the new information was roughly consistent with prior 

expectations. The analysis and potential impacts discussed in those documents still apply for proposed 

EPA Lease Sale 226.

4.2.1.22.2. Demographics

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different from the adjacent CPA lease blocks with regards to 

socioeconomic impacts to demographics. The EPA proposed action is on a smaller scale than a CPA 

proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by reference. 

BOEM has reexamined the analysis for demographics presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented below. No new significant information was discovered 

that would alter the impact conclusion for demographics presented in those NEPA documents. The 

analysis and potential impacts discussed in those documents still apply for proposed EPA Lease Sale 246.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative events associated with the EPA proposed action are 

presented in Chapter 4.1.1.23.3 of the EPA 225/226 EIS and Chapter 4.2.1.23.3 of the 2012-2017 

WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.23.3 of the WPA 233/CPA 

231 Supplemental EIS and Chapter 4.1.1.23.3 of the CPA 235/241/247 Supplemental EIS. The following 

is a summary of the resource description and impact analysis incorporated from those NEPA documents. 

Any new information that has become available since those documents were published is presented 

below.

Impacts of Routine Activities and Accidental Events

In general, impact-producing factors that cause employment impacts, such as exploration and 

delineation activities, development and production activities, and coastal infrastructure development can 

have some impacts on the demographic characteristics of a particular area. However, routine activities 

associated with the EPA proposed action are projected to minimally affect the demographics of the 

analysis area. The projected impacts to population arising from a lease sale are calculated by multiplying 

the employment estimates from the mathematical model MAG-PLAN by an estimate of the number of 

members in a typical family. The projected population increases arising from a lease sale are then divided 

by the population forecasts in Woods and Poole, Inc. (2014), which yields the percentage impacts to 

population of a lease sale. Population impacts from the EPA proposed action are projected to be minimal 

(<0.1% of the total population) for all EIAs in the Gulf of Mexico region.

Accidental events associated with the EPA proposed action, such as low- to moderate-scale oil or 

chemical spills, blowouts, and vessel collisions, would likely have no effects on the long-term 

demographic characteristics of the Gulf coastal communities. This is because accidental events typically 

cause only short-term population movements as individuals seek employment related to the event or have 

their existing employment displaced during the event.

Cumulative Impacts

The cumulative analysis considers the effects of impact-producing factors related to OCS oil- and 

gas-related activities along with non-OCS oil- and gas-related impact-producing factors. The OCS oiland gas-related factors that could impact the demographics of any area consist of routine activities and 

accidental events arising from prior, current, and future OCS lease sales, including impact-producing 

factors that cause employment impacts (i.e., exploration and delineation activities, development and 

production activities, and coastal infrastructure development) as well as oil spills, blowouts, and vessel 

collisions. The impacts to population arising from the EPA proposed action are projected to be minimal 

(<0.1% of the total population) for any EIA in the Gulf of Mexico region based on the employment 

estimates from the mathematical model MAG-PLAN for low-case and high-case scenarios for OCS oiland gas-related activities. Accidental events should not have long-term effects on the demographic 

characteristics of the Gulf coastal communities because population movements from such events are 

typically short-term. For a detailed discussion on the employment and demographic impacts of a low-
4-206 Central and Eastern Planning Areas Supplemental EIS

probability catastrophic spill, which is not part of the EPA proposed action and not likely expected, refer 

to Appendix B. 

There are numerous non-OCS oil- and gas-related factors that could impact demographics, including 

fluctuations in workforce, net migration, relative income, oil and gas activity in State waters, offshore 

LNG activity, trends in tourism activities (refer to Chapter 4.2.1.21), and other economic factors (refer to 

Chapter 4.2.1.23.3). Common approaches in analyzing cumulative effects begin by assembling a list of 

other projects and actions that will likely be associated with the EPA proposed action. However, no such 

list of future projects and actions could be assembled that would be sufficiently current and 

comprehensive to support a cumulative analysis for all 132 of the coastal counties and parishes in the 

analysis area over a 40-year period. Instead, this analysis uses the economic and demographic projections 

from Woods & Poole Economics, Inc. (2014) as a reasonable approximation to define the contributions of 

other likely projects, actions, and trends to the cumulative case.

The EPA proposed action would contribute to the population impacts arising from the overall OCS 

Program. The EIAs TX-3, TX-1, LA-2, and LA-3 are projected to have some increases in the levels of 

their populations as a result of an increase in demand for OCS labor from both the EPA proposed action 

and the overall OCS Program. The EPA proposed action is projected to have an incremental contribution 

of less than 1 percent to the population level in any of the EIAs, in comparison with other factors 

influencing population growth, such as the status of the overall economy, fluctuations in workforce, net 

migration, health trends, and changes in income. Given both the low levels of population growth and 

industrial expansion associated with the EPA proposed action, it is expected that the baseline age and 

racial distribution patterns will continue through the analysis period.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

BOEM conducted a search of Internet resources and known data sources related to demographics. 

The primary source of new information is Woods & Poole Economics, Inc. (2014), which is an annual 

update of the data that were used in the CPA 235/241/247 Supplemental EIS. Woods & Poole 

Economics, Inc. (2014) provides projections of economic and demographic variables at the county/parish 

level. Table 4-9 provides projections of the evolution of the total population in all EIAs in future years, 

while Table 4-10 provides projections of the evolution of total employment in the same areas. These 

projections assume the continuation of existing social, economic, and technological trends at the time of 

the forecast. In 2013, the total Gulf Coast population was 25.51 million. In 2013, the EIAs with the 

largest populations were TX-3 (6.54 million), FL-4 (6.43 million), and FL-3 (3.77 million). The EIAs 

with the smallest populations were LA-1 (353,510), MS-1 (493,860), and LA-2 (603,940). For all EIAs 

combined, it is expected that the total population will grow at a 1.27 percent rate between 2014 and 2055. 

The fastest population growth is expected in TX-3 (1.65%), TX-1 (1.46%), and FL-3 (1.28%); the slowest 

population growth is expected in LA-4 (0.45%) and MS-1 (0.62%). Tables 4-11- through 4-23 provide 

projections of employment, income, wealth, business patterns, and racial composition for individual 

EIAs. In general, the projections of these variables have not changed noticeably from the projections in 

the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS.

Austin et al (2014a and 2014b) are two volumes of a recently completed study of the social impacts 

of the Deepwater Horizon oil spill. This study employed an ethnographic methodology that entailed 

analyzing data sources, examining various sources of descriptive information, and conducting field 

interviews with people in Louisiana, Mississippi, and Alabama. This study documents the complex and 

varied impacts of the Deepwater Horizon oil spill during the 20 months subsequent to the spill. This 

study found that the impacts of the spill on a particular community depended on a number of factors, such 

as its proximity to the spill, economic structure, social and political dynamics, organizational structure for 

dealing with disasters, and ability to adapt to the structures of the oil cleanup and damage claims 

processes. This study also provides background information regarding the demographic structures of 

certain communities.
Description of the Environment and Impact Analysis 4-207

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.2.12.2 

of the EPA 225/226 EIS, Chapter 4.2.1.23.2 of the 2012-2017 WPA/CPA Multisale EIS and WPA 

233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.2 of the CPA 235/241/247 Supplemental EIS, 

BOEM has identified incomplete or unavailable information related to demographics in the EPA. This 

incomplete information may be relevant to evaluating adverse effects because the full extent of potential 

impacts on demographics is not known. This incomplete or unavailable information relates to translating 

employment impacts of OCS oil- and gas-related activities into estimated population impacts. This 

information cannot be obtained at this time due to data limitations and the complexity of methodologies 

needed to accurately estimate population impacts arising from OCS oil- and gas-related activities. BOEM 

plans to initiate a study project to analyze population impacts more fully, although this potential study 

project will not be completed within the timeline contemplated in the NEPA analysis of this Supplemental 

EIS.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing this analysis and formulating the conclusions here. For example, BOEM used data from 

Woods & Poole Economics, Inc. (2014), which provides projections of the evolution of the total 

population in all EIAs in future years. These projections assume the continuation of existing social, 

economic, and technological trends at the time of the forecast. This incomplete or unavailable 

information is unlikely to significantly impact BOEM’s estimates of the impacts of OCS lease sales on 

demographics, in part because these impacts are fairly limited. In addition, increases in population arising 

from lease sales are generally positive, not adverse, impacts. Therefore, BOEM has determined that the 

incomplete or unavailable information is not essential to a reasoned choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for demographics presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented above. No new significant information was discovered 

that would alter the impact conclusion for demographics presented in those NEPA documents because the 

new Woods and Poole Economics, Inc. data did not change much from what was presented in those 

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.22.3. Economic Factors

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different from the adjacent CPA lease blocks with regards to 

socioeconomic impacts to economic factors. The EPA proposed action is on a smaller scale than the a 

CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 

Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by reference. 

BOEM has reexamined the analysis for economic factors presented in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS based on the additional information presented below. No new significant information was discovered 

that would alter the impact conclusion for economic factors presented in those NEPA documents. The 

analysis and potential impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts on 

economic factors from routine activities, accidental events, and cumulative events associated with the 

EPA proposed action are presented in Chapter 4.1.1.23.2 of the EPA 225/226 EIS and Chapter 4.2.1.23.3 

of the 2012-2017 WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.23.3 of the 

WPA 233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.3 of the CPA 235/241/247 Supplemental 

EIS. The following information is a summary of the resource description and impact analysis 
4-208 Central and Eastern Planning Areas Supplemental EIS

incorporated from those NEPA documents. Any new information that has become available since those 

documents were published is presented below.

Impacts of Routine Activities and Accidental Events

As a result of proposed EPA Lease Sale 226, there would only be minimal economic changes in the 

Texas, Louisiana, Mississippi, Alabama, and Florida EIAs. This is because the demand would be met 

primarily with the existing population and labor force. Most of the employment related to proposed EPA 

Lease Sale 226 is expected to occur in Texas (primarily in the EIA TX-3) and in the coastal areas of 

Louisiana. The EPA proposed action, irrespective of whether one analyzes the high-case or low-case 

production scenario, would not cause employment effects >0.1 percent in any EIA along the Gulf Coast.

Accidental events associated with the EPA proposed action, such as an oil spill, can cause a number 

of disruptions to local economies. Many of these effects are due to industries that depend on damaged 

resources. However, the impacts of an oil spill can be somewhat broader if companies further along 

industry supply chains are affected. These effects depend on issues such as the duration, methods, and 

logistics of the cleanup operations and the responses of policymakers to a spill. However, the impacts of 

small- to medium-sized spills should be localized and temporary.

Cumulative Impacts

The cumulative analysis considers the effects of OCS oil- and gas-related impact-producing factors 

along with non-OCS oil- and gas-related impact-producing factors that may occur and adversely affect 

economic factors in the same general area of the EPA proposed action. BOEM uses the model MAGPLAN to determine the direct, indirect, and induced employment arising from a particular scenario for oil 

and gas exploration and development activities (i.e., drilling, platform installations, and structure 

removals). The EPA proposed action would not cause employment effects >0.1 percent in any EIA along 

the Gulf Coast. Oil spills can cause a number of disruptions to local economies; however, small- to 

medium-sized spills should have localized, temporary impacts. A low-probability catastrophic spill, 

which is not part of the EPA proposed action and not likely expected, would have more noticeable 

impacts to the economy. However, the likelihood of another spill of this scale is quite low. A detailed 

analysis of a low-probability catastrophic spill can be found in Appendix B. 

Non-OCS oil- and gas-related impact-producing factors that can affect economic trends in economic 

areas in the Gulf of Mexico region include commercial, military, recreation/tourism (refer to Chapter 

4.2.1.21), and numerous other offshore and coastal activities. To estimate the cumulative impacts to 

economic factors from non-OCS oil- and gas-related impact-producing factors, BOEM employs the 

economic and demographic projections from Woods & Poole Economics, Inc. (2014). These projections 

are based on local, regional, and national trend data, as well as likely changes to local, regional, and 

national economic and demographic conditions. Therefore, the projections include employment

associated with the continuation of current patterns in OCS oil- and gas-related leasing activity, as well as 

the continuation of trends in other industries important to the region. For example, these forecasts include 

the contributions of State oil and gas activities, renewable energy activities, coastal land use, and tourismrelated activities.

The cumulative impacts of the EPA proposed action would be determined by the expected path of the 

economy and by the expected progression of the OCS oil and gas industry in upcoming years. The 

expected path of the overall economy is projected using the data provided by Woods and Poole 

Economics, Inc. (2014). The expected economic impacts of the OCS oil and gas industry in upcoming 

years are estimated using the mathematical model MAG-PLAN. The cumulative impacts of the EPA 

proposed action to the economies along the Gulf Coast are expected to be relatively small.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

BOEM conducted a search of Internet sources and known data sources regarding economic factors. 

Table 4-24 presents updated data from The Office of Natural Resources Revenue (2014) regarding sales 

volumes, sales values, and government revenues received from Federal offshore energy activities in the 
Description of the Environment and Impact Analysis 4-209

Gulf of Mexico. Panel A of Table 4-24 presents annual data regarding the quantities of royalty-bearing 

and nonroyalty-bearing sales volumes for natural gas, NGLs, and oil. In FY 2013, royalty-bearing natural 

gas sales continued on a long-term downward trend, falling from 1.12 billion Mcf (thousand cubic feet) in 

FY 2012 to 970 million Mcf in FY 2013. Sales volumes of royalty-bearing NGLs also continued on a 

steady downward trend in FY 2013, although sales volumes of nonroyalty-bearing NGLs increased in FY 

2013 compared with FY 2012. Sales volumes of royalty-bearing oil increased in FY 2013, while sales 

volumes of nonroyalty-bearing oil decreased. Panel B of Table 4-24 presents the sales values of gas, 

NGLs, and oil produced in Federal areas in the Gulf of Mexico. Sales values of oil and natural gas 

increased, while sales values of NGLs decreased. The increase in the sales value of natural gas reflects 

the higher average price for natural gas in FY 2013 compared with FY 2012. Panel C of Table 4-24

presents the Federal Government revenues received from offshore energy activities in the Gulf of Mexico. 

The Federal Government received $8.86 billion in revenue from energy sales and from OCS oil and gas 

lease sales that occurred during FY 2013, which was larger than any amount received since FY 2008. 

This increased revenue reflects the higher energy prices that prevailed in FY 2013, as well as the large 

amount of bonus bid revenue received from offshore oil and gas lease sales.

The U.S. Department of Energy’s Energy Information Administration has released its 2014 Annual 

Energy Outlook (USDOE, Energy Information Administration, 2014k). This report provides forecasts 

regarding a wide variety of issues related to energy markets. For example, this report provides forecasts 

of the levels of oil and gas production and prices that will occur in Gulf offshore waters in future years. 

In its reference scenario, this report forecasts that, from 2012 through 2040, Gulf offshore oil production 

will decrease at an average annual rate of 2.7 percent rate in shallow waters and will increase at an 

average rate of 1.6 percent in deepwater areas. This report forecasts that, from 2012 through 2040, Gulf 

offshore natural gas production will decrease at an average annual rate of 1.2 percent in shallow waters 

and will increase at an average rate of 2.7 percent in deepwater areas. This report forecasts that oil prices 

will slightly decrease through 2017 before gradually increasing in subsequent years. Natural gas prices 

are forecasted to gradually increase in future years from the very low prices observed in recent years. 

This report also notes the uncertainties associated with these forecasts and presents results for various 

scenarios that make different assumptions regarding energy prices, regulatory changes, and the path of the 

overall economy.

A report conducted by Smith (2014) provides an overview of the status of the oil and gas industries, 

with an emphasis on the status of Louisiana’s energy industry. This report describes how the large-scale 

development of onshore shale oil and gas activities will impact the competitive environment for offshore 

oil and gas activities. The report forecasts that nearshore natural gas production will continue to decline 

but that this decline will be partially offset by higher energy production in certain deepwater areas. This 

report also describes how the low price of natural gas is diverting development and production activities 

from extracting natural gas to extracting oil and NGLs.

New reports have become available regarding certain industries that are involved with offshore oil 

and gas activities. Beaubouef (2014a) reports that drilling activity has slightly declined in recent months, 

in part due to rising costs. For example, there were about 1,921 months of backlogged contract drilling 

work in May 2014 compared with 2,017 months of work in December 2013. Workboat.com (2014b) 

reports that day rates for four of the five classes of supply boats, as well as for both of the two classes of 

crew boats, increased from April 2013 to April 2014. IHS Petrodata (2014) reports that, in July 2014, 

79 of 88 marketed drilling rigs were under contract; 77 of 81 drilling rigs were under contract in July 

2013. Finally, Beaubouef (2014b) discusses a number of recent field discoveries and expanded 

developments of existing fields, which should help to support future oil and gas development and 

production activities.

Austin et al. (2014a and 2014b) are two volumes of a recently completed study of the social impacts 

of the Deepwater Horizon oil spill. This study employed an ethnographic methodology that entailed 

analyzing data sources, examining various sources of descriptive information, and conducting field 

interviews with people in Louisiana, Mississippi, and Alabama. This study documents the complex and 

varied impacts of the Deepwater Horizon oil spill during the 20 months subsequent to the spill. This 

study found that the impacts of the spill on a particular community depended on a number of factors, such 

as its proximity to the spill, its economic structure, its social and political dynamics, its organizational 

structure for dealing with disasters, and its ability to adapt to the structures of the oil cleanup and damage 

claims processes. This study also provides background information regarding the economic structures of 

certain communities.
4-210 Central and Eastern Planning Areas Supplemental EIS

The impacts of the proposed EPA lease sale and the OCS Program should be viewed in the context of 

overall economic conditions. In Table 4-10, data from Woods and Poole Economics, Inc. (2014) is used 

to generate forecasts of overall employment in all EIAs during the life of activities that would arise from 

the proposed EPA lease sale; these employment forecasts assume the continued progression of offshore 

oil and gas exploration and development activities. From 2014 to 2055, the fastest employment growth is

expected in EIA TX 3 (1.89%), TX-1 (1.73%), and FL-4 (1.64%); the slowest employment growth is 

expected in EIA MS-1 (0.84%) and LA-4 (0.95%). The growth forecasts from Woods and Poole 

Economics, Inc. (2014) show slight increases in the growth forecasts compared with the 2013 data in all 

EIAs except FL-2, whose forecasted employment growth slightly decreased compared with the 2013 data. 

Woods and Poole Economics, Inc. (2014) is also used to forecast various demographic variables; refer to 

Chapter 4.2.1.23.2 for more information regarding demographics. In general, the projections of these 

variables have not changed noticeably from the projections in the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental 

EIS.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS and in Chapter 4.1.1.23.3 

of the EPA 225/226 EIS, Chapter 4.2.1.23.3 of the 2012-2017 WPA/CPA Multisale EIS and WPA 

233/CPA 231 Supplemental EIS and Chapter 4.1.1.23.3 of the CPA 235/241/247 Supplemental EIS, 

BOEM has identified incomplete or unavailable information related to the potential impacts of EPA lease 

sales on economic factors. This information primarily relates to the onshore geographic distributions of 

economic impacts arising from the OCS Program, which would allow BOEM to better estimate routine 

and cumulative impacts. This information is difficult to obtain since most data sources do not adequately 

differentiate between onshore and offshore oil and gas activities.

BOEM used reasonably accepted scientific methodologies to extrapolate from existing information in 

completing the relevant analysis and formulating the conclusions presented here. In particular, BOEM 

used the most recent version of MAG-PLAN to estimate the impacts of the EPA proposed action and the 

OCS Program. In addition, BOEM is planning to launch a study project to explore new avenues for 

improving BOEM’s information regarding onshore distributions, although this project will take time and 

funding to pursue. However, any new information regarding onshore distributions of economic impacts 

is unlikely to significantly change BOEM’s estimates of the impacts of the OCS Program. In addition, 

the economic impacts arising from the OCS Program are generally positive, not adverse. Therefore, 

BOEM has determined that the incomplete or unavailable information is not essential to a reasoned 

choice among alternatives.

Summary and Conclusion

BOEM has reexamined the analysis for economic factors presented in the EPA 225/226 EIS, 2012-

2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for economic factors presented those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.22.4. Environmental Justice

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regard to potential onshore socioeconomic impacts to 

environmental justice. The EPA proposed action is on a smaller scale than a CPA proposed action that is 

analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 

235/241/247 Supplemental EIS, which are hereby incorporated by reference. BOEM has reexamined the 

analysis for environmental justice presented in the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale 
Description of the Environment and Impact Analysis 4-211

EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS based on the 

additional information presented below. No new significant information was discovered that would alter 

the impact conclusion for environmental justice presented in those NEPA documents. The analysis and 

potential impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action are 

presented in Chapter 4.1.1.22.1 of the EPA 225/226 EIS and Chapter 4.2.1.23.4 of the 2012-2017 

WPA/CPA Multisale EIS. Updated information is provided in Chapter 4.2.1.23.4 of the WPA 233/CPA 

231 Supplemental EIS and Chapter 4.1.1.23.4 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

discussed below.

The oil and gas industry and its associated support sectors are interlinked and widely distributed along 

the Gulf Coast. Offshore OCS oil- and gas-related industry operations resulting from the EPA proposed 

action would most likely utilize onshore facilities located within the CPA and WPA, rather than the EPA. 

Although the proposed EPA action would be approximately 125 mi (201 km) from Florida’s Panhandle 

region, the majority of socioeconomic impacts would not occur in Florida. Because of Florida’s historic 

opposition to oil and gas development in waters close to Florida and because of the almost complete 

absence of onshore support service bases in the State, BOEM anticipates that very few OCS oil- and gasrelated activities would be staged from Florida. Also, no new pipeline landfalls or other forms of coastal 

OCS oil- and gas-related infrastructure are projected to be constructed in Florida as a result of the EPA 

proposed action. Instead, Port Fourchon, Louisiana, is expected to serve as the primary service base and 

is more likely than areas in Florida, Mississippi, or Alabama to experience any population impacts that 

might result from the EPA proposed action. BOEM does not expect that population and environmental 

justice effects due to the EPA proposed action would be concentrated in the Florida Panhandle region, 

first, because most OCS oil- and gas-related jobs are in the fabrication sector and this sector is not 

strongly present in the Panhandle and, second, because OCS oil- and gas-related employment in general is 

widespread across the GOM region (i.e., offshore workers do not necessarily live near their place of 

work) and is not concentrated in the Florida Panhandle region. This analysis focuses on potential 

disproportionate impacts to minority and low-income populations living onshore. BOEM conducts a 

county-level analysis to determine the concentration of minority and low-income populations located in 

the same counties as OCS oil- and gas-related onshore coastal infrastructure (refer to Chapter 4.2.1.23.4.1 

and Figures 4-26 through 4-35 of the 2012-2017 WPA/CPA Multisale EIS).

During the NEPA process, BOEM provides opportunities for public input, which include minority 

and low-income populations. Some of the numerous avenues for public outreach employed by BOEM 

include the following: specific types of notices that are (1) mailed to public libraries, interest groups, 

industry, the general public, local, State, and Federal agencies, and Tribal Nations; (2) published in local 

newspapers; (3) posted on the Internet; and (4) published in the Federal Register. These notices reflect 

the stages of the NEPA process and include the Notice of Intent to Prepare an EIS (NOI), the Call for 

Information (Call), and Notice of Availability (NOA) for the Draft Supplemental EIS. A series of 

specified time periods after the NOI, Call, and NOA allow for public comments, all of which are 

considered and addressed. The formal scoping process is initiated by the NOI and Call, and public 

scoping meetings are held in several geographically separate cities to allow for public discussion and 

questions, and to identify all stakeholders’ concerns. All public comments and responses to comments 

are published in the Draft and Final Supplemental EISs. A detailed discussion of the complete scoping 

process can be found in Chapter 1.4. Public comments and responses to comments can be found in 

Chapter 5.3.1.

Impacts of Routine Activities and Accidental Events

The potential routine impact-producing factors on environmental justice related to the EPA proposed 

action that could affect environmental justice include the following: possible infrastructure changes or 

expansions including fabrication yards, support bases, and onshore disposal sites for offshore waste; 

increased commuter and truck traffic; and employment changes and immigration. Possible changes, 

expansion, or increases to any of these routine impact-producing factors occur within the context of the 

long-lived State and Federal oil and gas leasing programs and represents small, incremental additions to a 
4-212 Central and Eastern Planning Areas Supplemental EIS

robust offshore oil and gas industry. As a result, the impacts from routine events that would be produced 

by the EPA proposed action due to these factors would also be small and incremental. Particularly in the 

case of potential social impacts, it is often not possible to separate out the resulting additional impacts 

from the ongoing effects of the OCS Program because the economic and social conditions are dynamic, 

and they are influenced by many factors such as employment, consumer demand, interest rates, and 

educational resources.

Given the already existing, extensive distribution of the industry and its associated widespread 

support system, impacts related to routine operations are expected to be primarily economic in nature and 

to have a limited but positive effect because the EPA proposed action would contribute to the 

sustainability of current industry, related support services, and associated employment, especially in 

Louisiana where an extensive concentration of OCS oil- and gas-related infrastructure is located, e.g., 

Port Fourchon in Lafourche Parish, Louisiana. BOEM’s county-level analysis determined that there are 

limited concentrations of minority and low-income populations adjacent to OCS oil- and gas-related 

coastal infrastructure. The routine operations associated with the EPA proposed action are not expected 

to have a disproportionate effect on these populations. Rather, the EPA proposed action would contribute 

to the maintenance of current OCS oil- and gas-related activity and employment levels, resulting in some 

beneficial direct and indirect effects to low-income and minority populations.

Accidental disturbances resulting from the EPA proposed action, including oil spills, vessel 

collisions, blowouts, and chemical/drilling fluids spills have the potential to impact minority and lowincome populations through direct exposure to oil, dispersants, degreasers, and other chemicals that can 

affect human health; decreased access to natural resources due to environmental damages, fisheries

closures, or wildlife contamination; and proximity to onshore disposal sites used in support of oil and 

chemical spill cleanup efforts. Low-income and minority populations might be more sensitive to spills in 

coastal waters than are the general population because of their potentially higher dietary reliance on wild 

coastal resources, reliance on these resources for other subsistence purposes such as sharing and bartering, 

limited flexibility in substituting wild resources with purchased ones, and likelihood of participating in 

cleanup efforts and other mitigating activities. Little is known about subsistence along the Gulf Coast, 

and BOEM is currently funding a study to better document subsistence in the region.

As studies of past oil spills have highlighted, different cultural groups can possess varying capacities 

to cope with these types of events (Palinkas et al., 1992). Some minority and/or low-income groups may 

be more reliant on natural resources and/or less equipped to substitute contaminated or inaccessible 

natural resources with private market offerings than higher income level and/or nonminority groups. 

Because lower-income and/or minority populations may live near and may be directly involved with spill 

cleanup efforts, the vectors of exposure can be higher for them than for the general population, increasing 

the potential risks of long-term health effects. However, small-scale accidental oil spills, vessel 

collisions, blowouts, and chemical/drilling fluids spills are not likely to be of sufficient size or duration to 

have adverse and disproportionate long-term effects for minority and low-income populations in the 

analysis area.

Cumulative Impacts

The cumulative analysis considers impacts that may result from the EPA proposed action within the 

context of impact-producing factors related to OCS oil and gas activities, along with non-OCS oil- and 

gas-related activities that may occur and adversely affect minority and low-income populations. The 

OCS oil- and gas-related impact-producing include OCS leasing, exploration, development, and 

production activities and the accidental events arising from these OCS oil- and gas-related activities. 

Non-OCS oil- and gas-related impact-producing factors include all human activities and natural events 

and processes. The context in which people may find themselves and how that context affects their 

ability to respond to an additional change in the socioeconomic or physical environment is the heart of an 

environmental justice analysis.

The OCS oil- and gas-related impact-producing factors include the OCS Program, which includes 

OCS oil and gas leasing, exploration, development, and production activities that could result in potential 

infrastructure changes/expansions, including fabrication yards, support bases, and onshore disposal sites 

for offshore waste; increased commuter and truck traffic; and employment changes and immigration, as 

well as accidental events arising from these OCS oil- and gas-related activities, such as oil spills, vessel 

collisions, chemical/drilling-fluid spills, and the resultant cleanup that may temporarily impact low-
Description of the Environment and Impact Analysis 4-213

income populations who may experience direct exposure to contaminants through subsistence and 

cleanup operations. However, this exposure is expected to be small scale and short term and not result in 

disproportionate long-term effects. A detailed analysis of a low-probability catastrophic event, such as 

the Deepwater Horizon explosion, oil spill, and response, can be found in Appendix B. In general, the 

cumulative OCS oil- and gas-related effects are expected to be economic, widely distributed, and to have 

a limited but positive effect on low-income and minority populations. In Louisiana, these positive 

economic effects are expected to be greater because of the existence of an extensive and widespread 

support system for OCS oil- and gas-related activities and associated labor force, especially in Lafourche 

Parish, Louisiana, where Port Fourchon is located. Given the existing distribution of the OCS oil and gas 

industry and the limited concentrations of minority and low-income populations near oil and gas 

infrastructure, based on county-level analysis, the EPA proposed action and the cumulative OCS Program 

are not expected to have disproportionate high/adverse environmental or health effects on minority or 

low-income populations.

Non-OCS oil- and gas-related impact-producing factors cover a wide range of potential impactproducing factors, including all human activities, natural events, and processes that are not related to OCS 

oil- and gas-related activities in Federal waters. Some of the human activities that may disproportionately 

affect minority and low-income populations include, but are not limited to, the following: State oil and 

gas activities onshore and in State waters; urbanization; pollution (air, light, noise, garbage dumping, and 

contaminated runoff); commercial/residential/agricultural development; zoning ordinances; community 

development strategies (multi-purpose and single-use); expansions to the Federal, State, and local 

highway systems; expansions to regional port facilities; military activities; demographic shifts (inmigration and out-migration); economic shifts on the national, State, and local levels (job creation and job 

losses); educational systems (quality, availability, expansions, or contractions); family support systems 

(availability, proximity, and quality of mental health services, foster care, charity hospital systems, 

addictive disorders rehabilitation centers, family planning services, early-learning programs, etc.); 

governmental functions (municipal waterworks systems, sewage systems, tax structures, revenue 

collection, law enforcement, fire protection, traffic control, voting processes, legislative processes, court 

procedures and processes, real estate property assessments, construction permits, environmental 

protection services, land-use permits, etc.); contraction or expansion of the tourism industry; financial 

system (banking and investment services); State renewable energy activities; river channelization; 

dredging of waterways; State oil and gas activity; existing infrastructure associated with downstream 

activities such as petrochemical processing; and public health issues.

While human activities are extensive and nearly all-encompassing, there are a substantial number of 

natural events and processes that may be classified as non-OCS oil- and gas-related impact-producing 

factors that may disproportionally affect low-income and minority populations, including the following: 

oyster reef degradation; saltwater intrusion; sedimentation of rivers; sediment deprivation; barrier island 

migration and erosion; fish kills; red tide; beach strandings; coastal erosion/subsidence; sea-level rise; and 

coastal storms. Both human-induced and natural factors, unrelated to OCS oil- and gas-related activities, 

could affect minority and low-income populations through exposure to high levels of pollution, job loss, 

reduced social services, adverse infrastructure siting, decreased tourism, public health issues, 

displacement and increased risk of adverse impacts from storm surge, reduced opportunities for 

subsistence activities, and vulnerability of coastal communities to name a few. For a detailed discussion 

of these non-OCS oil- and gas-related impacts to minority and low-income populations, refer to Chapter 

4.1.1.23.4 of the CPA 235, 241, 247 Supplemental EIS.

To summarize, the cumulative effects of the EPA proposed action on minority and low-income

populations would be concentrated in coastal areas, particularly in Louisiana. Most OCS Program effects 

are expected to make a positive contribution to minority and low-income populations by helping to 

maintain current employment levels and contributing to economic stimulation. The contribution of the 

cumulative OCS Program to the cumulative impacts of all factors affecting environmental justice is 

expected to be minor; therefore, the incremental contribution of the EPA proposed action to the 

cumulative impacts would also be minor. State offshore leasing programs have similar, although more 

limited, effects due to their smaller scale. Cumulative effects from onshore infrastructure, including 

waste facilities, are also expected to be minor because existing infrastructure is regulated, because little 

new infrastructure is expected to result in the cumulative case, and because any new infrastructure will be 

subject to relevant permitting requirements. While all human activities and natural events and processes 

also may raise environmental justice issues, the cumulative consequences to environmental justice cannot 
4-214 Central and Eastern Planning Areas Supplemental EIS

be determined. The enormity of such a task, i.e., the time, labor, and funds that would be necessary to 

assess and analyze the entirety of non-OCS oil- and gas-related factors’ impacts, would not be cost 

effective or even possible to accomplish. When added to existing State and Federal leasing programs, the 

associated onshore infrastructure, onshore and offshore oil and gas activities, and all of the non-OCS oiland gas-related impacting factors, a single proposed EPA lease sale would make miniscule contributions 

to the cumulative effects on minority and low-income populations.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of various Internet information sources and trade publications (U.S. Department of Health 

and Human Services, National Institutes of Health; USEPA; USDOC, Bureau of the Census and Bureau 

of Labor Statistics; U.S. Department of Homeland Security, Federal Emergency Management Agency; 

RestoreTheGulf.gov website; Deepwater Horizon Claims Center; Deepwater Horizon Oil Spill Portal; 

Louisiana Department of Environmental Quality; Mississippi Department of Environmental Quality; 

Alabama Department of Environmental Management; State of Florida Department of Environmental 

Protection; Louisiana Recovery Authority; Louisiana Office of Community Development; The Greater 

Lafourche Port Commission; LA1 Coalition; Reuters; Rigzone; Oil and Gas Journal; and The Oil Drum), 

as well as recently published journal articles, was conducted to determine the availability of recent 

information on environmental justice. The search revealed the following new information on claims and 

human health impacts from the Deepwater Horizon explosion, oil spill, and response. This information is 

important because it expands our knowledge of the baseline environment following the Deepwater 

Horizon explosion, oil spill, and response.

The remaining Deepwater Horizon medical claims that were on appeal before the U.S. Court of 

Appeals for the Fifth Circuit were dismissed on February 11, 2014, and the effective date of the 

Deepwater Horizon Medical Benefits Settlement is February 12, 2014 (Deepwater Horizon CourtSupervised Settlement Program 2014). An Advisory regarding the Economics & Property Damages 

Settlement was issued. Even though the deadline to file claims in the Seafood Compensation Program 

was January 22, 2013, the Claims Administrator developed a “Procedure for Handling Untimely Seafood 

Claims,” which will allow the submittal of late claims with deadline extension requests. The procedure is 

located in the “Alerts” section of the Deepwater Horizon economic settlement website (Deepwater 

Horizon Claims Center, 2013). 

The Deepwater Horizon Research Consortia, headed by the National Institute for Environmental 

Health Sciences, developed university-community partnerships to address health effects resulting from 

the Deepwater Horizon explosion, oil spill, and response. The intent is that the Consortia’s research 

findings will inform community preparedness and disaster response, thereby limiting disaster-related 

health impacts, e.g., exposure to contaminants, emotional distress, and diet changes (National Institute of 

Environmental Health Sciences, 2014a). The funding allocation of $25.2 million is being spread across 

the Gulf region to fund numerous studies through several universities, covering several kinds of research 

topics. A few examples include the following: oil-spill impacts to the health of women and their 

children; Gulf resilience and women’s health; oil-spill impacts on pregnant women; seafood safety; 

individual, family, and community resilience along the Gulf Coast; social capital and resilience; and 

community/individual network building (Louisiana State University Health Sciences Center, School of 

Public Health, 2014; Tulane University, 2014; Center for Gulf Coast Environmental Health, 2014; 

University of Florida, 2014; Weiss, 2014).

The National Institute of Environmental Health Sciences’ ongoing GuLF Study (“Gulf Long-term 

Follow-up Study”) has completed Phase 1 and has started Phase 2 as of April 2014. Of the 

33,000 participants, preliminary findings from the first health exam indicated that cleanup workers were 

about 30 percent more likely to report moderate to severe depression, anxiety, and stress than participants 

who did no cleanup work. Researchers stated that it is unclear whether these mental health impacts were 

the result of exposure to spilled oil and/or dispersants or some other factor of the oil-spill experience and 

its aftermath. Cleanup workers also reported more physical symptoms, such as coughing, wheezing, and 

shortness of breath, than did those who were not cleanup workers. Some of the workers still reported 

these symptoms 3 years after the spill. However, it is too early to determine if cleanup exposures will 

lead to chronic diseases such as cancer or lung disease. Researchers stressed the importance of 
Description of the Environment and Impact Analysis 4-215

participants continuing in the 10-year study so that any potential long-term health impacts may be 

discovered (National Institute of Environmental Health Sciences, 2014b).

A new study published in April 2014, The Coastal Index: The Problem and Possibility of Our Coast, 

developed new indicators to measure progress toward sustainability in southeast Louisiana (Hobor et al., 

2014). Population shifts in coastal areas were tracked, and the study analyzed whether water management 

activities may diversify the regional economy toward a more positive trajectory. The study establishes a 

baseline from which social change may be measured in the future. As many people have been moving 

farther from the coast to avoid landloss, flooding, and coastal subsidence, low-income populations have 

not been able to relocate as readily, especially in areas such as Theriot and Dulac, Louisiana, where the 

poverty rates are over 40 percent. The study suggests that increases in water management activities such 

as diversions, hydraulic restoration, marsh creation, and barrier island restoration will produce positive 

economic benefits that will affect everyone, including low-income and minority populations (Hobor et al., 

2014).

A recently released BOEM-funded study, Offshore Oil and Deepwater Horizon: Social Effects on 

Gulf Coast Communities—Volume I: Methodology, Timeline, Context, and Communities; and Volume II: 

Key Economic Sectors, NGOs, and Ethnic Groups (Austin et al., 2014a and 2014b) researched the social 

impacts of the Deepwater Horizon explosion, oil spill, and response from April 2010 through December 

2012. The study sought to accurately describe and document how the Deepwater Horizon disaster was 

experienced and understood by the people it affected most directly as the events surrounding the spill 

unfolded. An ethnographic approach with several field workers in Louisiana, Mississippi, and Alabama 

coastal communities, the study did not attempt to quantify economic losses. The study found that the spill 

affected many different groups of people and individuals across the Gulf region. The economic effects 

were felt in the offshore oil and gas industry, commercial and recreational fishing industries, and tourism

industries, as well as oil and gas support sector services and other businesses from caterers to retail outlets 

and restaurants. Local and State governments and nongovernmental and community-based organizations 

were affected by the loss of revenues and by the need to respond to the economic needs of the people in 

the region. Programs such as BP’s Vessels of Opportunity and claims processes, aiming to mitigate 

negative economic conditions, had mixed results, with positive impacts distributed in a seemingly random 

manner through the communities. The ability of individuals and communities to secure resources 

depended on their political and legal status. The disaster did not generate the sorts of volunteer 

opportunities that follow hurricanes. With disasters such as hurricanes, the allocation of funds for social 

services is outlined explicitly in the Stafford Act, establishing a mechanism to help nonprofit 

organizations respond as needed, but there is no provision for social services to help people recover under 

the Oil Pollution Act of 1990. Environmental justice-focused NGOs found that funding resources after 

the spill were scarce because the spill was not designated a Federal disaster. The failure to declare this 

event a Federal disaster exacerbated its effects. People who would have normally donated funds to NGOs 

were not donating because they viewed it as BP’s responsibility to fund the recovery (Austin et al., 2014a 

and 2014b).

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the new information does 

not change the conclusions from the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed in this Supplemental EIS, as well as in the 

previously mentioned NEPA documents, BOEM has identified unavailable information regarding the 

impacts of the Deepwater Horizon explosion, oil spill, and response related to environmental justice. 

This information cannot be obtained because long-term health impact studies, subsistence studies, and the 

NRDA process are ongoing, and data from these efforts will be unavailable and unobtainable until the 

studies and NRDA process are complete. In order to fill this data gap, BOEM used existing information 

and reasonably accepted scientific methodologies to extrapolate from available information in completing 

the relevant analysis, including limited information that has been released after the Deepwater Horizon

explosion, oil spill, and response and studies of past oil spills, which indicate that a low-probability 

catastrophic spill, which is not part of the EPA proposed action and not likely expected, may have 

significant adverse impacts on lower-income and minority communities. Long-term effects are unknown 

at this time, but so far there has been little concrete evidence that health or subsistence effects have 
4-216 Central and Eastern Planning Areas Supplemental EIS

occurred (Brown et al., 2011; Dickey, 2012; King and Gibbons, 2011; Middlebrook et al., 2012; U.S. 

Dept. of Labor, Occupational Safety and Health Administration, 2010a and 2010b), although there is 

some dispute in the scientific community about proper risk assessment standards in seafood 

contamination research (Rotkin-Ellman et al., 2012; Rotkin-Ellman and Soloman, 2012). In addition, 

some studies have shown that different cultural groups can possess varying levels of coping capacities 

(Palinkas, 1992), and impacts to social cohesion, including increased distrust in government and other 

institutions, contributed to community anxiety (Tuler et al., 2009). Also, because lower-income and/or 

minority populations may live near and be involved directly with spill cleanup efforts, the vectors of 

exposure can be higher for them than for the general population, increasing the potential risks of longterm health effects. Therefore, because long-term health and subsistence impacts to low-income and 

minority populations are unknown, this information may be relevant to the evaluation of impacts from the 

Deepwater Horizon explosion, oil spill, and response to environmental justice. However, a subsistence 

study and long-term health studies are pending and will not be available within the timeline contemplated 

in the NEPA analysis of this Supplemental EIS. BOEM will continue to seek additional information as it 

becomes available and bases the previous analysis on the best information currently available. Although 

long-term health and subsistence impacts to minority and low-income populations may be relevant to this 

analysis, BOEM has determined that the incomplete information is not essential to a reasoned choice 

among alternatives based on the information discussed above.

Summary and Conclusion

BOEM has reexamined the analysis for environmental justice presented in the EPA 225/226 EIS, 

2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS based on the additional information presented above. No new significant information 

was discovered that would alter the impact conclusion for environmental justice presented in those NEPA

documents because of the available scientifically credible evidence in this analysis and based upon 

accepted scientific methods and approaches. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

4.2.1.23. Species Considered due to U.S. Fish and Wildlife Concerns

Though this Supplemental EIS pertains to the EPA proposed action and tiers from the EPA 225/226 

EIS, the EPA is not significantly different with regards to habitat, ecological function, and physical and 

biological resources from the adjacent CPA lease blocks. The EPA proposed action is on a smaller scale 

than a CPA proposed action that is analyzed in the 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 

231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS, which are hereby incorporated by 

reference. BOEM has reexamined the analysis for species considered due to FWS concerns presented in 

the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS. No new significant information was discovered that would alter the 

impact conclusions in those NEPA documents. The analysis and potential impacts discussed in those 

documents still apply for proposed EPA Lease Sale 226.

A detailed description of the affected environment and the full analyses of the potential impacts of 

routine activities, accidental events, and cumulative impacts associated with the EPA proposed action is 

provided in Chapter 4.1.1.23 of the EPA 225/226 EIS and Chapter 4.2.1.24 of the 2012-2017 WPA/CPA 

Multisale EIS. Updated information is provided in Chapter 4.2.1.24 of the WPA 233/CPA 231 

Supplemental EIS and Chapter 4.1.1.24 of the CPA 235/241/247 Supplemental EIS. The following 

information is a summary of the resource description and impact analysis incorporated from those NEPA

documents. Any new information that has become available since those documents were published is 

presented below.

There are five species that are not listed in Table 4-82 of the 2012-2017 WPA/CPA Multisale EIS and 

that are specific to Florida and the EPA proposed action. One of these five species, the Cape Sable 

seaside sparrow (Ammodramus maritimus mirabilis) is discussed in detail in Chapter 4.2.1.16 and not 

below.

The one mammal species (Florida salt marsh vole [Microtus pennsylvanicus dukecampbelli]) is 

endemic to the central Gulf Coast area of Florida (endangered as of January 14, 1991) and is known only 

from one coastal salt marsh site at Waccasassa Bay in Levy County, Florida, where it appears to exist in 
Description of the Environment and Impact Analysis 4-217

low numbers and has a very restricted range (USDOI, FWS, 2008). It appears to be most common in 

areas vegetated by seashore saltgrass (Distichlis spicata). Any natural or human-caused adverse impact 

to this species could result in its extinction. Major impact-producing factors and potential effects on the 

Florida salt marsh vole are similar to those discussed for beach mice (Chapter 4.2.1.15). Destruction of 

the habitat due to catastrophic spill and cleanup activities would increase the threat of extinction, but the 

potential for a low-probability catastrophic spill that would substantially affect Florida salt marsh vole 

habitat is low and is not part of the EPA proposed action and not likely expected. The greatest threat to 

this species is catastrophic weather events causing high water levels.

The one reptile species (American crocodile [Crocodylus acutus]) is known to, or is believed to, 

occur in Broward, Charlotte, Collier, Indian River, Lee, Martin, Miami-Dade, Monroe, Palm Beach, and 

St. Lucie Counties in Florida. The American crocodile is found primarily in mangrove swamps and along 

low-energy, mangrove-lined bays, creeks, and inland swamps (USDOI, FWS, 1999). Now threatened 

(October 28, 1975) in Florida populations, critical habitat for the American crocodile includes all land and 

water as defined in the Federal Register notice of September 22, 1977 (Federal Register, 1977). The 

greatest threat to this species is habitat alteration and human disturbances caused by urban and 

agricultural development.

The two candidate plant species are the aboriginal prickly-apple (Harrisia aboriginum) and Cape 

Sable thoroughwort (Chromolaena frustrata). The aboriginal prickly-apple is known to, or is believed to, 

occur in Charlotte, Lee, and Sarasota Counties in Florida (USDOI, FWS, 2012a). The aboriginal pricklyapple is a cactus occurring in coastal strand vegetation (relatively low salt-tolerant shrubs and grasses) 

and tropical coastal hammocks with trees, which includes gumbo limbo (Bursera simaruba), wild lime 

(Zanthoxylum fagara), or live oak (Quercus virginiana). Aboriginal prickly-apple populations are likely 

to be on shell mounds created by pre-European local residents or at least on sites with shelly substrates. 

Plants may be close to but not in the mangrove zone. The Cape Sable thoroughwort is known to, or is 

believed to, occur in Miami-Dade and Monroe Counties in Florida (USDOI, FWS, 2012b). The Cape 

Sable thoroughwort is an herb found most commonly in open sun to partial shade at the edges of rockland 

hammock and in coastal rock barren. Coastal rock barrens are open communities with no tree canopy and 

a sparse subcanopy of understory hardwoods. The greatest threats to these species are the loss of and/or 

modification to suitable habitat caused by urban and agricultural development.

Impacts of Routine Activities and Accidental Events

Adverse impacts due to routine activities resulting from the EPA proposed action such as operational 

discharges, noise, and marine debris are possible but unlikely. Lethal effects could occur from ingestion 

of released plastic materials from OCS oil- and gas-related vessels and facilities. However, there have 

been no reports to date on such incidences. Because of the mitigations that may be implemented 

(Chapter 2.3.1.3), routine activities (e.g., operational discharges, noise, and marine debris) related to the

EPA proposed action are not expected to have long-term adverse effects on the size and productivity of 

any of these species or populations in the Gulf of Mexico. Greatly improved handling of waste and trash

by industry and annual awareness training required by the marine debris mitigations are reducing the 

amount of plastics in the ocean, and therefore minimizing the devastating effects on offshore and coastal 

marine life. The routine activities of the EPA proposed action are unlikely to have significant adverse 

effects on the size and recovery of any of the above-mentioned species or populations in the GOM due to 

the distance of most activities, the heavy regulation of infrastructure and pipelines, and permitting and 

siting requirements.

Accidental blowouts, oil spills, and spill response activities resulting from the EPA proposed action 

have the potential to impact small to large areas in the Gulf of Mexico with physical oiling and habitat 

destruction. The severity of impacts depend on the magnitude and frequency of accidents, the ability to 

respond to accidents, the location and date of accidents, and various meteorological and hydrological 

factors (including tropical storms). Adverse impacts due to accidental events are also likely to be 

minimal because the habitats utilized by the species considered are far from OCS oil- and gas-related 

activities and are inland. Therefore, the EPA proposed action would be expected to have little or no effect 

on these species of concern.
4-218 Central and Eastern Planning Areas Supplemental EIS

Cumulative Impacts

The cumulative analysis considers activities that have occurred, are currently occurring, and could 

occur and adversely affect species considered due to FWS concerns. The OCS oil- and gas-related 

activities that could impact species considered due to FWS concerns include operational discharges, 

noise, marine debris, blowouts, oil spills, and spill-response activities. Routine activities are not 

anticipated to impact these species because of the mitigations and regulations implemented by BOEM, 

and accidental events are expected to be minimal to these species because the habitats utilized by the 

species considered are far from OCS oil- and gas-related activities and inland. A low-probability 

catastrophic spill, which is not part of the EPA proposed action and not likely expected, could impact 

species considered due to FWS concerns and is discussed in Appendix B. 

Non-OCS oil- and gas-related activities that could impact species considered due to FWS concerns

include State oil and gas activities, other governmental and private projects and activities, hurricanes, and 

natural processes and events that may occur and that adversely affect wetland habitat. Non-OCS oil- and 

gas-related activities posing the greatest potential harm to species considered due to FWS concerns are 

factors such as habitat loss and ecological competition. These factors have historically proved to be of 

greater threat to these species of concern. Impacts may also occur to these species if a hurricane passes 

over an oil spill or causes spills itself. However, at this time, there is no known record of a hurricane 

crossing the path of a large oil spill; the impacts of such have yet to be determined. The experience from 

Hurricanes Katrina and Rita in 2005 was that the oil released during the storms widely dispersed as far as 

the surge reached, reducing impacts from concentrated oil exposure (USDOC, NOAA, 2010).

Non-OCS oil- and gas-related activities have a greater potential to impact species considered due to 

FWS concerns than OCS oil- and gas-related activities, especially those factors that contribute to habitat 

loss. Because these species rely on terrestrial habitats to carry out their life-history functions at a 

considerable distance from the GOM, the activities of the EPA proposed action are unlikely to have 

significant adverse effects on the size and recovery of any of the above populations. Therefore, the 

incremental contribution of the EPA proposed action would not be likely to result in a significant 

incremental impact on these species within the EPA.

New Information Available Since Publication of the EPA 225/226 EIS, 2012-2017 

WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and CPA 235/241/247 

Supplemental EIS

A search of Internet information sources (FWS’s websites), as well as recently published journal 

articles was conducted to determine the availability of recent information on species considered due to 

FWS concerns. The search revealed no new information pertinent to this Supplemental EIS.

Incomplete or Unavailable Information

Even after evaluating the information above, BOEM has determined that the lack of new information 

does not change the conclusions of the EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 

233/CPA 231 Supplemental EIS, and CPA 235/241/247 Supplemental EIS; nevertheless, there is still 

incomplete or unavailable information. As discussed this Supplemental EIS and in Chapter 4.1.1.23 of 

the EPA 225/226 EIS, Chapter 4.2.1.24 of the 2012-2017 WPA/CPA Multisale EIS and WPA 233/CPA 

231 Supplemental EIS, and Chapter 4.1.1.24 of the CPA 235/241/247 Supplemental EIS, BOEM has 

identified incomplete information on the impacts to species considered due to FWS concerns as a result of 

the Deepwater Horizon explosion, oil spill, and response because little data have been released to the 

public. As data continue to be gathered and impact assessments completed, a better characterization of 

the full scope of impacts to populations in the GOM from the Deepwater Horizon explosion, oil spill, and 

response will be available. Relevant data on the status of populations after the Deepwater Horizon

explosion, oil spill, and response may take years to acquire and analyze, and impacts from the Deepwater 

Horizon explosion, oil spill, and response may be difficult or impossible to discern from other factors. 

Therefore, it is not possible for BOEM to obtain this information within the timeline contemplated in the 

NEPA analysis of this Supplemental EIS, regardless of the cost or resources needed. In light of the 

incomplete or unavailable information, BOEM’s subject-matter experts have extrapolated from available 

scientifically credible evidence in this analysis. Based on life histories of these species and the fact that 
Description of the Environment and Impact Analysis 4-219

they live inland, BOEM has determined that these species within the EPA were not affected to any 

discernible degree by the Deepwater Horizon explosion, oil spill, and response. Although the body of 

available information is incomplete, the information extrapolated from life history of the species and 

distance of the Macondo well from their habitats was sufficient to draw reasonable conclusions that they 

should not have been impacted by the Deepwater Horizon explosion, oil spill, and response; therefore, 

BOEM has determined that the incomplete information is not essential to a reasoned choice among 

alternatives.

Summary and Conclusion

There is a long-standing and well-developed OCS Program of more than 50 years within the EPA, 

which is directly adjacent to the EPA, and there are no data to suggest that activities from the preexisting 

OCS Program are significantly impacting the above-mentioned species populations; therefore, the EPA 

proposed action would be expected to have little or no effect on the above-mentioned species. Because of 

the mitigations that may be implemented, routine activities (e.g., operational discharges, noise, and 

marine debris) related to the EPA proposed action are not expected to have long-term adverse effects on 

the size and productivity of any of these species or populations in the GOM. Lethal effects could occur 

from ingestion of accidentally released plastic materials from OCS oil- and gas-related and non-OCS oiland gas-related vessels and facilities. However, there have been no reports to date on such incidences. 

BOEM employs several measures (e.g., marine debris mitigations) to reduce the potential impacts to any 

animal from routine activities associated with the EPA proposed action. Accidental blowouts, oil spills, 

and spill response activities resulting from the EPA proposed action have the potential to impact small to 

large areas in the GOM, depending on the magnitude and frequency of accidents, the ability to respond to 

accidents, the location and date of accidents, and various meteorological and hydrological factors 

(including tropical storms). The incremental contribution of the EPA proposed action would not be likely 

to result in a significant incremental impact on the above-mentioned species within the EPA; in 

comparison, non-OCS oil- and gas-related activities, such as habitat loss and competition, have 

historically proven to be a greater threat to the above-mentioned species.

BOEM has reexamined the analysis for species considered due to FWS concerns presented in the 

EPA 225/226 EIS, 2012-2017 WPA/CPA Multisale EIS, WPA 233/CPA 231 Supplemental EIS, and 

CPA 235/241/247 Supplemental EIS based on the additional information presented above. No new 

significant information was discovered that would alter the impact conclusion for species considered due 

to FWS concerns presented in those NEPA documents because of the available scientifically credible 

evidence in this analysis and based upon accepted scientific methods and approaches. The analysis and 

potential impacts discussed in those documents still apply for proposed EPA Lease Sale 226.

4.2.2. Alternative B—No Action

Description of the Alternative

Alternative B is the cancellation of the proposed EPA lease sale. If this alternative is chosen, the 

opportunity for development of the estimated 0-0.071 BBO and 0-0.162 Tcf of gas that could have 

resulted from the proposed EPA lease sale would be precluded during the current 2012-2017 Five-Year 

Program, but it could again be contemplated as part of a future Five-Year Program. Delay of the 

proposed EPA lease sale was not considered as a separate alternative from Alternative B because the 

potential impacts are the same, namely that most impacts related to Alternative A would not occur as 

described below. Any potential environmental impacts resulting from the proposed EPA lease sale would 

not occur, and these potential impacts were analyzed in Chapter 4.1.2 of the EPA 225/226 EIS. This 

alternative is also analyzed in the EIS for the 2012-2017 Five-Year Program on a nationwide 

programmatic level.

Effects of the Alternative

This Agency published a report that examined previous exploration and development activity 

scenarios (USDOI, MMS, 2007b). This Agency compared forecasted activity with the actual activity 

from 14 WPA and 14 CPA lease sales. The report shows that many lease sales contribute to the present 

level of OCS oil- and gas-related activity, and any single lease sale accounts for only a small percentage 
4-220 Central and Eastern Planning Areas Supplemental EIS

of the total OCS oil- and gas-related activities. In 2006, leases from 92 different sales contributed to Gulf 

of Mexico production. An average WPA lease sale contributed to 3 percent of oil production and 

3 percent of gas production in the WPA, while an average CPA lease sale contributed to 2 percent of oil 

production and 2 percent of gas production in the CPA. In 2006, leases from 15 different sales 

contributed to the installation of production structures in the Gulf of Mexico. An average WPA lease sale 

contributed to 6 percent of the installation of production structures in the WPA, while an average CPA 

lease sale, contributed to 6 percent of the installation of production structures in the CPA. In 2006, leases 

from 70 different sales contributed to wells drilled in the Gulf of Mexico. An average WPA lease sale 

contributed to 6 percent of the wells drilled in the WPA, while an average CPA lease sale contributed to 

4 percent of the wells drilled in the CPA.

The proposed EPA lease sale would contribute to maintaining the present level of OCS oil- and gasrelated activity in the Gulf of Mexico. Exploration and development activity, including service-vessel 

trips, helicopter trips, and construction that would result from the proposed EPA lease sale would replace 

activity resulting from existing leases that have reached, or are near the end of, their economic life.

In the short term, however, it is important to note that activities under previous lease sales would 

continue in the Gulf of Mexico, including exploration, development, production, and decommissioning

activities. As a decision on the proposed EPA lease sale will not affect those preexisting leases and 

activities related to them, there may still be environmental impacts occurring in the Gulf in the short term, 

even if the proposed EPA lease sale is cancelled.

Environmental Impacts

If the proposed EPA lease sale would be cancelled, the resulting development of oil and gas would 

not occur; however, as noted above, activities under previous lease sales would continue. The 

environmental impacts expected to result from the EPA proposed action, which are described above, 

would not occur in the short term, but they would likely be postponed to any future lease sale

contemplated as part of a future Five-Year Program. 

Economic Impacts 

Although environmental impacts may be reduced or postponed by cancelling the proposed EPA lease 

sale, the economic impacts of cancelling the scheduled lease sale should be given consideration. Chapter 

4.1.1.22.3 of the EPA 225/226 EIS discusses the potential economic impacts of the EPA proposed action. 

In the event that the proposed EPA lease sale is cancelled or postponed, there may be impacts to 

employment along the Gulf Coast, but these are not expected to be significant (e.g., less than 1% of total 

employment) or long term given the existing OCS infrastructure. 

Federal, State, and local governments would also have to forgo the revenue that would have been 

received from the proposed EPA lease sale. There could be minor impacts on global energy prices from 

cancelling the proposed EPA lease sale, along with minor changes in energy consumption patterns that 

would result from these price changes.

Other factors may minimize or exacerbate the economic impacts of cancelling the proposed EPA 

lease sale. For example, the longer-term economic impacts of cancelling the EPA proposed lease sale 

could be minimized if they were offset by a larger lease sale at a later date. The economic impacts may 

be exacerbated if additional lease sales are cancelled. The OCS industry is dependent on high capital 

investment costs and there may be long lags between the lease sale and the majority of production 

activities. Therefore, firms’ investment and spending decisions are dependent on their confidence that the 

OCS Program will be maintained in the future. In addition, while firms in the OCS industry are generally 

likely to be able to weather the cancellation of a single lease sale, the cancellation of multiple lease sales 

could lead to broader damage to firms and workers in the industry or decisions to operate in areas other 

than the Gulf. These economic impacts would be particularly damaging to the coastal counties and 

parishes in Texas and Louisiana for which the OCS industry as a whole is an important component of 

their economies.

Summary and Conclusion

Cancelling the proposed EPA lease sale would eliminate the effects described for Alternative A 

(Chapter 4.2.1); however, any single lease sale in the EPA accounts for only a small percentage of the 
Description of the Environment and Impact Analysis 4-221

total OCS oil- and gas-related activities in the GOM. If the proposed EPA lease sale would be cancelled, 

the resulting development of oil and gas would not occur during the 2012-2017 Five-Year Program, but 

would most likely be postponed to a future lease sale contemplated as part of a future Five-Year Program. 

The overall level of OCS oil- and gas-related activity in the EPA would only be reduced by a small 

percentage, if any. Therefore, the cancellation of the proposed EPA lease sale would not significantly 

change the environmental impacts of overall OCS oil- and gas-related activity in the long term.

Federal, State, and local governments would have to forgo the revenue that would have been received 

from the proposed EPA lease sale. There could be minor impacts on global energy prices from cancelling 

the proposed EPA lease sale, along with minor changes in energy consumption patterns that would result 

from these price changes. Other factors may minimize or exacerbate the economic impacts of cancelling 

the proposed EPA lease sale.

4.3. UNAVOIDABLE ADVERSE IMPACTS OF THE PROPOSED ACTIONS

Unavoidable adverse impacts associated with a CPA or EPA proposed action are expected to be

primarily short term and localized in nature and are summarized below. Adverse impacts from lowprobability catastrophic events could be of longer duration and extend beyond the local area. All OCS 

oil- and gas-related activities involve temporary and exclusive use of relatively small areas of the OCS 

over the lifetimes of specific projects. Lifetimes for these activities can be days, as in the case of seismic 

surveys; or decades, as in the case of a production structure or platform. No activities in the OCS 

Program involve the permanent or temporary use or “taking” of large areas of the OCS on a 

semicontinuous basis. Cumulatively, however, a multitude of individual projects results in a major use of 

OCS space.

Sensitive Coastal Habitats: If an oil spill contacts beaches or barrier islands, the removal of beach 

sand during cleanup activities could result in adverse impacts if the sand is not replaced. In addition, a 

beach could experience several years of tarballs washing ashore over time, causing an aesthetic impact. 

Sand borrowing on the OCS for coastal restorations involves the taking of a quantity of sand from the 

OCS and depositing it onshore, essentially moving small products of the deltaic system to another 

location. If sand is left where it is, it would eventually be lost to the deltaic system by redeposition or 

burial by younger sediments; if transported onshore, it would be lost to burial and submergence caused by 

subsidence and sea-level rise.

If an oil spill contacts coastal wetlands, adverse impacts could be high in localized areas. In more 

heavily oiled areas, wetland vegetation could experience suppressed productivity for several years; in 

more lightly oiled areas, wetland vegetation could experience die-back for one season. Epibionts on 

wetland vegetation and grasses in the tidal zone could be killed, and the productivity of tidal marshes for 

the vertebrates and invertebrates that use them to spawn and develop could be impaired. Much of the 

wetland vegetation would recover over time, but some wetland areas could be converted to open water. 

Some unavoidable impacts could occur during pipeline and other related coastal construction, but 

regulations are in place to avoid and minimize these impacts to the maximum extent practicable. 

Unavoidable impacts resulting from dredging, wake erosion, and other secondary impacts related to 

channel use and maintenance would occur as a result of a CPA or EPA proposed action.

Sensitive Coastal and Offshore Biological Habitats: Unavoidable adverse impacts would take place 

if an oil spill occurred and contacted sensitive coastal and offshore biological habitats, such as Sargassum

at the surface; fish, turtles, and marine mammals in the water column; or benthic habitats on the bottom. 

There could be some adverse impacts on organisms contacted by oil, dispersant chemicals, or emulsions 

of dispersed oil droplets and dispersant chemicals that, at this time, are not completely understood, 

particularly in subsurface environments.

Water Quality: Routine offshore operations would cause some unavoidable adverse impacts to 

varying degrees on the quality of the surrounding water. Drilling, construction, overboard discharges of 

drilling mud and cuttings, and pipelaying activities would cause an increase in the turbidity of the affected 

waters for the duration of the activity periods. This, however, would only affect water in the immediate 

vicinity of the construction activity or in the vicinity of offshore structures, rigs, and platforms. The 

discharge of treated sewage from manned rigs and platforms would increase the levels of suspended 

solids, nutrients, chlorine, and biochemical oxygen demand in a small area near the discharge point for a 

short period of time. Accidental spills from platforms and the discharge of produced waters could result 

in increases of hydrocarbon levels and trace metal concentrations in the water column in the vicinity of 
4-222 Central and Eastern Planning Areas Supplemental EIS

the platforms. Spilled oil from a tanker collision would affect the water surface in combination with 

dispersant chemicals used during spill response. A subsurface blowout would subject the surface, water 

column, and near-bottom environment to spilled oil and gas released from solution, dispersant chemicals, 

or emulsions of dispersed oil droplets and dispersant chemicals.

Unavoidable impacts to onshore water quality would occur as a result of chronic point- and nonpointsource discharges such as runoff and effluent discharges from existing onshore infrastructure used in 

support of lease sale activities. Vessel traffic contributes to the degradation of water quality by chronic 

low-quantity oil leakage, treated sanitary and domestic waste, bilge water, and contaminants known to 

exist in ship paints. Regulatory requirements of the State and Federal water authorities and some local 

jurisdictions would be applicable to point-source discharges from support facilities such as refineries and 

marine terminals.

Air Quality: Unavoidable short-term impacts on air quality could occur after large oil spills and 

blowouts because of evaporation and volatilization of the lighter components of crude oil, combustion 

from surface burning, and aerial spraying of dispersant chemicals. Short-term effects from spill events 

are uncontrollable and are likely to be aggravated or mitigated by the time of year the spills take place. 

Mitigation of long-term effects from offshore engine combustion during routine operations would be 

accomplished through existing regulations and the development of new control emission technology.

Threatened and Endangered Species: Because the proposed CPA lease sales and proposed EPA lease 

sale do not in and of themselves make any irreversible or irretrievable commitment of resources that 

would foreclose the development or implementation of any reasonable and prudent measures to comply 

with the Endangered Species Act, BOEM may proceed with publication of this Supplemental EIS and 

finalize a decision among these alternatives even if consultation is not complete, consistent with Section 

7(d) of the ESA (also refer to Chapter 5.6). Irreversible loss of individuals that are ESA-listed species 

may occur after a large oil spill from the acute impact of being oiled or the chronic impact of oil having 

eliminated, reduced, or rendered suboptimal the food species upon which they were dependent.

Nonendangered and Nonthreatened Marine Mammals: Unavoidable adverse impacts to 

nonendangered and nonthreatened marine mammals would be those that also affect endangered and 

threatened marine mammal species. Routine operation impacts (such as seismic surveys, water quality

and habitat degradation, helicopter disturbance, vessel collision, and discarded trash and debris) would be 

negligible or minor to a population, but they could be lethal to individuals as in the case of a vessel 

collision. A large oil spill would temporarily degrade habitat if spilled oil, dispersant chemicals, or 

emulsions of dispersed oil droplets and dispersant chemicals contact free-ranging pods or spawning 

grounds.

Coastal and Marine Birds: Unavoidable adverse impacts from routine operations on coastal birds 

could result from helicopter and OCS service-vessel traffic, facility lighting, and floating trash and debris. 

Marine birds could be affected by noise, platform lighting, aircraft disturbances, and trash and debris 

associated with offshore activities. Cross-Gulf migrating species could be affected by lighted platforms, 

helicopter and vessel traffic, and floating trash and debris. If a large oil spill occurs and contacts coastal 

or marine bird habitats, some birds could experience lethal and sublethal impacts from oiling, and birds 

feeding or resting in the water could be oiled and die. Coastal birds coming into contact with oil may 

migrate more deeply into marsh habitats, out of reach from spill responders seeking to count them or 

collect them for rehabilitation. Oil spills and oil-spill cleanup activities could also affect the food species 

for coastal, marine, and migratory bird species. Depending on the time of year, large oil spills could 

decrease the nesting success of species that concentrate nests in coastal environments due to direct effects 

of the spill and also disruption from oil-spill cleanup activities.

Fish Resources, Commercial Fisheries, and Recreational Fishing: Unavoidable adverse impacts 

from routine operations are loss of open ocean or bottom areas desired for fishing by the presence or 

construction of OCS oil- and gas-related facilities and pipelines. Loss of gear could occur from bottom 

obstructions around platforms and subsea production systems. Routine discharges from vessels and 

platforms are minor given the available area for fish habitat. If a large oil spill occurs, the oil, dispersant

chemicals, or emulsions of oil droplets and dispersant chemicals could temporarily displace mobile fish 

species on a population or local scale. There could also be impacts on prey and sublethal effects on fish. 

It is unlikely that fishermen would want, or be permitted, to harvest fish in the area of an oil spill, as 

spilled oil could coat or contaminate commercial fish species, rendering them unmarketable.

Recreational Beaches: Unavoidable adverse impacts from routine operations may result in the 

accidental loss overboard of some floatable debris that may eventually come ashore on frequented 
Description of the Environment and Impact Analysis 4-223

recreational beaches. A large oil spill could make landfall on recreational beaches, leading to local or 

regional economic losses and stigma effects, causing potential users to avoid the area after acute impacts 

have been removed. Some recreational beaches become temporarily soiled by weathered crude oil, and 

tarballs may come ashore long after stranded oil has been cleaned from shoreline areas.

Economic Activity: Net economic, political, and social benefits accrue from the production of 

hydrocarbon resources. Once these benefits become routine, unavoidable adverse impacts from routine 

operations follow trends in supply and demand based on the commodity prices for oil, gas, and refined 

hydrocarbon products. Declines in oil and gas prices can lead to activity ramp downs by operators until 

prices rise. A large oil spill would cause temporary increases in economic activity associated with spillresponse activity. An increase in economic activity from the response to a large spill could be offset by 

temporary work stoppages that are associated with spill-cause investigations and would involve a transfer 

or displacement of demand to different skill sets. An oil spill could also negatively impact industries such 

as tourism and fishing. Routine operations affected by new regulations that are incremental would not 

have much effect on the baseline of economic activity; however, temporary work stoppages or the 

introduction of several new requirements at one time, which are costly to implement, could cause a dropoff of activity as operators adjust to new expectations or use the opportunity to move resources to other 

basins where they have interests.

Archaeological Resources: Unavoidable adverse impacts from routine operations could lead to the 

loss of unique or significant archaeological information if unrecognized at the time an area is disturbed. 

Required archaeological surveys significantly reduce the potential for this loss by identifying potential 

archaeological sites prior to an interaction occurring, thereby making avoidance or mitigation of impacts 

possible. A large oil spill that makes landfall on or near protected archaeological landmarks could cause 

temporary aesthetic or cosmetic impacts until the oil is cleaned or degrades.

4.4. IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT OF RESOURCES

Irreversible or irretrievable commitment of resources refers to impacts or losses to resources that 

cannot be reversed or recovered. Examples are when a species becomes extinct or when wetlands are 

permanently converted to open water. In either case, the loss is permanent.

Wetlands: An irreversible or irretrievable loss of wetlands and associated biological resources could 

occur if wetlands are permanently lost because of impacts caused by dredging and construction activities 

that displace existing wetlands or from oil spills severe enough to cause permanent die-back of vegetation 

and conversion to open water. Construction and emplacement of onshore pipelines in coastal wetlands 

displace coastal wetlands in disturbed areas that are then subject to indirect impacts like saltwater 

intrusion or erosion of the marsh soils along navigation channels and canals. Ongoing natural and 

anthropogenic processes in the coastal zone, only one of which is OCS oil- and gas-related activity, can 

result in direct and indirect loss of wetlands. Natural losses as a consequence of the coastal area 

becoming hydrologically isolated from the Mississippi River that built it, sea-level rise, and subsidence of 

the delta platform in the absence of new sediment added to the delta plain appear to be much more 

dominant processes impacting coastal wetlands.

Sensitive Nearshore and Offshore Biological Resources: An irreversible loss or degradation of 

ecological habitat caused by cumulative activity tends to be incremental over the short term. Irretrievable 

loss may not occur unless or until a critical threshold is reached. It can be difficult or impossible to 

identify when that threshold is, or would be, reached. Oil spills and chronic low-level pollution can injure 

and kill organisms at virtually all trophic levels. Mortality of individual organisms can be expected to 

occur, and possibly a reduction or even elimination of a few small or isolated populations. The proposed 

biological stipulations, however, are expected to eliminate most of these risks.

Threatened and Endangered Species: Irreversible loss of individuals that are protected species may 

occur after a large oil spill from the acute impact of being oiled or the chronic impact of oil having 

eliminated, reduced, or rendered suboptimal the food species upon which they were dependent.

Fish Resources and Commercial Fisheries: Irreversible loss of fish and coral resources, including 

commercial and recreational species, are caused by structure removal using explosives. Fish in proximity 

to an underwater explosion can be killed. Without the structure to serve as habitat area, sessile, attached 

invertebrates and the fish that live among them are absent. Removing structures eliminates these special 

and local habitats and the organisms living there, including such valuable species as red snapper. 
4-224 Central and Eastern Planning Areas Supplemental EIS

Continued structure removal, regardless of the technique used, would reduce the net benefits to 

commercial fishing due to the presence of these structures.

Recreational Beaches: Impacts on recreational beaches from a large oil spill may, at the time, seem 

irreversible, but the impacts are generally temporary. Beaches fouled by a large oil spill would be 

temporarily unavailable to the people who would otherwise frequent them, but only during the period 

between landfall and cleanup of the oil, followed by an indefinite lag period during which stigma effects 

recede from public consciousness.

Archaeological Resources: Irreversible loss of a prehistoric or historic archaeological resource can 

occur if bottom-disturbing activity takes place without the surveys, where required, to demonstrate its 

absence before work proceeds. A resource can be completely destroyed, severely damaged, or the 

scientific context badly impaired by well drilling, subsea completions, and platform and pipeline 

installation, or sand borrowing.

Oil and Gas Development: Leasing and subsequent development and extraction of hydrocarbons as a 

result of a CPA or EPA proposed action represents an irreversible and irretrievable commitment by the 

removal and consumption of nonrenewable oil and gas resources. The estimated amount of resources to 

be recovered as a result of a CPA or EPA proposed action is presented in Table 3-1. 

Loss of Human and Animal Life: The OCS oil and gas exploration, development, production, and 

transportation are carried out under comprehensive, state-of-the-art, enforced regulatory procedures 

designed to ensure public and work place safety and environmental protection. Nevertheless, some loss 

of human and animal life may be inevitable from unpredictable and unexpected acts of man and nature 

(i.e., unavoidable accidents, accidents caused by human negligence or misinterpretation, human error, 

willful noncompliance, and adverse weather conditions). Some normal and required operations, such as 

structure removal, can kill sea life in proximity to explosive charges or by removal of the structure that 

served as the framework for invertebrates living on it and the fish that lived with it.

4.5. RELATIONSHIP BETWEEN THE SHORT-TERM USE OF MAN’S ENVIRONMENT 

AND THE MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY

The short-term effects on various components of the environment in the vicinity of a CPA or EPA 

proposed action are related to long-term effects and the maintenance and enhancement of long-term 

productivity.

Short-Term Use

Short-term refers to the total duration of oil and gas exploration and production activities. Extraction 

and consumption of offshore oil and natural gas is a short-term benefit. Discovering and producing 

domestic oil and gas now reduces the Nation’s dependency on foreign imports. Depleting a 

nonrenewable resource now removes these domestic resources from being available for future use. The 

production of offshore oil and natural gas as a result of a CPA or EPA proposed action would provide 

short-term energy, and as it delays the increase in the Nation’s dependency on foreign imports, it can also 

allow additional time for ramp-up and development of long-term renewable energy sources or substitutes 

for nonrenewable oil and gas. Economic, political, and social benefits would accrue from the availability 

of these natural resources.

The principle short-term use of the leased areas in the Gulf of Mexico would be for the production of 

0.460-0.894 BBO and 1.939-3.903 Tcf of gas from a typical CPA proposed action. The principle shortterm use of the leased areas in the Gulf of Mexico would be for the production of 0-0.071 BBO and 

0-0.162 Tcf of gas from a typical EPA proposed action. The cumulative impacts scenario in this 

Supplemental EIS extends approximately from 2012 to 2051. The 40-year time period is used because it 

is the approximate longest life span of activities conducted on an individual lease. The 40 years following 

a proposed CPA or EPA lease sale is the period of time during which the activities and impacting factors 

that follow as a consequence of a proposed CPA and/or EPA lease sale would be influencing the 

environment.

The specific impacts of a CPA or EPA proposed action vary in kind, intensity, and duration according 

to the activities occurring at any given time (Chapter 3). Initial activities, such as seismic surveying and 

exploration drilling, result in short-term, localized impacts. Development drilling and well workovers 

occur sporadically throughout the life of a CPA or EPA proposed action but also result in short-term, 
Description of the Environment and Impact Analysis 4-225

localized impacts. Activities during the production life of a platform may result in chronic impacts over a 

longer period of time (over 25 years), potentially punctuated by more severe impacts as a result of 

accidental events or a spill. Platform removal is also a short-term activity with localized impacts, 

including removal of the habitat for encrusting invertebrates and fish living among them. Many of the 

effects on physical, biological, and socioeconomic resources discussed in Chapters 4.1 and 4.2 are 

considered to be short term (being greatest during the construction, exploration, and early production 

phases). These impacts would be further reduced by the mitigating measures discussed in Chapter 2.2.2. 

The OCS oil- and gas- related development off Texas, Louisiana, Mississippi, and Alabama has 

enhanced recreational and commercial fishing activities, which in turn has stimulated the manufacture and 

sale of larger private fishing vessels and specialized recreational fishing equipment. Commercial 

enterprises such as charter boats have become heavily dependent on offshore structures for satisfying 

recreational customers. A CPA or EPA proposed action could increase these incidental benefits of 

offshore development. Offshore fishing and diving has gradually increased in the past three decades, with 

offshore structures and platforms becoming the focus of much of that activity. As mineral resources 

become depleted, platform removals would occur and may result in a decline in these activities.

The short-term exploitation of hydrocarbons for the OCS Program in the Gulf of Mexico may have 

long-term impacts on biologically sensitive coastal and offshore resources and areas if a large oil spill

occurs. A spill and spill-response activity could temporarily interfere with commercial and recreational 

fishing, beach use, and tourism in the area where the spill makes landfall and in a wider area based on 

stigma effects. The proposed leasing may also result in onshore development and population increases 

that could cause very short-term adverse impacts to local community infrastructure, particularly in areas 

of low population and minimal existing industrial infrastructure (Chapter 4.2.1.23.1 of the 2012-2017 

WPA/CPA Multisale EIS and WPA 233/CPA 231 Supplemental EIS, and Chapter 4.1.1.23.1 of the CPA 

235/241/247 Supplemental EIS).

Relationship to Long-Term Productivity

Long-term refers to an indefinite period beyond the termination of oil and gas production. Over a 

period of time after peak oil production has occurred in the Gulf of Mexico, a gradual easing of the 

specific impacts caused by oil and gas exploration and production would occur as the productive 

reservoirs in the Gulf have been discovered and produced, and have become depleted. The Oil Drum 

(2009) showed a graphic demonstrating that peak oil production in the Gulf occurred in June 2002 at 

1.73 MMbbl/day. Whether or not this date is correct can only be known in hindsight and only after a 

period of years while production continues. At this time, however, the trend is fairly convincing (The Oil 

Drum, 2009). There is disagreement on what future production trends may be in the Gulf of Mexico after 

several operators, BP among them, announced discoveries over the last 5 years (Oil and Gas Journal, 

2009) in the Lower Tertiary in ultra-deepwater (>5,000 ft; 1,524 m) with large projected reserves. These 

claims are as yet unproven and there are questions as to the difficulties that may be encountered 

producing these prospects because of their geologic age; burial depth and high-temperature, high-pressure 

in-situ conditions; lateral continuity of reservoirs; and the challenges of producing from ultra-deepwater 

water depths.

The Gulf of Mexico’s large marine ecosystem is considered a Class II, moderately productive 

ecosystem (mean phytoplankton primary production 150-300 gChlorophyll a/m2

-yr [The Encyclopedia of 

Earth, 2008]) based on Sea-viewing Wide Field-of-view Sensor (SeaWiFS) global primary productivity 

estimates (USDOC, NASA, 2003). After the completion of oil and gas production, a gradual ramp-down 

to economic conditions without OCS oil- and gas-related activity would be experienced, while the marine 

environment is generally expected to remain at or return to its normal long-term productivity levels that, 

in recent years, has been described as stressed (The Encyclopedia of Earth, 2008). The Gulf of Mexico’s 

large marine ecosystem shows signs of ecosystem stress in bays, estuaries, and coastal regions (Birkett 

and Rapport, 1999). There is shoreline alteration, pollutant discharge, oil and gas development, and 

nutrient loading. The overall condition for the U.S. section of this large marine ecosystem, according to 

USEPA’s seven primary indicators (Jackson et al., 2000), is good dissolved oxygen, fair water quality, 

poor coastal wetlands, poor eutrophic condition, and poor sediment, benthos, and fish tissue (The 

Encyclopedia of Earth, 2008).

To help sustain the long-term productivity of the Gulf of Mexico ecosystem, the OCS Program 

provides structures to use as site-specific artificial reefs and fish-attracting devices for the benefit of 
4-226 Central and Eastern Planning Areas Supplemental EIS

commercial and recreational fishermen and to sport divers and spear fishers. Additionally, the OCS 

Program continues to improve the knowledge and mitigation practices used in offshore development. 

Approximately 10 percent of the oil and gas structures removed from the OCS are eventually used for 

State artificial reef programs.
CHAPTER 5 

CONSULTATION AND COORDINATION

Consultation and Coordination 5-3 

5. CONSULTATION AND COORDINATION

5.1. DEVELOPMENT OF THE PROPOSED ACTIONS

This Supplemental EIS addresses two proposed oil and gas lease sales in the CPA, i.e., Lease Sales 

241 and 247, and one proposed oil and gas lease sale in the EPA, i.e., Lease Sale 226, of the Gulf of 

Mexico, as scheduled in the Five-Year Program (USDOI, BOEM, 2012a) (Figure 1-1). BOEM 

conducted early coordination with appropriate Federal and State agencies and other concerned parties to 

discuss and coordinate the prelease process for the proposed lease sales and this Supplemental EIS. Key 

agencies and organizations included the National Oceanic and Atmospheric Administration, NOAA’s 

National Marine Fisheries Service, FWS, U.S. Coast Guard, U.S. Department of Defense, USEPA, State 

Governors’ offices, Tribal Nations, nongovernmental organizations, and industry groups.

5.2. CALL FOR INFORMATION AND NOTICE OF INTENT TO PREPARE A

SUPPLEMENTAL EIS

On July 9, 2012, the Call for Information (Call) for proposed CPA Lease Sales 231, 235, 241, and 

247 was published in the Federal Register (2012b). The 30-day comment period closed on August 8, 

2012. BOEM received two comment letters in response to the Call. These comments are summarized 

below in Chapter 5.3.1. 

On November 18, 2011, the Call for Information/Notice of Intent to Prepare an EIS (Call/NOI) for 

proposed EPA Lease Sales 225 and 226 was published in the Federal Register. The 30-day comment 

period for the Call closed on December 19, 2011, and the 45-day comment period for the NOI closed on 

January 3, 2012. BOEM received three comment letters in response to the Call. These comments are 

summarized below in Chapter 5.3.1. 

On June 20, 2014, the Notice of Intent to Prepare a Supplemental EIS (NOI) for the proposed lease 

sales was published in the Federal Register. Additional public notices were distributed via local 

newspapers, the U.S. Postal Service, and the Internet. The 30-day comment period for the NOI closed on 

July 21, 2014. Federal, State, and local governments, Tribal Nations, nongovernmental organizations, 

and other interested parties were invited to send written comments to the Gulf of Mexico OCS Region on 

the scope of the Supplemental EIS. BOEM received five comment letters and seven emails in response to 

the NOI. These comments are summarized below in Chapter 5.3.2. 

5.3. DEVELOPMENT OF THE DRAFT SUPPLEMENTAL EIS

Scoping for the Draft Supplemental EIS was conducted in accordance with CEQ regulations for 

implementing NEPA. Scoping provides those with an interest in the OCS Program an opportunity to 

provide comments on the proposed actions. In addition, scoping provides BOEM an opportunity to 

update the Gulf of Mexico OCS Region’s environmental and socioeconomic information base. Public

scoping meetings were held in Florida, Alabama, Mississippi, and Louisiana on the following dates and at 

the times and locations indicated below: 

Tuesday, July 8, 2014 Wednesday, July 9, 2014

1:00 p.m. and 6.00 p.m. CDT 1:00 p.m. and 6:00 p.m. CDT

Hilton Garden Inn Panama City Hilton Garden Inn Mobile West

1101 U.S. Highway 231 828 West I-65 Service Road South

Panama City, Florida Mobile, Alabama

11 registered attendees 1 registered attendee

1 speaker 0 speakers
5-4 Central and Eastern Planning Areas Supplemental EIS

Thursday, July 10, 2014 Monday, July 14, 2014

1:00 p.m. and 6:00 p.m. CDT 1:00 p.m. CDT

Courtyard Marriott, Gulfport Beachfront Bureau of Ocean Energy Management

1600 East Beach Boulevard Gulf of Mexico OCS Region

Gulfport, Mississippi New Orleans, Louisiana

5 registered attendees 2 registered attendees

1 speaker 0 speakers

Monday, July 14, 2014

6:00 p.m. CDT

Larose Regional Park and Civic Center

307 E 5th Street

Larose, Louisiana

0 registered attendees

0 speakers

5.3.1. Summary of Comments Received in Response to the Calls for Information

In response to the Call for proposed CPA Lease Sales 231, 235, 241, and 247, BOEM received two 

comment letters: one letter from the Louisiana Department of Natural Resources and one letter from the 

American Petroleum Institute. The Louisiana Department of Natural Resources hopes that BOEM will be 

more attentive to the State of Louisiana’s comments during the prelease planning phase, believes that a 

better appraisal of coastal effects is necessary, and believes that BOEM must more efficiently revisit 

reviews of earlier OCS lease sales to determine whether the models and predictive techniques used were 

accurate. The American Petroleum Institute states that annual, predictable lease sales in these planning 

areas are needed to help ensure continued offshore exploration and production in the future because 

production from lease sales will take many years to develop. The American Petroleum Institute further 

encourages BOEM to pursue legislation that will allow the entry into force of the “Agreement between 

the United States of America and the United Mexican States Concerning Transboundary Hydrocarbon 

Reservoirs in the Gulf of Mexico” (Agreement). This Agreement, which was signed after issuance of the 

Call and entered into force on July 18, 2014, governs the development of reservoirs of petroleum and 

natural gas straddling the U.S.-Mexico maritime and continental shelf boundary in the Gulf of Mexico.

In response to the Call for proposed EPA Lease Sales 225 and 226, BOEM received three comment 

letters: one from the Louisiana Department of Natural Resources; one from ConocoPhillips Company; 

and one from Statoil USA E&P, Inc. All three letters supported proposed EPA Lease Sales 225 and 226. 

The Louisiana Department of Natural Resources hopes that BOEM will be more attentive to the State of 

Louisiana’s comments during the prelease planning phase, believes that a better appraisal of coastal 

effects is necessary, and believes that BOEM must more efficiently revisit reviews of earlier OCS lease 

sales to determine whether the models and predictive techniques used were accurate. ConocoPhillips 

Company states that, although most of the EPA is placed off limits, it is an area of high resource 

potential, is vitally important to America’s energy security, and is relatively close to existing 

infrastructure. Statoil USA E&P, Inc. states that the OCS holds the most promise for significant 

discoveries of hydrocarbons in meeting the Nation’s energy needs and that the emerging plays in the EPA 

are an integral part of that potential and would welcome the inclusion of an even greater area in the EPA 

for leasing in the future

5.3.2. Summary of Scoping Comments

Comments (both verbal and written) were received from the NOI and eight scoping meetings from 

Federal, State, and local governmental agencies; interest groups; industry; businesses; and the general 

public on the scope of this Supplemental EIS, significant issues that should be addressed, alternatives that 

should be considered, and mitigating measures. All scoping comments received, which were appropriate 

for a lease sale NEPA document, were considered in the preparation of the Draft Supplemental EIS. 

BOEM received five comment letters via mail on the NOI and seven comments via email during the 

scoping process. In addition, a total of two speakers provided comments at the eight scoping meetings. 

The following is a summary of the comments that were provided during the scoping process. 
Consultation and Coordination 5-5 

U.S. Department of the Interior, National Park Service (letter dated July 18, 2014) 

• The National Park Service (NPS) urges a cautious and rigorous environmental review 

for oil and gas operations off the coast of national park units, specifically the Gulf 

Islands National Seashore (GUIS).

• The NPS requests to participate as a cooperating agency in the preparation of this 

Supplemental EIS for all phases that could potentially affect the GUIS, particularly 

the development of alternatives, management actions, or options.

• Comments from the NPS had three overarching recommendations: (1) develop an 

alternative that excludes lease sales within 15 mi (24 km) of the GUIS; (2) add an 

NPS consultation stipulation to alternatives that include lease sales within 15 mi 

(24 km) of the GUIS; and (3) undertake a robust environmental analysis that

acknowledges the scenic and wilderness character of the GUIS.

• The NPS also included six specific comments: (1) a request that the Supplemental 

EIS analyze the potential for subsidence at the barrier islands of the GUIS as a result 

of oil and gas drilling; (2) an analysis of the direct and adverse effects to natural 

resources including wildlife of the GUIS from routine OCS oil- and gas-related 

operations; (3) an analysis of water quality and natural resource impacts from 

incidental oil or chemical spills and an offer to participate in the development of a 

spill prevention plan; (4) a request for more studies to be included in this 

Supplemental EIS, i.e., studies that quantify the potential adverse visual impacts to 

the GUIS, and an offer to develop standard lighting design feature requirements and 

conduct a visual impact analysis; (5) a request that this Supplemental EIS analyze the 

degradation of aesthetics and the wilderness character of Horn and Petit Bois islands; 

and (6) a request that this Supplemental EIS include appropriate surveys and analysis 

of the potential to impacts on any sensitive maritime archaeological resources in the 

project area.

Choctaw Nation of Oklahoma (email dated June 30, 2014) 

• The Choctaw Nation of Oklahoma requested that a copy of the Supplemental EIS be 

provided when available.

Louisiana Department of Natural Resources, Office of Coastal Management (letter dated

July 25, 2014) 

• The Louisiana Office of Coastal Management recommends that BOEM exert greater 

effort to quantify all secondary, indirect, and cumulative losses to their coastal zone 

from offshore energy development.

• The State of Louisiana supports exploration and development throughout all OCS 

waters, not just the Gulf of Mexico and offshore Alaska, but it does not believe that 

Louisiana has received compensatory mitigation commensurate to the impacts borne 

by their state.

American Petroleum Institute (API) (letter dated July 17, 2014) 

• The API supports analysis of the environmental and socioeconomic impacts 

associated with development activities stemming from upcoming lease sales and the 

timely preparation of this Supplemental EIS.

• BOEM must focus EIS analyses on currently available new information and should 

not speculate on future results from ongoing studies.
5-6 Central and Eastern Planning Areas Supplemental EIS

• BOEM should also take into consideration the new safety and regulatory 

improvements since the Deepwater Horizon explosion, oil spill, and response as a 

part of the new information analyzed.

• The API suggests that this Supplemental EIS be designed specifically for use as a 

tiering document for future environmental reviews and that data from the bestavailable, peer-reviewed scientific literature should be the basis of environmental 

analyses, and not speculation.

Consumer Energy Alliance (letter dated July 8, 2014) 

• It is important that BOEM allow access to the CPA and EPA because it will take 

years to develop the energy before it can be delivered to consumers.

• The Consumer Energy Alliance concurs with BOEM’s proposed actions with the 

exception of areas deferred by the Gulf of Mexico Energy Security Act of 2006 and 

the area known as the northern portion of the Eastern Gap.

• BOEM should begin to prepare for the lifting of the Congressional moratorium on the 

EPA to facilitate expeditious scheduling of lease sales.

• BOEM should promptly draft and finalize this Supplemental EIS and reject any 

requests to take actions that would in any way delay or prohibit leasing or 

development activity in the CPA.

Bay County Audubon Society (email dated July 9, 2014) 

• The chairman of the Bay County Audubon Society urged greater transparency in the 

NEPA process and requested to be informed of the public meeting for the Draft 

Supplemental EIS. 

General Public (emails and letter dated July 9 and 18, 2014) 

• The general public is concerned over the environmental effects of oil and gas 

exploration and production such as viewshed, pollution from operations, effects of 

dispersants on wildlife, and G&G surveys. 

• The general public is troubled by any lasting impacts from the Deepwater Horizon

explosion, oil spill, and response such as impacts to larval fishes from oil and the 

continued discovery and removal of tar mats. 

• The general public suggested changes to the regulation of the offshore oil and gas 

industry such as using taxpayer money to fund alternative fuels, postpone lease sales 

until BOEM can ensure safe operations, and reallocate a percentage of revenues to 

establish and maintain fisheries in Gulf coastal waters.

Verbal Comments Received at the Scoping Meetings

(Note: Verbal comments provided by the Consumer Energy Alliance at the Panama City, Florida, 

and Gulfport, Mississippi, scoping meetings are the same as those the Consumer Energy Alliance

submitted via email and are summarized above.) 

5.3.3. Additional Scoping Opportunities

Although the scoping process is formally initiated by the publication of the NOI and Call, scoping 

efforts and other coordination meetings have proceeded and will continue to proceed throughout the 

NEPA processes. The Gulf of Mexico OCS Region’s Information Transfer Meetings provide an 

opportunity for BOEM’s analysts to attend technical presentations related to OCS Program activities and 
Consultation and Coordination 5-7 

to meet with representatives from Federal, State, and local agencies; industry; BOEM contractors; and 

academia. Scoping and coordination opportunities were also available during BOEM’s requests for 

information, comments, input, and review of its other NEPA documents, including the following: 

• scoping and comments on the Five-Year Program EIS;

• scoping and comments on the 2012-2017 WPA/CPA Multisale EIS;

• scoping and comments on the WPA 233/CPA 231 Supplemental EIS; 

• scoping and comments on the EPA 225/226 EIS; and

• scoping and comments on the CPA 235/241/247 Supplemental EIS. 

5.3.4. Cooperating Agency

According to Part 516 of the DOI Departmental Manual, BOEM must invite eligible governmental 

entities to participate as cooperating agencies when developing an EIS in accordance with the 

requirements of NEPA and CEQ regulations. BOEM must also consider any requests by eligible 

government entities to participate as a cooperating agency with respect to a particular EIS, and then to 

either accept or deny such requests.

The NOI, which was published on June 20, 2014, included an invitation to other Federal agencies and 

State, Tribal, and local governments to consider becoming cooperating agencies in the preparation of this 

Supplemental EIS. The National Park Service requested to participate as a cooperating agency.

BOEM has carefully considered NPS’s scoping comments and request for participation as a 

cooperating agency. BOEM has reviewed CEQ and DOI implementing regulations of NEPA specific to 

cooperating agencies. Those criteria are as follows: 

(1) Jurisdiction by law (40 CFR § 1508.15) – for example, agencies with the authority to 

grant permits for implementing the action; and

(2) Special expertise (40 CFR § 1508.26) – cooperating agency status for specific 

purposes linked to special expertise requires more than an interest in a proposed 

action (Federal and non-Federal agencies may be requested [40 CFR §§ 1501.6 and

1508.5]). 

While the Gulf Islands National Seashore is not within the jurisdictional authority of BOEM, nor does 

NPS have jurisdictional authority for the OCS or OCS-related actions, NPS believes they have special 

expertise in order to ensure that pertinent NPS mission statements, legislative authorities, and polices are 

duly considered when developing any alternatives related to management action or options that could 

potentially affect units of the NPS. BOEM has engaged in a deliberative process to evaluate this request 

and determine if the cooperating agency will provide additional analysis or data that BOEM does not 

already have.

BOEM has entered into a Memorandum of Agreement (MOA) with NPS to establish expectations 

between the two agencies that apply for the duration of this Supplemental EIS, whereupon it terminates. 

This MOA outlines the responsibilities agreed to by BOEM and NPS for this Supplemental EIS project. 

A copy of the MOA is provided in Appendix C. BOEM provided NPS the opportunity to respond and 

provide any additional objective and analytical information to be included in the Draft Supplemental EIS. 

BOEM has incorporated many revisions to address NPS’s concerns.

5.4. DISTRIBUTION OF THE DRAFT SUPPLEMENTAL EIS FOR REVIEW AND 

COMMENT

BOEM sent copies of the Draft Supplemental EIS to the government, public, and private agencies and 

groups listed below. Local libraries along the Gulf Coast were provided copies of this document; a list of 

these libraries is available on BOEM’s Internet website at http://www.boem.gov/nepaprocess/. 
5-8 Central and Eastern Planning Areas Supplemental EIS

Federal Agencies

Congress

Congressional Budget Office

House of Representatives

House Resources Subcommittee on Energy 

and Mineral Resources

Senate Committee on Energy and Natural 

Resources

Department of Commerce

National Marine Fisheries Service

National Oceanic and Atmospheric 

Administration

Department of Defense

Department of the Air Force

Department of the Army

Corps of Engineers

Department of the Navy

Naval Mine and ASW Command

Department of Energy

Strategic Petroleum Reserve PMD

Department of Homeland Security

Coast Guard

Department of State

Bureau of Oceans and International 

Environmental and Scientific Affairs

Department of the Interior

Bureau of Ocean Energy Management

Bureau of Safety and Environmental 

Enforcement

Fish and Wildlife Service

Geological Survey

National Park Service

Office of Environmental Policy and 

Compliance

Office of the Solicitor

Department of Transportation

Office of Pipeline Safety

Environmental Protection Agency

Region 4

Region 6

Marine Mammal Commission

National Aeronautics and Space Administration

State and Local Agencies

Alabama

Governor’s Office

Alabama Highway Department

Alabama Historical Commission and State

Historic Preservation Officer

Alabama Public Library Service

Alabama Public Service Commission

City of Mobile

City of Montgomery

Department of Conservation and Natural

Resources

Department of Environmental Management

Geological Survey of Alabama

South Alabama Regional Planning 

Commission

State Legislature Natural Resources 

Committee

Town of Dauphin Island

Florida

Governor’s Office

Bay County

Citrus County

City of Destin

City of Fort Walton Beach

City of Gulf Breeze

City of Panama City

City of Pensacola

Department of Agriculture and Consumer 

Services

Department of Environmental Protection

Department of State Archives, History and 

Records Management

Escambia County

Florida Emergency Response Commission

Florida Fish and Wildlife Conservation 

Commission

Franklin County

Gulf County

Hernando County

Hillsborough City-County Planning 

Commission

Lee County

Monroe County

North Central Florida Regional Planning 

Council

Okaloosa County

Pasco County

Santa Rosa County

Sarasota County

Southwest Florida Regional Planning Council

State Legislature Agriculture and Natural 

Resources Committee

Tampa Bay Regional Planning Council

Walton County

West Florida Regional Planning Council

Withlacoochee Regional Planning Council

Louisiana

Governor’s Office

Calcasieu Parish

Cameron Parish

City of Lake Charles

City of Morgan City

City of New Orleans
Consultation and Coordination 5-9 

Department of Culture, Recreation, and 

Tourism

Department of Economic Development

Department of Environmental Quality

Department of Natural Resources

Department of Transportation and 

Development

Department of Wildlife and Fisheries

Jefferson Parish

Lafourche Parish

Louisiana Geological Survey

South Lafourche Levee District

St. Bernard Parish

State House of Representatives, Natural 

Resources Committee

State Legislature Natural Resources 

Committee

State of Louisiana Library

Terrebonne Parish

Town of Grand Isle

Mississippi

Governor’s Office

City of Bay St. Louis

City of Gulfport

City of Pascagoula

Department of Archives and History

Department of Environmental Quality

Department of Marine Resources

Department of Wildlife, Fisheries, and Parks

Jackson-George Regional Library System

Mississippi Development Authority

State Legislature Oil, Gas, and Other Minerals 

Committee

Tribal Nation or Organization

Adai Caddo Indians of Louisiana

Alabama-Coushatta Tribes of Texas

Apalachee Talimali Band of Louisiana

Atakapa-Ishak Nation

Biloxi Chitimacha Confederation-Bayou 

Lafourche Band

Caddo Nation

Chahta Tribe

Chitimacha Tribe of Louisiana

Choctaw-Apache Tribe of Ebarb

Choctaw Nation of Oklahoma

Clifton Choctaw Tribe of Louisiana

Coushatta Indian Tribe

Four Winds Cherokee Tribe

Grand Caillou/Dulac Band

Inter-Tribal Council of Louisiana, Inc.

Isle de Jean Charles Band

Jena Band of Choctaw Indians

Louisiana Choctaw Turtle Tribe

Louisiana Governor’s Office of Indian Affairs

Mississippi Band of Choctaw Indians

Point au Chien Tribe

Quapaw Tribe of Oklahoma

Seminole Tribe of Florida

Seminole Nation of Oklahoma

The Louisiana Choctaw Tribe

Tunica-Biloxi Indian Tribe of Louisiana

United Houma Nation

Industry

Adams and Reese, LLP

Alabama Petroleum Council

American Petroleum Institute

Applied Technology Research Corporation

Associated Gas Distributors of Florida

Baker Energy

Bepco, Inc.

C.H. Fenstermaker & Associates, Inc.

Century Exploration N.O., Inc.

Chet Morrison Contractors

Chevron U.S.A. Inc.

C-K Associates, LLC

Coastal Environments, Inc.

Columbia Gulf Transmission

CSA International

De Leon & Associates

Ecological Associates, Inc.

Ecosystem Management, Inc.

Energy Partners, Ltd.

Florida Natural Gas Association

Florida Petroleum Council

Florida Power and Light

Florida Propane Gas Association

Freeport-McMoRan, Inc.

General Insulation, Inc.

Global Industries, Ltd.

Halliburton Corporation

Han & Associates, Inc.

Horizon Marine, Inc.

John Chance Land Surveys, Inc.

L&M Botruc Rental, Inc.

Lampl Herbert Consultants

Larose Intercoastal Lands, Inc.

Linder Oil Company

Louisiana Oil and Gas Association

Magnum Steel Services Corp.

Mid Continent Oil and Gas Association

Nature’s Way Marine, LLC

Offshore Process Services, Inc.

Oil and Gas Property Management, Inc.

Phoenix International Holdings, Inc.

Project Consulting Services
5-10 Central and Eastern Planning Areas Supplemental EIS

R.B. Falcon Drilling

Raintree Resources, Inc.

Science Applications International 

Corporation

SEOT, Inc.

Shell Offshore, Inc.

Stone Energy Corporation

Strategic Management Services-USA

T. Baker Smith, Inc.

The SJI, LLC

The Times-Picayune

URS Corporation

Waring & Associates

Special Interest Groups

1000 Friends of Florida

Alabama Oil & Gas Board

Alabama Nature Conservancy

Alabama Wildlife Federation

Apalachee Regional Planning Council

Apalachicola Bay and Riverkeepers

Audubon Louisiana Nature Center

Audubon of Florida

Barataria-Terrebonne National Estuary 

Program 

Bay County Chamber of Commerce

Bay Defense Alliance

Citizens Assoc. of Bonita Beach

Clean Gulf Associates

Coalition to Restore Coastal Louisiana

Concerned Shrimpers of America

Conservancy of Southwest Florida

Earthjustice

Florida Chamber of Commerce

Florida Natural Area Inventory

Florida Wildlife Federation

Gulf and South Atlantic Fisheries 

Foundation, Inc.

Gulf Coast Environmental Defense

Gulf Coast Fisherman’s Coalition

Gulf Restoration Network

Houma-Terrebonne Chamber of Commerce

Izaak Walton League of America, Inc.

LA 1 Coalition, Inc.

League of Women Voters of the Pensacola 

Bay Area

Louisiana Wildlife Federation

Manasota-88

Mobile Bay National Estuary Program

Offshore Operators Committee

Organized Fishermen of Florida

Panama City Beach Convention and Visitors 

Bureau

Pensacola Archaeological Society

Perdido Key Association

Perdido Key Chamber of Commerce

Perdido Watershed Alliance

Restore or Retreat

Roffers Ocean Fishing Forecast Service

Santa Rosa Sound Coalition

Save the Manatee Club

Sierra Club

South Central Industrial Association

Surfrider Foundation

The Ocean Conservancy

The Nature Conservancy

Ports/Docks

Alabama

Alabama State Port Authority

Port of Mobile

Florida

Manatee County Port Authority

Panama City Port Authority

Port of Pensacola

Port St. Joe Port Authority

Tampa Port Authority

Louisiana

Abbeville Harbor and Terminal District

Greater Baton Rouge Port Commission

Greater Lafourche Port Commission

Grand Isle Port Commission

Lake Charles Harbor and Terminal District

Port of Iberia District

Port of New Orleans

St. Bernard Port, Harbor and Terminal District

West Cameron Port Commission

Mississippi

Mississippi State Port Authority

Educational Institutions/Research Laboratories

Dauphin Island Sea Laboratory

Florida A&M University

Florida Institute of Oceanography

Florida Institute of Technology

Florida Sea Grant College

Florida State University

Foley Elementary School

Gulf Coast Research Laboratory

Gulf Coast State College

Harbor Branch Oceanography

Louisiana Sea Grant College Program

Louisiana State University
Consultation and Coordination 5-11

Louisiana Tech University

Louisiana Universities Marine Consortium

Loyola University

McNeese State University

Mississippi State University

Mississippi-Alabama Sea Grant Consortium

Mote Marine Laboratory

Nicholls State University

Pensacola Junior College

Tulane University

University of Alabama

University of Florida

University of Louisiana at Lafayette

University of Miami

University of Mississippi

University of New Orleans

University of South Alabama

University of South Florida

University of Southern Mississippi

University of West Florida

5.5. COASTAL ZONE MANAGEMENT ACT

If a Federal agency’s activities or development projects within or outside of the coastal zone will have 

reasonably foreseeable coastal effects in the coastal zone, then the activity is subject to a Federal 

Consistency Determination (CD). A consistency review will be performed pursuant to the Coastal Zone 

Management Act (CZMA) and CDs will be prepared for each CZMA State prior to each of the proposed 

CPA and EPA lease sales. To prepare the CDs, BOEM reviews each State’s Coastal Management Plan 

and analyzes the potential impacts as outlined in this Supplemental EIS, new information, and applicable 

studies as they pertain to the enforceable policies of each CMP. The CZMA requires that Federal actions 

that are reasonably likely to affect any land or water use or natural resource of the coastal zone be 

“consistent to the maximum extent practicable” with relevant enforceable policies of the State’s federally 

approved coastal management program (15 CFR part 930 subpart C). 

Based on these and other analyses, BOEM’s Gulf of Mexico OCS Region’s Regional Director makes 

an assessment of consistency, which is then sent to the States of Louisiana, Mississippi, Alabama, and 

Florida for proposed CPA and EPA lease sales. If a State concurs, BOEM can proceed with the proposed 

lease sale. A State’s concurrence may be presumed when the State does not provide a response within the 

60-day review period. A State may request an extension of time to review the CD within the 60-day 

period, which the Federal agency shall approve for an extension of 15 days or less. If a State objects, it 

must do the following under the CZMA: (1) indicate how BOEM’s presale proposal is inconsistent with 

their CMP and suggest alternative measures to bring BOEM’s proposal into consistency with their CMP; 

or (2) describe the need for additional information that would allow a determination of consistency. In 

the event of an objection, the Federal and State agencies should use the remaining portion of the 90-day 

review period to attempt to resolve their differences (15 CFR § 930.43(b)). At the end of the 90-day 

review period, the Federal agency shall not proceed with the activity over a State agency’s objection 

unless the Federal agency concludes that, under the “consistent to the maximum extent practicable” 

standard described in 15 CFR § 930.32, consistency with the enforceable policies of the CMP is 

prohibited by existing law applicable to the Federal agency and the Federal agency has clearly described, 

in writing, to the State agency the legal impediments to full consistency; or, the Federal agency has 

concluded that its proposed action is fully consistent with the enforceable policies of the CMP, though the 

State agency objects. Unlike the consistency process for specific OCS plans and permits, there is no 

procedure for administrative appeal to the Secretary of Commerce for a Federal CD for presale activities. 

In the event that there is a serious disagreement between BOEM and a State, either agency may request 

mediation. Mediation is voluntary, and the Secretary of Commerce would serve as the mediator. 

Whether there is mediation or not, the final CD is made by DOI, and it is the final administrative action 

for the presale consistency process. Each Gulf State’s CMP is described in Appendix F of the 2012-2017 

WPA/CPA Multisale EIS and Appendix E of the EPA 225/226 EIS. 

5.6. ENDANGERED SPECIES ACT

The Endangered Species Act of 1973 (16 U.S.C. §§ 1531 et seq.), as amended, establishes a national 

policy designed to protect and conserve threatened and endangered species and the ecosystems upon 

which they depend. BOEM and BSEE are currently in consultation with NMFS and FWS regarding the

OCS oil and gas program in the Gulf of Mexico. BOEM is acting as the lead agency in the ongoing 

consultation, with BSEE’s assistance and involvement. The programmatic consultation was expanded in 
5-12 Central and Eastern Planning Areas Supplemental EIS

scope after the reinitiation of consultation by BOEM following the Deepwater Horizon explosion and oil 

spill, and it will include both existing and future OCS oil and gas leases in the Gulf of Mexico over a 

10-year period. This consultation also considers any changes in baseline environmental conditions 

following the Deepwater Horizon explosion, oil spill, and response. The programmatic consultation will 

also include postlease activities associated with OCS oil- and gas-related activities in the Gulf of Mexico, 

including G&G and decommissioning activities. While the programmatic Biological Opinion is in 

development, BOEM and NMFS have agreed to interim consultations on postlease approvals.

With consultation ongoing, BOEM and BSEE will continue to comply with all reasonable and 

prudent measures and the terms and conditions under the existing consultations, along with implementing 

the current BOEM- and BSEE-required mitigation, monitoring, and reporting requirements. Based on the 

most recent and best available information at the time, BOEM and BSEE will also continue to closely 

evaluate and assess risks to listed species and designated critical habitat in upcoming environmental 

compliance documentation under NEPA and other statutes.

5.7. MAGNUSON-STEVENS FISHERY CONSERVATION AND MANAGEMENT ACT

Pursuant to Section 305(b) of the Magnuson-Stevens Fishery Conservation and Management Act, 

Federal agencies are required to consult with NMFS on any action that may result in adverse effects to 

EFH. The NMFS published the final rule implementing the EFH provisions of the Magnuson-Stevens 

Fisheries Conservation and Management Act (50 CFR part 600) on January 17, 2002. Certain OCS oiland gas-related activities authorized by BOEM may result in adverse effects to EFH, and therefore, 

require EFH consultation.

Following the Deepwater Horizon explosion, oil spill, and response, NMFS requested a 

comprehensive review of the existing EFH consultation in a response letter dated September 24, 2010. In 

light of this request, Regional staff of BOEM and NMFS agreed on procedures that would incorporate a 

new programmatic EFH consultation into each prepared Five-Year Program EIS and that began with the 

2012-2017 Five-Year Program. BOEM has EFH Assessments for all planning areas in the GOM

(Appendix D of the 2012-2017 WPA/CPA Multisale EIS and EPA 225/226 EIS) that describe the OCS 

proposed activities, analyzes the effects of the proposed activities on EFH, and identifies proposed 

mitigating measures. The programmatic EFH consultation, which covers proposed CPA Lease Sales 241 

and 247 was initiated with the distribution and review of the 2012-2017 WPA/CPA Multisale EIS and 

with the subsequent written communications between BOEM and NMFS. The programmatic EFH 

consultation, which covers proposed EPA Lease Sale 226, was initiated with the distribution and review 

of the EPA 225/226 EIS and with the subsequent written communications between BOEM and NMFS. 

These documents formalized the conservation recommendations put forth by NMFS and by BOEM’s 

acceptance and response to these recommendations.

While the necessary components of the EFH consultation are complete, there is ongoing coordination 

among NMFS, BOEM, and BSEE. This coordination includes annual reports from BOEM to NMFS, 

meetings with Regional staff, and discussions of mitigation and relevant topics. All agencies will 

continue to communicate for the duration of the current Five-Year Program.

5.8. NATIONAL HISTORIC PRESERVATION ACT

In accordance with the National Historic Preservation Act (16 U.S.C. §§ 470 et seq.), Federal 

agencies are required to consider the effect of their undertakings on historic properties. The 

implementing regulations for Section 106 of the National Historic Preservation Act (16 U.S.C. § 470f), 

issued by the Advisory Council on Historic Preservation (16 CFR part 800), specify the required review 

process.

BOEM initiated a request for consultation on the 2012-2017 WPA/CPA Multisale EIS on 

November 12, 2010, via a formal letter. That letter was addressed to each of the affected Gulf Coast 

States and Tribal Nations, including the Alabama-Coushatta Tribes of Texas, Chitimacha Tribe of 

Louisiana, Choctaw Nation of Oklahoma, Coushatta Indian Tribe, Jena Band of Choctaw Indians, 

Miccosukee Indian Tribe of Florida, Mississippi Band of Choctaw Indians, Poarch Band of Creek 

Indians, Seminole Tribe of Florida, and Tunica-Biloxi Indian Tribe of Louisiana. A response timeline of 

30 days was provided and two responses were received.
Consultation and Coordination 5-13

The State of Louisiana, in a letter to this Agency dated December 16, 2010, indicated that no known 

historic properties on State land or within State waters will be affected by this undertaking and that 

consultation regarding the CPA proposed actions is not necessary. The Seminole Tribe of Florida-Tribal 

Historic Preservation Officer (STOF-THPO) responded to this Agency’s request for consultation on 

December 6, 2010. The STOF-THPO indicated that there was no objection to the proposed undertakings 

at this time. The STOF-THPO requested to review the impending remote-sensing survey reports that are 

to be conducted over the high-probability zones within the project area. Additionally, the STOF-THPO 

requested to be notified if cultural resources that are potentially ancestral or historically relevant to the 

Seminole Tribe of Florida are inadvertently discovered at any point during this process.

BOEM published an NOI for the WPA 233/CPA 231 Supplemental EIS on July 9, 2012. In a 

response letter dated July 18, 2012, the State of Alabama, requested that a “Maritime Cultural Resource 

Assessment which meets the AHC [Alabama Historical Commission] standards should be conducted for 

any action within these sale blocks” and that the resulting report should be forwarded to their office for 

review and approval. Additional correspondence with the State of Alabama explained that cultural 

resource assessments are site specific and are completed as part of BOEM’s postlease requirements and 

that they are completed prior to authorization or approval of all proposed OCS oil- and gas-related 

activities. When necessary, cultural resource reports are also forwarded to the appropriate State agency as 

part of the Section 106 consultation process. A subsequent letter from the State of Alabama, dated 

August 16, 2012, agreed with the proposed lease actions provided that submerged cultural resources are 

addressed prior to disturbance, as outlined above.

Also as part of the proposed EPA 225/226 EIS, BOEM initiated a request for consultation with the 

Florida State Historic Preservation Office via a formal letter on August 3, 2012. The letter requested 

concurrence with a “no effect” determination. A timeline of 30 days was provided and the State 

responded that it concurred with the “no effect” determination.

BOEM initiated a request for comment on the NOI for this Supplemental EIS via a formal letter on 

June 18, 2014. That letter was addressed to each of the affected Gulf Coast States and Tribal Nations, 

including the Alabama-Coushatta Tribes of Texas, Caddo Nation, Chitimacha Tribe of Louisiana, 

Choctaw Nation of Oklahoma, Coushatta Indian Tribe, Jena Band of Choctaw Indians, Miccosukee 

Indian Tribe of Florida, Mississippi Band of Choctaw Indians, Poarch Band of Creek Indians, Seminole 

Tribe of Florida, Seminole Nation of Oklahoma, and Tunica-Biloxi Indian Tribe of Louisiana. A 

response timeline of 30 days was provided and one Tribal response was received (refer to Chapter 5.9). 

BOEM will continue to impose mitigating measures and monitoring and reporting requirements to 

ensure that historic properties are not affected by the proposed undertakings. BOEM will reinitiate the 

consultation process with affected parties should such circumstances warrant further consultation.

5.9. GOVERNMENT-TO-GOVERNMENT

In accordance with Executive Order 13175, “Consultation and Coordination with Indian Tribal 

Governments,” Federal agencies are required “to establish regular and meaningful consultation and 

collaboration with Tribal officials in the development of Federal policies that have Tribal implications, to 

strengthen the United States’ government-to-government relationships with Indian tribes, and to reduce 

the imposition of unfunded mandates upon Indian tribes.” BOEM initiated a request for comment with 

12 federally recognized Tribal Nations on the NOI for this Supplemental EIS via a formal letter on 

June 18, 2014. One Tribal Nation, the Choctaw Nation of Oklahoma, requested a copy of the Draft 

Supplemental EIS. 

CHAPTER 6 

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America, PNAS Early Edition, Special Feature, March 27, 2012. 6 pp.

Whitehead, A., B. Dubansky, C. Bodinier, T.I. Garcia, S. Miles, C. Pilley, V. Raghunathan, J.L. Roach, 

N. Walker, R.B. Walter, C.D. Rice, and F. Galvez. 2011. Genomic and physiological footprint of the 

Deepwater Horizon oil spill on resident marsh fishes. Proceedings of the National Academy of 

Sciences 108(15):6193-6198.
References Cited 6-27

Wiese, F.K., W.A. Montevecchi, G.K. Davoren, F. Huettmann, A.W. Diamond, and J. Linke. 2001. 

Seabirds at risk around offshore oil platforms in the north-west Atlantic. Marine Pollution Bulletin 

42:1285-1290.

Wilkinson, E.B., L.C. Branch, and D.L. Miller. 2013. Functional habitat connectivity for beach mice 

depends on perceived predation risk. Landscape Ecology 28:547-558.

Wilson, C.A., A. Pierce and M.W. Miller. 2003. Rigs and reefs: A comparison of the fish communities 

at two artificial reefs, a productions platform and a natural reef in the northern Gulf of Mexico. U.S. 

Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. 

OCS Study MMS 2003-009. 95 pp.

Wilson, D.L., R, Billing, R. Oommen, B. Lange, J. Marik, S. Mcclutchey, and H. Perez. 2010. Year 

2008 Gulfwide emission inventory study. U.S. Dept. of the Interior, Bureau of Ocean Energy 

Management, Regulation and Enforcement, Gulf of Mexico OCS Region, New Orleans, LA. OCS 

Study BOEMRE 2010-045.

Wilson, M.J., J.K. Wickliffe, and E. Overton. 2014. A critique of the manuscript: Distribution and 

concentrations of petroleum hydrocarbons associated with the BP/Deepwater Horizon oil spill, Gulf 

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American Institute of Biological Sciences. Pp. 629-632.

Wood, R.C. and L.S. Hales. 2001. Comparison of northern diamondback terrapin (Malaclemys terrapin 

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Woods & Poole Economics, Inc. 2011. The 2012 complete economic and demographic data source 

(CEDDS) on CD-ROM.

Woods & Poole Economics, Inc. 2014. The 2014 complete economic and demographic data source 

(CEDDS) on CD-ROM.

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content.aspx?id=4294968399. Accessed on July 18, 2014.

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of chemically dispersed oil and subsequent recovery in Diploria strigosa. Marine Ecology 7:23-42.

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City, FL. June 30, 2014.

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the Deepwater Horizon blowout. Deep-Sea Research Part II. Internet website: 

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2014.

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and the Deepwater Horizon oil spill: The role of planting in ecological recovery. Gulf of Mexico Oil 

Spill & Ecosystem Science Conference, January 26-29, 2014, Mobile, AL. 

Zhou, Z, Z. Liu, and L. Guo. 2013. Chemical evolution of Macondo crude oil during laboratory 

degradation as characterized by fluorescence EEMs and hydrocarbon composition. Marine Pollution 

Bulletin 66:164-175.

CHAPTER 7 

PREPARERS

Preparers 7-3 

7. PREPARERS

Gary D. Goeke, Chief, Environmental Assessment Section

Jennifer Bosyk, Headquarters’ Coordinator, Environmental Specialist

Lissa Lyncker, Unit Supervisor, Environmental Protection Specialist

Tershara Matthews, NEPA Co-Coordinator, Unit Supervisor, Environmental Protection Specialist

Helen Rucker, NEPA Coordinator, Environmental Scientist

Pat Adkins, Information Management Specialist

Bruce Baird, Marine Biologist

Mark Belter, Marine Biologist

Idrissa Boube, Environmental Scientist

Darice K. Breeding, Environmental Protection Specialist

Alicia Caporaso, Marine Archaeologist

Sindey Chaky, Environmental Protection Specialist

Leonard Coats, Supervisor, Geographer

Kasey Couture, Program Analyst

Thierry DeCort, Chief, Geological and Geophysical Section

Ross Del Rio, Environmental Scientist

Chris DuFore, Oceanographer

Donald (Tre) W. Glenn III, Protected Species Biologist

Stephen Gonzales, Geographer

Mike Gravois, Geographer

Allison Hernandez, Protected Species Biologist

Mark Jensen, Economist

Matthew Johnson, Marine Biologist

Doug Jones, Marine Archaeologist

Jack Irion, Unit Supervisor, Marine Archaeologist

Agatha-Marie Kaller, Unit Supervisor, Marine Biologist

Carla Langley, Geographer

Jessica Mallindine, Protected Species Biologist

Charles (Jay) McCreery, Physical Scientist

Stacie Merritt, Physical Scientist

Margaret Metcalf, Chief, Physical/Chemical Sciences Section

Deborah H. Miller, Technical Editor

Megan Milliken, Environmental Protection Specialist

David P. Moran, Biologist

S. Erin O’Reilly, Physical Scientist

Christopher Oos, Geographer

Catherine A. Rosa, Environmental Protection Specialist

Shane Stradley, Geographer

Ariel White, Environmental Scientist

CHAPTER 8 

GLOSSARY

Glossary 8-3 

8. GLOSSARY

Acute—Sudden, short term, severe, critical, 

crucial, intense, but usually of short duration.

Anaerobic—Capable of growing in the absence of 

molecular oxygen.

Annular preventer—A component of the 

pressure control system in the BOP that forms 

a seal in the annular space around any object 

in the wellbore or upon itself, enabling well 

control operations to commence.

Anthropogenic—Coming from human sources, 

relating to the effect of humankind on nature.

API gravity—A standard adopted by the 

American Petroleum Institute for expressing 

the specific weight of oil.

Aromatic—Class of organic compounds 

containing benzene rings or benzenoid 

structures.

Attainment area—An area that is shown by 

monitored data or by air-quality modeling 

calculations to be in compliance with primary 

and secondary ambient air quality standards 

established by USEPA.

Barrel (bbl)—A volumetric unit used in the 

petroleum industry; equivalent to 42 U.S. 

gallons or 158.99 liters.

Benthic—On or in the bottom of the sea.

Biological Opinion—The FWS or NMFS 

evaluation of the impact of a proposed action 

on endangered and threatened species, in 

response to formal consultation under 

Section 7 of the Endangered Species Act.

Block—A geographical area portrayed on official 

BOEM protraction diagrams or leasing maps 

that contains approximately 2,331 ha (9 mi2

). 

Blowout—An uncontrolled flow of fluids below 

the mudline from appurtenances on a wellhead 

or from a wellbore.

Blowout preventer (BOP)—One of several 

valves installed at the wellhead to prevent the 

escape of pressure either in the annular space 

between the casing and drill pipe or in open 

hole (i.e., hole with no drill pipe) during 

drilling completion operations. Blowout 

preventers on jackup or platform rigs are 

located at the water’s surface; on floating 

offshore rigs, BOP’s are located on the 

seafloor.

Bottom kill—A wild well-control procedure 

involving the intersection of an uncontrolled 

well with a relief well for the purpose of 

pumping heavy mud or cement into the wild 

well to stanch the flow of oil or gas (the wellcontrol strategy for the Macondo spill 

deployed in mid-July 2010 that resulted in the 

successful capping of the well). 

Cetacean—Aquatic mammal of the order Cetacea, 

such as whales, dolphins, and porpoises.

Chemosynthetic—Organisms that obtain their 

energy from the oxidation of various inorganic 

compounds rather than from light 

(photosynthetic).

Coastal waters—Waters within the geographical 

areas defined by each State’s Coastal Zone 

Management Program.

Coastal wetlands—forested and nonforested 

habitats, mangroves, and marsh islands 

exposed to tidal activity. These areas directly 

contribute to the high biological productivity 

of coastal waters by input of detritus and 

nutrients, by providing nursery and feeding 

areas for shellfish and finfish, and by serving 

as habitat for birds and other animals.

Coastal zone—The coastal waters (including the 

lands therein and thereunder) and the adjacent 

shorelands (including the waters therein and 

thereunder) strongly influenced by each other 

and in proximity to the shorelines of several 

coastal states; the zone includes islands, 

transitional and intertidal areas, salt marshes, 

wetlands, and beaches, and it extends seaward 

to the outer limit of the United States 

territorial sea. The zone extends inland from 

the shorelines only to the extent necessary to 

control shorelands, the uses of which have a 

direct and significant impact on the coastal 

waters. Excluded from the coastal zone are 

lands the use of which is by law subject to the 

discretion of or which is held in trust by the 

Federal Government, its officers, or agents

(also refer to State coastal zone boundaries). 

Completion—Conversion of a development well 

or an exploration well into a production well.

Condensate—Liquid hydrocarbons produced with 

natural gas; they are separated from the gas by 

cooling and various other means. Condensates 

generally have an API gravity of 50o

-120o. 
8-4 Central and Eastern Planning Areas Supplemental EIS

Continental margin—The ocean floor that lies 

between the shoreline and the abyssal ocean 

floor, includes the continental shelf, 

continental slope, and continental rise.

Continental shelf—General term used by 

geologists to refer to the continental margin 

province that lies between the shoreline and 

the abrupt change in slope called the shelf 

edge, which generally occurs in the Gulf of 

Mexico at about the 200-m (656-ft) water 

depth. The continental shelf is characterized 

by a gentle slope (about 0.1o

). This is 

different from the juridical term used in 

Article 76 of the United Nations Convention 

on the Law of the Sea Royalty Payment (refer 

to the definition of Outer Continental Shelf).

Continental slope—The continental margin 

province that lies between the continental 

shelf and continental rise, characterized by a 

steep slope (about 3o

-6o). 

Critical habitat—Specific areas essential to the 

conservation of a protected species and that 

may require special management 

considerations or protection.

Crude oil—Petroleum in its natural state as it 

emerges from a well or after it passes through 

a gas-oil separator, but before refining or 

distillation. An oily, flammable, bituminous 

liquid that is essentially a complex mixture of 

hydrocarbons of different types with small 

amounts of other substances.

Delineation well—A well that is drilled for the 

purpose of determining the size and/or volume 

of an oil or gas reservoir.

Demersal—Living at or near the bottom of the 

sea.

Development—Activities that take place 

following discovery of economically 

recoverable mineral resources, including 

geophysical surveying, drilling, platform 

construction, operation of onshore support 

facilities, and other activities that are for the 

purpose of ultimately producing the resources.

Development and Production Plan (DPP)—A 

document that must be prepared by the 

operator and submitted to BOEM for approval 

before any development and production 

activities are conducted on a lease or unit in 

any OCS area other than the western Gulf of 

Mexico.

Development Operations Coordination 

Document (DOCD)—A document that must 

be prepared by the operator and submitted to 

BOEM for approval before any development 

or production activities are conducted on a 

lease in the western Gulf of Mexico.

Development well—A well drilled to a known 

producing formation to extract oil or gas; a 

production well; distinguished from a wildcat 

or exploration well and from an offset well.

Direct employment—Consists of those workers 

involved the primary industries of oil and gas 

exploration, development, and production 

operations (Standard Industrial Classification 

Code 13—Oil and Gas Extraction).

Discharge—Something that is emitted; flow rate 

of a fluid at a given instant expressed as 

volume per unit of time.

Dispersant—A suite of chemicals and solvents 

used to break up an oil slick into small 

droplets, which increases the surface area of 

the oil and hastens the processes of weathering 

and microbial degradation.

Dispersion—A suspension of finely divided 

particles in a medium.

Drilling mud—A mixture of clay, water or 

refined oil, and chemical additives pumped 

continuously downhole through the drill pipe 

and drill bit, and back up the annulus between 

the pipe and the walls of the borehole to a 

surface pit or tank. The mud lubricates and

cools the drill bit, lubricates the drill pipe as it 

turns in the wellbore, carries rock cuttings to 

the surface, serves to keep the hole from 

crumbling or collapsing, and provides the 

weight or hydrostatic head to prevent 

extraneous fluids from entering the well bore 

and to downhole pressures; also called drilling 

fluid.

Economically recoverable resources—An 

assessment of hydrocarbon potential that takes 

into account the physical and technological 

constraints on production and the influence of 

costs of exploration and development and 

market price on industry investment in OCS 

exploration and production.

Effluent—The liquid waste of sewage and 

industrial processing.

Effluent limitations—Any restriction established 

by a State or the USEPA on quantities, rates, 

and concentrations of chemical, physical, 
Glossary 8-5 

biological, and other constituents discharged 

from point sources into U.S. waters, including 

schedules of compliance.

Epifaunal—Animals living on the surface of hard 

substrate.

Essential habitat—Specific areas crucial to the 

conservation of a species and that may 

necessitate special considerations.

Estuary—Coastal semienclosed body of water 

that has a free connection with the open sea 

and where freshwater meets and mixes with 

seawater.

Eutrophication—Enrichment of nutrients in the 

water column by natural or artificial methods 

accompanied by an increase of respiration, 

which may create an oxygen deficiency.

Exclusive Economic Zone (EEZ)—The maritime 

region extending 200 nmi (230 mi; 370 km)

from the baseline of the territorial sea, in 

which the United States has exclusive rights 

and jurisdiction over living and nonliving 

natural resources.

Exploration Plan (EP)—A plan that must be 

prepared by the operator and submitted to 

BOEM for approval before any exploration or

delineation drilling is conducted on a lease.

Exploration well—A well drilled in unproven or 

semi-proven territory to determining whether 

economic quantities of oil or natural gas 

deposit are present.

False crawls—Refers to when a female sea turtle 

crawls up on the beach to nest (perhaps) but 

does not and returns to the sea without laying 

eggs.

Field—An accumulation, pool, or group of pools 

of hydrocarbons in the subsurface. A 

hydrocarbon field consists of a reservoir in a 

shape that will trap hydrocarbons and that is 

covered by an impermeable, sealing rock.

Floating production, storage, and offloading 

(FPSO) system—A tank vessel used as a 

production and storage base; produced oil is 

stored in the hull and periodically offloaded to 

a shuttle tanker for transport to shore.

Gathering lines—A pipeline system used to bring 

oil or gas production from a number of 

separate wells or production facilities to a 

central trunk pipeline, storage facility, or 

processing terminal.

Geochemical—Of or relating to the science

dealing with the chemical composition of and 

the actual or possible chemical changes in the 

crust of the earth.

Geophysical survey—A method of exploration in 

which geophysical properties and relationships 

are measured remotely by one or more 

geophysical methods.

Habitat—A specific type of environment that is 

occupied by an organism, a population, or a 

community.

Hermatypic coral—Reef-building corals that 

produce hard, calcium carbonate skeletons and 

that possess symbiotic, unicellular algae 

within their tissues.

Harassment—An intentional or negligent act or 

omission that creates the likelihood of injury 

to wildlife by annoying it to such an extent as 

to significantly disrupt normal behavior 

patterns that include, but are not limited to, 

feeding or sheltering.

Hydrocarbons—Any of a large class of organic 

compounds containing primarily carbon and 

hydrogen. Hydrocarbon compounds are 

divided into two broad classes: aromatic and 

aliphatics. They occur primarily in petroleum, 

natural gas, coal, and bitumens.

Hypoxia—Depressed levels of dissolved oxygen 

in water, usually resulting in decreased 

metabolism.

Incidental take—Takings that result from, but are 

not the purpose of, carrying out an otherwise 

lawful activity (e.g., fishing) conducted by a 

Federal agency or applicant (refer to Taking).

Indirect employment—Secondary or supporting 

oil- and gas-related industries, such as the 

processing of crude oil and gas in refineries, 

natural gas plants, and petrochemical plants.

Induced employment—Tertiary industries that 

are created or supported by the expenditures of 

employees in the primary or secondary 

industries (direct and indirect employment), 

including consumer goods and services such 

as food, clothing, housing, and entertainment.

Infrastructure—The facilities associated with oil 

and gas development, e.g., refineries, gas 

processing plants, etc.

Jack-up rig—A barge-like, floating platform with 

legs at each corner that can be lowered to the 
8-6 Central and Eastern Planning Areas Supplemental EIS

sea bottom to raise the platform above the 

water.

Kick—A deviation or imbalance, typically sudden 

or unexpected, between the downward 

pressure exerted by the drilling fluid and the 

upward pressure of in-situ formation fluids or 

gases.

Landfall—The site where a marine pipeline 

comes to shore.

Lease—Authorization that is issued under 

Section 8 or maintained under Section 6 of the 

Outer Continental Shelf Lands Act and that 

authorizes exploration for, and development

and production of, minerals.

Lease sale—The competitive auction of leases 

granting companies or individuals the right to 

explore for and develop certain minerals under 

specified conditions and periods of time.

Lease term—The initial period for oil and gas

leases, usually a period of 5, 8, or 10 years 

depending on water depth or potentially 

adverse conditions.

Lessee—A party authorized by a lease, or an 

approved assignment thereof, to explore for 

and develop and produce the leased deposits in 

accordance with regulations at 30 CFR part 

250 and 30 CFR part 550. 

Lower marine riser package—The head 

assembly of a subsurface well at the point 

where the riser connects to a blowout 

preventer.

Macondo—Prospect name given by BP to the 

Mississippi Canyon Block 252 exploration 

well that the Deepwater Horizon rig was 

drilling when a blowout occurred on April 20, 

2010.

Macondo spill—The name given to the oil spill 

that resulted from the explosion and sinking of 

the Deepwater Horizon rig from the period 

between April 24, 2010, when search and 

recovery vessels on site reported oil at the sea 

surface, and September 19, 2010, when the 

uncontrolled flow from the Macondo well was 

capped. 

Marshes—Persistent, emergent, nonforested 

wetlands characterized by predominantly 

cordgrasses, rushes, and cattails.

Military warning area—An area established by 

the U.S. Department of Defense within which 

military activities take place.

Minerals—As used in this document, minerals 

include oil, gas, sulphur, and associated 

resources, and all other minerals authorized by 

an Act of Congress to be produced from 

public lands as defined in Section 103 of the 

Federal Land Policy and Management Act of 

1976.

Naturally occurring radioactive materials 

(NORM)—naturally occurring material that 

emits low levels of radioactivity, originating 

from processes not associated with the 

recovery of radioactive material. The 

radionuclides of concern in NORM are 

Radium-226, Radium-228, and other isotopes 

in the radioactive decay chains of uranium and 

thorium.

Nepheloid—A layer of water near the bottom that 

contains significant amounts of suspended 

sediment.

Nonattainment area—An area that is shown by 

monitoring data or by air-quality modeling 

calculations to exceed primary or secondary 

ambient air quality standards established by 

USEPA.

Nonhazardous oil-field wastes (NOW)—Wastes 

generated by exploration, development, or 

production of crude oil or natural gas that are 

exempt from hazardous waste regulation under 

the Resource Conservation and Recovery Act 

(Regulatory Determination for Oil and Gas 

and Geothermal Exploration, Development 

and Production Wastes, dated June 29, 1988, 

53 FR 25446; July 6, 1988). These wastes 

may contain hazardous substances.

Offloading—Unloading liquid cargo, crude oil, or 

refined petroleum products.

Operational discharge—Any incidental 

pumping, pouring, emitting, emptying, or 

dumping of wastes generated during routine 

offshore drilling and production activities.

Operator—An individual, partnership, firm, or 

corporation having control or management of 

operations on a leased area or portion thereof. 

The operator may be a lessee, designated 

agent of the lessee, or holder of operating 

rights under an approved operating agreement.

Organic matter—Material derived from living 

plants or animals.

Outer Continental Shelf (OCS)—All submerged 

lands that comprise the continental margin 
Glossary 8-7 

adjacent to the United States and seaward of 

State offshore lands.

Pelagic—Of or pertaining to the open sea; 

associated with open water beyond the direct 

influence of coastal systems.

Plankton—Passively floating or weakly motile 

aquatic plants (phytoplankton) and animals 

(zooplankton).

Platform—A steel or concrete structure from 

which offshore development wells are drilled.

Play—A prospective subsurface area for 

hydrocarbon accumulation that is 

characterized by a particular structural style or 

depositional relationship.

Primary production—Organic material produced 

by photosynthetic or chemosynthetic 

organisms.

Produced water—Total water discharged from 

the oil and gas extraction process; production 

water or production brine.

Production—Activities that take place after the 

successful completion of any means for the 

extraction of resources, including bringing the 

resource to the surface, transferring the 

produced resource to shore, monitoring 

operations, and drilling additional wells or 

workovers.

Province—A spatial entity with common geologic 

attributes. A province may include a single 

dominant structural element such as a basin or 

a fold belt, or a number of contiguous related 

elements.

Ram—The main component of a blowout 

preventer designed to shear casing and tools in 

a wellbore or to seal an empty wellbore. A 

blind shear ram accomplishes the former and a 

blind ram the latter.

Recoverable reserves—The portion of the 

identified hydrocarbon or mineral resource 

that can be economically extracted under 

current technological constraints.

Recoverable resource estimate—An assessment 

of hydrocarbon or mineral resources that takes 

into account the fact that physical and 

technological constraints dictate that only a 

portion of resources can be brought to the 

surface.

Recreational beaches—Frequently visited, sandy 

areas along the Gulf of Mexico shorefront that 

support multiple recreational activities at the 

land-water interface. Included are National 

Seashores, State Park and Recreational Areas, 

county and local parks, urban beachfronts, and 

private resorts.

Refining—Fractional distillation of petroleum, 

usually followed by other processing (e.g., 

cracking).

Relief—The difference in elevation between the 

high and low points of a surface.

Reserves—Proved oil or gas resources.

Rig—A structure used for drilling an oil or gas 

well.

Riser insertion tube tool—A “straw” and gasket 

assembly improvised during the Macondo spill 

response that was designed to siphon oil and 

gas from the broken riser of the Deepwater 

Horizon rig lying on the sea bottom (an early 

recovery strategy for the Macondo spill in 

May 2010). 

Royalty—A share of the minerals produced from 

a lease paid in either money or “in-kind” to the 

landowner by the lessee.

Saltwater intrusion—Saltwater invading a body 

of freshwater.

Sciaenids—Fishes belonging to the croaker family 

(Sciaenidae).

Seagrass beds—More or less continuous mats of 

submerged, rooted, marine, flowering vascular 

plants occurring in shallow tropical and 

temperate waters. Seagrass beds provide 

habitat, including breeding and feeding 

grounds, for adults and/or juveniles of many 

of the economically important shellfish and 

finfish. 

Sediment—Material that has been transported and 

deposited by water, wind, glacier, 

precipitation, or gravity; a mass of deposited 

material.

Seeps (hydrocarbon)—Gas or oil that reaches the 

surface along bedding planes, fractures, 

unconformities, or fault planes.

Sensitive area—An area containing species, 

populations, communities, or assemblages of 

living resources, that is susceptible to damage 

from normal OCS oil- and gas-related 

activities. Damage includes interference with 

established ecological relationships.

Shear ram—The component in a BOP that cuts, 

or shears, through the drill pipe and forms a 
8-8 Central and Eastern Planning Areas Supplemental EIS

seal against well pressure. Shear rams are 

used in floating offshore drilling operations to 

provide a quick method of moving the rig 

away from the hole when there is no time to 

trip the drill stem out of the hole.

Shoreline Cleanup and Assessment Team—The

on-the-scene responders for post-spill 

shoreline protection who established priorities, 

standardized procedures, and terminology. 

Spill of National Significance—Designation by 

the USEPA Administrator under 40 CFR § 

300.323 for discharges occurring in the inland 

zone and the Commandant of the U.S. Coast 

Guard for discharges occurring in the coastal 

zone, authorizing the appointment of a 

National Incident Commander for spillresponse activity.

State coastal zone boundary—The State coastal 

zone boundaries for each CZMA-affected 

State are defined at http://

coastalmanagement.noaa.gov/mystate/docs/

StateCZBoundaries.pdf. 

Structure—Any OCS facility that extends from 

the seafloor to above the waterline; in 

petroleum geology, any arrangement of rocks 

that may hold an accumulation of oil or gas.

Subarea—A discrete analysis area.

Subsea isolation device—An emergency 

disconnection and reconnection assembly for 

the riser at the seafloor. 

Supply vessel—A boat that ferries food, water, 

fuel, and drilling supplies and equipment to an 

offshore rig or platform and returns to land 

with refuse that cannot be disposed of at sea.

Taking—To harass, harm, pursue, hunt, shoot, 

wound, kill, trap, capture, or collect any 

endangered or threatened species, or to 

attempt to engage in any such conduct 

(including actions that induce stress, adversely 

impact critical habitat, or result in adverse 

secondary or cumulative impacts). 

Harassments are the most common form of 

taking associated with OCS Program 

activities.

Tension-leg platform (TLP)—A production 

structure that consists of a buoyant platform 

tethered to concrete pilings on the seafloor 

with flexible cable.

Total dissolved solids—The total amount of 

solids that are dissolved in water.

Total suspended particulate matter—The total 

amount of suspended solids in water.

Total suspended solids—The total amount of 

suspended solids in water.

Trunkline—A large-diameter pipeline receiving 

oil or gas from many smaller tributary 

gathering lines that serve a large area; 

common-carrier line; main line.

Turbidity—Reduced water clarity due to the 

presence of suspended matter.

Volatile organic compound (VOC)—Any 

organic compound that is emitted to the 

atmosphere as a vapor.

Water test areas—Areas within the eastern Gulf 

where U.S. Department of Defense research, 

development, and testing of military planes, 

ships, and weaponry take place.

Weathering (of oil)—The aging of oil due to its 

exposure to the atmosphere, causing marked 

alterations in its physical and chemical 

makeup.
FIGURES

Figures Figures-3

Figure 1-1. Gulf of Mexico Planning Areas, Proposed CPA and EPA Lease Sale Areas, and Locations of Major Cities. 
Figures-4 Central and Eastern Planning Areas Supplemental EIS

Figure 2-1. Location of Proposed Stipulations and Deferrals.
Figures Figures-5

Figure 2-2. Military Warning Areas and Eglin Water Test Areas in the Gulf of Mexico.
Figures-6 Central and Eastern Planning Areas Supplemental EIS

Figure 3-1. Offshore Subareas in the Gulf of Mexico.
Figures Figures-7 

Figure 4-1. Location of Live Bottom Features and Stipulation Blocks on the Mississippi, Alabama, and Florida 

Continental Shelf.
Figures-8 Central and Eastern Planning Areas Supplemental EIS

Figure 4-2. OCS Leasing Activity Near the Gulf Islands National Seashore.
Figures Figures-9 

Figure 4-3. Photograph of the View from Petit Bois Island Looking South (modified and reprinted with permission 

from Marsh, 2014).
Figures-10 Central and Eastern Planning Areas Supplemental EIS

Figure 4-4. Federal OCS Lease Blocks Subject to the Gulf Island National Seashore Information to Lessees.
TABLES

Tables Tables-3 

Table 3-1

Projected Oil and Gas in the Gulf of Mexico OCS

Typical Lease Sale OCS Cumulative

(2012-2051)

Western Planning Area

 Reserve/Resource Production

 Oil (BBO) 0.116-0.200 2.510-3.696

 Gas (Tcf) 0.538-0.938 12.539-18.434

Central Planning Area

 Reserve/Resource Production

 Oil (BBO) 0.460-0.894 15.825-21.733

 Gas (Tcf) 1.939-3.903 63.347-92.691

Eastern Planning Area

 Reserve/Resource Production

 Oil (BBO) 0-0.071 0-0.211

 Gas (Tcf) 0-0.162 0.502

BBO = billion barrels of oil

Tcf = trillion cubic feet
Tables-4 Central and Eastern Planning Areas Supplemental EIS

Table 3-2

Offshore Scenario Information Related to a Typical Lease Sale in the Central Planning Area

 

Offshore Subareas1

Total CPA2

0-60 m 60-200 m 200-800 m 800-1,600 m 1,600-2,400 m >2,400 m

Wells Drilled

 Exploration and Delineation Wells 62-121 24-46 21-42 15-29 18-36 28-55 168-329

 Development and Production Wells 78-152 32-58 26-53 20-38 24-46 35-70 215-417

 Producing Oil Wells 11-21 5-8 16-32 12-23 15-29 22-43 81-156

 Producing Gas Wells 58-115 23-44 7-15 5-10 6-11 9-19 108-241

Production Structures

 Installed 28-54 3-6 1-2 1 1-2 1-2 35-67

 Removed Using Explosives 18-36 2-4 0 0 0 0 20-40

 Total Removed 25-49 3-5 1-2 1 1-2 1-2 32-61

Method of Transportation3

 Percent Piped >99% >99% >99% >99% 90->99% 93->99%

 Percent Barged <1% 0% 0% 0% 0% <1%

 Percent Tankered4 0% 0% 0% 0% 0-10% 0-6%

Length of Installed Pipelines (km)5 216-586 NA NA NA NA NA 628-1870

Service-Vessel Trips (1,000’s round trips) 32-61 5-10 3-6 17-19 18-35 19-37 94-168

Helicopter Operations (1,000’s operations) 557-1,470 63-163 21-54 14-36 21-54 21-54 696-1,815

1 See Figure 3-1. 2 Subareas totals may not add up to the planning area total because of rounding. 3 100% of gas is assumed to be piped. 4 Tankering is forecasted to occur only in water depths >1,600 m.

5 Projected length of pipelines does not include length in State waters.

NA = not available.
Tables Tables-5 

Table 3-3

Offshore Scenario Information Related to a Typical Sale 

in the Eastern Planning Area1 for the Years 2012-2051

 Water Depth 

>800 m

Total EPA

Wells Drilled

 Exploration and Delineation Wells 3-12 3-12

 Development and Production Wells 0-17 0-17

 Producing Oil Wells 0-10 0-10

 Producing Gas Wells 0-4 0-4

Production Structures

 Installed 0-1 0-1

 Removed Using Explosives 0 0

 Total Removed 0-1 0-1

Method of Transportation2

 Percent Piped >99.9% >99.9%

 Percent Barged <0.01% <0.01%

 Percent Tankered <0.01% <0.01%

Length of Installed Pipelines (km)3 0-82 0-82

Service-Vessel Trips (1,000’s round trips) 0.144-17 0.144-17

Helicopter Operations (1,000’s operations) 0-0.027 0-0.027 1 Refer to Figure 3-1. 2 100% of gas is assumed to be piped. 3 Projected length of pipelines does not include length in State waters.
Tables-6 Central and Eastern Planning Areas Supplemental EIS

Table 3-4

Offshore Scenario Information Related to OCS Program Activities

in the Gulf of Mexico (WPA, CPA, and EPA) for 2012-2051

Offshore Subareas1

Total OCS2

0-60 m 60-200 m 200-800 m 800-1,600 m 1,600-2,400 m >2,400 m

Wells Drilled

 Exploration and Delineation Wells 2,730-3,900 990-1,390 920-1,350 700-960 770-1,030 790-1,170 6,910-9,827

 Development and Production Wells 3,380-4,820 1,240-1,730 1,130-1,670 860-1,190 950-1,280 970-1,450 8,530-12,180

 Producing Oil Wells 520-701 215-278 704-1,030 574-783 663-873 620-915 3,296-4,605

 Producing Gas Wells 2,510-3,629 885-1,272 306-470 196-287 187-267 250-385 4,334-6,320

Production Structures

 Installed 1,210-1,720 110-160 26-40 25-30 32-33 32-38 1,435-2,026

 Removed Using Explosives 796-1,139 69-104 3-4 0 0 0 868-1,247

 Total Removed 1,090-1,560 100-150 24-34 20-28 23-30 22-33 1,279-1,837

Method of Transportation3

 Percent Piped >99% >99% >99% >99% 87->99% 92->99%

 Percent Barged <1% 0% 0% 0% 0% <1%

 Percent Tankered4 0% 0% 0% 0% 0-13% 0-7%

Length of Installed Pipelines (km)5 10,482-21,121 NA NA NA NA NA 30,428-69,749

Service-Vessel Trips (1,000’s round trips) 1,366-1,942 196-280 111-162 466-619 584-626 587-719 3,310-4,382

Helicopter Operations (1,000’s operations) 24,221-47,322 2,297-4,444 595-1,174 574-1,111 676-1,287 888-1,738 28,710-55,605

1 See Figure 3-1. 2 Subareas totals may not add up to the planning area total because of rounding.

3 100% of gas is assumed to be piped.

4 Tankering is forecasted to occur only in water depths >1,600 m.

5 Projected length of pipelines does not include length in State waters.

NA = not available.
Tables Tables-7

Table 3-5

Offshore Scenario Information Related to OCS Program Activities

in the Central Planning Area for 2012-2051

Offshore Subareas1

Total CPA2

0-60 m 60-200 m 200-800 m 800-1,600 m 1,600-2,400 m >2,400 m

Wells Drilled

 Exploration and Delineation Wells 2,230-3,160 820-1,160 700-1,030 540-730 700-940 730-1,090 5,720-8,110

 Development and Production Wells 2,760-3,900 1,020-1,440 860-1,270 670-900 870-1,160 900-1,350 7,080-10,020

 Producing Oil Wells 446-592 188-240 534-775 449-592 609-796 575-848 2,801-3,843

 Producing Gas Wells 2,034-2,918 722-1,050 236-365 151-218 171-244 235-362 3,549-5,157

Production Structures

 Installed 990-1,390 90-130 20-30 20-25 30 30-35 1,180-1,640

 Removed Using Explosives 650-920 55-83 2-3 0 0 0 707-1,006

 Total Removed 890-1,260 80-120 18-26 16-21 21-27 21-31 1,046-1,485

Method of Transportation3

 Percent Piped >99% >99% >99% >99% 90->99% 93->99%

 Percent Barged <1% 0% 0% 0% 0% >1%

 Percent Tankered4 0% 0% 0% 0% 0-10% 0-6%

Length of Installed Pipelines (km)5 8,515-16,993 NA NA NA NA NA 25,204-57,177

Service-Vessel Trips (1,000’s round trips) 1,117-1,570 161-230 85-126 371-469 546-569 549-663 2,829-3,627

Helicopter Operations (1,000’s operations) 19,975-37,825 1,902-3,560 404-801 404-668 595-801 595-890 23,780-44,500

1 See Figure 3-1. 2 Subareas totals may not add up to the planning area total because of rounding.

3 100% of gas is assumed to be piped.

4 Tankering is forecasted to occur only in water depths >1,600 m.

5 Projected length of pipelines does not include length in State waters.

NA = not available.
Tables-8 Central and Eastern Planning Areas Supplemental EIS

Table 3-6 

Offshore Scenario Information Related to OCS Program Activities

in the Eastern Planning Area1 for the Years 2012-2051 

 Water Depth 

>800 m

Total EPA

Wells Drilled

 Exploration and Delineation Wells 10-27 10-27

 Development and Production Wells 0-40 0-40

 Producing Oil Wells 0-25 0-25

 Producing Gas Wells 0-10 0-10

Production Structures

 Installed 0-2 0-2

 Removed Using Explosives 0 0

 Total Removed 0-2 0-2

Method of Transportation2

 Percent Piped >99.9% >99.9%

 Percent Barged <0.01% <0.01%

 Percent Tankered <0.01% <0.01%

Length of Installed Pipelines (km)3 0-233 0-233

Service-Vessel Trips (1,000’s round trips) 0.48- 35 0.48- 35

Helicopter Operations (1,000’s operations) 0-0.054 0-0.054 1 Refer to Figure 3-1. 2 100% of gas is assumed to be piped. 3 Projected length of pipelines does not include length in State waters.

Table 3-7 

Annual Volume of Produced Water Discharged by Depth

(millions of bbl)

Year Shelf

0-60 m

Shelf

60-200 m

Slope

200-400 m

Deepwater

400-800 m

Deepwater

800-1,600 m

UltraDeepwater

1,601-2,400 m

UltraDeepwater

>2,400 m

Total

2000 370.6 193.1 35.5 25.6 12.2 0.0 0.0 637.0

2001 364.2 185.2 35.0 32.0 16.6 0.0 0.0 633.0

2002 344.6 180.4 32.5 35.2 21.4 0.0 0.0 614.1

2003 359.4 182.9 31.2 39.0 35.5 0.2 0.0 648.2

2004 346.7 160.5 29.3 36.9 39.2 1.9 0.0 614.5

2005 270.1 113.5 23.1 33.5 43.0 5.8 0.0 489.0

2006 260.3 99.7 20.6 35.1 61.5 12.4 0.0 489.6

2007 307.0 139.4 22.2 40.0 70.3 15.5 0.1 594.5

2008 252.7 118.6 15.9 32.7 60.1 16.5 0.1 496.6

2009 263.9 108.3 19.9 39.2 65.3 25.0 0.1 521.7

2010 275.8 115.7 20.9 40.7 56.7 32.5 0.1 542.4

2011 271.3 116.9 20.5 39.7 67.7 32.2 0.1 548.4

2012 237.2 109.0 20.8 35.0 71.3 31.8 0.1 505.2

2013 242.0 103.0 19.9 31.8 75.4 35.3 0.3 507.7

Source: Langley, official communication, 2014.
Tables Tables-9

Table 3-8

Properties and Persistence by Oil Component Group

Properties and Persistence Light Weight Medium Weight Heavy Weight

Hydrocarbon Compounds Up to 10 carbon atoms 10-22 carbon atoms >20 carbon atoms

API o >31.1o 31.1o-22.3o <22.3o

Evaporation Rate Rapid (within 1 day) and complete Up to several days; not complete at 

ambient temperatures

Negligible

Solubility in Water High Low (at most a few mg/L) Negligible

Acute Toxicity High due to monoaromatic 

hydrocarbons (BTEX) 

Moderate due to diaromatic hydrocarbons 

(naphthalenes – 2 ring PAHs) 

Low, except due to smothering (i.e., 

heavier oils may sink)

Chronic Toxicity None, does not persist due to 

evaporation

PAH components components (e.g., 

naphthalenes – 2 ring PAHs)

PAH components (e.g., phenanthrene, 

anthracene – 3 ring PAHs)

Bioaccumulation Potential None, does not persist due to 

evaporation

Moderate Low, may bioaccumulate through 

sediment sorption

Compositional Majority Alkanes and cycloalkanes Alkanes that are readily degraded Waxes, asphaltenes, and polar 

compounds (not significantly 

bioavailable or toxic)

Persistence Low due to evaporation Alkanes readily degrade, but the 

diaromatic hydrocarbons are more 

persistent

High; very low degradation rates and 

can persist in sediments as tarballs or 

asphalt pavements

API = American Petroleum Institute

BTEX = benzene, toluene, ethylbenzene, and xylene 

mg/L = milligram per liter

PAH = polycyclic aromatic hydrocarbons

Sources: Michel, 1992; Canadian Center for Energy Information, 2010.
Tables-10 Central and Eastern Planning Areas Supplemental EIS

Table 4-1 

Unusual Mortality Event Cetacean Data for the Northern Gulf of Mexico

Cetaceans Stranded Phase of Oil-Spill Response Dates

114 cetaceans stranded Prior to the response phase for the 

oil spill

February 1, 2010-April 29, 2010

121 cetaceans stranded or 

were reported dead offshore

During the initial response phase to 

the oil spill

April 30, 2010-November 2, 2010

1,048 cetaceans stranded* After the initial response phase 

ended

November 3, 2010-November 16, 2014**

Note: Numbers are preliminary and may be subject to change. As of November 16, 2014, the unusual mortality 

event involves 1,283 cetacean “strandings” in the northern Gulf of Mexico (USDOC, NMFS, 2014a).

* This number includes 8 dolphins that were killed incidental to fish-related scientific data collection and

1 dolphin that was killed incidental to trawl relocation for a dredging project.

** The initial response phase ended for all four states on November 2, 2010. Response reopened for eastern and 

central Louisiana on December 3, 2010, and closed again on May 25, 2011.
Tables Tables-11

Table 4-2

Dead, Sick, or Injured Sea Turtles Documented in Florida during 2011 

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Nassau 

Caretta caretta 0 0 3 2 4 4 1 0 0 0 1 0 15

Chelonia mydas 0 0 0 0 0 1 0 0 0 0 0 0 1

Lepidochelys kempii 0 0 1 1 1 0 0 0 0 0 2 0 5

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 1 0 0 0 0 0 0 0 0 0 1

Totals 0 0 5 3 5 5 1 0 0 0 3 0 22

Duval

Caretta caretta 0 0 2 9 8 11 3 4 5 0 0 2 44

Chelonia mydas 1 0 0 2 3 0 0 0 3 2 3 2 16

Lepidochelys kempii 0 0 0 5 0 2 0 0 1 2 4 1 15

Eretmochelys imbricata 0 0 0 0 0 1 0 0 0 0 0 0 1

Dermochelys coriacea 1 0 0 0 0 0 0 0 0 0 0 0 1

Unidentified 0 0 0 0 0 1 0 0 0 0 0 0 1

Totals 2 0 2 16 11 15 3 4 9 4 7 5 78

St. John’s

Caretta caretta 0 0 4 13 13 15 3 1 0 3 3 8 63

Chelonia mydas 1 0 2 5 4 4 2 1 2 4 2 2 29

Lepidochelys kempii 0 0 2 3 0 0 0 0 1 0 0 2 8

Eretmochelys imbricata 0 0 2 0 0 0 0 0 0 0 0 0 2

Dermochelys coriacea 0 0 0 0 1 0 1 0 0 0 0 0 2

Unidentified 0 0 0 1 1 0 0 0 0 0 0 0 2

Totals 1 0 10 22 19 19 6 2 3 7 5 12 106

Flagler

Caretta caretta 0 0 2 4 1 0 0 1 1 0 0 0 9

Chelonia mydas 0 0 4 1 1 0 1 0 1 1 0 1 10

Lepidochelys kempii 0 0 0 0 1 1 0 0 0 0 0 0 2

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 2 0 2

Unidentified 0 0 1 0 1 0 1 0 0 0 0 0 3

Totals 0 0 7 5 4 1 2 1 2 1 2 1 26
Tables-12 Central and Eastern Planning Areas Supplemental EIS

Table 4-2. Dead,Sick,orInjuredSeaTurtlesDocumented in Florida during 2011 (continued).

County Species Jan FebMar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Volusia

Caretta caretta 131 20 10 15265248 15101

Chelonia mydas 133 21 1145423355 79

Lepidochelys kempii0011100000115

Eretmochelys imbricata0000000000000

Dermochelys coriacea0000000000101

Unidentified0000100010013

Totals 264 42 22 217 10767 15 22189

Brevard

Caretta caretta59 67 29 32 29 132 10177211

Chelonia mydas 21 34 55 26 22 10 1371455203

Lepidochelys kempii36 16300100101 31

Eretmochelys imbricata0010010000002

Dermochelys coriacea0200010000014

Unidentified0020001000003

Totals 29 51141 58 54 41 289 116 12 14454

Indian River

Caretta caretta23 13741701021 41

Chelonia mydas5 12 19 1098843 1043 95

Lepidochelys kempii0030000000003

Eretmochelys imbricata0000000000000

Dermochelys coriacea0000000000000

Unidentified0010000000001

Totals7 15 36 17 139 1544 1064140

St. Lucie

Caretta caretta029436420311 35

Chelonia mydas8 10 13944345435 72

Lepidochelys kempii0000000000000

Eretmochelys imbricata0000200000002

Dermochelys coriacea0000000000000

Unidentified0000000000000

Totals8 12 22 139 10765746109
Tables Tables-13

Table 4-2. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2011 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Martin

Caretta caretta 2 1 2 6 4 10 6 0 1 1 2 1 36

Chelonia mydas 4 6 2 5 5 6 4 5 2 5 3 0 47

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 1 0 1

Eretmochelys imbricata 1 0 0 1 0 0 0 0 0 0 0 0 2

Dermochelys coriacea 0 0 0 1 1 0 0 0 0 0 0 0 2

Unidentified 0 0 0 0 0 1 0 0 0 0 0 0 1

Totals 7 7 4 13 10 17 10 5 3 6 6 1 89

Palm Beach

Caretta caretta 1 3 2 4 5 4 4 4 1 3 4 2 37

Chelonia mydas 6 7 7 4 4 15 3 4 2 2 6 8 68

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 1 0 0 1

Eretmochelys imbricata 0 1 1 1 0 0 0 0 0 0 1 0 4

Dermochelys coriacea 0 0 1 0 0 0 0 0 1 0 1 1 4

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 7 11 11 9 9 19 7 8 4 6 12 11 114

Broward

Caretta caretta 1 2 3 3 1 0 2 1 0 3 1 0 17

Chelonia mydas 2 3 5 3 7 4 5 2 1 3 0 1 36

Lepidochelys kempii 0 0 2 0 0 0 0 0 0 0 1 0 3

Eretmochelys imbricata 0 0 0 0 0 0 0 2 0 0 0 0 2

Dermochelys coriacea 1 0 0 0 0 0 0 0 0 0 0 0 1

Unidentified 0 0 0 0 0 0 0 0 0 0 1 0 1

Totals 4 5 10 6 8 4 7 5 1 6 3 1 60

Dade

Caretta caretta 0 1 1 0 2 3 0 2 1 1 2 2 15

Chelonia mydas 1 9 2 0 3 2 0 0 0 6 3 1 27

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0

Eretmochelys imbricata 1 0 1 1 1 0 0 0 0 0 0 0 4

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 2 10 4 1 6 5 0 2 1 7 5 3 46
Tables-14 Central and Eastern Planning Areas Supplemental EIS

Table 4-2. Dead,Sick,orInjuredSeaTurtlesDocumented in Florida during 2011 (continued).

County Species Jan FebMar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Monroe

Caretta caretta347368 10 113525 67

Chelonia mydas776789666445 75

Lepidochelys kempii0001000000001

Eretmochelys imbricata0111000120006

Dermochelys coriacea0000000000000

Unidentified0000102000003

Totals 10 12 14 12 15 17 18 18 1196 10152

Collier

Caretta caretta104132231110 19

Chelonia mydas1431000000009

Lepidochelys kempii0011210000106

Eretmochelys imbricata0000000000000

Dermochelys coriacea0000000000000

Unidentified0000000000000

Totals248353231120 34

Lee

Caretta caretta002322351202 22

Chelonia mydas173201000201 17

Lepidochelys kempii010201102056 18

Eretmochelys imbricata0000000000000

Dermochelys coriacea0000000000000

Unidentified0000000000000

Totals185724453459 57

Charlotte

Caretta caretta0000023000106

Chelonia mydas1320000000107

Lepidochelys kempii0000000000000

Eretmochelys imbricata0000000000000

Dermochelys coriacea0000000000000

Unidentified0000000001001

Totals132002300120 14
Tables Tables-15

Table 4-2. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2011 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Sarasota

Caretta caretta 0 0 2 0 2 0 2 1 1 0 1 1 10

Chelonia mydas 1 8 3 3 1 0 0 1 0 0 0 1 18

Lepidochelys kempii 0 0 0 0 0 2 0 1 0 1 0 0 4

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 1 8 5 3 3 2 2 3 1 1 1 2 32

Manatee

Caretta caretta 0 0 1 1 0 1 2 2 0 0 0 0 7

Chelonia mydas 2 4 5 3 1 0 0 0 0 0 1 1 17

Lepidochelys kempii 0 0 0 1 0 0 0 0 0 0 0 1 2

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 2 4 6 5 1 1 2 2 0 0 1 2 26

Hillsborough

Caretta caretta 0 0 0 0 0 2 1 1 0 0 0 0 4

Chelonia mydas 0 0 0 0 0 0 0 0 0 0 0 0 0

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 0 0 0 0 0 2 1 1 0 0 0 0 4

Pinellas

Caretta caretta 0 2 2 3 5 1 3 5 1 0 1 1 24

Chelonia mydas 4 10 12 2 5 1 1 0 2 0 6 7 50

Lepidochelys kempii 0 2 2 4 2 0 3 0 1 3 1 0 18

Eretmochelys imbricata 0 0 1 0 0 0 0 0 0 0 0 0 1

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 1 0 0 1 0 0 0 0 0 0 2

Totals 4 14 18 9 12 3 7 5 4 3 8 8 95
Tables-16 Central and Eastern Planning Areas Supplemental EIS

Table 4-2. Dead,Sick,orInjuredSeaTurtlesDocumented in Florida during 2011 (continued).

County Species Jan FebMar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Pasco-Wakulla

Caretta caretta0000000100001

Chelonia mydas013211121111 15

Lepidochelys kempii0010210110006

Eretmochelys imbricata0000000000000

Dermochelys coriacea0001000000001

Unidentified0000000010001

Totals014332143111 24

Franklin

Caretta caretta101401111000 10

Chelonia mydas0130100000106

Lepidochelys kempii002212140000 12

Eretmochelys imbricata0010000000001

Dermochelys coriacea0000000000000

Unidentified0001001000002

Totals117723351010 31

Gulf

Caretta caretta0001020001004

Chelonia mydas275100001001 17

Lepidochelys kempii0500100100007

Eretmochelys imbricata0000000000000

Dermochelys coriacea0000000000000

Unidentified0000000000000

Totals2 125212011101 28

Bay

Caretta caretta012102132000 12

Chelonia mydas061211200010 14

Lepidochelys kempii002612101000 13

Eretmochelys imbricata0000000000000

Dermochelys coriacea0000000000000

Unidentified0012000000003

Totals076 1125433010 42
Tables Tables-17

Table 4-2. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2011 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Walton

Caretta caretta 0 0 0 1 0 0 0 0 1 0 1 0 3

Chelonia mydas 0 0 0 0 0 0 0 0 0 0 0 0 0

Lepidochelys kempii 0 1 0 2 1 0 0 0 0 1 1 0 6

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 1 1 0 0 0 0 1 0 0 0 3

Totals 0 1 1 4 1 0 0 0 2 1 2 0 12

Okaloosa

Caretta caretta 0 0 0 3 0 0 0 0 0 0 0 0 3

Chelonia mydas 2 0 2 0 2 0 0 0 0 0 0 0 6

Lepidochelys kempii 0 1 8 8 1 2 0 0 0 0 0 0 20

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 2 1 10 11 3 2 0 0 0 0 0 0 29

Santa Rosa

Caretta caretta 0 0 0 1 0 0 1 0 0 0 0 0 2

Chelonia mydas 0 0 2 0 0 0 0 0 0 0 0 0 2

Lepidochelys kempii 0 0 1 1 1 0 1 0 0 0 1 0 5

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 0 0 3 2 1 0 2 0 0 0 1 0 9

Escambia

Caretta caretta 0 0 1 4 0 1 0 1 1 1 0 0 9

Chelonia mydas 3 2 0 1 3 1 0 0 1 0 0 0 11

Lepidochelys kempii 1 1 2 2 2 0 1 0 1 0 0 0 10

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 4 3 3 7 5 2 1 1 3 1 0 0 30

Note: The data are organized by county, species, and month. Data used come from the State of Florida, Fish and Wildlife Conservation Commission, Fish

and Wildlife Research Institute, Sea Turtle Stranding and Salvage Network Data Base (December 31, 2012). 

Source: State of Florida, Fish and Wildlife Conservation Commission, 2014.
Tables-18 Central and Eastern Planning Areas Supplemental EIS

Table 4-3

Dead, Sick, or Injured Sea Turtles Documented in Florida during 2012

County Species Jan FebMar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Nassau

Caretta caretta015283130001 24

Chelonia mydas2012100000017

Lepidochelyskempii0111010000004

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals227594130002 35

Duval

Caretta caretta112881112020 27

Chelonia mydas121000010140 10

Lepidochelyskempii0200010001116

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000001000001

Totals253882222271 44

St. John’s 

Caretta caretta64 11755134230 51

Chelonia mydas136121125102 25

Lepidochelyskempii0201000001105

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000011000002

Totals79 17977359442 83
Tables Tables-19

Table 4-3. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2012 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Flagler

Caretta caretta 0 0 2 1 2 0 1 0 4 1 0 0 11

Chelonia mydas 1 2 2 0 1 1 0 2 2 0 1 0 12

Lepidochelys kempii 0 0 1 0 0 0 0 0 0 0 0 0 1

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 1 0 0 0 0 0 0 0 0 0 0 0 1

Totals 2 2 5 1 3 1 1 2 6 1 1 0 25

Volusia

Caretta caretta 3 6 15 8 1 2 0 4 2 3 0 2 46

Chelonia mydas 3 5 1 0 0 0 1 2 2 1 2 2 19

Lepidochelys kempii 0 2 0 0 0 0 0 0 0 0 0 1 3

Eretmochelys imbricata 0 1 0 0 0 0 0 0 0 0 0 0 1

Dermochelys coriacea 0 0 0 0 0 0 0 1 0 0 0 0 1

Unidentified 0 0 0 2 0 1 0 0 0 0 0 0 3

Totals 6 14 16 10 1 3 1 7 4 4 2 5 73

Brevard

Caretta caretta 8 10 17 25 19 11 10 13 7 4 1 3 128

Chelonia mydas 6 7 6 5 13 4 6 5 5 3 0 5 65

Lepidochelys kempii 0 0 1 0 0 0 0 1 0 0 0 0 2

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 14 17 24 30 32 15 16 19 12 7 1 8 195

Indian River

Caretta caretta 2 6 5 11 6 3 4 3 0 1 0 0 41

Chelonia mydas 3 3 5 6 1 5 4 7 10 6 2 1 53

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 5 9 10 17 7 8 8 10 10 7 2 1 94
Tables-20 Central and Eastern Planning Areas Supplemental EIS

Table 4-3. Dead,Sick,orInjuredSeaTurtlesDocumented in Florida during 2012 (continued).

County Species Jan FebMar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

St. Lucie

Caretta caretta431431212221 26

Chelonia mydas322253311164 33

Lepidochelyskempii0000000000000

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals753684523385 59

Martin

Caretta caretta023350410320 23

Chelonia mydas736632406352 47

Lepidochelyskempii0000000000000

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0001110000003

Unidentified0000010000102

Totals759 1094816682 75

Palm Beach

Caretta caretta142147623121 34

Chelonia mydas53265 10342744 55

Lepidochelyskempii0000000000000

Eretmochelysimbricata0110000000002

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals68579 17965865 91

Broward

Caretta caretta001214110101 12

Chelonia mydas241362654301 37

Lepidochelyskempii0000000000000

Eretmochelysimbricata0110000000013

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals253576764403 52
Tables Tables-21

Table 4-3. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2012 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Dade

Caretta caretta 1 1 2 0 1 1 2 0 2 2 0 3 15

Chelonia mydas 5 1 4 2 2 3 1 5 2 1 2 5 33

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0

Eretmochelys imbricata 0 1 2 0 0 0 0 1 0 0 0 0 4

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 6 3 8 2 3 4 3 6 4 3 2 8 52

Monroe

Caretta caretta 6 0 4 9 9 9 3 10 2 2 2 2 58

Chelonia mydas 14 5 4 16 11 11 10 5 3 3 12 13 107

Lepidochelys kempii 0 0 0 0 0 0 1 0 0 0 1 0 2

Eretmochelys imbricata 0 0 0 0 1 0 0 0 0 0 0 0 1

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 1 0 0 1 0 0 0 0 0 0 0 2

Totals 20 6 8 25 22 20 14 15 5 5 15 15 170

Collier

Caretta caretta 1 1 1 3 3 0 1 4 0 1 0 0 15

Chelonia mydas 0 1 0 1 1 1 0 0 0 0 0 0 4

Lepidochelys kempii 2 0 5 0 2 0 1 0 2 2 1 0 15

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 3 2 6 4 6 1 2 4 2 3 1 0 34

Lee

Caretta caretta 1 2 2 4 6 0 5 4 2 3 0 1 30

Chelonia mydas 0 1 0 2 1 1 3 2 0 2 4 4 20

Lepidochelys kempii 6 0 0 3 1 2 3 1 2 11 3 2 34

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 1 0 0 1

Totals 7 3 2 9 8 3 11 7 4 17 7 7 85
Tables-22 Central and Eastern Planning Areas Supplemental EIS

Table 4-3. Dead,Sick,orInjuredSeaTurtlesDocumented in Florida during 2012 (continued).

County Species Jan FebMar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Charlotte

Caretta caretta0210301100008

Chelonia mydas0001001001003

Lepidochelyskempii0002100010015

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals021340211101 16

Sarasota

Caretta caretta1011301020009

Chelonia mydas0001110001004

Lepidochelyskempii1000012100005

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0100000000001

Totals211242312100 19

Manatee

Caretta caretta1102200110019

Chelonia mydas0010121000005

Lepidochelyskempii0010100000125

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals112242111013 19

Hillsborough

Caretta caretta1000000001002

Chelonia mydas0100000000001

Lepidochelyskempii0000101000002

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals1100101001005
Tables Tables-23

Table 4-3. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2012 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Pinellas

Caretta caretta 3 1 1 4 5 7 3 5 0 1 1 0 31

Chelonia mydas 6 6 2 1 6 0 1 1 0 4 15 9 51

Lepidochelys kempii 0 0 2 2 3 3 0 1 2 4 0 5 22

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 1 1

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 9 7 5 7 14 10 4 7 2 9 16 15 105

Pasco‐Wakulla

Caretta caretta 0 0 0 1 1 0 1 0 0 0 0 0 3

Chelonia mydas 0 1 0 0 0 1 3 3 1 1 2 0 12

Lepidochelys kempii 0 0 0 0 0 1 2 1 1 0 0 0 5

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 1 0 0 0 0 0 0 0 0 0 0 1

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 0 2 0 1 1 2 6 4 2 1 2 0 21

Franklin

Caretta caretta 0 0 3 0 3 0 1 0 0 0 0 1 8

Chelonia mydas 0 0 0 0 0 1 0 0 1 0 0 0 2

Lepidochelys kempii 2 0 0 0 1 0 0 0 0 0 0 0 3

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 1 0 0 0 0 0 0 0 1

Totals 2 0 3 0 5 1 1 0 1 0 0 1 14

Gulf

Caretta caretta 1 0 0 0 0 1 0 0 0 0 0 0 2

Chelonia mydas 1 0 0 0 0 1 0 0 0 2 0 1 5

Lepidochelys kempii 0 0 0 1 0 0 1 0 1 0 0 0 3

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0

Totals 2 0 0 1 0 2 1 0 1 2 0 1 10
Tables-24 Central and Eastern Planning Areas Supplemental EIS

Table 4-3. Dead,Sick,orInjuredSeaTurtlesDocumented in Florida during 2012 (continued).

County Species Jan FebMar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Bay

Caretta caretta0011001300017

Chelonia mydas0013000000004

Lepidochelyskempii102211020200 11

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals104611150201 22

Walton

Caretta caretta1012000000004

Chelonia mydas1000000000102

Lepidochelyskempii024100010004 12

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals225300010014 18

Okaloosa

Caretta caretta0000100000001

Chelonia mydas0130211000008

Lepidochelyskempii1112210000109

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0000000000000

Totals124252100010 18

Santa Rosa 

Caretta caretta0001100001003

Chelonia mydas0000000000101

Lepidochelyskempii0000003001105

Eretmochelysimbricata0000000000000

Dermochelyscoriacea0000000000000

Unidentified0001000000001

Totals000210300220 10
Tables Tables-25

Table 4-3. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2012 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Escambia

Caretta caretta 1 0 0 1 0 0 0 1 0 0 0 1 4

Chelonia mydas 0 0 0 0 2 0 2 1 0 1 0 0 6

Lepidochelys kempii 2 0 2 0 1 1 0 0 1 0 1 0 8

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0

Unidentified 0 0 0 0 1 0 0 0 0 0 0 0 1

Totals 3 0 2 1 4 1 2 2 1 1 1 1 19

Note: The data are organized by county, species, and month. Data used come from the State of Florida, Fish and Wildlife Conservation Commission, Fish

and Wildlife Research Institute, Sea Turtle Stranding and Salvage Network Data Base (December 31, 2012).

Source: State of Florida, Fish and Wildlife Conservation Commission, 2014.
Tables-26 Central and Eastern Planning Areas Supplemental EIS

Table 4-4

Dead, Sick, or Injured Sea Turtles Documented in Florida during 2013

County Species Jan Feb Mar Apr May Jun JulAug Sep OctNov Dec Totals

Nassau 

Caretta caretta 0 0 2 5 8 3 4 3 1 1 0 0 27 Chelonia mydas 1 0 5 0 2 0 2 1 0 1 3 1 16

Lepidochelys kempii 0 0 0 3 0 0 0 0 0 0 0 0 3 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 1 0 7 8 10 3 6 4 1 2 3 1 46

Duval

Caretta caretta 0 0 2 8 5 5 3 3 0 2 0 0 28 Chelonia mydas 1 3 6 14 4 1 0 2 1 1 0 4 37

Lepidochelys kempii 0 2 0 2 3 0 0 1 0 0 1 0 9 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 1 0 0 0 0 0 0 0 1 Totals 1 5 8 24 13 6 3 6 1 3 1 4 75

St. John’s

Caretta caretta 2 5 3 10 10 1 4 3 2 1 0 0 41 Chelonia mydas 5 1 10 22 7 0 3 3 2 1 6 6 66

Lepidochelys kempii 0 0 1 4 3 1 0 0 0 0 3 1 13

Eretmochelys imbricata 0 0 0 0 0 1 0 0 0 0 0 0 1 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 1 1 2 

Unidentified 0 0 0 0 0 0 0 0 0 0 1 0 1 Totals 7 6 14 36 20 3 7 6 4 2 11 8 124
Tables Tables-27

Table 4-4. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Flagler

Caretta caretta 0 1 1 3 3 0 1 3 0 0 0 0 12

Chelonia mydas 0 0 0 10 5 2 0 0 0 1 0 1 19

Lepidochelys kempii 0 0 1 0 0 0 1 0 1 0 1 0 4 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 

Totals 0 1 2 13 8 2 2 3 1 1 1 1 35

Volusia

Caretta caretta 6 5 9 28 20 4 9 4 3 1 1 14 104

Chelonia mydas 8 10 4 14 12 2 3 0 0 5 5 5 68

Lepidochelys kempii 1 1 1 3 3 0 0 0 0 0 2 0 11

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 1 0 0 0 0 1 1 0 0 0 0 0 3 

Totals 16 16 14 45 35 7 13 4 3 6 8 19 186

Brevard

Caretta caretta 14 14 10 37 39 18 18 16 6 3 3 6 184

Chelonia mydas 5 11 5 6 3 8 4 8 3 4 4 9 70

Lepidochelys kempii 2 2 0 0 0 0 0 0 0 0 0 0 4 

Eretmochelys imbricata 0 0 0 0 1 0 0 0 0 0 0 0 1 

Dermochelys coriacea 0 0 0 0 0 1 0 0 0 0 1 0 2 

Unidentified 1 0 1 0 1 0 0 0 0 0 0 0 3 

Totals 22 27 16 43 44 27 22 24 9 7 8 15 264
Tables-28 Central and Eastern Planning Areas Supplemental EIS

Table 4-4. Dead, Sick, or 

Injured

Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun JulAug Sep OctNov Dec Totals

Indian River

Caretta caretta 1 3 5 10 5 5 5 2 0 4 2 1 43 Chelonia mydas 1 3 8 5 6 1 7 7 2 6 1 3 50

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 2 6 13 15 11 6 12 9 2 10 3 4 93

St. Lucie

Caretta caretta 1 2 4 5 7 2 5 0 0 4 0 0 30 Chelonia mydas 6 2 2 3 3 2 4 3 3 1 4 2 35

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0 

Eretmochelys imbricata 0 1 0 0 0 0 0 0 0 0 0 0 1 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 7 5 6 8 10 4 9 3 3 5 4 2 66

Martin

Caretta caretta 1 2 3 3 2 3 1 2 1 4 6 0 28 Chelonia mydas 5 2 8 2 1 4 5 2 1 2 2 4 38

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0 

Eretmochelys imbricata 0 0 0 0 0 1 0 0 0 0 0 0 1 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 6 4 11 5 3 8 6 4 2 6 8 4 67
Tables Tables-29

Table 4-4. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Palm Beach* 

Caretta caretta 3 1 3 1 2 2 2 4 2 2 1 1 24

Chelonia mydas 5 5 2 8 6 8 2 6 6 3 6 4 61

Lepidochelys kempii 0 0 0 0 1 0 0 0 0 0 0 0 1 

Eretmochelys imbricata 0 0 0 5 0 0 0 0 0 0 1 0 6 

Dermochelys coriacea 0 1 0 0 0 0 0 0 0 0 0 0 1 

Unidentified 0 0 0 1 0 0 0 0 0 0 1 0 2 

Totals 8 7 5 15 9 10 4 10 8 5 9 6 96

Broward

Caretta caretta 1 0 2 2 1 1 2 2 4 2 2 1 20

Chelonia mydas 3 1 1 2 8 6 3 0 11 4 4 4 47

Lepidochelys kempii 0 0 0 1 0 0 0 0 0 1 0 0 2 

Eretmochelys imbricata 0 0 1 3 4 0 1 1 0 1 0 0 11

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 

Totals 4 1 4 8 13 7 6 3 15 8 6 5 80

Dade

Caretta caretta 1 1 2 3 1 1 2 1 2 0 2 2 18

Chelonia mydas 6 0 1 4 1 1 0 2 2 4 2 2 25

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 1 0 0 0 1 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 

Totals 7 1 3 7 2 2 2 3 5 4 4 4 44
Tables-30 Central and Eastern Planning Areas Supplemental EIS

Table 4-4. Dead, Sick, or 

Injured

Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun JulAug Sep OctNov Dec Totals

Monroe 

Caretta caretta 4 2 7 3 5 6 10 7 1 2 2 0 49 Chelonia mydas 6 13 14 7 10 13 5 14 8 9 19 12 130

Lepidochelys kempii 0 1 1 1 0 0 0 0 0 0 0 0 3 

Eretmochelys imbricata 0 0 0 0 1 3 0 0 0 1 1 0 6 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 1 0 0 0 0 0 0 0 0 0 0 1 Totals 10 17 22 11 16 22 15 21 9 12 22 12 189

Collier

Caretta caretta 0 3 1 2 1 0 2 1 0 1 0 0 11 Chelonia mydas 0 0 1 2 2 0 0 0 0 0 0 0 5 

Lepidochelys kempii 4 5 2 1 1 0 1 1 0 0 0 0 15

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 4 8 4 5 4 0 3 2 0 1 0 0 31

Lee

Caretta caretta 0 3 3 8 10 4 2 3 1 0 1 1 36 Chelonia mydas 1 4 4 3 1 3 0 0 3 2 4 1 26

Lepidochelys kempii 5 9 5 1 3 1 2 4 2 0 3 0 35

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 6 16 12 12 14 8 4 7 6 2 8 2 97
Tables Tables-31

Table 4-4. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Charlotte

Caretta caretta 0 1 3 1 1 1 1 1 0 0 0 0 9 

Chelonia mydas 0 0 0 0 0 0 1 0 0 0 0 0 1 

Lepidochelys kempii 0 3 1 0 0 0 0 0 0 0 0 0 4 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 1 0 0 0 0 0 0 1 

Totals 0 4 4 1 1 2 2 1 0 0 0 0 15

Sarasota

Caretta caretta 0 2 1 1 2 0 1 1 2 0 2 2 14

Chelonia mydas 0 1 0 1 2 0 0 2 2 0 1 1 10

Lepidochelys kempii 2 0 0 1 0 0 1 0 0 1 0 0 5 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 1 0 0 0 0 0 0 0 0 1 

Totals 2 3 1 4 4 0 2 3 4 1 3 3 30

Manatee

Caretta caretta 0 0 2 1 0 0 0 2 2 0 0 0 7 

Chelonia mydas 1 0 0 0 1 0 1 1 0 0 0 0 4 

Lepidochelys kempii 0 0 1 0 0 2 0 0 0 0 0 0 3 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 1 0 0 1 

Totals 1 0 3 1 1 2 1 3 2 1 0 0 15
Tables-32 Central and Eastern Planning Areas Supplemental EIS

Table 4-4. Dead, Sick, or 

Injured

Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun JulAug Sep OctNov Dec Totals

Hillsborough 

Caretta caretta 0 0 1 0 0 0 0 0 1 0 0 0 2 Chelonia mydas 0 0 0 0 0 0 0 0 0 0 0 0 0 

Lepidochelys kempii 0 0 0 0 0 0 0 0 0 0 0 0 0 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 0 0 1 0 0 0 0 0 1 0 0 0 2 

Pinellas

Caretta caretta 1 1 1 3 2 4 2 4 5 0 2 1 26 Chelonia mydas 5 8 14 5 1 3 3 2 2 6 2 5 56

Lepidochelys kempii 2 2 6 3 5 7 3 3 1 2 1 1 36

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 1 0 1 0 0 0 2 Totals 8 11 21 11 8 14 9 9 9 8 5 7 120

Pasco-Wakulla

Caretta caretta 0 0 1 0 0 0 1 0 1 0 1 0 4 Chelonia mydas 1 0 1 2 0 0 0 2 0 1 0 0 7 

Lepidochelys kempii 0 0 0 1 1 0 1 0 1 1 0 0 5 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 1 0 2 3 1 0 2 2 2 2 1 0 16
Tables Tables-33

Table 4-4. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Franklin

Caretta caretta 0 0 1 2 3 0 2 0 0 0 1 0 9 

Chelonia mydas 0 0 1 0 2 0 0 0 0 0 0 1 4 

Lepidochelys kempii 0 0 1 0 4 1 1 1 0 0 2 1 11

Eretmochelys imbricata 0 0 0 1 1 0 0 0 0 0 0 0 2 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 1 0 0 1 0 0 0 2 

Totals 0 0 3 3 10 2 3 1 1 0 3 2 28

Gulf 

Caretta caretta 0 1 0 2 3 4 0 0 0 0 0 0 10

Chelonia mydas 0 0 0 0 0 0 0 0 0 0 0 0 0 

Lepidochelys kempii 0 0 0 0 1 2 0 0 0 0 0 0 3 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 1 0 0 0 0 0 0 0 1 

Totals 0 1 0 2 5 6 0 0 0 0 0 0 14

Bay

Caretta caretta 0 0 1 1 2 4 0 2 1 1 0 0 12

Chelonia mydas 0 0 0 0 0 1 0 0 1 1 0 0 3 

Lepidochelys kempii 0 1 0 0 6 6 1 1 1 0 1 0 17

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 

Totals 0 1 1 1 8 11 1 3 3 2 1 0 32
Tables-34 Central and Eastern Planning Areas Supplemental EIS

Table 4-4. Dead, Sick, or 

Injured

Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun JulAug Sep OctNov Dec Totals

Walton 

Caretta caretta 0 0 1 0 1 2 1 0 0 0 0 0 5 Chelonia mydas 0 0 0 0 0 1 0 0 0 0 0 0 1 

Lepidochelys kempii 0 0 0 2 0 0 0 0 1 1 0 0 4 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 0 0 1 2 1 3 1 0 1 1 0 0 10

Okaloosa 

Caretta caretta 0 0 0 0 0 0 0 0 1 0 1 0 2 Chelonia mydas 0 0 0 0 1 0 2 1 1 0 1 0 6 

Lepidochelys kempii 0 0 1 1 1 0 2 1 0 0 0 0 6 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 1 0 0 0 0 0 0 0 0 1 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 0 0 1 2 2 0 4 2 2 0 2 0 15

Santa Rosa 

Caretta caretta 1 0 0 0 0 0 2 0 1 0 0 0 4 Chelonia mydas 0 0 0 0 1 0 0 0 1 0 0 0 2 

Lepidochelys kempii 0 0 1 2 1 2 0 0 0 2 0 0 8 

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 0 0 0 0 0 0 0 0 0 0 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 Totals 1 0 1 2 2 2 2 0 2 2 0 0 14
Tables Tables-35

Table 4-4. Dead, Sick, or Injured Sea Turtles Documented in Florida during 2013 (continued).

County Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Totals

Escambia

Caretta caretta 0 0 0 1 0 0 0 1 0 0 0 1 3 

Chelonia mydas 0 0 0 1 0 1 1 0 0 0 0 0 3 

Lepidochelys kempii 2 0 0 7 7 2 1 0 1 0 0 0 20

Eretmochelys imbricata 0 0 0 0 0 0 0 0 0 0 0 0 0 

Dermochelys coriacea 0 0 0 1 0 0 0 0 0 0 0 0 1 

Unidentified 0 0 0 0 0 0 0 0 0 0 0 0 0 

Totals 2 0 0 10 7 3 2 1 1 0 0 1 27

Note: The data are organized by county, species, and month. Data used come from the State of Florida, Fish and Wildlife Conservation Commission, Fish

and Wildlife Research Institute, Sea Turtle Stranding and Salvage Network Data Base (April 29, 2014). 

*There was one olive ridley (Lepidochelys olivacea) found in Palm Beach County during December.

Source: State of Florida, Fish and Wildlife Conservation Commission, 2014.
Tables-36 Central and Eastern Planning Areas Supplemental EIS

Table 4-5

Angler Trips in the Gulf of Mexico by Location and Mode from 2008 through 2013 

State Area 2008 2009 2010 2011 2012 2013 % State Total 

in 2013

Alabama Shore Ocean (<3 nmi) 249,893 322,126 447,041 603,546 750,159 1,250,811 43.70%

Shore Inland 452,192 449,470 365,234 598,700 461,221 515,982 18.03%

Charter Ocean (<3 nmi) 9,967 9,166 8,860 19,874 15,785 20,615 0.72%

Charter Ocean (>3 nmi) 38,046 36,259 17,424 48,616 28,340 56,145 1.96%

Charter Inland 7,700 10,656 7,221 6,351 14,536 12,976 0.45%

Private/Rental Ocean (<3 nmi) 247,876 131,997 114,816 191,563 137,321 118,801 4.15%

Private/Rental Ocean (>3 nmi) 74,074 134,411 69,335 188,994 131,897 278,821 9.74%

Private/Rental Inland 624,197 618,502 656,226 825,821 766,027 608,280 21.25%

Total 1,703,945 1,712,587 1,686,157 2,483,465 2,305,286 2,862,431

West Florida Shore Ocean (<9 nmi) 3,076,591 2,688,011 1,610,807 1,982,194 2,199,810 3,745,909 23.49%

Shore Inland 3,704,990 3,793,756 4,034,208 3,862,665 4,016,544 3,191,141 20.01%

Charter Ocean (<9 nmi) 187,810 196,753 159,317 179,880 242,666 199,908 1.25%

Charter Ocean (>9 nmi) 255,300 262,005 203,201 236,088 307,121 322,185 2.02%

Charter Inland 127,801 113,842 98,440 119,826 149,315 161,479 1.01%

Private/Rental Ocean (<9 nmi) 3,624,073 2,605,196 2,257,349 1,901,217 2,087,991 2,572,325 16.13%

Private/Rental Ocean (>9 nmi) 1,242,935 751,869 681,551 500,067 755,470 1,136,161 7.12%

Private/Rental Inland 5,277,665 5,265,888 5,221,323 5,118,740 5,021,267 4,619,920 28.97%

Total 17,497,165 15,677,320 14,266,196 13,900,677 14,780,184 15,949,028

Louisiana Shore Ocean (<3 nmi) 62,712 38,930 11,664 48,893 152,094 247,502 5.31%

Shore Inland 870,042 730,053 717,006 1,073,035 978,657 1,101,517 23.63%

Charter Ocean (<3 nmi) 10,468 3,931 2,762 6,937 3,646 5,058 0.11%

Charter Ocean (>3 nmi) 32,805 21,173 8,106 15,742 19,827 15,373 0.33%

Charter Inland 135,915 157,692 68,018 90,057 91,192 101,935 2.19%

Private/Rental Ocean (<3 nmi) 97,797 81,008 59,347 77,986 116,854 82,512 1.77%

Private/Rental Ocean (>3 nmi) 89,859 99,352 11,568 80,952 88,503 65,730 1.41%

Private/Rental Inland 3,320,459 2,995,875 2,984,016 3,182,645 2,685,791 3,041,527 65.25%

Total 4,620,057 4,128,014 3,862,487 4,576,247 4,136,564 4,661,154
Tables Tables-37

Table 4-5. Angler Trips in the Gulf of Mexico by Location and Mode from 2008 through 2013 (continued).

State Area 2008 2009 2010 2011 2012 2013 % State Total 

in 2013

Mississippi Shore Ocean (<3 nmi) 0 143 0 0 811 0 0.00%

Shore Inland 359,438 309,612 596,544 760,788 947,075 763,983 43.39%

Charter Ocean (<3 nmi) 4,286 2,803 904 3,123 1,628 2,190 0.12%

Charter Ocean (>3 nmi) 718 330 949 221 125 153 0.01%

Charter Inland 8,229 7,656 4,989 7,891 9,738 8,911 0.51%

Private/Rental Ocean (<3 nmi) 12,056 16,962 12,419 18,682 4,116 6,124 0.35%

Private/Rental Ocean (>3 nmi) 28,007 26,316 4,626 12,974 41,137 53,886 3.06%

Private/Rental Inland 555,951 715,505 612,162 811,711 945,819 925,512 52.56%

Total 968,685 1,079,327 1,232,593 1,615,390 1,950,449 1,760,759

Gulf Total Shore Ocean (<3 nmi) 3,389,196 3,049,210 2,069,512 2,634,633 3,102,874 5,244,222 20.78%

Shore Inland 5,386,662 5,282,891 5,712,992 6,295,188 6,403,497 5,572,623 22.09%

Charter Ocean (<3 nmi) 212,531 212,653 171,843 209,814 263,725 227,771 0.90%

Charter Ocean (>3 nmi) 326,869 319,767 229,680 300,667 355,413 393,856 1.56%

Charter Inland 279,645 289,846 178,668 224,125 264,781 285,301 1.13%

Private/Rental Ocean (<3 nmi) 3,981,802 2,835,163 2,443,931 2,189,448 2,346,282 2,779,762 11.02%

Private/Rental Ocean (>3 nmi) 1,434,875 1,011,948 767,080 782,987 1,017,007 1,534,598 6.08%

Private/Rental Inland 9,778,272 9,595,770 9,473,727 9,938,917 9,418,904 9,195,239 36.44%

Total 24,789,852 22,597,248 21,047,433 22,575,779 23,172,483 25,233,372

Notes: This table presents the sum of fishing data from Louisiana, Mississippi, Alabama, and West Florida.

State waters in Florida extend 9 nmi from the coast rather than the typical 3 nmi.

Source: USDOC, NMFS, 2014b.
Tables-38 Central and Eastern Planning Areas Supplemental EIS

Table 4-6

Fish Species Caught by Recreational Anglers from 2008 through 2013

Species 2008 2009 2010 2011 2012 2013

Panel A: Number of Fish Caught in Louisiana, Mississippi, and Alabama Combined

Atlantic Croaker 4,648,460 4,696,500 4,907,698 7,461,690 4,757,605 4,562,458

Black Drum 1,819,040 1,645,416 1,544,695 1,768,605 1,629,633 2,472,942

Blackfin Tuna 57,274 59,046 1,793 33,008 64,007 35,705

Cobia 31,484 21,575 3,519 50,263 25,105 40,448

Dolphins 96,899 7,200 2,174 911 9,418 31,524

Gag 45,383 42,835 10,274 13,523 12,939 20,573

Gray Snapper 233,841 255,943 33,479 142,062 451,724 375,596

Great Amberjack 29,728 28,422 16,982 56,163 15,962 30,410

King Mackerel 35,373 82,508 38,069 70,898 124,839 124,211

Little Tuny 18,529 9,520 14,175 28,660 40,005 17,172

Pinfishes 474,606 454,356 521,732 1,460,956 1,101,630 1,227,257

Red Drum 7,292,431 6,467,215 7,486,800 6,809,940 6,305,267 9,009,223

Red Grouper 12 774 2,296 0 168 2,326

Red Snapper 905,870 894,732 368,901 851,662 607,516 1,743,402

Sand Seatrout 4,052,323 5,294,998 5,715,702 7,115,540 5,194,418 3,768,286

Sheepshead 1,643,546 1,422,352 1,183,531 1,966,957 1,163,684 1,334,601

Southern Flounder 557,809 825,776 982,237 964,675 1,016,969 1,320,715

Southern Kingfish 1,350,161 1,190,382 1,045,644 1,075,935 760,688 1,180,114

Spanish Mackerel 196,011 200,662 397,247 541,435 844,101 2,525,453

Spotted Seatrout 24,013,172 21,657,958 15,118,683 19,843,879 20,452,196 22,327,595

Striped Mullet 322,245 293,375 866,308 1,412,632 1,163,763 1,623,070

White Grunt 0 1,084 0 0 0 0

Panel B: Number of Fish Caught in West Florida

Atlantic Croaker 372,271 333,201 429,614 488,456 468,451 437,425

Black Drum 156,391 125,064 218,938 115,842 112,817 219,579

Blackfin Tuna 80,613 25,933 30,354 20,821 44,190 56,765

Cobia 128,670 64,532 58,880 59,124 69,045 71,391

Dolphins 543,588 394,692 267,944 455,918 359,146 1,922,167

Gag 4,511,351 2,926,723 2,250,467 1,255,515 1,112,826 1,382,809

Gray Snapper 7,082,879 4,190,312 2,418,388 2,658,705 4,073,840 6,618,012

Great Amberjack 219,182 183,807 365,690 194,791 151,623 327,080

King Mackerel 338,965 591,022 252,995 173,914 242,302 291,727

Little Tuny 185,031 158,836 126,299 173,102 296,492 157,557

Pinfishes 15,637,922 9,422,451 9,893,857 7,390,804 12,258,510 9,675,256

Red Drum 3,017,880 1,665,659 2,231,738 3,182,220 2,713,322 2,560,823

Red Grouper 3,105,147 3,171,464 2,240,450 2,009,532 2,009,920 3,166,786
Tables Tables-39

Table 4-6. Fish Species Caught by Recreational Anglers from 2008 through 2013 (continued). 

Species 2008 2009 2010 2011 2012 2013

Panel B: Number of Fish Caught in West Florida (continued)

Red Snapper 1,883,804 2,046,716 1,400,636 1,189,850 1,408,331 2,322,435

Sand Seatrout 1,282,681 1,337,450 613,338 1,152,573 2,157,703 899,277

Sheepshead 1,412,235 1,489,548 1,700,583 1,882,258 1,805,203 1,608,128

Southern Flounder 37,117 11,332 9,522 23,120 33,346 28,887

Southern Kingfish 240,040 227,140 404,764 87,367 74,894 93,384

Spanish Mackerel 3,742,003 2,938,091 3,643,511 2,934,531 2,434,336 4,986,910

Spotted Seatrout 11,127,967 9,042,259 9,584,787 12,856,960 12,545,581 9,165,609

Striped Mullet 1,083,471 674,022 925,554 801,743 1,395,641 1,555,565

White Grunt 3,721,050 2,283,923 2,494,075 2,852,807 3,405,536 4,701,436

Source: USDOC, NMFS, 2014c.

Table 4-7

Economic Impact of Recreational Fishing in the Gulf of Mexico in 2012 

Expenditures

(thousand $)

Sales

(thousand $)

Value Added

(thousand $) Employment

Alabama 719,416 691,547 425,328 7,501

West Florida 6,228,719 9,142,920 5,259,726 75,268

Mississippi 177,755 143,890 85,497 1,649

Louisiana 1,790,653 1,964,494 1,099,216 16,972

Texas 1,455,623 1,719,709 1,005,040 13,944

Total 10,372,166 13,662,560 7,874,807 115,334

Source: USDOC, NMFS, 2014d.
Tables-40 Central and Eastern Planning Areas Supplemental EIS

Table 4-8

Employment in the Leisure/Hospitality Industry in Selected Geographic Regions

Region 2008 2009 2010 2011 2012 2013

Panel A: Economic Impact Area (EIA)

TX-1 54,551 53,772 54,750 56,753 60,670 62,260

TX-2 16,883 16,718 16,934 18,197 19,915 20,384

TX-3 240,231 240,425 244,821 253,071 267,390 280,953

LA-1 14,295 14,214 13,979 14,489 14,635 14,693

LA-2 21,364 20,675 20,618 21,345 22,137 23,054

LA-3 46,037 44,414 44,796 47,121 48,930 50,014

LA-4 68,605 68,161 72,757 76,552 78,978 80,842

MS-1 27,702 26,904 26,981 27,826 28,409 29,064

AL-1 26,516 25,872 26,925 27,300 28,307 29,867

FL-1 40,001 41,002 42,550 45,160 46,720 48,519

FL-2 22,502 21,689 22,111 22,466 23,579 24,424

FL-3 146,368 142,302 145,324 148,103 158,030 166,107

FL-4 283,359 279,839 289,247 304,093 319,912 333,866

TX EIA Total 311,665 310,915 316,505 328,021 347,975 363,597

LA EIA Total 150,301 147,464 152,150 159,507 164,680 168,603

MS EIA Total 27,702 26,904 26,981 27,826 28,409 29,064

AL EIA Total 26,516 25,872 26,925 27,300 28,307 29,867

FL EIA Total 492,230 484,832 499,232 519,822 548,241 572,916

EIA Total 1,008,414 995,987 1,021,793 1,062,476 1,117,612 1,164,047

Panel B: Coastal

TX 67,087 67,818 68,260 71,041 75,895 77,772

LA 45,545 45,418 49,432 51,742 53,802 55,479

MS 25,575 25,055 25,186 25,900 26,353 27,015

AL 24,319 23,825 24,816 25,145 25,941 27,354

FL 386,892 383,959 396,485 415,379 437,509 454,677

Coastal Total 549,418 546,075 564,179 589,207 619,500 642,297

Panel C: Statewide

TX 995,445 982,840 1,006,277 1,039,839 1,094,916 1,137,190

LA 194,905 190,589 194,387 202,704 208,284 213,627

MS 121,033 115,868 116,204 117,874 120,472 123,294

AL 168,413 165,953 165,230 166,671 170,854 176,078

FL 922,534 896,383 929,448 962,616 1,011,874 1,050,263

State Total 2,402,330 2,351,633 2,411,546 2,489,704 2,606,400 2,700,452

Notes: (1) The EIAs are defined in Figure 4-20 of the 2012-2017 WPA/CPA Multisale EIS.

 (2) The “Coastal” category refers to the counties/parishes within the EIAs that are directly along the coast 

of the U.S.

 (3) The “Statewide” category refers to the number of employees within the borders of the entire state.

 (4) The leisure/hospitality industry is defined according to the North American Industrial Classification 

System (NAICS). 

 (5) The employment figure for any given year corresponds to the total number of employees in December 

of that year.

 (6) Data for 2013 are preliminary.

Source: U.S. Dept. of Labor, Bureau of Labor Statistics, 2014.
Tables Tables-41

Table 4-9

Baseline Population Projections (in thousands) by Economic Impact Area

Calendar

Year TX-1 TX-2 TX-3 LA-1 LA-2 LA-3 LA-4 MS-1 AL-1 FL-1 FL-2 FL-3 FL-4 Total

2010 1,799.29 626.91 6,202.21 346.02 585.06 1,142.41 1,242.69 482.30 725.87 882.80 659.96 3,626.40 6,170.12 24,492.03

2011 1,827.28 633.41 6,309.03 346.51 588.41 1,147.53 1,260.01 486.36 727.78 889.79 661.80 3,663.94 6,273.04 24,814.88

2012 1,856.04 642.00 6,421.63 349.98 596.10 1,162.47 1,267.26 490.07 734.42 900.02 669.64 3,716.36 6,352.84 25,158.82

2013 1,885.42 650.77 6,536.83 353.51 603.94 1,177.70 1,274.66 493.86 741.19 910.45 677.64 3,769.85 6,434.20 25,510.00

2014 1,915.39 659.71 6,654.44 357.09 611.91 1,193.18 1,282.17 497.70 748.05 921.04 685.77 3,824.28 6,516.92 25,867.66

2015 1,945.76 668.77 6,773.88 360.70 619.95 1,208.79 1,289.69 501.55 754.94 931.71 693.97 3,879.31 6,600.40 26,229.40

2016 1,976.53 677.92 6,895.11 364.32 628.07 1,224.52 1,297.18 505.40 761.85 942.45 702.22 3,934.90 6,684.57 26,595.04

2017 2,007.70 687.19 7,018.20 367.96 636.25 1,240.39 1,304.67 509.25 768.79 953.27 710.54 3,991.09 6,769.48 26,964.77

2018 2,039.30 696.57 7,143.18 371.61 644.52 1,256.39 1,312.15 513.12 775.75 964.17 718.93 4,047.88 6,855.15 27,338.71

2019 2,071.28 706.06 7,269.96 375.28 652.85 1,272.50 1,319.60 516.98 782.72 975.13 727.37 4,105.22 6,941.47 27,716.42

2020 2,103.58 715.61 7,398.25 378.95 661.22 1,288.68 1,326.97 520.81 789.68 986.10 735.84 4,162.92 7,028.15 28,096.76

2021 2,135.87 725.16 7,526.82 382.55 669.51 1,304.66 1,334.05 524.53 796.47 996.93 744.21 4,220.25 7,113.95 28,474.96

2022 2,168.66 734.83 7,657.62 386.18 677.90 1,320.85 1,341.17 528.27 803.33 1,007.88 752.67 4,278.36 7,200.81 28,858.52

2023 2,201.95 744.63 7,790.70 389.85 686.40 1,337.24 1,348.33 532.04 810.24 1,018.94 761.23 4,337.28 7,288.72 29,247.53

2024 2,235.76 754.56 7,926.09 393.55 695.00 1,353.83 1,355.52 535.84 817.21 1,030.13 769.88 4,397.01 7,377.71 29,642.07

2025 2,270.08 764.62 8,063.83 397.29 703.71 1,370.62 1,362.75 539.66 824.24 1,041.44 778.64 4,457.56 7,467.78 30,042.22

2026 2,303.74 774.46 8,199.25 400.82 712.11 1,386.74 1,369.29 543.19 830.83 1,052.24 787.03 4,516.22 7,554.49 30,430.40

2027 2,337.89 784.42 8,336.94 404.39 720.60 1,403.06 1,375.85 546.75 837.47 1,063.16 795.52 4,575.65 7,642.20 30,823.90

2028 2,372.55 794.51 8,476.95 407.99 729.20 1,419.56 1,382.44 550.32 844.17 1,074.19 804.10 4,635.86 7,730.93 31,222.78

2029 2,407.73 804.73 8,619.31 411.62 737.89 1,436.26 1,389.07 553.93 850.92 1,085.34 812.77 4,696.86 7,820.70 31,627.13

2030 2,443.43 815.09 8,764.06 415.28 746.69 1,453.15 1,395.73 557.55 857.73 1,096.60 821.53 4,758.67 7,911.50 32,037.01

2031 2,478.42 825.19 8,906.20 418.73 755.15 1,469.33 1,401.68 560.87 864.08 1,107.33 829.92 4,818.43 7,998.73 32,434.07

2032 2,513.92 835.42 9,050.64 422.21 763.70 1,485.69 1,407.66 564.21 870.48 1,118.16 838.39 4,878.94 8,086.92 32,836.35

2033 2,549.93 845.78 9,197.43 425.72 772.35 1,502.22 1,413.67 567.56 876.92 1,129.10 846.95 4,940.22 8,176.08 33,243.94
 

Tables- 42 Central and Eastern Planning Areas Supplemental EIS

Table 4-9. Baseline Population Projections (in thousands) by Economic Impact Area (continued).

Calendar

Year TX-1 TX-2 TX-3 LA-1 LA-2 LA-3 LA-4 MS-1 AL-1 FL-1 FL-2 FL-3 FL-4 Total

2034 2,586.45 856.27 9,346.60 429.26 781.10 1,518.95 1,419.70 570.94 883.42 1,140.15 855.59 5,002.26 8,266.22 33,656.90

2035 2,623.50 866.88 9,498.19 432.83 789.95 1,535.86 1,425.76 574.34 889.96 1,151.30 864.33 5,065.08 8,357.36 34,075.32

2036 2,660.18 877.35 9,648.20 436.24 798.54 1,552.22 1,431.30 577.50 896.15 1,162.06 872.78 5,126.41 8,445.87 34,484.81

2037 2,697.38 887.95 9,800.57 439.68 807.22 1,568.76 1,436.88 580.69 902.39 1,172.92 881.32 5,188.48 8,535.33 34,899.56

2038 2,735.09 898.67 9,955.36 443.14 816.00 1,585.48 1,442.47 583.89 908.67 1,183.87 889.94 5,251.30 8,625.73 35,319.62

2039 2,773.34 909.53 10,112.59 446.63 824.88 1,602.38 1,448.08 587.10 915.00 1,194.93 898.64 5,314.89 8,717.09 35,745.07

2040 2,812.12 920.51 10,272.30 450.15 833.85 1,619.45 1,453.72 590.34 921.37 1,206.10 907.43 5,379.25 8,809.42 36,175.99

2041 2,851.44 931.63 10,434.53 453.69 842.92 1,636.71 1,459.38 593.59 927.78 1,217.36 916.31 5,444.38 8,902.73 36,612.44

2042 2,891.31 942.88 10,599.33 457.27 852.08 1,654.15 1,465.06 596.86 934.24 1,228.74 925.27 5,510.30 8,997.02 37,054.50

2043 2,931.73 954.27 10,766.73 460.87 861.35 1,671.78 1,470.76 600.15 940.74 1,240.22 934.32 5,577.02 9,092.31 37,502.25

2044 2,972.73 965.79 10,936.77 464.50 870.72 1,689.59 1,476.49 603.46 947.29 1,251.80 943.46 5,644.55 9,188.62 37,955.76

2045 3,014.29 977.46 11,109.50 468.16 880.19 1,707.59 1,482.24 606.79 953.88 1,263.50 952.69 5,712.90 9,285.94 38,415.11

2046 3,056.44 989.26 11,284.95 471.84 889.76 1,725.79 1,488.01 610.13 960.52 1,275.30 962.01 5,782.07 9,384.29 38,880.38

2047 3,099.18 1,001.21 11,463.18 475.56 899.44 1,744.18 1,493.80 613.49 967.21 1,287.22 971.41 5,852.09 9,483.69 39,351.64

2048 3,142.51 1,013.30 11,644.22 479.31 909.22 1,762.77 1,499.61 616.87 973.94 1,299.24 980.92 5,922.95 9,584.13 39,828.99

2049 3,186.45 1,025.54 11,828.12 483.08 919.11 1,781.55 1,505.45 620.27 980.72 1,311.38 990.51 5,994.66 9,685.65 40,312.49

2050 3,231.01 1,037.93 12,014.93 486.88 929.10 1,800.54 1,511.31 623.69 987.55 1,323.63 1,000.20 6,067.25 9,788.23 40,802.24

2051 3,276.18 1,050.46 12,204.68 490.72 939.21 1,819.72 1,517.19 627.13 994.42 1,336.00 1,009.98 6,140.71 9,891.91 41,298.32

2052 3,321.99 1,063.15 12,397.44 494.58 949.42 1,839.11 1,523.10 630.58 1,001.34 1,348.48 1,019.86 6,215.07 9,996.68 41,800.81

2053 3,368.44 1,075.99 12,593.23 498.48 959.75 1,858.71 1,529.03 634.06 1,008.31 1,361.07 1,029.84 6,290.32 10,102.56 42,309.80

2054 3,415.54 1,088.98 12,792.12 502.41 970.19 1,878.52 1,534.98 637.55 1,015.33 1,373.79 1,039.91 6,366.49 10,209.56 42,825.37

2055 3,463.30 1,102.13 12,994.15 506.36 980.74 1,898.54 1,540.95 641.06 1,022.40 1,386.62 1,050.08 6,443.58 10,317.70 43,347.62

2014/2055 

growth

1.46% 1.26% 1.65% 0.86% 1.16% 1.14% 0.45% 0.62% 0.76% 1.00% 1.04% 1.28% 1.13% 1.27%

Notes: Actual Woods & Poole data for 2010 through 2020, 2025, 2030, 2035, and 2040.

Missing estimates through 2040 calculated using average annual growth rate for the 5-year period; projections after 2040 calculated using the average annual growth 

rate from 2035 to 2040.

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-43

Table 4-10

Baseline Employment Projections (in thousands) by Economic Impact Area

Calendar

Year TX-1 TX-2 TX-3 LA-1 LA-2 LA-3 LA-4 MS-1 AL-1 FL-1 FL-2 FL-3 FL-4 Total

2010 806.89 305.43 3,598.02 177.97 328.88 674.25 750.90 241.07 374.37 474.27 320.53 1,832.29 3,367.36 13,252.22

2011 820.21 312.06 3,682.63 179.50 333.42 681.06 758.43 237.96 375.73 481.21 320.83 1,846.30 3,430.32 13,459.65

2012 834.82 316.94 3,752.42 181.84 339.08 691.34 766.12 240.09 381.01 487.94 324.64 1,875.79 3,489.82 13,681.85

2013 849.66 321.93 3,823.50 184.23 344.80 701.78 773.87 242.26 386.35 494.78 328.48 1,905.67 3,550.17 13,907.48

2014 864.76 326.99 3,895.93 186.63 350.61 712.40 781.67 244.42 391.77 501.71 332.38 1,935.91 3,611.37 14,136.55

2015 880.09 332.14 3,969.75 189.07 356.48 723.17 789.50 246.60 397.25 508.69 336.34 1,966.53 3,673.45 14,369.05

2016 895.67 337.37 4,044.98 191.54 362.44 734.10 797.39 248.79 402.81 515.77 340.34 1,997.53 3,736.39 14,605.11

2017 911.50 342.70 4,121.61 194.03 368.47 745.18 805.31 250.99 408.42 522.94 344.38 2,028.94 3,800.21 14,844.68

2018 927.59 348.13 4,199.69 196.56 374.58 756.44 813.30 253.19 414.11 530.18 348.47 2,060.72 3,864.92 15,087.90

2019 943.92 353.64 4,279.26 199.12 380.77 767.88 821.31 255.42 419.86 537.52 352.62 2,092.90 3,930.55 15,334.76

2020 960.54 359.26 4,360.32 201.70 387.03 779.48 829.39 257.66 425.70 544.94 356.83 2,125.50 3,997.07 15,585.39

2021 977.35 364.98 4,442.91 204.31 393.33 791.25 837.44 259.89 431.58 552.43 361.09 2,158.28 4,064.10 15,838.95

2022 994.46 370.78 4,527.06 206.96 399.74 803.21 845.58 262.14 437.55 560.02 365.40 2,191.57 4,132.26 16,096.73

2023 1,011.88 376.69 4,612.81 209.64 406.25 815.34 853.79 264.41 443.59 567.71 369.76 2,225.38 4,201.56 16,358.81

2024 1,029.59 382.68 4,700.18 212.36 412.86 827.66 862.09 266.70 449.73 575.51 374.18 2,259.70 4,272.02 16,625.26

2025 1,047.62 388.77 4,789.21 215.11 419.58 840.17 870.47 269.01 455.94 583.42 378.64 2,294.56 4,343.66 16,896.16

2026 1,065.83 395.00 4,879.89 217.88 426.29 852.86 878.77 271.29 462.20 591.35 383.19 2,329.42 4,415.40 17,169.39

2027 1,084.36 401.33 4,972.29 220.69 433.11 865.74 887.16 273.60 468.54 599.40 387.79 2,364.82 4,488.32 17,447.15

2028 1,103.22 407.75 5,066.44 223.54 440.04 878.81 895.63 275.93 474.98 607.55 392.45 2,400.75 4,562.45 17,729.52

2029 1,122.40 414.28 5,162.37 226.42 447.08 892.08 904.18 278.28 481.50 615.82 397.16 2,437.23 4,637.80 18,016.58

2030 1,141.91 420.92 5,260.12 229.33 454.23 905.55 912.81 280.64 488.10 624.20 401.93 2,474.26 4,714.39 18,308.39

2031 1,161.64 427.70 5,359.67 232.27 461.37 919.22 921.38 282.99 494.76 632.61 406.78 2,511.31 4,791.08 18,602.79

2032 1,181.71 434.58 5,461.10 235.25 468.62 933.09 930.04 285.36 501.51 641.14 411.69 2,548.92 4,869.01 18,902.03

2033 1,202.13 441.58 5,564.46 238.27 475.98 947.17 938.78 287.75 508.35 649.79 416.66 2,587.09 4,948.21 19,206.22
 

Tables- 44 Central and Eastern Planning Areas Supplemental EIS

Table 4-10. Baseline Employment Projections (in thousands) by Economic Impact Area (continued).

Calendar

Year TX-1 TX-2 TX-3 LA-1 LA-2 LA-3 LA-4 MS-1 AL-1 FL-1 FL-2 FL-3 FL-4 Total

2034 1,222.90 448.69 5,669.77 241.33 483.46 961.46 947.60 290.16 515.28 658.55 421.69 2,625.83 5,028.70 19,515.43

2035 1,244.03 455.92 5,777.07 244.42 491.06 975.97 956.50 292.59 522.31 667.43 426.78 2,665.15 5,110.50 19,829.74

2036 1,265.41 463.29 5,886.34 247.54 498.64 990.68 965.36 295.00 529.39 676.35 431.97 2,704.51 5,192.38 20,146.85

2037 1,287.16 470.78 5,997.67 250.69 506.34 1,005.61 974.31 297.43 536.57 685.39 437.21 2,744.45 5,275.56 20,469.17

2038 1,309.29 478.39 6,111.11 253.89 514.16 1,020.77 983.33 299.88 543.84 694.55 442.53 2,784.97 5,360.08 20,796.79

2039 1,331.79 486.12 6,226.69 257.13 522.10 1,036.15 992.44 302.35 551.21 703.83 447.90 2,826.10 5,445.95 21,129.78

2040 1,354.68 493.98 6,344.46 260.40 530.17 1,051.77 1,001.64 304.84 558.68 713.24 453.34 2,867.83 5,533.20 21,468.24

2041 1,377.97 501.97 6,464.46 263.72 538.35 1,067.62 1,010.92 307.36 566.25 722.77 458.85 2,910.18 5,621.85 21,812.27

2042 1,401.65 510.09 6,586.73 267.08 546.67 1,083.72 1,020.29 309.89 573.93 732.43 464.42 2,953.15 5,711.91 22,161.95

2043 1,425.74 518.33 6,711.30 270.49 555.11 1,100.05 1,029.74 312.44 581.71 742.22 470.06 2,996.76 5,803.42 22,517.38

2044 1,450.25 526.72 6,838.24 273.94 563.68 1,116.63 1,039.28 315.02 589.59 752.14 475.77 3,041.01 5,896.40 22,878.66

2045 1,475.18 535.23 6,967.58 277.43 572.39 1,133.46 1,048.91 317.61 597.58 762.19 481.55 3,085.92 5,990.86 23,245.89

2046 1,500.53 543.89 7,099.36 280.96 581.23 1,150.55 1,058.63 320.23 605.68 772.38 487.40 3,131.49 6,086.84 23,619.16

2047 1,526.32 552.68 7,233.63 284.55 590.20 1,167.89 1,068.43 322.87 613.89 782.70 493.32 3,177.73 6,184.35 23,998.57

2048 1,552.56 561.62 7,370.45 288.17 599.32 1,185.49 1,078.33 325.53 622.21 793.16 499.32 3,224.65 6,283.43 24,384.24

2049 1,579.24 570.70 7,509.85 291.85 608.58 1,203.36 1,088.32 328.21 630.65 803.76 505.38 3,272.27 6,384.10 24,776.26

2050 1,606.39 579.92 7,651.89 295.57 617.97 1,221.50 1,098.41 330.92 639.19 814.50 511.52 3,320.59 6,486.37 25,174.74

2051 1,634.00 589.30 7,796.62 299.33 627.52 1,239.91 1,108.58 333.64 647.86 825.39 517.73 3,369.62 6,590.29 25,579.79

2052 1,662.08 598.83 7,944.08 303.15 637.21 1,258.59 1,118.86 336.39 656.64 836.42 524.02 3,419.38 6,695.87 25,991.53

2053 1,690.65 608.51 8,094.33 307.01 647.05 1,277.56 1,129.22 339.16 665.54 847.60 530.39 3,469.87 6,803.14 26,410.05

2054 1,719.71 618.35 8,247.43 310.93 657.04 1,296.82 1,139.68 341.96 674.56 858.93 536.83 3,521.11 6,912.14 26,835.48

2055 1,749.27 628.35 8,403.42 314.89 667.19 1,316.37 1,150.24 344.78 683.70 870.41 543.35 3,573.11 7,022.87 27,267.94

2014-2055 

growth

1.73% 1.61% 1.89% 1.28% 1.58% 1.51% 0.95% 0.84% 1.37% 1.35% 1.21% 1.51% 1.64% 1.62%

Notes: Actual Woods & Poole data for 2010 through 2020, 2025, 2030, 2035, and 2040.

Missing estimates through 2040 calculated using average annual growth rate for the 5-year period; projections after 2040 calculated using the average annual growth 

rate from 2035 to 2040.

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-45

Table 4-11

Demographic and Employment Baseline Projections for Economic Impact Area AL-1 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 692.65 725.87 727.78 734.42 741.19 748.05 754.94 782.72 824.24 857.73 921.37

Age under 19 years 28.1% 27.1% 26.7% 26.6% 26.5% 26.4% 26.3% 26.2% 25.9% 25.5% 24.6%

Age 20 to 34 18.7% 18.6% 18.8% 18.8% 18.7% 18.6% 18.4% 17.5% 16.7% 16.4% 16.9%

Age 35 to 49 21.3% 19.7% 19.3% 19.0% 18.8% 18.6% 18.5% 18.5% 18.6% 18.5% 17.4%

Age 50 to 64 18.3% 20.1% 20.4% 20.5% 20.6% 20.6% 20.7% 20.1% 18.6% 17.8% 18.5%

Age 65 and over 13.5% 14.4% 14.7% 15.1% 15.5% 15.8% 16.2% 17.6% 20.2% 21.8% 22.6%

Median Age of Population (years) 38.2 39.9 40.2 40.5 40.8 41.0 41.2 41.8 43.0 43.8 45.1

White Population (in thousands) 66.2% 65.2% 65.0% 65.0% 64.9% 64.8% 64.7% 64.4% 63.7% 63.2% 62.2%

Black Population (in thousands) 29.6% 29.6% 29.6% 29.6% 29.5% 29.5% 29.5% 29.5% 29.5% 29.5% 29.2%

Native American Population (in thousands) 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.2% 1.2% 1.2%

Asian and Pacific Islander Population

(in thousands)

1.2% 1.4% 1.4% 1.5% 1.5% 1.5% 1.5% 1.6% 1.8% 1.9% 2.1%

Hispanic or Latino Population (in thousands) 1.9% 2.7% 2.8% 2.9% 3.0% 3.1% 3.1% 3.4% 3.9% 4.3% 5.4%

Male Population (in thousands) 48.3% 48.4% 48.4% 48.4% 48.4% 48.4% 48.4% 48.5% 48.5% 48.5% 48.4%

Total Employment (in thousands of jobs) 363.84 374.37 375.73 381.01 386.35 391.77 397.25 419.86 455.94 488.10 558.68

Farm Employment 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.3% 1.2% 1.1% 1.0%

Forestry, Fishing, Related Activities 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 0.9% 0.9% 0.8% 0.8%

Mining 0.3% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.5% 0.5% 0.5% 0.5%

Utilities 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.3% 0.3%

Construction 8.5% 7.4% 6.3% 6.3% 6.2% 6.2% 6.2% 6.0% 5.8% 5.7% 5.3%

Manufacturing 8.7% 7.2% 7.5% 7.4% 7.2% 7.1% 7.0% 6.5% 5.9% 5.4% 4.5%

Wholesale Trade 3.5% 3.0% 3.2% 3.1% 3.1% 3.1% 3.1% 3.0% 2.9% 2.8% 2.6%

Retail Trade 12.4% 11.8% 11.9% 11.9% 11.8% 11.8% 11.7% 11.6% 11.3% 11.0% 10.5%

Transportation and Warehousing 3.7% 3.6% 3.6% 3.6% 3.6% 3.6% 3.6% 3.5% 3.3% 3.2% 3.0%

Information Employment 1.3% 1.0% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.8% 0.8%

Finance and Insurance 3.4% 3.8% 4.3% 4.3% 4.3% 4.3% 4.3% 4.3% 4.3% 4.2% 4.1%

Real Estate/Rental and Lease 4.4% 5.1% 5.1% 5.1% 5.1% 5.1% 5.1% 5.1% 5.1% 5.0% 5.0%

Professional and Technical Services 4.4% 4.6% 4.6% 4.6% 4.7% 4.7% 4.7% 4.8% 5.0% 5.1% 5.3%
 

Tables- 46 Central and Eastern Planning Areas Supplemental EIS

Table 4-11. Demographic and Employment Baseline Projections for Economic Impact Area AL-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Management 0.2% 0.3% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.5% 0.5% 0.6%

Administrative and Waste Services 6.4% 7.2% 7.1% 7.2% 7.2% 7.3% 7.3% 7.6% 7.9% 8.2% 8.8%

Educational Services 1.4% 1.7% 1.8% 1.9% 1.9% 1.9% 1.9% 2.0% 2.2% 2.4% 2.6%

Health Care and Social Assistance 8.5% 9.4% 9.5% 9.6% 9.7% 9.8% 10.0% 10.4% 11.1% 11.7% 12.9%

Arts, Entertainment, and Recreation 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.4% 1.4% 1.4%

Accommodation and Food Services 6.8% 7.3% 7.6% 7.7% 7.8% 7.8% 7.9% 8.2% 8.7% 9.1% 9.8%

Other Services, Except Public Administration 7.7% 8.1% 8.1% 8.2% 8.3% 8.3% 8.4% 8.7% 9.1% 9.4% 10.1%

Federal Civilian Government 0.9% 1.0% 0.9% 0.9% 0.9% 0.9% 0.8% 0.8% 0.8% 0.7% 0.6%

Federal Military 1.3% 1.2% 1.2% 1.2% 1.2% 1.2% 1.1% 1.1% 1.0% 0.9% 0.8%

State and Local Government 12.0% 11.6% 11.4% 11.3% 11.2% 11.1% 11.0% 10.6% 10.1% 9.6% 8.7%

Total Earnings (in millions of 2005 dollars) 14,014.96 14,966.90 15,143.01 15,422.61 15,761.05 16,106.59 16,459.36 17,945.78 20,419.98 22,730.96 28,142.17

Farm 0.8% 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4% 0.4%

Forestry, Fishing, Related Activities 1.0% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.1% 1.1% 1.0% 0.9%

Mining 0.4% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.7%

Utilities 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 0.9% 0.9% 0.8%

Construction 8.9% 8.6% 6.9% 6.9% 6.8% 6.7% 6.7% 6.4% 6.0% 5.6% 5.0%

Manufacturing 13.6% 12.4% 13.1% 13.0% 12.9% 12.7% 12.6% 12.0% 11.1% 10.4% 9.1%

Wholesale Trade 5.2% 4.7% 4.8% 4.8% 4.8% 4.8% 4.8% 4.7% 4.7% 4.6% 4.4%

Retail Trade 8.9% 8.1% 8.1% 8.1% 8.0% 7.9% 7.8% 7.5% 7.0% 6.5% 5.8%

Transportation and Warehousing 4.8% 5.3% 5.5% 5.4% 5.4% 5.4% 5.3% 5.1% 4.9% 4.7% 4.2%

Information 1.6% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.3% 1.3%

Finance and Insurance 4.9% 4.2% 6.0% 6.1% 6.1% 6.1% 6.1% 6.2% 6.3% 6.4% 6.4%

Real Estate/Rental and Lease 2.3% 2.1% 2.0% 2.0% 2.0% 2.0% 2.0% 2.0% 2.0% 2.0% 1.9%

Professional and Technical Services 5.5% 5.7% 5.7% 5.8% 5.9% 5.9% 6.0% 6.2% 6.6% 6.9% 7.6%

Management 0.3% 0.5% 0.6% 0.5% 0.5% 0.5% 0.5% 0.6% 0.8% 0.9% 1.2%

Administrative and Waste Services 3.7% 4.3% 3.9% 4.0% 4.1% 4.1% 4.2% 4.4% 4.7% 4.9% 5.5%

Educational Services 0.9% 1.0% 1.1% 1.1% 1.1% 1.1% 1.1% 1.2% 1.3% 1.4% 1.7%

Health Care and Social Assistance 9.8% 10.9% 10.8% 11.0% 11.2% 11.3% 11.5% 12.1% 13.1% 14.0% 15.8%

Arts, Entertainment, and Recreation 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5%

Accommodation and Food Services 3.2% 3.4% 3.5% 3.6% 3.6% 3.7% 3.7% 3.9% 4.1% 4.3% 4.7%

Other Services, Except Public Administration 4.8% 5.1% 5.1% 5.1% 5.2% 5.2% 5.3% 5.4% 5.7% 5.9% 6.3%
Tables Tables-47

Table 4-11. Demographic and Employment Baseline Projections for Economic Impact Area AL-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Federal Civilian Government 2.2% 2.3% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.2% 2.1% 2.0%

Federal Military 1.8% 1.7% 1.7% 1.4% 1.4% 1.4% 1.4% 1.5% 1.5% 1.5% 1.5%

State and Local Government 13.8% 14.6% 14.1% 14.1% 14.0% 14.0% 13.9% 13.7% 13.3% 13.0% 12.2%

Total Personal Income per Capita 

(in 2005 dollars)

29,183 31,525 32,073 32,315 32,647 33,020 33,425 35,293 38,730 42,084 50,167

Woods & Poole Economics Wealth Index 

(U.S. = 100)

68.7 73.2 72.6 72.6 72.6 72.6 72.6 72.6 72.6 72.6 72.7

Persons per Household (in number of people) 2.5 2.6 2.6 2.6 2.6 2.5 2.5 2.5 2.5 2.5 2.6

Mean Household Total Personal Income 

(in 2005 dollars)

74,227 80,979 82,094 83,334 83,643 84,101 84,687 88,368 96,803 105,827 128,090

Number of Households (in thousands) 272.33 282.58 284.33 284.79 289.29 293.70 297.97 312.61 329.76 341.10 360.86

Income <$10,000 

(thousands of households, 2000$)

11.7% 12.0% 11.7% 11.4% 11.4% 11.2% 11.1% 10.5% 9.2% 8.1% 6.3%

Income $10,000 to $19,999 14.3% 14.4% 14.5% 14.4% 14.3% 14.1% 13.9% 13.2% 11.7% 10.4% 8.2%

Income $20,000 to $29,999 12.7% 12.9% 12.8% 12.9% 12.9% 12.7% 12.6% 12.0% 10.8% 9.6% 7.7%

Income $30,000 to $44,999 16.3% 15.6% 15.7% 15.4% 15.4% 15.3% 15.2% 14.8% 13.6% 12.4% 9.9%

Income $45,000 to $59,999 13.0% 12.9% 12.7% 12.8% 12.9% 13.0% 13.1% 13.5% 14.2% 14.0% 12.0%

Income $60,000 to $74,999 9.0% 9.2% 9.7% 9.8% 9.8% 9.9% 10.0% 10.6% 11.9% 13.2% 14.8%

Income $75,000 to $99,999 10.4% 10.3% 10.3% 10.5% 10.6% 10.7% 10.8% 11.4% 12.9% 14.5% 18.4%

Income $100,000 or more 12.6% 12.7% 12.6% 12.8% 12.9% 13.0% 13.2% 14.0% 15.8% 17.8% 22.7%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
 

Tables- 48 Central and Eastern Planning Areas Supplemental EIS

Table 4-12

Demographic and Employment Baseline Projections for Economic Impact Area FL-1 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 861.80 882.80 889.79 900.02 910.45 921.04 931.71 975.13 1,041.44 1,096.60 1,206.10

Age Under 19 Years 26.1% 25.0% 24.5% 24.3% 24.2% 24.1% 24.1% 24.3% 24.5% 24.3% 23.6%

Age 20 to 34 20.1% 20.5% 20.9% 21.1% 21.1% 21.1% 20.9% 19.8% 18.0% 17.4% 18.6%

Age 35 to 49 22.3% 20.1% 19.5% 18.9% 18.4% 18.0% 17.8% 17.9% 19.1% 19.7% 17.4%

Age 50 to 64 18.2% 20.1% 20.6% 20.7% 20.8% 20.9% 21.0% 20.4% 18.3% 16.4% 17.9%

Age 65 and over 13.3% 14.3% 14.6% 15.0% 15.5% 15.8% 16.2% 17.5% 20.1% 22.2% 22.6%

Median Age of Population (years) 39.5 40.3 40.5 40.6 40.7 40.8 40.8 41.1 41.7 42.4 42.7

White Population (in thousands) 79.1% 77.2% 76.8% 76.6% 76.4% 76.2% 76.0% 75.1% 73.8% 72.6% 70.1%

Black Population (in thousands) 13.5% 14.0% 14.2% 14.2% 14.2% 14.3% 14.3% 14.5% 14.7% 14.9% 15.1%

Native American Population 

(in thousands)

0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.7% 0.6% 0.5%

Asian and Pacific Islander Population 

(in thousands)

2.5% 2.8% 2.8% 2.9% 2.9% 2.9% 2.9% 3.0% 3.2% 3.3% 3.4%

Hispanic or Latino Population 

(in thousands)

4.0% 5.1% 5.4% 5.6% 5.7% 5.9% 6.0% 6.7% 7.7% 8.7% 10.9%

Male Population (in thousands) 50.1% 50.2% 50.2% 50.2% 50.3% 50.3% 50.3% 50.4% 50.7% 50.8% 51.1%

Total Employment (in thousands of jobs) 487.45 474.27 481.21 487.94 494.78 501.71 508.69 537.52 583.42 624.20 713.24

Farm Employment 0.5% 0.6% 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4%

Forestry, Fishing, Related Activities 0.5% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.5%

Mining 0.2% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

Utilities 0.3% 0.5% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.5% 0.5% 0.5%

Construction 9.0% 6.1% 5.8% 5.8% 5.8% 5.7% 5.7% 5.6% 5.4% 5.3% 4.9%

Manufacturing 3.4% 2.9% 2.8% 2.8% 2.7% 2.7% 2.6% 2.4% 2.1% 1.9% 1.5%

Wholesale Trade 2.6% 2.2% 2.1% 2.1% 2.1% 2.1% 2.0% 2.0% 1.9% 1.9% 1.7%

Retail Trade 12.0% 11.2% 11.3% 11.3% 11.3% 11.3% 11.3% 11.2% 11.0% 10.9% 10.5%

Transportation and Warehousing 1.8% 1.7% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.7% 1.7%

Information Employment 1.9% 1.5% 1.4% 1.4% 1.3% 1.3% 1.3% 1.3% 1.2% 1.2% 1.1%

Finance and Insurance 3.6% 4.2% 4.1% 4.1% 4.2% 4.2% 4.2% 4.3% 4.4% 4.4% 4.6%

Real Estate/Rental and Lease 5.5% 5.6% 5.6% 5.6% 5.6% 5.6% 5.6% 5.7% 5.7% 5.7% 5.7%
Tables Tables-49

Table 4-12. Demographic and Employment Baseline Projections for Economic Impact Area FL-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Professional and Technical Services 5.2% 5.8% 5.8% 5.9% 6.0% 6.0% 6.1% 6.4% 6.8% 7.2% 8.0%

Management 0.5% 0.7% 0.7% 0.8% 0.8% 0.8% 0.8% 0.9% 1.0% 1.1% 1.3%

Administrative and Waste Services 7.0% 6.6% 6.8% 6.9% 6.9% 7.0% 7.0% 7.3% 7.6% 7.9% 8.5%

Educational Services 1.0% 1.3% 1.3% 1.3% 1.3% 1.4% 1.4% 1.4% 1.5% 1.6% 1.8%

Health Care and Social Assistance 8.9% 10.3% 10.1% 10.2% 10.2% 10.3% 10.4% 10.6% 11.0% 11.3% 11.8%

Arts, Entertainment, and Recreation 1.7% 2.0% 2.0% 2.0% 2.1% 2.1% 2.1% 2.2% 2.3% 2.4% 2.6%

Accommodation and Food Services 8.8% 9.4% 10.0% 10.1% 10.1% 10.2% 10.2% 10.4% 10.7% 10.9% 11.3%

Other Services, Except Public 

Administration

6.2% 6.1% 6.0% 6.0% 6.0% 6.1% 6.1% 6.2% 6.3% 6.3% 6.5%

Federal Civilian Government 3.5% 4.0% 4.0% 3.9% 3.9% 3.8% 3.8% 3.6% 3.4% 3.2% 2.9%

Federal Military 6.9% 7.0% 6.9% 6.8% 6.7% 6.6% 6.5% 6.2% 5.8% 5.4% 4.8%

State and Local Government 9.1% 9.6% 9.4% 9.3% 9.2% 9.2% 9.1% 8.8% 8.3% 7.9% 7.2%

Total Earnings (in millions of 2005 dollars) 20,751.11 20,572.00 20,811.53 21,392.36 21,898.20 22,415.45 22,944.36 25,181.93 28,935.09 32,468.98 40,831.98

Farm 0.1% 0.2% 0.3% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1%

Forestry, Fishing, Related Activities 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Mining 0.1% 0.1% 0.1% 0.2% 0.2% 0.2% 0.2% 0.2% 0.1% 0.1% 0.1%

Utilities 0.5% 0.9% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.9% 0.9% 1.0%

Construction 8.1% 5.4% 5.3% 5.2% 5.1% 5.0% 5.0% 4.7% 4.4% 4.1% 3.6%

Manufacturing 4.8% 4.2% 4.1% 4.0% 3.9% 3.9% 3.8% 3.5% 3.2% 2.9% 2.4%

Wholesale Trade 3.0% 2.7% 2.7% 2.7% 2.7% 2.7% 2.6% 2.6% 2.5% 2.5% 2.3%

Retail Trade 7.9% 7.0% 7.1% 7.0% 6.9% 6.9% 6.8% 6.5% 6.1% 5.7% 5.0%

Transportation and Warehousing 1.8% 1.7% 2.0% 1.9% 1.9% 1.9% 1.9% 1.8% 1.8% 1.7% 1.6%

Information 2.4% 1.9% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6%

Finance and Insurance 3.9% 3.9% 3.7% 3.7% 3.7% 3.7% 3.8% 3.8% 4.0% 4.0% 4.2%

Real Estate/Rental and Lease 3.1% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.7% 1.7%

Professional and Technical Services 6.6% 7.4% 7.6% 7.7% 7.8% 7.9% 8.0% 8.5% 9.3% 10.0% 11.4%

Management 0.8% 0.3% 0.5% 1.1% 1.1% 1.2% 1.2% 1.3% 1.6% 1.8% 2.4%

Administrative and Waste Services 4.5% 4.1% 4.1% 4.2% 4.2% 4.3% 4.3% 4.5% 4.8% 5.0% 5.4%

Educational Services 0.7% 0.7% 0.7% 0.7% 0.8% 0.8% 0.8% 0.8% 0.9% 0.9% 1.1%

Health Care and Social Assistance 10.0% 11.7% 11.6% 11.6% 11.7% 11.8% 11.9% 12.2% 12.7% 13.1% 13.8%

Arts, Entertainment, and Recreation 0.6% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.8% 0.8% 0.9%
 

Tables- 50 Central and Eastern Planning Areas Supplemental EIS

Table 4-12. Demographic and Employment Baseline Projections for Economic Impact Area FL-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Accommodation and Food Services 4.6% 4.5% 4.9% 4.9% 4.9% 4.9% 5.0% 5.0% 5.2% 5.3% 5.4%

Other Services, Except Public 

Administration

4.4% 4.1% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 4.0%

Federal Civilian Government 6.8% 8.3% 8.4% 8.3% 8.3% 8.3% 8.2% 8.1% 7.9% 7.7% 7.4%

Federal Military 14.5% 17.1% 17.1% 17.0% 16.9% 16.9% 16.9% 16.7% 16.4% 16.1% 15.6%

State and Local Government 10.5% 11.3% 10.9% 10.8% 10.7% 10.7% 10.6% 10.4% 10.0% 9.6% 8.9%

Total Personal Income per Capita 

(in 2005 dollars)

33,680 35,157 35,821 36,140 36,444 36,802 37,200 39,089 42,648 46,133 54,499

Woods & Poole Economics Wealth Index 

(U.S. = 100)

85.9 87.6 87.2 87.3 87.2 87.1 87.0 86.7 86.4 86.3 86.1

Persons per Household (in number of people) 2.5 2.5 2.5 2.6 2.5 2.5 2.5 2.5 2.5 2.5 2.5

Mean Household Total Personal Income 

(in 2005 dollars)

85,186 89,563 90,928 92,459 92,646 93,020 93,549 97,201 105,968 115,420 138,697

Number of Households (in thousands) 340.73 346.54 350.54 351.79 358.14 364.40 370.50 392.14 419.13 438.31 473.92

Income < $10,000 

(thousands of households, 2000$)

7.3% 7.6% 7.5% 7.5% 7.5% 7.4% 7.3% 6.9% 6.1% 5.4% 4.3%

Income $10,000 to $19,999 11.5% 11.9% 12.0% 12.0% 12.0% 11.8% 11.7% 11.0% 9.8% 8.7% 6.9%

Income $20,000 to $29,999 12.1% 11.6% 11.4% 11.6% 11.6% 11.5% 11.3% 10.7% 9.5% 8.5% 6.8%

Income $30,000 to $44,999 17.4% 16.6% 17.8% 17.5% 17.4% 17.2% 17.1% 16.2% 14.4% 12.9% 10.3%

Income $45,000 to $59,999 14.3% 13.7% 13.7% 13.4% 13.4% 13.5% 13.6% 13.9% 13.7% 12.9% 10.3%

Income $60,000 to $74,999 10.8% 11.1% 11.1% 11.2% 11.3% 11.4% 11.5% 12.2% 13.6% 14.7% 14.9%

Income $75,000 to $99,999 11.9% 12.2% 11.6% 12.0% 12.1% 12.2% 12.4% 13.1% 14.8% 16.5% 20.7%

Income $100,000 or more 14.7% 15.2% 15.0% 14.7% 14.8% 15.0% 15.1% 16.1% 18.2% 20.4% 25.8%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-51

Table 4-13

Demographic and Employment Baseline Projections for Economic Impact Area FL-2 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 861.80 882.80 889.79 900.02 910.45 921.04 931.71 975.13 1,041.44 1,096.60 1,206.10

Age Under 19 Years 26.1% 25.0% 24.5% 24.3% 24.2% 24.1% 24.1% 24.3% 24.5% 24.3% 23.6%

Age 20 to 34 20.1% 20.5% 20.9% 21.1% 21.1% 21.1% 20.9% 19.8% 18.0% 17.4% 18.6%

Age 35 to 49 22.3% 20.1% 19.5% 18.9% 18.4% 18.0% 17.8% 17.9% 19.1% 19.7% 17.4%

Age 50 to 64 18.2% 20.1% 20.6% 20.7% 20.8% 20.9% 21.0% 20.4% 18.3% 16.4% 17.9%

Age 65 and over 13.3% 14.3% 14.6% 15.0% 15.5% 15.8% 16.2% 17.5% 20.1% 22.2% 22.6%

Median Age of Population (years) 39.5 40.3 40.5 40.6 40.7 40.8 40.8 41.1 41.7 42.4 42.7

White Population (in thousands) 79.1% 77.2% 76.8% 76.6% 76.4% 76.2% 76.0% 75.1% 73.8% 72.6% 70.1%

Black Population (in thousands) 13.5% 14.0% 14.2% 14.2% 14.2% 14.3% 14.3% 14.5% 14.7% 14.9% 15.1%

Native American Population 

(in thousands)

0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.7% 0.6% 0.5%

Asian and Pacific Islander Population 

(in thousands)

2.5% 2.8% 2.8% 2.9% 2.9% 2.9% 2.9% 3.0% 3.2% 3.3% 3.4%

Hispanic or Latino Population 

(in thousands)

4.0% 5.1% 5.4% 5.6% 5.7% 5.9% 6.0% 6.7% 7.7% 8.7% 10.9%

Male Population (in thousands) 50.1% 50.2% 50.2% 50.2% 50.3% 50.3% 50.3% 50.4% 50.7% 50.8% 51.1%

Total Employment 

(in thousands of jobs)

487.45 474.27 481.21 487.94 494.78 501.71 508.69 537.52 583.42 624.20 713.24

Farm Employment 0.5% 0.6% 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4%

Forestry, Fishing, Related Activities 0.5% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.5%

Mining 0.2% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

Utilities 0.3% 0.5% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.5% 0.5% 0.5%

Construction 9.0% 6.1% 5.8% 5.8% 5.8% 5.7% 5.7% 5.6% 5.4% 5.3% 4.9%

Manufacturing 3.4% 2.9% 2.8% 2.8% 2.7% 2.7% 2.6% 2.4% 2.1% 1.9% 1.5%

Wholesale Trade 2.6% 2.2% 2.1% 2.1% 2.1% 2.1% 2.0% 2.0% 1.9% 1.9% 1.7%

Retail Trade 12.0% 11.2% 11.3% 11.3% 11.3% 11.3% 11.3% 11.2% 11.0% 10.9% 10.5%

Transportation and Warehousing 1.8% 1.7% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.7% 1.7%

Information Employment 1.9% 1.5% 1.4% 1.4% 1.3% 1.3% 1.3% 1.3% 1.2% 1.2% 1.1%

Finance and Insurance 3.6% 4.2% 4.1% 4.1% 4.2% 4.2% 4.2% 4.3% 4.4% 4.4% 4.6%
 

Tables- 52 Central and Eastern Planning Areas Supplemental EIS

Table 4-13. Demographic and Employment Baseline Projections for Economic Impact Area FL-2 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Real Estate/Rental and Lease 5.5% 5.6% 5.6% 5.6% 5.6% 5.6% 5.6% 5.7% 5.7% 5.7% 5.7%

Professional and Technical Services 5.2% 5.8% 5.8% 5.9% 6.0% 6.0% 6.1% 6.4% 6.8% 7.2% 8.0%

Management 0.5% 0.7% 0.7% 0.8% 0.8% 0.8% 0.8% 0.9% 1.0% 1.1% 1.3%

Administrative and Waste Services 7.0% 6.6% 6.8% 6.9% 6.9% 7.0% 7.0% 7.3% 7.6% 7.9% 8.5%

Educational Services 1.0% 1.3% 1.3% 1.3% 1.3% 1.4% 1.4% 1.4% 1.5% 1.6% 1.8%

Health Care and Social Assistance 8.9% 10.3% 10.1% 10.2% 10.2% 10.3% 10.4% 10.6% 11.0% 11.3% 11.8%

Arts, Entertainment, and Recreation 1.7% 2.0% 2.0% 2.0% 2.1% 2.1% 2.1% 2.2% 2.3% 2.4% 2.6%

Accommodation and Food Services 8.8% 9.4% 10.0% 10.1% 10.1% 10.2% 10.2% 10.4% 10.7% 10.9% 11.3%

Other Services, Except Public 

Administration

6.2% 6.1% 6.0% 6.0% 6.0% 6.1% 6.1% 6.2% 6.3% 6.3% 6.5%

Federal Civilian Government 3.5% 4.0% 4.0% 3.9% 3.9% 3.8% 3.8% 3.6% 3.4% 3.2% 2.9%

Federal Military 6.9% 7.0% 6.9% 6.8% 6.7% 6.6% 6.5% 6.2% 5.8% 5.4% 4.8%

State and Local Government 9.1% 9.6% 9.4% 9.3% 9.2% 9.2% 9.1% 8.8% 8.3% 7.9% 7.2%

Total Earnings 

(in millions of 2005 dollars)

20,751.11 20,572.00 20,811.53 21,392.36 21,898.20 22,415.45 22,944.36 25,181.93 28,935.09 32,468.98 40,831.98

Farm 0.1% 0.2% 0.3% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1%

Forestry, Fishing, Related Activities 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Mining 0.1% 0.1% 0.1% 0.2% 0.2% 0.2% 0.2% 0.2% 0.1% 0.1% 0.1%

Utilities 0.5% 0.9% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.9% 0.9% 1.0%

Construction 8.1% 5.4% 5.3% 5.2% 5.1% 5.0% 5.0% 4.7% 4.4% 4.1% 3.6%

Manufacturing 4.8% 4.2% 4.1% 4.0% 3.9% 3.9% 3.8% 3.5% 3.2% 2.9% 2.4%

Wholesale Trade 3.0% 2.7% 2.7% 2.7% 2.7% 2.7% 2.6% 2.6% 2.5% 2.5% 2.3%

Retail Trade 7.9% 7.0% 7.1% 7.0% 6.9% 6.9% 6.8% 6.5% 6.1% 5.7% 5.0%

Transportation and Warehousing 1.8% 1.7% 2.0% 1.9% 1.9% 1.9% 1.9% 1.8% 1.8% 1.7% 1.6%

Information 2.4% 1.9% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6%

Finance and Insurance 3.9% 3.9% 3.7% 3.7% 3.7% 3.7% 3.8% 3.8% 4.0% 4.0% 4.2%

Real Estate/Rental and Lease 3.1% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.7% 1.7%

Professional and Technical Services 6.6% 7.4% 7.6% 7.7% 7.8% 7.9% 8.0% 8.5% 9.3% 10.0% 11.4%

Management 0.8% 0.3% 0.5% 1.1% 1.1% 1.2% 1.2% 1.3% 1.6% 1.8% 2.4%

Administrative and Waste Services 4.5% 4.1% 4.1% 4.2% 4.2% 4.3% 4.3% 4.5% 4.8% 5.0% 5.4%

Educational Services 0.7% 0.7% 0.7% 0.7% 0.8% 0.8% 0.8% 0.8% 0.9% 0.9% 1.1%
Tables Tables-53

Table 4-13. Demographic and Employment Baseline Projections for Economic Impact Area FL-2 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Health Care and Social Assistance 10.0% 11.7% 11.6% 11.6% 11.7% 11.8% 11.9% 12.2% 12.7% 13.1% 13.8%

Arts, Entertainment, and Recreation 0.6% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.8% 0.8% 0.9%

Accommodation and Food Services 4.6% 4.5% 4.9% 4.9% 4.9% 4.9% 5.0% 5.0% 5.2% 5.3% 5.4%

Other Services, Except Public 

Administration

4.4% 4.1% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 4.0%

Federal Civilian Government 6.8% 8.3% 8.4% 8.3% 8.3% 8.3% 8.2% 8.1% 7.9% 7.7% 7.4%

Federal Military 14.5% 17.1% 17.1% 17.0% 16.9% 16.9% 16.9% 16.7% 16.4% 16.1% 15.6%

State and Local Government 10.5% 11.3% 10.9% 10.8% 10.7% 10.7% 10.6% 10.4% 10.0% 9.6% 8.9%

Total Personal Income per Capita 

(in 2005 dollars)

33,680 35,157 35,821 36,140 36,444 36,802 37,200 39,089 42,648 46,133 54,499

Woods & Poole Economics Wealth 

Index (U.S. = 100)

85.9 87.6 87.2 87.3 87.2 87.1 87.0 86.7 86.4 86.3 86.1

Persons per Household 

(in number of people)

2.5 2.5 2.5 2.6 2.5 2.5 2.5 2.5 2.5 2.5 2.5

Mean Household Total Personal Income 

(in 2005 dollars)

85,186 89,563 90,928 92,459 92,646 93,020 93,549 97,201 105,968 115,420 138,697

Number of Households (in thousands) 340.73 346.54 350.54 351.79 358.14 364.40 370.50 392.14 419.13 438.31 473.92

Income < $10,000 

(thousands of households, 2000$)

7.3% 7.6% 7.5% 7.5% 7.5% 7.4% 7.3% 6.9% 6.1% 5.4% 4.3%

Income $10,000 to $19,999 11.5% 11.9% 12.0% 12.0% 12.0% 11.8% 11.7% 11.0% 9.8% 8.7% 6.9%

Income $20,000 to $29,999 12.1% 11.6% 11.4% 11.6% 11.6% 11.5% 11.3% 10.7% 9.5% 8.5% 6.8%

Income $30,000 to $44,999 17.4% 16.6% 17.8% 17.5% 17.4% 17.2% 17.1% 16.2% 14.4% 12.9% 10.3%

Income $45,000 to $59,999 14.3% 13.7% 13.7% 13.4% 13.4% 13.5% 13.6% 13.9% 13.7% 12.9% 10.3%

Income $60,000 to $74,999 10.8% 11.1% 11.1% 11.2% 11.3% 11.4% 11.5% 12.2% 13.6% 14.7% 14.9%

Income $75,000 to $99,999 11.9% 12.2% 11.6% 12.0% 12.1% 12.2% 12.4% 13.1% 14.8% 16.5% 20.7%

Income $100,000 or more 14.7% 15.2% 15.0% 14.7% 14.8% 15.0% 15.1% 16.1% 18.2% 20.4% 25.8%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
 

Tables- 54 Central and Eastern Planning Areas Supplemental EIS

Table 4-14

Demographic and Employment Baseline Projections for Economic Impact Area FL-3 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 3,435.22 3,626.40 3,663.94 3,716.36 3,769.85 3,824.28 3,879.31 4,105.22 4,457.56 4,758.67 5,379.25

Age Under 19 Years 23.9% 23.2% 22.8% 22.7% 22.7% 22.6% 22.6% 22.5% 22.6% 22.6% 22.9%

Age 20 to 34 18.5% 18.6% 18.9% 19.0% 19.1% 19.2% 19.2% 19.1% 18.4% 18.0% 18.4%

Age 35 to 49 21.3% 19.8% 19.4% 18.9% 18.5% 18.2% 17.9% 17.5% 17.8% 18.3% 17.7%

Age 50 to 64 18.5% 20.2% 20.6% 20.7% 20.7% 20.8% 20.8% 20.3% 18.5% 16.8% 16.8%

Age 65 and over 17.8% 18.2% 18.3% 18.6% 18.9% 19.2% 19.5% 20.6% 22.7% 24.2% 24.1%

Median Age of Population (years) 41.7 42.9 43.3 43.5 43.7 43.8 43.9 44.3 44.7 45.0 45.1

White Population (in thousands) 73.9% 70.0% 69.4% 68.9% 68.3% 67.8% 67.2% 65.0% 61.8% 59.0% 53.3%

Black Population (in thousands) 11.4% 12.0% 12.3% 12.4% 12.4% 12.5% 12.6% 12.8% 13.1% 13.4% 13.8%

Native American Population 

(in thousands)

0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2%

Asian and Pacific Islander 

Population (in thousands)

2.6% 3.1% 3.2% 3.3% 3.3% 3.4% 3.5% 3.8% 4.3% 4.7% 5.5%

Hispanic or Latino Population 

(in thousands)

11.8% 14.5% 14.8% 15.2% 15.6% 16.0% 16.4% 18.1% 20.6% 22.7% 27.2%

Male Population (in thousands) 48.6% 48.6% 48.6% 48.6% 48.7% 48.7% 48.7% 48.8% 48.9% 48.9% 48.9%

Total Employment 

(in thousands of jobs)

1,944.15 1,832.29 1,846.30 1,875.79 1,905.67 1,935.91 1,966.53 2,092.90 2,294.56 2,474.26 2,867.83

Farm Employment 1.0% 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.0% 0.9% 0.9%

Forestry, Fishing, Related 

Activities

0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4%

Mining 0.1% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Utilities 0.4% 0.4% 0.4% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

Construction 7.3% 5.1% 4.9% 4.9% 4.9% 4.9% 5.0% 5.0% 5.1% 5.2% 5.4%

Manufacturing 5.0% 4.1% 4.2% 4.1% 4.0% 4.0% 3.9% 3.7% 3.4% 3.2% 2.8%

Wholesale Trade 3.4% 3.2% 3.2% 3.2% 3.2% 3.2% 3.2% 3.1% 3.1% 3.1% 3.0%

Retail Trade 11.4% 11.2% 11.3% 11.3% 11.3% 11.4% 11.4% 11.5% 11.7% 11.8% 11.9%

Transportation and Warehousing 2.3% 2.2% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.4% 2.4%

Information Employment 2.2% 1.9% 1.9% 1.9% 1.9% 1.9% 1.9% 1.8% 1.7% 1.7% 1.6%
Tables Tables-55

Table 4-14. Demographic and Employment Baseline Projections for Economic Impact Area FL-3 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Finance and Insurance 5.8% 6.5% 6.8% 6.8% 6.8% 6.8% 6.7% 6.7% 6.6% 6.6% 6.4%

Real Estate/Rental and Lease 4.5% 4.5% 4.6% 4.5% 4.5% 4.5% 4.5% 4.4% 4.3% 4.1% 3.9%

Professional and Technical Services 6.4% 7.2% 7.3% 7.3% 7.3% 7.3% 7.3% 7.3% 7.2% 7.2% 7.1%

Management 0.8% 1.2% 1.2% 1.2% 1.3% 1.3% 1.3% 1.3% 1.4% 1.5% 1.6%

Administrative and Waste Services 10.8% 7.9% 7.5% 7.6% 7.7% 7.8% 7.8% 8.1% 8.6% 9.0% 9.8%

Educational Services 1.3% 1.8% 1.9% 1.9% 2.0% 2.0% 2.0% 2.2% 2.5% 2.7% 3.3%

Health Care and Social Assistance 10.3% 12.4% 12.5% 12.6% 12.6% 12.7% 12.8% 13.0% 13.3% 13.5% 14.0%

Arts, Entertainment, and Recreation 2.0% 2.4% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5%

Accommodation and Food Services 6.8% 7.1% 7.2% 7.2% 7.1% 7.1% 7.1% 7.0% 6.8% 6.7% 6.4%

Other Services, Except Public 

Administration

5.9% 5.9% 6.0% 6.0% 6.0% 6.0% 6.1% 6.1% 6.2% 6.2% 6.3%

Federal Civilian Government 1.3% 1.6% 1.5% 1.5% 1.5% 1.5% 1.5% 1.4% 1.3% 1.3% 1.1%

Federal Military 0.7% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.6% 0.6% 0.5%

State and Local Government 9.9% 10.6% 10.4% 10.3% 10.2% 10.1% 10.1% 9.7% 9.2% 8.9% 8.1%

Total Earnings 

(in millions of 2005 dollars)

85,752.60 82,664.03 83,293.04 85,719.91 87,934.35 90,200.08 92,518.16 102,336.23 118,829.95 134,369.43 171,103.77

Farm 0.5% 0.3% 0.3% 0.4% 0.4% 0.4% 0.4% 0.4% 0.3% 0.3% 0.3%

Forestry, Fishing, Related 

Activities

0.3% 0.3% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Mining 0.3% 0.1% 0.1% 0.3% 0.3% 0.3% 0.3% 0.3% 0.4% 0.4% 0.4%

Utilities 1.0% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9%

Construction 7.5% 4.8% 4.6% 4.6% 4.5% 4.5% 4.5% 4.4% 4.3% 4.2% 4.1%

Manufacturing 6.8% 5.9% 5.8% 5.8% 5.7% 5.6% 5.6% 5.4% 5.0% 4.7% 4.2%

Wholesale Trade 4.9% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7%

Retail Trade 8.3% 7.8% 7.9% 7.8% 7.8% 7.7% 7.7% 7.5% 7.1% 6.9% 6.3%

Transportation and Warehousing 2.2% 2.1% 2.2% 2.1% 2.1% 2.1% 2.1% 2.1% 2.1% 2.1% 2.0%

Information 3.3% 3.0% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1% 3.2%

Finance and Insurance 8.0% 8.0% 8.4% 8.4% 8.4% 8.4% 8.4% 8.3% 8.3% 8.3% 8.1%

Real Estate/Rental and Lease 2.3% 1.9% 1.9% 1.9% 1.9% 1.9% 1.9% 1.8% 1.8% 1.7% 1.6%

Professional and Technical Services 8.1% 9.7% 9.7% 9.7% 9.7% 9.8% 9.8% 9.9% 10.1% 10.2% 10.4%

Management 1.6% 2.2% 2.4% 2.4% 2.5% 2.5% 2.6% 2.8% 3.1% 3.4% 4.2%
 

Tables- 56 Central and Eastern Planning Areas Supplemental EIS

Table 4-14. Demographic and Employment Baseline Projections for Economic Impact Area FL-3 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Administrative and Waste Services 7.1% 5.0% 4.8% 4.8% 4.9% 4.9% 5.0% 5.2% 5.6% 5.9% 6.6%

Educational Services 0.8% 1.2% 1.3% 1.3% 1.3% 1.4% 1.4% 1.5% 1.8% 2.0% 2.5%

Health Care and Social Assistance 12.1% 14.8% 14.8% 14.8% 14.9% 15.0% 15.0% 15.3% 15.7% 16.1% 16.7%

Arts, Entertainment, and Recreation 1.5% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.7%

Accommodation and Food Services 3.9% 3.6% 3.6% 3.6% 3.6% 3.6% 3.5% 3.5% 3.4% 3.3% 3.2%

Other Services, Except Public 

Administration

4.0% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8%

Federal Civilian Government 2.7% 3.5% 3.4% 3.4% 3.4% 3.4% 3.4% 3.3% 3.3% 3.2% 3.1%

Federal Military 1.2% 1.6% 1.6% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.4%

State and Local Government 11.8% 13.1% 12.7% 12.6% 12.5% 12.4% 12.4% 12.1% 11.7% 11.4% 10.7%

Total Personal Income per Capita 

(in 2005 dollars)

35,810 35,952 36,280 36,533 36,788 37,105 37,466 39,232 42,635 45,972 53,929

Woods & Poole Economics Wealth 

Index (U.S. = 100)

78.9 79.4 78.7 78.7 78.6 78.6 78.5 78.2 77.8 77.5 76.9

Persons per Household 

(in number of people)

2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.5

Mean Household Total Personal 

Income (in 2005 dollars)

84,866 87,077 87,589 88,922 89,017 89,311 89,765 93,124 101,406 110,345 132,237

Number of Households (in thousands) 1,449.50 1,497.25 1,517.61 1,526.86 1,557.98 1,588.81 1,619.14 1,729.47 1,874.15 1,982.57 2,193.76

Income < $10,000 

(thousands of households, 2000$)

7.6% 8.1% 8.6% 8.6% 8.5% 8.5% 8.4% 7.9% 7.0% 6.3% 5.1%

Income $10,000 to $19,999 12.6% 13.0% 13.1% 13.2% 13.1% 13.0% 12.8% 12.2% 10.7% 9.6% 7.8%

Income $20,000 to $29,999 13.0% 13.1% 12.9% 13.2% 13.1% 13.0% 12.9% 12.2% 10.8% 9.6% 7.8%

Income $30,000 to $44,999 17.3% 17.5% 17.5% 17.3% 17.2% 17.1% 17.0% 16.3% 14.4% 12.9% 10.4%

Income $45,000 to $59,999 13.5% 13.1% 13.4% 13.5% 13.5% 13.6% 13.8% 14.3% 15.0% 14.6% 12.1%

Income $60,000 to $74,999 9.6% 9.9% 9.8% 9.6% 9.7% 9.8% 9.9% 10.4% 11.9% 13.3% 15.0%

Income $75,000 to $99,999 10.8% 10.6% 10.5% 10.6% 10.6% 10.7% 10.8% 11.4% 13.0% 14.5% 18.1%

Income $100,000 or more 15.6% 14.7% 14.1% 14.1% 14.1% 14.3% 14.5% 15.2% 17.2% 19.2% 23.8%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-57

Table 4-15

Demographic and Employment Baseline Projections for Economic Impact Area FL-4 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 5,934.95 6,170.12 6,273.04 6,352.84 6,434.20 6,516.92 6,600.40 6,941.47 7,467.78 7,911.50 8,809.42

Age Under 19 Years 24.4% 23.3% 23.0% 22.8% 22.7% 22.5% 22.4% 22.3% 22.1% 21.9% 21.6%

Age 20 to 34 18.4% 18.3% 18.6% 18.7% 18.7% 18.8% 18.8% 18.5% 17.9% 17.4% 17.3%

Age 35 to 49 22.2% 21.1% 20.7% 20.3% 19.9% 19.5% 19.2% 18.5% 18.2% 18.5% 17.6%

Age 50 to 64 17.8% 19.4% 19.7% 19.8% 19.9% 20.1% 20.2% 20.1% 19.2% 17.6% 16.8%

Age 65 and over 17.1% 17.9% 18.1% 18.4% 18.7% 19.0% 19.3% 20.6% 22.7% 24.6% 26.6%

Median Age of Population (years) 44.0 45.5 45.9 46.0 46.2 46.3 46.4 46.9 46.9 46.8 46.5

White Population (in thousands) 45.8% 42.3% 42.1% 41.5% 41.0% 40.5% 40.0% 38.1% 35.3% 33.1% 29.2%

Black Population (in thousands) 16.7% 16.7% 16.8% 16.8% 16.8% 16.9% 16.9% 16.9% 17.1% 17.1% 17.2%

Native American Population 

(in thousands)

0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.1%

Asian and Pacific Islander 

Population (in thousands)

2.0% 2.2% 2.2% 2.3% 2.3% 2.4% 2.4% 2.5% 2.7% 2.9% 3.2%

Hispanic or Latino Population 

(in thousands)

35.3% 38.6% 38.7% 39.2% 39.7% 40.1% 40.6% 42.3% 44.7% 46.7% 50.4%

Male Population (in thousands) 48.6% 48.6% 48.7% 48.7% 48.7% 48.7% 48.7% 48.7% 48.7% 48.6% 48.3%

Total Employment 

(in thousands of jobs)

3,395.35 3,367.36 3,430.32 3,489.82 3,550.17 3,611.37 3,673.45 3,930.55 4,343.66 4,714.39 5,533.20

Farm Employment 0.6% 0.6% 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4%

Forestry, Fishing, Related Activities 0.4% 0.4% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4% 0.4% 0.4% 0.4%

Mining 0.1% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Utilities 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.1%

Construction 8.0% 5.0% 4.8% 4.8% 4.8% 4.8% 4.8% 4.9% 4.9% 5.0% 5.0%

Manufacturing 3.6% 2.7% 2.7% 2.7% 2.6% 2.6% 2.5% 2.4% 2.1% 1.9% 1.6%

Wholesale Trade 4.5% 4.3% 4.3% 4.3% 4.3% 4.2% 4.2% 4.1% 4.0% 3.8% 3.6%

Retail Trade 11.2% 11.0% 11.1% 11.2% 11.2% 11.2% 11.2% 11.2% 11.2% 11.1% 11.1%

Transportation and Warehousing 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8% 3.8%

Information Employment 2.0% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.5% 1.4% 1.4% 1.3%

Finance and Insurance 5.0% 5.7% 5.9% 5.9% 5.9% 5.9% 5.9% 5.9% 5.9% 5.9% 5.9%
 

Tables- 58 Central and Eastern Planning Areas Supplemental EIS

Table 4-15. Demographic and Employment Baseline Projections for Economic Impact Area FL-4 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Real Estate/Rental and Lease 6.0% 6.5% 6.5% 6.4% 6.4% 6.4% 6.4% 6.4% 6.4% 6.4% 6.4%

Professional and Technical Services 6.5% 7.1% 7.1% 7.1% 7.2% 7.2% 7.2% 7.2% 7.3% 7.3% 7.4%

Management 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.8% 0.8% 0.8% 0.8%

Administrative and Waste Services 9.0% 8.1% 8.1% 8.2% 8.3% 8.3% 8.4% 8.7% 9.0% 9.4% 10.1%

Educational Services 1.8% 2.4% 2.5% 2.5% 2.5% 2.6% 2.6% 2.7% 2.8% 2.9% 3.2%

Health Care and Social Assistance 9.1% 10.7% 10.7% 10.7% 10.8% 10.8% 10.9% 11.0% 11.3% 11.5% 11.9%

Arts, Entertainment, and Recreation 2.2% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5%

Accommodation and Food Services 7.2% 7.7% 7.9% 7.9% 7.9% 7.9% 7.9% 7.9% 7.9% 7.8% 7.8%

Other Services, Except Public 

Administration

7.7% 8.1% 8.2% 8.2% 8.2% 8.3% 8.3% 8.4% 8.6% 8.8% 9.1%

Federal Civilian Government 1.0% 1.1% 1.0% 1.0% 1.0% 1.0% 1.0% 0.9% 0.9% 0.9% 0.8%

Federal Military 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4% 0.4% 0.3%

State and Local Government 9.0% 9.0% 8.7% 8.6% 8.5% 8.4% 8.3% 8.0% 7.5% 7.1% 6.3%

Total Earnings 

(in millions of 2005 dollars)

158,627.01 149,490.08 151,501.99 155,403.01 159,468.65 163,630.35 167,890.18 185,951.93 216,353.63 245,046.34 312,977.23

Farm 0.5% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.3% 0.3% 0.3%

Forestry, Fishing, Related Activities 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Mining 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1%

Utilities 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4%

Construction 9.4% 5.5% 5.1% 5.1% 5.1% 5.1% 5.1% 5.0% 4.8% 4.7% 4.5%

Manufacturing 4.4% 3.5% 3.6% 3.5% 3.5% 3.4% 3.4% 3.2% 2.9% 2.7% 2.4%

Wholesale Trade 6.8% 7.0% 7.2% 7.2% 7.2% 7.1% 7.1% 7.0% 6.9% 6.7% 6.5%

Retail Trade 8.5% 8.2% 8.4% 8.3% 8.3% 8.2% 8.1% 7.9% 7.5% 7.2% 6.6%

Transportation and Warehousing 4.0% 4.1% 4.1% 4.1% 4.1% 4.1% 4.1% 4.1% 4.0% 3.9% 3.8%

Information 3.6% 3.0% 3.0% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1%

Finance and Insurance 6.9% 7.1% 7.2% 7.1% 7.2% 7.2% 7.2% 7.2% 7.3% 7.4% 7.5%

Real Estate/Rental and Lease 3.7% 3.0% 2.9% 2.9% 2.9% 2.9% 2.9% 2.8% 2.8% 2.8% 2.7%

Professional and Technical Services 8.3% 9.5% 9.7% 9.7% 9.8% 9.8% 9.9% 10.1% 10.5% 10.8% 11.3%

Management 1.3% 1.6% 1.7% 1.7% 1.7% 1.7% 1.8% 1.9% 2.1% 2.2% 2.6%

Administrative and Waste Services 6.2% 4.9% 4.9% 5.0% 5.0% 5.1% 5.1% 5.3% 5.6% 5.8% 6.4%

Educational Services 1.5% 2.0% 2.1% 2.2% 2.2% 2.2% 2.2% 2.3% 2.5% 2.7% 3.0%
Tables Tables-59

Table 4-15. Demographic and Employment Baseline Projections for Economic Impact Area FL-4 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Health Care and Social Assistance 9.5% 12.1% 12.1% 12.2% 12.2% 12.3% 12.4% 12.7% 13.1% 13.4% 14.1%

Arts, Entertainment, and Recreation 1.6% 1.7% 1.7% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.7%

Accommodation and Food Services 4.3% 4.5% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7% 4.7%

Other Services, Except Public 

Administration

4.2% 4.6% 4.6% 4.6% 4.7% 4.7% 4.7% 4.8% 4.8% 4.9% 5.0%

Federal Civilian Government 2.2% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.5% 2.4% 2.4%

Federal Military 0.6% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.6% 0.6%

State and Local Government 11.8% 13.1% 12.6% 12.5% 12.4% 12.3% 12.3% 11.9% 11.4% 11.0% 10.1%

Total Personal Income per Capita 

(in 2005 dollars)

40,637 40,179 40,450 40,704 41,055 41,486 41,976 44,366 49,014 53,636 64,938

Woods & Poole Economics Wealth 

Index (U.S. = 100)

118.7 115.8 114.7 114.6 114.5 114.5 114.6 115.1 116.6 118.1 121.3

Persons per Household 

(in number of people)

2.5 2.6 2.6 2.6 2.6 2.6 2.6 2.5 2.5 2.6 2.6

Mean Household Total Personal 

Income (in 2005 dollars)

102,546 104,107 104,480 106,007 106,300 106,859 107,629 112,733 124,847 137,930 170,766

Number of Households (in thousands) 2,351.92 2,381.27 2,428.65 2,439.31 2,484.99 2,530.07 2,574.19 2,731.85 2,931.79 3,076.48 3,350.01

Income < $10,000 

(thousands of households, 2000$)

7.6% 8.2% 8.6% 8.7% 8.7% 8.6% 8.5% 7.9% 7.1% 6.4% 5.1%

Income $10,000 to $19,999 11.2% 12.2% 12.6% 12.6% 12.5% 12.4% 12.3% 11.5% 10.3% 9.3% 7.4%

Income $20,000 to $29,999 11.3% 11.9% 12.0% 12.2% 12.1% 12.0% 11.9% 11.1% 10.0% 9.0% 7.2%

Income $30,000 to $44,999 15.5% 16.1% 16.3% 16.2% 16.1% 16.0% 15.9% 14.9% 13.3% 12.1% 9.6%

Income $45,000 to $59,999 13.2% 12.8% 12.7% 12.6% 12.7% 12.8% 12.8% 13.2% 13.1% 12.3% 9.8%

Income $60,000 to $74,999 9.8% 9.8% 10.0% 9.8% 9.8% 9.9% 10.0% 10.7% 12.0% 13.0% 13.0%

Income $75,000 to $99,999 11.7% 10.9% 10.6% 10.7% 10.8% 10.9% 11.0% 11.8% 13.2% 14.7% 18.4%

Income $100,000 or more 19.8% 18.1% 17.2% 17.1% 17.2% 17.3% 17.5% 18.7% 21.0% 23.3% 29.4%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
 

Tables- 60 Central and Eastern Planning Areas Supplemental EIS

Table 4-16

Demographic and Employment Baseline Projections for Economic Impact Area LA-1 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 338.48 346.02 346.51 349.98 353.51 357.09 360.70 375.28 397.29 415.28 450.15

Age Under 19 Years 29.3% 28.5% 28.0% 28.2% 28.3% 28.3% 28.3% 28.7% 28.9% 28.5% 27.5%

Age 20 to 34 21.6% 21.3% 21.5% 21.2% 20.9% 20.7% 20.4% 18.8% 17.8% 18.2% 19.5%

Age 35 to 49 20.9% 19.3% 19.0% 18.8% 18.6% 18.5% 18.5% 19.1% 19.4% 18.5% 16.6%

Age 50 to 64 16.4% 18.5% 18.9% 18.9% 19.1% 19.2% 19.2% 18.7% 17.3% 16.8% 18.0%

Age 65 and over 11.8% 12.4% 12.6% 12.9% 13.1% 13.3% 13.5% 14.7% 16.7% 17.9% 18.3%

Median Age of Population (years) 34.9 36.2 36.3 36.4 36.5 36.6 36.8 37.4 38.0 38.2 38.4

White Population (in thousands) 74.8% 73.4% 73.0% 72.8% 72.7% 72.6% 72.5% 72.0% 71.2% 70.5% 69.1%

Black Population (in thousands) 20.7% 21.4% 21.6% 21.6% 21.6% 21.6% 21.6% 21.6% 21.6% 21.7% 21.7%

Native American Population (in thousands) 0.7% 0.9% 0.8% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9%

Asian and Pacific Islander Population (in thousands) 1.0% 1.2% 1.2% 1.3% 1.3% 1.3% 1.3% 1.4% 1.6% 1.7% 1.9%

Hispanic or Latino Population (in thousands) 2.7% 3.1% 3.3% 3.4% 3.5% 3.6% 3.7% 4.1% 4.6% 5.2% 6.4%

Male Population (in thousands) 50.0% 50.0% 49.9% 49.9% 50.0% 50.0% 50.0% 50.1% 50.1% 50.1% 50.1%

Total Employment (in thousands of jobs) 171.65 177.97 179.50 181.84 184.23 186.63 189.07 199.12 215.11 229.33 260.40

Farm Employment 1.9% 2.0% 1.9% 1.9% 1.9% 1.9% 1.8% 1.8% 1.7% 1.6% 1.4%

Forestry, Fishing, Related Activities 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 0.9% 0.9% 0.9%

Mining 1.1% 1.3% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.5% 1.5% 1.5%

Utilities 0.3% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.3% 0.3% 0.3% 0.2%

Construction 8.7% 8.0% 7.9% 7.9% 7.9% 7.9% 7.9% 8.0% 8.0% 8.0% 7.9%

Manufacturing 6.7% 6.5% 6.4% 6.3% 6.2% 6.1% 5.9% 5.5% 4.9% 4.4% 3.5%

Wholesale Trade 2.2% 2.1% 2.2% 2.2% 2.1% 2.1% 2.1% 2.0% 1.9% 1.8% 1.6%

Retail Trade 11.0% 10.2% 10.1% 10.2% 10.2% 10.2% 10.3% 10.4% 10.6% 10.8% 11.0%

Transportation and Warehousing 3.2% 2.8% 3.0% 3.0% 3.0% 3.0% 3.0% 3.0% 3.1% 3.1% 3.1%

Information Employment 1.0% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.6%

Finance and Insurance 2.5% 3.0% 3.0% 3.0% 3.0% 3.0% 3.0% 3.0% 2.9% 2.8% 2.7%

Real Estate/Rental and Lease 2.4% 3.0% 3.2% 3.2% 3.2% 3.2% 3.2% 3.2% 3.3% 3.3% 3.4%

Professional and Technical Services 4.7% 4.3% 4.4% 4.4% 4.5% 4.5% 4.5% 4.7% 4.9% 5.1% 5.4%
Tables Tables-61

Table 4-16. Demographic and Employment Baseline Projections for Economic Impact Area LA-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Management 0.7% 0.8% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7%

Administrative and Waste Services 3.8% 4.2% 4.3% 4.3% 4.4% 4.4% 4.4% 4.6% 4.9% 5.1% 5.6%

Educational Services 1.0% 1.1% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2%

Health Care and Social Assistance 9.5% 10.3% 10.3% 10.4% 10.6% 10.7% 10.8% 11.4% 12.2% 12.9% 14.4%

Arts, Entertainment, and Recreation 2.3% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.3% 1.3% 1.2% 1.1%

Accommodation and Food Services 7.9% 7.8% 7.9% 8.0% 8.0% 8.1% 8.1% 8.3% 8.5% 8.7% 9.1%

Other Services, Except Public Administration 6.2% 6.2% 6.2% 6.2% 6.3% 6.4% 6.4% 6.6% 6.9% 7.2% 7.7%

Federal Civilian Government 2.1% 2.2% 2.1% 2.1% 2.1% 2.1% 2.0% 2.0% 1.8% 1.8% 1.6%

Federal Military 5.7% 6.3% 6.4% 6.3% 6.3% 6.2% 6.1% 5.8% 5.4% 5.1% 4.5%

State and Local Government 14.0% 14.2% 13.9% 13.8% 13.7% 13.6% 13.4% 13.0% 12.3% 11.8% 10.7%

Total Earnings (in millions of 2005 dollars) 7,449.88 8,254.72 8,481.64 8,757.57 8,945.94 9,138.23 9,334.50 10,160.97 11,534.46 12,814.51 15,798.99

Farm 0.5% 0.3% 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4% 0.4%

Forestry, Fishing, Related Activities 0.7% 0.8% 0.8% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.6%

Mining 1.7% 1.4% 1.5% 1.8% 1.8% 1.8% 1.9% 1.9% 1.9% 2.0% 2.0%

Utilities 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.7% 0.6%

Construction 7.6% 8.6% 8.4% 8.2% 8.2% 8.2% 8.1% 8.0% 7.7% 7.5% 7.0%

Manufacturing 14.6% 14.0% 14.2% 13.8% 13.6% 13.3% 13.1% 12.2% 11.0% 10.1% 8.3%

Wholesale Trade 2.7% 2.6% 2.6% 2.6% 2.6% 2.6% 2.6% 2.5% 2.4% 2.3% 2.2%

Retail Trade 6.3% 5.6% 5.5% 5.4% 5.4% 5.4% 5.4% 5.3% 5.1% 5.0% 4.7%

Transportation and Warehousing 3.6% 3.3% 3.4% 3.4% 3.4% 3.4% 3.4% 3.4% 3.3% 3.3% 3.3%

Information 2.6% 1.0% 0.9% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.2%

Finance and Insurance 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.2% 2.2% 2.2% 2.2%

Real Estate/Rental and Lease 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2%

Professional and Technical Services 5.4% 5.0% 5.0% 5.0% 5.1% 5.1% 5.2% 5.5% 5.9% 6.3% 7.0%

Management 1.5% 0.6% 0.6% 0.7% 0.7% 0.7% 0.8% 0.8% 0.8% 0.9% 0.9%

Administrative and Waste Services 2.3% 2.3% 2.4% 2.4% 2.4% 2.4% 2.5% 2.6% 2.9% 3.1% 3.5%

Educational Services 0.6% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.8% 0.8% 0.8% 0.8%

Health Care and Social Assistance 8.7% 10.2% 10.3% 10.4% 10.5% 10.7% 10.9% 11.5% 12.6% 13.5% 15.5%

Arts, Entertainment, and Recreation 1.5% 0.6% 0.7% 0.7% 0.7% 0.6% 0.6% 0.6% 0.6% 0.6% 0.5%

Accommodation and Food Services 3.7% 3.8% 3.7% 3.7% 3.7% 3.8% 3.8% 3.9% 4.1% 4.2% 4.4%

Other Services, Except Public Administration 3.7% 3.6% 3.5% 3.5% 3.5% 3.6% 3.6% 3.7% 3.9% 4.1% 4.4%
 

Tables- 62 Central and Eastern Planning Areas Supplemental EIS

Table 4-16. Demographic and Employment Baseline Projections for Economic Impact Area LA-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Federal Civilian Government 3.8% 3.9% 3.8% 3.8% 3.8% 3.8% 3.7% 3.7% 3.7% 3.6% 3.5%

Federal Military 10.6% 13.2% 14.1% 14.0% 14.0% 14.0% 14.0% 14.1% 14.2% 14.3% 14.4%

State and Local Government 13.8% 14.1% 13.4% 13.2% 13.1% 13.1% 13.0% 12.8% 12.4% 12.1% 11.4%

Total Personal Income per Capita (in 2005 dollars) 29,511 32,958 34,005 34,470 34,772 35,111 35,480 37,175 40,274 43,278 50,426

Woods & Poole Economics Wealth Index 

(U.S. = 100)

69.2 81.0 81.4 81.8 81.8 81.8 81.8 81.6 81.3 80.9 80.3

Persons per Household (in number of people) 2.6 2.7 2.7 2.7 2.7 2.6 2.6 2.6 2.6 2.6 2.6

Mean Household Total Personal Income 

(in 2005 dollars)

77,937 88,001 90,444 92,356 92,519 92,834 93,279 96,428 104,035 112,254 132,305

Number of Households (in thousands) 128.17 129.59 130.28 130.62 132.86 135.06 137.19 144.68 153.80 160.11 171.57

Income < $10,000 (thousands of households, 2000$) 10.4% 9.4% 9.6% 9.4% 9.3% 9.2% 9.1% 8.7% 7.9% 7.1% 5.8%

Income $10,000 to $19,999 15.0% 14.3% 14.0% 13.9% 13.9% 13.7% 13.6% 12.9% 11.7% 10.5% 8.6%

Income $20,000 to $29,999 12.8% 12.8% 13.4% 13.3% 13.2% 13.1% 13.0% 12.4% 11.1% 10.1% 8.2%

Income $30,000 to $44,999 17.5% 16.5% 16.3% 15.9% 15.8% 15.7% 15.6% 14.9% 13.5% 12.1% 9.9%

Income $45,000 to $59,999 12.5% 12.7% 12.3% 12.4% 12.4% 12.6% 12.7% 13.2% 13.7% 13.5% 11.3%

Income $60,000 to $74,999 9.1% 9.9% 9.7% 9.7% 9.8% 9.9% 10.0% 10.5% 11.6% 12.7% 14.4%

Income $75,000 to $99,999 10.6% 10.9% 11.1% 11.2% 11.2% 11.4% 11.5% 12.1% 13.5% 15.0% 18.3%

Income $100,000 or more 12.0% 13.5% 13.5% 14.2% 14.3% 14.5% 14.6% 15.4% 17.1% 19.0% 23.3%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-63

Table 4-17

Demographic and Employment Baseline Projections for Economic Impact Area LA-2 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 558.42 585.06 588.41 596.10 603.94 611.91 619.95 652.85 703.71 746.69 833.85

Age Under 19 Years 30.0% 29.0% 28.6% 28.5% 28.5% 28.5% 28.5% 28.6% 28.5% 28.1% 26.9%

Age 20 to 34 20.6% 21.1% 21.4% 21.3% 21.2% 21.0% 20.7% 19.4% 17.9% 17.9% 19.0%

Age 35 to 49 21.8% 19.5% 19.1% 18.7% 18.4% 18.2% 18.2% 18.5% 19.7% 19.4% 17.5%

Age 50 to 64 16.1% 18.6% 19.0% 19.3% 19.5% 19.6% 19.6% 19.3% 17.3% 16.4% 18.3%

Age 65 and over 11.5% 11.9% 12.0% 12.2% 12.5% 12.7% 13.0% 14.1% 16.6% 18.1% 18.4%

Median Age of Population (years) 35.0 35.7 35.7 35.8 36.0 36.1 36.2 37.0 38.1 38.9 39.2

White Population (in thousands) 69.3% 67.6% 67.4% 67.2% 67.1% 66.9% 66.8% 66.2% 65.2% 64.4% 62.6%

Black Population (in thousands) 27.1% 27.9% 27.9% 28.0% 28.0% 28.0% 28.0% 28.1% 28.3% 28.4% 28.7%

Native American Population (in thousands) 0.3% 0.3% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4%

Asian and Pacific Islander Population 

(in thousands)

1.2% 1.3% 1.4% 1.4% 1.4% 1.4% 1.4% 1.5% 1.7% 1.8% 1.9%

Hispanic or Latino Population 

(in thousands)

2.1% 2.8% 3.0% 3.1% 3.2% 3.3% 3.4% 3.8% 4.4% 5.1% 6.4%

Male Population (in thousands) 48.7% 48.8% 48.8% 48.8% 48.8% 48.8% 48.9% 49.0% 49.1% 49.1% 49.2%

Total Employment (in thousands of jobs) 297.51 328.88 333.42 339.08 344.80 350.61 356.48 380.77 419.58 454.23 530.17

Farm Employment 1.9% 1.8% 1.7% 1.7% 1.7% 1.7% 1.6% 1.5% 1.4% 1.3% 1.1%

Forestry, Fishing, Related Activities 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6%

Mining 6.9% 7.8% 8.1% 8.0% 7.9% 7.9% 7.8% 7.5% 7.1% 6.8% 6.2%

Utilities 0.2% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

Construction 6.7% 6.3% 6.1% 6.1% 6.1% 6.1% 6.0% 6.0% 6.0% 5.9% 5.8%

Manufacturing 6.1% 5.8% 6.2% 6.1% 6.0% 6.0% 5.9% 5.6% 5.2% 4.9% 4.3%

Wholesale Trade 3.7% 3.6% 3.6% 3.6% 3.6% 3.5% 3.5% 3.5% 3.4% 3.3% 3.1%

Retail Trade 11.5% 10.8% 10.8% 10.8% 10.8% 10.8% 10.8% 10.9% 10.9% 10.9% 10.9%

Transportation and Warehousing 3.5% 2.9% 2.8% 2.8% 2.9% 2.9% 2.9% 2.9% 2.9% 3.0% 3.1%

Information Employment 1.5% 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1%

Finance and Insurance 3.4% 3.6% 3.6% 3.6% 3.6% 3.6% 3.5% 3.4% 3.3% 3.2% 2.9%

Real Estate/Rental and Lease 4.0% 4.5% 4.6% 4.6% 4.6% 4.6% 4.6% 4.6% 4.6% 4.7% 4.7%
 

Tables- 64 Central and Eastern Planning Areas Supplemental EIS

Table 4-17. Demographic and Employment Baseline Projections for Economic Impact Area LA-2 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Professional and Technical Services 4.7% 5.2% 5.2% 5.2% 5.3% 5.3% 5.3% 5.3% 5.4% 5.5% 5.6%

Management 1.1% 1.3% 1.3% 1.3% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2%

Administrative and Waste Services 4.6% 4.8% 4.8% 4.8% 4.8% 4.8% 4.8% 4.9% 5.1% 5.2% 5.3%

Educational Services 1.2% 1.3% 1.3% 1.3% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.5%

Health Care and Social Assistance 11.2% 12.0% 12.2% 12.4% 12.5% 12.7% 12.9% 13.5% 14.5% 15.4% 17.1%

Arts, Entertainment, and Recreation 1.5% 1.7% 1.7% 1.7% 1.7% 1.7% 1.7% 1.8% 1.9% 2.0% 2.1%

Accommodation and Food Services 6.4% 6.1% 6.1% 6.2% 6.2% 6.2% 6.2% 6.3% 6.4% 6.5% 6.6%

Other Services, Except Public 

Administration

7.0% 6.7% 6.5% 6.6% 6.6% 6.7% 6.7% 6.9% 7.2% 7.4% 7.9%

Federal Civilian Government 0.6% 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4% 0.3% 0.3%

Federal Military 0.9% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.6% 0.5%

State and Local Government 10.8% 10.4% 9.9% 9.9% 9.8% 9.7% 9.7% 9.4% 9.0% 8.6% 7.9%

Total Earnings (in millions of 2005 dollars) 12,447.44 15,056.94 15,441.31 15,733.44 16,146.69 16,569.39 17,001.76 18,831.45 21,898.55 24,779.07 31,546.99

Farm 0.8% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.1% 1.0% 0.9% 0.8%

Forestry, Fishing, Related Activities 0.3% 0.3% 0.2% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2%

Mining 13.7% 14.1% 14.5% 14.2% 14.1% 14.1% 14.0% 13.7% 13.3% 13.0% 12.2%

Utilities 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5%

Construction 7.1% 7.4% 7.4% 7.3% 7.2% 7.2% 7.1% 6.9% 6.6% 6.3% 5.8%

Manufacturing 7.5% 7.8% 8.6% 8.5% 8.4% 8.4% 8.3% 8.1% 7.8% 7.5% 7.0%

Wholesale Trade 4.7% 4.7% 4.7% 4.8% 4.8% 4.8% 4.8% 4.7% 4.6% 4.6% 4.4%

Retail Trade 7.9% 6.8% 6.9% 6.9% 6.8% 6.8% 6.7% 6.5% 6.2% 5.9% 5.4%

Transportation and Warehousing 4.6% 4.3% 4.1% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 3.8% 3.8%

Information 1.7% 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.2% 1.2% 1.3% 1.3%

Finance and Insurance 4.1% 2.9% 2.8% 2.9% 2.8% 2.8% 2.8% 2.7% 2.7% 2.6% 2.4%

Real Estate/Rental and Lease 3.5% 3.6% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 3.8% 3.8% 3.8%

Professional and Technical Services 6.0% 6.4% 6.7% 6.8% 6.8% 6.9% 6.9% 7.2% 7.5% 7.8% 8.3%

Management 1.6% 1.6% 1.5% 1.5% 1.6% 1.6% 1.6% 1.6% 1.7% 1.8% 1.9%

Administrative and Waste Services 3.1% 3.2% 3.0% 3.1% 3.1% 3.1% 3.1% 3.2% 3.4% 3.5% 3.7%

Educational Services 0.7% 0.8% 0.8% 0.8% 0.9% 0.9% 0.9% 0.9% 0.9% 1.0% 1.1%

Health Care and Social Assistance 11.3% 12.6% 12.2% 12.5% 12.7% 12.9% 13.0% 13.8% 14.9% 15.9% 17.9%

Arts, Entertainment, and Recreation 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.6% 0.6%
Tables Tables-65

Table 4-17. Demographic and Employment Baseline Projections for Economic Impact Area LA-2 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Accommodation and Food Services 2.5% 2.5% 2.5% 2.5% 2.5% 2.6% 2.6% 2.6% 2.7% 2.7% 2.8%

Other Services, Except Public 

Administration

4.5% 4.6% 4.4% 4.4% 4.4% 4.5% 4.5% 4.6% 4.8% 5.0% 5.3%

Federal Civilian Government 1.2% 1.1% 1.0% 1.0% 1.0% 1.0% 1.0% 0.9% 0.9% 0.8% 0.7%

Federal Military 0.9% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8%

State and Local Government 11.3% 11.2% 10.6% 10.6% 10.6% 10.5% 10.5% 10.3% 10.1% 9.8% 9.3%

Total Personal Income per Capita 

(in 2005 dollars)

30,899 36,282 37,161 37,038 37,371 37,748 38,158 40,046 43,488 46,795 54,565

Woods & Poole Economics Wealth Index 

(U.S. = 100)

72.9 84.2 84.3 83.5 83.5 83.5 83.4 83.2 82.8 82.4 81.6

Persons per Household (in number of people) 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.5 2.5 2.5 2.6

Mean Household Total Personal Income 

(in 2005 dollars)

81,039 95,267 97,212 97,581 97,754 98,095 98,577 101,968 110,105 118,808 139,762

Number of Households (in thousands) 212.92 222.81 224.93 226.26 230.88 235.47 239.98 256.40 277.94 294.10 325.54

Income < $10,000 

(thousands of households, 2000$)

13.9% 12.3% 12.2% 11.5% 11.4% 11.2% 11.1% 10.7% 9.6% 8.7% 7.1%

Income $10,000 to $19,999 15.5% 15.5% 15.7% 15.6% 15.5% 15.3% 15.2% 14.5% 13.0% 11.8% 9.6%

Income $20,000 to $29,999 12.6% 12.0% 11.4% 11.8% 11.7% 11.6% 11.5% 11.0% 9.9% 9.0% 7.4%

Income $30,000 to $44,999 15.4% 15.0% 15.4% 14.9% 14.8% 14.8% 14.7% 14.4% 13.2% 12.0% 9.9%

Income $45,000 to $59,999 11.7% 11.6% 11.6% 11.8% 11.8% 11.9% 12.0% 12.4% 13.1% 13.0% 11.4%

Income $60,000 to $74,999 8.7% 9.2% 9.2% 8.9% 8.9% 9.0% 9.1% 9.5% 10.5% 11.6% 13.2%

Income $75,000 to $99,999 9.7% 10.2% 10.1% 10.9% 11.0% 11.1% 11.2% 11.7% 12.9% 14.3% 17.4%

Income $100,000 or more 12.6% 14.3% 14.3% 14.7% 14.9% 15.0% 15.2% 15.8% 17.6% 19.6% 24.0%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
 

Tables- 66 Central and Eastern Planning Areas Supplemental EIS

Table 4-18

Demographic and Employment Baseline Projections for Economic Impact Area LA-3 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 1,051.06 1,142.41 1,147.53 1,162.47 1,177.70 1,193.18 1,208.79 1,272.50 1,370.62 1,453.15 1,619.45

Age Under 19 Years 29.6% 28.3% 28.0% 27.9% 27.9% 27.9% 27.9% 27.9% 28.0% 27.6% 26.6%

Age 20 to 34 22.3% 22.8% 22.9% 22.8% 22.7% 22.5% 22.2% 20.7% 18.8% 18.4% 19.1%

Age 35 to 49 21.5% 19.6% 19.2% 18.9% 18.7% 18.5% 18.4% 19.0% 20.1% 20.0% 17.8%

Age 50 to 64 16.4% 18.3% 18.6% 18.7% 18.9% 18.9% 19.0% 18.4% 16.9% 16.3% 18.4%

Age 65 and over 10.3% 11.0% 11.3% 11.6% 11.9% 12.2% 12.6% 13.9% 16.2% 17.6% 18.0%

Median Age of Population (years) 34.6 35.7 35.8 36.0 36.2 36.4 36.5 37.5 38.9 39.9 40.5

White Population (in thousands) 65.3% 62.4% 62.2% 61.9% 61.7% 61.5% 61.2% 60.3% 59.0% 57.9% 55.5%

Black Population (in thousands) 29.4% 31.1% 31.1% 31.2% 31.3% 31.4% 31.4% 31.7% 32.2% 32.5% 33.0%

Native American Population (in thousands) 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.2% 1.2% 1.2%

Asian and Pacific Islander Population 

(in thousands)

1.5% 1.7% 1.7% 1.7% 1.8% 1.8% 1.8% 2.0% 2.1% 2.2% 2.5%

Hispanic or Latino Population 

(in thousands)

2.6% 3.7% 3.9% 4.0% 4.1% 4.3% 4.4% 4.9% 5.5% 6.2% 7.9%

Male Population (in thousands) 48.7% 48.9% 48.8% 48.8% 48.8% 48.9% 48.9% 48.9% 49.0% 49.0% 49.1%

Total Employment (in thousands of jobs) 606.81 674.25 681.06 691.34 701.78 712.40 723.17 767.88 840.17 905.55 1,051.77

Farm Employment 0.7% 0.7% 0.7% 0.6% 0.6% 0.6% 0.6% 0.6% 0.5% 0.5% 0.4%

Forestry, Fishing, Related Activities 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.6% 0.6% 0.6%

Mining 1.5% 2.0% 1.9% 1.9% 1.9% 1.8% 1.8% 1.7% 1.6% 1.5% 1.3%

Utilities 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2% 0.2% 0.2% 0.2%

Construction 9.8% 8.9% 8.9% 8.8% 8.8% 8.7% 8.6% 8.4% 8.0% 7.6% 7.0%

Manufacturing 6.8% 6.2% 6.4% 6.3% 6.2% 6.1% 6.0% 5.7% 5.2% 4.7% 4.0%

Wholesale Trade 3.2% 2.8% 2.9% 2.9% 2.8% 2.8% 2.8% 2.7% 2.6% 2.5% 2.3%

Retail Trade 10.9% 10.3% 10.2% 10.2% 10.1% 10.1% 10.0% 9.8% 9.5% 9.2% 8.5%

Transportation and Warehousing 4.4% 4.3% 4.4% 4.4% 4.4% 4.4% 4.4% 4.4% 4.5% 4.5% 4.5%

Information Employment 1.4% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.0% 1.0% 0.9%

Finance and Insurance 3.5% 3.9% 4.1% 4.1% 4.0% 4.0% 4.0% 4.0% 3.9% 3.8% 3.5%

Real Estate/Rental and Lease 3.6% 4.2% 4.2% 4.2% 4.2% 4.2% 4.2% 4.2% 4.2% 4.2% 4.2%
Tables Tables-67

Table 4-18. Demographic and Employment Baseline Projections for Economic Impact Area LA-3 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Professional and Technical Services 4.8% 5.2% 5.1% 5.2% 5.2% 5.3% 5.3% 5.5% 5.7% 5.9% 6.3%

Management 1.0% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.3% 1.3%

Administrative and Waste Services 5.8% 6.2% 6.3% 6.4% 6.5% 6.7% 6.8% 7.2% 7.9% 8.5% 9.8%

Educational Services 1.1% 1.4% 1.4% 1.4% 1.4% 1.5% 1.5% 1.5% 1.7% 1.8% 2.0%

Health Care and Social Assistance 8.8% 9.8% 9.9% 10.0% 10.2% 10.3% 10.4% 11.0% 11.8% 12.5% 13.9%

Arts, Entertainment, and Recreation 1.3% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.7% 1.7% 1.8% 1.9%

Accommodation and Food Services 6.6% 6.3% 6.6% 6.7% 6.7% 6.8% 6.8% 7.0% 7.2% 7.5% 7.9%

Other Services, Except Public Administration 6.7% 6.9% 6.8% 6.9% 7.0% 7.0% 7.1% 7.4% 7.9% 8.3% 9.0%

Federal Civilian Government 0.6% 0.7% 0.6% 0.6% 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4%

Federal Military 0.8% 0.9% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.6%

State and Local Government 15.6% 14.5% 14.0% 13.8% 13.7% 13.5% 13.4% 12.8% 11.9% 11.2% 9.8%

Total Earnings (in millions of 2005 dollars) 26,073.66 31,814.85 32,091.25 32,704.47 33,455.43 34,223.77 35,009.88 38,340.94 43,948.74 49,252.34 61,885.78

Farm 0.3% 0.4% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2% 0.2% 0.2% 0.2%

Forestry, Fishing, Related Activities 0.3% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Mining 2.6% 3.0% 2.7% 2.8% 2.8% 2.7% 2.7% 2.6% 2.5% 2.4% 2.1%

Utilities 0.7% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4%

Construction 10.3% 11.0% 11.0% 10.7% 10.5% 10.4% 10.3% 9.8% 9.0% 8.4% 7.3%

Manufacturing 12.4% 11.7% 12.3% 12.4% 12.2% 12.1% 11.9% 11.4% 10.5% 9.9% 8.5%

Wholesale Trade 4.4% 3.9% 4.0% 4.0% 4.0% 4.0% 4.0% 3.9% 3.8% 3.7% 3.5%

Retail Trade 7.2% 6.2% 6.2% 6.2% 6.1% 6.0% 5.9% 5.6% 5.2% 4.8% 4.2%

Transportation and Warehousing 6.0% 7.3% 7.5% 7.7% 7.7% 7.7% 7.7% 7.8% 7.8% 7.8% 7.7%

Information 1.7% 1.3% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4%

Finance and Insurance 4.3% 4.2% 4.5% 4.2% 4.2% 4.3% 4.3% 4.3% 4.3% 4.3% 4.2%

Real Estate/Rental and Lease 2.1% 2.3% 2.2% 2.1% 2.1% 2.1% 2.1% 2.1% 2.0% 2.0% 1.9%

Professional and Technical Services 6.0% 6.4% 6.3% 6.5% 6.5% 6.6% 6.7% 7.1% 7.7% 8.1% 9.1%

Management 1.4% 1.7% 1.7% 1.8% 1.8% 1.8% 1.9% 2.0% 2.2% 2.4% 2.8%

Administrative and Waste Services 3.5% 3.9% 3.9% 3.9% 4.0% 4.1% 4.2% 4.6% 5.3% 5.8% 7.1%

Educational Services 0.6% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.8% 0.9% 0.9% 1.1%

Health Care and Social Assistance 9.2% 9.6% 9.6% 9.8% 10.0% 10.2% 10.3% 11.0% 12.1% 12.9% 14.7%

Arts, Entertainment, and Recreation 0.7% 0.6% 0.6% 0.5% 0.5% 0.5% 0.6% 0.6% 0.6% 0.6% 0.7%

Accommodation and Food Services 2.7% 2.5% 2.6% 2.7% 2.7% 2.7% 2.7% 2.8% 3.0% 3.1% 3.3%
 

Tables- 68 Central and Eastern Planning Areas Supplemental EIS

Table 4-18. Demographic and Employment Baseline Projections for Economic Impact Area LA-3 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Other Services, Except Public Administration 4.1% 4.0% 4.0% 4.0% 4.1% 4.1% 4.2% 4.3% 4.6% 4.8% 5.2%

Federal Civilian Government 1.2% 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.0%

Federal Military 0.9% 1.0% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9%

State and Local Government 17.5% 16.5% 15.8% 15.7% 15.6% 15.5% 15.4% 15.0% 14.4% 13.8% 12.6%

Total Personal Income per Capita 

(in 2005 dollars)

32,957 36,886 37,501 37,603 37,902 38,242 38,616 40,361 43,609 46,795 54,473

Woods & Poole Economics Wealth Index 

(U.S. = 100)

78.2 89.3 89.2 88.6 88.5 88.5 88.4 88.1 87.7 87.4 87.2

Persons per Household (in number of people) 2.7 2.7 2.7 2.7 2.7 2.7 2.6 2.6 2.6 2.6 2.6

Mean Household Total Personal Income 

(in 2005 dollars)

87,838 98,809 100,044 101,039 101,133 101,396 101,805 104,964 112,932 121,677 143,312

Number of Households (in thousands) 394.36 426.46 430.14 432.63 441.37 450.02 458.52 489.30 529.27 558.86 615.56

Income < $10,000 

(thousands of households, 2000$)

10.7% 9.7% 9.7% 9.2% 9.2% 9.1% 9.0% 8.6% 7.7% 7.0% 5.8%

Income $10,000 to $19,999 13.1% 13.4% 13.4% 13.5% 13.4% 13.3% 13.2% 12.5% 11.3% 10.3% 8.5%

Income $20,000 to $29,999 11.6% 11.3% 11.3% 11.2% 11.2% 11.1% 10.9% 10.4% 9.4% 8.6% 7.1%

Income $30,000 to $44,999 15.6% 14.9% 15.1% 14.6% 14.6% 14.5% 14.4% 13.8% 12.5% 11.4% 9.5%

Income $45,000 to $59,999 12.3% 12.1% 11.9% 11.8% 11.8% 11.9% 11.9% 12.1% 12.1% 11.4% 9.5%

Income $60,000 to $74,999 9.6% 9.7% 9.9% 9.8% 9.8% 9.9% 10.0% 10.5% 11.5% 12.3% 12.5%

Income $75,000 to $99,999 11.6% 11.6% 11.5% 12.2% 12.2% 12.3% 12.5% 13.1% 14.5% 15.9% 19.2%

Income $100,000 or more 15.6% 17.3% 17.2% 17.7% 17.8% 18.0% 18.1% 19.0% 21.0% 23.0% 27.9%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-69

Table 4-19

Demographic and Employment Baseline Projections for Economic Impact Area LA-4 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 1,431.31 1,242.69 1,260.01 1,267.26 1,274.66 1,282.17 1,289.69 1,319.60 1,362.75 1,395.73 1,453.72

Age Under 19 Years 28.0% 26.1% 25.8% 25.8% 25.7% 25.7% 25.7% 26.0% 26.0% 25.7% 24.8%

Age 20 to 34 20.6% 21.3% 21.5% 21.4% 21.3% 21.1% 20.8% 19.1% 17.2% 17.3% 18.5%

Age 35 to 49 22.2% 20.1% 19.6% 19.3% 19.1% 19.0% 18.9% 19.6% 20.8% 20.3% 17.3%

Age 50 to 64 17.9% 20.3% 20.6% 20.7% 20.7% 20.8% 20.8% 20.0% 18.1% 17.5% 19.7%

Age 65 and over 11.4% 12.3% 12.5% 12.8% 13.1% 13.4% 13.8% 15.3% 17.8% 19.3% 19.6%

Median Age of Population (years) 36.0 36.7 36.8 37.0 37.1 37.2 37.3 38.1 39.3 39.8 40.0

White Population (in thousands) 53.7% 54.8% 54.5% 54.3% 54.1% 53.8% 53.6% 52.8% 51.5% 50.4% 48.4%

Black Population (in thousands) 38.1% 34.5% 34.6% 34.6% 34.6% 34.5% 34.5% 34.4% 34.1% 33.9% 33.2%

Native American Population (in thousands) 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.5% 0.5% 0.5%

Asian and Pacific Islander Population (in thousands) 2.4% 2.8% 2.8% 2.9% 2.9% 2.9% 3.0% 3.1% 3.4% 3.6% 3.8%

Hispanic or Latino Population (in thousands) 5.4% 7.6% 7.7% 7.9% 8.1% 8.3% 8.5% 9.3% 10.5% 11.6% 14.2%

Male Population (in thousands) 48.1% 48.7% 48.7% 48.7% 48.7% 48.8% 48.8% 48.9% 48.9% 49.0% 49.0%

Total Employment (in thousands of jobs) 740.50 750.90 758.43 766.12 773.87 781.67 789.50 821.31 870.47 912.81 1,001.64

Farm Employment 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2%

Forestry, Fishing, Related Activities 0.5% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6%

Mining 1.3% 1.5% 1.5% 1.5% 1.5% 1.5% 1.4% 1.4% 1.3% 1.2% 1.0%

Utilities 0.5% 0.4% 0.4% 0.4% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2% 0.2%

Construction 6.2% 6.6% 6.5% 6.5% 6.5% 6.4% 6.4% 6.3% 6.1% 6.0% 5.7%

Manufacturing 5.6% 5.0% 4.8% 4.7% 4.6% 4.5% 4.4% 4.1% 3.6% 3.3% 2.6%

Wholesale Trade 3.6% 3.3% 3.3% 3.3% 3.3% 3.3% 3.3% 3.3% 3.3% 3.3% 3.2%

Retail Trade 10.0% 9.4% 9.5% 9.5% 9.5% 9.5% 9.4% 9.4% 9.3% 9.3% 9.1%

Transportation and Warehousing 4.1% 4.0% 4.1% 4.1% 4.1% 4.1% 4.1% 4.1% 4.0% 4.0% 3.9%

Information Employment 1.6% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.1%

Finance and Insurance 3.9% 4.2% 4.3% 4.3% 4.3% 4.2% 4.2% 4.0% 3.8% 3.6% 3.3%

Real Estate/Rental and Lease 4.0% 4.5% 4.6% 4.6% 4.6% 4.6% 4.6% 4.6% 4.7% 4.7% 4.7%

Professional and Technical Services 5.7% 6.5% 6.5% 6.5% 6.5% 6.5% 6.5% 6.4% 6.4% 6.4% 6.2%

Management 1.1% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2%
 

Tables- 70 Central and Eastern Planning Areas Supplemental EIS

Table 4-19. Demographic and Employment Baseline Projections for Economic Impact Area LA-4 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Administrative and Waste Services 6.4% 6.7% 6.6% 6.6% 6.7% 6.7% 6.8% 7.0% 7.3% 7.5% 8.1%

Educational Services 3.1% 3.2% 3.3% 3.3% 3.3% 3.4% 3.4% 3.4% 3.6% 3.6% 3.8%

Health Care and Social Assistance 8.8% 9.3% 9.4% 9.5% 9.6% 9.7% 9.8% 10.2% 10.8% 11.4% 12.6%

Arts, Entertainment, and Recreation 2.5% 2.5% 2.5% 2.5% 2.5% 2.6% 2.6% 2.7% 2.8% 2.9% 3.1%

Accommodation and Food Services 8.8% 9.0% 9.4% 9.4% 9.5% 9.5% 9.6% 9.8% 10.1% 10.3% 10.7%

Other Services, Except Public Administration 6.5% 6.7% 6.8% 6.8% 6.9% 6.9% 7.0% 7.2% 7.5% 7.8% 8.4%

Federal Civilian Government 2.1% 1.8% 1.7% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.5% 1.4%

Federal Military 1.4% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.1% 1.1% 1.0% 0.9%

State and Local Government 11.9% 11.0% 10.5% 10.4% 10.3% 10.2% 10.1% 9.8% 9.2% 8.7% 7.9%

Total Earnings (in millions of 2005 dollars) 36,490.43 38,052.69 38,259.52 39,141.19 39,862.24 40,594.91 41,339.39 44,439.04 49,474.55 54,052.90 64,373.74

Farm 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1%

Forestry, Fishing, Related Activities 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Mining 4.4% 3.4% 3.5% 3.4% 3.4% 3.4% 3.4% 3.2% 3.1% 2.9% 2.6%

Utilities 1.2% 1.1% 1.1% 1.1% 1.0% 1.0% 1.0% 1.0% 0.9% 0.9% 0.8%

Construction 6.5% 7.4% 7.5% 7.6% 7.5% 7.4% 7.4% 7.1% 6.6% 6.3% 5.6%

Manufacturing 8.6% 9.2% 9.0% 8.7% 8.6% 8.5% 8.3% 7.8% 7.0% 6.5% 5.4%

Wholesale Trade 5.3% 5.1% 5.2% 5.2% 5.2% 5.2% 5.3% 5.4% 5.5% 5.6% 5.7%

Retail Trade 6.2% 5.7% 5.8% 5.7% 5.7% 5.6% 5.6% 5.4% 5.1% 4.9% 4.4%

Transportation and Warehousing 5.1% 5.3% 5.4% 5.4% 5.3% 5.3% 5.2% 5.1% 4.9% 4.7% 4.3%

Information 1.7% 1.4% 1.3% 1.3% 1.4% 1.4% 1.4% 1.4% 1.4% 1.5% 1.5%

Finance and Insurance 5.1% 4.4% 4.6% 4.8% 4.8% 4.8% 4.7% 4.6% 4.4% 4.2% 3.9%

Real Estate/Rental and Lease 2.6% 1.5% 1.5% 1.5% 1.5% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6%

Professional and Technical Services 8.0% 9.5% 9.6% 9.7% 9.7% 9.8% 9.8% 10.0% 10.2% 10.4% 10.6%

Management 1.8% 1.8% 1.9% 2.0% 2.0% 2.0% 2.1% 2.2% 2.3% 2.4% 2.7%

Administrative and Waste Services 4.0% 4.3% 4.0% 4.1% 4.1% 4.2% 4.2% 4.4% 4.7% 5.0% 5.6%

Educational Services 2.2% 2.5% 2.5% 2.5% 2.6% 2.6% 2.6% 2.7% 2.9% 3.0% 3.3%

Health Care and Social Assistance 8.7% 9.5% 9.5% 9.6% 9.7% 9.8% 10.0% 10.5% 11.3% 12.0% 13.4%

Arts, Entertainment, and Recreation 2.1% 1.7% 1.7% 1.7% 1.8% 1.8% 1.8% 1.9% 1.9% 2.0% 2.2%

Accommodation and Food Services 4.4% 4.5% 4.7% 4.7% 4.8% 4.8% 4.8% 5.0% 5.1% 5.3% 5.6%

Other Services, Except Public Administration 3.7% 3.9% 3.9% 4.0% 4.0% 4.0% 4.1% 4.2% 4.4% 4.6% 4.9%

Federal Civilian Government 4.2% 3.6% 3.5% 3.5% 3.5% 3.5% 3.5% 3.6% 3.7% 3.7% 3.9%
Tables Tables-71

Table 4-19. Demographic and Employment Baseline Projections for Economic Impact Area LA-4 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Federal Military 1.8% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.7% 1.7% 1.8%

State and Local Government 12.1% 12.3% 11.7% 11.6% 11.6% 11.5% 11.5% 11.3% 10.9% 10.7% 10.1%

Total Personal Income per Capita (in 2005 dollars) 34,100 41,089 41,125 41,603 41,989 42,430 42,914 45,159 49,294 53,302 62,818

Woods & Poole Economics Wealth Index (U.S. = 100) 77.3 93.7 91.3 90.1 89.9 89.8 89.7 89.1 88.4 87.8 86.7

Persons per Household (in number of people) 2.7 2.6 2.6 2.6 2.6 2.5 2.5 2.5 2.5 2.5 2.5

Mean Household Total Personal Income 

(in 2005 dollars)

91,188 105,654 105,247 107,289 107,566 108,042 108,686 112,963 122,998 133,719 159,824

Number of Households (in thousands) 535.25 483.28 492.35 491.40 497.57 503.54 509.23 527.53 546.16 556.36 571.38

Income < $10,000 (thousands of households, 2000$) 10.8% 9.8% 10.7% 10.6% 10.5% 10.4% 10.3% 9.7% 8.6% 7.7% 6.2%

Income $10,000 to $19,999 13.8% 13.2% 13.3% 13.4% 13.4% 13.2% 13.1% 12.4% 11.1% 10.0% 8.2%

Income $20,000 to $29,999 12.3% 11.9% 11.8% 12.0% 12.0% 11.9% 11.7% 11.2% 10.1% 9.1% 7.6%

Income $30,000 to $44,999 16.0% 15.1% 15.4% 14.9% 14.9% 14.8% 14.7% 14.3% 13.1% 12.0% 10.0%

Income $45,000 to $59,999 12.0% 12.0% 11.9% 11.8% 11.8% 11.9% 12.0% 12.2% 12.3% 12.0% 10.5%

Income $60,000 to $74,999 8.8% 9.5% 9.4% 9.2% 9.2% 9.3% 9.4% 9.9% 10.9% 11.6% 11.9%

Income $75,000 to $99,999 10.6% 11.0% 10.8% 11.0% 11.1% 11.2% 11.3% 11.9% 13.3% 14.7% 17.6%

Income $100,000 or more 16.1% 17.5% 16.7% 17.0% 17.1% 17.3% 17.5% 18.5% 20.7% 22.9% 27.9%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
 

Tables- 72 Central and Eastern Planning Areas Supplemental EIS

Table 4-20

Demographic and Employment Baseline Projections for Economic Impact Area MS-1 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 483.49 482.30 486.36 490.07 493.86 497.70 501.55 516.98 539.66 557.55 590.34

Age Under 19 Years 28.4% 27.7% 27.4% 27.3% 27.2% 27.2% 27.2% 27.6% 27.6% 27.2% 26.4%

Age 20 to 34 19.8% 19.9% 20.1% 20.1% 20.0% 19.8% 19.6% 18.4% 17.6% 17.6% 18.6%

Age 35 to 49 22.0% 20.3% 19.9% 19.6% 19.3% 19.1% 18.9% 19.0% 19.1% 18.9% 17.5%

Age 50 to 64 17.8% 19.4% 19.7% 19.8% 19.9% 20.1% 20.1% 19.7% 18.4% 17.5% 18.1%

Age 65 and over 12.0% 12.7% 12.9% 13.2% 13.6% 13.8% 14.2% 15.3% 17.3% 18.8% 19.3%

Median Age of Population (years) 36.4 37.4 37.5 37.7 37.8 37.9 38.0 38.5 39.0 39.6 39.7

White Population (in thousands) 75.8% 73.9% 73.2% 73.0% 72.8% 72.7% 72.5% 71.8% 70.7% 69.7% 67.9%

Black Population (in thousands) 18.7% 19.3% 19.8% 19.9% 19.9% 20.0% 20.0% 20.3% 20.7% 21.0% 21.5%

Native American Population (in 

thousands)

0.5% 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4% 0.4%

Asian and Pacific Islander Population 

(in thousands)

2.0% 2.1% 2.1% 2.1% 2.1% 2.2% 2.2% 2.2% 2.3% 2.3% 2.3%

Hispanic or Latino Population 

(in thousands)

3.0% 4.2% 4.4% 4.5% 4.6% 4.7% 4.8% 5.3% 5.9% 6.6% 7.9%

Male Population (in thousands) 49.7% 49.9% 49.9% 49.9% 49.8% 49.8% 49.8% 49.8% 49.8% 49.8% 49.7%

Total Employment (in thousands of jobs) 238.83 241.07 237.96 240.09 242.26 244.42 246.60 255.42 269.01 280.64 304.84

Farm Employment 1.4% 1.4% 1.4% 1.4% 1.4% 1.3% 1.3% 1.3% 1.3% 1.3% 1.2%

Forestry, Fishing, Related Activities 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8%

Mining 0.2% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2% 0.2%

Utilities 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.7%

Construction 7.5% 8.0% 7.5% 7.5% 7.5% 7.5% 7.5% 7.5% 7.4% 7.3% 7.2%

Manufacturing 9.5% 9.4% 8.7% 8.6% 8.5% 8.3% 8.2% 7.7% 7.1% 6.5% 5.6%

Wholesale Trade 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.4% 1.3% 1.3%

Retail Trade 10.9% 10.3% 10.5% 10.5% 10.6% 10.6% 10.6% 10.6% 10.7% 10.7% 10.7%

Transportation and Warehousing 2.4% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.2% 2.2%

Information Employment 1.4% 0.9% 0.9% 0.9% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.8%

Finance and Insurance 2.5% 2.9% 2.9% 2.9% 2.9% 2.9% 2.9% 2.9% 2.9% 2.9% 2.9%

Real Estate/Rental and Lease 3.1% 3.4% 3.6% 3.6% 3.6% 3.6% 3.6% 3.7% 3.8% 3.9% 4.0%
Tables Tables-73

Table 4-20. Demographic and Employment Baseline Projections for Economic Impact Area MS-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Professional and Technical Services 3.8% 4.1% 4.1% 4.2% 4.2% 4.2% 4.2% 4.3% 4.5% 4.6% 4.8%

Management 0.5% 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5%

Administrative and Waste Services 5.4% 6.7% 6.4% 6.5% 6.5% 6.6% 6.7% 7.1% 7.6% 8.1% 9.1%

Educational Services 0.5% 0.7% 0.8% 0.8% 0.9% 0.9% 0.9% 1.0% 1.2% 1.3% 1.7%

Health Care and Social Assistance 6.3% 6.4% 6.6% 6.7% 6.7% 6.8% 6.9% 7.1% 7.5% 7.8% 8.4%

Arts, Entertainment, and Recreation 2.2% 2.2% 2.2% 2.2% 2.2% 2.3% 2.3% 2.3% 2.4% 2.5% 2.6%

Accommodation and Food Services 12.0% 10.4% 11.0% 10.9% 10.9% 10.8% 10.8% 10.6% 10.4% 10.1% 9.6%

Other Services, Except Public 

Administration

5.5% 5.0% 5.1% 5.1% 5.2% 5.3% 5.4% 5.7% 6.1% 6.5% 7.4%

Federal Civilian Government 3.9% 3.9% 3.9% 3.9% 3.8% 3.8% 3.8% 3.7% 3.5% 3.4% 3.2%

Federal Military 5.7% 5.5% 5.4% 5.4% 5.3% 5.3% 5.2% 5.1% 4.9% 4.7% 4.3%

State and Local Government 12.3% 12.9% 12.9% 12.8% 12.8% 12.7% 12.7% 12.4% 12.0% 11.7% 11.0%

Total Earnings (in millions of 2005 dollars) 10,100.79 10,982.84 10,749.28 10,953.83 11,146.80 11,342.69 11,541.49 12,366.85 13,699.64 14,902.96 17,585.88

Farm 0.3% 0.0% 0.0% 0.2% 0.2% 0.2% 0.2% 0.2% 0.1% 0.1% 0.1%

Forestry, Fishing, Related Activities 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5%

Mining 0.2% 0.2% 0.2% 0.3% 0.3% 0.3% 0.3% 0.3% 0.2% 0.2% 0.2%

Utilities 2.1% 1.7% 1.8% 1.8% 1.8% 1.8% 1.8% 1.9% 1.9% 1.9% 2.0%

Construction 6.0% 8.1% 7.7% 7.7% 7.6% 7.6% 7.5% 7.3% 7.0% 6.7% 6.2%

Manufacturing 15.4% 16.6% 16.0% 15.7% 15.5% 15.3% 15.2% 14.4% 13.4% 12.5% 10.9%

Wholesale Trade 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.6% 1.5%

Retail Trade 7.0% 6.2% 6.4% 6.3% 6.3% 6.3% 6.2% 6.0% 5.8% 5.5% 5.1%

Transportation and Warehousing 2.3% 2.2% 2.2% 2.2% 2.2% 2.2% 2.1% 2.1% 2.1% 2.0% 1.9%

Information 1.4% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 1.0% 1.0% 1.0%

Finance and Insurance 2.1% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.4% 2.4% 2.4% 2.4%

Real Estate/Rental and Lease 1.0% 0.9% 0.9% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.1%

Professional and Technical Services 4.6% 4.9% 5.0% 5.0% 5.1% 5.1% 5.2% 5.4% 5.7% 6.0% 6.6%

Management 0.6% 0.6% 0.9% 0.7% 0.7% 0.8% 0.8% 0.8% 0.8% 0.9% 1.0%

Administrative and Waste Services 3.1% 3.9% 3.5% 3.6% 3.6% 3.7% 3.7% 3.9% 4.3% 4.6% 5.2%

Educational Services 0.3% 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.6% 0.7% 0.8% 1.1%

Health Care and Social Assistance 6.7% 6.7% 6.8% 6.8% 6.9% 7.0% 7.1% 7.4% 7.8% 8.2% 8.9%

Arts, Entertainment, and Recreation 1.5% 1.1% 1.2% 1.2% 1.2% 1.2% 1.2% 1.3% 1.3% 1.3% 1.4%
 

Tables- 74 Central and Eastern Planning Areas Supplemental EIS

Table 4-20. Demographic and Employment Baseline Projections for Economic Impact Area MS-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Accommodation and Food Services 7.9% 5.9% 6.1% 6.1% 6.1% 6.0% 6.0% 5.9% 5.8% 5.7% 5.4%

Other Services, Except Public 

Administration

3.3% 3.2% 3.2% 3.3% 3.3% 3.3% 3.4% 3.6% 3.9% 4.1% 4.6%

Federal Civilian Government 8.4% 7.9% 8.1% 8.1% 8.1% 8.1% 8.1% 8.2% 8.3% 8.3% 8.4%

Federal Military 10.2% 9.9% 9.8% 9.8% 9.8% 9.9% 9.9% 10.0% 10.2% 10.4% 10.7%

State and Local Government 13.2% 14.4% 14.5% 14.5% 14.5% 14.5% 14.4% 14.3% 14.2% 14.0% 13.7%

Total Personal Income per Capita 

(in 2005 dollars)

29,738 32,644 32,301 32,500 32,751 33,038 33,352 34,810 37,493 40,086 46,208

Woods & Poole Economics Wealth Index 

(U.S. = 100)

67.8 74.6 71.8 71.8 71.7 71.7 71.6 71.1 70.2 69.5 67.9

Persons per Household 

(in number of people)

2.6 2.7 2.7 2.7 2.7 2.6 2.6 2.6 2.6 2.6 2.7

Mean Household Total Personal Income 

(in 2005 dollars)

78,314 87,120 85,836 87,060 87,186 87,453 87,845 90,693 97,647 105,151 123,335

Number of Households (in thousands) 183.59 180.72 183.02 182.95 185.52 188.02 190.43 198.43 207.21 212.55 221.17

Income < $10,000 

(thousands of households, 2000$)

9.5% 8.9% 9.3% 9.3% 9.3% 9.2% 9.1% 8.7% 7.8% 7.0% 5.6%

Income $10,000 to $19,999 13.4% 13.5% 13.5% 13.8% 13.8% 13.7% 13.5% 13.0% 11.7% 10.6% 8.5%

Income $20,000 to $29,999 13.0% 12.5% 12.9% 12.7% 12.6% 12.5% 12.4% 11.8% 10.6% 9.5% 7.6%

Income $30,000 to $44,999 17.9% 16.3% 16.2% 16.2% 16.2% 16.0% 15.9% 15.3% 13.6% 12.3% 9.8%

Income $45,000 to $59,999 13.8% 13.4% 13.5% 13.2% 13.2% 13.4% 13.5% 14.0% 14.6% 14.3% 11.9%

Income $60,000 to $74,999 9.5% 10.6% 10.6% 10.4% 10.4% 10.5% 10.6% 11.1% 12.4% 13.8% 15.7%

Income $75,000 to $99,999 10.7% 11.4% 10.9% 11.4% 11.5% 11.6% 11.7% 12.3% 13.7% 15.3% 19.3%

Income $100,000 or more 12.3% 13.3% 13.1% 13.0% 13.0% 13.2% 13.3% 13.9% 15.6% 17.3% 21.6%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated 

using personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-75

Table 4-21

Demographic and Employment Baseline Projections for Economic Impact Area TX-1 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 1,643.97 1,799.29 1,827.28 1,856.04 1,885.42 1,915.39 1,945.76 2,071.28 2,270.08 2,443.43 2,812.12

Age Under 19 Years 35.4% 34.9% 34.7% 34.5% 34.3% 34.2% 34.1% 33.7% 32.6% 32.2% 31.1%

Age 20 to 34 21.4% 20.5% 20.6% 20.5% 20.5% 20.4% 20.3% 20.0% 20.4% 20.2% 20.2%

Age 35 to 49 18.9% 18.7% 18.5% 18.5% 18.4% 18.2% 18.1% 17.9% 17.0% 16.8% 16.9%

Age 50 to 64 13.7% 15.1% 15.1% 15.2% 15.3% 15.4% 15.4% 15.4% 15.4% 15.2% 14.5%

Age 65 and over 10.6% 10.9% 11.1% 11.3% 11.5% 11.8% 12.0% 13.0% 14.6% 15.7% 17.2%

Median Age of Population (years) 33.8 35.7 35.4 35.5 35.6 35.7 35.8 36.2 36.7 37.0 37.4

White Population (in thousands) 18.2% 16.1% 15.8% 15.5% 15.3% 15.0% 14.8% 13.8% 12.5% 11.5% 9.8%

Black Population (in thousands) 1.2% 1.2% 1.3% 1.3% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2%

Native American Population (in thousands) 0.2% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1%

Asian and Pacific Islander Population 

(in thousands)

0.9% 1.0% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1%

Hispanic or Latino Population 

(in thousands)

79.5% 81.6% 81.7% 82.0% 82.3% 82.5% 82.8% 83.7% 85.1% 86.1% 87.9%

Male Population (in thousands) 48.8% 48.8% 48.9% 48.9% 48.9% 48.9% 48.8% 48.8% 48.7% 48.6% 48.3%

Total Employment (in thousands of jobs) 728.91 806.89 820.21 834.82 849.66 864.76 880.09 943.92 1,047.62 1,141.91 1,354.68

Farm Employment 1.7% 1.6% 1.5% 1.5% 1.5% 1.4% 1.4% 1.3% 1.1% 1.0% 0.7%

Forestry, Fishing, Related Activities 1.2% 1.2% 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.0% 1.0% 0.9%

Mining 1.8% 2.2% 2.6% 2.6% 2.6% 2.5% 2.5% 2.4% 2.2% 2.0% 1.8%

Utilities 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

Construction 7.2% 6.3% 6.0% 6.0% 5.9% 5.9% 5.8% 5.6% 5.4% 5.1% 4.7%

Manufacturing 4.0% 3.1% 3.1% 3.0% 3.0% 2.9% 2.9% 2.7% 2.4% 2.1% 1.8%

Wholesale Trade 2.8% 2.6% 2.7% 2.7% 2.6% 2.6% 2.6% 2.5% 2.4% 2.3% 2.0%

Retail Trade 12.0% 11.6% 11.5% 11.5% 11.5% 11.5% 11.5% 11.5% 11.5% 11.5% 11.4%

Transportation and Warehousing 3.3% 3.3% 3.4% 3.4% 3.4% 3.4% 3.4% 3.4% 3.4% 3.4% 3.4%

Information Employment 1.2% 1.0% 1.0% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.8%

Finance and Insurance 3.1% 3.7% 3.9% 3.9% 3.9% 3.9% 3.9% 3.9% 4.0% 4.0% 4.0%

Real Estate/Rental and Lease 3.0% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1% 3.1% 3.0% 3.0% 2.9%
 

Tables- 76 Central and Eastern Planning Areas Supplemental EIS

Table 4-21. Demographic and Employment Baseline Projections for Economic Impact Area TX-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Professional and Technical Services 3.3% 3.3% 3.3% 3.3% 3.3% 3.4% 3.4% 3.4% 3.5% 3.5% 3.6%

Management 0.2% 0.3% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Administrative and Waste Services 5.4% 5.6% 5.7% 5.8% 5.8% 5.9% 5.9% 6.1% 6.3% 6.5% 6.8%

Educational Services 0.9% 1.0% 1.0% 1.1% 1.1% 1.1% 1.1% 1.1% 1.2% 1.2% 1.3%

Health Care and Social Assistance 15.6% 17.4% 17.6% 17.8% 18.0% 18.3% 18.5% 19.4% 20.8% 22.0% 24.5%

Arts, Entertainment, and Recreation 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.0%

Accommodation and Food Services 7.2% 7.4% 7.5% 7.5% 7.5% 7.5% 7.6% 7.6% 7.8% 7.8% 7.9%

Other Services, Except Public 

Administration

6.5% 6.1% 6.1% 6.1% 6.1% 6.1% 6.1% 6.2% 6.2% 6.3% 6.4%

Federal Civilian Government 1.7% 2.0% 1.9% 1.9% 1.8% 1.8% 1.8% 1.7% 1.6% 1.5% 1.3%

Federal Military 1.3% 1.0% 1.0% 1.0% 1.0% 1.0% 0.9% 0.9% 0.8% 0.7% 0.6%

State and Local Government 15.1% 14.9% 14.5% 14.4% 14.3% 14.2% 14.1% 13.7% 13.1% 12.6% 11.5%

Total Earnings (in millions of 2005 dollars) 26,195.82 30,353.80 31,195.76 31,890.93 32,754.54 33,640.93 34,550.73 38,436.40 45,079.92 51,469.18 67,061.12

Farm 1.6% 1.2% 1.1% 1.0% 1.0% 1.0% 1.0% 0.9% 0.8% 0.7% 0.5%

Forestry, Fishing, Related Activities 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.6% 0.6% 0.5%

Mining 3.6% 4.5% 5.7% 5.5% 5.5% 5.4% 5.4% 5.2% 4.9% 4.6% 4.1%

Utilities 0.6% 0.7% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.7% 0.7%

Construction 7.5% 7.1% 6.9% 6.8% 6.7% 6.6% 6.5% 6.2% 5.6% 5.2% 4.4%

Manufacturing 5.9% 4.9% 5.0% 5.0% 4.9% 4.8% 4.7% 4.4% 4.0% 3.7% 3.1%

Wholesale Trade 4.2% 3.8% 4.1% 4.1% 4.0% 4.0% 4.0% 3.9% 3.8% 3.7% 3.4%

Retail Trade 8.8% 8.0% 8.0% 8.0% 8.0% 7.9% 7.8% 7.6% 7.2% 6.8% 6.1%

Transportation and Warehousing 3.6% 4.3% 4.5% 4.5% 4.5% 4.5% 4.5% 4.4% 4.3% 4.3% 4.1%

Information 1.5% 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.2% 1.2% 1.2% 1.3%

Finance and Insurance 3.4% 3.0% 3.0% 3.0% 3.0% 3.0% 3.0% 3.1% 3.2% 3.2% 3.4%

Real Estate/Rental and Lease 1.4% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.2% 1.2% 1.2% 1.1%

Professional and Technical Services 4.6% 3.8% 3.7% 3.8% 3.8% 3.8% 3.9% 4.0% 4.2% 4.3% 4.6%

Management 0.1% 0.3% 0.3% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.3%

Administrative and Waste Services 3.0% 3.2% 3.3% 3.4% 3.4% 3.5% 3.5% 3.7% 3.9% 4.0% 4.4%

Educational Services 0.6% 0.7% 0.6% 0.7% 0.7% 0.7% 0.7% 0.7% 0.8% 0.8% 0.9%

Health Care and Social Assistance 14.9% 17.0% 16.6% 17.0% 17.2% 17.5% 17.8% 18.9% 20.7% 22.2% 25.4%

Arts, Entertainment, and Recreation 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4%
Tables Tables-77

Table 4-21. Demographic and Employment Baseline Projections for Economic Impact Area TX-1 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Accommodation and Food Services 3.4% 3.3% 3.4% 3.4% 3.4% 3.4% 3.5% 3.5% 3.6% 3.7% 3.7%

Other Services, Except Public 

Administration

4.5% 4.3% 4.3% 4.3% 4.3% 4.3% 4.3% 4.4% 4.4% 4.4% 4.5%

Federal Civilian Government 4.9% 5.4% 5.4% 5.5% 5.4% 5.4% 5.4% 5.3% 5.1% 4.9% 4.6%

Federal Military 2.8% 2.4% 2.3% 2.2% 2.2% 2.2% 2.2% 2.2% 2.1% 2.1% 2.0%

State and Local Government 17.8% 18.4% 17.6% 17.6% 17.6% 17.6% 17.6% 17.5% 17.2% 17.0% 16.4%

Total Personal Income per Capita 

(in 2005 dollars)

22,661 25,356 25,749 25,916 26,191 26,491 26,810 28,248 30,827 33,327 39,329

Woods & Poole Economics Wealth Index 

(U.S. = 100)

67.9 76.7 79.3 78.6 79.0 79.3 79.5 80.5 81.4 82.1 83.1

Persons per Household 

(in number of people)

3.2 3.3 3.2 3.3 3.2 3.2 3.2 3.2 3.2 3.2 3.3

Mean Household Total Personal Income 

(in 2005 dollars)

72,965 82,534 83,514 84,735 85,117 85,625 86,245 89,976 98,320 107,222 129,227

Number of Households (in thousands) 510.57 552.77 563.40 567.67 580.16 592.58 604.86 650.28 711.76 759.46 855.84

Income < $10,000 

(thousands of households, 2000$)

15.0% 14.5% 14.3% 13.7% 13.6% 13.5% 13.3% 12.6% 11.1% 9.9% 8.0%

Income $10,000 to $19,999 18.0% 17.9% 17.7% 17.3% 17.1% 16.9% 16.7% 15.8% 13.9% 12.4% 10.0%

Income $20,000 to $29,999 14.5% 13.6% 13.7% 13.6% 13.5% 13.4% 13.2% 12.6% 11.0% 9.8% 7.8%

Income $30,000 to $44,999 15.4% 16.0% 16.1% 16.1% 16.1% 16.2% 16.3% 16.4% 15.9% 14.5% 11.7%

Income $45,000 to $59,999 11.0% 11.2% 11.1% 11.2% 11.2% 11.4% 11.5% 12.1% 13.6% 14.7% 14.8%

Income $60,000 to $74,999 7.6% 8.0% 8.4% 8.5% 8.6% 8.7% 8.8% 9.2% 10.6% 11.8% 14.4%

Income $75,000 to $99,999 8.2% 8.1% 7.9% 8.5% 8.6% 8.7% 8.8% 9.2% 10.5% 11.8% 14.6%

Income $100,000 or more 10.3% 10.6% 10.7% 11.1% 11.2% 11.3% 11.4% 12.0% 13.6% 15.1% 18.7%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
 

Tables- 78 Central and Eastern Planning Areas Supplemental EIS

Table 4-22

Demographic and Employment Baseline Projections for Economic Impact Area TX-2 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 581.75 626.91 633.41 642.00 650.77 659.71 668.77 706.06 764.62 815.09 920.51

Age Under 19 Years 29.6% 29.1% 29.0% 29.0% 29.0% 29.0% 29.1% 29.3% 29.3% 29.2% 29.1%

Age 20 to 34 18.6% 18.3% 18.5% 18.4% 18.4% 18.3% 18.3% 17.9% 18.5% 18.9% 19.8%

Age 35 to 49 22.3% 20.6% 20.1% 19.8% 19.4% 19.2% 19.0% 18.6% 17.5% 17.2% 17.4%

Age 50 to 64 17.1% 19.2% 19.4% 19.6% 19.6% 19.7% 19.7% 19.0% 17.4% 16.4% 15.3%

Age 65 and over 12.4% 12.8% 13.0% 13.2% 13.5% 13.8% 14.0% 15.2% 17.2% 18.3% 18.5%

Median Age of Population (years) 39.1 40.5 40.5 40.6 40.6 40.5 40.4 40.2 39.2 38.2 36.4

White Population (in thousands) 58.3% 54.0% 53.3% 52.6% 52.0% 51.3% 50.7% 48.2% 44.4% 41.3% 35.2%

Black Population (in thousands) 9.3% 10.2% 10.3% 10.4% 10.4% 10.5% 10.6% 10.8% 11.2% 11.6% 12.5%

Native American Population (in thousands) 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

Asian and Pacific Islander Population (in thousands) 2.4% 3.4% 3.4% 3.5% 3.6% 3.6% 3.7% 4.0% 4.3% 4.6% 5.0%

Hispanic or Latino Population (in thousands) 29.6% 32.1% 32.6% 33.2% 33.7% 34.2% 34.7% 36.7% 39.7% 42.2% 47.0%

Male Population (in thousands) 50.2% 50.2% 50.2% 50.2% 50.1% 50.1% 50.1% 50.1% 50.0% 49.9% 49.6%

Total Employment (in thousands of jobs) 287.61 305.43 312.06 316.94 321.93 326.99 332.14 353.64 388.77 420.92 493.98

Farm Employment 7.4% 6.9% 6.6% 6.6% 6.5% 6.5% 6.4% 6.2% 5.8% 5.6% 5.0%

Forestry, Fishing, Related Activities 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.1% 1.0% 1.0% 0.9% 0.8%

Mining 2.4% 3.2% 3.6% 3.6% 3.6% 3.6% 3.7% 3.8% 3.9% 4.0% 4.2%

Utilities 1.0% 1.0% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.8% 0.8% 0.7%

Construction 9.6% 8.9% 9.2% 9.2% 9.3% 9.3% 9.3% 9.5% 9.6% 9.8% 10.1%

Manufacturing 9.8% 8.7% 8.9% 8.8% 8.7% 8.6% 8.5% 8.1% 7.6% 7.2% 6.3%

Wholesale Trade 2.7% 2.7% 2.7% 2.7% 2.7% 2.7% 2.8% 2.8% 2.8% 2.8% 2.8%

Retail Trade 11.3% 11.1% 10.9% 10.9% 10.9% 10.9% 10.9% 11.0% 11.0% 11.1% 11.1%

Transportation and Warehousing 2.8% 2.7% 2.7% 2.7% 2.7% 2.7% 2.7% 2.6% 2.6% 2.5% 2.4%

Information Employment 0.8% 0.7% 0.7% 0.7% 0.7% 0.7% 0.7% 0.6% 0.6% 0.6% 0.5%

Finance and Insurance 3.4% 4.2% 4.2% 4.3% 4.3% 4.3% 4.4% 4.5% 4.7% 4.9% 5.3%

Real Estate/Rental and Lease 3.4% 3.7% 3.8% 3.8% 3.9% 3.9% 3.9% 4.0% 4.1% 4.1% 4.3%

Professional and Technical Services 3.9% 4.1% 4.2% 4.2% 4.2% 4.2% 4.2% 4.3% 4.3% 4.4% 4.5%

Management 0.2% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.5% 0.5%
Tables Tables-79

Table 4-22. Demographic and Employment Baseline Projections for Economic Impact Area TX-2 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Administrative and Waste Services 4.6% 4.2% 4.3% 4.3% 4.3% 4.4% 4.4% 4.5% 4.7% 4.8% 5.1%

Educational Services 0.9% 1.0% 1.1% 1.1% 1.1% 1.1% 1.1% 1.2% 1.3% 1.3% 1.4%

Health Care and Social Assistance 7.4% 8.2% 8.0% 8.1% 8.2% 8.3% 8.4% 8.7% 9.2% 9.6% 10.5%

Arts, Entertainment, and Recreation 1.2% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.3% 1.2%

Accommodation and Food Services 5.6% 5.9% 6.1% 6.1% 6.2% 6.2% 6.2% 6.4% 6.7% 6.9% 7.4%

Other Services, Except Public Administration 6.5% 6.0% 5.9% 5.9% 5.9% 5.9% 5.9% 5.9% 5.9% 5.8% 5.7%

Federal Civilian Government 0.5% 0.5% 0.4% 0.4% 0.4% 0.4% 0.4% 0.3% 0.3% 0.3% 0.2%

Federal Military 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4% 0.4% 0.3%

State and Local Government 12.9% 13.0% 12.5% 12.4% 12.2% 12.1% 12.0% 11.6% 11.0% 10.4% 9.4%

Total Earnings (in millions of 2005 dollars) 11,144.90 12,256.96 12,903.46 13,073.11 13,410.85 13,757.68 14,113.81 15,636.58 18,246.55 20,763.13 26,920.43

Farm 3.5% 1.7% 2.0% 2.0% 2.0% 1.9% 1.9% 1.8% 1.7% 1.6% 1.4%

Forestry, Fishing, Related Activities 0.7% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.5% 0.5%

Mining 4.3% 4.6% 5.2% 5.3% 5.4% 5.4% 5.5% 5.7% 6.0% 6.3% 6.9%

Utilities 2.7% 2.8% 2.4% 2.5% 2.5% 2.5% 2.6% 2.6% 2.7% 2.7% 2.8%

Construction 11.7% 11.7% 12.3% 12.2% 12.2% 12.2% 12.1% 12.0% 11.7% 11.5% 11.0%

Manufacturing 20.2% 18.5% 19.0% 19.0% 18.8% 18.6% 18.4% 17.7% 16.6% 15.7% 13.9%

Wholesale Trade 3.5% 4.3% 4.3% 3.8% 3.8% 3.8% 3.9% 4.0% 4.1% 4.3% 4.5%

Retail Trade 8.1% 8.1% 7.8% 7.8% 7.8% 7.7% 7.6% 7.4% 7.0% 6.7% 6.1%

Transportation and Warehousing 3.2% 3.4% 3.5% 3.1% 3.1% 3.0% 3.0% 2.9% 2.8% 2.7% 2.5%

Information 0.8% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6%

Finance and Insurance 3.0% 2.9% 2.9% 3.1% 3.1% 3.1% 3.2% 3.4% 3.6% 3.9% 4.4%

Real Estate/Rental and Lease 1.5% 1.7% 2.0% 1.9% 1.9% 1.9% 1.9% 1.9% 1.9% 2.0% 2.0%

Professional and Technical Services 3.9% 3.9% 3.9% 3.9% 3.9% 4.0% 4.0% 4.2% 4.4% 4.6% 5.0%

Management 0.1% 0.2% 0.2% 0.4% 0.5% 0.5% 0.5% 0.5% 0.6% 0.7% 0.8%

Administrative and Waste Services 2.5% 2.4% 2.4% 2.5% 2.6% 2.6% 2.6% 2.7% 2.9% 3.1% 3.4%

Educational Services 0.4% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.6% 0.6% 0.7%

Health Care and Social Assistance 6.8% 8.1% 7.7% 7.8% 8.0% 8.1% 8.2% 8.7% 9.5% 10.1% 11.5%

Arts, Entertainment, and Recreation 0.4% 0.5% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4%

Accommodation and Food Services 2.2% 2.4% 2.4% 2.5% 2.5% 2.5% 2.5% 2.6% 2.8% 2.9% 3.2%

Other Services, Except Public Administration 5.2% 4.9% 4.7% 4.8% 4.8% 4.8% 4.8% 4.8% 4.8% 4.8% 4.7%

Federal Civilian Government 0.9% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.7% 0.6% 0.6%
 

Tables- 80 Central and Eastern Planning Areas Supplemental EIS

Table 4-22. Demographic and Employment Baseline Projections for Economic Impact Area TX-2 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Federal Military 0.6% 0.6% 0.5% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.5%

State and Local Government 13.9% 14.7% 13.8% 13.9% 13.9% 13.8% 13.8% 13.6% 13.3% 13.0% 12.4%

Total Personal Income per Capita (in 2005 dollars) 32,034 35,398 36,450 36,559 36,972 37,417 37,889 40,006 43,822 47,528 56,453

Woods & Poole Economics Wealth Index (U.S. = 100) 78.4 86.3 87.2 87.2 87.5 87.7 88.0 89.0 90.7 92.2 95.5

Persons per Household (in number of people) 2.7 2.8 2.8 2.8 2.8 2.8 2.8 2.7 2.7 2.8 2.8

Mean Household Total Personal Income 

(in 2005 dollars)

88,006 98,664 101,206 102,374 102,941 103,653 104,498 109,413 120,299 131,909 160,791

Number of Households (in thousands) 211.75 224.92 228.13 229.27 233.73 238.15 242.49 258.17 278.53 293.69 323.19

Income < $10,000 (thousands of households, 2000$) 7.6% 7.0% 7.0% 6.9% 6.8% 6.8% 6.7% 6.2% 5.5% 5.0% 4.0%

Income $10,000 to $19,999 12.3% 11.9% 11.8% 12.1% 12.0% 11.8% 11.7% 10.9% 9.6% 8.7% 6.9%

Income $20,000 to $29,999 11.7% 11.2% 11.2% 10.9% 10.8% 10.7% 10.6% 9.9% 8.8% 8.0% 6.3%

Income $30,000 to $44,999 15.2% 14.3% 14.4% 14.1% 14.1% 14.0% 13.8% 13.0% 11.6% 10.6% 8.6%

Income $45,000 to $59,999 12.7% 12.4% 12.8% 13.0% 13.0% 13.0% 13.0% 13.1% 12.7% 11.8% 9.4%

Income $60,000 to $74,999 9.9% 10.1% 10.0% 9.9% 9.9% 10.0% 10.1% 10.5% 11.0% 11.3% 10.6%

Income $75,000 to $99,999 12.4% 12.2% 11.7% 11.9% 12.0% 12.1% 12.2% 13.0% 14.5% 15.8% 18.6%

Income $100,000 or more 18.2% 20.8% 21.0% 21.3% 21.4% 21.7% 21.9% 23.3% 26.2% 28.7% 35.6%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
Tables Tables-81

Table 4-23

Demographic and Employment Baseline Projections for Economic Impact Area TX-3 

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Total Population (in thousands) 5,518.20 6,202.21 6,309.03 6,421.63 6,536.83 6,654.44 6,773.88 7,269.96 8,063.83 8,764.06 10,272.30

Age Under 19 Years 30.7% 30.3% 30.1% 30.1% 30.1% 30.1% 30.1% 30.1% 29.7% 29.5% 29.1%

Age 20 to 34 22.2% 21.8% 21.8% 21.7% 21.6% 21.5% 21.4% 20.8% 21.0% 21.1% 21.3%

Age 35 to 49 22.8% 21.3% 21.0% 20.8% 20.5% 20.4% 20.3% 20.1% 19.2% 18.7% 18.4%

Age 50 to 64 15.8% 17.5% 17.7% 17.8% 17.9% 17.9% 17.9% 17.4% 16.4% 15.9% 15.4%

Age 65 and over 8.5% 9.1% 9.3% 9.6% 9.8% 10.1% 10.4% 11.6% 13.6% 14.7% 15.7%

Median Age of Population (years) 37.4 38.2 38.3 38.4 38.5 38.5 38.5 38.6 38.7 38.7 38.3

White Population (in thousands) 45.8% 41.7% 41.3% 40.6% 39.9% 39.3% 38.6% 36.1% 32.5% 29.8% 24.9%

Black Population (in thousands) 17.6% 17.8% 17.6% 17.5% 17.4% 17.3% 17.2% 16.7% 16.0% 15.4% 14.2%

Native American Population 

(in thousands)

0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

Asian and Pacific Islander Population 

(in thousands)

5.7% 6.5% 6.5% 6.7% 6.8% 6.9% 7.1% 7.6% 8.4% 9.0% 10.1%

Hispanic or Latino Population 

(in thousands)

30.6% 33.8% 34.2% 34.9% 35.5% 36.2% 36.8% 39.3% 42.8% 45.5% 50.5%

Male Population (in thousands) 49.8% 49.8% 49.8% 49.8% 49.8% 49.8% 49.8% 49.7% 49.6% 49.5% 49.2%

Total Employment (in thousands of jobs) 3,218.66 3,598.02 3,682.63 3,752.42 3,823.50 3,895.93 3,969.75 4,279.26 4,789.21 5,260.12 6,344.46

Farm Employment 0.6% 0.6% 0.6% 0.6% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4% 0.4%

Forestry, Fishing, Related Activities 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2% 0.2%

Mining 2.8% 3.2% 3.5% 3.5% 3.5% 3.5% 3.5% 3.6% 3.6% 3.6% 3.6%

Utilities 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.5% 0.4%

Construction 8.0% 7.5% 7.3% 7.3% 7.3% 7.4% 7.4% 7.4% 7.4% 7.5% 7.5%

Manufacturing 7.4% 6.8% 7.0% 6.9% 6.8% 6.7% 6.6% 6.2% 5.7% 5.3% 4.6%

Wholesale Trade 4.5% 4.4% 4.5% 4.5% 4.5% 4.5% 4.5% 4.5% 4.5% 4.5% 4.5%

Retail Trade 10.2% 9.5% 9.4% 9.4% 9.4% 9.4% 9.3% 9.2% 9.1% 9.0% 8.7%

Transportation and Warehousing 4.3% 4.2% 4.2% 4.1% 4.1% 4.1% 4.1% 4.0% 3.9% 3.8% 3.5%

Information Employment 1.5% 1.2% 1.2% 1.1% 1.1% 1.1% 1.1% 1.1% 1.0% 0.9% 0.8%

Finance and Insurance 4.5% 5.1% 5.2% 5.2% 5.2% 5.3% 5.3% 5.3% 5.4% 5.4% 5.4%
 

Tables- 82 Central and Eastern Planning Areas Supplemental EIS

Table 4-23. Demographic and Employment Baseline Projections for Economic Impact Area TX-3 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Real Estate/Rental and Lease 4.1% 4.3% 4.3% 4.3% 4.3% 4.3% 4.3% 4.3% 4.2% 4.2% 4.2%

Professional and Technical Services 7.8% 7.9% 7.9% 8.0% 8.0% 8.0% 8.0% 8.2% 8.3% 8.5% 8.7%

Management 0.6% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9% 0.9%

Administrative and Waste Services 7.4% 7.3% 7.6% 7.6% 7.7% 7.7% 7.8% 7.9% 8.2% 8.4% 8.8%

Educational Services 1.6% 1.7% 1.7% 1.7% 1.7% 1.7% 1.7% 1.7% 1.8% 1.8% 1.8%

Health Care and Social Assistance 8.2% 9.2% 9.2% 9.3% 9.4% 9.5% 9.6% 10.1% 10.9% 11.5% 12.7%

Arts, Entertainment, and Recreation 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5% 1.5%

Accommodation and Food Services 6.5% 6.6% 6.7% 6.8% 6.8% 6.8% 6.9% 7.0% 7.2% 7.3% 7.6%

Other Services, Except Public 

Administration

6.0% 5.9% 5.9% 5.9% 5.9% 5.9% 5.9% 6.0% 6.1% 6.2% 6.2%

Federal Civilian Government 1.0% 0.9% 0.8% 0.8% 0.8% 0.8% 0.8% 0.7% 0.6% 0.6% 0.5%

Federal Military 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.4% 0.3% 0.3% 0.3%

State and Local Government 10.3% 9.9% 9.5% 9.4% 9.4% 9.3% 9.2% 8.8% 8.4% 8.0% 7.2%

Total Earnings (in millions of 2005 dollars) 202,185.34 226,898.60 237,509.70 244,420.42 251,920.11 259,653.01 267,626.35 302,075.94 362,333.17 421,701.96 571,319.56

Farm 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.0% 0.0% 0.0%

Forestry, Fishing, Related Activities 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1%

Mining 12.3% 9.6% 10.5% 10.3% 10.3% 10.4% 10.4% 10.5% 10.7% 10.8% 10.8%

Utilities 1.6% 1.9% 1.8% 1.9% 1.9% 1.9% 1.9% 1.9% 2.0% 2.0% 2.1%

Construction 8.2% 8.3% 8.0% 8.0% 8.0% 7.9% 7.9% 7.6% 7.3% 7.0% 6.5%

Manufacturing 11.7% 10.8% 11.0% 10.9% 10.7% 10.6% 10.4% 9.8% 8.9% 8.3% 7.0%

Wholesale Trade 6.2% 6.7% 6.9% 7.0% 7.0% 7.1% 7.1% 7.2% 7.3% 7.5% 7.7%

Retail Trade 5.2% 4.8% 4.8% 4.7% 4.7% 4.6% 4.6% 4.3% 4.0% 3.7% 3.2%

Transportation and Warehousing 5.6% 6.1% 6.1% 6.1% 6.1% 6.0% 6.0% 5.7% 5.4% 5.1% 4.6%

Information 1.7% 1.3% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2% 1.2%

Finance and Insurance 5.5% 5.4% 5.4% 5.4% 5.4% 5.4% 5.5% 5.6% 5.7% 5.8% 6.0%

Real Estate/Rental and Lease 2.4% 1.9% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.8% 1.7% 1.7%

Professional and Technical Services 10.8% 11.5% 11.4% 11.5% 11.6% 11.7% 11.9% 12.3% 12.9% 13.4% 14.5%

Management 0.6% 1.2% 1.3% 1.3% 1.3% 1.3% 1.4% 1.5% 1.6% 1.7% 2.1%

Administrative and Waste Services 4.4% 4.4% 4.7% 4.7% 4.8% 4.8% 4.8% 5.0% 5.3% 5.5% 5.9%

Educational Services 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.0% 1.1% 1.1% 1.2% 1.2%

Health Care and Social Assistance 6.5% 7.6% 7.4% 7.5% 7.6% 7.8% 7.9% 8.3% 9.0% 9.6% 10.8%
Tables Tables-83

Table 4-23. Demographic and Employment Baseline Projections for Economic Impact Area TX-3 (continued).

2005 2010 2011 2012 2013 2014 2015 2020 2025 2030 2040

Arts, Entertainment, and Recreation 0.7% 0.7% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6% 0.6%

Accommodation and Food Services 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.3% 2.4% 2.4% 2.5% 2.6%

Other Services, Except Public 

Administration

3.1% 3.4% 3.3% 3.3% 3.4% 3.4% 3.4% 3.4% 3.4% 3.4% 3.4%

Federal Civilian Government 1.7% 1.6% 1.5% 1.5% 1.4% 1.4% 1.4% 1.3% 1.2% 1.1% 1.0%

Federal Military 0.3% 0.4% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3% 0.3%

State and Local Government 8.3% 8.9% 8.3% 8.3% 8.2% 8.2% 8.1% 8.0% 7.7% 7.5% 7.0%

Total Personal Income per Capita 

(in 2005 dollars)

42,471 43,854 45,374 46,029 46,517 47,060 47,647 50,340 55,300 60,188 72,156

Woods & Poole Economics Wealth Index 

(U.S. = 100)

84.6 93.3 93.5 93.6 93.6 93.7 93.7 93.6 93.5 93.5 93.7

Persons per Household 

(in number of people)

2.8 2.8 2.8 2.9 2.8 2.8 2.8 2.8 2.8 2.9 2.9

Mean Household Total Personal Income 

(in 2005 dollars)

116,971 124,887 128,705 131,731 132,446 133,388 134,530 141,237 156,159 172,160 212,416

Number of Households (in thousands) 2,003.61 2,177.90 2,224.21 2,243.83 2,295.85 2,347.73 2,399.14 2,591.20 2,855.59 3,063.95 3,489.41

Income < $10,000 

(thousands of households, 2000$)

7.0% 7.3% 7.5% 7.3% 7.3% 7.2% 7.1% 6.7% 6.0% 5.5% 4.3%

Income $10,000 to $19,999 10.4% 11.0% 11.0% 10.8% 10.7% 10.6% 10.5% 9.8% 8.8% 8.1% 6.4%

Income $20,000 to $29,999 10.6% 11.0% 10.7% 10.9% 10.8% 10.7% 10.6% 10.0% 9.0% 8.2% 6.6%

Income $30,000 to $44,999 14.5% 14.9% 15.0% 14.7% 14.7% 14.6% 14.4% 13.5% 12.2% 11.2% 9.0%

Income $45,000 to $59,999 12.4% 12.0% 12.0% 12.0% 12.0% 12.0% 12.0% 11.8% 11.0% 10.2% 8.2%

Income $60,000 to $74,999 9.5% 9.6% 9.9% 9.7% 9.7% 9.8% 9.9% 10.4% 11.1% 11.3% 9.8%

Income $75,000 to $99,999 12.5% 11.7% 11.7% 12.0% 12.1% 12.2% 12.3% 13.1% 14.4% 15.5% 17.8%

Income $100,000 or more 23.0% 22.6% 22.2% 22.5% 22.6% 22.9% 23.1% 24.7% 27.5% 30.0% 37.9%

Notes: Median Age and The Wealth Index are defined using averages of the original Woods & Poole values for the counties in the EIA; income per capita calculated using 

personal income/total population for the EIA; persons per household calculated using total population/number of households for the EIA. 

Source: Woods & Poole Economics, Inc., 2014.
 

Tables- 84 Central and Eastern Planning Areas Supplemental EIS

Table 4-24

Sales Volumes, Sales Values, and Revenues

Fiscal Year

2008 2009 2010 2011 2012 2013

Panel A: Sales Volumes

Gas (royalty) (Mcf) 2,143,025,840 1,728,872,720 1,685,736,473 1,386,890,198 1,117,174,582 969,558,880

Gas (nonroyalty) (Mcf) 319,971,195 462,806,700 359,380,589 274,566,212 228,879,954 197,898,700

NGL (royalty) (gal) 2,045,198,057 1,746,719,986 2,033,407,631 1,794,328,667 1,564,235,458 1,506,799,338

NGL (nonroyalty) (gal) 164,425,802 155,790,669 376,697,377 336,415,238 282,395,427 326,089,182

Oil (royalty) (bbl) 274,769,555 393,068,662 413,843,666 358,198,122 336,215,213 357,383,873

Oil (nonroyalty) (bbl) 162,507,054 125,837,700 177,500,611 137,919,150 121,710,533 96,283,955

Panel B: Sales Values

Gas ($) 19,783,276,001 7,895,954,197 7,894,516,113 5,942,396,884 3,252,264,280 3,593,682,083

NGL ($) 3,067,687,538 1,268,806,694 2,069,278,438 2,814,128,996 1,738,915,377 1,302,281,476

Oil ($) 29,407,481,996 21,080,156,402 31,052,123,264 35,322,996,383 36,839,364,707 38,009,687,312

Other Products ($) 423,743 173,955 84,219 60,125 48,228 66,780

Total Sales Value ($) 52,258,869,278 30,245,091,247 41,016,002,033 44,079,582,388 41,830,592,592 42,905,717,650

Panel C: Revenues

Gas ($) 2,873,950,871 1,110,388,831 1,112,167,319 840,978,575 457,248,784 509,506,758

NGL ($) 287,868,515 120,258,451 243,292,473 280,174,746 216,595,485 157,812,075

Oil ($) 4,057,786,252 2,766,270,473 4,090,113,535 4,795,103,633 5,022,322,667 5,186,978,444

Rents ($) 231,517,822 228,450,250 238,557,438 217,625,912 218,313,871 236,572,594

Bonus ($) 6,817,546,915 1,174,069,762 986,997,466 37,054,282 606,446,360 2,732,922,142

Other Revenues ($) 3,245,974 -30,044,645 46,794,397 4,371,526 5,124,807 34,414,627

Total Revenues ($) 14,271,916,347 5,369,393,121 6,717,922,628 6,175,308,674 6,526,051,974 8,858,206,640

bbl = barrel

gal = gallon

Mcf = thousand cubic feed

NGL = natural gas liquid

Note: Data in this table refer to the years in which sales occurred (not to the years in which government revenues were received).

Source: USDOI, Office of Natural Resources Revenue, 2014.
Tables Tables-85

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archived-stranding-data/. Accessed June 27, 2014.

U.S. Dept. of Commerce. National Marine Fisheries Service. 2014a. 2010-2014 cetacean unusual 

mortality event in the northern Gulf of Mexico. Internet website: http://www.nmfs.noaa.gov/pr/

health/mmume/cetacean_gulfofmexico.htm. Updated November 16, 2014. Accessed November 21, 

2014.

U.S. Dept. of Commerce. National Marine Fisheries Service. 2014b. Marine recreational information 

program query results; angler trips in the Gulf of Mexico by location and mode from 2008 through 

2013.

U.S. Dept. of Commerce. National Marine Fisheries Service. 2014c. Marine recreational information 

program query results; fish species caught by recreational anglers from 2008 through 2013.

U.S. Dept. of Commerce. National Marine Fisheries Service. 2014d. Fisheries economics of the U.S.—

2014. Internet website: http://www.st.nmfs.noaa.gov/economics/publications/feus/fisheries_

economics_2012. Accessed July 30, 2014.

U.S. Dept. of Labor. Bureau of Labor Statistics. 2014. Quarterly census of employment and wages.

U.S. Dept. of the Interior. Office of Natural Resources Revenue. 2014. Statistical information online 

query. Internet website: http://statistics.onrr.gov/ReportTool.aspx. Accessed April 28, 2014.

Woods & Poole Economics, Inc. 2014. The 2014 complete economic and demographic data source 

(CEDDS) on CD-ROM.

APPENDIX A 

 

COMMONLY APPLIED MITIGATING MEASURES

Commonly Applied Mitigating Measures A-3 

A. COMMONLY APPLIED MITIGATING MEASURES

Postlease mitigating measures have been implemented for over 40 years in the Gulf of Mexico region, 

as they relate to OCS plans and pipeline applications. These mitigating measures have been amended 

over time to address changes in regulations, new technology, and new methods of operating. Many of 

these mitigating measures have been adopted and incorporated into regulations and/or guidelines 

governing OCS oil and gas exploration, development, and production activities. All plans for OCS oiland gas-related activities (e.g., exploration and development plans, pipeline applications, geological and 

geophysical activities, and structure-removal applications) go through rigorous BOEM review and 

approval to ensure compliance with established laws and regulations. Existing mitigating measures must 

be incorporated and documented in plans submitted to BOEM. Operational compliance of the mitigating 

measures is enforced through the Bureau of Safety and Environmental Enforcement’s (BSEE’s) onsite 

inspection program.

Mitigating measures are an integral part of BOEM’s program to ensure that postlease operations are 

always conducted in an environmentally sound manner (with an emphasis on minimizing any adverse 

impact of routine operations on the environment). For example, post-activity surveys are carried out to 

ensure that a site has been cleared of potential snags to commercial fishing gear, and pre-activity surveys 

seek to avoid archaeological sites and biologically sensitive areas such as pinnacles, topographic features, 

and chemosynthetic communities.

Some BOEM-identified mitigating measures are incorporated into OCS operations through 

cooperative agreements or efforts with industry and State and Federal agencies. These mitigating 

measures include the National Marine Fisheries Service’s (NMFS’s) Observer Program to protect marine 

mammals and sea turtles during explosive removals, labeling operational supplies to track possible 

sources of debris or equipment loss, development of methods of pipeline landfall to eliminate impacts to 

beaches or wetlands, and beach cleanup events.

Site-specific mitigating measures are also applied by BOEM during plan and permit reviews. BOEM 

realized that many of these site-specific mitigations were recurring and developed a list of “standard” or 

commonly applied mitigations. There are currently over 120 standard mitigations. The wording of a 

standard mitigation is developed by BOEM in advance and may be applied whenever conditions warrant. 

Standard mitigation text is revised as often as is necessary (e.g., to reflect changes in regulatory citations, 

agency/personnel contact numbers, and internal policy). Site-specific mitigation “categories” include the 

following: air quality; archaeological resources; artificial reef material; chemosynthetic communities; 

Flower Garden Banks; topographic features; hard bottoms/pinnacles; military warning areas and Eglin 

Water Test Areas (EWTAs); hydrogen sulfide (H2S); drilling hazards; remotely operated vehicle surveys; 

geophysical survey reviews; and general safety concerns. Site-specific mitigation “types” include the 

following: advisories; conditions of approval; hazard survey reviews; inspection requirements; 

notifications; post-approval submittals; and safety precautions. In addition to standard mitigations, 

BOEM may also apply nonrecurring mitigating measures that are developed on a case-by-case basis.

Following a lease sale, an applicant seeks approvals to develop their lease by preparing and 

submitting OCS plans. The OCS plans are reviewed by BOEM and, depending on what is proposed to 

take place in a specific place, BOEM may assign conditions of approval (COA). The COAs become part 

of the approved postlease authorization and include environmental protections, requirements that maintain 

conformance with law, the requirements of other agencies having jurisdiction, or safety precautions.

Some of BOEM’s conditions of approval include the following:

(1) other approvals prerequisite to BOEM’s approval (e.g., the Coastal Zone 

Management Act); 

(2) safety precautions (e.g., H2S present);

(3) post-approval submittals (e.g., surveys and interpretive reports);

(4) inspection requirements (e.g., pipeline pressure testing);

(5) pre-deployment notifications (e.g., U.S. Department of Defense use restrictions & 

Military Warning Areas); and
A-4 Central and Eastern Planning Areas Supplemental EIS

(6) reduce or avoid environmental impacts on resources identified in NEPA or other 

laws (e.g., the National Historic Preservation Act).

BOEM is continually revising applicable mitigations to allow the Gulf of Mexico OCS Region to 

more easily and routinely track mitigation compliance and effectiveness. A primary focus of this effort is 

requiring post-approval submittal of information within a specified timeframe or after a triggering event 

(e.g., end of operations reports for plans, construction reports for pipelines, and removal reports for 

structure removals).

Table A-1 provides a list and description of standard postlease mitigating measures that may be 

required by BOEM or BSEE as a result of plan and permit review processes for the Gulf of Mexico OCS 

Region. 
Commonly Applied Mitigating Measures

A-5

Table A-1

Commonly Applied or “Standard” Mitigating Measures

Mitigation 

Number Mitigating Measure Title Description of Mitigation

0.0 Non-Recurring Mitigation A non-recurring mitigation is a mitigation measure that is used for a unique, special, one-time-only 

mitigation that is added to certain plans.

Boat Traffic Mitigations

1.04 Seismic Vessels (protected species 

requirements)

The applicant will comply with Notice to Lessees and Operators (NTL) 2012-JOINT-G02, 

“Implementation of Seismic Survey Mitigation Measures and Protected Species Observer 

Program.” Additionally, the applicant will comply with the guidance under this NTL when 

operating in all water depths (not just in water depths >200 m [656 ft] or in the Eastern Planning 

Area), and the NTL’s “Shut-Down Conditions” will be applied towards manatees.

1.05 Seismic Vessels (vessel-strike 

avoidance/reporting) 

The applicant will follow the guidance provided under NTL 2012-JOINT-G01, “Vessel Strike 

Avoidance and Injured/Dead Protected Species Reporting.” This provides guidance on how a 

seismic applicant should implement monitoring programs to minimize the risk of vessel strikes to 

protected species and report observations of injured or dead protected species. In lieu of a formal 

observer program, NTL 2012-JOINT-G01 provides specific guidelines that should be followed to 

identify and avoid injury to marine mammals and sea turtles.

1.06 Progressive-Transport/“Hopping”

(structure removals)

In accordance with the Outer Continental Shelf Lands Act (OCSLA) requirements (30 CFR § 

250.1727(g)), if at any point in the decommissioning schedule progressive-transport/“hopping” 

activities are required to section the jacket assembly or support material barge loading, a prior 

written request must be submitted and approval must be obtained from the Bureau of Safety and 

Environmental Enforcement’s (BSEE’s) Regional Supervisor, Field Operations. The applicant’s 

request to use progressive-transport must include a detailed procedural narrative and separate 

location plat for each “set-down” site, showing pipelines, anchor patterns for the derrick barge, and 

any known archaeological and/or potentially sensitive biological features. The diagram/map of the 

route to be taken from the initial structure location along the transport path to each site must also be 

submitted with the request. If the block(s) that the applicant intends to use as “set-down” sites have 

not been surveyed as per NTL 2009-G39, “Biologically-Sensitive Underwater Features and Areas,” 

and NTL 2005-G07, “Archaeological Resource Surveys and Reports,” the applicant may be 

required to conduct the necessary surveys/reporting prior to mobilizing on site and conducting any 

seafloor-disturbing activities.

1.07 Seismic Vessels (notification 

requirements)

In accordance with 30 CFR § 550.208(b)(2), the applicant is hereby required to notify other users of 

the Outer Continental Shelf (OCS) before conducting the proposed ancillary activities. Prior to 

commencing the survey(s), the applicant must inform the operators of all leases affected by the 

proposed activities of when and where the applicant intends to conduct the vessel operations to 

ensure that proper navigation and safety protocol are observed.
A-6 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

Air Quality Mitigations

2.05 Fuel Usage or Run Time 

Documentation

The projected nitrogen oxides (NOx) emissions amounts in the plan were calculated using historic 

(insert fuel consumption rates, run times). Maintain monthly records of the total annual (insert fuel 

consumption, run times) for the (specify the affected vessels or equipment) with a limit of (insert 

limit in gallons/year, limit in hours/year) and provide the information to the Bureau of Ocean 

Energy Management’s (BOEM’s) Regional Supervisor, Office of Leasing and Plans, Plans Section 

annually by February 1st of each year, beginning in the year (insert year). If no activities were 

conducted during a calendar year, provide a statement to that effect in lieu of the required records. 

If at any time during the applicant’s activities these records indicate that the NOx annual emissions 

may exceed the annual limit approved in your plan or the total annual (insert fuel consumption, run 

time) limit, the applicant must immediately prepare a revised plan pursuant to 30 CFR § 550.283 to 

include the recalculated emissions amounts. The applicant will not proceed with the actions that 

could cause the potential annual increase in emissions until the revised plan has been submitted to 

and approved by BOEM.

2.08 Potential to Exceed SO2

Significance Levels (flaring)

Should hydrogen sulfide (H2S) concentrations greater than (insert number) ppm be encountered, the 

3- and 24-hour sulphur oxides (SO2) onshore ambient air concentration significance levels as 

prescribed by 30 CFR § 550.303(e) could be exceeded during the proposed well test flaring. 

Therefore, the applicant is advised that, should H2S concentrations greater than (insert number) 

ppm be encountered, they shall use the graph included in their plan to determine the maximum 

allowable flow rate for the flaring operation. The applicant is responsible for ensuring that their 

maximum emission concentrations remain below the aforementioned significance levels. In 

accordance with 30 CFR § 250.1164(c), the applicant is hereby required to submit monthly reports 

that contain the following: (1) the daily volume and duration (number of hours) of each flaring 

episode; (2) the H2S concentration (ppm) in the flared gas; and (3) the calculated amount of SO2

emitted.

2.11 Using Ultra-Low Sulfur Content 

Fuel

As proposed, use ultra-low sulfur content diesel fuel (sulfur concentration 0.0015% or less by 

weight) while conducting these operations. Sulfur content records must be maintained on the 

platform and made available to authorized BSEE personnel upon request.

2.12 Verification of Emissions Factors

(clean burn engines)

The rating, manufacturer, and type of engine(s) proposed in the applicant’s plan will be operated 

and maintained in accordance with the manufacturer’s specifications. Using a U.S. Environmental 

Protection Agency (USEPA)-approved or equivalent method, perform an emissions stack test on 

the subject engine(s) within 60 days following installation and at least every 3 years thereafter. 

These tests will be performed at loads representing 25, 50, 75, and 100 percent of the rated capacity 

or at minimum, average, and highest operational loads to verify that the emission factors are not 

exceeding those used in calculating the proposed emissions in the plan.

Prepare a report of the results of each stack test and submit it to BOEM’s Regional Supervisor, 

Office of Leasing and Plans, Plans Section within 45 days of the test. During engine operation, the 

applicant will maintain the baseline parameters (such as air-fuel rations) established during the most 
Commonly Applied Mitigating Measures

A-7

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

recent successful stack test. The applicant must monitor and record these parameters daily to 

ensure consistency with those observed during the most recent successful stack test. Records of 

these parameters must be maintained on the platform and made available to authorized BSEE 

personnel upon request. In addition, the applicant must submit this information to BOEM’s

Regional Supervisor, Office of Leasing and Plans, Plans Section annually by February 1st of each 

year, beginning in the year (insert year). If no activities were conducted during a calendar year, 

provide a statement to that effect in lieu of the required records.

2.13 Monitoring of NOx Emissions

(catalytic converters)

The rating, manufacturer, and type, and catalytic converter(s) proposed in the plan must be operated 

and maintained in accordance with the manufacturer’s specifications. Using a USEPA-approved or 

equivalent method, perform an emissions stack test on the subject engine(s) and catalytic 

converter(s) within 60 days following installation and at least every 3 years thereafter. These tests 

will be performed at loads representing 25, 50, 75, and 100 percent of the rated capacity or at 

minimum, average, and highest operational loads to verify that the emissions factors are not 

exceeding those used in calculating the proposed emissions in the plan. The applicant must contact 

BSEE at least 30 days prior to conducting the test to determine proper protocol for the stack test 

and also to have the BSEE representative witness the test. Prepare a report of the results of each 

stack test and submit it to BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section 

within 45 days of the test.

During operation, the applicant will maintain the baseline parameters, such as air-fuel ratios for the 

engine(s) and the pressure drop and temperature increase across the catalytic converter(s) 

established during the most recent successful stack test. The applicant must monitor and record 

these parameters daily to ensure they remain consistent with those observed during the most recent 

successful stack test. The records of these parameters will be maintained on the platform and made 

available to authorized BSEE personnel upon request. In addition, the applicant must submit this 

information to BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section annually 

by February 1st of each year, beginning in the year (insert year). If no activities were conducted 

during a calendar year, the applicant must provide a statement to that effect in lieu of the required 

records.

2.15 Sulfur Recovery Unit, Flaring 

Episodes, Production Curtailment

If a shutdown of the sulfur recovery unit necessitates diverting the acid gas stream and if the 

resulting increased emissions would cause the SO2 onshore ambient air concentration significance 

levels as prescribed by 30 CFR § 550.303(e) to be exceeded, begin curtailing production within 

6 hours of the onset of the increased emissions. If curtailment is necessary, the appropriate reduced 

production rate will be reached no later than 8 hours from the onset of the increased emissions and 

will continue until such time that normal operation of the sulfur recovery unit can resume.

2.16 Monitoring of SO2 Emissions

(sulfur recovery units)

The amine unit and the (specify name of sulfur recovery unit) proposed in the plan must be 

operated and maintained in accordance with the manufacturer’s specifications. Using a USEPAapproved or equivalent method, perform an emissions stack test on the subject sulfur recovery unit 

within 60 days following installation. This test will be performed at loads representing 25, 50, 75, 

and 100 percent of the rated capacity of the amine unit or at minimum, average, and highest 
A-8 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

operational loads of the amine unit to verify that the emission factors are not exceeding those used 

in calculating the proposed emissions in the plan. Contact BSEE’s Environmental Enforcement 

Division at least 30 days prior to conducting the test to determine proper protocol for the stack test 

and also to have the BSEE representative witness the test. Prepare a report of the results of each 

stack test and submit it to BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section 

within 45 days of the test.

The applicant must monitor and record these parameters daily to ensure they remain consistent with 

the approved baseline parameters from the most recent successful stack test. Records of these 

parameters must be maintained on the platform and made available to authorized BSEE personnel 

upon request. In addition, the applicant must submit this information to BOEM’s Regional 

Supervisor, Office of Leasing and Plans, Plans Section annually by February 1st of each year, 

beginning in the year (insert year). If no activities were conducted during a calendar year, provide a 

statement to that effect in lieu of the required records.

2.17 Verification of Emissions Factors 

(general)

The rating, manufacturer, and type of engine(s) proposed in the plan will be operated and 

maintained in accordance with the manufacturer’s specifications. Using a USEPA-approved or 

equivalent method, perform an emissions stack test on the subject engine(s) within 60 days 

following installation and at least every 3 years thereafter. These tests will be performed at loads 

representing 25, 50, 75, and 100 percent of the rated capacity or at minimum, average, and highest 

operational loads to verify that the emission factors are not exceeding those used in calculating the 

proposed emissions in the plan. Contact BSEE’s Environmental Enforcement Division at least 

30 days prior to conducting the test to determine proper protocol for the stack test and also to have 

the BSEE representative witness the test.

Prepare a report of the results of each stack test and submit it to BOEM’s Regional Supervisor, 

Office of Leasing and Plans, Plans Section within 45 days of the test. During engine operation, the 

applicant will maintain the baseline parameters (such as air-fuel rations) established during the most 

recent successful stack test. The applicant must monitor and record these parameters daily to 

ensure consistency with those observed during the most recent successful stack test. Records of 

these parameters must be maintained on the platform and made available to authorized BSEE 

personnel upon request. In addition, the applicant must submit this information to BOEM’s

Regional Supervisor, Office of Leasing and Plans, Plans Section annually by February 1st of each 

year, beginning in the year (insert year). If no activities were conducted during a calendar year, 

provide a statement to that effect in lieu of the required records.

2.18 Alternative Monitoring of NOx

Emissions (catalytic converters)

Using your established baseline parameters listed below, monitor the performance of the engine(s) 

and catalytic converter(s) and record daily to ensure that performance remains consistent. Air to 

fuel ratio for engine: (insert baseline parameters); pressure drop across catalytic converter: (insert 

baseline parameters); and temperature increase across catalytic converter: (insert baseline 

parameters). 
Commonly Applied Mitigating Measures

A-9

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

Records of these parameters must be maintained on the platform and made available to authorized 

BSEE personnel upon request. In addition, the applicant must submit a summary of these data to 

BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section annually by February 1st 

of each year, beginning in the year (insert year). The summary will report minimum, average, and 

maximum values for the above-listed parameters, on a monthly basis, for the year. If no activities 

were conducted during a calendar year, provide a statement to that effect in lieu of the required 

records. Notify BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section as soon 

as practical but no later than 24 hours after the event, whenever the engine(s) or catalytic 

converter(s) exceed these parameters for periods greater than a day. File a detailed report with this 

office within 5 days of the termination of any such event. At a minimum, this report will include a 

chronology of the event, NOx emissions rates in pounds per hour, total NOx emissions for the 

duration of the event, and any measures taken to regain operation within these parameters or to 

prevent a recurrence of similar events. If exceeding the above parameters results in increased 

emissions that would cause onshore NOx concentration to exceed BOEM significance levels 

(30 CFR § 550.303(e)), curtail the use of the (identify equipment associated with catalytic 

converter) within 2 days of the onset of the increased emissions and continue curtailment until such 

time that normal operation of the catalytic converter can resume.

Archaeology Mitigations

3.00 Archaeology Non-Recurring 

Mitigation

A non-recurring mitigation is a mitigation measure that is used for a unique, special, one-time-only 

mitigation that is added to certain plans.

3.02 Buried Channels (pipeline 

applications)

BOEM’s review indicates that the proposed activities are in the vicinity of buried channel margin 

features that may contain significant archaeological resources. In accordance with 30 CFR § 

250.1007(a)(5), the applicant must either (1) conduct an underwater archaeological investigation 

(diver and/or remotely operated vehicle (ROV) investigations) prior to commencing activities to 

determine whether these features represent archaeological resources or (2) ensure that the depth of 

the pipeline trench in the vicinity of these features does not exceed 3 ft and that all other seafloordisturbing actions resulting from the proposed activities avoid the subject channel margins (see the 

enclosed map depicting the avoidance area in the application). If the applicant conducts an 

underwater archaeological investigation prior to commencing operations, the applicant should 

contact BOEM, Gulf of Mexico OCS Region, Office of Environment, and BSEE, Environmental 

Enforcement Branch at least 2 weeks prior to performing operations to obtain the investigation 

methodology. If the applicant chooses to avoid the features, then the applicant should submit 

anchor position plats, at a scale of 1 in = 1,000 ft with differential global positioning system 

(DGPS) accuracy, with your pipeline construction report required by 30 CFR § 250.1008(b). These 

plats must depict the “as-placed” location of all anchors, anchor chains, wire ropes, and cables on 

the seafloor (including sweep) and demonstrate that the features were not physically impacted by 

the construction activities. If the applicant chooses to avoid the features and no anchoring activities 

were conducted during pipeline construction, provide a statement to that effect in lieu of the 

required anchor position plats. This mitigation may be applied by BSEE at the post-approval stage.
A-10 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

3.03 Buried Channels (plans) BOEM’s review indicates that the proposed activities are in the vicinity of buried channel margin 

features that may contain significant archaeological resources. In accordance with 30 CFR § 

550.194, the applicant must either (1) conduct an underwater archaeological investigation (diver 

and/or ROV investigations) prior to commencing activities to determine whether these features 

represent archaeological resources or (2) ensure that all seafloor-disturbing actions resulting from 

the proposed activities avoid the subject features (see the enclosed map depicting the avoidance 

area in the application). If the applicant conducts an underwater archaeological investigation prior 

to commencing operations, contact BOEM’s Office of Environment, Gulf of Mexico OCS Region 

least 2 weeks prior to performing operations to obtain the investigation methodology.

If the applicant chooses to avoid the features, then submit an as-built map at a scale of 1 in = 

1,000 ft with DGPS accuracy, showing the location of all seafloor disturbances (e.g., the rig or 

platform, anchors, anchor chains, wire ropes, cables, etc.) relative to these features, to BOEM’s

Regional Supervisor, Office of Leasing and Plans, Plans Section at the same time that the applicant 

submits its (specify submittal type).

3.04 and 

3.05

Magnetic Anomalies and/or SideScan Sonar Targets (pipeline 

applications - multiple features)

Magnetic Anomalies and/or SideScan Sonar Targets (pipeline 

application – singular feature)

BOEM’s review indicates that the proposed activities are in the vicinity of the unidentified (insert 

magnetic anomalies, side-scan sonar targets, magnetic anomalies and side-scan sonar targets) listed 

in the enclosure, features that may represent significant archaeological resources. In accordance 

with 30 CFR § 250.1007(a)(5), the applicant must either (1) conduct an underwater archaeological 

investigation (diver and/or ROV investigations) prior to commencing activities to determine 

whether these features represent archaeological resources or (2) ensure that all seafloor-disturbing 

actions resulting from the proposed activities avoid the unidentified features by a distance greater 

than that listed in the enclosure. If the applicant conducts an underwater archaeological 

investigation prior to commencing operations, then the applicant must contact BOEM’s Office of 

Environment, Gulf of Mexico OCS Region at least 2 weeks prior to performing operations to obtain 

the investigation methodology. If the applicant chooses to avoid the features, then submit anchor 

position plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, with the pipeline construction 

report required by 30 CFR § 250.1008(b). These plats must depict the “as-placed” location of all 

anchors, anchor chains, wire ropes, and cables on the seafloor (including sweep) and demonstrate 

that the features were not physically impacted by the construction activities. If the applicant 

chooses to avoid the features and no anchoring activities were conducted during pipeline 

construction, then provide a statement to that effect in lieu of the required anchor position plats. 

This mitigation may be applied by BSEE at the post-approval stage.

3.06 and 

3.07

Magnetic Anomalies and/or SideScan Sonar Targets (plans – 

multiple features)

Magnetic Anomalies and/or SideScan Sonar Targets (plans – 

singular feature)

BOEM’s review indicates that the proposed activities are in the vicinity of the unidentified (insert 

magnetic anomalies, side-scan sonar targets, magnetic anomalies and side-scan sonar targets) listed 

in the enclosure of the application, features that may represent significant archaeological resources. 

In accordance with 30 CFR § 550.194, the applicant must either (1) conduct an underwater 

archaeological investigation (diver and/or ROV investigations) prior to commencing the activities 

to determine whether these features represent archaeological resources or (2) ensure that all 

seafloor-disturbing actions resulting from the proposed activities avoid the subject features by a 
Commonly Applied Mitigating Measures

A-11

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

distance greater than that listed in the enclosure of the application. If the applicant conducts an 

underwater archaeological investigation, then the applicant must contact BOEM’s Office of 

Environment, Gulf of Mexico OCS Region at least 2 weeks prior to performing operations to obtain 

the investigation methodology. If the applicant chooses to avoid the features, submit an as-built 

map at a scale of 1 in = 1,000 ft with DGPS accuracy, showing the location of all seafloor 

disturbances (e.g., the rig or platform, anchors, anchor chains, wire ropes, cables, etc.) relative to 

these features to BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section at the 

same time the applicant submits the plan.

3.08 Buried Channels (lease block 

survey review

BOEM’s review of the archaeological assessment indicates that there are buried channel margin 

features that may contain significant archaeological resources in the lease block(s). The enclosed 

map in the application identifies the areas to be avoided during any future development within the 

block(s). In accordance with 30 CFR § 550.194, the applicant must either (1) conduct an 

underwater archeological investigation (diver and/or ROV investigations) to determine whether 

these features represent archaeological resources or (2) ensure that all seafloor-disturbing actions 

required by future exploration or development will avoid the subject features. If the applicant 

chooses to conduct an underwater archaeological investigation, then the applicant must contact 

BOEM’s Office of Environment, Gulf of Mexico OCS Region at least 2 weeks prior to performing 

operations to obtain the investigation methodology.

3.09 and 

3.10

Magnetic Anomaly and/or SideScan Sonar Target (survey review – 

single feature)

Magnetic Anomaly and/or SideScan Sonar Target (survey review – 

multiple features)

BOEM’s review of the archaeological assessment indicates the presence of the unidentified 

magnetic anomaly(ies), side-scan sonar target(s), or magnetic anomaly(ies) and side-scan sonar 

target(s) listed in the enclosure of the application, features that may represent significant 

archaeological resources. In accordance with 30 CFR § 550.194, the applicant must either 

(1) conduct an underwater archaeological investigation (diver and/or ROV investigations) to 

determine whether these features represent archaeological resources or (2) ensure that all seafloordisturbing actions required by future exploration and development avoid the unidentified features 

by a distance greater than that listed in the enclosure of the application. If the applicant conducts an 

underwater archaeological investigation, then the applicant must contact BOEM’s Office of 

Environment, Gulf of Mexico OCS Region at least 2 weeks prior to performing operations to obtain 

the investigation methodology.

3.11 Unsurveyed Area (plans) Avoid impacts to the seafloor in the unsurveyed area approximately (insert number) feet to the 

(insert direction) of the proposed (specifyWell X, Wells X and Y, Platform X, etc.). This area has 

been identified as requiring a (insert 50-meter or 300-meter) line spacing archaeological resource 

survey to determine the potential for archaeological resources. BOEM has no archaeological 

resource assessment on file for this area and, therefore, cannot determine the potential effects to 

archaeological resources outside of the applicant’s survey coverage. Submit an as-built map at a 

scale of 1 in = 1,000 ft with DGPS accuracy, showing the location of all seafloor disturbances (e.g., 

the rig or platform, anchors, anchor chains, wire ropes, cables, etc.) relative to the unsurveyed area 

to BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section at the same time the 

applicant submits the plan.
A-12 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

3.12 and 

3.13

Magnetic Anomalies and/or SideScan Sonar Targets (structure 

removals – multiple features)

Magnetic Anomalies and/or SideScan Sonar Targets (structure 

removals – single feature)

BOEM’s review indicates that the proposed activities are in the vicinity of the unidentified 

magnetic anomaly(ies), side-scan sonar target(s), or magnetic anomaly(ies) and side-scan sonar 

target(s) listed in the table in the application, a feature that may represent a significant 

archaeological resource. In accordance with 30 CFR § 250.194(c), the applicant must either 

(1) conduct an underwater archaeological investigation (diver and/or ROV investigations) prior to 

commencing activities to determine whether this feature represents an archaeological resource or 

(2) ensure that all anchoring operations (e.g., anchors, anchor chains, wire ropes, cables, etc.) avoid 

the unidentified feature by a distance greater than that listed in the table in the application. If the 

applicant plans to conduct an underwater archaeological investigation prior to commencing 

operations, then the applicant must contact BOEM’s Office of Environment, Gulf of Mexico OCS

Region to obtain the investigation methodology at least 2 weeks prior to performing operations and 

contact BOEM, Gulf of Mexico OCS Region, Office of Environment, and BSEE, Environmental 

Enforcement Branch. If the applicant chooses to avoid the feature, then include in the post-removal 

report as-built plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, the position of anchors, 

anchor chains, wire ropes, and cables deployed during the structure removal relative to the feature. 

In addition, supply a copy of ALL vessel logs related to the removal operations (e.g., anchor 

handling vessels, lift boats, dive vessels, and tug boats). This mitigation may be applied by BSEE 

at the post-approval stage.

3.16 ROV Surveys (plans) The proposed operations are in an area designated by BOEM’s Regional Director as having a high 

potential for the location of historic shipwrecks. In accordance with 30 CFR § 550.194(a)(2), prior 

to commencing the operations, conduct an ROV investigation (using video, sector-scanning sonar, 

or multibeam bathymetry) of the seafloor areas that could be disturbed by the operations (e.g., the 

rig or platform, anchors, anchor chains, wire ropes, cables, etc.) to ensure that the applicant will 

avoid harming potentially significant archaeological sites. The applicant must contact BOEM’s

Office of Environment, Gulf of Mexico OCS Region at least 2 weeks prior to performing 

operations to obtain the investigation methodology. The applicant must submit a report of this 

investigation prepared by a qualified marine archaeologist, along with an “as-placed” anchor plat 

and copies of the ROV video and acoustic recordings of the investigation to BOEM’s Regional 

Supervisor, Office of Leasing and Plans, Plans Section at the same time the applicant submits the 

plan. If the applicant discovers any potential archaeological resource (i.e., cannot be definitively 

identified as modern debris or refuse) while conducting this investigation or future operations, the 

applicant must immediately halt any seafloor-disturbing activities and report the discovery to 

BOEM’s Regional Supervisor, Office of Environment.

3.17 Conditional Approval for ROV 

Surveys (plans)

Drilling permits will not be issued for proposed well(s) and well name(s) until the applicant submits 

an archaeological report to BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans 

Section and receives approval. This report must be based on an ROV investigation (using video, 

sector-scanning sonar, or multibeam bathymetry) of the seafloor areas that could be disturbed by 

the operations. The report must be prepared by a qualified marine archaeologist and must include 

copies of the ROV video and acoustic recordings of the investigation, along with an “as-placed” 

anchor plat. If the applicant discovers any potential archaeological resource (i.e., cannot be 
Commonly Applied Mitigating Measures

A-13

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

definitively identified as modern debris or refuse) while conducting this investigation, the applicant 

must immediately halt any seafloor-disturbing activities and report the discovery to BOEM’s

Regional Supervisor, Office of Environment. The applicant must contact BOEM’s Office of 

Environment at least 2 weeks prior to performing this survey to obtain the investigation 

methodology.

3.18 Buried Channels (structure

removal)

BOEM’s review indicates that the proposed activities are in the vicinity of buried channel margin 

features that may contain significant archaeological resources. In accordance with 30 CFR § 

250.194(c), the applicant must either (1) conduct an underwater archaeological investigation (diver 

and/or ROV investigations) prior to commencing activities to determine whether these features 

represent archaeological resources or (2) ensure that all seafloor-disturbing actions resulting from 

the proposed activities (e.g., site-clearance trawling, anchors, anchor chains, wire ropes, cables, 

etc.) avoid the subject features (see the enclosed map depicting the avoidance area in the 

application). If the applicant plans to conduct an underwater archaeological investigation prior to 

commencing operations, then the applicant must contact BOEM’s Office of Environment at least 

2 weeks prior to performing operations to obtain the investigation methodology and contact BOEM, 

Gulf of Mexico OCS Region, Office of Environment, and BSEE, Environmental Enforcement 

Branch. If the applicant chooses to avoid the features, then include in the Post- removal Report 

as-built plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, the position of anchors, anchor 

chains, wire ropes, and cables deployed during the structure removal relative to these features. In 

addition, supply a copy of ALL vessel logs related to the removal operations (e.g., anchor handling 

vessels, lift boats, dive vessels, and tug boats). This mitigation may be applied by BSEE at the 

post-approval stage.

3.20 Avoidance of Potential 

Archaeological Resources

BOEM’s review indicates that the proposed operations have the potential to impact submerged 

archaeological resources that could be in the area of potential effect, which encompasses all 

portions of the seafloor where bottom-disturbing activities are to occur. Before conducting any 

authorized, bottom-disturbing activities, the company will follow the guidance provided at http://

www.boem.gov/Environmental-Stewardship/Archaeology/Gulf-of-Mexico-ArchaeologicalInformation.aspx, which includes minimum survey recommendations, requisite certification 

submittals, and post-activity reporting standards needed to ensure compliance with the regulations 

under 30 CFR § 550.194. This mitigation may be applied by BSEE at the post-approval stage.

3.21 and 

3.22

Side-Scan Sonar Targets (site 

clearance – single features)

Side-Scan Sonar Targets (site 

clearance – multiple features)

BOEM’s review indicates that the proposed activities are in the vicinity of the unidentified sidescan sonar target(s) listed in the table in the application, features that may represent significant 

archaeological resources. In accordance with 30 CFR § 250.194(c), the applicant must conduct an 

underwater archaeological investigation (diver and/or ROV investigation) under the supervision of 

a professional archaeologist to determine whether these features represent archaeological resources 

potentially eligible to the National Register of Historic Places prior to conducting site-clearance 

trawling activities. This mitigation may be applied by BSEE at the post-approval stage.

3.23 Protection of Potential 

Archaeological Resources (all 

structure removals)

Per 30 CFR § 250.194(c) and clarified in 2005-G07, if, during site clearance operations the 

applicant discovers any object of potential archaeological significance, the applicant is required to 

immediately halt operations. In addition, the applicant must immediately report this discovery to 
A-14 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

BSEE’s Environmental Enforcement Branch. Additional guidance will be provided to the applicant 

as to what steps will be needed to protect any potentially submerged archaeological resources. In 

order for BSEE to ensure compliance with 30 CFR § 250.194(c) and as specified under 30 CFR § 

250.1743, the applicant is required to provide the trawling logs for both heavy-duty nets and 

verification nets, with descriptions of each item recovered. Should the applicant only pull siteclearance verification nets, the applicant must clearly state this within the body of the Site 

Clearance Report. The applicant is also requested to provide the following as an appendix in the 

Site Clearance Report: a CD or DVD of all digital photographs of the items recovered during the 

use of both the heavy-duty trawl nets and the site-clearance verification trawl nets. This mitigation 

may be applied by BSEE at the post-approval stage.

Artificial Reef Material Mitigations

4.01 Louisiana (artificial reef area) The proposed anchoring operations are located within 500 ft of an artificial reef permit area 

established by the State of Louisiana. At least 2 weeks prior to conducting anchoring operations 

(including the use of anchors, anchor chains, and wire ropes) that could disturb the seafloor within 

500 ft (152 m) of an artificial reef permit area, the applicant must contact the Louisiana Artificial 

Reef Coordinator to ensure that the proposed anchoring operations do not damage reefal material. 

Prior to conducting anchoring operations, the applicant must send an email to BSEE’s

Environmental Enforcement Branch confirming that the Louisiana Artificial Reef Coordinator has 

been contacted.

If the anchoring operations intersect or cross-over the artificial reef permit area, then submit anchor 

position plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, depicting the “as-placed” location 

of all anchors, anchor chains, wire ropes, and cables (including sweep if applicable) on the seafloor 

relative to the reefal material. For plans, submit the plats to BOEM’s Regional Supervisor, Office 

of Leasing and Plans, Plans Section at the same time the applicant submits the End of Operations 

Report (Form BSEE-0125) to the appropriate BSEE, Gulf of Mexico OCS Region, District Office 

and/or notification of platform installation date and final as-built location data as directed in 

30 CFR § 250.900(e). For pipelines, submit the plats with the pipeline construction report required 

by 30 CFR § 250.1008(b). For structure removals, submit the plats with the post-removal report. 

This mitigation may be applied by BSEE at the post-approval stage.

4.02 Texas (artificial reef general permit 

area)

The proposed operations are located within an artificial reef General Permit Area established by the 

State of Texas. At least 2 weeks prior to conducting operations (including the use of anchors, 

anchor chains, and wire ropes) that could disturb the seafloor within the artificial reef General 

Permit Area, contact the Texas Artificial Reef Coordinator to ensure that the proposed operations 

do not damage reefal material. Prior to conducting operations, the applicant must send an email to

BSEE’s Environmental Enforcement Branch confirming that the Texas Artificial Reef Coordinator 

has been contacted. This mitigation may be applied by BSEE at the post-approval stage.
Commonly Applied Mitigating Measures

A-15

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

4.021 Texas (artificial reef permit area –

anchoring)

The proposed anchoring operations are located within 1,000 ft of an artificial reef permit area 

established by the State of Texas. At least 2 weeks prior to conducting anchoring operations 

(including the use of anchors, anchor chains, and wire ropes) that could disturb the seafloor within 

1,000 ft of the artificial reef permit area, contact the Texas Artificial Reef Coordinator to ensure 

that the proposed anchoring operations do not damage reefal material. Prior to conducting 

anchoring operations, the applicant must send an email to BSEE’s Environmental Enforcement 

Branch confirming that the Texas Artificial Reef Coordinator has been contacted.

If the anchoring operations intersect or cross-over the artificial reef permit area, submit anchor 

position plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, depicting the “as-placed” location 

of all anchors, anchor chains, wire ropes, and cables (including sweep if applicable) on the seafloor 

relative to the reefal material. For plans, submit the plats to BOEM’s Regional Supervisor, Office 

of Leasing and Plans, Plans Section at the same time the applicant submits the End of Operations 

Report (Form BSEE-0125) to the appropriate BSEE, Gulf of Mexico OCS Region, District Office 

and/or notification of platform installation date and final as-built location data as directed in 

30 CFR § 250.900(e). For pipelines, submit the plats with the pipeline construction report required 

by 30 CFR § 250.1008(b). For structure removals, submit the plats with the post-removal report. 

This mitigation may be applied by BSEE at the post-approval stage.

4.03 Mississippi (artificial reef area) The proposed anchoring operations are located within 500 ft (152 m) of an artificial reef permit area 

established by the State of Mississippi. At least 2 weeks prior to conducting anchoring operations 

(including the use of anchors, anchor chains, and wire ropes) that could disturb the seafloor within 

500 ft (152 m) of an artificial reef structure or an artificial reef permit area, contact the Mississippi 

Artificial Reef Coordinator to ensure that the proposed anchoring operations do not damage reefal 

material. Prior to conducting anchoring operations, the applicant must send an email to BSEE’s

Environmental Enforcement Branch confirming that the Mississippi Artificial Reef Coordinator has 

been contacted. This mitigation may be applied by BSEE at the post-approval stage.

4.04 Alabama (artificial reef general 

permit area)

The proposed operations are in a General Permit Area established by the State of Alabama for the 

placement of artificial reef material. At least 2 weeks prior to conducting operations, contact the 

Alabama Artificial Reef Coordinator to ensure that the proposed operations do not damage reefal 

material. Prior to conducting operations, the applicant must send an email to BSEE’s

Environmental Enforcement Branch confirming that the Alabama Artificial Reef Coordinator has 

been contacted. This mitigation may be applied by BSEE at the post-approval stage.

4.05 Florida (artificial reef general 

permit area)

The proposed operations are in a General Permit Area established by the State of Florida for the 

placement of artificial reef material. At least 2 weeks prior to conducting operations, contact the 

Florida Artificial Reef Coordinator to ensure that the proposed operations do not damage reefal 

material. Prior to conducting operations, the applicant must send an email to BSEE’s

Environmental Enforcement Branch confirming that the Florida Artificial Reef Coordinator has 

been contacted. This mitigation may be applied by BSEE at the post-approval stage.
A-16 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

4.06 Post-Reefing Survey Requirements BOEM’s review indicates that the structure proposed for decommissioning will be abandoned-inplace as an artificial reef under the Rigs-to-Reefs Program. In order to verify compliance with 

OCSLA reefing (30 CFR § 250.1727(g)) and obstruction clearance requirements (30 CFR § 

250.1740(a)(2)), the applicant is required to conduct a high-resolution sonar survey (500 kHz or 

greater) of the permitted reefal material. The applicant must design the line spacing (for side-scan) 

or sonar drops (for sector-scanning) and the display range to ensure that 100 percent of the material 

permitted under this action is covered and that it is demonstrated that the associated seabed is clear 

of all obstructions apart from the reefal material. The applicant is required to submit the sonar 

data/survey report to BSEE’s Environmental Enforcement Branch at the same time as the postremoval report. This mitigation may be applied by BSEE at the post-approval stage.

Chemosynthetic Communities Mitigations

5.00 Chemosynthetic Communities 

Non-Recurring Mitigation

A non-recurring mitigation is a mitigation measure that is used for a unique, special, one-time-only 

mitigation that is added to certain plans.

5.01 Anchor Positioning (GPS) (plans) The proposed activities are in the vicinity of areas that could support high-density deepwater 

benthic communities. Use a state-of-the-art positioning system (e.g., DGPS) on the anchor 

handling vessel to ensure that any seafloor disturbance resulting from the use of anchors (including 

that caused by the anchors, anchor chains, and wire ropes) does not occur within 250 ft (76 m) of 

such areas (see the enclosed map/Map xxx [specify map by name], submitted with the survey 

report, which depicts the areas). Submit plats for Well(s) (insert number[s] or name[s]), which 

depict the “as-placed” location of all anchors and any associated anchor chains and wire ropes on 

the seafloor, at a scale of 1 in = 1,000 ft with DGPS accuracy, to BOEM’s Regional Supervisor, 

Office of Leasing and Plans, Plans Section at the same time the applicant submits the End of 

Operations Report (Form BSEE-0125) to the appropriate BSEE, Gulf of Mexico OCS Region,

District Office to demonstrate that the features were not physically impacted by these anchoring 

activities. This mitigation may be applied by BSEE at the post-approval stage.

5.02 Conventional Pipeline Laying 

Vessels (GPS) (pipeline 

applications)

The proposed pipeline construction activities are in the vicinity of areas that could support highdensity deepwater benthic communities. Use a state-of-the-art positioning system (e.g., DGPS) on 

the pipeline laying vessel and the anchor handling vessels to ensure that any seafloor disturbance 

(including that caused by anchors, anchor chains, and wire ropes) during pipeline construction 

activities does not occur within 250 ft of such areas (see the enclosed map/Map xxx [specify map 

by name], submitted with the pipeline application, which depicts the areas). Additionally, include 

lay barge anchor position plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, with the pipeline 

construction report required by 30 CFR § 250.1008(b), which depict the “as-placed” location of all 

anchors, anchor chains, and wire ropes on the seafloor and which demonstrate that the features were 

not physically impacted by the construction activities. This mitigation may be applied by BSEE at 

the post-approval stage.

5.03 Anchor Positioning (ROV) (plans) The proposed activities are in the vicinity of areas that could support high-density deepwater 

benthic communities. Use an ROV to ensure that any seafloor disturbance resulting from the use of 

anchors (including that caused by the anchors, anchor chains, and wire ropes) does not occur within 
Commonly Applied Mitigating Measures

A-17

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

250 ft of such areas (see the enclosed map/Map xxx [specify map by name], submitted with your 

survey report which depicts the areas). Submit plats for Well(s) (insert number[s] or name[s]),

which depict the “as-placed” location of all anchors and any associated anchor chains and wire 

ropes on the seafloor, at a scale of 1 in = 1,000 ft with DGPS accuracy, along with the highresolution ROV video on disc or removable drive, to BOEM’s Regional Supervisor, Office of 

Leasing and Plans, Plans Section at the same time the applicant submits the End of Operations 

Report (Form BSEE-0125) to the appropriate BSEE, Gulf of Mexico OCS Region, District Office 

to demonstrate that the features were not physically impacted by these anchoring activities. The 

ROV video screen should show time, date, depth, heading, and location coordinates. Observational 

notes and a corresponding map showing the ROV heading shall also be provided. If still images are 

collected, include the same information in the images’ integrated data. This mitigation may be 

applied by BSEE at the post-approval stage.

5.04 Conventional Pipeline Laying 

Vessels (ROV) (pipeline 

applications)

The proposed pipeline construction activities are in the vicinity of areas that could support highdensity deepwater benthic communities. Use an ROV to ensure that any seafloor disturbance 

(including that caused by the anchors, anchor chains, and wire ropes) during pipeline construction 

activities does not occur within 250 ft of such areas (see the enclosed map/Map “xxx” [specify map 

by name], submitted with the pipeline application, which depicts the areas). Submit lay barge 

anchor position plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, with the pipeline 

construction report required by 30 CFR § 250.1008(b), which depict the “as-placed” location of all 

anchors, anchor chains, and wire ropes on the seafloor and which demonstrate that the features were 

not physically impacted by the construction activities. Additionally, submit the high-resolution 

ROV video on disc or removable drive. The ROV video screen should show time, date, depth, 

heading, and location coordinates. Observational notes and a corresponding map showing the ROV 

heading shall also be provided. If still images are collected, include the same information in the 

images’ integrated data. This mitigation may be applied by BSEE at the post-approval stage.

5.05 Dynamically Positioned Pipeline 

Laying Vessels (GPS) (pipeline 

applications)

The proposed pipeline construction activities are in the vicinity of areas that could support highdensity deepwater benthic communities. Use a state-of-the-art positioning system (e.g., DGPS) on 

the dynamically positioned pipeline laying vessel to ensure that any seafloor disturbance resulting 

from the pipeline construction activities does not occur within 250 ft of such areas (see the enclosed 

map/Map “xxx” [specify map by name], submitted with the pipeline application, which depicts the 

areas). Additionally, include “as-built” location plats, at a scale of 1 in = 1,000 ft with DGPS 

accuracy, with the pipeline construction report required by 30 CFR § 250.1008(b), which depict the 

location of the pipeline(s) relative to these features to demonstrate that the features were not 

physically impacted by the construction activities. This mitigation may be applied by BSEE at the 

post-approval stage.

5.06 Well Positioning (ROV) (plans) BOEM’s review indicates that the applicant has stated in the plan that the proposed activities are in 

the vicinity of areas that could support high-density chemosynthetic communities. Use an ROV to 

ensure that any seafloor disturbance resulting from the activities does not occur in such areas that 

are within 1,500 ft of your proposed location (see the enclosed map/Map “xxx” [specify map by 

name], submitted with the survey report which depicts these areas). Submit plats for Wells(s) 
A-18 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

(insert number[s] or name[s]), which depict the “as-drilled” location of the well(s), at a scale of 1 in 

= 1,000 ft with DGPS accuracy, at the same time the applicant submits the End of Operations report 

(Form BSEE-0125) to the appropriate BSEE, Gulf of Mexico OCS Region, District Office to 

demonstrate that the features were not physically impacted. This mitigation may be applied by 

BSEE at the post-approval stage.

5.07 Anchor Positioning (GPS and ROV) The proposed activities are in the vicinity of areas that could support high-density deepwater 

benthic communities. Use a state-of-the-art positioning system (e.g., DGPS) on the anchor 

handling vessel and use an ROV to ensure that any seafloor disturbance resulting from the use of 

anchors (including that caused by the anchors, anchor chains, and wire ropes) does not occur within 

250 ft of such areas. Submit plats for Well(s) (insert number[s] or name[s]), which depict the “asplaced” location of all anchors and any associated anchor chains and wire ropes on the seafloor, at a 

scale of 1 in = 1,000 ft with DGPS accuracy, along with the high-resolution ROV video on disc or 

removable drive, to BOEM’s Regional Supervisor, Office of Leasing and Plans, Plans Section at 

the same time the applicant submits the End of Operations Report (Form BSEE-0125) to the 

appropriate BSEE, Gulf of Mexico OCS Region, District Office to demonstrate that the features 

were not physically impacted by these anchoring activities. The ROV video screen should show 

time, date, depth, heading, and location coordinates. Observational notes and a corresponding map 

showing the ROV heading shall also be provided. If still images are collected, include the same 

information in the images’ integrated data. This mitigation may be applied by BSEE at the postapproval stage.

5.08 Well Placement Variance (plans) There is an area capable of supporting high-density deepwater benthic communities within 2,000 ft 

of the proposed well(s), also known as the chemosynthetic well parameter. The proposed well(s) 

is/are (insert chemosynthetic distance parameter) from the area capable of supporting high-density 

deepwater benthic communities, which in this case provides adequate protection from muds and 

cuttings during operations. The actual well(s) shall not be placed closer than (CHEMO 

DISTANCE PARAMETER 1) from the potential habitat (see the chemosynthetic map parameter, 

which depicts the area). Provide a map showing the final as-placed well(s), potential habitat, and 

distance of the well(s) from the potential habitat to BOEM’s Regional Supervisor, Office of 

Leasing and Plans, Plans Section at the same time the applicant submits the End of Operations 

Report (Form BSEE-0125) to the appropriate BSEE, Gulf of Mexico OCS Region, District Office 

to demonstrate that the feature(s) were not physically impacted by the drilling activity. This 

mitigation may be applied by BSEE at the post-approval stage.

5.09 Well Placement Variance – “Zero 

Discharge” (plans)

There is an area capable of supporting high-density deepwater benthic communities within 2,000 ft 

of the proposed well(s) (insert chemosynthetic wells parameter). Since this area is (insert 

chemosynthetic distance parameter) from your well site(s), chemosynthetic reason parameter, 

BSEE permits the activity with the following mitigations added.

1. Do not move the well(s) any closer to the area capable of supporting high-density 

deepwater benthic communities (see chemosynthetic map parameter, which depicts the 

area).
Commonly Applied Mitigating Measures

A-19

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

2. Follow “zero discharge” practices (i.e., no muds or cuttings shall be discharged near the 

sea surface in the vicinity of the permitted activity).

3. In this instance, it is understood that the discharge of muds and cuttings will occur on or 

near the seafloor for the riserless portion of the drilling operations ONLY as part of the 

“zero discharge” practice.

4. No muds or cuttings shall be discharged near the seafloor or at the sea surface once the 

blowout preventer and marine riser have been installed. No additional or excess muds 

or cuttings beyond those necessary to properly accomplish the riserless portion of the 

drilling activity shall be discharged on or near the seafloor.

5. Perform an assessment survey after the drilling of the well(s) is complete. (a) Conduct 

an ROV survey to assess sedimentation and its effects on the area capable of supporting 

high-density deepwater benthic communities (see chemosynthetic map parameter 1, 

which depicts the area. Transects must be run no more than 50 ft apart). (b) Ensure 

that the imagery in the ROV survey is high enough quality to adequately assess drilling 

effects. (This can be accomplished by employing the use of high-resolution still 

photography, high-resolution video, and/or lower resolution imaging through the use of 

close-up photography.) (c) The surveyed areas shall be recorded and documented on 

disc or removable drive for review, and the screen should show time, date, depth, 

heading, and location coordinates.

This mitigation may be applied by BSEE at the post-approval stage.

Coastal Zone Management Mitigations

6.01 Texas (Coastal Zone Management) Drilling permits cannot be issued for the proposed wells until concurrence with the coastal zone 

management consistency certification has been received by BOEM’s Office of Environment from 

the Texas General Land Office or until concurrence with the certification has been conclusively 

presumed.

6.02 Louisiana (Coastal Zone 

Management)

Drilling permits cannot be issued for the proposed wells until concurrence with the coastal zone 

management consistency certification has been received by BOEM’s Office of Environment from 

the Louisiana Department of Natural Resources or until concurrence with the certification has been 

conclusively presumed.

6.03 Alabama (Coastal Zone 

Management)

Drilling permits cannot be issued for the proposed wells until concurrence with the coastal zone 

management consistency certification has been received by BOEM’s Office of Environment from 

the Alabama Department of Environmental Management or until concurrence with the certification 

has been conclusively presumed.
A-20 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

6.04 Mississippi (Coastal Zone 

Management)

Drilling permits cannot be issued for the proposed wells until concurrence with the coastal zone 

management consistency certification has been received by BOEM’s Office of Environment from 

the Mississippi Department of Marine Resources or until concurrence with the certification has 

been conclusively presumed.

6.05 Florida (Coastal Zone Management) Drilling permits cannot be issued for the proposed wells until concurrence with the coastal zone 

management consistency certification has been received by BOEM’s Office of Environment from 

the Florida Department of Environmental Protection or until concurrence with the certification has 

been conclusively presumed.

Flower Garden Banks Mitigations

7.07 Environmental Monitoring Plan Develop a plan for the early initiation of environmental monitoring of the effects of a hydrocarbon 

spill that may occur as a result of the proposed activities on the resources of the Flower Garden 

Banks National Marine Sanctuary, including water quality, pelagic fish, and benthic communities.

7.09 Pressure Sensor Testing High- and low-pressure sensors protecting the proposed pipeline will be tested at least once 

bi-weekly with no more than 3 weeks elapsing between each test. The applicant will maintain these 

records on the platform and will make them available to BSEE personnel upon request.

7.10 Pressure Sensor Setting The low-pressure sensor protecting the proposed pipeline will be set no lower than 10 percent 

below the lower limit of the normal operating pressure range.

Hydrogen Sulfide Mitigations

8.01, 8.02, 

and 8.03

H2S Present (plans)

H2S Unknown (plans)

H2S Absent (plans)

In response to the request accompanying your plan for a hydrogen sulfide (H2S) classification, the 

area in which the proposed drilling operations are to be conducted is hereby classified, in 

accordance with 30 CFR § 250.490(c), as “H2S present,” “H2S unknown,” or “H2S absent.”

Accordingly, comply with the appropriate requirements of 30 CFR § 250.490 if H2S is present or 

unknown.

8.04 H2S Concentration Deviation The plan indicates that the applicant anticipates H2S at a concentration of approximately (specify 

the ppm). Should the applicant actually encounter H2S at a concentration greater than 500 ppm, 

revise the plan in accordance with 30 CFR § 550.285 to include toxic modeling and an analysis of 

any potential environmental impacts. Contact BOEM’s Office of Environment to obtain the 

methodology for modeling an H2S plume. The applicant must receive approval of the revised plan 

before additional permits filed under the plan will be approved.

8.05 Corrosion Inspections (H2S

pipelines)

Inspect the pipeline(s) bi-annually, annually, or biennially for an indication of corrosion or other 

flaws. Report the results of these inspections to BSEE’s Office of Field Operations within 30 days 

of completion. This mitigation may be applied by BSEE at the post-approval stage.

8.07 National Ocean Service Notification 

(H2S pipelines)

When the applicant provides the National Ocean Service, Nautical Data Section with a copy of the 

pipeline construction report plat, the applicant must also request that the National Ocean Service, 

Nautical Data Section include the pipeline(s) on their navigation charts and identify it/them as (an) 

H2S or toxic sour gas pipeline(s).
Commonly Applied Mitigating Measures

A-21

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

8.08 USCG Notification (H2S pipelines) Immediately after the applicant begins operation of the pipeline(s), the applicant must notify the 

U.S. Coast Guard Commander, Eighth Coast Guard District, that the pipeline(s) is/are in operation 

and request that the USCG publish information about the pipeline(s), including the fact that it is or 

they are transporting natural gas with a high concentration of H2S, in the Eighth District Local 

Notice to Mariners, Gulf of Mexico.

8.09 H2S Concentration Deviation 

(pipeline applications)

The application indicated that the applicant anticipates the H2S concentration of the product to be 

transported in the proposed pipeline is approximately (specify the ppm). Should the applicant 

determine at some future date that the H2S concentration is greater than 500 ppm, immediately 

submit an application to modify the pipeline in accordance with 30 CFR § 250.1007(b) to include 

toxic modeling and an analysis of any potential environmental impacts. Contact BOEM’s Office of 

Environment to obtain the methodology for modeling an H2S plume.

8.10 Notification to Federal Aviation 

Administration

Prior to initiating operations approved in your plan or pipeline application, the applicant shall 

update their emergency notification list in their H2S contingency plan to include the Federal 

Aviation Administration (FAA: Houston Air Traffic Control/Traffic Management Control Desk). 

In the event of an above-water or below-water sour gas release greater than 100 standard cubic feet, 

notify the FAA that air traffic (except evacuation and medical aircraft) should be routed safely 

away from the site until further notice. For purposes of avoidance recommendations to the FAA, a 

distance of 10 nautical miles and an altitude of 4000 ft, as minimal, shall be used. In the case of a 

release of H2S (that constitutes an emergency), notify all facilities that might be exposed to 

atmospheric concentrations of 20 ppm or more of H2S (i.e., all facilities located within [insert 

number] miles of the H2S release). The applicant must also assist in the removal of all personnel as 

well as any other persons observed within the affected area.

8.11 H2S Absent and H2S Present or 

Unknown below Certain Depths 

(plans)

In response to the request accompanying the plan for a H2S classification, the area in which the 

proposed drilling operations are to be conducted above (specify depth) is hereby classified, in 

accordance with 30 CFR § 250.490(c), as H2S absent. However, the area in which the proposed 

drilling operations are to be conducted below (specify depth) is hereby classified, in accordance 

with 30 CFR § 250.490(c), as H2S present or unknown. Accordingly, comply with the appropriate 

requirements of 30 CFR § 250.490.

Live Bottom Areas

9.00 Hard Bottoms/Pinnacles/Potentially 

Sensitive Biological Features NonRecurring Mitigation

A non-recurring mitigation is a mitigation measure that is used for a unique, special, one-time-only 

mitigation that is added to certain plans.

9.01 Hard Bottoms/Pinnacles/Potentially 

Sensitive Biological Features 

(conventional lay barge) (pipeline 

applications)

BOEM’s analysis indicates that there are hard bottoms/pinnacles/potentially sensitive biological 

features (PSBFs) that likely provide habitat for biological assemblages located within the scope of 

the anchor array of the pipeline lay barge. The pipeline construction activities (including the use of 

anchors, chains, and wire ropes) must avoid these hard bottoms/pinnacles/PSBFs as depicted on the 

enclosed map(s) in the application by a distance of at least 100 ft. Include lay barge anchor position 

plats, at a scale of 1 in = 1,000 ft with DGPS accuracy, with the pipeline construction report 

required by 30 CFR § 250.1008(b), which depict the “as-placed” location of all anchors, anchor 
A-22 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

chains, and wire ropes on the seafloor and which demonstrate that the features were not physically 

impacted by the construction activities. This mitigation may be applied by BSEE at the postapproval stage.

9.03 Hard Bottoms/Pinnacles/Potentially 

Sensitive Biological Features 

(plans)

BOEM’s analysis indicates that there are hard bottoms/pinnacles/PSBFs located in the vicinity of 

the activities proposed in the plan that likely provide habitat for biological assemblages. Any 

bottom-disturbing activities associated with the activities proposed in the plan must avoid these 

hard bottoms/pinnacles/PSBFs as depicted on the enclosed map(s) in the application by a distance 

of at least 100 ft. Submit to BSEE’s Office of Field Operations at the same time you submit your 

End of Operations report (Form BSEE-0125) to the appropriate BSEE, Gulf of Mexico OCS 

Region, District Office an as-built map at a scale of 1 in = 1,000 ft with DGPS accuracy, showing 

the location of any seafloor disturbance (e.g., jack-up rig, barge anchors, etc.) relative to these 

features. This mitigation may be applied by BSEE at the post-approval stage.

9.04 Hard Bottoms/Pinnacles/Potentially 

Sensitive Biological Features (DP 

lay barge) (pipeline applications)

BOEM’s analysis indicates that there are hard bottoms/pinnacles/PSBFs that likely provide habitat 

for biological assemblages located on or near the proposed pipeline route. The pipeline 

construction activities must avoid these hard bottoms/pinnacles/PSBFs as depicted on the enclosed 

map(s) in the application by a distance of at least 100 ft. This mitigation may be applied by BSEE 

at the post-approval stage.

9.05 Hard Bottoms/Pinnacles/Potentially 

Sensitive Biological Features 

(structure removal)

BOEM’s review of the application indicates that there are hard bottoms/pinnacles/PSBFs located in 

the vicinity of the activities proposed in the application that likely provide habitat for biological 

assemblages. Any bottom-disturbing activities associated with the activities proposed in the 

application must avoid these hard bottoms/pinnacles/PSBFs as depicted on the enclosed map(s) in 

the application by a distance of at least 100 ft. Include in the post-removal report the as-built plats, 

at a scale of 1 in = 1,000 ft with DGPS accuracy, which depict the “as-placed” location of all 

anchors, anchor chains, and wire ropes on the seafloor deployed during the structure removal 

relative to these features. This mitigation may be applied by BSEE at the post-approval stage.

9.10 ROV Survey Required NonRecurring MitigationA non-recurring mitigation is a mitigation measure that is used for a unique, special, one-time-only 

mitigation that is added to certain plans.

Military Mitigations

10.09 Naval Coastal Systems Center Please be reminded of the lease stipulation requires the applicant to enter into an agreement with the 

Coastal Test and Evaluation Division, Coastal System Station/Code E21, Panama City, Florida 

32407, concerning the control of your electromagnetic emissions and use of boats and aircraft in the 

Naval Coastal Systems Center Area.

11.11 Military Warning Area (all) BOEM’s review indicates that the proposed pipeline route and/or the routes to be taken by boats and 

aircraft in support of the proposed activities are located in or could traverse Military Warning Area W-

(insert number) or Eglin Water Test Area EWTA-(insert number) (see BOEM’s Internet website at http://

www.boem.gov/MWA-Boundaries/ for a map of the areas). Contact the appropriate individual military 

command headquarters (see BOEM’s Internet website at http://www.boem.gov/Military-Contacts-forWarning-and-Water-Test-Areas/ for a list of the contacts) concerning the control of electromagnetic 

emissions and the use of boats and aircraft in this area(s) before commencing such traffic.
Commonly Applied Mitigating Measures

A-23

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

12.01 Unexploded Ordnance The proposed operations are located in an area that was used until 1970 by the U.S. Department of 

Defense as an explosives dumping area. Please be advised that precautions should therefore be 

taken while conducting operations that involve any disturbance of the seafloor in order to avoid 

possible unexploded ordnance.

12.02 Naval Mine Warfare Area

(MU 732, 733, and 734)

The proposed operations are located within a stipulated area designated by the Naval Mine Warfare 

Command for mine operations. Therefore, surface structures for exploration activities are subject 

to approval by BOEM’s Gulf of Mexico OCS Region’s Regional Director after consultation with 

the Commander, Mine Warfare Command. No permanent structures or debris of any kind will be 

allowed in the area during exploration operations. Plans for any above seafloor development 

operations within the designated area must be coordinated with the Commander, Mine Warfare 

Command, 325 Fifth Street, SE, Corpus Christi, Texas 78491-5032.

Shallow Drilling Hazards Mitigations (Plans)

14.01 Shallow Gas and/or Water Flow Exercise caution while drilling due to indications of shallow gas (and/or faulting) (and/or possible 

water flow).

14.02 Seafloor Instability Exercise caution during drilling rig placement due to indications of seafloor instability.

14.03 Insufficient Information Exercise caution during drilling rig placement due to insufficient information regarding seafloor 

foundation integrity.

Shallow Hazards Mitigations

15.01 and 

15.02

Multiple Hazards (plans)

Single Hazard (plans)

BOEM’s review indicates that there are pipeline(s), unidentified magnetic anomaly(ies), 

unidentified side-scan sonar contact(s), or other specified hazard(s) in the vicinity of (insert name of 

platform(s) or well(s)) that may pose a hazard to the proposed operations. Therefore, take 

precautions in accordance with NTL 2008-G05, Section VI.B, prior to performing operations.

15.05 and 

15.06

Multiple Hazards (plans/pipelines) 

(anchoring activities)

Single Hazard (plans) (anchoring)

BOEM’s review indicates that there is a pipeline(s), unidentified magnetic anomaly(ies), 

unidentified side-scan sonar contact(s), or other specified hazard(s) in the vicinity of (insert name of 

platform(s) or well(s)) that may pose a hazard due to anchoring activities associated with the 

proposed operations. If any of these activities will take place within 150 m (490 ft) of the potential 

hazard, take precautions in accordance with NTL 2008-G05, Section VI.B, prior to performing 

operations.

15.07 Pipeline Spanning BOEM’s review indicates areas of seafloor relief in the vicinity of the proposed pipeline route, 

which may cause spanning problems for the pipeline. Use an ROV in conjunction with the pipeline 

construction activities to ensure that these areas are avoided to the extent possible. Additionally, 

include a report with the pipeline construction report, which is required by 30 CFR § 250.1008(b)

and which analyzes the as-laid pipeline with respect to spanning and describes the protective 

measures taken to ensure pipeline integrity for those portions of the pipeline where the areas of 

seafloor relief could not be avoided. This mitigation may be applied by BSEE at the post-approval 

stage.

15.08 Conflict with Anchors Please be advised that exploration activities have been approved or are pending approval for (insert 

lease, block, area), which could potentially interfere with the proposed activities. Therefore, the 
A-24 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

applicant should contact (insert contact name, company, address, phone number) prior to 

commencement of the activities in order to avoid any potential conflicts.

Topographic Features Mitigations

16.00 Topographic Features NonRecurring MitigationA non-recurring mitigation is a mitigation measure that is used for a unique, special, one-time-only 

mitigation that is added to certain plans.

16.01 Shunting All Wells (plans) The proposed activities are within the “4-mile, 3-mile, 1-mile, or 1,000-meter zone” of (insert name 

of topographic feature). Shunt all drill cuttings and drilling fluids to the seafloor through a 

downpipe that terminates an appropriate distance, but no more than 10 m, from the bottom.

16.02 Shunting Some Wells (plans) Some of the proposed activities are within the “4-mile, 3-mile, 1-mile, or 1,000-meter zone” of 

(insert name of topographic feature). For (insert name of wells to be shunted”, shunt all drill 

cuttings and drilling fluids to the seafloor through a downpipe that terminates an appropriate 

distance, but no more than 10 m, from the bottom.

16.03 No Activity Zone (right-of-way

pipeline applications)

BOEM’s analysis indicates that the “no activity zone(s)” of the biologically sensitive feature(s) 

shown on the enclosed map(s) in the application may be located within the scope of the anchor 

array of the pipeline lay barge. Anchors, anchor chains, and wire ropes associated with the 

proposed pipeline construction activities must avoid this/these “no activity zone(s)” by a distance of 

at least 500 ft. Include lay barge anchor positions plats, at a scale of 1 in = 1,000 ft with DGPS 

accuracy, with the pipeline construction report required by 30 CFR § 250.1008(b), which depict the 

“as-placed” location of all anchors, anchor chains, and wire ropes on the seafloor, and which 

demonstrate that the “no activity zone(s)” was/were not physically impacted by the construction 

activities. This mitigation may be applied by BSEE at the post-approval stage.

16.04 No Activity Zone (plans) Bottom-disturbing activities associated with the activities proposed in the plan must avoid the “no 

activity zone” of the biologically sensitive feature shown on the enclosed map in the application by 

a distance of at least 500 ft. Submit to BSEE’s Office of Field Operations, at the same time the End 

of Operations report (Form BSEE-0125) is submitted to the appropriate BSEE, Gulf of Mexico 

OCS Region, District Office, an as-built map at a scale of 1 in = 1,000 ft with DGPS accuracy, 

showing the location of any seafloor disturbance (e.g., jack-up rig placement, rig anchors, 

construction barge anchors, etc.) to demonstrate that the “no activity zone(s)” was not physically 

impacted. This mitigation may be applied by BSEE at the post-approval stage.

16.05 No Activity Zone (structure 

removal)

Bottom-disturbing activities associated with the activities proposed in the application must avoid 

the “no activity zone” of the biologically sensitive feature shown on the enclosed map in the 

application by a distance of at least 500 ft. Include in the post-removal report an as-built plat, at a 

scale of 1 in = 1,000 ft with DGPS accuracy, depicting the “as-placed” location of all anchors, 

anchor chains, and wire ropes on the seafloor deployed during the structure-removal activities to 

show that the “no activity zone” was not physically impacted. This mitigation may be applied by 

BSEE at the post-approval stage.
Commonly Applied Mitigating Measures

A-25

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

Non-Plan and Pipeline Mitigations

17.02 Fish (structure removals using 

explosives)

Under the Magnuson-Stevens Fisheries Conservation and Management Act, 50 CFR § 600.725 

prohibits the use of explosives to take reef fish in the Exclusive Economic Zone. Consequently, 

those involved in explosive structure removals must not take such stunned or killed fish on board 

their vessels. Should this happen, they could be charged by the National Marine Fisheries Service 

(NMFS) with violation of the Act.

17.04 Site-Clearance Trawling Reporting If trawling is used to comply with the site-clearance verification requirements under 30 CFR §§ 

250.1740-1743, which mandates that turtle excluder devices (TED) be removed from the trawl nets 

to facilitate the collection of seabed debris, the applicant must abide by maximum trawl times of 

30 minutes, allowing for the removal of any captured sea turtles. If, during trawling activities, the 

applicant captures a sea turtle in the nets, the applicant must (1) contact BSEE’s Environmental 

Enforcement Branch and the National Marine Fisheries Services’ (NMFS’s) Southeast Regional 

Office immediately, (2) resuscitate and release any captured sea turtles as per NMFS’s guidelines 

found online at http://www.sefsc.noaa.gov/turtles/TM_NMFS_SEFSC_580_2010.pdf (refer to 

page 3-6, Plate 3-1), and (3) photograph the turtle and complete a sea turtle stranding form for each 

sea turtle caught in the nets. The form can be found at http://www.sefsc.noaa.gov/species/turtles/

strandings.htm and submitted to NMFS and BSEE.

Conservation Information Document Mitigations

18 Self-Burial Approval BOEM hereby concurs with the determination that the subject pipeline will be installed in an area 

that is prone to self-burial. However, in the future, should it be determined that the pipeline(s) 

constitute(s) a hazard to navigation or commercial fishing operations or unduly interferes(s) with 

other uses of the OCS, the applicant will be required to bury it (them).

18.01 Conservation Information 

Document – Condition of Approval

Within 15 days after the proposed well is or wells are completed and logged, submit a revision to 

the plan consisting of the information required for a Conservation Information Document in 

accordance with NTL 2000-N05.

18.02 Conservation Information 

Document – Operations Approval

At the applicant’s request, we are approving your development operation coordination document 

(DOCD) prior to the completion of our review of the accompanying Conservation Information 

Document (CID). However, please be advised that, if the CID review indicates that any of the 

proposed activities do not conform to sound conservation, engineering, and economic practices as 

cited in 30 CFR §§ 550.202(a) and 550.1101(a), we will, in accordance with 30 CFR § 

550.281(4)(b), require such revisions to the DOCD as are necessary to make the activities conform 

to such practices.

ROV Survey Mitigations

19.01 ROV Survey Required –

Exploration Plans (EP)

In accordance with NTL 2008-G06, the applicant must conduct the two ROV surveys proposed in 

the plan. The first survey will be for the first well location approved under this plan which is 

actually drilled. The post-drilling survey can be conducted at the time the applicant is preparing to 

leave this location. The applicant must submit both survey reports within 60 days after the rig 

leaves the well location. This mitigation may be applied by BSEE at the post-approval stage.
A-26 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

19.02 ROV Survey Required – DOCD In accordance with NTL 2008-G06, the applicant must conduct the ROV surveys proposed in the 

plan for the facility location approved under this plan. The applicant must submit the pre- and postinstallation survey reports within 60 days after the facility installation is completed. This mitigation 

may be applied by BSEE at the post-approval stage.

19.03 ROV Survey Not Required In accordance with NTL 2008-G06, BOEM has determined that the applicant will not need to 

conduct the two ROV surveys proposed in the plan. This mitigation may be applied by BSEE at the 

post-approval stage.

Surveys Mitigations

21.01 Archaeology Assessment Not 

Acceptable

BOEM’s review has determined that the archaeological analysis included in the survey report does 

not meet current BOEM requirements.

21.02 Archaeology Assessment 

Acceptable

BOEM’s review has determined that the archaeological analysis included in the survey report meets 

current BOEM requirements.

21.03 Geophysical Review Acceptable BOEM’s review has determined that the subject survey report complies with the provisions of NTL 

2008-G05 and, based on available data regarding any man-made hazards that may have been 

present at the time the survey was conducted, contains sufficient information to prepare an 

acceptable shallow hazards analysis for specific drilling or platform sites that the applicant may 

propose in future EPs or DOCDs. However, prior to submitting any such EPs or DOCDs, the 

applicant should update the accompanying anomaly map, if appropriate, to indicate the location of 

any man-made hazards, e.g., pipelines, abandoned wells, etc., that did not exist at the time the 

survey was performed. Additionally, please be reminded that under the guidelines of NTL 

2008-G04, the applicant should submit high-resolution survey data from the line closest to any 

proposed well or platform location, with one copy of each such EP or DOCD.

21.04 Geophysical Survey Report Not 

Acceptable

BOEM’s review has also determined the subject survey report does not comply with the provisions 

of NTL 2008-G05.

21.05 3D Survey Waiver Use of three-dimensional (3D) seismic data in lieu of high-resolution survey data as per NTL 

2008-G05 is acceptable for the requested locations.

Pipeline Section Mitigations and Conditions

22 Concrete Mats The applicant’s request to install protective concrete mats over the pipeline crossings in water less 

than 200 ft deep is hereby approved pursuant to 30 CFR § 250.141.

25 Pipeline High-Pressure (PSH) 

Higher Than 15%

The applicant’s request to set the PSH higher than 15 percent above the normal operating pressure 

range is hereby approved pursuant to 30 CFR § 250.142. The pipeline PSH shall be set no more 

than 5 percent above the latest shut-in tubing pressure of the well and will not be set above the 

maximum allowable operating pressure of the pipeline.

26 Denied Self-Burial BOEM cannot concur with the applicant’s determination that the subject pipeline will be installed 

in an area that is prone to self-burial. BOEM will only allow self-burial in areas with a soil strength 

that does not exceed 200 pounds per square foot. Therefore, the portions of the pipeline in water 

depths less than or equal to 200 ft shall be buried.
Commonly Applied Mitigating Measures

A-27

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

28 Hydrostatic Head to Raise 

Maximum Allowable Operating 

Pressure

The applicant’s request to determine the internal design pressure of the submerged portion of the 

pipeline by considering the effects of the external hydrostatic pressure, in lieu of using the standard 

formula outlined in 30 CFR § 250.1002(a), is hereby approved pursuant to 30 CFR § 250.141(a).

National Marine Fisheries Service Mitigations

28.001 Species Protective Measures The applicant must comply with the following species protective measures in all activities 

conducted pursuant to the plan: NTL 2012-JOINT-G01, “Vessel Strike Avoidance and 

Injured/Dead Protected Species Reporting”; NTL 2012-JOINT-G02, “Implementation of Seismic 

Survey Mitigation Measures and Protected Species Observer Program”; and NTL 2012-BSEE-G01, 

“Marine Trash and Debris Awareness and Elimination.” These measures are designed to promote 

environmental protection, consistent environmental policy, compliance with environmental laws, 

and safety.

29 Oil Spill Financial Responsibility 

(OSFR) Coverage

BOEM’s review of the application indicates that, per 30 CFR §§ 553.3(1)-(3), the proposed rightof-way pipeline is classified as a covered offshore facility (COF) and requires oil-spill financial 

responsibility (OSFR) coverage. At this time, BSEE’s records do not indicate that the required 

OSFR coverage is in place. The applicant is advised that they may begin construction of the 

proposed pipeline immediately. However, in accordance with 30 CFR § 553.15(b), the applicant

may not begin operation of the pipeline until they have submitted an application showing evidence 

of OSFR coverage and that demonstration has been approved by BSEE.

99 Department of Transportation 

Right-of-Way Pipeline

The applicant shall construct, operate, and maintain the pipeline in accordance with the appropriate 

U.S. Department of Transportation regulations.

110 Spanning Potential There are several fault scarps along with the proposed pipeline route. Include with the construction 

report a listing of the location and length of any pipeline “spanning,” resulting from laying the 

pipeline over these fault scarps. Also include a description of any remedial action necessary to 

minimize “spanning” and prevent pipeline damage. This mitigation may be applied by BSEE at the 

post-approval stage.

Office of Structural Technical Support Mitigations

120.1 Reminder of NTL 2008-G05 If there are pipelines within the immediate proximity of the proposed platform site, precautions 

outlined in NTL 2008-G05, “Shallow Hazards Program,” shall be taken while conducting 

operations.

120.15 Notify National Imagery and 

Mapping

In order to assure publication of onsite activity as it affects marine navigation safety, the applicant

must notify the National Imagery and Mapping Agency in advance of commencement of platform 

installation.

120.2 Send Report to Office of Structural 

and Technical Support (OSTS)

Written notification shall be submitted to the Office of Structural and Technical Support (OSTS) 

and the Pipeline Section within 15 calendar days of completion of the platform installation 

operations, at which time the applicant will be provided with the “Complex Identification Number” 

(CPXID) that has been assigned to this structure. The CPXID should be included with other 

pertinent information (i.e., the right-of-way number, area code, block number, platform name, etc.) 

in all future correspondence related to this structure. Should significant problems occur during 
A-28 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

structure installation operations, please inform OSTS immediately. If for any reason the applicant 

decides not to install this structure, they shall submit a written cancellation letter.

120.7 Downhole Well Plugging In accordance with 30 CFR § 250.1710, the applicant must downhole plug and abandon all wells on 

(insert area/block platform name) (except [insert well names]), no later than (insert date). However, 

the applicant will not be required to sever the casings, remove the wellhead, or clear the site until 

the right-of-use expires.

Geological and Geophysical Mitigations (deep-penetration applications)

(no assigned mitigation numbers)

Vessel-Strike Avoidance/Reporting The applicant will follow the guidance provided under NTL 2012-JOINT-G01, “Vessel Strike 

Avoidance and Injured/Dead Protected Species Reporting.” The NTL 2012-JOINT-G01 provides 

guidance on how a seismic operator should implement monitoring programs to minimize the risk of 

vessel strikes to protected species and should report observations of injured or dead protected 

species. In lieu of a formal observer program, this NTL provides specific guidelines that should be 

followed to identify and avoid injury to marine mammals and sea turtles.

Seismic Survey Operation, Monitoring, and 

Reporting Guidelines

The applicant will follow the guidance provided under NTL 2012-JOINT-G02, “Implementation of 

Seismic Survey Mitigation Measures and Protected Species Observer Program.” Additionally, the 

applicant will comply with the guidance under this NTL when operating in all water depths (not 

just in water depths >200 m or in the Eastern Planning Area), and the NTL’s “shut-down 

conditions” will be applied towards manatees.

Pre-Activity Sound-Source and Array Calibration 

Verification

Prior to conducting survey activities, the applicant will verify in writing that the proposed airgun 

arrays to be used are of the lowest sound intensity level that still achieves the survey goals. The 

written verification must include confirmation that the airgun array has been calibrated/tuned to 

maximize subsurface illumination and minimize, to the extent practicable, horizontal propagation of 

noise.

Mandatory Separation Buffer between Survey 

Operations

The applicant will be required to maintain, to the extent it can practicably and safely do so, a 

minimum separation distance of 30 km from any other vessels concurrently conducting deeppenetration seismic surveys and 40 km when operating within an Area of Concern. To assist in 

implementation of this measure, BOEM will provide the applicant with contact information for all 

deep-penetration seismic applicants concurrently permitted/authorized to operate within or near the 

proposed survey area.

Supplemental Reporting Requirements In addition to the reporting requirements under NTL 2012-JOINT-G02, the applicant is required to 

submit bi-weekly reports containing the information listed below. The reporting periods end on the 

1st and 15th of each month. These bi-weekly reports are required for the total duration of the 

permit. When applicable, the reports must be submitted with survey navigation data for the 2-week 

reporting period. BOEM has a suggested format for the written report. If BOEM’s suggested 

written format is not used, the following information must be submitted along with the navigation 

data: (1) the dates, locations, and duration of any deep-penetration seismic operations conducted 

during the reporting period (the navigation data provides this information); (2) any circumstances 

that caused the total energy output of the airgun source array to exceed that set forth in the permit 
Commonly Applied Mitigating Measures

A-29

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

application; (3) confirmation that the permittee maintained, to the extent they could practicably and 

safely do so, the minimum separation distance (If applicable, submit a written explanation of why 

the minimum separation distance was not maintained.); and (4) confirmation that the permittee 

complied with the other terms of Section V of the Settlement Agreement.

Military Warning Area Coordination BOEM’s review indicates that the routes to be taken by boats in support of the applicant’s activities 

traversed Military Warning Areas W-92, W-147AB, and W-602. The applicant shall contact the 

appropriate individual military command headquarters concerning the control of electromagnetic 

emissions and use of boats in each of the areas before commencing the operations.

Marine Trash and Debris Awareness and 

Elimination

The applicant will follow the guidance provided under NTL 2012-BSEE-G01, “Marine Trash and 

Debris Awareness and Elimination.” The NTL 2012-BSEE-G01 provides information on reducing, 

if not eliminating, trash intentionally jettisoned into the Gulf of Mexico. The programs described in 

the NTL to assist in the reduction of marine trash and debris are the marine trash and debris 

placards, marine trash and debris awareness training, and the marine trash and debris awareness 

training and certification process.

Geological and Geophysical Mitigation

Natural Resource Defense Council Area of Concern (equal to or greater than 20-m water depth)

(no assigned mitigation numbers)

Seismic Survey Restriction Period BOEM’s review indicates that the proposed survey area falls within a portion of an unusual 

mortality event area declared/established by the National Marine Fisheries Service for cetaceans 

(whales and dolphins). The applicant shall adhere to a restriction period between March 1 and 

April 30 (primary bottlenose dolphin calving season) for deep penetration seismic surveys on the 

Federal Outer Continental Shelf in coastal waters out to the 20-m isobath in the Northern Gulf of 

Mexico to avoid potential impacts to dolphins in regards to behavioral disruptions to mother/calf 

bonding or masking of important acoustic cues. No airgun use, including the use of mitigation 

guns, is permitted during the restriction period.

Geological and Geophysical Mitigation

Natural Resource Defense Council Area of Concern (equal to or greater than 100-m water depth)

(no assigned mitigation numbers)

Required Passive Acoustic Monitoring (PAM) BOEM requires that the applicant use passive acoustic monitoring (PAM) in water depths of 100 m 

or greater at times of reduced visibility (darkness, rain, fog, etc.) as part of their protected species 

observer program. The PAM will be monitored at all times of reduced visibility. Applicants will 

be required to provide BSEE with a description of the passive acoustic system, the software used, 

and the monitoring plan prior to its use. Additionally, after survey completion, the applicant will 

provide an assessment of the usefulness, effectiveness, and problems encountered with the use of 

PAM for marine mammal detection to BSEE for review.

Mitigation for High-Resolution Surveys

Vessel-Strike Avoidance/Reporting The applicant will follow the guidance provided under NTL 2012-JOINT-G01, “Vessel Strike 

Avoidance and Injured/Dead Protected Species Reporting.” The NTL 2012-JOINT-G01 provides 
A-30 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

guidance on how a seismic operator should implement monitoring programs to minimize the risk of 

vessel strikes to protected species and should report observations of injured or dead protected 

species. In lieu of a formal observer program, this NTL provides specific guidelines that should be 

followed to identify and avoid injury to marine mammals and sea turtles.

Marine Trash and Debris Awareness and 

Elimination

The applicant will follow the guidance provided under NTL 2012-BSEE-G01, “Marine Trash and 

Debris Awareness and Elimination.” The NTL 2012-BSEE-G01 provides information on reducing, 

if not eliminating, trash intentionally jettisoned into the Gulf of Mexico. The programs described in 

the NTL to assist in the reduction of marine trash and debris are the marine trash and debris 

placards, marine trash and debris awareness training, and the marine trash and debris awareness 

training and certification process.

Geological and Geophysical Non-Recurring Mitigations

Benthic Communities Review of BOEM’s 3D seismic database of water bottom anomalies identified both confirmed 

deepwater benthic communities and features that could potentially support communities within the 

area of the proposed activities. Based on BOEM’s review of exploration activities proposed in the 

applicant’s application, the following non-recurring mitigations are applied to the area encompassed 

by the plan:

1. BOEM’s 3D seismic database of water bottom anomalies and confirmed communities 

shall be used to identify features for the purpose of applying this mitigation.

2. The following nine water bottom anomaly categories will be considered as supporting 

or potentially supporting deepwater benthic communities, unless proved otherwise 

through high- resolution surveys: anom_conf_coral;, anom_conf_mvol;, 

anom_conf_orgs,; anom_poss_oil_pos,; wb_anom_lith,; wb_anom_mvol,; 

wb_anom_neg,; wb_anom_pock,; and wb_anom_pos.

3. These shape files may be downloaded from http://www.boem.gov/Oil-and-Gas-EnergyProgram/Mapping-and-Data/Map-Gallery/Seismic-Water-Bottom-Anomalies-MapGallery.aspx. 

4. Features shall be either avoided or surveyed to confirm the presence or absence of 

deepwater benthic communities.

5. Per NTL 2009-G40, a minimum separation of 250 ft must be maintained between 

documented communities or features that could potentially support high-density 

deepwater benthic communities and bottom-disturbing activities (e.g., sensors deployed 

on the seafloor).
Commonly Applied Mitigating Measures

A-31

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

a. Therefore, a minimum distance of separation for planned sensor deployment 

sites from any feature or community documented in BOEM’s water bottom 

anomaly database must be at least 250 ft.

b. If at any time it is determined that a node has landed within 250 ft of any 

feature or community documented in BOEM’s water bottom anomaly database, 

an ROV must be used to document the seafloor surrounding the landing 

location. The seafloor beneath the node and arms must be surveyed visually 

with an ROV for damages. All images collected during this survey, showing 

the area within the footprint of the node, must be returned to BOEM’s Gulf of 

Mexico OCS Region, Biological Sciences Unit for evaluation.

6. As required by NTL 2009-G40, for bottom-disturbing activities occurring within 500 ft 

of a high-density deepwater benthic community, the operator must provide BOEM with 

an as-placed plat showing the actual location of the disturbance on the seafloor, in 

relation to documented anomalies and communities. This requirement will apply to 

sensors placed within 500 ft of a documented anomaly or community, as shown in 

BOEM’s 3D seismic database.

For sensor deployments requiring as-placed plats, prepare at a scale of 1 in = 1,000 ft and submit to 

BOEM’s Regional Supervisor, Office of Resource Evaluation, Data Acquisition and Special 

Projects Unit.

Tethered Ocean Bottom Node Surveys Acoustic buoy releases, tethered acoustic pingers, and nodal tethering lines pose an entanglement 

risk to sea turtles and other marine life. Implementing the following measures act to reduce the risk 

of entanglement and ensure proper reporting of entanglement situations. Reasonable measures are 

available to applicants using this deployment technique to reduce the risk of entanglement. These 

measures include the following: (1) shortening the acoustic buoy line and tethered acoustic pinger 

line to the shortest length practical; and (2) replacing tether rope lines equal to or greater than 1⁄4-in 

diameter with a thicker, more rigid tether line, modifying the line by tying knots in the line to 

increase the diameter and rigidness in order to minimize the risk of entanglement. Additional 

measures include ensuring that a Protected Species Observer (PSO) is onboard each vessel during 

tethered node retrieval operations. The PSOs will document any entanglement of marine species in 

the nodal gear, specifically noting the location where entanglement occurred (e.g., pinger tether, 

acoustic buoy line, etc.). If a marine protected species becomes entangled, specifically a sea turtle, 

the PSO will immediately begin resuscitation procedures as described in the National Oceanic and 

Atmospheric Administration’s guidelines that can be found at http://www.st.nmfs.noaa.gov/Assets/

Observer-Program/pdf/Shrimp_Reef_fish_Manual_9_22_10.pdf. The PSO must also contact the 

sea turtle stranding network’s State coordinator to report the incident, condition of the turtle, and 

request additional instructions to reduce risk of injury or mortality, including rehabilitation and 

salvage techniques.
A-32 Central and Eastern Planning Areas Supplemental EIS

Table A-1. Commonly Applied or “Standard” Mitigating Measures (continued).

Mitigation 

Number Mitigating Measure Title Description of Mitigation

Topographic Features The applicant must adhere to the provisions of the topographic features lease stipulation and the 

policy described in NTL 2009-G39, which restrict any bottom-disturbing activities within 152 m of 

the designated “no activity zone” of a topographic feature, as well as all applicable requirements 

described in the NTL.

Potential Archaeological Resource Protection BOEM’s review of the application indicates that numerous targets identified by existing remotesensing data are located in the project area where the ocean bottom cables (OBCs) are proposed to 

be deployed. Therefore, in order to demonstrate compliance with 30 CFR § 551.6(a)(5), the 

applicant will either (1) ensure that all seafloor-disturbing actions required for the OBC deployment 

avoid the features by a distance greater than that listed in the tables or (2) conduct an underwater 

archaeological investigation prior to cable deployment to determine whether the feature represents 

an archaeological resource. If the applicant chooses to avoid the feature, they will be required to 

submit a plat, at a scale of 1 in = 1000 ft with DGPS accuracy, with their final report as required by 

30 CFR § 551.8(c)(2), which demonstrates the feature was not physically impacted by the OBC 

deployment and retrieval or by any other associated bottom disturbances. If the applicant chooses 

to conduct an underwater archaeological investigation, they will be required to comply with the 

investigation methodology and reporting guidelines found on BOEM’s website at http://

www.boem.gov/gom-archaeology/. 

This is only a partial list of potential archaeological sites within the project area, based on existing 

remote-sensing data. There are significant portions of the project area within the OCS that have 

received either limited or no previous archaeological survey, and these areas are likely to contain 

additional archaeological materials that may be impacted by the proposed operations. If the 

applicant discovers additional man-made debris that appears to indicate the presence of a shipwreck 

(e.g., a sonar image or visual confirmation of an iron, steel, or wooden hull; wooden timbers; 

anchors; concentrations of man-made objects such as bottles or ceramics; and piles of ballast rock) 

within or adjacent to the proposed action area during the proposed survey operations, they will be 

required to immediately halt operations, take steps to ensure that the site is not disturbed in any 

way, and contact BOEM’s Regional Supervisor, Office of Environment within 48 hours of its 

discovery. They must cease all operations within 1,000 ft (305 m) of the site until BOEM’s

Regional Director instructs you on what steps you must take to assess the site’s potential historic 

significance and what steps you must take to protect it. If an OBC becomes snagged on any 

submerged object, divers are required to un-snag and retrieve the OBC, and the applicant must 

submit a report detailing each instance of this activity. This report should include the coordinates 

of the snag (to DGPS accuracy), the diver’s description of the submerged object creating the snag, 

any damage that may have resulted from the OBC placement or retrieval operations, and any 

photographic or video imagery that is collected. The applicant must submit a report of any data 

collected as a result of these investigations.
APPENDIX B 

 

CATASTROPHIC SPILL EVENT ANALYSIS: 

HIGH-VOLUME, EXTENDED-DURATION OIL SPILL

RESULTING FROM LOSS OF WELL CONTROL 

ON THE GULF OF MEXICO OUTER CONTINENTAL SHELF

Catastrophic Spill Event Analysis B-iii

TABLE OF CONTENTS

Page

FIGURES..................................................................................................................................................B-v

TABLES ...................................................................................................................................................B-v

B. CATASTROPHIC SPILL EVENT ANALYSIS: HIGH-VOLUME, EXTENDED-DURATION 

OIL SPILL RESULTING FROM LOSS OF WELL CONTROL ON THE GULF OF MEXICO 

OUTER CONTINENTAL SHELF ....................................................................................................B-1

B.1. Introduction............................................................................................................................. B-1

B.1.1. What is a Catastrophic Event?..................................................................................B-1

B.1.2. Methodology ............................................................................................................B-2

B.1.2.1. Geographic Scope ...................................................................................B-2

B.1.2.2. Impact-Producing Factors and Scenario .................................................B-3

B.1.2.3. OSRA Catastrophic Run .........................................................................B-3

B.1.2.4. Environmental and Socioeconomic Impacts...........................................B-3

B.1.3. How to Use This Analysis........................................................................................B-3

B.2. Impact-Producing Factors and Scenario (Phases 1-4) ............................................................B-4

B.2.1. Phase 1—Initial Event..............................................................................................B-4

B.2.2. Phase 2—Offshore Spill...........................................................................................B-4

B.2.2.1. Duration of Spill......................................................................................B-4

B.2.2.1.1. Shallow Water......................................................................B-5

B.2.2.1.2. Deep Water...........................................................................B-5

B.2.2.2. Area of Spill............................................................................................B-5

B.2.2.3. Volume of Spill.......................................................................................B-5

B.2.2.3.1. Shallow Water......................................................................B-6

B.2.2.3.2. Deep Water...........................................................................B-6

B.2.2.4. Oil in the Environment: Properties and Persistence...............................B-6

B.2.2.5. Release of Natural Gas............................................................................B-7

B.2.2.6. Deepwater Subsea Containment .............................................................B-7

B.2.2.7. Offshore Cleanup Activities....................................................................B-8

B.2.2.7.1. Shallow Water......................................................................B-8

B.2.2.7.2. Deep Water...........................................................................B-9

B.2.2.7.3. Vessel Decontamination Stations.......................................B-10

B.2.2.8. Severe Weather .....................................................................................B-10

B.2.3. Phase 3—Onshore Contact.....................................................................................B-11

B.2.3.1. Duration ................................................................................................B-11

B.2.3.1.1. Shallow Water....................................................................B-11

B.2.3.1.2. Deep Water.........................................................................B-11

B.2.3.2. Volume of Oil Contacting Shore...........................................................B-12

B.2.3.3. Length of Shoreline Contacted..............................................................B-12

B.2.3.3.1. Shallow Water....................................................................B-12

B.2.3.3.2. Deep Water.........................................................................B-12

B.2.3.4. Severe Weather .....................................................................................B-13

B.2.3.5. Onshore Cleanup Activities ..................................................................B-13

B.2.3.5.1. Shallow Water....................................................................B-13

B.2.3.5.2. Deep Water.........................................................................B-14
B-iv Central and Eastern Planning Areas Supplemental EIS

B.2.3.5.3. Response Considerations for Sand Beaches for Both 

Shallow-Water and Deepwater Spills................................. B-14

B.2.3.5.4. Response Considerations for Marshes for Both ShallowWater and Deepwater Spills...............................................B-14

B.2.3.5.5. Response Considerations for Nearshore Waters for Both 

Shallow-Water and Deepwater Spills................................. B-15

B.2.4. Phase 4—Post-Spill, Long-Term Recovery ...........................................................B-15

B.2.4.1. Response Considerations for Sand Beaches, Marshes, and Nearshore 

Waters for both Shallow-Water and Deepwater Spills .........................B-16

B.3. Description of the Environment and Impact Analysis..........................................................B-17

B.3.1. Long Duration—Large Volume Spill within the Gulf of Mexico..........................B-17

B.3.1.1. Air Quality ............................................................................................B-17

B.3.1.2. Water Quality........................................................................................B-19

B.3.1.3. Coastal Barrier Beaches and Associated Dunes....................................B-23

B.3.1.4. Wetlands................................................................................................B-25

B.3.1.5. Seagrass Communities..........................................................................B-28

B.3.1.6. Live Bottoms (Pinnacle Trend and Low Relief)...................................B-30

B.3.1.7. Topographic Features............................................................................B-36

B.3.1.8. Sargassum Communities.......................................................................B-42

B.3.1.9. Chemosynthetic Deepwater Benthic Communities...............................B-45

B.3.1.10. Nonchemosynthetic Deepwater Benthic Communities.........................B-48

B.3.1.11. Soft Bottom Benthic Communities.......................................................B-52

B.3.1.12. Marine Mammals..................................................................................B-58

B.3.1.13. Sea Turtles.............................................................................................B-61

B.3.1.14. Diamondback Terrapins........................................................................B-65

B.3.1.15. Beach Mice ...........................................................................................B-67

B.3.1.16. Coastal, Marine, and Migratory Birds...................................................B-68

B.3.1.17. Fish Resources and Essential Fish Habitat............................................B-74

B.3.1.18. Commercial Fisheries............................................................................B-77

B.3.1.19. Recreational Fishing..............................................................................B-79

B.3.1.20. Recreational Resources.........................................................................B-80

B.3.1.21. Archaeological Resources.....................................................................B-82

B.3.1.22. Land Use and Coastal Infrastructure.....................................................B-85

B.3.1.23. Demographics .......................................................................................B-86

B.3.1.24. Economic Factors..................................................................................B-87

B.3.1.25. Environmental Justice ...........................................................................B-89

B.3.1.26. Species Considered due to U.S. Fish and Wildlife Service Concerns ..B-92

B.4. Preparers ............................................................................................................................... B-94

B.5. References............................................................................................................................. B-94
Catastrophic Spill Event Analysis B-v 

FIGURES

Page

Figure B-1. Location of Seven Hypothetical Oil-Spill Launch Points for OSRA within the 

Gulf of Mexico. ............................................................................................................... B-121

Figure B-2. Spatial Frequency (%) of the Watermass Associated with the Loop Current in the 

Eastern Gulf of Mexico based on Data for the Period 1976-2003 ..................................B-122

Figure B-3. Summary of Avian Species Collected by Date Obtained from the U.S. Fish and Wildlife 

Service as Part of the Deepwater Horizon Post-Spill Monitoring and Collection Process 

through May 12, 2011..................................................................................................... B-123

TABLES

Page

Table B-1. Blowout Scenarios and Key Differences in Impacts, Response, and/or Intervention.....B-124

Table B-2. Properties and Persistence by Oil Component Group.....................................................B-125

Table B-3. Annual Volume of Produced Water Discharged by Depth (millions of barrels)............B-126

Table B-4. Description of the Scenario for a Catastrophic Spill Event Occurring in Shallow Water 

or Deep Water (assumptions are described in detail in the text)....................................B-127

Table B-5. Birds Collected and Summarized by the U.S. Fish and Wildlife Service: PostDeepwater Horizon Explosion, Oil Spill, and Response in the Gulf of Mexico ............B-130

Table B-6. Federally Listed Avian Species Considered by State and Associated Planning Area in 

the Gulf of Mexico.......................................................................................................... B-137

Catastrophic Spill Event Analysis B-1 

B. CATASTROPHIC SPILL EVENT ANALYSIS: HIGH-VOLUME, 

EXTENDED-DURATION OIL SPILL RESULTING FROM LOSS 

OF WELL CONTROL ON THE GULF OF MEXICO OUTER 

CONTINENTAL SHELF

B.1. INTRODUCTION

In 1986, the Council on Environmental Quality (CEQ) regulations were amended to rescind the 

requirement to prepare a “worst-case analysis” for an environmental impact statement (EIS) (refer to 

40 CFR § 1502.22(b)(4)). The regulation, as amended, states that catastrophic, low-probability impacts 

must be analyzed if the analysis is “supported by credible scientific evidence, is not based on pure 

conjecture, and is within the rule of reason.”

The August 16, 2010, CEQ report, prepared following the Deepwater Horizon explosion, oil spill, 

and response in the Gulf of Mexico, recommended that the Bureau of Ocean Energy Management 

(BOEM), formerly the Minerals Management Service (MMS) and Bureau of Ocean Energy Management, 

Regulation and Enforcement (BOEMRE), should “ensure that National Environmental Policy Act 

(NEPA) documents provide decisionmakers with a robust analysis of reasonably foreseeable impacts, 

including an analysis of reasonably foreseeable impacts associated with low-probability catastrophic 

spills for oil and gas activities on the Outer Continental Shelf” (CEQ, 2010). This evaluation is a robust 

analysis of the impacts from low-probability catastrophic spills and will be made available to all 

applicable decisionmakers including, but not limited to, the Secretary of the Department of the Interior 

(USDOI) for the National Five-Year Program, the Assistant Secretary of Land and Minerals Management 

for an oil and gas lease sale, and the Regional Supervisors of the Gulf of Mexico OCS Region’s Office of 

Environment and Office of Leasing and Plans.

It should be noted that the analysis presented here is intended to be a general overview of the 

potential effects of a catastrophic spill in the Gulf of Mexico. As such, the Catastrophic Spill Event 

Analysis should be read with the understanding that further detail about accidental oil impacts on a 

particular resource may be found in the Gulf of Mexico OCS Oil and Gas Lease Sales: 2014-2016, 

Western Planning Area Lease Sales 238, 246, and 248, Final Supplemental Environmental Impact 

Statement (WPA 238/246/248 Supplemental EIS) analysis or previous relevant NEPA analyses (e.g., the 

Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017; Western Planning Area Lease Sales 229, 233, 

238, 246, and 248; Central Planning Area Lease Sales 227, 231, 235, 241, and 247, Final Environmental 

Impact Statement [2012-2017 WPA/CPA Multisale EIS; USDOI, BOEM, 2012]; the Gulf of Mexico OCS 

Oil and Gas Lease Sales: 2013-2014; Western Planning Area Lease Sale 233; Central Planning Area 

Lease Sale 231, Final Supplemental Environmental Impact Statement [WPA 233/CPA 231 Supplemental 

EIS; USDOI, BOEM, 2013a]; the Gulf of Mexico OCS Oil and Gas Lease Sales: 2015-2017; Central 

Planning Area Lease Sales 235, 241, and 247, Final Supplemental Environmental Impact Statement 

[CPA 235/241/247 Supplemental EIS, USDOI, BOEM, 2014a]; and the Gulf of Mexico OCS Oil and Gas 

Lease Sales: 2014 and 2016, Eastern Planning Area Lease Sales 225 and 226, Final Environmental 

Impact Statement [EPA 225/226 EIS; USDOI, BOEM, 2013b]). 

B.1.1. What is a Catastrophic Event?

As applicable to NEPA, Eccleston (2008) defines a catastrophic event as “large-scale damage 

involving destruction of species, ecosystems, infrastructure, or property with long-term effects, and/or 

major loss of human life.” For oil and gas activities on the Outer Continental Shelf (OCS), a catastrophic 

event is a high-volume, extended-duration oil spill regardless of the cause, whether natural disaster (i.e., 

hurricane) or manmade (i.e., human error and terrorism). This high-volume, extended-duration oil spill, 

or catastrophic spill, has been further defined by the National Oil and Hazardous Substances Pollution 

Contingency Plan as a “spill of national significance” or “a spill which, because of its severity, size, 

location, actual or potential impact on the public health and welfare or the environment, or the necessary 

response effort, is so complex that it requires extraordinary coordination of federal, state, local, and 

responsible party resources to contain and cleanup the discharge” (40 CFR part 300, Appendix E).
B-2 Central and Eastern Planning Areas Supplemental EIS

Each oil-spill event is unique; its outcome depends on several factors, including time of year and 

location of release relative to winds, currents, land, and sensitive resources; specifics of the well (i.e., 

flow rates, hydrocarbon characteristics, and infrastructure damage); and response effort (i.e., speed and 

effectiveness). For this reason, the severity of impacts from an oil spill cannot be predicted based on 

volume alone, although a minimum volume of oil must be spilled to reach catastrophic impacts.

Though large spills may result from a pipeline rupture, such events will not result in a catastrophic 

spill because the ability to detect leaks and shut off pipelines limits the amount of the spill to the contents 

of the pipeline. The largest, non-blowout-related spill on the Gulf of Mexico OCS occurred in 1967, a 

result of internal pipeline corrosion following initial damage by an anchor. In 13 days, 160,638 barrels 

(bbl) of oil leaked (USDOI, BSEE, 2012); however, no significant environmental impacts were recorded 

as a result of this spill.

Although loss of well control is defined as the uncontrolled flow of reservoir fluid that may result in 

the release of gas, condensate, oil, drilling fluids, sand, or water, it is a broad term that includes very 

minor well control incidents as well as the most severe well control incidents. Historically, loss of well 

control incidents occurred during development drilling operations, but loss of well control incidents can 

occur during exploratory drilling, production, well completions, or workover operations. These losses of 

well control incidents may occur between formations penetrated in the wellbore or at the seafloor.

Prior to the Deepwater Horizon explosion, oil spill, and response, the two largest spills resulting from 

a loss of well control in U.S. waters of the Gulf of Mexico occurred in 1970 and released 30,000 and 

53,000 bbl of oil, respectively (USDOI, BSEE, 2012). These incidents resulted in four human fatalities. 

Although these incidents occurred only 8-14 miles (mi) (13-26 kilometers [km]) from shore, there was 

minor shoreline contact with oil (USDOC, NOAA, Office of Response and Restoration, 2010a and 

2010b). In 1987, a blowout of the Mexican exploratory oil well, YUM II, resulted in a spill of 58,640 bbl 

and 75 mi (121 km) of impacted shoreline (USDOC, NOAA, Hazardous Materials Response and 

Assessment Division, 1992). However, none of these spills met the previously described definitions of a 

catastrophic event or spill.

A blowout is a more severe loss of well control incident that creates a greater risk of a large oil spill 

and serious human injury. Two blowouts that resulted in catastrophic spills have occurred in U.S. and 

Mexican waters of the Gulf of Mexico. On June 3, 1979, the Ixtoc I well blowout in shallow water (water 

depth of 164 feet [ft] [50 meters [m]] and 50 mi [80 km] offshore in the Bay of Campeche, Mexico) 

spilled 3.5 million barrels (MMbbl) of oil in 10 months (USDOC, NOAA, Office of Response and 

Restoration, 2010c; USDOC, NOAA, Hazardous Materials Response and Assessment Division, 1992; 

ERCO, 1982). On April 20, 2010, the Macondo well blowout (Deepwater Horizon explosion, oil spill, 

and response) in deep water (4,992 ft; 1,522 m) 48 mi (77 km) offshore in Mississippi Canyon Block 252, 

spilled an estimated 4.9 MMbbl of oil until it was capped approximately 3 months later. Due to being 

classified as catastrophic, the Ixtoc I and Macondo well blowouts and spills were utilized to develop the 

catastrophic spill event scenario in this analysis. 

B.1.2. Methodology

Two general approaches are utilized to analyze a catastrophic event under NEPA. The first approach 

is a bounding analysis for each individual resource category (e.g., marine mammals and sea turtles). A 

bounding analysis involves selecting and evaluating a different set of factors and scenarios for each 

resource in the context of a worst-case analysis. The second approach involves the selection of a single 

set of key circumstances that, when combined, result in catastrophic consequences. The second approach 

is used for a site-specific analysis and, consequently, its possible application is more limited. 

Accordingly, this analysis combines the two approaches, relying on a generalized scenario while 

identifying site-specific severity factors for individual resources. This combined approach allows for the 

scientific investigation of a range of possible, although not necessarily probable, consequences of a 

catastrophic blowout and oil spill in the Gulf of Mexico.

B.1.2.1. Geographic Scope

The Gulf of Mexico is a semi-enclosed basin with an extensive history of oil and gas activities and 

unique environmental conditions and hydrocarbon reservoir properties; consequently, this analysis is only 

applicable to the Gulf of Mexico OCS and is not intended for other OCS regions.
Catastrophic Spill Event Analysis B-3 

B.1.2.2. Impact-Producing Factors and Scenario

A hypothetical, yet feasible, scenario (Chapter B.2) was developed to provide a framework for 

identifying the impacts of an extended oil spill from an uncontrolled blowout. Unless noted, this scenario 

is based on the large magnitude, blowout-related oil spills that have occurred in the Gulf of Mexico, i.e., 

Ixtoc I and Macondo well blowouts and spills (discussed in Chapter B.1.1). As noted above, because 

each spill event is unique, its outcome depends on many factors. Therefore, the specific impacts from 

future spills cannot be predicted based on this scenario.

B.1.2.3. OSRA Catastrophic Run

A special Oil-Spill Risk Analysis (OSRA) model run was conducted to estimate the impacts of a 

possible future catastrophic or high-volume, extended-duration oil spill. This analysis emphasized 

modeling a spill that continued for 90 consecutive days by launching spills on each of 90 consecutive 

days, with each trajectory tracked for up to 60 days. The OSRA was conducted for only the trajectories 

of oil spills from hypothetical spill locations to various onshore and offshore environmental resources. 

Data from three hypothetical spill locations located in the Central Planning Area (CPA) and two 

hypothetical spill locations located in the Eastern Planning Area (EPA) were included and are intended 

for use as examples of this type of exercise (Figure B-1). Information on previous catastrophic OSRA 

runs for the CPA can be found in Appendix C of the CPA 235/241/247 Supplemental EIS and 2012-2017 

WPA/CPA Multisale EIS. Information on previous catastrophic OSRA runs for the EPA can be found in 

Appendix C of the EPA 225/226 EIS. 

The probability of an oil spill contacting a specific resource within a given time of travel from a spill 

point is termed a conditional probability; the condition being that a spill is assumed to have occurred. 

Each trajectory was allowed to continue for as long as 60 days. However, once a hypothetical spill 

contacts land, the spill trajectory is terminated, and the contact is recorded. Although, overall OSRA is 

designed for use as a risk-based assessment, for this analysis, only the conditional probability, the 

probability of contact to the resource, was calculated. The probability of a catastrophic spill occurring 

was not calculated; thus, the combination of the probability of a spill and the probability of contact to the 

resources from the hypothetical spill locations were not calculated. Results from this trajectory analysis 

provide input to the final product by estimating where spills might travel on the ocean’s surface and what 

environmental resources might be contacted if and when another catastrophic spill occurs, but it does not 

provide input on the probability of another catastrophic spill occurring. Further detail on this catastrophic 

OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS and EPA 225/226 

Multisale EIS. 

B.1.2.4. Environmental and Socioeconomic Impacts

This analysis evaluates the impacts to the Gulf of Mexico’s biological, physical, and socioeconomic 

resources from a catastrophic blowout, oil spill, and associated cleanup activities.

Although the most recent EISs prepared by this Agency for oil and gas lease sales in the Gulf of 

Mexico analyze the potential impacts from smaller oil spills that are more reasonably foreseeable 

(USDOI, MMS, 2007 and 2008), this analysis focuses on the most likely and most significant impacts 

created by a high-volume, extended-duration spill. Because catastrophic consequences may not occur for 

all resources, factors affecting the severity of impacts are identified by the individual resource.

B.1.3. How to Use This Analysis

The purpose of this technical analysis is to assist BOEM in meeting CEQ requirements that require a 

discussion of impacts from catastrophic events. This analysis, based on credible scientific evidence, 

identifies the most likely and most significant impacts from a high-volume blowout and oil spill that 

continues for an extended period of time. The scenario and impacts discussed in Chapters B.2 and B.3

should not be confused with the scenario and impacts anticipated to result from routine activities or the 

more reasonably foreseeable accidental events of a CPA or EPA proposed action.

Chapter B.2 is intended to clearly describe the scenario presented for all four phases of a catastrophic 

blowout event and identify the impact-producing factors associated with each phase. Chapter B.3 is 

intended to analyze the impacts of each phase of a catastrophic blowout on various environmental 
B-4 Central and Eastern Planning Areas Supplemental EIS

resources. These chapters can be used to differentiate the conditions of a catastrophic spill from the 

routine activities and accidental events described in this Supplemental EIS.

This technical analysis is designed to be incorporated by reference in future NEPA documents and 

consultations. Therefore, factors that affect the severity of impacts of a high-volume, extended-duration 

spill on individual resources are highlighted for use in subsequent site-specific analyses.

To analyze a hypothetical catastrophic event in an area such as the Gulf of Mexico, several 

assumptions and generalizations were made. However, future project-specific analyses should also 

consider specific details such as potential flow rates for the specific proposed activity, the properties of 

the targeted reservoir, and the proximity to environmental resources of the proposed activities.

B.2. IMPACT-PRODUCING FACTORS AND SCENARIO (PHASES 1-4)

For the purposes of this analysis, an event similar to the Ixtoc I well blowout and spill that occurred in 

1979 in 160-ft (50-m) water depth will be used as the basis for a shallow water spill and an event similar 

to the Macondo well blowout and spill that occurred in 2010 in the Mississippi Canyon area in 5,000-ft 

(1,524-m) water depth will be used to represent a deepwater spill.

B.2.1. Phase 1—Initial Event

Phase 1 of the scenario is the initiation of a catastrophic blowout incident. While most of the 

environmental and socioeconomic impacts of a catastrophic blowout would occur during the ensuing 

high-volume, extended-duration spill (refer to Chapter B.3), it is important to acknowledge the deadly 

events that could occur in the initial phase of a catastrophic blowout. The following scenario was 

developed to provide a framework for identifying the most likely and most significant impacts during the 

initial phase.

Impacts, response, and intervention depend on the spatial location of the blowout and release. While 

there are several points where a blowout could occur, four major distinctions that are important to the 

analysis of impacts are described in Table B-1. 

For this analysis, an explosion and subsequent fire are assumed to occur. If a blowout associated with 

the drilling of a single exploratory well occurs, a fire could result that would burn for 1 or 2 days. If a 

blowout occurs on a production platform, other wells could feed the fire, allowing it to burn for over a 

month (USDOC, NOAA, Office of Response and Restoration, 2010b). The drilling rig or platform may 

sink. If the blowout occurs in shallow water, the sinking rig or platform may land in the immediate 

vicinity; if the blowout occurs in deep water, the rig or platform could land a great distance away, beyond 

avoidance zones. For example, when the drilling rig Deepwater Horizon sank, it landed 1,500 ft (457 m) 

away on the seafloor. Regardless of water depth, the immediate response would be from search and 

rescue vessels and aircraft, such as U.S. Coast Guard (USCG) cutters, helicopters, and rescue planes.

B.2.2. Phase 2—Offshore Spill

Phase 2 of the analysis focuses on the spill and response in Federal and State offshore waters.

B.2.2.1. Duration of Spill

The duration of the offshore spill from a blowout depends on the time needed for intervention and the 

time the remaining oil persists offshore. If a blowout occurs and the damaged surface facilities preclude 

well reentry operations, a relief well may be needed to regain control. The time required to drill the relief 

well depends on the complexity of the intervention, the location of a suitable rig, the type of operation 

that must be terminated to release the rig (e.g., casing may need to be run before releasing the rig), and the 

logistics in mobilizing personnel and equipment to the location. A blown-out well may also be 

successfully capped prior to completion of relief wells, as occurred in the Macondo well blowout. In 

terms of persistence of spilled oil on surface waters, oil from the Macondo well blowout did not persist 

for more than 30 days (OSAT, 2010). However, based on BOEM’s weathering modeling (refer to 

Appendix C of the CPA 235/241/247 Supplemental EIS and EPA 225/226 EIS), it is assumed that oil 

could persist on surface waters for as long as 1-2 months, depending on the season and year.
Catastrophic Spill Event Analysis B-5 

B.2.2.1.1. Shallow Water

If a blowout occurs in shallow water, it is estimated that the entire well intervention effort including 

drilling relief wells, if deemed necessary, could take 2 weeks to 3 months. This estimate would include 

1-3 weeks to transport the drilling rig to the well site. Spilled surface oil is not expected to persist more 

than 1-2 months (depending upon the season and environmental conditions) after the flow is stopped. 

Spilled oil is more likely to persist in the offshore environment during colder weather and during wind 

and hydrodynamic conditions that keep the oil offshore. Therefore, the estimated spill duration resulting 

from a shallow water blowout is 11⁄2-5 months (approximately 2 weeks to 3 months for active spillage and 

1-2 months for oil persistence in the environment).

B.2.2.1.2. Deep Water

If a blowout occurs in deep water, it is estimated that it would take 2-4 weeks to remove debris and to 

install a capping stack or a cap and flow system on a well, if conditions allow this type of intervention. 

The entire intervention effort, if it required drilling relief wells, could take 3-4 months (USDOI, MMS, 

2000; Regg, 2000). This includes 2-4 weeks to transport the drilling rig to the well site. Spilled surface 

oil is not expected to persist more than 1-2 months (depending upon the season and environmental 

conditions) after the flow is stopped. Spilled oil is more likely to persist in the offshore environment 

during colder weather and during wind and hydrodynamic conditions that keep the oil offshore. 

Therefore, the estimated spill duration from a deepwater blowout is 11⁄2-6 months (approximately 2 weeks

to 4 months for active spillage and 1-2 months for oil persistence in the environment).

B.2.2.2. Area of Spill

When oil reaches the sea surface, it spreads. The speed and extent of spreading depends on the type 

and volume of oil that is spilled. However, a catastrophic spill would likely spread to hundreds of square 

miles. Also, the oil slick may break into several smaller slicks, depending on local wind patterns that 

drive the surface currents in the spill area.

Subsurface oil observed during both the Ixtoc I and Macondo well blowouts and spills could also 

spread to significant distances depending on environmental conditions (such as hydrodynamics), oil 

chemistry and weathering, and the application of subsea dispersants or mechanical conditions at the 

release point that would diffuse the oil.

B.2.2.3. Volume of Spill

After 50 years of oil and gas exploration and development activity on the continental shelf of the Gulf 

of Mexico, most of the largest oil and natural gas reservoirs thought to exist in shallow-water areas of the 

GOM at drill depths less than 15,000 ft (4,572 m) subsea have been identified. Large undiscovered 

hydrocarbon reservoirs are still thought to exist in shallow-water areas. However, results taken from 

BOEM’s most recent resource assessment study and a review of the more recent shallow-water drilling 

and leasing activity suggest that future discoveries of large reservoirs in the shallow-water areas of the 

GOM are likely to exist greater than 15,000 ft (4,572 m) below sea level where geologic conditions are 

more favorable for natural gas reservoirs to exist than oil reservoirs. In contrast to the shallow-water 

areas of the GOM where the discovery of a new, large, prolific oil reservoir is considered a lowprobability event, the results from BOEM’s resource assessment study pertaining to the deeper water 

areas of the GOM suggest that there is a high probability that many large oil and gas reservoirs have yet 

to be discovered in deep water. BOEM’s forecast for deep water has support from other public and 

private sector resource studies. The forecast is also supported by the results of BOEM’s analysis of 

deepwater leasing and drilling activity, which indicates that the industry is leasing acreage in deepwater 

areas of the GOM where large prospects can be identified and where the majority of exploration and 

development drilling activity targets potentially thick oil reservoirs capable of achieving the high 

production rates necessary to offset the high costs associated with deep water oil development in the 

GOM.
B-6 Central and Eastern Planning Areas Supplemental EIS

B.2.2.3.1. Shallow Water

For this analysis, an uncontrolled flow rate of 30,000 bbl per day is assumed for a catastrophic 

blowout in shallow water. This assumption is based upon the results of well tests in shallow water and 

the maximum flow rate from the 1979 Ixtoc I well blowout, which occurred in shallow water. Using this 

flow rate, the total volume of oil spilled from a catastrophic blowout in shallow water is estimated at 

900,000 bbl to 3 MMbbl from spillage occurring over 1-3 months. In addition to the flow rate, it is 

assumed that any remaining diesel fuel from a sunken drilling rig or platform would also leak.

B.2.2.3.2. Deep Water

For the purposes of this analysis, an uncontrolled flow rate of 30,000-60,000 bbl per day is assumed 

for a catastrophic blowout in deep water. This flow rate is based on the assumption in Chapter B.2.2.3.1

above, well test results, and the maximum flow rate estimated for the Macondo well blowout and spill 

occurred in deep water. Therefore, the total volume of oil spilled is estimated to be 0.9-7.2 MMbbl over 

1-4 months. In addition, deepwater drilling rigs or platforms hold a large amount of diesel fuel 

(10,000-20,000 bbl). Therefore, it is assumed that any remaining diesel fuel from a sunken structure 

would also leak and add to the spill.

B.2.2.4. Oil in the Environment: Properties and Persistence

The fate of oil in the environment depends on many factors, such as the source and composition of the 

oil, as well as its persistence (NRC, 2003). Persistence can be defined and measured in different ways 

(Davis et al., 2004), but the National Research Council (NRC) generally defines persistence as how long 

oil remains in the environment (NRC, 2003; page 89). Once oil enters the environment, it begins to 

change through physical, chemical, and biological weathering processes (NRC, 2003). These processes 

may interact and affect the properties and persistence of the oil through the following:

• evaporation (volatilization);

• emulsification (the formation of a mousse);

• dissolution;

• oxidation (including respiration); and

• transport processes (NRC, 2003; Scholz et al., 1999).

Horizontal transport takes place via spreading, advection, dispersion, and entrainment while vertical 

transport takes place via dispersion, entrainment, Langmuir circulation, sinking, overwashing, 

partitioning, and sedimentation (NRC, 2003). The persistence of an oil slick is influenced by the 

effectiveness of oil-spill response efforts and affects the resources needed for oil recovery (Davis et al., 

2004). The persistence of an oil slick may also affect the severity of environmental impacts as a result of 

the spilled oil.

Crude oils are not a single chemical, but instead are complex mixtures with varied compositions. 

Thus, the behavior of the oil and the risk the oil poses to natural resources depends on the composition of 

the specific oil encountered (Michel, 1992). Generally, oils can be divided into three groups of 

compounds: (1) light-weight; (2) medium-weight; and (3) heavy-weight components. On average, these 

groups are characterized as outlined in Table B-2. 

Of the oil reservoirs sampled in the Gulf of Mexico OCS, the majority fall within the light-weight 

category, while less than one quarter are considered medium-weight and a small portion are considered 

heavy-weight. Oil with an American Petroleum Institute (API) gravity of 10.0 or less would sink and has 

not been encountered in the Gulf of Mexico OCS; therefore, it is not analyzed in this Appendix (USDOI, 

BOEMRE, 2010a).

Heavy-weight oil may persist in the environment longer than the other two types of oil, but the 

medium-weight components within oil present the greatest risks to organisms because, with the exception 

of the alkanes, these medium-weight components are persistent, bioavailable, and toxic (Michel, 1992).
Catastrophic Spill Event Analysis B-7 

Previous studies (e.g., Johansen et al., 2001) supported the theory that most, if not all, released oil 

would reach the surface of the water column. However, data and observations from the Macondo well 

blowout and spill challenge that theory. While analyses are in their preliminary stages, it appears that 

measurable amounts of hydrocarbons (dispersed or otherwise) were detected in the water column as 

subsurface “plumes” and on the seafloor in the vicinity of the release. While not all of these

hydrocarbons have been definitively traced back to releases from the Macondo well, these early 

measurements and results warrant a reassessment of previous theories of the ultimate fate of hydrocarbons 

from unintended subsurface releases. It is important to note that the North Sea experiment (Johansen 

et al., 2001) did not include the use of dispersants at or near the source of the subsea oil discharge.

B.2.2.5. Release of Natural Gas

The quality and quantity of components in natural gas vary widely by the field, reservoir, or location 

from which the natural gas is produced. Although there is not a “typical” makeup of natural gas, it is 

primarily composed of methane (NaturalGas.org, 2012). Thus, if natural gas were to leak into the 

environment, methane may be released into the environment. Limited research is available for the 

biogeochemistry of hydrocarbon gases in the marine environment (Patin, 1999, page 233). Theoretically, 

methane could stay in the marine environment for long periods of time (Patin, 1999, page 237) as 

methane is highly soluble in seawater at the high pressures and cold temperatures found in deepwater 

environments (NRC, 2003, page 108). Methane diffusing through the water column would likely be 

oxidized in the aerobic zone and would rarely reach the air-water interface (Mechalas, 1974, page 23). 

Methane is a carbon source and its introduction into the marine environment could result in diminished 

dissolved oxygen concentrations due to microbial degradation.

The Macondo well blowout and spill resulted in the emission of an estimated 9.14 x 109 to 1.29 x 1010

moles of methane from the wellhead (Kessler et al., 2011; Valentine et al., 2010) with maximum 

subsurface methane concentrations of 183-315 micromoles measured in May/June 2010 (Valentine et al., 

2010; Joye et al., 2011). This methane release corresponded to a measurable decrease in oxygen in the 

subsurface plume due to respiration by a community of methanotrophic bacteria. During the Macondo

well blowout and spill, methane and oxygen distributions were measured at 207 stations throughout the 

affected region (Kessler et al., 2011). Based on these measurements, it was concluded that within 

~120 days from the onset of release ~3.0 x 1010 to 3.9 x 1010 moles of oxygen were respired, primarily by 

methanotrophs, and left behind a residual microbial community containing methanotrophic bacteria. The 

researchers further suggested that a vigorous deepwater bacterial bloom respired nearly all the released 

methane within this time and that by analogy, large-scale releases of methane from hydrates in the deep 

ocean are likely to be met by a similarly rapid methanotrophic response. However, hypoxic conditions 

were never reached (OSAT, 2010). Hypoxic conditions are generally agreed to occur when dissolved 

oxygen falls below 2 milligrams/liter (1.4 milliliter/liter) (OSAT, 2010). Note that methane released from 

the Macondo well blowout and spill was generally confined to the subsurface, with minimal amounts 

reaching the atmosphere (Kessler et al., 2011; Ryerson et al., 2011).

B.2.2.6. Deepwater Subsea Containment

To address the new improved containment systems’ expectations to rapidly contain a spill as a result 

of a loss of well control from a subsea well as addressed in Notice to Lessees and Operators (NTL) 

2010-N10, the Marine Well Containment Company (MWCC) and Helix Well Containment Group 

(HWCG) initiated the development of new, rapid response systems. These systems are designed to fully 

contain oil flow in the event of a potential future underwater blowout and to address a variety of 

scenarios. The systems consist of specially designed equipment constructed, tested, and available for 

rapid response. Both the MWCC and HWCG systems are anticipated to be fully operational within days 

to weeks after a spill event occurs. The availability of these systems can significantly reduce the length of 

time a blowout continues, thereby reducing the amount of oil potentially spilled during a catastrophic 

spill. However, this assumes that a particular blowout situation lends itself to the use of this subsea 

containment technology, whereas there are some situations that may delay or make its use improbable, 

such as the location of debris resulting from the blowout and the condition of the well.

The MWCC system is designed to operate in up to a 10,000-ft (3,048-m) water depth and adds 

containment capability of 60,000 bbl of oil per day. In November 2013, the MWCC announced that the 
B-8 Central and Eastern Planning Areas Supplemental EIS

single ram capping stack, which is part of the company’s interim containment system, can now cap a well 

that has fluids with temperatures up to 350 oF (177 oC). The MWCC is the only well containment 

provider that has this industry-first capping stack capable of handling temperatures of 350 oF (177 oC) at 

pressures up to 15,000 pounds per square inch (Marine Well Containment Company, 2013). The HWCG 

system focuses on the utilization of the Helix Producer I and the Q4000 vessels. Each of these vessels 

played a role in the Macondo well blowout and spill response, and each of these vessels are continually 

working in the Gulf. The HWCG system has the ability to fully operate in up to 10,000 ft (3,048 m) of 

water and has intervention equipment to cap and contain a well with the mechanical integrity to be 

shut-in. The HWCG system also has the ability to capture and process 57,000 bbl of oil per day, 

72,000 bbl of liquid per day at 10,000 pounds per square inch (Helix Energy Solutions Group, 2014).

In addition, industry has a multitude of vendors available within the GOM region that can provide the 

services and supplies necessary for debris removal capability, dispersant injection capability, and top-hat 

deployment capability. Many of these vendors are already cited for use by MWCC and HWCG.

The BSEE has indicated to BOEM that, it will not allow an operator to begin drilling operations until 

adequate subsea containment and collection equipment, as well as subsea dispersant capability is 

determined by BSEE to be available to the operator and is sufficient for use in response to a potential 

incident from the proposed well(s) (refer to NTL 2010-N10). The BSEE conducted a successful 

deployment drill of the MWCC’s subsea containment capping stack in the summer of 2012. A successful 

deployment drill of the HWCG’s subsea containment capability was conducted in the spring of 2013. 

The HWCG was required to lower its capping stack through some 5,047 ft (1,538 m) of water to the 

seafloor by wire and then latch it to a test wellhead and pressurize the system. These types of exercises 

assist BSEE by spotlighting potential problems before an emergency and by identifying lessons that can 

be shared with the oil and gas industry to protect the environment and improve the safety of offshore 

operations. For instance, during the test of the MWCC equipment, it was discovered that a containment 

response should have “mud mats” on hand to ensure a stable platform for heavy equipment that otherwise 

might sink into soft seabed.

B.2.2.7. Offshore Cleanup Activities

As demonstrated by the Ixtoc I and Macondo well blowouts and spills, a large-scale response effort is 

certain to follow a catastrophic blowout. The number of vessels and responders would steadily increase 

as the spill continued. In the event of a spill, particularly a loss of well control, there is no single method 

of containment and removal that would be 100 percent effective. Removal and containment efforts to 

respond to an ongoing spill offshore would likely require multiple technologies, including source 

containment, mechanical cleanup, in-situ burning of the slick, and chemical dispersants. Even with the 

deployment of all of these spill-response technologies, it is likely that, with the operating limitations of 

today’s spill-response technology, not all of the oil could be contained and removed offshore.

B.2.2.7.1. Shallow Water

The following are estimates for the deployment of equipment and personnel during a shallow-water 

spill response. Within the first week of an oil spill originating in shallow water, 25 vessels are estimated 

to respond, which would steadily increase to over 3,000 by the end of the spill. This includes about 

25 skimmers in the vicinity of the well at any given time. In addition, recovered oil may be barged to 

shore from recovery vessels. Within the first week, over 500 responders are estimated to be deployed to a 

spill originating in shallow water, which would steadily increase up to 25,000 before the well is capped or 

killed within 2-4 months. Up to 25 planes and 50 helicopters are estimated to respond per day by the end 

of a shallow-water spill. Response to an oil spill in shallow water is expected to involve over 10,000 ft 

(3,048 m) of boom within the first week and would steadily increase up to 5 million feet (~950 mi; 

~1,520 km) for use offshore and nearshore; the amount is dependent upon the location of the potentially 

impacted shoreline, environmental considerations, and agreed upon protection strategies involving the 

local potentially impacted communities.

Dispersant use must be in accordance with the Regional Response Team’s (RRT) Preapproved 

Dispersant Use Manual and with any conditions outlined within an RRT’s site-specific, dispersant 

approval given after a spill event. Consequently, dispersant use would be in accordance with the 

restrictions for specific water depths, distances from shore, and monitoring requirements. At this time, 
Catastrophic Spill Event Analysis B-9 

this manual does not give preapproval for the application of dispersant use subsea. Aerial dispersants 

would likely be applied from airplanes as a mist, which settles on the oil on the water’s surface. Along 

the Gulf Coast, surface dispersants are presently preapproved for use greater than 3 nautical miles (nmi) 

(3.5 mi; 5.6 km) from shore and in water depths greater than 33 ft (10 m), with the exception of Florida 

(U.S. Dept. of Homeland Security, CG, 2010). At this time, pursuant to a letter from the Florida 

Department of Environmental Protection dated May 5, 2011, sent to USCG, preapproval for dispersant 

use is not approved for any Florida State waters. However, the U.S. Environmental Protection Agency 

(USEPA) is presently revisiting these RRT preapprovals in light of the dispersant issues, such as subsea 

application that arose during the Macondo well blowout and spill response. In addition, revisions are 

presently being made to the RRT IV and VI’s Preapproved Dispersant Use Manuals. The USEPA issued 

a letter dated December 2, 2010, that provided interim guidance on the use of dispersants for major spills 

that are continuous and uncontrollable for periods greater than 7 days and for expedited approval of 

subsurface applications. This letter outlined the following exceptions to the current preapprovals until 

they are updated:

• dispersants may not be applied to major spills that are continuous in nature and 

uncontrollable for a period greater than 7 days;

• additional dispersant monitoring protocols and sampling plans may be developed that 

meet the unique needs of the incident; and

• subsurface dispersants may be approved on an incident-specific basis as requested by 

the USCG On-Scene Commander.

More robust documentation of dispersant usage may be required. This documentation would include 

daily reports that contain the products used, the specific time and locations of application, equipment used 

for each application, spotter aircraft reports, photographs, vessel data, and analytical data. In addition to 

dispersants, controlled burns may also occur. It is estimated that 5-10 controlled burns would be 

conducted per day in suitable weather. About 500 burns in all would remove 5-10 percent of the oil.

B.2.2.7.2. Deep Water

The following are estimates for the deployment of equipment and personnel during a deepwater spill 

response. Within the first week of an oil spill originating in deep water, 50 vessels are estimated to 

respond, which would steadily increase to over 7,000 by the end of the spill. This includes about 

25 skimmers in the vicinity of the well at a time. In addition, recovered oil may be shuttle tankered to 

shore from recovery vessels. For an oil spill in deep water, over 1,000 responders are estimated to be 

deployed within the first week, which would steadily increase up to 50,000 before capping or killing the 

well within 4-5 months. Over 20,000 ft (6,096 m) of boom is estimated to be deployed within the first 

week of a deepwater spill, which would steadily increase up to 13.5 million feet (~2,257 mi; ~4,115 km)

offshore and nearshore. The amount of boom would be dependent upon the location of the potentially 

impacted shoreline, environmental considerations, and agreed upon protection strategies involving the 

local potentially impacted communities. Up to 50 planes and 100 helicopters are estimated to respond per 

day by the end of a deepwater spill.

With the exception of special Federal management areas or designated exclusion areas, dispersants 

have been preapproved in the vicinity of a deepwater blowout (U.S. Dept. of Homeland Security, CG, 

2010). However, USEPA is presently examining these preapprovals, and restrictions are anticipated 

regarding the future use of dispersants as a result. No preapproval presently exists for the use of subsea 

dispersants, and approval must be obtained before each use of this technology. The use of subsea 

dispersants depends on the location of the blowout, as discussed in Table B-1. Aerial dispersants are 

usually applied from airplanes as a mist, which settles on the oil on the water’s surface. Major spills that 

are continuous and uncontrollable for periods greater than 7 days and the approval of subsurface 

dispersant application are presently subject to the guidance outlined in USEPA’s letter dated December 2, 

2010. This letter provides interim guidance on the use of dispersants for major spills and outlines 

exceptions to the current preapprovals until they are updated, as discussed more fully in Chapter 

B.2.2.7.1. For a deepwater spill, dispersant application may be a preferred response in the open-water 

environment to prevent oil from reaching a coastal area, in addition to mechanical response. However, 
B-10 Central and Eastern Planning Areas Supplemental EIS

the window of opportunity for successful dispersant application may be somewhat narrower for some 

deepwater locations depending on the physical and chemical properties of the oil, which tend to be 

somewhat heavier or more likely to emulsify than those found closer to shore. A significant reduction in 

the window of opportunity for dispersant application may render this response option ineffective.

In addition to dispersants, controlled burns may also occur. It is estimated that 5-10 controlled burns 

would be conducted per day in suitable weather. About 500 burns in all would remove 5-10 percent of 

the oil.

B.2.2.7.3. Vessel Decontamination Stations

To avoid contaminating inland waterways, multiple vessel decontamination stations may be 

established offshore in Federal and State waters. The selected locations to conduct decontamination of 

oiled vessels will, due to the unique aspects of each spill response, be decided by the Unified Command 

during the spill response effort. Since the Unified Command includes representatives of the affected 

state(s), the states will have a prominent voice regarding whether a location in State waters will be 

acceptable.

Vessels responding to the spill and commercial and recreational vessels passing through the spill 

would anchor, awaiting inspection. If decontamination is required, work boats would use fire hoses to 

clean oil from the sides of the vessels. This could result in some oiling of otherwise uncontaminated 

waters. While these anchorage areas would be surveyed for buried pipelines that could be ruptured by 

ship anchors, they may not be surveyed adequately for benthic communities or archaeological sites. 

Therefore, some damage to benthic communities or archaeological sites may occur because of vessel 

decontamination activities associated with an oil spill (Alabama State Port Authority, 2010; State of 

Florida, Office of the Governor, 2010; Nodar, 2010; Unified Incident Command, 2010a-c; USDOC, 

NOAA, 2010a; USEPA, 2012).

B.2.2.8. Severe Weather

A hurricane could accelerate biodegradation, increase the area affected by the spill, and slow or stop 

the response effort. The movement of oil would depend on the track, wind speed, and size of a hurricane. 

The official Atlantic hurricane season runs from June 1st through November 30th, with a peak of 

hurricane probability in September. In an average Atlantic season, there are 11 named storms, 

6 hurricanes, and 2 Category 3 or higher storms (USDOC, NOAA, National Weather Service, 2010). As 

a result of a hurricane, high winds and seas would mix and weather the oil from an oil spill. This can help 

accelerate the biodegradation process (USDOC, NOAA, National Weather Service, 2012). The high 

winds may distribute oil over a wider area (USDOC, NOAA, National Weather Service, 2012).

Weather has been recognized as one of the most important factors in predicting oil-spill fate and 

behavior and in predicting the success of an oil-spill response. During an oil spill, booms, skimmers, oil 

burn, and the use of dispersants have been used to remove oil from the water surface. Adverse weather 

conditions will affect the use, performance, and effectiveness of booms and skimmers. Skimmers work 

best in calm wind; for wave heights greater than 1 m (3 ft), some skimmers will not work effectively. 

Conventional booms will not work at a current velocity of 0.5 meters per second (m/sec) (1.6 feet per 

second [ft/sec]) or greater. For oil burn, ignition cannot be carried out at wind speeds greater than 

10 m/sec (33 ft/sec). The minimum wind speed for dispersant use is about 5 m/sec (16 ft/sec), and the 

maximum wind speed for the limit of dispersant applications is about 12-14 m/sec (39-46 ft/sec) (Fingas, 

2004).

There are tradeoffs in deciding where and when to place boom because, once deployed, boom is time 

consuming to tend and to relocate. As previously noted, booming operations are sensitive to wind, wave, 

and currents, and those sections of boom need to be tethered and secured to keep them from moving. 

Furthermore, it was discovered during the Deepwater Horizon explosion, oil spill, and response that hard 

boom often did more damage than anticipated in the marsh it was intended to protect after weather 

conditions ended up stranding the boom back into the marsh. Due to time constraints prior to a hurricane 

event, it is therefore unlikely that much effort could be expended to move large amounts of deployed 

boom, particularly given the effort that would be required to move skimming equipment to safer locations 

inland and to move large numbers of response personnel to safer areas. However, since the conditions for 

each spill response are unique, these considerations would be examined and a site-specific hurricane 
Catastrophic Spill Event Analysis B-11

response plan developed during the actual spill response effort by the Unified Command at the beginning 

of the official hurricane season.

In addition, adverse weather would reduce ability to respond to the spill and could result in delayed 

transport and placement of the capping stack. The action of wind on the water surface will generate 

waves. Typically, waves greater than 3 ft (1 m) will prevent smaller vessels from skimming in offshore 

waters; waves greater than 5 ft (1.5 m) will prevent even the larger vessels from getting offshore to skim. 

The new high-speed skimmers under development are very promising; some skimmers have recovered oil 

with wave heights of up to 10 ft (3 m) with corresponding winds of up to 15 m/sec (49 ft/sec).

In the event of a hurricane, vessels would evacuate the area, delaying response efforts, including the 

drilling of relief wells and any well capping or collection efforts. Severe weather, such as a hurricane, 

would delay the transport and placement of the capping stack. If a cap is applied and oil is flowed to a 

collection vessel, severe weather would cause the collection vessel to vacate its location and the oil would 

flow until the collection vessel could return and resume collection. Severe weather could also require that 

response assets be relocated inland. The response would be delayed because following the severe weather 

event the assets would need to be transported back to the staging areas. The speed with which the assets 

could be brought back to the locations would depend upon on the condition of the roads and bridges for 

traffic resumption and the amount of debris potentially blocking the roads.

B.2.3. Phase 3—Onshore Contact

B.2.3.1. Duration

The duration of shoreline oiling is measured from initial shoreline contact until the well is capped or 

killed and the remaining oil dissipates offshore. The time needed to cap or kill a well may vary, 

depending on, among other things, the well’s water depth, its location, the well and geologic formation 

characteristics, and the associated debris. Depending on the spill’s location in relation to winds and 

currents and the well’s distance to shore, oil could reach the coast within 1 week to 1 month, based on 

evidence from previous spills in the Gulf of Mexico OCS (e.g., it was nearly 4 weeks after the Macondo

well blowout and spill). While it is assumed that the majority of spilled oil would dissipate offshore 

within 30-60 days of stopping the flow, some oil may remain in coastal areas for some time after a spill, 

as was observed along the Gulf Coast following the Macondo well blowout and spill.

B.2.3.1.1. Shallow Water

Due to the distance from shore, oil spilled as a result of a blowout in shallow water could reach shore 

within 1-3 weeks and could continue until the well is killed or capped and the oil dissipates offshore. 

Therefore, it is estimated that initial shoreline oiling would likely occur for 2-5 months following a 

catastrophic blowout. Some shoreline areas could be re-oiled during this timeframe dependent upon the 

weather conditions at the time of the spill as well as the persistence of the spilled oil.

B.2.3.1.2. Deep Water

Intervention is more difficult and would take longer in deeper water, in part, because at these water 

depths these intervention efforts are conducted by remotely operated vehicles. In general, most of the 

deep water in the Gulf of Mexico is located farther from shore and, therefore, it is assumed that oil would 

reach shore within 2-4 weeks. However, for the few deepwater areas that are located closer to shore, such 

as in the Mississippi Canyon Area, the amount of estimated time until shoreline contact could be the same 

as the shallow-water scenario above (1-3 weeks). The length of shoreline oiled would continue to 

increase and previously oiled areas could be re-oiled until the well is killed or capped (3-4 months) and 

the oil dissipates offshore (1-2 months). Therefore, initial shoreline oiling could occur from 3 months up 

to 6 months following a catastrophic blowout. Persistent shoreline oiling is discussed in Chapter B.2.4

(Phase 4) below.
B-12 Central and Eastern Planning Areas Supplemental EIS

B.2.3.2. Volume of Oil Contacting Shore

In the event of a catastrophic spill, not all of the oil spilled would contact shore. The amount of oil 

recovered and chemically or naturally dispersed would vary. For example, the following are recovery and 

cleanup rates from previous high-volume, extended spills:

• 10-40 percent of oil recovered or cleaned up (including burned, chemically dispersed, 

and skimmed);

• 25-40 percent of oil naturally dispersed, evaporated, or dissolved; and

• 20-65 percent of the oil remains available for offshore or inshore contact.

In the case of the Macondo well blowout and spill, the “expected” scenario, developed by the Oil 

Budget Calculator Science and Engineering Team of The Federal Interagency Solutions Group, suggests 

that more than one quarter (29%) was naturally or chemically dispersed into Gulf waters, while burning, 

skimming, and direct recovery from the wellhead removed one quarter (25%) of the oil released. Less 

than one quarter (23%) of the total oil naturally evaporated or dissolved. The residual amount, just under 

one quarter (23%), remained in the Gulf of Mexico as a light sheen or as tarballs that have washed ashore 

or are buried in sand and other sediments (The Federal Interagency Solutions Group, 2010).

For planning purposes, USCG estimates that 5-30 percent of oil will reach shore in the event of an 

offshore spill (33 CFR part 154, Appendix C, Table 2). Using the USCG assumptions, a catastrophic spill 

could result in a large amount of oil reaching shore.

B.2.3.3. Length of Shoreline Contacted

While larger spill volumes increase the chance of oil reaching the coast, other factors that influence 

the length and location of shoreline contacted include the duration of the spill and the well’s location in 

relation to winds, currents, and the shoreline. Depending upon winds and currents throughout the spill 

event, already impacted areas could be re-oiled. As seen with the Deepwater Horizon oil spill, as the spill 

continued, the length of oiled shoreline at any one time increased by orders of magnitude as follows:

Duration of Spill Length of Shoreline Oiled1

30 days 0-50 miles

60 days 50-100 miles

90 days 100-1,000 miles

120 days >1,000 miles2

1 Not cumulative.

2 Length was extrapolated.

Source: USDOC, NOAA, 2011a.

B.2.3.3.1. Shallow Water

While a catastrophic spill from a shallow-water blowout is expected to be lower in volume than a 

deepwater blowout, as explained in Chapter B.2.2.3, the site would typically be closer to shore, allowing 

less time for oil to be weathered, dispersed, and recovered. This could result in a more concentrated and 

toxic oiling of the shoreline.

B.2.3.3.2. Deep Water

While a catastrophic spill from a deepwater blowout is expected to have a much greater volume than 

a shallow-water blowout (refer to Chapter B.2.2.3), the site would typically be farther from shore, 

allowing more time for oil to be weathered, dispersed, and recovered. This could result in broader, 

patchier oiling of the shoreline.

Translocation of the spilled oil via winds and currents is also a factor in the length of shoreline 

contacted. For example, oil could enter the Loop Current and then the Gulf Stream. However, the longer 
Catastrophic Spill Event Analysis B-13

it takes oil to travel, the more it would degrade, disperse, lose toxicity, and break into streamers and 

tarballs (USDOC, NOAA, Office of Response and Restoration, 2010d).

B.2.3.4. Severe Weather

The official Atlantic hurricane season runs from June 1st through November 30th, with a peak in 

hurricane probability in September. In an average Atlantic season, there are 11 named storms, 

6 hurricanes, and 2 Category 3 or higher storms (USDOC, NOAA, National Weather Service, 2010). In 

the event of a hurricane, vessels would evacuate the area, delaying response efforts, including the drilling 

of relief wells. The storm surge may push oil to the coastline and inland as far as the surge reaches, or the 

storm surge may remove the majority of oil from shore, as seen in some of the previous spills reviewed.

Movement of oil during a hurricane would depend greatly on the track of the hurricane in relation to 

the slick. A hurricane’s winds rotate counter-clockwise. In general, a hurricane passing to the west of the 

slick could drive oil to the coast, while a hurricane passing to the east of the slick could drive the oil away 

from the coast.

Severe weather may distribute spilled oil over a wide area. Storm surge may carry oil into the coastal 

and inland waters and shore. Debris resulting from severe weather may be contaminated by oil. Thus, 

the responders need to take proper precautions if weathered oil is present. Weather that results in waves 

greater than 3 ft (1 m) prevents skimming in coastal waters so there is greater likelihood of contact with 

the shoreline. Severe weather would also displace or destroy shoreline boom so that oil could come into 

contact with the shoreline until responders put the boom back in place. Severe weather could require that 

assets be relocated inland. The response would be delayed because following the severe weather event 

the assets would need to be transported back to the staging areas. The speed with which the assets could 

be brought back to the locations would depend upon on the condition of the roads and bridges for traffic 

resumption and the amount of debris potentially blocking the roads.

The USEPA, USCG, other Federal response agencies, and applicable State agencies would work 

together to address oil spills reported to the National Response Center or reported by emergency 

responders before, during, or after a hurricane occurs. Response personnel will cleanup significant spills 

and take other actions appropriate to protect public health and the environment. This response would 

cover any OCS spills that may occur as a result of the hurricane or preexisting at the time of the 

hurricane. Response activities may be interrupted or complicated during a hurricane event. Oil from an 

ongoing OCS spill event may be washed ashore during a hurricane event; could be weathered, diluted, or 

washed farther inland; and could be mixed with other contaminants from other sources released during a 

hurricane event (e.g., heating oil or industrial chemicals). For example, onshore sources account for most 

of the oil spilled during the past few hurricane seasons that has resulted in oiled property. After 

Hurricane Sandy, some oil heating tanks flooded and caused oiling of a property owner’s own building(s). 

As such, depending on circumstances, a hurricane event during an OCS spill event could complicate and 

exacerbate spill impacts and response operations, but could also increase weathering and dilution.

B.2.3.5. Onshore Cleanup Activities

A large-scale response effort would be expected for a catastrophic blowout. The number of vessels 

and responders would increase steadily as the spill continued. In addition to the response described in 

Chapter B.2.2.7, the following response is also estimated to occur once the spill contacts the shore.

B.2.3.5.1. Shallow Water

• There would be 5-10 staging areas established.

• Weathering permitting, about 200-300 skimmers could be deployed near shore to 

protect coastlines.
B-14 Central and Eastern Planning Areas Supplemental EIS

B.2.3.5.2. Deep Water

• There would be 10-20 staging areas established.

• Weather permitting, about 500-600 skimmers could be deployed near shore to protect 

coastlines. As seen in Louisiana following the Macondo well blowout and spill, a 

few hundred coastal skimmers could still be in operation a few months after the well 

is capped or killed (State of Louisiana, 2010).

B.2.3.5.3. Response Considerations for Sand Beaches for Both Shallow-Water and 

Deepwater Spills

• No mechanical techniques allowed in some areas.

• Surface residence balls (SRBs), also commonly known as tarballs, and surface 

residence patties (SRPs) are subject to smearing during the day; therefore, much of 

the beach cleanup can be expected to be conducted at night, if the weather is warm.

• There are marked differences in the sediments on the central Louisiana coast as 

compared with the Gulf beaches of Alabama, Florida, and Mississippi; therefore, no 

single technique will be universally applicable for cleaning sand beaches.

• Typically, sand sieving, shaking, and sifting beach cleaning machines will be 

utilized. The depth of cut below the sand surface can be expected to typically range 

from 0 to 12 inches (in) (0 to 30 centimeters [cm]) when using this equipment.

• It is anticipated that the responders will be instructed that no disturbance will be 

allowed below 18 in (46 cm). However, oil can be expected down to a depth of 

24-26 in (61-66 cm) below the sand surface.

• Repetitive tilling and mixing may be used at beaches such as Grand Isle, using 

agriculture plows and discs in combination with beach cleaning machines. Sand 

washing treatment also may take place at beaches such as Grand Isle’s beach. Sand 

washing includes a sand sieve/shaker to remove debris and large oil particles and a 

heated washing system. Average daily throughput for these systems would be 

290 cubic yards per day. Sand treated in this manner is typically treated by sediment 

relocation, which is where the sand is moved to an active intertidal zone

B.2.3.5.4. Response Considerations for Marshes for Both Shallow-Water and 

Deepwater Spills

• Lightly oiled marsh may be allowed to recover naturally; the oil may be allowed to 

degrade in place or to be removed by tidal or wave action.

• Moderately or heavily oiled marsh could be cleaned by vacuuming or skimming from 

boats in conjunction with flushing to enhance oil recovery rates, low pressure 

flushing (with water comparable to marsh type), manual removal by hand or 

mechanized equipment, or vegetation cutting.

• In some heavily oiled areas, in-situ burning may be an option if water covers the 

sediment surface. This technique is only considered when the source is contained 

due to potential re-oiling of the area. Surface washing agents are also a technique 

that might be utilized.

• Bioremediation may be utilized but mostly as a secondary treatment after bulk 

removal.
Catastrophic Spill Event Analysis B-15

B.2.3.5.5. Response Considerations for Nearshore Waters for Both Shallow-Water 

and Deepwater Spills

• Nearshore submerged oil is difficult to recover and hard to locate; vacuums and 

snares could be used.

• In the vicinity of marsh areas, skimming techniques with flushing could be utilized 

where warranted. In areas too shallow to use skimmers, oil removal could be 

accomplished using vacuum systems, in conjunction with flushing as needed. 

Booming could also be used to temporarily contain mobile slicks until they are 

recovered.

B.2.4. Phase 4—Post-Spill, Long-Term Recovery

During the final phase of a catastrophic blowout and spill, it is presumed that the well has been 

capped or killed and that cleanup activities are concluding. While it is assumed that the majority of 

spilled oil floating on surface waters would be dissipated within 30-60 days of stopping the flow, oil has 

the potential to persist in the environment long after a spill event and has been detected in sediment 

30 years after a spill dependent upon the impacted environment (USDOI, FWS, 2004). On sandy 

beaches, oil can sink deep into the sediments. In tidal flats and salt marshes, oil may seep into the muddy 

bottoms (USDOI, FWS, 2010a).

The multiple-year response required for the Deepwater Horizon explosion, oil spill, and response

provided one example of a long-term recovery to a catastrophic spill in the Gulf of Mexico. After the 

Deepwater Horizon explosion, oil spill, and response, a multi-agency Operational Science Advisory 

Team (OSAT), under the direction of the USCG, was convened to provide information to help guide 

response activities and to provide a better understanding of the potential environmental and health risks 

after the Deepwater Horizon explosion, oil spill, and response. A summary of the OSAT findings include

the following: 

• OSAT, issued in December 2010, concluded that no recoverable Macondo oil 

remained in the water column. In addition, none of the roughly 17,000 water samples 

collected and analyzed exceeded the USEPA’s benchmarks for protection of human 

health.

• OSAT-2, issued in February 2011, found that residual oil in nearshore and sandy 

shoreline areas was highly weathered, and concentrations of constituents of concern 

were well below levels of concern for human health.

• The OSAT Ecotoxicity Addendum, issued in July 2011, found that, with respect to 

the indicators considered in the OSAT (2010) report, the results discussed in this 

addendum are consistent with the OSAT conclusions that “no exceedances of the 

USEPA’s dispersant benchmarks were observed” and that “since 3 August 2010 (last 

day with potentially recoverable oil on the ocean surface), <1% of water samples and 

~1% of sediment samples exceeded EPA’s aquatic life benchmarks for polycyclic 

aromatic hydrocarbons (PAH’s).” In addition, results of the toxicity tests support the 

conclusions of the OSAT report regarding the distribution of actionable (i.e., 

amenable to removal actions) oil and dispersant-related constituents (OSAT 

Addendum, 2011).

• OSAT-3, finalized in early 2014, used a sophisticated scientific approach to identify 

potential discrete pockets of subsurface material. The OSAT-3 information was used 

to locate and recover potential subsurface material (British Petroleum, 2014a). The 

OSAT-3 report also identified actions to be taken for reducing potential recurrence of 

oil along the northeastern shores of the Gulf of Mexico. In addition, the report 

evaluated the feasibility of each action taken to recover or remove Macondo oil and 

the net environmental benefit of employing each recovery technique recommended. 

This scientific support was provided to the Federal On-Scene Coordinator with 
B-16 Central and Eastern Planning Areas Supplemental EIS

shoreline segment-specific information to facilitate the operational decisionmaking 

process to recover residual Macondo oil (OSAT-3, 2013).

If a shoreline is oiled, the selection of the type of shoreline remediation to be used will depend on the 

following: (1) the type and amount of oil on the shore; (2) the nature of the affected coastline; (3) the 

depth of oil penetration into the sediments; (4) the accessibility and the ability of vehicles to travel along 

the shoreline; (5) the possible ecological damage of the treatment to the shoreline environment; 

(6) weather conditions; (7) the current state of the oil; and (8) jurisdictional considerations. To determine 

which cleanup method is most appropriate during a spill response, decisionmakers must assess the 

severity and nature of the injury using Shoreline Cleanup and Assessment Team survey observations. 

These onsite decisionmakers must also estimate the time it will take for an area to recover in the absence 

of cleanup (typically considering short term to be 1-3 years, medium term to be 3-5 years, and long term 

greater than 5 years) (National Response Team, 2010).

B.2.4.1. Response Considerations for Sand Beaches, Marshes, and Nearshore 

Waters for both Shallow-Water and Deepwater Spills

Once oiled, it can be expected that the shoreline response techniques employed in the initial phase of 

a response will become more extensive and continue for some time (Chapters B.2.3.5.3, B.2.3.5.4, and 

B.2.3.5.5). For example, spill response post-Macondo continued for years in some of the more heavily 

oiled areas in Louisiana and in other areas, such as Florida, Mississippi, and Alabama, which experienced 

periodic re-oiling from submerged oil mats that lie in the inshore surf zone in troughs between the sand 

bars or from buried oil onshore that resurfaces. The three types of oil residue that were identified as 

challenging or potentially damaging to the environment if removed includes the following: (1) supra-tidal 

buried oil (buried below the 6-in [15-cm] surface cleaning depth restriction near sensitive habitats); 

(2) small surface residual balls, which are oil residue left behind after beaches are cleaned; and (3) surf 

zone submerged oil mats. Active shoreline cleanup ended in June 2013 for the States of Florida, 

Mississippi, and Alabama. Active shoreline cleanup for Louisiana ended on April 15, 2014 (British 

Petroleum, 2014a). However, efforts will continue to clean up any reported re-oiled shoreline in the 

GOM area as it is reported to the USCG. Although the re-oiling of some areas was anticipated to 

sporadically continue, it was determined that a better and more efficient long-term cleanup effort at this 

stage could be handled through the USCG. As of April 15, 2014, aerial reconnaissance flights were flown 

across approximately 14,000 mi (22,531 km) of shoreline during this spill response effort. Nearly 4,400 

mi (7,081 km) were ground-surveyed, with teams identifying 1,104 mi (1,777 km) that experienced some 

level of oiling and 778 mi (1,252 km) that required some measure of cleaning (British Petroleum, 2014a). 

Amenity beaches were generally cleaned to depths of up to 5 ft (1.5 m), using mechanical equipment 

that sifts out residual oil and other debris from below the beach surface while returning clean sand to the 

beach. Nonrecreational beaches and environmentally sensitive areas were generally hand-cleaned to 

depths of up to 6 in (15 cm), but they were cleaned deeper if it was ecologically safe and approved by the 

USCG, stakeholders, and others. Multiple techniques were used to treat oiled marsh areas, with the goal 

of promoting natural attenuation without causing further damage. A scientific effort was launched in 

mid-2012 to locate and remove potential pockets of subsurface material in Louisiana. During this effort, 

more than 40,000 holes and pits were excavated across seven barrier islands. The vast majority either had 

no visible oil or levels so low that treatment was not appropriate or required. For example, just 3 percent 

of the more than 16,000 auger holes had oiling levels that required cleanup and less than 2 percent of the 

over 24,000 pits had heavy or moderate oiling. Assessment teams continuously surveyed the shoreline 

and recommended treatment options. More than 100,000 tons of material were collected from the 

cleanup efforts. The total consists of not only the mixed residual material, which was typically 

10-15 percent residual oil and 85-90 percent sand, shells, and water but, during the first year of 

operations, it also included other solid material such as debris and protective clothing (British Petroleum, 

2014a). Additional information regarding shoreline response considerations can be found in Chapter 

3.2.1.9. 
Catastrophic Spill Event Analysis B-17

B.3. DESCRIPTION OF THE ENVIRONMENT AND IMPACT ANALYSIS

B.3.1. Long Duration—Large Volume Spill within the Gulf of Mexico

The following resource descriptions and impact analyses examined only the applicable portions of the 

scenario (described fully in Chapter 3 and summarized in Table B-4). 

B.3.1.1. Air Quality

Phase 1—Initial Event

A catastrophic blowout close to the water surface would initially emit large amounts of methane and 

other gases into the atmosphere. If high concentrations of sulfur are present in the produced gas, 

hydrogen sulfide (H2S) could present a hazard to personnel. The natural gas H2S concentrations in the 

Gulf of Mexico OCS are generally low; however, there are areas such as the Norphlet formation in the 

northeastern Gulf of Mexico, for example, that contain levels of H2S up to 9 percent. Ignition of the 

blowout gas and subsequent fire would result in emissions of nitrogen oxides (NOx), sulfur oxides (SOx), 

carbon monoxide (CO), volatile organic compounds (VOCs), particulate matter (PM10), and fine 

particulate matter (PM2.5). The fire could also produce PAHs, which are known to be hazardous to human 

health. The pollutant concentrations would decrease with downwind distance. A large plume of black 

smoke would be visible at the source and may extend a considerable distance downwind. However, with 

increasing distance from the fire, the gaseous pollutants would undergo chemical reactions, resulting in 

the formation of fine particulate matter (PM2.5) that includes nitrates, sulfates, and organic matter. The 

PM2.5 concentrations in the plume would have the potential to temporarily degrade visibility in any 

affected Prevention of Significant Deterioration (PSD) Class I areas (i.e., National Wilderness Areas and 

National Parks) and other areas where visibility is of significant value. Organic aerosols formed 

downwind from the Macondo well blowout and spill (de Gouw et al., 2011), during which the lightest 

compounds, the VOCs, in the oil from the Macondo well blowout and spill evaporated within hours and 

during which the heavier compounds took longer to evaporate, contributing to the formation of air 

pollution particles downwind.

Phase 2—Offshore Spill

In the Gulf of Mexico, evaporation from the oil spill would result in concentrations of VOCs in the 

atmosphere, including chemicals that are classified as being hazardous. The VOC concentrations would 

occur anywhere where there is an oil slick, but they would be highest at the source of the spill because the 

rate of evaporation depends on the volume of oil present at the surface. The VOC concentrations would 

decrease with distance as the layer of oil gets thinner. The lighter compounds of VOCs would be most 

abundant in the immediate vicinity of the spill site. The heavier compounds would be emitted over a 

longer period of time and over a larger area. Some of the compounds emitted could be hazardous to 

workers in close vicinity of the spill site. The hazard to workers can be reduced by monitoring and using 

protective gear, including respirators, as well as limiting exposure through limited work shifts, rotating 

workers in close vicinity of the spill site. The hazard to workers can be reduced by monitoring and using 

protective gear, including respirators, as well as limiting exposure through limited work shifts, rotating 

workers out of high exposure areas, and pointing vessels into the wind. During the Macondo well 

blowout and spill, air samples collected by individual offshore workers of British Petroleum (BP), the 

Occupational Safety and Health Administration (OSHA), and USCG showed levels of benzene, toluene, 

ethylbenzene, and xylene that were mostly under detection levels. All samples had concentrations below 

the OSHA permissible exposure limits and the more stringent ACGIH (American Conference of 

Governmental Industrial Hygienists) threshold limit values (U.S. Dept. of Labor, OSHA, 2010a).

The VOC emissions that result from the evaporation of oil contribute to the formation of particulate 

matter (PM2.5) in the atmosphere. In addition, VOCs could cause an increase in ozone levels, especially if 

the release were to occur on a hot, sunny day with sufficient concentrations of NOx present in the lower 

atmosphere. However, because of the distance of the proposed CPA or EPA lease sale area from shore, 

the oil slick would not likely have any effects on onshore ozone concentrations; however, if there were 

any effects to onshore ozone concentrations, they would be likely only be temporary in nature and last at 

most the length of time of the spill duration.
B-18 Central and Eastern Planning Areas Supplemental EIS

It is assumed that response efforts would include hundreds of in-situ or controlled burns, which would 

remove an estimated 5-10 percent of the volume of oil spilled. This could be as much as 720,000 bbl of 

oil for a spill of 60,000 bbl per day for 90 days. In-situ burning would result in ambient concentrations of 

CO, NOx, SO2, PM10, and PM2.5 very near the site of the burn and would generate a plume of black 

smoke. The levels of PM2.5 could be a hazard to personnel working in the area, but this could be 

effectively mitigated through monitoring and relocating vessels to avoid areas of highest concentrations. 

In an experiment of an in-situ burn off Newfoundland, it was found that CO, SO2, and NO2 were 

measured only at background levels and were frequently below detection levels (Fingas et al., 1995). 

Limited amounts of formaldehyde and acetaldehyde were measured, but concentrations were close to 

background levels. Measured values of dioxins and dibenzofurans were at background levels. 

Measurements of PAH in the crude oil, the residues, and the air indicated that the PAH in the crude oil are 

largely destroyed during combustion (Fingas et al., 1995).

While containment operations may be successful in capturing some of the escaping oil and gas, 

recovery vessels may not be capable of storing the crude oil or may not have sufficient storage capacity. 

In this case, excess oil would be burned; captured gas cannot be stored or piped to shore so it would be 

flared. For example, in the Macondo well blowout and spill, gas was flared at the rate of 100-200 million 

cubic feet per day and oil burned at the rate of 10,000-15,000 bbl per day. The estimated NOx emissions 

are about 13 tons per day. The SO2 emissions would be dependent on the sulfur content of the crude oil. 

For crude oil with a sulfur content of 0.5 percent, the estimated SO2 emissions are about 16 tons per day. 

Particulate matter in the plume would also affect visibility. Flaring or burning activities upwind of a PSD 

Class I area, e.g., the Breton National Wilderness Area, could adversely affect air quality there because of 

increased levels of SO2, PM10, and PM2.5, and because of reduced visibility.

Phase 3—Onshore Contact

As the spill nears shore, there would be low-level concentrations of odor-causing pollutants 

associated with evaporative emissions from the oil spill. These may cause temporary eye, nose, or throat 

irritation, nausea, or headaches, but the doses are not thought to be high enough to cause long-term harm 

(USEPA, 2010a). However, responders could be exposed to levels higher than OSHA occupational 

permissible exposure levels (U.S. Department of Labor, OSHA, 2010b). During the Deepwater Horizon

explosion, oil spill, and response, USEPA took air samples at various onshore locations along the length 

of the Gulf coastline. All except three measurements of benzene were below 3 parts per billion (ppb). 

The highest level was 91 ppb. Emissions of benzene to the atmosphere result from gasoline vapors, auto 

exhaust, and chemical production and user facilities. Ambient concentrations of benzene up to and 

greater than 5 ppb have been measured in industrial areas such as Houston, Texas; in various urban areas 

during rush hour; and inside the homes of smokers (U.S. Dept. of Health and Human Services, 2007). 

The following daily median benzene air concentrations were reported in the Volatile Organic Compound 

National Ambient Database (1975-1985): remote (0.16 ppb); rural (0.47 ppb); suburban (1.8 ppb); urban 

(1.8 ppb); indoor air (1.8 ppb); and workplace air (2.1 ppb). The outdoor air data represent 300 cities in 

42 states, while the indoor air data represent 30 cities in 16 states (Shah and Singh, 1988).

During the Deepwater Horizon explosion, oil spill, and response, air samples collected by BP, 

OSHA, and USCG near shore showed levels of benzene, toluene, ethylbenzene, and xylene that were 

mostly under detection levels. Among the 28,000 personal benzene samples taken by BP, there was only 

1 sample where benzene exceeded the OSHA occupational permissible exposure limits, and 6 additional 

validated constituents were in excess of the ACGIH threshold limit value. All other sample 

concentrations were below the more stringent ACGIH threshold limit values (U.S. Department of Labor, 

OSHA, 2010a). All measured concentrations of toluene, ethylbenzene, and xylene were well within the 

OSHA occupational permissible exposure levels and ACGIH threshold limit values.

Phase 4—Post-Spill, Long-Term Recovery and Response

There would be some residual air quality impacts after the well is capped or killed. As most of the oil 

would have been burned, evaporated, or weathered over time, air quality would return to pre-oil spill 

conditions. While impacts to air quality are expected to be localized and temporary, adverse effects that 

may occur from the exposure of humans and wildlife to air pollutants could have long-term consequences.
Catastrophic Spill Event Analysis B-19

Overall Summary and Conclusion (Phases 1-4)

The OCS oil- and gas-related catastrophic event could include the release of oil, condensate, or 

natural gas or chemicals used offshore or pollutants from the burning of these products. The air pollutants 

include criteria National Ambient Air Quality Standards (NAAQS) pollutants, volatile and semi-volatile 

organic compounds, H2S, and methane. If a fire was associated with the event, it would produce a broad 

array of pollutants, including all NAAQS-regulated primary pollutants, including NO2, CO, SOx, VOC, 

PM10, and PM2.5. Response activities that could impact air quality include in-situ burning, the use of 

flares to burn gas and oil, and the use of dispersants applied from aircraft. Measurements taken during an 

in-situ burning show that a major portion of compounds was consumed in the burn; therefore, pollutant 

concentrations would be expected to be within the NAAQS. In a recent analysis of air in coastal 

communities, low levels of dispersant components, which are also used in everyday household products, 

were identified. These response activities are temporary in nature and occur offshore; therefore, there are 

little expected impacts from these actions to onshore air quality. Catastrophic events involving high 

concentrations of H2S could result in deaths as well as environmental damage. Regulations and NTLs 

mandate safeguards and protective measures, which are in place, to protect workers from H2S releases. 

Other emissions of pollutants into the atmosphere from catastrophic events are not projected to have 

significant impacts on onshore air quality because of the prevailing atmospheric conditions, emissions 

height, emission rates, and the distance of these emissions from the coastline.

Overall, since loss of well-control events, blowouts, and fires are rare events and of short duration, 

potential impacts to air quality are not expected to be significant except in the rare case of a catastrophic 

event. To date, air monitoring conducted following the Macondo well blowout and spill, has not found 

any pollutants at levels expected to cause long-term harm (USEPA, 2010b). 

B.3.1.2. Water Quality

Phase 1—Initial Event

Offshore Water Quality

During the initial phase of a catastrophic blowout, water quality impacts include the disturbance of 

sediments and the release and suspension of oil and natural gas (primarily methane) into the water 

column. These potential impacts are discussed below. As this chapter deals with the immediate effects of 

a blowout that would be located at least 3 nmi (3.5 mi; 5.6 km) from shore, it is assumed that there would 

be no impacts on coastal water quality during this initial stage.

Disturbance of Sediments

A catastrophic blowout below the seafloor, outside the wellbore (Table B-1) has the potential to 

resuspend sediments and disperse potentially large quantities of bottom sediments. Some sediment could 

travel several kilometers, depending on particle size and subsea current patterns. In the deep Gulf of 

Mexico, surficial sediments are mostly composed of silt and clay, and, if resuspended, could stay in the 

water column for several hours to days. Bottom current measurements in the deep Gulf of Mexico were 

synthesized as part of the MMS Deepwater Reanalysis study and have been measured to reach 

90 centimeters/second (cm/sec) (35.4 inches/second [in/sec]) with mean flows of 0.4-21 cm/sec 

(0.2-8.3 in/sec) (Nowlin et al., 2001). At these mean flow rates, resuspended sediment could be

transported 0.3-18 km per day (0.2-11 mi per day).

Sediment resuspension can lead to a temporary change in the oxidation-reduction chemistry in the 

water column, including a localized and temporal release of any formally sorbed metals, as well as 

nutrient recycling (Caetano et al., 2003; Fanning et al., 1982). Sediments also have the potential to 

become contaminated with oil components.

A subsea release also has the potential to destabilize the sediments and create slumping or larger scale 

sediment movements along depth gradients. These types of events would have the potential to move 

and/or damage any infrastructure in the affected area.
B-20 Central and Eastern Planning Areas Supplemental EIS

Release and Suspension of Oil into the Water Column

A subsea release of hydrocarbons at a high flow rate has the potential to disperse and suspend plumes 

of oil droplets (chemically dispersed or otherwise) within the water column and to induce large patches of 

sheen and oil on the surface. These dispersed hydrocarbons may adsorb onto marine detritus (marine 

snow), suspended sediments, or may be mixed with drilling mud and deposited near the source. 

Mitigation efforts such as burning may introduce hydrocarbon byproducts into the marine environment, 

which would be distributed by surface currents. The acute and chronic sublethal effects of these dilute 

suspended “plumes” are not well understood and require future research efforts.

As a result of the Macondo well blowout and spill, a subsurface oil and gas plume was discovered in 

deep waters between ~1,100 and 1,300 m (3,609 and 4,265 ft) (e.g., Diercks et al., 2010) in addition to the 

surface slick. Measurable amounts of hydrocarbons (dispersed or otherwise) were detected in the 

subsurface plumes and on the seafloor in the vicinity of the release (e.g., Diercks et al., 2010; OSAT, 

2010). In the Macondo well blowout and spill subsurface plume, half-lives were estimated for petroleum 

hydrocarbons and n-alkanes on the order of 1 month and several days, respectively, indicating the impacts 

of various weathering processes (Reddy et al., 2011 and references therein). After the Ixtoc I well 

blowout and spill in 1979, which was located 50 mi (80 km) offshore in the Bay of Campeche, Mexico, 

some subsurface oil was also observed dispersed within the water column (Boehm and Fiest, 1982); 

however, the scientific investigations were limited (Reible, 2010). The water quality of offshore waters 

would be affected by the dissolved components and oil droplets that are small enough that they do not rise 

to the surface or are mixed down by surface turbulence. In the case of subsurface oil plumes, it is 

important to remember that these plumes would be affected by subsurface currents, dilution, and natural 

physical, chemical, and biological degradation processes including weathering.

Large quantities of oil put into offshore water may alter the chemistry of the sea with unforeseeable 

results. The properties and persistence of oil, including oil in the Gulf of Mexico, is further discussed in 

Chapter B.2.2.4. The VOCs, including benzene, toluene, ethylbenzene, and xylenes (also referred to as 

BTEX), are highly soluble and can have acutely toxic effects; however, VOCs are light-weight oil 

components and tend to evaporate rather than persist in the environment (Michel, 1992). Middle-weight 

organic components tend to pose the greatest risk in the environment because they are more persistent in 

the environment, are more bioavailable, and include PAHs, which have high toxicities (Michel, 1992). 

To determine the overall toxicity of PAHs in water or sediment, the contributions of every individual 

PAH compound in the petroleum mixture must be included (USEPA, 2011). This approach was used 

during the Macondo well blowout, spill and response in determining the potential risk of PAHs in both 

water and sediment to humans or animals in the environment (OSAT, 2010). Heavier components of 

crude oil tend to pose less risk of toxicity because they are not very soluble in water and therefore are less 

bioavailable.

The oil that entered the Gulf of Mexico from the Macondo well blowout and spill was a South 

Louisiana sweet crude oil (i.e., low in sulfur) (USDOC, NOAA, 2010b). This oil is less toxic than other 

crude oils in general because this oil is lower in PAHs than many other crude oils. Studies indicate that 

the oil contained approximately 3.9 percent PAHs by weight, which results in an estimated release of 

2.1 x 1010 grams of PAHs (Reddy et al., 2011; Reddy, official communication, 2012). The oil was also 

fairly high in alkanes (organic compounds containing only carbon and hydrogen and single bonds, 

sometimes called paraffin or aliphatic compounds) (USDOC, NOAA, 2010b). Because alkanes are 

simple hydrocarbons, these oils are likely to undergo biodegradation more easily (USDOC, NOAA, 

2010b).

Release of Natural Gas (Methane) into the Water Column

A catastrophic blowout could release natural gas into the water column; the amount of gas released is 

dependent upon the water depth, the natural gas content of the formation being drilled, and its pressure. 

Methane is the primary component of natural gas. Methane may stay in the marine environment for long 

periods of time (Patin, 1999; page 237), as methane is highly soluble in seawater at the high pressures and 

cold temperatures found in deepwater environments (NRC, 2003; page 108). However, methane 

diffusing through the water column would likely be oxidized in the aerobic zone and would rarely reach 

the air-water interface (Mechalas, 1974; page 23). In addition to methane, natural gas contains smaller 

percentages of other gases such as ethane, propane, and to a much lesser degree H2S (NaturalGas.org, 
Catastrophic Spill Event Analysis B-21

2012), which can be toxic in the environment. The majority of natural gas components including methane 

are carbon sources, and their introduction into the marine environment could result in reducing the 

dissolved oxygen levels because of microbial degradation potentially creating hypoxic or “dead” zones. 

Unfortunately, little is known about methane toxicity in the marine environment, but there is concern as to 

how methane in the water column might affect fish. Further discussion of natural gas released during the 

Macondo well blowout and spill is given in Chapter B.2.2.5.

Phase 2—Offshore Spill

Offshore Water Quality

The water offshore of the Gulf’s coasts can be divided into two regions: the continental shelf and 

slope (<1,000 ft; 305 m) and deep water (>1,000 ft; 305 m). Waters on the continental shelf and slope are 

heavily influenced by the Mississippi and Atchafalaya Rivers, the primary sources of freshwater, 

sediment, nutrients, and pollutants from a huge drainage basin encompassing 55 percent of the continental 

U.S. (Murray, 1998). Lower salinities are characteristic nearshore where freshwater from the rivers mix 

with Gulf waters. The presence or extent of a nepheloid layer, a body of suspended sediment at the sea 

bottom (Kennett, 1982, page 524), affects water quality on the shelf and slope. Deep waters east of the 

Mississippi River are affected by the Loop Current and associated warm-core (anti-cyclonic) eddies, 

which flush the area with clear, low-nutrient water (Muller-Karger et al., 2001) (Figure B-2). However, 

cold-core cyclonic eddies (counter-clockwise rotating) also form at the edge of the Loop Current and are 

associated with upwelling and nutrient-rich, high-productivity waters, although the extent of this flushing 

can vary seasonally.

While response efforts would decrease the fraction of oil remaining in Gulf waters, significant 

amounts of oil would remain. Natural processes will physically, chemically, and biologically aid the 

degradation of oil (NRC, 2003). The physical processes involved include evaporation, emulsification, 

and dissolution, while the primary chemical and biological degradation processes include photo-oxidation 

and biodegradation (i.e., microbial oxidation). Water quality would not only be impacted by the oil, gas, 

and their respective components, but also to some degree, from cleanup and mitigation efforts, such as 

from increased vessel traffic and the addition of dispersants and methanol to the marine environment.

In the case of a catastrophic subsea blowout in deep water, it is assumed that large quantities of 

subsea dispersants would be used. The positive effect of using dispersants is that the oil, once dispersed, 

may be more available to be degraded (however, we note that contrary findings for beached oil were 

presented by Hamdan and Fulmer, 2011). The negative effect is that the oil, once dispersed, is also more 

bioavailable to have toxic effects to microorganisms as well. The toxicity of dispersed oil in the 

environment would depend on many factors, including the effectiveness of the dispersion, temperature, 

salinity, degree of weathering, type of dispersant, and degree of light penetration in the water column 

(NRC, 2005). The toxicity of dispersed oil is primarily because of the toxic components of the oil itself 

(Australian Maritime Safety Authority, 2010).

As a result of the use of dispersants, it would be more likely for clouds or plumes of dispersed oil to 

occur near the blowout site as was seen during the Macondo well blowout and spill. Dissolved oxygen 

levels are a concern with any release of a carbon source, such as oil and natural gas, and became a 

particular concern during the Macondo well blowout and spill since dispersants were used in deep waters 

for the first time. In areas where plumes of dispersed oil were previously found, dissolved oxygen levels 

decreased by about 20 percent from long-term average values in the GOM of ~6.9 milligrams/liter (spring 

climatological mean at 1,500-m [4,921 -ft] depth); however, scientists reported that these levels stabilized 

and were not low enough to be considered hypoxic (Joint Analysis Group, 2010; USDOC, NOAA, 

2010c). The drop in oxygen, which did not continue over time, has been attributed to microbial 

degradation of the oil.

Phase 3—Onshore Contact

Coastal Water Quality 

Water quality governs the suitability of waters for plant, animal, and human use. Water quality is 

important in the bays, estuaries, and nearshore coastal waters of the Gulf because these waters provide 

feeding, breeding, and/or nursery habitat for many invertebrates and fishes, as well as sea turtles, birds, 
B-22 Central and Eastern Planning Areas Supplemental EIS

and marine mammals. A catastrophic spill would significantly impact coastal water quality in the Gulf of 

Mexico. Water quality prior to the Macondo well blowout and spill was rated as fair while sediment 

quality was rated as poor (USEPA, 2008). In addition, the coastal habitat index, a rating of wetlands 

habitat loss, was also rated as poor. Both the sediment quality and the coastal habitat index affect water 

quality.

Though response efforts would decrease the amount of oil remaining in Gulf waters and reduce the 

amount of oil contacting the coastline, significant amounts of oil would remain. Coastal water quality 

would be impacted not only by the oil, gas, and their respective components but also to some degree from 

cleanup and mitigation efforts. Increased vessel traffic, hydromodification, and the addition of 

dispersants and methanol in an effort to contain, mitigate, or clean up the oil may also tax the 

environment.

The use of dispersants as a response tool involves a tradeoff. The purpose of chemical dispersants is 

to facilitate the movement of oil into the water column in order to encourage weathering and biological 

breakdown of the oil (i.e., biodegradation) (NRC, 2005; Australian Maritime Safety Authority, 2010). 

Thus, the tradeoff is generally considered to be oiling of the shoreline and surface of the water versus the 

water column and benthic resources (NRC, 2005). If the oil moves into the water column and is not on 

the surface of the water, it is less likely to reach sensitive shore areas (USEPA, 2010a). Since sea birds 

are often on the surface of the water or in shore areas, dispersants are also considered to be very effective 

in reducing the exposure of sea birds to oil (Australian Maritime Safety Authority, 2010). In addition to 

dispersion being enhanced by artificial processes, oil may also be dispersed from natural processes 

including both (bio)chemical and physical processes. For instance, microbial metabolism of crude oil 

results in the dispersion of oil (Bartha and Atlas, 1983), and conditions at the source of the oil/gas leak 

(e.g., orifice size and shape) may cause physical dispersion of the oil. Dispersion has both positive and 

negative effects. The positive effect is that the oil, once dispersed, is more available to be degraded. The 

negative effect is that the oil, once dispersed, is also more bioavailable to have toxic effects to 

microorganisms as well. For example, a recent study using mesocosm experiments suggested that 

dispersed oil could disrupt coastal microbial foodwebs in the northern Gulf of Mexico, reducing the flow 

of carbon to higher trophic levels (Ortmann et al., 2012). The toxicity of dispersed oil in the environment 

will depend on many factors, including the effectiveness of the dispersion, temperature, salinity, the 

degree of weathering, type of dispersant, and the degree of light penetration in the water column (NRC, 

2005). The toxicity of dispersed oil is primarily because of the toxic components of the oil itself 

(Australian Maritime Safety Authority, 2010).

Oxygen and nutrient concentrations in coastal waters vary seasonally. The zone of hypoxia (depleted 

oxygen) on the Louisiana-Texas shelf occurs seasonally and is affected by the timing of freshwater 

discharges from the Mississippi and Atchafalaya Rivers. The hypoxic conditions continue until local 

wind-driven circulation mixes the water again. The 2010 hypoxic zone could not be linked to the 

Macondo well blowout and spill in either a positive or a negative manner (Louisiana Universities Marine 

Consortium, 2010). Nutrients from the Mississippi River nourished phytoplankton and contributed to the 

formation of the hypoxic zone.

Phase 4—Post-Spill, Long-Term Recovery and Response

The leading source of contaminants that impairs coastal water quality in the Gulf of Mexico is urban 

runoff. It can include suspended solids, heavy metals, pesticides, oil, grease, and nutrients (such as from 

lawn fertilizer). Urban runoff increases with population growth, and the Gulf Coast region has 

experienced a 109 percent population growth since 1970, with an additional expected 15 percent increase 

expected by 2020 (USDOC, NOAA, 2011b). Other pollutant source categories include (1) agricultural 

runoff, (2) municipal point sources, (3) industrial sources, (4) hydromodification (e.g., dredging), and 

(5) vessel sources (e.g., shipping, fishing, and recreational boating). The NRC (2003, Table I-4, 

page 237) estimated that, on average, approximately 26,324 bbl of oil per year entered Gulf waters from 

petrochemical and oil refinery industries in Louisiana and Texas. The Mississippi River introduced 

approximately 3,680,938 bbl per year (NRC, 2003, Table I-9, page 242) into the waters of the Gulf. 

Hydrocarbons also enter the Gulf of Mexico through natural seeps in the Gulf at a rate of approximately 

980,392 bbl per year (a range of approximately 560,224-1,400,560 bbl per year) (NRC, 2003, page 191). 

Produced water (formation water) is, by volume, the largest waste stream from the oil and gas industry 

that enters Gulf waters (e.g., Table B-3). The NRC has estimated the quantity of oil in produced water 
Catastrophic Spill Event Analysis B-23

entering the Gulf per year to be 473,000 bbl (NRC, 2003, page 200, Table D-8).1

 These sources total 

about 5.5 MMbbl of oil per year that routinely enters Gulf of Mexico waters. In comparison, a 

catastrophic spill of 30,000-60,000 bbl per day for 90-120 days would spill a total of 2.7-7.2 MMbbl of 

oil. When added to the other sources of oil listed above, this would result in a 48- to 129-percent increase 

in the volume of oil entering the water during the year of the spill. In addition, the oil from a catastrophic 

spill will be much more concentrated in some locations than the large number of other activities that 

release oil into the Gulf of Mexico. Chapter B.2.2.4 discusses the properties and persistence of oil in the 

environment.

Overall Summary and Conclusion (Phases 1-4)

During Phase 1 of the catastrophic blowout scenario, impacts are not expected to coastal water 

quality. Instead, the initial impacts will include degradation of offshore water quality, disturbance and 

degradation of sediments, and the release and suspension of oil and natural gas into the water column, 

including the possible formation of plumes. Fine sediments could be transported away from the spill site.

As the spill continues during Phase 2, response efforts and natural degradation processes would 

decrease the amount of oil in the Gulf, but significant amounts of oil would remain to impact water and 

sediment quality. Water and sediment quality would not only be impacted by the oil, gas, and their 

respective components but also to some degree from cleanup and mitigation efforts. The use of 

dispersants as a response tool may make the oil more available to degradation, but it can also make the oil 

more bioavailable to have toxic effects on microorganisms as well. Furthermore, dispersed oil is more 

likely to form a plume.

Onshore contact is made during Phase 3, so coastal sediment and water quality will be significantly 

impacted during this phase despite response efforts. Response efforts may even tax the coast to some 

degree. Natural and chemical dispersion may reduce the contact of oil with the shoreline but result in 

more oil in the water column and greater bioavailability of the dispersed oil.

The long-term recovery (Phase 4) of the water and sediment quality of the Gulf will depend on the 

properties and persistence of the oil as noted in Chapter B.2.2.4. Though the spill will increase the 

amount of oil entering the Gulf of Mexico, oil regularly enters the Gulf through sources such as oil 

refineries, the Mississippi River, produced water, and natural seeps. However, oil from a spill will be 

more concentrated than the oil input from these other sources.

B.3.1.3. Coastal Barrier Beaches and Associated Dunes

Phase 1—Initial Event

There would likely be no adverse impacts to coastal barrier beaches and associated dunes as a result 

of the events and the potential impact-producing factors that could occur throughout Phase 1 of a 

catastrophic spill event because these resources would not be contacted until the oil reached the shoreline.

Phase 2—Offshore Spill

There would likely be no adverse impacts to coastal barrier beaches and associated dunes as a result 

of the events and the potential impact-producing factors that could occur throughout Phase 2 of a 

catastrophic spill event because these resources would not be contacted until the oil reached the shoreline.

Phase 3—Onshore Contact

Barrier islands make up more than two-thirds of the northern Gulf of Mexico shore. Each of the 

barrier islands is either high profile or low profile, depending on the elevations and morphology of the 

island (Morton et al., 2004). The distinguishing characteristics of the high- and low-profile barriers relate 

to the width of the islands along with the continuity of the frontal dunes. Low-profile barriers are narrow 

with discontinuous frontal dunes easily overtopped by storm surge, which makes the island susceptible to 

 1 These numbers were generated from converting the units reported in the noted reference and do not imply any 

level of significance.
B-24 Central and Eastern Planning Areas Supplemental EIS

over wash and erosion. This over wash can create channels to bring sand onto the island or into lagoons 

formed on these islands. High-profile barrier islands are generally wider than the low-profile islands and 

have continuous, vegetated, frontal dunes with elevations high enough to prevent over wash from major 

storm surge and, therefore, are less susceptible to erosion. The sand stored in these high-profile dunes 

allows the island to withstand prolonged erosion and therefore prevents breaching, which could result in 

damaging the island core.

The effects from oil spills depend on the geographic location, volume, and rate of the spill; type of 

oil; oil-slick characteristics; oceanic conditions and season at the time of the spill; and response and 

cleanup efforts. The effects could include changes in plant species diversity that could result in changes 

in forage areas for species using microfauna as a food base (Teal and Howarth, 1984). Further detail on 

this catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS and 

EPA 225/226 EIS. 

As a result of a catastrophic spill, many of the barrier islands and beaches would receive varying 

degrees of oiling. Oil disposal on sand and vegetated sand dunes was shown in experiments by Webb 

(1988) to have little deleterious effects on the existing vegetation or on the recolonization of the oiled 

sands by plants. However, other studies have documented toxic effects of oil on barrier beach vegetation 

(Ko and Day, 2004). The depth of oiling would be variable, based on the wave environment and 

sediment source at a particular beach head. Layering of oil and sand could occur if it was not cleaned 

before another tidal cycle. However, most areas of oiling are expected to be light, and sand removal 

during cleanup activities should be minimized. The severity of oiling dictates the appropriate cleanup 

method to be utilized (refer to Table B-4). 

In areas designated as natural wilderness areas (e.g., Breton National Wildlife Refuge and Gulf 

Islands National Seashore), land managers may require little to no disruption of the natural system. In 

these environments, it is preferred to let the oil degrade naturally without aggressive and intrusive cleanup 

procedures. Manual rather than mechanized removal techniques would be used in these areas and only if 

heavy oiling has occurred. Thus, these areas may not be treated as thoroughly as other shorelines. Oil 

would remain in place longer, weathering gradually while continuing to contaminate habitat, though 

mechanical disturbance would be minimized.

Once oil has reached the beaches and barrier islands and becomes buried or sequestered, it becomes 

difficult to treat. During wave events when the islands and beaches erode, the oil can become 

remobilized and transported. Thus, the fate of oil is not as simple as either reaching land, becoming 

sequestered, or being treated; but, it must be considered in terms of a continuing process of sequestration, 

remobilization, and transport.

For spilled oil to move onto beaches or across dunes, strong southerly winds must persist for an 

extended time prior to or immediately after the spill to elevate water levels. Strong winds, however, 

could reduce the impact severity at a landfall site by accelerating the processes of oil-slick dispersal, spill 

spreading, and oil weathering.

Bik et al. (2012) found that, despite the disappearance of visible surface oil on heavily oiled Gulf 

beaches impacted by the Macondo well blowout and spill, microbial communities showed significant 

changes in community structure, with a decrease in diversity and a shift toward dominance by fungal taxa, 

particularly known hydrocarbon-degrading genera. Likewise, nematode communities showed decreased 

diversity and increased dominance by predatory and scavenger taxa alongside an increased abundance of 

juveniles.

Due to the distance of beaches from deepwater blowouts and the combination of weathering and 

dispersant treatment of the oil offshore, the toxicity and quantity of the oil reaching shore should be 

greatly reduced, thereby minimizing the chances of irreversible damage to the impacted areas. A blowout 

in shallower waters near shore may have equal or greater impacts because of a shorter period of 

weathering and dispersion prior to shoreline contact, even though a smaller volume of spilled oil would 

be expected.

Vessel traffic in close proximity to barrier islands has been shown to move considerably more bottom 

sediment than tidal currents, thus increasing coastal and barrier island erosion rates. If staging areas for 

cleanup of a catastrophic spill are in close proximity to these islands, recovery time of the barrier islands 

could be greatly extended because of the large number of response vessels.
Catastrophic Spill Event Analysis B-25

Phase 4—Post-Spill, Long-Term Recovery and Response

Oil or its components that remain in the sand after cleanup may be (1) released periodically when 

storms and high tides resuspend or flush beach sediments, (2) decomposed by biological activity, or 

(3) volatilized and dispersed. While it is assumed that the majority of spilled oil would be dissipated 

offshore within 1-2 months (depending on season and temperature) of stopping the flow, oil has the 

potential to persist in the environment long after a spill event. For example on sandy beaches, oil can sink 

deep into the sediments. As stranded oil weathers, some oil may become buried through natural beach 

processes and appear as surface residual balls (SRBs; <10 cm [4 in]) or as surface residual patties (SRPs; 

10 cm to 1 m [4 in to 3 ft]) (Table B-4). Such balls continue to provide a source of contamination with 

accompanying toxic effects.

The cleanup impacts of a catastrophic spill could result in short-term (up to 2 years) adjustments in 

beach profiles and configurations as a result of sand removal and disturbance during cleanup operations. 

Some oil contact to lower areas of sand dunes is expected. This contact would not result in significant 

destabilization of the dunes. The long-term stressors to barrier beach communities caused by the physical 

effects and chemical toxicity of an oil spill may lead to decreased primary production, plant dieback, and 

hence, further erosion (Ko and Day, 2004).

The protection once afforded to inland marshes by coastal barrier beaches has been greatly reduced 

because of decreased elevations and the continued effect of subsidence, sea-level rise, and saltwater 

intrusion. A catastrophic spill has the potential to contribute to this reduction through increased erosion 

as a result of plant dieback and cleanup efforts.

Overall Summary and Conclusion (Phases 1-4)

As a result of a catastrophic spill, many of the barrier islands and beaches would receive varying 

degrees of oiling. However, most areas of oiling are expected to be lightly oiled, and sand removal 

during cleanup activities should be minimal. The long-term stressors to barrier beach communities 

caused by the physical effects and chemical toxicity of an oil spill may lead to decreased primary 

production, plant dieback, and hence, further erosion.

B.3.1.4. Wetlands

Phase 1—Initial Event

There would likely be no adverse impacts to wetlands as a result of the events and the potential 

impact-producing factors that could occur throughout Phase 1 of a catastrophic spill event because these 

resources would not be contacted until the oil reached the shoreline.

Phase 2—Offshore Spill

There would likely be no adverse impacts to wetlands as a result of the events and the potential 

impact-producing factors that could occur throughout Phase 2 of a catastrophic spill event because these 

resources would not be contacted until the oil reached the shoreline.

Phase 3—Onshore Contact

Coastal wetland habitats in the Gulf of Mexico occur as bands around waterways; broad expanses of 

saline, brackish, and freshwater marshes; mud and sand flats; and forested wetlands of cypress-tupelo 

swamps and bottomland hardwoods. Offshore oil spills would have a low probability of contacting and 

damaging any wetlands along the Gulf Coast, except in the case of a catastrophic event. This is because 

of the distance of the spill to the coast, the likely weathered condition of oil (through evaporation, 

dilution, and biodegradation) should it reach the coast, and because wetlands are generally protected by 

barrier islands, peninsulas, sand spits, and offshore currents.

While a catastrophic spill from a shallow-water blowout is expected to be lower in volume than a 

deepwater blowout, a potential shallow-water site could be closer to shore, allowing less time for oil to be 

weathered, dispersed, and recovered before it impacted coastal resources. A spill from a catastrophic 

blowout could oil a few to several hundred acres of wetlands depending on the depth of inland penetration 
B-26 Central and Eastern Planning Areas Supplemental EIS

(Burdeau and Collins, 2010). This would vary from moderate to heavy oiling. One study of the impacts 

of the Deepwater Horizon explosion, oil spill, and response to salt marshes in Louisiana estimated the 

area affected to be between 350 and 400 km2 (135 and 154 mi2

) (Mishra et al., 2012). Further detail on 

the catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS and 

EPA 225/226 EIS. 

The NOAA Environmental Sensitivity Index (ESI) ranks shorelines according to their sensitivity to 

oil, the natural persistence of oil, and the expected ease of cleanup after an oil spill. These factors cause 

oil to persist in coastal and estuarine areas (USDOI, MMS, 2010). According to the ESI, the most 

sensitive shoreline types (i.e., sheltered tidal flats, vegetated low banks, salt/brackish-water marshes, 

freshwater marshes/swamps, and scrub-shrub wetlands) tend to accumulate oil and are difficult to clean, 

thus causing oil to persist in these coastal and estuarine areas (USDOI, MMS, 2010).

In the case of catastrophic spills in the GOM, preemptive oil-response strategies would be initiated 

and include the deployment of oil booms, skimmer ships, and barge barriers to protect the beaches and 

adjacent wetlands. Boom deployment must also include plans for monitoring and maintaining the 

protective boom systems to assure that these systems are installed and functioning properly and that they 

are not damaging the wetlands they are trying to protect. In most cases, the beach face would take the 

most oil; however, in areas where the marsh is immediately adjacent to the beach face or embayments, or 

in the case of small to severe storms, marshes would be oiled. For example, in Alabama, Mississippi, and 

Florida, severe weather could push oil into the tidal pools and back beach areas that support tidal marsh 

vegetation.

The primary factors that affect vegetation responses to oil are toxicity of the oil and extent of plant 

coverage, amount of contact with and penetration of the soil, plant species affected, oiling frequency, 

season, and cleanup activities (Mendelssohn et al., 2012). Previous studies of other large spills have 

shown that, when oil has a short residence time in the marsh and it is not incorporated into the sediments, 

the marsh vegetation has a high probability of survival, even though aboveground die-off of marsh 

vegetation may occur (Lin et al., 2002). However, if re-oiling occurs after the new shoots from an initial 

oiling are produced, such that the new shoots are killed, then the marsh plants may not have enough 

stored energy to produce a second round of new shoots. Other studies noted the utilization of dispersants 

in the proper dosages results in a reduction in marsh damage from oiling (Lin and Mendelssohn, 2009). 

The works of several investigators (Webb et al., 1981 and 1985; Alexander and Webb, 1983 and 1987; 

Lytle, 1975; Delaune et al., 1979; Fischel et al., 1989) evaluated the effects of potential spills to area 

wetlands. For wetlands along the central Louisiana coast, the critical oil concentration is assumed to be 

0.025 gallons per ft2 (1.0 liter per m2

) of marsh. Concentrations less than this may cause diebacks for one 

growing season or less, depending upon the concentration and the season during which contact occurs. 

The duration and magnitude of a spill resulting from a catastrophic blowout could result in concentrations 

above this critical level and would result in longer term effects to wetland vegetation, including some 

plant mortality and loss of land.

Due to the distance of deep water from shore, the possibility of a spill from a deepwater blowout 

reaching coastal wetlands with the toxicity to significantly impact the coastal wetlands is low because of 

the response procedures implemented during a catastrophic spill. (It is assumed that oil would reach 

shore within 2-4 weeks.) Therefore, a spill from a shallow-water blowout is more likely to contribute to 

wetland damage. However, for the few deepwater areas that are located closer to shore, such as in the 

Mississippi Canyon Area, the amount of time before shoreline contact could occur could be estimated to 

be the same as the estimate given for the shallow-water scenario, i.e., 1-3 weeks.

Offshore skimming, burning, and dispersal treatments for the oil near the spill site would result in 

capture, detoxification, and dilution of the majority of oil spilled. The utilization of nearshore booming 

protection for beaches and wetlands could also help to reduce oiling of these resources, if done correctly. 

Booms deployed adjacent to marsh shorelines can be lifted by wave action onto marsh vegetation, 

resulting in plant mortality under the displaced booms. The activity of oil cleanup can result in additional 

impacts on wetlands if not done properly. During the Deepwater Horizon explosion, oil spill, and 

response, aggressive onshore and marsh cleanup methods (such as the removal by mechanized equipment, 

in-situ burning, etc.) were not extensively utilized. The severity of oiling is the main factor that dictates 

the appropriate marsh cleanup method to be utilized (refer to Table B-4). 
Catastrophic Spill Event Analysis B-27

Phase 4—Post-Spill, Long-Term Recovery and Response

Wetlands serve a number of important ecological functions. For example, Louisiana’s coastal 

wetlands support more than two-thirds of the wintering waterfowl population of the Mississippi Flyway 

(Louisiana Department of Wildlife and Fisheries, 2012). Therefore, loss of wetlands would also impact a 

significant portion of the waterfowl population. Another important ecological function of wetlands is 

their use as a nursery for estuarine-dependent species of fish and shellfish. Wetland loss would reduce the 

available nursery habitat.

The duration and magnitude of a spill resulting from a catastrophic blowout could result in high 

concentrations of oil that would result in long-term effects to wetland vegetation, including some plant 

mortality and loss of land. Silliman et al. (2012) found that after the Macondo well blowout and spill, oil 

coverage of Louisiana salt marshes was primarily concentrated on their seaward edges. Oil-driven plant 

death on the edges of these marshes more than doubled the rates of shoreline erosion, further driving 

marsh platform loss that is likely to be permanent. Eighteen months after the Macondo well blowout and 

spill, in previously oiled, noneroded areas, marsh grasses had largely recovered, and the elevated 

shoreline retreat rates observed at oiled sites had decreased to levels at reference marsh sites. Studies of 

impacted wetlands have demonstrated that wetlands can recover from the impacts of oil spills, but the 

recovery process varies from extremely slow in mangrove swamps (Burns et al., 1993 and 1994) to 

relatively rapid in grass-dominated marshes subject to in-situ burning of oil (Baustian et al., 2010).

Land loss caused by the oiling of wetlands would add to continuing impacts of other factors, such as 

hurricanes, subsidence, saltwater intrusion, and sea-level rise. The wetlands along the Gulf Coast have 

already been severely damaged by the 2005 and 2008 hurricane seasons, leaving the mainland less 

protected. It was estimated in 2000 that coastal Louisiana would continue to lose land at a rate of 

approximately 2,672 hectares/year (10 mi2

/year) over the next 50 years. Further, it was estimated that an 

additional net loss of 132,794 hectares (512 mi2

) may occur by 2050, which is almost 10 percent of 

Louisiana’s remaining coastal wetlands (Barras et al., 2003). Barras (2006) indicated an additional 

562 km2 (217 mi2

) of land lost during the 2005 hurricane season. A catastrophic spill occurring nearshore 

would contribute further to this landloss. Following Hurricanes Katrina and Rita, another series of 

hurricanes (Gustav and Ike) made landfall along the Louisiana and Texas coasts in September 2008. 

Hurricane Gustav made landfall as a Category 2 storm near Cocodrie, Louisiana, pushing large surges of 

saline water into the fresh marshes and coastal swamps of Louisiana from Grand Isle westward. While 

Hurricane Gustav did not impact the quantity of wetlands that Hurricanes Katrina and Rita impacted, it 

did have a severe and continuing effect on the coastal barrier islands and the wetlands associated with 

backshore (back of the island) and foreshore (front of the island). While Hurricane Gustav affected the 

eastern portion of the Louisiana coast closer to Grand Isle and Houma, Hurricane Ike concentrated on 

Louisiana’s western coast. The Texas coast received the brunt of Hurricane Ike where it made landfall 

slightly east of Galveston. The storm surge heavily eroded the dune systems and significantly lowered 

the beach elevations along the eastern portion of the Texas coast near Galveston and the Bolivar 

Peninsula. The erosion and wash-over associated with Hurricane Ike’s tidal surge breeched beach ridges 

and opened the inland freshwater ponds and their associated wetlands to the sea. As a result of the four 

successive storms, the Louisiana and Texas coasts have lost protective elevations, barrier islands, and 

wetlands, and they now have the potential for transitioning to a less productive salt-marsh system in areas 

where fresh-marsh systems once existed. In addition, the loss of these protective elevations has increased 

the vulnerability of coastal wetlands to catastrophic oil-spill events.

A poorly executed oil cleanup can result in additional impacts. Aggressive onshore and marsh 

cleanup methods (such as removal by mechanized equipment, in-situ burning, marsh cutting, and foot 

entry into the marsh for manual removal) probably would not be initiated until the oil spill has been 

stopped. Depending on the marsh remediation methods used, further impacts to the wetlands may occur 

from cleanup activities. Boat traffic in marsh areas from the thousands of response vessels associated 

with a catastrophic spill would produce an incremental increase in erosion rates, sediment resuspension, 

and turbidity (i.e., an adverse but not significant impact to coastal wetland and seagrass habitats).

Overall Summary and Conclusion (Phases 1-4)

A spill from a catastrophic blowout could impact a few to several hundred square kilometers of 

wetlands depending on the depth of inland penetration (Burdeau and Collins, 2010; Mishra et al., 2012). 
B-28 Central and Eastern Planning Areas Supplemental EIS

This would vary from moderate to heavy oiling. Impacts to wetlands would vary according to the 

severity of the oiling. The duration and magnitude of the spill could result in severe oiling of wetlands in 

some areas, causing long-term effects to wetland vegetation, including some plant mortality and loss of 

land.

B.3.1.5. Seagrass Communities

Phase 1—Initial Event

There would likely be no adverse impacts to submerged vegetation as a result of the events and the 

potential impact-producing factors that could occur throughout Phase 1 of a catastrophic spill event 

because of the likely distance from the spill event to the nearest submerged vegetation beds.

Phase 2—Offshore Spill

There would likely be no adverse impacts to submerged vegetation as a result of the events and the 

potential impact-producing factors that could occur throughout Phase 2 of a catastrophic spill because of 

the likely distance from the spill event to the nearest submerged vegetation beds.

Phase 3—Onshore Contact

According to the most recent and comprehensive data available, approximately 500,000 hectares 

(1.25 million acres; 505,857 hectares) of submerged seagrass beds are estimated to exist in exposed, 

shallow coastal waters and embayments of the northern Gulf of Mexico, and over 80 percent of this area 

is in Florida Bay and Florida coastal waters (calculated from Handley et al., 2007). Submerged 

vegetation distribution and composition depend on an interrelationship among a number of environmental 

factors that include water temperature, depth, turbidity, salinity, turbulence, and substrate suitability 

(Kemp, 1989; Onuf, 1996; Short et al., 2001). Marine seagrass beds generally occur in shallow, relatively 

clear, protected waters with predominantly sand bottoms (Short et al., 2001). Freshwater submerged 

aquatic vegetation (SAV) species occur in the low-salinity waters of coastal estuaries (Castellanos and

Rozas, 2001). Seagrasses and freshwater SAVs provide important nursery and permanent habitat for 

sunfish, killifish, immature shrimp, crabs, drum, trout, flounder, and several other nekton species, and 

they provide a food source for species of wintering waterfowl and megaherbivores (Rozas and Odum, 

1988; Rooker et al., 1998; Castellanos and Rozas, 2001; Heck et al., 2003; Orth et al., 2006). Further 

detail on this catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental 

EIS and EPA 225/226 EIS. 

If oil comes into areas with submerged beds, increased water turbulence from waves, storms, or 

vessel traffic could break apart the surface oil sheen and disperse some oil into the water column or mix 

oil with sediments that would settle and coat an entire plant. Coating of the plat from the oil and sediment 

mixture would cause reduced chlorophyll production and could lead to a decrease in vegetation (Teal and 

Howarth, 1984; Burns et al., 1994; Erftemeijer and Lewis, 2006). This coating situation also happens 

when oil is treated with dispersants because the dispersants break down the oil and it sinks into the water 

column (Thorhaug et al., 1986; Runcie et al., 2004). However, as reviewed in Runcie et al. (2004), oil 

mixed with dispersants has shown an array of effects on seagrass depending on the species and dispersant 

used. With a greater distance from shore, there is a greater chance of the oil being weathered by natural 

and mechanical processes by the time it reaches the nearshore habitat.

Depending on the species and environmental factors (e.g., temperature and wave action), seagrasses 

may exhibit minimal impacts, such as localized loss of pigmentation, from a spill; however, communities 

residing within the beds could accrue greater negative outcomes (den Hartog and Jacobs, 1980; Jackson 

et al., 1989; Kenworthy et al., 1993; Taylor et al., 2006). Community effects could range from either 

direct mortality due to smothering or indirect mortality from loss of food sources and habitat to a decrease 

in ecological performance of the entire system depending on the severity and duration of the spill event 

(Zieman et al., 1984).

Prevention and cleanup efforts could also affect the health of submerged vegetation communities 

(Zieman et al., 1984). Many physical prevention methods such as booms, barrier berms, and diversions 

can alter hydrology, specifically changing salinity and water clarity. These changes would harm certain 

species of submerged vegetation because they are tolerant to specific salinities and light levels (Zieman 
Catastrophic Spill Event Analysis B-29

et al., 1984; Kenworthy and Fonseca, 1996; Frazer et al., 2006). With cleanup, there is increased boat and 

human traffic in these sensitive areas that generally are protected from this degree of human disturbance 

prior to the response. Increased vessel traffic would lead to elevated water turbidity and increased 

propeller scarring. While the elevated levels of water turbidity from vessels would be short-term and the 

possible damages from propellers could be longer, both events would be localized during the prevention 

and cleanup efforts (Zieman, 1976; Dawes et al., 1997).

Phase 4—Post-Spill, Long-Term Recovery and Response

According to the most recent and comprehensive data available, approximately 500,000 hectares 

(1.25 million acres; 505,857 hectares) of submerged seagrass beds are estimated to exist in exposed, 

shallow coastal waters and embayments of the northern Gulf of Mexico, and over 80 percent of this area 

is in Florida Bay and Florida coastal waters (calculated from Handley et al., 2007). Submerged 

vegetation distribution and composition depend on an interrelationship among a number of environmental 

factors that include water temperature, depth, turbidity, salinity, turbulence, and substrate suitability 

(Kemp, 1989; Onuf, 1996; Short et al., 2001). Seagrasses and freshwater SAVs provide important 

nursery and permanent habitat for sunfish, killifish, immature shrimp, crabs, drum, trout, flounder, and 

several other nekton species, and they provide a food source for species of wintering waterfowl and 

megaherbivores (Rozas and Odum, 1988; Rooker et al., 1998; Castellanos and Rozas, 2001; Heck et al., 

2003; Orth et al., 2006).

A source of potential long-term impacts to submerged beds from a catastrophic spill event is the 

possibility of buried or sequestered oil becoming resuspended after a disturbance, which would have 

similar effects as the original oiling event. This could occur in the event of hurricane impacts, which 

exacerbate the problem with numerous other short-terms stresses, such as turbidity, abrasion, breakage, 

uprooting SAV and seagrasses, and the alteration of bottom profiles and hydrology. Because different 

species have different levels of sensitivity to oil, it is difficult to compare studies and extrapolate what 

variables caused the documented differences in vegetation and community health (Thorhaug et al., 1986; 

Runcie et al., 2004). In general, studied seagrasses did not show significant negative effects from an oil 

spill (den Hartog and Jacobs, 1980; Kenworthy et al., 1993; Taylor et al., 2006 and 2007).

If bays and estuaries accrue oil, there is an assumption that there would be a decrease in seagrass 

cover and negative community impacts. Submerged vegetation serves important ecological functions. 

For example, seagrasses and freshwater SAVs provide important habitat and are a food source for a wide 

range of species in multiple life history stages (Castellanos and Rozas, 2001; Short and Coles, 2001; 

Caldwell, 2003). Therefore, loss of submerged vegetation would adversely impact these species with a 

loss of valuable habitat and food.

Overall Summary and Conclusion (Phases 1-4)

Because of the likely distance of an initial catastrophic spill event to submerged vegetation 

communities, there would be no adverse impacts to submerged vegetation resulting from the initial event 

(Phase 1). Also, with regards to an offshore spill event, there would likely be no adverse impacts to 

submerged vegetation before the spill reaches shore (Phase 2). An estimated probability of oil contacting 

its coastline from the CPA example OSRA run can be found in Appendix C of the CPA 235/241/247 

Supplemental EIS (Phase 3). An estimated probability of oil contacting its coastline from the EPA 

example OSRA run can be found in Appendix C of the EPA 225/226 EIS (Phase 3). It is assumed when 

these coastlines are contacted with oil, all associated habitat are considered oiled. If oil comes into areas 

with submerged beds, oil mixed with sediments or with dispersants could settle and coat an entire plant 

and could cause reduced chlorophyll production and could lead to a decrease in vegetation. Depending 

on the species and environmental factors (e.g., temperature and wave action), seagrasses may exhibit 

minimal impacts, such as localized loss of pigmentation, from an oil spill; however, communities residing 

within the beds could accrue greater negative outcomes. Increased vessel traffic from cleanup efforts 

would lead to elevated water turbidity and increased propeller scarring. A source of potential long-term 

impacts to submerged beds from a catastrophic spill event is the possibility of buried or sequestered oil 

becoming resuspended after a disturbance, which would have similar effects as the original oiling event 

(Phase 4). While there are impacts on submerged vegetation from an oiling event, the probabilities of an 

event to occur and contact coastlines are generally low and any impacts that can occur depend on a 
B-30 Central and Eastern Planning Areas Supplemental EIS

variety of factors (e.g., plant species, oil type, current environmental conditions, etc.). In general, studied 

seagrasses did not show significant negative effects from a spill (den Hartog and Jacobs, 1980; 

Kenworthy et al., 1993; Taylor et al., 2006 and 2007).

B.3.1.6. Live Bottoms (Pinnacle Trend and Low Relief)

The Gulf of Mexico has hard-bottom features upon which encrusting and epibenthic organisms attach 

on the continental shelf in water depths less than 300 m (984 ft). Live bottom features occur in the 

northeastern portion of the CPA and in the EPA. The Pinnacle Trend is located in the northeastern 

portion of the central Gulf of Mexico at the outer edge of the Mississippi-Alabama shelf between the 

Mississippi River and De Soto Canyon. Live bottom (Pinnacle Trend) features are defined in NTL 

2009-G39 as “small, isolated, low to moderate relief carbonate reefal features or outcrops of unknown 

origin or hard substrates exposed by erosion that provide area for the growth of sessile invertebrates and 

attract large numbers of fish.” Fish are attracted to outcrops that provide hard substrate for sessile 

invertebrates to attach. BOEM does not allow bottom-disturbing activities to occur within 30 m (98 ft) of 

any hard bottoms/pinnacles in 74 lease blocks in the CPA (each block is typically 3 mi x 3 mi).

Live bottom (low relief) features are defined in NTL 2009-G39 as “seagrass communities; areas that 

contain biological assemblages consisting of sessile invertebrates living upon and attached to naturally 

occurring hard or rocky formations with rough, broken, or smooth topography; and areas where hard 

substrate and vertical relief may favor the accumulation of turtles, fishes, or other fauna.” These features 

also include the reef communities like those found on the Florida Escarpment. BOEM has stipulations to 

protect these features from impacts, including bottom-disturbing activity. This chapter discusses the hard 

substrate, as seagrasses are covered in Chapter B.3.1.5. 

Phase 1—Initial Event

A blowout from an oil well could result in a catastrophic spill event. A catastrophic blowout would 

result in released oil rapidly rising to the sea surface because all known reserves in the GOM have 

specific gravity characteristics that would preclude oil from sinking immediately after release at a 

blowout site. The oil would surface almost directly over the source location. However, if the oil is 

ejected under high pressure, micro-droplets of oil may form and become entrained in the water column 

(Boehm and Fiest, 1982; Adcroft et al., 2010). The upward movement of the oil may be reduced if 

methane mixed with the oil is dissolved into the water column, reducing the oil’s buoyancy (Adcroft 

et al., 2010). Large oil droplets would rise to the sea surface, but smaller droplets, formed by vigorous 

turbulence in the plume or the injection of dispersants, may remain neutrally buoyant in the water column, 

creating a subsurface plume (Adcroft et al., 2010; Joint Analysis Group, 2010). Dispersed oil in the water 

column begins to biodegrade and may flocculate with particulate matter, promoting sinking of the 

particles. Subsea plumes or sinking oil on particulates may contact live bottom features.

A catastrophic blowout outside the well casing and below the seafloor or at the seafloor-water 

interface could resuspend large quantities of bottom sediments and create a large crater, destroying many 

organisms within a few hundred meters of the wellhead. Some fine sediment could travel up to a few 

thousand meters before redeposition, negatively impacting a localized area of benthic communities. If a 

blowout were to occur close enough to a live bottom feature, suspended sediment may impact the 

organisms living on the feature.

A catastrophic blowout that occurs above the seabed (at the rig, along the riser between the seafloor 

and sea surface, or through leak paths on the BOP/wellhead) would not disturb the sediment.

The use of subsea dispersants would increase the exposure of offshore benthic habitats to dispersed 

oil droplets in the water column, as well as the chemicals used in the dispersants. The use of subsea 

dispersants is not likely to occur for seafloor blowouts outside the well casing.

Impacts to Live Bottom Features

Impacts that occur to benthic organisms on live bottom features as a result of a blowout would depend 

on the type of blowout, distance from the blowout, relief of the biological feature, and surrounding 

physical characteristics of the environment (e.g., turbidity). The distancing of bottom-disturbing activities 

from Pinnacle and live bottom, low-relief features helps to prevent blowouts in the immediate vicinity of 

a live bottom feature or its associated biota. Much of the oil released from a blowout would rise to the sea 
Catastrophic Spill Event Analysis B-31

surface, therefore minimizing the impact to benthic communities by direct oil exposure. However, small 

droplets of oil that are entrained in the water column for extended periods of time may migrate into areas 

that have live bottom features. Although these small oil droplets will not sink themselves, they may 

attach to suspended particles in the water column and then be deposited on the seafloor (McAuliffe et al., 

1975). The resultant long-term impacts, such as reduced recruitment success, reduced growth, and 

reduced coral or other epibenthic cover, as a result of impaired recruitment, are discussed in Phase 4 

(“Post-Spill, Long-Term Recovery and Response”). Also, if the blowout were to occur beneath the 

seabed, suspension and subsequent deposition of disturbed sediment may smother localized areas of live 

bottom communities.

Following a catastrophic, subsurface blowout, benthic communities on a live bottoms exposed to 

large amounts of resuspended and then deposited sediments could be subject to sediment suffocation, 

exposure to resuspended toxic contaminants and to reduced light availability. Impacts to fauna found on 

hard bottoms as a result of sedimentation would vary based on species, the height to which the organism 

grows, degree of sedimentation, length of exposure, burial depth, and the organism’s ability to clear the 

sediment. Impacts may range from sublethal effects (such as reduced or slower growth, alteration in 

form, and reduced recruitment and productivity) to suffocation and death (Rogers, 1990; Fucik et al., 

1980).

The initial blowout impact would be greatest to communities located in clear waters that experience 

heavy sedimentation. The most sensitive organisms are typically elevated above soft sediments, making 

them less likely to be buried, and it is unlikely that corals would experience heavy sedimentation because 

they are located within Live Bottom (Low Relief) Stipulation blocks that distance bottom-disturbing 

activity from the features. None of the Live Bottom Stipulation blocks were included in the current 

proposed lease sale, farther distancing oil and gas activity from live bottoms. In addition, BOEM 

conducts case-by-case reviews of plans submitted by operators to ensure that the proposed activity will 

not impact sensitive seafloor features. It is possible, however, for some live bottoms to experience some 

turbidity or sedimentation impacts from a blowout if they are downstream of a current transporting 

sediment. Corals may experience discoloration or bleaching as a result of sediment exposure, although 

recovery from such exposure may occur within 1 month (Wesseling et al., 1999).

Initial impacts would be much less extreme in a turbid environment (Rogers, 1990). For example, the 

Pinnacle Trend community exists in a relatively turbid environment, starting just 65 km (37 mi) east of 

the mouth of the Mississippi River and trending to the northeast, and many low-relief live bottoms are 

frequently covered with a thin sand veneer that moves with waves and bottom currents, exposing and 

covering up areas with movement (Phillips et al., 1990; Gittings et al., 1992). Sediment from a blowout, 

if it occurred nearby, may have a reduced impact on these communities compared with an open-water reef 

community, as these organisms are more tolerant of suspended sediment (Gittings et al., 1992). Many of 

the organisms that predominate in this community also grow tall enough to withstand the sedimentation 

that results from their turbid environment or have flexible structures that enable the passive removal of 

sediments (Gittings et al., 1992). Those organisms that have a lesser relief could experience 

sedimentation, abrasion, and suffocation. However, many organisms present in the lower relief, live 

bottom habitat are motile, can burrow in the sediment, or have mechanisms for dealing with turbidity and 

can be tolerant of short-term high turbidity events. For example, bivalves can reduce their filtration rates 

if the suspended sediment concentrations become elevated and can reject excess sediment through 

pseudofeces (Clarke and Wilber, 2000). Many crustaceans are able to tolerate high levels of suspended 

sediment; for example, crabs and shrimp spend a portion of their lives in estuaries and nearshore waters 

that are turbid (Wilber et al., 2005). These organisms are also able to move away from turbid areas that 

have sediment concentrations that become too high (Clarke and Wilber, 2000; Wilber et al., 2005). 

Oysters, on the other hand, are not able to move away from turbidity, but they are tolerant of this 

environmental factor as they tend to live near the mouths of rivers that deposit sediment into their habitat 

(Wilber et al., 2005). Many of these organisms can also rapidly repopulate an area affected by 

sedimentation (Fucik et al., 1980).

A portion or the entire rig may sink to the seafloor as a result of a blowout. The benthic features and 

communities upon which the rig settles would be destroyed or smothered. Encrusting organisms would 

be crushed by a rig if it lands on a live bottom feature. A settling rig may suspend sediments, which may 

smother nearby benthic communities if the sediment is redeposited on sensitive features. The habitats 

beneath the rig may be permanently lost; however, the rig itself may become an artificial reef upon which 

epibenthic organisms may settle. The surrounding benthic communities that were smothered by sediment 
B-32 Central and Eastern Planning Areas Supplemental EIS

would repopulate from nearby stocks through spawning recruitment and immigration if the hard substrate 

upon which they live was not physically destroyed. Destruction of a live bottom community by a sinking 

rig is highly unlikely because BOEM requires infrastructure to be distanced from live bottoms.

Phase 2—Offshore Spill

A spill from a shallow-water blowout could impact benthic communities on the continental shelf 

because of the blowout’s proximity to these habitats. The scenario (Table B-4) for a catastrophic spill on 

the continental shelf is assumed to last 2-5 months and to release 30,000 bbl per day. A total volume of 

0.9-3.0 MMbbl of South Louisiana midrange paraffinic sweet crude oil could be released, which will float 

(APIo >10). An anticipated 35,000 bbl of dispersant may be applied to the surface waters.

A spill from a deepwater blowout could also impact shelf communities if surface oil is transported to 

these areas. The scenario (Table B-4) for a catastrophic spill in deep water is assumed to last 4-6 months 

and to release 30,000-60,000 bbl per day. A total volume of 2.7-7.2 MMbbl of South Louisiana midrange 

paraffinic sweet crude oil will be released, which will float (APIo >10). Oil properties may change as it 

passes up the well and through the water column, and it may become emulsified. An anticipated 

33,000 bbl of dispersant may be applied to the surface waters and 16,500 bbl may be applied subsea. 

Weathering and dilution of the oil will also occur as it travels from its release point. It is unlikely that a 

subsurface plume from a deepwater blowout would impact shelf communities. The oil is anticipated to 

remain in deep water and to be directed by water currents in the deep water. These currents do not 

typically transit from deep water up onto the shelf (Pond and Pickard, 1983; Inoue et al., 2008).

Impacts to Live Bottom Features

Impacts from Surface Oil

Sensitive live bottom communities can flourish on hard bottoms in the Gulf of Mexico. The eastern 

Gulf of Mexico contains scattered, low-relief live bottoms, including areas of flat limestone shelf rock 

and the Pinnacle Trend area, located on the Mississippi Alabama continental shelf, which includes lowand high-relief features that are 60-120 m (197-394 ft) below the sea surface. The depth at which 

Pinnacles and most live bottom, low-relief features flourish below the sea surface helps to protect these 

habitats from a surface oil spill. Rough seas may mix the oil into subsurface water layers, where it may 

impact sessile biota. The longer the seas are rough, the greater the amount of oil from a surface slick 

would be mixed into the water column. Measurable amounts of oil have been documented to mix from 

the surface down to a 10-m (33-ft) depth, although modeling exercises have indicated such oil may reach 

a depth of 20 m (66 ft). At this depth, however, the oil is found at concentrations several orders of 

magnitude lower than the amount shown to have an effect on corals and other benthic organisms (Lange, 

1985; McAuliffe et al., 1975 and 1981a; Knap et al., 1985; Scarlett et al., 2005; Hemmer et al., 2010; 

George-Ares and Clark, 2000). Low-relief, live bottom habitats located in shallow coastal water may be 

at greater risk of surface oil mixing to the depth where their active growth occurs; however, because oil 

and gas activities currently take place far from the coastlines where nearshore live bottoms are located, 

the surface oil will be well dispersed and diluted by the time it reaches waters above the shallow live 

bottoms. Further detail on this catastrophic OSRA run is contained in Appendix C of the CPA 

235/241/247 Supplemental EIS and EPA 225/226 EIS. 

Impacts from Subsurface Oil

The presence of a subsurface oil plume on the continental shelf from a shallow-water blowout may 

affect benthic communities on live bottom features. A majority of oil released is expected to rise rapidly 

to the sea surface above the release point because of the specific gravity characteristics of the oil reserves 

in the GOM, thus not impacting sensitive benthic communities. If oil is ejected under high pressure, oil 

droplets may become entrained in the water column (Boehm and Fiest, 1982; Adcroft et al., 2010). The 

upward movement of the oil may be reduced if methane mixed with the oil is dissolved into the water 

column, reducing the oil’s buoyancy (Adcroft et al., 2010). Large oil droplets would rise to the sea 

surface, but smaller droplets, formed by vigorous turbulence in the plume or the injection of dispersants, 

may remain neutrally buoyant in the water column, creating a subsurface plume (Adcroft et al., 2010; 

Joint Analysis Group, 2010). Dispersed oil in the water column begins to biodegrade and may flocculate 
Catastrophic Spill Event Analysis B-33

with particulate matter, promoting sinking of the particles. Subsurface plumes generated by high-pressure 

dissolution of oil may come in contact with live bottom habitats. A sustained spill would continuously 

create surface slicks and possibly subsurface spill plumes. Some of the oil in the water column will 

become diluted or evaporated over time, reducing any localized transport to the seafloor (Vandermeulen, 

1982). In addition, microbial degradation of the oil occurs in the water column so that the oil would be 

less toxic as it travels from the source (Hazen et al., 2010). However, a sustained spill may result in 

elevated exposure concentrations to benthic communities if the plume reaches them. The longer the spill 

takes to stop, the longer the exposure time and the higher the exposure concentration may be.

Live bottom, low-relief features have a greater chance of being impacted by subsea plumes than some 

Pinnacle features because currents may sweep around the larger features, as they do with topographic 

features (Rezak et al., 1983; McGrail, 1982). The lower relief live bottoms (including low-relief features 

in the Pinnacle Trend) may fall in the path of the plume because the feature is not large enough to divert a 

current. Low-level exposures of organisms to oil from a subsea plume may result in chronic or temporary 

impacts. For example, feeding activity or reproductive ability may be reduced when coral is exposed to 

low levels of oil; however, impacts may be temporary or unable to be measured over time. Experiments 

indicated that oil exposure reduced the normal feeding activity of coral, and oiled reefs produced smaller 

gonads than unoiled reefs, resulting in reproductive stress (Lewis, 1971; Guzmán and Holst, 1993). In 

addition, photosynthesis and growth may be reduced with oil exposure, and petroleum may be 

incorporated into coral tissue (Cook and Knap, 1983; Dodge et al., 1984; Burns and Knap, 1989; Knap 

et al., 1982; Kennedy et al., 1992). Sublethal responses of other marine invertebrates on live bottoms may 

result in population level changes (Suchanek, 1993) at concentrations as low as 1-10 ppb (Hyland and 

Schneider, 1976). Sublethal impacts may include reduced feeding rates, reduced ability to detect food, 

erratic movement, ciliary inhibition, tentacle retraction, reduced movement, decreased aggression, and 

altered respiration (Scarlett et al., 2005; Suchanek, 1993). Embryonic life stages of benthic organisms 

may experience toxic effects at lower levels than adult stages (Fucik et al., 1995; Suchanek, 1993; Beiras 

and Saco-Álvarez, 2006; Byrne, 1989). 

It is unlikely that a subsurface plume from a deepwater blowout would impact live bottom shelf 

communities. The oil is anticipated to remain in deep water and be directed by water currents in the deep 

water. These currents do not typically transit from deep water up onto the shelf (Pond and Pickard, 1983; 

Inoue et al., 2008).

Impacts from Dispersed Oil

If dispersants are used at the sea surface, oil may mix into the water column. If applied subsea, they 

can travel with currents through the water, and they may contact or settle on sensitive features. Note that, 

as indicated above, a deepwater plume would not travel onto the continental shelf, but a plume formed on 

the continental shelf could impact live bottom features. If near the source, the dispersed oil could be 

concentrated enough to harm the community. If the oil remains suspended for a longer period of time, it 

would be more dispersed and present at lower concentrations. Reports on dispersant usage on surface oil 

indicate that a majority of the dispersed oil remains in the top 10 m (33 ft) of the water column, with 

60 percent of the oil in the top 2 m (6 ft) (McAuliffe et al., 1981a). Dispersant usage also reduces the 

oil’s ability to stick to particles in the water column, minimizing oil adhering to sediments and traveling 

to the seafloor (McAuliffe et al., 1981a). There is very little information on the mixing and dispersion of 

subsea dispersants.

Dispersed oil reaching live bottoms in the Gulf of Mexico would be expected to occur at very low 

concentrations (<1 part per million [ppm]) (McAuliffe et al., 1981a). Such concentrations would not be 

life threatening to larval or adult stages at this depth below the sea surface based on experiments 

conducted with benthic organisms. Any dispersed oil in the water column that comes in contact with live 

bottoms may evoke short-term negative responses by the organisms (Wyers et al., 1986; Cook and Knap, 

1983; Dodge et al., 1984; Scarlett et al., 2005; Renzoni, 1973).

The impact of dispersants on benthic organisms is dependent on the dispersant used, length of 

exposure, and the physical barriers the organism has to protect itself from the dispersant. Organisms with 

shells appear to be more tolerant of dispersants than those with only a tissue barrier (Scarlett et al., 2005). 

In addition, organisms that produce mucus, such as coral, have an elevated tolerance for oil exposure 

(Mitchell and Chet, 1975; Ducklow and Mitchell, 1979). Concentrations of 100 ppm and 1,000 ppm oil 

plus dispersant in a ratio of 4:1 were necessary for oyster and mussel fertilization and development to 
B-34 Central and Eastern Planning Areas Supplemental EIS

become reduced when the larvae was exposed to the mixture (Renzoni, 1973). After 48 hours of 

exposure to dispersants, the blue mussel (Mytilus edulis) died at dispersant concentrations of 250 ppm, 

although reduced feeding rates were observed at 50 ppm (Scarlett et al., 2005). The snakelocks anemone 

(Anemonia viridis), which does not have a protective shell, was much more sensitive to dispersants. It 

retracted its tentacles and failed to respond to stimuli after 48 hours of exposure to 40 ppm dispersant 

(Scarlett et al., 2005). Corals exposed to dispersed oil showed mesenterial filament extrusion, extreme 

tissue contraction, tentacle retraction, localized tissue rupture, and reduced photosynthesis (Wyers et al., 

1986; Cook and Knap, 1983). Respiratory damage to organisms does not appear to be reversible; 

however, if the exposure is short enough, nervous system damage may be reversed and organisms may 

recover (Scarlett et al., 2005). Experiments using both anemones and corals showed recovery after 

exposure to dispersants (Scarlett et al., 2005; Wyers et al., 1986). 

Concentrations used in historical experiments are generally much higher than the exposure that would 

occur in the field (Renzoni, 1973; George-Ares and Clark, 2000). Although historical experiments seem 

to indicate that the toxicity of oil increases with the addition of the dispersant, the toxicity of the oil 

actually remains the same as it was when it was not dispersed, but exposure increases due to the dispersed 

components of the oil (George-Ares and Clark, 2000). However, the increase of oil into the water column 

with the addition of dispersants is temporary, as the dispersed oil is more easily diluted with the 

surrounding water and biodegraded by bacteria (George-Ares and Clark, 2000). Therefore, concentrated 

dispersants are not anticipated to reach live bottoms, and any impacts that do occur should be sublethal 

and temporary.

Impacts from Oil Adhering to Sediments

BOEM’s policy, described in NTL 2009-G39, prevents wells from being placed immediately adjacent 

to sensitive communities. In the event of a seafloor blowout, however, some oil could be carried to live 

bottoms as a result of oil droplets adhering to suspended particles in the water column. Oiled sediment 

that settles to the seafloor may affect organisms attached to hard-bottom substrates. Impacts may include 

reduced recruitment success, reduced growth, and reduced benthic cover as a result of impaired 

recruitment. Experiments have shown that the presence of oil on available substrate for larval coral 

settlement has inhibited larval metamorphosis and larval settlement in the area. Oil exposure also 

increased the number of deformed polyps after metamorphosis occurred (Kushmaro et al., 1997). In 

addition, exposure to oiled sediment has also been shown to reduce the growth rate of clams (Dow, 1975).

The majority of organisms exposed to sedimented oil, however, are anticipated to experience lowlevel concentrations because as oiled sediments settle to the seafloor they become widely dispersed. 

Many organisms on live bottoms will be able to protect themselves from low levels of oiled sediment that 

may settle out of the water column. Organisms with shells will not experience direct contact with the oil, 

and mobile organisms will be able to move away from areas where oiled sediment has accumulated. 

Coral may also be able to protect itself from low concentrations of sedimented oil that settles from the 

water column through mucus that will not only act as a barrier to protect coral from the oil in the water 

column but which also been shown to aid in the removal of oiled sediment on coral surfaces (Bak and 

Elgershuizen, 1976). In addition, because many organisms in live bottom habitats are tolerant of turbidity 

and sedimentation, slight addition of sediment to the area should not impact survival.

Impacts from Oil-Spill Response Activity

Oil-spill-response activity may also impact sessile benthic features. Booms anchored to the seafloor 

are sometimes used to control the movement of oil at the water surface. Boom anchors can physically 

impact sessile benthic organisms, especially when booms are moved around by waves (USDOC, NOAA, 

2010d). Vessel anchorage and decontamination stations set up during response efforts may also break or 

kill live bottoms that have unmapped locations if anchors are set on the habitat. Injury to live bottom 

habitat as a result of anchor impact may result in long-lasting damage or failed recovery. Effort should be 

made to keep vessel anchorage areas as far from sensitive benthic features as possible to minimize 

impact.

Drilling muds comprised primarily of barite may be pumped into a well to stop a blowout. If a “kill” 

is not successful, the mud (possibly tens of thousands of barrels) may be forced out of the well and 

deposited on the seafloor near the well site. Any organisms beneath the extruded drilling mud would be 
Catastrophic Spill Event Analysis B-35

buried. Based on stipulations as described in NTL 2009-G39, a well should be far enough away from a 

Pinnacle feature to prevent extruded drilling muds from smothering sensitive benthic communities. 

However, if drilling muds were to travel far enough or high enough in the water column to contact a 

sensitive community, the fluid would smother the existing community. Burial may lead to the elimination 

of a live bottom community.

Phase 3—Onshore Contact

There would likely be no adverse impacts to live bottom features as a result of the events and the 

potential impact-producing factors that could occur throughout Phase 3 of a catastrophic spill because the 

live bottom features are located offshore.

Phase 4—Post-Spill, Long-Term Recovery and Response

Live bottoms exposed to large amounts of resuspended sediments following a catastrophic, 

subsurface blowout could be subject to sediment suffocation, exposure to resuspended toxic 

contaminants, and reduced light penetration. The greatest impacts would occur to communities that exist 

in clear water with very low turbidity, such as the live bottoms off Florida. The consequences of a 

blowout near one of these features could be long lasting, although the occurrence of a blowout near such 

sensitive communities is unlikely because of stipulations described in NTL 2009-G39, which distances 

bottom-disturbing activity from live bottom features. In addition, BOEM conducts case-by-case reviews 

of submitted plans and pipelines so that sensitive seafloor habitat is avoided. Impacts to a community in 

more turbid waters, such as those on the Mississippi-Alabama Shelf, would be greatly reduced, as the 

species are tolerant of suspended sediments, and recovery would occur quicker. Recovery time from 

sediment exposure would depend on the amount of sediment an organism was exposed to, if an entire 

population was demolished, and the extent of the loss.

Impacts may also occur from low-level or long-term oil exposure. This type of exposure has the 

potential to impact live bottom communities, resulting in impaired health. Long-term impacts such as 

reduced recruitment success, reduced growth, and reduced organism cover as a result of impaired 

recruitment may occur. Recovery may be fairly rapid from brief, low-level exposures, but it could be 

much longer if acute concentrations of oil contact organisms. Recovery time would then depend on 

recruitment from outside populations that were not affected by oiling.

Overall Summary and Conclusion (Phases 1-4)

A catastrophic spill on the continental shelf would have a greater impact on live bottom features than 

a deepwater spill. Surface oil from a deepwater spill would be weathered and diluted by the time it 

reaches the surface waters over live bottom features (if it ever reaches them), and it would be unlikely, 

except in shallow coastal waters, that it would mix to the depth of the live bottoms in concentrations that 

could cause toxicity. Subsea plumes formed in deep water would not travel onto the continental shelf 

because deep-sea currents do not travel up a slope.

A catastrophic blowout and spill on the continental shelf has a greater chance to impact live bottom 

features. If a blowout on the continental shelf occurs close enough to sensitive features, the organisms 

may be smothered by settling sediment that is displaced by the blowout. The farther a feature is from the 

blowout, the lower its chance of being covered with settling sediment or sediment upon which oil 

adhered. The distancing of oil and gas activity from live bottom features helps to prevent heavy 

sedimentation, as well as features being crushed by a sinking rig.

In most cases, the impacts from oil would be sublethal. Surface oil is not expected to mix to the zone 

of active growth, and any oil components that do reach that depth would be at sublethal concentrations. 

Subsea plumes may contact the live bottom features; however, because currents tend to travel around 

instead of over large seafloor features, the Pinnacle features should be protected from subsea plumes, 

while lower relief live bottoms may be impacted. The current oil and gas activity in the GOM, however, 

is distanced from low-relief live bottoms because no live bottom, low-relief blocks have been leased with 

the current proposed lease sales. Overall impacts of dispersed oil would be similar to subsea plumes. 

Spill response activity may impact low-relief, live bottom features if they are unmarked on nautical charts 

and vessels anchor on the features, but it is doubtful that a vessel would anchor on a marked Pinnacle 

feature.
B-36 Central and Eastern Planning Areas Supplemental EIS

Overall, a catastrophic spill would have a fairly low probability of impacting live bottom features 

because the bottom-disturbing activities of oil and gas activities are distanced from live bottom features 

within the Live Bottom Stipulation blocks, as described in NTL 2009-G39, and because BOEM conducts 

a case-by-case review of all plans to ensure that activities do not impact these seafloor features. In 

addition, the Live Bottom Stipulation blocks have not been leased as part of these proposed lease sales, 

creating farther distance between oil and gas activities and live bottoms. Also, live bottom features are 

protected by the limited mixing depth of surface oil compared with the depth of the live bottom features, 

currents sweeping around larger features, and the weathering and dispersion of oil that would occur with 

distance from the source as it travels toward the features. Low-relief features could have impacts from a 

blowout as their relief would not divert currents. In addition, the locations of these features are not all 

known so accidental anchor impacts may result in breakage of the features and possibly destruction. 

These low-relief features, however, would be protected by the regulated distance of current oil and gas 

activities, which increases the chance of oil becoming well dispersed before it reaches the features.

B.3.1.7. Topographic Features

The Gulf of Mexico has a series of topographic features (banks or seamounts) on the continental shelf 

in water depths less than 300 m (984 ft). Topographic features are isolated areas of moderate to high 

relief that provide habitat for hard-bottom communities of high biomass and moderate diversity. These 

features support prolific algae, invertebrate, and fish communities, and they provide shelter and food for 

large numbers of commercially and recreationally important fish. There are 37 named topographic 

features in the Gulf of Mexico with specific BOEM protections, including the Flower Garden Banks. 

BOEM has created “No Activity Zones” around topographic features in order to protect these habitats 

from disruption by oil and gas activities. A “No Activity Zone” is a protective perimeter drawn around 

each feature that is associated with a specific isobath (depth contour) surrounding the feature in which 

structures, drilling rigs, pipelines, and anchoring are not allowed. These “No Activity Zones” are areas 

where activity is prohibited based on BOEM’s policy. NTL 2009-G39 recommends that drilling should 

not occur within 152 m (500 ft) of a “No Activity Zone” of a topographic feature.

Potentially sensitive biological features (PSBFs) are features that have moderate to high relief (8 ft 

[2 m] or higher), provide hard surface for sessile invertebrates, and attract fish, but they are not located 

within the “No Activity Zone” of topographic features. These features are frequently located near 

topographic features. No bottom-disturbing activities that may cause impact to these features are 

permitted.

Phase 1—Initial Event

A blowout from an oil well could result in a catastrophic spill event. A catastrophic blowout would 

result in released oil rapidly rising to the sea surface because all known reserves in the GOM have 

specific gravity characteristics that would preclude oil from sinking immediately after release at a 

blowout site. The oil would surface almost directly over the source location. However, if the oil is 

ejected under high pressure, micro-droplets of oil may form and become entrained in the water column 

(Boehm and Fiest, 1982; Adcroft et al., 2010). The upward movement of the oil may be reduced if 

methane mixed with the oil is dissolved into the water column, reducing the oil’s buoyancy and slowing 

its rise to the surface (Adcroft et al., 2010). Large oil droplets would rise to the sea surface, but smaller 

droplets, formed by vigorous turbulence in the plume or the injection of dispersants, may remain neutrally 

buoyant in the water column, creating a subsurface plume (Adcroft et al., 2010; Joint Analysis Group, 

2010). Dispersed oil in the water column begins to biodegrade and may flocculate with particulate 

matter, promoting sinking of the particles. Subsea plumes or sinking oil on particulates may contact 

topographic features.

A catastrophic blowout outside the well casing and below the seafloor or at the seafloor-water 

interface could resuspend large quantities of bottom sediments and create a large crater, destroying many 

organisms within a few hundred meters of the wellhead. Fine sediment could travel up to a few thousand 

meters before redeposition, negatively impacting a localized area of benthic communities. If a blowout 

were to occur near a topographic feature, suspended sediment may impact the organisms living on the 

lower levels of the topographic feature (since water currents flow around the banks rather than traveling 

uphill).
Catastrophic Spill Event Analysis B-37

A catastrophic blowout that occurs above the seabed (at the rig, along the riser between the seafloor 

and sea surface, or through leak paths on the BOP/wellhead) would not disturb the sediment.

The use of subsea dispersants would increase the exposure of offshore benthic habitats to dispersed 

oil droplets in the water column, as well as the chemicals used in the dispersants. The use of subsea 

dispersants is not likely to occur for seafloor blowouts outside the well casing.

Impacts to Topographic Features

Impacts that occur to benthic organisms on topographic features as a result of a blowout would 

depend on the type of blowout, distance from the blowout, relief of the biological feature, and 

surrounding physical characteristics of the environment (e.g., turbidity). The NTL 2009-G39 

recommends the use of buffers to prevent blowouts in the immediate vicinity of a topographic feature or 

its associated biota. Much of the oil released from a blowout would rise to the sea surface, therefore 

minimizing the impact to benthic communities by direct oil exposure. However, small droplets of oil that 

are entrained in the water column for extended periods of time may migrate into No Activity Zones that 

surround the topographic feature. In addition, they may come in contact with PSBFs. Although these 

small oil droplets will not sink themselves, they may attach to suspended particles in the water column 

and then be deposited on the seafloor (McAuliffe et al., 1975). The resultant long-term impacts, such as 

reduced recruitment success, reduced growth, and reduced coral cover as a result of impaired recruitment, 

are discussed in Phase 4 (Post-Spill, Long-Term Recovery and Response). Also, if the blowout were to 

occur beneath the seabed, suspension and subsequent deposition of disturbed sediment may smother 

localized areas of benthic communities, possibly including organisms within No Activity Zones or on 

PSBFs.

Benthic communities on a topographic feature or PSBF exposed to large amounts of resuspended and 

deposited sediments following a catastrophic, subsurface blowout could be subject to sediment 

suffocation, exposure to resuspended toxic contaminants, and reduced light availability. Impacts to corals 

as a result of sedimentation would vary based on coral species, the height to which the coral grows, 

degree of sedimentation, length of exposure, burial depth, and the coral’s ability to clear the sediment. 

Impacts may range from sublethal effects such as reduced growth, alteration in form, and reduced 

recruitment and productivity to slower growth or death (Rogers, 1990). Corals may also experience 

discoloration or bleaching as a result of sediment exposure, although recovery from such exposure may 

occur within 1 month (Wesseling et al., 1999).

The initial blowout impact would be greatest to communities located in clear waters with little 

suspended sediment that experience heavy sedimentation as a result of the blowout. Reef-building corals 

are sensitive to turbidity and may be killed by heavy sedimentation (Rogers, 1990; Rice and Hunter, 

1992). However, it is unlikely that reef-building corals would experience heavy sedimentation as a result 

of a blowout because drilling activity is not allowed near sensitive organisms in the No Activity Zones 

based on the lease stipulations as described in NTL 2009-G39. The most sensitive organisms are also 

typically elevated above soft sediments, making them less likely to be buried. The lower levels of 

topographic banks and the PSBFs, which are generally small features with only a few meters of relief, 

typically experience turbid conditions. Vigorous bottom currents (often generated by storms) frequently 

resuspend bottom sediments and bathe these features in turbid waters, which results in sedimentation. As 

a result, the organisms that live in this environment near the seafloor are those adapted to frequent 

sedimentation.

Initial impacts would be much less extreme in a turbid environment (Rogers, 1990). For example, the 

South Texas Banks exist in a relatively turbid environment (the Nepheloid Zone). They generally have 

lower relief than the farther offshore banks at the shelf edge, may have a sediment cover, and exhibit 

reduced biota. Sediment from a blowout, if it occurred nearby, may have a reduced impact on these 

communities compared with an open-water reef community, as these organisms are more tolerant of 

suspended sediment (Gittings et al., 1992). Many of the organisms that predominate in this community 

also grow tall enough to withstand the sedimentation that results from their turbid environment or have 

flexible structures that enable the passive removal of sediments (Gittings et al., 1992).

A portion or the entire rig may sink to the seafloor as a result of a blowout. The benthic features and 

communities upon which the rig settles would be destroyed or smothered. Encrusting organisms would 

be crushed by a rig if it lands on a topographic feature or PSBF. A settling rig may suspend sediments, 

which may smother nearby benthic communities if the sediment is redeposited on sensitive features. The 
B-38 Central and Eastern Planning Areas Supplemental EIS

habitats beneath the rig may be permanently lost; however, the rig itself may become an artificial reef 

upon which epibenthic organisms may settle. The surrounding benthic communities that were smothered 

by sediment would repopulate from nearby stocks through spawning recruitment and immigration if the 

hard substrate upon which they live was not physically destroyed.

Phase 2—Offshore Spill

A spill from a shallow-water blowout could impact benthic communities on the continental shelf 

because of the blowout’s proximity to these habitats. The scenario (Table B-4) for a catastrophic spill on 

the continental shelf is assumed to last 2-5 months and to release 30,000 bbl per day. A total volume of 

0.9-3.0 MMbbl of South Louisiana midrange paraffinic sweet crude oil could be released, which will float 

(APIo >10). An anticipated 35,000 bbl of dispersant may be applied to the surface waters.

A spill from a deepwater blowout could also impact shelf communities if surface oil is transported to 

these areas. The scenario (Table B-4) for a catastrophic spill in deep water is assumed to last 4-6 months 

and to release 30,000-60,000 bbl per day. A total volume of 2.7-7.2 MMbbl of South Louisiana midrange 

paraffinic sweet crude oil will be released, which will float (APIo >10). Oil properties may change as it 

passes up the well and through the water column, and it may become emulsified. An anticipated 

33,000 bbl of dispersant may be applied to the surface waters and 16,500 bbl may be applied subsea. 

Weathering and dilution of the oil will also occur as it travels from its release point. It is unlikely that a 

subsurface plume from a deepwater blowout would impact shelf communities. The oil is anticipated to 

remain in deep water and be directed by water currents in the deep water. These currents do not typically 

transit from deep water up onto the shelf (Pond and Pickard, 1983; Inoue et al., 2008).

Impacts to Topographic Features

Impacts from Surface Oil

Sensitive reef communities flourish on topographic features and PSBFs in the Gulf of Mexico. Their 

depth below the sea surface helps to protect these habitats from a surface oil spill. Rough seas may mix 

the oil into subsurface water layers, where it may impact sessile biota. The longer the amount of time the 

seas are rough, the greater the amount of oil from a surface slick would be mixed into the water column. 

Measurable amounts of oil have been documented to mix from the surface down to a 10-m (33-ft) water 

depth, although modeling exercises have indicated such oil may reach a water depth of 20 m (66 ft). At 

this depth, however, the oil is found at concentrations several orders of magnitude lower than the amount 

shown to have an effect on corals (Lange, 1985; McAuliffe et al., 1975 and 1981a; Knap et al., 1985). 

None of the topographic features or PSBFs in the GOM are shallower than 10 m (33 ft), and only the 

Flower Garden Banks are shallower than 20 m (66 ft). Further detail on this catastrophic OSRA run is 

contained in Appendix C of the CPA 233/241/247 Supplemental EIS and EPA 225/226 EIS. 

Impacts from Subsurface Oil

The presence of a subsurface oil plume on the continental shelf from a shallow-water blowout may 

affect benthic communities on topographic features and PSBFs. A majority of the oil released is expected 

to rise rapidly to the sea surface above the release point because of the specific gravity characteristics of 

the oil reserves in the GOM, thus not impacting sensitive benthic communities. If the oil is ejected under 

high pressure, oil droplets may become entrained in the water column (Boehm and Fiest, 1982; Adcroft et 

al., 2010). The upward movement of the oil may be reduced if methane mixed with the oil is dissolved 

into the water column, reducing the oil’s buoyancy and slowing its rise to the surface (Adcroft et al., 

2010). Large oil droplets would rise to the sea surface, but smaller droplets, formed by vigorous 

turbulence in the plume or the injection of dispersants, may remain neutrally buoyant in the water column, 

creating a subsurface plume (Adcroft et al., 2010; Joint Analysis Group, 2010). Dispersed oil in the water 

column begins to biodegrade and may flocculate with particulate matter, promoting sinking of the 

particles. Subsurface plumes generated by high-pressure dissolution of oil may come in contact with 

topographic features and PSBFs. A sustained spill would continuously create surface slicks and possibly 

subsurface spill plumes. Some of the oil in the water column will become diluted or evaporated over 

time, reducing any localized transport to the seafloor (Vandermeulen, 1982). In addition, microbial 

degradation of the oil occurs in the water column so that the oil would be less toxic as it travels from the 
Catastrophic Spill Event Analysis B-39

source (Hazen et al., 2010). However, a sustained spill may result in elevated exposure concentrations to 

benthic communities if the plume reaches them. The longer the spill takes to stop, the longer the 

exposure time and higher the exposure concentration may be.

The PSBFs have a greater chance of being impacted by subsea plumes than topographic features 

because currents tend to sweep around topographic features (Rezak et al., 1983; McGrail, 1982). The 

lower relief PSBFs may fall in the path of the plume because the feature is not large enough to divert a 

current. Low-level exposures of corals to oil from a subsea plume may result in chronic or temporary 

impacts. For example, feeding activity or reproductive ability may be reduced when coral is exposed to 

low levels of oil; however, impacts may be temporary or unable to be measured over time. Experimental 

simulations of exposure indicated that normal feeding activity of Porites porites and Madracis asperula

were reduced when exposed to 50 ppm oil (Lewis, 1971). In addition, reefs of Siderastrea siderea that 

were oiled in a spill produced smaller gonads than unoiled reefs, resulting in reproductive stress (Guzmán 

and Holst, 1993).

Elevated concentrations of oil may be necessary to measure reduced photosynthesis or growth in 

corals. Photosynthesis of the zooxanthellae in Diplora strigosa exposed to approximately 18-20 ppm 

crude oil for 8 hours was not measurably affected, although other experiments indicate that 

photosynthesis may be impaired at higher concentrations (Cook and Knap, 1983). Measurable growth of 

Diploria strigosa exposed to oil concentrations up to 50 ppm for 6-24 hours did not show any reduced 

growth after 1 year (Dodge et al., 1984).

Corals exposed to subsea oil plumes may incorporate petroleum hydrocarbons into their tissue. 

Records indicate that Siderastrea siderea, Diploria strigosa, and Montastrea annularis accumulate oil 

from the water column and incorporate petroleum hydrocarbons into their tissues (Burns and Knap, 1989; 

Knap et al., 1982; Kennedy et al., 1992). Most of the petroleum hydrocarbons are incorporated into the 

coral tissues, not their mucus (Knap et al., 1982). However, hydrocarbon uptake may also modify lipid 

ratios of coral (Burns and Knap, 1989). If lipid ratios are modified, mucus synthesis may be impacted, 

adversely affecting the coral’s ability to protect itself from oil through mucus production (Burns and 

Knap, 1989).

It is unlikely that a subsurface plume from a deepwater blowout would impact shelf communities. 

The oil is anticipated to remain in deep water and be directed by water currents in the deep water. These 

currents do not typically transit from deep water up onto the shelf (Pond and Pickard, 1983; Inoue et al., 

2008).

Impacts from Dispersed Oil

If dispersants are used at the sea surface, oil may mix into the water column, or if applied subsea, they 

can travel with currents through the water and may contact or settle on sensitive features. Note that, as 

indicated above, a deepwater plume would not travel onto the continental shelf, but a plume formed on 

the continental shelf could impact topographic features and PSBFs. If located near the source, the 

dispersed oil could be concentrated enough to harm the community. If the oil remains suspended for a 

longer period of time, it would be more dispersed and exist at lower concentrations. Reports on 

dispersant usage on surface oil indicate that a majority of the dispersed oil remains in the top 10 m (33 ft) 

of the water column, with 60 percent of the oil in the top 2 m (6 ft) (McAuliffe et al., 1981a). Dispersant 

usage also reduces the oil’s ability to stick to particles in the water column, minimizing oil adhering to 

sediments and traveling to the seafloor (McAuliffe et al., 1981a). However, after the Deepwater Horizon

oil spill, there was the formation of a dense layer of marine snow that aggregated and collected everything 

that it came in contact with it as it fell through the water column and settled on the seafloor (Passow et al., 

2012).

Dispersed oil reaching the topographic features and PSBFs in the Gulf of Mexico would be expected 

to be at very low concentrations (<1 ppm) (McAuliffe et al., 1981a). Such concentrations would not be 

life threatening to larval or adult stages at the depth of the features based on experiments conducted with 

coral. Any dispersed oil in the water column that comes in contact with corals may evoke short-term 

negative responses by the organisms (Wyers et al., 1986; Cook and Knap, 1983; Dodge et al., 1984).

Reductions in feeding and photosynthesis could occur in coral exposed to dispersed oil. Short-term, 

sublethal responses of Diploria strigosa were reported after exposure to dispersed oil at a concentration of 

20 ppm for 24 hours. Although concentrations in this experiment were higher than what is anticipated for 

dispersed oil at depth, effects exhibited included mesenterial filament extrusion, extreme tissue 
B-40 Central and Eastern Planning Areas Supplemental EIS

contraction, tentacle retraction, and localized tissue rupture (Wyers et al., 1986). Normal behavior 

resumed within 2 hours to 4 days after exposure (Wyers et al., 1986). Diploria strigosa exposed to 

dispersed oil (20:1, oil:dispersant) showed an 85 percent reduction in zooxanthellae photosynthesis after 

8 hours of exposure to the mixture (Cook and Knap, 1983). However, the response was short term, as 

recovery occurred between 5 and 24 hours after exposure and return to clean seawater. Investigations 

1 year after Diploria strigosa was exposed to concentrations of dispersed oil between 1 and 50 ppm for 

periods between 6 and 24 hours did not reveal any impacts to growth (Dodge et al., 1984).

Historical studies indicate dispersed oil to be more toxic to coral species than oil or dispersant alone. 

The greater toxicity may be a result of an increased number of oil droplets caused by the use of 

dispersant, resulting in greater contact area between oil, dispersant, and water (Elgershuizen and 

De Kruijf, 1976). The dispersant causes a higher water-soluble amount of oil to contact the cell 

membranes of the coral (Elgershuizen and De Kruijf, 1976). The mucus produced by coral, however, can 

protect the organism from oil. Both hard and soft corals have the ability to produce mucus, and mucus 

production has been shown to increase when corals are exposed to crude oil (Mitchell and Chet, 1975; 

Ducklow and Mitchell, 1979). Dispersed oil, however, which has very small oil droplets, does not appear 

to adhere to coral mucus, and larger untreated oil droplets may become trapped by the mucus barrier 

(Knap, 1987; Wyers et al., 1986). However, entrapment of the larger oil droplets may increase the coral’s 

long-term exposure to oil if the mucus is not shed in a timely manner (Knap, 1987; Bak and Elgershuizen, 

1976). Additionally, more recent field studies, using more realistic concentrations of dispersants did not 

result in the toxicity historically reported (Yender and Michel, 2010).

Although historical studies indicated dispersed oil may be more toxic than untreated oil to corals 

during exposure experiments, untreated oil may remain in the ecosystem for long periods of time, while 

dispersed oil does not (Baca et al., 2005; Ward et al., 2003). Twenty years after an experimental oil spill 

in Panama, oil and impacts from untreated oil were still observed at oil treatment sites, but no oil or 

impacts were observed at dispersed oil or reference sites (Baca et al., 2005). Long-term recovery of the 

coral at the dispersed oil site had already occurred as reported in a 10-year monitoring update, and the site 

was not significantly different from the reference site (Ward et al., 2003).

Impacts from Oil Adhering to Sediments

BOEM’s policy, as described in NTL 2009-G39, prevents wells from being placed immediately 

adjacent to sensitive communities. In the event of a seafloor blowout, however, some oil could be carried

to topographic features or PSBFs as a result of oil droplets adhering to suspended particles in the water 

column. Oiled sediment that settles to the seafloor may affect organisms attached to hard-bottom 

substrates. Impacts may include reduced recruitment success, reduced growth, and reduced coral cover as 

a result of impaired recruitment. Experiments have shown that the presence of oil on available substrate 

for larval coral settlement has inhibited larval metamorphosis and larval settlement in the area. An 

increase in the number of deformed polyps after metamorphosis also took place because of exposure to oil 

(Kushmaro et al., 1997).

The majority of organisms exposed to sedimented oil are expected to experience low-level 

concentrations because as the oiled sediments settle to the seafloor they are widely distributed. Coral may 

also be able to protect itself from low concentrations of sedimented oil that settles from the water column. 

Coral mucus may not only act as a barrier to protect coral from the oil in the water column, but it has also 

been shown to aid in the removal of oiled sediment on coral surfaces (Bak and Elgershuizen, 1976). 

Coral may use a combination of increased mucus production and the action of cilia to rid themselves of 

oiled sediment (Bak and Elgershuizen, 1976).

Impacts from Oil-Spill-Response Activity

Oil-spill-response activity may also impact sessile benthic features. Booms anchored to the seafloor 

are sometimes used to control the movement of oil at the water surface. Boom anchors can physically 

impact corals and other sessile benthic organisms, especially when booms are moved around by waves 

(USDOC, NOAA, 2010d). Vessel anchorage and decontamination stations set up during response efforts 

may also break or kill PSBFs if their location is unmapped and anchors are set on the features. Injury to 

coral reefs as a result of anchor impact may result in long-lasting damage or failed recovery (Rogers and 
Catastrophic Spill Event Analysis B-41

Garrison, 2001). Effort should be made to keep vessel anchorage areas as far from sensitive benthic 

features as possible to minimize impact.

Drilling muds comprised primarily of barite may be pumped into a well to stop a blowout. If a “kill” 

is not successful, the mud (possibly tens of thousands of barrels) may be forced out of the well and 

deposited on the seafloor near the well site. Any organisms beneath the extruded drilling mud would be 

buried. Based on stipulations as described in NTL 2009-G39, a well should be far enough away from a 

topographic feature to prevent extruded drilling muds from smothering sensitive benthic communities. 

However, if drilling muds were to travel far enough or high enough in the water column to contact a 

sensitive community, the fluid would smother the existing community. Experiments indicate that corals 

perish faster when buried beneath drilling mud than when buried beneath carbonate sediments 

(Thompson, 1980). Burial may lead to the elimination of a live bottom community.

Phase 3—Onshore Contact

There would likely be no adverse impacts to topographic features and PSBFs as a result of the events 

and the potential impact-producing factors that could occur throughout Phase 3 of a catastrophic spill 

because the topographic features and PSBFs are located offshore.

Phase 4—Post-Spill, Long-Term Recovery and Response

Topographic features and PSBFs exposed to large amounts of resuspended sediments following a 

catastrophic, subsurface blowout could be subject to sediment suffocation, exposure to resuspended toxic 

contaminants, and reduced light penetration. The greatest impacts would occur to communities that exist 

in clear water with very low turbidity. The consequences of a blowout along, directly on, or near one of 

these features could be long lasting, although the occurrence of a blowout near such sensitive 

communities is unlikely because of stipulations described in NTL 2009-G39, which prevents drilling 

activity near sensitive hard bottom habitats. Impacts to a community in more turbid waters, such as the 

South Texas Banks, would be greatly reduced, as the species on these features are tolerant of suspended 

sediments, and recovery would occur quicker.

Impacts may also occur from low-level or long-term oil exposure. This type of exposure has the 

potential to impact reef communities, resulting in impaired health. Recovery may be fairly rapid from 

brief, low-level exposures, but it could be much longer with acute concentrations or long-term exposure 

to oil, such as in observations from Panama where untreated oil remained in the ecosystem for long 

periods of time, inhibiting coral recovery (Baca et al., 2005; Ward et al., 2003). Recovery time would 

therefore depend on recruitment from outside populations that were not affected by oiling and residence 

time of oil in an ecosystem.

Overall Summary and Conclusion (Phases 1-4)

A catastrophic spill on the continental shelf would have a greater impact on topographic features and 

PSBFs than a deepwater spill. Surface oil from a deepwater spill would be weathered and diluted by the 

time it reaches the surface waters over topographic features and PSBFs (if it ever reaches them), and it 

would be unlikely that it would mix to the depth of active growth in concentrations that could cause 

toxicity. Subsea plumes formed in deepwater would not travel onto the continental shelf because deepsea currents do not travel up a slope.

A catastrophic blowout and spill on the continental shelf has a greater chance to impact topographic 

features and PSBFs. If the blowout occurs close enough to sensitive features, the organisms may be 

smothered by settling sediment that was displaced by the blowout. The farther the feature is from the 

blowout, the less its chance of being covered with settling sediment or sediment upon which oil adhered. 

In addition, distancing oil and gas activities from topographic features prevents the settlement of a sinking 

rig on top of a topographic feature, although it may destroy a PSBF.

In most cases, impacts from oil would be sublethal. Surface oil is not expected to mix to the zone of 

active growth, and any oil components that do reach that depth would be in sublethal concentrations. 

Subsea plumes may contact the features; however, because currents tend to travel around, instead of over, 

topographic features, the topographic features should be protected from subsea plumes, while lower relief 

PSBFs may be impacted. Overall impacts of dispersed oil would be similar to subsea plumes. Spill 
B-42 Central and Eastern Planning Areas Supplemental EIS

response activity should not impact topographic features because it is unlikely that vessels would anchor 

on the features, but they could anchor on unmapped, lower relief PSBFs.

Overall, a catastrophic spill would have a low probability of impacting topographic features because 

of the distancing requirements included in leases, as described in NTL 2009-G39, of oil and gas activities 

from topographic features, the depth of mixing of surface oil compared with the depth of the active 

growing zone, currents that sweep around the topographic features, and the weathering and dispersion of 

oil that would occur with distance from the source as it travels toward the features. The PSBFs could 

have greater impacts from a blowout as oil and gas activities are not as far distanced from them as 

topographic features; they have a lower relief than topographic features, which would not divert currents; 

and the locations of these features are not all known so accidental anchor impacts may result in breakage 

of the features and possibly destruction. The PSBFs would, however, have similar protection as for 

topographic features from surface oil.

B.3.1.8. Sargassum Communities

Pelagic Sargassum algae is a floating brown algae that occurs in all parts of the GOM throughout the 

year. It has a seasonal cycle so that its abundance greatly increases spring through fall, when it is carried 

by water currents around the south of Florida and then up the east coast (Gower and King, 2011). It 

occurs in patches, floating on and near the sea surface. Wind and water currents commonly drive it into 

long lines or windrows; when conditions are turbulent, it becomes more scattered and mixed into the 

upper water column. A key to understanding impacts to Sargassum is that the algae is ubiquitous and 

occurs in scattered patches in the very top part of the water column. Sargassum also provides habitat for 

pelagic species, including fish, invertebrates, and sea turtles.

Phase 1—Initial Event

During the initial phase of a catastrophic blowout, impacts may include disturbance of sediments, 

destruction of the drilling rig, release of oil and natural gas (methane), and emergency response efforts. 

This chapter deals with the immediate effects of a blowout that would be located at least 3 nmi (3.5 mi; 

5.6 km) from shore.

Since Sargassum is a floating pelagic (open ocean) algae, it would only be affected by impacts that

occur in the top-most part of the water column. In deep water (≥ 300 m, 984 ft), sediment disturbed by 

the blowout would not affect Sargassum because the sediment would not reach the surface waters. 

However, in shallow water, sediment from a blowout could have minor effects on Sargassum algae in the 

immediate vicinity. The sediment would have little effect on the algae itself, producing only slight, 

temporary silting that could reduce photosynthesis. If the sediment is contaminated with oil, then the oil 

could have adverse effects on the algae. Depending on the severity of oiling, the algae could be damaged 

or destroyed; but this would only affect the algae in the local vicinity of the blowout. Sediment and oil 

would have a more acute effect on the associated invertebrate, fish, and sea turtle community that utilizes 

the habitat of the Sargassum. Impacts to these organisms may include “changes in respiration rate, 

abrasion and puncturing of structures, reduced feeding, reduced water filtration rates, smothering, delayed 

or reduced hatching of eggs, reduced larval growth or development, abnormal larval development, or 

reduced response to physical stimulus” (Anchor Environmental CA, L.P., 2003).

Destruction of the oil drilling rig and associated equipment could have an acute effect on patches of 

Sargassum algae that happen to be caught in the structure (if it sinks) or destroyed by fuel leaks and 

possible fire on the sea surface. This could destroy local patches of Sargassum, but it would have no 

measurable effect on the Sargassum community as a whole.

The release of oil during the initial blowout event would be expected to cover local patches of 

Sargassum algae with oil, destroying the algae and associated organisms. Methane gas may also bathe 

local patches of algae as it rises through the sea surface; it would have little effect on the algae itself but 

may poison associated organisms. The initiation of oil and gas release (as defined for this phase) at the 

site of the blowout event would affect only local patches of Sargassum, but it would have no measurable 

effect on the Sargassum community as a whole.

Emergency response activities would have minor impacts to Sargassum algae that comes in contact 

with vessels. This is mostly the simple impingement of the algae on the ships’ water intake screens, 
Catastrophic Spill Event Analysis B-43

including water that may be pumped in fire-fighting efforts. This minor and local effect would have no 

measurable effect on the Sargassum community as a whole.

Phase 2—Offshore Spill

During the second phase of a catastrophic blowout, the major impact of concern is the release of oil 

and methane over time. Response efforts may produce additional minor impacts to Sargassum. This 

chapter deals with the growing effects of a blowout that releases oil and methane into the offshore 

environment.

Since Sargassum is a floating pelagic (open ocean) algae, it would be affected by impacts that occur 

in the top-most part of the water column. This makes Sargassum habitat particularly susceptible to 

damage from offshore oil spills. Oceanographic processes that concentrate Sargassum into mats and rafts 

would also concentrate toxic substances. Therefore, it may be assumed that Sargassum would be found in 

areas where oil, dispersants, and other chemicals have accumulated following a catastrophic spill. Oil 

spreads on the sea surface to form extremely thin layers (0.01-0.1 micrometers) that cover large areas 

(MacDonald et al., 1996). Since Sargassum is ubiquitous in surface waters of the GOM, oil spreading on 

the sea surface can be expected to coincide with floating mats of the algae. The larger the quantity of 

spill and the longer it flows, the larger the area of sea surface it would cover. A catastrophic spill would 

cover a large area and result in impacts to a large quantity of Sargassum algae. For example, Macondo

well oil spill covered up to one-third of the northern GOM (McCrea-Strub and Pauly, 2011; USDOC, 

NMFS, 2011a) and may have affected about one-third of the Sargassum algae in the northern GOM at the 

time.

The severity of oiling to Sargassum depends largely on physical conditions. Factors include the 

quantity of oil at a particular launch point and its physical state, distance from the source, weather 

conditions, and the possible use of dispersants. Further detail on this catastrophic OSRA run is contained 

in Appendix C of the CPA 235/241/247 Supplemental EIS and EPA 225/226 EIS. 

Obviously, more oil leads to increased oiling, but the physical state of the oil changes as it weathers, 

biodegrades, dissipates, and emulsifies over time and distance. Storms can mix oil into the water column 

(expected maximum of 10-20 m [33-66 ft]; Lange, 1985; McAuliffe et al., 1975 and 1981a; Knap et al., 

1985; Scarlett et al., 2005; Hemmer et al., 2010; George-Ares and Clark, 2000), possibly increasing its 

contact with Sargassum as it also mixes the Sargassum into the water column. However, when storms are 

not mixing the oil, they are also not mixing the Sargassum, so the Sargassum would float near the sea 

surface, just as the oil would. Convergence zones, places in the ocean where strong opposing currents 

meet, would collect both oil and Sargassum. Sea turtles, especially post-hatchlings and juveniles, use 

these areas for food and cover. Witherington et al. (2012) surveyed sea turtles in the eastern Gulf of 

Mexico and Atlantic Ocean off Florida and found that 89 percent of the turtles documented were observed 

within 1 m (3 ft) of floating Sargassum. The use of dispersants on surface oil slicks could increase the 

exposure of Sargassum to oil by promoting mixing of oil into the upper few meters of the water column. 

This also promotes the dispersion of oil, speeding its decline toward low concentrations that would be less 

toxic. Regardless, any exposure that is enough to cause visible oiling can be expected to have significant 

detrimental effects on the organisms associated with Sargassum and, likely, effects on the Sargassum

itself. Heavy oiling of Sargassum near the source of the spill would destroy the affected algae. Very 

light exposure far from the oil source may have little effect.

The specific effects of oil on Sargassum depend on the severity of oiling. High to moderate levels of 

oiling would likely cause complete mortality. Low levels of exposure may result in a range of sublethal 

effects to the algae and its associated community. Powers et al. (2013) suggest that exposure to oil and/or 

dispersants can result in direct, sublethal, and indirect effects to Sargassum, resulting in death or a 

decrease in Sargassum-related ecosystem services. Sublethal responses in organisms associated with 

Sargassum may occur at concentrations as low as 1-10 ppb (Hyland and Schneider, 1976). Rogers (1990) 

documented impacts such as reduced growth, alteration in form, and reduced recruitment and 

productivity. Other sublethal impacts may include reduced feeding rates, reduced ability to detect food, 

erratic movement, ciliary inhibition, tentacle retraction, reduced movement, decreased aggression, and 

altered respiration (Scarlett et al., 2005; Suchanek, 1993). Embryonic life stages of organisms may 

experience toxicity at lower levels than the adult stages (Fucik et al., 1995; Suchanek, 1993; Beiras and 

Saco-Álvarez, 2006; Byrne, 1989). The algae itself would be less sensitive than many of its associates, 

since the algae produces oils of its own and has a waxy coating that may protect it from physical oiling.
B-44 Central and Eastern Planning Areas Supplemental EIS

Response efforts aimed at removing oil from the affected area would have minor impacts on 

Sargassum algae as well. Response vessels would impinge a small amount of the algae on their 

propellers and cooling-water intakes. Cleanup processes such as booming, skimming, and in-situ burning 

would also trap and destroy patches of Sargassum; however, these activities would take place in areas of 

high concentration of surface oil, where Sargassum would likely be destroyed by oil contamination even 

if the cleanup activity were absent.

Phase 3—Onshore Contact

This third phase of a catastrophic blowout focuses on the approach of oil to the shoreline. This 

involves the possible oiling of coastal resources including beaches, wetlands, SAV and seagrasses, the 

shallow seafloor, and any resources drifting in the water column (e.g., Sargassum). Response efforts can 

produce additional serious impacts. 

There would likely be little additional impact to pelagic Sargassum algae as oil approaches a 

shoreline. Since both the algae and surface oil approaching shore would be guided by the same forces 

(wind and water currents), they would likely be already traveling together, with the algae already 

contaminated. Once it is onshore, the Sargassum would die, regardless of oil contamination. Sargassum

that washes ashore has some value to the ecosystem as it provides food and shelter for some organisms as 

it decays. This value would be mostly lost if the Sargassum is oiled when it reaches shore.

Phase 4—Post-Spill, Long-Term Recovery and Response

The final phase of a catastrophic blowout is the long-term response of the ecosystem and its recovery. 

Both, the natural rate of recovery and the persistence of oil in natural habitats over time determine the 

long-term effects. Contaminants biodegrade over time, but they may become sequestered as inert forms 

(e.g., buried in sediment) until disturbed (by storms) and re-activated, producing renewed impacts.

Sargassum algae has a yearly seasonal cycle of growth and a yearly cycle of migration from the GOM 

to the western Atlantic. A catastrophic spill could affect a large portion of the annual crop of the algae. 

A large event, such as the Macondo well blowout and spill, could reduce the standing crop of Sargassum

in the GOM and subsequently in the western Atlantic if it coincided with a period when Sargassum

distribution was limited to the northwest GOM in an area known to be a nursery area. This could have a 

cascading effect down current (in the Atlantic) that would stress the cycles of other organisms that depend 

on the Sargassum habitat. However, the effect can be expected to diminish with remoteness from the 

direct impacts of the spill, i.e., the algae community itself would be most affected, with lesser effects on 

organisms that utilize the habitat as a nursery, for feeding, as shelter, or other purposes.

While a large spill event could affect a large portion of the standing crop of Sargassum, several 

factors contribute to the quick recovery of the habitat. Sargassum algae is predominately found in the 

open-ocean pelagic habitat. Once the spill event subsides, the pelagic habitat would quickly regain its 

typically very high water quality. The pelagic habitat far from shore is also far from land-based sources 

of pollution. Only part of the Sargassum stocks would be affected; algae not affected by the spill event 

would continue to grow normally and repopulate the habitat. Since Sargassum has a seasonal cycle of 

growth in the summer and reduction in the winter, populations in the winter following a catastrophic 

event may be similar to populations of any other year. Relatively small populations survive each winter, 

subsequently repopulating the habitat each year. With this pattern, recovery from the effects of a 

catastrophic event is expected within 1-2 growing seasons.

Overall Summary and Conclusion (Phases 1-4)

Pelagic Sargassum algae is one of the most likely habitats to be affected by a catastrophic offshore oil 

spill; however, because of its ubiquitous distribution and seasonal cycle, recovery is expected within 

1-2 years. Sargassum algae floats on and near the sea surface and occurs in patches that can be collated 

into windrows by wind and water currents. Oil from a spill offshore would accumulate in the same 

waters, making it inevitable that some patches of Sargassum would be severely affected.

The initial catastrophic event (Phase 1) could destroy Sargassum patches in the immediate vicinity of 

the accident. Impingement, fire, and the initial concentrated spillage of oil and fuels would destroy local 

patches. Sediments disturbed by the accident would only affect Sargassum if the event occurred in 

shallow waters.
Catastrophic Spill Event Analysis B-45

The duration of the spill event (Phase 2) would have the most effect on floating Sargassum algae. 

Patches of algae within the entire coverage of the oil slick would be subject to severe damage and death. 

Algae in areas farther from the spill, receiving lower level impacts, may still suffer damage, especially the 

sensitive invertebrate and fish communities associated with the habitat. Efforts to remove the oil could 

gather Sargassum with the oil, but these algae patches would likely be destroyed by the oil anyway since 

the collection activities would occur in areas of concentrated oil.

As oil approaches shore (Phase 3), impacts to floating Sargassum algae would not increase much, as 

the algae would likely already be exposed to the oil since wind and water currents drive both the algae 

and the oil.

The recovery of floating Sargassum algae (Phase 4) may occur within 1-2 years because the algae has 

a yearly cycle of subsidence and re-growth. As long as the nursery grounds are not completely saturated 

with oil, the pelagic habitat would quickly regain its high level of water quality after the cessation of a 

spill. Not all of the Sargassum habitat would be affected, even by a catastrophic spill; healthy algae 

would continue to grow and replenish the population. Within 1-2 years, the Sargassum algae community 

may have completely recovered from the impacts of a catastrophic spill.

B.3.1.9. Chemosynthetic Deepwater Benthic Communities

Deepwater benthic communities of the Gulf of Mexico include soft bottom, chemosynthetic, and 

coral habitats. Deep water, for ecology in the GOM, is defined as water depths over 300 m (984 ft) 

because chemosynthetic communities and Lophelia coral habitats have not been found in waters 

shallower than these depths. The possible impacts to these benthic communities from a catastrophic 

blowout depend on the location and the nature of the event.

Phase 1—Initial Event

During the initial phase of a catastrophic blowout, impacts may include the disturbance of sediments, 

destruction of the drilling rig, release of oil and natural gas (methane), and emergency response efforts. 

This chapter deals with the immediate effects of a blowout located at least 3 nmi (3.5 mi; 5.6 km) from 

shore.

A catastrophic blowout outside the well casing and below the seafloor or at the seafloor-water 

interface could resuspend large quantities of bottom sediments and create a large crater, destroying many 

organisms within a few hundred meters of the wellhead. Some fine sediment could travel up to a few 

thousand meters before redeposition, negatively impacting a localized area of benthic communities. If a 

blowout were to occur close enough to a chemosynthetic community, suspended sediment may impact the 

organisms. Restrictions described in NTL 2009-G40 require drilling to be removed at least 610 m 

(2,000 ft) from possible chemosynthetic communities. During a blowout, sediment may become 

contaminated with oil and subsequently deposit that oil down-current from the source. The highest 

concentrations of contamination would be nearest the well, and concentrations would diminish with 

distance. A catastrophic blowout that occurs above the seabed (at the rig, along the riser between the 

seafloor and sea surface, or through leak paths on the BOP/wellhead) would not disturb the sediment.

Destruction of the oil drilling rig and associated equipment could have an acute effect on any 

chemosynthetic communities caught under the direct impact of the equipment when it falls to the seafloor. 

However, the restrictions described in NTL 2009-G40 require drilling locations to be 610 m (2,000 ft) 

from any possible indications of chemosynthetic communities, reducing the possibility that a rig would 

settle directly on sensitive habitat.

A catastrophic blowout would likely result in released oil rapidly rising to the sea surface because 

typical reserves in the GOM have specific gravity characteristics that are much lighter than water (refer to 

Chapter 3.2.1.3 of this Supplemental EIS; Environment Canada, 2011; Trudel et al., 2001). The oil 

would surface almost directly over the source location. Oil floating to the sea surface would be 

effectively removed from affecting chemosynthetic communities on the seafloor. Even oil treated with 

chemical dispersants on the sea surface would not be expected to have widespread impacts to deepwater 

communities. Reports on dispersant usage on surface oil indicate that a majority of the dispersed oil 

remains in the top 10 m (33 ft) of the water column, with 60 percent of the oil in the top 2 m (6 ft) 

(McAuliffe et al., 1981a; Lewis and Aurand, 1997). Lubchenco et al. (2010) reports that chemically 

dispersed surface oil from the Macondo well blowout and oil spill remained in the top 6 m (20 ft) of the 
B-46 Central and Eastern Planning Areas Supplemental EIS

water column where it mixed with surrounding waters and biodegraded. However, if the oil is ejected 

under high pressure, micro-droplets of oil may form and become entrained in the water column (Boehm 

and Fiest, 1982; Adcroft et al., 2010). Upward movement of oil may also be reduced if methane mixed 

with the oil is dissolved into the water column, reducing the buoyancy of the oil/gas stream (Adcroft 

et al., 2010). Large oil droplets would rise to the sea surface, but smaller droplets, formed by vigorous 

turbulence in the plume or the injection of dispersants, may remain neutrally buoyant in the water column, 

creating a subsurface plume (Adcroft et al., 2010; Joint Analysis Group, 2010a). It is unlikely that any 

chemosynthetic community would be affected by the initial stage of a catastrophic event due to the 

required separation of drilling activities from sensitive habitats, because released oil would rise rapidly to 

a level above the habitat, and because surface oil would not mix to the depths of the chemosynthetic 

communities. The required separation distance would also allow for a subsea plume to mix with the 

surrounding water and become diluted before it reached a deepwater community.

Phase 2—Offshore Spill

During the second phase of a catastrophic blowout, the major impact of concern is the release of oil 

and methane over time. Response efforts may produce additional impacts. This chapter deals with the 

growing effects of a blowout that releases oil and methane into the offshore environment.

A spill resulting from a catastrophic blowout in deep water has the potential to impact offshore 

benthic communities; however, it is not likely that deepwater benthic communities would be affected by a 

spill from a shallow-water blowout. Although subsurface plumes can be generated when oil is ejected 

under high pressure or dispersants are used subsea, a majority of the oil originating from a seafloor 

blowout in deep water is expected to rise rapidly to the sea surface. Upward movement of the oil may 

also be reduced if methane mixed with the oil is dissolved into the water (Adcroft et al., 2010). A 

sustained spill would continuously create surface slicks and possibly subsurface spill plumes. Some of 

the oil in the water column would become diluted over time, reducing transport to the seafloor 

(Vandermeulen, 1982). Concentrations of dispersed and dissolved oil in the Macondo well blowout and 

spill subsea plume were reported to be in the part per million range or less and were generally lower away 

from the water’s surface and away from the wellhead (Adcroft et al., 2010; Haddad and Murawski, 2010; 

Joint Analysis Group, 2010; Lubchenco et al., 2010). In addition, microbial degradation of oil occurs in 

the water column rendering oil less toxic when it contacts the seafloor (Hazen et al., 2010). Oil can 

precipitate to the seafloor by adhering to other particles, much like rainfall (Kingston et al., 1995; 

International Tanker Owners Pollution Federation Limited, 2011). Oil would also reach the seafloor 

through planktonic consumption and associated excretion, which is distributed over the seafloor 

(International Tanker Owners Pollution Federation Limited, 2011). These mechanisms would result in a 

wide distribution of small amounts of oil. Throughout these processes, oil would be biodegraded from 

bacterial action, which would continue on the seafloor, resulting in scattered microhabitats with an 

enriched carbon environment (Hazen et al., 2010).

A sustained spill may result in elevated exposure concentrations to chemosynthetic features if a 

subsea oil plume contacts them directly. Dispersed oil is mixed with water, and its movement is then 

dictated by water currents and the physical, chemical, and biodegradation pathways. BOEM’s policy 

(refer to NTL 2009-G39) prevents wells from being placed immediately adjacent to sensitive 

communities; however, in the event of a seafloor blowout, some oil could be carried to chemosynthetic 

communities by subsea plumes. Impacts may include reduced recruitment success, reduced growth, and 

reduced biological cover as a result of impaired recruitment. Concentrated oil plumes reaching 

chemosynthetic communities could cause oiling of organisms, resulting in the death of entire populations 

on localized sensitive habitats. The longer the oil remains suspended in the water column, the more 

dispersed, less concentrated, and more biodegraded it would become. Depending on how long oil 

remained suspended in the water column, it may be thoroughly degraded by biological action before 

contacting the seafloor (Hazen et al., 2010; Valentine et al., 2010). Biodegradation rates in cold, 

deepwater environments are not well understood at this time. In general, potential impacts to 

chemosynthetic communities would be localized due to the directional movement of oil plumes by the 

water currents and because the sensitive habitats have a scattered, patchy distribution. While a few patch 

habitats may be affected, the Gulfwide ecosystem of chemosynthetic communities would be expected to 

suffer no significant effects.
Catastrophic Spill Event Analysis B-47

Drilling muds comprised primarily of barite may be pumped into a well to stop a blowout. If a “kill” 

is not successful, the mud (possibly tens of thousands of barrels) may be forced out of the well and 

deposited on the seafloor near the well site. Any organisms beneath the extruded drilling mud would be 

buried. Based on stipulations as described in NTL 2009-G40, a well should be far enough away from a 

chemosynthetic community to prevent extruded drilling muds from smothering sensitive benthic 

communities.

Phase 3—Onshore Contact

The third phase of a catastrophic blowout focuses on the approach of oil to the shoreline. This 

involves the possible oiling of coastal resources including beaches, wetlands, SAV and seagrasses, the 

shallow seafloor, and any resources drifting in the water column. Response efforts can produce additional 

serious impacts. There would be no additional adverse impacts to chemosynthetic communities in deep 

water as a result of the events and the potential impact-producing factors that could occur throughout 

Phase 3 of a catastrophic spill because the chemosynthetic communities are located offshore in deep 

water (>300 m, 610 ft).

Phase 4— Post-Spill, Long-Term Recovery and Response

The final phase of a catastrophic blowout is the long-term response of the ecosystem and its recovery. 

Both the natural rate of recovery and the persistence of oil in natural habitats over time determine what 

long-term effects may occur. Contaminants degrade over time but may become sequestered as inert 

forms (e.g., buried in sediment) until disturbed and reactivated, producing renewed impacts.

If oil is ejected under high pressure or dispersants are applied at the source near the seafloor, oil 

would mix into the water column, be carried by underwater currents, and eventually contact the seafloor 

in some form, either concentrated (near the source) or dispersed and decayed (farther from the source). 

The oil could then impact patches of chemosynthetic community habitat in its path. The farther the 

dispersed oil travels, the more diluted it would become as it mixes with surrounding water. 

Chemosynthetic communities located at more than 610 m (2,000 ft) away from a blowout could 

experience minor impacts from suspended sediments that travel with currents, although the sediment 

concentration would be diluted with distance from the well. Studies indicate that periods of decades to 

hundreds of years are required to reestablish a seep community once it has disappeared (depending on the 

community type) (Powell, 1995; Fisher, 1995). There is evidence that substantial impacts on these 

communities could permanently prevent reestablishment, particularly if hard substrate required for 

recolonization is buried by resuspended sediments from a blowout. A catastrophic spill combined with 

the application of dispersant has the potential to cause devastating effects on local patches of habitat in 

the path of subsea plumes where they physically contact the seafloor. Sublethal effects are possible for 

communities that receive a lower level of impact. Examples of these effects could include temporary lack 

of feeding, expenditure of energy to remove the oil, loss of gametes and reproductive delays, and loss of 

tissue mass. Oil plumes that remain in the water column for longer periods would disperse and decay, 

having only minimal effect. Depending on how long it remains in the water column, oil may be 

thoroughly degraded by biological action before contacting the seafloor. Water currents can carry a 

plume to contact the seafloor directly but a more likely scenario would be for oil to adhere to other 

particles and precipitate to the seafloor, much like rainfall (Kingston et al., 1995; International Tanker 

Owners Pollution Federation Limited, 2011). Oil would also reach the seafloor through planktonic 

consumption and associated excretion, which is distributed over the seafloor (International Tanker 

Owners Pollution Federation Limited, 2011). These mechanisms would result in a wide distribution of 

small amounts of oil (or oil by-products). This oil would be in the process of biodegradation from 

bacterial action, which would continue on the seafloor, resulting in scattered microhabitats with an 

enriched carbon environment (Hazen et al., 2010). Habitats directly under the path of the oil plume as it 

disperses and “rains” down to the seafloor may experience minor effects, but since the oil would be 

deposited in a widely scattered and decayed state, little effect is anticipated.

Overall Summary and Conclusion (Phases 1-4)

Chemosynthetic communities would potentially be subject to detrimental effects from a catastrophic 

seafloor blowout. Sediment and oiled sediment from the initial event (Phase 1) are not likely to reach 
B-48 Central and Eastern Planning Areas Supplemental EIS

chemosynthetic communities in heavy amounts because of requirements described in NTL 2009-G40. 

Fine sediment from a blowout may reach the location of sensitive habitats, producing sublethal effects. 

The initial accident could result in the drilling rig and equipment falling on a sensitive seafloor habitat if 

the structure travels more than 610 m (2,000 ft) from the well site.

The ongoing spill event (Phase 2) would have the most effect on chemosynthetic communities. 

Chemosynthetic communities are at risk from subsea oil plumes that could directly contact localized 

patches of sensitive habitat. Oil plumes reaching chemosynthetic communities could cause oiling of 

organisms, resulting in the death of entire populations on localized sensitive habitats. However, potential 

impacts would be localized due to the directional movement of oil plumes by the water currents and 

because the sensitive habitats have a scattered, patchy distribution. The more likely scenario would be 

exposure to widely dispersed, biodegraded particles that “rain” down from a passing oil plume. While a 

few patch habitats may be affected, the Gulfwide ecosystem of chemosynthetic communities would be 

expected to suffer no significant effects.

As oil approaches shore (Phase 3), there would be no additional adverse impacts to chemosynthetic 

communities because the chemosynthetic communities are located offshore in deep water (>300 m; 

610 ft). 

The recovery of chemosynthetic communities (Phase 4) depends on the severity of initial impacts. A 

catastrophic spill combined with the application of dispersant has the potential to cause devastating 

effects on local patches of habitat in the path of subsea plumes where they physically contact the seafloor. 

Studies indicate that periods from decades to hundreds of years are required to reestablish a seep 

community once it has disappeared (depending on the community type) (Powell, 1995; Fisher, 1995). 

The burial of hard substrate could permanently prevent recovery. Sublethal effects are possible for 

communities that receive a lower level of impact. Examples of these effects could include temporary lack 

of feeding, expenditure of energy to remove the oil, loss of gametes and reproductive delays, and loss of 

tissue mass. However, most chemosynthetic community habitats are expected to experience no impacts 

from a catastrophic seafloor blowout because of the directional movement of oil plumes by the water 

currents and because the sensitive habitats have a scattered, patchy distribution.

B.3.1.10. Nonchemosynthetic Deepwater Benthic Communities

Deepwater benthic communities of the Gulf of Mexico include soft bottom, chemosynthetic, and live 

bottom communities (mostly deepwater coral communities). Deep water, for ecology in the GOM, is 

defined as water depths over 300 m (984 ft) because nonchemosynthetic communities and Lophelia coral 

habitats have not been found in waters shallower than these depths. The possible impacts to 

nonchemosynthetic deepwater benthic communities from a catastrophic blowout depend on the location 

and the nature of the event.

Phase 1—Initial Event

During the initial phase of a catastrophic blowout, impacts may include disturbance of sediments, 

destruction of the drilling rig, release of oil and natural gas (methane), and emergency response efforts. 

This phase deals with the immediate effects of a blowout located at least 3 nmi (3.5 mi; 5.6 km) from 

shore.

A catastrophic blowout outside the well casing and below the seafloor or at the seafloor-water 

interface could resuspend large quantities of bottom sediments and create a large crater, destroying many 

organisms within a few hundred meters of the wellhead. A blowout that occurs outside the well casing 

can rapidly deposit 30 cm (12 in) or more of sediment within a few hundred meters and may smother 

much of the soft bottom community in a localized area. Some fine sediment could travel up to a few 

thousand meters before redeposition, negatively impacting a localized area of benthic communities. 

Many of the organisms on soft bottoms live within the sediment and have the ability to migrate upward in 

response to burial by sedimentation. In situations where soft bottom infaunal communities are negatively 

impacted, recolonization by populations from neighboring soft bottom substrate would be expected over a 

relatively short period of time for all size ranges of organisms, in a matter of days for bacteria and 

probably less than 1 year for most macrofauna and megafauna species. Recolonization could take longer 

for areas affected by direct contact of concentrated oil.
Catastrophic Spill Event Analysis B-49

If a blowout were to occur close enough to a sensitive deepwater live bottom community, suspended 

sediment may impact the organisms. Restrictions described in NTL 2009-G40 require drilling to be 

removed at least 610 m (2,000 ft) from possible live bottom communities. During a blowout, suspended 

sediment may become contaminated with oil and subsequently deposit that oil down-current from the 

source. The highest concentrations of contamination would be nearest the well, and concentrations would 

diminish with distance. A catastrophic blowout that occurs above the seabed (at the rig, along the riser 

between the seafloor and sea surface, or through leak paths on the BOP/wellhead) would not disturb the 

sediment.

Destruction of the oil drilling rig and associated equipment could have an acute effect on any 

nonchemosynthetic communities caught under the direct impact of the equipment when it falls to the 

seafloor. However, the restrictions described in NTL 2009-G40 require drilling locations to be 610 m 

(2,000 ft) from any possible indications of sensitive live bottom communities, reducing the possibility 

that a rig would settle directly on sensitive habitat.

A catastrophic blowout would likely result in released oil rapidly rising to the sea surface because 

typical reserves in the GOM have specific gravity characteristics that are much lighter than water (refer to 

Chapter 3.2.1.3 of this Supplemental EIS; Environment Canada, 2011; Trudel et al., 2001). The oil 

would surface almost directly over the source location. Oil floating to the sea surface would be 

effectively removed from affecting nonchemosynthetic communities on the seafloor. Even oil treated 

with chemical dispersants on the sea surface would not be expected to have widespread impacts to 

deepwater communities. Reports on dispersant usage on surface oil indicate that a majority of the 

dispersed oil remains in the top 10 m (33 ft) of the water column, with 60 percent of the oil in the top 2 m 

(6 ft) (McAuliffe et al., 1981a; Lewis and Aurand, 1997). Lubchenco et al. (2010) report that chemically 

dispersed surface oil from the Macondo well blowout and oil spill remained in the top 6 m (20 ft) of the 

water column where it mixed with surrounding waters and biodegraded. However, if the oil is ejected 

under high pressure, micro-droplets of oil may form and become entrained in the water column (Boehm 

and Fiest, 1982; Adcroft et al., 2010). Upward movement of the oil may also be reduced if methane 

mixed with the oil is dissolved into the water column, reducing the buoyancy of the oil/gas stream 

(Adcroft et al., 2010). Large oil droplets would rise to the sea surface, but smaller droplets, formed by 

vigorous turbulence in the plume or the injection of dispersants, may remain neutrally buoyant in the 

water column, creating a subsurface plume (Adcroft et al., 2010; Joint Analysis Group, 2010). It is 

unlikely that any deepwater live bottom community would be affected by the initial stage of a 

catastrophic event due to the required separation of drilling activities from sensitive habitats, because 

released oil would rapidly rise to a level above the habitat, and because surface oil would not mix to the 

depths of such communities. The required separation distance would also allow for a subsea plume to 

mix with the surrounding water and become diluted before it reached a deepwater community.

Phase 2—Offshore Spill

During the second phase of a catastrophic blowout, the major impact of concern is the release of oil 

and methane over time. Response efforts may produce additional impacts. This chapter deals with the 

growing effects of a blowout that releases oil and methane into the offshore environment.

A spill resulting from a catastrophic blowout in deep water has the potential to impact offshore 

benthic communities; however, it is not likely that deepwater benthic communities would be affected by a 

spill from a shallow-water blowout. Although subsurface plumes can be generated when oil is ejected 

under high pressure or when dispersants are used subsea, a majority of the oil originating from a seafloor 

blowout in deep water is expected to rise rapidly to the sea surface. Oil and chemical spills that originate 

at the sea surface are not considered to be a potential source of measurable impacts on deepwater, live 

bottom communities because of the water depths at which these communities are located. Oil spills at the 

surface would tend not to sink, and the risk of weathered components of a surface slick reaching the 

benthos in any measurable concentration would be very small. Surface oil also could not physically mix 

to depths of deepwater communities under natural conditions (Lange, 1985; McAuliffe et al., 1975 and

1981a; Tkalich and Chan, 2002).

Upward movement of the oil may also be reduced if methane mixed with the oil is dissolved into the 

water (Adcroft et al., 2010). A sustained spill would continuously create surface slicks and possibly 

subsurface spill plumes. One deepwater coral site at a depth of 1,370 m (4,495 ft) has been reported as 

severely damaged following the Macondo well blowout and oil spill. The site is in Mississippi Canyon 
B-50 Central and Eastern Planning Areas Supplemental EIS

Block 294, 11 km (7 mi) southwest of the spill location. The site includes hard substrate supporting coral 

in an area approximately 10 x 12 m (33 x 39 ft) (White et al., 2012). The published results document 

damage to the coral community. Forty-three coral colonies were analyzed via close-up imagery: 

86 percent exhibited signs of impact; 46 percent exhibited impact to at least 50 percent of the colony; and 

23 percent of the colonies sustained impact to more than 90 percent of the colony (White et al., 2012). 

Many other associated invertebrates also exhibited signs of stress. This appears to be an exceptional case, 

since the numerous other communities investigated since the spill remained healthy (White et al., 2012). 

Some of the oil in the water column would become diluted over time, reducing transport to the seafloor 

(Vandermeulen, 1982). Concentrations of dispersed and dissolved oil in the Macondo well blowout and 

spill subsea plume were reported to be in the part per million range or less and were generally lower away 

from the water’s surface and away from the wellhead (Adcroft et al., 2010; Haddad and Murawski, 2010; 

Joint Analysis Group, 2010; Lubchenco et al., 2010). In addition, microbial degradation of the oil occurs 

in the water, rendering the oil less toxic when it contacts the seafloor (Hazen et al., 2010). However, as 

evidenced by the report of White et al. (2012), subsea plumes can still retain toxic concentrations over a 

distance of at least 11 km (7 mi). Oil in a plume can adhere to other particles and precipitate to the 

seafloor, much like rainfall (Kingston et al., 1995; International Tanker Owners Pollution Federation 

Limited, 2011). Oil also would reach the seafloor through consumption by plankton, with excretion 

distributed over the seafloor (International Tanker Owners Pollution Federation Limited, 2011). These 

mechanisms would result in a wide distribution of small amounts of oil. Throughout these processes, oil 

would be biodegraded from bacterial action, which would continue on the seafloor, resulting in scattered 

microhabitats with an enriched carbon environment (Hazen et al., 2010).

A sustained spill may result in elevated exposure concentrations to live bottom features if a subsea oil 

plume contacts them directly. Dispersed oil is mixed with water, and its movement is then dictated by 

water currents and the physical, chemical, and biological degradation pathways. BOEM’s policy (refer to 

NTL 2009-G40) prevents wells from being placed immediately adjacent to sensitive communities; 

however, in the event of a seafloor blowout, some oil could be carried to live bottom communities by 

subsea plumes. Impacts may include reduced recruitment success, reduced growth, and reduced 

biological cover as a result of impaired recruitment. Concentrated oil plumes reaching live bottom 

communities could cause oiling of organisms, resulting in the death of entire populations on localized 

sensitive habitats. The longer the oil remains suspended in the water column the more dispersed, less 

concentrated, and more degraded it would become. Depending on how long oil remained suspended in 

the water column, it may be thoroughly degraded by biological action before contacting the seafloor 

(Hazen et al., 2010; Valentine et al., 2010). Biodegradation rates in cold, deepwater environments are not 

well understood at this time. In general, the potential impacts to deepwater live bottom communities 

would be localized due to the directional movement of oil plumes by the water currents and because the 

sensitive habitats have a scattered, patchy distribution. While a few patch habitats may be affected, the 

Gulfwide ecosystem of deepwater live bottom communities would be expected to suffer no significant 

effects.

Drilling muds comprised primarily of barite may be pumped into a well to stop a blowout. If a “kill” 

is not successful, the mud (possibly tens of thousands of barrels) may be forced out of the well and 

deposited on the seafloor near the well site. Any organisms beneath the extruded drilling mud would be 

buried. Based on stipulations as described in NTL 2009-G40, a well should be far enough away from 

sensitive live bottom communities to prevent extruded drilling muds from smothering them.

Phase 3—Onshore Contact

The third phase of a catastrophic blowout focuses on the approach of oil to the shoreline. This 

involves the possible oiling of coastal resources including beaches, wetlands, SAV and seagrasses, the 

shallow seafloor, and any resources drifting in the water column. Response efforts can produce additional 

serious impacts. There would be no adverse impacts to nonchemosynthetic benthic communities in deep 

water as a result of the events and the potential impact-producing factors that could occur throughout 

Phase 3 of a catastrophic spill because the communities are located offshore in deep water (>300 m; 

610 ft). 
Catastrophic Spill Event Analysis B-51

Phase 4—Post-Spill, Long-Term Recovery and Response

The final phase of a catastrophic blowout is the long-term response of the ecosystem and its recovery. 

Both the natural rate of recovery and the persistence of oil in natural habitats over time determine what 

long-term effects may occur. Contaminants degrade over time, but they may become sequestered as inert 

forms (e.g., buried in sediment) until disturbed and re-activated, producing renewed impacts.

Although deepwater coral and other live bottom communities often live in close association with 

hydrocarbon seeps (since the carbonate substrate is precipitated by chemosynthetic communities), this 

does not mean they are necessarily tolerant to the effects of oil contamination. Natural seepage is very 

constant and at very low rates as compared with the potential volume of oil released from a catastrophic 

event (blowout or pipeline rupture). In addition, live bottom organisms, such as Lophelia pertusa, inhabit 

areas around the perimeter of seeps and sites where hydrocarbon seepage has reduced its flow or stopped. 

Typical Gulf of Mexico oil is light and floats rapidly to the surface rather than being carried horizontally 

across benthic communities by water currents (Johansen et al., 2001; MacDonald et al., 1995; Trudel 

et al., 2001). So, although deepwater live bottom communities are found near oil seeps, they are not 

typically exposed to concentrated oil.

If oil is ejected under high pressure or dispersants are applied at the source near the seafloor, oil 

would mix into the water column, be carried by underwater currents, and eventually contact the seafloor 

in some form, either concentrated (near the source) or dispersed and decayed (farther from the source). 

The oil could then impact patches of live bottom community habitat in its path. The farther the dispersed 

oil travels, the more diluted it would become as it mixes with surrounding water. Sensitive live bottom 

communities located at more than 610 m (2,000 ft) away from a blowout could experience minor impacts 

from suspended sediments that travel with currents, although the sediment concentration would be diluted 

with distance from the well.

There have been no experiments showing the response of deepwater corals to oil exposure. 

Experiments with shallow tropical corals indicate that corals have a high tolerance to oil exposure. The 

mucus layers on coral resist penetration of oil and slough off the contaminant. Longer exposure times and 

areas of tissue where oil adheres to the coral are more likely to result in tissue damage and death of 

polyps. Corals with branching growth forms appear to be more susceptible to damage from oil exposure 

(Shigenaka, 2001). The most common deepwater coral, Lophelia pertusa, is a branching species. Tests 

with shallow tropical gorgonians indicate relatively low toxic effects to the coral (Cohen et al., 1977), 

suggesting deepwater gorgonians may have a similar response. Depending on the level of exposure, the 

response of deepwater coral to oil from a catastrophic spill would vary. Exposure to widely dispersed oil 

adhering to organic detritus and partially degraded by bacteria may be expected to result in little effect. 

Direct contact with plumes of relatively fresh dispersed oil droplets in the vicinity of the incident could 

cause the death of affected coral polyps through exposure and potential feeding on oil droplets by polyps. 

Median levels of exposure to dispersed oil in a partly degraded condition may result in effects similar to 

those of shallow tropical corals, with often no discernible effects other than temporary contraction and 

some sloughing. The health of corals may be degraded by the necessary expenditure of energy as the 

corals respond to oiling (Shigenaka, 2001). Communities exposed to more concentrated oil may 

experience detrimental effects, including death of affected organisms, tissue damage, lack of growth, 

interruption of reproductive cycles, and loss of gametes. Many invertebrates associated with deepwater 

coral communities, particularly the crustaceans, would likely be more susceptible to damage from oil 

exposure. The recolonization of severely damaged or destroyed communities could take years or decades. 

Burial of hard substrate could permanently prevent recovery. However, because of the scarcity of 

deepwater hard bottoms, their comparatively low surface area, and the distancing requirements set by 

BOEM in NTL 2009-G40, it is unlikely that a sensitive habitat would be located adjacent to a seafloor 

blowout or that concentrated oil would contact the site.

A catastrophic spill combined with the application of dispersant has the potential to cause devastating 

effects on local patches of habitat in the path of subsea plumes where they physically contact the seafloor. 

Sublethal effects are possible for communities that receive a lower level of impact. Examples of these 

effects could include temporary lack of feeding, expenditure of energy to remove the oil, loss of gametes 

and reproductive delays, and loss of tissue mass. Oil plumes that remain in the water column for longer 

periods would disperse and decay, having only minimal effect. Depending on how long it remains in the 

water column, oil may be thoroughly degraded by biological action before contacting the seafloor. Water 

currents can carry a plume to contact the seafloor directly, but a more likely scenario would be for oil to 
B-52 Central and Eastern Planning Areas Supplemental EIS

adhere to other particles and precipitate to the seafloor, much like rainfall (Kingston et al., 1995; 

International Tanker Owners Pollution Federation Limited, 2011). Oil also would reach the seafloor 

through consumption by plankton with excretion distributed over the seafloor (International Tanker 

Owners Pollution Federation Limited, 2011). These mechanisms would result in a wide distribution of

small amounts of oil (or oil by-products). This oil would be in the process of biodegradation from 

bacterial action, which would continue on the seafloor, resulting in scattered microhabitats with an 

enriched carbon environment (Hazen et al., 2010). Habitats directly under the path of the oil plume as it 

disperses and “rains” down to the seafloor may experience minor effects, but since the oil would be 

deposited in a widely scattered and decayed state, little effect is anticipated.

Overall Summary and Conclusion (Phases 1-4)

Nonchemosynthetic communities would potentially be subject to detrimental effects from a 

catastrophic seafloor blowout. Sediment and oiled sediment from the initial event (Phase 1) are not likely 

to reach sensitive live bottom communities in heavy amounts because of requirements described in NTL 

2009-G40. Fine sediment from a blowout may reach the location of sensitive habitats, producing 

sublethal effects. The initial accident could result in the drilling rig and equipment falling on a sensitive 

seafloor habitat if the structure travels more than 610 m (2,000 ft) from the well site.

The ongoing spill event (Phase 2) would have the most effect on nonchemosynthetic communities. 

Deepwater live bottom communities are at risk from subsea oil plumes that could directly contact 

localized patches of sensitive habitat. Oil plumes reaching live bottom communities could cause oiling of 

organisms, resulting in the death of entire populations on localized sensitive habitats. However, the 

potential impacts would be localized due to the directional movement of oil plumes by the water currents 

and because the sensitive habitats have a scattered, patchy distribution. The more likely result would be 

exposure to widely dispersed, biodegraded particles that “rain” down from a passing oil plume. While a 

few patch habitats may be affected, the Gulfwide ecosystem of live bottom communities would be 

expected to suffer no significant effects.

As oil approaches shore (Phase 3), there would be no adverse impacts to nonchemosynthetic 

communities because the communities are located offshore in deep water (>300 m; 610 ft).

The recovery of nonchemosynthetic communities (Phase 4) depends on the severity of initial impacts. 

A catastrophic spill combined with the application of dispersant has the potential to cause devastating 

effects on local patches of sensitive habitat in the path of subsea plumes where they physically contact the 

seafloor. The recolonization of severely damaged or destroyed communities could take years or decades. 

Burial of hard substrate could permanently prevent recovery. Sublethal effects are possible for 

communities that receive a lower level of impact. Examples of these effects could include temporary lack 

of feeding, expenditure of energy to remove the oil, loss of gametes and reproductive delays, and loss of 

tissue mass. However, most live bottom community habitats are expected to experience no impacts from 

a catastrophic seafloor blowout because of the directional movement of oil plumes by the water currents 

and because the sensitive habitats have a scattered, patchy distribution.

B.3.1.11. Soft Bottom Benthic Communities

The seafloor on the continental shelf in the Gulf of Mexico consists primarily of muddy to sandy 

sediments. Benthic organisms found on the seafloor include infauna (animals that live in the substrate, 

including mostly burrowing worms, crustaceans, and mollusks) and epifauna (animals that live on or are 

attached to the substrate; mostly crustaceans, as well as echinoderms, mollusks, hydroids, sponges, soft 

and hard corals, and demersal fishes). Infauna is comprised of meiofauna, small organisms (63-500 μm) 

that live among the grains of sediment; and macroinfauna, slightly larger organisms (>0.5 mm; 0.02 in) 

that live in the sediment (Dames and Moore, Inc., 1979). Shrimp and demersal fish are closely associated 

with the benthic community. The most abundant organisms on the continental shelf are the depositfeeding polychaetes. The slope and deep sea consist of vast areas of primarily fine sediments that support 

benthic communities with lower densities and biomass but higher diversity than the continental shelf 

(Rowe and Kennicutt, 2001).
Catastrophic Spill Event Analysis B-53

Phase 1—Initial Event

A blowout from an oil well could result in a catastrophic spill event. A catastrophic blowout would 

result in released oil rapidly rising to the sea surface because all known reserves in the GOM have 

specific gravity characteristics that would preclude oil from sinking immediately after release at a 

blowout site. The oil would surface almost directly over the source location. However, if the oil is 

ejected under high pressure, micro-droplets of oil may form and become entrained in the water column 

(Boehm and Fiest, 1982; Adcroft et al., 2010). The upward movement of the oil may be reduced if 

methane mixed with the oil is dissolved into the water column, reducing the oil’s buoyancy (Adcroft 

et al., 2010). Large oil droplets would rise to the sea surface, but smaller droplets, formed by vigorous 

turbulence in the plume or the injection of dispersants, may remain neutrally buoyant in the water column, 

creating a subsurface plume (Adcroft et al., 2010; Joint Analysis Group, 2010). Dispersed oil in the water 

column begins to biodegrade and may flocculate with particulate matter, promoting sinking of the 

particles. Subsea plumes or sinking oil on particulates may contact portions of the seafloor.

A catastrophic blowout outside the well casing and below the seafloor or at the seafloor-water 

interface could resuspend large quantities of bottom sediments and create a large crater, destroying many 

organisms within a few hundred meters of the wellhead. Some fine sediment could travel up to a few 

thousand meters before redeposition, negatively impacting a localized area of benthic communities. The 

localized seafloor habitat around which a seafloor blowout occurs would be impacted by suspended and 

redeposited sediment.

A catastrophic blowout that occurs above the seabed (at the rig, along the riser between the seafloor 

and sea surface, or through leak paths on the BOP/wellhead) would not disturb the sediment.

The use of subsea dispersants would increase the exposure of offshore benthic habitats to dispersed 

oil droplets in the water column, as well as the chemicals used in the dispersants. The use of subsea 

dispersants is not likely to occur for seafloor blowouts outside the well casing.

Impacts to Soft Bottom Benthic Communities

Impacts that occur to benthic organisms as a result of a blowout would depend on the type of blowout 

and their distance from the blowout. Also, if the blowout were to occur beneath the seabed, soft sediment 

habitat would be destroyed by the formation of a crater, and the suspension and subsequent deposition of 

disturbed sediment would smother localized areas of benthic communities. A blowout that occurs outside 

the well casing can rapidly deposit 30 cm (12 in) or more of sediment within a few hundred meters and 

may smother much of the soft bottom community in a localized area. Benthic communities exposed to 

large amounts of resuspended and deposited sediments following a catastrophic, subsurface blowout 

could be subject to smothering, sediment suffocation, and exposure to resuspended toxic contaminants. 

Impacts to organisms as a result of sedimentation would vary based on species tolerance, degree of 

sedimentation, length of exposure, burial depth, and vertical migration ability through sediment.

A portion or the entire rig may sink to the seafloor as a result of a blowout. The benthic features and 

communities upon which the rig settles would be destroyed or smothered. A settling rig may suspend 

sediments, which may smother nearby benthic communities. The habitats beneath the rig may be 

permanently lost; however, the rig itself may become an artificial reef upon which epibenthic organisms 

may settle. The surrounding benthic communities that were smothered by sediment would repopulate 

from nearby stocks through spawning recruitment and immigration if the hard substrate upon which they 

live was not physically destroyed.

Phase 2—Offshore Spill

A spill from a shallow-water blowout could impact benthic communities on the continental shelf. 

The scenario (Table B-4) for a catastrophic spill on the continental shelf is assumed to last 2-5 months 

and to release 30,000 bbl per day. A total volume of 0.9-3.0 MMbbl of South Louisiana midrange 

paraffinic sweet crude oil could be released, which would float (APIo >10). An anticipated 35,000 bbl of 

dispersant may be applied to the surface waters.

A spill from a deepwater blowout could also impact shelf communities and deepwater communities. 

The scenario (Table B-4) for a catastrophic spill in deep water is assumed to last 4-6 months and to 

release 30,000-60,000 bbl per day. A total volume of 2.7-7.2 MMbbl of South Louisiana midrange 

paraffinic sweet crude oil could be released, which would float (APIo >10). Oil properties may change as 
B-54 Central and Eastern Planning Areas Supplemental EIS

it passes up the well and through the water column, and it may become emulsified. An anticipated 

33,000 bbl of dispersant may be applied to the surface waters and 16,500 bbl may be applied subsea. 

Weathering and dilution of the oil would also occur as it travels from its launch point. It is unlikely that a 

subsurface plume from a deepwater blowout would impact shelf communities. The oil is anticipated to 

remain in deep water and be directed by water currents in the deep water. These currents do not typically 

transit from deep water up onto the shelf (Pond and Pickard, 1983; Inoue et al., 2008).

Impacts to Soft Bottom Benthic Communities

Impacts from Surface Oil

Surface oil slicks can spread over a large area; however, the majority of the slick is comprised of a 

very thin surface layer of oil moved by winds and currents (Lewis and Aurand, 1997). The potential of 

surface oil slicks to affect benthic habitats is limited by its ability to mix into the water column. Soft 

bottom benthic communities below 10-m (33-ft) water depth are protected from surface oil because of its 

lack of ability to mix with water (Lange, 1985; McAuliffe et al., 1975 and 1981a; Tkalich and Chan, 

2002). Benthic organisms would not become physically coated or smothered by surface oil. However, if 

this surface oil makes its way into the water column through physical mixing, the use of dispersants, or 

the sedimenting to particles in the water column, benthic communities may be impacted. These scenarios 

are discussed in later sections.

Disturbance of the sea surface by storms can mix surface oil into the water column, but the effects are 

generally limited to the upper 10-20 m (33-66 ft) (Lange, 1985; McAuliffe et al., 1975 and 1981a; Tkalich 

and Chan, 2002). Therefore, soft bottom benthic communities located in shallow water have the potential 

to be fouled by oil that is floating on shallow water and mixes to the depth of the seafloor. Nearshore oil 

deposits that occur in sheltered areas, such as bays, may remain in the sediment and impact organisms for 

long periods. Oil in nearshore sediments was found in high concentrations 8 years following the Exxon 

Valdez spill (Dean and Jewett, 2001). Benthic communities located in deeper water would not be 

impacted by oil physically mixed into the water column. However, if dispersants are used, they would 

enable oil to mix into the water column and possibly impact organisms in deeper water. Dispersants are 

discussed later in this chapter. Further detail on this catastrophic OSRA run is contained in Appendix C 

of the CPA 235/241/247 Supplemental EIS and EPA 225/226 EIS. 

Impacts from Subsurface Oil

The presence of a subsurface oil plume on the continental shelf from a shallow-water blowout may 

affect soft bottom benthic communities. A majority of the oil released is expected to rise rapidly to the 

sea surface above the launch point because of the specific gravity characteristics of the oil reserves in the 

GOM, thus not directly sinking to the seafloor and smothering benthic communities. If the oil is ejected 

under high pressure, oil droplets may become entrained in the water column (Boehm and Fiest, 1982; 

Adcroft et al., 2010). The upward movement of the oil may be reduced if methane mixed with the oil is 

dissolved into the water column, reducing the oil’s buoyancy (Adcroft et al., 2010). Large oil droplets 

would rise to the sea surface, but smaller droplets, formed by vigorous turbulence in the plume or the 

injection of dispersants, may remain neutrally buoyant in the water column, creating a subsurface plume 

(Adcroft et al., 2010; Joint Analysis Group, 2010). Dispersed oil in the water column begins to 

biodegrade and may flocculate with particulate matter, promoting sinking of the particles. Subsurface 

plumes generated by high-pressure dissolution of oil may come in contact with portions of the seafloor as 

it travels from the source. A sustained spill would continuously create surface slicks and possibly 

subsurface plumes. Some of the oil in the water column will become diluted or evaporated over time, 

reducing any localized transport to the seafloor (Vandermeulen, 1982). In addition, microbial degradation 

of the oil occurs in the water column so that the oil would be less toxic as it travels from the source 

(Hazen et al., 2010). However, a sustained spill may result in elevated exposure concentrations to benthic 

communities if the plume reaches them. The longer the spill takes to stop, the longer the exposure time 

and higher the exposure concentration may be.

Soft bottom infaunal communities that come into direct contact with oil may experience sublethal 

and/or lethal effects. The greatest effects of oil exposure would occur close to the well and impacts 

would decrease with distance. A subsurface plume that contacts the seafloor may result in acute toxicity. 

The water accommodated fraction (WAF) or water soluble fraction (WSF) of oil that dissolves in water 
Catastrophic Spill Event Analysis B-55

may be the most toxic to organisms, especially larvae and embryos in the water column or at the water 

sediment interface. Lethal effects for marine invertebrates have been reported at exposures between 

0.10 ppm to 100 ppm WSF of oil (Suchanek, 1993). The WSF of petroleum hydrocarbons was reportedly 

highly toxic to the embryos of oysters and sea urchins, while sediment containing weathered fuel was not 

toxic to the same species (Beiras and Saco-Álvarez, 2006). Quahog clam embryos and larvae also 

experienced toxicity and deformation of several different crude oils at WSF concentrations between 

0.10 ppm and 10 ppm (Byrne and Calder, 1977). An experiment indicated that the WSF of No. 2 fuel oil 

at a concentration of 5 ppm disrupted the cellular development of 270 out of 300 test organisms within 

3 hours of exposure (Byrne, 1989). After 48 hours exposure, all of the test organisms died and the 

48-hour LC50 (lethal concentration for 50% of the test population) was calculated to be 0.59 ppm (Byrne, 

1989). Another experiment indicated that a WSF of 0.6 ppm and greater of No. 2 fuel oil depressed 

respiration, reduced mobility of sperm, interfered with cell fertilization and embryonic cleavage, and 

retarded larval development of sand dollar eggs (Nicol et al., 1977). Experiments that exposed sea urchin 

embryos to 10-30 ppm WSF of diesel oil for 15-45 days resulted in defective embryonic development and 

nonviable offspring (Vashchenko, 1980). Therefore, any dissolved petroleum hydrocarbon constituents 

that reach larval benthic organisms may cause acute toxicity and other developmental effects to this life 

stage. The WAF and WSF, however, should be considered “worst-case scenario” values as they are 

based on a closed system at equilibrium with the contaminant and, due to its size and complexity, the 

GOM will not reach equilibrium with released oil.

Oil in the water column may impact pelagic eggs and larvae of invertebrates. Toxicity tests indicated 

that eggs of many species were killed by diesel oil in seawater, and in general, the smaller eggs died 

earlier (Chia, 1973). Bivalve fertilization and sperm fertility were depressed with exposure to crude oil 

(Renzoni, 1975). The WSF of crude oil was also highly toxic to gametes, embryos, and larvae of bivalves 

(Renzoni, 1975). Oil concentrations of 0.1 and 1 ppm caused a decrease in fertilization, development of 

embryos, survival or larvae, and larval growth in the bivalves Crassostrea virginica and Mulinia lateralis

(Renzoni, 1975). Another experiment, however, calculated the LC50 for a 6-hour exposure of the 

gametes, eggs, and larvae of three bivalves (Crassostrea angulata, Crassostrea gigas, and Mytilus 

galloprovincialis) to be 1,000 ppm oil and 1,000 ppm oil plus dispersant (Renzoni, 1973). Toxicity varies 

widely among species and oil types.

Sublethal responses of marine invertebrates may result in population level changes (Suchanek, 1993). 

Such sublethal responses may occur at concentrations as low as 1-10 ppb (Hyland and Schneider, 1976). 

Sublethal impacts may include reduced feeding rates, reduced ability to detect food, ciliary inhibition, 

reduced movement, decreased aggression, and altered respiration (Suchanek, 1993).

The farther a subsea plume travels, the more physical and biological changes occur to the oil before it 

reaches benthic organisms. Oil would become diluted as it physically mixes with the surrounding water, 

and significant evaporation occurs from surface slicks. The most toxic compounds of oil are lost within 

the first 24 hours of a spill, leaving the heavier, less toxic compounds in the system (Ganning et al., 

1984). An even greater component of the lighter fuel oils dissipates through evaporation. Water currents 

could carry a plume to contact the seafloor directly, but a likely scenario would be for the oil to adhere to 

other particles and precipitate to the seafloor, much like rainfall (International Tanker Owners Pollution 

Federation Limited, 2011; Kingston et al., 1995). Oil also would reach the seafloor through consumption 

by plankton, with excretion distributed over the seafloor (International Tanker Owners Pollution 

Federation Limited, 2011). The longer and farther a subsea plume travels in the sea, the more dilute the 

oil would be (Vandermeulen, 1982; Tkalich and Chan, 2002). In addition, microbial degradation of the 

oil occurs in the water column, reducing toxicity (Hazen et al., 2010; McAuliffe et al., 1981b). The oil 

would move in the direction of prevailing currents (S.L. Ross Environmental Research Ltd., 1997) and, 

although the oil would weather with the distance it travels, low levels of oil transported in subsea plumes 

would impact benthic communities. These mechanisms would result in a wide distribution of small 

amounts of oil. This oil would be in the process of biodegradation from bacterial action, which would 

continue on the seafloor, resulting in scattered microhabitats with an enriched carbon environment (Hazen 

et al., 2010).

Localized areas of lethal effects would be recolonized by populations from neighboring soft bottom 

substrate once the oil in the sediment has been sufficiently reduced to a level able to support marine life 

(Sanders et al., 1980; Lu and Wu, 2006; Ganning et al., 1984; Gómez Gesteira and Dauvin, 2000; Dean 

and Jewett, 2001). This initial recolonization process may be fairly rapid, but full recovery may take up 

to 10 years depending on the species present, substrate in the area, toxicity of oil spilled, concentration 
B-56 Central and Eastern Planning Areas Supplemental EIS

and dispersion of oil spilled, and other localized environmental factors that may affect recruitment 

(Kingston et al., 1995; Gómez Gesteira and Dauvin, 2000; Sanders et al., 1980; Conan, 1982). 

Opportunistic species would take advantage of the barren sediment, repopulating impacted areas first. 

These species may occur within the first recruitment cycle of the surrounding populations or from species 

immigration from surrounding stocks and may maintain a stronghold in the area until community 

succession begins (Rhodes and Germano, 1982; Sanders et al., 1980).

It is unlikely that a subsurface plume from a deepwater blowout would impact shelf communities. 

The oil is anticipated to remain in deep water and be directed by water currents in the deep water. These 

currents do not typically transit from deep water up onto the shelf (Pond and Pickard, 1983; Inoue et al., 

2008). However, the impacts to deepwater soft bottom benthic communities as a result of a blowout 

would similar to those on the continental shelf.

Impacts from Dispersed Oil

If dispersants are used at the sea surface, oil may mix into the water column, and if they are applied 

subsea, dispersed oil can travel with currents and contact the seafloor. Chemically dispersed oil from a 

surface slick is not anticipated to result in lethal exposures to organisms on the seafloor. The chemical 

dispersion of oil may increase the weathering process and allow surface oil to be diluted by greater 

amounts of water. Reports on dispersant usage on surface plumes indicate that a majority of the dispersed 

oil remains in the top 10 m (33 ft) of the water column, with 60 percent of the oil in the top 2 m (6 ft) 

(McAuliffe et al., 1981a). Dispersant usage also reduces the oil’s ability to stick to particles in the water 

column, minimizing oiled sediments from traveling to the seafloor (McAuliffe et al., 1981a). If applied, 

subsea benthic communities near the source could be exposed to dispersed oil that is concentrated enough 

to harm the benthic community. If the oil remains suspended for a longer period of time, it would be 

more dispersed and less concentrated. There is very little information on the behavior of subsea 

dispersants.

Dispersed oil used at the sea surface reaching the benthic communities in the Gulf of Mexico would 

be expected to be at very low concentrations (<1 ppm) (McAuliffe et al., 1981a). Such concentrations 

would not be life threatening to larval or adult stages on the seafloor based on experiments conducted 

with benthic and pelagic species (Scarlett et al., 2005; Hemmer et al., 2010; George-Ares and Clark, 

2000). Any dispersed oil in the water column that comes in contact with benthic communities may evoke 

short-term negative responses by the organisms (Scarlett et al., 2005). Sublethal responses may include 

reduced feeding rate, erratic movement, and tentacle retraction (Scarlett et al., 2005). In addition, 

although dispersants were detected in waters off Louisiana after the Macondo well blowout and spill, they 

were below USEPA benchmarks of chronic toxicity (OSAT, 2010). The rapid dilution of dispersants in 

the water column and lack of transport to the seafloor was also reported by OSAT (2010) where no 

dispersants were detected in sediment on the Gulf floor following the Macondo well blowout and spill. 

Impacts from Oil Adhering to Sediments

Oiled sediment that settles to the seafloor may affect organisms upon which it settles. The greatest 

impacts would be closest to the well where organisms may become smothered by particles and exposed to 

hydrocarbons. High concentrations of suspended sediment in the water column may lend to large 

quantities of oiled sediment (Moore, 1976). Deposition of oiled sediment is anticipated to begin 

occurring within days or weeks of the spill and may be fairly deep near the source (Ganning et al., 1984; 

Gómez Gesteira and Dauvin, 2000). Oily sand layers were reported to be 10 cm (4 in) deep on the 

seafloor near the Amoco Cadiz spill (Gómez Gesteira and Dauvin, 2000). Acute toxicity may occur near 

the spill, eliminating benthic communities.

Much of the oil released from a blowout would rise to the sea surface, therefore dispersing the 

released oil before it makes its way back to the seafloor through flocculation, by deposition from 

organisms that pass it through their systems with food, and by adhering to sinking particles in the water 

column. In addition, small droplets of oil that are entrained in the water column for extended periods of 

time may migrate a great distance from their point of release and may attach to suspended particles in the 

water column and later be deposited on the seafloor (McAuliffe et al., 1975). The majority of organisms 

exposed to oiled sediment are anticipated to experience low-level concentrations because as the oiled 
Catastrophic Spill Event Analysis B-57

sediments settle to the seafloor they are widely dispersed. Impacts may include reduced recruitment 

success, reduced growth, and altered community composition as a result of impaired recruitment.

Impacts from Oil-Spill-Response Activity

Continued localized disturbance of soft bottom communities may occur during oil-spill response 

efforts. Anchors used to set booms to contain oil or vessel anchors in decontamination zones may affect 

infaunal communities in the response activity zone. Infaunal communities may be altered in the anchor 

scar, and deposition of suspended sediment may result from the setting and resetting of anchors. The 

disturbed benthic community should begin to repopulate from the surrounding communities during their 

next recruitment event and through immigration of organisms from surrounding stocks. Any 

decontamination activities, such as cleaning vessel hulls of oil, may also contaminate the sediments of the 

decontamination zone, as some oil may settle to the seabed, impacting the underlying benthic community.

If a blowout occurs at the seafloor, drilling muds (primarily barite) may be pumped into a well in 

order to “kill” it. If a kill is not successful, the mud (possibly tens of thousands of barrels) may be forced 

out of the well and deposited on the seafloor near the well site. Any organisms beneath heavy layers of 

the extruded drilling mud would be buried. Base fluids of drilling muds are designed to be low in toxicity 

and biodegradable in offshore marine sediments (Neff et al., 2000). However, as bacteria and fungi break 

down the drilling fluids, the sediments may temporarily become anoxic (Neff et al., 2000). Benthic 

macrofaunal recovery would occur when drilling mud concentrations are reduced to levels that enable the 

sediment to become re-oxygenated (Neff et al., 2000). Complete community recovery from drilling mud 

exposure may take 3-5 years, although microbial degradation of drilling fluids, followed by an influx of 

tolerant opportunistic species, is anticipated to begin almost immediately (Neff et al., 2000). In addition, 

the extruded mud may bury hydrocarbons from the well, making them a hazard to the infaunal species 

and difficult to remove.

Phase 3—Onshore Contact

There would likely be no additional adverse impacts to soft bottom benthic communities as a result of 

events and the potential impact producing factors that could occur throughout Phase 3 of a catastrophic 

spill because these soft bottom benthic communities are located below the water line.

Phase 4—Post-Spill, Long-Term Recovery and Response

Benthic Habitats

In situations where soft bottom infaunal communities are negatively impacted, recolonization by 

populations from neighboring soft bottom substrate would be expected over a relatively short period. 

Recolonization would begin with recruitment and immigration of opportunistic species from surrounding 

stocks. More complex communities would follow with time. Repopulation could take longer for areas 

affected by direct oil contact in higher concentrations.

Many of the organisms on soft bottoms live within the sediment and have the ability to migrate 

upward in response to burial by sedimentation. A blowout that occurs outside the well casing can rapidly 

deposit 30 cm (12 in) or more of sediment within a few hundred meters and may smother much of the soft 

bottom community in a localized area. In situations where soft bottom infaunal communities are 

negatively impacted, recolonization by populations from neighboring soft bottom substrate would be 

expected over a relatively short period of time for all size ranges of organisms, in a matter of days for 

bacteria, and probably less than 1 year for most macrofauna and megafauna species. Recolonization 

could take longer for areas affected by direct contact of concentrated oil. Initial repopulation from nearby 

stocks of pioneering species, such as tube-dwelling polychaetes or oligochaetes, may begin with the next 

recruitment event (Rhodes and Germano, 1982). Full recovery would follow as later stages of 

successional communities overtake the pioneering species (Rhodes and Germano, 1982). The time it 

takes to reach a climax community may vary depending on the species and degree of impact. Full benthic 

community recovery may take years to decades if the benthic habitat is heavily oiled (Gómez Gesteira 

and Dauvin, 2000; Sanders et al., 1980; Conan, 1982). A slow recovery rate would result in a community 

with reduced biological diversity and possibly a lesser food value for predatory species.
B-58 Central and Eastern Planning Areas Supplemental EIS

Localized areas of lethal effects would be recolonized by populations from neighboring soft bottom 

substrate once the oil in the sediment has been sufficiently reduced to a level able to support marine life 

(Sanders et al., 1980; Lu and Wu, 2006; Ganning et al., 1984; Gómez Gesteira and Dauvin, 2000; Dean 

and Jewett, 2001). This initial recolonization process may be fairly rapid, but full recovery may take up 

to 10 years depending on the species present, substrate in the area, toxicity of oil spilled, concentration 

and dispersion of oil spilled, and other localized environmental factors that may affect recruitment 

(Kingston et al., 1995; Gómez Gesteira and Dauvin, 2000; Sanders et al., 1980; Conan, 1982). 

Opportunistic species would take advantage of the barren sediment, repopulating impacted areas first. 

These species may occur within the first recruitment cycle of the surrounding populations or from species 

immigration from surrounding stocks and may maintain a stronghold in the area until community 

succession begins (Rhodes and Germano, 1982; Sanders et al., 1980).

Overall Summary and Conclusion (Phases 1-4)

A catastrophic blowout and spill would have the greatest impact on the soft bottom benthic 

communities in the immediate vicinity of the spill. Turbidity, sedimentation, and oiling would be 

heaviest closest to the source, and decrease with distance from the source. Complete loss of benthic 

populations may occur with heavy sedimentation and oil deposition. Farther from the well, a less thick 

layer of sediment would be deposited and oil would be dispersed from the source, resulting in sublethal 

impacts. The recovery of benthic populations would begin with recruitment from surrounding areas fairly 

rapidly.

B.3.1.12. Marine Mammals

Phase 1—Initial Event

Phase 1 of the scenario is the initiation of a catastrophic blowout event. Impacts, response, and 

intervention depend on the spatial location of the blowout and leak. For this analysis, an explosion and 

subsequent fire are assumed to occur. If a blowout associated with the drilling of a single exploratory 

well occurs, this could result in a fire that would burn for 1 or 2 days. If a blowout occurs on a production 

platform, other wells could feed the fire, allowing it to burn for over a month. The drilling rig or platform 

may sink. If the blowout occurs in shallow water, the sinking rig or platform may land in the immediate 

vicinity; if the blowout occurs in deep water, the rig or platform could land a great distance away, beyond 

avoidance zones. Regardless of water depth, the immediate response would be from search and rescue 

vessels and aircraft, such as USCG cutters, helicopters, and rescue planes, and firefighting vessels. 

Potential impacts reflect the explosion, subsequent fire for 1-30 days, and the sinking of the platform in 

the immediate vicinity and up to 1 mi (1.6 km) from the well.

Depending on the type of blowout, the pressure waves and noise generated by the eruption of gases 

and fluids would likely be significant enough to harass, injure, or kill marine mammals, depending on the 

proximity of the animal to the blowout. A high concentration of response vessels could result in

harassment or displacement of individuals and could place marine mammals at a greater risk of vessel 

collisions, which would likely cause fatal injuries.

The scenarios for each phase, including cleanup methods, can be found in Table B-4. 

Phase 2—Offshore Spill

Phase 2 of the analysis focuses on the spill and response in Federal and State offshore waters. A 

catastrophic spill would likely spread hundreds of square miles. Also, the oil slick may break into several 

smaller slicks, depending on local wind patterns that drive the surface currents in the spill area. Potential 

impacts reflect spill and response in Federal and State offshore waters. Season and temperature variations 

can result in different resource impacts due to variations in oil persistence and oil and dispersant toxicity 

and because of differences in potential exposure of the resources throughout various life cycle stages.

An oil spill and related spill-response activities can impact marine mammals that come into contact 

with oil and remediation efforts. The marine mammals’ exposure to hydrocarbons persisting in the sea 

may result in sublethal impacts (e.g., decreased health, reproductive fitness, longevity, and increased 

vulnerability to disease), some soft tissue irritation, respiratory stress from inhalation of toxic fumes, food 

reduction or contamination, direct ingestion of oil and/or tar, and temporary displacement from preferred 
Catastrophic Spill Event Analysis B-59

habitats or migration routes. More detail on the potential range of effects to marine mammals from 

contact with spilled oil can be found in Geraci and St. Aubin (1990). The best available information does 

not provide a complete understanding of the effects of the spilled oil and active response/cleanup 

activities on marine mammals. For example, it is expected that the large amount of chemical dispersants 

being used on the oil may act as an irritant on the marine mammals’ tissues and sensitive membranes.

The increased human presence after an oil spill (e.g., vessels) would likely add to changes in behavior 

and/or distribution, thereby potentially stressing marine mammals further and perhaps making them more 

vulnerable to various physiologic and toxic effects. In addition, the large number of response vessels 

could place marine mammals at a greater risk of vessel collisions, which could cause fatal injuries.

The potential biological removal (PBR) level is defined by the Marine Mammal Protection Act as the 

maximum number of animals, not including natural mortalities that may be removed from a marine 

mammal stock while allowing that stock to reach or maintain its optimum sustainable population. 

However, in the Gulf of Mexico, many marine mammal species have unknown PBRs or PBRs with 

outdated abundance estimates, which are considered undetermined. The biological significance of any 

injury or mortality would depend, in part, on the size and reproductive rates of the affected stocks, as well 

as the number, age, and size of the marine mammals affected.

The Deepwater Horizon explosion, oil spill, and response in Mississippi Canyon Block 252 

(including use of dispersants) have impacted marine mammals that have come into contact with oil and 

remediation efforts. According to the “Dolphins and Whales of the Gulf of Mexico Oil Spill” website, 

within the designated Deepwater Horizon explosion, oil spill, and response area, 171 marine mammals 

(89% of which were deceased) were reported. This includes 155 bottlenose dolphins, 2 Kogia spp., 

2 melon-headed whales, 6 spinner dolphins, 2 sperm whales, and 4 unknown species (USDOC, NMFS, 

2011b). All marine mammals collected either alive or dead were found east of the Louisiana/Texas 

border through Apalachicola, Florida. The highest concentration of strandings has occurred off eastern 

Louisiana, Mississippi, and Alabama, with a significantly lesser number off western Louisiana and 

western Florida (USDOC, NMFS, 2011b). Due to known low-detection rates of carcasses, it is possible 

that the number of deaths of marine mammals is underestimated (Williams et al., 2011). It is also 

important to note that evaluations have not yet confirmed the cause of death, and it is possible that many, 

some, or no carcasses collected were related to the Deepwater Horizon explosion, oil spill, and response. 

These stranding numbers are significantly greater than reported in past years; though it should be further 

noted that stranding coverage (i.e., effort in collecting strategies) has increased considerably due to the 

Deepwater Horizon explosion, oil spill, and response. Further detail on this catastrophic OSRA run is 

contained in Appendix C of the CPA 235/241/247 Supplemental EIS and EPA 225/226 EIS. 

Phase 3—Onshore Contact

Phase 3 focuses on nearshore (e.g., inside bays and in close proximity to shoreline) and onshore spill 

response and oil initially reaching the shoreline during the spill event or while the oil still persists in the 

offshore environment once the spillage has been stopped. It is likely that Phases 2 and 3 could occur 

simultaneously. The duration of the initial shoreline oiling is measured from initial shoreline contact until 

the well is capped or killed and the remaining oil dissipates offshore. Re-oiling of already cleaned or 

previously impacted areas could be expected during Phase 3. In addition to the response described in 

Phase 2, nearshore and onshore efforts would be introduced in Phase 3 as oil entered coastal areas and 

contacted shore. Potential impacts reflect the spill and response in very shallow coastal waters and once 

along the shoreline. Season and temperature variations can result in different resource impacts due to 

variations in oil persistence and oil and dispersant toxicity and because of differences in potential 

exposure of the resources throughout various life cycle stages.

A high-volume oil spill lasting 90 days could directly impact over 22 species of marine mammals. As 

a spill enters coastal waters, manatees and coastal and estuarine dolphins would be the most likely to be 

affected.

Manatees primarily inhabit open coastal (shallow nearshore) areas and estuaries, and they are also 

found far up in freshwater tributaries. Florida manatees have been divided into four distinct regional 

management units: the Atlantic Coast Unit that occupies the east coast of Florida, including the Florida 

Keys and the lower St. Johns River north of Palatka, Florida; the Southwest Unit that occurs from Pasco 

County, Florida, south to Whitewater Bay in Monroe County, Florida; the Upper St. Johns River Unit that 

occurs in the river south of Palatka, Florida; and the Northwest Unit that occupies the Florida Panhandle 
B-60 Central and Eastern Planning Areas Supplemental EIS

south to Hernando County, Florida (Waring et al., 2012). Manatees from the Northwest Unit are more 

likely to be seen in the northern GOM, and they can be found as far west as Texas; however, most 

sightings are in the eastern GOM (Fertl et al., 2005).

During warmer months (June to September), manatees are common along the Gulf Coast of Florida 

from the Everglades National Park northward to the Suwannee River in northwestern Florida. Although 

manatees are less common farther westward, manatee sightings increase during the warmer summer 

months. Winter habitat use is primarily influenced by water temperature as animals congregate at natural 

(springs) and/or artificial (power plant outflows) warm water sources (Alves-Stanley et al., 2010). 

Manatees are infrequently found as far west as Texas (Powell and Rathbun, 1984; Rathbun et al., 1990; 

Schiro et al., 1998). If a catastrophic oil spill reached the Florida coast when manatees were in or near 

coastal waters, the spill could have population-level effects.

It is possible that manatees could occur in coastal areas where vessels traveling to and from the spill 

site could affect them. A manatee present where there is vessel traffic could be injured or killed by a 

vessel strike (Wright et al., 1995). Due to the large number of vessels responding to a catastrophic spill 

both in coastal waters and traveling through coastal waters to the offshore site, manatees would have an 

increased risk of collisions with boats. Vessel strikes are the primary cause of death of manatees.

The best available count of Florida manatees is 4,824 animals, based on a January 2014 aerial survey 

of warm water refuges (Florida Fish and Wildlife Conservation Commission, 2014a). By February 2014, 

there were 114 manatee carcasses collected in Florida, 20 of these animals died of human causes (Florida 

Fish and Wildlife Conservation Commission, 2014b). Human causes included water control structures, 

entanglement in and ingestion of marine debris, entrapment in pipes/culverts, and collisions with 

watercraft. Seventy percent of the manatees that died of human causes were killed by watercraft (Florida 

Fish and Wildlife Conservation Commission, 2014b). Therefore, if a catastrophic spill and response 

vessel traffic occurred near manatee habitats in the eastern Gulf of Mexico, population-level impacts 

could occur because the possibility exists for the number of mortalities to exceed the potential biological 

removal.

There have been no experimental studies and only a few observations suggesting that oil impacts have 

harmed any manatees (St. Aubin and Lounsbury, 1990). Types of impacts to manatees and dugongs from 

contact with oil include (1) asphyxiation because of inhalation of hydrocarbons, (2) acute poisoning 

because of contact with fresh oil, (3) lowering of tolerance to other stress because of the incorporation of 

sublethal amounts of petroleum components into body tissues, (4) nutritional stress through damage to 

food sources, and (5) inflammation or infection and difficulty eating because of oil sticking to the sensory 

hairs around their mouths (Preen, 1989, in Sadiq and McCain, 1993; Australian Maritime Safety 

Authority, 2003). For a population whose environment is already under great pressure, even a localized 

incident could be significant (St. Aubin and Lounsbury, 1990). Spilled oil might affect the quality or 

availability of aquatic vegetation, including seagrasses, upon which manatees feed.

Bottlenose dolphins were the most affected species of marine mammals from the Deepwater Horizon

explosion, oil spill, and response. Bottlenose dolphins can be found throughout coastal waters in the Gulf 

of Mexico. Like manatees, dolphins could be affected, possibly to population level, by a catastrophic oil 

spill if it reaches the coast (as well as affecting them in the open ocean), through direct contact, 

inhalation, ingestion, and stress, as well as through collisions with cleanup vessels.

Phase 4—Post-Spill, Long-Term Recovery and Response

Phase 4 focuses on long term recovery once the well has been capped and the spill has stopped. 

During the final phase of a catastrophic blowout and spill, it is presumed that the well has been capped or 

killed and cleanup activities are concluding. While it is assumed that the majority of spilled oil would be 

dissipated offshore within 1-2 months (depending on season and temperature) of stopping the flow, oil 

has the potential to persist in the environment long after a spill event and has been detected in sediment 

30 years after a spill. On sandy beaches, oil can sink deep into the sediments. In tidal flats and salt 

marshes, oil may seep into the muddy bottoms. Potential impacts reflect long term persistence of oil in 

the environment and residual and long term clean-up efforts.

Even after the spill is stopped, oilings or deaths of marine mammals would still likely occur because 

of oil and dispersants persisting in the water, past marine mammal/oil or dispersant interactions, and 

ingestion of contaminated prey. The animals’ exposure to hydrocarbons persisting in the sea may result 

in sublethal impacts (e.g., decreased health, reproductive fitness, and longevity; and increased 
Catastrophic Spill Event Analysis B-61

vulnerability to disease) and some soft tissue irritation, respiratory stress from inhalation of toxic fumes,

food reduction or contamination, direct ingestion of oil and/or tar, and temporary displacement from 

preferred habitats or migration routes. A catastrophic oil spill could lead to increased mortalities, 

resulting in potential population-level effects for some species/populations (USDOC, NMFS, 2010a). 

On December 13, 2010, NMFS declared an unusual mortality event (UME) for cetaceans (whales and 

dolphins) in the Gulf of Mexico. An UME is defined under the Marine Mammal Protect Act as a 

“stranding that is unexpected, involves a significant die-off of any marine mammal population, and 

demands immediate response.” Evidence of the UME was first noted by NMFS as early as February 1, 

2010, before the Deepwater Horizon explosion, oil spill, and response. As of November 16, 2014, a total 

of 1,283 cetaceans (6% stranded alive and 94% stranded dead) have stranded since the start of the UME, 

with a vast majority of these strandings between Franklin County, Florida, and the Louisiana/Texas 

border. After the initial response phase ended, there were eight dolphins killed during a fish-related 

scientific study and one dolphin killed incidental to trawl relocation for a dredging project. More detail 

on the UME can be found on NMFS’s website (USDOC, NMFS, 2014).

On May 9, 2012, NOAA declared an UME for bottlenose dolphins in five Texas counties. The cause 

of this UME is unknown and cannot be attributed directly to the Deepwater Horizon explosion, oil spill, 

and response. The strandings were coincident with a harmful algal bloom of Karenia brevis that started 

in September 2011 in southern Texas, but researchers have not determined that was the cause of the 

event. The UME lasted from November 2011-March 2012, when 126 bottlenose dolphins stranded in 

Aransas, Calhoun, Kleberg, Galveston, and Brazoria Counties in Texas. Of the 126 animals stranded, 

only 4 were found alive. Preliminary findings included infection in the lung, poor body condition, 

discoloration of the teeth, and in four animals, a black/grey, thick mud-like substance in the stomachs was 

found. Currently, there are no red tide blooms occurring in the region, and stranding rates have returned 

to normal levels (USDOC, NMFS, 2013).

Overall Summary and Conclusion (Phases 1-4)

Accidental events related to a CPA and EPA proposed action have the potential to have adverse, but 

not significant impacts to marine mammal populations in the GOM. Accidental blowouts, oil spills, and 

spill-response activities may impact marine mammals in the GOM. Characteristics of impacts (i.e., acute 

vs. chronic impacts) depend on the magnitude, frequency, location, and date of accidents; characteristics 

of spilled oil; spill-response capabilities and timing; and various meteorological and hydrological factors.

B.3.1.13. Sea Turtles

Phase 1—Initial Event

Phase 1 of the scenario is the initiation of a catastrophic blowout incident. Impacts, response, and 

intervention depend on the spatial location of the blowout and leak. For this analysis, an explosion and 

subsequent fire are assumed to occur. If a blowout associated with the drilling of a single exploratory 

well occurs, this could result in a fire that would burn for 1-2 days. If a blowout occurs on a production 

platform, other wells could feed the fire, allowing it to burn for over a month. The drilling rig or platform 

may sink. If the blowout occurs in shallow water, the sinking rig or platform may land in the immediate 

vicinity; if the blowout occurs in deep water, the rig or platform could land a great distance away, beyond 

avoidance zones. Regardless of water depth, the immediate response would be from search and rescue 

vessels and aircraft, such as USCG cutters, helicopters, and rescue planes, and firefighting vessels. 

Potential impacts reflect the explosion, subsequent fire for 1-30 days, and the sinking of the platform in 

the immediate vicinity and up to 1 mi (1.6 km) from the well.

Five species of sea turtles are found in the waters of the Gulf of Mexico: green, leatherback, 

hawksbill, Kemp’s ridley, and loggerhead. All species are protected under the Endangered Species Act 

(ESA), and all are listed as endangered except the loggerhead turtle, which is listed as threatened. 

Depending on the type of blowout, an eruption of gases and fluids may generate significant pressure

waves and noise that may harass, injure, or kill sea turtles, depending on their proximity to the accident. 

A high concentration of response vessels could place sea turtles at a greater risk of fatal injuries from 

vessel collisions. All sea turtle species and life stages are vulnerable to the harmful effects of oil through 

direct contact or by fouling of their habitats and prey.
B-62 Central and Eastern Planning Areas Supplemental EIS

Further, mitigation by burning puts turtles at risk because they tend to be gathered up in the corralling 

process necessary to concentrate the oil in preparation for the burning. Trained observers should be 

required during any mitigation efforts that include burning. The scenarios for each phase, including 

cleanup methods, can be found in Table B-4. 

Phase 2—Offshore Spill

Phase 2 of the analysis focuses on the spill and response in Federal and State offshore waters. A 

catastrophic spill would likely spread hundreds of square miles. Also, the oil slick may break into several 

smaller slicks, depending on local wind patterns that drive the surface currents in the spill area. Potential 

impacts reflect spill and response in Federal and State offshore waters. Season and temperature variations 

can result in different resource impacts due to variations in oil persistence and oil and dispersant toxicity 

and because of differences in potential exposure of the resources throughout various life cycle stages.

Sea turtles are more likely to be affected by a catastrophic spill in shallow water than in deep water 

because not all sea turtles occupy a deepwater habitat. For example, Kemp’s ridley sea turtles are 

unlikely to be in water depths of 160 ft (49 m) or greater. Hawksbill sea turtles are commonly associated 

with coral reefs, ledges, caves, rocky outcrops, and high energy shoals. Green sea turtles are commonly 

found in coastal benthic feeding grounds, although they may also be found in the convergence zones of 

the open ocean. Convergence zones are areas that also may collect oil. Leatherback sea turtles are 

commonly pelagic and are the sea turtle species most likely to be affected by a deepwater oil spill. As the 

spilled oil moves toward land, additional species of sea turtles are more likely to be affected.

The Deepwater Horizon explosion, oil spill, and response in Mississippi Canyon Block (including use 

of dispersants) have impacted sea turtles that have come into contact with oil and remediation efforts. For 

the latest available information on oiled or affected sea turtles documented in the area, refer to NMFS’s 

“Sea Turtles and the Gulf of Mexico Oil Spill” website (USDOC, NMFS, 2011c).

According to this NMFS website, 1,146 sea turtles have been collected (537 alive, 609 deceased) as 

of February 15, 2011. Of these, 201 were greens, 16 hawksbills, 809 Kemp’s ridleys, 88 loggerheads, 

and the remaining 32 unknown (USDOC, NMFS, 2011c). Individuals were documented either through 

strandings or directed offshore captures. Due to low detection rates of carcasses in prior events, it is 

possible that the number of deaths of sea turtles is underestimated (Epperly et al., 1996). It is also 

important to note that evaluations have not yet confirmed the cause of death, and it is possible that not all 

carcasses were related to the Deepwater Horizon explosion, oil spill, and response. Over the last 2 years, 

NOAA has documented increased numbers of sea turtle strandings in the northern GOM. Many of the 

stranded turtles were reported from Mississippi and Alabama waters, and very few showed signs of 

external oiling (believed to be related to the Deepwater Horizon explosion, oil spill, and response). 

Necropsy results from many of the stranded turtles indicate mortality due to forced submergence, which is 

commonly associated with fishery interactions. In May 2012, NMFS published the Draft EIS to reduce 

incidental bycatch and mortality of sea turtles in the southeastern U.S. shrimp fishery (Federal Register, 

2012). Further detail on this catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 

Supplemental EIS and EPA 225/226 EIS. 

The Ixtoc I well blowout and spill in the Bay of Campeche, Mexico, on June 3, 1979, resulted in the 

release of 500,000 metric tons (140 million gallons) of oil and the transport of this oil into the Gulf of 

Mexico (ERCO, 1982). Three million gallons of oil impacted Texas beaches (ERCO, 1982). According 

to the ERCO study, “Whether or not hypoxic conditions could, in fact, be responsible for areawide 

reductions in [invertebrate] faunal abundance is unclear, however.” Of the three sea turtles found dead in 

the U.S., all had petroleum hydrocarbons in the tissues examined, and there was selective elimination of 

portions of this oil, indicating chronic exposure (Hall et al., 1983). Therefore, the effects of the Ixtoc I

well blowout and spill on sea turtles in waters off Texas are still unknown.

Phase 3—Onshore Contact

Phase 3 focuses on nearshore (e.g., inside bays and in close proximity to shoreline) and onshore spill 

response, and on oil initially reaching the shoreline during the spill event or while the oil still persists in 

the offshore environment once the spillage has been stopped. It is likely that Phases 2 and 3 could occur 

simultaneously. The duration of the initial shoreline oiling is measured from initial shoreline contact until 

the well is capped or killed and the remaining oil dissipates offshore. The re-oiling of already cleaned or 
Catastrophic Spill Event Analysis B-63

previously impacted areas could be expected during Phase 3. In addition to the response described in 

Phase 2, nearshore and onshore efforts would be introduced in Phase 3 as oil entered coastal areas and 

contacted shore. Potential impacts reflect the spill and response in very shallow coastal waters and once 

along the shoreline. Season and temperature variations can result in different resource impacts due to 

variations in oil persistence and oil and dispersant toxicity and because of differences in potential 

exposure of the resources throughout various life cycle stages.

Out of the five species of sea turtle that occur in the Gulf of Mexico, only four nest in the GOM. The 

largest nesting location for the Kemp’s ridley sea turtle is in Rancho Nuevo, Mexico, but they also nest in 

Texas and Alabama. Loggerhead sea turtles nest in all states around the Gulf of Mexico. Green sea 

turtles have been cited nesting in Texas, Alabama, and Florida. Leatherback sea turtles mostly nest on the 

east coast of Florida but are recorded in Texas. Kemp’s ridley, loggerhead, and green sea turtles are 

therefore most likely to be affected by a catastrophic oil spill when there is onshore and/or offshore 

contact.

Several recent reports are available concerning Gulf of Mexico loggerheads’ nesting habitats and 

movements (Hart et al., 2013); post-nesting behavior (Foley et al., 2013); foraging sites (Foley et al., 

2014); and body size effects on growth rates (Bjorndal et al., 2013). These reports confirm the 

importance of Gulf of Mexico beaches, specifically for loggerheads. On September 22, 2011, NMFS 

issued the final rule to list 9 Distinct Population Segments (DPSs) of loggerhead sea turtles under the 

ESA and designated the GOM as the Northwest Atlantic Ocean DPS (76 FR 58868). 

Female sea turtles seasonally emerge during the warmer summer months to nest on beaches. 

Thousands of sea turtles nest along the Gulf Coast, and turtles could build nests on oiled beaches. Nests 

could also be disturbed or destroyed by cleanup efforts. Untended booms could wash ashore and become 

a barrier to sea turtle adults and hatchlings (USDOC, NOAA, 2010c). Hatchlings, with a naturally high 

mortality rate, could traverse the beach through oiled sand and swim through oiled water to reach 

preferred habitats of Sargassum floats. Response efforts could include mass movement of eggs from 

hundreds of nests or thousands of hatchlings from Gulf Coast beaches to the east coast of Florida or to the 

open ocean to prevent hatchlings entering oiled waters (Jernelöv and Lindén, 1981; USDOI, FWS, 

2010b). Due to poorly understood mechanisms that guide female sea turtles back to the beaches where 

they hatched, it is uncertain if relocated hatchlings would eventually return to the Gulf Coast to nest 

(Florida Fish and Wildlife Conservation Commission, 2010). Therefore, shoreline oiling and response 

efforts may affect future population levels and reproduction (USDOI, NPS, 2010). Sea turtle hatchling 

exposure to, fouling by, or consumption of tarballs persisting in the sea following the dispersal of an oil 

slick would likely be fatal. 

As a preventative measure during the Deepwater Horizon explosion, oil spill, and response, NMFS 

and FWS translocated a number of sea turtle nests and eggs that were located on beaches affected or 

potentially affected by spilled oil. The NMFS stranding network website (USDOC, NMFS, 2011c) 

translocated a total of 274 nests from GOM beaches to the east coast of Florida. These nests were mainly 

for hatchlings that would enter waters off Alabama and Florida’s northwest Gulf Coast. Of these, 4 were 

from green turtles, 5 from Kemp’s ridley, and 265 were loggerheads. The translocation effort ended 

August 19, 2010, at the time when biologists determined that risks to hatchlings emerging from beaches 

and entering waters off Alabama and Florida’s northwest Gulf Coast had diminished significantly and that 

the risks of translocating nests during late incubation to the east coast of Florida outweighed the risks of 

letting hatchlings emerge into the Gulf of Mexico. The hatchlings resulting from the translocations were 

all released as of September 9, 2010.

In addition to the impacts from direct contact with hydrocarbons, spill-response activities could 

adversely affect sea turtle habitat and cause displacement from suitable habitat to inadequate areas. 

Impacting factors might include artificial lighting from night operations, booms, machine and human 

activity, equipment on beaches and in intertidal areas, sand removal and cleaning, and changed beach 

landscape and composition. Some of the resulting impacts from cleanup could include interrupted or 

deterred nesting behavior, crushed nests, entanglement in booms, and increased mortality of hatchlings 

because of predation during the increased time required to reach the water (Newell, 1995; Lutcavage 

et al., 1997). The strategy for cleanup operations should vary, depending on the season.
B-64 Central and Eastern Planning Areas Supplemental EIS

Phase 4—Post-Spill, Long-Term Recovery and Response

Phase 4 focuses on long-term recovery once the well has been capped and the spill has stopped. 

During the final phase of a catastrophic blowout and spill, it is presumed that the well has been capped or 

killed and that cleanup activities are concluding. While it is assumed that the majority of spilled oil 

would be dissipated offshore within 1-2 months (depending on season and temperature) of stopping the 

flow, oil has the potential to persist in the environment long after a spill event and has been detected in 

sediment 30 years after a spill. On sandy beaches, oil can sink deep into the sediments. In tidal flats and 

salt marshes, oil may seep into the muddy bottoms. Potential impacts reflect long-term persistence of oil 

in the environment and residual and long-term cleanup efforts.

Sea turtles take many years to reach sexual maturity. Green sea turtles reach maturity between 20 and 

50 years of age; loggerheads may be 35 years old before they are able to reproduce; and hawksbill sea 

turtles typically reach lengths of 27 in (69 cm) for males and 31 in (79 cm) for females before they can 

reproduce (USDOC, NMFS, 2010a). Declines in the food supply for sea turtles, which include 

invertebrates and sponge populations, could also affect sea turtle populations. While all of the pathways 

that an oil spill or the use of dispersants can affect sea turtles is poorly understood, some pathways may 

include the following: (1) oil or dispersants on the sea turtle’s skin and body can cause skin irritation, 

chemical burns, and infections; (2) inhalation of volatile petroleum compounds or dispersants can damage 

the respiratory tract and lead to diseases; (3) ingesting oil or dispersants may cause injury to the 

gastrointestinal tract; and (4) chemicals that are inhaled or ingested may damage internal organs. In most 

foreseeable cases, exposure to hydrocarbons persisting in the sea following the dispersal of an oil slick 

would result in sublethal impacts (e.g., decreased health, reproductive fitness, and longevity and increased 

vulnerability to disease) to sea turtles. Other possible internal impacts might include harm to the liver, 

kidney, and brain function, as well as causing anemia and immune suppression, or they could lead to 

reproductive failure or death. The deaths of subadult and adult sea turtles may also drastically reduce the 

population.

Since January 1, 2011, a notable increase in sea turtle strandings has occurred in the northern GOM, 

primarily in Mississippi. While turtle strandings in this region typically increase in the spring, the recent 

increase is a cause for concern. The Sea Turtle Stranding and Salvage Network is monitoring and 

investigating this increase. The network encompasses the coastal areas of the 18 states from Maine 

through Texas and includes portions of the U.S. Caribbean. There are many possible reasons for the 

increase in strandings in the northern GOM, both natural and human caused (USDOC, NMFS, 2012a). 

One sea turtle had a small amount of tar from the Deepwater Horizon explosion, oil spill, and response on 

its shell. No visible external or internal oil was observed in any other animals. These sea turtle species 

include loggerhead, green, Kemp’s ridley, leatherback, hawksbill, and unidentified. The NMFS has also 

identified strandings in Texas (upper Texas coast—Zone 18). Refer to Chapter 4.1.1.12 for updated 

turtle stranding data for the Gulf of Mexico.

Over the last 2 years, NOAA has documented necropsy results from many of the stranded turtles, 

indicating mortality due to forced submergence, which is commonly associated with fishery interactions, 

and acute toxicosis. On May 10, 2012, NMFS published the Draft EIS to reduce incidental bycatch and 

mortality of sea turtles in the southeastern U.S. shrimp fishery (77 FR 27411) (Federal Register, 2012).

Overall Summary and Conclusion (Phases 1-4)

Accidental blowouts, oil spills, and spill-response activities resulting from a CPA or EPA proposed 

action have the potential to impact small to large numbers of sea turtles in the GOM, depending on the 

magnitude and frequency of accidents, the ability to respond to accidents, the location and date of 

accidents, and various meteorological and hydrological factors. Impacts on sea turtles from smaller 

accidental events are likely to affect individual sea turtles in the spill area, but they are unlikely to rise to 

the level of population effects (or significance) given the size and scope of such spills.

Unavailable information on the effects to sea turtles from the Deepwater Horizon explosion, oil spill, 

and response and increased stranding events (and thus changes to the sea turtle baseline in the affected 

environment) makes an understanding of the effects less clear.

For low-probability catastrophic spills, this analysis concludes that there is a potential for a lowprobability catastrophic event to result in significant, population-level effects on affected sea turtle 

species.
Catastrophic Spill Event Analysis B-65

B.3.1.14. Diamondback Terrapins

Phase1—Initial Event

Phase 1 of the scenario is the initiation of a catastrophic blowout event. Impacts, response, and 

intervention depend on the spatial location of the blowout and leak. For this analysis, an explosion and 

subsequent fire are assumed to occur. If a blowout associated with the drilling of a single exploratory 

well occurs, this could result in a fire that would burn for 1-2 days. If a blowout occurs on a production 

platform, other wells could feed the fire, allowing it to burn for over a month. The drilling rig or platform 

may sink. If the blowout occurs in shallow water, the sinking rig or platform may land in the immediate 

vicinity; if the blowout occurs in deep water, the rig or platform could land a great distance away, beyond 

avoidance zones. Regardless of water depth, the immediate response would be from search and rescue 

vessels and aircraft, such as USCG cutters, helicopters, and rescue planes, and firefighting vessels. 

Potential impacts reflect the explosion, subsequent fire for 1-30 days and the sinking of the platform in 

the immediate vicinity and up to 1 mi (1.6 km) from the well.

The scenarios for each phase, including cleanup methods, can be found in Table B-4. 

There would likely be no adverse impacts to diamondback terrapins as a result of the events and the 

potential impact-producing factors that could occur throughout Phase 1 of a catastrophic spill event 

because these species exclusively inhabit estuarine waters and salt marshes. 

Phase 2—Offshore Spill

Phase 2 of the analysis focuses on the spill and response in Federal and State offshore waters. A 

catastrophic spill would likely spread hundreds of square miles. Also, the oil slick may break into several 

smaller slicks, depending on local wind patterns that drive the surface currents in the spill area. Potential 

impacts reflect spill and response in Federal and State offshore waters. Season and temperature variations 

can result in different resource impacts due to variations in oil persistence and oil and dispersant toxicity 

and because of differences in potential exposure of the resources throughout various life cycle stages.

There would likely be no adverse impacts to diamondback terrapins as a result of the events and the 

potential impact-producing factors that could occur throughout Phase 2 of a catastrophic spill event 

because these species exclusively inhabit estuarine waters and salt marshes. 

Phase 3—Onshore Contact

Phase 3 focuses on nearshore (e.g., inside bays and in close proximity to shoreline) and onshore spill 

response and on oil initially reaching the shoreline during the spill event or while the oil still persists in 

the offshore environment once the spillage has been stopped. It is likely that Phases 2 and 3 could occur 

simultaneously. The duration of the initial shoreline oiling is measured from initial shoreline contact until 

the well is capped or killed and the remaining oil dissipates offshore. The re-oiling of already cleaned or 

previously impacted areas could be expected during Phase 3. In addition to the response described in 

Phase 2, nearshore and onshore efforts would be introduced in Phase 3 as oil entered coastal areas and 

contacted shore. Potential impacts reflect the spill and response in very shallow coastal waters and once 

along the shoreline. Season and temperature variations can result in different resource impacts due to 

variations in oil persistence and oil and dispersant toxicity and because of differences in the potential 

exposure of the resources throughout various life cycle stages.

The major impact-producing factors resulting from the low-probability catastrophic event at may 

affect the five terrapin subspecies that occur in the CPA and EPA include offshore and coastal oil spills 

and spill-response activities.

Terrapins inhabit brackish waters including coastal marshes, tidal flats, creeks, and lagoons behind 

barrier beaches (Hogan, 2003). Their diet consists of fish, snails, worms, clams, crabs, and marsh plants 

(Cagle, 1952). Courtship and mating occur in March and April, and the nesting season extends through 

July, with possibly multiple clutches (U.S. Dept. of the Army, COE, 2002; Butler et al., 2006). Terrapins 

nest on dunes, beaches, sandy edges of marshes, islands, and dike roads (Roosenburg, 1994). The 

common factor for proper egg development is sandy soil, which does not clog eggshell pores, thus 

allowing sufficient gas exchange between the developing embryo and the environment (Roosenburg, 

1994). Nesting occurs primarily in the daytime during high tide on high sand dunes with gentle slopes 

and minimal vegetation (Burger, 1977). Clutch size ranges from 4 to 22 eggs, and incubation time ranges 
B-66 Central and Eastern Planning Areas Supplemental EIS

from 61 to 104 days (Butler et al., 2006; Burger, 1977). Female terrapins may nest 2-3 times in the same 

nesting season. Gender determination is temperature dependent. Hatching occurs from July through 

October in northeastern Florida (Butler et al., 2004).

Spending most of their lives at the aquatic-terrestrial boundary in estuaries, terrapins are susceptible 

to habitat destruction from oil-spill cleanup efforts as well as direct contact with oil. However, most 

impacts cannot be quantified at this time. Even after oil is no longer visible, terrapins may still be 

exposed while they forage in the salt marshes lining the edges of estuaries, where oil may have 

accumulated under the sediments and within the food chain. Terrapin nests can also be disturbed or 

destroyed by cleanup efforts. The range of the possible chronic effects from contact with oil and 

dispersants include lethal or sublethal oil-related injuries that may include skin irritation from the oil or 

dispersants, respiratory problems from the inhalation of volatile petroleum compounds or dispersants, 

gastrointestinal problems caused by the ingestion of oil or dispersants, and damage to other organs 

because of the ingestion or inhalation of these chemicals.

Accidental blowouts, oil spills, and spill-response activities resulting from a CPA or EPA proposed 

action have the potential to impact small to large numbers of terrapins within their habitat, depending on 

the magnitude and frequency of accidents, the ability to respond to accidents, the location and date of 

accidents, and various meteorological and hydrological factors. Populations of terrapins in the Gulf may 

be exposed to residuals of oils spilled as a result of a CPA or EPA proposed action during their lifetimes. 

Chronic or acute exposure may result in the harassment, harm, or mortality to terrapins occurring in the 

GOM. In the most likely scenarios, exposure to hydrocarbons persisting within the wetlands following 

the dispersal of an oil slick could result in sublethal impacts (e.g., decreased health, reproductive fitness, 

and longevity; and increased vulnerability to disease). Terrapin hatchling exposure to, fouling by, or 

consumption of tarballs persisting inland following the dispersal of an oil slick could likely be fatal but 

unlikely. Impacts from the dispersants are unknown, but they may have similar irritants to tissues and 

sensitive membranes as are known to occur in seabirds and sea turtles (NRC, 2005). The impacts to 

diamondback terrapins from chemical dispersants could include nonlethal injury (e.g., tissue irritation and 

inhalation), long-term exposure through bioaccumulation, and potential shifts in distribution from some 

habitats.

Burger (1994) described the behavior of 11 female diamondback terrapins that were oiled during the 

January 1990 spill of No. 2 fuel oil in Arthur Kill, New York. The terrapins were hibernating at the time 

of the spill, and when they emerged from hibernation, they were found to be oiled. The terrapins voided 

oil from their digestive tracks for 2 weeks in rehabilitation. At 3 weeks, the terrapins scored low on 

strength tests and were slow to right themselves when placed on their backs. At 4 weeks, they developed 

edema and appetite suppression. Eight of the 11 died; these animals had traces of oil in their tissues and 

exhibited lesions in their digestive tract consistent with oil exposure (Burger, 1994). Further detail on this 

catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS and EPA 

225/226 EIS. 

The Deepwater Horizon explosion, oil spill, and response may have potentially impacted the terrapin 

community. Impacts from a catastrophic spill may impact terrapin communities. Impacts can be either 

direct (mortality or injury) or indirect (e.g., reduced prey availability); however, most impacts cannot be 

quantified at this time. The best available information does not provide a complete understanding of the 

effects of the spilled oil and active response/cleanup activities on the potentially affected terrapin 

environment. Current available information includes photographic evidence of one terrapin found oiled 

on Grand Terre Island, Louisiana, on June 8, 2010 (State of Louisiana, Coastal Protection and 

Restoration, 2012).

Phase 4—Post-Spill, Long-Term Recovery and Response

Phase 4 focuses on long term recovery once the well has been capped and the spill has stopped. 

During the final phase of a catastrophic blowout and spill, it is presumed that the well has been capped or 

killed and cleanup activities are concluding. While it is assumed that the majority of spilled oil would be 

dissipated offshore within 1-2 months (depending on season and temperature) of stopping the flow, oil 

has the potential to persist in the environment long after a spill event and has been detected in sediment 

30 years after a spill. On sandy beaches, oil can sink deep into the sediments. In tidal flats and salt 

marshes, oil may seep into the muddy bottoms. Potential impacts reflect long term persistence of oil in 

the environment and residual and long-term cleanup efforts.
Catastrophic Spill Event Analysis B-67

The Deepwater Horizon explosion, oil spill, and response and associated oil spill may have impacted 

the terrapin community and associated brackish habitats. According to OSAT-2 (2011), possible 

environmental effects from the Deepwater Horizon explosion, oil spill, and response could occur within 

terrapin marsh habitat via food or to nesting habitat since no active intervention (natural remediation) is 

the preferred protocol.

Behavioral effects and nonfatal exposure to or intake of OCS oil- and gas-related contaminants or 

discarded debris may stress and/or weaken individuals of a local group or population and predispose them 

to infection from natural or anthropogenic sources. Even after the oil is no longer visible, terrapins may 

still be exposed while they forage in the salt marshes lining the edges of estuaries where oil may have 

accumulated under the sediments and within the food chain (Burger, 1994; Roosenburg et al., 1999). 

Nests can also be disturbed or destroyed by cleanup efforts. Through NRDA, ongoing research and 

analysis of the presence of contaminants in terrapin eggs following the Deepwater Horizon oil spill is 

being conducted (USDOC, NOAA, 2012a). Hatching success studies at various oiled nesting sites of the 

northern diamondback terrapin suggest that spills may result in a reduction in nest size and increased 

mortality of spring emergers (hatched turtles) at the oiled sites (Wood and Hales, 2001). However, 

research on the PAH exposure and toxicology of eggs in the vicinity of a spill site found no correlation to 

substrate PAHs when compared with egg toxicology. The level of PAHs found in the eggs may be the 

result of maternal transfer and represent the exposure level of the nesting female rather than 

environmental exposure to PAHs from oil at the site of the nest (Holliday et al., 2008).

Habitat destruction, road construction, drowning in crab traps, and nest predation are the most recent 

threats to diamondback terrapins. Tropical storms, hurricanes, and beach erosion threaten their preferred 

nesting habitats. Destruction of the remaining habitat because of a catastrophic spill and response efforts 

could drastically affect future population levels and reproduction.

Overall Summary and Conclusion (Phases 1-4)

Impacts on diamondback terrapins from smaller accidental events are likely to affect individual 

diamondback terrapins in the spill area, as described above, but are unlikely to rise to the level of 

population effects (or significance) given the probable size and scope of such spills. Possible catastrophic 

environmental effects from an oil spill and cleanup could occur within terrapin marsh habitat via food or 

to the nesting habitat. Since terrapins do not move far from where they are hatched, it is possible that 

entire subpopulations could incur high mortality rates and community disruptions, though this would be 

highly localized depending on the time, place, and size of the spill.

The OSRA analyses in this Supplemental EIS conclude that there is a low probability for catastrophic 

spills and that there is a potential for a low-probability catastrophic event to result in significant, 

population-level effects on affected diamondback terrapin species.

For those terrapin populations that may not have been impacted by the Deepwater Horizon explosion, 

oil spill, and response, it is unlikely that a future accidental event related to a CPA or EPA proposed 

action would result in significant impacts due to the distance of most terrapin habitat from offshore OCS 

energy-related activities.

B.3.1.15. Beach Mice

Phase 1—Initial Event

There would likely be no adverse impacts to beach mice as a result of the events and the potential 

impact-producing factors that could occur throughout Phase 1 of a catastrophic spill event because 

Phase 1 is the initiation of a catastrophic blowout incident, and initiation would occur well offshore from 

beach mouse habitat.

Phase 2—Offshore Spill

There would likely be no adverse impacts to beach mice as a result of the events and the potential 

impact-producing factors that could occur throughout Phase 2 of a catastrophic spill event because 

Phase 2 of the analysis focuses on the spill and response in Federal and State offshore waters away from 

beach mouse habitat.
B-68 Central and Eastern Planning Areas Supplemental EIS

Phase 3—Onshore Contact

Five subspecies of the field mouse, collectively known as beach mice, live along the Gulf Coast, and 

two beach mouse subspecies live on the Atlantic Coast of Florida. Five subspecies of beach mice 

(Alabama, Perdido Key, Choctawhatchee, St. Andrew, and Anastasia Island) are listed as State and 

federally endangered; also, the southeastern beach mouse is listed as federally threatened. Beach mice are 

restricted to the coastal barrier sand dunes along the Gulf Coasts of Alabama and Florida. Erosion caused 

by the loss of vegetation because of oiling would likely cause more damage than the direct oiling of beach 

mice because of the degradation or loss of habitat. In addition, vehicular traffic and activity associated 

with cleanup can trample or bury beach mice nests and burrows or cause displacement from preferred 

habitat. Improperly trained personnel and vehicle and foot traffic during shoreline cleanup of a 

catastrophic spill would disturb beach mouse populations and would degrade or destroy habitat.

The Alabama, Choctawhatchee, St. Andrew, Perdido Key, Anastasia Island, and southeastern beach 

mice are designated as protected species under the Endangered Species Act, mostly because of the loss 

and fragmentation of coastal habitat (Federal Register, 1989; USDOI, MMS, 2007). Some of the 

subspecies have coastal habitat that is designated as their critical habitat. For example, the endangered 

Alabama beach mouse’s (Peromyscus polionotus ammobates) designated critical habitat is 1,211 acres 

(450 hectares) of frontal dunes covering just 10 mi (16 km) of shoreline (USDOI, FWS, 2007). Critical 

habitat is the specific geographic areas that are essential for the conservation of a threatened or 

endangered species.

All designated critical habitat for beach mice officially extends landward from the mean high water 

line (Federal Register, 2006; USDOI, FWS, 2007). Therefore, spilled oil could contact critical habitat 

even without a concurrent storm surge; contact would require only that the water level would be at mean 

high tide. However, a concurrent storm surge of considerable height would be required to oil the portion 

of the critical habitat substantially landward of the mean high water line (over the tops of the primary, 

secondary, and tertial dunes). With the potential oiling of over 1,000 mi (1,609 km) of shoreline that 

could result from a catastrophic spill event and a concurrent storm surge of considerable height that 

occurs within a close proximity to the critical habitat, there is the potential for the entire critical habitat 

for a subspecies of beach mice to be completely oiled. Thus, destruction of critical habitat because of a 

catastrophic spill, a concurrent storm surge of considerable height and over a considerable length of 

shoreline, and cleanup activities would increase the threat of extinction of several subspecies of beach 

mice. Further detail on this catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 

Supplemental EIS and EPA 225/226 EIS. 

Phase 4—Post-Spill, Long-Term Recovery and Response

Within the last 20-30 years, the combination of habitat loss because of beachfront development, the 

isolation of the remaining beach mouse habitat areas and populations, and the destruction of the 

remaining habitat by tropical storms and hurricanes has increased the threat of extinction of several 

subspecies of beach mice. On sandy beaches, oil can sink deep into the sediments and become exposed 

again after erosion of sand by wave action. Oil may therefore persist near beach mouse habitat for the 

long term. The destruction of the remaining habitat because of a catastrophic spill and cleanup activities 

would increase the threat of extinction.

Overall Summary and Conclusion (Phases 1-4)

Impacts to beach mice would vary according to the severity of the oiling. Further detail on this 

catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS and EPA 

225/226 EIS. 

B.3.1.16. Coastal, Marine, and Migratory Birds

Phase 1—Initial Event

Some migratory birds use offshore platforms or rigs as potential stopover sites during their longdistance migrations across the GOM during the spring and fall (Russell, 2005). In addition, it has been 

well documented that seabirds are attracted to offshore platforms and rigs for a myriad of reasons; i.e., 
Catastrophic Spill Event Analysis B-69

concentrations of baitfish, roost sites, etc. (Tasker et al., 1986; Wiese et al., 2001; Burke et al., 2012). 

The numbers of birds present at a platform or rig tend to be greater on platforms or rigs closer to shore, 

particularly during drilling operations (Baird, 1990). Birds resting on the drilling rig or platform during a 

catastrophic blowout at the surface (similar to the Deepwater Horizon explosion, oil spill, and response) 

are more likely to be killed by the explosion. While it is assumed that most birds in trans-Gulf migration 

would likely avoid the fire and smoke plume during the day, it is possible that the light from the fire could 

interfere with nocturnal migration, especially during poor visibility conditions, i.e., fog or low clouds. It 

has been documented that seabirds are attracted to natural gas flares at rigs and platforms (Russell, 2005; 

Wiese et al., 2001); therefore, additional bird fatalities could result from the fire following the blowout. 

Though different species migrate differentially throughout the year, the largest number of species 

migrates through the proposed area from mid-April through mid-May (spring migration back north) and 

from mid-August through early November (fall migration south) (Russell, 2005, Table 6.12; Farnsworth 

and Russell, 2007). A blowout during this time would potentially result in a greater number of bird 

fatalities (see below).

Of the four phases considered herein, avian mortality associated with this Phase is certainly expected 

to be much lower than avian mortality associated with either Phase 2 or Phase 3. However, this 

anticipated result is highly dependent on the location of the platform and the timing of the event. The 

only scenario considered is the case where a blowout and explosion occurred at the surface (Table B-4). 

If the catastrophic event, in this case a blowout and explosion at the surface (refer to Table B-4), occurs 

more proximal to the coast during the breeding season or during a peak migration period (late March to 

late May and mid-August to early November), then the level of avian mortality is expected to be higher. 

In comparison, a blowout and explosion at the surface on a platform more distant from the coast (greater 

than or equal to the distance of the Macondo well from the coast) would result in much lower avian 

mortality, particularly if the event did not overlap temporally with either the breeding season or either of 

the trans-Gulf migrations.

While the species composition and species-specific mortality estimates are unknown and would be 

dependent on the blowout location and time of year, the initial mortalities would almost certainly not 

result in population-level impacts for species present at the time of the blowout and resulting fire (Arnold 

and Zink, 2011; also refer to Table 4-7 of the 2012-2017 WPA/CPA Multisale EIS). If the event occurred 

during the breeding season or wintering period, species of seabirds or diving birds would have the 

greatest potential to be affected, whereas if the event occurred during either the spring or fall migration, 

species of passerines would most likely have the greatest potential to be affected due to the diversity and 

sheer numbers of individuals in this avian species group (Rappole and Ramos, 1994; Lincoln et al., 1998; 

Russell, 2005; also refer to Chapters 4.1.1.16 and 4.2.1.16 of this Supplemental EIS, Chapter 4.2.1.16.1 

of the 2012-2017 WPA/CPA Multisale EIS, Chapter 4.2.1.16 of the WPA 233/CPA 231 Supplemental 

EIS, and Chapter 4.1.1.16 of the CPA 235/241/247 Supplemental EIS). 

Phase 2—Offshore Spill

During Phase 2 of a catastrophic spill, the primary concern for marine and migratory birds would be 

their vulnerability to oiling or ingesting oil, which is primarily a function of their behavior and diets. 

Wading birds (e.g., herons, egrets, etc.) and species that feed by plunge-diving into the water to catch 

small fish (e.g., pelicans, gannets, terns, gulls, and pelagic birds) and those that use water as a primary 

means of locomotion, foraging (e.g., black skimmers), or resting and preening (e.g., diving ducks, 

cormorants, pelicans, etc.) are highly vulnerable to becoming oiled and also to ingesting oil (Table B-5 of 

this Supplemental EIS; also refer to Table 4-13 and Figure 4-13 of the 2012-2017 WPA/CPA Multisale 

EIS). Seabirds, in particular, tend to feed and concentrate in convergence zones, eddies, upwellings, and 

near Sargassum mats (Haney, 1986a-c; Moser and Lee, 2012). In addition to concentrating prey, these 

areas are also known to aggregate oil (Unified Incident Command, 2010d). Oiling interferes with the 

birds’ ability to fly (thus to obtain food) and compromises the insulative characteristics of down and 

contour feathers, making it difficult to regulate body temperature. Attempts by oiled birds to remove the 

oil via preening can cause them to ingest oil and may result in mortality. In addition, the ingestion of 

contaminated prey can result in physiological impairment and even death. Refer to Chapter 4.2.1.16.3 of 

the 2012-2017 WPA/CPA Multisale EIS for additional detailed information on oiling effects to birds.

Though several species or species groups are mentioned above, the most vulnerable species to spilled 

oil in the offshore environment in the GOM during Phase 2 would be representatives of the diving bird 
B-70 Central and Eastern Planning Areas Supplemental EIS

(≤10 species) and seabird (≥20 species) groups (King and Sanger, 1979; Ribic et al., 1997; Davis et al., 

2000). Unlike Phase 1, where passerines may be affected depending on the timing of the catastrophic 

event, timing or seasonal effects would be less important under the Phase 2 scenario (Table B-4) due to 

the spilled oil being restricted to the offshore environment, thereby limiting the potential impacts to the 

several avian species groups relegated to the coastal and nearshore environment (Table B-5 of this 

Supplemental EIS; also refer to Chapters 4.1.1.16 and 4.2.1.16 of this Supplemental EIS, Chapter 

4.2.1.16.1 of the 2012-2017 WPA/CPA Multisale EIS, Chapter 4.2.1.16 of the WPA 233/CPA 231 

Supplemental EIS, and Chapter 4.1.1.16 of the CPA 235/241/247 Supplemental EIS). However, it is 

highly probable that representative species of diving birds and seabirds would differentially be impacted 

(Table B-5 of this Supplemental EIS; also refer to Table 4-12 of the 2012-2017 WPA/CPA Multisale 

EIS). Table 4-12 of the 2012-2017 WPA/CPA Multisale EIS shows the actual number of birds identified 

to the species level for each of the species groups. This number is fairly representative of the suite of 

species available to be oiled. However, this number is dependent on efforts to correctly assign species to 

unidentified birds or unknowns, which is also a function of search effort. Search effort likely declined 

dramatically once the Macondo well was plugged/capped. The species composition and species-specific 

mortality estimates associated with a Phase 2 catastrophic event are unknown and would be dependent 

primarily on the blowout location, as well as the distribution, coverage, and proximity to the shoreline of 

spilled oil. Overall, avian mortalities for this Phase would probably not result in population-level impacts 

for species present at the time of the blowout (refer to Table B-5 of this Supplemental EIS and to Figure 

4-13 of the 2012-2017 WPA/CPA Multisale EIS). However, it should be clear that many species of 

seabirds and diving birds have life-history strategies that do not allow subpopulations to recover quickly 

from major mortality events or perturbations (Ricklefs, 1983 and 1990; Russell, 1999; Saether et al., 

2004; also refer to Table 4-13 and Figure 4-18 of the 2012-2017 WPA/CPA Multisale EIS).

Some discussion of available information provided from the Deepwater Horizon explosion, oil spill, 

and response is relevant here with respect to temporal aspects of oiled birds (Figure B-3). The first oiled 

bird (northern gannet, a seabird) recovered after the Macondo well event was collected just 10 days postblowout. While gannets breed in coastal colonies in the Canadian North Atlantic, the population, 

including a major concentration in the northern GOM, over-winters in the deeper waters of the offshore 

environment. Belanger et al. (2010) provided some interesting results relative to live versus dead birds 

collected based on the actual date each bird was collected. Interestingly, they documented a dramatic and 

statistically significant decline in the number of live birds collected after 110 days compared with live 

birds collected during the first 72 days. These authors also documented a dramatic and statistically 

significant increase in the number of dead birds collected after 110 days (Belanger et al., 2010, Figures 2 

and 3). As a temporal reference, oil reached the shoreline near Venice, Louisiana, ≥10 days postblowout, covering a distance of approximately 90 mi (145 km) (Oil Spill Commission, 2011; also refer to 

Chapter 4.2.1.3.1 of the 2012-2017 WPA/CPA Multisale EIS and Chapter 4.2.1.3 of the WPA 233/CPA 

231 Supplemental EIS) (Figure B-3). It should be understood that, for the Phase 2 scenario considered 

here, it is assumed that spilled oil will not contact the shoreline.

Overall, avian mortality estimates are unknown and are difficult to predict given the uncertainty 

(Conroy et al., 2011, pages 1209-1210; Williams, 2011, page 1348) associated with the scenario and 

specific characteristics associated with the spill (refer to Appendix C of the WPA 238/246/248 

Supplemental EIS), as well as environmental conditions that are probably a function of spill location and 

timing. Even recognizing the uncertainty associated with the scenario, spill characteristics, and the 

environmental conditions at the time of the spill, Phase 2 would likely be second only to Phase 3 in total 

avian mortality. Phase 3 would include much greater avian species diversity and abundance due to the oil 

reaching nearshore, coastal beach/dune, salt- and brackish marsh habitats (Table B-5 of this 

Supplemental EIS; also refer to Table 4-12 of the 2012-2017 WPA/CPA Multisale EIS).

Phase 3—Onshore Contact

Gulf coastal habitats are essential to the annual cycles of many species of breeding, wintering, and 

migrating diving birds, seabirds, shorebirds, passerines, marsh- and wading birds, and waterfowl (refer to 

Chapters 4.1.1.16 and 4.2.1.16 of this Supplemental EIS, Chapter 4.2.1.16.1 of the 2012-2017 

WPA/CPA Multisale EIS, Chapter 4.2.1.16 of the WPA 233/CPA 231 Supplemental EIS, and Chapter 

4.1.1.16 of the CPA 235/241/247 Supplemental EIS). For example, the northern Gulf Coast supports a 

large proportion of populations of several beach-nesting bird species (USDOI, FWS, 2010c). During 
Catastrophic Spill Event Analysis B-71

Phase 3, oil is expected to contact not only the beach but also other important habitats used by a diverse 

and abundant assemblage of avian species. Habitats potentially impacted by a catastrophic spill would 

also likely include the nearshore environment, as well as the salt- and brackish marsh habitats. Potential 

impacts and total avian mortality from Phase 3 would be greater than any of the other phases considered 

herein due to (1) avian diversity and abundance in the nearshore environment (Table B-5 of this 

Supplemental EIS; also refer to Tables 4-9 through 4-11 of the 2012-2017 WPA/CPA Multisale EIS) and 

(2) the dispersion of oil from a catastrophic spill, which would reach the shoreline and enter the salt- and 

brackish marsh environments. Similar to Phases 1 and 2, the timing and location of the spill are 

important factors in determining the severity of impacts to the avian community. In addition, the duration 

of potential oil exposure to various species of birds would also be important.

As the Macondo well blowout and spill is the only historic catastrophic oil spill to occur in U.S. 

waters in the GOM, the information obtained from the Deepwater Horizon explosion, oil spill, and 

response relative to avian mortality may be reasonably relevant for any future catastrophic spills, 

recognizing of course the variation and uncertainty associated with individual oil spills. At present, the 

estimates of avian mortality associated with the Exxon Valdez oil spill far exceed current estimates of 

avian mortality associated with the Deepwater Horizon explosion, oil spill, and response even though the 

Deepwater Horizon spill volume/size far exceed that of the Exxon Valdez (refer to Table 4-15 of the 

2012-2017 WPA/CPA Multisale EIS). Based on data from the Deepwater Horizon explosion, oil spill, 

and response, a similar catastrophic spill would probably result in >10,000 carcasses collected 

(Deepwater Horizon explosion, oil spill, and response = 7,258 collected) representing >100 potentially 

impacted species (Deepwater Horizon explosion, oil spill, and response = 104 species identified) (refer to 

Table B-5, superscript 1 and also superscript b). It should be recognized that the number of avian 

carcasses collected post-spill represents some unknown fraction or proportion of the total modeled 

estimate of realized mortality (Flint et al., 1999; Byrd et al., 2009; Ford and Zafonte, 2009); the number 

of avian carcasses collected is biased low (Piatt et al., 1990a-b; Piatt and Ford, 1996; Castège et al., 

2007). Figure 4-13 of the 2012-2017 WPA/CPA Multisale EIS should provide reasonable estimates of 

oiling rates for the seven avian species groups in the northern Gulf of Mexico if another catastrophic spill 

were to occur and the timing, oil spill characteristics, and spill behavior were similar to the Deepwater 

Horizon explosion, oil spill, and response. It should be noted that the top five most impacted (based on 

number collected) avian species from the Deepwater Horizon explosion, oil spill, and response were all 

representatives of the seabird group: laughing gull (n = 2,981, 40% oiling rate); brown pelican (n = 826, 

41% oiling rate); northern gannet (n = 475, 63% oiling rate); royal tern (n = 289, 52% oiling rate); and 

black skimmer (n = 253, 22% oiling rate) (Table B-5 of this Supplemental EIS and Figure 4-13 of the 

2012-2017 WPA/CPA Multisale EIS).

Additional information is provided herein from an OSRA catastrophic oil-spill analysis (refer to 

Appendix C of the WPA 238/246/248 Supplemental EIS, Tables C-4 and C-5). 

It should be noted that oil from the Deepwater Horizon explosion and oil spill reached the shoreline 

less than 14 days after the blowout occurred (Oil Spill Commission, 2011). The OSRA does not take into 

account or consider the following with respect to avian resources and their habitats: (1) species-specific 

densities; (2) species-specific habitat preferences, food habits, or behavior; (3) relative vulnerabilities to 

oiling among the avian species groups or among species within each of the groups (Table B-5 of this 

Supplemental EIS and Figure 4-13 of the 2012-2017 WPA/CPA Multisale EIS; also refer to Williams 

et al., 1995; Camphuysen, 2006); and (4) it does not take into account or consider species-specific lifehistory strategies, their demography, or a species’ recovery potential (refer to Table 4-13 and Figures 4-18 

and 4-19 of the 2012-2017 WPA/CPA Multisale EIS). 

In summary, Phase 3 of a catastrophic oil spill has the greatest potential for negative impacts (i.e., 

direct mortality) to avian resources due to its contact with the shoreline and inundation of other habitats 

occupied by a much greater diversity and abundance of birds, particularly during the breeding season. 

Avian mortality estimates are presently unknown and are difficult to predict with any level of precision 

given the uncertainty associated with the scenario, specific characteristics associated with the spill, spatial 

and temporal variation in environmental conditions, and recognition that the avian resources (both species 

diversity and abundance) available to be oiled will also vary temporally and spatially. A worst-case 

scenario in the event of a catastrophic oil spill that reached the nearshore environment would occur in the 

presence of a hurricane with strength or magnitude similar to Hurricanes Katrina, Rita, or Ike during the 

breeding season. Such an overlap of two low-probability events during the breeding season could 

potentially push spilled oil even farther inland and also distribute oil vertically into the vegetation. Such 
B-72 Central and Eastern Planning Areas Supplemental EIS

an event would not only negatively impact diving birds, seabirds, shorebirds, marsh- and wading birds, 

and waterfowl but also the more terrestrial avian species groups including passerines and raptors. Such 

effects would most likely be long-term (due to direct mortality of individuals, but also due to major 

habitat loss) and could potentially result in population-level impacts to a number of avian species. 

Threatened and endangered avian species would likely be the most severely impacted by such an event 

depending on the spatial and temporal aspects of both the spill and the hurricane.

Endangered and Threatened Birds 

A detailed discussion of threatened and endangered species is provided in Chapter 4.2.1.16.1 of the 

2012-2017 WPA/CPA Multisale EIS and in Chapter 4.1.1.16.1 of the EPA 225/226 EIS. Of the 17 

species considered, 11 species are known to occur in the CPA (Table B-6). Of the 18 species considered, 

13 species are known to occur in the EPA (Table B-6). However, only the piping plover (Charadrius 

melodus), roseate tern (Sterna dougallii dougallii), wood stork (Mycteria americana), whooping crane 

(Grus americana), Mississippi sandhill crane (Grus canadensis pulla), bald eagle (Haliaeetus 

leucocephalus), eastern brown pelican (Pelecanus occidentalis), and red knot (Calidris canutus rufa) 

were analyzed and are considered further here. Phase 3 would likely result in the greatest net negative 

impacts (primarily direct mortality) to threatened and endangered avian species due to contact with the 

shoreline and potential movement of spilled oil inland to other habitats during this phase (Table B-4). In 

addition, the presence of spilled oil would result in indirect and potentially long-term effects to threatened 

and endangered avian species’ habitats and their preferred foods. Phases 1 and 2 would likely result in 

very limited impacts, if any, due to the scenarios as defined with oil restricted to the offshore 

environment.

In general, the potential direct impact (i.e., mortality) to any or all of these threatened or endangered 

(including recently delisted and candidate) species is directly a function of their presence at the time of a 

catastrophic oil spill. Indirect effects from a catastrophic oil spill could negatively affect the quality and 

functional availability of their habitats and the availability, distribution, and energetic benefits of their 

preferred foods in the absence of a given species. Of the species listed, the wood stork, Mississippi 

sandhill crane, bald eagle, eastern brown pelican, and Cape Sable seaside sparrows are year-round 

residents, whereas the piping plover, roseate tern, whooping crane, and red knot represent either wintering 

species or transients that utilize coastal habitats in the GOM as staging areas during migration. There are 

“resident” whooping cranes considered as “nonessential, experimental flocks” within the Gulf Coast 

States of Alabama, Louisiana, Mississippi, and Florida. These birds would be considered as “resident,” 

whereas the component of the ESA-listed species occurring primarily as a wintering flock in Texas (i.e., 

the Aransas National Wildlife Refuge) is considered a migratory flock. It is important to recognize these 

differences relative to whether or not individuals of a given species would be present and available to be 

oiled should a catastrophic oil spill event occur. Similarly, species-specific differences in habitat use and 

behavior would further separate which species would be most vulnerable to a spill given the timing of the 

spill, spill distribution, and other spill-related characteristics.

Of the species considered, probably only the eastern brown pelican and possibly the bald eagle 

(ingestion of contaminated fish and birds) would potentially be impacted during Phases 1 and 2. The 

other species are restricted to the nearshore, coastal, salt- and brackish, and upland habitats, which would 

not be impacted during these phases given the scenario (Table B-4). Phase 4 impacts to threatened and 

endangered avian species would probably be limited to short-term disturbance-related effects and 

potential impacts to habitats including destruction, alteration, or fragmentation from associated recovery 

activities (American Bird Conservancy, 2010; National Audubon Society, Inc, 2010).

As the Macondo well blowout and spill is the only historic catastrophic oil spill to occur in U.S. 

waters in the GOM, the information obtained from the Deepwater Horizon explosion, oil spill, and 

response relative to avian mortality may be reasonably relevant for any future catastrophic spills, 

recognizing of course the variation and uncertainty associated with individual oil spills. Of the threatened 

and endangered avian species considered, only a single, unoiled piping plover was collected as part of the 

post-Deepwater Horizon explosion, oil spill, and response monitoring program (Table B-5). There were 

106 least terns (Sterna antillarum) collected (n = 106, 46% oiling rate), but these individuals were 

considered as members of the coastal breeding population and not the ESA-listed population (Interior or 

noncoastal population). Of the species considered, only the eastern brown pelican was impacted by the 

Deepwater Horizon explosion, oil spill, and response (n = 826, 41% oiling rate); this species was delisted 
Catastrophic Spill Event Analysis B-73

on November 17, 2009 (Federal Register, 2009). No other carcasses of threatened and endangered 

species were collected as part of the post-Deepwater Horizon explosion, oil spill, and response

monitoring efforts (Table B-5; USDOI, FWS, 2011a). 

Additional information is provided herein from an OSRA catastrophic oil-spill analysis (refer to 

Appendix C of the WPA 238/246/248 Supplemental EIS, Tables C-4 and C-5). 

Caveats regarding the OSRA catastrophic run with respect to avian resources were addressed above 

and would also apply to threatened and endangered avian resources considered here.

Phase 4—Post-Spill, Long-Term Recovery and Response

There is a high probability of underestimating the impacts of oil spills on avian species potentially 

encountering oil. Despite being oiled, some birds are capable of flight and may later succumb to the 

oiling for a myriad of reasons (refer to Chapter 4.2.1.14 of the 2012-2017 WPA/CPA Multisale EIS for 

additional detailed information). Often overlooked and understudied are the long-term, sublethal, chronic 

effects due to sublethal exposure to oil (Butler et al., 1988; Alonso-Alvarez et al., 2007; Pérez et al., 

2010). Also, individuals having been oiled in the Gulf of Mexico as the result of a catastrophic oil spill 

during the overwinter period or while staging in the GOM could exhibit carry-over effects to the northern 

breeding grounds. Affected individuals in poor body condition may arrive at their breeding grounds later 

than nonaffected individuals, which could, in turn, negatively affect habitat-use decisions, territory 

establishment, pairing success, and ultimately lead to reduced reproductive success (Norris, 2005 and 

Norris et al., 2006; Harrison et al., 2011). Some oiled individuals may forego breeding altogether (Zabala 

et al., 2010). If oil-affected, long-distance migrants represent important prey items for various species of 

raptors, then the ingestion of affected individuals could also negatively affect individual birds of prey 

(Zuberogoitia et al., 2006). Refer to Henkel et al. (2012) for a review of potential carry-over effects to 

shorebirds potentially impacted by the Deepwater Horizon explosion, oil spill, and response.

The long-term impacts of potential food-induced stress for bird species from an altered ecosystem due 

to a catastrophic spill are unknown, but disturbances to the ecosystem can cause long-term sublethal 

impacts, including reduced food intake, prey switching, increased energy expenditures, decreased 

reproductive success, and decreased survival. Decreases in either reproductive success or survival (or 

both) could result in population-level effects as was observed for certain avian species more than 10 years 

after the Exxon Valdez catastrophic spill (Esler et al., 2002 and 2010; Golet et al., 2002). Long-term, 

sublethal, chronic effects may exceed immediate losses (i.e., direct mortality of oiled birds) if residual 

effects influence a significant proportion of the population or disproportionately impact an important 

aspect of the population demographic, i.e., breeding-age females (Croxall and Rothery, 1991; Oro et al., 

2004). Depending on the effects and the life-history strategy of impacted species, some populations could 

take years or decades before reaching pre-spill population numbers and age-sex structure; some 

populations for some species may never recover (refer to Figure 4-13 of the 2012-2017 WPA/CPA 

Multisale EIS; refer to Peterson et al., 2003, but also to Wiens et al., 2010).

In general, potential effects associated with Phase 4 should be limited to short-term disturbance 

effects (personnel and equipment) and potential indirect effects to various avian species groups due to 

habitat loss, alteration, or fragmentation from restoration efforts. There may be cases whereby incubating 

individuals are flushed from nests exposing their eggs or young to either weather-related mortality or 

depredation by avian or mammalian predators (American Bird Conservancy, 2010; National Audubon 

Society, Inc., 2010). However, efforts to minimize potential effects of post-oil spill monitoring and 

restoration efforts, particularly during the breeding season, should be sufficient to protect nesting birds as 

a function of oversight by Federal and State agencies charged with the conservation of migratory bird 

resources.

Limited information available to date with respect to avian impacts from the Deepwater Horizon

explosion, oil spill, and response suggests much lower mortality than would have been predicted by the 

spill size or volume alone (Belanger et al., 2010), though spill volume or size tends to be a poor predictor 

of avian mortality (Burger, 1993; Tan et al., 2010). The final modeled estimates of avian mortality will 

greatly exceed the number of avian carcasses collected (n = 7,258; Table B-5), but overall, the Deepwater 

Horizon explosion, oil spill, and response appears to have directly resulted in far fewer dead, oiled birds 

than the Exxon Valdez catastrophic spill (refer to Table 4-15 of the 2012-2017 WPA/CPA Multisale EIS). 

It should be recognized that the avian-related mortality associated with the Deepwater Horizon explosion, 

oil spill, and response (considered a catastrophic event) represents a small fraction of birds killed when 
B-74 Central and Eastern Planning Areas Supplemental EIS

compared with collisions with offshore oil and gas platforms. Russell (2005, page 304) states, “an 

average Gulf platform may cause 50 deaths by collision [only] per year,” so using this number, the 

number of deaths the Deepwater Horizon rig would have caused through collisions had it remained intact 

for its 40-year term would be about 2,000. That is about 5,258 less than the number of avian carcasses 

collected due to the Deepwater Horizon explosion, oil spill, and response just given above. In the GOM, 

an estimated 200,000-321,000 avian deaths occur annually; primarily due to collisions with platforms 

(Table 4-7 of the 2012-2017 WPA/CPA Multisale EIS; also refer to Russell, 2005). Over the life of the 

GOM platform archipelago, the estimated total avian mortality is on the order of 7-12 million birds (refer 

to Figure 4-15 of the 2012-2017 WPA/CPA Multisale EIS). Oil spills, regardless of size, are but one of a 

myriad of anthropogenic avian mortality sources. Even the cumulative total avian mortality associated 

with all the North American oil spills to date is only a small fraction when compared with estimates of 

annual avian mortality attributed to collisions with buildings and windows, predation by housecats, and 

collisions with powerlines and communication towers (Klem, 2009; Manville, 2009; Table 4-7 of the 

2012-2017 WPA/CPA Multisale EIS).

Overall Summary and Conclusion (Phases 1-4)

While the species composition and species-specific mortality estimates are unknown and would be 

dependent on the blowout location and time of year, the mortalities for the initial event (Phase 1) would 

almost certainly not result in population-level impacts for species present at the time of the blowout and 

resulting fire. Seabirds are highly vulnerable to becoming oiled and also to ingesting oil during Phase 2 

(the offshore spill). Even recognizing the uncertainty associated with the scenario, spill characteristics, 

and the environmental conditions at the time of the spill, Phase 2 would likely be second only to Phase 3 

(onshore contact) in total avian mortality. Phase 3 would include impacts to much greater avian species’ 

richness and abundance (particularly during the breeding season) due to oil reaching habitats, including 

the nearshore, coastal beaches and dunes, and salt and brackish marshes. In general, the potential effects 

associated with Phase 4 (long-term recovery and response) should be limited to short-term disturbance 

effects (by cleanup personnel and equipment) and potential indirect effects to various bird species groups 

from habitat loss, alteration, or fragmentation from restoration efforts.

Phases 1 (initial event) and 2 (offshore spill) would likely result in very limited impacts to threatened 

and endangered bird species because the two scenarios have oil restricted to the offshore environment. 

Phase 3 (onshore contact) would likely result in the greatest net negative impacts to threatened and 

endangered bird species due to contact with the shoreline and potential movement of spilled oil inland to 

other habitats during this phase.

B.3.1.17. Fish Resources and Essential Fish Habitat

Phase 1—Initial Event

Depending on the type of blowout and the proximity of marine life to it (Table B-1), an eruption of 

gases and fluids may generate not only a toxic effect but also pressure waves and noise significant enough 

to injure or kill local biota. Within a few thousand meters of the blowout, resuspended sediments may 

clog fish gills and interfere with respiration. Settlement of resuspended sediments may, in turn, smother 

invertebrates or interfere with their respiration. Essential fish habitat (EFH) in the vicinity of the blowout 

could have adverse effects from the event. These EFH resources are discussed in the water quality 

(Chapter B.3.1.2), live bottoms (Chapter B.3.1.6), topographic features (Chapter B.3.1.7), Sargassum

communities (Chapter B.3.1.8), chemosynthetic and nonchemosynthetic deepwater benthic communities 

(Chapters B.3.1.9 and B.3.1.10, respectively), and soft bottom benthic communities (Chapter B.3.1.11) 

chapters.

Phase 2—Offshore Spill

With the initiation of a catastrophic blowout incident, an explosion and subsequent fire are assumed 

to occur. If a blowout associated with the drilling of a single exploratory well occurs, this could result in 

a fire that would burn for 1 or 2 days, but if a blowout occurs on a production platform and other wells 

feed the fire, it could burn for over a month. The drilling rig or platform may sink, and if this occurs in 

shallow water, the sinking rig or platform may land in the immediate vicinity. If the blowout occurs in 
Catastrophic Spill Event Analysis B-75

deep water, the rig or platform could land a great distance away and could be beyond avoidance zones. 

Regardless of water depth, the immediate response would be from search and rescue vessels and aircraft, 

such as USCG cutters, helicopters, rescue planes, and firefighting vessels.

Early life stages of animals are usually more sensitive to oil than adults (Boesch and Rabalais, 1987; 

NRC, 2005). Weathered crude oil has been shown in laboratory experiments to cause malformation, 

genetic damage, and even mortality at low levels in fish embryos of Pacific herring (Carls et al., 1999). 

Because natural crude oil found in the Gulf of Mexico would generally float on the surface, fish species 

whose eggs and larvae are found at or near the water surface are most at risk from an offshore spill. 

Species whose spawning periods coincide with the timing of the highest oil concentrations would be at 

greatest risk.

Adult fish may be less at risk than earlier life stages, in part because they are less likely to concentrate 

at the surface and may avoid contact with floating oil. The effects of oil on organisms can include direct 

lethal toxicity, sublethal disruption of physiological processes (internal lesions), the effects from direct 

coating by oil (suffocation by coating gills), incorporation of hydrocarbons in organisms (tainting or 

accumulation in the food chain), and changes in biological habitat (decreased dissolved oxygen) (Moore 

and Dwyer, 1974). The extent of the impacts of the oil would depend on the properties of the oil and the 

time of year of the event.

If there is a subsea catastrophic blowout, it is assumed dispersants would be used. Then there could 

be effects on multiple life history stages and trophic levels. There is limited knowledge of the toxicity of 

dispersants mixed with oil to specific species or life stages of ichthyoplankton and the likely extent of 

mortality because the combination of factors is difficult to determine. The combined toxic effects of the 

oil and any dispersants that may be used would not be apparent unless a significant portion of a year-class 

is absent from next year’s fishery (e.g., shrimps, crabs, snapper, and tuna). An example of a catastrophic 

event in the CPA and EPA was modeled using OSRA (Appendix C of the CPA 235/241/247 

Supplemental EIS [Tables C-4 and C-5] and Appendix B of the EPA 225/226 EIS [Tables B-5 through 

B-8]). Because fish occur throughout the GOM, it is assumed that some individuals would be contacted 

with oil. Specific habitats that are discussed with regards to the Central Planning Area and Eastern 

Planning Area OSRA examples and in the Appendix are water quality (Chapter B.3.1.2), wetlands 

(Chapter B.3.1.4), seagrass communities (Chapter B.3.1.5), live bottoms (Chapter B.3.1.6), 

topographic features (Chapter B.3.1.7), Sargassum communities (Chapter B.3.1.8), chemosynthetic and 

nonchemosynthetic deepwater communities (Chapters B.3.1.9 and B.3.1.10, respectively), and soft 

bottom benthic communities (Chapter B.3.1.11). 

Studies by USEPA, Office of Research and Development (2010) using representative species provide 

some indication of the relative toxicity of Louisiana sweet crude oil, dispersants, and oil/dispersant mixes. 

Bioassays were conducted using two Gulf species—a mysid shrimp (Amercamysis bahia) and a small 

estuarine fish, the inland silverside (Menidia beryllinina)—to evaluate the acute toxic effects of oil, eight 

dispersants, and oil/dispersant mixtures. In addition, USEPA used standard in vitro techniques using the 

same dispersants to (1) evaluate the acute toxicity on three cell lines over a range of concentrations and

(2) evaluate the effects of these dispersants on androgen and estrogen function using human cell lines (to 

see if they are likely to disrupt hormonal systems). All dispersants showed cytotoxicity in at least one cell 

type at concentrations between 10 and 110 ppm. Results of the in vitro toxicity tests were similar to the 

whole animal tests. For all eight dispersants, for both species, the dispersants alone were less toxic than 

the dispersant/oil mixture. Louisiana sweet crude oil alone was determined to be more toxic to both the 

mysid shrimp and silverside fish than the dispersants alone. The results of the testing for disruption of 

androgen and estrogen function indicate that the dispersants do not show biologically significant 

endocrine activity via androgen or estrogen pathways (USEPA, Office of Research and Development, 

2010).

The GOM waters out to 100 fathoms (182 m; 600 ft) have EFHs described and identified for managed 

species (GMFMC, 2005; USDOC, NOAA, 2009). There are Fisheries Management Plans for shrimp, red 

drum, reef fishes, coastal migratory pelagics, spiny lobsters, coral and coral reefs, and highly migratory 

species (GMFMC, 2004; USDOC, NOAA, 2009). These species could use the GOM for EFH at different 

life history stages. The Highly Migratory Species Fisheries Management Plan was recently amended to 

update EFH and Habitat Areas of Particular Concerns for the Atlantic bluefin tuna spawning area 

(USDOC, NOAA, 2009).

These EFHs in the Gulf of Mexico are discussed in various chapters of this Appendix: water column 

(Chapter B.3.1.2); wetlands (Chapter B.3.1.4); seagrass communities (Chapter B.3.1.5), live bottoms 
B-76 Central and Eastern Planning Areas Supplemental EIS

(Chapter B.3.1.6); topographic features (Chapter B.3.1.7), Sargassum communities (Chapter B.3.1.8); 

chemosynthetic and nonchemosynthetic deepwater benthic communities (Chapters B.3.1.9 and B.3.1.10, 

respectively), and soft bottom benthic communities (Chapter B.3.1.11); these EFHs are also summarized 

in Appendix D of the 2012-2017 WPA/CPA Multisale EIS. There are current NTLs (NTL 2009-G39 and 

NTL 2009-G40) and stipulations that provide guidance and clarification of the regulations with respect to 

many of these biologically sensitive underwater features and areas and benthic communities, which are 

considered EFH.

Plankton 

Open-water organisms, such as phytoplankton and zooplankton, are essential to the marine food web. 

They play an important role in regulating climate, contribute to marine snow, and are an important source 

of nutrients for mesopelagic and benthic habitats. Also, monthly ichthyoplankton collections over the 

years 2004-2006 offshore of Alabama have confirmed that peak seasons for ichthyoplankton 

concentrations on the shelf are spring and summer (Hernandez et al., 2010). If a catastrophic blowout 

occurs in the spring and summer, it could cause greater harm to fish populations and not just individual 

fish. Therefore, an offshore oil spill would not only have an impact on these populations but also on the 

species that depend on them.

The microbial community can also be affected by an offshore oil spill. The microbial loop is an 

essential part of the marine ecosystem. Changes in the microbial community because of an oil spill could 

have significant impacts on the rest of the marine ecosystem. However, several laboratory and field 

experiments and observations have shown that impacts to planktonic and marine microbial populations 

are generally short lived and do not affect all groups evenly, and in some cases stimulate growth of 

important species (Gonzalez et al., 2009; Graham et al., 2010; Hing et al., 2011).

Phase 3—Onshore Contact

It is estimated that shoreline oiling would last 1-5 months from a shallow-water catastrophic spill 

event and 3-4 months from a deepwater catastrophic spill. It is estimated that there would be contact to 

the shoreline within 30 days of the spill for both shallow-water and deepwater spill locations. Though 

response methods would be monitored, there would also be some impact from these efforts on contacted 

coastal habitats. Further detail on this catastrophic OSRA run is contained in Appendix C of the CPA 

235/241/247 Supplemental EIS and Appendix B of the EPA 225/226 EIS. 

The life history of estuarine-dependent species involves spawning on the continental shelf; the 

transportation of eggs, larvae, or juveniles back to the estuary nursery grounds; and migration of the 

adults back to the sea for spawning (Deegan, 1989; Beck et al., 2001). Estuaries in the Gulf of Mexico 

are extremely important nursery areas and are considered EFH for fish and other aquatic life (Beck et al., 

2001). Oiling of these areas, depending on the severity, can destroy nutrient-rich marshes and erode 

coastlines that have been significantly damaged by recent hurricanes.

The Gulf of Mexico supports a wide variety of finfish, and most of the commercial finfish resources 

are linked either directly or indirectly to the estuaries that ring the Gulf of Mexico. Darnell et al. (1983) 

observed that the density distribution of fish resources in the Gulf was highest nearshore off of the central 

Gulf Coast. For all seasons, the greatest abundance occurred between Galveston Bay and the mouth of 

the Mississippi River. Oyster beds could be damaged by freshwater diversions that release tens of 

thousands of cubic feet of freshwater per second for months in an effort to keep oil out of the marshes. 

Adult oysters survive well physiologically in salinities from those of estuarine waters (about 7.5 parts per 

thousand sustained) to full strength seawater (Davis, 1958). While oysters may tolerate small changes in 

salinity for a few weeks, a rapid decrease in salinity over months would kill oysters. In the event of a 

catastrophic oil spill, at least 1 year’s oyster production in the area receiving fresh water would be lost 

because of exposure to freshwater and/or oil.

Phase 4—Post-Spill, Long-Term Recovery and Response

In addition to possible small fish kills because of direct impacts (as described under Phases 2 and 3), a 

catastrophic spill could affect fish populations in the long term. Due to a catastrophic spill, a significant 

portion of a year class of fish could be absent from the following year’s fishery, reducing overall 

population numbers. However, sublethal impacts, especially for long-lived species (e.g., snapper and 
Catastrophic Spill Event Analysis B-77

grouper), could be masked by reduced fishing pressure because of closures. In addition, healthy fish 

resources and fishery stocks depend on ideal habitat (EFH) for spawning, breeding, feeding, and growth 

to maturity. There could be long-term effects to coastal habitats from buried or sequestered oil becoming 

resuspended after a disturbance. Thus, a catastrophic spill that affects these areas could result in longterm impacts, including destruction to a portion of their natural habitats.

Overall Summary and Conclusion (Phases 1-4)

Depending on the type of blowout and the proximity of marine life to it, an eruption of gases and 

fluids may generate not only a toxic effect but also pressure waves and noise significant enough to injure 

or kill local biota and destroy habitat in the immediate vicinity (Phase 1). Adult fish may be less at risk 

than earlier life stages, in part because they are less likely to concentrate at the surface and may avoid 

contact with floating oil. Effects of oil on organisms can include direct lethal toxicity, sublethal 

disruption of physiological processes (internal lesions), the effects from direct coating by oil (suffocation 

by coating gills), incorporation of hydrocarbons in organisms (tainting or accumulation in the food chain), 

and changes in biological habitat (decreased dissolved oxygen) (Phase 2). Estuaries in the Gulf of 

Mexico are extremely important nursery areas and are considered EFH for fish and other aquatic life 

(Beck et al., 2001). Oiling of these areas, depending on the severity, can destroy nutrient-rich marshes 

and erode coastlines that have been significantly damaged by recent hurricanes (Phase 3). Due to a 

catastrophic spill, a significant portion of a year class of fish could be absent from the following year’s 

fishery, reducing overall population numbers. However, sublethal impacts, especially for long-lived 

species (e.g., snapper and grouper), could be masked by reduced fishing pressure because of closures 

(Phase 4).

B.3.1.18. Commercial Fisheries

Phase 1—Initial Event

The initial explosion and fire could endanger commercial fishermen in the immediate vicinity of the 

blowout. Although commercial fishing vessels in the area would likely aid in initial search-and-rescue 

operations, the subsequent fire could burn for over a month, during which time commercial vessels would 

be expected to avoid the area so as to not interfere with response activities. This could impact the 

livelihood and income of these commercial fishermen. The extent of the economic impact on the fishing 

community would depend largely on the season during which the blowout occurred, the depth of water in 

which it occurred, and its distance from shore.

Phase 2—Offshore Spill

The Gulf of Mexico is one of the largest producers of seafood in the continental United States. In 

2010 the Gulf of Mexico provided 40 percent of the commercial fishery landings in the continental U.S. 

(excluding Alaska), with over 1.5 billion pounds valued at nearly $670 million (USDOC, NMFS, 2012b). 

Various commercial species are fished from State waters through the Exclusive Economic Zone and are 

found throughout the water column as well as at the surface and near the seafloor. Commercial species 

occupy many different habitats throughout the area, and many commercial species occupy different 

habitats during different life stages. Most commercial species spend at least part of their life cycles in the 

productive shelf and estuarine habitat. In the event of a catastrophic offshore spill, it is assumed that a 

large quantity of oil would be released daily whether this spill occurred in State or Federal waters. 

Although the oil would generally float, it is also assumed that dispersants would be used preventing much 

of the oil from reaching the surface.

As an example of the areas that could be affected by such a catastrophic oil spill in the CPA, OSRA 

model runs were performed using three different launch points as described in Chapter B.1.2.3. The 

resulting tables show conditional probabilities (expressed as percent chance) of an oil spill contacting 

resources in the GOM for each launch point and for each season, the condition being that a spill is 

assumed to have occurred at the given location. Because the commercial species are so widespread over 

the GOM, all of the tables are referenced (Appendix C of the CPA 235/241/247 Supplemental EIS, Tables 

C-4 and C-5). 
B-78 Central and Eastern Planning Areas Supplemental EIS

Oil that is not volatilized, dispersed, or emulsified by dispersants has the potential to affect finfish 

through direct ingestion of hydrocarbons or ingestion of contaminated prey. Finfish are, however, mobile 

and generally avoid adverse conditions. Less mobile species or planktonic larval stages are more 

susceptible to the effects of oil and dispersants.

Actual effects of any oil that is released and comes in contact with populations of commercially 

important species will depend on the API gravity of the oil, its ability to be metabolized by 

microorganisms, and the time of year of the spill. The effects on the populations will be at a maximum 

during the spawning season of any commercially important population, exposing larvae and juveniles to 

oil. The effects on commercial species may also include tainting of flesh or the perception of tainting in 

the market. This can, depending on the extent and duration of the spill, affect marketability of 

commercial species.

Even though sensory testing may show no detectable oil or dispersant odors or flavors and the 

chemical test results could be well below the known levels of concern, NOAA Fisheries would be 

expected to close large portions of the Gulf of Mexico during a high-volume spill. This would be done as 

a precautionary measure to ensure public safety and to assure consumer confidence in Gulf seafood 

(USDOC, NMFS, 2010b). Up to 30-40 percent of the Gulf of Mexico’s Exclusive Economic Zone could 

be closed to commercial fishing as the spill continues and expands (USDOC, NMFS, 2010c). This area 

could represent 50-75 percent of the Gulf’s seafood production (Flynn, 2010). The size of the closure 

area may peak about 50 days into the spill and could persist another 2-3 months until the well is killed or 

capped and the remaining oil is recovered or dissipates. During this period, portions or all of individual 

State waters would also be closed to commercial fishing.

The economic impacts of closures on commercial fishing are difficult to predict because they are 

dependent on the season and would vary by fishery. If fishers cannot make up losses throughout the 

remainder of the season, a substantial part of their annual income would be lost. In some cases, 

commercial fishers will leave the industry and some may move to areas still open to fishing, but at a 

greater cost because of longer transit times. Marketing issues are also possible; even if the catch is 

uncontaminated, the public may lack confidence in the product. The duration of the public’s perception 

of seafood tainting is also difficult to predict and depends to some extent on the duration of the spill and 

public awareness of the spill.

Phase 3—Onshore Contact

Shoreline contact of oil is estimated to persist from 1 to 5 months in the event of a shallow-water 

catastrophic spill and for up to 6 months from a deepwater catastrophic spill. The OSRA probability 

tables show the conditional probabilities (expressed as percent chance) for a shoreline contact for each 

season, the condition being that a spill is assumed to have occurred at the given location. Further detail 

on this catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS

and Appendix B of the EPA 225/226 EIS. 

This scenario, depending on the sea son of occurrence, would cause disruption in commercial fishing 

activity because many commercial fishermen operate inshore in State waters.

In addition to closures in Federal waters, portions of individual State waters would also be closed to 

commercial fishing. The economic impacts of closures on commercial fishing are complicated to predict 

because it is dependent on season and would vary by fishery. If fishers cannot make up losses in the 

remainder of the season, a substantial part of their annual income will be lost. In some cases, commercial 

fishers may move to areas still open to fishing, but at a greater cost because of longer transit times and, in 

some instances, additional license costs. Some commercial fishermen may also augment their income by 

aiding in the cleanup effort and/or renting the boats as vessels of opportunity.

Phase 4—Post-Spill, Long-Term Recovery and Response

The Gulf of Mexico is an important biological and economic area in terms of commercial seafood 

production and recreational fishing. Commercial fishermen in the Gulf of Mexico harvested over 

1.5 billion pounds of finfish and shellfish in 2010 (USDOC, NMFS, 2012b). The economic impacts of 

closures on commercial fishing are complicated to predict because the economic effects are dependent on 

season and would vary by fishery. If fishermen cannot make up losses by fishing the remainder of the 

season or by participating as contractors in the cleanup, a substantial part of their annual income could be 
Catastrophic Spill Event Analysis B-79

lost and may force them out of the industry. While the commercial fishing industry of Texas did not 

sustain measurable direct or indirect economic effects following the 1979 Ixtoc I blowout and spill 

(Restrepo et al., 1982), there is a documented phenomenon that, long after an incident, the perception of 

tainted fish and shellfish from the impacted area persists (Keithly and Diop, 2001). Data regarding the 

duration of the negative perception of Gulf seafood following the Deepwater Horizon explosion, oil spill, 

and response are not yet available. It is reasonable to assume that a negative perception could impact the 

value of commercial fish resources for several seasons.

Overall Summary and Conclusion (Phases 1-4)

The Gulf of Mexico is one of the largest producers of seafood in the continental United States. 

Various commercial species are fished from State waters through the Exclusive Economic Zone and are 

found throughout the water column. The primary economic impacts of oil spill on commercial fisheries 

are the closure of State or Federal waters to fishing and the perception of seafood tainting by the market. 

Both of these factors are difficult to predict. Closures depend on the size, timing, depth of water, and 

location of the spill as well as the fishery involved. Perception depends on length of the spill and public 

perception. Both of these factors could affect the livelihood of the fishing community.

B.3.1.19. Recreational Fishing

Phase 1—Initial Phase

About 20 percent of the recreational fishing activity in the Gulf of Mexico occurs within 300 ft 

(91 m) of oil and gas structures (Hiett and Milon, 2002). Therefore, an explosion and fire could endanger 

recreational fishermen and divers in the immediate vicinity of the blowout, especially if the blowout is 

located close to shore. Recreational vessels in the area would likely aid in initial search-and-rescue 

operations but they would also be in danger during the explosion and subsequent fire. The subsequent 

fire could burn for up to a month, during which recreational vessels would be expected to avoid the area 

and to not interfere with response activities. It is also possible that recreational fishing could be impacted 

in areas beyond the immediate area of the event due to the perceptions of the public.

Phase 2—Offshore Spill

If a catastrophic spill were to occur, a substantial portion of ocean waters could be closed. For 

example, 88,522 square miles (mi2

) (229,271 square kilometers [km2]) were closed to recreational fishing 

activity at the peak of the Macondo well oil spill. However, the majority of recreational fishing activity 

occurs fairly close to shore. Therefore, while the spill remains offshore, the impacts would be particularly 

felt with respect to fishing of offshore species such as king mackerel and red snapper (the impacts of a 

catastrophic spill on fish populations are discussed in Chapter B.3.1.17). The NOAA’s Center for 

Coastal Monitoring and Assessment (USDOC, NOAA, CFCMAA, 2012b) provides a set of maps that 

display the locations in the Gulf of Mexico where certain fish species are prevalent. However, even while 

the spill remains offshore, there could be impacts to inshore recreational fishing due to misperceptions 

regarding the extent of the spill or due to concerns regarding the tainting of fish species. These 

misperceptions could also reduce tourism activity, which would impact tourism-based recreational fishing 

activity.

In 2011, the percent of each Gulf Coast State’s recreational fishing activity that occurred in State and 

Federal ocean waters combined (i.e., not inland waters) were as follows: Texas (6%); Louisiana (5%); 

Mississippi (2%); Alabama (42%); and West Florida (34%) (USDOC, NMFS, 2012c; Texas Parks and 

Wildlife Department, 2012). Chapter 4.1.1.17 of this Supplemental EIS provides a further breakdown of 

recreational fishing activity by state. Further detail on this catastrophic OSRA run is contained in 

Appendix C of the CPA 235/241/247 Supplemental EIS and Appendix B of the EPA 225/226 EIS. 

Phase 3—Onshore Contact

If a catastrophic spill were to reach shore, there would likely be noticeable impacts to recreational 

fishing activity. Since most recreational fishing activity occurs fairly close to shore, there would be a 

number of direct impacts to angler activity due to the fishing closures that would likely arise. This is 
B-80 Central and Eastern Planning Areas Supplemental EIS

particularly true since anglers would find it more difficult to find substitute fishing sites in the case of a 

catastrophic spill. In 2011, the percent of each Gulf State’s recreational fishing activity that occurred 

inland were as follows: Texas (94%); Louisiana (95%); Mississippi (98%); Alabama (58%); and West 

Florida (66%) (USDOC, NMFS, 2012c; Texas Parks and Wildlife Department, 2012). The impacts to 

recreational fishing would also depend on the time of year of the spill. In 2011, 31 percent of angler trips 

in the Gulf occurred between January and April, 41 percent of angler trips occurred between May and 

August, and 28 percent of angler trips occurred between September and December (USDOC, NMFS, 

2012c). In addition, fishing tournaments are often scheduled for the summer months and would be 

difficult to reschedule in the aftermath of a catastrophic spill. Further detail on this catastrophic OSRA 

run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS and Appendix B of the EPA 

225/226 EIS. 

There would also be various economic impacts along the recreational fishing supply chain. Gentner 

Consulting Group (2010) estimates that recreational fishing activity supports $9.8 million in direct 

expenditures and $23 million in total sales per day in the Gulf of Mexico. There could be further impacts 

if the fishing closures persisted long enough to affect purchases of boats and other durable fishing 

equipment. There could also be further impacts if the loss of opportunities for recreational fishing 

activity exacerbated the fall in tourism activity that would arise due to the spill.

Phase 4—Post-Spill, Long-Term Recovery and Response

The long-term impacts of a catastrophic spill on recreational fishing activity would primarily depend 

on the extent to which fish populations recover (refer to Chapter B.3.1.17 for more information). 

However, the longer term impacts of a spill on recreational fishing activity would also depend on the 

extent to which public perceptions of fish tainting can be assuaged. In addition, the longer-term impacts 

would depend on the extent to which the various firms that serve the recreational fishing industry would 

be able to weather the downturn in activity resulting from the spill.

Overall Summary and Conclusion (Phases 1-4)

Recreational fishing activity could be noticeably impacted in the event of a catastrophic spill. This is 

particularly the case if the spill reached shore or if the spill occurred during peak times and places of 

recreational fishing activity. The long-term impacts of a catastrophic spill would depend on the extent to 

which fish populations recover and the length of time it would take to convince the public that it was 

again safe to fish in the affected areas.

B.3.1.20. Recreational Resources

Phase 1—Initial Event

The most immediate impacts of a catastrophic spill would be on the recreational fishing and 

recreational diving activity in the vicinity of the blowout. About 20 percent of the recreational fishing 

activity and 90 percent of the recreational diving activity in the Gulf of Mexico from Alabama to Texas 

occurs within 300 ft (91 m) of oil and gas structures (Hiett and Milon, 2002). The impacts on recreational 

fishing and recreational diving would be greater the closer the blowout occurred to shore. The immediate 

response activities could also impact ocean-based recreational activity. Finally, there could be impacts to 

tourism activity since a catastrophic spill would likely receive a large amount of media attention.

Phase 2—Offshore Spill

While the spill is still offshore, there could be some ocean-dependent recreation that is affected (e.g., 

fishing, diving, and boating), as discussed above. In addition, there may be some effects due either to 

perceived damage to onshore recreational resources that has not yet materialized or to general hesitation 

on the part of travelers to visit the overall region because of the spill. A Congressional hearing into this 

matter (U.S. House of Representatives, 2010) provides a broad overview of some of the effects that were 

felt along the Gulf Coast subsequent to the Deepwater Horizon explosion, oil spill, and response. For 

example, a representative of Pinellas County estimated that this area had lost roughly $70 million in hotel 

revenue even though beaches in this area did not receive any oil damage. This type of effect could be due 
Catastrophic Spill Event Analysis B-81

to misperceptions about the spill, uncertainty about the future of the spill, or concerns about whether a 

tourism experience will be affected even if the destination is only within close proximity to a spill.

As previously mentioned, recreational diving is one offshore recreational activity that would be 

particularly affected by a catastrophic oil spill. Further detail on this catastrophic OSRA run is contained 

in Appendix C of the CPA 235/241/247 Supplemental EIS and Appendix B of the EPA 225/226 EIS. 

Phase 3—Onshore Contact

A catastrophic spill has the potential to noticeably impact the Gulf Coast recreation and tourism 

industries. The water-dependent and beach-dependent components of these industries would be 

particularly vulnerable. Environmental Sensitivity Indexes (ESIs) provide overall measures of the 

sensitivity of a particular coastline to a potential oil spill. The ESIs rank coastlines from 1 (least 

sensitive) to 10 (most sensitive). Marshes and swamps are examples of resources that have ESIs of 10 

due to the extreme difficulty of removing oil from these areas; marsh and swamp areas are particularly 

prevalent in Louisiana. The ESIs for beach areas generally range from 3 to 6, depending on the type of 

sand and the extent to which gravel is mixed into the beach area; beach areas are particularly prevalent in 

Texas, Mississippi, Alabama, and Florida. The ESI maps for any coastline along the Gulf of Mexico can 

be viewed using the National Oceanic and Atmospheric Administration’s ERMA mapping system 

(USDOC, NOAA, 2012b and USDOC, NOAA, Office of Response and Restoration, 2014). The ESI 

maps also provide point indicators for recreational resources.

A catastrophic spill would also raise a number of issues regarding recreational activity that is based 

on tourism. One important point is that a spill of the Deepwater Horizon’s dimensions can influence a 

much broader range of individuals and firms than can a smaller spill. For example, a small, localized spill 

may lead some travelers to seek substitute recreational opportunities in nearby areas. However, a large 

spill is more likely to dissuade travelers from visiting a broader economic region. Similarly, small- and 

mid-sized restaurant chains and hotels may be able to find other customers or to simply weather a smaller 

spill. However, a spill the size of the Deepwater Horizon is more likely to affect these types of firms 

since they are less able to diversify their customer base. These effects can be seen in the makeup of those 

who filed damage claims with BP (Gulf Coast Claims Facility, 2012); the Gulf Coast Claims Facility 

closed in early 2012 subsequent to preliminary court approval of a settlement program. For example, the 

bulk of the claims by individuals have been made in the food, beverage, and lodging sector and in the 

retail, sales, and service sector. Claims have also been made by individuals and firms in a broad range of 

geographic regions, many of which were not directly impacted by oil.

Murtaugh (2010) provides data on the change in hotel and sales tax receipts for individual Gulf Coast 

counties in the months immediately following the Deepwater Horizon explosion, oil spill, and response. 

During the summer of 2010, the spill caused substantial declines in hotel receipts in the following 

counties: Baldwin, Alabama (33.2% decline); Santa Rosa, Florida (24.8% decline); Okaloosa, Florida 

(24.1% decline); Walton, Florida (12.3% decline); and Bay, Florida (7.4% decline). However, coastal 

counties west of Baldwin, Alabama (as far west as St. Mary, Louisiana), generally experienced noticeable 

increases in hotel receipts. This was particularly true in Mobile, Alabama; Jackson, Mississippi; and in 

the coastal parishes of Louisiana. For example, in Louisiana, St. Mary, Terrebonne, and Lafourche 

Parishes each reported increases in hotel tax receipts of over 80 percent in the summer of 2010. These 

effects are likely due to the influx of oil-spill relief workers to these areas in the immediate aftermath of 

the Deepwater Horizon explosion, oil spill, and response. Overall sales tax receipts in counties from 

Baldwin, Alabama, eastward also generally fell during 2010, although to a lesser extent than hotel tax 

receipts. Sales tax receipts in counties and parishes west of Baldwin, Alabama, did not show as clear a 

pattern as did hotel tax receipts. For example, overall sales tax receipts fell by 12.5 percent in Hancock 

County (Mississippi), receipts were almost unchanged in Harrison County (Mississippi), and receipts 

increased by 8.3 percent in Orleans Parish (Louisiana). These results suggest that the impacts of a future 

catastrophic spill will be influenced by the structure of a particular county/parish’s recreational economy, 

as well as by the extent to which oil-spill-response activities will mitigate some of the negative impacts of 

the spill in certain areas.

There could also be effects on tourist activities in areas far away from the areas directly affected by 

oil. For example, in Texas subsequent to the Deepwater Horizon explosion, oil spill, and response, some 

tourists may have stayed away from Texas Gulf Coast beaches due to misperceptions regarding the extent 

to which these beaches were damaged due to the spill. Conversely, there may have been some 
B-82 Central and Eastern Planning Areas Supplemental EIS

substitution of beach visitation away from beaches in the eastern Gulf towards the beaches in Texas, 

which were farther from the spill. While it is difficult to quantify these effects, some anecdotal evidence 

regarding this substitution effect can be found in Pack (2010). Hotel occupancy data suggest that these 

two effects may have largely offset each other. Source Strategies Inc. (2010) reports that total hotel 

occupancy in the three metro regions in Texas closest to the Gulf Coast increased just 1.9 percent during 

the third quarter of 2010 compared with the third quarter of 2009. Further detail on this catastrophic 

OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental EIS and Appendix B of the 

EPA 225/226 EIS. 

Phase 4—Post-Spill, Long-Term Recovery and Response

The longer-term implications of a catastrophic event on tourism would depend on the extent to which 

any structural/ecological damage can be repaired and the extent to which economic mitigation actions 

would occur. The long-term implications of a catastrophic spill would also depend on the extent to which 

public confidence in the various components of the recreational and tourism economies can be restored. 

For example, restaurants in the region would be impacted to the extent to which they are perceived to use 

seafood products caught or raised in contaminated waters. Similarly, although beaches can be 

decontaminated not long after a spill has been stopped, lingering perceptions can be expected to 

negatively impact tourism even after a spill has ended.

Oxford Economics (2010) attempts to quantify these effects by analyzing the impacts of recent 

catastrophic events on recreational economies. For example, they analyzed the Ixtoc I well blowout and 

spill of 1979, the scale and nature of which was reasonably similar to the Macondo well blowout and spill 

of 2010. In this example, it took approximately 3 years for beaches to be cleaned and for recreational 

activity to return to similar levels as before the spill. They also looked at the Prestige oil spill of 2002 off 

the coast of Spain. Given the nature and size of that spill, recreational activity was able to return to prespill levels in approximately 1 year. Alaska’s tourism economy took approximately 2 years to recover 

from the Exxon Valdez spill.

Overall Summary and Conclusion (Phases 1-4)

A catastrophic spill can cause noticeable impacts to recreational resources such as beaches. A 

catastrophic spill can also have complex effects on recreational activity that depends on tourism. The 

longer-term implications of a catastrophic oil spill on tourism would depend on the extent to which any 

structural/ecological damage can be repaired, the extent to which economic mitigation actions would 

occur, and the speed at which public confidence in the various components of the affected recreational 

and tourism economies would be restored.

B.3.1.21. Archaeological Resources

Phase 1—Initial Event

Offshore Archaeological Resources

BOEM protects all known, discovered, and potentially historic and prehistoric archaeological 

resources on the OCS by requiring appropriate avoidance criteria as well as directives to investigate these 

resources. Onshore archaeological resources, prehistoric and historic sites, would not be immediately 

impacted during the initial phase of a catastrophic blowout because the distance of a blowout site from 

shore is at least 3 nmi (3.5 mi; 5.6 km). However, offshore catastrophic blowouts, when compared with 

spills of lesser magnitude, may initially impact multiple archaeological resources. Resources adjacent to 

a catastrophic blowout could be damaged by the high volume of escaping gas, buried by large amounts of 

dispersed sediments, crushed by the sinking of the rig or platform, destroyed during emergency relief well 

drilling, or contaminated by the hydrocarbons.

Based on historical information, over 2,100 potential shipwreck locations have been identified on the 

Gulf of Mexico OCS (USDOI, MMS, 2007). This number is a conservative estimate and is heavily 

weighted toward post-19th century, nearshore shipwrecks, where historic records documenting the loss of 

the vessels were generated more consistently. BOEM currently has confirmed locational data for 
Catastrophic Spill Event Analysis B-83

approximately 380 potential wreck sites, though the historic significance for the majority of these sites 

has not been determined.

BOEM’s Regional Director may require the preparation of an archaeological report to accompany the 

exploration plan, development operations coordination document, or development and production plan, 

under 30 CFR § 550.194, and BSEE’s Regional Director may do likewise under 30 CFR § 250.194 if a 

potential wreck is encountered during operations. As part of the environmental reviews conducted for 

postlease activities, available information is evaluated regarding the potential presence of archaeological 

resources within a CPA and EPA proposed action area to determine if additional archaeological resource 

surveys and mitigations are warranted. Having complete knowledge of seafloor resources before a spill 

occurs would enable responders to quickly plan countermeasures in a way that would minimize adverse 

effects occurring from the spill response.

Phase 2—Offshore Spill

Offshore Archaeological Resources

Due to the response methods (i.e., subsea dispersants) and magnitude of the response (i.e., thousands 

of vessels), a catastrophic blowout and spill have a greater potential to impact offshore archaeological 

resources than other accidental events.

Deep Water

In contrast to smaller spills or spills in shallow water, large quantities of subsea dispersants could be 

used for a catastrophic subsea blowout in deep water. This could result in currently unknown effects from 

dispersed oil droplets settling to the seafloor. Though information on the actual impacts to submerged 

cultural resources is inconclusive at this time, oil settling to the seafloor could come in contact with 

archaeological resources. At present, there is no evidence of this having occurred. A recent experimental 

study has suggested that, while the degradation of wood in terrestrial environments is initially retarded by 

contamination with crude oil, at later stages, the biodeterioration of wood is accelerated (Ejechi, 2003). 

While there are different environmental constraints that affect the degradation of wood in terrestrial and 

waterlogged environments, soft-rot fungal activity, one of the primary wood degrading organisms in 

submerged environments, was shown to be increased in the presence of crude oil (Ejechi, 2003). There is 

a possibility that oil from a catastrophic blowout could come in contact with wooden shipwrecks and 

artifacts on the seafloor and accelerate their deterioration.

Ancillary damages from vessels associated with oil-spill-response activities (e.g., anchoring) in deep 

water are unlikely because of the use of dynamically positioned vessels responding to a deepwater 

blowout. If response and support vessels were to anchor near a deepwater blowout site, the potential to 

damage undiscovered vessels in the area would be high because of the required number and the size of 

anchors and the length of mooring chains needed to safely secure vessels. Additionally, multiple offshore 

vessel decontamination stations would likely be established in shallow water outside of ports or entrances 

to inland waterways, as seen for the Deepwater Horizon explosion, oil spill, and response. The anchoring 

of vessels could result in damage to both known and undiscovered archaeological sites; the potential to 

impact archaeological resources increases as the density of anchoring activities in these areas increases.

Shallow Water 

The potential for damaging archaeological resources increases as the oil spill and related response 

activities progress landward. In shallower waters, most of the damage would be associated with oil 

cleanup and response activities. Thousands of vessels would respond to a shallow-water blowout and 

would likely anchor, potentially damaging both known and undiscovered archaeological sites. Additional 

anchoring would be associated with offshore vessel decontamination stations, as described above. As the 

spill moves into the intertidal zone, the chance of direct contact between the oil and archaeological 

resources increases. As discussed above, this could result in increased degradation of wooden shipwrecks 

and artifacts.

Additionally, in shallower waters, shipwrecks often act as a substrate to corals and other organisms, 

becoming an essential component of the marine ecosystem. These organisms often form a protective 

layer over the shipwreck, virtually encasing the artifacts and hull remains. If these fragile ecosystems 
B-84 Central and Eastern Planning Areas Supplemental EIS

were destroyed as a result of the oil spill and the protective layer was removed, the shipwreck would then 

be exposed to increased degradation until it reaches a new level of relative stasis with its surroundings.

Regardless of water depth, because oil is a hydrocarbon, heavy oiling could contaminate organic 

materials associated with archaeological sites, resulting in erroneous dates from standard radiometric 

dating techniques (e.g., 14C-dating). Interference with the accuracy of 14C-dating would result in the loss 

of valuable data necessary to understand and interpret the sites.

Phase 3—Onshore Contact

Onshore Archaeological Resources

Regardless of the water depth in which the catastrophic blowout occurs, it is assumed that more than 

1,000 mi (1,609 km) of shoreline could be oiled to some degree. Onshore prehistoric and historic sites 

would be impacted to some extent by a high-volume spill from a catastrophic blowout that reaches shore. 

Sites on barrier islands could suffer the heaviest impact, and a few prehistoric sites located inland from 

the coastline, in the marsh, and along bayous could also experience some light oiling. Impacts would 

include the loss of ability to accurately date organic material from archaeological sites because of 

contamination or increased research costs to clean samples for analysis. Efforts to prevent coastal cultural 

resources from becoming contaminated by oil would likely be overwhelmed in the event of a hurricane 

and by the magnitude of shoreline impacted.

The most significant damage to archaeological sites could be related to cleanup and response efforts. 

Fortunately, important lessons were learned from the Exxon Valdez spill in Alaska in 1989, in which the 

greatest damage to archaeological sites was related to cleanup activities and looting by cleanup crews 

rather than from the oil itself (Bittner, 1996). As a result, cultural resources were recognized as 

significant early in the Deepwater Horizon response and cleanup, and archaeologists were embedded in 

Shoreline Cleanup Assessment Teams (SCAT) and consulting with cleanup crews. Historic preservation 

representatives were present at both the Joint Incident Command as well as each Area Command under 

the general oversight of the National Park Service to coordinate response efforts (Odess, official 

communication, 2010). Despite these efforts, some archaeological sites suffered damage from looting or 

from spill cleanup activities, most notably the parade ground at Fort Morgan, Alabama (Odess, official 

communication, 2011).

Phase 4—Post-Spill, Long-Term Recovery and Response

Onshore Archaeological Resources

Regardless of the water depth in which the catastrophic blowout occurs, it is assumed that more than 

1,000 mi (1,609 km) of shoreline could be oiled to some degree. Onshore prehistoric and historic sites 

would be impacted to some extent by a high-volume spill from a catastrophic blowout that reaches shore. 

A few prehistoric sites in Louisiana, located inland from the coastline in the marsh and along bayous, 

could experience some light oiling. As discussed above, impacts would include the permanent loss of 

ability to accurately date organic material from archaeological sites because of contamination. The most 

significant damage to archaeological sites would be related to cleanup and response efforts. Long-term 

recovery would prove difficult if not impossible. Historic structures such as coastal forts that are exposed 

to oiling are generally constructed of brick or other porous, friable materials that are difficult to clean 

without causing further damage (Chin and Church, 2010). Funding for any sort or archaeological 

recovery is problematic outside of Federal lands because of existing laws and regulations (Varmer, 2014). 

Most coastal prehistoric sites in Louisiana, for example, are on private lands where there is no mechanism 

to recover damages. Section 106 of the National Historic Preservation Act is triggered by a Federal 

undertaking, which in the case of a spill, would be the response and not the actual spill. The Natural 

Resource Damage Assessment (NRDA) process codified by the Oil Pollution Act of 1990 is a legal 

process to determine the type and amount of restoration needed to compensate the public for harm to 

natural resources that occurs as a result of an oil spill, but it does not cover cultural, archaeological, or 

historic properties.
Catastrophic Spill Event Analysis B-85

Overall Summary and Conclusion (Phases 1-4)

Archaeological resources are finite, unique, irreplaceable, nonrenewable records of mankind’s past, 

which, once destroyed or damaged, are gone forever. In the event of a catastrophic oil spill, the most 

likely source of irreversible impact is, ironically, from the spill response, and the danger increases 

dramatically as the response approaches the shoreline. This damage can, to a large extent, be mitigated 

by the early integration of archaeologists and State and Tribal historic preservation officers in the 

response to protect sites from impact. Mitigation of impacts from the oil itself is likely to meet with 

varied success depending upon the type of site and availability of funding.

B.3.1.22. Land Use and Coastal Infrastructure

Phase 1—Initial Event

There would likely be no adverse impacts to land use and coastal infrastructure as a result of the 

events and the potential impact-producing factors that could occur throughout Phase 1 of a catastrophic 

spill event because of the long distance (>3 nmi; 3.5 mi; 5.6 km) from shore and the short duration of the 

initial event, fire, and/or explosion.

Phase 2—Offshore Spill

Impacts to tourism and recreational resources are addressed in Chapter B.3.1.20. Possible fisheries 

closures are addressed in Chapters B.3.1.18 and B.3.1.19. As cleanup and remediation efforts evolve, 

there would be increased activity at ports and coastal cities, leading to increased traffic on road 

infrastructure and at port facilities. This follows from consideration of BOEM’s scenario estimates of up 

to 3,000 vessels, 25-50 planes/helicopters, and up to 25,000 workers for a shallow-water event and up to 

7,000 vessels, 50-100 planes/helicopters, and up to 50,000 workers for a deepwater event. Waste disposal 

activities associated with boom deployment and retrieval would increase demand at waste disposal 

facilities. BOEM’s scenario estimates 5 million feet (1.5 million meters) of boom deployment and 

35,000 bbl of dispersant applied at the surface for a shallow-water event or 11 million feet (3.4 million 

meters) of boom deployment and 33,000 bbl of dispersant applied at the surface and 16,500 bbl of 

dispersant applied subsea for a deepwater event. Also, vessel decontamination sites would be set up 

offshore and the staffing/maintenance of these sites would contribute to increased activity at port facilities

and traffic congestion on coastal waterways and highways.

Phase 3—Onshore Contact

In the event of a catastrophic spill, impacts on land use and infrastructure would be temporary and 

variable in nature. The scale of impact would depend on the nature of the event and whether it occurs in 

shallow or deep water. These impacts would include land use in staging areas, waste disposal locations 

and capacities, and potential delays because of vessel decontamination stations near ports, as described 

below.

For a shallow-water event, BOEM estimates 5-10 staging areas and 200-300 skimmers. For a 

deepwater event, scenario estimates call for 10-20 staging areas and 500-600 skimmers. Given these 

estimates and the several thousand responders that would be involved in the effort, BOEM expects a 

further increase in traffic congestion and some possible competing land-use issues near the staging areas, 

depending on the real estate market at the time of the event. Some infrastructure categories, such as 

vessels, ports, docks and wharves, would likely become very engaged in response activities and this could 

result in a shortage of space and functionality at infrastructure facilities if ongoing drilling activities were 

simultaneously occurring. However, if drilling were to be suspended, conflicting demands on 

infrastructure facilities would likely fail to materialize.

In the category of waste disposal, the impacts would be more visible as thousands of tons of oily 

liquid and solid wastes from the oil-spill cleanup would be disposed of in onshore landfills. As was the 

case in the Deepwater Horizon explosion, oil spill, and response, USEPA, in consultation with USCG, 

would likely issue solid-waste management directives to address the issue of contaminated materials and 

solid or liquid wastes that are recovered as a result of cleanup operations (USEPA, 2010c and 2010d). 
B-86 Central and Eastern Planning Areas Supplemental EIS

For navigation and port use, there would also be the potential for delays in cargo handling and slow 

vessel traffic because of decontamination operations at various sites along the marine transportation 

system (USDOT, 2010). However, vessel decontamination activities most likely would be complete 

within a year of the event, so impacts would be expected to be limited in duration.

Phase 4—Post-Spill, Long-Term Recovery and Response

Based on the rapid recovery of infrastructure that was heavily damaged by the catastrophic 2005 

hurricane season and the region’s experience in the few years since the Deepwater Horizon explosion, oil 

spill, and response, BOEM would not expect any long-term impacts to land use and coastal infrastructure 

as a result of a catastrophic oil-spill event. However, if a catastrophic oil spill were to occur, BOEM 

would (as it is currently with regard to the Deepwater Horizon explosion, oil spill, and response) monitor 

the post-spill, long-term recovery phase of the event for any changes that indicate otherwise. A 

catastrophic spill could generate several thousand tons of oil-impacted solid materials disposed in 

landfills along the Gulf Coast. This waste may contain debris, beach, or marsh material (sand/silt/clay), 

vegetation, and personal protection equipment collected during cleanup activities. BOEM does not 

expect that landfill capacity would be an issue at any phase of the oil-spill event or the long-term 

recovery. In the case of the Deepwater Horizon explosion, oil spill, and response, USEPA reported that 

existing landfills receiving oil-spill waste had plenty of capacity to handle waste volumes; the Deepwater 

Horizon explosion, oil spill, and response’s waste that was disposed of in landfills represented less than 

7 percent of the total daily waste normally accepted at these landfills (USEPA, 2012).

It is not expected that any long-term, land-use impacts would arise from properties that are utilized 

for restoration activities and would somehow have their future economic use compromised. The rise or 

fall of property values would not be solely a function of some kind of economic impact from a 

catastrophic oil-spill event. There are many other factors that influence the value of property and its best 

economic use. To date, it is not clear from past experiences whether vegetation loss or erosion created by 

a spill could result in changes in land use. The amount and location of erosion and vegetation loss could 

be influenced by the time of year the spill occurs, its location, and weather patterns, including hurricane 

landfalls.

Overall Summary and Conclusion (Phases 1-4)

There would likely be no adverse impacts to land use and coastal infrastructure throughout Phase 1 of 

a catastrophic spill event. Response efforts in Phases 2 and 3 would require considerable mobilization of 

equipment and people. While these efforts might temporarily displace traditional users of coastal land 

and infrastructure, these interruptions would not be long lasting. The post-spill, long-term recovery and 

response efforts during Phase 4 could generate several thousand tons of oil-impacted solid materials 

disposed in landfills along the Gulf Coast, but this would account for no more than 7 percent of the total 

daily waste normally accepted in these landfills. It is also not expected that any properties utilized for 

restoration activities throughout Phase 3 would not suffer any long-term land use or economic impacts.

B.3.1.23. Demographics

Phase 1—Initial Event

The impacts of a catastrophic spill on demographics would primarily be driven by the spill’s impacts 

on employment (refer to Chapter B.3.1.24). Since the impacts of a catastrophic spill on employment 

would take time to evolve, the initial impacts on demographics would be minimal. Therefore, there 

would likely be no adverse impacts to demographics as a result of the events and the potential impactproducing factors that could occur throughout Phase 1 of a catastrophic spill event.

Phase 2—Offshore Spill

The impacts of a catastrophic spill on demographics would primarily be driven by the spill’s impacts 

on employment (refer to Chapter B.3.1.24). For example, there could be some suspension of oil/gas 

activities in the immediate aftermath of the spill. This could cause some workers to seek employment 

outside of the OCS industry, for example in onshore oil/gas extraction or on overseas offshore projects. 
Catastrophic Spill Event Analysis B-87

However, since the OCS oil and gas industry would likely eventually recover, the long-term impacts on 

demographics would be small. There could also be impacts on demographics if employment in 

recreation, tourism, or fishing industries were affected, due to either actual or perceived impacts of the 

spill. However, the impacts on these industries would become more acute if the spill were to reach shore.

Phase 3—Onshore Contact

The impacts of a catastrophic spill on demographics would primarily be driven by the spill’s impacts 

on employment (refer to Chapter B.3.1.24). For example, impacts to recreation/tourism and recreational 

and commercial fishing activities would become more acute if the spill were to reach shore. There would 

also be a larger presence of cleanup workers in some areas if the spill were to reach shore. For example, 

48,200 workers were employed in response activities at the peak of the response effort following the 

Macondo well blowout and spill (RestoreTheGulf.gov, 2011). However, these impacts would be 

temporary and would be governed by the dynamics of the particular spill. There could also be impacts to 

demographics if there were impacts on the response workers’ health or if the demographics of the 

response workers were noticeably different from the local population.

Phase 4—Post-Spill, Long-Term Recovery and Response

The impacts of a catastrophic spill on demographics would primarily be driven by the spill’s impacts 

on employment (refer to Chapter B.3.1.24). The spill’s impacts on employment, and therefore 

demographics, would primarily be felt in the oil/gas, recreational fishing, commercial fishing, and 

recreation/tourism industries. However, it is unlikely that a catastrophic spill would cause substantial 

long-term changes to a region’s demographics. For example, the demographics data in Woods and Poole 

Economics, Inc. (2011) did not suggest large demographic changes to any Gulf regions subsequent to the 

Deepwater Horizon explosion, oil spill, and response.

Overall Summary and Conclusion (Phases 1-4)

The impacts of a catastrophic spill on demographics would primarily be driven by the spill’s impacts 

on employment (refer to Chapter B.3.1.24). These impacts would likely be temporary and would be 

governed by the particular dynamics of the spill.

B.3.1.24. Economic Factors

Phase 1—Initial Event

The most immediate economic impacts of a catastrophic spill would be on the oil/gas production and 

employment associated with the area of the spill. There could also be impacts on commercial fishing 

(Chapter B.3.1.18), recreational fishing (Chapter B.3.1.19), and recreational resources (Chapter 

B.3.1.20). However, the primary economic impacts of a catastrophic spill would depend how the spill 

evolves, which is discussed in subsequent sections.

Phase 2—Offshore Spill

In contrast to a less severe accidental event, suspension of some oil and gas activities would be likely 

following a catastrophic event. Depending on the duration and magnitude, this could impact hundreds of 

oil-service companies that supply the steel tubing, engineering services, drilling crews, and marine supply 

boats critical to offshore exploration. An interagency economic report estimated that the suspension 

arising from the Deepwater Horizon explosion, oil spill, and response may have directly and indirectly 

resulted in up to 8,000-12,000 fewer jobs along the Gulf Coast (USDOC, Economics and Statistics 

Administration, 2010). Greater New Orleans, Inc. (2012) provides an overview of the impacts of 

decreased oil and gas industry operations subsequent to the Deepwater Horizon explosion, oil spill, and 

response. This report provides survey evidence regarding the various economic strains felt by businesses 

in Louisiana due to the Deepwater Horizon explosion, oil spill, and response. For example, this report 

found that 41 percent of the respondents were not making a profit due to the slowdown in operations. The 

economic impacts of a catastrophic spill would likely be more heavily concentrated in smaller businesses 
B-88 Central and Eastern Planning Areas Supplemental EIS

than in the larger companies due to their difficulty in finding substitute revenue sources. Much of the 

employment loss would be concentrated in coastal oil-service parishes in Louisiana (St. Mary, 

Terrebonne, Lafourche, Iberia, and Plaquemines Parishes) and counties/parishes where drilling-related 

employment is most concentrated (Harris County, Texas, in which Houston is located, and Lafayette 

Parish, Louisiana). There could also be economic impacts due to the impacts on commercial fishing 

(Chapter B.3.1.18), recreational fishing (Chapter B.3.1.19), and recreational resources (Chapter 

B.3.1.20). 

Phase 3—Onshore Contact

By the end of a catastrophic spill, a large number of personnel (up to 25,000 in the event of a shallowwater spill and up to 50,000 in the event of a deepwater spill) would be expected to have responded to 

protect the shoreline and wildlife and to cleanup vital coastlines. The degree to which new cleanup jobs 

offset job losses would vary greatly from county to county (or parish to parish). However, these new jobs 

would not make up for lost jobs, in terms of dollar revenue. In most cases, cleanup personnel are paid 

less (e.g., $15-$18 per hour compared with roughly $45 per hour on a drilling rig), resulting in consumers 

in the region having reduced incomes overall and thus, spending less money in the economy (Aversa, 

2010). In addition, the economic impacts of relief workers would likely vary by county or parish, causing 

noticeable positive economic impacts to some counties or parishes while having fairly small positive 

impacts in other counties or parishes (Murtaugh, 2010). However, the influx of relief workers could also 

cause some negative impacts if it disrupted some of the normal functioning of economies. In addition, if 

the spill reaches shore, the impacts to commercial fishing (Chapter B.3.1.18), recreational fishing 

(Chapter B.3.1.19), and recreational resources (Chapter B.3.1.20) would likely be greater.

In the unfortunate event of a future disaster, the creation of a large financial claims administration 

process, similar to the Gulf Coast Claims Facility, would be likely. This administrative body would be 

responsible for distributing funds made available by the responsible party to parties financially hurt by the 

disaster. As demonstrated by the actions of Gulf Coast Claims Facility recipients following the 

Deepwater Horizon explosion, oil spill, and response, funds will likely be used by individuals to pay for 

necessities such as mortgages or groceries, while businesses who receive funds will likely use them to 

maintain payroll and current payments on equipment. As of March 2012, over $6 billion had been paid 

through the Gulf Coast Claims Facility, which mitigated some of the economic impacts of the Deepwater 

Horizon explosion, oil spill, and response (Gulf Coast Claims Facility, 2012).

Phase 4—Post-Spill, Long-Term Recovery and Response

While a catastrophic spill could immediately impact several Gulf Coast States for several months 

through fishing closures, loss of tourism, and any suspension of oil and gas activities, anticipating the 

long-term economic and employment impacts in the Gulf of Mexico is a difficult task. Many of the 

potentially affected jobs, like fishing charters, are self-employed. Thus, they would not necessarily file 

for unemployment and will not be included in business establishment surveys used to estimate State 

unemployment levels. In addition, unemployment numbers in states are based on nonagricultural jobs, 

and the fishing industry is considered within the agriculture category. On the other side, it is also a 

challenge to estimate how many of these displaced workers have been hired to clean up the spill. For 

example, while thousands of vessels of opportunity would be active in the spill response, not all of these 

would be displaced commercial fishermen from the affected areas. The positive employment impacts 

related to response activities are likely to be shorter term than the negative impacts discussed above. 

However, the long-term economic impacts of a catastrophic spill will likely depend on the speed at which 

the oil/gas, commercial fishing, recreational fishing, and recreational industries recover.

Overall Summary and Conclusion (Phases 1-4)

There would be a number of economic impacts that would arise from a catastrophic oil spill. The 

most direct effects would be on the recreation/tourism, commercial fishing, and recreational fishing 

industries that depend on damaged resources. There could also be substantial negative effects on the 

oil/gas industry due to moratoriums or rule changes that would arise. Finally, there could be substantial 

impacts due to the relief operations and economic mitigation activities that would occur in the aftermath 

of a catastrophic spill.
Catastrophic Spill Event Analysis B-89

B.3.1.25. Environmental Justice

Phase 1—Initial Event

There would likely be no adverse impacts to environmental justice as a result of the events and the 

potential impact-producing factors that could occur throughout Phase 1 of a catastrophic spill event 

because of the long distance (>3 nmi; 3.5 mi; 5.6 km) from shore and the short duration of the initial 

event, fire, and/or explosion.

Phase 2—Offshore Spill

The environmental justice policy, based on Executive Order 12898 of February 11, 1994, directs 

agencies to incorporate into NEPA documents an analysis of potentially disproportionate and detrimental 

environmental and health effects of their proposed actions on minorities and low-income populations and 

communities. While the spill is still offshore, the primary environmental justice concern would be large 

commercial fishing closures disproportionately impacting minority fishers. In the event of a catastrophic 

spill, Federal and State agencies would be expected to close substantial portions of the Gulf to 

commercial and recreational fishing (USDOC, NOAA, 2010e). While oystering occurs “onshore,” oyster 

beds are also likely to be closed to harvests during Phase 2 of a catastrophic spill because of concerns 

about oil contamination and increased freshwater diversions to mitigate oil intrusion into the marshes. 

These closures would directly impact commercial fishermen and oystermen, and indirectly impact such 

downstream activities as shrimp processing facilities and oyster shucking houses. The mostly AfricanAmerican communities of Phoenix, Davant, and Point a la Hache in Plaquemines Parish, Louisiana, are 

home to families with some of the few black-owned oyster leases. Just as these leases have been 

threatened by freshwater diversion projects for coastal restoration, they could be threatened by Phase 2 of 

a catastrophic spill (Mock, 2010).

The Gulf Coast hosts multiple minority and low-income groups whose use of natural resources of the 

offshore and coastal environments make them vulnerable to fishing closures. While not intended as an 

inventory of the area’s diversity, we have identified several Gulf Coast populations of particular concern. 

An estimated 20,000 Vietnamese American fishermen and shrimpers live along the Gulf Coast; by 1990, 

over 1 in 20 Louisiana fishers and shrimpers had roots in Southeast Asia even though they comprised less 

than half a percent of the State’s workforce (Bankston and Zhou, 1996). Vietnamese Americans account 

for about one-third of all the fishermen in the central Gulf of Mexico (Ravitz, 2010). Islaños, African 

Americans, and Native American groups are also engaged in commercial fishing and oystering. 

Historically, Vietnamese Americans and African Americans have worked in the fish processing and 

oyster shucking industries. Shucking houses particularly, have provided an avenue into the mainstream 

economy for minority groups.

Therefore, fishing closures during Phase 2 of a catastrophic spill impacting the central Gulf of 

Mexico may disproportionately affect such minority groups as the Vietnamese Americans, Native 

Americans, African Americans, and Islaños (Hemmerling and Colten, 2003).

Phase 3—Onshore Contact

While most coastal populations along the Gulf Coast are not generally minority or low income, 

several communities on the coasts of St. Mary, Lafourche, Terrebonne, St. Bernard, and Plaquemines 

Parishes, Louisiana, have minority or low-income population percentages that are higher than their state 

average. These minority populations are predominately Native American, Isleños, or African American. 

For example, a few counties or parishes along the Gulf Coast have more than a 2-percent Native 

American population (USDOI, MMS, 2007); about 2,250 Houma Indians (a State of Louisiana 

recognized tribe) are concentrated in Lafourche Parish, Louisiana, comprising 2.4 percent of the parish’s 

population, and about 800 Chitimacha (a federally recognized tribe) make up 1.6 percent of St. Mary 

Parish’s population. While these are not significant numbers on their own, viewed in the context of 

Louisiana’s overall 0.6 percent Native American average, these communities take on greater 

environmental justice importance.

Gulf Coast minority and low-income groups are particularly vulnerable to the coastal impacts of a 

catastrophic oil spill due to their greater than average dependence on the natural resources in the offshore 

and coastal environments. Besides their economic reliance on commercial fishing and oystering, coastal 
B-90 Central and Eastern Planning Areas Supplemental EIS

low-income and minority groups rely heavily on these fisheries and other traditional subsistence fishing, 

hunting, trapping, and gathering activities to augment their diets and household incomes (refer to 

Hemmerling and Colton, 2003, for an evaluation of environmental justice considerations for south 

Lafourche Parish). Regular commuting has continued this reliance on the natural resources of the coastal 

environments even when populations have been forced to relocate because of landloss and the destruction 

from hurricane events.

State fishery closures because of a catastrophic oil spill could disproportionately affect minority and 

low-income groups. Shoreline impacts could generate additional subsistence-related effects. Therefore, 

these minority groups may be disproportionately affected if these coastal areas were impacted by a 

catastrophic spill and the resulting response.

Phase 4—Post-Spill, Long-Term Recovery and Response

After the spill is stopped, the primary environmental justice concerns relate to possible long-term 

health impacts to cleanup workers, a predominately minority population, and to possible disposal of oilimpacted solid waste in predominantly minority areas.

An analysis of socioeconomic characteristics shows that people of Cajun ethnicity in the Gulf Coast 

States are often found to be of a comparatively low socioeconomic status and to work jobs in the textile 

and oil industries (Henry and Bankston, 1999). Past studies suggest that a healthy offshore petroleum 

industry also indirectly benefits low-income and minority populations (Tolbert, 1995). One BOEMfunded study in Louisiana found income inequality decreased during the oil boom of the 1980’s and 

increased with the decline (Tolbert, 1995). If there is a suspension of oil and gas activities in response to 

a catastrophic spill, many oil- and gas-related service industries would attempt to avoid massive layoffs 

by cutting costs and deferring maintenance during the recovery. This was the case with the Deepwater 

Horizon explosion, oil spill, and response, and the long-term impacts are still not fully understood.

Onshore and Offshore Cleanup Workers

By the end of a catastrophic spill, up to 25,000 (shallow water) or 50,000 (deepwater) personnel 

would be expected to be responding to the spill. The majority of these would be field responders (United 

Incident Command, 2010e). As seen by the Deepwater Horizon explosion, oil spill, and response, the 

racial composition of cleanup crews was so conspicuous that Ben Jealous, the president of the National 

Association for the Advancement of Colored People, sent a public letter to BP Chief Operations Officer 

Tony Hayward on July 9, 2010, demanding to know why African Americans were over-represented in 

“the most physically difficult, lowest paying jobs, with the most significant exposure to toxins” (National 

Association for the Advancement of Colored People, 2010). While regulations require the wearing of 

protective gear and only a small percentage of cleanup workers suffer immediate illness and injuries 

(Center for Disease Control and Prevention, 2010), exposure could have long-term health impacts (e.g., 

increased rates of some types of cancer) (Savitz and Engel, 2010; Kirkeleit et al., 2008). Aguilera et al. 

(2010) compiled and reviewed existing studies on the repercussions of spilled oil exposure on human 

health for patterns of health effects and found evidence of the relationship between exposure and “acute 

physical, psychological, genotoxic, and endocrine effects in the exposed individuals.” Acute symptoms 

from exposure to oil, dispersants, and degreasers include headaches, nausea, vomiting, diarrhea, sore 

eyes, runny nose, sore throat, cough, nose bleeds, rash, blisters, shortness of breath, and dizziness 

(Sathiakumar, 2010). The USEPA’s monitoring data have not shown that the use of dispersants during 

the Deepwater Horizon explosion, oil spill, and response resulted in a presence of chemicals that 

surpassed human health benchmarks (Trapido, 2010). The potential for the long-term human health 

effects are largely unknown. However, the National Institute of Environmental Health Sciences is 

conducting a study known as the “Gulf Long-Term Follow-Up Study” that should provide a better 

understanding of the long-term and cumulative health impacts, such as the consequences of working close 

to a spill and of consuming contaminated seafood. The “Gulf Long-Term Follow-up Study” will monitor 

oil-spill cleanup workers for 10 years and represents a national effort to determine if the Gulf oil spill led 

to physical or mental health problems (U.S. Dept. of Health and Human Services, NIEHS, 2010). The 

study has a target goal of 55,000 participants. As of October 2012, the National Institute of 

Environmental Health Sciences announced that over 29,000 cleanup workers and volunteers have 

enrolled in the “Gulf Long-Term Follow-up Study” (U.S. Dept. of Health and Human Services, NIEHS, 
Catastrophic Spill Event Analysis B-91

2012). Prior research on post-spill cleanup efforts found that the duration of cleaning work was a risk 

factor for acute toxic symptoms and that seamen had the highest occurrence of toxic symptoms compared 

with volunteers or paid workers. Therefore, participants in the “Vessels of Opportunity” program, which 

recruited local boat owners (including Cajun, Houma Indian, and Vietnamese American fishermen) to 

assist in cleanup efforts, would likely be one of the most exposed groups. African Americans are thought 

to have made up a high percentage of the cleanup workforce. The Occupational Safety and Health 

Administration (OSHA) released two matrices of gear requirements for onshore and offshore Gulf 

operations that were organized by task (U.S. Dept. of Labor, OSHA, 2010a). Of past oil-spill workers, 

uninformed and poorly informed workers were at more risk of exposure and symptoms, demonstrating the 

importance of education and proper training of workers (Sathiakumar, 2010). Therefore, a catastrophic 

spill may disproportionately affect seamen and onshore workers such as Cajuns, Vietnamese Americans, 

Houma Indian, and African Americans.

Solid-Waste Disposal 

Following a catastrophic spill, environmental justice concerns arise related to the disposal of cleanuprelated wastes near minority and/or low-income communities (Schleifstein, 2010). It is estimated that a 

catastrophic spill could generate several thousand tons of oil-impacted solid materials that would be 

disposed in landfills along the Gulf Coast. While no new landfills would be built because of a 

catastrophic spill, the use of existing landfills might exacerbate existing environmental justice issues. For 

example, Mobile, Alabama, and Miami, Florida, are majority minority urban centers with a majority of 

minority residents living within a 1-mi (1.6-km) radius of chosen landfills or liquid processing centers. 

While only a small percentage of Deepwater Horizon explosion, oil spill, and response waste was sent to 

these facilities—13 percent of the liquid waste to Liquid Environmental Solutions in Mobile and only 

0.28 percent of the total liquid waste to Cliff Berry in Miami—they may receive more from potential 

future spills. Disposal procedures for the Deepwater Horizon explosion, oil spill, and response involved 

sorting waste materials into standard “waste stream types” at small, temporary stations, and then sending 

each type to existing facilities that were licensed to dispose of them. The location of temporary sorting 

stations was linked to the location of containment and cleanup operations. Hence, future locations of any 

sorting stations are not predictable since they would be determined by the needs of cleanup operations. 

However, waste disposal locations were determined by the specializations of existing facilities and by 

contractual relationships between them and the cleanup and containment firms. Louisiana received about 

82 percent of the Deepwater Horizon explosion, oil spill, and response liquid waste recovered; of this, 

56 percent was manifested to mud facilities located in Venice in Plaquemines Parish, Louisiana, and to 

Port Fourchon in Lafourche Parish, Louisiana, and then transferred to a processing facility in Port Arthur, 

Texas. The waste remaining after processing was sent to deep well injection landfills located in Fannett 

and Big Hill, Texas. The sites located in Venice and Port Fourchon, Louisiana, and in Port Arthur, 

Fannett, and Big Hill, Texas, have low-minority populations, but a few of these areas have substantial 

poverty rates relative to State and parish/county means.

Overall Summary and Conclusion (Phases 1-4)

For Phase 1 (Initial Event) of a catastrophic spill, there would likely be no adverse impacts to 

minority and low-income communities because of the long distance (>3 nmi; 3.5 mi; 5.6 km) from shore, 

as well as the short duration of the initial event, fire, and/or explosion. The primary environmental justice 

concerns during Phase 2 (Offshore Spill) would be large-scale fishing closures, oyster bed contamination 

and closures, and subsequent impacts to downstream activities such as shrimp processing facilities and 

oyster shucking houses. These may disproportionately affect such minority groups as the Vietnamese 

Americans, Native Americans, African Americans, and Islaños. Phase 3 (Onshore Contact), depending 

on the location, could result in disproportional impacts to those groups that rely heavily on oystering, 

commercial fishing, and other traditional subsistence fishing, hunting, trapping, and gathering activities to 

augment their diets and household incomes. During Phase 4 (Post-Spill, Long-Term Recovery and 

Response), the primary environmental justice concerns relate to possible long-term health impacts to 

cleanup workers, a predominately minority population, and to the possible disposal of oil-impacted solid 

waste in predominantly minority areas. As in the case of the Deepwater Horizon explosion, oil spill, and 

response, understanding long-term impacts would be dependent on the outcome of ongoing research by 
B-92 Central and Eastern Planning Areas Supplemental EIS

various interested parties, such as the National Institutes of Health and BOEM. Overall, depending on a 

number of mainly geographic variables such as the location of fisheries closures and oyster bed 

contamination and closures, as well as the demographic composition of cleanup workers, and if waste 

disposal was not distributed across the region at many different facilities, a catastrophic oil-spill event 

may have disproportionate effects on minority and low-income populations.

B.3.1.26. Species Considered due to U.S. Fish and Wildlife Service Concerns

Phase 1—Initial Event

Phase 1 of the scenario is the initiation of a catastrophic blowout incident. Impacts, response, and 

intervention depend on the spatial location of the blowout and leak. For this analysis, an explosion and 

subsequent fire are assumed to occur. If a blowout associated with the drilling of a single exploratory 

well occurs, this could result in a fire that would burn for 1 or 2 days. If a blowout occurs on a production 

platform, other wells could feed the fire, allowing it to burn for over a month. The drilling rig or platform 

may sink. If the blowout occurs in shallow water, the sinking rig or platform may land in the immediate 

vicinity; if the blowout occurs in deep water, the rig or platform could land a great distance away, beyond 

avoidance zones. Regardless of water depth, the immediate response would be from search and rescue 

vessels and aircraft, such as USCG cutters, helicopters, and rescue planes, and firefighting vessels. The 

potential impacts reflect the explosion, subsequent fire for 1-30 days, and the sinking of the platform in 

the immediate vicinity and up to 1 mi (1.6 km) from the well.

The scenarios for each phase, including cleanup methods, can be found Table B-4. 

BOEM has only focused on species within coastal counties and parishes because those are the species 

that could be potentially impacted by oil and gas development activities, including a potential OCS spill. 

There would likely be no adverse impacts to the species considered due to FWS concerns as a result of 

the events and the potential impact-producing factors that could occur throughout Phase 1 of a 

catastrophic spill event due to the distance of most activities, the heavy regulation of infrastructure and 

pipelines, and permitting and siting requirements.

Phase 2—Offshore Spill

Phase 2 of the analysis focuses on the spill and response in Federal and State offshore waters. A 

catastrophic spill would likely spread hundreds of square miles. Also, the oil slick may break into several 

smaller slicks, depending on local wind patterns that drive the surface currents in the spill area. The 

potential impacts reflect spill and response in Federal and State offshore waters. Season and temperature 

variations can result in different resource impacts due to variations in oil persistence and oil and 

dispersant toxicity and because of differences in potential exposure of the resources throughout various 

life cycle stages.

There would likely be no adverse impacts to the species considered due to FWS concerns as a result 

of the events and the potential impact-producing factors that could occur throughout Phase 2 of a 

catastrophic spill event due to the distance of most activities, the heavy regulation of infrastructure and 

pipelines, and permitting and siting requirements.

Phase 3—Onshore Contact

Phase 3 focuses on nearshore (e.g., inside bays and in close proximity to shoreline) and onshore spill 

response and oil initially reaching the shoreline during the spill event or while the oil still persists in the 

offshore environment once the spillage has been stopped. It is likely that Phases 2 and 3 could occur 

simultaneously. The duration of the initial shoreline oiling is measured from initial shoreline contact until 

the well is capped or killed and the remaining oil dissipates offshore. Re-oiling of already cleaned or 

previously impacted areas could be expected during Phase 3. In addition to the response described in 

Phase 2, nearshore and onshore efforts would be introduced in Phase 3 as oil entered coastal areas and 

contacted shore. The potential impacts reflect the spill and response in very shallow coastal waters and 

once along the shoreline. Season and temperature variations can result in different resource impacts due 

to variations in oil persistence and oil and dispersant toxicity and because of differences in potential 

exposure of the resources throughout various life cycle stages.
Catastrophic Spill Event Analysis B-93

The FWS has explicitly communicated interest in specific species within State boundaries along the 

Gulf Coast. The species within Louisiana, Mississippi, Alabama, and Florida have been designated as 

endangered, threatened, candidate, listed with critical habitat, proposed nonessential experimental 

population, or distinct vertebrate population. The greatest threats to the majority of these species are the 

loss of and/or modification to suitable habitat caused by urban and agricultural development. Further 

detail on this catastrophic OSRA run is contained in Appendix C of the CPA 235/241/247 Supplemental 

EIS and Appendix B of the EPA 225/226 EIS. 

At this time, there is no known record of a hurricane crossing the path of a large oil spill; the impacts 

of such have yet to be determined. The experience from Hurricanes Katrina and Rita in 2005 was that the 

oil released during the storms widely dispersed as far as the surge reached (USDOC, NOAA, National 

Weather Service, 2012). Due to their reliance on terrestrial habitats to carry out their life-history 

functions at a considerable distance from the GOM, the activities of a CPA or EPA proposed action are 

unlikely to have significant adverse effects on the size and recovery of any of the FWS-mentioned species 

or populations in Texas, Louisiana, Mississippi, Alabama, and Florida. 

There would likely be no adverse impacts to the species considered due to FWS concerns as a result 

of the events and the potential impact-producing factors that could occur throughout Phase 3 of a 

catastrophic spill event due to the distance of most activities, the heavy regulation of infrastructure and 

pipelines, and permitting and siting requirements.

Phase 4—Post-Spill, Long-Term Recovery and Response

Phase 4 focuses on long-term recovery once the well has been capped and the spill has stopped. 

During the final phase of a catastrophic blowout and spill, it is presumed that the well has been capped or 

killed and cleanup activities are concluding. While it is assumed that the majority of spilled oil would be 

dissipated offshore within 1-2 months (depending on season and temperature) of stopping the flow, oil 

has the potential to persist in the environment long after a spill event and has been detected in sediment 

30 years after a spill. On sandy beaches, oil can sink deep into the sediments. In tidal flats and salt 

marshes, oil may seep into the muddy bottoms. The potential impacts reflect long-term persistence of oil 

in the environment and residual and long-term cleanup efforts.

As data continue to be gathered and impact assessments completed, a better characterization of the 

full scope of impacts to populations in the GOM from the Deepwater Horizon explosion, oil spill, and 

response will be available. Relevant data on the status of populations after the Deepwater Horizon

explosion, oil spill, and response may take years to acquire and analyze, and impacts from the Deepwater 

Horizon explosion, oil spill, and response may be difficult or impossible to discern from other factors. 

Therefore, it is not possible for BOEM to obtain this information within the timeline contemplated in this 

Supplemental EIS, regardless of the cost or resources needed. In light of the incomplete or unavailable 

information, BOEM’s subject-matter experts have used available scientifically credible evidence in this 

analysis and applied it using accepted methods and approaches. Nevertheless, a complete understanding 

of the missing information is not essential to a reasoned choice among alternatives for this Supplemental 

EIS. As of October 2014, there are 4,167 active leases in the CPA and 106 active leases in the EPA, with 

ongoing (or the potential for) exploration, drilling, and production activities. In addition, non-OCS 

energy-related activities will continue to occur in the CPA or EPA irrespective of a CPA or EPA 

proposed action (i.e., habitat loss and competition). The potential for effects from changes to the affected 

environment (post-Deepwater Horizon explosion, oil spill, and response), accidental spills (including 

low-probability catastrophic spills), and cumulative effects remains whether or not the No Action or an 

Action alternative is chosen under this Supplemental EIS.

There would likely be no adverse impacts to the species considered due to FWS concerns as a result 

of the events and the potential impact-producing factors that could occur throughout Phase 4 of a 

catastrophic spill event due to the distance of most activities, the heavy regulation of infrastructure and 

pipelines, and permitting and siting requirements.

Overall Summary and Conclusion (Phases 1-4)

Accidental blowouts, oil spills, and spill-response activities resulting from a CPA or EPA proposed 

action have the potential to impact small to large areas in the GOM, depending on the magnitude and 

frequency of accidents, the ability to respond to accidents, the location and date of accidents, and various 
B-94 Central and Eastern Planning Areas Supplemental EIS

meteorological and hydrological factors (including tropical storms). The incremental contribution of a 

CPA or EPA proposed action would not be likely to result in a significant incremental impact on the 

FWS-mentioned species within the CPA or EPA; in comparison, non-OCS-related activities, such as 

habitat loss and competition, have historically proved to be of greater threat to the FWS-mentioned 

species.

In conclusion, within the CPA, which is directly adjacent to the EPA, there is a long-standing and 

well-developed OCS Program (more than 50 years); there are no data to suggest that activities from the 

preexisting OCS Program are significantly impacting the FWS mentioned species populations; therefore, 

a CPA or EPA proposed action would be expected to have little or no effect on the FWS mentioned 

species.

B.4. PREPARERS

Pat Adkins, Information Management Specialist

Bruce Baird, Biologist

Mark Belter, Marine Biologist

Darice Breeding, Physical Scientist

Sindey Chaky, Social Scientist

Chris DuFore, Oceanographer

Stephanie Gambino, Chief, Biological/Social Sciences Section

Donald (Tre) W. Glenn III, Protected Species Biologist

Gary D. Goeke, Chief, Environmental Assessment Section

Allison Hernandez, Protected Species Biologist

Chester Huang, Meteorologist

Jack Irion, Unit Supervisor, Marine Archaeologist, Social Sciences Unit

Mark D. Jensen, Economist

Matthew Johnson, Marine Biologist

Doug Jones, Marine Archaeologist

Arie R. Kaller, Unit Supervisor, Environmental Scientist, Biological Sciences Unit

Lissa Lyncker, Unit Supervisor, Environmental Scientist, Environmental Assessment Section

Jessica Mallindine, Protected Species Biologist

Megan Milliken, Economist

Tershara Matthews, Unit Supervisor, Environmental Scientist, Environmental Assessment Section

Margaret Metcalf, Chief, Physical/Chemical Sciences Unit

Deborah H. Miller, Technical Editor

David P. Moran, Biologist

Erin O’Reilly, Physical Scientist

Catherine A. Rosa, Environmental Assessment Program Specialist

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B-120 Central and Eastern Planning Areas Supplemental EIS

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Catastrophic Spill Event Analysis B-121

Figure B-1. Location of Seven Hypothetical Oil-Spill Launch Points for OSRA within the Gulf of Mexico. 

(Spatial variability of the Loop Current is from Vukovich [2007] and is shown as percent of time that 

the Loop Current watermass is associated with a particular location.)
B-122 Central and Eastern Planning Areas Supplemental EIS

Figure B-2. Spatial Frequency (%) of the Watermass Associated with the Loop Current in the Eastern Gulf of 

Mexico based on Data for the Period 1976-2003 (Vukovich, 2005).
Catastrophic Spill Event Analysis B-123

Figure B-3. Summary of Avian Species Collected by Date Obtained from the U.S. Fish and Wildlife Service as 

Part of the Deepwater Horizon Post-Spill Monitoring and Collection Process through May 12, 2011 

(USDOI, FWS, 2011a). (This figure represents the date the data were released and reported and does 

not represent the actual date individual birds were collected. Data on the Y-axis reflects the 

cumulative # of individual birds collected, identified, and summarized by date; data on the Z-axis 

reflects proportional change from one reporting date to the next. The data used in this figure are 

verified as per FWS’s QA/QC processes. The mean # of birds collected between intervals is 184.4 + 

89.3 SE [-807 min, 526 max for 13 collection intervals] and the mean % change between intervals is 

3.0 + 1.3% [-11.12% min., 8.27% max]. Unfortunately, we have no data on change in search effort 

temporally (or spatially) and also lack data prior to September 14, 2010; therefore, data at that point 

represent the baseline or “0” for determining interval differences. Disclaimer: All data should be 

considered provisional, incomplete, and subject to change. For more information, refer to FWS’s 

Weekly Bird Impact Data and Consolidated Wildlife Reports [USDOI, FWS, 2011a]; for additional 

information on the chronological change in number of birds collected, refer to Belanger et al., 2010).
B-124 Central and Eastern Planning Areas Supplemental EIS

Table B-1

Blowout Scenarios and Key Differences in Impacts, Response, and/or Intervention

Location of Blowout and Leak Key Differences in Impacts, Response, and/or Intervention

Blowout occurs at the sea surface 

(i.e., at the rig)

Offers the least chance for oil recovery because of the restricted access to the 

release point; therefore, greater impacts to coastal ecosystems. In addition to 

relief wells, there is potential for other intervention measures such as capping 

and possible manual activation of blowout-preventer (BOP) rams.

Blowout occurs along the riser 

anywhere from the seafloor to the 

sea surface. However, a severed 

riser would likely collapse, 

resulting in a leak at the seafloor.

In deep water, the use of subsea dispersants, if approved, may reduce impacts 

to coastal ecosystems; however, their use may increase exposure of deepwater 

marine resources to dispersed oil. There is a possibility for limited recovery of 

oil at the source. In addition to relief wells, there is potential for other 

intervention measures, such as capping and possible manual activation of BOP 

rams.

At the seafloor, through leak paths 

on the BOP/wellhead

In deep water, the use of subsea dispersant, if approved, may reduce impacts to 

coastal ecosystems; however, their use may increase exposure of deepwater 

marine resources to dispersed oil.

With an intact subsea BOP, intervention may involve the use of drilling mud to 

kill the well. If the BOP and well stack are heavily compromised, the only 

intervention method may be relief wells. Greatest possibility for recovery of 

oil at the source, until the well is capped or killed.

Below the seafloor, outside the 

wellbore (i.e., broached)

Disturbance of a large amount of sediments resulting in the burial of benthic 

resources in the immediate vicinity of the blowout. The use of subsea 

dispersants would likely be more difficult (PCCI Marine and Environmental 

Engineering, 1999). Stopping this kind of blowout would probably involve 

relief wells. Any recovery of oil at the seabed would be very difficult.
Catastrophic Spill Event Analysis B-125

Table B-2

Properties and Persistence by Oil Component Group

Properties and 

Persistence Light-Weight Medium-Weight Heavy-Weight

Hydrocarbon 

Compounds

Up to 10 carbon atoms 10-22 carbon atoms >20 carbon atoms

API o >31.1o 31.1o-22.3o <22.3o

Evaporation Rate Rapid (within 1 day) and 

complete

Up to several days; not 

complete at ambient 

temperatures

Negligible

Solubility in Water High Low (at most a few 

milligrams/liter)

Negligible

Acute Toxicity High because of 

monoaromatic 

hydrocarbons (BTEX)

Moderate because of 

diaromatic hydrocarbons 

(naphthalenes—2 ring 

PAHs)

Low except because of 

smothering (i.e., heavier oils 

may sink)

Chronic Toxicity None, does not persist 

because of evaporation

PAH components (e.g., 

naphthalenes—2 ring 

PAHs)

PAH components (e.g., 

phenanthrene, anthracene—

3 ring PAHs)

Bioaccumulation 

Potential

None, does not persist 

because of evaporation

Moderate Low, may bioaccumulate 

through sediment sorption

Compositional 

Majority

Alkanes and cycloalkanes Alkanes that are readily 

degraded

Waxes, asphaltenes, and 

polar compounds (not 

significantly bioavailable or 

toxic)

Persistence Low because of 

evaporation

Alkanes readily degrade, 

but the diaromatic 

hydrocarbons are more 

persistent

High; very low degradation 

rates and can persist in 

sediments as tarballs or 

asphalt pavements

API = American Petroleum Institute.

BTEX = benzene, ethylbenzene, toluene, and xylene

PAH = polycyclic aromatic hydrocarbon

Sources: Michel, 1992; Canadian Center for Energy Information, 2010.
B-126 Central and Eastern Planning Areas Supplemental EIS

Table B-3

Annual Volume of Produced Water Discharged by Depth

(millions of barrels)

Year Shelf

0-60 m

Shelf

60-200 m

Slope

200-400 m

Deepwater

400-800 m

Deepwater

800-1,600 m

UltraDeepwater

1,601-2,400 m

UltraDeepwater

>2,400 m

Total

2000 370.6 193.1 35.5 25.6 12.2 0.0 0.0 637.0

2001 364.2 185.2 35.0 32.0 16.6 0.0 0.0 633.0

2002 344.6 180.4 32.5 35.2 21.4 0.0 0.0 614.1

2003 359.4 182.9 31.2 39.0 35.5 0.2 0.0 648.2

2004 346.7 160.5 29.3 36.9 39.2 1.9 0.0 614.5

2005 270.1 113.5 23.1 33.5 43.0 5.8 0.0 489.0

2006 260.3 99.7 20.6 35.1 61.5 12.4 0.0 489.6

2007 307.0 139.4 22.2 40.0 70.3 15.5 0.1 594.5

2008 252.7 118.6 15.9 32.7 60.1 16.5 0.1 496.6

2009 263.9 108.3 19.9 39.2 65.3 25.0 0.1 521.7

Source: USDOI, BOEMRE, 2010b.
Catastrophic Spill Event Analysis

B-127

Table B-4 

Description of the Scenario for a Catastrophic Spill Event Occurring in Shallow Water or Deep Water 

(assumptions are described in detail in the text)

Scenario Shallow-Water Location Deepwater Location

Phase 1. Initial Event

Vertical Location of Blowout 4 possible locations including sea surface, along 

the riser, at the seafloor, and below the seafloor

4 possible locations including sea surface, along the riser, at 

the seafloor, and below the seafloor

Duration of Uncontrolled Fire 1-30 days 1-30 days

Phase 2. Offshore Spill

Duration of Spill 2-5 months 4-6 months

Rate of Spill 30,000 bbl per day* 30,000-60,000 bbl per day

Total Volume of Spill (1) 0.9-3.0 MMbbl crude oil 2.7-7.2 MMbbl crude oil

10,000-20,000 bbl diesel fuel 

APIo Gravity Fresh oil will float (APIo >10) Fresh oil will float (APIo >10)

Characteristics of Oil Released Typical South Louisiana midrange paraffinic 

sweet crude oil 

Typical South Louisiana midrange paraffinic sweet crude 

oil; crude properties changed after oil traveled up the 

wellbore and passed through the water column, undergoing 

rapid depressurization and turbulence. Oil reached the 

surface as an emulsion stripped of many of its volatile 

components.

Response

Number of Vessels Up to 3,000 Up to 7,000

Number of Workers Up to 25,000 Up to 50,000

Number of Planes/Helicopters 25/50 50/100

Boom (million feet) 5 13.5

Dispersant Application

(surface application) (2)

35,000 bbl 33,000-bbl surface application and 16,500-bbl subsea 

application 

Number of Miles of Shoreline 

Requiring Some Measure of 

Mechanical or Manual Cleaning

778 778

In-situ Burn Yes, will occur Yes, will occur

Vessel Decontamination Stations Yes Yes

Severe Weather The potential for severe weather is noted, which 

could temporarily halt containment and response 

efforts.

The potential for severe weather is noted, which could 

temporarily halt containment and response efforts.

Fisheries Closure During the peak, anticipate approximately 37% or 

88,522 mi2 (229,270 km2) closed to recreational and 

commercial fishing.
 B-128 Central and Eastern Planning Areas Supplemental EIS

Table B-4. Description of the Scenario for a Catastrophic Spill Event Occurring in Shallow Water or Deep Water (assumptions are described in detail in 

the text) (continued).

Scenario Shallow-Water Location Deepwater Location

Phase 3. Onshore Contact

Shoreline Oiling Duration 1-5 months 3-6 months

Response

Number of Staging areas 5-10 10-20

Number of Skimmers 200-300 500-600

Length of Shoreline Contacted

30 days1 = 0-50 miles2 30 days1 = 0-50 miles2

60 days = 50-100 miles 60 days = 50-100 miles

90 days = 100-1,000 miles 90 days = 100-1,000 miles

120 days = >1,000 miles 120 days = >1,000 miles 1 Not cumulative.

2 Length was extrapolated

Oil Characteristics and Appearance —Essentially stable emulsions mixed with sand.

—Typically initially stranded as surface layers and as 

discrete droplets/summer 2010.

Response Considerations for Sand 

Beaches

—No mechanical techniques allowed in some 

areas.

—Much of the beach cleanup conducted at night.

—Typically sand sieving, shaking, and sifting 

beach cleaning machines.

—Repetitive tilling and mixing using agriculture 

plows and discs in combination with beach 

cleaning machines.

—Sand washing treatment—sand sieve/shaker to 

remove debris and large oil particles and heated 

washing systems.

—Nearshore submerged oil difficult to recover 

and hard to locate; vacuums and snares could be 

used.

—No mechanical techniques allowed in some areas.

—Much of the beach cleanup conducted at night.

—Typically sand sieving, shaking, and sifting beach 

cleaning machines.

—Repetitive tilling and mixing using agriculture plows and 

discs in combination with beach cleaning machines.

—Sand washing treatment—sand sieve/shaker to remove 

debris and large oil particles and heated washing systems.

—Nearshore submerged oil difficult to recover and hard to 

locate; vacuums and snares could be used.

Response Considerations for Marshes —Lightly oiled—allowed to recovery naturally; 

degrade in place or removed by tidal or wave 

action.

—Moderately/heavily oiled—vacuumed or 

skimmed from boats possibly in conjunction with 

flushing; low-pressure flushing (with water 

comparable to marsh type); manual removal by 

—Lightly oiled—allowed to recovery naturally; degrade in 

place or removed by tidal or wave action.

—Moderately or heavily oiled—vacuumed or skimmed 

from boats possibly in conjunction with flushing; lowpressure flushing (with water comparable to marsh type); 

manual removal by hand or mechanized equipment; and 

vegetation cutting.
Catastrophic Spill Event Analysis

B-129

hand or mechanized equipment; and vegetation 

cutting.

—Heavily oiled areas—in-situ burning may be an 

option if water covers the sediment surface.

—Bioremediation may be utilized but mostly as a 

secondary treatment after bulk removal. 

—Heavily oiled areas—in-situ burning may be an option if 

water covers the sediment surface.

—Bioremediation may be utilized but mostly as a 

secondary treatment after bulk removal.

Response Considerations for 

Nearshore Waters

Marsh areas—skimming and vacuum (in areas too 

shallow to use skimmers) systems used in 

conjunction with flushing, and booming to 

temporarily contain mobile slicks.

Marsh areas—skimming and vacuum (in areas too shallow 

to use skimmers) systems used in conjunction with flushing, 

and booming to temporarily contain mobile slicks.

Phase 4. Recovery Phase

Response

Number of Vessels 

– 24-36 months post-spill/greater 

than 36 months

Fewer than 10/0 designated—called up only if 

new residual oil reported 

Fewer than 10/0 designated—called up only if new residual 

oil reported

Number of Workers 

– 24-36 months post-spill/greater 

than 36 months

230/0 designated—called up only if new residual 

oil reported 

230/0 designated—called up only if new residual oil 

reported

Miles of Shoreline Undergoing 

Regular Patrolling and 

Maintenance 

– 30-36 months post-spill/greater 

than 36 months

Fewer than 20/0 Fewer than 20/0

End Date for Dispersant 

Application

No dispersant usage 2 weeks after spillage ends No dispersant usage 2 weeks after spillage ends

Remaining Sources of Unrecoverable 

Weathered Oil

Buried or in surface pockets in coastal sand, 

sediment, or muddy bottoms and in pockets on the 

seafloor.

Buried or in surface pockets in coastal sand, sediment, or 

muddy bottoms and in pockets on the seafloor.

Oil Characteristics and Appearance As stranded oil weathered, some became buried through 

natural beach processes and appeared as surface residual 

balls (SRB) <10 cm (4 in) or as patties (SRP) 10 cm-1 m 

(4 in-3 ft).

Response Considerations for Sand 

Beaches, Marshes, and Nearshore 

Waters

See Phase 3 above. See Phase 3 above.

(1) A blowout may contain crude oil, natural gas, and condensate. Because the majority of environmental damage is due to the release of oil, this text 

assumes the spill to be an oil spill. However, a natural gas release would result in a less visible and less persistent adverse impact than an oil release.

(2) Subsea dispersal application must be individually approved.
 B-130 Central and Eastern Planning Areas Supplemental EIS

Table B-5 

Birds Collected and Summarized by the U.S. Fish and Wildlife Service: 

Post-Deepwater Horizon Explosion, Oil Spill, and Response in the Gulf of Mexico1, 2

Common Name Species 

Group3

Grand 

Total

Visibly Oiled Not Visibly Oiled Unknown Oiling Oiling 

Rate4 Dead Alive Total Dead Alive Total Dead Alive Total

Amer. Coot Marsh/Wading 3 2 2 2 0 0 0 1 0 1 0.67

Amer. Oystercatcher Shorebird 13 7 3 7 3 0 3 1 3 3 0.54

Amer. Redstart Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Amer. White Pelican Seabird 19 5 3 8 4 0 4 4 8 7 0.42

Audubon’s Shearwater Seabird 36 1 1 1 35 0 35 0 2 0 0.03

Barn Owl Raptor 1 0 0 0 1 0 1 0 0 0 0.00

Barn Swallow Passerine 1 1 0 1 0 0 0 0 0 0 1.00

Belted Kingfisher Passerine 1 0 0 0 1 0 1 0 1 0 0.00

Bl.-crown. Night Heron Marsh/Wading 18 6 3 8 7 0 7 1 4 3 0.44

Black Skimmer Seabird 253 51 16 55 153 0 153 40 14 45 0.22

Black Tern Seabird 9 1 0 1 7 0 7 1 3 1 0.11

Bl.-bell. Whistl. Duck Waterfowl 2 0 0 0 0 0 0 0 2 2 0.00

Black-necked Stilt Shorebird 3 0 0 0 3 0 3 0 0 0 0.00

Blue-winged Teal Waterfowl 6 0 0 0 6 0 6 0 0 0 0.00

Boat-tailed Grackle Passerine 1 0 0 0 1 0 1 0 1 0 0.00

Broad-winged Hawk Raptor 1 0 0 0 1 0 1 0 1 0 0.00

Brown Pelican Seabird 826 152 227 339 248 0 248 177 149 239 0.41

Brown-headed Cowbird Passerine 1 0 0 0 0 0 0 0 1 1 0.00

Bufflehead Waterfowl 1 0 1 1 0 0 0 0 0 0 1.00

Canada Goose Waterfowl 4 0 1 1 1 0 1 1 2 2 0.25

Caspian Tern Seabird 17 7 3 8 4 0 4 2 6 5 0.47

Cattle Egret Marsh/Wading 36 4 4 7 25 0 25 3 4 4 0.19

Clapper Rail Marsh/Wading 120 27 5 29 64 0 64 20 14 27 0.24
Catastrophic Spill Event Analysis

B-131

Table B-5. Birds Collected and Summarized by the U.S. Fish and Wildlife Service: Post-Deepwater Horizon Explosion, Oil Spill, and Response in the 

Gulf of Mexico1, 2 (continued).

Common Name Species 

Group3

Grand 

Total

Visibly Oiled Not Visibly Oiled Unknown Oiling Oiling 

Rate4

Dead Alive Total Dead Alive Total Dead Alive Total

Common Loon Diving 75 33 27 39 24 0 24 4 20 12 0.52

Common Moorhen Marsh/Wading 4 1 0 1 3 0 3 0 0 0 0.25

Common Nighthawk Passerine 1 0 0 0 0 0 0 0 1 1 0.00

Common Tern Seabird 25 15 12 16 9 0 9 0 0 0 0.64

Common Yellowthroat Passerine 2 0 0 0 2 0 2 0 0 0 0.00

Cooper’s Hawk Raptor 1 0 0 0 1 0 1 0 1 0 0.00

Cory’s Shearwater Seabird 4 0 0 0 3 0 3 0 1 1 0.00

Dbl-crest. Cormorant Diving 23 2 1 2 17 0 17 2 7 4 0.09

Eastern Kingbird Passerine 2 1 0 1 1 0 1 0 0 0 0.50

Eastern Meadowlark Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Eur. Collared-dove Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Eur. Starling Passerine 2 0 1 1 1 0 1 0 0 0 0.50

Forster’s Tern Seabird 40 17 8 20 12 0 12 6 7 8 0.50

Fulvous Whistl. Duck Waterfowl 1 0 0 0 0 0 0 0 1 1 0.00

Glossy Ibis Marsh/Wading 2 1 1 1 1 0 1 0 0 0 0.50

Great Blue Heron Marsh/Wading 42 5 3 6 26 0 26 4 16 10 0.14

Great Cormorant Diving 1 0 0 0 1 0 1 0 0 0 0.00

Great Egret Marsh/Wading 31 6 6 7 15 0 15 8 3 9 0.23

Great-horned Owl Raptor 1 0 0 0 1 0 1 0 0 0 0.00

Greater Shearwater Seabird 89 7 4 7 55 0 55 27 4 27 0.08

Green Heron Marsh/Wading 16 2 0 2 8 0 8 1 6 6 0.13

Gull-billed Tern Seabird 4 0 0 0 2 0 2 2 4 2 0.00

Herring Gull Seabird 31 10 11 13 10 0 10 2 13 8 0.42

House Sparrow Passerine 2 0 0 0 2 0 2 0 1 0 0.00

Killdeer Shorebird 3 0 0 0 3 0 3 0 0 0 0.00
 B-132 Central and Eastern Planning Areas Supplemental EIS

Table B-5. Birds Collected and Summarized by the U.S. Fish and Wildlife Service: Post-Deepwater Horizon Explosion, Oil Spill, and Response in the 

Gulf of Mexico1, 2 (continued).

Common Name Species 

Group3

Grand 

Total

Visibly Oiled Not Visibly Oiled Unknown Oiling Oiling 

Rate4

Dead Alive Total Dead Alive Total Dead Alive Total

King rail Marsh/Wading 1 0 0 0 0 0 0 0 1 1 0.00

Laughing Gull Seabird 2,981 1,025 355 1,182 1,390 0 1,390 304 371 409 0.40

Leach’s Storm-petrel Seabird 1 1 0 1 0 0 0 0 1 0 1.00

Least Bittern Marsh/Wading 4 0 0 0 4 0 4 0 2 0 0.00

Least Tern Seabird 106 46 7 49 43 0 43 12 3 14 0.46

Less. Bl.-backed Gull Seabird 4 1 1 1 1 0 1 1 2 2 0.25

Less. Scaup Waterfowl 1 0 0 0 0 0 0 1 0 1 0.00

Little Blue Heron Marsh/Wading 5 0 0 0 4 0 4 1 1 1 0.00

Long-bill. Dowitcher Shorebird 1 0 0 0 0 0 0 0 1 1 0.00

Magnif. Frigatebird Seabird 8 3 3 4 2 0 2 1 2 2 0.50

Mallard Waterfowl 26 5 4 6 16 0 16 0 7 4 0.23

Manx Shearwater Seabird 6 1 0 1 5 0 5 0 0 0 0.17

Masked Booby Seabird 9 4 3 4 1 0 1 0 4 4 0.44

Mottled Duck Waterfowl 6 0 0 0 5 0 5 1 1 1 0.00

Mourning Dove Passerine 15 3 1 3 8 0 8 0 6 4 0.20

Muscovy Duck Waterfowl 1 0 0 0 1 0 1 0 1 0 0.00

Neotropic Cormorant Diving 5 0 0 0 2 0 2 3 0 3 0.00

Northern Cardinal Passerine 3 0 0 0 3 0 3 0 0 0 0.00

Northern Gannet Seabird 475 225 189 297 99 0 99 30 107 79 0.63

Northern Mockingbird Passerine 5 0 0 0 4 0 4 0 2 1 0.00

Osprey Raptor 11 2 1 3 6 0 6 0 3 2 0.27

Pied-billed Grebe Diving 32 18 24 24 7 0 7 1 3 1 0.75

Piping Plover Shorebird 1 0 0 0 1 0 1 0 0 0 0.00

Purple Gallinule Marsh/Wading 2 0 0 0 2 0 2 0 0 0 0.00

Purple Martin Passerine 5 1 0 1 3 0 3 0 1 1 0.20
Catastrophic Spill Event Analysis

B-133

Table B-5. Birds Collected and Summarized by the U.S. Fish and Wildlife Service: Post-Deepwater Horizon Explosion, Oil Spill, and Response in the 

Gulf of Mexico1, 2 (continued).

Common Name Species 

Group3

Grand 

Total

Visibly Oiled Not Visibly Oiled Unknown Oiling Oiling 

Rate4

Dead Alive Total Dead Alive Total Dead Alive Total

Red-breasted Merg. Waterfowl 2 1 1 1 1 0 1 0 1 0 0.50

Reddish Egret Marsh/Wading 2 1 1 1 1 0 1 0 1 0 0.50

Red-shouldered Hawk Raptor 1 0 0 0 0 0 0 0 1 1 0.00

Red-tailed Hawk Raptor 1 0 0 0 1 0 1 0 0 0 0.00

Red-winged Blackbird Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Ring-billed Gull Seabird 2 0 1 1 1 0 1 0 0 0 0.50

Rock Dove (pigeon) Passerine 16 2 2 3 4 0 4 2 10 9 0.19

Roseate Spoonbill Marsh/Wading 15 7 3 7 3 0 3 5 1 5 0.47

Royal Tern Seabird 289 116 66 149 104 0 104 19 47 36 0.52

Ruddy Duck Waterfowl 1 1 0 1 0 0 0 0 0 0 1.00

Ruddy Turnstone Shorebird 13 1 3 3 8 0 8 1 5 2 0.23

Sanderling Shorebird 26 4 2 4 20 0 20 1 6 2 0.15

Sandwich Tern Seabird 70 28 20 34 25 0 25 8 14 11 0.49

Seaside Sparrow Passerine 9 4 0 4 5 0 5 0 0 0 0.44

Semipalm. Sandpiper Shorebird 3 2 1 3 0 0 0 0 0 0 1.00

Short-bill. Dowitcher Shorebird 1 0 0 0 1 0 1 0 0 0 0.00

Snowy Egret Marsh/Wading 22 12 9 14 6 0 6 2 3 2 0.64

Sooty Shearwater Seabird 1 0 0 0 0 0 0 0 1 1 0.00

Sooty Tern Seabird 3 0 1 1 2 0 2 0 1 0 0.33

Sora Marsh/Wading 5 2 1 2 1 0 1 2 0 2 0.40

Spotted Sandpiper Shorebird 1 0 0 0 1 0 1 0 0 0 0.00

Surf Scoter Waterfowl 1 1 1 1 0 0 0 0 0 0 1.00

Tri-colored Heron Marsh/Wading 31 9 5 11 7 0 7 11 2 13 0.35

Virginia Rail Marsh/Wading 3 0 0 0 3 0 3 0 1 0 0.00

White Ibis Marsh/Wading 7 1 1 1 4 0 4 2 3 2 0.14
 B-134 Central and Eastern Planning Areas Supplemental EIS

Table B-5. Birds Collected and Summarized by the U.S. Fish and Wildlife Service: Post-Deepwater Horizon Explosion, Oil Spill, and Response in the 

Gulf of Mexico1, 2 (continued).

Common Name Species 

Group3

Grand 

Total

Visibly Oiled Not Visibly Oiled Unknown Oiling Oiling 

Rate4

Dead Alive Total Dead Alive Total Dead Alive Total

White-tail. Tropicbird Seabird 1 0 0 0 1 0 1 0 0 0 0.00

White-wing. Dove Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Willet Shorebird 13 2 1 3 8 0 8 1 3 2 0.23

Wilson’s Plover Shorebird 3 0 0 0 2 0 2 1 0 1 0.00

Yellow-billed Cuckoo Passerine 2 2 0 2 0 0 0 0 0 0 1.00

Yel.-cr. Night Heron Marsh/Wading 9 1 0 1 7 0 7 0 3 1 0.11

Unid. Blackbird Passerine 1 0 0 0 0 0 0 0 1 1 0.00

Unid. Booby Seabird 1 0 0 0 1 0 1 0 1 0 0.00

Unid. Cormorant Diving 14 3 0 3 10 0 10 1 0 1 0.21

Unid. Dowitcher Shorebird 2 1 0 1 1 0 1 0 1 0 0.50

Unid. Duck Waterfowl 2 0 0 0 1 0 1 1 0 1 0.00

Unid. Egret Marsh/Wading 15 2 0 2 11 0 11 2 1 2 0.13

Unid. Flycatcher Passerine 1 1 0 1 0 0 0 0 0 0 1.00

Unid. Grebe Diving 4 2 1 2 2 0 2 0 0 0 0.50

Unid. Gull Seabird 248 79 1 80 134 0 134 33 4 34 0.32

Unid. Hawk Raptor 2 0 0 0 2 0 2 0 0 0 0.00

Unid. Heron Marsh/Wading 15 5 0 5 8 0 8 1 1 2 0.33

Unid. Loon Diving 7 2 2 4 3 0 3 0 1 0 0.57

Unid. Mockingbird Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Unid. Owl Raptor 1 0 0 0 1 0 1 0 0 0 0.00

Unid. Passerine Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Unid. Pelican Seabird 25 5 1 5 15 0 15 4 1 5 0.20

Unid. Pigeon Passerine 14 2 1 3 6 0 6 1 6 5 0.21

Unid. Rail Marsh/Wading 4 1 0 1 3 0 3 0 0 0 0.25

Unid. Raptor Raptor 1 0 0 0 1 0 1 0 0 0 0.00
Catastrophic Spill Event Analysis

B-135

Table B-5. Birds Collected and Summarized by the U.S. Fish and Wildlife Service: Post-Deepwater Horizon Explosion, Oil Spill, and Response in the 

Gulf of Mexico1, 2 (continued).

Common Name Species 

Group3

Grand 

Total

Visibly Oiled Not Visibly Oiled Unknown Oiling Oiling 

Rate4

Dead Alive Total Dead Alive Total Dead Alive Total

Unid. Sandpiper Shorebird 2 0 0 0 2 0 2 0 2 0 0.00

Unid. Shearwater Seabird 6 0 0 0 5 0 5 1 0 1 0.00

Unid. Shorebird Shorebird 3 2 0 2 0 0 0 1 0 1 0.67

Unid. Skimmer Seabird 6 0 0 0 5 0 5 1 0 1 0.00

Unid. Sparrow Passerine 3 0 0 0 1 0 1 2 0 2 0.00

Unid. Swallow Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Unid. Tern Seabird 132 38 1 39 79 0 79 13 2 14 0.30

Unid. Warbler Passerine 1 0 0 0 1 0 1 0 0 0 0.00

Unknown spp. 593 51 2 53 451 0 451 88 1 89 0.09

Other 106 31 3 34 52 0 52 7 14 20 0.32

Column Totals 7,258 2,121 2,642 3,387 3,387 873 1,229 0.24 1 Data obtained from the U.S. Fish and Wildlife Service (FWS) as part of the Deepwater Horizon post-spill monitoring and collection process are summarized for May 12, 

2011 (USDOI, FWS, 2011a). The data used in this table are verified as per FWS’s QA/QC processes. Disclaimer: All data should be considered provisional, incomplete, 

and subject to change (USDOI, FWS, 2011a). For more information, refer to the Weekly Bird Impact Data and Consolidated Wildlife Reports. Numbers in this table have

been verified against the original data from FWS’s website (USDOI, FWS, 2011a). 2 As of May 12, 2011, 104 avian species had been collected and identified through the Deepwater Horizon post-spill monitoring and collection process (USDOI, FWS, 

2011a). Note: Though the process was triggered by the Deepwater Horizon explosion and oil spill, not all birds recovered were oiled (36% = oiled, 47% = unoiled, 17% = 

unknown), suggesting that “search effort” alone accounted for a large proportion of the total (n = 7,258) birds collected (Piatt et al., 1990a, page 127). Some of the live 

birds collected may have been incapable of flight due to age or molt, and some of the dead birds collected may have died due to natural mortality, predation, or other 

anthropogenic sources of mortality. The overall oiling rate across species including “others” and “unknowns” was 0.24 versus 0.25 for individuals identified to species. 

The oiling rate for the Top 5 (see bold rows in table) most-impacted avian species was 0.43 and included representatives only from the seabird group. These are listed in 

descending order based on the number collected: laughing gull (2,981 collected, 0.40 oiling rate); brown pelican (826 collected, 0.41 oiling rate); northern gannet 

(475 collected, 0.63 oiling rate); royal tern (289 collected, 0.52 oiling rate); and black skimmer (253 collected, 0.22 oiling rate). Note: There is a difference between the 

table structure here compared with the original table on FWS’s website. Herein, columns for live birds that later died were not included. Totals associated with each larger 

grouping are correct and sum to those column totals for the May 12, 2011, Collection Report values. Six new species or rows were added and 3 species were removed 

between the December 14, 2010, Collection Report (USDOI, FWS, 2010d) and the May 12, 2011, Collection Report (USDOI, FWS, 2011a). The major difference in 

number (-807) between the more recent and older versions was due to an ~10% overestimate in the previous report representing live birds that later died, as these individuals 

were counted twice in the December 14, 2010, Collection Report (USDOI, FWS, 2010d). 3 For additional information on oiling rates by Species Group and additional statistics, refer to Table 4-12 of the 2012-2017 WPA/CPA Multisale EIS.
 B-136 Central and Eastern Planning Areas Supplemental EIS

Table B-5. Birds Collected and Summarized by the U.S. Fish and Wildlife Service Post-Deepwater Horizon Explosion, Oil Spill, and Response in the Gulf 

of Mexico1, 2 (continued).

4 Oiling Rate: For each species, an oiling rate was calculated by dividing the “total” number of oiled individuals (∑ alive + dead) /∑ of total individuals collected for a given 

species/row. In general, it has been well documented that the number of birds collected after a spill event represents a small fraction of the total oiled population (direct 

mortality) due to various factors: species-specific differences in vulnerability to spilled oil, species-specific differences in distribution, habitat use and behavior; speciesspecific differences in abundance; species-specific differences in carcass deposition rates, persistence rates, and detection probabilities; overall search effort and temporal 

and spatial variation in search effort; and carcass loss due to predation, habitat, weather, tides, and currents (Piatt et al., 1990a and 1990b; Ford et al., 1996; Piatt and Ford, 

1996; Fowler and Flint, 1997; Flint and Fowler, 1998; Flint et al., 1999; Hampton and Zafonte, 2005; Ford, 2006; Castège et al., 2007; Ford and Zafonte, 2009; Byrd et al., 

2009; Flint et al., 2010). For example, Piatt and Ford (1996, Table 1) estimated a mean carcass recovery rate of only 17% for a number of previous oil-bird impact studies. 

Burger (1993) and Wiese and Jones (2001) estimated recovery rates of 20% with the latter study based on a drift-block design to estimate carcass recovery rate from 

beached-bird surveys. Due to the fact that the coastline directly inshore of the well blowout location is primarily marsh and not sandy beaches, due to the distance from the 

blowout location to the coast, and due to predominant currents and wind directions during the event, the number of birds collected will likely represent a recovery estimate 

in the lower ranges of those provided in the literature to date (≤10%). A range of mortality estimates given the total number of dead birds collected through May 12, 2011, 

of 7,258 birds x recovery rates from the literature (0-59% in Piatt and Ford, 1996, Table 1) suggests a lower range of 12,302 birds* (59% recovery rate), an upper range of 

725,800 birds* (0% recovery rate), and 42,694 birds based on the 17% mean recovery rate from Piatt and Ford (1996). The lower range of estimates (i.e., high carcass 

recovery rates) is likely biased low because it assumes no search effort after May 2011 (i.e., no more birds were collected after that date) and does not account for any of the 

detection probability parameters that are currently unknown. The actual avian mortality estimate will likely not be available until the NRDA process has been completed; 

this should include a combination of carcass drift experiments, drift-block experiments, corrections for carcass deposition and persistence rates, scavenger rates, and 

detection probability with additional modeling to more precisely derive an estimate. For additional information on oiling rates by Species Group and additional statistics, 

refer to Table 4-12 of the 2012-2017 WPA/CPA Multisale EIS. Note: Spill volume tends to be a poor predictor of bird mortality associated with an oil spill (Burger, 1993), 

though it should be considered for inclusion in any models to estimate total bird mortality, preferably with some metric of species composition and abundance (preferably 

density) pre-spill (Wilhelm et al., 2007). 

* Corrected values are based on revisiting the original calculations after publication of the 2012-2017 WPA/CPA Multisale EIS. An additional estimate for total mortality 

based on Piatt and Ford (1996) is also provided.
Catastrophic Spill Event Analysis

B-137

Table B-6 

Federally Listed Avian Species Considered by State and Associated Planning Area in the Gulf of Mexico1

Species Status Critical Habitat IUCN Red List

Status2 States Planning Area

Red-cockaded Woodpecker Endangered No rules published Vulnerable AL, FL, LA, MS, TX WPA, CPA, EPA

Least Tern3 Endangered No rules published Least Concern AL, LA, TX (FL, MS) WPA, CPA, EPA

Piping Plover Threatened Designated Near Threatened AL, FL, LA, MS, TX WPA, CPA, EPA

Roseate Tern Threatened No rules published Least Concern FL only EPA

Wood Stork Endangered No rules published Least Concern AL, FL, MS CPA, EPA

Whooping Crane Endangered Designated Endangered TX, LA4, FL4 WPA, CPA, EPA

Mississippi Sandhill Crane Endangered Designated Not Yet Assessed MS only CPA

Attwater’s Prairie Chicken Endangered No rules published Not Yet Assessed TX only WPA

N. Aplomado Falcon Endangered No rules published Not Yet Assessed TX only WPA

Everglades Snail Kite Endangered Designated Not Yet Assessed FL only EPA

Cape Sable Seaside Sparrow Endangered Designated Not Yet Assessed FL only EPA

Audubon’s Crested Caracara Threatened No rules published Not Yet Assessed FL only EPA

Sprague’s Pipit Candidate NA – Priority 2 Vulnerable LA, TX WPA, CPA

Bald Eagle Delisted No rules published Least Concern AL, FL, LA, MS, TX WPA, CPA, EPA

Peregrine Falcon Delisted Designated Least Concern AL, FL, LA, MS, TX WPA, CPA, EPA

Eastern Brown Pelican Delisted No rules published Least Concern AL, FL, LA, MS, TX WPA, CPA, EPA

Red Knot Proposed 

Threatened

NA – proposed threatened Least Concern FL, LA, TX WPA, CPA, EPA

1 Information contained in this table was obtained via an email attachment from the U.S. Fish and Wildlife Service (FWS) on April 6, 2012 (USDOI, FWS, 2012) and from 

FWS’s “Endangered Species” website and associated queries for “species” available from FWS’s website (USDOI, FWS, 2011b). Additional information for each species 

can be found at NatureServe Explorer (2011). Note: All species listed in this table are considered, but only the piping plover, roseate tern, whooping crane, wood stork, 

Mississippi sandhill crane, bald eagle, eastern brown pelican, and red knot will be analyzed. 2 International Union for Conservation of Nature (IUCN) – The Red List classifies species as imperiled (Critically Endangered, Endangered, or Vulnerable), not imperiled 

(Near Threatened or Least Concern), extinct (Extinct, Extinct in the Wild), or Data Deficient (Butchart et al., 2004 and 2005; Harris et al., 2012). If species meet the 

quantitative thresholds of any of the following criteria, they will be added to the Red List: (1) decline in population size; (2) small geographic range; (3) small population 

size plus decline; (4) very small population size; or (5) quantitative analysis. 3 The Interior population of the least tern was listed as endangered on May 28, 1985 (Federal Register, 1985) throughout much of its breeding range in the Midwest. This 

designation does not provide or extend Endangered Species Act (ESA) protection to the breeding population of Gulf Coast “population” of least terns. Similarly, ESA 

protection for breeding least terns only applies to certain segments or areas (inland rivers and lakes ~50 mi [80 km] inland) of Louisiana, Mississippi, and Texas. 4 The whooping crane is considered endangered throughout its range in the U.S. except where nonessential, experimental flocks have been established. More recently, a 

release site (White Lake Wetlands Conservation Area, Vermilion Parish) was added in Louisiana (Table 4-14 of the 2012-2017 WPA/CPA Multisale EIS) with a release of

10 birds on February 22, 2011. To date, only 3 of the original 10 released cranes remain; an additional release of 16 cranes occurred on December 1, 2011. The Gulf Coast 

States that have these nonessential, experimental flocks include Alabama, Louisiana, Mississippi, and Florida; as well, wild whooping cranes may rarely occur as transients 

in Mississippi and Alabama, but they are not known to breed in either state. 5 The red knot is currently a proposed threatened species as of September 30, 2013 (Federal Register, 2013).

APPENDIX C 

 

MEMORANDUM OF AGREEMENT

BETWEEN THE BUREAU OF OCEAN ENERGY MANAGEMENT 

AND THE NATIONAL PARK SERVICE

Memorandum of Agreement C-3 
C-4 Central and Eastern Planning Areas Supplemental EIS
Memorandum of Agreement C-5 

KEYWORD INDEX

Keyword Index Keywords-3 

KEYWORD INDEX

Air Quality, xi, xii, 1-13, 2-7, 2-8, 2-9, 2-10, 2-16, 3-12, 4-6, 4-9, 4-10, 4-11, 4-12, 4-67, 4-112, 4-118, 

4-119, 4-120, 4-121, 4-122, 4-177, 4-222

Alternate Use, 3-34, 4-13, 4-124

Alternative Energy, 4-13, 4-124

Archaeological Resources, xii, xvi, 1-13, 2-7, 2-9, 2-10, 2-11, 2-16, 2-17, 4-8, 4-86, 4-87, 4-88, 4-89, 

4-90, 4-91, 4-92, 4-112, 4-118, 4-193, 4-194, 4-195, 4-196, 4-197, 4-198, 4-199, 4-223, 4-224, 5-5 

Artificial Reefs, xv, 1-13, 1-14, 2-7, 3-30, 3-33, 4-30, 4-74, 4-80, 4-81, 4-87, 4-88, 4-91, 4-181, 4-189, 

4-194, 4-195, 4-197, 4-198, 4-225

Beach Mice, xii, xiv, 2-9, 2-11, 2-16, 4-63, 4-64, 4-65, 4-66, 4-112, 4-118, 4-173, 4-174, 4-175, 4-176, 

4-217

Blowout Preventer, 3-26, 4-13, 4-124

Blowouts, viii, ix, xv, xvi, 2-12, 3-26, 3-27, 4-10, 4-13, 4-16, 4-19, 4-27, 4-30, 4-31, 4-33, 4-34, 4-37, 

4-41, 4-42, 4-43, 4-45, 4-46, 4-47, 4-49, 4-52, 4-57, 4-74, 4-90, 4-98, 4-104, 4-109, 4-110, 4-112, 

4-120, 4-123, 4-126, 4-129, 4-137, 4-139, 4-140, 4-142, 4-145, 4-149, 4-150, 4-151, 4-153, 4-154, 

4-155, 4-156, 4-157, 4-161, 4-166, 4-181, 4-205, 4-212, 4-217, 4-218, 4-219, 4-222

Catastrophic Spill, ix, xiii, xv, 2-11, 2-17, 3-17, 3-19, 4-4, 4-6, 4-7, 4-9, 4-10, 4-13, 4-16, 4-20, 4-21, 

4-22, 4-23, 4-24, 4-25, 4-26, 4-27, 4-28, 4-31, 4-34, 4-39, 4-41, 4-42, 4-43, 4-44, 4-45, 4-47, 4-48, 

4-54, 4-55, 4-56, 4-58, 4-60, 4-62, 4-64, 4-67, 4-68, 4-71, 4-72, 4-74, 4-75, 4-78, 4-80, 4-81, 4-83, 

4-84, 4-88, 4-91, 4-98, 4-101, 4-105, 4-108, 4-109, 4-115, 4-117, 4-119, 4-120, 4-124, 4-126, 4-130, 

4-131, 4-132, 4-133, 4-134, 4-135, 4-136, 4-137, 4-140, 4-146, 4-147, 4-149, 4-150, 4-151, 4-153, 

4-154, 4-155, 4-157, 4-163, 4-164, 4-165, 4-167, 4-169, 4-171, 4-174, 4-177, 4-178, 4-182, 4-186, 

4-188, 4-189, 4-195, 4-197, 4-206, 4-208, 4-213, 4-215, 4-217, 4-218, 4-221

Chemosynthetic Communities, xiii, 1-9, 1-13, 2-5, 2-7, 3-10, 4-40, 4-41, 4-42, 4-43, 4-45, 4-148, 4-149, 

4-150, 4-151, 4-152, 4-153

Chemosynthetic Deepwater Benthic Communities, 2-10, 2-16, 4-40, 4-73, 4-118, 4-148, 4-149, 4-180

Coastal and Marine Birds, xii, xiv, 2-9, 2-10, 2-11, 2-15, 2-16, 4-5, 4-64, 4-66, 4-67, 4-68, 4-69, 4-70, 

4-112, 4-117, 4-118, 4-174, 4-176, 4-177, 4-178, 4-179, 4-222

Coastal Barrier Beaches, xii, 2-9, 2-10, 2-16, 4-18, 4-19, 4-20, 4-21, 4-22, 4-112, 4-118, 4-128, 4-129, 

4-130, 4-131, 4-132

Coastal Zone Management, xii, 1-6, 1-10, 1-14, 4-5, 4-116, 5-11

Collisions, viii, xvi, 3-27, 3-40, 4-13, 4-16, 4-19, 4-24, 4-31, 4-57, 4-61, 4-68, 4-69, 4-93, 4-98, 4-104, 

4-105, 4-123, 4-124, 4-126, 4-129, 4-134, 4-140, 4-166, 4-170, 4-178, 4-179, 4-200, 4-205, 4-212, 

4-222

Commercial Fisheries, xii, xv, 2-9, 2-11, 2-17, 4-76, 4-77, 4-78, 4-80, 4-112, 4-118, 4-184, 4-185, 4-186, 

4-188, 4-222, 4-223

Commercial Fishing, xii, xv, 2-9, 2-11, 2-17, 4-76, 4-77, 4-78, 4-80, 4-112, 4-118, 4-184, 4-185, 4-186, 

4-188, 4-222, 4-223

Consultation and Coordination, viii, 1-6, 1-8, 2-7, 3-17, 5-13

Cumulative Activities, viii, xiv, 3-28, 3-29, 3-30, 3-31, 3-32, 3-33, 3-35, 3-38, 4-4, 4-62, 4-64, 4-115, 

4-171, 4-174

Cumulative Impacts, viii, xii, xiv, 1-5, 3-28, 3-30, 4-3, 4-5, 4-9, 4-10, 4-12, 4-13, 4-14, 4-15, 4-16, 4-18, 

4-20, 4-22, 4-23, 4-24, 4-26, 4-28, 4-29, 4-31, 4-33, 4-34, 4-36, 4-37, 4-38, 4-40, 4-42, 4-44, 4-45, 
Keywords-4 Central and Eastern Planning Areas Supplemental EIS

4-48, 4-49, 4-50, 4-51, 4-52, 4-53, 4-56, 4-57, 4-58, 4-60, 4-62, 4-63, 4-64, 4-65, 4-66, 4-67, 4-68, 

4-69, 4-70, 4-71, 4-72, 4-74, 4-76, 4-78, 4-80, 4-81, 4-83, 4-86, 4-87, 4-90, 4-91, 4-92, 4-93, 4-95, 

4-98, 4-101, 4-103, 4-104, 4-106, 4-108, 4-109, 4-111, 4-113, 4-116, 4-119, 4-120, 4-123, 4-124, 

4-125, 4-126, 4-128, 4-130, 4-132, 4-133, 4-134, 4-136, 4-137, 4-139, 4-140, 4-141, 4-142, 4-144, 

4-146, 4-149, 4-150, 4-151, 4-152, 4-154, 4-157, 4-158, 4-159, 4-160, 4-162, 4-165, 4-166, 4-167, 

4-170, 4-171, 4-173, 4-174, 4-175, 4-176, 4-177, 4-178, 4-179, 4-180, 4-182, 4-185, 4-186, 4-188, 

4-189, 4-191, 4-192, 4-193, 4-194, 4-197, 4-199, 4-200, 4-202, 4-205, 4-208, 4-210, 4-211, 4-212, 

4-213, 4-216, 4-218, 4-224

Decommissioning, xiv, xvi, 1-14, 2-7, 2-8, 3-12, 3-14, 3-26, 3-33, 4-30, 4-31, 4-33, 4-34, 4-40, 4-41, 

4-44, 4-48, 4-51, 4-52, 4-57, 4-74, 4-77, 4-78, 4-79, 4-81, 4-83, 4-87, 4-90, 4-91, 4-101, 4-112, 4-114, 

4-140, 4-142, 4-149, 4-153, 4-157, 4-161, 4-166, 4-167, 4-181, 4-182, 4-186, 4-187, 4-189, 4-191, 

4-193, 4-194, 4-197, 4-208, 4-220, 4-223, 4-224, 5-12

Deepwater, xii, xv, xvi, 1-8, 2-4, 2-5, 2-6, 2-9, 2-10, 2-15, 3-7, 3-11, 3-13, 3-14, 3-17, 3-18, 3-19, 3-20, 

3-23, 3-25, 3-26, 3-28, 3-31, 3-34, 3-39, 4-4, 4-5, 4-6, 4-7, 4-8, 4-11, 4-14, 4-15, 4-17, 4-18, 4-21, 4-22, 

4-25, 4-26, 4-27, 4-28, 4-29, 4-31, 4-32, 4-34, 4-35, 4-38, 4-40, 4-41, 4-42, 4-43, 4-44, 4-45, 4-46, 

4-47, 4-48, 4-50, 4-52, 4-53, 4-54, 4-55, 4-56, 4-58, 4-59, 4-60, 4-63, 4-64, 4-65, 4-66, 4-68, 4-69, 

4-71, 4-72, 4-73, 4-74, 4-75, 4-76, 4-79, 4-80, 4-82, 4-85, 4-86, 4-88, 4-95, 4-99, 4-102, 4-105, 4-106, 

4-107, 4-108, 4-110, 4-115, 4-116, 4-117, 4-121, 4-124, 4-125, 4-127, 4-128, 4-131, 4-132, 4-134, 

4-135, 4-136, 4-137, 4-138, 4-140, 4-141, 4-143, 4-144, 4-147, 4-148, 4-149, 4-150, 4-151, 4-152, 

4-153, 4-154, 4-155, 4-156, 4-157, 4-159, 4-161, 4-162, 4-163, 4-164, 4-165, 4-167, 4-169, 4-172, 

4-174, 4-175, 4-176, 4-178, 4-179, 4-181, 4-182, 4-184, 4-185, 4-187, 4-188, 4-189, 4-190, 4-192, 

4-193, 4-195, 4-202, 4-206, 4-209, 4-213, 4-214, 4-215, 4-218, 4-225, 5-6, 5-12

Deepwater Horizon, xii, xv, xvi, 1-8, 2-10, 2-15, 3-13, 3-17, 3-18, 3-19, 3-20, 3-23, 3-25, 3-26, 3-31, 

3-39, 4-4, 4-5, 4-6, 4-7, 4-8, 4-11, 4-14, 4-15, 4-17, 4-18, 4-21, 4-22, 4-25, 4-26, 4-27, 4-28, 4-29, 4-31, 

4-32, 4-34, 4-35, 4-38, 4-40, 4-43, 4-46, 4-47, 4-48, 4-53, 4-54, 4-55, 4-56, 4-58, 4-59, 4-60, 4-63, 

4-64, 4-65, 4-66, 4-68, 4-69, 4-71, 4-72, 4-74, 4-75, 4-76, 4-79, 4-80, 4-82, 4-85, 4-86, 4-95, 4-99, 

4-102, 4-105, 4-106, 4-107, 4-108, 4-110, 4-115, 4-116, 4-117, 4-121, 4-124, 4-125, 4-127, 4-128,

4-131, 4-132, 4-134, 4-135, 4-136, 4-137, 4-138, 4-140, 4-141, 4-143, 4-144, 4-147, 4-148, 4-151, 

4-155, 4-157, 4-159, 4-162, 4-163, 4-164, 4-165, 4-167, 4-169, 4-172, 4-174, 4-175, 4-176, 4-178, 

4-179, 4-182, 4-184, 4-187, 4-188, 4-190, 4-192, 4-193, 4-202, 4-206, 4-209, 4-213, 4-214, 4-215, 

4-218, 5-6, 5-12

Demographics, xvi, 2-9, 2-11, 2-17, 4-8, 4-98, 4-99, 4-100, 4-102, 4-118, 4-205, 4-206, 4-207, 4-210

Diamondback Terrapins, xii, xiv, 4-60, 4-61, 4-62, 4-63, 4-170, 4-171, 4-172

Discharges, xi, xii, xiii, xv, 2-12, 3-11, 3-13, 3-16, 3-25, 4-13, 4-14, 4-15, 4-16, 4-30, 4-31, 4-33, 4-34, 

4-36, 4-37, 4-40, 4-41, 4-42, 4-44, 4-45, 4-50, 4-51, 4-57, 4-64, 4-67, 4-68, 4-70, 4-73, 4-74, 4-77, 

4-80, 4-109, 4-110, 4-123, 4-124, 4-126, 4-140, 4-142, 4-145, 4-146, 4-149, 4-150, 4-153, 4-154, 

4-159, 4-160, 4-166, 4-173, 4-177, 4-178, 4-180, 4-181, 4-182, 4-185, 4-189, 4-217, 4-218, 4-219, 

4-221, 4-222

Dispersants, xv, 3-20, 3-23, 3-24, 3-25, 4-9, 4-13, 4-16, 4-19, 4-35, 4-38, 4-39, 4-41, 4-42, 4-45, 4-52, 

4-70, 4-71, 4-87, 4-104, 4-107, 4-112, 4-120, 4-123, 4-126, 4-129, 4-143, 4-147, 4-150, 4-154, 4-161, 

4-194, 4-197, 4-212, 4-214, 4-221, 4-222, 5-6 

Dunes, xii, 2-9, 2-10, 2-16, 4-18, 4-19, 4-20, 4-21, 4-22, 4-65, 4-66, 4-112, 4-118, 4-128, 4-129, 4-130, 

4-131, 4-132, 4-174, 4-175, 4-176

Economic Factors, xvi, 2-9, 2-11, 2-17, 4-8, 4-81, 4-84, 4-95, 4-98, 4-100, 4-101, 4-103, 4-118, 4-189, 

4-192, 4-202, 4-206, 4-207, 4-208, 4-210

Employment, xvi, 4-10, 4-82, 4-83, 4-84, 4-98, 4-99, 4-100, 4-101, 4-102, 4-104, 4-105, 4-106, 4-114, 

4-120, 4-190, 4-191, 4-192, 4-205, 4-206, 4-207, 4-208, 4-210, 4-211, 4-212, 4-213, 4-220

Environmental Justice, xii, xvi, 1-7, 2-9, 2-11, 2-17, 4-8, 4-103, 4-104, 4-105, 4-106, 4-107, 4-108, 4-119, 

4-210, 4-211, 4-212, 4-213, 4-214, 4-215, 4-216
Keyword Index Keywords-5 

Essential Fish Habitat, xii, xv, 1-6, 2-9, 2-11, 2-17, 4-5, 4-33, 4-72, 4-73, 4-74, 4-75, 4-76, 4-77, 4-112, 

4-116, 4-118, 4-142, 4-179, 4-180, 4-181, 4-182, 4-183, 4-184, 4-185, 4-222, 4-223, 5-12

Explosive Removals, 4-71

Fish Resources, xii, xv, 2-9, 2-11, 2-17, 4-72, 4-73, 4-74, 4-75, 4-76, 4-77, 4-112, 4-118, 4-179, 4-180, 

4-181, 4-182, 4-183, 4-184, 4-185, 4-222, 4-223

Fisheries, xiv, xv, 1-13, 2-10, 2-15, 4-5, 4-46, 4-47, 4-64, 4-68, 4-71, 4-75, 4-76, 4-77, 4-78, 4-80, 4-81, 

4-82, 4-104, 4-117, 4-154, 4-156, 4-174, 4-178, 4-182, 4-183, 4-184, 4-185, 4-186, 4-188, 4-189, 

4-190, 4-212, 5-3, 5-6, 5-8, 5-9, 5-10, 5-12

Flaring, 1-13, 4-9, 4-10, 4-119, 4-120

Flower Garden Banks, 2-7, 2-11, 4-30, 4-34, 4-35, 4-143

Gulf Sturgeon, xii, xv, 2-9, 2-10, 2-17, 4-70, 4-71, 4-72, 4-112, 4-118, 4-179, 4-180, 4-181, 4-182, 4-183

Human Resources, 2-9, 2-11, 2-17, 4-92, 4-112, 4-118, 4-119, 4-199

Hurricanes, xi, xii, 3-37, 3-38, 3-39, 4-10, 4-13, 4-19, 4-23, 4-24, 4-26, 4-31, 4-34, 4-35, 4-37, 4-38, 4-53, 

4-55, 4-62, 4-64, 4-65, 4-74, 4-81, 4-88, 4-91, 4-107, 4-109, 4-120, 4-123, 4-129, 4-133, 4-134, 4-136, 

4-140, 4-142, 4-146, 4-162, 4-164, 4-171, 4-174, 4-175, 4-182, 4-189, 4-195, 4-198, 4-215, 4-218

Income, xvi, 4-84, 4-98, 4-99, 4-103, 4-104, 4-105, 4-106, 4-107, 4-108, 4-192, 4-206, 4-211, 4-212, 

4-213, 4-215

Infrastructure, viii, xii, xiii, xv, xvi, 1-9, 1-11, 2-8, 2-9, 2-11, 2-17, 3-3, 3-9, 3-10, 3-11, 3-14, 3-15, 3-27, 

3-29, 3-30, 3-35, 3-36, 3-38, 3-39, 4-8, 4-18, 4-20, 4-23, 4-24, 4-27, 4-29, 4-33, 4-48, 4-58, 4-70, 4-73, 

4-77, 4-80, 4-83, 4-87, 4-90, 4-92, 4-93, 4-94, 4-95, 4-96, 4-97, 4-98, 4-103, 4-104, 4-105, 4-106, 

4-109, 4-114, 4-118, 4-128, 4-130, 4-133, 4-134, 4-139, 4-157, 4-167, 4-180, 4-188, 4-191, 4-192, 

4-194, 4-199, 4-200, 4-201, 4-202, 4-203, 4-204, 4-205, 4-211, 4-212, 4-213, 4-217, 4-220, 4-222, 

4-225, 5-4 

Land Use, xii, xvi, 2-9, 2-11, 2-17, 3-15, 4-8, 4-83, 4-92, 4-93, 4-94, 4-95, 4-96, 4-97, 4-101, 4-105, 

4-112, 4-118, 4-119, 4-191, 4-199, 4-200, 4-201, 4-202, 4-203, 4-204, 4-208, 4-213

Live Bottoms, x, xii, xiii, 1-7, 2-5, 2-6, 2-9, 2-10, 2-12, 2-16, 3-10, 4-29, 4-30, 4-31, 4-32, 4-34, 4-35, 

4-44, 4-45, 4-46, 4-47, 4-48, 4-50, 4-72, 4-73, 4-111, 4-112, 4-113, 4-118, 4-139, 4-140, 4-141, 4-143, 

4-152, 4-153, 4-154, 4-155, 4-156, 4-159, 4-180, 4-181, 4-223

Low Relief, xiii, 2-9, 3-10, 4-29, 4-30, 4-31, 4-32, 4-73, 4-112, 4-118, 4-139, 4-140, 4-141, 4-181

Macondo, 3-13, 4-8, 4-28, 4-35, 4-43, 4-48, 4-63, 4-110, 4-138, 4-151, 4-156, 4-159, 4-172, 4-219

Mangroves, 4-61, 4-170, 4-217

Marine Mammals, xii, xiv, 1-6, 1-7, 1-13, 2-5, 2-7, 2-9, 2-11, 2-16, 3-13, 4-5, 4-7, 4-51, 4-52, 4-53, 4-54, 

4-55, 4-56, 4-57, 4-58, 4-59, 4-112, 4-116, 4-118, 4-160, 4-161, 4-162, 4-163, 4-164, 4-165, 4-166, 

4-167, 4-168, 4-221, 4-222, 5-8 

Meteorological Conditions, 3-24

Mitigating Measures, vii, viii, ix, x, xi, xiii, xiv, 1-10, 1-13, 2-3, 2-5, 2-6, 2-7, 2-11, 2-14, 2-17, 4-5, 4-6, 

4-8, 4-23, 4-28, 4-41, 4-83, 4-111, 4-112, 4-117, 4-133, 4-137, 4-149, 4-150, 4-225, 5-4, 5-12, 5-13

Mitigation, x, xi, xv, 1-11, 1-12, 1-13, 2-6, 2-7, 2-8, 3-38, 4-6, 4-8, 4-13, 4-23, 4-27, 4-31, 4-33, 4-34, 

4-35, 4-41, 4-42, 4-44, 4-51, 4-52, 4-56, 4-57, 4-61, 4-71, 4-73, 4-75, 4-77, 4-85, 4-97, 4-109, 4-110, 

4-111, 4-113, 4-117, 4-124, 4-133, 4-137, 4-140, 4-149, 4-150, 4-151, 4-153, 4-160, 4-161, 4-166, 

4-170, 4-181, 4-182, 4-185, 4-204, 4-217, 4-218, 4-219, 4-222, 4-223, 4-226, 5-5, 5-12

NEPA, vii, ix, x, xi, 1-3, 1-4, 1-5, 1-6, 1-10, 1-11, 1-12, 1-14, 2-3, 2-4, 2-5, 2-6, 2-7, 2-9, 2-10, 2-11, 

2-15, 4-4, 4-5, 4-6, 4-7, 4-8, 4-9, 4-12, 4-15, 4-18, 4-22, 4-26, 4-27, 4-28, 4-29, 4-32, 4-33, 4-36, 4-40, 

4-43, 4-44, 4-48, 4-50, 4-51, 4-55, 4-56, 4-60, 4-63, 4-65, 4-66, 4-69, 4-70, 4-72, 4-76, 4-79, 4-80, 

4-82, 4-83, 4-86, 4-89, 4-90, 4-92, 4-93, 4-97, 4-98, 4-100, 4-103, 4-108, 4-110, 4-111, 4-115, 4-116, 
Keywords-6 Central and Eastern Planning Areas Supplemental EIS

4-117, 4-118, 4-119, 4-121, 4-122, 4-123, 4-125, 4-126, 4-128, 4-132, 4-136, 4-137, 4-138, 4-139, 

4-141, 4-142, 4-144, 4-148, 4-149, 4-151, 4-152, 4-157, 4-159, 4-160, 4-164, 4-165, 4-169, 4-170, 

4-173, 4-175, 4-176, 4-179, 4-180, 4-184, 4-185, 4-187, 4-188, 4-190, 4-191, 4-193, 4-196, 4-197, 

4-198, 4-199, 4-204, 4-205, 4-207, 4-208, 4-210, 4-211, 4-215, 4-216, 4-218, 4-219, 5-3, 5-4, 5-6, 5-7, 

5-12

Noise, xiv, xv, 1-9, 3-6, 3-12, 3-13, 4-51, 4-52, 4-53, 4-57, 4-58, 4-67, 4-68, 4-83, 4-84, 4-105, 4-109, 

4-110, 4-160, 4-161, 4-162, 4-166, 4-167, 4-177, 4-178, 4-191, 4-213, 4-217, 4-218, 4-219, 4-222

Nonchemosynthetic Deepwater Benthic Communities, xiii, 2-10, 2-16, 4-44, 4-45, 4-47, 4-48, 4-73, 

4-112, 4-118, 4-152, 4-153, 4-154, 4-155, 4-156, 4-157, 4-180

Oil Spills, viii, ix, xi, xii, xiii, xiv, xv, xvi, 1-8, 2-10, 2-11, 2-15, 2-17, 2-19, 3-13, 3-17, 3-18, 3-19, 3-20, 

3-21, 3-22, 3-23, 3-24, 3-25, 3-26, 3-27, 3-39, 3-40, 4-4, 4-5, 4-6, 4-7, 4-8, 4-10, 4-11, 4-13, 4-14, 4-15, 

4-17, 4-18, 4-19, 4-20, 4-21, 4-22, 4-23, 4-24, 4-25, 4-26, 4-27, 4-28, 4-29, 4-30, 4-31, 4-32, 4-33, 

4-34, 4-35, 4-36, 4-38, 4-40, 4-41, 4-42, 4-43, 4-45, 4-46, 4-47, 4-48, 4-49, 4-52, 4-53, 4-54, 4-55, 

4-56, 4-57, 4-58, 4-59, 4-60, 4-61, 4-62, 4-63, 4-64, 4-65, 4-66, 4-67, 4-68, 4-69, 4-70, 4-71, 4-72, 

4-74, 4-75, 4-76, 4-77, 4-78, 4-79, 4-80, 4-81, 4-82, 4-83, 4-84, 4-85, 4-86, 4-87, 4-88, 4-90, 4-91, 

4-93, 4-95, 4-98, 4-99, 4-100, 4-101, 4-102, 4-104, 4-105, 4-106, 4-107, 4-108, 4-109, 4-110, 4-112, 

4-115, 4-116, 4-117, 4-120, 4-121, 4-123, 4-124, 4-125, 4-127, 4-128, 4-129, 4-130, 4-131, 4-132, 

4-133, 4-134, 4-135, 4-136, 4-137, 4-138, 4-139, 4-140, 4-141, 4-142, 4-143, 4-147, 4-148, 4-149, 

4-150, 4-151, 4-153, 4-154, 4-155, 4-156, 4-157, 4-159, 4-161, 4-162, 4-163, 4-164, 4-165, 4-166, 

4-167, 4-169, 4-170, 4-171, 4-172, 4-173, 4-174, 4-175, 4-176, 4-177, 4-178, 4-179, 4-182, 4-183, 

4-184, 4-185, 4-186, 4-187, 4-188, 4-189, 4-190, 4-191, 4-192, 4-193, 4-194, 4-197, 4-200, 4-202, 

4-205, 4-206, 4-208, 4-209, 4-212, 4-214, 4-215, 4-217, 4-218, 4-219, 4-221, 4-222, 4-223, 4-224, 

4-225, 5-6, 5-12

OSRA, 3-19, 3-21

Physical Oceanography, 1-9, 3-39, 4-89, 4-92, 4-196, 4-199

Pinnacle Trend, x, xiii, 2-5, 2-6, 2-9, 2-12, 4-29, 4-30, 4-31, 4-32, 4-73, 4-112, 4-118, 4-139, 4-140, 

4-141, 4-181

Pipelines, xi, xiii, xv, 2-8, 3-9, 3-10, 3-12, 3-13, 3-15, 3-18, 3-20, 3-21, 3-23, 3-27, 3-29, 3-30, 3-33, 4-13, 

4-15, 4-19, 4-23, 4-24, 4-27, 4-33, 4-73, 4-81, 4-91, 4-96, 4-109, 4-123, 4-126, 4-129, 4-130, 4-133, 

4-137, 4-180, 4-189, 4-198, 4-203, 4-217, 4-222, 4-223

Port Fourchon, xvi, 3-15, 3-25, 4-93, 4-104, 4-105, 4-200, 4-211, 4-212, 4-213

Produced Waters, 3-11, 4-29, 4-41, 4-44, 4-67, 4-73, 4-77, 4-139, 4-149, 4-153, 4-177, 4-180, 4-185, 

4-221

Public Services, xii

Recreational Fishing, xii, xv, 2-9, 2-11, 2-17, 4-8, 4-58, 4-75, 4-78, 4-80, 4-81, 4-82, 4-84, 4-107, 4-112, 

4-118, 4-167, 4-182, 4-186, 4-188, 4-189, 4-190, 4-191, 4-215, 4-222, 4-225

Recreational Resources, xii, xv, 2-9, 2-11, 2-17, 4-8, 4-83, 4-84, 4-85, 4-86, 4-112, 4-118, 4-191, 4-192, 

4-193

Renewable Energy, 1-4, 1-12, 2-6, 3-30, 3-34, 3-35, 4-16, 4-87, 4-88, 4-91, 4-101, 4-105, 4-126, 4-194, 

4-195, 4-198, 4-208, 4-213, 4-224

Resource Estimates, 3-3, 3-4 

Sargassum, xii, xiii, 2-9, 2-10, 2-16, 4-36, 4-37, 4-38, 4-39, 4-40, 4-58, 4-73, 4-112, 4-118, 4-144, 4-145, 

4-146, 4-147, 4-148, 4-168, 4-180, 4-221

Sea Turtles, xii, xiv, 1-13, 2-5, 2-7, 2-9, 2-11, 2-16, 4-7, 4-38, 4-39, 4-56, 4-57, 4-58, 4-59, 4-60, 4-109, 

4-112, 4-118, 4-146, 4-147, 4-165, 4-166, 4-167, 4-168, 4-169

Seagrass Communities, xii, xiii, 2-9, 2-10, 2-16, 4-23, 4-26, 4-27, 4-28, 4-29, 4-72, 4-74, 4-75, 4-112, 

4-118, 4-133, 4-136, 4-137, 4-138, 4-139, 4-180, 4-182
Keyword Index Keywords-7 

Service Base, 3-14, 4-24, 4-93, 4-134, 4-200, 4-211

Site Clearance, xvi, 1-14, 2-7 

Smalltooth Sawfish, 4-180, 4-181, 4-182, 4-183

Soft Bottoms, xii, xiii, 2-9, 2-11, 2-16, 3-33, 4-6, 4-33, 4-46, 4-47, 4-48, 4-49, 4-50, 4-51, 4-73, 4-112, 

4-118, 4-142, 4-155, 4-156, 4-157, 4-158, 4-159, 4-160, 4-180

Stipulation, x, xi, xiii, xv, 1-6, 1-13, 2-3, 2-4, 2-5, 2-6, 2-7, 2-11, 2-12, 2-13, 2-14, 2-17, 2-18, 3-32, 3-33, 

4-5, 4-6, 4-8, 4-28, 4-29, 4-30, 4-31, 4-33, 4-34, 4-35, 4-42, 4-49, 4-53, 4-56, 4-57, 4-58, 4-62, 4-73, 

4-111, 4-113, 4-117, 4-137, 4-140, 4-142, 4-150, 4-157, 4-162, 4-166, 4-167, 4-171, 4-181, 4-223, 5-5 

Submerged Vegetation, 4-27, 4-28, 4-137, 4-138

Synthetic-Based Drilling Fluids, 3-28

Topographic Features, ix, x, xii, xiii, 2-4, 2-5, 2-6, 2-7, 2-9, 2-10, 2-11, 2-14, 2-16, 3-10, 4-6, 4-30, 4-32, 

4-33, 4-34, 4-35, 4-36, 4-72, 4-73, 4-111, 4-112, 4-113, 4-118, 4-141, 4-142, 4-143, 4-144, 4-180, 

4-181

Tourism, xii, 4-20, 4-81, 4-83, 4-85, 4-98, 4-101, 4-105, 4-107, 4-130, 4-189, 4-191, 4-192, 4-206, 4-208, 

4-213, 4-215, 4-223, 4-225, 5-9 

Trash, xii, xiv, 3-16, 3-17, 4-51, 4-56, 4-57, 4-61, 4-62, 4-63, 4-64, 4-68, 4-83, 4-85, 4-109, 4-160, 4-166, 

4-167, 4-170, 4-171, 4-173, 4-174, 4-177, 4-178, 4-192, 4-217, 4-222

Waste Disposal, 3-17, 4-23, 4-93, 4-200

Wastes, xiii, 2-8, 3-11, 3-12, 3-16, 3-17, 4-16, 4-23, 4-126, 4-133

Water Quality, xii, xiii, 2-8, 2-9, 2-10, 2-16, 3-15, 4-6, 4-12, 4-13, 4-14, 4-15, 4-16, 4-17, 4-18, 4-37, 

4-38, 4-51, 4-57, 4-70, 4-71, 4-72, 4-73, 4-75, 4-81, 4-112, 4-118, 4-122, 4-123, 4-124, 4-125, 4-126, 

4-127, 4-128, 4-145, 4-146, 4-160, 4-166, 4-180, 4-181, 4-182, 4-189, 4-221, 4-222, 4-225, 5-5 

Wetlands, xi, xiii, 1-7, 1-9, 2-7, 2-9, 2-10, 2-15, 2-16, 3-37, 3-38, 4-5, 4-6, 4-18, 4-19, 4-21, 4-22, 4-23, 

4-24, 4-25, 4-26, 4-28, 4-72, 4-75, 4-78, 4-81, 4-83, 4-84, 4-109, 4-112, 4-117, 4-118, 4-128, 4-129, 

4-131, 4-132, 4-133, 4-134, 4-135, 4-136, 4-138, 4-180, 4-182, 4-183, 4-186, 4-189, 4-191, 4-218, 

4-221, 4-223, 4-225

The Department of the Interior Mission

As the Nation’s principal conservation agency, the Department of the Interior has 

responsibility for most of our nationally owned public lands and natural 

resources. This includes fostering the sound use of our land and water 

resources, protecting our fish, wildlife and biological diversity; preserving the 

environmental and cultural values of our national parks and historical places; and 

providing for the enjoyment of life through outdoor recreation. The Department 

assesses our energy and mineral resources and works to ensure that their 

development is in the best interests of all our people by encouraging stewardship 

and citizen participation in their care. The Department also has a major 

responsibility for American Indian reservation communities and for people who 

live in island communities. 

The Bureau of Ocean Energy Management 

The Bureau of Ocean Energy Management (BOEM) works to manage the 

exploration and development of the nation's offshore resources in a way that 

appropriately balances economic development, energy independence, and 

environmental protection through oil and gas leases, renewable energy 

development and environmental reviews and studies.