U.S. Department of the Interior

Bureau of Ocean Energy Management, 

Regulation and Enforcement

Alaska OCS Region

OCS EIS/EA

BOEMRE 2011-039

Alaska Outer Continental Shelf

Beaufort Sea Planning Area

Shell Offshore Inc.

2012 Revised Outer Continental Shelf Lease Exploration Plan

Camden Bay, Beaufort Sea, Alaska

Flaxman Island Blocks 6559, 6610 & 6658

Beaufort Sea Lease Sales 195 & 202

Environmental assessment

Prepared By:

Office of Leasing and Environment

Alaska OCS Region

August 2011
This Page Intentionally Left Blank
2012 Shell Camden Bay EP EA 

Table of Contents i

Table of Contents 

1.0 Purpose and Need ......................................................................................................................... 1

1.1. Purpose of the Proposed Action ................................................................................................... 1

1.2. Previous Applicable NEPA Analyses, Biological Opinions and Related Analyses. .................... 3

1.3. Statutory Framework .................................................................................................................... 4

1.3.1. Outer Continental Shelf Lands Act and BOEMRE Operating Regulations .............................. 4

1.3.2. Endangered Species Act ............................................................................................................ 5

1.3.3. Marine Mammal Protection Act ................................................................................................ 5

1.3.4. Coastal Zone Management Act ................................................................................................. 6

1.3.5. Clean Air Act............................................................................................................................. 6

1.3.6. Clean Water Act ........................................................................................................................ 7

1.3.7. The Oil Pollution Act ................................................................................................................ 8

1.3.8. National Historic Preservation Act ............................................................................................ 8

1.3.9. National Invasive Species Act ................................................................................................... 9

2.0 Proposed Action and Alternatives .............................................................................................. 11

2.1. Background ................................................................................................................................. 11

2.2. Summary of Alternatives ............................................................................................................ 11

2.2.1. Alternative 1 – No Action ....................................................................................................... 11

2.2.2. Alternative 2 – The Proposed Action ...................................................................................... 11

2.2.3. Other Alternatives Considered But Not Analyzed .................................................................. 12

2.3. Description of Alternative 2 – The Proposed Action ................................................................. 12

2.3.1. Overview ................................................................................................................................. 12

2.3.2. Drill Sites and Operating Environment ................................................................................... 14

2.3.3. Seafloor Conditions at the Drill Sites ...................................................................................... 15

2.3.4. Drillship, Support Vessels, and Aircraft .................................................................................. 17

2.3.5. Discharges and Waste Management ........................................................................................ 18

2.3.6. Emissions ................................................................................................................................ 19

2.3.7. Sound Generation. ................................................................................................................... 21

2.3.8. Local Hire ................................................................................................................................ 24

2.3.9. Analysis of Accidental Oil Spills ............................................................................................ 25

2.3.10. Oil Spill Prevention and Contingency Planning ...................................................................... 26

2.3.11. Compliance with Lease Stipulations ....................................................................................... 27

2.3.12. Other Mitigation ...................................................................................................................... 31

2.3.13. Environmental Monitoring ...................................................................................................... 35

3.0 Affected Environment ................................................................................................................ 37

3.1. Meteorology ................................................................................................................................ 37

3.1.1. Climate Change ....................................................................................................................... 37

3.1.2. Expected Weather Conditions at the Drill Sites ...................................................................... 38

3.1.3. Expected Ice Conditions at the Drill Sites ............................................................................... 39

3.2. Potentially Affected Resources. .................................................................................................. 40

3.2.1. Air Quality. .............................................................................................................................. 40

3.2.2. Water Quality. ......................................................................................................................... 43

3.2.3. Lower Trophic Levels ............................................................................................................. 45

3.2.4. Fish and Essential Fish Habitat. .............................................................................................. 46

3.2.5. Marine and Coastal Birds. ....................................................................................................... 51
2012 Shell Camden Bay EP EA 

ii Table of Contents 

3.2.6. Marine Mammals. ................................................................................................................... 55

3.2.7. Sociocultural Systems ............................................................................................................. 60

3.2.8. Subsistence Activities .............................................................................................................. 61

3.2.9. Economy .................................................................................................................................. 63

3.2.10. Environmental Justice ............................................................................................................. 64

3.2.11. Public Health ........................................................................................................................... 64

3.2.12. Archaeological Resources ....................................................................................................... 65

4.0 Environmental Consequences ..................................................................................................... 67

4.1. Alternative 1 – the No Action Alternative .................................................................................. 67

4.1.1. Direct and Indirect Effects ....................................................................................................... 67

4.1.2. Cumulative Effects .................................................................................................................. 67

4.2. Alternative 2 – The Proposed Action ......................................................................................... 67

4.2.1. Air Quality ............................................................................................................................... 67

4.2.2. Water Quality .......................................................................................................................... 71

4.2.3. Cumulative Effects: ................................................................................................................. 74

4.2.4. Lower Trophic Levels ............................................................................................................. 75

4.2.5. Fish and Essential Fish Habitat ............................................................................................... 77

4.2.6. Marine and Coastal Birds ........................................................................................................ 80

4.2.7. Marine Mammals .................................................................................................................... 86

4.2.8. Sociocultural Systems ........................................................................................................... 102

4.2.9. Subsistence Activities ............................................................................................................ 103

4.2.10. Economy ................................................................................................................................ 106

4.2.11. Environmental Justice ........................................................................................................... 107

4.2.12. Public Health ......................................................................................................................... 107

5.0 Post Deepwater Horizon Event Environmental Review ........................................................... 109

5.1. Deepwater Horizon Oil Spill. ................................................................................................... 109

5.2. Government Reports and Recommendations ........................................................................... 109

5.3. Transparency, Public Accountability, and Sound Decisionmaking .......................................... 112

5.3.1. OCS Well Control Incident Rates. ........................................................................................ 112

5.4. Rule Changes Following the Deepwater Horizon Event .......................................................... 114

5.5. Site Specific Differences from Macondo .................................................................................. 117

5.5.1. Geological and Physical Conditions. ..................................................................................... 117

5.5.2. Arctic Specific Measures to Prevent Oil Spills ..................................................................... 118

5.6. Oil Spill Effects and Response ................................................................................................. 120

5.6.1. Overview of Oil Spill Effects and Response Analysis .......................................................... 120

5.7. Large Oil Spill Effects .............................................................................................................. 121

5.8. Very Large Oil Spill Effects ..................................................................................................... 129

5.9. Oil Spill Response .................................................................................................................... 134

5.9.1. Oil Spill Discharge Prevention and Contingency Plan (ODPCP) ......................................... 134

5.9.2. Additional Pollution Prevention and Response Measures ..................................................... 135

5.9.3. Effectiveness of Oil Spill Response. ..................................................................................... 136

6.0 Consultation and Coordination ................................................................................................. 137

6.1. Endangered Species Act Consultation ...................................................................................... 137

6.2. Essential Fish Habitat Consultation .......................................................................................... 138

6.3. Marine Mammal Protection Act ............................................................................................... 138
2012 Shell Camden Bay EP EA 

Table of Contents iii

6.4. National Historic Preservation Act ........................................................................................... 138

6.5. Reviewers and Preparers .......................................................................................................... 138

6.6. Public Involvement ................................................................................................................... 139

7.0 References .................................................................................................................................... 141

A. Oil-Spill Analysis and Scenario Framework of Accidental Oil Spills in this Environmental 

Assessment. .................................................................................................................................. A-1

A-1.1. Summary: Estimated Accidental Spills by BOEMRE Size Categories................................. A-1

A-1.2. Oil-Spill Volume and Type Estimates. .................................................................................. A-2

A-1.3. Historical and Modeled Oil Spill Information. ...................................................................... A-5

A-1.4. Oil-Spill Analysis Framework. ............................................................................................ A-12

A-1.5. References. .......................................................................................................................... A-18

B. Level of Effect Definitions .......................................................................................................... B-1

B-1. Air Quality ................................................................................................................................ B-1

B-2. Water Quality ........................................................................................................................... B-2

B-3. Lower Trophics ......................................................................................................................... B-3

B-4. Fish ........................................................................................................................................... B-3

B-5. Marine and Coastal Birds ......................................................................................................... B-5

B-6. Marine Mammals ...................................................................................................................... B-6

B-7. Sociocultural Systems ............................................................................................................... B-7

B-8. Subsistence ............................................................................................................................... B-8

B-9. Economy ................................................................................................................................... B-8

B-10. Public Health ............................................................................................................................ B-9

B-11. Archaeology ............................................................................................................................ B-10

B-12. Reference ................................................................................................................................ B-10

C. CUMULATIVE EFFECTS ......................................................................................................... C-1

C-1. Cumulative Effects Defined ..................................................................................................... C-1

C-2. Impact Sources ......................................................................................................................... C-1

C-2.1. Marine Vessel Traffic ............................................................................................................ C-1

C-2.2. Aircraft Traffic ...................................................................................................................... C-2

C-2.3. Oil and Gas Related Activities .............................................................................................. C-2

C-3. Miscellaneous Associated Activities ........................................................................................ C-2

C-3.1. Other Vessel Traffic .............................................................................................................. C-2

C-3.2. Scientific Research ................................................................................................................ C-2

C-3.3. Reasonable and Foreseeable Planned Activities ................................................................... C-3

C-3.4. Climate Change and Ocean Acidification ............................................................................. C-4

C-4. References ................................................................................................................................ C-5

D. Air Quality ................................................................................................................................... D-1

D-1. Regulatory Overview ................................................................................................................ D-3

D-1.1. Lead ....................................................................................................................................... D-5

D-1.2. Nitrogen Dioxide (NO2) ........................................................................................................ D-5

D-1.3. Ozone .................................................................................................................................... D-5

D-1.4. Particulate Matter (PM10 and PM2.5) ...................................................................................... D-5

D-1.5. Sulfur Dioxide (SO2) ............................................................................................................. D-5

D-1.6. OCS Air Regulations ............................................................................................................. D-6
2012 Shell Camden Bay EP EA 

iv List of Figures 

D-1.7. Definitions ................................................................................................................................... D-6

D-1.8. Air Operating Permits ................................................................................................................. D-8

D-2. NEPA Air Quality Analysis .......................................................................................................... D-10

D-3. Air Quality Levels of Effect ......................................................................................................... D-12

D-3.1. CAA Title V Requirements ....................................................................................................... D-12

D-3.2. PSD Requirements .................................................................................................................... D-13

D-3.3. Defining the Four Levels of Effect ............................................................................................ D-14

D-4. References: ................................................................................................................................... D-18

List of Figures 

Figure 1 An overview of the locality of Shell's proposed Camden Bay exploration wells. .................. 1

Figure 2 The Torpedo and Sivulliq Proposed Exploration Drill Sites ................................................ 11

Figure 3 Mean September Sea Ice Extents 1982 to 2007 at 5-Year Increments (Shell, 2011a) ......... 40

Figure 4 Arctic Cod Essential Fish Habitat ........................................................................................ 48

List of Tables 

Table 1 Comparison of Shell’s 2010 Camden Bay EP and the 2012 Revised Camden Bay EP. ........ 2

Table 2 Proposed Exploration Drill Sites. ......................................................................................... 12

Table 3 Planned Support Vessels for the Kulluk or Discoverer. ....................................................... 17

Table 4 Estimated spill volume and oil type in each BOEMRE spill size category from Shell’s 

potential discharge volumes. ................................................................................................ 25

Table 5 Water column measurements in Camden Bay, Alaska, over four days in August 2008 

(after Trefry and Trocine, 2009) ........................................................................................... 43

Table 6 Fish Species most likely to occur in the Proposed Drilling Areas, or which could be 

affected by drilling activities ................................................................................................ 47

Table 7 EFH target species that occur (designated in the Arctic Fishery Management Plan, 2009) 

and ecosystem component species that likely occur in the Camden Bay project area, 

Beaufort Sea, Alaska. ........................................................................................................... 49

Table 8 Marine and coastal birds most likely to be affected by the Proposed Action ....................... 52

Table 9 The stock, habitat, and estimated abundance of marine mammals occurring within the 

Proposed Action area. ........................................................................................................... 59

Table 10 Annual Emissions allowable under the state and federal CAA Title V air permits for the 

drillship Kulluk. .................................................................................................................... 68

Table 11 Annual Emissions allowable under the state and federal CAA PSD air permits for the 

drillship Discoverer. ............................................................................................................. 69

Table 12 Waste (bbls) to be discharged from four exploration wells proposed into the Beaufort 

Sea. ....................................................................................................................................... 72

Table 13 Estimated surface area disturbed and volume of sediment excavated by two drill ships to 

construct a maximum of four mud cellars in Camden Bay during the Proposed Action. .... 72

Table 14 Seafloor scarring as a result of anchor sets at four proposed drilling sites in Camden 

Bay. ....................................................................................................................................... 73

Table 15 Waste (bbls) to be collected and transported out (“Not Discharged”) from four 

exploration wells proposed in the Beaufort Sea. .................................................................. 73

Table 16 Waste Streams and the Effects on Water Quality in 2012 the Proposed Action. ................. 74
2012 Shell Camden Bay EP EA 

List of Tables v

Table 17 Proposed Exploration Drilling Activities and Potential Effects on Fish and Essential 

Fish Habitat in Camden Bay, Alaska. .................................................................................... 77

Table 18 Potential benthic habitat disturbance by anchoring drill ships at a total of four drill sites 

in Camden Bay ...................................................................................................................... 78

Table 19 Comparison of Very Large Oil Spill Scenario Elements to Worst Case Discharge 

Information. ......................................................................................................................... 113

Table 20 Comparison of Deepwater Horizon / Macondo and Torpedo H Wells. .............................. 117

Table 21 Effectiveness of oil spill countermeasures .......................................................................... 136
2012 Shell Camden Bay EP EA 

vi List of Tables 

Page Intentionally Left Blank 
Shell 2012 Camden Bay EP EA

Purpose and Need - Purpose of the Proposed Action 1

1.0 PURPOSE AND NEED 

1.1. Purpose of the Proposed Action 

Shell Offshore Inc. (Shell) submitted to the Bureau of Ocean Energy Management, Regulation and 

Enforcement (BOEMRE) a Revised Exploration Plan (EP) Revised Outer Continental Shelf Lease 

Exploration Plan, Camden Bay,Beaufort Sea, Alaska, (2011 Camden Bay EP) dated May 2011, 

deemed submitted July 5, 2011 (Shell, 2011a) to conduct exploration drilling to evaluate the oil and 

gas resource potential of three of the company’s Outer Continental Shelf (OCS) leases north of Point 

Thomson near Camden Bay in the U.S. Beaufort Sea. The purpose of the 2011 Camden Bay EP is for 

Shell to evaluate the mineral resource potential of three lease tracts within two distinct oil and gas 

prospects named by Shell as “Sivulliq” (NR 06-04 Flaxman Island, block 6658, OCS-Y-1805) and 

“Torpedo” (NR 06-04 Flaxman Island, block 6659, OCS-Y-1936 and NR 06-04 Flaxman Island, 

block 6610, OCS-Y-1941) (Figure 1). The need for this action is established by BOEMRE’s 

responsibility under the Outer Continental Shelf Lands Act (OCSLA) to make OCS lands 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. 

Figure 1 An overview of the locality of Shell's proposed Camden Bay exploration wells. 

Shell acquired the leases through OCS Lease Sales 195 (March 2005) and 202 (April 2007). Under 

OCS leasing regulations at 30 CFR 256 and operating regulations at 30 CFR 250.180, a lease expires 

at the end of its primary lease term unless the lessee is conducting operations on the lease. Shell’s 

leases have a primary lease term of ten years (30 CFR 256.37). Shell’s exploration of their Beaufort 

Sea leases would be consistent with the overall objectives of the Outer Continental Shelf Lands Act 

(OCSLA) to determine the extent of the oil and natural gas resources of the OCS at the earliest 

practicable time. 
Shell 2012 Camden Bay EP EA

2 Purpose and Need - Purpose of the Proposed Action 

The revised plan makes changes to Shell’s 2010 Outer Continental Shelf Lease Exploration Plan, 

Camden Bay, Alaska, dated June 2009; deemed submitted August 10, 2009; amended September 18, 

2009) (Shell, 2009). BOEMRE completed a technical and environmental review of the initial EP and 

supporting documents and published an Environmental Assessment (EA) (USDOI, MMS, 2009a) and 

a Finding of No Significant Impact (FONSI) (USDOI, MMS, 2009b) in October 2009. The EA and 

FONSI are incorporated by reference into this document. BOEMRE (then MMS) conditionally 

approved the EP on October 16, 2009. 

Shell submitted a revised Camden Bay EP in 2011 under BOEMRE operating regulations at 30 CFR 

250 Subpart B. Shell proposes to drill four exploration wells on three leases during successive JulyOctober open-water-drilling seasons, starting in 2012 and continuing in following open-water seasons 

until completion of the four-well plan. Two wells would be drilled on each prospect (Sivulliq and 

Torpedo) (Figure 2). The drilling operations would be conducted using the Mobile Offshore Drilling 

Unit (MODU) Kulluk (Kulluk), an Arctic Class IV hull design drilling vessel. Alternatively, drilling 

operations could be conducted using the M/V Discoverer (Discoverer) a modern drillship that has 

been retrofitted and ice reinforced for operations in Arctic waters. 

In support of the 2011 Camden Bay EP, Shell submitted an environmental impact analysis (2011 

Camden Bay EIA) (Shell, 2011b) which is appendix F of the 2011 Camden Bay EP, a Beaufort Sea 

Regional oil discharge prevention and contingency plan (ODPCP) for the drilling program (Shell, 

2011c), environmental information and reports, site-specific geohazards survey data and assessment, 

mitigation measures, and other project-specific information pursuant to 30 CFR 250.212 and 227. 

Shell also submitted, with the revised EP, a project-specific Plan of Cooperation (POC) addendum to 

reduce potential conflicts with subsistence activities, a description of their Cultural Awareness and 

Environmental Awareness Programs, and other information as required by BOEMRE regulations and 

lease stipulations. 

Table 1 Comparison of Shell’s 2010 Camden Bay EP and the 2012 Revised Camden Bay EP. 

Parameter Initial Camden Bay EP (2010) Revised Camden Bay EP (2012 planned start) 

Drilling seasons July 10 - October 31, 2010. 

July 10 - October 31 beginning in 2012 and continuing 

each subsequent open-water season until the 

completion of all four wells. 

OCS Lease Blocks Flaxman Island 6610 and 6658 Flaxman Island 6559, 6610, and 6658 

Wells Two - Sivulliq N and Torpedo H Four - Sivulliq G and N; Torpedo H and J 

Drilling unit Drillship Discoverer CDU Kulluk or Drillship Discoverer

Waste Discharge 

Spent water-based drilling fluids; 

drill cuttings with adhered drilling 

fluids; sanitary waste; domestic 

waste; hazardous waste; used oil; 

bilge water; and ballast water 

discharged to ocean floor. 

14,902 barrels of spent water-based drilling fluids; drill 

cuttings with adhered drilling fluids; sanitary waste; 

domestic waste; hazardous waste; used oil; bilge 

water; and ballast water collected, stored and then 

transported to an approved treatment / disposal site 

outside of the Alaskan Arctic. 

Primary Support Fleet 

Anchor handler, ice management 

vessel, offshore supply vessels 

(OSV), West Dock shuttle 

Similar fleet with the following variations: OSV to 

collect waste streams from the Kulluk Deck barge and 

tug and waste barge and tug to store the waste 

streams. Additional OSV for offshore supply 

Oil Spill Response Oil Spill Response (OSR) Tug and 

Barge; OSR Vessel, Arctic Tanker

OSR Tug and Barge; Arctic Tanker, OSR barge 

carrying containment system 

Air permit 

Discoverer – Prevention of 

Significant Deterioration (PSD) 

permit authorization 

R10OCS/PSD-AK-2010-01 

Discoverer – PSD permit authorization R10OCS/PSDAK-2010-01 Kulluk – Minor Source Permit application 

for Beaufort Sea submitted February 28, 2011 

The BOEMRE has completed a technical and environmental review of the revised EP and supporting 

information to ensure the proposed activities would be conducted in a manner that is consistent with 

protection of the human, marine, and coastal environments. 

In accordance with the National Environmental Policy Act (NEPA), Council on Environmental 

Quality (CEQ) regulations at 40 CFR 1501.3(b) and 1508.9, Department of the Interior (DOI) 

regulations implementing NEPA at 43 CFR Part 46, and DOI policy in Section 516 of the Department 

of the Interior Manual (DM) Chapter 15 (516 DM 15), BOEMRE prepared an EA to assist BOEMRE 
Shell 2012 Camden Bay EP EA

Purpose and Need - Previous Applicable NEPA Analyses 3

planning and decisionmaking. In keeping with CEQ regulations at 40 CFR 1506.5(a),(b) (see below) 

and the intent of BOEMRE operating regulations at 30 CFR 250.227, the information and analysis 

provided in Shell’s EIA was reviewed, evaluated, verified, and the results were used to prepare this 

EA. A list of BOEMRE staff responsible for reviewing, evaluating, and verifying the information 

submitted by Shell is in Section 6.5 of this EA. 

Sec. 1506.5 Agency responsibility. 

(a) Information. If an agency requires an applicant to submit environmental information for 

possible use by the agency in preparing an environmental impact statement, then the agency 

should assist the applicant by outlining the types of information required. The agency shall 

independently evaluate the information submitted and shall be responsible for its accuracy. If 

the agency chooses to use the information submitted by the applicant in the environmental 

impact statement, either directly or by reference, then the names of the persons responsible for 

the independent evaluation shall be included in the list of preparers (Sec. 1502.17). It is the 

intent of this paragraph that acceptable work not be redone, but that it be verified by the 

agency. 

(b) Environmental assessments. If an agency permits an applicant to prepare an 

environmental assessment, the agency, besides fulfilling the requirements of paragraph (a) of 

this section, shall make its own evaluation of the environmental issues and take responsibility 

for the scope and content of the environmental assessment. 

1.2. Previous Applicable NEPA Analyses, Biological Opinions and Related 

Analyses. 

The NEPA mandates that Federal agencies conduct an environmental review of certain Federal 

projects at each stage of the OCSLA process. The level of NEPA review depends on the OCSLA 

stage (516 DM 15), the scope of the proposed activities, and the agency’s findings on the potential 

effects of the proposed activities. 

The BOEMRE has completed numerous NEPA reviews of Beaufort Sea OCS activities. In recent 

years NEPA reviews that are relevant to the Proposed Action have included the following: 

 Draft Environmental Impact Statement – Beaufort and Chukchi Sea Planning Areas Oil 

and Gas Lease Sales 209, 212, 217, and 221 (OCS EIS/EA MMS 2008-0055) (USDOI, 

MMS, 2008a) (hereafter “Arctic Multiple-Sale Draft EIS”). 

 Environmental Assessment — Shell Offshore Inc., Beaufort Sea Exploration Plan, 2007-

2009 (OCS EIS/EA MMS 2007-009) (USDOI, MMS, 2007) (hereafter “2007 Beaufort Sea 

EP”). 

 Environmental Assessment — Proposed OCS Lease Sale 202, Beaufort Sea Planning Area 

and Finding of No Significant Impacts (OCS EIS/EA MMS 2006-001) (USDOI, MMS, 

2006a) (hereafter "Sale 202 EA"). 

 Environmental Assessment Proposed Oil and Gas Lease Sale 195, Beaufort Sea Planning 

Area and Finding of No Significant Impacts (OCS EIS/EA MMS 2004-028) (USDOI, 

MMS, 2004) (hereafter “Sale 195 EA”). 

 Final Environmental Impact Statement — Beaufort Sea Planning Area Oil and Gas Lease 

Sales 186, 195, and 202 (OCS EIS/EA MMS 2003-001) (USDOI, MMS, 2003) (hereafter 

“Beaufort Sea Multiple-Sale EIS”). 

 Final Environmental Impact Statement – Outer Continental Shelf Oil and Gas Leasing 

Program: 2002-2007 (OCS EIS/EA MMS 2002-006) (USDOI, MMS, 2002) (hereafter 

“2002-2007 Five Year Program EIS”) 

These documents are available on the BOEMRE Alaska website at: http://www.boemre.gov/alaska/ 

ref/EIS_EA.htm and http://www.boemre.gov/5-year/history2002-2007.htm. Relevant sections of the 

documents are summarized and incorporated by reference into this EA. This EA tiers from the 

Beaufort Sea Multiple-Sale EIS and the 2002-2007 Five Year Plan EIS. 
Shell 2012 Camden Bay EP EA

4 Purpose and Need - Statutory Framework 

This EA also summarizes and incorporates by reference relevant information and analyses from the 

following documents: 

 Environmental Assessment — Shell Offshore Inc., 2010 Outer Continental Shelf Lease 

Exploration Plan, Camden Bay, Alaska, (OCS EIS/EA MMS 2009-0052) (USDOI, MMS, 

2009a) (hereafter “2009 Camden Bay EA”). 

 Final Programmatic Environmental Assessment, Arctic Ocean Outer Continental Shelf, 

Seismic Surveys – 2006 (OCS EIS/EA MMS 2006-038) (USDOI, MMS, 2006b) June 

2006. (2006 Final Seismic PEA). 

 Environmental Assessment for the Shell Offshore, Inc. Incidental Harassment 

Authorization to Take Marine Mammals Incidental to Conducting an Offshore Drilling 

Project in the U.S. Beaufort Sea Under the Marine Mammal Protection Act (USDOC, 

NOAA, NMFS, 2007a). 

 Finding of No Significant Impact for the Shell Offshore, Inc. Incidental Harassment 

Authorization to Take Marine Mammals Incidental to Conducting an Offshore Drilling 

Project in the U.S. Beaufort Sea Under the Marine Mammal Protection Act (USDOC, 

NOAA, NMFS, 2007b). 

 NMFS Biological Opinion for Oil and Gas Leasing and Exploration Activities in the U.S. 

Beaufort and Chukchi Seas, Alaska and Authorization of Small Takes Under the Marine 

Mammal Protection Act (USDOC, NOAA, NMFS, 2008) 

 FWS Biological Opinion for Beaufort and Chukchi Sea Program Area Lease Sales and 

Associated Seismic Surveys and Exploratory Drilling (USDOI, FWS, 2009) 

1.3. Statutory Framework 

Shell’s proposed exploration drilling activities are subject to an established regulatory framework that 

includes Federal and State regulations as they relate to OCS leases and oil and gas exploration 

activities. Some, but not all, of the statutory framework governing the exploration program is 

described below. 

1.3.1. Outer Continental Shelf Lands Act and BOEMRE Operating Regulations 

The OCSLA establishes a four-stage process for exploration and development of the OCS: (1) a fiveyear leasing program for the OCS; (2) individual lease sales; (3) exploration; and (4) development 

and production. The BOEMRE conducts appropriate NEPA review at each stage. 

The BOEMRE is responsible for regulating and monitoring the oil and gas operations on the Federal 

OCS. The BOEMRE regulates operations to promote orderly exploration, development, and 

production 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 on-lease oil and 

gas operations are specified in 30 CFR 250. Regulations for oil-spill prevention and response are 

specified in 30 CFR 254. 

Prior to any exploration activities being conducted on a lease, an EP and supporting information must 

be submitted to BOEMRE for review and approval. Supporting information includes environmental 

information, a geohazard report, a biological report, other environmental data determined necessary, 

and an analysis of offshore and onshore impacts that may occur as a result of the activities. 

The BOEMRE has completed a technical and environmental review of the activities proposed in 

Shell’s EP, including an evaluation for geohazards and manmade hazards, archaeological resources 

(i.e., submerged vessels or geomorphological features that may have been occupied when sea levels 

were lower than at present), endangered species, sensitive biological features, water and air quality, 

oil-spill response, and other uses of the OCS. 
Shell 2012 Camden Bay EP EA

Purpose and Need - Endangered Species Act 5

The BOEMRE has reviewed the proposed activities for compliance with applicable lease stipulations. 

Lease stipulations are enforceable measures intended to mitigate potential impacts. Shell’s actions in 

compliance with the applicable lease stipulations are presented in Section 2.3.11 of this EA. 

The BOEMRE issues Notices to Lessees and Operators (NTLs) to provide clarification, description, 

or interpretation of OCS regulations or standards. The NTLs provide guidelines on the 

implementation of lease stipulations or regional requirements, and provide industry with a better 

understanding of the scope and meaning of regulations by explaining BOEMRE’s intent of 

requirements. A listing of applicable NTLs is published on the Alaska Region website at: 

http://www.BOEMRE.gov/alaska/regs/NTLs.htm. Additional regulatory requirements and guidelines 

provided in NTLs since previous environmental reviews are highlighted in section 5. 

Shell must conduct operations in accordance with BOEMRE’s comprehensive and stringent 

regulations for safety and pollution prevention, which generally are requirements to use the best 

available and safest technology [30 CFR 250.107(c)]. Lessees are required to take precautions to 

keep all exploratory well drilling under control at all times. 

Prior to conducting drilling operations under an approved EP, the operator is required to submit and 

obtain approval for an Application for Permit to Drill (APD). The APD requires detailed information 

about the drilling program to allow evaluation of operational safety and pollution-prevention 

measures. The BOEMRE will not approve an APD until all conditions of EP approval have been 

met. 

1.3.2. Endangered Species Act 

The Endangered Species Act (ESA) requires the protection and conservation of threatened and 

endangered species and the habitat in which they live. The Fish and Wildlife Service (FWS) and 

National Marine Fisheries Service (NMFS) administer the ESA. Section 7 of the ESA governs interagency cooperation and consultation for oil and gas activities, including exploration. Through this 

consultation process, the FWS and NMFS set terms and conditions and make conservation 

recommendations for OCS activities to minimize potential adverse impacts to listed species and 

critical habitats. It is the responsibility of BOEMRE to ensure that measures to protect endangered 

and threatened species are implemented and followed. 

Under the ESA, no incidental take of a protected species is authorized unless an Incidental Take 

Statement (ITS) is issued by the NMFS or FWS for the proposed activity. Any approval of Shell’s 

EP will be a conditional approval. Under the conditional approval, an APD will not be approved and 

commencement of activities will not be authorized until appropriate ITSs from both NMFS and FWS 

have been issued. 

1.3.3. Marine Mammal Protection Act 

The Marine Mammal Protection Act (MMPA) establishes Federal responsibility to conserve marine 

mammals. The NMFS has jurisdiction over all Arctic marine mammals except for the polar bear and 

Pacific walrus, which fall under FWS jurisdiction. 

The MMPA prohibits the “taking” of a marine mammal without a permit or exemption. Section 

101(a)(5)(D) of the MMPA establishes an expedited process by which citizens of the United States 

can apply for an authorization to incidentally take small numbers of marine mammals by harassment. 

The term "take" under the MMPA means "to harass, hunt, capture, or kill, or attempt to harass, hunt, 

capture, or kill any marine mammal. Except with respect to certain activities not pertinent here, the 

MMPA defines “harassment” as: any act of pursuit, torment, or annoyance which (i) has the potential 

to injure a marine mammal or marine mammal stock in the wild [Level A harassment]; or (ii) has the 

potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of 

behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or 

sheltering [Level B harassment]. Incidental take will be granted if the NMFS or USFWS finds that 

the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable 

adverse impact on the availability of the species or stock(s) for subsistence uses. The authorization 
Shell 2012 Camden Bay EP EA

6 Purpose and Need - Clean Air Act 

sets for the permissible methods of taking and requirements pertaining to the mitigation, monitoring, 

and reporting of such takings. If an activity may affect the availability of a marine mammal species or 

stock for taking for subsistence uses, the proposed monitoring plan must be independently peerreviewed prior to issuance of the MMPA authorization (16 U.S.C. 1371(a)(5)(D) and 50 CFR 

216.108(d)). The MMPA authorizations require that operators conduct monitoring, which should be 

designed to result in an increased knowledge of the species and an understanding of the level and type 

of takings that result from the authorized activities. 

Shell has applied for an Incidental Harassment Authorization (IHA) from NMFS (dated May 2011; 

Shell, 2011a: Appendix C) and a Letter of Authorization (LOA) from FWS (dated May 2011; Shell, 

2011a: Appendix E) as part of their exploration program. Any approval of Shell’s EP by BOEMRE 

will be a conditional approval. Under the conditional approval, an APD will not be approved and 

commencement of activities will not be authorized until Shell’s receipt of all necessary permits and 

authorizations including an IHA from NMFS and an LOA from FWS. 

Shell has developed a site-specific monitoring program and adopted mitigation measures specifically 

designed to prevent or minimize any incidental harm to marine mammals. Those measures are 

summarized in Section 2.3.12 of this EA. 

1.3.4. Coastal Zone Management Act 

The Coastal Zone Management Act (CZMA) mandates that a State with an approved Coastal Zone 

Management (CZM) plan reviews certain OCS activities to ensure that they are conducted 

consistently with the State’s approved plan. State participation is on a voluntary basis and the State 

of Alaska's program ended at midnight, June 30, 2011, after the state legislature did not reauthorize 

statutory support for the program. Prior to June 30, 2011, the Alaska Coastal Management Program 

(ACMP) implemented the CZMA and required projects in Alaska’s coastal zone, including potential 

shore bases and projects that require an OCS Plan, to be reviewed for consistency with statewide 

standards. 

All of the work that was required to comply with the CZMA was completed for this EA. However, 

due to the fact that Alaska's ACMP program terminated on June 30, 2011, the ACMP Coastal Project 

Questionnaire and Certification Statements are no longer required for consistency review. 

Although a copy of Shell’s Coastal Project Questionnaire and Certification Statement was included as 

Section 15 of the 2011 Camden Bay EP, further work on this is no longer required. Prior to June 30, 

2011, as part of BOEMRE’s review process, the EP and supporting environmental information were 

sent to the ACMP for consistency-certification review and response. Shell is no longer required to 

obtain a receipt of consistency concurrence from the State of Alaska. 

1.3.5. Clean Air Act 

The Clean Air Act (CAA) (43 U.S.C. § 7401, et seq.) governs the control of air pollutant emissions 

from both stationary and mobile sources. As such, the Environmental Protection Agency (EPA) is 

authorized to establish National Ambient Air Quality Standards (NAAQS) to limit the concentration 

of harmful air emissions that, when occurring in sufficient concentrations, can harm human life and 

wildlife. The CAA has been amended several times since the first version in 1963. The amendments 

relevant to air operating permits required for the implementation of the 2011 Camden Bay EP 

occurred in 1977 and 1990 (Martineau and Novello, 2004). Jurisdiction for approving air operating 

permits depends on the type of permit and the location of the proposed federal action. State permits, 

such as minor-source permits, on the Alaska OCS fall under the jurisdiction of the Alaska Department 

of Environmental Conservation (ADEC); whereas permits for larger sources of emissions are under 

EPA Region 10 jurisdiction for the Alaska OCS. 

The 1977 Clean Air Act Amendments established the New Source Review (NSR) program under 

Title I of the Act. The NSR is a pre-construction permitting program to ensure that air quality is not 

significantly degraded by new and modified stationary sources of emissions. The program further 

assures the public that the stationary source will be as clean as possible, employing the latest 
Shell 2012 Camden Bay EP EA

Purpose and Need - Clean Air Act 7

advancements in pollution control, referred to as Best Available Control Technology (BACT). Under 

the federal NSR program there are two types of permits, (1) the Prevention of Significant 

Deterioration (PSD) permit, required for major new or modified stationary sources of emissions in an 

otherwise clean-air area not in violation of the NAAQS (attainment area) (40 CFR 52.21); and (2) the 

NSR permit required for major stationary sources in an area already in violation of the NAAQS 

(nonattainment area). While these are federal rules, they can be adopted into the state administrative 

code and, in either case, construction cannot begin until the permit is approved and issued. 

Under the 1990 Amendments, the CAA Title V operating permit program was established. This state 

air operating permit is issued for the purpose of enforcing minimum state standards and is issued after 

the major stationary source has begun to operate (post-construction). A state may also require a 

minor source permit. While most Title V permits are issued by state and local permitting authorities, 

the EPA also issues Title V permits for special circumstances, such as in Indian country and on the 

OCS, therefore Alaska Title V permits fall under the jurisdiction of EPA Region 10. In any of these 

cases, the permit constitutes an enforceable agreement between the EPA or state and the project 

sponsor. 

On the Alaskan Outer Continental Shelf (OCS), air permits may be issued as nonattainment NSR 

permits, PSD attainment area pre-construction permits, Title V post-construction operating permits, 

minor source pre-construction State permits, or a combination of these (CAA Section 328(a)(1)). 

Regardless of the type of federal permit, actions on the OCS are regulated under 40 CFR Part 55.13. 

This regulation directs the project sponsor to comply with 40 CFR 52.21, the PSD permit regulation, 

and 40 CFR Part 71, the Title V regulation. The PSD permit must be obtained before construction 

begins (pre-construction permit) and the Title V operating permit is applied for following 

implementation of the Proposed Action, and thereafter on a regular recurring basis. Shell has applied 

for federal and/or state permits for both the drillship Kulluk and the drillship Discoverer for 

operations on the Beaufort and Chukchi seas. The status of the permits for each drillship is provided 

in Section 2.3.1, in the discussion of Alternative 2 - The Proposed Action. Any approval of the 2011 

Camden Bay EP by the Bureau of Ocean Energy Management, Regulation and Enforcement 

(BOEMRE) will be conditional until all required air operating permits are issued. Under the 

conditional approval, the Application for Permit to Drill (APD) cannot be approved by BOEMRE, 

and commencement of activities will not be authorized, until receipt of all necessary permits and 

authorizations. 

1.3.6. Clean Water Act 

The Clean Water Act (CWA) has several sections or programs applicable to activities in offshore 

waters, including U.S. Coast Guard (USCG) implementing regulations (33 CFR Part 151). 

The EPA has promulgated regulations (40 CFR 125) to ensure OCS lessees do not create conditions 

that will pose an unreasonable risk to public health, life, property, aquatic life, wildlife, recreation, 

navigation, commercial fishing, or other uses of the ocean. Operational discharges are regulated by 

the EPA through the National Pollution Discharge Elimination System (NPDES) program. The 

EPA’s NPDES Arctic General Permit for Offshore Oil and Gas Operations on the OCS and 

contiguous State Waters (Permit Number AKG280000) authorizes certain discharges from oil and gas 

exploration facilities located in or adjacent to the Beaufort Sea and establishes effluent limitations, 

monitoring requirements, and other conditions. Permitted discharges related to exploration drilling 

and logistics include drilling fluids and cuttings, deck drainage, sanitary waste, blowout-preventer 

fluid, uncontaminated ballast water, and bilge water (EPA, 2006). The current Arctic general permit, 

which restricts the seasons of operation, discharge depths, and areas of operation, and has monitoring 

requirements and other conditions, expired on June 26, 2011. The EPA will reissue separate NPDES 

exploration General Permits for the Beaufort Sea and the Chukchi Sea prior to the 2012 drilling 

season. EPA expects that tribal consultation and public comment on the new proposed Arctic oil and 

gas exploration permits would occur during the fall of 2011. 
Shell 2012 Camden Bay EP EA

8 Purpose and Need - The Oil Pollution Act 

Shell has submitted NOIs to EPA requesting authorization for the Discoverer to discharge wastes 

regulated under the NPDES General Permit at the Torpedo (lease blocks 6559 and 6610) and Sivulliq 

(lease block 6658) drill sites (NOIs dated December 16, 2010, Shell, 2011a: Appendix B). Any 

approval of Shell’s EP will be a conditional approval. Under the conditional approval, an APD will 

not be approved and commencement of activities will not be authorized until Shell’s receipt of all 

necessary permits and authorizations including Shell’s receipt of the required NPDES permits. 

1.3.7. The Oil Pollution Act 

The Oil Pollution Act of 1990 (OPA) establishes a program governing removal of spilled oil and 

requiring planning for and responding to oil spills. Under OPA and BOEMRE regulations at 

30 CFR 254, Shell is required to develop an Oil Discharge Prevention and Contingency Plan 

(ODPCP) as a fundamental component of the proposed exploration drilling program. 

Shell’s Beaufort Sea Regional Exploration ODPCP (Shell, 2011c) is a regional oil-spill-response plan 

that demonstrates Shell’s capabilities to prevent, or rapidly and effectively manage, oil spills that may 

result from exploratory drilling operations. Despite the extremely low likelihood of a large oil-spill 

occurring during exploration, Shell has designed its response program for a regional capability of 

responding to a range of spill volumes that increase from small operational spills up to and including 

a Worst Case Discharge (WCD) scenario from an exploration well blowout, as required under 

30 CFR 254.47. Shell’s program is based on a WCD scenario that meets the response planning 

requirements of the State of Alaska and Federal oil-spill-planning regulations. 

The ODPCP includes information regarding Shell’s regional oil-spill organization and dedicated 

response assets, potential spill volumes, and sensitive environmental resources. The ODPCP also 

details Shell’s spill-prevention programs, including personnel training and the procedures and 

management practices to prevent discharges. The spill response information addresses personnel and 

equipment mobilization from various locations, equipment operating characteristics, and the 

availability of additional response resources, both onsite and offsite. 

Shell has updated and revised the Regional ODPCP to include information specific to the well sites, 

including worst-case discharge oil spill estimates and the worst-case discharge oil spill scenario. The 

revised ODPCP is currently being reviewed given this new information and appropriate actions will 

be taken pending the evalutation of this new information and how it impacts Shell's capability to 

respond to an oil spill event. 

1.3.8. National Historic Preservation Act 

The Archaeological Resource requirements are contained in BOEMRE operational regulations at 

30 CFR 250.194. The technical requirements for the archaeological resource surveys and reports that 

may be required under the regulations are detailed in the Alaska OCS Region NTL 05-A02 and 

NTL 05-A03. These NTLS are available at: http://alaska.boemre.gov/regs/NTLS.HTM. 

Information to Lessees (p) Archaeological and Geologic Hazards Reports and Surveys in the Final 

Notice of Sale for both Beaufort Sea Sale 195 and Beaufort Sea Sale 202 specified the blocks for 

which an archaeological report would be required. Section III.C.4.a of the Beaufort Sea MultipleSale EIS identified blocks having high potential for the occurrence of archaeological resources. 

Shell’s proposed drill sites are not on blocks listed in the ITL. 

Under Section 106 of the National Historic Preservation Act, BOEMRE consults with the Alaska 

State Historic Preservation Office (SHPO) for OCS activities during the pre-lease process. Section 

106 consultation for the Beaufort Sea Planning Area was completed in conjunction with completing 

the Beaufort Sea Multiple-Sale EIS and again recently in conjunction with the Arctic Multiple-Sale 

Draft EIS (SHPO concurrence dated September 24, 2008). 

The BOEMRE’s review of the site-specific geophysical data indicates that there are no historic 

properties at Shell’s proposed drill sites. On June 29, 2011, BOEMRE concluded Section 106 

consultation with the Alaska State Historic Preservation Officer (SHPO). BOEMRE informed the 

SHPO of the determination that drilling of the four wells and related activities will have no effect on 
Shell 2012 Camden Bay EP EA

Purpose and Need - National Invasive Species Act 9

historic properties. The SHPO concurred with BOEMRE's determination of no historic properties 

affected on July 6, 2011. 

1.3.9. National Invasive Species Act 

The Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (NANPCA) (16 U.S.C. 

4701-4751) as amended by the National Invasive Species Act of 1996 (NISA) regulates activities 

with a potential for introducing invasive species into the marine environment. 

Potential vectors for introducing invasive species into the marine environment are ballast-water 

discharge, hull fouling, and equipment placed overboard (e.g., anchors, seismic airguns, hydrophone 

arrays, and ocean-bottom-survey cables). The USCG developed regulations (33 CFR 151) that 

implement provisions of the NANPCA and NISA. Vessels brought into State of Alaska or Federal 

waters would be subject to current Coast Guard regulations at 33 CFR 151, which are intended to 

reduce the transfer of invasive species. Section 151.2035 (a)(6) requires the “removal of fouling 

organisms from hull, piping, and tanks on a regular basis and dispose of any removed substances in 

accordance with local, State, and Federal regulations.” All vessels equipped with ballast water tanks 

must develop and maintain Ballast Water Management Plans. Ballast replacement is required by the 

International Maritime Organization and it must be accomplished before entering U.S. waters and 

reporting to the Captain of the Port, or going from one Captain of the Port zone to another. 
Shell 2012 Camden Bay EP EA

10 Purpose and Need - National Invasive Species Act 

Page Intentionally Left Blank 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Summary of Alternatives 11

2.0 PROPOSED ACTION AND ALTERNATIVES 

2.1. Background 

Shell proposes to drill four exploration wells, two on the Sivulliq prospect and two on the Torpedo 

prospect, near Camden Bay in the Beaufort Sea OCS Planning Area (Figure 2). Eight OCS 

exploration wells were drilled in the vicinity of Shell's proposed exploration wells between 1985 and 

1997. Two of these wells, drilled in 1985 and 1986, were on the Sivulliq Prospect (previously named 

the Hammerhead Prospect). One of the Hammerhead wells was determined to be producible under 

BOEMRE regulations (30 CFR 250.115). The BOEMRE estimated the reservoir contains 100-200 

million barrels of oil (USDOI, MMS, 2006a). 

Figure 2 The Torpedo and Sivulliq Proposed Exploration Drill Sites 

2.2. Summary of Alternatives 

2.2.1. Alternative 1 – No Action 

Under Alternative 1 – No Action, BOEMRE would disapprove Shell’s proposed exploration drilling 

activities. This alternative would delay or preclude Shell from evaluating the potential hydrocarbon 

resources of three lease blocks acquired under OCS Lease Sales 195 and 202, as would any potential 

environmental impacts associated with Alternative 2. 

2.2.2. Alternative 2 – The Proposed Action 

Under Alternative 2 - The Proposed Action, Shell would drill four exploration wells on three oil and 

gas leases (OCS Y-1805, 1941 and 1936) acquired in Federal Beaufort Sea OCS lease sales 195 and 

202 held in 2005 and 2007, respectively. Two wells each would be drilled into two distinct oil and 

gas prospects named by Shell as “Sivulliq” and “Torpedo.” Shell proposes to drill the four wells 

during the open-water season (July through October) starting in 2012 and continuing until the fourwell program is completed. Shell’s proposed activities include a mid-drilling-season suspension of 

activities beginning August 25 to avoid conflicts with the fall subsistence bowhead whale hunts of the 

villages of Kaktovik and Nuiqsut and a reduction in the exploration drilling waste stream discharged 
Shell 2012 Camden Bay EP EA

12 Proposed Action and Alternatives - Alternative 2 – The Proposed Action 

into the Beaufort Sea and transportation of some waste to an approved treatment/disposal facility 

outside of the Arctic. 

Shell would conduct drilling operations from the Kulluk with the option of using the Discoverer in 

lieu of the Kulluk. The Kulluk or Discoverer would be supported by additional vessels for ice 

management, anchor handling, crew transport and supplies, waste storage and transport and spill 

response. Additional vessels and fixed-wing aircraft would support Shell’s Marine Mammal 

Monitoring and Mitigation Plan (4MP) and scientific research efforts. All of the vessels to be used in 

the Proposed Action are ice-class and specifically equipped for operating in Arctic waters. 

2.2.3. Other Alternatives Considered But Not Analyzed 

Other alternatives considered but not analyzed include: 

 Temporally restricting the activities to one drilling season. 

 The use of alternative technologies to explore the mineral potential of the three lease tracts 

[or the Sivulliq and Torpedo oil and gas prospects]. 

Conducting the exploration plan in one drilling season to limit the impacts to only one season was not 

analyzed further due to the inability of Shell to test all three lease tracts (four wells) in only one openwater season. The BOEMRE’s evaluation does not show that a multi-year program will have additive 

effects on the affected resources and thus a full analysis of this proposed alternative is not necessary. 

The BOEMRE is unaware of any alternative techniques that will serve the purpose of the Proposed 

Action. Shell’s Proposed Action uses the safest technique known for determining whether a site is 

capable of producing hydrocarbons in sufficient quantities to justify commercial development. 

2.3. Description of Alternative 2 – The Proposed Action 

2.3.1. Overview 

Shell’s proposal, as detailed in the EP (Shell, 2011a), is to use a single MODU, the Kulluk

(alternatively, the Discoverer), to complete a four-well exploration drilling program at locations near 

Camden Bay in the Beaufort Sea. Two wells would be drilled on each of two distinct oil and gas 

prospects named by Shell as “Sivulliq” (site G and N) and “Torpedo” (site H and J) (Figure 2). 

Shell’s proposed activities would be conducted during the summer open-water season as Arctic 

waters are inaccessible to floating drilling units for up to eight months of the year because of pack ice. 

Location information for each drill site is presented in Table 2. Each drill site has been surveyed by 

Shell, and verified by BOEMRE, and determined not to contain any shallow hazards or 

archaeological and historical resources. 

Table 2 Proposed Exploration Drill Sites. 

Surface Location (NAD 83) 

Drill Site Lease File 

Number 

NR06-04 

Lease 

Block 

Number Latitude (N) Longitude (W) 

PTVD1

(ft) 

Water Depth 

(ft) 

Sivulliq G OCS-Y 1805 6658 70° 23’ 46.82” 146° 01’ 03.46” 7,000 110 

Sivulliq N OCS-Y-1805 6658 70° 23’ 29.58” 145° 58’ 52.53” 7,000 107 

Torpedo H OCS-Y-1941 6610 70° 27’ 01.62” 145° 49’ 32.07” 10,000 120 

Torpedo J OCS-Y-1936 6559 70° 28’ 56.94” 145° 53’ 47.15” 9,800 124 

Source: Shell, 2011a, Table 1.a-1 1

PTVD = proposed total vertical depth 

The activities are planned to begin on or about July 10th each year until the four-well program is 

complete. Shell’s plans include a mid-drilling-season suspension of activities to accommodate fall 

subsistence bowhead whaling. All operations would be suspended prior to the beginning of the fall 

whale hunts on August 25 and all vessels, including the drillship, would proceed from the project area 

to an area north of 71.25oN latitude and west of 146.4o W longitude, which was mutually-agreed upon 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Alternative 2 – The Proposed Action 13

between Shell and the Alaska Eskimo Whaling Commission (AEWC). All vessels will remain in this 

area until the Kaktovik and Nuiqsut (Cross Island) whale hunts have concluded. Activiites may be 

resumed after completion of subsistence hunts (as determined by consultation with the village's 

Whaling Captains' Association) and extend through October 31, depending on ice and weather. 

Once the drilling vessel is mobilized to a drill site and securely anchored to the seafloor, drilling 

operations would commence. Each Sivulliq well would take approximately 34 days to drill. Each 

Torpedo well would take approximately 44 days to drill. Each well would be plugged and abandoned 

in accordance with BOEMRE requirements upon completion of drilling (30 CFR 250(q)). Based on 

these operational limitations, the maximum wells drilled in one season is limited to two wells. If a 

well cannot be completed during the open-water season it will be capped and completed during the 

following open-water season. 

Shell’s proposed operations must comply with applicable Federal, State, and local laws, regulations, 

and lease and permit requirements. The BOEMRE retains the specific authority to require additional 

mitigation, including shut down, as appropriate to respond to actual conditions encountered. In 

addition, Shell would have trained personnel and monitoring programs in place to ensure such 

compliance. The BOEMRE and other Federal regulatory agencies would maintain continuing 

oversight of all of Shell’s exploration activities. The following are the major applicable permits and 

authorizations that collectively impose mandatory requirements to ensure safety, protect the 

environment, avoid interference with subsistence resources and activities, and mitigate potential 

adverse impacts: 

 National Pollutant Discharge Elimination System Permit (NPDES) under the Clean Water 

Act from the EPA. The EPA NPDES Arctic General Permit for Offshore Oil and Gas 

Operations on the OCS and contiguous State Waters Permit Number AKG280000 impose 

limitations on permissible discharges. Shell has submitted Notices of Intent (NOIs) to EPA 

requesting authorization for the Kulluk and Discoverer to discharge wastes regulated under 

the NPDES General Permit at the Torpedo (lease block 6610 and 6659) and Sivulliq (lease 

block 6658) prospects (NOIs dated October 10, 2010 and December 16, 2010; Shell, 

2011a: Appendix B). 

 Air Quality Permits under the Clean Air Act (CAA), issued by EPA Region 10. The EPA 

has the jurisdiction to approve and issue air quality permits for new oil and gas exploration 

operations on the Alaska OCS. These permits include the Prevention of Significant 

Deterioration (PSD) permit and the CAA Title V permit under 40 CFR Part 71. The PSD 

permit is a pre-construction permit intended to limit and regulate air emissions in an area 

of otherwise clean air. The CAA Title V permit is an operating permit required to assist 

states in controlling sources of air pollution on an ongoing basis regardless of the current 

status of air quality conditions. While State of Alaska permits are required for the 2012 

Camden Bay EP, EPA Region 10 has the jurisdiction to approve and issue the permits, 

which involve operations in federal waters. These state and federal permits for each of the 

drillships, the Kulluk and the Discoverer, must be issued before approval of the 2012 

Camden Bay EP is final. Shell has applied for multiple state and federal air operating 

permits for the drillship, Kulluk, in the application submitted on March 29, 2011. Shell has 

requested that review of the permits be consolidated so that only one permit is issued. The 

permit is currently under review by the EPA. Shell submitted revised information to EPA 

with regard to the PSD permits that were remanded in December 2010 for operations by 

the Discoverer in both the Beaufort and Chukchi seas. The permit relevant to operations in 

the Beaufort Sea is EPA Permit R10OCS/PSD-AK-10-01. The EPA Region 10 revised the 

permits, which were released for public comment on July 6, 2011. The comment period 

will end on August 5, 2011, and a public hearing is scheduled for August 4, 2011, in 

Barrow, Alaska. Should the permits be approved by EPA, issuance of the permits is 

required before the Proposed Action may begin. A more thorough discussion of the 
Shell 2012 Camden Bay EP EA

14 Proposed Action and Alternatives - Drill Sites and Operating Environment 

permits, and access to the documentation, is provided in Appendix D, Air Quality, Section 

D-1.8, Air Operating Permits. 

 Incidental Harassment Authorization (IHA) from NMFS regulating the incidental nonlethal harassment of protected species under the Marine Mammal Protection Act (MMPA) 

and ensuring no unmitigable adverse impact on the availability of marine mammal species 

or stocks for taking for subsistence uses. Shell has applied for an IHA from NMFS (dated 

May 2011; Shell, 2011a: Appendix C). 

 Letter of Authorization (LOA) from FWS regulating the incidental non-lethal harassment 

of protected species under MMPA. Shell has applied for an LOA from FWS (dated May 

2011; Shell, 2011a: Appendix C. 

 Nationwide Permit No. 8 coverage from the U.S. Army Corps of Engineers (USACE) for 

compliance with the provisions of fairway regulations (33 CFR 322.5(l)) and effects on 

navigation and national security (33 CFR 322.5(f)) under the Rivers and Harbors Act. 

Although a copy of Shell’s Coastal Project Questionnaire and Certification Statement was included as 

Section 15 of the 2011 Camden Bay EP, Shell is no longer required to obtain a receipt of consistency 

concurrence from the State of Alaska because its coastal consistency program ended on June 30th, 

2011. 

Shell’s proposed compliance with applicable OCS lease stipulations is documented in the EP and 

includes the following supporting information submitted with the EP: 

 Shell's Environmental Orientation Program (Shell, 2011a: Section 11.0) which informs 

Shell personnel and contractors regarding applicable laws and compliance obligations 

(Lease Stipulation 2, Sales 192 and 202). 

 Marine Mammal Monitoring and Mitigation Plan (4MP) (Shell, 2011a: Appendix D) to 

avoid impacts to marine mammals and collect scientific data on marine mammal species 

(Lease Stipulation 4, Sales 195 and 202); 

 Plan of Cooperation (POC) Addendum (Shell, 2011a: Appendix H) to coordinate 

exploration activities with Alaskan Native subsistence activities to avoid unreasonable 

interference with subsistence resources and activities (Lease Stipulation 5, Sales 195 and 

202); 

 Shell’s Alaska Fuel Transfer Operating Conditions and Procedures (Shell, 2011a: Section 

9.0, Appendix M) (Lease Stipulation 6, Sales 195 and 202) ; and 

 Bird Strike Avoidance and Lighting Plan, Beaufort Sea, Alaska (Shell, 2011a: Appendix I) 

(Lease Stipulation 7, Sales 195 and 202). 

Under this EP, Shell would employ personnel and contractors experienced in operating in the Arctic 

OCS and would train employees in Federal and State laws regulating field operations. Shell has 

committed in its EP to local hire, local contracting, and local purchasing to the maximum extent 

possible (Shell, 2011b: p. xviii). 

2.3.2. Drill Sites and Operating Environment 

Shell proposes exploration drilling on lease OCS-Y-1805 at planned drill sites Sivulliq G and Sivulliq 

N, on lease OCS-Y-1941 at planned drill site Torpedo H, and on lease OCS-Y-1936 at planned drill 

site Torpedo J (Figures 1-1 and 1-2). The Sivulliq drill sites and the Torpedo drill sites are located on 

the continental shelf north of the Camden Bay area of the Beaufort Sea. Sediment at both locations is 

composed predominately of silty sands and mud. The water depth is approximately 110 ft (33 m) at 

the Sivulliq sites and 120 ft (37 m) at the Torpedo sites. The seafloor at all these locations has been 

extensively ice gouged. 

The Sivulliq G (Flaxman Island NR06-04 Official Protraction Diagram block 6658, Lease OCS-Y1805) drill site is located at latitude 70 ̊23’46.82” N., longitude 146 ̊01’03.46.5284” W in 110 feet of 

water. 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Seafloor Conditions at the Drill Sites 15

 16 miles (26 km) from Point Thompson  58 mi (93 km) from Deadhorse 

 45 mi (72 km) from Cross Island  60 mi (97 km) from Kaktovik 

 60 mi (97 km) from West Dock  119 mi (192 km) from Nuiqsut 

The Sivulliq N (Flaxman Island NR06-04 Official Protraction Diagram block 6658, Lease OCS-Y1805) drill site is located at latitude 70 ̊23’29.58” N., longitude 145 ̊58’52.53” W in 107 feet of water. 

 16 miles (26 km) from Point Thompson  58 mi (93 km) from Deadhorse 

 47 mi (75 km) from Cross Island  60 mi (97 km) from Kaktovik 

 60 mi (97 km) from West Dock  118 mi (190 km) from Nuiqsut 

The Torpedo H (Flaxman Island NR06-04 Official Protraction Diagram block 6610, Lease OCS-Y1941) drill site is located at latitude 70 ̊27’01.62” N., longitude 145 ̊49’32.07” W in 120 feet of water. 

 22 mi (35 km) From Point Thompson  64 mi (103 km) from Deadhorse 

 50 mi (81 km) from Cross Island  55 mi (89 km) from Kaktovik 

 64 mi (103 km) from West Dock  125 mi (201 km) from Nuiqsut 

The Torpedo J (Flaxman Island NR06-04 Official Protraction Diagram block 6659, Lease OCS-Y1936) drill site is located at latitude 70 ̊28’56.94” N., longitude 145 ̊53’47.15” W in 120 feet of water. 

 23 mi (37 km) from Point Thompson  63 mi (101 km) from Deadhorse 

 48 mi (77 km) from Cross Island  60 mi (97 km) from Kaktovik 

 62 mi (100 km) from West Dock  122 mi (196 km) from Nuiqsut 

The two communities in closest proximity to the planned exploration activities are: Kaktovik (aka 

Barter Island) to the east and Nuiqsut to the west. Deadhorse, the logistics and support base for North 

Slope oil and gas operations, is located between the drill site locations and Nuiqsut to the west. The 

existing shore facilities at West Dock and facilities at Deadhorse would support the exploration 

activities. 

2.3.3. Seafloor Conditions at the Drill Sites 

The BOEMRE regulations (30 CFR 250.214) require shallow hazards assessment be conducted prior 

to drilling or installing mobile drilling units for oil and gas activities. Geophysical surveys conducted 

over the sites are analyzed to identify shallow hazards and conditions that would pose engineering 

constraints. A hazard is defined as a feature or condition that presents difficulties that cannot be easily 

mitigated by design, implementation, or procedures. A constraint is defined as a feature or condition 

that presents difficulties but can be mitigated by design, implementation, or procedures. Shell also 

collected shallow cores for geochemical and geotechnical studies. A summary of the shallow-hazards 

assessment is presented in the 2011 Camden Bay EIA, Sections 1 and 3 (Shell, 2011b). A short 

chronology and summary of pertinent shallow-hazards surveys and assessments are presented here. 

In 1985-1986, Union Oil Company conducted shallow-hazards surveys at Sivulliq (then called 

Hammerhead) in the proximity of the 2012 Sivulliq and Torpedo drill sites. In 2006, Shell collected 

shallow-hazards data at the Sivulliq N drill site. 

In 2007, Shell contracted Geo LLC to conduct shallow-hazards across the Torpedo prospect. The 

following parameters were assessed and analyzed for both shallow hazards and engineering 

constraints. 

 Bathymetry  Faulting 

 Ice gouging  Seismicity 

 Buried channels  Shallow gas 

 Seafloor obstructions  Gas hydrates 

 Surficial sediments  Water column anomalies 

 Permafrost  Archaeological features 
Shell 2012 Camden Bay EP EA

16 Proposed Action and Alternatives - Seafloor Conditions at the Drill Sites 

In 2008, the historic hazard survey data was augmented with bathymetric data and data collected by 

remotely operated vehicle during the shallow-hazards surveys conducted by Geo LLC. These data 

were collected in accordance with Notice to Lessees (NTL 2005-A02). 

Copies of the shallow-hazards reports for portions of the Sivulliq and Torpedo prospects were 

submitted to BOEMRE under separate cover in June 2007, March 2008, and March 2009. These 

reports are titled: 

 Exploration Wellsites Clearance Assessments, Sivulliq Prospect, Beaufort Sea, Alaska, 

prepared by Geo LLC 

 2007 Exploration Wellsites Geohazards Assessments, Sivulliq Prospect, Beaufort Sea 

Alaska, Addendum 1, prepared by Geo LLC 

 Exploration Wellsites Geohazards Assessments, Torpedo Prospect, Beaufort Sea, Alaska, 

prepared by Geo LLC 

 Shallow Hazards Assessment, Sivulliq G, V, W and Supplemental N Wellsites, Blocks 

6658, 6659, 6708, and 6709, Flaxman Island Area, Beaufort Sea Alaska, Report No. 

27.2008-2266, prepared by Fugro Geoconsulting, Inc. 

 Shallow Hazards Assessment, Torpedo, A, B, G, and H Wellsites, Blocks 6609 and 6610, 

Flaxman Island Area, Beaufort Sea, Alaska, Report No. 27.2008-2267, prepared by Fugro 

Geoconsulting, Inc. 

 Drill Site Clearance Letter, Proposed Torpedo J Drill Site, Block 6559, Flaxman Island, 

Beaufort Sea, Alaska. Report No. 27.2010-2375-10, prepared by Frugo Geoconsulting, 

Inc. 

The analyses found no evidence of shallow hazards, human-made obstructions (historic or 

prehistoric) at the Torpedo J drillsite (USDOI, MMS, 2009; Shell, 2011b: pp. 1-9 to 1-10) 

Sivulliq Prospect. Based on the shallow hazards survey data, the planned Sivulliq drill sites are 

determined to be free of historic properties (vessels such as shipwrecks or downed aircraft) and 

geologic risks. Recent shallow hazards survey results for the Sivulliq drill sites did not identify any 

shallow hazards or constraints other than ice gouging. The installation of a mudline cellar (MLC) at 

the Sivulliq drill sites would mitigate this constraint. The MLC would be sufficiently deep 

(approximately 37 ft [11.2 m]) to ensure that, if the drill site were to be temporarily abandoned during 

an emergency, wellhead equipment would be below the maximum ice-scour depth of 8.2 ft (2.5 m) 

(Shell 2011b: p. 3-27). The wellhead equipment would thereby be protected from the maximum 

anticipated ice-keel scour. 

The BOEMRE concurs with Shells assessment that no shallow hazards exist at the proposed Sivulliq 

drill sites. The BOEMRE has determined, based on agency verification of Shell's analysis, that there 

are no indications of historic sites or prehistoric archaeological resources at the proposed Sivulliq drill 

sites. The BOEMRE also reviewed the seafloor survey for potential seafloor habitat and benthic 

communities. No unique seafloor habitat (that would distinguish the site from the surrounding area) 

or benthic communities were identified at the proposed Sivulliq drill sites (Shell, 2011a, Section 11). 

Torpedo Prospect. Drill sites Torpedo H and J were studied during shallow-hazards surveys 

conducted in 2007-2008 by Geo LLC. The shallow hazards surveys identified no historic properties 

(vessels such as shipwrecks or downed aircraft) or geologic risks. Recent shallow hazards survey 

results for the Torpedo H and J sites did not identify any shallow hazards or constraints other than ice 

gouging. The installation of MLCs at the Torpedo drill sites would mitigate this constraint. The MLC 

would be sufficiently deep (approximately 37 ft [11.2 m]) to ensure that, if the drill site were to be 

temporarily abandoned during an emergency, wellhead equipment would be below the maximum icescour depth of 4.1 ft (1.3 m) (Shell 2011b: p. 3-27). The wellhead equipment would thereby be 

protected from the maximum anticipated ice-keel scour. 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Drillship, Support Vessels, and Aircraft 17

The BOEMRE has reviewed the data and reports and concurs with Shell’s assessment that no shallow 

hazards occur at the proposed Torpedo drill sites. The BOEMRE has determined, based on Shell's 

analysis, that there are no indications of historic sites or prehistoric archaeological resources at the 

proposed Torpedo drill sites. 

The BOEMRE also reviewed the seafloor survey data for potential seafloor habitat and benthic 

communities. No unique seafloor habitat or communities were identified at the proposed Torpedo 

drill sites (Shell, 2011a, Section 11). 

2.3.4. Drillship, Support Vessels, and Aircraft 

Shell would conduct drilling operations using the Kulluk or, alternatively, the Discoverer using the 

latest drilling technologies and techniques. 

The Kulluk has an Arctic Class IV hull design that is conically shaped and is towed to the location. 

The Kulluk is capable of drilling in water depths up to 600 ft (182.9 m) and is moored using a 12-

point anchoring system. The Kulluk is designed to maintain its location in drilling mode in moving 

ice with thickness up to 4 ft (1.2 m) without the aid of active ice management. With the aid of the ice 

management vessels, the Kulluk would be able to withstand more severe ice conditions. In more 

open-water conditions, the Kulluk can maintain its drilling location during storm events with wave 

heights up to 18 ft (5.5 m) while drilling, and can withstand wave heights of up to 40 ft (12.2 m) 

when not drilling and disconnected (assuming a storm duration of 24 hours). Detailed specifications 

for the Kulluk are provided in the 2011 Camden Bay EP (Shell, 2011a: Section 1, 2011b) 

The Discoverer is a modern drillship retrofitted for operating in Arctic OCS waters and has state-ofthe-art drilling and well-control equipment. It is a 514 ft (156 m) drilling vessel with the drilling 

equipment on a turret amidship and an eight-point mooring system. Detailed specifications for the 

Discoverer are provided in the 2011 Camden Bay EP (Shell, 2011a: Section 1, 2011b) 

The Kulluk or Discoverer would be attended by approximately eleven vessels that would be used for 

ice management, anchor handling, oil spill response, refueling, resupply, waste storage and transport 

and servicing. These vessels and their functions are identified in Table 3 and described in greater 

detail in the 2011 Camden Bay EIA (pp. 2-4 to 2-18). Although shell expects to use eleven support 

vessels, the actual number of support vessels may vary due to operational needs. 

The primary ice management vessel is the Nordica, which would be located several miles from the 

drill site when not being used for ice management. Hull 247 is used for secondary ice management 

and anchor handling. Hull 247 will also serve as the tow vessel for the Kulluk and provide additional 

berthing (accommodations). 

Drilling operations will require transfer of supplies from Deadhorse/West Dock and Dutch Harbor to 

the drilling vessels (up to 24 trips/tie ups to the Kulluk and 8 trips/tie ups to the Discoverer). The 

Arctic Seal is the designated resupply vessel to be used from West Dock. The Harvey Spirit will be 

used as the offshore resupply vessel (OSV) bringing supplies from Dutch Harbor. The Carol Chouest

will serve as back up vessel to the Harvey Spirit for bringing supplies from Dutch Harbor. 

Table 3 Planned Support Vessels for the Kulluk or Discoverer. 

Support Vessel (or similar) Kulluk or Discoverer 

Primary Ice Management Nordica 

Secondary Ice Management / Anchor Handling Hull 247 (also acts as tow vessel for the Kulluk and a berthing 

vessel for OSR) 

Shallow water resupply Arctic Seal 

Offshore Resupply Vessel (OSV) Harvey Spirit 

Waste Streams Transfer Vessel Carol Chouest 

Waste Streams Temporary Storage and Transit to 

Disposal Facility (deck barge and tug; [deck barge]) Southeast Provider and Ocean Ranger* 

Waste storage barge and tug (waste barge) To be determined 

Primary Oil Spill Response (OSR) Point Oliktok Tug and Endeavor Barge 
Shell 2012 Camden Bay EP EA

18 Proposed Action and Alternatives - Drillship, Support Vessels, and Aircraft 

Support Vessel (or similar) Kulluk or Discoverer 

OSR Liquid Storage and Refuel Supply Vessel Mikhail Ulyanov 

OSR Containment System Invader Class tug and barge 

Anchor Handler – support for the Containment System 

Barge To be determined 

Source: Shell, 2011b: Table 2.2.1 

Rather than discharge certain wastes (drilling muds and cuttings, treated sanitary waste, domestic 

waster, bilge water, and ballast water) from the drilling vessels into the marine environment, Shell 

will transfer the wastes from the drilling vessel to a deck barge and tug (Southeast Provider and 

Ocean Ranger) or to a waste storage barge and tug (to be identified). Because the waste barge-tug 

cannot safely tie to the drilling vessel, waste transfer to the barge will be accomplished using the 

Harvey Spirit or Carol Chouest. At the end of each drilling season, the barges and tugs will transport 

the stored waste out of the Arctic for disposal at an approved disposal facility. 

The oil spill response (OSR) vessels would include an ice-capable Oil Spill Response Barge (OSRB) 

and associated tug (Point Oliktok tug and Endeavor barge), a tank vessel for storage of any recovered 

liquids (Mikhal Ulyanov), and associated smaller workboats. The OSRB and tug with a full 

complement of crew and spill-response equipment, with Hull 247 providing berthing, would be 

staged near the drilling vessel). 

Other vessels and aircraft would be deployed to the site as needed to support Shell's 4MP (Shell, 

2011a: Appendix D) and scientific research efforts. There would be up to two flights per day, 

approximately 12 per week, by a support helicopter from the shore base to the drill site to transfer 

crews and supplies. A fixed-wing aircraft would be used for daily marine mammal monitoring 

overflights of 6 hours per day. Shell’s aerial monitoring program is described in the 4MP. 

The 2011 Camden Bay EIA (Shell, 2011b) lists the specifications of the drilling vessels (EIA Table 

2.2-4 for the Kulluk and Table 2.2-5 for the Discoverer) and support vessels (EIA Tables 2.2-1 and 

2.2-2) Shell is proposing to use. 

Drilling days per drill site for the Torpedo drill sites are estimated at 44 days. Drilling days per drill 

site for the Sivulliq drill sites are estimated at 34 days. The days onsite for the Torpedo and Sivulliq 

drill sites include one day to set anchors, five days for constructing the MLC one day to remove 

anchors, and one day to move off of the site. 

Shell’s Critical Operations and Curtailment Plan (COCP) (Shell, 2011a, Section 9 and Appendix J) 

addresses the methods by which Shell would cease, limit, or not initiate specific critical operations 

due to environmental conditions that may be encountered at the drill sites. 

Facilities will be consolidated at Deadhorse to support drilling, logistics, and oil spill response. 

Approximately 30 Shell personnel will be based in Deadhorse. Facilities include accommodations at 

the Prudhoe Bay Hotel and Service Area 10 facility and the use of existing facilities. No new 

construction is planned at Deadhorse. 

Aircraft travel would be controlled by Federal Aviation Administration approved flight paths and 

would comply with flight restrictions imposed by the Sale 195 and Sale 202 lease stipulations 

regarding sensitive biological areas. A flight altitude of 1,500 ft (457 m) would be maintained by all 

non-marine mammal monitoring flights to minimize impacts on marine mammals, terrestrial species, 

and subsistence hunters. As indicated in the EP, Shell would implement flight restrictions prohibiting 

aircraft from flying within 1,000 ft (300 m) of marine mammals or below 1,500 ft (457 m) altitude 

(except during takeoffs and landings or in emergency situations) while over land or sea. 

2.3.5. Discharges and Waste Management 

The Arctic National Pollutant Discharge Elimination System (NPDES) General Permit AKG280000 

(EPA, 2006) for the offshore areas of Alaska, including the Beaufort Sea, authorizes discharges from 

oil and gas exploration facilities. The current Arctic general permit, which restricts the seasons of 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Emissions 19

operation, discharge depths, and areas of operation, and has monitoring requirements and other 

conditions, expired on June 26, 2011. The EPA will reissue separate NPDES exploration General 

Permits for the Beaufort Sea and the Chukchi Sea prior to the 2012 drilling season. EPA expects that 

tribal consultation and public comment on the new proposed Arctic oil and gas exploration permits 

would occur during the fall of 2011. 

The EPA regulations (40 CFR 125.122) require a determination that the permitted discharge will not 

cause unreasonable degradation to the marine environment. Under the NPDES General Permit 

AKG280000, eleven separate effluent streams are allowed for the Kulluk or Discoverer. Each effluent 

stream, and the associated projected amount of discharge, is listed in the 2011 Camden Bay EIA 

(Table 2.7.1 for Sivulliq G, 2.7.2 for Sivulliq N, 2.7.3 for Torpedo H, and 2.7.4 for Torpedo J). 

Shell would only use water-based drilling fluids. Only seawater will be used during construction of 

the mud lined cellar (MLC), the 36-in hole section for the 30-in casing, and the 26-in hole section for 

the 20-inch casing. Below the 26-in hole section, Shell will use water based fluids during drilling. 

These water based fluids and cuttings will be collected aboard the drilling vessel, transferred to a 

storage vessel for ultimate transportation and disposal at an EPA-approved disposal site. The 

anticipated amounts of fluids and cuttings with adhered mud that will be generated, collected and 

disposed of per well is: Sivulliq G and N – 1,426 bbl each; Torpedo H – 3,045 bbl; and Torpedo J – 

3,007 bbl. Drilling fluid volumes and chemistry would comply with NPDES General Permit 

conditions. 

The drilling vessel (Kulluk or Discoverer) would be used to construct the MLC, set casing, and drill 

the well to total depth for each well (7,000 feet for Sivulliq G and N, 10,000 feet for Torpedo H and 

9,800 feet for Torpedo J). Shell would recycle drilling fluids (e.g., use those fluids on multiple wells), 

to the extent practicable based on operational considerations (e.g., fluid properties cannot be used 

further after they have deteriorated a certain amount), to reduce discharges from its operations. At the 

end of each drilling phase, the used drilling fluids would be transported to another well for reuse, if 

feasible, or transferred to a storage vessel for ultimate transfer and disposal. At the end of each 

drilling season, up to 1,500 bbl of drilling fluids, stored in the reserve tank on board the drillship, will 

be transferred for disposal. 

All waste not captured for off-site disposal will be discharged to the ocean through the vessels 

disposal caisson. The base of the disposal caisson on the Kulluk is approximately 38 to 41 feet (11.5 

to 12.5 m) below the water surface and on the Discoverer is 19.6 ft (6.0 m) below the water surface. 

A list of the components that may be added to the drilling fluid is summarized in the 2011 Camden 

Bay EIA, Table 2.7-5. The component list and the associated volumes account for drilling needs at 

various depths from the MLC to total depth for both the Sivulliq and Torpedo wells. 

The discharge from the water cooling unit is expected reach ambient temperature at a horizontal 

distance of 164 ft (50 m) from the discharge point on the Kulluk and 256 ft (78 m) from the discharge 

point of the Discoverer. 

Solid wastes (trash) would be segregated and disposed of or recycled at approved disposal or 

recycling facilities on land. Hazardous waste and used oil would be stored onboard in approved 

containers and then transferred by boat to an approved disposal facility out of the Arctic. 

2.3.6. Emissions 

Potential new emissions of harmful pollutants caused by a proposed oil exploration plan (EP) on the 

Alaska Outer Continental Shelf (OCS) must be approved by the U.S. Environmental Protection 

Agency (EPA), Region 10. The regulated pollutants include those controlled under the Clean Air Act 

(42 U.S.C. 7401) National Ambient Air Quality Standards (NAAQS) (40 CFR Part 50) and also 

include precursor pollutants such as Volatile Organic Compounds (VOC). These VOC compounds 

combine with emissions of nitrogen oxides and sunlight to form ozone, a pollutant regulated under 

the NAAQS. Approval for new emissions is obtained through the issuance of federal or state air 

quality operating permits and construction permits. The type of permit depends on the type of 
Shell 2012 Camden Bay EP EA

20 Proposed Action and Alternatives - Drillship Kulluk Permit 

emission source proposed, such as new, modified, or existing; stationary or mobile; and permanent or 

temporary. The type of permit is also based on the location of the proposed drilling prospects, 

meaning whether the drillship is proposed to be located within or beyond 25 nautical miles of 

Alaska’s seaward boundary in the Beaufort Sea (three nautical miles from shore) (40 CFR Part 55.2; 

Alaska Department of Natural Resources, 2005). Further, the type of permit required depends on the 

potential maximum annual emissions expected from the source being permitted, which would fall into 

one of two categories, a major source or a minor source (40 CFR 52.21(b)(1)). 

Under the EPA OCS Air Regulations at 40 CFR Part 55, the activities required to implement the 2011 

Camden Bay EP constitute an exploratory OCS source (new facility), attached to the seabed 

(stationary) in one location for less than three years (temporary), which has the potential to emit 

(PTE) any of the regulated air pollutants (30 CFR Part 250.302). Only the stationary-source aspects of 

the facility are regulated through the EPA permitting process. Shell proposes to drill from the 

drillship Kulluk with the option of using the drillship Discoverer in lieu of the Kulluk. As such, 

emissions from operations associated with the two drillships are addressed separately in the EPA 

permitting process. 

Emissions on the Kulluk or Discoverer would primarily be associated with the generation of 

electricity, compressed air, and hydraulic energy to support drilling. All others are secondary and 

related to general purpose heating, transfer of materials about the deck, pumping of cement, 

incineration of (primarily) domestic waste, and other small emission sources. The majority of the 

project emissions will be generated from the Kulluk or Discoverer’s support vessels (e.g., ice 

management, anchor management, and oil spill response vessels). 

The drilling vessels will be attended by a approximately eleven vessels that would be used for ice 

management, anchor handling, spill response, waste storage and transportation, refueling, resupply, 

and servicing. The primary sources of the emissions by the drilling vessels and support vessels would 

be combustion engines including the vessel engines, generators, compressors, draw works, and 

pumps. Emission units are associated primarily with the generation of electricity, compressed air, and 

hydraulic energy to support drilling. All others are secondary and related to general purpose heating, 

transfer of materials about the deck, pumping of cement, incineration of (primarily) domestic waste, 

and other small emission sources. Although shell expects to use eleven support vessels, the actual 

number of support vessels may vary due to operational needs. 

Additional emission sources include vessels and aircraft necessary to implement the proposed 4MP, 

support crew and supply transport, and support scientific research. Specific details of the emissions 

associated with either drillship are included in the air quality analysis provided in Section 4.2.1.1., 

Table 10 and Table 11. 

Drillship Kulluk Permit and Emission Reduction Measures. Shell submitted an air quality permit 

application for the Kulluk in three parts for approval to operate both within and beyond 25 nautical 

miles of the Alaskan seaward boundary in the Beaufort Sea. Overall, the application is intended to 

show operations of the proposed EP would not result in violations of the NAAQS. 

Shell applied for a Minor Source permit for the Kulluk to operate in the Beaufort Sea on indefinite 

number of future drilling seasons. Shell's OCS Permit Application for a Minor Source permit for the 

Kulluk was submitted on March 29, 2011, and is available online at: http://yosemite.epa.gov/r10/

airpage.nsf/Permits/Kullukap/. 

The minor source permit will regulate air emissions from the Kulluk and from the support vessels 

when within 25 mi (40 km) of the anchored Kulluk. The implementation of best available control 

technology (BACT) and compliance with other provisions of the permit will ensure that air emissions 

are minimized. 

The permit includes a description of the emission reduction measures that would limit emissions to 

the applicable PSD thresholds that define a major source, which is the potential to emit 250 tons per 

year or more of any regulated pollutant. The proposed emission reduction measures are also described 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Sound Generation 21

in the 2011 Camden Bay EP: Section 7.0 Air Emissions Information, and in the 2011 Camden Bay 

EIA. The emission reduction measures proposed for the Kulluk include the use of: 

 Selective catalytic reduction (SCR) devices as NOX tailpipe emission controls on the 

primary engines. The primary generators will have oxidation catalysts installed for control 

of fine particulate matter with a diameter less than 2.5 micrometers (PM2.5), VOC, and CO. 

 Oxidation catalysts for control of PM2.5, VOC, and CO emissions from the other engines 

normally used in the exploration drilling activities, including air compressors, the MLC, 

hydraulic power units (HPU), and cranes. Control of engine emissions is assumed to be 

50% for PM2.5, 80% for CO, and 70% for VOC. 

 SCR device as a NOX tailpipe emission control on the engines aboard the ice management 

vessels and anchor handlers. 

 Ultra-low sulfur content (0.0015%) diesel fuel for both the Kulluk and the support vessels 

to reduce SO2 emissions. 

Uncontrolled emissions from implementation of the EP using the drillship Kulluk would be 

comprised primarily of NOX emissions, with the potential to exceed the PSD threshold of 250 tons 

per year. Therefore, the use of the Best Available Control Technology (BACT) summarized above 

would be engaged to ensure the reduction of NOX emissions below 250 tons per year. Emissions of 

NOX would comprise 50.7% of total emissions of criteria pollutants. Emissions of CO would 

comprise 36.0% while emissions from the remaining relevant pollutants would be much lower, 

ranging from 1.0% for SO2 emissions to 12.3% for PM. 

Drillship Discoverer Permit and Emission Reduction Measures. 

The Discoverer permit includes a description of the emission reduction measures that would limit 

emissions but would not decrease emissions of NOX to a level below 250 tons per year. The proposed 

emission reduction measures are also described in the 2011 Camden Bay EP, Section 7.0 Air 

Emissions Information, and in Appendix F, the Environmental Impact Assessment. The emission 

reduction measures proposed for the Discoverer include: 

 Selective catalytic reduction (SCR) device as a NOX tailpipe emission control on the 

primary generators to reduce NOX emissions to under 0.5 grams per kilowatt hour (g/kWhr). Oxidation catalysts will be installed for control of fine particulate matter with a 

diameter less than 10 micrometers (PM10), VOC, and CO. 

 Retrofit all other engines on the Discoverer with Catalytic Diesel particulate Filters to 

reduce CO, VOC, and PM10, or use Tier 3 (low emissions) engines. 

 Selective catalyst reduction and oxidation catalyst emission controls on all propulsion and 

generation engines on the primary ice management vessel. 

 Ultra-low sulfur content (0.0015%) diesel fuel will be purchased for the Discoverer and 

the support vessels to reduce SO2 emissions. 

Emissions from implementation of the EP using the drillship Discoverer would be comprised 

primarily of NOX emissions, with the potential to exceed the PSD threshold of 250 tons per year for 

emissions of NOX. Therefore, the use of the Best Available Control Technology (BACT) and ownerrequested restrictions (ORR) summarized above would be engaged to ensure NOX emissions are 

reduced to the lowest reasonable and available level. Emissions of NOX comprise 62.9% of total 

emissions of criteria pollutants. Emissions of CO would comprise 28.8% of total emissions while 

emissions from the remaining relevant pollutants is much lower, ranging from 0.25% for SO2

emissions to 8.0% of PM. 

2.3.7. Sound Generation. 

The level of continuous sound introduced into the water during exploratory drilling operations is 

likely to differ between the Kulluk and the Discoverer. 
Shell 2012 Camden Bay EP EA

22 Proposed Action and Alternatives - Sound Generation 

Drilling Sound. Sounds from the Kulluk were measured in the Beaufort Sea in 1986 and reported by 

Greene (1987a, 1987b cited in Shell 2011b: Section 2.9). The back propagated broadband source 

level from the measurements (185.5 dB re: 1 microPascal (μPa) · m rms; calculated from the reported 

1/3-octave band levels), which included sounds from a support vessel operating nearby, were used to 

model sound propagation at the Sivulliq prospect near Camden Bay. The model estimated that sounds 

would decrease to 120 dB re: 1 μPa · m rms at ~8.25 mi(~13.27 km) from the Kulluk (Zykov and 

Hannay, 2007). As a precautionary approach, that distance was multiplied by 1.5 and the resulting 

radius of 12.37 mi (19.91 km) was used to estimate the total area that may be exposed to continuous 

sounds ≥120 dB re: 1 μPa rms by the Kulluk at each drill site. If one well site is drilled in one season, 

the total area of water ensonified to 120 dB rms in each season will be 480.7 mi2 (1,245 km2

). 

Sounds generated by the Discoverer have not been directly measured in Alaska and noise propagation 

measurements are not available. However, measurements of sounds produced by the Discoverer were 

made in the South China Sea in 2009 (Austin and Warner 2010). The activities included repositioning 

of the ship on its turret using the thrusters, tripping, drill string handling, drilling, and anchor 

retrieval. Some of these activities were simulated by running most, but not all, of the required 

equipment. The measured underwater sound levels generated during the study of the Discoverer in 

the South China Sea are presented in 2011 Camden Bay EIA Table 2.9-1. The results of those 

measurements were used to model the sound propagation from the Discoverer (including a nearby 

support vessel) at planned drilling locations in the Chukchi and Beaufort Seas (Warner and Hannay, 

2011). Ensonified areas from exploration drilling activities with a nearby support vessel were 

estimated using JASCO Applies Science’s Marine Operations Noise Model (MONM) at the Sivulliq 

and Torpedo prospects. The model predicts the transmission loss or reduction in sound that would 

occur with distance from the drilling vessel. Results are presented in EIA Table 2.9-2 Sound 

transmission loss was found to vary with the season due to changes in water temperature and salinity. 

Broadband source levels of sounds produced by the Discoverer varied by activity and direction from 

the ship, but were generally between 177 and 185 decibels (dB) re: 1 μPa · m root mean square (rms) 

(Austin and Warner 2010). Propagation modeling at the Sivulliq and Torpedo prospects yielded 

somewhat different results, with sounds expected to propagate shorter distances at the Sivulliq site 

(Warner and Hannay, 2011). As a precautionary approach, the larger distance to which sounds ≥120 

dB (3.32 km) are expected to propagate at the Torpedo site have been used to estimate the area of 

water potentially exposed at both locations. The estimated 2.06 mi (3.32 km) distance was multiplied 

by 1.5 (= 3.09 mi [4.98 km]) as a further precautionary measure before calculating the total area that 

may be exposed to continuous sounds ≥120 dB re 1 μPa rms by the Discoverer at each drill site. 

Assuming one well will be drilled in each season (summer and fall), the total area of water ensonified 

to ≥120 dB rms in each season would be 30.12 mi2 (78 km2). 

When an ice-management vessel is transiting open-water, the sound generated is less than when the 

vessel is managing or breaking ice. The greatest sound generated during ice-breaking operations is 

produced by cavitations of the propeller as opposed to the engines or the ice on the hull (Richardson 

et al. 1995a). Ice-management activities may be necessary in early July or towards the end of 

operations in late October, if ice is present. Little to no ice management is expected to occur during 

the bowhead migration. Based on measurements in Greene (1987), sounds produced by an icebreaker, 

the Robert Lamonte, actively managing ice in this area were estimated to fall below 160 dB rms 

at <100 m from the vessel and to fall below 120 dB rms at ~8 km from the vessel. For estimation 

purposes, Shell assumed that most ice-management activities would occur at a distance of 10-15 km 

from the drilling operation and that one-third of that distance band would be exposed to ≥160 dB rms 

at some point by those activities. This area lies outside of the area exposed to ≥160 dB rms by the 

Discoverer. Waters are ≤40 m deep in areas that may be exposed to sounds ≥160 dB by both the 

Discoverer and ice-management activities. The ice-management area is 10-15 km around the drill 

site. The ice-management area plus the area an additional 8 km beyond the ice-management area 

potentially would be exposed to sounds levels of ≥120 dB rms by any ice-management activities. 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Other Sound 23

Shell would verify the modeled sound-level radii though field measurements. Acoustic monitoring 

would measure the sound decibels produced by drilling activities, including variations with time, 

distance, and direction from the drillship. Acoustic monitoring would measure the sound levels 

produced by support vessels, including ice-management vessels. Drilling and vessel sounds would be 

measured and recorded using two methods, which may be used separately or together. The first 

method employs hydrophones mounted on the seafloor around the drilling vessel. This system would 

be located within 1,640-3,281 ft (500-1,000 m) from the drilling vessel. These hydrophones would 

feed real-time sound data to the drillship. An activity log would correlate sound levels with vessel 

activities. The second method for recording sound levels would employ additional hydrophone 

systems at various distances and locations around operations. Acoustic data from the second system 

would be stored digitally for later retrieval. Drilling sound monitoring equipment would be deployed 

soon after the drilling vessel is onsite and before drilling commences. 

Vertical Seismic Profile. Shell may conduct a geophysical survey referred to as Vertical Seismic 

Profiling (VSP) at each drill site where a well is drilled (Shell, 2011b). During VSP surveys, an 

airgun array is deployed at a location near or adjacent to the drilling vessel, while receivers are placed 

(temporarily anchored) in the wellbore. Airguns function by venting high-pressure air into the water. 

The pressure signature of an individual airgun consists of a sharp rise and then fall in pressure, 

followed by several positive and negative pressure excursions caused by oscillation of the resulting 

air bubble. The sizes, arrangement, and firing times of the individual airguns in an array are designed 

and synchronized to suppress the pressure oscillations subsequent to the first cycle. Typical highenergy airgun arrays emit most energy at 10-120 Hz. However, the pulses contain significant energy 

up to 500-1,000 Hz and some energy at higher frequencies (Goold and Fish, 1998; Potter et al., 2007). 

The estimated source level used to model sound propagation from the airgun array is ~241 dB re 

1μPa · m rms, with most energy between 20 and 140 Hz. 

The sound source (airgun array) is fired repeatedly, and the reflected sonic waves are recorded by 

receivers (geophones) located in the wellbore. The geophones, typically a string of them, are then 

raised up to the next interval in the wellbore and the process is repeated until the entire wellbore has 

been surveyed, typically over a period of 10 – 14 hours. The purpose of the VSP is to gather 

geophysical information at various depths, which can then be used to tie-in or ground-truth 

geophysical information from the previous seismic surveys with geological data collected within the 

wellbore. Typical receivers would consist of a Schlumberger wireline four-level Vertical Seismic 

Imager (VSI) tool, which has four receivers 50 ft (15.2 m) apart. 

Shell will likely be conducting a particular form of VSP referred to as a ZVSP, in which the sound 

source is maintained at a constant location near the wellbore. A typical sound source that would be 

used by Shell for the Camden Bay exploration drilling is the ITAGA eight-airgun array, which 

consists of four 150-in.3 (2,458-cm3) airguns and four 40-in.3 (655-cm3) airguns. These airguns can 

be activated in any combination and Shell would utilize the minimum airgun volume required to 

obtain an acceptable signal. 2011 Camden Bay EIA (Table 2.9-6) lists specifications for the sound 

source of the airgun array. 

Sound propagation measurements will be performed on the drilling vessel and the ZVSP airgun 

source in the first drilling season, once it is on location near Camden Bay. The results of those 

measurements will be used during the season to implement mitigation measures as required by the 

permit. 

Other Sound 

Vessel Sound. In addition to either drilling vessel, various types of vessels will be used in support of 

the operations including ice management vessels, anchor handler, OSV(s), and oil-spill response 

vessels (Shell, 2011b). Sounds from boats and vessels have been reported extensively (Greene and 

Moore, 1995; Blackwell and Greene 2002, 2005, 2006). Numerous measurements of underwater 

vessel sound have been performed in support of recent industry activity in the Chukchi and Beaufort 

seas. Results of these measurements were reported in various 90-day and comprehensive reports since 
Shell 2012 Camden Bay EP EA

24 Proposed Action and Alternatives - Local Hire 

2007. For example, Garner and Hannay (2009) estimated sound pressure levels of 100 dB at distances 

ranging from approximately 1.5-2.3 mi (2.4-3.7 km) from various types of barges. MacDonald et al. 

(2008) estimated higher underwater sound pressure levels from the seismic vessel Gilavar of 120 dB 

at approximately 13 mi (21 km) from the source, although the sound level was only 150 dB at 85 ft 

(26 m) from the vessel. Like other industry-generated sound, underwater sound from vessels is 

generally at relatively low frequencies. 

The primary sources of sounds from all vessel classes are propeller cavitation, propeller singing, and 

propulsion or other machinery. Propeller cavitation is usually the dominant noise source for vessels 

(Ross, 1976). Propeller cavitation and singing are produced outside the hull, whereas propulsion or 

other machinery noise originates inside the hull. There are additional sounds produced by vessel 

activity, such as pumps, generators, flow noise from water passing over the hull, and bubbles 

breaking in the wake. Icebreakers contribute greater sound levels during ice-breaking activities than 

ships of similar size during normal operation in open-water (Richardson et al., 1995a). This higher 

sound production results from the greater amount of power and propeller cavitation required when 

operating in thick ice. 

Aircraft Sound. Aircraft would not operate below 1,500 ft (457 m) unless the aircraft is engaged in 

marine mammal monitoring, approaching, landing, or taking off; providing assistance to a whaler; or 

in poor weather (low ceilings) or any other emergency situations. Aircraft engaged in marine mammal 

monitoring would not operate below 1,500 ft (457 m) in areas of active whaling; such areas would be 

identified through communications with established Communication Centers. Except for fixed-wing 

aircraft (airplanes) engaged in marine mammal monitoring, aircraft would use a flight path that keeps 

the aircraft at least 5 mi (8 km) inland until the aircraft is directly south of its offshore destination; 

then at that point, they would fly directly north to their destination. As a result of community input 

during Government-to-Government meetings held by BOEMRE for Shell’s 2007 EP, the inland 

helicopter route was developed to mitigate potential interference with subsistence caribou hunting 

along the coast. Helicopters would be used for air support and crew changes. The level and duration 

of sound received underwater from helicopters depends on altitude and water depth. Received sound 

level decreases with increasing altitude. At an altitude of 1,000 ft (305 m), there were no measured 

sound levels at a water depth of 121 ft (37 m) (Green, 1985, cited in Richardson et al., 1989). 

2.3.8. Local Hire 

Shell has several programs that involve the training and subsequent hiring of local residents. These 

programs include the following: 

 Marine Mammal Observer (MMO) program 

 Subsistence Advisor (SA) program 

 Communication and Call Centers (Com Centers) program 

The MMO program employs, among others, local Iñupiat residents to monitor and document marine 

mammals in the project area. The MMOs participate in intensive training for marine mammal 

identification and documentation, and in computer use and health and safety regulations. 

The SA program recruits a local resident from each village to communicate local concerns and 

subsistence issues from residents to Shell. The SA speaks with other village members and documents 

subsistence information. Shell may use that information to develop appropriate mitigation measures 

to address issues related to subsistence activities and avoid potential conflicts with exploration 

activities. 

The Com Center program involves hiring one or two individuals from each of the Beaufort Sea and 

Chukchi Sea villages. These individuals monitor and relay radio transmissions between subsistence 

vessels and industry vessels. This sharing of information is intended to reduce or eliminate the 

potential conflict between subsistence users and industry vessels. 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Analysis of Accidental Oil Spills 25

In the EP, Shell has committed to efforts to hire and train local residents for the exploration program. 

Providing these employment opportunities to local residents creates the potential for positive 

economic benefits to the communities most affected by Shell’s activities. These efforts also would 

provide a conduit for communication between Shell and residents. 

2.3.9. Analysis of Accidental Oil Spills 

The BOEMRE analyzed a range of oil spill sizes, grouped by category from small (<1,000 bbl) to 

very large (≥150,000 bbl), and likely consequences to environmental, social, and economic resources 

in the Beaufort Sea Multiple-Sale EIS from which this EA tiers. The BOEMRE updated those oil 

spill and impact analyses in the Sale 195 EA, Sale 202 EA, 2009 Camden Bay EA and the Arctic 

Multisale EIS, which this EA incorporates by reference. 

The BOEMRE used Shell’s potential discharge volumes, summarized below in Error! Reference 

source not found. and in Appendix A of this EA, as the spill volume and oil type for each of 

BOEMRE’s small (<1,000 bbl), large (≥1,000 bbl), and very large (≥150,000 bbls) spill size 

categories (Shell, 2011a: Table 2-1). The potential discharge volumes are estimated without 

mitigation or response efforts. The effects of mitigation and response are discussed in Sections 5.5 – 

5.7, and a detailed description of the very large oil spill volume estimate is provided in Table 19. 

Table 4 Estimated spill volume and oil type in each BOEMRE spill size category from Shell’s potential 

discharge volumes. 

BOEMRE Spill-Size 

Categories Type Oil Type Potential Discharge Volume1 Volume estimated to reach water 

Small (<1,000 bbl) Fuel Transfer Diesel 48 bbl 48 bbl 

Large (≥1,000 bbl) Diesel Tank Diesel 1,555 bbl 0 bbl 

Very Large (≥150,000 

bbl) Blowout Crude Oil 480,000 bbl 142,020 bbl2

Note: 1Total volume estimated with no mitigation or response 

2Total volume estimated with mitigation and response as described in Sections 5.5.2 – 5.6 of this EA. 

The BOEMRE reviewed and considered published documents and NEPA assessments on the 

likelihood of the potential discharges in the three spill size categories to determine a reasonably 

foreseeable spill analysis scenario for the no action and Proposed Action alternative in order to 

evaluate the potential impact producing factors of an accidental oil spill for this EA. Further 

analytical details are found within Appendix A of this EA. 

For purposes of analysis of the no action alternative, no small, large, or very large spills are estimated 

to occur since no exploration activities occur. 

For purposes of analysis of the Proposed Action alternative, BOEMRE estimates it is likely a small 

refined oil spill could occur. This estimate is based on the 35 exploration spills while drilling 35 wells 

on the Arctic OCS. No large spills (≥1,000 bbl) or very large (≥150,000 bbls) crude oil spills are 

estimated, based on calculations and analyses presented in Appendix A of this EA, from the proposed 

exploration activities. 

The large and very large crude oil spill occurrence estimates are based on: (1) the low rate of OCS 

exploratory drilling well-control incidents spilling fluids per well drilled; (2) since 1971, only one 

very large spill has occurred during temporary abandonment out of more than 15,000 exploratory 

wells drilled; (3) the low number (four) of exploration wells proposed in this action; (4) no crude oil 

would be produced and the wells would be permanently plugged and abandoned; (5) the history of 

Arctic OCS exploration spills, all of which have been small; (6) No small spills occured while drilling 

36 wells in the Arctic OCS; and (7) pollution prevention and oil spill response regulations and 

methods implemented by BOEMRE and Shell, respectively, since the Deepwater Horizon event 

discussed in Section 0. 

Based on the six points listed above for large and very large spills, and that a small spill is considered 

likely to occur during exploration activities the most likely size spill occurring from the Proposed 
Shell 2012 Camden Bay EP EA

26 Proposed Action and Alternatives - Oil Spill Prevention and Contingency Planning 

Action would be a small (<1,000 bbl) spill. For purposes of analysis, the BOEMRE chose a 48-bbl 

fuel-transfer spill, as identified in Shell’s Beaufort Sea ODPCP Summary of Potential Discharges, for 

a representative spill volume and oil type for the effects analysis of a small spill (Shell, 2011c, Table 

2-1). 

To provide information to evaluate the potential effect of a 48-bbl diesel-fuel oil spill, the BOEMRE 

estimates how much diesel fuel would evaporate, how much diesel fuel would naturally disperse, and 

how much diesel fuel would remain after a certain time period using the SINTEF oil weathering 

model (OWM). A 48-bbl diesel-fuel spill could evaporate and disperse in less than 3 days (Appendix 

A: Table A-4). The SINTEF OWM estimates of a 48-bbl (7.6 m3

) fuel spill do not include the 

mitigating effects of potential containment and recovery operations to remove spilled product. Prebooming downwind of vessels prior to transfer operations would be used in accordance with 

BOEMRE lease stipulations, USCG requirements, and Shell’s operating procedures. Response 

equipment and trained personnel deploy recovery equipment for the control and removal of diesel 

fuel spilled into the environment mitigating the impacts of a small spill. Should a 48-bbl diesel-fuel 

spill occur, the spill would be localized and persist less than 3 days. 

2.3.10. Oil Spill Prevention and Contingency Planning 

As required by both Federal and State regulations, Shell has developed and would implement a 

comprehensive Oil Discharge Prevention and Contingency Plan (ODPCP) (Shell, 2011c) during its 

exploration drilling operations. The ODPCP must be reviewed and approved by both Federal and 

State regulators to ensure that Shell has the spill-response resources necessary to respond to any spill 

that might occur. 

Shell’s Beaufort Sea Regional Exploration ODPCP is a regional oil-spill-response plan that 

demonstrates Shell’s capabilities to prevent, or rapidly and effectively manage, oil spills that may 

result from exploratory drilling operations. Despite the extremely low likelihood of a large oil-spill 

occurring during exploration, Shell has designed its response program for a regional capability of 

responding to a range of spill volumes that increase from small operational spills up to and including 

a Worst Case Discharge (WCD) scenario from an exploration well blowout, as required under 30 

CFR 254.47. Shell’s program is based on a WCD scenario that meets the response planning 

requirements of the State of Alaska and Federal oil-spill-planning regulations. 

Shell has designed its response program based on a regional capability of responding to a worst case 

discharge (WCD) from an exploration well blowout. A dedicated OSRB would be staged in the 

vicinity of the drilling vessel when critical drilling operations into hydrocarbon-bearing zones are 

underway and possess sufficient capacity to provided containment, recovery, and storage for the 

initial operational period. Two vessel of opportunity skimming systems (VOSS) would also be 

employed to assist with containment and recovery operations. Shell also will mobilize an OSRB 

from operations in the Chukchi Sea to be on-site within 42 hours following notification to further 

support containment and recovery operation. An arctic oil storage tanker (OST) would arrive at the 

recovery site to provide interim storage of recovered fluids. The OST would possess sufficient 

capacity to store all recovered liquids from a 30-day blowout. Skimming and lightering operations 

would be conducted on a 24-hour basis ensuring uninterrupted recovery operations as skimming 

vessels transfer recovered fluids to the OST on a rotational basis. 

Shell’s primary response action contractors are Alaska Clean Sea (ACS) and Arctic Slope Regional 

Corporation Energy Services - Response Operations, LLC (AES-RO). The AES-RO’s response 

personnel and oil-spill-response equipment would be maintained on standby while critical drilling 

operations into hydrocarbon-bearing zones are underway; and provide offshore response operations in 

the unlikely event of an oil-spill incident. The ACS provides manpower and equipment resources 

from Deadhorse for Beaufort Sea spill containment and recovery. The ACS and AES-RO would 

conduct response activities in both open ocean and near shore enviroments using the the ACS 

Technical Manual and the Shell Beaufort and Chukchi Seas Regional Tactics Manual. 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Compliance with Lease Stipulations 27

2.3.11. Compliance with Lease Stipulations 

Shell’s leases were obtained under the Beaufort Sea Oil and Gas Lease Sale 195 on March 30, 2005, 

and the Beaufort Sea Oil and Gas Lease Sale 202 on April 18, 2007. Identical lease stipulations were 

included in both sales. A summary of the lease stipulations and Shell’s planned actions to comply 

with each stipulation is provided below. The full text of the lease stipulations for Sale 195 is available 

on the BOEMRE website at: alaska.boemre.gov/cproject/beaufortsale/FNOS195Package/

04.%20%20FNOS%20Stipulations.pdf. The full text of the Sale 202 stipulations is on the BOEMRE 

website: www.boemre.gov/alaska/cproject/beaufortsale/Sale202/FNOS/FNOS202package.htm. The 

BOEMRE’ analysis of the effectiveness of the stipulations is in the Beaufort Sea Multiple-Sale EIS 

(USDOI, MMS, 2003: Section II.H.1). 

Stipulation No. 1 - Protection of Biological Resources 

If biological populations or habitats that may require additional protection are identified in the lease 

area by the RS/FO, the RS/FO may require the lessee to conduct biological surveys to determine the 

extent and composition of such biological populations or habitats. The RS/FO shall give written 

notification to the lessee of the RS/FO’s decision to require such surveys. 

Shell Actions: As required by 30 CFR 250.214, and as specified in BOEMRE Alaska OCS Region 

NTL 05-A01, Shell acquired shallow-hazards surveys over the planned drill sites. The surveys’ data 

includes detailed bathymetry and identification of seafloor features through the use of subbottom 

profilers and side scan sonar methods. 

Recently acquired shallow-hazards survey data over the Sivulliq and Torpedo drill sites in 2006, 

2007, 2008, and 2009 did not identify any special benthic communities at these drill sites. Hardbottom biological communities have high species diversity and provide valuable habitat for fish and 

invertebrates. To date, no confirmed boulder patch-type habitat has been identified at either of the 

planned drill sites. No other biological resources that require additional protection were found. The 

BOEMRE has reviewed the submitted survey data and assessments, and concurs with Shell’s 

conclusions. 

During 2008, Shell commissioned both biological and chemical studies of water and sediment 

samples at and around the proposed drill sites (Shell, 2011a: Section 5.0a). 

To establish a baseline data set in advance of future oil and gas exploration, samples were collected in 

and around the planned Sivulliq N drill site (12 locations), around the 1985 Hammerhead well (10 

locations), along a possible pipeline corridor (5 locations), and at random in the project area (19 

locations). The sample locations and a more detailed account of the results of the sampling are 

discussed in the 2011 Camden Bay EIA (Shell, 2011b). 

The following samples types were collected: 

 Seafloor surface sediment samples 

 Sediment cores, 3- 4 in (8-10 cm) in length 

 Hydrographic profiles and water samples 

Stipulation No. 2 - Orientation Program 

The lessee shall include in any exploration or development and production plans submitted under 

30 CFR 250.203 and 250.204 a proposed orientation program for all personnel involved in 

exploration or development and production activities (including personnel of the lessee’s agents, 

contractors, and subcontractors) for review and approval by the RS/FO. The program shall be 

designed in sufficient detail to inform individuals working on the project of specific types of 

environmental, social, and cultural concerns that relate to the sale and adjacent areas. The program 

shall address the importance of not disturbing archaeological and biological resources and habitats, 

including endangered species, fisheries, bird colonies, and marine mammals and provide guidance 

on how to avoid disturbance. This guidance would include the production and distribution of 
Shell 2012 Camden Bay EP EA

28 Proposed Action and Alternatives - Compliance with Lease Stipulations 

information cards on endangered and/or threatened species in the sale area. The program shall be 

designed to increase the sensitivity and understanding of personnel to community values, customs, 

and lifestyles in areas in which such personnel would be operating. The orientation program shall 

also include information concerning avoidance of conflicts with subsistence, commercial fishing 

activities, and pertinent mitigation. 

Shell Actions: Shell has provided a proposed orientation program for Shell and contractor personnel 

involved in Shell’s exploration activities. Shell submitted an orientation program to BOEMRE for 

review. BOEMRE reviewed the program and determined it satisfied the requirements of the 

stipulation. All Shell and contractor personnel involved in field exploration activities would attend 

the orientation training annually. All other Shell and contractor personnel would attend the orientation 

program at least once at the time they join the team. Shell would maintain a record, not to exceed five 

years, of all personnel who attend the program, including relevant attendee and program information. 

Shell’s orientation program addresses environmental, social, and cultural concerns specific to the 

project area. The program is designed to increase sensitivity and understanding by Shell and its 

contractors of community values, customs, and lifestyles of the local communities, and how to avoid 

conflicts with subsistence activities. The program stresses the importance of not disturbing local 

communities, archaeological resources, and biological resources and habitats, including endangered 

species, fisheries, bird colonies, and marine mammals, and provides guidance on how to avoid 

disturbance of these resources. 

Shell’s Cultural Awareness Program addresses the following: 

 Alaska Native Ethnic Composition 

 Formation of regional corporations, and 

region within which Shell is working 

 Brief history of land claims 

 Comparison of cultural values of Alaskan 

Natives vs. non-Natives 

 History of the North Slope 

 Cultural diversity 

 Patterns of language 

 Communication skills and body language 

 Guidelines on cultural artifacts 

 Local community values and customs 

 Whaling 

Shell’s Environmental Awareness Program addresses the following: 

 Endangered Species Act (ESA) 

 Endangered and threatened species 

 Sensitive Habitats on the North Slope 

 Marine mammal interactions 

 MMPA of 1972 

 Wildlife interactions 

 Prohibited activities of hunting, trapping, 

and fishing 

 Environmental requirements for air, spills, 

and waste 

 Environmental training 

 Conflict Avoidance Agreements 

Stipulation No. 3 - Transportation of Hydrocarbons 

This stipulation is not applicable to the activities described in the EP. 

Stipulation No. 4 - Industry Site-Specific Bowhead Whale Monitoring Program 

Lessees proposing to conduct exploratory drilling operations, including seismic surveys, during the 

bowhead whale migration would be required to conduct a site-specific monitoring program approved 

by the RS/FO; unless, based on the size, timing, duration, and scope of the proposed operations, the 

RS/FO, in consultation with the North Slope Borough (NSB) and the Alaska Eskimo Whaling 

Commission (AEWC), determine that a monitoring program is not necessary. The RS/FO would 

provide the NSB, AEWC, and the State of Alaska a minimum of 30 but no longer than 60 calendar 

days to review and comment on a proposed monitoring program prior to approval. The monitoring 

program must be approved each year before exploratory drilling operations can be commenced. 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Compliance with Lease Stipulations 29

Shell Actions: Shell submitted a copy of their 4MP, which is also included in Shell’s application for 

an IHA (Shell, 2011a: Appendix D and Appendix C, respectively). Shell’s 4MP is a combination of 

active monitoring of the project area and the implementation of mitigation measures designed to 

minimize project impacts to marine resources. The 4MP describes a site-specific bowhead whale 

monitoring program. The BOEMRE has determined that the level and scope of the monitoring 

program would enable Shell to assess when bowhead whales are present in the vicinity of the 

proposed lease operations and the extent of behavioral effects on bowhead whales because of the 

operations. A summary of key components of the 4MP is presented below. 

Marine Mammal Observers: The presence of MMOs onboard all vessels would be a core 

component of compliance with the 4MP. The drillship, ice-management vessels, and all other support 

vessels would have MMOs on duty during drilling operations to monitor for marine mammals and to 

advise on mitigation measures. All support vessels would have MMOs on duty during transit and 

other related activities. If marine mammals are observed within or about to enter specific safety radii 

around the proposed drilling operation, mitigation would be initiated by vessel-based MMOs. The 

MMOs would be responsible for collecting basic data on observations of marine mammals and birds 

and for advising on appropriate mitigation measures. Observations made by MMOs serve as the 

primary basis for estimation of impacts to marine mammals and birds. 

Aerial Monitoring Program: The main goal of the aerial monitoring program is to monitor marine 

mammal populations and movements in support of the vessel-based 4MP during the drilling program. 

Aerial monitoring, designed primarily for detecting cetaceans, would be used to identify any largescale distributional changes of cetaceans relative to the activities and add to the existing database on 

the abundance and distribution of observed species. 

Passive Acoustic Program: The acoustic program would characterize the sounds produced by the 

drilling activities and support vessels, and document the potential reactions of marine mammals in the 

project area, particularly bowhead whales, to those sounds and activities. A combination of acoustic 

recorder technologies would be used to document the overall distribution of marine mammals in the 

project area; the distribution of marine mammals in relation to drilling activities; to add clarity to 

drilling sound levels, character, and propagation; and to document presence of marine mammals. This 

would be accomplished by deploying several acoustic recorder buoys in a wide area surrounding the 

planned drill sites. 

Sound Modeling: Sound modeling is required for the proposed activities. Shell’s sound modeling is 

summarized in Shell’s IHA and LOA applications (Shell, 2011a: Appendixes C and E, respectively) 

where the size of the 180 and 190 dB re 1 μPa (rms) safety radii were modeled. These radii would be 

used to initiate mitigation during initial drilling activities, at which time an acoustics contractor would 

measure underwater sound propagation from the drilling activities to empirically determine the size of 

safety radii (see Sound Source Verification below). Additional modeling using field data would be 

done during the drilling season. The sound data would enable Shell to refine sound-level thresholds 

and use the thresholds to more accurately define marine mammal take estimates. 

Sound Source Verification: Field measurement of the sound-propagation profiles of the drillship 

and support vessels would be conducted during operations. 

Stipulation No. 5 - Plan of Cooperation 

Exploration and development and production operations shall be conducted in a manner that 

prevents unreasonable conflicts between the oil and gas industry and subsistence activities 

(including, but not limited to, bowhead whale subsistence hunting). Prior to submitting an 

exploration plan or development and production plan (including associated oil-spill contingency 

plans) to BOEMRE for activities proposed during the bowhead whale migration period, the lessee 

shall consult with the directly affected subsistence communities, Barrow, Kaktovik, or Nuiqsut, the 

NSB, and the AEWC to discuss potential conflicts with the siting, timing, and methods of proposed 

operations and safeguards or mitigating measures which could be implemented by the operator to 

prevent unreasonable conflicts. Through this consultation, the lessee shall make every reasonable 
Shell 2012 Camden Bay EP EA

30 Proposed Action and Alternatives - Compliance with Lease Stipulations 

effort, including such mechanisms as a conflict avoidance agreement, to assure that exploration, 

development, and production activities are compatible with whaling and other subsistence hunting 

activities and would not result in unreasonable interference with subsistence harvests. 

Shell Actions: Lease Stipulation 5 requires that all exploration operations be conducted in a manner 

that prevents unreasonable conflicts between oil and gas activities and subsistence resources and 

subsistence hunting activities of the residents of the North Slope. Specifically, Lease Stipulation 5 

requires the operator to consult directly with potentially affected North Slope subsistence 

communities, the NSB, and the AEWC. Consultation is “to discuss potential conflicts with the siting, 

timing, and methods of proposed operations and safeguards or mitigating measures which could be 

implemented by the operator to prevent unreasonable conflicts.” Lease Stipulation 5 requires the 

operator to document its contacts and the substance of its communications with subsistence 

stakeholder groups during the operator’s consultation process. The requirements of Lease Stipulation 

5 parallel requirements for incidental take authorizations from FWS and NMFS under MMPA at 50 

CFR 216.104(a)(12). 

Shell’s Plan of Cooperation Addendum (POC) (Shell, 2011a: Appendix H) identifies the measures 

Shell has developed and would implement during its proposed exploration drilling program to 

minimize any adverse effects on the availability of marine mammals for subsistence uses. The POC 

addendum details Shell’s communications and consultations with local communities concerning its 

proposed exploration drilling program, potential conflicts with subsistence activities, and means of 

resolving any such conflicts. Summaries of the substance of Shell’s communications, and responses 

thereto, are included in the POC. A summary of Shell’s POC meetings is provided below. Table 4.2-1 

of the POC provides a list of public meetings attended by Shell as it developed the POC (Shell, 

2011a: Appendix H). Attachment B of the POC provides tables summarizing the feedback at each 

meeting, Shell’s responses to the feedback, and any mitigation measures developed using information 

received during the meetings (Shell, 2011a: Appendix H). Attachment B of the POC also includes 

copies of the sign-in sheets from the meetings and the presentation materials used at the meetings 

(Shell, 2011a: Appendix H). The BOEMRE concludes that methods of proposed operations, 

safeguards and mitigation measures detailed in the POC and EP meet the requirements of Stipulation 

5 (Lease Sales 195 and 202). The mitigation measures in the POC would be requirements of plan 

approval and are assumed to be part of the proposed activities for the analysis in this EA. 

In preparation for its revised Camden Bay exploration drilling program, Shell engaged in an active 

consultation program with both Federal and State regulatory agencies, as well as local governments 

and interested residents of the NSB communities. Consistent with Shell’s obligations under Lease 

Stipulation 5, as well as the requirements of the FWS and NMFS under MMPA, Shell has 

communicated and consulted extensively with North Slope subsistence groups and their 

representatives and has committed to continuing to build on these relationships. 

Affected and subsistence communities that were consulted regarding Shell’s proposed activities 

include Barrow, Kaktovik, and Nuiqsut. Beginning in January 2011, Shell held one-on-one meetings 

with representatives from the NSB and Northwest Arctic Borough (NWAB), subsistence-user group 

leadership, and Village Whaling Captain Association representatives. Several one-on-one meetings 

were also held throughout the villages. 

Stipulation No. 6 - Pre-Booming Requirements for Fuel Transfers 

Fuel transfers (excluding gasoline transfers) of 100 barrels or more occurring 3 weeks prior to or 

during the bowhead whale migration would require pre-booming of the fuel barge(s). The fuel barge 

must be surrounded by an oil-spill-containment boom during the entire transfer operation to help 

reduce any adverse effects from a fuel spill. This stipulation is applicable to the blocks and migration 

times listed in the stipulation on Industry Site-Specific Bowhead Whale-Monitoring. The lessee’s oilspill-contingency plans must include procedures for the pre-transfer booming of the fuel barge(s). 

Shell Actions: Shell’s fuel-transfer plan – Alaska Fuel Transfer Operating Conditions and Procedures 

– is included as in the 2011 Camden Bay EP (Shell, 2011a: Section 9.0 and Appendix M). The fuel-
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Other Mitigation 31

transfer plan establishes special operating conditions and procedures for vessel-to-vessel fuel 

transfers. The fuel-transfer plan affirms that booming equipment would be deployed for all fuel oil 

transfers. Shell’s fuel-transfer plan does not fully comply with the requirement of the lease stipulation 

to surround the fuel barge. The U.S. Coast Guard previously expressed concerns about the 

appropriateness and safety of encircling the fuel barge or vessel, as required by Lease Stipulation 6. 

As a condition of approval of the initial exploration plan (Shell, 2009), Shell would be required to 

either modify their fuel-transfer plan to comply with the stipulation or provide justification of how 

their proposed alternative configuration would provide an equivalent level of response preparedness 

(Shell, 2011a, Section 11). 

Stipulation No. 7 - Lighting of Lease Structures to Minimize Effects to Spectacled and Steller’s 

Eiders 

In accordance with the Biological Opinion for the Beaufort Sea Lease Sale 186 issued by the Fish 

and Wildlife Service (FWS) on October 22, 2002, and FWS’ subsequent amendment of the Incidental 

Take Statement on September 21, 2004, lessees must adhere to lighting requirements for all 

exploration or delineation structures so as to minimize the likelihood that migrating spectacled or 

Steller’s eiders would strike these structures. Lessees are required to implement lighting 

requirements aimed at minimizing the radiation of light outward from exploration/delineation 

structures to minimize the likelihood that spectacled or Steller’s eiders would strike those structures. 

These requirements establish a coordinated process for a performance based objective rather than 

pre-determined prescriptive requirements. The performance based objective is to minimize the 

radiation of light outward from exploration/delineation structures. 

Shell Actions: Lighted vessels and structures in open-waters pose a collision risk to many species of 

birds. Growing scientific evidence indicates some bird species are attracted to light sources, which 

may increase the risk of bird strikes. Most related studies conclude that increased darkness coupled 

with inclement weather increases attraction by birds to lighted vessels and structures. Birds drawn to 

light often become disoriented and collide with these structures, which may result in injury and death. 

Shell’s Bird Strike Avoidance and Lighting Plan, Camden Bay, Alaska (lighting plan) (Shell, 2011a: 

Appendix I) outlines Shell’s bird strike avoidance strategy for drilling operations near Camden Bay 

for 201I. Emphasis is on the prevention of bird strikes into the drillship by threatened spectacled 

eiders (Somateria fischeri) and Steller’s eiders (Polysticta stelleri). The chances of bird strikes to the 

drillship are considered to be low. This low probability of bird strikes would be reduced further by 

Shell’s implementation of the lighting modifications as specified in their lighting plan. In addition, if 

a bird strike is observed, reporting the bird strike and the conditions under which it occurred would 

help in better understanding the risks of bird strikes associated with the drillship. 

2.3.12. Other Mitigation 

Some of the additional mitigation measures Shell has adopted and would implement during its 

exploration drilling operations are presented below. Shell first presented their planned mitigation 

measures to community leaders and subsistence users in January 2009 and Shell states that the 

measures have since evolved in response to comments and concerns expressed during the consultation 

process. 

Protection of Subsistence Activities. To minimize any cultural or resource impacts to subsistence 

whaling activities from its exploration operations, exploration drilling activities at the Sivulliq or 

Torpedo drill sites are planned to begin on or about July 10 and run through October 31, with a 

suspension of all operations beginning August 25 for the Nuiqsut (Cross Island) and Kaktovik 

subsistence bowhead whale hunts. During the suspension for the whale harvests, the Kulluk or 

Discoverer and support vessels will leave the Camden Bay project area and move to an area north of 

71.25oN latitude and west of 146.4o W longitude as mutually agreed upon between Shell and AEWC. 

Should the drilling vessel or support vessels anchor during the suspension, none will anchor in known 

environmentally, or archaeologically sensitive areas. Shell will return to resume activities after the 
Shell 2012 Camden Bay EP EA

32 Proposed Action and Alternatives - Other Mitigation 

subsistence bowhead whale hunts conclude. Exploration drilling activities will be completed by 

October 31, depending on ice and weather. 

In addition to the adoption of this suspension measure, Shell would implement the following 

additional mitigation measures to ensure coordination of its activities with local subsistence users to 

minimize further the risk of impacting marine mammals and interfering with the subsistence hunt: 

 To minimize impacts to marine mammals, birds, and subsistence activities, the drilling 

vessel and support vessels will transit north through the Bering Strait on or after July 1. 

The drilling vessel and support fleet will transit through the Chukchi Sea along a route that 

lies offshore of the polynya zone. In the event the transit outside of the polynya zone 

results in Shell having to break ice (as opposed to managing ice by pushing it out of the 

way), the drilling vessel and support vessels will enter into the polynya zone far enough so 

that ice breaking is not necessary. If it is necessary to move into the polynya zone, Shell 

will notify the local communities, via the Com Centers, of the change in the transit route. 

As soon as the fleet transits past the ice, it will exit the polynya zone and continue a path in 

the open sea toward the Camden Bay drill sites. 

 Shell has developed a Communication Plan and will implement this plan before initiating 

exploration drilling operations to coordinate activities with local subsistence users, as well 

as Village Whaling Captains’ Associations, to minimize the risk of interfering with 

subsistence hunting activities, and keep current as to the timing and status of the bowhead 

whale hunt and other subsistence hunts. The Communication Plan includes procedures for 

coordination with Com Centers to be located in coastal villages along the Chukchi and 

Beaufort Seas during Shell’s proposed exploration drilling activities. 

 Shell will employ local Subsistence Advisors (SA) from the Beaufort and Chukchi Sea 

villages that are potentially impacted by Shell’s exploration drilling activities. The SAs 

will provide consultation and guidance regarding the whale migration and subsistence 

activities. There will be one SA per village, working approximately 8-hrs per day and 40-

hrs per week during the drilling seasons. The SA will use local knowledge (Traditional 

Knowledge) to gather data on subsistence lifestyle within the community and to advise 

Shell in ways to minimize and mitigate potential negative impacts to subsistence resources 

during the drilling season. Responsibilities include reporting any subsistence concerns or 

conflicts; coordinating with subsistence users; reporting subsistence-related comments, 

concerns, and information; coordinating with the Com and Call Center personnel; and 

advising how to avoid subsistence conflicts. Shell will provide the SA's with a handbook 

that will specify work tasks in more detail. 

 Aircraft will not operate below 1,500 ft (457 m) unless the aircraft is engaged in marine 

mammal monitoring, approaching, landing or taking off, in poor weather (fog or low 

ceilings), or in an emergency situation. Aircraft engaged in marine mammal monitoring 

shall not operate below 1,500 ft (457 m) in areas of active whaling; such areas will be 

identified through communications with the Com Centers. 

 Except for airplanes engaged in marine mammal monitoring, aircraft shall use a flight path 

that keeps the aircraft at least 5 mi (8 km) inland until the aircraft is south of its offshore 

destination, then at that point it shall fly directly north through the Mary Sachs Entrance 

(Mary Sachs Entrance is the name of a channel between barrier islands, located south of 

the drill site area) to its destination. Shell reserves the right to use an alternative flight 

route in the event that transit through the Mary Sachs Entrance is unsafe due to weather, 

other environmental conditions, or in the event of an emergency. 

Protection of Marine Mammals and other Wildlife. Marine mammal mitigation measures would 

use MMOs to minimize disturbance to marine mammal resources and interference with the 

subsistence hunt of those resources. The MMOs would be stationed on all drilling and support vessels 

to monitor the exclusion zone (areas within isopleths of certain sound levels for different species) for 

marine mammals. The MMOs would initiate mitigation measures when appropriate. The MMOs 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Other Mitigation 33

would visually survey inside the exclusion zone (area within isopleths of specific sound level for 

different species) and operational zones (areas of prescribed proximity that may require avoidance 

measures for marine mammals). For vessels in transit, if a marine mammal is sighted from a vessel 

within its acoustic or operational safety radii, the Shell vessel would take appropriate mitigation 

measures, which may include reducing speed, changing course to avoid the animals, avoiding 

multiple course changes, avoiding separating members from a group, or minimizing vessel activities. 

Specifically, moving vessels would avoid polar bears, walrus, and groups of whales by a distance of 

1,500 ft (457 m), and would reduce speed if within 900 ft (274 m) of other marine mammals. Full 

activity would not be resumed until all marine mammals are outside of the exclusion zone and there 

are no other marine mammals likely to enter the exclusion zone. The complete MMO protocol is 

included in the 4MP (Shell, 2011a: Appendix D). 

Shell’s Aerial Survey Program, described in the 4MP, would enhance the monitoring of onboard 

MMOs and acoustic monitoring. Aerial surveys would begin 5-7 days prior to field operations and 

continue 5-7 days after operations at a site are complete. Aerial surveys would occur daily during 

operations, subject to weather and flight conditions, and follow predetermined survey grids tailored 

for Shell’s specific operations. Each survey flight would have two monitors seated at bubble windows 

(to facilitate downward viewing) on either side of the aircraft. Aerial monitors would be in real-time 

communication with operating vessels. Aerial monitors would advise vessels of the presence of 

marine mammals in the project area and collect data on the distribution, numbers, and movements of 

marine mammals near the drilling vessel and support vessels. 

Anchored vessels would remain at anchor and continue ongoing operations if approached by a marine 

mammal. The anchored vessel would remain in place and continue ongoing operations to avoid 

possibly causing avoidance behavior by suddenly changing sound energy conditions. 

While onsite, the drillship would remain at anchor and continue ongoing operations if approached by 

a marine mammal (i.e., no predetermined “real-time” mitigation would be implemented for anchored 

vessels). Modeled sound radii indicate that the drillship activities would generate a 120 dB re 1 μPa at 

13.27 km from the Kulluk and 3.32 km from the Discoverer (Shell, 2011a: Table 10.b-1, page 10-4). 

The NMFS uses a 120-dB rms isopleth to indicate where Level B harassment begins for continuous 

acoustic sources, such as drillships. 

Aerial monitors would record data on observable effects, if any, to migrating whales (e.g., the 

distance between the operations and the whale(s)). 

Shell provided a plan to ensure that potential threats are adequately addressed regarding polar bears 

and Pacific walrus (Shell, 2011a: Appendix E). 

In addition, Shell would implement the following measures to further minimize disturbance to marine 

mammals (Shell, 2011a : Section 12; Shell, 2011b, Section 2.11 and Section 4.3.3): 

 A marine mammal monitoring protocol; 

 Aircraft will not operate within 1,000 ft (300 m) of marine mammals; 

 Aircraft and vessels would not operate within 0.5 mi (800 m) of walrus, or polar bears 

when observed on land or ice; 

 All vessels must maintain cruising speed not to exceed 9 knots while transiting the 

Beaufort Sea. This measure would reduce the risk of ship-whale collisions. 

 Vessel speed to be reduced during inclement weather conditions to avoid collisions with 

marine mammals; 

 All vessel transit routes will avoid known fragile ecosystems and critical habitat areas, 

including the Ledyard Bay Critical Habitat Unit, and will include coordination through 

Com Centers. 

 When within 900 ft (274 m) of marine mammals, vessels will reduce speed, avoid 

separating member from a group and avoid multiple course changes. 
Shell 2012 Camden Bay EP EA

34 Proposed Action and Alternatives - Reduced Discharge 

 A polar bear culvert trap would be established for oil-spill response needs near Point 

Thompson or Kaktovik prior to drilling. 

 Airguns will be ramped up slowly during Vertical Seismic Profiling to warn cetaceans and 

pinnipeds in the vicinity of the airguns and provide time for them to leave the area and 

avoid potential injury or impairment of their hearing abilities. Ramp ups from a cold start 

when no airguns have been firing will begin by firing a single airgun in the array. A ramp 

up to the required airgun array volume will not begin until there has been a minimum of 30 

min of observation of the safety zone by MMOs to assure that no marine mammals are 

present. The safety zone is the extent of the 180 dB radius for cetaceans and 190 dB for 

pinnipeds. The entire safety zone must be visible during the 30-min lead-in to an array 

ramp up. If a marine mammal(s) is sighted within the safety zone during the 30-min watch 

prior to ramp up, ramp up will be delayed until the marine mammal(s) is sighted outside of 

the safety zone or the animal(s) is not sighted for at least 15-30 min: 15 min for small 

odontocetes and pinnipeds, or 30 min for baleen whales and large odontocetes; and 

 Lighting on the drilling vessel will use ClearSky lighting and would be shaded. ClearSky 

lighting is designed to minimize the disorientation and attraction of birds to the lighted 

drilling vessel to reduce the possibility of a bird collision (see the Bird Strike Avoidance 

and Lighting Plan in Appendix I of the revised Camden Bay EP). 

Reduced Discharge 

 Shell will collect (not-discharge) used drilling mud and cuttings-with-adhered-drilling mud 

from well sections below the 26-in. (20-in. casing) hole section. Sanitary waste water, 

domestic wastes, bilge water and ballast water will also be collected (not discharged). 

These waste streams will be transported out of the Arctic to an approved disposal facility. 

 Drilling mud will be cooled to mitigate any potential permafrost thawing or thermal 

dissociation of any methane hydrates encountered during drilling, if such materials are 

present at the drill site. 

 Drilling muds will be recycled to the extent practicable based on operational 

considerations (e.g., whether mud properties have deteriorated to the point where they 

cannot be used further) so that the volume of the spent mud is reduced. 

Pollution Prevention Measures. In addition to the maintenance and implementation of its ODPCP, 

Shell would implement the following additional measures to further minimize the chance of an oil 

spill that might impact marine mammals and interfere with the subsistence hunt: 

 Shell has established and would follow transit routes that avoid known fragile ecosystems 

and critical habitat areas to reduce the possibility of impacting those resources in the 

unlikely event of a vessel accident that resulted in a diesel spill. 

 Shell has developed and would implement an Ice Management Plan (IMP) (Shell, 2011a: 

Section 9.0 and Appendix K) to ensure real-time ice and weather forecasting to identify 

conditions that might put operations at risk and modify its activities accordingly. The IMP 

also contains ice-threat classification levels depending on the time available to suspend 

drilling operations, secure the well, and escape from advancing hazardous ice. 

 Shell has developed and would implement a Critical Operations and Curtailment Plan 

(COCP) (Shell, 2011a: Section 9.0 and Appendix J), which establishes protocols to be 

followed in the event potential hazards, including ice, are identified in the vicinity of the 

drilling operations (e.g., ice floes, inclement weather, etc.). Like the IMP, the COCP threat 

classifications are based on the time available to prepare the well and escape the location. 

The COCP also contains provisions for not initiating certain critical operations, if there is 

insufficient time available before the arrival of the hazard at the drill site. 
Shell 2012 Camden Bay EP EA

Proposed Action and Alternatives - Environmental Monitoring 35

 Shell has engineered each of its exploration wells (hole sizing, mud program, casing 

design, casing cementing depth, wellhead equipment, etc.) specifically to minimize the risk 

of uncontrolled flows from the wellbore due to casing or other equipment failures. 

 Shell requires its drilling supervisors, toolpushers, drillers, and assistant drillers to hold an 

International Association of Drilling Contractors (IADC) WellCap (or equivalent) 

certificate showing mastery of well-control procedures and principles, and its crews must 

participate in regular training and drills in kick control to minimize the risk of a wellcontrol event that might lead to a spill. 

 Shell would use state-of-the-art automatic kick-detection equipment, including pit-volume 

totalizers, a flow detector, and various gas detectors placed about the rig, to provide early 

warning of a potential well-control event. 

 The blowout preventer Shell would install on the high-pressure wellhead housing on the 

20-in conductor casing on each exploration well includes redundant mechanical barriers to 

provide multiple means of closing in the well to prevent oil flow to the surface. 

 Shell would install multiple barriers, including manual and automated valves, on the 

drilling rig to prevent flows from coming up the drill string. 

 Shell has developed and would implement a Well Control Contingency Plan (WCCP) 

(Shell, 2011a: Section 9.0 and Appendix L) in the extremely unlikely event of a wellcontrol event to minimize the risk of oil coming in contact with the water. As part of the 

WCCP, Shell would prepare a Relief Well Drilling Plan for each location in advance of 

spudding the well to ensure that a relief well can be started quickly to kill the well. 

 Shell has developed and would implement a Fuel Transfer Plan (FTP) (Shell, 2011a: 

Section 9.0 and Appendix M), which requires, among other things, the deployment of 

containment boom prior to any refueling operation. 

 Shell would station and maintain its OSRVs in the immediate vicinity of its drilling 

operations to ensure timely response to any spill event. 

 In addition to the OSR fleet, capping stack equipment will be available for use in the 

unlikely event of a blowout. The capping stack system will be carried as equipment on an 

ice management vessel and the containment barge will be located in the Beaufort Sea 

where it can respond as required as discussed in Section 5.5.2. 

 Capping Stack equipment will be stored aboard one of the ice management vessels and 

will be available for immediate deployment in the unlikely event of a blowout. Capping 

Stack equipment consist of subsea devices assembled to provide direct surface intervention 

capability with the following priorities: 

 Attaching a device or series of devices to the well to affect a seal capable of 

withstanding the maximum anticipated wellhead pressure (MAWP) and closing the 

assembly to completely seal the well against further flows (commonly called 

“capping and killing”) 

 Attaching a device or series of devices to the well and diverting flow to surface 

vessel(s) equipped for separation and disposal of hydrocarbons (commonly called 

“capping and diverting”) 

2.3.13. Environmental Monitoring 

In addition to monitoring of marine mammals, a comprehensive environmental monitoring program 

will be implemented during exploration drilling operations (Shell, 2011a: Section 10). A dedicated 

science vessel staffed by a team of physical and biological oceanographers will be responsible for 

assessing pre-drilling, during, and post drilling conditions in both biota and water and sediment 

quality. All drilling locations have been sampled at multiple times during the last three years to 

provide a baseline understanding of pre-existing conditions and interannual variability at these sites. 
Shell 2012 Camden Bay EP EA

36 Proposed Action and Alternatives - Environmental Monitoring 

Meteorological and physical oceanographic characteristics that will be monitored continuously at 

each location throughout the drilling process include: surface wind direction and speed, ambient air 

temperature, current speed and direction throughout the water column, water temperature through the 

water column and salinity through the water column. 

Water chemistry and characteristics that will be monitored will include assessment of metals and 

organics through the water column at multiple fixed and random locations around the drilling 

operation. These measurements will be made regularly before, during, and after drilling and will 

capture conditions during all noteworthy phases of drilling operations and potential discharge. 

Physical characteristics of the water column will also be assessed including turbidity, temperature, 

and oxygen content in an effort to document and model plumes of released discharges. 

Biological observations will include assessments of benthos, epibenthos, zooplankton and 

phytoplankton, and fishes. In addition to characterization of the communities of these organisms at 

and near the drillsites before, during, and after operations, samples of biota will be collected before 

and after operations for tissue analysis for metals and organics. 

Bird and mammal observations will be made from all surface operation vessels throughout the 

exploration drilling activity in accordance with the 4MP and Bird Strike Lighting and Avoidance Plan 

(Shell, 2011a: Appendix I). 
Shell 2012 Camden Bay EP EA

Affected Environment - Meteorology 37

3.0 AFFECTED ENVIRONMENT 

Introduction 

The following sections summarize environmental conditions and resources in areas that could be 

affected by the Proposed Action and No Action alternative. The summaries are focused on aspects of 

resources that are relevant to an analysis of potential effects from the Proposed Action and 

alternatives. Information relevant to the analysis of potential effects that has become available 

subsequent to the 2009 Camden Bay EA is indicated and summarized. A detailed discussion of the 

marine, coastal, and human environment of the Beaufort Sea planning area is contained in the lease 

sale NEPA documents listed in Section 1.2 which are incorporated by reference into this EA. 

3.1. Meteorology 

3.1.1. Climate Change 

Climate describes the behavior pattern of weather in a particular region, or globally, over a long 

period of time, usually exceeding 30 years, whereas weather describes the changing conditions at 

smaller defined locations over a short period of time, minutes to months. Generally, climate is what to 

expect and weather is what happens; and meteorology is the underlying science that studies the 

physics, chemistry, and dynamics of both. Meteorological studies that investigate weather and climate 

are ongoing, particularly with respect to the factors that drive climate change, which in the Arctic 

include the movement of heat, water, pollutants, and salinity into the region through atmospheric and 

oceanic circulation. Also ongoing are the expansion and further development of the current suite of 

computer models that simulate impacts from climate change. While not every contributing factor is 

well-represented in the current models, the existing suite of models used to simulate climate change 

in the Arctic is able to represent some aspects fairly well (Clow et al., 2011). 

While climate is considered long-term average weather, there are mechanisms that cause repeated, 

and predictable, short term systematic changes, such as El Niño and La Niña. These two mechanisms 

occur every two to seven years and directly involve the tropical Pacific but have a global impact. 

Conversely, a long time-scale climate mechanism is associated with the high latitudes of the Arctic, 

referred to as the Arctic Oscillation (AO). Occurring every 10 to 30 years, the AO is characterized by 

changes in the severity of winter weather and the frequency of storms. Fluctuating between positive 

and negative phases, the AO phase defines the location of pressure systems that drive weather 

systems. In the positive phase, there is higher pressure at the middle latitudes while lower pressure 

rests over the Arctic. This phase steers storms farther north and brings wet and warmer weather to 

Alaska. In the negative phase the situation is reversed. There is higher-than-normal pressure over the 

Arctic and lower-than-normal pressure in the middle latitudes causing cold air to plunge into the 

middle United States. Thus, the climate in the Arctic ‘oscillates’ between the positive and negative 

phases, and is currently in the negative phase of Arctic warming (Vincent and Renwick, 2011). 

Research focusing on future atmospheric circulations suggests the 21st century will bring a change in 

the distribution of winter storms in the Arctic. Some studies indicate winter weather in the Arctic, 

usually driven by the semi-permanent Aleutian low pressure center, might track further north to the 

west coast of Alaska with increasing frequency; this could cause an increase in the frequency of 

storms, particularly in the winter (Chapman and Walsh, 2007). Other studies suggest there is no 

general agreement that the number and/or intensity of Northern Hemisphere storms have changed 

over the past decades (Bader et al., 2011). In any case, the exploration operations proposed by Shell 

for the Beaufort Sea would occur in the summer through the end of October. Therefore, while the 

anticipated frequency and intensity of winter storms in the Beaufort and Chukchi seas remains 

debatable (Clow et al., 2011), an increase in frequency or intensity of winter storms over the shortterm period of exploration would not impact the Proposed Action. 

Along with the changes in atmospheric circulation, adjustments in oceanic circulation are causing an 

increase in the loss of sea ice in the Arctic. The loss of sea-ice could increase the presence of internal 

waves bringing deep waters to the surface, which are rich in nutrients. Consequently, there may be 
Shell 2012 Camden Bay EP EA

38 Affected Environment - Expected Weather Conditions at the Drill Sites 

effects to habitat and other natural resources that could change the distribution and abundance of 

particular species. These conditions could shift migration routes or affect food sources of species or 

species groups. Storm surges may produce changes in the dynamics of rivers and deltas affecting 

habitat and some populations of fish species (Weller, 1998). Further, the loss of sea-ice could increase 

wave action that would contribute to degradation of the coastline of the Beaufort Sea. The likelihood 

of permafrost degradation is a concern and is expected to continue for decades (Clow et al., 2011). 

However, permafrost degradation along the coast will continue with or without OCS exploration 

projects. No permanent onshore infrastructure vulnerable to permafrost degradation would be 

developed during exploration operations. 

The extent of sea-ice cover over time affects current prevailing atmospheric conditions by changing 

the exchange of heat, momentum, and moisture. Thus, the decrease in sea-ice cover would increase 

the availability of water vapor in the precipitation process (Bader, et al., 2011). Combined with the 

possible change in track of the Aleutian low pressure center to a more northerly location, the increase 

in water vapor available above the ocean surface could cause an increase in the amount of 

precipitation over the Arctic. However, there has been no prediction in the magnitude of the increase, 

which would reduce the salinity of the upper portion of the ocean (Clow et al., 2011). 

A thorough scientific examination of climate change in the Arctic is provided by the Intergovernmental Panel on Climate Change (IPCC, 2007a) and the Arctic Climate Impact Assessment 

(ACIA, 2005). The two reviews offer the most comprehensive compilation of information available 

on climate change, agreeing that the Arctic is experiencing variations that are accelerating faster than 

previously realized (Karcher et al., 2010). Other research concurs the Arctic is undergoing rapid 

transition, including surface warming (affecting cloudiness) and changes in the cryosphere, the frozen 

water part of the Earth system that includes sea ice (Matthes, Rinke, and Dethloff, 2009) . While 

some aspects of the Arctic climate that drive the changes are not yet represented in the current 

simulation models, the existing suite of models used to simulate climate change in the Arctic is able 

to represent other aspects fairly well (USGS, 2011). The BOEMRE is actively engaged in updating 

general circulation models for use in OCS decision making. A recent workshop on OSRA Hindcast 

specifically addressed these uncertainties in modeling with general circulation models and provided 

recommendations for BOEMRE to consider. There is a potential for climate change impacts to natural 

resources, and those impacts are considered in the individual evaluations provided in Section 4.0, 

Environmental Consequences, where relevant. 

3.1.2. Expected Weather Conditions at the Drill Sites 

The annual prevailing winds along the northern Alaska coastline of the Beaufort Sea vary somewhat 

by season and flow predominately from the east most of the year, turning west in December and 

January (WRCC, 2011). Average wind speeds throughout the year are less than 15 miles per hour 

(mph) with lower wind speeds in the summer than in winter. A multiyear meteorological study that 

includes data from stations along the coastline at Barter Island, Kaktovik, Deadhorse, and Nuiqsut 

provides a trend for wind patterns on the North Slope that are influenced by the Brooks Range 

(Veltkamp and Wilcox, 2007). The study shows that the regardless of whether the winds are from the 

east or west, the flow over the eastern portion of the Beaufort Sea coastline is influenced by the 

orographic effects of the Brooks Range, and can effect wind direction as far as 30 miles offshore 

along the area extending from Camden Bay to Mackenzie Bay. The influence of the Brooks Range 

causes wind to flow roughly parallel to the north side of the range in a general northeast to southwest 

orientation. While the incidence of wind channeling is strongest on the eastern coastline near Barter 

Island, orographic influence of the range is present all along the coast. Influence from the mountain 

range decreases to the west and shows little influence at Barrow where wind direction is influenced 

largely by surface pressure systems rather than any orographic feature. 

With little warning, occasional sudden storms can occur in the Alaskan Beaufort Sea where the lack 

of natural wind barriers results in unrestricted winds. These storms bring cold temperatures and occur 

most frequently between September and November. Consequently, strong storms may occur around 

the close of the drilling season proposed in the EP. The storms can produce gale-force winds up to 46 
Shell 2012 Camden Bay EP EA

Affected Environment - Expected Ice Conditions at the Drill Sites 39

mph and hurricane strength winds (greater than 74 mph) have been recorded in the region (Veltkamp 

and Wilcox, 2007). The combined effect of high winds during storms and cold temperatures makes 

the North Slope of Alaska a risk to persons exposed for even brief periods of time. Frostbite can occur 

following less than five minutes of exposure when the wind chill drops as low as minus 90 degrees 

Fahrenheit (deg. F) during these storms (NWS, 2009). In gale-force wind conditions, the sea begins to 

roll, spray reduces visibility, and waves can be as high as 20 feet (NWS, 2008). 

On average, semi-permanent low pressure systems produce summer storms that bring more than half 

of the annual five inches of total precipitation to the North Slope (Ahrens, 2009). Most of the rainfall 

occurs from June until October, during the proposed drilling season for the EP. The relative humidity 

during the summer is usually around 85%. Average minimum temperatures stay above freezing from 

May until October, which would be true throughout the drilling season proposed in the EP. The 

highest average temperatures occur in the summer months of June through August when the greatest 

amount of precipitation occurs. Average temperatures in the summer average around 38 deg. F and by 

winter, temperatures are bitterly cold averaging around minus 11° F (Veltkamp and Wilcox, 2007). 

When considering the average wind speeds and temperatures common to the North Slope, wind chills 

will likely be around minus 10° F by late September (WRCC, 2011; NWS, 2001). 

3.1.3. Expected Ice Conditions at the Drill Sites 

The sea-ice descriptions in Sale 193 Revised SEIS (USDOI, BOEMRE, 2011), Arctic Multiple-Sale 

Draft EIS (USDOI, MMS, 2008), and the 2011 Camden Bay EIA (Shell, 2011b) are incorporated by 

reference and salient points are summarized as follows. There are three general forms of sea ice in 

the project area: (1) landfast ice, which is attached to the shore, is relatively immobile, and extends 

variable distances offshore; (2) stamukhi ice, which is grounded and ridged ice; and (3) pack ice, 

which includes first-year and multiyear ice, which moves under the influence of winds and currents. 

The proposed drill sites are seaward of the typical extent of landfast ice during the time of operations 

(Wendler, G., M. Shulski, and B. Moore, 2010). Stamukhi ice is not anticipated in the project area at 

the time of operations. Pack ice could move into the project area during the time of operations due to 

wind or currents. Freeze-up analysis in 2009 and 2010 indicates initiation of freeze-up occurring in 

the later part of October (Coastal Frontiers Corp and Vaudrey andAssociates, Inc. 2010, Coastal 

Frontiers Corp. 2011). In 2008, 2009 and 2010, Shell deployed on-ice buoys near the project area 

(AES-RTS, 2009a, 2009b, 2011). While the overall trend of the buoy movement was to the 

northwest, the buoys recorded periods with little to no movement or movement back to the east or 

southeast. 

The arctic sea ice is undergoing rapid changes. There are reported changes in sea-ice extent, 

thickness, distribution, age, and melt duration. In general the sea-ice extent is decreasing in area and 

thickness (Figure 3) and is younger (Maslanik et al., 2011). Satellite data shows a decreasing trend of 

2.7% per decade from 1979-2010 in March (Perovich et al., 2010) and an 11.5% per decade decrease 

for September (NSIDC, 2010), and the decline in sea-ice extent is increasing. The thickness of 

Beaufort sea ice is decreasing (Alfred Wegener Institute for Polar and Marine Research, 2011). The 

distribution of ice is changing, and its age is decreasing. The melt duration is increasing. These 

factors lead to a decreasing perennial arctic ice pack. Many scientists believe that the Arctic will 

become ice free in the summer, but at this time there is considerable uncertainty about when that 

would happen. (See also USDOI, BOEMRE, 2011: USDOI, MMS, 2003, 2004, 2006a, and 2008a). 
Shell 2012 Camden Bay EP EA

40 Affected Environment - Potentially Affected Resources 

Figure 3 Mean September Sea Ice Extents 1982 to 2007 at 5-Year Increments (Shell, 2011a) 

3.2. Potentially Affected Resources. 

3.2.1. Air Quality. 

Outside air becomes polluted and air quality conditions deteriorate when small particles, liquids, and 

potentially harmful gases are released into the atmosphere by a variety of sources. The emission 

sources may be natural or man-made, and may be stationary or mobile. Natural (biogenic) sources of 

air pollutants include, but are not limited to, volcanoes and forest fires that produce dust and smoke; 

sea salt aerosols; and vegetation that is a source of pollen and organic compounds during evaporation 

(EPA, 2010d). Man-made (anthropogenic) sources are related to human activities such as 

transportation (motor vehicles, aircraft, and marine vessels); industrial and residential heating; 

construction; and specifically any activity associated with the combustion of fossil fuels (EPA, 

2010d). Stationary anthropogenic sources are fixed-site producers of emissions, which are primarily 

power-generating-plants requiring fuel combustion, and industrial processes, such as refineries, 

chemical manufacturing facilities, and smelting (EPA, 2010f). A drillship temporarily anchored to the 

seabed floor on the Outer Continental Shelf (OCS) is also considered a stationary source 

(40 CFR Part 55). All other anthropogenic sources are mobile and either move under onboard power 

or can be moved from place to place. Mobile sources account for more than half of all the air 

pollution in the United States, where the primary source is the automobile (EPA, 2010e). Other 

mobile sources include marine vessels, aircraft, equipment used for construction, agriculture, and 

recreation. Regardless of the type of emissions source, or whether sources are permanent or 

temporary, emissions can build up in the atmosphere in concentrations larger than what can be 

tolerated without humans suffering some sort of harm. 

This section describes the existing air quality environment of the area likely to be affected by the 

Proposed Action described in the 2011 Camden Bay EP. The contents of this section provide an 

overview of the federal and state regulatory framework governing air quality relative to the operation 

and location of the Proposed Action. Also included is an examination of the existing condition of air 
Shell 2012 Camden Bay EP EA

Affected Environment - Air Quality 41

quality in northern Alaska, particularly over the land areas of the North Slope adjacent to the Beaufort 

Sea. The comprehensive evaluation and analysis of air quality is provided in Appendix D, Air 

Quality. A summary of the weather conditions typical for the location of the Proposed Action is 

provided in Section 0. 

Regulatory Overview. Elevated concentrations of air pollution in the ambient air, which is outside 

air where the general public has access, have been shown to cause harm to human health and the 

natural environment (EPA, 2010a). As such, federal and state air agencies are obliged to develop 

plans, regulations, and guidelines to protect ambient air as a natural resource (EPA, 2010b). The 

following sections explore the various regulatory provisions established to protect air quality, 

particularly in the area of the Proposed Action. A thorough review of all the rules, regulations, and 

guidelines that apply to an air quality assessment for an OCS exploration plan is provided in 

Appendix D, Air Quality. 

Clean Air Act. The Clean Air Act, including the 1990 Amendments (CAA), is the comprehensive 

law giving the Environmental Protection Agency (EPA) authority to clean up areas of polluted air in 

the United States. Originating in 1963, the CAA is revised periodically to expand and refine programs 

to protect the nation’s ambient air. Through these revisions, the CAA gives authority to the EPA to 

establish and maintain maximum limits defining healthful concentrations of pollutants in the ambient 

air, referred to as the National Ambient Air Quality Standards (NAAQS). The NAAQS include the 

six pollutants referred to as criteria pollutants, which are carbon monoxide (CO), nitrogen dioxide 

(NO2), sulfur dioxide (SO2), particulate matter, both coarse (PM10) and fine (PM2.5), lead (Pb), and 

ozone (O3) (40 CFR Part 50). The State of Alaska adds ammonia (NH3) and reduced sulfur 

compounds (RSC) to the listed regulated pollutants (18 AAC Part 50.010). The NAAQS are 

compared to actual monitored data, which discloses the average concentration of air pollutants over a 

period of time, such as an 8-hour average or annual average, at a specific geographical location. 

Geographical areas that are shown to meet the NAAQS are designated by the EPA as attainment 

areas. Areas that exceed the standards are designated nonattainment and are subject to rules that 

require additional analyses and a demonstration of compliance to the CAA. A complete description of 

the NAAQS and definitions for attainment and nonattainment areas are given in Appendix D, Air 

Quality. 

The CAA establishes air permitting programs, specifically a program for the prevention of significant 

deterioration (PSD) for areas of the country already in compliance with the NAAQS (Martineau and 

Novello, 2004). These permits are usually required for federal actions proposed for the OCS, and 

there is a section of the CAA that is relevant specifically to federal actions proposed to occur on or 

above the OCS. Title III Section 328, Air Pollution from Outer Continental Shelf Activities (42 USC 

7627) directs the EPA to establish requirements for the control of air pollution from sources on the 

OCS in order to maintain the NAAQS. Other operating and pre-construction permits may also be 

required, such as those required under CAA Title V. 

Federal OCS Air Regulations. Pursuant to CAA Section 328, the EPA establishes requirements to 

control air pollution from sources on the OCS, including Alaska. The requirements are published in 

the Code of Federal Regulations (CFR), Title 40, Part 55, and are referred to as the federal OCS Air 

Regulations (40 CFR Part 55). The federal OCS Air Regulations make a distinction between OCS 

sources located within 25 miles of the State’s three- mile seaward boundary and sources located 

beyond the 25- mile threshold. The federal OCS Air Regulations provide an outline of the federal air 

quality requirements that apply at an OCS source relative to the 25-mile threshold, and describes the 

operating permit requirements. 

Alaska Air Quality Control Rules. Air quality management is regulated by the Alaska Department 

of Environmental Conservation (ADEC). The ADEC is responsible for the control of anthropogenic 

sources of emissions in all parts of Alaska, including permitting requirements and mitigating 

measures to conserve the clean air resources that are enjoyed in many locations in Alaska. These 

mitigation measures and controls are summarized in the Alaska State Air Quality Control Plan 

(AQCP) (ADEC, 2008). Those portions of the AQCP that address federal air quality control 
Shell 2012 Camden Bay EP EA

42 Affected Environment - Air Quality 

requirements are submitted for EPA approval and become part of the federally-required Alaska State 

Implementation Plan (SIP). In addition, the AQCP contains state requirements and control measures 

that are not necessarily required by the EPA and are not included in the SIP. The entire AQCP is 

adopted by reference into the Alaska Administrative Code (AAC) (18 AAC 50), making the SIP an 

enforceable plan that outlines how the state will achieve and maintain the established state and federal 

air quality standards. 

Air Quality on the Alaskan North Slope. The EPA does not specify the air quality conditions of 

locations over the open sea; only landside geographical locations with homogeneous air quality 

characteristics are classified according to quality of the air. These geographic regions are referred to 

as air quality control regions (AQCR). Sources of emission on the OCS that are within 25 miles (46.3 

km) of the State’s 3 mi (5.6 km) seaward boundary (a total of 28 mi (51.8 km)), are subject to the 

local requirements of the Corresponding Onshore Area (COA), which would be the onshore area that 

is geographically closest to the OCS source (40 CFR 55(3)(b)). The COA for the Proposed Action 

would be Alaska’s North Slope, adjacent to the Beaufort Sea. The EPA has defined Alaska’s North 

Slope to be within the Northern Alaska Intrastate Air Quality Control Region (NAI-AQCR9), which 

includes all the area of Alaska north of the Brooks Range (40 CFR Part 81.246), and is designated as 

a Class II area (18 AAC Part 50.015). The EPA has classified the North Slope as a clean air resource 

(attainment) as pollutant concentrations in the area are well below the NAAQS and the Alaska 

Ambient Air Quality Standards (AAAQS) (EPA, 2011). 

Attainment Status. The EPA reports that the pollutant concentrations within the North Slope 

Borough from the very few sources of emissions are far below the NAAQS throughout the AQCR9 

due to dispersion caused by nearly constant wind and low precipitation over the area (Serreze and 

Barrett, 2011). The wind is also the long-range transport mechanism of anthropogenic pollution from 

sources on the Eurasian continent during the winter and early spring. 

Existing Sources of Emissions on the North Slope. There are few industrial development areas on 

the North Slope to contribute to the budget of air emissions. The largest source of emissions is the 

Prudhoe Bay Oil Field, the largest oil field in North America. Prudhoe Bay is a large work camp for 

the oil and gas industry employing over 5,000 workers in drilling, pipeline operations, and cargo 

transportation. Most inhabitants of Prudhoe Bay are employees of companies supporting oil drilling 

or oil production, including Shell. A small petroleum refinery operates on-site to supply vehicle fuel 

for workers and equipment on the oil field. Operations on the site include flaring, which is the 

controlled burning of natural gas. Emissions from a flare stack are comprised mainly of water vapor 

and carbon dioxide. At the Prudhoe Bay site, flaring is used for power generation and to control 

equipment pressure. Natural gas is used to heat the buildings and to generate electricity. Numerous 

flights of medium-range jet aircraft operate at the nearby airport at Deadhorse to facilitate the 

workers’ rotating schedules and for delivery of equipment and supplies; a state-owned heliport is 

located at Prudhoe Bay. Implementation of the proposed exploration plan would require Shell to use 

the existing onshore facilities and no new construction is planned. Therefore, there would be no 

expected increase in onshore emissions associated with the proposed exploration. 

Arctic Haze. The ADEC reports the Arctic atmosphere becomes contaminated with anthropogenic 

pollution through long-range transport from Europe and Russia in the winter months. Meteorological 

studies support the suggestion that about 95% of the pollution is coming from Europe and Russia 

propelled by winds associated with the seasonal Siberian high-pressure system (Serreze and Barrett, 

2011). The phenomena is referred to as Arctic haze, and consists of mostly sulfur oxides and soot, but 

includes both gaseous and aerosol components. The phenomenon usually begins in early winter and 

reaches a peak impact in March, after which time the haze dissipates. The haze particles are very 

lightweight, with a diameter usually in the range of 0.4-0.8 micrometers, so the particles may be 

suspended in the air for weeks, allowing light to scatter, which affects visibility. Based on haze 

composition and the source regions, the primary contributors to Arctic haze are coal burning and 

metal smelting. In the absence of Arctic haze, visibility in the area is greater than 160 Statute Miles 

(mi) (257 km). The EPA has determined the regional air quality over AQCR9 continues to be better 
Shell 2012 Camden Bay EP EA

Affected Environment - Water Quality 43

than the NAAQS even with the seasonal occurrence of Arctic haze. Arctic haze would only be visible 

during the last stages of the Proposed Action, mostly likely in late October in the phenomena's initial 

stages, and is not expected to interfere with exploration operations. 

3.2.2. Water Quality. 

There is very little development in the watersheds of the U.S. Arctic and because of this nonpoint 

pollution runoff from watersheds into the Beaufort Sea is limited. The rivers, lakes and wetlands of 

the region carry naturally-occurring loads of sediment, trace metals and hydrocarbons into the 

Alaskan Beaufort Sea environment. The pathways of wind, currents, precipitation and drifting seaice affect the water quality of the Beaufort Sea through long-range transport of constituents and 

contaminants. Pollutants such as polycyclic aromatic hydrocarbons can be transported long distances 

and ultimately affect the U.S. arctic. The sources of these global contaminants include: airborne 

industrial pollutants, vessels, existing oil and gas operations, coastal development runoff and 

discharges. Pollution in the arctic is described in “Arctic Pollution Issues: A State of the Arctic 

Environmental Report” (Arctic Monitoring and Assessment Program, 1997) and is incorporated here 

by reference. 

Beaufort Sea waters are influenced by mixing by wind and storms, spring river runoff, and sea ice 

formation and melt. Trefry and Trocine (2009) conducted vertical water column profiles at 8 stations 

in Camden Bay over 4 days in August 2008 (depths 22-38 m) to obtain discrete baseline data on 

temperature, salinity, pH, dissolved oxygen, turbidity, total suspended solids (TSS) and particulate 

organic carbon (POC). At the four more offshore, deeper sites (33-38m), strong temperature 

stratification was observed at depths greater than 20-25 m (6  ̊C at the surface, 0.3  ̊C below 25 m). 

Salinity at these four deeper sites also showed a marked change below 25 m, increasing from 27-28 

ppt at the surface to 31-32 ppt below 25 m. At the four stations that were nearer to shore and more 

shallow (22-31 m), stratification was less strong, particularly for salinity. Lower water temperatures 

at these sites were generally measured below 25 m, however, the most shallow site (22 m) showed a 

relatively uniform vertical profile of 4 – 5  ̊C. 

During the four days of sampling, concentrations of dissolved oxygen were at 89% to 104% 

saturation. pH ranged from 7.8 to 8.4. Turbidity was low and relatively similar across all samplings 

(1.8 to 3 NTU). Total suspended solids (TSS) ranged from 0.26 ± 0.13 mg/L (at 2 to 3m) and 0.73 ± 

0.31 mg/L (10 to 25 m). Concentrations of particulate organic carbon (POC) averaged 26% (at 2 to 3 

m layer) and 11% (at 10 to 25 m layer) of the TSS, indicating that the surface contained a relatively 

higher concentration of POC than deeper waters. Table 5 presents a summary of the range of 

measurements collected over all 8 stations. 

Table 5 Water column measurements in Camden Bay, Alaska, over four days in August 2008 (after 

Trefry and Trocine, 2009) 

Variable Surface Water Bottom Water ( >20m) 

Salinity (ppt) 25.3 to 29.2 29.7 to 31.7 

Temperature (°C) 4.3 to 6.4 0.24 to 0.38 

Turbidity (NTU) 1.8 to 2.6 2.0 to 3.0 

pH 7.8 to 8.4 7.7 to 8.0 

Dissolved Oxygen (mg/L) 9.5 to 10.4 11 to 12.2 

Oxygen Saturation (%) 89 to 98 96 to 104 

TSS (mg/L) 0.26 ± 0.13 0.73 ± 0.31 

POC (mg/L) 0.066 ± 0.038 0.081 ± 0.0.025 

POC as % of TSS 25.7 ± 6.4 10.0 ± 3.5 

Water quality in the Beaufort Sea has been documented through many studies and regulatory 

programs over years. Specific to the proposed exploration sites, Trefry and Trocine (2009) found 

background (non-elevated) levels of total metals in surface and subsurface sediment samples in the 
Shell 2012 Camden Bay EP EA

44 Affected Environment - Water Quality 

immediate vicinity of the Sivulliq drill site; an exception was elevated concentrations of total barium 

in eight out of 42 sediment samples. The authors attributed these elevated barium measurements to 

past discharges of drilling mud and cuttings. Trefry and Trocine also found that total petroleum 

hydrocarbons and total polycyclic aromatic carbons were at background levels (non-elevated) at 45 of 

46 sample locations in the area; the one exception was a sample taken near an earlier drill site. 

Dunton et al. (2009) found that inorganic nitrogen in the water column in the Sivulliq area of Camden 

Bay was close to undetectable, but that ammonium in sediment pore-water was high, indicating active 

biogeochemical processes between the water column and pore water in the benthic sediments. They 

also found through isotope studies that carbon in the area is derived primarily from marine sources, 

not terrestrial sources. The water column production, they conclude, is coupled with the benthos, 

providing a strong feedback between the sediments and overlying water. 

Ocean acidification in the marine environment is a concern in the Beaufort Sea. As carbon dioxide 

(CO2) increases in the atmosphere, the ocean absorbs more CO2. This increase in CO2 in seawater 

forces an increase in hydrogen ion concentration and a lowering of pH over time. Decreasing pH 

changes the equilibrium of the inorganic carbon system in the sea by reducing the concentration of 

carbonate ions (CO3

-2), an essential molecule for many organisms that produce structures of calcium 

carbonate (CaCO3). 

Seawater worldwide is normally alkaline; however, seawater is now acidifying and losing its 

buffering alkalinity, causing pH to decrease to levels exponentially below its historic global average 

of 8.1. The average pH of ocean water worldwide is predicted to continue to decrease in the future 

(Caldeira and Wickett, 2003, 2005). If carbon dioxide in the atmosphere continues to increase at 

today’s rate, the rate of pH decrease towards the end of this century is predicted to be even greater 

than the current rate of pH decrease (IPCC, 2007a; Steinacher et al., 2009). 

Other factors such as seawater temperature, the presence or absence of ice, the degree of freshwater 

input, the degree of mixing and increases in phytoplankton also affect the amount of CO2 taken up by 

the sea. Therefore, other aspects of climate change, such as melting ice, increased riverine discharge, 

storm frequency and intensity, and changes in precipitation type, volume and timing also play into 

acidification of the ocean (IPCC, 2007a; Mathis, Cross and Bates, 2011). 

The greatest degree of ocean acidification worldwide is predicted to occur in the Arctic Ocean. This 

amplified scenario in the Arctic is due to the effects of increased freshwater input from melting ice 

and snow and increased CO2 uptake by the sea as a result of sea ice retreat (Steinacher et al, 2009). 

Measurements in the Canada Basin of the Arctic Ocean demonstrated that over 11 years, melting sea 

ice forced change in pH and the inorganic carbon equilibrium, resulting in decreased saturation of 

calcium carbonate in the seawater (Yamamoto-Kawai, 2009). Bates, Mathis and Cooper (2009) 

showed the effects of decreasing pH on the saturation states of inorganic carbonate in the Chukchi 

and Beaufort Sea. 

Increasing ocean acidification is predicted to cause changes in ecosystem processes and present 

additional stressors to organisms (Fabry et al, 2008; Yamamoto-Kawai, 2009; Steinacher, 2009; 

Bates, Mathis, and Cooper, 2009). Decreased thickness of calcium carbonate structures has been 

shown, and in some cases, increased structure thickness has been demonstrated (Reis et al, 2009). 

Decreased pH can also affect other important physiological functions such as cell function in marine 

biota, some of which are important species in the Arctic (Fabry et al, 2008; Dupont et al, 2008). 

Additional information on the water quality and water chemistry in the Beaufort Sea is presented in 

the following NEPA documents and is incorporated here by reference: Arctic Multiple-Sale Draft EIS 

USDOI, MMS, 2008a); and the 2009 Camden Bay EA (USDOI, MMS, 2009). 

Existing Regulatory Control of Discharges. The principal regulatory method for controlling 

pollutant discharges into waters of the U.S. is the Clean Water Act (CWA) of 1972, as amended. 

Section 402 establishes the National Pollution Discharge Elimination System (NPDES). The General 

NPDES Permit issued by EPA for offshore oil and gas exploration facilities in Alaska (AKG280000) 
Shell 2012 Camden Bay EP EA

Affected Environment - Lower Trophic Levels 45

permits authorized discharges, with restrictions, into the Beaufort Sea. EPA regulations 

(40 CFR 125.122) require a determination that the permitted discharge will not cause unreasonable 

degradation of the marine environment. EPA issued an NPDES Vessel General Permit (VGP) for 

“Discharges Incidental to the Normal Operation of a Vessel;” the EPA VGP for Alaska was finalized 

in February, 2009 (EPA, 2009). The final VGP applies to owners and operators of non-recreational 

vessels that are 79 feet (24.08 meters) and greater in length, as well as to owners and operators of 

commercial vessels of less than 79 feet which discharge ballast water. 

The latest information on water-quality standards for the EPA is available in 40 CFR § 131 or at the 

agency’s internet web site at www.epa.gov. State of Alaska water quality standards are available in 

18 AAC 70 or at the Alaska Department of Environmental Conservation website (ADEC, 2011). 

3.2.3. Lower Trophic Levels 

The lower trophic organisms living within the Beaufort Sea of the Alaska OCS consist of three 

diverse and abundant groups (Hopcroft et al., 2008). These are the pelagic, the epontic, and the 

benthic organisms. The components of the pelagic communities are made primarily of two groups 

living at the surface and near-surface levels, the phytoplankton and zooplankton. Phytoplankton are 

the one-celled algae adapted to living in the photic zone (the upper areas where light adequate for 

phytoplankton penetrates the water) in the upper layers of the ocean surface (Steidinger and Garcces, 

2006). Within Arctic waters, the combination of cold temperature, sea ice, and seasonal fluctuations 

in light regimes creates variation in the timing and extent of seasonal blooms. Phytoplankton blooms 

(with concurrent zooplankton and meroplankton stocks) tend to occur in two separate events of early 

and late summer, generally from July to August, with density and duration dependent upon weather 

conditions and nutrient fluxes (Kirchman et al, 2009). Zooplankton consist of the metazoan, or multicelled organisms including permanent residents of the planktonic mass such as copepods, and the 

animals exhibiting complex life cycles that include a developmental stage within the plankton blooms 

such as the larvae of fish, crustaceans, barnacles, polychaetes, and mollusks (Brusca and Brusca, 

2002). The pelagic expanses between the surface and the benthic realms are diverse and abundant, 

and include the larvaceans, pteropods, ctenophores, jellyfish, salps, squid, and other invertebrate 

organisms that contribute to the productivity of the region (Hopcroft et al., 2008). 

The epontic organisms are the ice-dwellers, organisms that live on or in the matrix of the ice during 

the winter season (Gradinger, Bluhm, and Iken, 2010). Essential in the primary productivity of the 

region (Lee et al., 2008) these organisms include the ice algae, amphipods, nematodes, polychaetes, 

and euphausiids (Hopcroft et al., 2008). Although essential to the primary productivity of the region, 

these organisms are not present in abundance during the July through October exploration activities 

described in the 2011 Camden Bay EP. 

The final group are the benthic organisms, consisting of both those groups living within the upper 

sedimentary matrix (infaunal organisms) and those living on or just above the benthic surface, or 

strongly associated with the benthic surface (epifaunal organisms). Offshore benthic communities can 

be quite diverse, but organisms commonly found in surveys include echinoderms, sipunculids, 

mollusks, polychaetes, copepods, and amphipods (Dunton, Schonberg, and McTigue, 2009; Rand and 

Logerwell, 2011). Most seafloor substrates on the Beaufort Sea OCS consist of aggregations of fine 

sands, muds, and silts, with percentages of substrate consisting of mud ranging from 17% to 84% 

(cANIMIDA, 2010; Trefry and Trocine, 2009). Limited extents of scattered cobblestone or pebbles 

are found at shallower depths (Dunton, Schonberg, and McTigue, 2009). Historically, ice gouging in 

the area of the proposed site has had effects to depths of up to 8.2 ft (2.5 m) (Gradinger and Bluhm, 

2005) above the projected 41 ft (12.5 m) depth of the MLC. A focus on differences in communities 

based on physical factors is addressed in the BOEMRE-sponsored cANIMIDA studies on 

hydrocarbon chemistry and substrate composition (cANIMIDA, 2010), the Beaufort Sea MultipleSale EIS, and the 2006 Final Seismic PEA. No known unique geological surface features, key 

reproductive sites, or unique biological communities exist at the proposed drill sites. 
Shell 2012 Camden Bay EP EA

46 Affected Environment - Fish and Essential Fish Habitat 

3.2.4. Fish and Essential Fish Habitat. 

3.2.4.1. Fish 

Spring melt and river runoff greatly influence the characteristics of the inshore and nearshore 

Beaufort Sea. This freshwater influx sets up a band (2-10 km) of brackish waters along the coast that 

then breaks down in later summer due to decreased runoff and mixing by wind. This Beaufort Sea 

inshore habitat and the fish that depend on the band were examined by Craig (1984). He found that 

arctic cisco, least cisco and Arctic char were dominant species in the coastal Beaufort. In late summer 

two marine species, Arctic cod and four-hour sculpin, moved nearshore as the salinity in the band 

increased. 

Jarvela and Thorsteinson (1999) studied the occurrence of epipelagic fish along the eastern Beaufort 

Sea coast up to 30 km offshore. The study area stretched from the Colville River east to the U.S.-

Canada boundary, including Camden Bay. The most abundant epipelagic fish caught were Arctic 

cod, capelin and snailfishes. Surface water temperatures and salinities varied seasonally and 

interannually and this influenced the spatial and temporal distribution patterns of the fish species. 

From 2004 to 2009, nearshore fishes were sampled with a beach seine and bottom trawl near Cooper 

Island, a barrier island in the western Beaufort Sea. A total of 2,807 fish representing 16 species were 

captured in all sampling periods and with both gear types. Some of the more abundant species 

captured were capelin, Arctic cod, and slender eelblenny (Johnson et al., 2010). 

In the summer of 2008, a field survey of fish and benthic invertebrates of the Beaufort Sea was 

conducted by NOAA, University of Washington and University of Alaska (Logerwell et al., 2010; 

Rand and Logerwell, 2011; Logerwell et al., 2011). They began sample transects 20-30 km off the 

Beaufort coastline between Point Barrow and Cape Halkett (approximately 180 km west of Camden 

Bay). Following are some of the important findings from the 2008 Beaufort survey: 

 36 taxa of fish were caught and identified 

 Across all bottom trawls, 6% of all weight was comprised of vertebrate fish species and 

94% by weight was invertebrates 

 Arctic cod (Boreogadus saida) were the most abundant fish caught during the 2008 survey, 

both by weight and numbers. Walleye pollack (Theragra chalcogramma) were present, but 

primarily as subadults 

 Fifteen species of smaller fish (eelpouts and sculpins) contributed a great number of fish to 

the total catch of the 2008 survey, however, they did not contribute much in terms of total 

biomass (weight) 

 The pollock caught in the survey were in densities far lower than in the Bering Sea where 

they are fished commercially 

 No specimens of adult or juvenile Pacific salmon species (Oncorhynchus sp.) were 

captured during sampling in the 2008 survey 

 The dominant benthic species at the shelf break (arctic cod, opilio crab, eelpouts) were 

associated with cold, high salinity water derived from the Chukchi Sea 

 Comparing the results of the NOAA 2008 data to opportunistic offshore bottom-trawl 

surveys conducted by Frost and Lowry (1983) in 1976 and 1977, the authors suggest that 

there may have been a shift in fish species composition and community structure in the 

central Beaufort Sea over the past three decades. However, they note that without more 

extensive surveys, it is difficult to conclude that changes in species communities have 

occurred 

Based on the studies described above and other studies (Fruge et al. 1989; Johnson et al., 2010; 

Thorsteinson, Jarvela, and Hale, 1992), Table 6 presents a list of fish species most likely to occur in 

the proposed drilling areas, or which could be affected by drilling activities: 
Shell 2012 Camden Bay EP EA

Affected Environment - Fish and Essential Fish Habitat 47

Table 6 Fish Species most likely to occur in the Proposed Drilling 

Areas, or which could be affected by drilling activities 

Common Name Latin Name 

Arctic cod Boreogadus saida 

Arctic flounder Pleuronectes glacialis 

Saffron cod Eleginus gracilis 

Capelin Mallotus villosus 

Dolly Varden Salvelinus malma malma 

Fourhorn sculpin Myoxocephalus quadricornis 

Arctic cisco Coregonus autumnalis 

Least cisco Coregonus sardinella 

Humpback whitefish Coregonus pidschian 

Kelp Snailfish Liparis tunicatus 

Ninespine Stickleback Pungitius pungitius 

Pink salmon Oncorhynchus gorbuscha 

Chum salmon Oncorhynchus keta 

rainbow smelt Osmerus mordax 

Commercial fishing has not occurred in the Beaufort region aside from a few artisanal fisheries 

involving village fishers in State waters. Therefore the typically published stock assessments and 

monitoring data associated with commercial fishing do not exist. The literature on fish in the U.S. 

Arctic most often addresses the general occurrence, distribution and abundance of adult fish in the 

open-water season. Limited published literature is available at this time regarding discrete 

populations, movement patterns and life history of most fish species in the U.S. Arctic. Subsistence 

fishing, however, has long been an integral part of life along the coasts of the Beaufort and Chukchi 

seas and, therefore, there is an abundance of traditional knowledge about fish that occur nearshore in 

the region. 

The effects of ongoing climate change in the Arctic, such as warming sea temperatures and increased 

acidity, affect fish in many ways including changes in lower trophic food sources and changes in ice 

habitat extent and qualities (Hopcroft et al., 2006). 

Additional information on the fish in the region of the proposed drilling is incorporated here from two 

earlier documents, the 2009 Camden Bay EA (USDOI, MMS, 2009a), and the 2011 Camden Bay EP. 

3.2.4.2. Essential Fish Habitat 

The Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA) (16 U.S.C. 1801-

1884) mandated the identification of Essential Fish Habitat (EFH) for managed species as well as 

measures to conserve and enhance the habitat necessary to fish to carry out their lifecycles. The 

MSFCMA requires cooperation among the National Marine Fisheries Service (NMFS), the Fishery 

Management Councils, fishing participants, Federal and State agencies, and others in achieving EFH 

protection, conservation, and enhancement. 

Fishery Management Plans in the U.S. Beaufort Sea 

The Salmon Fishery Management Plan for Coastal Alaska (1990) applies to all life stages of the five 

Pacific salmon species in the U.S. Beaufort Sea. Pacific salmon occur in the Beaufort marine and 

estuarine environments, however, their numbers are low compared to the Bering Sea. Salmon, 

primarily pink and chum, have been captured in the Beaufort nearshore (Craig, 1984; Craig and 

Haldorson, 1986; Fechhelm and Griffiths, 2001; Fechhelm et al., 2009). As climate change occurs 
Shell 2012 Camden Bay EP EA

48 Affected Environment - Fish and Essential Fish Habitat 

(ice reduction, warming waters) salmon are moving further north in greater numbers (Moss et al., 

2009; Kondzela et al., 2009). 

The Arctic Fishery Management Plan (2009) identifies three commercial target species in the U.S. 

Arctic: Arctic cod, saffron cod, and snow crab (opilio crab). Adult and juvenile Arctic cod EFH are 

the only designated habitats that occur in the proposed Camden Bay project area (Figure 4). The 

Arctic Fishery Management Plan describes Arctic cod adult and late juvenile EFH as follows (NMFS 

has not yet determined EFH for eggs and larvae of the Arctic cod): 

Arctic Cod EFH, Adult and Late Juvenile: “the general distribution areas for this life stage is 

located in pelagic and epipelagic waters from the nearshore to offshore areas along the entire 

shelf (0-200 m [0-656 ft]) and upper slope (200-500 m [656-1,640 ft]) throughout Arctic 

waters and often associated with ice floes which may occur in deeper waters” (NPFMC, 

2009). 

The MSFCMA provides authority for an ecosystem-based approach to the management and 

protection of fish and fish habitat. The intent of designating Ecosystem Component Species is to 

understand the habitat of ecosystem component species, promote ecosystem-based management and 

provide sound conservation and sustainability of fish and fisheries. 

Figure 4 Arctic Cod Essential Fish Habitat 

The Arctic Fishery Plan describes eight ecosystem component species that “are thought to be, should 

conditions allow, commercially viable”. These ecosystem component species are: yellowfin sole, 

Alaska plaice, flathead sole, Bering Flounder, starry flounder, capelin, rainbow smelt, and blue king 

crab. Based on literature published on various fish surveys, it is likely that yellowfin sole, Bering 

flounder, starry flounder, capelin, and rainbow smelt occur in the vicinity of the Proposed Action 

(Error! Reference source not found.) (Logerwell et al., 2010, 2011; Rand and Logerwell, 2011; 
Shell 2012 Camden Bay EP EA

Affected Environment - Fish and Essential Fish Habitat 49

Frost and Lowry, 1983; Fechhelm et al., 2009, Craig, 1984). Habitat descriptions for these ecosystem 

component species are available at the Arctic Fishery Management Plan web-site (NPFMC, 2011). 

The policy of designating Ecosystem Component Species recognizes the “complex interactions 

among ecosystem components, and seeks to protect important species utilized by other ecosystem 

component species, potential target species, other organisms such as marine mammals and birds, and 

local residents and communities” (NPFMC, 2009). 

Table 7 EFH target species that occur (designated in the Arctic Fishery Management 

Plan, 2009) and ecosystem component species that likely occur in the Camden Bay project 

area, Beaufort Sea, Alaska. 

Fish Species Designated EFH Species and Ecosystem Component 

Species in the Area of Proposed Action 

Arctic cod (Boreogadus saida), 

Late Juvenile and Adult EFH Species 

Yellowfin sole (Limanda aspera) Ecosystem Component Species 

Bering flounder (Hippoglossoides robustus) Ecosystem Component Species 

Starry flounder (Platichthys stellatus) Ecosystem Component Species 

Capelin (Mallotus villosus) Ecosystem Component Species 

Rainbow smelt (Osmerus mordax) Ecosystem Component Species 

Arctic Cod. Arctic cod is widely distributed in the U.S. Arctic in the pelagic, demersal and nearshore 

environments. The absolute numbers of Arctic cod and their biomass is one of the highest of any 

finfish in the region (Logerwell et al., 2010, 2011; Rand and Logerwell, 2011; Frost and Lowry, 

1983). The various life stages of Arctic cod occur across a broad range of habitats. Commonly they 

are associated with sea ice, using it as forage habitat to feed on microorganisms on the underside and 

as shelter. The Arctic Fishery Management Plan describes the Arctic ice forage habitat: 

All life stages of certain amphipod and copepod species are associated with perennial ice, 

suggesting an ice-specific community exists in addition to open-water zooplankton species 

feeding opportunistically on ice algae. In addition, turbellarians and nematodes are part of 

these perennial ice communities (Gradinger et al., 2005). Densities of these invertebrates can 

be locally high attracting foraging fish, most commonly the Arctic cod, Boreogadus saida 

(Gulliksen and Lonne, 1991). However, most observations of Arctic cod and other larger 

animals are associated with the extremely productive (and more easily studied) ice edge 

habitat. (NPFMC, 2009) 

The primary foods of Arctic cod include planktonic copepods and amphipods, ice-associated 

amphipods and epibenthic crustaceans. (Bradstreet and Cross, 1982; Gulliksen and Lonne, 1991). 

Arctic cod move and feed in different groupings - dispersed, in small schools and very large schools 

throughout the water column (Welch, Crawford, and Hop, 1993). Frost and Lowry (1983) found 

smaller Arctic cod occurred more often in water less than 100 m deep. 

In the summer of 2008, an Arctic fish survey was conducted by NOAA/University of 

Washington/University of Alaska in the western Beaufort Sea (Logerwell et al., 2010; Logerwell, 

Rand, and Weingartner, 2011; Rand and Logerwell, 2011). Results of this survey showed that Arctic 

cod were the most abundant fin-fish caught during the summer survey, both by weight and absolute 

numbers. Pelagic yearling-and-older Arctic cod were most abundant at the continental shelf-break 

(100 m). Pelagic young-of-year were most commonly found inshore. Arctic cod (of all age classes) 

comprised 99% by-weight of all midwater fish surveys (acoustic and trawl) and 96% by weight of 

demersal fish trawls. Johnson et al. (2010) describes Arctic cod as one of the most abundant species 

captured by beach seine and bottom trawl near Cooper Island in the western Beaufort Sea. Arctic cod 

captured by beach seine were mostly young-of-the-year, whereas Arctic cod captured by trawl 

included fish as old as age-3. 

Trophic Linkages. Arctic cod are an important species in the Arctic foodweb both as prey and 

predator. The Arctic Fishery Management Plan (NPFMC, 2009) discusses these trophic linkages: 
Shell 2012 Camden Bay EP EA

50 Affected Environment - Invasive Species 

Both the limited available survey data and the more comprehensive Arctic marine mammal 

and bird literature prominently feature Arctic cod and saffron cod as locally abundant species 

in the Alaskan Arctic and as critical components of pelagic food webs. In open-water and/or 

ice edge habitats, Arctic cod are a key link converting the production of small animals 

(pelagic zooplankton and ice-associated small invertebrates) into useful forage for large 

animals (birds and mammals. (Welch, Crawford, and Hop, 1993) 

Ringed seals, ribbon seals, spotted seals, beluga whales and several seabird species depend heavily on 

Arctic cod. Ice seals particularly depend upon Arctic cod in the winter (Bluhm and Gradinger 2008; 

Dehn et al., 2007; Divoky, 1984; Frost and Lowry, 1981; Frost and Lowry 1984; Welch, Crawford, 

and Hop, 1993). Arctic cod feed on zooplankton, euphausiid/krill, pelagic amphipods, ice-associated 

amphipods and epibenthic crustaceans. Other species feed on these same organisms, placing the 

Arctic cod in competition during low productivity years with species such as bowhead whales and 

ringed seals. 

The biomass of Arctic cod (as both predator and prey) transfers energy throughout the food web. The 

Arctic Fishery Management Plan (NPFMC, 2009) presents the results of a Beaufort Sea study by 

Frost and Lowry (1984): 

Frost and Lowry (1984) estimated the consumption requirements for the most common 

marine mammals and birds in the pelagic food web of the Alaskan Beaufort shelf, and 

included Arctic cod as both forage for these predators and as a predator on zooplankton. An 

estimated 123,000 tons of Arctic cod were required to feed the Belugas, ringed seals, marine 

birds, and Arctic cod themselves in the Beaufort Sea. Belugas and ringed seals in particular 

were dependent on Arctic cod for a majority of their consumption, and birds for half their 

consumption requirements. A total of 2,000,000 metric tons of forage (copepods, euphausiids, 

pelagic amphipods, Arctic cod, and other prey) was required for all predators including Arctic 

cod, of which nearly half was copepods. (NPFMC, 2009) 

The abundance, wide distribution and the role in the food web of the Arctic cod in the Beaufort Sea 

make this species very important in the overall ecosystem of the Arctic region. 

There are several factors that are currently influencing the Arctic environment EFH such as the 

presence and transit of cargo barges, research vessels and onshore oil and gas industrial activities. 

These activities could contribute noise, fuel spills, petroleum spills and nonpoint runoff to the sea. 

Climate change is currently having an effect on the Arctic environment EFH including warming sea 

surface, reduction in sea ice, and increased ocean acidification. These effects would continue during 

the proposed activities. 

3.2.4.3. Invasive Species. 

An invasive species is defined as “a species whose introduction does or is likely to cause economic or 

environmental harm or harm to human health where it is introduced”. (Executive Order 13112 of 

February 3, 1999: Invasive Species) 

An aquatic invasive species can be a plant, animal or microscopic pathogen. A variety of invasive 

species ranging across numerous taxa have been introduced around the world (GISP/UNEP, 2011). 

Potential vectors for introducing aquatic invasive species include vessel dockage to land, fouled ship 

hulls, ballast-water discharge, oil rigs, and equipment placed overboard (e.g., anchors, seismic 

airguns, hydrophone arrays, ocean-bottom-survey cables). In a more passive manner, floating plastic 

debris can also serve as a vector for transporting non-native species from one point to another. 

Across all vectors and pathways, climate change can influence the dispersal of invasive species, 

presenting the potential for increased risk of invasion of non-native species (EPA, 2008, Rahel and 

Olden, 2008, Hellman et al., 2008). Ice cover, cold sea temperatures, ocean salinity and river 

discharge are important factors in the U.S. Arctic that may be influenced by climate change and 

therefore act synergistically with invasion of non-native species. 

The Arctic Fishery Management Plan (NPFMC, 2009) discusses the potential introduction of invasive 

species into Alaska arctic waters and the potential effects. The Plan states: “Relatively few exotic, 
Shell 2012 Camden Bay EP EA

Affected Environment - Marine and Coastal Birds 51

invasive species have been documented in Alaska. It is believed that this is due to a combination of 

factors, including geographic isolation; harsh climate conditions and cold temperatures; fewer 

concentrated, highly disturbed habitat areas; and the state’s stringent plant and animal transportation 

laws. Alaska waters are, however, vulnerable to exotic species invasion. Potential introduction 

pathways include... the movement of large ships and ballast water from the United States West Coast 

and Asia” (Fay, 2002). 

A non-native marine crustacean (amphipod) has been found in harbors ranging from Ketchikan in 

Southeast Alaska to Dutch Harbor in the Aleutian Islands. This is one of the few known cases of nonnative marine organisms spread widely in Alaska (Ashton et al., 2008). An invasive colonial tunicate 

(Didemnum vexillum), which encrusts surfaces in a thick adhesive mat was found extensively in a 

Sitka harbor in June 2010. It is believed to have been introduced through previously used dock and 

pier timbers relocated to the state or through ballast water discharge or fouled hulls (ADFG, 2011). 

Invasive rats, although not an aquatic species, are adept swimmers and have been introduced into new 

regions, including Alaska, through vessel transit and groundings. Besides swimming, they can ride 

floating debris. Invasive rats are established in Alaska in at least three mainland communities, in three 

island communities in Southeast Alaska, on 11 islands in the Aleutians and on numerous smaller 

Aleutian islets. (Ebbert et al., 2007). 

The Nonindigenous Aquatic Nuisance Prevention and Control Act (NANPCA) (16 U.S.C. 4701-

4751) was passed in 1990 and amended by the National Invasive Species Act of 1996 (NISA). The 

U.S. Coast Guard developed regulations (33 CFR 151) that implement provisions of this Act and its 

amendment. Vessels brought into the State of Alaska or Federal waters are subject to these Coast 

Guard regulations which are intended to reduce the transfer of invasive species. The regulations 

require the “removal of fouling organisms from hull, piping, and tanks on a regular basis and dispose 

of any removed substances in accordance with local, State, and Federal regulations,” however, the 

regulations do not require the same removal procedures for ocean-bottom cables or seismic 

equipment. 

3.2.5. Marine and Coastal Birds. 

The general distribution and abundance of birds for the Beaufort Sea has been updated from resource 

information contained in the Beaufort Multi-Sale EIS (USDOI, MMS, 2003: III-49 through III-54). 

Most marine birds that occur in the Beaufort and Chukchi seas are there during the open-water 

season. Arrival times usually coincide with the formation of leads during spring migration to coastal 

breeding areas. Migration times vary between species, but spring migration for most species takes 

place between late March and late May. Those birds that are most likely to be affected by the 

Proposed Action are summarized in Table 8. As with other analyses incorporated by reference, 

BOEMRE assumes that any contact with oil by a bird will be fatal. 

Some birds that breed on the North Slope migrate to or through the project area twice each year. 

Some marine and coastal birds may breed outside the project area, but spend time in the Beaufort Sea 

after breeding or during their non-breeding seasons. Departure times from the Beaufort Sea for the 

fall and winter vary between species and often by sex within the same species, but most marine and 

coastal birds will have moved out of the Beaufort Sea by late October before the formation of sea ice. 

Descriptions of Species or Species Groups 

Marine and coastal birds can be grouped according to certain aspects of their life-history or status: 

ESA-listed birds, loons and waterfowl, seabirds, shorebirds, and raptors/ravens). The timing and 

specific location of the proposed activities influence which birds could be affected. Birds listed as 

threatened or candidate (four species) or abundant in the proposed project area (five species) have the 

greatest potential for adverse effects and are described further (Table 8). These nine species were 

carried forward to the Environmental Consequences section. 
Shell 2012 Camden Bay EP EA

52 Affected Environment - ESA-Listed Birds 

Table 8 Marine and coastal birds most likely to be affected by the Proposed Action 

Species Threatened or candidate species Abundant in offshore action 

area 

Carried forward under 

effects analysis 

ESA-Listed Species 

Spectacled Eider Yes Yes 

Steller's Eider Yes Yes 

Kittlitz's Murrelet Yes Yes 

Yellow-billed Loon Yes Yes 

Loons and Waterfowl 

Long-tailed Duck Yes Yes 

Common Eider Yes Yes 

King Eider Yes Yes 

Seabirds 

Northern Fulmar Yes Yes 

Short-tailed Shearwater Yes Yes 

Note: An empty cell indicates Not Applicable. 

3.2.5.1. ESA-Listed Birds 

The distribution, abundance and legal status of birds designated as threatened or listed as candidate 

species under the ESA are most recently described in the ESA Section 7 consultation documents 

(USDOI, MMS, 2009a; USDOI, FWS, 2009). These include the Steller’s eider (Polysticta stelleri; 

threatened), the spectacled eider (Somateria fisheri; threatened), the Kittlitz’s murrelet 

(Brachyramphus brevirostris; candidate species), and the yellow-billed loon (Gavia adamsii; 

candidate species) and are often collectively referred to as ESA-listed birds. These four species, due 

to their special status, are carried forward into Environmental Consequences (Table 8). None of the 

Proposed Action operations will take place in the Ledyard Bay Critical Habitat Unit, which is an area 

of importance to spectacled eiders. 

Spectacled Eider. The North Slope spectacled eider population seems to be stable, at least since the 

initiation of aerial surveys of the Arctic Coastal Plain (ACP) in 1992 (Larned et al., 2009). Spectacled 

eiders breed in low densities across the Alaskan ACP east to about the Shaviovik River. Males leave 

the breeding grounds along the ACP for the ocean around mid- to late June at the onset of incubation 

by female eiders. Males are followed by females whose nests fail, and finally by successful breeding 

females and young birds in August and September. Female spectacled eiders have been documented 

migrating west along the Alaska coast as far as 40 km offshore (TERA, 1999). Most spectacled eiders 

will have migrated from the Beaufort Sea by mid-October, although small numbers of spectacled 

eiders could be encountered in nearshore locations of the Beaufort Sea. 

Steller’s Eider. A small number of Steller’s eiders breed on the ACP of Alaska, most conspicuously 

near Barrow. Steller’s eiders have been observed east of Barrow to the Prudhoe Bay area where they 

are considered rare (TERA, 1997). They are rare east of Barrow and even rarer as the season 

progresses due to molt migration, failed breeding, etc. As with the more common spectacled eider, 

these birds move to nearshore coastal waters after their breeding season. Few if any Steller’s eiders 

would likely be in the southern Beaufort Sea during or after the open-water season. 

Yellow-billed Loon. Yellow-billed loons typically nest on low islands or narrow peninsulas on the 

edges of large, deep, tundra lakes (Johnson and Herter, 1989). The yellow-billed loon is relatively 

rare in the Arctic region (North, 1994). Dau and Larned (2005, 2006, 2007, 2008) and Dau and 

Bollinger (2009) observed 23, 99, 46, 18, and 59 yellow-billed loon(s), respectively, during a lateJune survey of the coast and barrier islands between Omalik Lagoon and the Canadian Border. Of the 

approximately 3,300 yellow-billed loons present on the breeding grounds on the North Slope, 

primarily between the Meade and Colville rivers in the National Petroleum Reserve-Alaska (NPR-A), 

it is likely that there are fewer than 1,000 nesting pairs because some of the 3,300 are nonbreeders. 

Additionally, there are approximately 1,500 yellow-billed loons (presumably juvenile nonbreeders) 
Shell 2012 Camden Bay EP EA

Affected Environment - Other Birds 53

that remain in nearshore marine waters or in large rivers during the breeding season. In total, there are 

fewer than 5,000 yellow-billed loons on the North Slope breeding grounds and nearshore marine 

habitat (Earnst et al., 2005). 

Satellite-tagging of eight yellow-billed loons from the ACP showed that in late September most 

yellow-billed loons leave Arctic waters as they migrate to the Kamchatka Peninsula or the Kuril 

Islands (Rizzollo and Schmutz, 2008, 2009, 2010). 

Kittlitz’s Murrelet. This species may nest as far north as Cape Beaufort (100 km northeast of Cape 

Lisburne). Kittlitz’s murrelets have been observed on a regular basis in the Chukchi Sea in late 

summer and early fall by Divoky (1987), but they have not been subsequently observed by others on 

similar cruises in the Chukchi Sea, suggesting that there is a great deal of annual variation in their 

occurrence. Murrelet foraging areas may occur near Barrow. The Kittlitz’s murrelet was reported just 

west of Barrow in September-October 2007 (Renner, Hunt, and Kuletz, 2008). A few individual 

Kittlitz’s murrelets could occur in close proximity to Barrow during the open-water season. The only 

recent notable change in the baseline information is recent documentation that individual Kittlitz’s 

murrelets occur in the Beaufort Sea, near Kaktovik (Day, Gall, and Prichard, 2011). 

3.2.5.2. Other Birds 

3.2.5.2.1. Loons and Waterfowl 

The Pacific loon (Gavia pacifica), red-throated loon (G. stellata), Pacific brant (Branta bernicla 

nigricans), lesser snow goose (Chen caerulescens caerulescens), greater white-fronted goose (Anser 

albifrons frontalis), and tundra swan (Cygnus columbianus) occur in nearshore coastal waters of the 

Beaufort and Chukchi seas (USDOI, MMS, 2003; 2008). Waterfowl species that are more abundant 

and occur in more offshore areas of the Beaufort and Chukchi seas include the long-tailed duck 

(Clangula hyemalis), the common eider (Somateria mollissima), and the king eider (Somateria 

spectabilis) and are described below. 

Long-tailed Duck. The long-tailed duck population has decreased considerably since 1989, but it 

remains a common species in the Beaufort Sea during the open-water period (Mallek, Platte, and 

Stehn, 2007). Many long-tailed ducks molt in the lagoons along the Beaufort Sea coast. In late June 

and early July, most male and nonbreeding female long-tailed ducks migrate to coastal molting areas 

where they are flightless for a 3- to 4-week period. Breeding females molt on freshwater lakes during 

the last phases of duckling development before departing the North Slope in fall (Johnson and Herter, 

1989). While most long-tailed ducks migrate within 45 km (28 mi) of shore (roughly along the 20-m 

[~ 66-ft] isobath), infrequent observations of long-tailed ducks in pelagic waters occur in late 

September (Divoky, 1987). 

The molt is an energetically costly time, and long-tailed ducks have abundant food resources in the 

shallow water lagoons (Flint et al., 2003). During the molt, long-tailed ducks tend to stay in or near 

the lagoons, especially near passes between the lagoon and the sea (Johnson, Frost, and Lowry, 1992; 

Johnson, Wiggins, and Wainwright, 1992; Kinney, 1985). Brackney and Platte (as cited in Lysne, 

Mallek, and Dau, 2004) observed long-tailed ducks feeding heavily in passes between barrier islands. 

Common Eider. The common eider population in the Beaufort Sea declined by 53% between 1976 

and 1996 (Suydam et al., 2000). Common eiders were surveyed in marine waters within 100 km of 

the Beaufort Sea shoreline between Barrow and Demarcation Point by Fischer and Larned (2004) 

during summers in 1999-2001. In general, common eiders were concentrated in shallow waters (<10 

m [<33 ft]), with the highest densities occurring in segments between Oliktok Point and Prudhoe Bay 

and between Tigvariak Island and Brownlow Point. Common eiders were most commonly associated 

with barrier islands in these segments, becoming less commonly observed up to 50 km seaward. 

Common eider densities were highest in areas of low ice cover. 

Fischer and Larned (2004) concluded that because eider densities did not vary between summer 

months, the eiders they observed near barrier islands were local breeders rather than molt or fall 
Shell 2012 Camden Bay EP EA

54 Affected Environment - Seabirds 

migrants. This is consistent with Petersen and Flint (2002), who showed that satellite-tagged common 

eider hens remained in shallow waters close to their breeding sites through September. 

Common eiders nest on barrier islands or spits along the Beaufort Sea coast. Dau and Larned (2005) 

observed 1,819 common eiders along the Beaufort Sea coast with 652 on barrier islands and 1,167 on 

the mainland. Dau and Larned (2007) observed a total of 1,936 common eiders. Of these, 871 were 

along the Beaufort Sea coast with 423 along the barrier islands and 448 along the mainland. The 

highest concentrations were on survey segments on both sides of Kaktovik. In 2007, total birds and 

indicated breeding pairs were down 37.6% and 44.0%, respectively, from 2006 counts of 3,102 birds 

and 1,207 pairs. Total birds and indicated breeding pairs in 2007 were down 30.0 and 27.8%, 

respectively, from the 1999-2006 averages of 2,766+885 (1 standard deviation, range 1,353-4,449) 

birds and 937+264 (1 standard deviation, range 572-1,340) pairs (Dau and Larned, 2007). In 2009, 

Dau and Bollinger (2009) reported that common eider numbers, while continuing to show 

considerable annual variation over the 1999-2009 time period, have declined by 1.4%/year while the 

number of indicated breeding pairs has showed less variability and is increasing at 3%/year. 

Male common eiders begin moving out of the Beaufort Sea beginning in late June. After the molt is 

completed, some common eiders move offshore into pelagic waters, but most eiders remain close to 

shore (Divoky, 1987). When traveling along the northwest coast of Alaska, these eiders tend to stay 

along the 20-m isobath, approximately 45 km (28 mi) from shore. Most males are out of the Beaufort 

Sea by late August or early September, and most females were gone by late October or early 

November. Most breeding female common eiders and their young begin to migrate to molt locations 

in late August and September, although large numbers of female common eiders were observed 

molting in the eastern Beaufort Sea in Canada (Johnson and Herter, 1989). 

King Eider. Most king eiders begin to arrive in the Beaufort Sea by the middle of May. Arrival times 

in the Beaufort Sea are dependent upon the location and timing of offshore leads along the Chukchi 

Sea (Barry, 1986). Most king eiders nesting on the North Slope between Icy Cape and the western 

boundary of ANWR nested in three general areas: between the Colville River and Prudhoe Bay, 

southeast of Teshekpuk Lake and a large area near Atqasuk (Larned, Stehn, and Platte, 2006). Dau 

and Larned (2005, 2006, 2007, 2008; Dau and Bollinger, 2009) surveyed the Chukchi Sea and 

Beaufort Sea mainland coastlines found 800, 3,045, and 1,621, 2,227, and 565 king eiders in 2005, 

2006, and 2007, 2008, and 2009, respectively. 

The king eider population in the Beaufort Sea appeared to remain stable between 1953 and 1976 but 

declined by 56% between 1976 and 1996 (Suydam et al., 2000). Fischer and Larned (2004) surveyed 

king eiders in marine waters within 100 km of the Beaufort Sea shoreline between Barrow and 

Demarcation Point during summers in 1999 and 2001. King eiders were the second most abundant 

species counted during the survey periods. King eider densities varied according to water depth, 

offshore distance, and percent of ice cover. Large flocks of king eiders concentrated in the mid-depth 

(10-20 m [33-66 ft]) zone offshore of Barrow and Oliktok Point. In 1999 and 2000, these flocks were 

in waters >10 m (>33 ft) deep but were found in the shallow (<10 m [<33 ft]) and mid-depth zone in 

July 2001. King eiders were unique among species surveyed by occurring in higher densities in low 

(31%) and moderate (31-60%) ice cover (Fischer and Larned, 2004). 

Satellite telemetry was used to determine that most king eiders spent more than 2 weeks staging 

across all offshore areas of the Beaufort Sea, especially Harrison Bay and Smith Bay, but including 

areas off Camden Bay, prior to fall migration (Phillips, 2005; Powell et al., 2005). Female king eiders 

may need to remain in the Beaufort Sea longer than males to replenish fat stores depleted during egg 

laying and incubation (Powell et al., 2005). Prior to molt migration, king eiders in the Beaufort Sea 

usually were found about 13 km offshore; however, during migration to molting areas, king eiders 

occupied a wide area ranging from shoreline to >50 km (>31 mi) offshore (Phillips, 2005). 

3.2.5.2.2. Seabirds 

The common murre (Uria aalge), thick-billed murre (U. lomvia), tufted puffin (Fratercula cirrhata), 

horned puffin (F. corniculata), black-legged kittiwake (Rissa tridactyla), black guillemot (Cepphus 
Shell 2012 Camden Bay EP EA

Affected Environment - Marine Mammals 55

grylle), Ross’ gull (Rhodostethia rosea), ivory gull (Pagophila eburnea), Arctic tern (Sterna 

paradisaea), pomarine jaeger (S. pomarinus), parasitic jaeger (S. parasiticus), long-tailed jaeger (S. 

longicaudus), and glaucous gull (Larus hyperboreus) occur in the Beaufort Sea and Chukchi Sea 

(USDOI, MMS, 2003, 2008). Seabird species that are more abundant and occur in offshore areas 

include the northern fulmar (Fulmarus glacialis) and the short-tailed shearwater (Puffinus 

tenuirostris) and are described below. 

Northern Fulmar. Fulmars do not breed in the Proposed Action area, and those observed during the 

summer are nonbreeders or failed breeders from southern areas. Fulmars are most numerous from late 

August to mid-September. 

Short-Tailed Shearwater. Shearwaters do not breed in the Arctic region. These birds breed in the 

southern hemisphere. At northern latitudes, short-tailed shearwaters likely forage at highly productive 

patches of euphausiids and amphipods. Divoky (1987) reported short-tailed shearwaters north of 

Barrow and into Arctic Canada, depending on the presence of sea ice. In certain years, an estimated 

100,000 short-tailed shearwaters passed Point Barrow in 1 day in mid-September (Divoky, 1987). 

3.2.5.2.3. Shorebirds 

The most common shorebird species include dunlin (Calidris alpina) and phalaropes (Phalaropus 

spp.) (Alaska Shorebird Working Group, 2004). Nearshore and shoreline habitats are especially 

important habitats where shorebirds replenish energy reserves after breeding and prior to southward 

migration, but these habitats are out of the project action area and these species are not evaluated 

further. 

3.2.5.2.4. Raptors and Ravens 

Raptors along nearshore and shoreline areas of the Beaufort Sea consist of small numbers of snowy 

owls (Nyctea scandiaca) and transient peregrine falcons (Falco peregrinus), golden eagles (Aquila 

chrysaetos), northern harriers (Circus cyaneus), and rough-legged hawks (Buteo lagopus). Ravens 

(Corvus corax) have recently expanded their distribution across portions of the North Slope. These 

species do not typically extend into offshore areas during the open-water season and are not evaluated 

further. A few snowy owls have occasionally been observed on icebergs or floes during the openwater season where they rest or scavenge carrion. 

Climate Change Effects 

Scientific and public interest in the Arctic is at an all-time high, attributed largely to a multitude of 

warming-induced changes now under way and a growing appreciation for the region’s importance to 

the global climate system. Temperatures over Arctic land areas have risen and continue to rise at 

roughly twice the rate of the rest of the world (IPCC, 2007b). Some trends from climate change to 

coastal and marine birds are evident and are anticipated to continue. The draft Arctic Multi-Sale EIS 

(USDOI, MMS, 2008, section 3.3.5.1) briefly described likely ongoing effects on coastal and marine 

birds from changes in oceanographic processes and sea-ice distribution, duration of snow and ice 

cover, distribution of wetlands and lakes, and sea level rise. That section concluded that continued 

climate change can result in short- and long-term and beneficial or detrimental population-level 

effects on coastal and marine birds. Exactly how Arctic birds/bird groups are responding to climate 

change over time and space cannot be predicted, but, considering the short duration of this action, 

precise response data is not required for this analysis. 

3.2.6. Marine Mammals. 

There are 15 marine mammal species that can occur in the Proposed Action area (Table 9). In the 

following description, these are divided into two groups: 1) those afforded special protection under 

the Endangered Species Act (ESA) and 2) others. All marine mammals in the Proposed Action area 

are protected by the Marine Mammal Protection Act.. Marine mammals listed under the ESA, or are 

common in the Proposed Action area are analyzed further (Table 9). Rare or uncommon species are 

not evaluated further. 
Shell 2012 Camden Bay EP EA

56 Affected Environment - ESA-listed Marine Mammals 

3.2.6.1. ESA-listed Marine Mammals 

The general distribution, abundance and legal status of several marine mammals designated as 

endangered, threatened, proposed for listing, or candidate species under the ESA are most recently 

described in the ESA Section 7 consultation documents (USDOI, MMS, 2008b, 2009c; USDOI, 

FWS, 2009, USDOC, NOAA, NMFS, 2008). These include the bowhead whale (Balaena mysticetes, 

endangered), the fin whale (Balaenoptera physalus, endangered), the humpback whale (Megaptera 

novaeangliae, endangered), the ringed seal (Phoca hispida, proposed for listing), the bearded seal 

(Erignathus barbatus, proposed for listing), the polar bear (Ursus maritimus, threatened), and the 

Pacific walrus (Odobenus rosmarus, candidate) and are often collectively referred to as ESA-listed 

marine mammals. These seven species, due to their special status, are carried forward into 

Environmental Consequences (Section 4.2.7). Additional information on marine mammals occurring 

in the Beaufort and Chukchi seas is in the Arctic Multiple-Sale Draft EIS. 

Bowhead Whale. The bowhead whale occurs seasonally in the Beaufort and Chukchi seas. This 

stock of bowhead whales is currently referred to as the Western Arctic stock. Bowhead whales are 

currently increasing in abundance at a rate of approximately 3.2% per year. During the spring (midMarch to approximately mid-June), bowhead whales migrate north and east through leads in the 

Chukchi Sea on their way to their primary summer feeding grounds in the eastern U.S. Beaufort Sea 

and Canadian Beaufort Sea. 

Bowhead whales are present in the eastern Beaufort Sea throughout the summer (Moore, Clarke, and 

Ljungblad, 1989; Moore and Reeves, 1993; Moore et al., 2000; Moore et al., 2002). Some bowhead 

whales may remain in or return to the Chukchi Sea throughout the summer. In the autumn, bowhead 

whales move from the Beaufort Sea westward toward and across the Chukchi Sea as they migrate 

back to the Chukotka Peninsula waters and the Bering Sea wintering areas from about mid-September 

through November (Moore et al, 1995). Some bowhead whales killed during the late summer/fall had 

prey in their stomachs, indicating that a portion of bowhead whales may feed in the U.S. Beaufort 

Sea, including the Camden Bay area (Lowry, Sheffield, and George, 2004). Bowhead whales migrate 

southward through the Bering Strait in late October through early November. 

Bowhead whales are often associated with heavy ice cover and remain over the shallow continental 

shelf waters most of the year. The Western Arctic stock of bowhead whales overwinter in the Bering 

Sea, where most mating probably occurs. Recent satellite telemetry data indicate use of areas in the 

Chukchi and Bering seas with extensive ice (Moore and DeMaster, 1997; Moore et al., 2000). 

All recent available information indicates that the population has continued to increase in abundance 

over the past several decades and may have doubled in size since about 1978. The estimated current 

annual rate of increase is similar to the estimate for the 1978-1993 time series. The Western Arctic 

bowhead whale stock may have reached, or is approaching, the lower limit of its historic population 

size (Allen and Angliss, 2010). 

The bowhead whale was listed as endangered under a precursor to the ESA in 1970 (35 FR 18319, 

December 2, 1970) and have remained on the list since the ESA was passed in 1973. The NMFS 

received a petition in February 2000, requesting that portions of the U.S. Beaufort and Chukchi Seas 

be designated as critical habitat for the Western Arctic stock of bowhead whales. The NMFS 

determined not to designate critical habitat for this stock because: (1) the population decline was due 

to over exploitation by commercial whaling, and habitat issues were not a factor in the decline; (2) the 

population is abundant and increasing; (3) there is no indication that habitat degradation is having any 

negative impact on the increasing population; and (4) existing laws and practices adequately protect 

the species and its habitat (67 FR 55767, August 30, 2002). 

Fin Whale. The fin whale appears to be expanding into Arctic waters. Individual and small groups 

of fin whales are considered infrequent visitors to the U.S. Chukchi Sea during the open-water period. 

Observations from industry (Funk et al., 2011; Funk et al., 2007; Ireland et al., 2009) based 

monitoring and research programs (Clarke and Ferguson, 2010; Delarue et al., 2010) since 2006 have 

annually documented through observation and passive acoustic monitoring individual or small groups 
Shell 2012 Camden Bay EP EA

Affected Environment - ESA-listed Marine Mammals 57

of fin whales in the U.S. Chukchi Sea. Fin whales have not been documented to occur in the Beaufort 

Sea. 

Fin whales were listed as endangered under a precursor to the ESA in 1970 (35 FR 18319, December 

2, 1970) and have remained on the list since the ESA was passed in 1973. A final recovery plan was 

completed in July 2010 (USDOC, NOAA, NMFS, 2010). No critical habitat has been designated for 

fin whales in the North Pacific. 

Humpback Whale. The humpback whale also appears to be expanding into Arctic waters. Agency 

researchers and industry monitoring programs have indicated the presence of humpback whales in the 

U.S. Chukchi Sea since 2007. Hashagen, Green, and Adams (2009) noted a humpback adult and calf 

in the western Beaufort Sea in August 2007. 

All stocks of humpback whales in U.S. waters were listed as endangered under the precursor to ESA 

in 1970 (35 FR 18319, December 2, 1970) and have remained on the list since the ESA was passed in 

1973. A Final Recovery Plan for the humpback whale was completed in November, 1991 (USDOC, 

NOAA, NMFS, 1991). No critical habitat has been designated for this species. 

Ringed Seal. The ringed seal is considerably more abundant than other ice seals in the Beaufort and 

Chukchi seas, particularly during the winter and spring, and is the ice seal most likely to be 

encountered in the Proposed Action area (Burns, 1970). They are closely associated with ice, and in 

early summer the highest densities of ringed seals are found in nearshore fast and pack ice. Ringed 

seals have the unique ability to maintain breathing holes in thick ice. During the open-water season, 

ringed seals are dispersed throughout the open-water. Ringed seals construct lairs in landfast or 

drifting pack ice, and give birth in mid-March through April (Smith and Stirling, 1975; Smith and 

Hammill, 1981). 

Kelly et al. (2010) estimates that over one million ringed seals inhabit the Beaufort, Chukchi and 

Bering Seas based on information from existing surveys and studies. Ringed seal numbers are 

believed to be considerably higher in the Bering and Chukchi seas, particularly during winter and 

early spring (71 FR 9783). Bengston et al. (2005) reported an abundance estimate of 252,488 ringed 

seals in the eastern Chukchi Sea, while Frost and Lowry (1981) estimated 80,000 ringed seals in the 

Beaufort Sea during summer and 40,000 during winter. Kelly et al. (2010) placed their maximum 

density estimate of ringed seals at Prudhoe Bay and along the coast south of Kivalina at 1.62 

seals/km2

. 

The NMFS initiated a status review to determine if listing the ringed seal under the ESA was 

warranted (73 FR 16617-16619, March 28, 2008). The NMFS proposed to list ringed seals in the 

Alaskan Arctic as threatened under the ESA (75 FR 77476, December 10, 2010). The listing proposal 

was based on the NMFS conclusion that the Arctic ringed seal population in Alaska, numbering 

around a million, will face a significant extinction risk due to anticipated changes in sea ice 

conditions and snow cover in the Arctic from climate changes (Kelly et al., 2010). Critical habitat for 

the ringed seal has not been designated. 

Bearded Seal. Bearded seals are the largest of the northern phocids, and have a circumpolar 

distribution. During the open-water period, bearded seals occur mainly in relatively shallow areas, 

preferring areas no deeper than 200 meters. Most bearded seals are found in the Bering and Chukchi 

seas and are predominantly benthic feeders, feeding on a variety of invertebrates (Burns, 1970; 

Stirling, Kingsley and Calvert, 1982; Stirling, 1997). 

Cameron et al. (2010) developed a crude estimate of 3,150 resident bearded seals in the Beaufort Sea 

that was uncorrected for submersed seals or seasonal migrants, and around 27,000 resident bearded 

seals in the Chukchi Sea. Cameron et al. (2010) estimated the maximum density of bearded seals 

from Prudhoe Bay to the coast south of Kivalina to be about 0.14 seals/km2

. 

The Beringian Distinct Population Segment (DPS) of bearded seals, a population which includes the 

bearded seals located in the vicinity of the proposed exploration wells, has been proposed for listing 

under the ESA based on the NMFS conclusion that they will be threatened with extinction because of 
Shell 2012 Camden Bay EP EA

58 Affected Environment - ESA-listed Marine Mammals 

anticipated decoupling of sea ice cover and benthic feeding habitat, a loss in adequate molting habitat, 

and projected decreases in prey density and/or availability due to climate change (Cameron et al., 

2010). Critical habitat for the Beringian DPS of bearded seals has not been designated. 

Polar Bear. Polar bears occur on the pack and shorefast ice, along the coast, and on barrier islands. 

Polar bears have occasionally been observed in open-water in the Beaufort and Chukchi seas while 

transiting between pack ice and shore. There are two polar bear stocks recognized in Alaska: the 

southern Beaufort Sea and the Chukchi/Bering Seas stocks; though there is considerable overlap 

between the two. A third stock, the Northern Beaufort Sea stock could be encountered in offshore 

waters and on the pack ice in the northeastern Beaufort Sea. 

The polar bear is listed as threatened throughout their range under the ESA (73 FR 28212, May 15, 

2008). Polar bear habitat use and distribution may reflect prey availability, time allocated for hunting 

prey, and the use of retreat habitats (Durner et al., 2004). Modeling of polar bear ice habitat selection 

showed that shallow-water areas where different ice types intersected were preferred (Durner et al., 

2004, 2007). The FWS designated critical habitat for the polar bear (74 FR 76058, December 7, 

2010). Three different critical habitat units were identified: sea ice, terrestrial denning, and barrier 

island habitats. 

Pacific Walrus. The Pacific walrus is associated with the moving pack ice year-round. Walrus winter 

in the Bering Sea and the majority of the population summers throughout the Chukchi Sea and the 

westernmost part of the Beaufort Sea. Pacific walruses are usually found in waters of 100 m or less, 

possibly because of higher productivity of their benthic foods in the shallower water (Fay, 1982). In 

recent years, climate change has caused walrus to move to terrestrial haulouts in the Chukchi Sea in 

summer when the sea ice retreats northward. 

The following information is drawn from 76 FR 13454 (March 11, 2011). In the spring and early 

summer, most of the walrus population follows the retreating pack ice northward into the Chukchi 

Sea; however, several thousand animals, primarily adult males, remain in the Bering Sea. During the 

summer months, walruses are widely distributed across the shallow continental shelf waters of the 

Chukchi Sea. Substantial summer concentrations are normally found in the unconsolidated pack ice 

west of Point Barrow. Small herds of walruses occasionally range east of point Barrow into the 

Beaufort Sea in late summer. While typically considered uncommon in the Beaufort Sea, abundance 

is dependent on ice concentrations, and in some years walrus can be more abundant than is commonly 

believed (see Ireland et al., 2009). As the ice edge advances southward in the fall, walruses reverse 

their migration and re-group on the Bering Sea pack ice. 

In 2006, U.S. and Russian researchers surveyed walrus groups in the pack ice of the Bering Sea using 

thermal imaging systems to detect walruses hauled out on sea ice and satellite transmitters to account 

for walruses in the water. The number of walruses within the surveyed area was estimated at 129,000 

individuals (95% C.I. 55,000-507,000). Existing abundance estimates do not support an evaluation of 

population trend. 

Walruses rely on floating pack ice as a substrate for resting and generally require ice thicknesses of 

50 cm (20 in) or more to support their weight. Although walruses can break through ice up to 20 cm 

(8 in) thick, they usually occupy areas with natural openings. Concentrations in summer tend to be in 

areas of unconsolidated pack ice, usually within 100 km (30 mi) of the leading edge of the ice pack. 

When suitable pack ice is not available, walruses haul out to rest on land, a behavior that is becoming 

more common in the Chukchi Sea. Isolated sites, such as barrier islands, points, and headlands, are 

most frequently occupied. Social factors, learned behavior, and proximity to their prey base are also 

thought to influence the location of haulout sites. 

Although capable of diving to deeper depths, walruses are generally found in shallow waters of 100 m 

(300 ft) or less, possibly because of higher productivity of their benthic foods in shallower water. 

They feed almost exclusively on benthic invertebrates. Prey densities are thought to vary across the 

continental shelf according to sediment type and structure. Preferred feeding areas are typically 

composed of sediments of soft, fine sands. The juxtaposition of ice over appropriate depths for 
Shell 2012 Camden Bay EP EA

Affected Environment - Other Marine Mammals 59

feeding is especially important for females and their dependent young that are not capable of deep 

diving or long exposure in the water. The mobility of the pack ice is thought to help prevent walruses 

from overexploiting their prey resource. 

The FWS completed a status review of the Pacific walrus and determined that listing the species was 

warranted; however listing was precluded by higher priority actions and is a candidate species 

(76 FR 7634, February 10, 2011). 

Table 9 The stock, habitat, and estimated abundance of marine mammals occurring within the 

Proposed Action area. 

Species Stock Habitat Estimated Abundance Analyzed further? 

Beluga Whale Eastern Chukchi Sea 

Open leads and 

polynyas, coastal areas, 

ice edges 

3,710 Yes, due to relative 

abundance 

Beluga Whale Beaufort Sea 

Open leads and 

polynyas, coastal areas, 

ice edges 

32,453 Yes, due to relative 

abundance 

Narwhal 

Offshore, ice edge, 

heavy pack ice, open 

leads 

86,000, Rare in 

Chukchi/Beaufort 

No, due to relative 

abundance 

Killer Whale Offshore Open-water Not estimated, but rare in 

Chukchi/Beaufort 

No, due to relative 

abundance 

Harbor Porpoise Bering Sea Coastal waters <100m 

depth, Chukchi only 

40,039, Rare in 

Chukchi/Beaufort 

No, due to relative 

abundance 

Bowhead Whale Western Arctic Ice edge, polynyas and 

leads, open-water 9,472 Yes, endangered species

Gray Whale Eastern North Pacific Open and coastal waters 17,752, Rare in 

Chukchi/Beaufort 

No, due to relative 

abundance 

Fin Whale Northeast Pacific Open-water 5,700, Rare in 

Chukchi/Beaufort Yes, endangered species

Minke Whale Alaska Open-water Rare in Chukchi/Beaufort No, due to relative 

abundance 

Humpback Whale Central North Pacific Open-water 5,833, Rare in 

Chukchi/Beaufort Yes, endangered species

Bearded Seal Alaskan Arctic Pack ice and open-water 30,000 Yes, proposed for listing 

Spotted Seal Alaska Pack ice, ice edge and 

coastal habitat 59,214 Yes, due to relative abundance 

Ringed Seal Alaska Shorefast and pack ice 249,000 Yes, proposed for listing 

Ribbon Seal Alaska Open-water and pack ice 49,000, Rare in 

Chukchi/Beaufort 

No, due to relative 

abundance 

Pacific Walrus Chukchi/ Bering Pack ice and coastal 

haulouts 

129,000, Rare in 

Chukchi/Beaufort 

No, due to relative 

abundance 

Polar Bear Southern Beaufort Sea Coastal, barrier islands, 

pack ice 1,526 Yes, threatened species 

Polar Bear Northern Beaufort Sea Coastal, barrier islands, 

pack ice 1,200 Yes, threatened species 

Polar Bear Chukchi/ Bering Coastal, barrier islands, 

pack ice 2,000 Yes, threatened species 

Note: Species listed under the Endangered Species Act are analyzed further; rare or uncommon species are 

not analyzed further. 

Source: Allen and Angliss, 2010. 

3.2.6.2. Other Marine Mammals 

Of the remaining species, the beluga whale and spotted seal are most widely distributed and common 

within the Proposed Action area. Additional information on marine mammals occurring in the 

Beaufort and Chukchi seas can be found in the Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008). 

Five cetacean species (harbor porpoise, minke whale, killer whale, narwhal, and gray whale) could 

occur in the project area during the open-water period. These species occur in low densities and are 

most likely to be within 100 km of shore and in waters less than 200m deep or along the shelf break. 
Shell 2012 Camden Bay EP EA

60 Affected Environment - Sociocultural Systems 

Recent evidence from Funk et al. (2009) during 2006-2009 in the Chukchi and Beaufort seas suggest 

that harbor porpoise and minke whale are uncommon or rare in the Chukchi and Beaufort seas, but 

may be increasing in these areas during the open-water season. Small numbers of killer whales have 

also been recorded during industry surveys. The narwhal occurs in Canadian waters, but is rarely seen 

in the U.S. Beaufort Sea. Small numbers of gray whales occur in continental shelf waters along the 

Chukchi Sea coast in summer and to a lesser extent along the Beaufort Sea coast. These species are 

not discussed further because they are rare or uncommon in the Proposed Action area and mitigation 

measures would avoid or minimize any chance of adverse interaction. 

One other ice seal species that could occur in the action area is the ribbon seal. The ribbon seal is 

uncommon in the Chukchi Sea and there are few sightings in the Beaufort Sea. This species is not 

discussed further because it is uncommon in the Proposed Action area and mitigation measures would 

avoid or minimize any chance of adverse interaction. 

Beluga Whale. The Beaufort Sea and Chukchi Sea beluga whale stocks winter in the Bering Sea and 

summer in the Beaufort and Chukchi seas, migrating around western and northern Alaska along the 

spring lead system in April and May (Richard, Martin, and Orr, 2001; Angliss and Outlaw, 2005). 

Belugas generally are associated with ice and relatively deep water throughout the summer and 

autumn. During late summer and autumn, most belugas migrate westward far offshore near the 

continental shelf break and the pack ice (Frost, Lowry, and Burns, 1988; Hazard, 1988; Clarke, 

Moore, and Johnson, 1993; Miller et al., 1999). During fall aerial surveys in the U.S. Beaufort Sea, 

Christie, Lyons, and Koski (2009) reported the highest beluga sighting rates during the first two 

weeks of September and in the northern part of their survey area. 

Moore (2000) and Moore, DeMaster, and Dayton (2000) suggested that beluga whales select deeper 

water near the continental shelf break independent of ice cover. However, during the westward 

migration in late summer and autumn, small numbers of belugas are sometimes seen near the 

Beaufort Sea coast of Alaska (e.g., Johnson, 1979). Christie, Lyons, and Koski (2009) reported higher 

beluga sighting rates at locations >60 km offshore than at locations nearer shore during aerial surveys 

in the U.S. Beaufort Sea in 2006–2008. Belugas were not recorded, however, during Arctic cruises by 

the Healy in 2005 or 2006 (Haley, 2006; Haley and Ireland, 2006). This could be due to avoidance of 

the icebreaker by beluga. Icebreakers may be audible to beluga over distances of 35 to 78 km (Erbe 

and Farmer, 2000). Eastern Chukchi belugas move into coastal areas along Kotzebue Sound and 

Kasegaluk Lagoon in late June and remain there until mid to late July (Suydam et al., 2001; Suydam, 

Lowry, and Frost, 2005). 

Spotted Seal. The Bering Sea DPS of spotted seals inhabit the Bering and Chukchi seas as well as the 

more southern portion of the Beaufort Sea. Spotted seals are more abundant in the Chukchi Sea and 

occur in small numbers in the Beaufort Sea. Spotted seals are associated with sea ice from late fall 

through spring, especially during the breeding and molting seasons (April through June). During the 

remainder of the year, spotted seals rest on sea ice or at coastal haul outs between foraging trips. 

Spotted seals prey upon a wide variety of fish and invertebrate species. They typically migrate south 

from the Chukchi Sea and into the Bering Sea in October or November (Burns, 1970; Stirling, 

Kingsley, and Calvert, 1982; Stirling, 1997; Boveng et al., 2009). 

3.2.7. Sociocultural Systems 

Sociocultural systems encompass three concepts: (1) social organization, (2) cultural values, and (2) 

institutional organizations of communities. By “social organization” we mean how people are divided 

into social groups and networks. By “cultural values” we mean desirable values that are widely 

shared explicitly and implicitly by members of a social group. By “institutional organization” we 

refer to the government and non-government entities that provide services to the community. These 

three concepts are interrelated. For most Alaska Natives, subsistence (and the relationship between 

people, land, water, and its resources) is the expression of cultural identity, and production of 

subsistence foods is the activity around which social organization and generational transmission of 

the culture occurs. Institutional organizations, in turn, reflect and affect the social organization and 
Shell 2012 Camden Bay EP EA

Affected Environment - Subsistence Activities 61

cultural values. For the North Slope of Alaska, Iñupiat traditions and practices largely define social 

organization and cultural values, while the civil and tribal governments and ANCSA Native 

corporations largely define institutional organization. A detailed explanation of Sociocultural factors 

appears in Section 3.4.3 of the Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008a). 

Although there have been substantial social, economic, and technological changes in Iñupiat lifestyle, 

subsistence continues to be the visible central organizing value of Iñupiat sociocultural systems and it 

is primarily through impacts to subsistence activities that impacts to sociocultural systems are 

assessed (USDOI, MMS, 2008a). 

The Arctic is undergoing climate change, which affects subsistence hunting. For example, subsistence 

hunters report dispatching seals in the water rather than on ice floes (SRB&A, 2010). The Cross 

Island bowhead whale hunt is now typically starting earlier, by the end of August, rather than in 

September as in years past (Applied Sociocultural Research, 2011). Fishers are noting more salmon in 

streams that formerly supported primarily whitefish (Carothers, 2011). In sum, shifts in timing and 

regime changes are leading to adaptation on the part of subsistence harvesters. 

3.2.8. Subsistence Activities 

Subsistence activities are assigned the highest cultural values by the Iñupiat Eskimo of the North 

Slope and provide a sense of identity in addition to being an important economic pursuit. Subsistence 

resources are shared between house holds, communities, kin groups, and friends in a deeply 

embedded prescribed network that bonds the culture in tangible and concrete ways. These sharing 

networks, the joyful connection the harvester feels when attuned to the environment, transmission of 

strategies, skills, and traditional knowledge from one generation to the next all underscore the view 

held by Alaska Natives that subsistence is not just as an activity that is imbedded in the culture; it is 

very culture itself. Unlike the Western concept of subsistence as a practice that helps one eke out a 

living, among Alaska Natives there is not even a term for subsistence, because it is the richness and 

wealth that life on this earth provides the harvester (Wheeler and Thornton, 2005). 

The bowhead whale is a subsistence resource of paramount importance, and, consequently, 

descriptions of the social organization pertaining to the crew, the hunt, quantity, and distribution of 

the whale dominate subsistence discourse in North Slope Iñupiat Eskimo communities (USDOI, 

MMS, 2009a). 

Bowhead whaling traditions underscore the central values and activities for the Iñupiat of the North 

Slope. Bowhead whale hunting strengthens family and community ties and the sense of a common 

Iñupiat heritage, culture, and way of life, and provides a strength, purpose, and unity in the face of 

rapid change (USDOI, MMS, 2008a; EDAW/AECOM, 2007). Although bowhead whaling traditions 

are unquestionably important, harvest of other wild resources, including caribou, fish, avian species, 

and other marine mammals are important to the local inhabitants to provide a variety in the diet and 

nutrition or to provide nutritional needs if few or no bowhead whales are taken (USDOI, MMS, 

2009a). 

Subsistence Communities 

This discussion focuses on the subsistence activities, related subsistence resources, and subsistence 

distribution levels that generally occur during the period of Shell’s proposed exploration at the 

Sivulliq and Torpedo prospects in Camden Bay, from about July 10 through October 31. 

Kaktovik. Kaktovik’s subsistence-harvest areas are depicted in detail in Figures 3.4.2-1 through 

3.4.2-7 of the Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008a) and in the MMS OCS Study 

2009-003, Subsistence Mapping of Nuiqsut, Kaktovik, and Barrow (SRB&A, 2010: Maps 61-110). 

Subsistence resources used by Kaktovik are listed in Tables 3.4.2-3 through 3.4.2-5 of the Arctic 

Multiple-Sale Draft EIS. Kaktovik’s annual harvest of bowhead whales from the 1980s to 2005 is 

shown in Table 3.4.2-9 of the Arctic Multiple-Sale Draft EIS. 

Summer Months (July-August): During summer, the people of Kaktovik engage in a communitybased subsistence fishery. Most households gillnet at beach sites on Barter Island near Kaktovik, 
Shell 2012 Camden Bay EP EA

62 Affected Environment - Subsistence Activities 

where the primary fish harvested is sea run Dolly Varden, or char. In fact, “Kaktovik” means “place 

where people fish on the beach” (Leffingwell, 1919). Some Kaktovik households also fish to the east, 

where the primary fish harvested is Arctic cisco (SRB&A, 2010: Map 67). Some households have 

fished westward in the Canning River, but the main level of effort is on Barter Island. In 2002, one of 

two years actively censused, 79% of the households fished in summer (Pedersen and Linn, 2005; 

USDOI, MMS, 2009a; SRB&A, 2010, Maps 66-75). 

Caribou and bearded seals are also important resources taken during the summer months. A peak 

harvest time for taking caribou is in July, when hunters selectively harvest fat bulls along the coast. 

Over a 4-year period, researchers determined that the summer hunt represented about 40% of all 

caribou taken on an annual basis and were hunted as far west as the Canning River (USDOI, MMS, 

2009a; Pedersen and Coffing, 1984). Residents travel both inside and outside the barrier islands 

(SRB&A, 2010). Bearded and ringed seal hunting may coincide with caribou hunting or seals might 

be the sole prey. Most seals are hunted during the open water season in July, August and sometimes 

into September when basking on ice floes (SRB&A, 2010). Waterfowl are also taken in the summer 

months (Impact Assessment Inc., 1990b; SRB&A, 2010). 

Late Summer to Early Autumn (August 25-end of September): The bowhead whaling effort takes 

precedence over any other subsistence activity, and occurs only in the fall. Although Nuiqsut's Cross 

Island bowhead whale hunt is well documented as part of monitoring and mitigation efforts stemming 

from petroleum development, less is known about the Kaktovik bowhead whale hunt. Whaling crews 

use Kaktovik as their home base, leaving the village and returning on a daily basis. The core whaling 

area is within 12 mi of the village with a periphery ranging about 8 mi farther, if necessary. This core 

whaling area is about 48 mi from the project area. The extreme limits of the Kaktovik whaling limit 

would be the middle of Camden Bay to the west. The timing of the Kaktovik bowhead whale hunt 

roughly parallels the Cross Island whale hunt (Impact Assessment Inc, 1990b; SRB&A, 2010: Map 

64). The Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008a) describes the hunting of beluga 

whales from Kaktovik. As best as can be ascertained, about one beluga is harvested annually in 

conjunction with the bowhead whale hunt, but most households obtain beluga through exchanges 

with other communities (USDOI, MMS, 2009a). 

When people again mobilize for subsistence activities in fall after the bowhead whale hunt, they 

direct their subsistence efforts inland to hunt caribou, moose, Dall sheep, and avian species, and to 

fish if the channel separating Barter Island from the mainland has frozen deep enough to bear the 

weight of fourwheelers or snowmachines. In the fall/winter, the people fish inland under river ice 

using nets, mainly catching Dolly Varden, Arctic cisco, and lake trout (SRB&A, 2010: Map 70; 

Impact Assessment Inc, 1990b; Pedersen and Linn, 2005; Pedersen and Coffing, 1984; USDOI, 

MMS, 2009a; SRB&A 2010, Maps 72, 73, 69, and 70). 

Nuiqsut. Nuiqsut’s subsistence-harvest areas are depicted in detail in Figures 3.4.2-11 through 3.4.2-

27 of the Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008a) and in MMS OCS Study 2009-003, 

Subsistence Mapping of Nuiqsut, Kaktovik, and Barrow (SRB&A, 2010: Maps 111-162). Subsistence 

resources used by Nuiqsut are listed in Tables 3.4.2-7 through 3.4.2-8 of the Arctic Multiple-Sale 

Draft EIS. Nuiqsut’s annual harvest of bowhead whales from the 1980s to 2005 is shown in Tables 

3.4.2-9 of the Arctic Multiple-Sale Draft EIS. 

Summer Months (July-August): During summer, the people of Nuiqsut catch whitefish, primarily 

along channels of the Colville River. They also harvest Arctic char, dog salmon, pink salmon, and the 

spotted seals that follow the fish upriver. Waterfowl are hunted, as are summer caribou (Research 

Foundation of State University of New York, 1984; SRB&A, 2010: Map 112). 

People of Nuiqsut hunt ringed seal, bearded seal and eiders offshore of the Colville River eastward to 

the mouth west bank of the Canning River in the summer. Residents reported traveling as far as 

Camden Bay to the east in search seals. The most intensive use was reported offshore from the 

Colville River delta between Atigaru Point and Thetis Island, up to 25 miles offshore, although a few 

residents reported traveling as much as 40 miles offshore when hunting seals. A number of Nuiqsut 
Shell 2012 Camden Bay EP EA

Affected Environment - Economy 63

hunters reported hunting seals and eiders from Thetis Island, sometimes camping there for several 

days. Others reported taking only day trips from the community. The distance residents travel 

depends primarily on the location of the ice pack, as the seals migrate with the ice pack, resting on the 

ice floes and feeding near the ice. July is the peak month for sealing with high numbers taken also in 

June and in August (SRB&A 2010: Maps 134, 132, 134, 135, and 295). Although seal is not a 

preferred meat for human consumption, people use the oil as a condiment, and send the bearded seal 

skins to Barrow for covering umiat. Seals are hunted in nearshore waters during this time. There was 

general agreement that the best place to harvest them is off the Colville delta (Impact Assessment 

Inc., 1990a; SRB&A 2010; USDOI, MMS, 2009a). 

Late Summer to Early Autumn (August 25-end of September): Bowhead whaling takes 

precedence over any other subsistence activity, and occurs only in the fall. The 2010 Cross Island 

bowhead whale hunting season was the shortest known on Cross Island, lasting for a period of 5 days. 

The season had on early start with the arrival on Cross Island of three crews with seven boats on 

August 28. A fourth crew with 3 boats arrived on August 29, and the fifth and sixth crews arrived on 

August 20, each with two boats. Single whales were landed on August 29 and August 31, and 2 

whales were landed on September 1. The whales landed on August 29 were large, and towed to Cross 

Island late in the day, so all crews were required for butchering on August 30. Five crews scouted on 

August 31 and a whale was landed early in the day. Four crews scouted on September 1, and 2 whales 

were landed, one in the afternoon and one in the evening. On September 2, three crews hoisted their 

whaling flags for the first time in memory (Applied Sociocultural Research, 2010). 

Whale strikes occurred at an average distance of about 16 mi (about 27 km) from Cross Island. The 

shorter 2010 season compares with the 21-day season in 2006 and the 27-day season in 2005. Over 

the past 9 years of reported monitoring (2001-2008), the majority of the bowhead whales have been 

harvested in the northeast quadrant off Cross Island (Applied Sociocultural Research, 2011; USDOI, 

MMS, 2009a; SRB&A, 2010: Maps 113 and 114). 

In recent years, the Cross Island whalers focus exclusively on taking bowhead whales. They do not 

hunt for belugas, and crew members must ask for permission from the whaling captain to kill a polar 

bear that might be in the vicinity of the harvested whale carcasses because it would entail hours away 

from the bowhead whale hunt (Applied Sociocultural Research, 2009). Scheduling and logistical 

conflicts with bowhead whaling do not mean that the people have abandoned these beluga whale and 

polar bear as subsistence resources, and hunts for these resources may resume in the future (SRB&A, 

2010). 

3.2.9. Economy 

OCS oil and gas activities generate economic effects on the NSB, State of Alaska, and the Federal 

government in the form of direct and indirect employment, personal income associated with 

employment, and various types of revenues accruing to each level of government. The NSB receives 

revenues primarily from property taxes from high value onshore oil and gas infrastructure, as well the 

Federal government, State of Alaska, and local governments. The State of Alaska receives revenues 

from oil and gas activities in the form of property taxes, state corporate income tax, revenues 

associated with the Trans-Alaska Pipeline System (TAPS), and OCS revenue. Under section 8(g) of 

the OCS Lands Act, coastal states are entitled to receive 27% of revenues from offshore leases in 

Federal waters that are located within 3 miles of the State's seaward jurisdictional boundary. Oil and 

gas activities generate revenues for the Federal government through royalties, bonus bids, and rental 

revenues. The description and analysis of effects on the economy below focuses on the economy of 

the NSB, as the location, timing, and scale of the activities described in the 2011 Camden Bay EP are 

not expected to generate economic effects at the State or Federal level, because the activities 

described in the Proposed Action are short term and limited in scale in terms of the 'footprint', they 

will generate very small economic benefits at the State or Federal level. Economic benefits at the 

State and Federal level would be much more noteworthy if development and production occur in the 

future. 
Shell 2012 Camden Bay EP EA

64 Affected Environment - Environmental Justice 

Local Employment and Personal Income: Descriptions of the NSB economy in the 2011 Camden 

Bay EP (Shell, 2011a) and EIA (Shell, 2011b) are incorporated by reference, and salient points are 

summarized below. Additional information on the NSB economy is also provided below. The NSB is 

a mixed economy, characterized by a traditional cash economy and subsistence economy. The NSB 

economy is characterized by high unemployment and underemployment. Training programs and 

workforce development will continue to be important in the future to increase the low number of NSB 

residents that receive employment and personal income in the oil industry. As noted in the 

exploration plan, only 23 NSB residents were directly employed in the oil industry in 2003. More 

local hire is needed to increase employment and personal income benefits from oil and gas activities 

within the local communities. 

Revenues: The NSB government receives a large share of its revenues from property taxes levied on 

high value onshore oil and gas infrastructure. As the depreciable value of that infrastructure has 

decreased, the revenues accruing to the NSB from oil and gas activities have also declined. 

3.2.10. Environmental Justice 

The Environmental Justice (EJ) Executive Order requires each Federal Agency to make the 

consideration of EJ part of its mission. The Executive Order requires an evaluation in an EIS or EA as 

to whether the proposed project would have “disproportionately high adverse human health (i.e., 

community health) and environmental effects...on minority populations and low income 

populations.” Alaska Iñupiat Natives, a recognized minority, are the predominant residents of the 

North Slope and the Northwest Arctic Boroughs, the area potentially affected by survey activities. 

The ethnic composition of Kaktovik, Nuiqsut, and Barrow demonstrates that all three communities 

would be classed as minority communities on the basis of their proportional American Indian and 

Alaskan Native membership. The Statewide population is 15.4% American Indian and Alaskan 

Native. On this basis, an evaluation of disproportionate impacts is required. BOEMRE has found in 

past analyses that the best indicator of disproportionate impacts on the minority and low income 

populations of the North Slope are the impacts to subsistence practice and any consequent impacts on 

the sociocultural systems (USDOI, MMS, 2008a). 

3.2.11. Public Health 

The health and welfare of the residents of the NSB is a primary concern of any offshore oil and gas 

activity in the Beaufort Sea. Public health descriptions in the 2011 Camden Bay EP are incorporated 

by reference, and salient points are summarized below. The main public health issues in the NSB 

include: 

 General health  Psychosocial health 

 Accidental injuries  Nutrition 

 Cultural stress mitigation  Noncommunicable disease 

 Cardiovascular and cerebrovascular disease  Chronic lung disease 

 Cancer  Respiratory Infections 

 HIV  Maternal child health 

 Sanitation  Health services infrastructure 

 Contaminant exposure to environmental pollutants 

Indicators of general population health include life expectancy, mortality rates, infant mortality, and 

general health and well being surveys. North Slope communities have experienced a decline in 

epidemic infectious disease, with mortality rates declining and life expectancy increasing. Since the 

era of epidemic infectious diseases the health status of North Slope communities is now characterized 

by increases in diabetes, cancer, and ongoing social and psychological stress and change. 

As noted in the 2011 Camden Bay EP, the project is designed to avoid any interference with public 

health in the communities of Kaktovik and Nuiqsut, in the following manner: 
Shell 2012 Camden Bay EP EA

Affected Environment - Archaeological Resources 65

 Helicopters will be based out of Deadhorse and provide support for crew change, provision 

resupply, SAR operations on isolated flight paths; 

 Exploration drilling activities at the Sivulliq or Torpedo drill sites are planned to begin on 

or about July 10 and run through October 31, with a suspension of all operations beginning 

August 25 for the Nuiqsut (Cross Island) and Kaktovik subsistence bowhead whale hunts. 

The drilling vessel and support vessels will leave the Camden Bay project area and will 

return to resume activities after the Nuiqsut (Cross Island) and Kaktovik subsistence 

bowhead whale hunts conclude. Activities will extend to midnight October 31, depending 

on ice and weather; and 

 The distance from these two communities to the exploration site is sufficient to avoid any 

project operations from intruding on everyday community life. The project area is 

approximately 60 mi (96.5 km) from Kaktovik and 120 mi (193 km) from Nuiqsut. 

3.2.12. Archaeological Resources 

The Archaeological Resource requirements are contained in NHPA and 36 CFR 800 as well as in 

BOEMRE operational regulations under 30 CFR 250.194. The technical requirements for the 

archaeological resource surveys and reports that may be required under the regulations are detailed in 

the Alaska OCS Region NTL 05-02 and NTL 05-A03. 

Under Section 106 of the National Historic Preservation Act, BOEMRE consults with the Alaska 

State Historic Preservation Office (SHPO) for OCS activities during the pre-lease process. Section 

106 consultation for the Beaufort Sea Planning Area was completed in conjunction with completing 

the Beaufort Sea Multiple-Sale EIS and again recently in conjunction with the Arctic Mutliple-Sale 

Draft EIS (SHPO concurrence dated September 24, 2008). 

The BOEMRE’s review of the site-specific geophysical data indicates that there are no historic 

properties at Shell’s proposed drill sites. On June 29, 2011, BOEMRE concluded Section 106 

consultation with the Alaska State Historic Preservation Officer (SHPO). BOEMRE informed the 

SHPO of the determination that drilling of the four wells and related activities will have no effect on 

historic properties. The SHPO concurred with BOEMRE's determination of no historic properties 

affected on July 6, 2011. 
Shell 2012 Camden Bay EP EA

66 Affected Environment - Archaeological Resources 

Page Intentionally Left Blank 
Shell 2012 Camden Bay EP EA

Environmental Consequences - The Proposed Action 67

4.0 ENVIRONMENTAL CONSEQUENCES 

Analytical Process. Each alternative was analyzed for direct and indirect effects to the resources 

identified in Section 3.0. The analysis also included the identification of mitigation, where 

appropriate, which could be used to limit these effects. Each alternative was then analyzed for its 

incremental contribution to the cumulative effect of all past, present, and reasonably foreseeable 

future actions for each resource. A summary of prior analyses which included the effects of a large 

and a very large oil spill is provided in Sections 5.6 – 5.8. A level of effect determination (negligible, 

minor, moderate or major), based on the definitions provided in Appendix B, is provided for each 

resource in the following sections. 

4.1. Alternative 1 – the No Action Alternative 

4.1.1. Direct and Indirect Effects 

Under Alternative 1- the No Action Alternative, Shell’s 2011 Camden Bay EP would not be 

approved, a permit to drill would not be issued, and the proposed activities would not occur. Not 

issuing the permit to drill the exploratory wells at the Sivulliq and Torpedo prospects could delay the 

evaluation of borehole data required to increase the human understanding of the geology and 

petrophysical characteristics of the rocks needed for the assessment of geologic origin and potential 

petroleum reserves. Not approving the EP and issuing a permit to drill would result in lost or delayed 

opportunities for discovery and production of natural resources and any associated economic benefits 

Under Alternative 1 – The No Action Alternative, there would be no disturbance to any resources 

attributable to the proposed exploration drilling activities. There would be no effects on biological or 

subsistence resources. 

4.1.2. Cumulative Effects 

The Arctic Ocean ecosystem is rapidly changing, with melting sea ice and increasing sediment input 

from numerous regional river systems. Open water seasons are longer than in past years and there has 

been a reduction in multi-year ice. Activities which are currently ongoing in the U.S. Arctic region or 

which may occur in the foreseeable future which may affect OCS resources include: increased marine 

vessel and air traffic, fuel and petroleum spills, permitted and non-permitted discharges, long-distance 

aerosol-transported pollutants, pollutants, warming temperatures, melting of sea ice, ocean 

acidification, and risk of invasive species from ship hulls and equipment deployed. Specific activities 

which are reasonably foreseeable to occur during the period of the Proposed Action and which are 

included in the analysis of cumulative effects are summarized in Appendix C, Cumulative Effects, of 

this EA. 

The 2006 Seismic PEA, Lease Sale 195 and 202 EAs, and the Beaufort Sea Multiple-Sale EIS 

provide detailed descriptions of past activities, reasonably foreseeable future activities and the 

environmental consequences of these activities in the Beaufort Sea. If the Proposed Action does not 

take place, no additional effects would be added to the effects associated with ongoing or reasonably 

foreseeable future activities in the Beaufort Sea that are described in Appendix C, Cumulative 

Effects. 

4.2. Alternative 2 – The Proposed Action 

4.2.1. Air Quality 

The condition of local air quality could be adversely affected by the introduction of additional 

emissions from new pollution sources. This section evaluates the potential for adverse air quality 

effects due to pollutant sources required for the proposed Shell Offshore Inc. (Shell) Revised 

Exploration Plan (EP) (2011 Camden Bay EP). Implementation of the 2011 Camden Bay EP would 

require the use of a large drilling ship and support marine vessels in Camden Bay, and aircraft 

operating from nearby Deadhorse Airport. The air quality analysis of the emissions associated with 

the Proposed Action was provided by Shell in the Environmental Impact Assessment (EIA) appended 
Shell 2012 Camden Bay EP EA

68 Environmental Consequences - Air Quality 

to the 2011 Camden Bay EP (2011 Camden Bay EIA). Additional information was available through 

review of the air operating permits for the drillship Kulluk (Shell, 2011d; Shell, 2011e), and the 

drillship, Discoverer (Shell, 2010; Shell, 2011d). Information reviewed and incorporated into this 

assessment also included the air quality evaluations provided in the 2002-2007 Five-Year Program 

Environmental Impact Statement (EIS) (USDOI, MMS, 2002), the 2003 Beaufort Sea Multiple-Sale 

EIS (USDOI, MMS, 2003), and the 2009 Camden Bay EA (USDOI, MMS, 2009a). The collective 

information was reviewed and evaluated for potential adverse air quality impacts relative to the 

specific federal action proposed for the 2011 Camden Bay EP. The specific action is the proposed 

drilling of four exploratory wells on two prospects in Camden Bay, adjacent to Alaska’s North Slope 

Borough, in the Beaufort Sea. 

Other sections in this environmental review provide information relative to regulations, meteorology 

and climate of the Arctic, existing air quality on the North Slope, and characteristics of the emission 

sources considered in the air quality assessment. A list of the relevant sections is provided in 

Appendix D, Air Quality. The statutory framework guiding the assessment of air quality impacts is 

found in the discussion of the Clean Air Act (CAA) earlier in Section 1.3.5, which includes details of 

the air operating permits required for operation of the 2011 Camden Bay EP. Meteorological 

conditions at the location of the drill sites are described earlier in Section 0., Expected Weather 

Conditions at the Drill Sites. 

The existing character of air quality on the North Slope is discussed earlier in Section 3.2.1, which 

includes an overview of the regulations that guide pollution control on the Outer Continental Shelf 

(OCS). The characteristics of the pollutant sources associated with the Proposed Action are described 

earlier in Section 2.3.4, Drillship, Support Vessels, and Aircraft, and Section 2.3.6, Emissions, which 

includes descriptions of the emission reduction measures and Best Available Control Technology 

(BACT) proposed for the drillship Kulluk and the optional drillship, Discoverer. Additional 

information, including tables reflecting the air quality analysis results are provided in Appendix D, 

Air Quality. 

4.2.1.1. Direct and Indirect Effects 

The assessment of potential air quality impacts due to the Proposed Action is based on the air quality 

technical analysis provided in the 2011 Camden Bay EP. The 2011 Camden Bay EP includes the 

2011 Camden Bay EIA, and references the drillships Kulluk and Discoverer air operating permit 

applications that were submitted to the EPA Region 10 for review and approval. The 2011 Camden 

Bay EIA and the permit applications, together with all subsequent supporting documentation, were 

reviewed and found to include all drillship emission information and emission reduction measures 

required for the EP, which complies with 30 CFR 250.218. In addition, the documentation provided 

by Shell included emission information for support vessels, aircraft, and onshore and offshore 

emission sources needed for support of the proposed EP, as required under 30 CFR 250.224 and 

250.225. Therefore, the data provided in the 2011 Camden Bay EP was adequate for BOEMRE to 

make the regulatory assessment of potential air quality impacts pursuant to the OCS Air Regulations 

(40 CFR Part 55). 

Table 10 Annual Emissions allowable under the state and federal CAA Title V air permits for the 

drillship Kulluk. 

Emissions 

Pollutant Group (tons per year)

NOX PM2.5 PM10 CO SO2 VOC Pb NH3 RSC CO2e

Stationary OCS Source 

Kulluk Drillship 48.66 6.15 6.39 42.36 1.09 12.31 0.02 1.00 0.14 13168.61 

Support Vessels 127.02 17.31 17.51 77.39 3.08 16.24 0.03 12.43 0.13 44189.30 

OSR Vessels 37.93 2.84 3.06 38.35 0.37 10.23 0.02 NA 0.12 2359.01 

OSR Work Boats 15.01 1.20 1.20 4.05 0.05 1.49 0.00 NA 0.00 697.07 

Total Stationary 

OCS Source 228.62 27.51 28.16 162.15 4.59 40.26 0.07 13.43 0.39 60,413.99 

Mobile Source 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Air Quality 69

Emissions 

Pollutant Group (tons per year)

NOX PM2.5 PM10 CO SO2 VOC Pb NH3 RSC CO2e

Aircraft 2.84 0.10 3.93 0.35 1.73 NA NA NA 960.28 

Total Project 

Emissions 231.46 27.51 28.26 166.08 4.94 41.99 0.07 13.43 0.39 61,374.27 

Major Source 

Threshold 250 250 250 250 250 250 250 None None 100,000 

Note: CO2e is carbon dioxide equivalent, and represents greenhouse gas (GHG) emissions. 

Annual refers to the drilling season, approximately 120 days. 

RSC represents hydrogen sulfide (H2S), upper limit of total reduced sulfur and reduced sulfur 

compound emissions. 

NA is not available. 

Source: Shell, May 2011, Environmental Impact Analysis – Revised Outer Continental Shelf Lease Exploration 

Plan, Section 2.8, Air Emissions, Table 2.8-1, Kulluk Annual Potentials to Emit. 

Shell, April 28, 2011, Engineering Calculations [Kulluk_Beaufort EI 20110429.xls] 

The direct and indirect emissions caused by implementation of the Proposed Action include the 

drillship, the support vessels, and the aircraft. Shell prepared an emission inventory of these sources 

in support of the air quality permits required by the Environmental Protection Agency (EPA) and the 

Alaska Department of Environmental Conservation (ADEC). The emission inventory included the 

use of Best Available Control Technology (BACT) and owner-requested restrictions (ORR) to lower 

emissions, particularly emissions of nitrogen oxides and carbon monoxide from drilling operations. 

The total projected annual emissions from the drillship, Kulluk, and the alternate drillship, 

Discoverer, are given in Table 10 and Table 11. 

Table 11 Annual Emissions allowable under the state and federal CAA PSD air permits for the drillship 

Discoverer. 

Emissions 

Pollutant Group (tons per year) 

NOX PM2.5 PM10 CO SO2 VOC Pb NH3 RSC CO2e 

Stationary OCS Source 

Discoverer

Drillship 

20.80 2.52 2.57 6.46 0.22 3.13 0.02 0.16 0.14 57,585.72 

Support Vessels 125.68 13.74 14.10 69.58 0.55 17.74 0.03 0.36 0.13 

Offshore 

Management 72.51 2.14 2.51 46.11 0.26 11.05 0.00 0.00 0.00 

OSR Vessels 98.07 1.04 1.41 27.63 0.27 9.75 0.02 0.00 0.12 

OSR Work Boats 19.06 1.34 1.34 4.11 0.01 1.51 0.00 0.00 0.00 

Total Stationary 

OCS Source 336.12 20.78 21.93 153.89 1.31 43.18 0.07 0.52 0.39 57,586.00 

Mobile Source 

Aircraft 2.84 0.10 3.93 0.35 1.73 NA NA NA 960.28 

Total Project 

Emissions 338.96 20.78 22.03 157.82 1.66 44.91 0.07 0.52 0.39 58,546.00 

Major Source 

Threshold 250 250 250 250 250 250 250 None None 100,000 

Notes: CO2e is carbon dioxide equivalent, and represents greenhouse gas (GHG) emissions. 

CO2e emissions shown for the drillship Discoverer is the total for all the marine vessels required for the 

exploration plan and listed in this table. 

Annual refers to the drilling season, approximately 120 days. 

RSC represents hydrogen sulfide (H2S), upper limit of total reduced sulfur and reduced sulfur 

compound emissions. 

NA is not available. 

Source: Shell, May 2011, Environmental Impact Analysis – Revised Outer Continental Shelf Lease Exploration 

Plan, Section 2.8, Air Emissions, Table 2.8-2, Discoverer Annual Potentials to Emit. 

Shell, April 28, 2011, Engineering Calculations [Discoverer_Beaufort_EI 20110519_D.xls] 

Values given in Table 10 and Table 11 represent emissions after the application of reduction 

strategies, such as, BACT and other owner-requested restrictions (ORR). For the drillship Kulluk, 

emissions of NOX, and CO, and SO2 were greater than the threshold of 250 tons per year before 
Shell 2012 Camden Bay EP EA

70 Environmental Consequences - Air Quality 

application of the reduction strategies but were reduced to less than 250 tons per year when the 

emission reduction strategies were applied, defining the Kulluk as a minor source. Emissions of NOX

for the Discoverer remained above the threshold even after emission reduction strategies were 

applied, defining the Discoverer as a major source. 

In the 2011 Camden Bay EIA, the emission inventories of the OCS stationary sources (not including 

mobile sources) were translated into pollutant concentrations using computer modeling for 

comparison to the National Ambient Air Quality Standards (NAAQS) and the Alaska Ambient Air 

Quality Standards (AAAQS). The results of the dispersion analysis provided by Shell are included in 

Appendix D, Air Quality. The results show the Proposed Action, using either the drillship Kulluk or 

Discoverer, would not cause emissions that would result in pollutant concentrations that would equal 

or exceed the NAAQS or the AAAQS. 

In the assessment of air quality impacts associated with the Proposed Action, Shell considered the 

emissions of greenhouse gases (GHG) and carbon dioxide equivalent emissions (CO2e). In a June 

2010 ruling by the EPA, referred to as the Tailoring Rule, the agency establishes a schedule for the 

applicability criteria that determine which new stationary sources are required to report GHG 

emissions from federal actions (75 FR 31514, 2010). The Tailoring Rule states that as of July 1, 2011, 

a new stationary source is not subject to GHG regulations unless the federal action emits or has the 

potential to emit 100,000 tons per year or more of CO2e. The 2011 Camden Bay EP inventory shows 

potential emissions of CO2e from either ship would be less than 65,000 tons per year. As such, the 

requirement to report GHG would not apply to the Proposed Action. 

Black carbon, commonly referred to as soot, is a pollutant with high radiative forcing that supports 

warming trends in the Arctic. Radiative forcing is the result of the difference between the expected 

amount of incoming and outgoing solar energy, where radiative forcing is measured in watts per 

square meter. The analysis required to find the actual value of this ratio is complicated and difficult, 

and involves not only black carbon but other factors such as natural deforestation and volcanic 

activity (Chandler, 2010). Arctic haze contributes to the budget of black carbon in the Arctic, and 

along with soot emissions from diesel engines, black carbon has a tendency to decrease the albedo, or 

reflectivity, of sea ice. The decrease in albedo contributes to the warming and loss of sea ice. The 

drillship proposed for the exploration plan uses diesel engines for drilling and would be the largest 

source of black carbon attributable to the exploration plan. The loss of sea ice is not affected solely by 

black carbon deposits, but depends on snow cover, ice age, ice thickness, and state of melting (Dorn, 

Dethloff, and Rinke, 2009). Also, the magnitude of Arctic snow albedo effects is seasonal, and the 

effect is not measurable in the dark Arctic winter (Kopp and Mauzerall, 2010). A mitigation strategy 

to decrease the emissions of particulate matter (PM), the main source of black carbon from a diesel 

engine, is the use of low sulfur fuel. Sulfur is emitted directly as a component of burning crude oil 

and is found in both gasoline and diesel. Low sulfur diesel fuel (~10 to 15 parts per million) controls 

emissions of NOX and PM. Particulate filters on engines using low sulfur fuel reduce PM from 50 

percent to near 100%. The State of Alaska finalized a rule making the use of low-sulfur fuel (15 ppm 

maximum) mandatory in all highway, nonroad, locomotive, and marine diesel engines (71 FR 3250 

June 6, 2006). Although the exploration plan proposed for the Beaufort Sea would occur in the 

summer months, the drillship and all the support marine vessels are required to use ultra-low-sulfur 

fuel, as required by the State of Alaska. In addition, the drillship vessel would be equipped with other 

emission reduction equipment, as required in the air quality permits for the Kulluk and the 

Discoverer. Thus, emissions of black carbon would be reduced to the greatest extent possible. 

Upon reviewing and evaluating the relevant documents, BOEMRE expects the same level of effect 

from the Proposed Action as characterized in the 2011 Camden Bay EP. As such, the BOEMRE 

considers the Proposed Action to be compliant with state and federal air quality standards and without 

potential to cause or contribute to any violation of the NAAQS or the AAAQS that define healthful 

air quality. Also, the annual emissions are considered compliant with the plans and milestones 

included in the Alaska Air Quality Control Plan, including the Alaska State Implementation Plan 

(SIP). Further, the Proposed Action is considered compliant with the relevant provisions of the Clean 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Water Quality 71

Air Act (CAA), including Title I, Section 176(c)(1), Limitations on Certain Federal Assistance, Title 

I, Part C, Prevention of Significant Deterioration of Air Quality, and Title III, Section 328, Air 

Pollution from Outer Continental Shelf Activities. As such, the level of effect on air quality caused by 

the Proposed Action is considered minor for the exploration plan using either the drillship Kulluk or 

the drillship Discoverer. The levels of effect relevant to air quality impacts are provided in Appendix 

B. The effects evaluated will occur each season that Shell conducts exploratory drilling operations 

under this exploration plan. The minor effects, however, are temporally limited and consecutive years 

of activity would not have an additive effect. 

4.2.1.2. Cumulative Effects 

The Proposed Action includes the temporary use of marine vessels and aircraft, which are pollutant 

sources that could contribute to the emission budget within the North Slope Borough. In addition, the 

proposed action may impact other activities in the same region of the Beaufort Sea that could have an 

adverse cumulative effect on air quality. Specifically, any additional activities occurring during the 

same time period and in the same general area requiring the use of large marine vessels or aircraft 

may cause emissions to build up in the atmosphere to levels harmful to human health or wildlife, 

particularly when combined with existing emissions in the area. However, when considering 

prevailing wind conditions over the open sea, the few emission sources onshore, and the distance of 

the proposed drilling sites from the shoreline, emissions from the proposed action, when combined 

with other operations in the Beaufort Sea, would likely be diluted and dispersed resulting in pollutant 

concentrations below the air quality standards at the shoreline. A thorough description of the relevant 

additional activities that are recent, ongoing, or reasonably foreseeable during the period of time as 

the Proposed Action, and that could result in measurable adverse cumulative air quality impacts, is 

provided in Appendix C. 

Projects that are reasonably foreseeable to occur during the same time period or in the same general 

area as the proposed action include, (1) the multiple-well exploration drilling in the Chukchi Sea 

proposed by Shell; (2) the Bowhead Whale Feeding Ecology Study (BOWFEST), sponsored by the 

National Oceanographic and Atmospheric Administration (NOAA) and the National Marine Mammal 

Laboratory since 2007, and planned to continue from August through September 2012, (3) the 

Chukchi Acoustics, Oceanography, and Zooplankton (CHAOZ) study, which is planned to take place 

from July through September 2012 in the Bering, Chukchi, and Beaufort seas; (4) the Chukchi 

Offshore Monitoring in Drilling Area (COMIDA) aerial cetacean survey, which is planned to take 

place from mid-June through October 2012, in the northeast Chukchi Sea; and (5) periodic occurrence 

of Arctic haze. Arctic haze is a seasonal occurrence in the winter through the summer months, and 

even with the past contribution of temporary marine vessel emissions in the area, the EPA considers 

the North Slope Borough as a clean air resource where the pollution does not violate federal clean air 

standards and is not a threat to human health or wildlife habitats. 

Due to prevailing wind conditions over the open sea, because of the few emission sources in the 

onshore areas of the North Slope Borough, and due to the distance of the projects from the North 

Slope, the level of air quality effect when considered together with the emissions from the proposed 

action would be minor and would not result in adverse cumulative impacts to air quality. The 

reasonably foreseeable cumulative effects will occur at nearly the same level each season that Shell 

conducts exploratory drilling operations under this exploration plan. For the life of the project, the 

impacts to air quality from the Proposed Action and from reasonably foreseeable cumulative activities 

would amount to a minor level of effect. 

4.2.2. Water Quality 

4.2.2.1. Direct and Indirect Effects 

The exploratory drilling proposed in Camden Bay for the open-water seasons of 2012 and 

subsequently, until completion of 4 exploratory wells, would be conducted under NPDES General 

Permit AK280000 (Offshore Oil and Gas Exploration Facilities in Alaska) as authorized by EPA. The 

type and degree of effects on water quality from discharges into the marine environment are 
Shell 2012 Camden Bay EP EA

72 Environmental Consequences - Water Quality 

influenced by several physical factors including: rate of discharge, depth of discharge, concentration 

of contaminants, currents, bathymetry, density layers, oxygen concentration and water temperature. 

These factors would be considered by EPA under its NPDES permitting process. 

Cuttings (without drilling mud) from well intervals and construction of mud cellars would be 

discharged to the seafloor under this General Permit. Shell estimates that a total of 36,750 bbl of 

cuttings from the four drill holes would be discharged or deposited to the sea floor. Discharge of 

these cuttings would increase turbidity and suspended sediment in the water column in the vicinity of 

the drill holes (Table 12). 

Waste streams from desalination, treated deck drainage, cooling water, blow-out preventer fluid and 

cement would also be discharged according to NPDES AK280000. 

Seawater withdrawn for use as non-contact cooling water would be discharged from the drillship (at a 

depth of 41 ft (12.5 m) or 19.6 ft (6.0 m)) at temperatures above-ambient sea temperature. These 

thermal wastewaters would discharge into the sea above the stratification for salinity and temperature 

(found at approximately 20m) and would likely mix quickly. It is estimated that the thermal discharge 

would affect water temperatures within an area 164 ft long and 13 ft wide at the drillship Discoverer

and 256 ft long and 16 ft wide at the drillship Kulluk (Shell, 2011a). Desalination brine would be 

discharged as a waste stream with higher salinity and other dissolved constituents than the ambient 

receiving water (Table 12). 

Table 12 Waste (bbls) to be discharged from four exploration wells proposed into the Beaufort Sea. 

Type of Waste Sivulliq G Sivulliq N Torpedo H Torpedo J 

Total Discharge 

from 4 Lease 

Blocks 

Drill Cuttings without 

Drilling Muds - 

Discharged 

9,035 9,041 9,337 9,337 36,750 

Non-Contact Cooling 

Water - Discharged 1,978, 052 1,978, 052 2,559,832 2,559,832 9,075,768 

Desalination Brine - 

Discharged 4,200 4,200 5,500 5,500 19,400 

Deck Drainage - 

Discharged 170 170 220 220 780 

Blow-Out Preventer Fluid 

-Discharged 56 56 56 56 224 

Excess Cement - 

Discharged 50 50 50 50 200 

Note: 1bbl = 42 gallons, 5.614 ft3 and 0.159 m3

A total of 15,862 bbl of seafloor material would be excavated to construct four mud cellars and those 

cuttings would be deposited on the seafloor (Table 13) below the temperature and salinity 

stratification layer. The excavation of mud cellars would increase sediment, suspended solids and 

turbidity in the lower water column above background levels (1.8 – 3, NTU; 0.26 – 0.73 mg/L TSS as 

measured over four days in August, 2008). 

Table 13 Estimated surface area disturbed and volume of sediment excavated by two drill ships to 

construct a maximum of four mud cellars in Camden Bay during the Proposed Action. 

Drill Ship 

(# of Mud Cellars) 

Diameter of Mud 

Cellar 

Total Surface Area 

Disturbed 

(2 mud cellars) 

Depth of Mud Cellar 

Total Volume 

Extracted (2 Mud 

Cellars) 

Discoverer (2) ≥20 ft (6.1 m) ≥628 ft2 41 ft (12 m) ≥6,098 bbl (969.4 m3) 

Kulluk (2) ≥24 ft (7.3 m) ≥904 ft2 41 ft (12 m) ≥8,764 bbl (1393 m3) 

Note: 1bbl = 42 gallons, 5.614 ft3 and 0.159 m3

Anchoring would include setting 8 to 12 anchors at each site depending on which drill ship is in use. 

The seafloor area affected and the volume excavated in anchoring is presented in Table 14. 

Anchoring would introduce suspended sediment and turbidity into the lower water column causing 

concentrations above background levels. 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Water Quality 73

Table 14 Seafloor scarring as a result of anchor sets at four proposed drilling sites in Camden Bay. 

Drill Ship 

(# of Drill Sites) 

# of Anchors 

Deployed/ Drill Site 

Scar Area for Each 

Anchor and Chain 

Total Scar Area for all 

Anchors at 2 Drill Sites 

Seafloor Penetration 

of Anchor 

Kulluk (2) 12 3,249 ft2(302 m2) 77,976 ft2

 

(7,244 m2) 

down to 10 ft 

(3.06 m) 

Discoverer (2) 8 2,124 ft2

(197 m) 

33,984 ft2

( 3,157 m2) 

down to 11 ft 

(3.4 m) 

Note: 1bbl = 42 gallons, 5.614 ft3 and 0.159 m3

Shell has proposed for 2012 and 2013 (with additional seasons as necessary until completion of four 

wells) to not discharge spent water-based drilling fluids; drill cuttings with adhered drilling fluids; 

sanitary waste; domestic waste; hazardous waste; used oil; bilge water; and ballast water (Table 15). 

Instead, these waste streams would be collected at the drilling site, contained and shipped via barge 

out of the Beaufort Sea to an approved facility in Arlington, Oregon. It is estimated that 14,902 

barrels of spent water-based drilling muds and cuttings with adhered drilling muds would be 

generated and then shipped to the disposal facility, thus reducing the potential effects on water quality 

in Camden Bay. Domestic waste (92,112 bbls) would be collected, contained and shipped out of the 

Arctic, reducing the nutrients and contaminants. 

Table 15 Waste (bbls) to be collected and transported out (“Not Discharged”) from four exploration 

wells proposed in the Beaufort Sea. 

Type of Waste Sivulliq G Sivulliq N Torpedo H Torpedo J 

Total Waste NotDischarged from 4 

Lease Blocks 

Water-Based Mud – 

Not Discharged 2,213 2,213 3,022 3,003 10,451 

Drill Cuttings with 

Water-Based Mud – 

Not Discharged 

713 713 1,522 1,503 4,451 

Sanitary Waste – Not 

Discharged 5,391 5,391 6,977 6,977 24,736 

Domestic Waste – Not 

Discharged 20,075 20.075 25,981 25,981 92,112 

Ballast Water – Not 

Discharged 1,670 1,670 1,720 1,720 6,780 

Bilge Water – Not 

Discharged 612 612 792 792 2,198 

Used Oil – Not 

Discharged 50 50 50 50 200 

Hazardous Waste – 

Not Discharged 10 10 10 10 40 

Note: 1bbl = 42 gallons, 5.614 ft3 and 0.159 m3

Specific information is available on the water chemistry (Trefry and Trocine, 2009) and benthic 

habitats (Dunton, Schonberg, and McTigue, 2009) in the proposed drilling area. These studies were 

conducted in light of past drilling activity in the lease area (one well in 1985 and 1 well in 1986). The 

results from the research of Trefry and Trocine (2009) showed that levels of total metals, total 

petroleum hydrocarbons and total polycyclic aromatic carbons were not elevated above background at 

most of the 46 sites they sampled in the Sivulliq area in the summer of 2008. The exceptions to the 

background levels were found near the two sites drilled in the mid-1980s. This suggests that the 

drilling muds deposited on the seafloor showed some residual chemical signatures twenty years later. 

In the current drilling proposal, drilling fluids and cuttings with adhered drilling fluids would not be 

deposited or discharged but instead barged out of the Beaufort Sea. The elimination of this waste 

stream would result in a reduction of materials and chemical constituents entering the sea at the drill 

site and subsequently, reduced turbidity, suspended sediment and chemical residues at the drill sites 

(Table 16). 
Shell 2012 Camden Bay EP EA

74 Environmental Consequences - Water Quality 

Table 16 Waste Streams and the Effects on Water Quality in 2012 the Proposed Action. 

Activity/Waste Stream Effects on Water Quality 

Spent water-based drilling fluids and drill cuttings with 

adhered drilling fluids collected and shipped out by 

barge 

No effect on water quality 

Sanitary waste; domestic waste; hazardous waste; 

used oil; bilge water; and ballast water collected and 

shipped out by barge 

No effect on water quality 

Drill cuttings without drilling fluids discharged or 

deposited to seafloor 

Turbidity, suspended sediments in water column as 

permitted under NPDES 

Desalination brine waters, cooling waters treated deck 

drainage, excess cement and blow-out preventer fluid 

discharged subsurface 

Warming in immediate area, increased salinity in 

immediate subsurface waters, fluid and cement 

chemical constituents into subsurface and seafloor as 

permitted under NPDES 

There is a potential for fuel spills during fuel transfers. A fuel spill would introduce hydrocarbons 

and temporary toxicity effects to the surface water. The effects of a fuel spill would be limited by 

required deployment of booming equipment during fuel transfers and automatic shutdown of fuel 

lines triggered by decreased pressure. 

A small oil spill of 48 barrels was estimated based on the oil spill analysis discussed in section 2.3.9. 

An oil spill of this size would introduce petroleum hydrocarbons to the surface water and water 

column. Acute hydrocarbon toxicity levels in the water column could occur initially, however, at 

these concentrations, the acute toxicity would be short-lived and spatially limited. The chronic 

hydrocarbon concentrations, however, would persist for less than three days in the immediate area of 

the spill. 

The following are ways in which water quality effects would be mitigated: 

 Barging waste streams instead of discharging or depositing at the drill site 

 Booming fuel transfer activities 

 Equipment for early warning of a potential well-control event 

 Oil spill response vessels in the immediate vicinity of the drilling operations 

 Operations conducted under NPDES permit authorized and administered by EPA 

 Adherence to the following plans: Critical Operations and Curtailment Plan (in the event 

hazards are identified in the vicinity of the drilling operations); Ice Management Plan; 

Well Control Contingency Plan; and Fuel Transfer Plan 

After mitigation, the effects of the proposed actions on water quality would be minor. The minor 

effects evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The direct and indirect effects, however, are temporally limited and consecutive 

years of activity would not have an additive effect. 

4.2.3. Cumulative Effects: 

The activities described in this analysis are projected for a near future time frame of July-October, 

2012, July-October 2013 and potentially July-October in following years. The cumulative effects of 

these activities on water quality are expected to be minor in the immediate Camden Bay area of the 

drilling operation and minor on the regional Beaufort Sea scale. 

Climate change is having an effect on the Arctic environment now and is anticipated to have major 

effects in the future including warming sea surface, reduction in sea ice and increased ocean water 

acidity. The number of cargo, tourism and research vessels in the region is increasing as the ice cover 

is reduced. This increases the risk of vessel accidents, groundings and potential oil and cargo spills 

and introduction of marine invasive species. These ongoing effects would be the background effects 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Lower Trophic Levels 75

on which Shell’s July-October, 2012 and July-October, 2013 (and potentially July-October in 

following years) Camden Bay operation would occur. 

Over the four drilling sites and associated activities, the effects on water quality in Camden Bay 

would be minor. The effects of the proposed exploratory drilling, in addition to other ongoing 

activities in Camden Bay, would be minor. The reasonably foreseeable cumulative effects will occur 

at nearly the same level each season that Shell conducts exploratory drilling operations under this 

exploration plan. For the life of the project, the impacts to water quality from the Proposed Action 

and from reasonably foreseeable cumulative activities would amount to a minor level of effect. 

4.2.4. Lower Trophic Levels 

4.2.4.1. Direct and Indirect Effects 

Direct and indirect effects on the lower trophic resources include the sediments displaced during 

anchoring of drilling rigs, construction of the mud line cellar (MLC), and early drilling phases, 

permitted water discharges through the EPA NPDES permit, potential of invasive species 

introduction, and potential liquid hydrocarbon spills. Although the effects on lower trophic 

populations include past and future deposition of mercury, barium, and hydrogen sulfide on surface 

sediments due to sediment disruption, problems with the mechanical turbation of benthic 

environments due to ice gouging and ice melt, or a paucity of life cycle information on many 

invertebrate species (USDOI, USGS, 2011), these factors would not be a factor during the time period 

analyzed within this analysis. There are no known sensitive or unique biological communities in the 

vicinity of the exploration drill sites that would be affected by these activities. 

The 2011 Shell Camden Bay EIA (Section 2.2) discusses two possible drilling rigs, the Kulluk and the 

Discoverer. The Kulluk will deploy a total of 12 anchors, and the Discoverer a total of 8 anchors. 

Drilling vessels and anchor handling vessels would deploy and retrieve anchors a total of 4 times at 

each of the proposed 4 drill sites during the 2012 and 2013 exploration periods. This will account for 

deployment of anchors during exploration initiation in July, retrieval of anchors during suspension of 

drilling activities and movement of the drill ships offsite in August to enable mitigation for the 

migration of Bowhead whales and subsistence hunting activities, and repeat of deployment and 

retrieval of anchors to proceed for the second half of the work season from August through October. 

At each anchor site, seafloor disturbance will occur and sediment will be displaced during the 

placement and setting of anchors. Embedment type anchors will be used, designed to anchor and drag 

through the seafloor for approximately 2-3 times the anchor length (anchor maximum length of 21.5 

ft (6.5 m), depending on drill ship and anchors used). The anchor chain and any landed anchor wires 

will create an anchor trough while being dragged after placement of the anchor on the seafloor that 

will add to the anchor scar. The dimensions of these anchor scars vary with the size of the anchor, the 

length of the chain, and seafloor characteristics. The scars in the case of the Kulluk are expected to 

have an average surface area of 3,249 ft2

 (302 m2) and a disturbed volume of 543 yd3 (415 m3) per 

anchor. The total scar area for all 12 anchors would be 38,988 ft2

 (3,622 m2), with a total volume of 

6,516 yd3

 (4,980 m3) per drill site. (A detailed discussion of this process including sizes of anchors 

and volumes of sediment displaced can be found in Section 2.3 of the 2011 Camden Bay EP.) The 

known composition of the seafloor sediments in the region of the proposed drill sites, and studies of 

ice gouge affects of reshaping the benthic environments implying they will be disturbed by ice 

gouging activities as much as the anchor placements, leads to a conclusion of a negligible effect on 

benthic lower trophic populations caused by these activities. 

A MLC will be constructed at each of the 4 drill sites as preparation for the drilling operations. The 

MLC is a circular working platform drilled into the hard mud under the surface of the benthic 

environment at the seafloor. For the Kulluk, the diameter will be at least 24 ft (7.3 m), with a depth of 

approximately 41 ft (11.3 m) below mudline. Estimated volume of displaced or disturbed sediment is 

approximately 4,382 bbl (696 m3

). Early drilling phases will displace sediments to the level of the 

first drill casing, but proposed capture of drilling discharges and muds will negate release of 

sediment. (A detailed discussion of MLC construction and resulting discharges can be found in 
Shell 2012 Camden Bay EP EA

76 Environmental Consequences - Lower Trophic Levels 

Section 2.3 of the Shell Revised OCS EP). The displaced sediments of these activities have been 

modeled by Shell to cover approximately 1,592 ft (0.48 km) from the discharge source. The cuttings 

pile would be greatest approximately 66 ft (20 m) down-current from the discharge site, with 

dimensions of 10 ft (3.0 m) thick and 328 ft (100 m) wide. At approximately 886 ft (270 m) downcurrent of the source, the cuttings were estimated to be 0.4 in. (1 cm) thick and 246 ft (75 m) wide. A 

total of 36,750 barrels of cuttings (without drilling mud) would be discharged to the seafloor during 

the drilling of four exploration wells. The effects of these sediment deposits downstream from the 

creation of the MLC would result in a localized and temporary loss of pelagic and benthic 

communities directly affected by the suspension and deposition of the displaced sediments. 

Permitted NPDES discharges that are not reclaimed, stored and shipped by barge will include 

desalination brine waters, cooling waters, treated deck drainage, excess cement and blow-out 

preventer fluid. These will cause local and temporary effects to surface and pelagic environments that 

will be negligible. 

Several factors may potentially introduce invasive species during the Proposed Action. These include 

the use of equipment imported from other regions that may contain internal or surface viable life 

stages of invertebrate organisms that potentially could be released into the environment during the 

normal use of the equipment for work purposes, the presence of fouling organisms on hulls or 

propellers, and the release of ballast waters not properly discharged in transit. At the present time, 

invasive marine species have not been documented in Arctic waters. Therefore, the level of effects is 

negligible. However, with the potential of climate change, increase in ocean acidification, and 

increased industry and research activity in the Arctic regions, there is a corresponding potential of 

greater future risks for introduction of invasive species to the Beaufort and Chukchi Sea waters. 

Oil spill effects, mitigation of oil spills, and their potential of occurrence are discussed in detail in 

Sections 2.3.9 and 2.3.10 of this document. The effects of small (<1,000 bbl) to large (≥1,000 bbl) oil 

spills on lower trophic level organisms are dependent upon seasonality, duration, and weather 

conditions during and following the event. Spills of these magnitudes would likely have lethal, but 

localized, effects to limited numbers of the populations of lower trophic-level organisms by exposing 

them to petroleum-based compounds at, or above, acute or chronic toxicity levels and result in 

negligible to minor effects. 

In summary, all the above listed direct and indirect effects from the Proposed Action alternative on 

pelagic, benthic, and epontic lower trophic organisms would be limited by the coverage area of the 

four proposed drill sites and the time scale of the two work seasons considered in the exploration 

plan. Therefore, the effects are considered to be short-term and negligible. The effects evaluated will 

occur each season that Shell conducts exploratory drilling operations under this exploration plan. The 

negligible to minor effects, however, are temporally limited and consecutive years of activity would 

not have an additive effect. 

4.2.4.2. Cumulative Effects 

Cumulative effects are discussed in detail in the Arctic Multi-Sale Draft EIS (USDOI, MMS, 2008a: 

pp. 4-1 – 4-13) and in Appendix C of the current document, and are summarized below. Within this 

section, the natural and anthropogenic cumulative effects are discussed for the surface and pelagic 

waters and the benthic seafloor environments within the area of the Torpedo and Sivulliq prospects 

and the time period of the proposed July through October exploration period. 

The effects of climate change on surface and pelagic waters of the proposed drill sites include 

warming of the surface temperatures, changes in sea ice resulting in an increase in length of the open 

water season in the region, and resultant ocean acidification stemming from these changes. 

Anthropogenic effects include deposition of soot from air emissions, accidental spills of petroleum 

byproducts from vessel refueling and other vessel activities, and surface disturbance from the passage 

of military, research, recreation, subsistence, and industry aircraft and marine vessels. These activities 

present a potential for adverse environmental effects in the proposed time period of the project, but 

the duration of the project would make the cumulative effects negligible, localized and temporary. 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Fish and Essential Fish Habitat 77

Natural cumulative effects for the Proposed Action and specific to the benthic environment within the 

proposed drill sites include ice gouging and ice melt from glaciers and winter snow cover contributing 

to the seasonal influx of nutrients and sediments from the Canning, Colville, Sagavanirktok River, 

and other regional rivers and streams that will be deposited over benthic environments. Anticipated 

anthropogenic effects include anchor deployment and retrieval for drilling rigs and other associated 

support vessels, and MLC construction and subsequent release of sediments. Anchor deployment and 

retrieval will also occur for the airgun array used during vertical seismic profiling and the data 

collection buoys utilized during ancillary activities. Other activities are benthic sampling including 

fish trawls, van Veen grabs, vibracore, and cone penetration tests conducted for biological, chemical 

and geological analysis. These activities present a potential for adverse environmental effects in the 

proposed time period of the project, but the duration of the project and the sand, silt, and mud 

substrate of the benthic environment would make the cumulative effects negligible. The reasonably 

foreseeable cumulative effects will occur at nearly the same level each season that Shell conducts 

exploratory drilling operations under this exploration plan. For the life of the project, the impacts to 

lower benthic resources from the Proposed Action and from reasonably foreseeable cumulative 

activities would amount to a negligible level of effect. 

4.2.5. Fish and Essential Fish Habitat 

4.2.5.1. Direct and Indirect Effects 

Fish and Essential Fish Habitat (EFH) in the project area would be affected by several aspects of the 

proposed exploration drilling activities including: vessel traffic, vessel noise, and vessel anchoring; 

mud cellar construction; drilling noise and drill cuttings; permitted waste stream discharges (under 

NPDES Permit AKG280000, expired June 2011 and expected to be re-issued in 2012 before openwater season); water withdrawals; small refueling spills; and oil spills from vessel accidental spills or 

well releases. These activities and potential effects are presented in (Table 17). 

Table 17 Proposed Exploration Drilling Activities and Potential Effects on Fish and Essential Fish Habitat in 

Camden Bay, Alaska. 

Exploration Activities and Accidental Discharges Effects on Fish and EFH 

Excavation of mudcellar and well-hole drilling Loss of physical benthic habitat; sediment plume; increase in 

turbidity and total suspended solids (TSS); reduced visibility 

Deposition of cuttings on the seafloor (with no drilling mud) 

Loss of physical benthic habitat; sediment plume; increase in 

turbidity and TSS; loss of benthic-obligate fish, eggs, and 

larvae in the immediate vicinity 

Anchoring of drillships (Table 18), potential for introduction of 

invasive species. 

Loss of physical benthic habitat; localized increase in turbidity 

and TSS; loss of benthic-obligate fish, eggs, and larvae in the 

immediate vicinity 

Intake and discharge of non-contact cooling water 

Injury to small eggs and larval fish from withdrawal of seawater 

through 5 mm mesh at 6 cm/sec, exposure of pelagic eggs, 

larvae and juveniles in the vicinity of discharge to water 

temperatures above ambient 

Discharge of desalination brine Exposure of fish, eggs and larvae to increased salinity in 

immediate vicinity of discharge (at 41 ft/12.5m depth) 

Discharge of deck drainage, blow-out preventer fluid and 

cement 

Exposure of fish, eggs and larvae to low-level chemical 

constituents in immediate vicinity of discharge area 

Fuel spills, small oil spills 

Exposure of fish, eggs, larvae and habitat to localized 

petroleum hydrocarbon contaminants that could temporarily 

affect normal fish behavior and physiological responses. 

Large oil spills, well-blowouts 

Acute and chronic hydrocarbon contaminant effects on egg, 

larvae, juvenile and adult fish life stages and on fish prey; oil 

contact and covering of benthic and pelagic EFH in the marine, 

estuarine and freshwater environments. 
Shell 2012 Camden Bay EP EA

78 Environmental Consequences - Fish and Essential Fish Habitat 

Exploration Activities and Accidental Discharges Effects on Fish and EFH 

Vessel and drilling noise, Seismic surveys 

Startle response and scattering of adult pelagic fish which 

could interupt on-going feeding or reproductive behaviors; 

repeated or sustained exposure of benthic-obligate fish which 

are unable or less able to escape noise; exposure and 

potential injury of pelagic and benthic eggs and larvae in the 

marine and estuarine environments; potential for introduction 

of invasive species from vessels and equipment. 

Table 18 Potential benthic habitat disturbance by anchoring drill ships at a total of four drill sites in 

Camden Bay 

Drill Ship Name # of Drill Sites 

# of Anchors 

Deployed/ Drill 

Site 

Scar Area for 

Each Anchor and 

Chain 

Total Scar Area 

for all Anchors at 

2 Drill Site 

Seafloor 

Penetration of 

Anchor 

Kulluk 2 12 3,249 ft2 77,976 ft2

 

(7,244 m2) 

down to 10 ft 

(3.06 m) 

Discoverer 2 8 2,124 ft2

(197 m) 

33,984 ft2 

( 3,157 m2) 

down to 11 ft 

(3.4 m) 

Drillship anchoring at four sites would cause a loss of a total of 111,960 ft2 of benthic fish habitat. 

The areas affected and volumes excavated of each of the two drillships are presented in Table 18. 

Anchoring would introduce suspended sediment and turbidity into the lower water column causing 

decreased visibility and suspended particulate that would be drawn in over fish’ gills. Arctic cod 

lower-water-column EFH could be affected by the increased suspended sediment. 

Each of the four mud cellars constructed would disturb between 314 and 452 ft2 of benthic fish 

habitat to a sub-seafloor depth of 41 ft (12 m). Between 3,049 – 4,382 bbl (484.7 – 696.7 m3) would 

be excavated to construct each mud cellar (a potential total of 15,862 bbl excavated for 4 mud 

cellars). Cuttings from mud cellar construction would be deposited on the seafloor. 

Cuttings-without-drilling-mud would be discharged (a total of 36,750 bbls) to the seafloor during the 

drilling of four exploration wells. A model of the deposition of cuttings from the mud cellar and well 

holes was developed by Shell (Shell, 2011a). The model results show that the cuttings deposition 

would extend approximately 1,592 ft (0.48 km) down-current from discharge source. The cuttings 

pile would be greastest at approximately 66 ft (20 m) down-current from the discharge site where it 

would reach 10 ft thick (3.0 m) and 328 ft wide (100 m). 

The excavation of 4 mud cellars and the drilling of 4 well holes would cause: loss of benthic fish 

habitat through excavation and deposition of cuttings on benthic fish habitat; and increase above 

background levels of suspended sediment, suspended solids and turbidity in the lower water column, 

which includes Arctic cod EFH. Effects of turbidity and suspended sediments on benthic habitat 

would vary as a function of the distnace from the distrubance; benthic habitat will be lost at teh site of 

the mud cellars and in the immediate area from smothering by settling sediment. The areal effects of 

suspended sepdiment for this project have been modeled (Shell, 2011a). 

Over the 4 drill sites, 9,075,768 barrels of seawater are projected to be withdrawn across 5mm screens 

at a velocity of approximately 12 ft/min (6 cm/sec) for use as non-contact cooling water and for other 

uses. The majority of the withdrawn water would be discharged back to the sea at temperatures 

slightly above ambient at a depth above the salinity and temperature stratification (found at 

approximately 20m) and would likely mix quickly in this upper layer. It is estimated that the thermal 

discharge would affect water temperatures within areas 164 ft long by 13 ft wide (Discoverer) and 

256 ft long by 16 ft wide (Kulluk) (Shell, 2011a). 

Desalination operations at the 4 drill sites would discharge an estimated total of 19,400 bbls of brine 

water with greater concentrations of salinity and other dissolved constituents than the ambient 

receiving water. 

Free-swimming life stages of some pelagic and demersal fish species, such as the ecologically 

important adult Arctic cod and adult capelin, are potentially capable of avoiding the turbidity, 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Fish and Essential Fish Habitat 79

sedimentation, contaminants, brine water, warmer water, and noise and seismic sources in their 

immediate vicinity that are created by activities in the project area. Adult fish that can escape these 

effects may at first experience startle responses and disruption of ongoing behaviors before scattering 

from the vicinity of the effects. Weak-swimming or non-swimming developmental life stages of 

larvae, fry, smolt, or eggs of fishes that may be present in or pass through the area during the 

proposed activities, however, would be negatively affected, such as epipelagic Arctic cod eggs and 

larvae and capelin juveniles. 

Demersal fish life stages with strong affinities to benthic habitats, such as sculpins, flounder, 

snailfish, saffron cod eggs, capelin eggs and Arctic cod juveniles and adults, are not expected to avoid 

the temporary disturbances to their immediate environment (Mecklenberg, Mecklenberg, and 

Thorsteinson, 2002). Individual fish mortatlities would most likely in the benthic environmnet in the 

area of the drilling activities as a result of benthic habitat excavation or cuttings deposition. Seismic 

activity has been shown to cause changes in distribution patterns and abundance of fish in a study 

area (Engas et al. 1996). 

Noise from ships, sound from seismic surveys and other sound sources would affect fish through 

interference with sensory orientation and navigation, decreased feeding efficiency, scattering of fish 

away from a food source and redistribution of fish schools and shoals (Fay, 2009; Radford et al., 

2010; Simpson, 2010; Slabbekoorn, et al., 2010; Purser and Radford, 2011). Pelagic species, such as 

adult Arctic cod, adult salmon and similar species would startle and scatter as noise continues and, in 

theory, receive reduced levels of sound. Sedentary, burrowing, territorial, benthic-obligated fish, 

shallower near-shore fish, fish eggs and fish larvae in the area of the rig and oil spill would be 

exposed to higher noise levels due to their limited swimming behaviors, obligate life history 

characteristics, behavioral traits or spatial limitations. Foraging and reproduction behaviors of these 

benthic-obligate fish could be affected negatively by seismic activities and noise. 

A small oil spill of 48 barrels was estimated based on an oil spill analysis. An oil spill of this size 

would introduce petroleum hydrocarbons to the surface water and water column. Acute hydrocarbon 

levels in the water column could occur initially, however, at these concentrations, the spill effects 

would be short-lived and spatially limited. The effects of hydrocarbon concentrations of a small oil 

spill, however, could continue longer in the immediate area of the spill, depending on the size, 

location, season and species of fish present. A small oil spill or fuel spill could adversely affect the 

surface water quality; epipelagic adult fish and developmental stages (including Arctic cod eggs and 

adults); and surface water EFH of Arctic cod and Pacific salmon. 

The most likely Pacific salmon species that would be affected are pink and chum salmon in the 

nearshore environment. Salmon nearshore and freshwater EFH in the Beaufort could be affected 

outside of Camden Bay if there was a large oil spill or well blow-out. There are 8 anadromous coastal 

streams and rivers in the immediate vicinity of Camden Bay known to support anadromous Dolly 

Varden: Katakturik River, Marsh Creek, Carter Creek, Nataroarok Creek, and four unnamed streams. 

Dolly Varden in the Camden Bay region could be affected by small or large oil spills or vessel 

accident spills that reach the inshore or nearshore environments. 

Some waste streams would be collected and transported out of the Beaufort Sea to an approved 

facility including: 14,902 barrels of spent water-based drilling muds and cuttings-with-adhereddrilling-muds; and 92,112 bl of domestic waste, used oil and hazardous waste. The collection and 

transport of these waste discharges would greatly reduce potential negative effects on benthic fish 

habitat, benthic fish, developmental stages of pelagic fish populations, and on Arctic cod and Pacific 

salmon EFH in the Camden Bay region. 

Mitigation measures in the Proposed Action that reduce potential effect to fish and EFH include the 

following: 

 Barging certain waste streams instead of discharging or depositing on the seafloor 

 Water quality monitoring at fixed and random locations around the drilling operations 
Shell 2012 Camden Bay EP EA

80 Environmental Consequences - Marine and Coastal Birds 

 Booming fuel transfer activities 

 Equipment for early warning of a potential well-control event 

 Oil spill response vessels in the immediate vicinity of the drilling operations 

 Adherance to the following plans: Critical Operations and Curtailment Plan (in the event 

hazards are identified in the vicinity of the drilling operations); Ice Management Plan; 

Well Control Contingency Plan; and Fuel Transfer Plan 

Following the implementation of these mitigation measures and the analysis of effects above, 

BOEMRE finds the level of effects would be minor. The effects evaluated will occur each season that 

Shell conducts exploratory drilling operations under this exploration plan. The minor effects, 

however, are temporally limited and consecutive years of activity would not have an additive effect. 

4.2.5.2. Cumulative Effects: 

The activities described in this analysis are projected for a near future time frame of July-October, 

2012, July- October 2013 and potentially July-October in following years. Overall, the proposed 

activities would result in negative minor effects to fish at the individual level, primarily due to benthic 

habitat loss. The proposed activities, however, would have a negligible effect on fish population 

levels on a Beaufort Sea regional scale. The reasonably foreseeable cumulative effects will occur at 

nearly the same level each season that Shell conducts exploratory drilling operations under this 

exploration plan. For the life of the project, the impacts to fish from the Proposed Action and from 

reasonably foreseeable cumulative activities would amount to a minor level of effect. 

Climate change is having an effect on the Arctic environment now and is anticipated to have major 

effects in the future including warming sea surface, reduction in sea ice and increased ocean water 

acidity. The number of cargo, tourism and research vessels in the region is increasing as the ice cover 

is reduced. This increases the risk of vessel accidents, groundings and potential oil and cargo spills 

and introduction of marine invasive species. These ongoing effects would be the background effects 

on which Shell’s July-October, 2012 and July-October, 2013 (and potentially July-October in 

following years) Camden Bay operation would occur. 

The most recent EFH consultation on Pacific salmon for OCS exploration activities in the Beaufort 

Sea was conducted in 2009, concurrent with the preparation and public review of the Arctic MultipleSale Draft EIS (USDOI, MMS, 2008a). The BOEMRE received NMFS’ conservation 

recommendations in a letter dated June 26, 2009. Arctic cod EFH consultation for the drilling 

proposed by Shell in Camden Bay in 2012 and 2013 is being conducted in a separate EFH document. 

The determination of effects on EFH will be stated in that document. 

4.2.6. Marine and Coastal Birds 

4.2.6.1. Direct and Indirect Effects 

Nine species listed as threatened or candidate (four species) or abundant in the proposed project area 

(five species) have the greatest potential for adverse effects and are carried forward to the effects 

analysis. 

ESA-listed Birds 

ESA-listed birds include the Steller’s eider, the spectacled eider, the Kittlitz’s murrelet, and the 

yellow-billed loon. 

Spectacled Eider. The Proposed Action includes a commitment that specifically avoids any programrelated vessel travel within the Ledyard Bay Critical Habitat Unit (LBCHU), an area of importance to 

spectacled eiders, except for emergencies for human health or navigation safety. All incursions into 

the LBCHU for emergencies or safety must be reported within 24 hours. Implementation of this 

mitigation measure would result in no adverse effects on this critical habitat unit. 

Spectacled eiders would not be in areas where they could experience adverse effects from seismic 

airgun noise, drilling noise, icebreaking or ice management, or permitted discharges. Accidental 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Other Marine and Coastal Birds 81

small spills are not expected to reach areas where spectacled eiders occur. Few eiders would be 

migrating in offshore areas where collisions are probable and mitigation measures are expected to 

avoid the potential for spectacled eiders striking project facilities/vessels. Flight altitude restrictions 

and consistent vessel/aircraft travel routes would mitigate adverse effects to any spectacled eiders in 

nearshore coastal areas and a negligible level of effect is anticipated. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The 

negligible effects, however, are temporally limited and consecutive years of activity would not have 

an additive effect. 

Steller’s Eider. Steller’s eiders would not be in areas where they could experience adverse effects 

from seismic airgun noise, drilling noise, icebreaking or ice management, or permitted discharges. 

Accidental small spills are not expected to reach areas where Steller’s eiders occur. Few Steller’s 

eiders would be migrating in offshore areas where collisions are probable and mitigation measures are 

expected to avoid the potential for eiders striking project facilities/vessels. Flight altitude restrictions 

and consistent vessel/aircraft travel routes would mitigate adverse effects to any Steller’s eiders in 

nearshore coastal areas and a negligible level of effect is anticipated. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The 

negligible effects, however, are temporally limited and consecutive years of activity would not have 

an additive effect. 

Kittlitz’s Murrelet. There are only two reported observations of the Kittlitz’s murrelet in the 

Beaufort Sea, both at considerable distances from the drill sites. These are just east of Barrow and 

offshore of Kaktovik. There is little potential for interaction between the exploration drilling 

activities and individual Kittlitz’s murrelets. Flight altitude restrictions and consistent vessel/aircraft 

travel routes would mitigate adverse effects to any Kittlitz’s murrelets in nearshore coastal areas and a 

negligible level of effect is anticipated. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

Yellow-billed Loon. There are fewer than 5,000 yellow-billed loons on the North Slope breeding 

grounds and nearshore marine habitat. Yellow-billed loons may occur in the project area; however, 

they begin nesting in coastal lakes around mid-June, remaining in nearshore areas and wetlands until 

their fall migration in late August thru mid-September. Juveniles or non-breeders may remain in 

nearshore marine waters or in large rivers during the breeding season. 

Because of the location of the project area in relation to their lifecycle requirements, few yellowbilled loons are expected to occur in the vicinity of the proposed drilling activity. Few yellow-billed 

loons are expected to be affected by seismic airgun noise, drilling noise, icebreaking or ice 

management, permitted discharges, collisions with program facilities/vessels, or accidental oil spills. 

Flight altitude restrictions and consistent vessel/aircraft travel routes would mitigate adverse effects to 

loons in nearshore coastal areas and a negligible level of effect is anticipated. The effects evaluated 

will occur each season that Shell conducts exploratory drilling operations under this exploration plan. 

The negligible effects, however, are temporally limited and consecutive years of activity would not 

have an additive effect. 

Other Marine and Coastal Birds 

Marine and coastal bird species that are more abundant and occur in more offshore areas of the 

Beaufort Sea include the common eider, king eider, the long-tailed duck, the northern fulmar, and the 

short-tailed shearwater. These species are carried forward into the effects analysis. 

Common Eider. Most breeding female common eiders and their young begin to migrate to molt 

locations in late August and September, although large numbers of female common eiders were 

observed molting in the eastern Beaufort Sea in Canada near Cape Parry and Cape Bathurst (Johnson 

and Herter, 1989). Johnson, Wiggins, and Wainwright (1992) observed between 1,125 and 2,031 

common eiders in early September during aerial surveys in 1989 and 1990 during the molt period. 
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82 Environmental Consequences - Other Marine and Coastal Birds 

After the molt is completed, some common eiders move offshore into pelagic waters, but most eiders 

remain close to shore (Divoky, 1987). 

Common eiders were surveyed in marine waters within 100 km (62 mi) of the Beaufort Sea shoreline 

between Barrow and Demarcation Point by Fischer and Larned (2004) during summers in 1999-2001. 

In general, common eiders were concentrated in shallow waters (<10 m), with the highest densities 

occurring in segments between Oliktok point and Prudhoe Bay and between Tigvariak Island and 

Brownlow Point. Common eiders were most commonly associated with barrier islands in these 

segments, becoming less commonly observed up to 50 km seaward. Our most recent information 

indicates that male common eiders begin leaving the Beaufort Sea beginning in late June and are gone 

by late August or early September, and most females are gone by late October to early November. 

When traveling west along the Beaufort Sea coast, approximately 90% of the common eiders migrate 

within 48 km (29.8 mi) of the coast; 7% migrate 13-16 km (8 -9.9 mi) from shore, roughly along the 

17-20 m isobath (Johnson and Herter, 1989, citing Bartels, 1973). 

The largest potential for the Proposed Action to affect common eiders concerns flocks of postbreeding or migrating eiders around the barrier islands. The impact-producing factors that could 

affect long-tailed ducks are vessel traffic and noise, aircraft traffic and noise, and oil spills. Seismic 

airgun noise, drilling noise, icebreaking and ice management, and permitted discharges associated 

with the Proposed Action are not expected to affect long-tailed ducks. Changes to vessel lighting and 

the location of the drilling operation are expected to avoid the potential for eiders striking project 

facilities/vessels. 

Vessel Traffic and Noise. The Proposed Action includes predetermined vessel travel routes that avoid 

or minimize adverse effects to common eiders in nearshore coastal areas. A negligible level of effect 

is anticipated from vessel traffic. The effects evaluated will occur each season that Shell conducts 

exploratory drilling operations under this exploration plan. The negligible effects, however, are 

temporally limited and consecutive years of activity would not have an additive effect. 

Aircraft Traffic and Noise. The Proposed Action includes flight altitude restrictions and 

predetermined flight routes that avoid or minimize adverse effects to common eiders in nearshore 

coastal areas. A negligible level of effect is anticipated from aircraft traffic. The effects evaluated 

will occur each season that Shell conducts exploratory drilling operations under this exploration plan. 

The negligible effects, however, are temporally limited and consecutive years of activity would not 

have an additive effect. 

Oil Spills. Section 2.3.10 describes spill prevention and response. While there is some potential for a 

fuel spill during the proposed operations, few common eiders are anticipated to occur in the project 

area and few could be exposed to an accidental spill. Post-breeding common eiders would likely 

avoid spill response activities. Accidental small spills that are immediately contained would have a 

negligible level of effect on common eiders. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

If a small accidental spill were to escape containment or response measures, it would not persist very 

long, resulting in few opportunities to contact many common eiders. Limited mortality from a small 

spill would be considered a minor level of effect. As with other analyses incorporated by reference, 

BOEMRE assumes that any contact with oil by a bird will be fatal.The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The 

minor effects, however, are temporally limited and consecutive years of activity would not have an 

additive effect. 

King Eider. Most tagged king eiders spent more than 2 weeks staging offshore in the Beaufort Sea 

prior to migrating to molt locations in the Bering Sea (Phillips, 2005; Powell et al., 2005). Female 

king eiders may need to remain in the Beaufort Sea longer than males to replenish fat stores depleted 

during egg laying and incubation (Powell et al., 2005). Prior to molt migration, king eiders in the 

Beaufort Sea usually were found about 13 km (8 mi) offshore; however, during migration to molting 
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Environmental Consequences - Other Marine and Coastal Birds 83

areas, king eiders occupied a wide area ranging from shoreline to >50 km (31 mi) offshore (Phillips, 

2005). Fischer and Larned (2004) surveyed king eiders in marine waters within 100 km (62 mi) of the 

Beaufort Sea shoreline between Barrow and Demarcation Point during summers in 1999 and 2001. 

King eiders were the second most abundant species counted during the survey periods. King eider 

densities varied according to water depth, offshore distance, and% of ice cover. Large flocks of king 

eiders concentrated in the mid-depth (10-20 m) zone offshore of Barrow and Oliktok Point. In 1999 

and 2000, these flocks were in waters >10 m (32 ft) deep but were found in the shallow (<10 m) and 

mid-depth zone in July 2001. King eiders were unique among species surveyed by occurring in higher 

densities in low (31%) and moderate (31-60%) ice cover (Fischer and Larned, 2004). 

The largest potential for the Proposed Action to affect king eiders concerns flocks of migrating eiders 

in ice-laden areas offshore. The impact-producing factors that could affect king eiders are vessel 

traffic and noise, aircraft traffic and noise, ice management, and oil spills. Seismic airgun noise, 

drilling noise, and permitted discharges associated with the Proposed Action are not expected to 

affect king eiders. Changes to vessel lighting and the location of the drilling operation are expected to 

avoid the potential for eiders striking project facilities/vessels. 

Vessel Traffic and Noise. The Proposed Action includes predetermined vessel travel routes that avoid 

or minimize adverse effects to king eiders in nearshore and offshore areas. A negligible level of 

effect is anticipated from vessel traffic. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

Aircraft Traffic and Noise. The Proposed Action includes flight altitude restrictions and 

predetermined flight routes that avoid or minimize adverse effects to king eiders in nearshore coastal 

areas. A negligible level of effect is anticipated from aircraft traffic. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The 

negligible effects, however, are temporally limited and consecutive years of activity would not have 

an additive effect. 

Icebreaking and Ice Management. King eiders were more commonly observed in ice-laden waters 

and would have a greater potential for interactions with an active icebreaker. King eiders would be 

expected to move away from an active icebreaker. These eiders are expected to move to other areas 

unharmed. A negligible level of effect is anticipated from icebreaker operations. The effects 

evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The negligible effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Oil Spills. While there is some potential for a fuel spill during the proposed operations, few king 

eiders are anticipated to regularly occur in the project area and few could be exposed to an accidental 

spill. The vessel activity associated with spill response could help keep king eiders away from a spill. 

Based on the mitigation measures, accidental small spills will be immedieately contained and would 

have only a negligible level of effect on king eiders. As with other analyses incorporated by 

reference, BOEMRE assumes that any contact with oil by a bird will be fatal.The effects evaluated 

will occur each season that Shell conducts exploratory drilling operations under this exploration plan. 

The negligible effects, however, are temporally limited and consecutive years of activity would not 

have an additive effect. 

If a small accidental spill were to escape containment or response measures, it would not persist very 

long, resulting in few opportunities to contact king eiders. Should a small spill escape containment, 

depending on location, it could contact a small number of king eiders. Limited mortality from a small 

spill would be considered a minor level of effect. The effects evaluated will occur each season that 

Shell conducts exploratory drilling operations under this exploration plan. The minor effects, 

however, are temporally limited and consecutive years of activity would not have an additive effect. 
Shell 2012 Camden Bay EP EA

84 Environmental Consequences - Other Marine and Coastal Birds 

Long-tailed Duck. In late June and early July, most male and non-breeding female long-tailed ducks 

migrate to coastal molting areas. Typical migration distances offshore for long-tailed ducks occur 

within 45 km of shore; infrequent observations of long-tailed ducks in pelagic waters occur in late 

September (Divoky, 1987). Molting long-tailed ducks are flightless for a 3- to 4-week period and 

breeding females molt on freshwater lakes during the last phases of duckling development before 

departing the North Slope in fall (Johnson and Herter, 1989). The largest potential for the Proposed 

Action to affect long-tailed ducks concerns concentrations of molting or migrating flocks around the 

barrier islands. 

The impact-producing factors that could affect long-tailed ducks are vessel traffic and noise, aircraft 

traffic and noise, and oil spills. Seismic airgun noise, drilling noise, icebreaking and ice management, 

and permitted discharges associated with the Proposed Action are not expected to affect long-tailed 

ducks. Changes to vessel lighting and the location of the drilling operation are expected to avoid the 

potential for long-tailed ducks striking project facilities/vessels. 

Vessel Traffic and Noise. The Proposed Action includes predetermined vessel travel routes that avoid 

or minimize adverse effects to long-tailed ducks in nearshore coastal areas. A negligible level of 

effect is anticipated from vessel traffic. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

Aircraft Traffic and Noise. The Proposed Action includes flight altitude restrictions and 

predetermined flight routes that avoid or minimize adverse effects to long-tailed ducks in nearshore 

coastal areas. A negligible level of effect is anticipated from aircraft traffic. The effects evaluated 

will occur each season that Shell conducts exploratory drilling operations under this exploration plan. 

The negligible effects, however, are temporally limited and consecutive years of activity would not 

have an additive effect. 

Oil Spills. Section 2.3.10 describes spill prevention and response. While there is some potential for a 

fuel spill during the proposed operations, few long-tailed ducks are anticipated to occur in the project 

area and few could be exposed to an accidental spill. Similarly, if a small accidental spill were to 

escape containment or response measures, it would not persist very long, resulting in few 

opportunities to contact long-tailed ducks. The vessel activity associated with spill response would 

have little success in keeping keep molting ducks away from a spill because they are flightless. 

Furthermore, later in the open-water season, new migrants would arrive in a spill area on a regular 

basis, making hazing difficult. Based on the mitigation measures, accidental small spills will be 

immedieately contained and would have only a negligible level of effect on long-tailed ducks. The 

effects evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The negligible effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Should a small spill escape containment, depending on location, it could contact molting or migrating 

long-tailed ducks. Limited mortality from a small spill would be considered a minor level of effect. 

The effects evaluated will occur each season that Shell conducts exploratory drilling operations under 

this exploration plan. The minor effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Northern Fulmar. Most northern fulmars in offshore areas migrate through the Bering Sea and 

spend most of their time in the Chukchi Sea. Divoky (1987) estimated 45,000 northern fulmars in 

pelagic waters of the Chukchi Sea (typically south of Cape Lisburne) during late August to midSeptember, but this number is relatively small compared with an estimated 2.1 million that are present 

in the Bering Sea in the summer (Gould, 1983). With such a large number of fulmars in the adjacent 

Chukchi Sea, thousands of fulmars are anticipated to occur in offshore areas of the U.S. Beaufort Sea. 

Fulmars form flocks at food concentrations, which change locations throughout the open-water 

season. 
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Environmental Consequences - Other Marine and Coastal Birds 85

The impact-producing factor that could affect northern fulmars is a small oil spill. Vessel traffic and 

noise, aircraft traffic and noise, seismic airgun noise, drilling noise, icebreaking and ice management, 

and permitted discharges associated with the Proposed Action are not expected to affect northern 

fulmars. Changes to vessel lighting and the location of the drilling operation are expected to avoid 

the potential for northern fulmars striking project facilities/vessels. 

Oil Spills. While there is some potential for a fuel spill during the proposed operations, few northern 

fulmars are anticipated to regularly occur in the project area and few could be exposed to an 

accidental spill. Similarly, if a small accidental spill were to escape containment or response 

measures, it would not persist very long, resulting in few opportunities to contact northern fulmars. 

The vessel activity associated with spill response could help keep fulmars away from a spill. Based 

on the mitigation measures, accidental small spills will be immedieately contained and would have 

only a negligible level of effect on northern fulmars. As with other analyses incorporated by 

reference, BOEMRE assumes that any contact with oil by a bird will be fatal. The effects evaluated 

will occur each season that Shell conducts exploratory drilling operations under this exploration plan. 

The negligible effects, however, are temporally limited and consecutive years of activity would not 

have an additive effect. 

Should a small spill escape containment, depending on location, it could contact a flock of northern 

fulmars. Limited mortality from a small spill would be considered a minor level of effect. The effects 

evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The minor effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Short-tailed Shearwater. Short-tailed shearwaters are routinely found across the entire U.S. Chukchi 

Sea, but are most common in the southern portion. Short-tailed shearwaters are most common from 

late August to late September. Divoky (1987) reported short-tailed shearwaters as far north as 

Barrow and into arctic Canada. In certain years, an estimated 100,000 short-tailed shearwaters passed 

Point Barrow in one day in mid-September (Divoky, 1987). Migrating shearwaters appear to migrate 

closer to shore, but these numbers indicate a substantial number also occur in offshore areas, 

especially during the spring and fall. 

At northern latitudes, short-tailed shearwaters forage on dense patches of euphausiids and amphipods. 

Short-tailed shearwaters form flocks at food concentrations, which change locations throughout the 

open-water season. 

The impact-producing factor that could affect short-tailed shearwaters is a small oil spill. Vessel 

traffic and noise, aircraft traffic and noise, seismic airgun noise, drilling noise, icebreaking and ice 

management, and permitted discharges associated with the Proposed Action are not expected to affect 

short-tailed shearwaters. Changes to vessel lighting and the location of the drilling operation are 

expected to avoid the potential for short-tailed shearwaters striking project facilities/vessels. 

Oil Spills. While there is some potential for a fuel spill during the proposed operations, few shorttailed shearwaters are anticipated to regularly occur in the project area and few could be exposed to 

an accidental spill. Similarly, if a small accidental spill were to escape containment or response 

measures, it would not persist very long, resulting in few opportunities to contact short-tailed 

shearwaters. The vessel activity associated with spill response could help keep shearwaters away 

from a spill. Based on the mitigation measures, accidental small spills will be immedieately 

contained and would have only a negligible level of effect on short-tailed shearwaters. As with other 

analyses incorporated by reference, BOEMRE assumes that any contact with oil by a bird will be 

fatal. The effects evaluated will occur each season that Shell conducts exploratory drilling operations 

under this exploration plan. The negligible effects, however, are temporally limited and consecutive 

years of activity would not have an additive effect. 

Should a small spill escape containment, depending on location, it could contact a flock of shorttailed shearwaters. Limited mortality from a small spill would be considered a minor level of effect. 

The effects evaluated will occur each season that Shell conducts exploratory drilling operations under 
Shell 2012 Camden Bay EP EA

86 Environmental Consequences - Marine Mammals 

this exploration plan. The minor effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Summary of Direct and Indirect Effects 

The Proposed Action includes mitigation measures that avoid or minimize impacts from vessel traffic 

and noise, aircraft traffic and noise, icebreaking and ice management, and oil spills to a negligible 

level of effect. Overall, no more than a minor level of effect on marine and coastal bird populations is 

anticipated. The effects evaluated will occur each season that Shell conducts exploratory drilling 

operations under this exploration plan. The minor effects, however, are temporally limited and 

consecutive years of activity would not have an additive effect. 

4.2.6.2. Cumulative Effects 

Activities associated with the Proposed Action do not have a cause-effect relationship that would 

influence aspects of climate change discussed in section 3.1.1. Appendix C describes reasonably 

foreseeable future events that could occur in the project area that could affect bird populations. These 

projects include vessels and aircraft that are not subject to altitude or route restrictions and likely have 

greater impacts than the Proposed Action. The incremental contribution of the Proposed Action to 

the collective impacts on bird populations in the project area is no more than minor. The reasonably 

foreseeable cumulative effects will occur at nearly the same level each season that Shell conducts 

exploratory drilling operations under this exploration plan. For the life of the project, the impacts to 

marine and coastal birds from the Proposed Action and from reasonably foreseeable cumulative 

activities would amount to no more than a minor level of effect. 

4.2.7. Marine Mammals 

4.2.7.1. Direct and Indirect Effects 

Of the 15 marine mammal species that can occur in the Proposed Action area, nine were carried 

forward for effects analysis because of their ESA-status or relative abundance. As in Section 3.2.6, 

these are divided into two groups: 1) ESA-listed Marine Mammals and 2) Other Marine Mammals. 

ESA-listed Marine Mammals 

ESA-listed marine mammals include the bowhead whale, the fin whale, the humpback whale, the 

ringed seal, the bearded seal, the polar bear, and the Pacific walrus. 

Bowhead Whale. The Proposed Action could affect bowhead whales through vessel traffic and noise, 

aircraft traffic and noise, seismic airgun noise, drilling noise, icebreaking and ice management, 

permitted discharges, and accidental oil spills. 

Vessel traffic and noise. Bowhead whales react to the approach of vessels at greater distances than 

they react to most other activities. Most bowhead whales exhibit avoidance of vessel traffic, although 

reactions are less dramatic to slower moving vessels and vessels that are not approaching the animals 

directly (USDOC, NMFS, 2008a). 

Bowhead whales observed in vessel-disturbance experiments in the Canadian Beaufort Sea began to 

orient away from an oncoming vessel at a range of 2-4 km (1.2-2.5 mi) and to move away at 

increased speeds when approached closer than 2 km (1.2 mi) (Richardson and Malme, 1993). Most 

bowhead whales began to swim rapidly away when vessels approach rapidly and directly. A few 

whales reacted at distances from 5-7 km (3.1-4.3 mi) and a few whales did not react until the vessel 

was <1 km (<0.62 mi) away. Received noise levels as low as 84 dB re 1 μPa or 6 dB above ambient 

elicited strong avoidance of an approaching vessel at a distance of 4 km (2.5 mi). Vessel disturbance 

during these experimental conditions temporarily disrupted activities and whales in social groups 

moved apart. 

The Proposed Action and required authorizations include measures to avoid or minimize adverse 

effects to bowhead whales (Shell, 2011a: Appendix D). Some whales may move away from 

transiting vessels, but no collisions with whales are likely to occur. Vessel traffic and noise from the 
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Environmental Consequences - ESA-listed Marine Mammals 87

Proposed Action are expected to result in a negligible level of effect on bowhead whales in the project 

area. The effects evaluated will occur each season that Shell conducts exploratory drilling operations 

under this exploration plan. The negligible effects, however, are temporally limited and consecutive 

years of activity would not have an additive effect. 

Aircraft Traffic and Noise. Most routine aircraft traffic would be completed along designated routes 

at an altitude >460 m (1,500 ft), but dedicated low-level marine mammal survey flights provide a 

frequent source of disturbance. Fixed wing aircraft typically are capable of producing tones mostly in 

the 68 to 102 Hz range and at noise levels up to 162 dB re 1 μPa-m at the source (Greene and Moore, 

1995: 102-105). 

Shallenberger (1978) reported baleen whale responses appear to vary depending on flight altitude and 

received sound levels; some individual whales were disturbed by overflights at 1,000 ft (305 m), 

whereas others showed no response at 500 ft (152 m). Reactions to low-level fixed-wing aircraft are 

sometimes conspicuous if the aircraft is below 300 m (1,000 ft), uncommon at 460 m (1,500 ft), and 

generally undetectable at 600 m (2,000 ft). Repeated low-altitude overflights at 150 m (500 ft) during 

studies of feeding bowhead whales sometimes caused abrupt turns and hasty dives (Richardson and 

Malme, 1993). 

Aircraft on a direct course usually produce audible noise for only tens of seconds, and the bowhead 

whales were likely to resume their normal activities within minutes (Richardson and Malme, 1993). 

Patenaude et al. (1997) found that few bowhead whales (2.2%) during the spring migration were 

observed to react to Twin Otter overflights at altitudes of 60-460 m. Reaction frequency diminished 

with increasing lateral distance and with increasing altitude. Most observed reactions by bowhead 

whales occurred when the Twin Otter was at altitudes of <182 m and lateral distances of <250 m. 

There was little, if any, reaction by bowhead whales when the aircraft circled at an altitude of 460 m 

and a radius of 1 km. The effects from an encounter with aircraft were brief and the whales resumed 

their normal activities within minutes. 

The Proposed Action and required authorizations include measures to avoid or minimize adverse 

effects to bowhead whales. Most routine aircraft traffic is completed along designated routes at an 

altitude >460 m (1,500 ft), but dedicated low-level marine mammal survey flights provide a frequent 

source of disturbance. Some individual whales may make an abrupt turn or hasty dive in response to 

low-level flight activity, but these whales should return to normal activities within minutes. Aircraft 

traffic and noise from the Proposed Action are expected to result in no more than a minor level of 

effect on bowhead whales in the project area. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The minor effects, however, are 

temporally limited and consecutive years of activity would not have an additive effect. 

Seismic Airgun Noise. Vertical seismic profiling (VSP) is conducted once some drilling has been 

completed. These programs use hydrophones suspended in the well at intervals which receive signals 

from external sound sources, usually an airgun(s) suspended from the drill rig or a nearby supply 

vessel. Data are used to aid in determining the structure of a particular petroleum-bearing zone. 

Purely defined, VSP refers to measurements made in a vertical wellbore using geophones inside the 

wellbore and a source at the surface near the well. The Proposed Action includes a geophysical 

survey referred to as zero-offset vertical seismic profile (ZVSP) at each drill site where a well is 

drilled. 

The potential effects of seismic airgun noise on bowhead whales have been evaluated and mitigation 

measures to minimize these effects have been factored into these assessments (USDOI, MMS, 2006a, 

b, 2008a, b; USDOC, NMFS, 2006, 2008). Industry seismic survey programs have implemented 

mitigation measures and monitored bowhead whale behaviors and distribution (e.g., Funk et al., 2011; 

Haley and Ireland, 2006). The typical mitigation measures and on-site monitoring, shut- and powerdown and ramp-up procedures appear effective in avoiding or minimizing adverse effects to whales to 

the lowest extent practicable. 
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88 Environmental Consequences - ESA-listed Marine Mammals 

The VSP could occur at each well location at the end of the drilling season. The entire VSP operation 

is anticipated to be completed within 24 hours. The airgun sources for the project are moderate size 

and would be used for a short time period for the survey. While there may be a small number of 

bowhead whales in the drillship vicinity, mitigation measures would avoid or minimize adverse 

effects to whales and it is unlikely that there would be any cases of temporary hearing impairment or 

non-auditory physical effects. The VSPs could result in short-term behavioral changes to a small 

number of whales; however, implementation of typical monitoring and mitigation measures avoid or 

minimize these impacts. Seismic airgun noise associated with the VSPs is anticipated to have no 

more than a negligible level of effect on bowhead whales in the project area. The effects evaluated 

will occur each season that Shell conducts exploratory drilling operations under this exploration plan. 

The negligible effects, however, are temporally limited and consecutive years of activity would not 

have an additive effect. 

Drilling Noise. The reactions of individual bowhead whales to drillship-operation noise are variable. 

Individuals whose behavior appeared normal have been observed on several occasions within 10-20 

km (6.2-12.4 mi) of drillships in the eastern Beaufort Sea, and there have been a number of reports of 

sightings within 0.2-5 km (0.12-3 mi) from drillships (Richardson et al., 1985; Richardson and 

Malme, 1993). On several occasions, the bowhead whales were well within the zone where drillship 

noise should be clearly detectable by them. In other cases, bowhead whales may avoid drillships at 

20-30 km (USDOI, MMS, 2003). Richardson and Malme (1993) point out that the data suggest 

stationary, continuous noise sources, such as stationary drillships, elicit less dramatic reactions with 

bowhead whales than mobile noise sources. Most observations of bowhead whales tolerating noise 

from stationary operations are based on opportunistic sightings of whales near ongoing oil-industry 

operations. 

The distance at which bowhead whales may react to drillships is variable and difficult to gauge, 

because some bowhead whales would be expected to respond to noise from drilling units by changing 

their migration speed and swimming direction to avoid closely approaching these noise sources. For 

example, in the study by Koski and Johnson (1987), one whale appeared to adjust its course to 

maintain a distance of 23-27 km (14.3-16.8 mi) from the center of the drilling operation. Migrating 

whales apparently avoided the area within 10 km (6.2 mi) of the drillship, passing both to the north 

and to the south of the drillship. The study detected no bowhead whales within 9.5 km (5.9 mi) of the 

drillship, and few were observed within 15 km (9.3 mi). The study concluded that bowhead whales 

appeared to avoid the offshore drilling operation during their fall migration in 1986. 

In another study, Richardson et al. (1995) concluded: 

...migrating bowheads tolerated exposure to high levels of continuous drilling noise if it was 

necessary to continue their migration. Bowhead migration was not blocked by projected 

drilling sounds, and there was no evidence that bowheads avoided the projector by distances 

exceeding 1 kilometer (0.54 nautical miles). However, local movement patterns and various 

aspects of the behavior of these whales were affected by the noise exposure, sometimes at 

distances considerably exceeding the closest points of approach of bowheads to the operating 

projector. 

Richardson et al. (1995) also reported that bowhead whale avoidance behavior has been observed in 

half of the animals when exposed to 115 dB re 1 μPa rms broadband drillship noises. However, 

reactions vary depending on the whale activity, noise characteristics, and the physical situation 

(Richardson and Greene, 1995). The study concluded that the demonstrated effects were localized and 

temporary and that playback effects of drilling noise on distribution, movements, and behavior were 

not biologically important. Offshore drilling operations occurred in the Beaufort Sea over the past 

several decades, during which time the Western Arctic bowhead whale stock increased to about 

10,545, an estimate that may approach the carrying capacity in the Beaufort and Chukchi seas 

(Section 3.2.6.1). 

Individual bowhead whales may respond to drillship noise by making slight adjustments to their 

swimming path. These responses may occur whenever the drillship is active, but are not anticipated 
Shell 2012 Camden Bay EP EA

Environmental Consequences - ESA-listed Marine Mammals 89

when drilling is not underway. For example, the withdrawal of the drillship from the drill site area 

starting August 25 would avoid disturbance impacts and any interference with the harvest of 

migrating bowhead whales by the villages of Kaktovik and Nuiqsut. 

Underwater noise could result in small deviations in the path of some bowhead whales in the vicinity 

of drilling operations and bowhead whales are anticipated to experience no more that a minor level of 

effect. The effects evaluated will occur each season that Shell conducts exploratory drilling 

operations under this exploration plan. The minor effects, however, are temporally limited and 

consecutive years of activity would not have an additive effect. 

Icebreaking and Ice Management. Whale response distances may vary, depending on icebreaker 

activities and sound-propagation conditions. Brewer et al. (1993) reported that in fall 1992, migrating 

bowhead whales avoided an icebreaker-accompanied drillship by over 25 km. The ship was 

icebreaking almost daily. Richardson et al. (1995) noted that in 1987, bowhead whales also avoided 

another drillship with little icebreaking. Based on models in earlier studies, Miles, Malme, and 

Richardson (1987) predicted that bowhead whales likely would respond to the sound of icebreakers 

that were 2-25 km (1.24-15.53 mi) away. That study predicted roughly half of the bowhead whales 

show avoidance responses to an icebreaker underway in open-water at a range of 2-12 km (1.25-7.46 

mi) or to an icebreaker pushing ice at a range of 4.6-20 km (2.86-12.4 mi) when the sound-to-noise 

ratio is 30 dB. 

Richardson et al. (1995) concluded that exposure to a single playback of variable icebreaker sounds 

can can effect movements and behavior of migrating whales in the lead system during the spring 

migration east of Point Barrow. The study indicated response distances for bowhead whales around 

an actual icebreaker could be highly variable; however, for typical traveling bowhead whales, 

detectable effects on movements and behavior are predicted to extend commonly out to radii of 10-30 

km (6.2-18.6 mi) and sometimes to over 50 km (31.1 mi). 

It should be noted that these predictions were based on reactions of whales to playbacks of icebreaker 

sounds in a lead system during the spring migration, and are subject to a number of qualifications that 

are not relevant because the Proposed Action is during the ice-free season. Richardson et al. (1995: 

322) summarized: 

The predicted typical radius of responsiveness around an icebreaker like the Robert Lemeur is 

quite variable, because propagation conditions and ambient noise vary with time and with 

location. In addition, icebreakers vary widely in engine power and thus noise output, with the 

Robert Lemeur being a relatively low-powered icebreaker. Furthermore, the reaction 

thresholds of individual whales vary by at least ±10 dB around the “typical” threshold, with 

commensurate variability in predicted reaction radius. 

Richardson et al. (1995: xxi) stated that: 

If bowheads react to an actual icebreaker at source to noise and RL values similar to those 

found during this study, they might commonly react at distances up to 10-50 km from the 

actual icebreaker, depending on many variables. Predicted reaction distances around an actual 

icebreaker far exceed those around an actual drillsite...because of (a) the high source levels of 

icebreakers and (b) the better propagation of sound from an icebreaker operating in water 

depths 40+ m than from a bottom-founded platform in shallower water. 

Although some bowhead whales may react to icebreaking and ice-management activities, the timing 

of this project during the open-water season, the low likelihood of the presence of large amounts of 

sea ice, and the short duration of the Proposed Action, icebreaking and ice-management activities are 

expected to have a minor level of effect on the Western Arctic bowhead whale stock. The effects 

evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The minor effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Permitted Discharges. Under the Proposed Action, spent drilling fluids and cuttings, sanitary 

wastewater, and domestic wastewater would be retained on a barge onsite for later removal and 
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90 Environmental Consequences - ESA-listed Marine Mammals 

disposal at a facility in the Pacific Northwest (Shell, 2011a). Few discharges will occur on site and 

few benthic organisms would be exposed to drill cuttings and other materials, because of the 

relatively small discharge plume and the plume’s proximity to the drillship. Mobile invertebrates and 

fishes are anticipated to avoid the area affected by the discharge plume, thereby avoiding exposure. 

With implementation of measures to retain discharges to the maximum amount practicable, there are 

few opportunities for unauthorized discharges to enter the marine environment. The likelihood of 

bowhead whales ingesting organisms contaminated by discharges associated with the proposed 

activities is very low and a negligible level of effect from permitted discharges to bowhead whales is 

anticipated. The effects evaluated will occur each season that Shell conducts exploratory drilling 

operations under this exploration plan. The negligible effects, however, are temporally limited and 

consecutive years of activity would not have an additive effect. 

Oil Spills. Section 2.3.10 describes spill prevention and response. While there is some potential for a 

fuel spill during the proposed operations, few bowhead whales are anticipated to occur in the project 

area and few could be exposed to an accidental spill. Similarly, if a small accidental spill were to 

escape containment or response measures, it would not persist very long, resulting in few 

opportunities to contact bowhead whales. Finally, the vessel activity associated with spill response 

would likely keep bowhead whales out of the spill area, and individual whales would likely avoid the 

spill by leaving the area during spill response activities. Accidental small spills are anticipated to 

have no more than a negligible level of effect on bowhead whales. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The 

negligible effects, however, are temporally limited and consecutive years of activity would not have 

an additive effect. 

Summary of Direct and Indirect Effects on the Bowhead Whale. The Proposed Action includes 

mitigation measures that avoid or minimize impacts from vessel traffic and noise, seismic airgun 

noise, permitted discharges, and oil spills to a negligible level of effect. Aircraft traffic and noise, 

icebreaking and ice management, and drilling noise associated with the Proposed Action are 

anticipated to result in no more than a minor level of effect. Taken together, these activities are 

anticipated to result in no more than a minor level of effect on the bowhead whale population per 

year. The effects evaluated will occur each season that Shell conducts exploratory drilling operations 

under this exploration plan. The minor effects, however, are temporally limited and consecutive 

years of activity would not have an additive effect. 

Fin Whale. Recent observations from monitoring and research programs and passive acoustic 

monitoring indicate individual and small groups of fin whales are infrequent visitors in the U.S. 

Chukchi Sea during the open-water period, but have not been documented to occur in the Beaufort 

Sea (Section 3.2.6.1). 

The potential effects of the Proposed Action on fin whales are anticipated to be the same as those 

described for bowhead whales, except there are very few fin whales in the action area and no fin 

whales have been documented to occur in the Beaufort Sea. Because of substantial mitigation 

measures incorporated into the Proposed Action that would avoid or minimize adverse effects on fin 

whales, no more than a negligible level of effect is anticipated. The effects evaluated will occur each 

season that Shell conducts exploratory drilling operations under this exploration plan. The negligible 

effects, however, are temporally limited and consecutive years of activity would not have an additive 

effect. 

Humpback Whale. Recent research and monitoring programs have indicated the presence of small 

numbers of humpback whales in the U.S. Chukchi Sea and Beaufort Sea (Section 3.2.6.1). 

The potential effects of the Proposed Action on humpback whales are anticipated to be the same as 

those described for bowhead whales, except there are very few humpback whales in the action area. 

Because of substantial mitigation measures incorporated into the Proposed Action that would avoid or 

minimize adverse effects on humpback whales, no more than a negligible level of effect is 

anticipated. The effects evaluated will occur each season that Shell conducts exploratory drilling 
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Environmental Consequences - ESA-listed Marine Mammals 91

operations under this exploration plan. The negligible effects, however, are temporally limited and 

consecutive years of activity would not have an additive effect. 

Ringed Seal and Bearded Seal. The Proposed Action includes activities that could affect ringed 

seals and bearded seals. The impact–producing factors include vessel traffic and noise, aircraft traffic 

and noise, seismic airgun noise, drilling noise, ice management, permitted discharges, and small 

spills. Due to the similarities in the vulnerability and responses of ringed seals and bearded seals in 

the Alaskan Arctic (Section 3.2.6.1), the potential effects of the Proposed Action on the two species 

are combined. 

Vessel Traffic and Noise. Vessel traffic associated with the Proposed Action would primarily be 

during the open-water season, when most ringed seals have followed the receding ice edge northward 

away from the project area. During that time period bearded seals would have moved into shallower 

waters closer to shore. Given the low densities of ice seals in general, relatively few ringed seals and 

bearded seals would be expected to be in the project area, but those present could be affected by 

vessel activity. 

Jansen et al. (2010) indicated that vessel presence and movement can motivate seals to alter their 

behavior. Richardson (1995) concluded that at least some seals may have a high tolerance to vessels 

and vessel noise, but it depends on vessel distance and whether seals are hauled out or not. Vessel 

noise did not seem to strongly affect pinnipeds already in the water, whereas hauled out seals often 

responded more strongly to the presence of vessels (Richardson, 1995). Jansen et al. (2006) reported 

that hauled out harbor seals approached by ships at 100 m were 25 times more likely to enter the 

water than those approached at 500 m. Brueggeman et al. (1992) observed hauled out ringed seals 

displaying short-term escape reactions when a ship approached within 0.25 mile. As there are no land 

haul-out sites for ringed near the drill site, no direct impacts to hauled out ringed seals would be 

expected from support vessels during drilling operations. Bearded seals do not haul out on land in the 

Proposed Action area. 

All project vessels must reduce speed and avoid course changes within 900 ft (274 m) of a ringed or 

bearded seal, whether hauled out or in open-water. On-board MMOs will assist vessels in 

implementing this mitigation measure to avoid collisions with ice-seals. 

Due to mitigation measures designed to minimize adverse effects on marine mammals, vessel traffic 

and noise would have a negligible level of effect on ringed seals and bearded seals in the project area. 

The effects evaluated will occur each season that Shell conducts exploratory drilling operations under 

this exploration plan. The negligible effects, however, are temporally limited and consecutive years 

of activity would not have an additive effect. 

Aircraft Traffic and Noise. Aircraft are needed to support the drillship and other parts of the overall 

operation. There is some potential that ringed seals and bearded seals could be disturbed by lowflying aircraft. 

Born et al. (1999) reported ringed seals showed a 21% probability of reacting to fixed-wing aircraft at 

100 m from the aircraft, 6% between 100 and 300 m from the flight track, and 2% between 300 and 

500 m from the flight track. The study also noted that the variables most likely to influence the 

probability of escape responses were time of day and temperature. 

Calvert and Stirling (1985) reported that counts of ringed seal calls in water in an area subjected to 

low-flying aircraft were similar to those in less disturbed areas. The Proposed Action has 

incorporated mitigation measures to reduce the likelihood of impacts to ringed seals and bearded 

seals including restricting aircraft to above 1,500 ft (457 m), unless the aircraft is landing or taking off 

or conducting surveys to monitor for marine mammals, or for navigational safety. Flight paths for 

aircraft leaving the shorebase would remain approximately 5 mi inland until reaching a point near Pt. 

Thompson, where aircraft would then turn north over water to reach the drilling sites. The flight plan 

would only present 16 mi of possible disturbance to ringed seals or bearded seals in the flight segment 
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92 Environmental Consequences - ESA-listed Marine Mammals 

between the drillship and the coast. The flight altitude restrictions along this route, however, would 

avoid or minimize disturbance to ice seals. 

Most routine aircraft traffic is completed along designated routes at an altitude >460 m (1,500 ft), but 

dedicated low-level marine mammal survey flights provide a frequent source of disturbance to ice 

seals. Some individual ice seals could respond to low-level flight activity, but these seals should 

return to normal activities within minutes. Aircraft traffic and noise from the Proposed Action are 

expected to result in no more than a minor level of effect on ringed seals and bearded seals in the 

project area. The effects evaluated will occur each season that Shell conducts exploratory drilling 

operations under this exploration plan. The minor effects, however, are temporally limited and 

consecutive years of activity would not have an additive effect. 

Seismic Airgun Noise. Vertical seismic profiling (VSP) is conducted once some drilling has been 

completed. These programs use hydrophones suspended in the well at intervals which receive signals 

from external sound sources, usually an airgun(s) suspended from the drill rig or a nearby supply 

vessel. Data are used to aid in determining the structure of a particular petroleum-bearing zone. 

Purely defined, VSP refers to measurements made in a vertical wellbore using geophones inside the 

wellbore and a source at the surface near the well. The Proposed Action includes a geophysical 

survey referred to as zero-offset vertical seismic profile (ZVSP) at each drill site where a well is 

drilled. 

The pulsed sounds associated with seismic exploration have higher peak levels than most other 

industrial sounds to which ice seals are routinely exposed. Most ice seals spend greater than 80% of 

their time submerged in the water (Gordon et al., 2004); consequently, some could be exposed to 

sounds from seismic surveys that occur in their vicinity. Underwater audiograms for ice seals 

suggest that they have very low hearing sensitivity below 1 kHz, though they can hear underwater 

sounds at frequencies up to 60 kHz, making calls between 90 Hz and 16 kHz (Thomson and 

Richardson, 1995). While seismic surveys can contain energy up to 1 kHz, most of the emitted 

energy is less than 200 Hz (Richardson et al., 1995). Gordon et al. (2004) suggested phocids may be 

susceptible to the masking of biologically important signals by low frequency sounds, such as those 

from seismic surveys, and while brief, small-scale masking episodes might have few long-term 

consequences. Southall et al. (2007) proposed that PTS could occur to pinnipeds exposed to single 

sound pulses at 218 dB re: 1 μPa in water, however, injury from seismic surveys may occur only if 

animals entered the zone immediately surrounding the sound source since noise loss occurs rapidly 

with distance from operating airguns. 

Reported seal responses to seismic surveys have been variable and often contradictory, although they 

suggest ice seals often remain within a few hundred meters of operating airgun arrays (Brueggeman et 

al., 1991; Harris, Miller, and Richardson, 2001; Miller and Davis, 2002). Brueggeman et al. (1991) 

reported that 96% of the seals they encountered during seismic operations in the Beaufort Sea were 

encountered during non-data acquisition activities, suggesting avoidance of active data acquisition 

operations, and Miller and Davis (2002) reported that on average seals in the Beaufort Sea were 

observed at 150 m from vessels when seismic surveys were inactive as opposed to 210 m when 

seismic surveys were being conducted, with sound levels of 190 dB re 1 μPa extended out to 210 m. 

Harris, Miller, and Richardson, (2001) observed sighting rates of ringed seals from a seismic vessel in 

the Beaufort Sea showed no difference between periods using the full airgun array, a partial array, or 

no airguns, although the mean distances to seals increased during full array operations, indicating 

some local avoidance at 190-200 dB re 1 μPa noise levels. These observations provide limited 

support for the Temporary Threshold Shift and Permanent Threshold Shift injury criteria as outlined 

in Southall et al. (2007) and localized avoidance by ringed seals (Harris, Miller, and Richardson, 

2001). In contrast, telemetry work by Thompson, Duck, and McConnel (1998) suggested that 

avoidance and behavioral reactions to small airgun sources could be more pronounced than ocular 

observations indicate. 2001 tagging studies (Cott, Hanna, and Dahl, 2003) reported that seismic 

surveys in the Beaufort Sea had no obvious effect on the timing or route of ringed seals migrating in 

the fall. 
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Environmental Consequences - ESA-listed Marine Mammals 93

Funk et al. (2010) reported the highest Marine Mammal Observer (MMO) effort was required where 

noise levels were <120 dB re 1 μPa during 2006-2008 Beaufort Sea and Chukchi Sea seismic survey 

activities. In the same report, pinniped sighting rates from monitoring vessels in the Beaufort Sea and 

Chukchi Sea were higher than those from seismic vessels, with the highest rates occurring in the <120 

dB re 1 μPa zone, suggesting localized avoidance of active seismic vessels. 

During a 2010 seismic survey in the Chukchi Sea, MMOs from the seismic vessel had the highest 

sighting rate in the ≥160 dB re 1 μPa zone, while MMOs on the monitoring vessels had their highest 

sighting rates in the 159-120 dB re 1 μPa (Blees et al., 2010). MMOs on both vessels observed 

roughly similar sighting rates of 12.5/1,000 km (seismic vessel) and 11.8/1,000 km (monitoring 

vessels) during periods of non-seismic activity or when dB levels were <120 dB re 1 μPa. Results 

from Blees et al. (2010) conflict with the position that seismic surveys would likely displace ringed 

seals from an area where received noise levels are in excess of 159 dB re 1 μPa because monitoring 

vessels recorded their highest seal sighting rates from monitoring vessels in the 159-120 dB re 1 μPa 

zone (18.8/1,000 km) as opposed to the seismic vessel where the highest seal sighting rate was in the 

≥160 dB re 1 μPa zone (31.5/1,000 km). Although 146 seals were observed from the seismic vessel 

during airgun operations only 10 were detected in the ≥190 dB re 1 μPa zone, while 154 seals were 

observed by monitoring vessels where there was no ≥190 dB re 1 μPa zone. 

Ultimately Blees et al. (2010) estimated 416 ringed seals may have been exposed to airgun pulses ~21 

each with pulses ≥160 dB re 1 μPa, based on the assumption that ~19.1% (416/2,180 = 0.191, and 

0.191 x 100% = 19.1%) of the seals observed were ringed seals. By applying this 19.1% estimate to 

the number of seals observed in the ≥190 dB re 1 μPa zone (652), a rough estimate (0.191 x 652 = 

124.5 ≈ 125 seals) can be derived suggesting 125 ringed seals were exposed to noise levels ≥190 dB 

re 1 μPa for approximately 2 times each if there was no avoidance of the sound source. Caution 

should be used in interpreting this calculation because Blees et al. (2010) did not specify the ringed 

seals estimate for the ≥190 dB re 1 μPa zone and the authors stated that the actual numbers of seals 

exposed to Received Sound Levels (RSL) ≥190 dB re 1 μPa was likely greater than the 10 

observations, but lower than the estimated 652 seal exposures. 

Similarly, Blees et al. (2010) estimated 1,681 bearded seals may have been exposed to airgun pulses 

~21 each with pulses ≥160 dB re 1 μPa, based on the assumption that ~77% (1,681/2,180) of the seals 

observed were ringed seals. By applying the 77.1% estimate to the number of seals observed in the 

≥190 dB re 1 μPa zone (652), a rough estimate (0.771 x 652 = 502.75 ≈ 503 bearded seals) can be 

derived suggesting 503 bearded seals were exposed to noise levels ≥190 dB re 1 μPa for 

approximately 2 times each if there was no avoidance of the sound source. Caution should be used in 

interpreting this calculation since Blees et al. (2010) did not specify the bearded seals estimate for the 

≥190 dB re 1 μPa zone, because the estimate of 652 exposed seals is much higher than the 10 seals 

that were actually witnessed in the zone, and because the author states that the actual numbers of seals 

exposed to RSL ≥190 dB re 1 μPa was likely greater than the 10 observations but lower than the 

estimated 652 seal exposures. 

Seismic surveying has limited potential to affect fishes and some invertebrate species that fall within 

the ice seal diet (USDOI, MMS, 2006a). The primary prey species for ringed seals from the late fall 

into the spring are Arctic cod. Potential effects to some prey species (i.e., some teleost fishes) may 

include displacement from foraging, staging, or spawning areas. For some species the displacement 

may last for days, weeks, or longer. If seismic surveys cause prey items to become scarce, either 

because they move out of an area or become more difficult to catch, seal distributions and feeding 

rates could be affected, especially newly weaned ringed seal pups (Gordon et al., 2004). The opposite 

potentially could occur because damaged or disoriented prey could attract ice seals to seismic-survey 

areas, providing robust short-term feeding opportunities (Gordon et al., 2004). 

The VSP could occur at each well location at the end of the drilling season. The entire VSP operation 

is anticipated to be completed within 24 hours. The airgun sources for the project are moderate size 

and would be used for a short time period for the survey. While there may be a small number of 

ringed seals or bearded seals around the drillship, mitigation measures would avoid or minimize 
Shell 2012 Camden Bay EP EA

94 Environmental Consequences - ESA-listed Marine Mammals 

adverse effects to ice seals and it is unlikely that there would be any cases of temporary hearing 

impairment or non-auditory physical effects. The VSPs could result in short-term behavioral changes 

to a small number of seals; however, implementation of typical monitoring and mitigation measures 

avoid or minimize these impacts. Seismic airgun noise associated with the VSPs are anticipated to 

have no more than a negligible level of effect on ringed seals and bearded seals in the project area. 

The effects evaluated will occur each season that Shell conducts exploratory drilling operations under 

this exploration plan. The negligible effects, however, are temporally limited and consecutive years 

of activity would not have an additive effect. 

Drilling Noise. Some ringed seals and bearded seals may be displaced around a drill site by active 

drilling operations (Richardson et al., 1995). The effects of offshore drilling on ringed seals in the 

Beaufort Sea were investigated in the past by Frost and Lowry (1988) and Moulton et al. (2005). 

Frost and Lowry (1988) concluded that local ringed seal populations were less dense within a 2 nmi 

buffer of man-made islands and offshore wells that were being constructed in 1985-1987. Moulton et 

al. (2005) found ringed seal densities on the same locations to be higher in years 2000 and 2001 after 

a period of habituation. 

Moulton et al. (2005) reported that during spring aerial surveys for ringed seals, there was no 

evidence that construction, drilling, and production activities at BP’s Northstar oil development in the 

Beaufort Sea affected local ringed seal distribution and abundance. The Northstar facility is on an 

artificial island. Drilling and production sounds from Northstar likely were audible to ringed seals, at 

least intermittently, out to approximately 1.5 km in water and 5 km in air (Blackwell et al., 2004). 

Underwater sounds from construction, drilling, and production reached background values at 2-4 km 

away (Richardson and Williams, 2004). Richardson and Williams (2004) concluded that there was 

little effect from the low to moderate level, low-frequency industrial sounds emanating from the 

Northstar facility on ringed seals during the open-water period and that the overall effects of the 

construction and operation of the facility were short-term and localized, with no consequences to seal 

populations as a whole. Adult ringed seals may habituate to drilling activities over several years, but 

are not assumed to do so in a single year. 

Harwood, Smith, and Melling (2007) evaluated the potential impacts of exploratory drilling on ringed 

seals in the near shore Canadian Beaufort Sea, during February to June 2003-2006. The first three 

years of the study (2003-2005) were conducted prior to industry activity in the area, while a fourth 

year of study (2006) was conducted during the latter part of a single exploratory drilling season. The 

distances from industrial sites to seal breathing holes and lairs were not substantially different 

between the pre-activity (2003 and 2004) and industrial activity (2006) periods. The movements, 

behavior, and home range size of ten seals tagged in 2006 also did not vary statistically between the 

19 days when industry was active (20 March to 8 April) and the following 19 days when industry 

operations were completed. Resting ringed seal densities did not differ among the different study 

years and were comparable to densities found in during surveys conducted in 1974-1979. No 

detectable effect on ringed seals could be discerned in the one season of drilling in the study area 

(Harwood, Smith, and Melling, 2007). As the Harwood study was conducted when seals were 

engaged in more sensitive periods of pupping, breeding, and molting, these results indicate that seals 

may be more tolerant of other potential disturbances after these activities are concluded. Potential 

effects to bearded seals are estimated to be the same as for ringed seals. 

Modeled sound radii indicate that the drillship activities would generate a 120 dB re 1 μPa at 13.27 

km from the Kulluk and 3.32 km from the Discoverer (Shell, 2011a, Table 10.b-1, page 10-4). The 

NMFS uses a 120-dB rms isopleth to indicate where Level B harassment begins for continuous 

acoustic sources, such as drillships. Modeling indicates there is no chance for bearded or ringed seals 

to encounter a noise level from the drill ship that could result in physical injury. Seals approaching 

the drill site would encounter increasing levels of underwater noise of their own volition. While a 

small number of ringed seals and bearded seals could move out of the immediate area, these 

movements to other nearby similar areas are anticipated to result in no more than a negligible level of 

effect. The effects evaluated will occur each season that Shell conducts exploratory drilling 
Shell 2012 Camden Bay EP EA

Environmental Consequences - ESA-listed Marine Mammals 95

operations under this exploration plan. The negligible effects, however, are temporally limited and 

consecutive years of activity would not have an additive effect. 

Icebreaking and Ice Management. Ice management activities associated with the Proposed Action 

are described in detail in Section 2.3.4. Project timing would alleviate harm to breeding seals, seal 

pups in lairs, and molting seals. The Proposed Action would occur after the ice-seal breeding season 

(which ends in mid June), during the open-water season. 

Some ringed or bearded seals could be associated with ice that could be encountered during 

movement of the fleet to or from the project site in the Beaufort Sea. Strandberg, Embacher, and 

Sagriff (1984) concluded that ringed seals tended to remain on the ice or in their breathing holes just a 

few tens of meters away from a ship moving through extensive pack ice in Admiralty Inlet, Canada. 

After the ship had passed, seals tended to move into the ship’s track, similar to their response to 

natural openings. Ringed or bearded seals hauled out on ice in close proximity (<1 km) to the fleet 

may enter the water. Extensive pack ice is not anticipated in the project area during the Proposed 

Action. 

Limited ice breaking might be needed to assist the fleet in accessing/exiting the project area if large 

amounts of ice pose a navigational hazard. Ice seals have variable responses to ice management 

activity. Alliston (1980, 1981) reported icebreaking activities did not adversely affect ringed seal 

abundance in the Northwest Territories and Labrador. Brueggeman et al. (1992) reported ringed seals 

and bearded seals diving into the water when an icebreaker was 0.93 km away; however, Kanik, 

Winsby, and Tanasichuk (1980) reported that ringed seals remained on sea ice when an icebreaker 

was 1-2 km away. 

The drill site is expected to be mostly ice-free during July, August, and September and the need for 

ice management should be infrequent. The presence of an icebreaker is primarily a safety precaution 

to protect the drill ship from damage. Ice-seals could be on isolated floes that may need to be 

managed for safety. Any ice seals on floes approaching the drill ship may be disturbed by ice 

management activities. Ringed seals and bearded seals on an ice floe are anticipated to enter the 

water before the icebreaker contacts the ice, remain in the water as the ice moves past the drill ship, 

and could reoccupy ice after it has moved safely past the drill ship. While a small number of ringed 

seals and bearded seals could leave ice haulouts and enter the water, these short-term disturbances to 

individual ice-seals are anticipated to result in no more than a negligible level of effect. The effects 

evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The negligible effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Permitted Discharges. Under the Proposed Action, spent drilling fluids and cuttings, sanitary 

wastewater, and domestic wastewater would be retained on a barge onsite for later removal and 

disposal at a facility in the Pacific Northwest (Shell, 2011a). Few discharges will occur on site and 

few benthic organisms would be exposed to drill cuttings and other materials, because of the 

relatively small discharge plume and the plume’s proximity to the drillship. Mobile invertebrates and 

fishes are anticipated to avoid the area affected by the discharge plume, thereby avoiding exposure. 

With implementation of measures to retain discharges to the maximum amount practicable, there are 

few opportunities for unauthorized discharges to enter the marine environment. The overall effect of 

the proposed activities may be temporary, non-lethal effects to fish populations. As a consequence, 

the likelihood of ice seals ingesting benthic organisms or fishes contaminated by discharges 

associated with the proposed activities is very low and a negligible level of effect from permitted 

discharges to ringed seals or bearded seals is anticipated. The effects evaluated will occur each season 

that Shell conducts exploratory drilling operations under this exploration plan. The negligible effects, 

however, are temporally limited and consecutive years of activity would not have an additive effect. 

Oil Spills. Oil spills are accidental events. The potential effects of small oil spills are described 

below. Large and very large oil spills are described in Section 5.7, and Section 5.8. 
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96 Environmental Consequences - ESA-listed Marine Mammals 

Section 2.3.10 describes spill prevention and response. While there is some potential for a fuel spill 

during the proposed operations, few ringed seals or bearded seals are anticipated to occur in the 

project area and few could be exposed to an accidental spill. Similarly, if a small accidental spill 

were to escape containment or response measures, it would not persist very long, resulting in few 

opportunities to contact ice seals. Finally, the vessel activity associated with spill response would 

likely keep ice seals out of the spill area, and individual seals would likely avoid the spill by leaving 

the area during spill response activities. Accidental small spills are anticipated to have no more than 

a negligible level of effect on ringed seals and bearded seals. The effects evaluated will occur each 

season that Shell conducts exploratory drilling operations under this exploration plan. The negligible 

effects, however, are temporally limited and consecutive years of activity would not have an additive 

effect. 

Polar Bear. Polar bears and critical habitat are described in Section 3.2.6.1. The Proposed Action 

could affect polar bears or their habitats through vessel traffic and noise, aircraft traffic and noise, 

icebreaking and ice management, and accidental oil spills. Permitted discharges and seismic airgun 

and drilling noise associated with the Proposed Action are not anticipated to affect polar bears. 

Vessel Traffic and Noise. Polar bears may be stressed by energy expenditures related to avoiding or 

investigating vessels in the lead systems or traffic on ice. Encounters are much less likely to occur 

during the open-water season when the proposed activities would occur, because most polar bears 

remain in the active ice zone (USDOI, FWS, 2009c). The Proposed Action specifies that project 

vessels will not operate within 0.5 mi (800 m) of polar bears observed by the Marine Mammal 

Observers onboard on land or sea ice. Vessels will follow specific corridors from West Dock to and 

from the drill site at least 1 mi from barrier islands (except traversing the Mary Sachs Entrance, or for 

navigation safety). The Proposed Action also includes measures to reduce the likelihood of impacts 

to polar bears; specifically identified in the Polar Bear, Pacific Walrus, and Grizzly Avoidance and 

Human Encounter /Interaction Plan (Shell, 2011b). Vessel operations, as monitored by MMOs, are 

anticipated to result in no more than a negligible level of effect on polar bears. The effects evaluated 

will occur each season that Shell conducts exploratory drilling operations under this exploration plan. 

The negligible effects, however, are temporally limited and consecutive years of activity would not 

have an additive effect. 

Aircraft Traffic and Noise. Most routine helicopter traffic would fly at least 1,500 ft AGL between 

shore facilities and the drill site (except during take-offs, landings, or for navigational safety). 

Helicopter traffic may travel between Deadhorse and the Beaufort Sea drill site, following a flight 

corridor that is 5 mi inland and then directly offshore through the Mary Sachs Entrance to the drill 

site (weather permitting). 

Dedicated low-level marine mammal survey flights could provide a frequent source of disturbance to 

polar bears; however, polar bears are expected to be uncommon in open-water areas. Aircraft traffic 

and noise from the Proposed Action are expected to result in no more than a negligible level of effect 

on polar bears in the project area. The effects evaluated will occur each season that Shell conducts 

exploratory drilling operations under this exploration plan. The negligible effects, however, are 

temporally limited and consecutive years of activity would not have an additive effect. 

Icebreaking and Ice Management. Polar bear reactions to icebreakers are variable. Polar bears are 

known to run from sources of noise and the sight of icebreakers, but other times polar bears have 

demonstrated curiosity towards icebreakers. During the open-water season, most polar bears remain 

offshore on the pack ice or land and are not normally present in the project area. Any encounters 

between a polar bear and icebreakers associated with this project are expected to elicit transitory 

short-term behavioral reactions in polar bears (USDOI, FWS, 2009) and a negligible level of effect is 

anticipated. The effects evaluated will occur each season that Shell conducts exploratory drilling 

operations under this exploration plan. The negligible effects, however, are temporally limited and 

consecutive years of activity would not have an additive effect. 
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Environmental Consequences - ESA-listed Marine Mammals 97

Oil Spills. Oil spills are accidental events. The potential effects of small oil spills are described 

below. Large and very large oil spills are described in Section 5.7, and Section 5.8. 

Section 2.3.10 describes spill prevention and response. While there is some potential for a fuel spill 

during the proposed operations, few polar bears are anticipated to occur in the project area and few 

could be exposed to an accidental spill. Similarly, if a small accidental spill were to escape 

containment or response measures, it would not persist very long, resulting in few opportunities to 

contact polar bears. Finally, the vessel activity associated with spill response would likely keep polar 

bears out of the spill area, and individual polar bears would likely avoid the spill by leaving the area 

during spill response activities. Accidental small spills are anticipated to have no more than a 

negligible level of effect on polar bears. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

Polar Bear Critical Habitat. The Proposed Action would occur during the open-water season when 

sea ice is approaching its minimum. The Proposed Action includes mitigation measures that avoid or 

minimize close approaches to barrier islands, areas seasonally important to polar bears. Ice 

management activities could be needed to protect the drillship and are not anticipated to be extensive 

in duration or aerial extent. No long-term adverse effects to designated critical habitat are anticipated. 

Activities associated with the Proposed Action do not have a cause-effect relationship that would 

influence aspects of climate change discussed in section 4.0, considered the largest threat to polar 

bear habitat. Climate change over the project timeframe are anticipated to result in a minor level of 

effect (short-term, widespread), but could be beneficial or adverse to sea ice depending on the 

vagaries of the Arctic weather. The incremental contribution of the Proposed Action to the collective 

impacts on polar bear habitats in the project area is negligible. The effects evaluated will occur each 

season that Shell conducts exploratory drilling operations under this exploration plan. The negligible 

effects, however, are temporally limited and consecutive years of activity would not have an additive 

effect. 

Pacific Walrus. The Pacific walrus is described in Section 3.2.6.1. The Proposed Action could affect 

Pacific walruses through vessel traffic and noise, aircraft traffic and noise, seismic airgun noise, 

drilling noise, icebreaking and ice management, permitted discharges, and accidental oil spills. 

Vessel Traffic and Noise. Richardson (1995) found that vessel noise does not seem to strongly affect 

pinnipeds (e.g., Pacific walrus) that are already in the water. Pacific walrus may avoid moving 

vessels, with most reactions occurring within 0.46 km (0.29 mi) (Richardson et al., 1995) or they may 

approach vessels out of curiosity. Mitigation measures in Shell’s Polar Bear, Pacific Walrus, and 

Grizzly Avoidance and Human Encounter/Interaction Plan (Shell, 2011b), include a 0.5 mi (800 m) 

exclusion zone around observed walrus for vessels in transit, which is expected to reduce contacts 

with and minimize adverse effects to Pacific walrus. Vessel traffic effects on walrus are expected to 

be transient and localized. Because of the timing of the project, the low number of walrus expected to 

occur in the central Beaufort Sea, and required mitigation measures, vessel traffic and noise from the 

Proposed Action are expected to result in a negligible level of effect on Pacific walrus. The effects 

evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The negligible effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Aircraft Traffic and Noise. Aircraft associated with the exploration activities would maintain a 1,500 

ft altitude, except during take-offs and landings or when conducting marine mammals surveys. Lowlevel marine mammal surveys have the potential to regularly affect Pacific walrus in the drilling area. 

Due to the low numbers of Pacific walrus expected in the project area, however, a minor level of 

effect on Pacific walrus from low-level survey flights is anticipated. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The minor 

effects, however, are temporally limited and consecutive years of activity would not have an additive 

effect. 
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98 Environmental Consequences - ESA-listed Marine Mammals 

Seismic Noise. Walrus use sound for communication and spend a great deal of time foraging 

underwater. They may be exposed to noise from seismic surveys. Temporary threshold shift (TTS) 

may occur after exposure to seismic pulses; however, this has not been documented in walrus. 

Walrus have good low-frequency hearing (Kastelein et al., 2002) and may be susceptible to masking 

of biologically important signals by low frequency sounds, such as airgun pulses from seismic 

surveys (Gordon et al., 2004). Masking of biologically important sounds by anthropogenic noise is 

equivalent to a temporary loss of hearing acuity. Brief, small-scale masking episodes might, in 

themselves, have few long-term consequences for individuals or populations of marine mammals. 

The potential for direct impacts causing injury from seismic surveys would be most likely if 

individuals entered a 180-dB zone immediately surrounding the high-energy noise source. Direct 

impacts potentially causing injury from seismic surveys are unlikely because walrus avoid active 

airgun operations and MMOs are required to decrease the sound levels by shutting down all or some 

of the airguns if marine mammals enter the 180/ 190 dB zones. 

The VSPs are short-duration activities that have specific monitoring requirements and mitigation 

measures designed to minimize adverse effects on walruses. A negligible level of effect on Pacific 

walrus is anticipated because VSPs would occur in areas of open-water where walrus densities are 

expected to be relatively low, would be of short in duration, and have safety zones that would be 

closely monitored. The effects evaluated will occur each season that Shell conducts exploratory 

drilling operations under this exploration plan. The negligible effects, however, are temporally limited 

and consecutive years of activity would not have an additive effect. 

Drilling Noise. Underwater noise associated with drilling could affect walruses near an active 

drillship. Modeled sound radii indicate that the sound associated with the proposed drilling 

operations from Discoverer would not exceed the 180-dB level. Sounds from drilling are modeled to 

reach 160 dB at 172 ft (52.5 m) from the drillship (USDOI, MMS, 2009a). Modeling indicates there 

is no chance for walrus to encounter a noise level from the drill ship that could result in physical 

injury. Walruses approaching the drill site would encounter increasing levels of underwater noise of 

their own volition. Such approaches are not considered take. While a small number of Pacific 

walruses could move out of the immediate area, these movements to other nearby similar areas are 

anticipated to result in no more than a negligible level of effect. The effects evaluated will occur each 

season that Shell conducts exploratory drilling operations under this exploration plan. The negligible 

effects, however, are temporally limited and consecutive years of activity would not have an additive 

effect. 

Icebreaking and Ice Management. Walrus near moving icebreakers exhibited avoidance behavior in 

a monitoring project during drilling in the Chukchi Sea (Brueggeman et al., 1991). During 

icebreaking, walrus moved 12-16 mi (20-25 km) from the operations to areas where sound energy 

levels approached ambient levels. Walrus did not show an avoidance reaction when vessels were 

anchored or drifting and did not appear affected by drilling sound. This was confirmed by the 

sightings of walrus near prospects during drilling operations (Brueggeman et al., 1991). 

Icebreakers, particularly those transiting through the Beaufort Sea, could have a minor effect on 

walrus herds hauled out on ice or in water. Ice-management may temporarily cause a few walrus 

foraging or resting in the Beaufort Sea to avoid the area of operations. However icebreakers 

temporarily alter habitat, which could benefit walrus by opening up new areas, or cause additional 

stress by fragmenting large ice floes where walrus haul out to rest. Moreover, this project is planned 

for the open-water season and extensive icebreaking and ice-management activity is not anticipated. 

Because of the timing of the project, the low number of Pacific walrus using the project area, and the 

short duration of the Proposed Action,BOEMREexpects a negligible level of effect on Pacific walrus. 

The effects evaluated will occur each season that Shell conducts exploratory drilling operations under 

this exploration plan. The negligible effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Other Marine Mammals 99

Permitted Discharges. Under the Proposed Action, spent drilling fluids and cuttings, sanitary 

wastewater, and domestic wastewater would be retained on a barge onsite for later removal and 

disposal at a facility in the Pacific Northwest (Shell, 2011a). Few discharges will occur on site and 

few benthic organisms would be exposed to drill cuttings and other materials, because of the 

relatively small discharge plume and the plume’s proximity to the drillship. Due to mitigation 

measures, there are few opportunities for unauthorized discharges to enter the marine environment. 

The likelihood of walruses ingesting benthic organisms contaminated by discharges associated with 

the Proposed Action is very low. 

With implementation of measures to retain discharges to the maximum amount practicable, permitted 

discharges would have no more than a negligible level of effect on Pacific walruses in the project 

area. The effects evaluated will occur each season that Shell conducts exploratory drilling operations 

under this exploration plan. The negligible effects, however, are temporally limited and consecutive 

years of activity would not have an additive effect. 

Oil Spills. Oil spills are accidental events. The potential effects of small oil spills are described 

below. Large and very large oil spills are described in Section 5.6. 

Section 2.3.10 describes spill prevention and response. While there is some potential for a fuel spill 

during the proposed operations, few walruses are anticipated to occur in the project area and few 

could be exposed to an accidental spill. Similarly, if a small accidental spill were to escape 

containment or response measures, it would not persist very long, resulting in few opportunities to 

contact walruses. Finally, the vessel activity associated with spill response would likely keep 

walruses out of the spill area, and individual walrus would likely avoid the spill by leaving the area 

during spill response activities. Accidental small spills are anticipated to have no more than a 

negligible level of effect on Pacific walruses. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

Other Marine Mammals 

Of the remaining marine mammal species, the beluga whale and spotted seal are most widely 

distributed and common within the Proposed Action area. These species have some potential for 

adverse effects. 

Beluga Whales. The Proposed Action could affect beluga whales through vessel traffic and noise, 

aircraft traffic and noise, seismic airgun noise, drilling noise, icebreaking and ice management, 

permitted discharges, and accidental oil spills. 

Vessel Traffic and Noise. Fraker, Sergeant, and Hoek (1978) described a startle response of belugas 

to vessels moving through areas with a high concentration of whales. Reactions of beluga whales to 

vessels varies among individuals and the amount of avoidance exhibited by individuals would depend 

upon the amount of previous exposure to moving vessels and level of importance of the need for an 

individual to be in the same area of vessel traffic (Finley and Davis, 1984). In some studies, more 

intense reactions to large vessels were seen, but these observations were made in deep water (Finley 

et al., 1990; LGL and Greeneridge, 1996). Such reactions are not expected in the relatively shallow 

waters of the project area, because most belugas will be feeding in the deeper waters along the ice 

front and the continental shelf break, far to the north and away from the project area (USDOI, MMS, 

2003). There are few opportunities for vessel traffic to encounter beluga whales in offshore areas and 

a negligible level of effect is anticipated. Should beluga whales move further inland, they could 

periodically encounter vessel traffic. Mitigation measures designed to avoid or minimize adverse 

effects from vessel noise or collisions would reduce impacts and no more than a minor level of effect 

would be anticipated to beluga whales moving through nearshore waters. The effects evaluated will 

occur each season that Shell conducts exploratory drilling operations under this exploration plan. The 

minor effects, however, are temporally limited and consecutive years of activity would not have an 

additive effect. 
Shell 2012 Camden Bay EP EA

100 Environmental Consequences - Other Marine Mammals 

Aircraft Traffic and Noise. As described in the Arctic Multiple-sale Draft EIS (USDOI, MMS, 

2008a), the greatest potential for helicopter or fixed-wing aircraft to cause adverse effects on beluga 

whales exists in areas where they are aggregated. Richardson et al. (1995) opportunistically observed 

the effects of helicopter overflights on migrating belugas near Point Barrow during 1989-1994. Of 

760 groups observed, 24 groups reacted overtly. Turbine-powered helicopter passes at about 250 m 

(820 ft) lateral distance from belugas and at altitudes up to 460 m ASL (1,500 ft) and Twin Otter 

passes at altitudes about 182 m (600 ft) ASL and at lateral distances about 250 m (820 ft) elicited 

pronounced reactions (e.g., vigorous swimming, abrupt dives, or tail thrashing) from belugas. 

However, most belugas observed showed no obvious reaction to single passes at altitudes >150 m 

ASL. Those belugas maintained their headings and continued respiring at the surface while the 

helicopter operated nearby (Richardson et al., 1995). In a few cases, belugas responded to direct 

overflights by turning away from the aircraft, but in others, belugas responded only by looking up at 

the aircraft (Richardson et al., 1995). The authors noted that the behavioral reactions of belugas were 

brief and inconsequential, and that there was no objective way to measure the biological importance 

of the behavioral reactions observed. 

The Proposed Action includes typical flight altitude restrictions and predetermined flight routes that 

avoid or minimize adverse effects to beluga whales in nearshore coastal areas. Low-level marine 

mammal monitoring flights could have a greater level of effect on beluga whales. No more than a 

minor level of effect is anticipated from aircraft traffic. The effects evaluated will occur each season 

that Shell conducts exploratory drilling operations under this exploration plan. The minor effects, 

however, are temporally limited and consecutive years of activity would not have an additive effect. 

Seismic Airgun Noise. Underwater sounds are important to beluga whale communication. Seismic 

noise has the potential to affect beluga whale communication (USDOI, MMS, 2006b). Seismic noise 

also has some potential to temporarily affect beluga whale hearing, most often referred to as a 

Temporary Threshold Shift (TTS). The Proposed Action includes a few Vertical Seismic Profiles 

(VSPs), once wells are drilled. Specific mitigation measures are used to avoid exposing marine 

mammals to seismic sounds during the brief (<24 hrs) period when the few VSPs are being 

conducted. These measures include direct observation of the esonified area by an MMO while the 

VSP is being conducted, with the requirement to shutdown the operation if a marine mammal 

approaches or is within the area where TTS could occur. 

The VSPs are short-duration activities that have specific monitoring requirements and mitigation 

measures designed to minimize adverse effects on beluga whales. A negligible level of effect on 

beluga whales is anticipated because VSPs would occur in areas where numbers of beluga whales are 

expected to be relatively low, would be of short in duration, and have safety zones that would be 

closely monitored. The effects evaluated will occur each season that Shell conducts exploratory 

drilling operations under this exploration plan. The negligible effects, however, are temporally limited 

and consecutive years of activity would not have an additive effect. 

Drilling Noise. Belugas are believed to have poor hearing of sounds below 1 Hz, the range of most 

drilling activities, but have shown some behavioral reactions to lower sounds. Brewer et al. (1993) 

observed belugas within 2.3 mi (3.7 km) of the drilling unit Kulluk during drilling. Belugas primarily 

use high-frequency sounds to communicate and locate prey; therefore, masking by low-frequency 

sounds associated with drilling activities is not expected to occur. If the distance between 

communicating whales does not exceed their distance from the drilling activity, the likelihood of 

potential impacts from masking would be low. At distances greater than 660-1,300 ft (200-400 m), 

recorded sounds from drilling activities did not affect behavior of beluga whales, even though the 

sound energy level and frequency were such that it could be heard several kilometers away 

(Richardson et al., 1995). This exposure resulted in whales being deflected from the sound energy and 

changing behavior. These brief changes are expected to be temporary and are not expected to affect 

whale population (Richardson et al., 1991; Richard, Martin, and Orr, 1998). Brewer et al. (1993) 

observed belugas within 2.3 mi (3.7 km) of the drilling unit Kulluk during drilling. A more detailed 

discussion of this information is provided in the Arctic Multiple-sale Draft EIS (USDOI, MMS, 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Other Marine Mammals 101

2008a). Some beluga whales may avoid the area in the vicinity of the drilling operations because of 

noise; however the level of effect is expected to be minor. 

Icebreaking and Ice Management. While observing the response of beluga whales to icebreakers, 

Finley and Davis (1984) reported avoidance behavior when icebreaker vessels approached at 

distances of 22-31 mi (35-50 km). Belugas are thought to have poor hearing below 1 Hz, the range of 

most drilling activities, but have been seen showing some behavioral reactions to the sounds (USDOI, 

MMS, 2008a). Beluga whales would not likely approach an active icebreaker, avoiding the noise 

associated with such activity. Beluga whales could alter their swimming paths to avoid the operation, 

which would be considered no more than a minor level of effect. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The minor 

effects, however, are temporally limited and consecutive years of activity would not have an additive 

effect. 

Permitted Discharges. Under the Proposed Action, spent drilling fluids and cuttings, sanitary 

wastewater, and domestic wastewater would be retained on a barge onsite for later removal and 

disposal at a facility in the Pacific Northwest (Shell, 2011a). Few discharges will occur on site and 

few benthic organisms would be exposed to drill cuttings and other materials, because of the 

relatively small discharge plume and the plume’s proximity to the drillship. Mobile invertebrates and 

fishes are anticipated to avoid the area affected by the discharge plume, thereby avoiding exposure. 

With implementation of measures to retain discharges to the maximum amount practicable, there are 

few opportunities for unauthorized discharges to enter the marine environment. The overall effect of 

the proposed activities may be temporary, non-lethal effects to fish populations. As a consequence, 

the likelihood of beluga whales ingesting benthic organisms or fishes contaminated by discharges 

associated with the proposed activities is very low and a negligible level of effect from permitted 

discharges to beluga whales is anticipated. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

Oil Spills. Section 2.3.10 describes spill prevention and response. While there is some potential for a 

fuel spill during the proposed operations, few beluga whales are anticipated to occur in the project 

area and few could be exposed to an accidental spill. Similarly, if a small accidental spill were to 

escape containment or response measures, it would not persist very long, resulting in few 

opportunities to contact beluga whales. Finally, the vessel activity associated with spill response 

would likely keep beluga whales out of the spill area, and individual whales would likely avoid the 

spill by leaving the area during spill response activities. Accidental small spills are anticipated to 

have no more than a negligible level of effect on beluga whales in the project area. The effects 

evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The negligible effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

Spotted Seals. The Proposed Action includes activities that could affect spotted seals. The impact–

producing factors include vessel traffic and noise, aircraft traffic and noise, seismic airgun noise, 

drilling noise, ice management, permitted discharges, and small spills. Although the spotted seal is 

less common than ringed seals or bearded seals, the vulnerability and responses of spotted seals to the 

Proposed Action would be the same as those previously described for ringed seals and bearded seals. 

As a consequence, the potential effects of the Proposed Action on spotted seals are anticipated to be 

the same as those described for ringed seals and bearded seals. Because of substantial mitigation 

measures incorporated into the Proposed Action that would avoid or minimize adverse effects on 

spotted seals, no more than a negligible level of effect is anticipated. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The 

negligible effects, however, are temporally limited and consecutive years of activity would not have 

an additive effect. 
Shell 2012 Camden Bay EP EA

102 Environmental Consequences - Summary of Direct and Indirect Effects on Marine Mammals 

4.2.7.2. Summary of Direct and Indirect Effects on Marine Mammals 

The Proposed Action includes mitigation measures that avoid or minimize impacts from seismic 

airgun noise, drilling noise, permitted discharges, and oil spills to a negligible level of effect. Aircraft 

traffic and noise, icebreaking and ice management, and drilling noise are anticipated to result in no 

more than a minor level of effect. Taken together, these activities are anticipated to result in no more 

than a minor level of effect on the marine mammal populations and critical habitat per year. 

4.2.7.3. Cumulative Effects 

Activities associated with the Proposed Action do not have a cause-effect relationship that would 

influence aspects of climate change discussed in section 4.0. Climate change over the project 

timeframe are anticipated to result in a minor level of effect (short-term, widespread), but could be 

beneficial or adverse to sea ice depending on the vagaries of the Arctic weather. Appendix C 

describes reasonably foreseeable future events that could occur in the project area that could affect 

marine mammals and critical habitat in the project area. These projects include vessels and aircraft 

that are not subject to altitude or route restrictions and likely have greater impacts than the Proposed 

Action. For example: 

 Marine mammal research flights often fly at low altitudes that result in direct impacts to 

marine mammals, especially when they circle for counts or photographs. 

 Research projects have deviated from designated transect routes to investigate reports of 

beluga whale concentrations. 

 Ice conditions and subsistence hunting are expected to have a greater impact on migration 

and survival of walrus than vessel traffic. 

The incremental contribution of the Proposed Action to the collective impacts on marine mammals in 

the project area is no more than minor. The reasonably foreseeable cumulative effects will occur at 

nearly the same level each season that Shell conducts exploratory drilling operations under this 

exploration plan. For the life of the project, the impacts to marine mammals from the Proposed 

Action and from reasonably foreseeable cumulative activities would amount to a minor level of 

effect. 

4.2.8. Sociocultural Systems 

Sociocultural systems encompass three concepts: (1) social organization, (2) cultural values, and (3) 

institutional organizations of communities. By “social organization” we mean how people are divided 

into social groups and networks. By “cultural values” we mean desirable values that are widely 

shared explicitly and implicitly by members of a social group. By “institutional organization” we 

refer to the government and quasi- government entities that provide services to the community. For 

the Proposed Action and communities described in the affected environment section, sociocultural 

systems effects are directly linked to the effects subsistence resources. 

4.2.8.1. Direct and Indirect Effects 

The Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) is committed to 

protecting subsistence activities. The BOEMRE Alaska Region has adopted through regulatory 

practice, a position on significance in the context of NEPA that supports the goal of protecting 

subsistence activities. This position is clearly aligned with the way BOEMRE regulates offshore oil 

and gas geophysical and geological surveys and exploratory drilling activities for several 

decades. The predominate attribute of this regulatory policy makes clear that BOEMRE will only 

permit offshore oil and gas activities when the disruption to subsistence harvest of resource can be 

minimized in such a manner that the disruption is short term and as a result of incidental or accidental 

encounters. Under the Proposed Action, these encounters will come primarily from vessel traffic and 

aircraft traffic associated with the project. As such, because of the negligible effects to subsistence 

described in Section 4.2.9 effects to sociocultural systems, such as social organization and 

institutional arrangement are not expected to occur. The effects evaluated will occur each season that 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Subsistence Activities 103

Shell conducts exploratory drilling operations under this exploration plan. The negligible effects, 

however, are temporally limited and consecutive years of activity would not have an additive effect. 

The BOEMRE views oil spills as having the potential to cause long term significant effects that 

would disrupt or nearly eliminate subsistence harvests. Oil spills are never permitted and are always 

in violation of the law. Operators would be held accountable and responsible for mitigation and 

monitoring loss or reduction of subsistence species on the local subsistence harvesters and the linked 

social organizations and institutions. 

4.2.8.2. Cumulative Effects 

This analysis considers that cumulative effects on subsistence and local economic opportunities from 

the activities listed in Appendix C, Cumulative Effects, which would most affect sociocultural 

systems. As described above under direct and indirect effects, BOEMRE permitted activities are only 

allowed when the disruption to subsistence harvest of resource can be minimized in such a manner 

that the disruption is short term and as a result of incidental or accidental encounters. Activities 

permitted or authorized by other government agencies have policies that are similar to those required 

by BOEMRE to reduce effects to subsistence to a negligible level. As such, cumulative effects to 

sociocultural systems are not expected to occur. The reasonably foreseeable cumulative effects will 

occur at nearly the same level each season that Shell conducts exploratory drilling operations under 

this exploration plan. For the life of the project, the impacts to sociocultural systems from the 

Proposed Action and from reasonably foreseeable cumulative activities would amount to a nonexistent or negligible level of effect. 

4.2.9. Subsistence Activities 

The Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) is committed to 

protecting subsistence activities. The BOEMRE Alaska Region has adopted through regulatory 

practice, a position on significance in the context of NEPA that supports the goal of protecting 

subsistence activities. This position is clearly aligned with the way BOEMRE regulates offshore oil 

and gas geophysical and geological surveys and exploratory drilling activities for several 

decades. The predominate attribute of this regulatory policy makes clear that BOEMRE will only 

permit offshore oil and gas activities when the disruption to subsistence harvest of resource can be 

minimized in such a manner that the disruption is short term and as a result of incidental or accidental 

encounters. Under the Proposed Action, these encounters will come primarily from vessel traffic and 

aircraft traffic associated with the project. As such, effects to sociocultural system are described in 

term of subsistence other components of sociocultural systems, such as social organization and 

institutional arrangement are not expected to occur. 

Incidental or accidental short term encounters from associated vessel and aircraft traffic can be further 

eliminated through effective communication between the communities and the BOEMRE and/or 

industry such as those identified in Section 2.3.11, Stipulation 5, Plan of Cooperation, and 2.3.12, 

Other Mitigation, Protection of Subsistence Activities. 

The BOEMRE views oil spills as having the potential to cause long term significant effects that 

would disrupt or nearly eliminate subsistence harvests. Oil spills are never permitted and are always 

in violation of the law. Operators would be held accountable and responsible for mitigation and 

monitoring loss or reduction of subsistence species on the local subsistence harvesters. 

This discussion is limited to subsistence harvest of resources taken in the summer from July 10-

August 25 and autumn in September and October when Shell may be actively working the Camden 

Bay prospects. 

Shell’s proposed Camden Bay activities at Sivulliq and Torpedo prospects present the potential for 

affecting subsistence harvesters at two Iñupiat communities: Nuiqsut, which lies 118 miles southwest 

of the leases, and Kaktovik, which lies 60 miles southeast of the prospects. Barrow lies 298 mi west 

of the proposed project area. Cross Island, from which Nuiqsut whalers launch their bowhead whale 

hunt, is 47 mi southwest of the proposed project area. 
Shell 2012 Camden Bay EP EA

104 Environmental Consequences - Subsistence Activities 

As described in greater detail above, the Proposed Action will drill 4 exploration wells, 2 in Sivulluq 

leases and 2 in Torpedo leases. The leases are located 16 – 20 mi north of Cape Thompson, on the 

north coast of Alaska, in Camden Bay, Beaufort Sea. Actual drilling is proposed during the open 

water season. Work would mobilize by July 10 during the open water season, when sea ice is not as 

extensive as in the spring, reducing the likelihood of requiring the use of any icebreaker and after 

most bowhead whales have migrated eastward to their summer localities. Regular crew support and 

rotation and ancillary support would be provided by helicopters flown from Deadhorse, Prudhoe Bay. 

Shell’s helicopters would fly a prescribed route previously agreed to during Government-toGovernment meetings in 2007 with local residents of Nuiqsut and Kaktovik to lessen effects on 

subsistence activities. This route crosses the coast over State lands about 10 mi west of the mouth of 

the Canning River, just off the west tip of Flaxman Island (Shell, 2011a: Figure 2-2). Helicopters 

would be required to fly at an altitude of between 1,500 and 1,000 ft, weather permitting, to reduce or 

eliminate effects to land and sea mammals and the people who hunt them for subsistence purposes. 

An ice-management vessel would be present to be used, if necessary, when the drill rig travels to the 

proposed drill sites. The drilling would occur for a relatively short duration (approximately 6 weeks at 

each drill site). 

Shell would suspend all activity and withdraw from the prospects during the Nuiqsut and Kaktovik 

bowhead whale hunt, out of consideration of the importance of the resource to the Iñupiat of Kaktovik 

and Nuiqsut. Shell would suspend all activity by August 25 and move offsite. Exploratory work 

would resume only after Kaktovik and Nuiqsut completed fall bowhead whaling. Shell may continue 

until October 31. 

When drilling is suspended on August 25, the borehole would be plugged and abandoned per 

BOEMRE requirements. All vessels, including the drillship, would withdraw from the area until 

whaling crews from both Nuiqsut, at Cross Island, and Kaktovik have completed fall bowhead 

whaling. There would be no overflights or industrial marine traffic during the bowhead whale hunt, 

and no subsidiary effects that might affect subsistence harvest, such as wastewater discharge in the 

migratory bowhead route during this time. Work may resume after completion of the Cross Island and 

Kaktovik bowhead whale hunts for up to another 6 weeks, or until October 31, depending on ice and 

weather. 

4.2.9.1. Direct and Indirect Effects 

No documented subsistence activities have occurred at the proposed offshore drill sites (SRB&A, 

2010). The proposed overland helicopter route crosses an area that is recognized as being subsistence 

territory occasionally used by the Iñupiat of Kaktovik and Nuiqsut. Past use has been prolonged and 

consistent, as evidenced by the numerous house sites, camps, and other cultural features that dot the 

landscape (Impact Assessment Inc., 1990a and 1990b; Pedersen and Coffing, 1984). 

An important consideration in assessing potential direct and indirect effects on subsistence activities 

is that most of Shell’s activities would occur in the summer from mid-July until late August. This is 

the time during which the Iñupiat from Kaktovik and Nuiqsut fish. Most Kaktovik residents fish the 

beaches at or east of the village; in the past, some have fished the Canning River. The people of 

Nuiqsut fish the Colville River. 

Summer fishing would not be affected by drilling and associated vessel or helicopter traffic. Drilling 

would occur out of range of fishers, about 20 mi offshore, and helicopter traffic would transect a 

prescribed route about 10 mi west of the Canning River. The proposed exploration would have either 

no effect or a negligible effect on the summer fishery as long as Shell adheres to the plan for overland 

flights, deployment from Deadhorse, and drilling about 20 mi offshore and works from 6-12-weeks. 

Short- and long-term effects on Nuiqsut and Kaktovik fisheries are considered to be non-existent to 

negligible. 

Hunting caribou or seals during summer would be unaffected by drilling or associated vessel traffic. 

Helicopter traffic would pass overland on a prescribed route about 10 mi west of the mouth of the 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Subsistence Activities 105

Canning River at an altitude of between 1,000 and 1,500 ft. This would have a negligible effect on 

hunting bull caribou or seals. The only possible effect would be if a hunter takes aim at a caribou or 

seal immediately below the prescribed helicopter route, and a flight passed overhead below 1,000 ft in 

altitude due to weather. In that case, the prey might become skittish and flee. The chance of this 

occurring is remote, because the area under consideration for the helicopter route was established by 

industry through discussions as it receives little use by Kaktovik or Nuiqsut subsistence harvesters. 

Current hunting localities based on (a) the distance from either community and the high cost of fuel; 

and (b) the proximity of on-shore petroleum development (Impact Assessment Inc., 1990a and 1990b; 

Pedersen and Coffing, 1984). Thus, the helicopter flight, deployment from Deadhorse, and drilling 

about 20 mi offshore also would have a negligible effect on subsistence users from Kaktovik and 

Nuiqsut. Short- and long-term effects on Nuiqsut and Kaktovik subsistence hunting of caribou or 

seals are considered to be non-existent to negligible since the proposed project is estimated to last 

from 6-12-weeks. 

All air and vessel traffic and drilling associated with the proposed exploration would be suspended for 

the duration of the Nuiqsut and Kaktovik bowhead whale hunt from August 25 until both 

communities reach their quotas and/or stop the hunt. There would be no auditory disturbance, 

refueling, or wastewater discharge at Sivulliq or Torpedo, no effect on the whale hunt harvest, or any 

other subsistence activity that would occur during this period. Short- and long-term effects on hunting 

for bowhead whales, beluga whales, or other any other subsistence resources are considered to be 

non-existent as long as Shell withdraws north or west of the migratory path of bowhead whales 

during the Nuiqsut and Kaktovik whale hunts. 

Bowhead whaling at Barrow (about 300 mi west of the proposed drill sites) may continue through 

October. It is unlikely any disturbance or deflection of bowhead whales by the proposed activities 

would affect whales as they migrated past Barrow. Short- and long-term effects on the Barrow 

subsistence hunt is expected to be non-existent to negligible because of the distance of the project 

area from Barrow. 

After the Nuiqsut and Kaktovik bowhead whale hunts, subsistence activities at both communities 

move away from the coast to the interior. During this time, people net fish under the river ice; shoot 

migratory waterfowl on the wing; hunt for moose, caribou, and mountain sheep (the latter by 

Kaktovik hunters); and trap furbearers. Kaktovik hunters and furbearer trappers use the foothills of 

the Brooks Range (SRB&A, 2010; Impact Assessment Inc., 1990b; Pedersen and Coffing, 1984). 

Short- and long-term effects on late fall to early winter subsistence activities are considered to be 

negligible, since Shell will alter the flight path from the interior to closer to the coast and maintain an 

altitude of 1,000-1,500 ft, will deploy from Deadhorse, and drills only the 4 prospects about 20 mi 

offshore. This brief analysis of subsistence activities discloses that in all likelihood, with mitigation 

measures in place, direct and indirect effects on subsistence would be negligible at the most. The 

effects evaluated will occur each season that Shell conducts exploratory drilling operations under this 

exploration plan. The negligible effects, however, are temporally limited and consecutive years of 

activity would not have an additive effect. 

4.2.9.2. Cumulative Effects 

This environmental analysis has identified vessel traffic, specifically marine vessel traffic, as the 

greatest impact source of anthropogenic sound introduced to the Beaufort Sea during the timeframe of 

the proposed activities. Marine vessel traffic would not be associated with the proposed exploration 

drilling, since no support vessels or aircraft would overfly the area during the shutdown period Shell 

would suspend all activity and withdraw from the prospects during the Nuiqsut and Kaktovik 

bowhead whale hunt, out of consideration of the importance of the resource to the Iñupiat of Kaktovik 

and Nuiqsut. Shell would suspend all activity by August 25 and depart the area. Exploratory work 

would resume only after Kaktovik and Nuiqsut completed fall bowhead whaling. Shell may continue 

until October 31. 
Shell 2012 Camden Bay EP EA

106 Environmental Consequences - Economy 

Other vessel traffic is not controlled by the proposed project, and should be assumed to continue 

through the whale hunt. These vessels could be icebreakers, Coast Guard vessels, other supply ships 

and tugs and barges, and vessels associated with scientific endeavors. Cross Island whalers have 

reported that anthropogenic noise related to vessel traffic makes bowhead whales “skittish,” more 

alert to sound and more difficult to approach (Applied Sociocultural Research, 2009). 

Air traffic not associated with the proposed project may involve flight patterns at a lower altitude than 

the 1,500 ft level that will be industry’s standard for this project. Airtraffic associated with the 

proposed project will also be suspended when Shell withdraws from the prospects during the Nuiqsut 

and Kaktovik bowhead whale hunts, but other air traffic associated with basic village transportation, 

freight and mail, and scientific endeavors would continue unabated. The air traffic noise has the 

potential to disrupt and disturb subsistence hunters from Nuiqsut and Kaktovik. Thus, it is possible 

that negligible cumulative effects will be experienced by subsistence hunters. The reasonably 

foreseeable cumulative effects will occur at nearly the same level each season that Shell conducts 

exploratory drilling operations under this exploration plan. For the life of the project, the impacts to 

subsistence from the Proposed Action and from reasonably foreseeable cumulative activities would 

amount to a minor level of effect. 

4.2.10. Economy 

4.2.10.1. Direct and Indirect Effects 

Descriptions of the NSB economy in the Shell Offshore Inc. 2011 Outer Continental Shelf Lease 

Exploration Plan, Camden Bay Alaska are incorporated by reference, and salient points are included 

below. Additional information on the NSB economy is also provided. 

Employment and Personal Income: Shell’s offshore exploration plan promises to provide specific 

benefits to some local residents in and around Barrow, Nuiqsut, and Kaktovik. Shell’s proposed 

exploration drilling would offer employment to a small number of local NSB residents. The MMO 

program would employ local Iñupiat residents to monitor and document marine mammals in the 

project area. The Subsistence Advisor program would recruit a local resident from each village to 

communicate local concerns and subsistence issues from residents to Shell. Shell’s Com Center 

program would involve hiring one or two individuals from each of the Beaufort and Chukchi Sea 

villages. The activities described in the Exploration Plan would also support employment of oil spill 

response personnel. A more detailed discussion of local hire can be found in section 2.3.8. 

Even with the potential employment associated with the proposed activities, it appears that 

employment opportunities for local residents, especially Alaskan Natives, would remain 

comparatively low in oil industry- related jobs on the North Slope. Goods and services would be 

obtained from local village contractors, when available, during the duration of the project. The 

proposed activities are short term and temporary and are expected to have a negligible effect on the 

economy of the NSB or communities of Kaktovik, Nuiqsut, and Barrow. These effects do not 

constitute an important change in the impacts previously identified and evaluated in the conditionally 

approved 2010 Camden Bay EP (USDOI, MMS, 2009a). 

Revenues: The proposed exploration activities will not result in additional onshore oil and gas 

infrastructure that the NSB and State of Alaska would receive property tax revenues from, and so the 

direct and indirect effect on revenues are expected to be negligible. The effects evaluated will occur 

each season that Shell conducts exploratory drilling operations under this exploration plan. The 

negligible effects, however, are temporally limited and consecutive years of activity would not have 

an additive effect. 

4.2.10.2. Cumulative Effects 

The sources of cumulative impacts affecting the 2011 Camden Bay EP and known activities planned 

for 2012 are listed in Appendix C – Cumulative Effects. The proposed activities are short term and 

temporary, involving low levels of new employment and no generation of property tax revenues 

accruing to the NSB or State of Alaska, and are therefore expected to have a negligible cumulative 
Shell 2012 Camden Bay EP EA

Environmental Consequences - Public Health 107

effect on employment, income, and revenue levels of the NSB and the communities of Kaktovik, 

Nuiqsut, and Barrow. The reasonably foreseeable cumulative effects will occur at nearly the same 

level each season that Shell conducts exploratory drilling operations under this exploration plan. For 

the life of the project, the economic impacts from the Proposed Action and from reasonably 

foreseeable cumulative activities would amount to a negligible level of effect. 

4.2.11. Environmental Justice 

4.2.11.1. Direct and Indirect Effects 

This analysis considers that proposed project direct and indirect effects on subsistence and public 

health as factors that would most affect environmental justice. Because the subsistence analysis 

concludes that the proposed project will have non-existent to very low direct and indirect effects on 

subsistence, it would follow that the proposed project will have non-existent to negligible direct and 

indirect effects on environmental justice. The effects evaluated will occur each season that Shell 

conducts exploratory drilling operations under this exploration plan. The negligible effects, however, 

are temporally limited and consecutive years of activity would not have an additive effect. 

4.2.11.2. Cumulative Effects 

Incidental or accidental short term encounters can be further eliminated through effective 

communication between the communities and the BOEMRE and/or industry. Stipulation 5, the 

Conflict Avoidance Mechanism to Protect Subsistence Whaling and Other Subsistence Harvesting 

Activities applied to sales 195 and 202 (USDOI MMS, 1995; USDOI MMS, 2006) and is an example 

of a remedy for these types of disruptions. 

The BOEMRE views oil spills as having the potential to cause long term significant effects that 

would disrupt or nearly eliminate subsistence harvests. Oil spills are never permitted and are always 

in violation of the law. Operators would be held accountable and responsible for mitigation and 

monitoring loss or reduction of subsistence species on the local subsistence harvesters. 

This analysis considers that cumulative effects on subsistence and local economic opportunities are 

factors that would most affect environmental justice. Because the analysis concludes reasonably 

foreseeable activities will have cumulative effects on subsistence will be negligible, it would follow 

that there will be negligible cumulative effects on environmental justice. A different conclusion about 

the level of cumulative effects on economics will lead to a different outcome herein. The reasonably 

foreseeable cumulative effects will occur at nearly the same level each season that Shell conducts 

exploratory drilling operations under this exploration plan. For the life of the project, the impacts to 

environmental justice from the Proposed Action and from reasonably foreseeable cumulative 

activities would amount to a negligible level of effect. 

4.2.12. Public Health 

4.2.12.1. Direct and Indirect Effects 

The activities associated with the EP would be staged out of Deadhorse, Prudhoe Bay, and the West 

Dock areas. Goods and services would be obtained from local village contractors, when available, for 

the duration of this project. These business interactions are not expected to adversely affect public 

health. Findings regarding air quality and emissions remain the same and are incorporated by 

reference. However, water quality will have an even smaller effect on public health than originally 

described. Shell's 2011 EP proposes to reduce discharges into the marine environment by not 

discharging water based drilling fluids, drilling cuttings with adhered drilling fluids, treated sanitary 

waste, bilge water, and ballast water to the ocean. Instead, a tug and barge would be added to the fleet 

of vessels to provide temporary storage for these wastes as needed. The wastes would be transported 

out of the Arctic for disposal in approved facilities in accordance with all applicable laws and 

regulations. The tug and barge would enter the Sivulliq drill site area at about the same time as the 

drillship and other vessels, and would remain with the fleet until the end of the drilling season. In 

public testimony about offshore oil and gas exploration and development, the Iñupiat have long 

expressed concern over the introduction of contaminants into the marine environment that could 
Shell 2012 Camden Bay EP EA

108 Environmental Consequences - Public Health 

affect subsistence resources. Storage of waste water and waste products such drilling cuttings and 

fluids and proper disposal beyond the arctic will go far to address persistent concerns held by the 

local community. The direct and indirect effects of the 2011 Camden Bay EP on public health are 

considered to be negligible. These effects do not constitute a significant change in the impacts to 

public health previously identified and evaluated in the conditionally approved 2010 Camden Bay EP 

(USDOI, MMS, 2009a). The effects evaluated will occur each season that Shell conducts exploratory 

drilling operations under this exploration plan. The negligible effects, however, are temporally limited 

and consecutive years of activity would not have an additive effect. 

4.2.12.2. Cumulative Effects 

Other reasonably foreseeable activities which may affect public health are listed in Appendix C. With 

the implementation of the mitigation described in sections 3.1.13 and 4.2.11., the cumulative effects 

from the Proposed Action in combination with other reasonably foreseeable activities are considered 

to be negligible. These effects do not constitute a substantive change in the impacts to public health 

previously identified and evaluated in the conditionally approved 2010 Camden Bay EP (USDOI, 

MMS, 2009a). The reasonably foreseeable cumulative effects will occur at nearly the same level each 

season that Shell conducts exploratory drilling operations under this exploration plan. For the life of 

the project, the impacts to public health from the Proposed Action and from reasonably foreseeable 

cumulative activities would amount to a negligible level of effect. 
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Post Deepwater Horizon Event Environmental Review - Oil Spill 109

5.0 POST DEEPWATER HORIZON EVENT ENVIRONMENTAL 

REVIEW 

The Deepwater Horizon (DWH) event and oil spill in the Gulf of Mexico is addressed in this 

analysis. This section provides a summary of the germane investigations, reports, and 

recommendations that followed the 2010 event. This section also includes a description of changes 

that were made to regulations governing OCS activities and a review of prior NEPA analyses to 

determine the continued adequacy of those analyses. 

5.1. Deepwater Horizon Oil Spill. 

The Deepwater Horizon was a semi-submersible mobile offshore drilling unit (MODU) operated by 

British Petroleum Exploration & Production, Inc. engaged in drilling the Macondo well on 

Mississippi Canyon Block 252 (MC252) in federal Outer Continental Shelf (OCS) waters located in 

the Gulf of Mexico, about 41 miles offshore of Louisiana. 

On April 20, 2010, the Deepwater Horizon caught fire and exploded while the vessel was in the 

process of capping the Macondo well prior to temporary abandonment. The blowout resulted in the 

release of oil in the Gulf of Mexico, 11 deaths, and numerous injuries. Response teams were not able 

to control the fire and the vessel sank on April 22, 2010 in about 5,000 feet of water approximately 

1,500 feet from the well center. Attempts to activate the blowout preventer failed, and an estimated 

4.9 million barrels of oil and an unknown quantity of natural gas was released before the well was 

capped on July 15, 2010. A relief well was completed On August 19, 2010, and the well was 

permanently plugged and abandoned. 

The BOEMRE and the U.S. Coast Guard (USCG) are conducting a joint investigation to identify the 

factors which led up to the event, and developing conclusions and recommendations for future 

procedural and/or policy changes. On April 22, 2011, the Deepwater Horizon Joint Investigation 

Team (JIT) released a preliminary report covering issues under Coast Guard jurisdiction including the 

explosions on the Mobile Offshore Drilling Unit (MODU) Deepwater Horizon; the resulting fire; 

evacuations; the flooding and sinking of the Deepwater Horizon; and the safety systems of the 

MODU and its owner, Transocean. The findings released do not include an analysis of what led to the 

loss of well control or other aspects of the investigation that fall under BOEMRE jurisdiction. The JIT 

has been granted an extension of the deadline for its final report and it was not available at the date of 

publication of this EA. This approval was provided by the USCG and BOEMRE. The DWH event 

also precipitated several changes to BOEMRE’s regulation of oil and gas activities on the OCS; these 

are addressed in the subsections below. This analysis assesses the relevance of the DWH event for the 

regulation of the Proposed Action, and incorporates into the present decision-making process the 

lessons learned. 

5.2. Government Reports and Recommendations 

Since the Deepwater Horizon event, several reviews from within or commissioned by the Federal 

government have offered formal recommendations regarding review and regulation of OCS oil and 

gas activities. 

Council on Environmental Quality (CEQ). As a direct result of the Deepwater Horizon accident 

and the Macondo oil and gas spill, the CEQ reviewed MMS NEPA policies, practices and procedures 

relating to OCS oil and gas exploration and development and issued a report on August 16, 2010 

(CEQ 2010). Contained in the report were recommendations made to BOEMRE to be used as 

"guideposts" to provide a consistent, rigorous, and transparent approach in NEPA reviews and other 

environmental analyses. Two of these recommendations apply to this EA: 

Transparency, Public Accountability, and Sound Decisionmaking 

Ensure that NEPA analyses fully inform and align with substantive decisions at all relevant 

decision points; that subsequent analyses accurately reflect and carry forward relevant 

underlying data; and that those analyses will be fully available to the public. 
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110 Post Deepwater Horizon Event Environmental Review - Government Reports 

Ensure that 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. 

Changed Circumstances 

Consider supplementing existing NEPA practices, procedures, and analyses to reflect changed 

assumptions and environmental conditions, due to circumstances surrounding the [Macondo] 

Oil Spill. 

Section 0 below places the very large oil spill analysis for the Beaufort Sea in the context of the 

Torpedo H drill site worst case discharge information; incorporats of the information emerging from 

the DWH event investigations into the environmental assessment; and presents summary information 

to the decision-maker on the prevention, response and environmental consequences of a very large oil 

spill although the risk that the proposed wells will result in such a spill is very low. 

The National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling (The 

National Commission). The National Commission issued its final report (PCR, 2011) on January 11, 

2011. This report described the causes of the incident and recommended “reforms to make offshore 

energy production safer.” Some of these recommendations are specific to the Arctic. The 

recommendations relate to: 

 How the NEPA process and related environmental analyses are conducted by BOEMRE. 

 Oil spill prevention and response. 

 Public administration and management of offshore resources, including specific 

recommendations for changes in legislation, conducting scientific studies, financing of 

bureau operations, and permitting and response by BOEMRE and other agencies such as 

the EPA. 

Recommendations regarding the NEPA process and environmental analyses were addressed by 

insuring early consultation by BOEMRE with other agencies. Consultations with the National Marine 

Fisheries Service (NMFS), the Fish and Wildlife Service (FWS) and others are enumerated in the 

consultation and coordination sections of this EA and related NEPA documents listed in Section 6, 

Consultation and Coordination. 

Most of the oil spill prevention and response recommendations are related to systems safety and 

reliability and additional mechanisms and processes for preventing pollution, specifically the loss of 

well control. This EA addresses compliance with operating regulations, describes inspections and 

other spill prevention actions the Bureau undertakes, including pollution prevention measures and oil 

spill prevention and response. 

U.S. Coast Guard Incident Specific Preparedness Review. Following major (≥2,381 bbls) oil 

spills, Coast Guard internal regulations call for an Incident Specific Preparedness Review (ISPR) to 

conduct a thorough examination of the Coast Guard preparedness process and to critically evaluate 

this process in conjunction with the implementation, integration, and effectiveness of national, 

regional, and local oil spill response plans. An ISPR provides an assessment of a major response 

along with recommendations for improvement. On March 18, 2011, the United States Coast Guard 

distributed the Final Action Memorandum for the Deepwater Horizon Oil Spill ISPR. 

The DWH ISPR contains a number of “lessons learned” and recommendations for many 

circumstances including the content of area contingency plans, identification of environmentally 

sensitive areas, worst case discharge scenarios in oil spill response plans, in-situ burning operations, 

spill containment, sustainability of offshore and nearshore response efforts, and use of vessels of 

opportunity. The review included recommendations that the Coast Guard request BOEMRE to take 

specific actions regarding the integration of oil spill contingency plans for regional response, review 

requirements for in-situ burning equipment, and take a number of actions regarding subsea 

containment. 
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Post Deepwater Horizon Event Environmental Review - Government Reports 111

United States Geological Survey Circular 1370. In April 2010, the Secretary of the Interior 

requested that USGS complete a special review of the state of information known about the Beaufort 

and Chukchi seas. On June 23, 2011, USGS released its report as USGS Circular 1370: “An 

Evaluation of the Science Needs to Inform Decisions on Outer Continental Shelf Energy 

Development in the Chukchi and Beaufort Seas, Alaska” (USDOI, USGS, 2011). The report 

summarizes key existing scientific information, develops a rapid process to identify where knowledge 

gaps exist, and provides initial guidance for what research is needed to improve decision making. 

Special consideration is given in the report to four identified “Issue Topics”: 

 Effects of climate change on physical, biological and social conditions as well as resource 

management strategies in the Arctic. 

 Developing foundational geospatial data on the Arctic OCS. 

 Synthesis of existing scientific information on a wide range of topics. 

 Spill-risk evaluation and response, and improving environmental data inputs for spill 

models. 

Independent of development of the USGS report, BOEMRE had begun or planned a large number of 

studies to address the knowledge “gaps” in the four topics subsequently identified by USGS. The 

report is generally consistent with the strategic planning undertaken by the BOEMRE Environmental 

Studies Program (ESP) and serves to validate the annual cycle of review of available data and 

knowledge gaps which identifies studies for funding undertaken by the BOEMRE ESP at the National 

and Regional levels. Alaska Region ESP information is available at: 

http://alaska.boemre.gov/ess/index.HTM. 

The BOEMRE reviewed the USGS report during the preparation of this EA. The review was focused 

in areas where the USGS identified information needs to determine whether these needs were critical 

for the decisionmaking process at the exploration stage of the OCS Lands Act four-stage process. 

Information Needs. The scope of the USGS report is the entire US Arctic and, therefore, many of the 

information needs or “data gaps” identified are of a regional nature, cover a broad category (e.g. 

anthropogenic noise), or are presented in the context of a long time period (e.g. climate change). For 

example, the USGS report found: 

Little work has been done as of yet projecting how circulation patterns in the Beaufort and 

Chukchi Seas may change during the next 50 years. Because those patterns are critical in 

shaping both the physical and biological environments of the Arctic OCS, and are an 

important element of spill response models, support for research aimed at better understanding 

how these patterns may change in the future is important. 

Exploration in this EA is anticipated to occur within 2-3 years from 2012. The extent to which the 

surface circulation pattern changes by midcentury (2050) is not relevant to this analysis, but the 

collection of the information is a good long-term goal. 

The scope of the EA is also much more focused and limited than the review completed by USGS. The 

EA addresses a discrete activity at a discrete location at a discrete time with a relatively short 

duration. For example, the USGS report found: 

Recent at-sea information on marine birds for most of the study area is lacking or 

unpublished. Similarly, with the exception of information from Cooper Island and Cape 

Lisburne, much of the seabird colony information is out-of-date. Filling these data gaps would 

enhance our ability to measure the effects of climate change and assess the impacts of 

development and transportation. 

While BOEMRE agrees this is a good goal for developing science on the Arctic, the information is 

not necessary to inform the decision-maker regarding the potential level of effects of the Proposed 

Action. BOEMRE has sufficient site specific information to complete a robust analysis of the 

impacts of the Proposed Action on marine birds. The BOEMRE requires an applicant to provide a 
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112 Post Deepwater Horizon Event Environmental Review - Transparency, Public Accountability 

variety of site-specific environmental, geological and geophysical detail within their proposed 

exploration plans which is then reviewed and independently verified. General information needs for 

the Arctic may not, therefore be relevant to specific exploration plans for which adequate information 

may exist. 

The BOEMRE has also taken a cautious approach where more information would be beneficial to this 

project. For example, the USGS report (USGS, 2011) found that there is a lack of information on the 

response of ice seals to aircraft. The Proposed Action has incorporated mitigation measures to reduce 

the likelihood of impacts to ringed seals and bearded seals by restricting flights to above 1,500 ft 

(457m). Based on Born et al. (1999), the BOEMRE has found that despite the general lack of 

information on the response of ice seals to the noise of aircraft, the mitigation measure will remove 

the possibility of impacting ice seals. 

Oil Spill Response Gap. The USGS report made several recommendations on oil spill prevention 

and response, recognizing that “effective Arctic technologies are the first step in oil spill 

minimization.” The report also examined the efficacy of oil spill counter measures and the oil spill 

“response gap.” A “response gap” occurs when activities that may produce an oil spill are conducted 

during times when an effective response cannot be achieved, either because available 

countermeasures will not be effective or their deployment is precluded by environmental conditions 

or safety issues. 

The Proposed Action incorporates several features, described in Section 2.3.12 - Pollution Prevention 

Measures, which use Arctic-specific technologies and incorporates several measures to increase 

response capabilities and minimize the response gap. These measures include stationing and 

maintaining spill response vessels in the immediate vicinity of drilling operations, the use of 

containment equipment designed for Arctic conditions, and the staging of capping stack equipment 

aboard an ice management vessel so it will be available for immediate deployment. Section 5.6.1 - 

Overview of Oil Spill Effects and Response Analysis, provides specific information on oil spill 

response in the Beaufort Sea. 

5.3. Transparency, Public Accountability, and Sound Decisionmaking 

The April 2010 Macondo well control incident and subsequent oil and gas spill occurred following 

the completion of the oil spill analysis for the Shell 2010 EPs (USDOI, MMS, 2009a, USDOI, MMS, 

2009b). An examination of OCS well control through 2010 is included below to update the data 

provided in the 2009 Camden Bay EA. 

5.3.1. OCS Well Control Incident Rates. 

This section updates information in the 2009 Camden Bay EA Appendix A, Section 1.3.2 which 

discussed OCS well control incidents from 1971-2007. The year 1971 is considered reflective of the 

modern regulatory environment. The term “loss of well control” was first defined in the 2006 update 

to the incident reporting regulations (30 CFR 250.188). Prior to this 2006 update, the incident 

reporting regulations included the requirement to report all blowouts, and the term blowout was 

undefined. 

Three relevant data sets are considered: (1) all well control incidents from 1971-2009 prior to the 

DWH event, then (2) well control incident rates from exploration and development drilling including 

the DWH event, and finally (3) spills associated with well control incidents from exploration drilling 

including the DWH event (USDOI, BOEMRE, AIB, 2011). 

Exploratory and Development/Production Operations From 1971-2009. There were 249 well 

control incidents during exploratory and development /production operations on the OCS from 1971-

2009 (this includes incidents associated with exploratory and development drilling, completion, 

workover, plug and abandon, and production operations). During this period, 41,514 wells were 

drilled on the OCS and 15.978 billion barrels (Bbbl) of oil were produced. Of the 249 well control 

incidents that occurred during this period, 50 (20%) resulted in the spillage of condensate/crude oil 
Shell 2012 Camden Bay EP EA

Post Deepwater Horizon Event Environmental Review - OCS Well Control Incident Rates 113

ranging from <1 bbl to 450 bbls. The total spilled from these 50 incidents was 1,829 bbls. This 

volume spilled was approximately 0.000011447% of the volume produced during this period. 

In 2010, four well control incidents occurred, including the DWH event. Although a final spillage 

volume from the DWH event has not been determined by BOEMRE, the current estimate from 

Lubchenco et al. (2010) is 4.9 million bbls. The three other well control incidents that occurred in 

2010 did not result in the spillage of condensate/crude oil. 

Development and Exploration Well Drilling From 1971-2010. From 1971 through 2010 there were 

a total of 41,781 wells drilled in the OCS comprising of 40,565 wells in the Gulf of Mexico, 1,086 

wells in the Pacific Region, 46 wells in the Atlantic Region and 84 wells in the Alaska Region. Of 

these, 26,245 were development wells, 15,491 were exploration wells and 43 were core tests or relief 

wells. The overall drilling well control incident rate is 1 well control incident per 292 wells drilled, 

compared to 1 well control incident per 410 development wells drilled, and 1 well control incident per 

201exploration wells drilled. These well control incident rates include all well control incidents 

related to drilling operations whether they spilled oil or not. 

Exploration Well Drilling From 1971-2010. From 1971 through 2010 industry drilled 223 

exploration wells in the Pacific OCS, 46 in the Atlantic OCS, 15,138 in the Gulf of Mexico OCS, and 

84 in the Alaska OCS, for a total of 15,491 exploration wells. During this period, there were 77 well 

control incidents associated with exploration drilling. Of those 77 well control incidents, 14 (18%) 

resulted in crude, condensate or oil in drilling mud spills ranging from 0.5 bbl to 200 bbls, for a total 

354 bbls, excluding the estimated volume from the DWH event. From 1971-2010 one well control 

incident resulted in a spill volume of 1,000 bbls or more and that was the DWH event. 

The 2009 Camden Bay EA stated that no large (greater than or equal to 1,000 bbl) oil spills from 

exploration and development well control incidents occurred from 1971-2007 while drilling 

approximately 38,000 wells. With the inclusion of the Macondo incident, one large spill occurred 

from 1971-2010 while drilling approximately 38,000 wells. The BOEMRE analyzed the effects of a 

low probability very large oil spill in the Beaufort Sea Lease Sale 186, 195 and 202 Environmental 

Impact Statement (Beaufort Sea Multiple Sale EIS, Section IV.J) (USDOI, MMS, 2003) and tiered to 

that analysis in the 2009 Camden Bay EA. 

The BOEMRE reviewed the oil spill elements analyzed in the Beaufort Sea Multiple Sale EIS 

(summarized in Table 19, column 2) to determine if the estimates are within the scope of the very 

large oil spill analysis in light of information provided by Shell in the Exploration Plan. In calculating 

the flow rate, length of flow, and volume, the Beaufort Sea Multiple-Sale EIS analysis did not 

consider a reduced volume that may be achieved through the use of oil spill countermeasures. 

The Torpedo H well was selected as the basis for comparison as it has the highest calculated worst 

case discharge (WCD) of the four wells proposed in the EP (Shell, 2011, p. 2-5). BOEMRE analysis 

(Table 19, column 3) establishes a flow rate of 2,498 bopd which differs from that provided by 

Shell’s estimate of 9,468 bopd (Table 19, column 4). This EA considers mitigation measures 

incorporated into Shell's EP including the use of a capping and containment system to stem the 

discharge of oil to the marine environment within 15 days of a loss of well control incident. It is 

important to note that the volume of a very large oil spill estimated from a loss of well control event 

at Torpedo H is within the range analyzed in the Beaufort Sea Multiple Sale EIS for both BOEMRE’s 

and Shell’s WCD scenario. 

Table 19 Comparison of Very Large Oil Spill Scenario Elements to Worst Case Discharge Information. 

Description Beaufort Multiplesale EIS Torpedo H (BOEMRE) Torpedo H (Shell) Relative Change 

(BOEMRE) 

Flow Rate 15,000 bopd 2,498 bopd 9,468 bopd1 One sixth the size 

Length of Flow 15 days 15 days 15 days Same 

Volume 225,000 barrels2 37,470 barrels 142, 020 barrels One sixth the size 
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114 Post Deepwater Horizon Event Environmental Review - Rule Changes 

Description Beaufort Multiplesale EIS Torpedo H (BOEMRE) Torpedo H (Shell) Relative Change 

(BOEMRE) 

Oil Type 38 °API 35 °API 35 °API Similar oil quality 

Location Surface 

Surface or Subsurface 

(subsurface modeled for 

WCD) 

Surface or Subsurface 

(subsurface modeled for 

WCD) 

Subsurface likely will surface 

within 1000 m of the location of 

loss of well control 

Mitigation Cleanup Potential for oil to be collected within 15 days with the capping and containment 

system prior to reaching the sea surface and spreading 

Source: Shell Offshore Inc. (2010) and BOEMRE (2010). 

Key: °API = American Petroleum Institute gravity (API) 

 Bopd = barrels of oil per day 1

Provided as required by 30 CFR 250.213 and 250.219 

2

Approximately 180,000 barrels estimated to reach the marine environment 

Information in Table 19 examines the same scenario elements as the previous analyses: 

 The information provides an estimated flow rate, a length of time, a total volume and oil 

property information. The estimated flow rate is approximately 6 times less than 

previously analyzed; 

 The final estimated volume is approximately one fifth of the volume reaching the gravel 

pad and water analyzed in the Beaufort Sea Multiple-Sale EIS (180,000 barrels), Section 

IV.I Low-Probability, Very Large Oil Spill (USDOI, MMS, 2003); and 

 The oil type is similar in composition, physical properties, and evaporation rate. 

BOEMRE determined that the low-probability, very large oil spill effects conclusions in the Beaufort 

Sea Multiple Sale EIS, Section IV.I remain valid for informing the decision maker of the effects of a, 

low-probability, very large oil spill in the vicinity of the Proposed Action. In addition to the original 

cleanup mitigation analyzed, the use of a capping stack and containment system could limit further 

the amount of oil reaching the sea surface and spreading should a loss of well control occur. 

The BOEMRE analyzed the potential impacts of a very large spill from a well-control incident 

(USDOI, MMS, 2003: IV-228 to IV-247), including mitigation of spill response, and the conclusions 

of that analysis are found in section 0 of this EA. There are no site-specific anomalies that 

differentiate a very large spill release at Launch Area (LA) 12 analyzed and from LA15 where Shell’s 

leases occur, and the oil-spill contacts are statistically similar. 

5.4. Rule Changes Following the Deepwater Horizon Event 

The aftermath of the DWH event provided new information about drilling on the OCS; in particular, 

it provided new information about (1) safety issues, (2) deficiencies of blowout containment 

technologies and strategies, and (3) shortcomings in oil spill response strategies and resources relative 

to spills in deepwater. The BOEMRE has addressed these issues by strengthening its regulations of 

OCS activities. A listing, followed by a summary, of new rules and rulemaking procedures are 

provided below: 

 The Drilling Safety Rule, Interim Final Rule to Enhance Safety Measures for Energy 

Development on the Outer Continental Shelf (Drilling Safety Rule). This rule strengthens 

requirements for safety equipment, well control systems, and blowout prevention practices 

on offshore oil and gas regulations. 

 The Workplace Safety Rule on Safety and Environmental Management Systems (SEMS 

Rule). This rule requires operators to develop and implement a comprehensive SEMS for 

identifying, addressing, and managing operational safety hazards and impacts; promoting 

both human safety and environmental protection; and improving workplace safety by 

reducing risk of human error. 

 NTL 2010-N06, “Information Requirements for Exploration Plans, Development and 

Production Plans, and Development Operations Coordination Documents on the OCS,” 

effective June 18, 2010 (Plans NTL). 
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Post Deepwater Horizon Event Environmental Review - Rule Changes 115

 NTL-2010-N10, “Statement of Compliance with Applicable Regulations and Evaluation of 

Information Demonstrating Adequate Spill Response and Well Containment Resources,” 

effective November 9, 2010 (Certification NTL). 

The Drilling Safety Rule. On October 14, 2010, BOEMRE issued an interim final rule entitled 

“Increased Safety Measures for Energy Development on the Outer Continental Shelf” (75 FR 63346). 

The interim rulemaking revises selected sections of 30 CFR 250 Subparts D, E, F, O, and Q. The 

Drilling Safety Rule includes new standards and requirements related to the design of wells and 

testing of the integrity of wellbores; the use of drilling fluids; and the functionality and testing of well 

control equipment including blowout preventers. To these ends, the rule is expected to promulgate 

OCS-wide provisions that will: 

 Establish new casing installation requirements; 

 Establish new cementing requirements; 

 Require independent third party verification of blind-shear ram capability; 

 Require independent third party verification of subsea BOP stack compatibility; 

 Require new casing and cementing integrity tests; 

 Establish new requirements for subsea secondary BOP intervention; 

 Require function testing for subsea secondary BOP intervention; 

 Require documentation for BOP inspections and maintenance; 

 Require a Registered Professional Engineer to certify casing and cementing requirements; 

 Establish new requirements for specific well control training to include deepwater 

operations. 

Safety and Environmental Management Systems Rule. A new subpart to 30 CFR Part 250: 

Subpart S – Safety and Environmental Management Systems (SEMS) is designed to reduce the 

hazards associated with drilling operations and further reduce the likelihood of a blowout scenario 

such as described for this VLOS analysis. The SEMS Rule requires all OCS operators to develop and 

implement a comprehensive management program for identifying, addressing, and managing 

operational safety hazards and impacts, with the goal of promoting both human safety and 

environmental protection. The interim final rule was published on October 14, 2010 (75 FR 63345), 

requiring full implementation of a SEMS program as recommended by the rule’s effective date of 

November 15, 2011. The 13 elements of the industry standard (American Petroleum Institute, 

Recommended Practice 75) that 30 CFR 250 Subpart S now makes mandatory are as follows: 

 defining the general provisions for implementation, planning and management review, and 

approval of the SEMS program; 

 identifying safety and environmental information needed for any facility such as design 

data, facility process such as flow diagrams, and mechanical components such as piping 

and instrument diagrams; 

 requiring a facility-level risk assessment; 

 addressing any facility or operational changes including management changes, shift 

changes, contractor changes; 

 evaluating operations and written procedures; 

 specifying safe work practices, manuals, standards, and rules of conduct; 

 training, safe work practices, and technical training, including contractors; 

 defining preventative maintenance programs and quality control requirements; 

 requiring a pre-startup review of all systems; 

 responding to and controlling emergencies, evacuation planning, and oil-spill contingency 

plans in place and validated by drills; 
Shell 2012 Camden Bay EP EA

116 Post Deepwater Horizon Event Environmental Review - Rule Changes 

 investigating incidents, procedures, corrective action, and follow-up; 

 requiring audits every 4 years, to an initial 2-year reevaluation and then subsequent 3-year 

audit intervals; and 

 specifying records and documentation that describe all elements of the SEMS program. 

NTL (Notice to Lessees) 2010-N06. Effective November 8, 2010, NTL No. 2010-NO6 requires that 

blowout intervention information be submitted with future Exploration or Development and 

Production Plans. The blowout scenarios required by 30 CFR 250.213(g) and 250.243(h) must 

include supporting information for any assertion that well bridging will constrain or terminate the 

flow or that surface intervention will stop the blowout. The availability of a rig to drill a relief well 

and rig package constraints must also be addressed. These scenarios must also specify as accurately 

as possible the time it would take to contract for a rig, move it on site, and drill a relief well, including 

the possibility of drilling a relief well from a neighboring platform or an onshore location. 

NTL (Notice to Lessees) 2010-N10. Also released on November 8, 2010 was NTL 2010-N10. This 

NTL explains that applications for well permits must include a statement that all authorized activities 

will be conducted in compliance with all applicable regulations, to include the new measures 

discussed above. For operations using subsea BOPs or surface BOPs on floating facilities, BOEMRE 

will evaluate whether each operator has submitted adequate information demonstrating that it has 

access to and can deploy subsea containment resources that can adequately and promptly respond to a 

blowout or other loss of well control. The BOEMRE will also evaluate whether each operator has 

adequately described the types and quantities of surface and subsea containment equipment that the 

operator can access in the event of a spill or threat of a spill. 

Joint Industry Task Forces. In response to the DWH event, several entities within the oil and gas 

industry cooperatively formed Joint Industry Task Forces. The stated purpose of each Task Force is 

“to review and evaluate current capacities, and to develop and implement a strategy to address future 

needs and requirements in equipment, practices or industry standards” applicable to the studied 

activity. Where possible, information developed by these Tasks Forces will be augmented with input 

from regulatory agencies, oil spill response and well control specialists, investigation panels, and 

other public sector and non-governmental organizations. To date, Task Forces on “Oil Spill 

Preparedness and Response” and “Subsea Well Control and Containment” have submitted draft 

recommendations. Joint Industry Task Force recommendations will not have the force of regulation, 

but may provide the basis for enhanced industry standards or future rulemaking processes. 

BOEMRE Inspection Program. Under the direction of the OCS Regional Office in Anchorage, 

Alaska, BOEMRE inspection program for Alaska provides review and inspection of oil and gas 

operations. BOEMRE conducts on-site inspections to ensure compliance with lease terms, Notices to 

Lessees, and approved plans, and to ensure that safety and pollution-prevention requirements of 

regulations are met. These inspections involve items of safety and environmental concern. Further 

information on the baseline for the inspection of lessee operations and facilities can be found in the 

National Office Potential Incident of Noncompliance List (USDOI, MMS, 2005). 

BOEMRE has taken steps to further strengthen its inspection program in light of the DWH event. 

BOEMRE is hiring additional inspectors. Also, the bureau is creating for the first time a National 

Offshore Training Center led by a training director dedicated to training inspectors on how to do their 

jobs. In the past, BOEMRE inspectors learned how to do their jobs through a combination of on-thejob training and industry-sponsored courses aimed at teaching how certain types of equipment 

functioned. Inspectors also received training from academia and third-party vendors. The Director of 

the National Offshore Training Center will develop national training strategies and programs to 

maintain and improve the technical capabilities of offshore inspections and compliance personnel 

throughout the bureau. 
Shell 2012 Camden Bay EP EA

Post Deepwater Horizon Event Environmental Review - Site Specific Differences from Macondo 117

5.5. Site Specific Differences from Macondo 

While BOEMRE responded to the Macondo well control incident with new nationwide regulations, it 

is important to note that there are important differences between the geological and physical 

conditions and the regulatory spill prevention requirements at the Macondo site in the Gulf of Mexico 

and the Sivulliq and Torpedo drill sites in the Beaufort Sea. The BOEMRE has compared the 

substantive differences and similarities between the Macondo and the proposed exploration drilling 

and concluded that the Macondo incident does not foreshadow any reasonably foreseeable events at 

the Sivulliq or Torpedo drill sites. The comparison data, summarized in Table 20, illustrates that the 

Macondo incident can not be directly correlated to reasonably foreseeable events in the Beaufort Sea 

as is described in detail in the following paragraphs. 

5.5.1. Geological and Physical Conditions. 

The Macondo well was drilled in approximately 5,000 ft of water, whereas the wells proposed by 

Shell will be drilled in approximately 107 to 124 ft of water among the 4 wells (EA tbl. 2). The 

shallower water depth allows for direct (non-acoustic) and faster communication with the blowout 

preventer (BOP) system allowing an operator to quickly activate the BOP. This translates to a much 

faster response time in the event of a well control incident with a well at the Sivulliq or Torpedo sites. 

The Macondo well was drilled to 18,000 ft and had a reservoir pressure reported to be approximately 

12,000 pounds per square inch (psi). The proposed Torpedo H well is expected to be drilled to a much 

shallower total depth (10,000 ft) and encounter an expected reservoir pressure of ~3,600 psi 

(BOEMRE model). The lower formation pressure results in a higher margin of safety. It also allows 

operators to change the weight of the drilling mud by several pounds per gallon to balance formation 

pressures. 

The discharge rates observed at the Macondo well are much higher than the estimates for the Torpedo 

H well. These higher rates are due primarily to very high formation pore pressures at Macondo 

compared with much lower pore pressures anticipated at Torpedo H and the very low viscosity oil at 

Macondo compared to the higher (by a factor of 3.5) viscosity oil predicted at Torpedo H. 

Table 20 Comparison of Deepwater Horizon / Macondo and Torpedo H Wells. 

Geologic Information and Flow Parameters1 Deepwater Horizon / Macondo Torpedo H (BOEMRE Model) 

Water Depth (ft) 5,000 ~120 

Distance From Shore (mi) 41 21 

Reservoir Depth (ft) 18,150 <10,000 

Reservoir Thickness (ft) 95.5 Proprietary 

Reservoir Age 12-16 mybp2 23-34 mybp2

Reservoir Porosity (%) 21.7 33 

Reservoir Permeability 223.7 141 

Reservoir Temperature (°F) 243 134 

Reservoir Pressure (psi) 11,856 ~3,600 

Oil Gravity (°API) 38.2 35 

Oil Viscosity (centipose) 0.168 0.58 

Oil Volume Factor (rbbl/stbbl)3 2.367 1.54 

Estimated Maximum Discharge Rate (bopd3) 53,000 – 62,000 2,498-9,4685

Note: 1Deepwater Horizon / Macondo geologic properties from PIV Study (2010, file pages 20-23; estimated 

maximum discharge rates from McNutt et al., 2011, p. 1)) 2

mybp = millions of years before present 

3

rbbl/stbbl = Reservoir Barrels per Stock-Tank Barrel. A stock-tank barrel is a barrel of oil at 60°F and 1 

atmosphere pressure (14.73 psia) 

4

bopd = barrels of oil per day 5Worst case discharge calculation (BOEMRE, 2,498 bopd, Shell 9,468 bopd) 
Shell 2012 Camden Bay EP EA

118Post Deepwater Horizon Event Environmental Review - Arctic Specific Measures to Prevent Oil Spills 

5.5.2. Arctic Specific Measures to Prevent Oil Spills 

Exploratory drilling activities conducted on the OCS must be conducted in accordance with 

BOEMRE regulations at 30 CFR 250. These regulations set comprehensive requirements for well 

design based on site specific shallow geohazards, site clearance information, and deep seismic data. 

They also mandate the staging of redundant pollution prevention equipment, testing and verification 

that equipment is working properly, and training and testing of personnel in well control procedures. 

These regulations also establish the technical specifications for the specific drilling rig and the 

drilling unit. The 30 CFR 250 regulations include specific requirements for conducting operations in 

the Arctic. These include: 

 Locating the blowout preventer (BOP) in a well cellar (a hole constructed in the sea bed) to 

position the top of the BOP below the maximum potential ice gouge depth. This protects 

the BOP and assures the well can be safely shut in, in the event the drilling unit has to 

move off location. 

 Using special cements in areas where permafrost is present. These special cements create 

less heat than normal cements when curing so that permafrost does not thaw. 

 Enclosing or protecting equipment to assure it will function under sub-freezing conditions. 

 Developing critical operations and curtailment procedures which detail the criteria and 

process through which the drilling program would be stopped, the well shut in and secured 

and the drilling unit moved off location before environmental conditions (such as ice) 

exceed the operating limits of the drilling vessel. 

In addition to the maintenance and implementation of its ODPCP, Shell would implement the 

following additional measures to further minimize the chance of an oil spill that might impact marine 

mammals and interfere with the subsistence hunt: 

 Shell has established and would follow transit routes that avoid known fragile ecosystems 

and critical habitat areas to reduce the possibility of impacting those resources in the 

unlikely event of a vessel accident that resulted in a diesel spill. 

 Shell has developed and would implement an Ice Management Plan (IMP) (Shell, 2011a: 

Section 9.0 and Appendix K) to ensure real-time ice and weather forecasting to identify 

conditions that might put operations at risk and modify its activities accordingly. The IMP 

also contains ice-threat classification levels depending on the time available to suspend 

drilling operations, secure the well, and escape from advancing hazardous ice. 

 Shell has developed and would implement a Critical Operations and Curtailment Plan 

(COCP) (Shell, 2011a: Section 9.0 and Appendix J), which establishes protocols to be 

followed in the event potential hazards, including ice, are identified in the vicinity of the 

drilling operations (e.g., ice floes, inclement weather, etc.). Like the IMP, the COCP 

threat classifications are based on the time available to prepare the well and escape the 

location. The COCP also contains provisions for not initiating certain critical operations, 

if there is insufficient time available before the arrival of the hazard at the drill site. 

 Shell has engineered each of its exploration wells (hole sizing, mud program, casing 

design, casing cementing depth, wellhead equipment, etc.) specifically to minimize the risk 

of uncontrolled flows from the wellbore due to casing or other equipment failures. 

 Shell requires its drilling supervisors, toolpushers, drillers, and assistant drillers to hold an 

International Association of Drilling Contractors (IADC) WellCap (or equivalent) 

certificate showing mastery of well-control procedures and principles, and its crews must 

participate in regular training and drills in kick control to minimize the risk of a wellcontrol event that might lead to a spill. 

 Shell would use state-of-the-art automatic kick-detection equipment, including pit-volume 

totalizers, a flow detector, and various gas detectors placed about the rig, to provide early 

warning of a potential well-control event. 
Shell 2012 Camden Bay EP EA

Post Deepwater Horizon Event Environmental Review - Arctic Specific Measures to Prevent Oil Spills119

 The blowout preventer Shell would install on the high-pressure wellhead housing on the 

20-in conductor casing on each exploration well includes redundant mechanical barriers to 

provide multiple means of closing in the well to prevent an oil flow to the surface. 

 Shell would install multiple barriers, including manual and automated valves, on the 

drilling rig to prevent flows from coming up the drill string. 

 Shell has developed and would implement a Well Control Contingency Plan (WCCP) 

(Shell, 2011a: Section 9.0 and Appendix L) in the extremely unlikely event of a wellcontrol event to minimize the risk of oil coming in contact with the water. As part of the 

WCCP, Shell would prepare a Relief Well Drilling Plan for each location in advance of 

spudding the well to ensure that a relief well can be started quickly to kill the well. 

 Shell has developed and would implement a Fuel Transfer Plan (FTP) (Shell, 2011a: 

Section 9.0 and Appendix M), which requires, among other things, the deployment of 

containment boom prior to any refueling operation. 

 Shell would station and maintain its OSRVs in the immediate vicinity of its drilling 

operations to ensure timely response to any spill event. 

 In addition to the OSR fleet, oil spill containment equipment will be available for use in 

the unlikely event of a blowout. The barge will be centrally located in the Beaufort Sea and 

supported by an Invader Class Tug and possibly an anchor handler. The containment 

equipment will be designed for conditions found in the Arctic including ice and cold 

temperatures. This equipment will also be designed for maximum reliability, ease of 

operation, flexibility and robustness so it could be used for a variety of blowout situations. 

 Capping Stack equipment will be stored aboard one of the ice management vessels and 

will be available for immediate deployment in the unlikely event of a blowout. Capping 

Stack equipment consist of subsea devices assembled to provide direct surface intervention 

capability with the following priorities: 

 Attaching a device or series of devices to the well to affect a seal capable of 

withstanding the maximum anticipated wellhead pressure (MAWP) and closing the 

assembly to completely seal the well against further flows (commonly called 

“capping and killing”) 

 Attaching a device or series of devices to the well and diverting flow to surface 

vessel(s) equipped for separation and disposal of hydrocarbons (commonly called 

“capping and diverting”) 

 Pre-booming for all fuel transfers between vessels. 

No drilling activity can be conducted until BOEMRE has approved an application for permit to drill 

(APD). The BOEMRE engineers and geoscientists review each APD for proper engineering 

considerations, site specific engineering and geologic conditions, and compliance with BOEMRE 

regulations. Any changes to an approved APD must be submitted, reviewed, and approved by 

BOEMRE. 

The BOEMRE Alaska OCS Region plans to continue its policy of maintaining a continuous 

inspection presence during exploratory drilling operations in the Arctic. This is in recognition of the 

high level of public concern, some of the unique operating conditions, and logistical considerations in 

rotating personnel between onshore staging locations and remote drill sites. The BOEMRE inspector 

witnesses all critical operations, including BOP tests, running casing, and cementing activities. While 

on site, BOEMRE conducts unannounced well control drills and written and verbal tests of industry 

personnel’s knowledge of well control procedures and processes. The BOEMRE inspectors have the 

authority to shut down drilling activity in the event of non-compliance with BOEMRE regulations. 

The BOEMRE Alaska OCS Region receives daily reports of on-going drilling activity. The 

BOEMRE engineering and geosciences staff independently review and compare ongoing drilling 

activities with the APD and the observed engineering and geological conditions encountered while 
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120 Post Deepwater Horizon Event Environmental Review - Oil Spill Effects and Response 

drilling. BOEMRE staff work closely with the drilling vessel operators throughout the project to 

make modifications to the well design or drilling procedures when appropriate. 

Wells are drilled in sections, with casings (or pipe) placed and cemented in each section before 

another section is drilled. The BOEMRE policy is to review the drilling prognosis and projected 

environmental conditions prior to drilling out each casing shoe (section of well and pipe). This 

ensures that no new drilling occurs and no open hole is exposed until BOEMRE is confident that 

there is sufficient time to drill to the next casing point, set casing, cement the casing, and secure the 

well with out interruption due to adverse weather conditions or ice. 

5.6. Oil Spill Effects and Response 

As previously explained, the effects of an oil spill on the human environment and the effects of 

response activities associated with an oil spill were analyzed at each stage of the NEPA process. This 

analysis began, as an area-wide analysis in the 2002-2007 Five Year Program EIS and became 

progressively more geographically focused through the Beaufort Sea Multiple-Sale EIS, Sale 195 EA, 

Sale 202 EA and finally addressed site-specific effects in the 2009 Camden Bay EA. A summary of 

the analysis at each level is provided below. Following the summary is a brief description of the 

effects of a very large oil spill on each resource. 

5.6.1. Overview of Oil Spill Effects and Response Analysis 

Five Year Program EIS. Outer Continental Shelf oil and Gas Leasing Program: 2002 to 2007, Final 

Environmental Impact Statement, April 2002, OCS EIS/EA MMS 2002-006, Volume II, Appendix C, 

Oil Spill Response Capabilities for Offshore Oil and Gas Operations, describes BOEMRE regulatory 

authority over a Oil Spill Response Plan (OSRP) and includes the BOEMRE review and approval 

process. The EIS analysis describes regional conditions affecting OCS oil-spill planning and response 

including: 

 The effects on response time in Alaska because of the remoteness of the area and other 

factors (page C-12 through C-14). 

 A description of the technology and techniques of oil spill containment and clean-up and 

effectiveness of each (various mechanical containment and cleanup equipment, in-situ 

burning, dispersants, bioremediation, various coastal clean up techniques, page C-17 

through C-28). 

 The effectiveness of oil spill response technology in Arctic environments including in-situ 

burning, oil spill response in broken ice conditions and its effectiveness, spilled oil trapped 

in or under ice (page C-28 through C-32). 

Beaufort Sea Multiple Sale EIS. Beaufort Sea Planning Area Oil and Gas Lease Sale 186, 195, and 

202 Final Environmental Impact Statement OCS EIS/EA MMS 2003-001, February 2003 continues 

the discussion of spill prevention and response to include: 

 Oil spill prevention and response regime and the technology and techniques of oil spill 

response (mechanical, in-situ burning, freezing oil) and factors that affect recovery 

effectiveness for Beaufort Sea conditions (Section IV.5, Spill Prevention and Response 

and Section IV.A. 6, page 4-16 to 4-18). 

 Effect of a large oil spill and response on physical, biological, and social resources 

(Section IV.C). (Note: while the analysis of large oil spills estimated that no large spills 

would occur during exploration or development, the effects analysis does analyze a 1,500 

barrel spill from a production facility and a 4,600 barrel spill from pipelines). 

 Effect of a very large oil spill (225,000 barrel spill) and clean up on the physical, 

biological and social resources of the Beaufort Sea (Section IV.I, page IV-227 through IV247). 

Specific Lease Sale EA. Environmental Assessment (EA/EIS MMS 2004-028) Proposed Oil and Gas 

Lease Sale 195, Beaufort Sea Planning Area considered information applicable to Lease Sale 195 that 
Shell 2012 Camden Bay EP EA

Post Deepwater Horizon Event Environmental Review - Large Oil Spill Effects 121

had become available since the multiple sale FEIS. The EA briefly reviewed the oil-spill analysis 

from the multiple sale EIS, provided new information on oil spills and oil-spill response, and, in-light 

of new information, updated the analysis of effects of a large oil spill on various resources. 

Exploration Plan EA—2010. Shell Offshore Inc. 2010 Outer Continental Shelf Lease Exploration 

Plan, Camden Bay, Alaska, OCS EIS/EA MMS 2009-052 June 2009 examined site specific 

conditions, including: 

 A list of specific proposed measures for oil spill prevention and response (Section 2.3.9, 

page 21). 

 A discussion of pollution prevention measures (p. 30) 

 The effects analysis does not address effects from an oil spill as no large (≥1,000 bbl) or 

very large (≥150,000 bbls) crude oil spills are estimated to occur from the proposed 

activities (see EA Section 2.3.8 and Appendix A). 

 The EA (Appendix A) concludes, for a very large oil spill, that there are no site-specific 

anomalies that differentiate a very large spill release at Launch Area (LA) 12 from LA15, 

and the oil-spill contacts are statistically similar. BOEMRE, therefore, analyzed the 

potential impacts from a very large well-control incident where fluids are released into the 

Beaufort Sea in the Multiple-Sale EIS and incorporated the analysis in the EA by 

reference. The Multiple-Sale EIS also considered the mitigation of spill response. 

 Shell’s ODPCP response scenario addressed the potential immediate release of crude oil to 

the environment by a loss of well control during drilling. 

5.7. Large Oil Spill Effects 

This section addresses the adequacy of the Beaufort Sea Multiple-Sale EIS large oil spill analysis for 

the purposes of analyzing this site-specific proposal. A large oil spill, as defined by BOEMRE, is an 

oil spill with a total volume that is greater than or equal to 1,000 bbls. The chance of one or more 

large spills occurring is low; however, BOEMRE comprehensively analyzed the potential 

consequences of a hypothetical large spill in the Beaufort Sea Multiple-Sale EIS (Section IV.C.), Sale 

202 EA, and the Arctic Multiple-Sale Draft EIS, (Section 4.4) for likely consequences to all 

resources. Based on OCS median spill sizes, the BOEMRE estimated a 1,500-bbl diesel or crude oil 

spill from a facility or a 4,600 -bbl crude oil spill from a pipeline for purposes of analyzing a large 

spill size (Anderson and LaBelle, 2000). The conditional probabilities estimated by the Oil-Spill Risk 

Analysis (OSRA) model (expressed as percent chance) of a spill ≥1,000 bbl contacting environmental 

resource areas or land segments within a given time frame from launch areas (LA1-18) and pipeline 

segments (P1-11) assuming a spill occurs are discussed in USDOI, MMS (2003, 2004, 2006, 2008). 

In the unlikely event of a large accidental oil spill within LA15, the location of Shell’s leases, the 

potential for major impacts exist from a large accidental oil spill as identified in previous analyses 

(USDOI, MMS, 2003, 2008). 

The following paragraphs describe the effects of a large oil spill on the identified resources. 

Air Quality. 

A large oil spill would cause an increase in the concentrations of gaseous hydrocarbons (volatile 

organic compounds) which could affect onshore air quality (USDOI, MMS, 2003, p. IV-245). 

Although effects would be localized and temporary, concentrations of criteria pollutants may exceed 

the federal and Alaska ambient air quality standards during the initial phases, particularly in the 

vicinity of the event. Major impacts at the spill-site may cause only minor impacts onshore, 

depending on how far from shore the spill occurs. The prospects under consideration in the 2012 

Camden Bay EP are 16 miles from the nearest onshore area (Point Thompson) and as far away as 125 

miles from Nuiqsut. Impact in the vicinity of Nuiqsut would be expected to be much lower as 

compared to Point Thompson. As surface oil evaporates or is removed, as any fires are extinguished, 

and as the use of additional clean-up equipment lessens, impacts will eventually decrease to a minor 
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122 Post Deepwater Horizon Event Environmental Review - Large Oil Spill Effects 

level. Thus, while initial impacts are estimated to be major at the spill site, the emissions from the oil 

spill at most onshore locations would be minor to moderate. 

Emissions from the occurrence and clean-up of a large oil spill on the outer continental shelf would 

consist primarily of hydrocarbons (volatile organic compounds) created from oil on the surface of the 

water. However, in the event of an initial explosion of gas and oil, the result would be a large black 

plume of smoke causing short-term emissions of particulate matter (PM) and the other products of 

combustion, such as NOX, SOX, CO, VOC, and CO2. The fire could also produce polycyclic aromatic 

hydrocarbons (PAHs), which are known to be hazardous to human health. The severity of impacts 

would decrease following the initial event and emissions would be limited to mostly VOC from the 

surface oil and emissions associated with engines from vessels and other equipment used for the 

clean-up process (USDOI, MMS, 2003, p. IV-245). By the time the oil reaches the shoreline, 

emissions from the surface oil would decrease due to weathering and decreased thickness of the oil 

layer. During the clean-up process, the impact to onshore air quality may increase slightly due to the 

combination of in situ burning, use of dispersants, and the use of vessels, surface vehicles, and 

aircraft to support the clean up. Eventually, the continuing decrease in surface oil (USDOI, MMS, 

2004, Sec. IV.A.1), less use of clean-up equipment, and the effect of Arctic winds would be expected 

to decrease any onshore air quality impacts to minor levels of effect. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Water Quality. 

Water quality would be adversely affected by hydrocarbons from a large oil spill, resulting in acute 

and chronic hydrocarbon contamination of the water. Hydrocarbons could exceed the 1.5 parts per 

million acute toxic criterion for water quality during the first day of a spill and the 0.015 parts per 

million chronic criterion for about a month thereafter. A broad-scale increase in dissolved petroleum 

in the surface water and water column would cause chronic toxicity conditions for organisms. Over 

the long-term, contamination of aquatic environments from oil leaching would continue from oil 

breakdown products such as polycyclic aromatic hydrocarbons (PAHs). Sunlight (UV radiation) 

increases the toxicity of PAHs so summer sunlight in arctic Alaska could exacerbate the amount and 

degree of toxicity. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Lower Trophic Organisms. 

The effects of a large oil spill on phytoplankton vary widely, depending on the concentration and type 

of oil or compounds used in the experiments and on the species being tested. Nevertheless, general 

patterns do exist, and both laboratory and field studies have shown that hydrocarbons typically inhibit 

phytoplankton growth at higher concentrations (USDOI, MMS, 2003: p. IV-30). In cases where 

studies have been conducted following small and large oil spills, there was found to be a lack of effect 

on phytoplankton populations at this level of a large oil spill. This is thought to be due to the 

relatively rapid turnaround rate of phytoplankton generations (9-12 hrs) and the influx of 

phytoplankton from unaffected areas that replace the population levels. Effects on phytoplankton 

populations would be highest in the summer during periods of bloom concentrations that are most 

likely to occur in early July and late August. It is likely that the effects of a large spill on 

phytoplankton are negligible due to the levels of oil released to the environment. 

The effects of petroleum based hydrocarbons on invertebrates have been observed by both field based 

observations and laboratory testing. Effects are highly varied and depend upon species tested and 
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levels of exposure. When considering zooplankton, it is known that exposure to sunlight increases 

toxicity of petroleum by the enhanced creation of polcyclic aromatic hydrocarbons from raw crude. A 

study by Shirley and Duesterloh (2002) noted increased toxicity in copepods with exposure to these 

products, with copepods being considered as important components of zooplanktonic masses. In 

general, the effect of the oil associated with a large oil spill would depend on the amount of sunlight, 

wind speed and duration, air and water temperature, and the composition of the oil. However, based 

on the assumptions associated with weathering of Prudhoe Bay crude oil, within 10 days of a spill 

occurring during the summer season, 26% of the oil would have evaporated, 58% would remain on 

the surface, and 16% would be dispersed through the water column (Table IV.A-6a). Dispersed and 

dissolved oil in the water column has the greatest potential of adversely affecting zooplankton and 

benthic or pelagic invertebrates. Effects of a large oil spill on these organisms would likely be 

negligible to minor due to the levels of oil released to the environment, with these effects being 

highly dependent upon the physical forcing mechanisms that move and break down the oil within the 

environment. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Fish and EFH. 

Effects of a large oil or diesel fuel spill on arctic fishes, including Pacific salmon, would depend on 

the season of the spill, the location of the spill; the lifestage of the fishes (adult, juvenile, larval, or 

egg) affected; and the duration of the exposure. A large oil spill would cause acute and chronic 

toxicity effects to individual fish and local fish populations that could take multiple generations to 

recover to their former status. 

A large oil spill that contacted estuarine and riverine waters and EFH could affect the year’s salmon 

smolts and eggs. If the oil contacted nearshore Beaufort Seafish spawning and feeding habitat, fish 

such as capelin and arctic cod would be affected. Depending on the location, timing and duration of a 

large oil spill, EFH and regional fish populations would be affected. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Marine and Coastal Birds 

Spectacled Eiders. Previous analyses in the multiple-sale EIS (USDOI, MMS, 2003: IV-91) found 

that spectacled eiders experiencing moderate or heavy oil contact would not survive; most lightly 

oiled birds also are not likely to survive at arctic water temperatures. Swallowed oil may cause 

reduced physiological function and production of fewer young. 

With any substantial mortality, the potential exists for a significant adverse effect on the spectacled 

eider population. Mortality of eiders from a large oil spill was expected to be fewer than 100 

individuals; however, any substantial losses (25+ individuals) would represent a considerable effect. 

Recovery from substantial mortality would not occur while the population exhibited a declining trend. 

The relatively small loss of spectacled eiders likely to result in the unlikely event of an oil or fuel spill 

in the Beaufort Sea, where so far there is little indication of large numbers gathering in offshore 

waters, may be difficult to separate from natural variation in population numbers. 

The Lease Sale 195 EA updated the conclusion that the potential level of effect on the spectacled 

eider population was still expected to be substantial and recovery from such mortality would not 

occur while the population exhibited a declining trend (USDOI, MMS, 2004: 31). Similarly, the 

Lease Sale 202 EA reached the same conclusion, but added that while an oil spill, under certain 

conditions, would result in a potentially significant effect to spectacled eiders, the coincidence of all 
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the factors that would have to occur simultaneously to result in such an impact to spectacled eiders is 

highly improbable, and large impacts to spectacled eiders were not anticipated (USDOI, MMS, 

2006a: 34). 

Steller’s Eiders. Previous analyses in the multiple-sale EIS (USDOI, MMS, 2003: IV-98) concluded 

that in the unlikely event a large oil spill occurs, Steller’s eiders experiencing moderate to heavy 

contact oil contact would not survive; most lightly oiled birds also are not likely to survive at arctic 

water temperatures. A minor proportion of the small Alaskan breeding population is likely to be 

vulnerable to an oil spill, because staging and migrating individuals generally are scattered in 

relatively few flocks along the coast during the brief summer/fall period of breeding and migration. 

Small numbers of spring migrant Steller’s eiders typically are observed during migration counts of 

eiders past Point Barrow, suggesting that many of the small population nesting in northwestern 

Alaska may arrive at the nesting areas via overland routes from the Chukchi Sea. If this is the case, 

relatively few eiders are likely to occupy leads offshore the northern coastline east of Point Barrow 

where they would be vulnerable to oil entering such habitat. Given the apparently small population 

seasonally occupying northwestern Alaska, low Steller’s eider mortality is likely from an oil spill; 

however, recovery of the Alaska population from spill-related losses is not likely to occur, if numbers 

on the breeding ground continue to decline and the reproductive rate remains relatively low. 

The Lease Sale 195 EA updated the conclusion that the potential level of effect on the Steller’s eider 

population was expected to be the same as stated in the multiple-sale EIS (USDOI, MMS, 2004: 32). 

Similarly, the Lease Sale 202 EA reached the same conclusion, but added that while an oil spill under 

certain conditions would result in a potentially significant effect to Steller’s eiders, the coincidence of 

all the factors that would have to occur simultaneously to result in such an impact to Steller’s eiders is 

improbable, and that considerable impacts to Steller’s eiders were not anticipated (USDOI, MMS, 

2006a: 34). 

Kittlitz’s Murrelet. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003) and subsequent 

EAs (USDOI, MMS, 2004, 2006) did not consider the Kittlitz’s murrelet to be present in the Beaufort 

Sea. 

Yellow-billed Loon. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003: 107) 

considered adverse effects from a large spill on the yellow-billed loon in general terms. No 

remarkable effects were identified because the species occurs in low densities across nearshore 

coastal areas of the Beaufort Sea. 

The Lease Sale 195 EA updated information on the yellow-billed loon (USDOI, MMS, 2004: 14). 

Yellow-billed loons had been observed in small numbers on the Colville River delta. This species had 

a small estimated Alaska population of 3,650. Fewer than 200 yellow-billed loons were observed 

during nearshore aerial surveys along the Arctic coast in late July – early August 2002 and 2003. The 

EA concluded there was no indication that species characterized as having a lower potential for 

noteworthy effects from oil and gas development were more susceptible than was concluded in the 

multiple-sale EIS. Most have exhibited relatively stable populations in recent surveys, although the 

yellow-billed loon was of some concern. 

The Lease Sale 202 EA updated conclusions regarding the potential for a large spill to affect the 

yellow-billed loon (USDOI, MMS, 2006a: 46). The EA concluded that studies involving population 

trends and distribution of yellow-billed loons indicated they had a higher potential for potentially 

significant effects from activities following Sale 202 than was stated in the multiple-sale EIS. 

However, the coincidence of factors that would have to occur simultaneously to have a considerable 

effect was improbable, and non-trivial impacts were not reasonably certain to occur. 

Common Eiders. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003: 106) considered 

adverse effects from a large spill on the common eider and concluded that most species with low 

reproductive rates or population effects (i.e., common eider) were not likely to suffer high mortality 

as a result of an oil spill, because they are not abundant in most of the proposed lease sale areas and 

do not occur in large feeding flocks, although any losses would be recovered slowly due to relatively 
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low reproductive rates. In the case of common eiders, because they have experienced substantial 

losses over the past several decades, mortality at the higher levels was expected to represent a 

significant effect. With any substantial mortality, which could occur if substantial proportions of 

migrants from nesting areas outside a contacted spill area were to be affected, the potential exists for 

a substantial adverse effect on Beaufort Sea common eider populations. 

The Sale 195 EA (USDOI, MMS, 2004: 32) updated the potential level of effect on the common eider 

population and expected them to be the same as stated in the multiple-sale EIS. However, the EA 

added that available research information indicated that fall-migrant individuals stop at least once 

while crossing the Beaufort Sea and potentially were more vulnerable to contact by a spill than 

previously considered. The Sale 202 EA updated the potential level of effect on the common eider 

population and expected them to be the same as stated in the multiple-sale EIS (USDOI, MMS, 

2006a: 46). 

King Eiders. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003: 106) considered 

adverse effects from a large spill on king eiders and concluded that species with or population effects 

(i.e., king eider) were not likely to suffer high mortality as a result of an oil spill, because they are not 

abundant in most of the proposed lease sale areas and do not occur in large feeding flocks, although 

any losses would be recovered slowly due to relatively low reproductive rates. In the case of king 

eiders, because they have experienced substantial losses over the past several decades, mortality at the 

higher levels was expected to represent a significant effect. With any substantial mortality, which 

could occur if substantial proportions of migrants from nesting areas outside a contacted spill area 

were to be affected, the potential exists for a notable adverse effect on Beaufort Sea king eider 

populations. 

The Lease Sale 195 and 202 EAs (USDOI, MMS, 2004: 32, 2006: 46) updated the potential level of 

effect on the king eider population and expected them to be the same as stated in the multiple-sale 

EIS. The latter EA added that available research information indicated that king eiders concentrated 

in deeper offshore waters and were potentially more vulnerable than previously considered. 

Long-tailed Ducks. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003: 106) 

considered adverse effects from a large spill on long-tailed ducks and concluded that high levels of 

mortality were expected to result in a significant long-term adverse effect on the regional population. 

Depending on population trend, the loss of several thousand long-tailed ducks could be recovered 

within several generations or not recover until the population experiences an increasing trend. With 

any substantial mortality, which could occur if substantial proportions of migrants from nesting areas 

outside a contacted spill area were to be affected, the potential exists for a substantial adverse effect 

on Beaufort Sea long-tailed ducks. 

The Lease Sale 195 and 202 EAs (USDOI, MMS, 2004: 32, 2006: 46) updated the potential level of 

effect on the long-tailed duck population and expected them to be the same as stated in the multiplesale EIS. 

Marine and Coastal Birds Summary. BOEMRE has analyzed and incorporated in this EA the best 

available science published since the Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s 

and the 2009 Camden Bay EA and expects the same level of effects from a hypothetical large oil 

spill associated with the Proposed Action as was characterized in these documents. 

Marine Mammals 

Bowhead Whales. In the unlikely event of a large oil spill, the probability of oil contacting whales is 

likely to be considerably less than the probability of oil contacting bowhead habitat. If a spill occurred 

and contacted bowhead habitat during the fall migration, it is likely that some whales would be 

contacted by oil (USDOI, MMS, 2003: IV-79). The number of whales contacting spilled oil would 

depend on the location, size, timing, and duration of the spill and the whales’ ability or inclination to 

avoid contact. The extent of the effects would depend on how many whales contacted oil, the duration 

of contact, and the age/degree of weathering of the spilled oil. It is likely that some whales would 
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experience temporary, nonlethal effects. Prolonged exposure to freshly spilled oil could kill some 

whales, but the number likely would be small. 

Reanalysis for the Sale 195 EA (USDOI, MMS, 2004: 40) concluded that whales exposed to spilled 

oil likely would experience temporary, nonlethal effects, although prolonged exposure to freshly 

spilled oil could kill some whales. There are, in some years and in some locations, relatively large 

aggregations of feeding bowhead whales within the proposed lease-sale area. If a large amount of 

fresh oil contacted a substantial portion of such an aggregation, effects potentially could be greater 

than typically would be assumed. However, based on available information about the effects of oil on 

large cetaceans, there was no evidence that any impact on this population from an oil spill would be 

likely to result in a considerable effect. The population is robust, and the population is, as evidenced 

by its continued increase despite a documented lethal removal in the subsistence hunt, resilient to 

relatively small removals. Based on published information, the amount of mortality, if any, due to an 

unlikely large oil spill, is not likely to be large. A reanalysis for the Lease Sale 202 EA (USDOI, 

MMS, 2006a: 35) also concluded that no noteworthy impacts to the bowhead whale were expected 

due to activities associated with proposed Sale 202, including the effects of an assumed oil spill. 

Fin Whales. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003) and subsequent EAs 

(USDOI, MMS, 2004, 2006) did not consider the fin whale to be present in the Beaufort Sea. 

Humpback Whales. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003) and 

subsequent EAs (USDOI, MMS, 2004, 2006) did not consider the humpback whale to be present in 

the Beaufort Sea. 

Ringed Seals. Previous analyses in the multiple-sale EIS (USDOI, MMS, 2003: IV-120) and two 

subsequent EAs (USDOI, MMS, 2004: 41, 2006: 35) concluded that a large spill could affect perhaps 

100-200 ringed seals, with the population recovering within about 1 year. In the context of new 

information that has become available since publication of the multiple-sale EIS, those NEPA 

conclusions remained consistent; thus the updated potential level of effect on pinnipeds was expected 

to be about the same as stated in the multiple-sale EIS. 

Bearded Seals. Previous analyses in the multiple-sale EIS (USDOI, MMS, 2003: IV-120) and two 

subsequent EAs (USDOI, MMS, 2004: 41, 2006: 35) concluded that a large spill could affect 30-50 

bearded seals, with the population recovering within about 1 year. In the context of new information 

that had become available since publication of the multiple-sale EIS, those NEPA conclusions 

remained consistent; thus the updated potential level of effect on pinnipeds was expected to be about 

the same as stated in the multiple-sale EIS. 

Polar Bears. Previous analysis in the multiple-sale EIS (USDOI, MMS, 2003: IV-120) concluded 

that polar bears were most likely to be oiled or eat oiled prey at a whale carcass on either Cross or 

Barter Island or at a concentration of seals in the sale area. The EIS concluded an estimated 5-30 

bears could be harmed. This estimate was based on the number of polar bears sometimes observed by 

the bowhead whale aerial surveys conducted in the Cross Island and Barter Island areas during the 

fall bowhead whale harvest. An estimated 5-30 bears could be lost to a spill, if the spill contacted 

Cross or Barter Island when and where that many polar bears may be concentrated during the 

subsistence-whale harvest. This represents a severe event. However, the probability of this occurrence 

is low. 

The multiple-sale EIS and two subsequent EAs (USDOI, MMS, 2004: 41, 2006: 35) concluded the 

more likely loss would be no more than 6-10 bears (5.7-10 bears, assuming a bear density of 1 bear 

per 25 km2 divided into 143-252 km2, the area swept by the large spill as a discontinuous slick in 

broken ice or meltout. The polar bear population was expected to recover individuals killed by the 

spill within 1 year and there would be no effect on the population. The new information did not 

change the conclusion of no significant population-level effects. 

Pacific Walrus. Previous analyses in the multiple-sale EIS (USDOI, MMS, 2003: IV-120) and two 

subsequent EAs (USDOI, MMS, 2004: 41, 2006: 35) concluded that a large spill could affect fewer 
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than 100 walruses, with the population recovering within about 1 year. The net westward movement 

of spills and the chance of spill contact to offshore primary feeding habitats of walruses during the 

summer open-water season (July 1 through October 1) are low, less than 0.5-6%, assuming a spill 

occurred in the Beaufort Sea Planning Area and contacted Ice/Sea Segments 46-51 within 180 days or 

less. Oil contamination of walruses probably would not result in direct mortality of healthy 

individuals. However, contamination could seriously stress diseased or injured animals and stress 

young calves, causing some deaths. Perhaps a small number of walrus calves (fewer than 100) and 

some adults could die from oil contamination, but such a loss is likely to be replaced within 1 year by 

natural recruitment in the population. 

Beluga Whales. Previous analyses in the multiple-sale EIS (USDOI, MMS, 2003: IV-121) and two 

subsequent EAs (USDOI, MMS, 2004: 41, 2006: 35) concluded that a large spill could affect fewer 

than 10 beluga whales, with the population recovering within about 1 year. Beluga whales would be 

most vulnerable to oil contact during the spring migration off Point Barrow. Contamination of the icelead system from an oil slick during spring migration (April-June) could directly expose several 

whales to some oil-spill contact. However, such contact is expected to be brief or intermittent and 

probably would not result in any deaths of healthy whales or have long-lasting sublethal effects after 

short exposure. The probability of oil-spill occurrence and contact to the lead system during the 

spring (May-June) period is very low (less than 0.5%). The likely physical reaction between oil, ice, 

water temperature, and wind off Point Barrow appreciably would reduce the chance of an oil slick 

persisting in the lead system. Therefore, belugas of the western Beaufort population may have some 

contact with an oil spill that would temporarily contaminate the lead system off Point Barrow; 

however, few, if any, beluga whales are likely to be seriously affected, even in a severe situation, with 

no long-term effect on the population. In the context of new information that had become available 

since publication of the multiple-sale EIS, subsequent NEPA conclusions remained consistent; thus 

the updated potential level of effect on beluga whales was expected to be about the same as stated in 

the multiple-sale EIS. 

Spotted Seals. Previous analyses in the multiple-sale EIS (USDOI, MMS, 2003: IV-120) and two 

subsequent EAs (USDOI, MMS, 2004: 41, 2006: 35) concluded that a large spill could affect 10-20 

spotted seals, with the population recovering within about 1 year. In the context of new information 

that had become available since publication of the multiple-sale EIS, those NEPA conclusions 

remained consistent; thus the updated potential level of effect on pinnipeds was expected to be about 

the same as stated in the multiple-sale EIS. 

Marine Mammals Summary. BOEMRE has analyzed and incorporated in this EA the best available 

science published since the Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 

2009 Camden Bay EA and expects the same level of effects from a hypothetical large oil spill 

associated with the Proposed Action as was characterized in these documents. 

Sociocultural Systems. 

The BOEMRE views oil spills as having the potential to cause long term significant effects that 

would disrupt or nearly eliminate subsistence harvests. Oil spills are never permitted and are always 

in violation of the law. Operators would be held accountable and responsible for mitigation and 

monitoring loss or reduction of subsistence species on the local subsistence harvesters. 

Effects on the sociocultural systems of the communities of Barrow, Nuiqsut, and Kaktovik would 

come from changes in population, employment and the effects of the oil spill and clean-up activities 

on subsistence harvests. Community activities and traditional practices for harvesting, sharing, and 

processing subsistence resources could be seriously disrupted in the short term, if there are concerns 

over the tainting of bowhead whales from an oil spill. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 
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Subsistence. 

A good source of information on spill effects is the Social Indicators Study of Alaskan Coastal 

Villages, Volume VI: Analysis of the Exxon Valdez Spill Area, 1988-1992 (Human Relations Area 

Files, Inc., 1994). The summary of findings section affirmed that, immediately after the spill and 

continuing into early 1990, Native people decreased their harvests of wild resources and relied on 

preserved foods harvested before the spill (USDOI, MMS, 2003, p. 153). By the winter of 1991, the 

Natives’ normal harvesting activities had begun to resume, but the proportions of wild foods in their 

diets remained below those of 1989. The study also demonstrated in its analysis that non-Natives and 

Natives “define the environment and resources within the environment very differently. Commodity 

valuation takes precedence” for non-Natives and “instrumental use and cultural and spiritual 

valuation take precedence” for Native people (Human Relations Area Files, Inc., 1994). 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Economy. 

A large oil spill could adversely impact the subsistence lifestyle of the North Slope Borough (USDOI, 

MMS, 2003, p. IV-239). An important segment of the Borough’s economy depends on subsistence 

resources, and a loss of those resources would translate into a substantial decline in noncash 

household income. This would be offset to some degree by employment opportunities associated with 

oil spill response activities. Approximately hundreds of cleanup jobs and associated personal income 

could be created for 1-2 years following a large oil spill. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Public Health. 

Because development and production activities would be enclave based, adverse impacts to the local 

village infrastructure, health care, and emergency response systems are expected to be minimal. 

Demands on local village infrastructure from construction, operation, maintenance, and abandonment 

activities would not be expected, because all these activities would be staged out of Prudhoe Bay. 

Stress created by the fear of a large oil spill is also a distinct predevelopment impact-producing factor 

within the human environment (USDOI, MMS, 2003, IV-C p. 168). Stress from this general fear can 

be broken down to the particular fears of: 

 being inundated during cleanup with outsiders who could disrupt local cultural continuity 

 the damage that spills would do to the present and future natural environment 

 drawn out oil-spill litigation 

 contamination of subsistence foods 

 lack of local resources to mobilize for advocacy and activism with regional, State, and 

Federal agencies 

 lack of personal and professional time to interact with regional, State, and Federal agencies 

 retracing the steps (and the frustrations involved) taken to oppose offshore development 

 responding repeatedly to questions and information requests posed by researchers and 

regional, State, and Federal outreach staff 

 having to employ and work with lawyers to draft litigation in attempts to stop proposed 

development. 
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BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Archaeological Resources. 

Cleanup and support activities, such as mobilizing equipment and personnel, removing soil, washing, 

etc., would have the greatest potential for damaging or destroying archaeological resources (USDOI, 

MMS, 2003, p. 175). Exposure of undocumented sites increases the possibility of vandalism. 

Increased human presence and activity increases the potential for archaeological sites to be 

recognized, resulting in the site having a higher chance of being vandalized. The discovery and 

reporting of archaeological sites during cleanup activities also would result in their being documented 

and protected. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical large oil spill associated with the Proposed 

Action as was characterized in these documents. 

5.8. Very Large Oil Spill Effects 

This section addresses the adequacy of the Beaufort Sea Multiple-Sale EIS very large oil spill 

analysis for the purposes of analyzing this site-specific proposal. A very large oil spill, as defined by 

BOEMRE, is an oil spill with a total volume that is greater than or equal to 150,000 bbls. As 

described in Appendix A, The chance of a very large spill (≥150,000) occurring is very low; however, 

BOEMRE comprehensively analyzed the potential effects of such a spill in the Beaufort Sea 

Multiple-Sale EIS Section IV.I Low-Probability, Very Large Oil Spill. The spill scenario was based 

on a 15,000-bbl flow-rate for 15 days totaling 225,000 bbl. In the unlikely event of a very large 

accidental oil spill, the potential for major impacts exist, as identified in USDOI, MMS (2003). The 

Beafort Sea Multiple Sale EIS spill scenario was based on a 15,000 bbl flow rate for 15 days totalling 

225,000 bbl which is much higher than the WCD for the site-specific scenario analyzed in this EA. 

The following paragraphs describe the effects of a very large oil spill on the identified resources. 

Air Quality. 

A very large oil spill could cause an increase in the concentrations of gaseous hydrocarbons (volatile 

organic compounds) which could affect onshore air quality (USDOI, MMS, 2003, p. IV-245). Any 

effects would be localized and temporary. Concentrations of criteria pollutants would likely remain 

well within Federal and Alaska ambient air quality standards. 

Typical emissions from outer continental shelf accidents consist of hydrocarbons (volatile organic 

compounds); only fires associated with blowouts or oil spill cleanup efforts (in situ burning) produce 

other pollutants, such as nitrogen oxides, carbon monoxide, sulfur dioxide, and particulate matter. 

The cleanup of a very large oil spill would require the operation of some equipment, such as boats 

and vehicles. Emissions from their operation would include nitrogen oxides, carbon monoxide, and 

sulfur dioxide. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Water Quality. 

A very large crude oil spill would cause elevated hydrocarbon concentrations on the ocean water 

surface, in the water column and in coastal riverine waters covering a very large area. These 

concentrations would exceed state and Federal water quality standards and present acute and chronic 

toxic conditions to aquatic organisms (USDOI, MMS, 2003, p. IV-230). Oil would be removed from 
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130 Post Deepwater Horizon Event Environmental Review - Very Large Oil Spill Effects 

the environment during clean-up processes, however, the amount of oil removed would be affected by 

several factors including weather and sea conditions during the clean-up. As oil was removed during 

the clean-up process, there would be less volume available to become dispersed or entrained in the 

environment. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Lower Trophic Levels. 

The spill would adversely affect some lower trophic-level organisms by exposing them to petroleumbased compounds at, or above, acute or chronic toxicity levels (USDOI, MMS, 2003, p. IV-231). An 

oil spill of 225,000 bbls is not expected to have a measurable effect on sub-tidal marine plants (e.g. 

Boulder Patch kelp habitat), which exist at depths lower in the water column than toxic 

concentrations of oil would generally appear. The nearshore area does support mobile benthic and 

epibenthic invertebrates (amphipods, mysids, copepods, euphasiids, clams, snails, crab, and shrimp), 

which are fed on by vertebrate consumers during the summer. If contacted by surface oil, these 

invertebrates are likely to die or be affected at a sub-lethal level. 

Oil that becomes incorporated into shoreline bottom sediments by wave action is expected to remain 

entrained in the sediment for several years. In areas where bottom sediments are heavily oiled, some 

lethal and sub-lethal effects could occur each summer, when seasonal benthic invertebrates return to 

those areas. Other lower trophic-level organisms likely to be contacted by oil in the water column are 

plankton. Because of similarities in habitat use and distribution, the percentage of other marineinvertebrate larva contacted by floating or dispersed oil is likely to be similar to that expected for 

plankton. Some lower trophic-level organisms on the shorelines would be adversely affected by use 

of shore based oil containment booms and other response tactics. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Fish. 

Effects to fishes would be more likely to occur from an oil spill moving into nearshore waters in 

summer, where fishes concentrate to feed and migrate (USDOI, MMS, 2003, p. IV-232). There may 

be sub-lethal or lethal effects on some marine and migratory fish. The number affected would depend 

on the size of the area affected, the concentration of petroleum present, the time and duration of 

exposure, and the stage of fish development involved (eggs, larva, and juveniles are most sensitive). 

While a very large oil spill would be expected to affect about 300 km of nearshore waters, 

particularly in shallow-water lagoons associated with barrier islands, and coastline, it would likely 

have mostly sub-lethal effects (e.g. changes in growth, feeding, fecundity, and temporary 

displacement) on marine and migratory fish. Juvenile fish (e.g. arctic cod), which are common in the 

nearshore area during summer, or nearshore spawners (e.g. capelin) are among the most likely 

candidates to be adversely affected. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Marine and Coastal Birds. 

A very large oil spill could result in marine and coastal bird mortality exceeding a few thousand 

individuals, if brood-rearing waterfowl or shorebirds contact stranded oil along a substantial 

proportion of affected shoreline (USDOI, MMS, 2003, p. IV-236). In lagoon habitats, long-tailed 
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Post Deepwater Horizon Event Environmental Review - Very Large Oil Spill Effects 131

duck densities suggest that when large concentrations of molting individuals are present, tens of 

thousands could be contacted by spilled oil. This would constitute a substantial loss to the regional 

population. Notable losses would also be experienced by post-breeding common eiders concentrated 

near barrier islands and in lagoons. A spill from Sivulliq N would be expected to contact several other 

species present in substantial numbers, including the king eider, scoters, northern pintail, Pacific loon, 

and glaucous gull. Any mortality, decreased fitness or productivity from indirect effects such as 

decreased availability of food a source or physiological effects caused by the ingestion of oil would 

be additive to the losses of oiled individuals. Effects of oil spill clean-up activities would be similar to 

that described for spectacled and Steller’s eiders (below). 

The very large oil spill is expected to cause spectacled and Steller’s eider mortality, if females with 

recently fledged young contact stranded oil in coastal habitats, or flocks of adult eiders or females 

with young feeding in lagoons and offshore waters are contacted by a spill sweeping over thousands 

of square kilometers (USDOI, MMS, 2003, p. IV-234). Any mortality, decreased fitness or 

productivity from indirect effects, such as decreased availability of food sources or physiological 

effects caused by the ingestion of oil, would be additive to the loss of oiled individuals. Mortality of a 

few spectacled and Steller’s eiders also would represent a substantial loss to the small regional 

populations. 

Containment, recovery, and cleanup activities associated with a very large oil spill are expected to 

involve hundreds of workers and numerous boats, aircraft, and onshore vehicles operating over an 

extensive area for more than 1 year. The presence of such a workforce is likely to act as a general 

hazing factor, displacing eiders from the immediate area of activity, perhaps within a few kilometers, 

which potentially might be viewed as a positive result, given the birds’ extreme vulnerability to oil in 

the environment. If a reliable system of locating eiders in a specific area can be devised, specific birds 

or groups in danger of oil contact could be targeted with specific hazing tactics. 

The nest disturbance of spectacled eiders caused by these activities is not expected to result in large 

increases in nest abandonment, loss of eggs through predation or exposure, or overall decrease in 

productivity. The primary reason for this level of effect is the low density of spectacled eiders nesting 

and the low frequency of nesting which occurs near the coast. Displacement by cleanup activity of 

females with broods from coastal habitats may have a negative effect if it prematurely forces them 

into the offshore marine environment where the high salinity could increase stress on the ducklings, 

which have a relatively low tolerance to salt (USDOI, MMS, 2003, p. IV-235). 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Marine Mammals. 

The probability of oil contacting bowhead whales is likely to be considerably less than the probability 

of oil contacting bowhead whale habitat (USDOI, MMS, 2003, p. IV-233). It is unlikely that a spill 

would cause an impediment to the fall migration. The migrating whales could come in contact with 

oil, but such contact likely would be brief. If bowheads feed in an area when spilled oil is present, 

some oil could be ingested. Most individuals exposed to spilled oil are expected to experience 

temporary, nonlethal effects from oiling of the skin, inhaling hydrocarbon vapors, ingesting 

contaminated prey, fouling of their baleen, a reduction in food sources, and a displacement from 

feeding areas. Exposure of bowhead whales to spilled oil could result in lethal effects to some 

individuals. 

The effect of a very large oil spill on other marine mammals is expected to be fairly long term (1-2 

generations, about 15 years) on pinnipeds and short term (about 1 year) on beluga whales (USDOI, 

MMS, 2003, p. IV-238). Assuming that all young ringed and bearded seals exposed to the oil died 

because of absorption (through the skin), inhalation, and/or ingestion of toxic hydrocarbons in the oil, 

this loss could take these marine mammal populations more than one to two generations to recover 
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132 Post Deepwater Horizon Event Environmental Review - Very Large Oil Spill Effects 

(up to about 15 years). Although some beluga whales might encounter spilled oil during the spring 

migration and summer few, if any, are likely to be adversely affected (loss of fewer than 20 whales 

with population recovery in 1 year). 

Polar bears exposed to petroleum hydrocarbons through direct contact or by ingesting oiled prey 

would probably not survive (Neff, 1990; St. Aubin, 1990). The density of polar bears in the Sivulliq 

N drilling area is low, if a spill reaches the environment there is a correspondingly low likelihood that 

polar bears would be exposed. Polar bears generally move offshore with the retreating pack ice while 

the exploratory drilling will take place in open-water. In the event of oil reaching the environment, it 

is likely that polar bears would be intentionally deterred to keep them away from the area, further 

reducing the likelihood of bears contacting the oil. Impacts associated with a very large oil spill 

would depend upon the time of year, weather conditions, clean up efforts and the efficiency of hazing 

bears away from the spill. Exposure would likely be limited to a small number of polar bears, 

resulting in the death of some bears that come into contact with oil. Large aggregations of bears 

periodically gather on shore during August through October near Point Barrow, Cross Island and 

Kaktovik. If a very large oil spill occurred during this time as many as 60-100 polar bears may be at 

risk of exposure. 

Terrestrial Mammals. The potential effect of a very large oil spill on terrestrial mammals including 

caribou, muskoxen, grizzly bear, and arctic fox is likely to be limited to caribou groups during the 

insect relief periods in coastal waters near shorelines with extensive oil contamination (USDOI, 

MMS, 2003, p. IV-239). Heavily oiled caribou might die from skin absorption and/or inhalation of 

toxic hydrocarbons. Small numbers of muskoxen, grizzly bear, and arctic fox may encounter oil and 

be adversely affected. Potential losses would represent a short-term effect, with populations 

recovering within 1 year. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Vegetation. 

Coastal wetlands and coastal salt marshes would comprise the vegetation habitats most likely to be 

affected by a very large oil spill (USDOI, MMS, 2003, p. IV-239). Marshy wetland habitats could be 

partially rehabilitated by using fertilizers to aid in biological weathering-breakdown of the oil, but 

recovery would be slow due to cool temperatures in summer and the short growing season. Complete 

recovery of oiled coastal wetlands could take several decades. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Sociocultural Systems. 

A very large oil spill would affect sociocultural systems in a number of ways including associated 

effects from significant effects to subsistence harvest resources which could lead to a breakdown of 

kinship networks and sharing patterns and increased social stress in the community (USDOI, MMS, 

2003, p. IV-243). A disruption of the kinship networks (i.e., social organization) could lead to a 

decreased emphasis on the importance of the family, cooperation, and sharing. Other effects might be 

a decreasing emphasis on subsistence as a livelihood, with an increased emphasis on wage 

employment, individualism, and entrepreneurism. Effects on the sociocultural system, such as 

increased drug and alcohol abuse, breakdown in family ties, and a weakening of social well-being, 

could lead to additional stresses on the health and social services available. Employment for oil-spill 

response and cleanup could disrupt subsistence harvest activities and disrupt some institutions and 

sociocultural systems. Employment opportunity increases associated with oil spill response activities 
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could have sudden and negative effects, including inflation and displacement of Native residents from 

their normal subsistence-harvest activities. Impacts could alter normal subsistence practices and put 

stresses on local village infrastructures by drawing workers away from village service jobs. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Subsistence Activities. 

Subsistence-harvest activities such as bird hunting, sealing, whaling, and the ocean netting of fish 

could be affected by a spill during the open-water season (USDOI, MMS, 2003, p. IV-240). A very 

large oil spill could threaten subsistence-harvest patterns, if the spilled oil contacts subsistenceresource and harvest areas. It is possible, although not likely, that the bowhead whale harvest might 

not be curtailed, but that the quota could be reduced for possibly 2 years, resulting in significant 

effects on the bowhead whale harvests for affected communities, making the bowhead less available 

for use or undesirable for an extended period. Lethal and sub-lethal effects on seals, polar bears, and 

fish would also result from a very large oil spill. 

The harvest of many subsistence species would require up to one or two generations for recovery due 

to population changes in abundance and/or distribution. Bearded seal harvests are not likely to occur 

during the season in which a spill occurred. In following years, harvests would be expected to occur 

in greatly reduced numbers. Marine and coastal bird harvests could also be reduced. Fish harvest, 

particularly in river delta areas and along the coast, would be expected to be available but in reduced 

numbers for 1 year before it returned to normal levels. It also is likely that for all subsistence 

resources, there could be reluctance to harvest any marine resources due to a perceived tainting from 

oil. Tainting could affect a wider area than the actual area of contact, as seals and whales move 

among resource areas; an animal oiled in one location potentially could be harvested in another area, 

well outside of the spill area. 

Disturbance to bowhead whales, seals, polar bears, caribou, fish, and birds potentially could increase 

from oil spill cleanup activities. In the offshore environment, cleanup vessels, workboats, barges, 

aircraft over flights, and in situ burning could cause whales to temporarily alter their migratory route. 

This displacement could cause some animals, including seals in ice-covered or broken-ice conditions, 

to avoid areas where they are normally harvested or to become more wary and difficult to harvest. In 

the nearshore and onshore environments, workers, boats, support vehicles, heavy equipment, and the 

intentional hazing and capture of animals could disturb coastal resource habitat, displace subsistence 

species, alter or reduce subsistence hunter access to these species, and alter or extend the normal 

subsistence hunt. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Economy. 

A very large oil spill could adversely impact the subsistence lifestyle of the North Slope Borough 

(USDOI, MMS, 2003, p. IV-239). A substantial segment of the Borough’s economy depends on 

subsistence resources, and a loss of those resources would translate into a substantial decline in 

noncash household income. This would be offset to some degree by employment opportunities 

associated with oil spill response activities. Approximately 3,000 cleanup jobs could be created for 1-

2 years following a very large oil spill. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 
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134 Post Deepwater Horizon Event Environmental Review - Oil Spill Response 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

Archaeological Resources. 

Offshore archaeological resources would likely not be disturbed by an offshore oil spill or from 

cleanup activities associated with an offshore oil spill (USDOI, MMS, 2003, p. IV 244). Known and 

previously undiscovered archaeological sites onshore would be vulnerable to inadvertent direct or 

indirect disturbance and increased vandalism. 

5.9. Oil Spill Response 

The BOEMRE reviewed Shell's Beaufort Sea Regional Exploration Oil Discharge Prevention and 

Contingency Plan (ODPCP) to ensure that the plan adequately addressed lessons learned from the 

Macondo / Deepwater Horizon incident and subsequent oil spill. The review also included additional 

prevention and response measures proposed by Shell. A summary of this review and the effectiveness 

of various response methods is provided in the paragraphs 5.6.1 through 1.5.3. 

BOEMRE has analyzed and incorporated in this EA the best available science published since the 

Beaufort Sea Multiple-Sale EIS, the Sale 195 and Sale 202 EA’s and the 2009 Camden Bay EA and 

expects the same level of effects from a hypothetical very large oil spill associated with the Proposed 

Action as was characterized in these documents. 

5.9.1. Oil Spill Discharge Prevention and Contingency Plan (ODPCP) 

As required by both Federal and State regulations, Shell has developed and would implement a 

comprehensive Oil Discharge Prevention and Contingency Plan (ODPCP) (Shell, 2011) during its 

exploration drilling operations. The ODPCP must be reviewed and approved by both Federal and 

State regulators to ensure that Shell has the spill-response resources necessary to respond to any spill 

that might occur. 

Shell’s Beaufort Sea Regional Exploration ODPCP is a regional oil-spill-response plan that 

demonstrates Shell’s capabilities to prevent, or rapidly and effectively manage, oil spills that may 

result from exploratory drilling operations. Despite the extremely low likelihood of a large oil-spill 

occurring during exploration, Shell has designed its response program for a regional capability of 

responding to a range of spill volumes that increase from small operational spills up to and including 

a Worst Case Discharge (WCD) scenario from an exploration well blowout, as required under 30 

CFR 254.47. Shell’s program is based on a WCD scenario that meets the response planning 

requirements of the State of Alaska and Federal oil-spill-planning regulations. 

Shell has designed its response program based on a regional capability of responding to a worst case 

discharge (WCD) from an exploration well blowout. A dedicated Oil-Spill Response Barge (OSRB) 

would be staged in the vicinity of the drilling vessel when critical drilling operations into 

hydrocarbon-bearing zones are underway and possess sufficient capacity to provided containment, 

recovery, and storage for the initial operational period. Two vessel of opportunity skimming systems 

(VOSS) would also be employed to assist with containment and recovery operations. Shell also will 

mobilize an OSRB from operations in the Chukchi Sea to be on-site within 42 hours following 

notification to further support containment and recovery operation. An arctic oil storage tanker (OST) 

would arrive at the recovery site to provide interim storage of recovered fluids. The OST would 

possess sufficient capacity to store all recovered petroleum hydrocarbons from a 30-day blowout. 

Skimming and lightering operations would be conducted on a 24-hour basis ensuring uninterrupted 

recovery operations as skimming vessels transfer recovered fluids to the OST on a rotational basis. 

Shell’s primary response action contractors are Alaska Clean Sea (ACS) and Arctic Slope Regional 

Corporation Energy Services - Response Operations, LLC (AES-RO). The AES-RO’s response 

personnel and oil-spill-response equipment would be maintained on standby while critical drilling 

operations into hydrocarbon-bearing zones are underway; and provide offshore response operations in 

the unlikely event of an oil-spill incident. The ACS provides manpower and equipment resources 
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Post Deepwater Horizon Event Environmental Review - ODPCP 135

from Deadhorse for Beaufort Sea spill containment and recovery. The ACS and AES-RO would 

conduct response activities in both open ocean and near shore environments using the ACS Technical 

Manual and the Shell Beaufort and Chukchi Seas Regional Tactics Manual. 

5.9.2. Additional Pollution Prevention and Response Measures 

In addition to the maintenance and implementation of its ODPCP, Shell committed to implement the 

measures described under Pollution Prevention Measures in the 2009 Camden Bay EA (USDOI, 

MMS, 2009a, p. 29-30) to further minimize the chance of an oil spill that might impact marine 

mammals and interfere with the subsistence hunt. 

In a letter to Shell on May 6, 2010, MMS requested that Shell identify additional measures that it 

would take to prevent or respond to a loss of well control event. Shell’s response to MMS, dated May 

14, 2010, which was reaffirmed in its response to Notice-to-Lessees (NTL) 2010-N06, included a 

number of mitigation measures listed above in Section 2.3.12, Other Mitigation and Section 5.5.2, 

Measures to Prevent Oil Spills. Many of these measures address mechanical and operations aspects of 

prevention and response. One technique, the development and deployment of a prefabricated sub-sea 

collection system with surface separation capability to capture and dispose of oil from a flowing well 

before it reaches the surface, is examined below. 

Sub-sea Containment System. BOEMRE issued NTL 2010 - N10 on November 8, 2010 that 

encouraged, but did not require, operators to revise their oil spill contingency plans to provide 

information on sub-sea containment and capture equipment to meet the requirements of 30 CFR 

250.254.23 and 30 CFR 250.26(d)(2). A sub-sea containment system is not required or necessary for 

Shell to comply with the existing 30 CFR 254 regulations for its proposed 2011 exploratory drilling 

program. Although the NTL does not require that operators submit revised Oil Spill Response Plans 

that include this containment information at this time, operators were notified of BOEMRE’s 

intention to evaluate the adequacy of each operator to comply in the operator’s current OSRP.. 

Shell has committed to having a pre-fabricated sub-sea collection system with surface capability to 

capture and dispose of oil. Shell has indicated that this system is in final design. Following 

construction, it will be staged on and OSRB. The selection of a final staging location will be 

dependent on logistics, permit considerations, local community interest and support, and 

infrastructure best suited for deployment. BOEMRE will require Shell to revise their ODPCP to 

document the staging location and deployment schedule for this system. BOEMRE will also require 

Shell to deploy and function-test the system prior to commencement of drilling activities. 

The use of a sub-sea containment device (containment dome) is not technically complicated. USDOI, 

MMS (1985) concluded that; 1) such a system is viable within existing technology and 2) most major 

components for such a system are available and have been field tested in various offshore oil and gas 

procedures and applications. 

Sub-sea containment technology has been successfully used in the past. Shell has prior experience 

with containment domes in the Gulf of Mexico. Shell used a containment dome in 20 ft of water to 

capture oil leaking from the damaged “Nakika” line while repairs were being performed (Coyne et al. 

2005, p.3). Shell also used a containment dome to capture oil from the Mars pipeline in 2,700 feet of 

water after it was damaged during Hurricane Katrina (Povloski , 2008). Taylor Energy used a 

containment dome to collect leaking oil from wellheads buried in a mudslide during Hurricane Ivan 

(AP, 2010). These examples are not directly comparable to a loss of well control event where large 

volumes of fluids and gas flow, but represent successful deployment and use of this technology. 

An oil spill containment structure was unsuccessfully deployed during the 1979 Ixtoc blowout. The 

dome used for the Ixtoc well was undersized and did not cover the well completely, allowing oil to 

leak out around the bottom of the containment structure (USDOI, MMS, 1999, p. 28-29). 

A containment dome was also used during the 2010 Macondo blowout. In the first attempt, methane 

hydrates crystallized and blocked flow through the riser to the surface. Following a redesign of the 
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136 Post Deepwater Horizon Event Environmental Review - Effectiveness of Oil Spill Response 

dome, a second system was successfully deployed and resulted in a collection rate of 15,000 barrels 

per day (PCR, 2011). 

There are substantial differences between the Ixtoc and Macondo incidents and Shell’s (2011) 

proposed Sivulliq and Torpedo exploratory program. These include: 

 New regulatory requirements for estimating worst case discharge volumes provide a better 

understanding of potential well control dynamics (flow rates and fluid properties) that can 

be factored into designing a containment system. 

 Constructing and pre-staging the containment system shortens response times and allows 

for pre-testing of the operability and functionality of the system. 

 The Sivulliq and Torpedo drill sites are in 107-124 feet of water where deployment and 

operation of the system would be less complicated than were experienced in the deep 

water Macondo well. 

 Shell will have dedicated support vessels on site to assist in deployment of the system, and 

will not need to identify and mobilize new assets. 

 Hydrates are not expected to occur from the Sivulliq or Torpedo wells: hydrate formation 

during the Macondo blowout was a result of high pressures and associated low 

temperatures found at water depths greater than 300 meters. Water temperatures at Sivulliq 

or Torpedo drill sites will be approximately 0° C. At this temperature, a water depth of 

nearly 1000 ft would be required to enable hydrates to form. 

In summary, Shell’s proposed subsurface collection system will be an added tool for responding to a 

potential well control incident where fluids flow and will increase response preparedness, but is not 

necessary or required to comply with 30 CFR 254.23 and 30 CFR 354.26(b)(2). Shell has the 

equipment and resources to contain and clean up the worst case discharge volume calculated for the 

Torpedo H exploratory well without a subsea containment system. 

5.9.3. Effectiveness of Oil Spill Response. 

Oil spill response capabilities are continually being improved as technological advances are applied to 

detection, containment, recovery and removal of spilled oil. There are many different types of 

countermeasures available to contain and remove or mitigate oil that has entered the environment. 

Response options can be grouped in four major categories: oil booms (for excluding, containing and 

directing floating oil); skimmers (for collecting oil); dispersants (for breaking down the molecular 

structure of the oil to increase dissolution and biodegradation) and in situ burning (for rapidly 

removing large quantities of oil from surface waters). 

The effectiveness of each countermeasure varies widely as a function of the environmental 

conditions, type of oil spilled, and the weathered state of the oil. In general, the effectiveness of the 

most common oil spill countermeasures is shown in Table 21 (USDOI, MMS, 2002). 

Table 21 Effectiveness of oil spill countermeasures 

Countermeasure Method Effectiveness (%) 

Booms and skimmers 10 – 20 

Dispersants 30 - 40 

In Situ Burning1 90 - 98 

Notes: 1 Assumes that burning is initiated soon after the spill before the oil emulsifies 
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Consultation and Coordination - Endangered Species Act Consultation 137

6.0 CONSULTATION AND COORDINATION 

The BOEMRE considered the resources and species that could potentially be affected by Shell’s 

proposed activities and three consultations were required for: 

 Federally listed or proposed threatened/endangered species (or those species’ designated 

proposed critical habitat) as defined by the Endangered Species Act (ESA). 

 Essential Fish Habitat as defined by the Magnuson-Stevens Fishery Conservation and 

Management Act (MSFCMA). 

 The protection of historic properties as defined by the National Historic Preservation Act 

(NHPA). 

6.1. Endangered Species Act Consultation 

Section 7(a)(2) of the ESA requires each Federal agency to ensure that any action they authorize, 

fund, or carry out is not likely to jeopardize the continued existence of a listed species or result in the 

adverse modification of designated critical habitat. The BOEMRE consults with FWS and NMFS for 

listed species under each Service’s jurisdiction. 

The BOEMRE completed formal consultation with NMFS, Alaska Region, on the potential effects of 

OCS oil and gas leasing and exploration on the Beaufort Sea and Chukchi Sea. NMFS provided a 

Biological Opinion (BO) for Oil and Gas Leasing and Exploration Activities in the U.S. Beaufort and 

Chukchi Seas, Alaska and Authorization of Small Takes Under the Marine Mammal Protection Act 

(USDOC, NOAA, NMFS, 2008). The BO considers the effects of oil and gas leasing and exploration 

on threatened and endangered species under the jurisdiction of NMFS. The NMFS concluded the 

described actions are not likely to jeopardize the continued existence of the fin, humpback, or 

bowhead whale. 

The December 2010, NMFS proposal (75 FR 77476) to list ringed seals and the Beringia DPS of 

bearded seals as threatened under the ESA requires BOEMRE to evaluate the likelihood that the 

proposed action would jeopardize the continued existence of these ice seals. BOEMRE has 

concluded that the proposed action would not jeopardize the continued existence of these ice seals 

and further consultation is not required under the ESA. 

The BOEMRE completed formal consultation with FWS, Alaska Region, on the potential effects of 

OCS oil and gas leasing and exploration in the Beaufort and Chukchi Seas to affect listed species 

under FWS jurisdiction. The FWS provided a BO for Beaufort and Chukchi Sea Program Area Lease 

Sales and Associated Seismic Surveys and Exploratory Drilling dated September 3, 2009 (USDOI, 

FWS, 2009). The FWS concluded that it is unlikely that seismic survey and exploratory drilling 

activities will violate section 7(a)(2) of the ESA. The FWS determined that adverse effects on listed 

species are anticipated. In the BO, FWS provided incidental take authorization for listed eiders and 

requires incidental take of polar bears to be authorized under the MMPA. 

The FWS designated polar bear critical habitat in December 2010 (75 FR 76086) and the BOEMRE 

has reinitiated formal consultation regarding the potential for the proposed action to destroy or 

adversely modify designated polar bear critical habitat. Based on the analysis in this EA, BOEMRE 

has preliminarily concluded that the proposed action would not destroy or adversely modify 

designated polar bear critical habitat. These findings are part of a new draft Biological Evaluation 

being prepared by BOEMRE for conveyance to FWS in the near future. 

The Pacific walrus was designated a candidate species under the ESA on 10 February 2011 (76 FR 

7634). While not required by the ESA, BOEMRE has initiated conferencing with the FWS regarding 

the potential for the proposed action to affect the Pacific walrus. Based on the analysis in this EA, 

BOEMRE has preliminarily concluded that the proposed action would not jeopardize the continued 

existence of the Pacific walrus. These findings are part of a new draft Biological Evaluation being 

prepared by BOEMRE for conveyance to FWS in the near future. 
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138 Consultation and Coordination - Reviewers and Preparers 

Under the ESA, no incidental take of a protected species is authorized unless an Incidental Take 

Statement (ITS) is issued by the NMFS or FWS for the proposed activity. Any approval of Shell’s 

EP will be a conditional approval. Under the conditional approval, an APD will not be approved and 

commencement of activities will not be authorized until appropriate ITSs from both NMFS and FWS 

have been issued. Conditional approval of the APD will also include any relevant Reasonable and 

Prudent Measures and associated Terms and Conditions required through the ESA consultation 

process and does not foreclose the formulation or implementation of any Reasonable and Prudent 

Alternatives. 

6.2. Essential Fish Habitat Consultation 

The Magnuson-Stevens Fishery Conservation and Management Act (MSFCMA) (16 U.S.C. 1801-

1884) mandated the identification of Essential Fish Habitat (EFH) for managed species as well as 

measures to conserve and enhance the habitat necessary to fish to carry out their lifecycles. The 

MSFCMA requires cooperation among the National Marine Fisheries Service (NMFS), the Fishery 

Management Councils, fishing participants, Federal and State agencies, and others in achieving EFH 

protection, conservation, and enhancement. 

BOEMRE conducted its most recent EFH consultation on Pacific salmon species for OCS exploration 

activities in the Beaufort Sea in 2009, concurrent with the preparation and public review of the Arctic 

Beaufort and Chukchi Sea Planning Areas Draft EIS (MMS, 2008). The BOEMRE received NMFS’ 

conservation recommendations in a letter dated June 26, 2009. Arctic cod EFH consultation for the 

drilling proposed by Shell in Camden Bay in 2012 and 2013 (and possibly subsequent open-water 

seasons) is currently being conducted in a separate EFH document. The determination of effects on 

EFH will be stated in that consultation document. 

6.3. Marine Mammal Protection Act 

Shell has applied for an Incidental Harassment Authorization (IHA) from the NMFS (dated May 

2011) and a Letter of Authorization from the USFWS (dated May 2011) as a component of the 2011 

Camden Bay Exploration Plan (Appendix C and E, respectively). Shell proposed to incorporate 

mitigation measures specifically designed to prevent or minimize any incidental harm to marine 

mammals. Those measures are summarized in Section 2.3.11 of this EA. 

To ensure compliance with the Marine Mammal Protection Act (MMPA), BOEMRE is requiring 

Shell to obtain an incidental take authorization (ITA) from NMFS and FWS —which could be in the 

form of an incidental harassment authorization (IHA) or letter of authorization (LOA)—before Shell 

commences BOEMRE-permitted exploration activities. Mitigation measures are included in the ITA 

to ensure the least practicable adverse impact on marine mammal species or stocks, and their habitat, 

and to ensure that potential impacts to marine mammals will be negligible and have no unmitigable 

adverse impacts on the availability of marine mammals for subsistence uses. 

6.4. National Historic Preservation Act 

Section 106 consultation, as required by the National Historic Preservation Act, is ongoing with the 

preparation of this EA. On June 29, 2011, BOEMRE concluded Section 106 consultation with the 

Alaska State Historic Preservation Officer (SHPO). BOEMRE informed the SHPO of the 

determination that drilling of the four wells and related activities will have no effect on historic 

properties. The SHPO concurred with this finding on June 6, 2011. 

6.5. Reviewers and Preparers 

As required by 40 CFR 1506.5(a)(b), the persons responsible for the review of Shell’s EP, supporting 

information and analysis, and the preparation of this EA are listed below: 

Name Title 

Jerry Brian Socioeconomic Specialist 

Chris Campbell Sociocultural Specialist 
Shell 2012 Camden Bay EP EA

Consultation and Coordination - Public Involvement 139

Nancy Deschu Fisheries Biologist 

Dan Holiday Biological Oceanographer 

James Lima Supervisory Environmental Protection Specialist 

Virginia Raps Meteorologist 

Mark Schroeder Wildlife Biologist 

Kirk Sherwood Geologist 

Caryn Smith Oceanographer 

Bill Swears Technical Editor 

Joseph Talbott NEPA Coordinator 

6.6. Public Involvement 

On Wednesday, May 11, 2011 BOEMRE posted the Shell Offshore Inc. Camden Bay Revised 

Exploration Plan at: http://alaska.boemre.gov/ref/ProjectHistory/2012Shell_BF/2012x.HTM. This 

project is similar in detail to the previously approved Shell Offshore Inc. 2010 Exploration Plan for 

Camden Bay at: http://alaska.boemre.gov/ref/ProjectHistory/Shell_CamdenBF/

2009_final_EP_camden_bay.pdf. 

On Tuesday, July 5, 2011 BOEMRE posted the Notice of Preparation of an Environmental 

Assessment for a 2012 Shell Camden Bay Revised Exploration Plan to the BOEMRE/Alaska website 

at: http://www.alaska.boemre.gov/ref/ProjectHistory/2012Shell_BF/2012x.HTM. Copies of the notice 

were distributed to stakeholders concurrently with this posting. Comments on the Notice of 

Preparation were received through midnight July 15, 2011. 

The BOEMRE received comments on the Notice of Preparation from the North Slope Borough, the 

Northwest Arctic Borough, The Marine Mammal Commission, and a consortium of environmental 

advocacy organizations. The comments were then aggregated and summarized for use in the EA 

analyses and by the decision-maker. 

Public participation relating to Shell’s proposed 2012 activities has been provided through a 

combination of notification of the receipt of an application and a notice of the preparation of an EA. 

Opportunities for public input on exploratory drilling in the Arctic OCS and related issues have also 

been provided during several prior NEPA processes. 
Shell 2012 Camden Bay EP EA

140 Consultation and Coordination 

Page Intentionally Left Blank 
Shell 2012 Camden Bay EP EA

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APPENDIX A 

ANALYSIS OF ACCIDENTAL OIL SPILLS
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i

Appendix A 

Table of Contents 

A. Oil-Spill Analysis and Scenario Framework of Accidental Oil Spills in this 

Environmental Assessment..........................................................................................................A-1

A-1.1. Summary: Estimated Accidental Spills by BOEMRE Size Categories. ...............A-1

A-1.2. Oil-Spill Volume and Type Estimates. .................................................................A-2

A-1.3. Historical and Modeled Oil Spill Information. .....................................................A-4

A-1.4. Oil-Spill Analysis Framework. ...........................................................................A-11

A-1.5. References...........................................................................................................A-17
Page Intentionally Left Blank 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - BOEMRE Size Categories A-1

A. OIL-SPILL ANALYSIS AND SCENARIO FRAMEWORK OF 

ACCIDENTAL OIL SPILLS IN THIS ENVIRONMENTAL 

ASSESSMENT. 

This Appendix describes the results of the oil-spill analysis and the supporting documentation for 

those results. The-oil-spill analysis considers the potential accidental oil spill discharges, their 

likelihood of occurrence, and then outlines the accidental oil spill scenario framework for the impact 

analysis of the alternatives in this EA. The vessel, drilling, and fuel-transfer activities described in the 

Exploration Plan (EP) for the proposed action were evaluated for both routine operations and accident 

conditions. It is not anticipated that oil spills occur as a routine activity, and, therefore are not a 

routine impact-producing factor. Oil spills are considered an accidental activity and are treated as an 

accidental impact-producing factor. An accident is an unplanned event or sequence of events that 

results in an undesirable consequence. 

The BOEMRE carefully and thoroughly analyzed a range of oil spill sizes (from small (<1,000 bbl) to 

very large (≥150,000 bbl)) and the likely consequences to environmental, social, and economic 

resources in the Beaufort Sea Multiple-Sale EIS, from which this EA tiers. The BOEMRE updated 

those oil spill and impact analyses in the Sale 195 EA, the Sale 202 EA, the Arctic Multiple Sale 

Draft EIS (especially the Beaufort Sea fault-tree information) and the 2007 and 2009 Camden Bay 

EAs, which this EA incorporates by reference. This Appendix also incorporates by reference the most 

recent information on OCS well-control incidents from the Revised LS 193 SEIS, and the 2011 

Camden Bay EIA. Brief summaries, where relevant, are provided below; the information is updated 

and augmented by new material as needed. 

Section 1.1 below begins with the summary of estimated oil spill factors (size, source, oil type, 

duration, likelihood of occurrence, weathering characteristics) used in the accidental oil spill scenario 

for the no action and proposed action alternatives in this EA. The remainder of this Appendix 

provides the information supporting the estimated oil spill factors used for accidental oil-spill analysis 

in this EA. 

A-1.1. Summary: Estimated Accidental Spills by BOEMRE Size Categories. 

For purposes of the no action alternative oil spill analysis, no small, large, or very large spills are 

estimated to occur in the proposed action area because no exploration activities occur. 

For purposes of the proposed action alternative oil spill analysis, it is likely that a small spill could 

occur and is reasonably foreseeable. For purposes of analysis, BOEMRE estimates a 48-bbl diesel 

fuel-transfer spill for the volume and type of a small spill, as identified in Shell’s Beaufort Sea Oil 

Discharge Prevention and Contingency Plan Revision 1 (ODPCP) summary of potential discharges 

(Shell Offshore Inc. 2011c, Table 2-1). 

For purposes of the proposed action alternative oil spill analysis, no large or very large crude or diesel 

oil spills are estimated from exploration activities based on a review of potential discharges, historical 

oil spill and modeling data, and likelihood of oil spill occurrence. This estimate is based on (1) the 

low rate of OCS exploratory drilling well-control incidents spilling fluids per well drilled; (2) since 

1971 one OCS spill (large and very large) has occurred during temporary abandonment while drilling 

more than 15,000 exploratory wells;(3) the low number (four) of exploration wells being drilled from 

this proposed action; (4) no crude oil would be produced and the wells would be permanently plugged 

and abandoned; (5) the history of exploration spills on the Arctic OCS, all of which have been small, 

and (6) pollution prevention and oil spill response regulations and methods, implemented by USDOI, 

BOEMRE and Shell Offshore Inc. respectively, since the Deepwater Horizon event discussed in 

Section 5.0 of this EA. 

A-1.1.1. Summary: Small Spills (<1,000 bbl) from Exploration Operations. 

Historical Beaufort Sea and Chukchi Sea OCS exploration spill data suggest a small spill is likely. 

Thirty five exploration wells were drilled in the Arctic OCS; 35 small spills have occurred spilling a 
2012 Shell Camden Bay EP EA 

A-2 Oil Spill Analysis - Oil-Spill Volume and Type Estimates

total of 26.7 bbl of which 24 bbl was recovered. The most likely cause of a small oil spill during 

exploration could be operational, such as a hose rupture, and the spill could be relatively small. The 

largest Arctic OCS exploration spill was approximately 20 bbl (Section 1.3.1). For purposes of 

analysis, a 48-bbl diesel fuel-transfer spill was estimated as the small spill volume and oil type, and it 

is estimated to last less than 3 days on the surface of the water, based on oil weathering model 

calculations. Section 4.0 of this EA analyzes the impacts of such a small spill in each of the EA 

sections on oil spill impacts to specific resources. Lease Stipulation 6 and Shell’s operating 

procedures require pre-booming during fuel transfers, which would reduce or negate adverse effects 

from a small 48-bbl diesel fuel-transfer spill. 

A-1.1.2. Summary: Large Spills (≥1,000 bbl) from Exploration Operations. 

For purposes of Shell’s proposed exploration drilling program starting during the 2012 open-water 

season, OCS historical crude and condensate spill data demonstrates that a large spill is an unlikely 

occurrence of Shell’s proposed exploration project. No oil will be produced. All wells will be 

permanently plugged and abandoned in accordance with BOEMRE requirements on completion of 

drilling. Since 1971, one OCS spill (large and very large) has occurred during temporary 

abandonment from a well-control incident while drilling approximately 15,000 OCS exploration 

wells. All fuel-storage tanks will be internal to the drillship or Mobile Offshore Drilling Unit, and 

should an internal storage tank rupture internally, it is unlikely a large diesel fuel spill would reach 

water. A large spill from internal diesel fuel tanks or a well-control incident is unlikely in connection 

with the exploration activities set forth in Shell’s EP, and therefore, this EA does not analyze the 

impacts of such a scenario, but tiers to previous analysis of large spills as discussed in Section 5.0 of 

this EA. 

A-1.1.3. Summary: Very Large Spills (≥150,000 bbl) from Exploration Operations. 

A very large oil spill from a well-control incident during OCS exploratory drilling is a similarly 

unlikely occurrence. There is no absence of reliable scientific data on the chance of an exploration 

well-control incident occurring, and further support for this conclusion is set forth below. A very 

large spill from a well-control incident is unlikely in connection with the exploration activities set 

forth in Shell’s EP, and therefore, this EA does not analyze the impacts of such a scenario, but tiers to 

previous analysis of very large spills as discussed in Section 5.0 of this EA. 

The BOEMRE analyzed the potential impacts of a very large spill from a well-control incident (OCS 

EIS/EA MMS 2003-001 at IV-228 to IV-247) and the conclusions of that analysis are found in 

section 5.0 of this EA. There are no site-specific anomalies that differentiate a very large spill release 

at Launch Area (LA) 12 analyzed and from LA15 where Shell’s leases occur, and the oil-spill 

contacts are statistically similar. Thus, BOEMRE has analyzed the potential impacts from a very large 

well-control incident where fluids are released into the Beaufort Sea and incorporates that analysis by 

reference (see Section 5.0 of this EA). This impact analysis in USDOI, MMS (2003) considers the 

mitigation of spill response. Shell’s ODPCP response scenario addresses the potential immediate 

release of crude oil to the environment by a loss of well-control during drilling. Shell’s ODPCP 

demonstrates that access to sufficient equipment and personnel needed to respond to a well blowout 

flow rate of 16,000 barrels of oil per day (bopd) for 30 days. 

A-1.2. Oil-Spill Volume and Type Estimates. 

Oil spills are an issue of great public concern in relation to the offshore oil and gas industry. Etkin 

(2009) estimates that petroleum industry spillage has decreased over the last 40 years; 70 percent less 

oil is spilling since the 1970s and 54 percent less in the decade 1998-2007 from the previous. 

Although oil spill volumes are decreasing, even with consumption of oil increasing, the Deepwater 

Horizon Event has heightened the public’s awareness to the potential impacts of very large oil spill 

events. 

Using information from Shell’s Beaufort Sea ODPCP, the BOEMRE reviewed and evaluated 

available information regarding the small, large, and very large oil spill volume estimates, oil spill 

types and the likelihood of the potential discharges, to determine a reasonably foreseeable spill 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - Worst-Case Discharge Calculation for the Oil Spill Response Plan A-3

analysis. The analysts used the reasonably foreseeable spill analysis to evaluate the potential oil spill 

impacts on their resources for this EA. 

A-1.2.1. Oil Spill Potential Discharge Volume. 

The BOEMRE used Shell’s potential discharge volumes, summarized below in Table A-1, as the 

likely spill volume and oil type for each of BOEMRE’s small (<1,000 bbl), large (≥1,000 bbl), and 

very large (≥150,000 bbls) spill size categories (Shell Offshore Inc., 2011c, Table 2-1). Within each 

of BOEMRE’s spill-size categories, the estimated potential discharge volume is considered the 

representative volume for that size category without pollution prevention and oil spill response 

measures. A 48-bbl diesel-transfer spill is the estimated volume of a small spill; a 1,555-bbl dieselfuel tank-rupture spill is the estimated volume of a large spill, and the blowout worst-case discharge 

of 480,000 bbl is in the estimated volume of very large spill without pollution prevention and oil spill 

response measures. The paragraph below describes why and how Shell calculated the worst-case 

discharge (WCD) and BOEMRE’s verification of the WCD. 

Table A-1 Summary of Potential Discharge Volumes and Relation to BOEMRE Spill Size Categories 

for Oil-Spill Analysis. 

BOEMRE 

Spill-Size 

Categories 

Type Cause Product Size Duration Prevent Potential Discharge

Small 

<1,000 bbl 

Transfer 

from fuel 

barge to 

drill 

vessel 

Hose rupture Diesel 

Approximately 

2,000 gallons 

48 bbl 

(Section 1.6) 

5.5 minutes 

(ODPCP 

Section 1.6) 

Transfer procedures in place; 

minimized by the weather restrictions, 

during unfavorable wind or sea 

conditions. Transfers are announced in 

advance; and verbal communication, in 

combination with visual inspection, is 

the best method of discharge 

detection. Booming is in place during 

transfer. 

Large 

≥1,000 bbl 

Diesel 

Tank Tank rupture Diesel 1,555 bbl Minutes to hours 

The diesel tanks are internal to each 

drilling vessel rather than deckmounted, where the potential for 

marine spills is much greater. As a 

result, a scenario involving tank 

rupture has not been included in the 

oil-spill-response plan, but will be 

monitored as part of an ongoing tank 

inspection program. 

Very Large 

≥150,000 bbl Blowout 

Uncontrolled 

flow at the 

mudline Crude oil 480,000 bbl 30 days 

(ODPCP 

Section 1) 

Blowout prevention equipment and 

related procedures for well-control. 

Layer I includes proper well planning, 

risk identification, training, routine 

tests, and drills on the rig. Layer II 

includes early kick detection and timely 

implementation of kick-response 

procedures. Layer III involves the use 

of mechanical barriers, including, but 

not limited to, blowout preventers, 

casing, and cement. Testing and 

inspections are performed to ensure 

competency. Shell (2011c): ODPCP 

Section 2.1.8 

Source: USDOI, BOEMRE, 2011. 

A-1.2.2. Worst-Case Discharge Calculation for the Oil Spill Response Plan. 

The BOEMRE regulations set forth how the volume for a WCD calculation is determined for an oilspill-response planning scenario (30 CFR and 254.47(b) and 250.213(g)). The WCD volume and 

storage capacities are calculated to address BOEMRE’s need to determine the adequacy of the 

company’s spill-response capabilities and are shown in Table A-2. 
2012 Shell Camden Bay EP EA 

A-4 Oil Spill Analysis - Historical and Modeled Oil Spill Information

Table A-2 Estimates of WCD Volume by Citation and Source. 

Citation Source Type and Location Product Size (bbl) Duration

30 CFR 254.47(b) Shell Offshore Inc. 2011c Uncontrolled 

flow at the mudline Crude oil 480,000 30 days 

(ODPCP Section 1) 

30 CFR 250.213(g) 

and NTL 2010-N06 Shell Offshore Inc. 2011c Uncontrolled flow at the mudline Crude oil 198,016-407,124 

Torpedo H or J well 

34-43 days to drill 

relief well 

BOEMRE 

Verification USDOI, BOEMRE, 2011 Uncontrolled 

flow at the mudline Crude oil 74,940 – 107,414 

Torpedo H well 

30-43 days to drill 

relief well 

Note: The size in bbls range is estimated from the lowest bopd rate multiplied by the shortest number of days to drill a relief

well to the highest bopd rate multiplied by the longest number of days to drill a relief well. 

The BOEMRE requires the WCD to be based upon the daily volume possible from an uncontrolled 

blowout flowing for 30 days (30 CFR 254.47(b) Determining the volume of oil of your worst case 

discharge scenario). The Shell planning scenario considers a daily release of 16,000 bbl of crude oil 

for 30 days (480,000 bbl total). This volume exceeds Shell’s WCD calculated for the Sivulliq and 

Torpedo wells (Section 2 of the revised Camden Bay EP). Shell’s Beaufort Sea ODPCP (Revision 1) 

demonstrates access to sufficient equipment and personnel needed to respond to a well blowout with 

this flow rate and total volume. 

Other BOEMRE regulations 250.213(g) require a scenario for a potential blowout that will have the 

highest volume and maximum duration. Shell’s blowout scenario provides for transiting and drilling a 

relief well for Sivulliq G or N in up to 29-38 days (with a resulting estimated total spill volume of 

17,226-34, 884 bbl). Shell’s blowout scenario provides for transiting and drilling a relief well for 

Torpedo H or J in up to 34-43 days (with a resulting estimated total spill volume of 198,016-407,124 

bbl). Again these oil spill volumes are calculated without factoring in any intervention or response. 

The daily flow rate for a loss of well control resulting in a blowout is based on the WCD estimate 

provided by Shell and verified by BOEMRE (USDOI, BOEMRE, 2011b). The WCD estimate does 

not include any intervention or response. The BOEMRE, Resource Evaluation conducted a 

verification of the WCD model submitted by Shell and concurs that the Torpedo H well has the 

highest potential discharge volume in both daily rate and cumulative flow. The BOEMRE WCD 

results find that the cumulative discharges are all considerably less than the cumulative discharges 

forecast by the Shell’s WCD model (USDOI, BOEMRE, 2011b). The BOEMRE estimates the 

cumulative oil discharge at 30 and 43 days for the Torpedo H well is 74,940 and 107,414 bbl, 

respectively. 

A-1.2.3. Pollution Prevention and Response 

A detailed description of pollution prevention and response is provided in Section 5.0. This section 

also details how the WCD is modified in terms of the very large oil spill scenario analysis. 

A-1.3. Historical and Modeled Oil Spill Information. 

The following sections review the historical and modeled information on crude and condensate spills 

from exploration operations and well-control incidents during all drilling operations. The historical oil 

spill and model data indicate it is unlikely to have a large or very large oil spill from a well-control 

incident during drilling or other exploration operations. The Arctic OCS historical oil spill data 

indicate it is likely to have a small refined spill during exploration operations. 

A-1.3.1. Historical Refined and Crude Spills from Exploration Operations on the 

Beaufort and Chukchi Outer Continental Shelf and Canadian Beaufort. 

The BOEMRE estimates the chance of a large (≥1,000 bbl) oil spill from OCS exploratory activities 

to be very low. On the Beaufort Sea and Chukchi Sea OCS, the oil industry drilled 35 exploratory 

wells. During the time of this drilling, industry has had 35 small spills totaling 26.7 bbl or 1,120 

gallons (gal). Of the 26.7 bbl spilled, approximately 24 bbl were recovered or cleaned up. Table A-3 

shows the exploration spills on the Beaufort Sea and Chukchi Sea OCS. All the explorations spills on 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - Historical and Modeled Oil Spill Information A-5

the Beaufort Sea and Chukchi Sea OCS have been small, with the largest spill approximately 20 bbl. 

OCS spill data shows that 99% of all spills on the OCS are < 50 bbl in size (Anderson and LaBelle 

2000, Table 13). Based on the historical OCS spill data and Arctic OCS exploration spill data, small 

spills of diesel, refined fuel, or crude oil may occur. Shell estimates a small spill size of 48 bbl for a 

transfer of diesel fuel during refueling operations in their potential discharge estimates. The 

BOEMRE estimates a small spill is a reasonably forseeable scenario during exploratory drilling in the 

Beaufort Sea. The historical data shows small spills often are onto containment on vessels, platforms, 

facilities, or gravel islands, or onto ice, and may be cleaned up. 

Table A-3 shows no large exploration spills occurred on the Beaufort Sea and Chukchi Sea OCS. One 

large exploration spill occurred in the Canadian Beaufort Sea from an exploration well site, when the 

island eroded during a storm and a facility fuel tank was damaged, spilling approximately 2,440 bbl 

of diesel P-50 fuel oil (Hart Crowser, 2000). Diesel tanks in the proposed action are internal to the 

drillship and erosion would not be a causal factor for a large oil spill. If the internal diesel fuel tanks 

on the ship failed or leaked, it is unlikely a large spill would reach water. 

A-1.3.2. Historical Crude and Condensate Oil Spills from Well-Control Incidents on 

the OCS and Alaska North Slope. 

The Gulf of Mexico and Pacific and Alaska OCS data show that a large spill likely would not be from 

a well-control incident. We consider well-control incidents that result in pollution to the environment 

to be very unlikely events. Well-control-incident events often are equated with catastrophic spills; 

however, in the last 40 years very few OCS well-control-incident events have resulted in spilled oil, 

and the volumes spilled often are small with the exception of the Deepwater Horizon. Five OCS wellcontrol-incident events ≥1,000 bbl occurred between 1964 and 1970 and a sixth, the Macondo Well 

252 (hereafter called the Deepwater Horizon (DWH) event) occurred in 2010 in the Gulf of Mexico 

(Table A-4). Following the Santa Barbara well-control incident in 1969 and two large well control 

incidents in 1970 in the Gulf of Mexico, amendments to the OCS Lands Act and implementing 

regulations significantly strengthened safety, inspection, and pollution-prevention requirements for 

OCS offshore activities. Well-control training, redundant pollution-prevention equipment, and 

subsurface safety devices are among the provisions that were adopted in the regulatory program 

(Visser, 2011). The year 1971 is considered reflective of the modern regulatory environment. For 39 

years no OCS well control incidents resulted in a large spill. In 2010 and 2011 new regulations were 

again implemented to significantly strengthen safety, inspection, and pollution-prevention 

requirements for OCS offshore activities after the DWH event. These new regulations are discussed 

in section 5.0 of this EA. 

A-1.3.2.1. OCS Well Control Incident Rates 

This section updates information in the 2009 Camden Bay EA Appendix A, Section A.1.c which 

discussed OCS well control incidents from 1971-2007 (USDOI, MMS, 2009). The year 1971 is 

considered reflective of the modern regulatory environment. The term “loss of well control” was first 

defined in the 2006 update to the incident reporting regulations (30 CFR 250.188). Prior to this 2006 

update, the incident reporting regulations included the requirement to report all blowouts, and the 

term blowout was undefined. Three relevant data sets are considered: (1) all well control incidents 

from 1971-2009 prior to the DWH event to update the 2009 Camden Bay 

Table A-3 Exploration Spills on the Beaufort Sea and Chukchi Sea OCS. 

Lease 

No. 

Sale 

Area Operator Date Facility Oil Amt. (Gal) Cause of Spill Response Action Rec. (gal)

0344 71 Sohio 7/22/1981 Mukluk Island Diesel 0.50 Leaking line on 

portable fuel trailer 

Sorbents used to remove spill. 

Contaminated gravel removed. 0.05 

0344 71 Sohio 7/22/1981 Mukluk Island Diesel 1.00 Overfilled fuel tank on 

equipment 

Sorbents used to remove spill. 

Contaminated gravel removed. 1.00 

0280 71 Exxon 8/7/1981 Beaufort Sea I Hydraulic 

Fluid 1.00 Broken hydraulic line on ditch witch. Fluid picked up with shovels. 1.00 

0280 71 Exxon 8/8/1981 Beaufort Sea I Trans. Fluid 0.25 Overfilling of 

transmission fluid. Fluid picked up and placed in plastic bags. 0.25 

0280 71 Exxon 1/11/1982 Beaufort Sea I Hydraulic 

Fluid 0.50 Broken hydraulic line. Fluid picked up and stored in plastic bags. 0.50 
2012 Shell Camden Bay EP EA 

A-6 Oil Spill Analysis - Historical and Modeled Oil Spill Information

Lease 

No. 

Sale 

Area Operator Date Facility Oil Amt. (Gal) Cause of Spill Response Action Rec. (gal)

0280 71 Exxon 1/11/1982 Alaska 

Beaufort Sea I Diesel 3.00 Overfilled catco 90-3 tank. Fluid picked up. 3.00 

0280 71 Exxon 1/17/1982 Beaufort Sea I Diesel 1.00 Tank on catco 90-14 

overfilled. Fluid picked up and stored in plastic bags. 1.00 

0280 71 Exxon 1/21/1982 Beaufort Sea I Hydraulic 

Fluid 0.25 Broken hydraulic line on ditch witch. Fluid picked up. 0.25 

0371 71 Amoco 3/16/1982 Sandpiper 

Gravel Island Unknown 1.00 Seeping from Gravel 

Island. Sorbent pads. Unknown 

0849 87 Union Oil 9/4/1982 Canmar 

Explorer II Unknown 1.00 Transfer of test tank from drillship to barge. None None 

0871 87 Shell 

Western 9/5/1982 Canmar Explorer II Light Oil 0.50 

Washing down 

cement unit, drains 

not plumbed to 

oil/water seperator. 

None None 

N/A 87 Shell 9/14/1982 Canmar II 

Drillship Diesel 30.00 Tank vent overflowed during fuel transfer. Deployed sorbent pads and pump. 30.00 

0191 BF Exxon 11/11/1982 Beechey Pt. 

Gravel Is. Lube Oil 1.00 Loader tipped over lube oil drum 

Oil cleaned up with sorbents. 

Contaminated gravel removed 1.00 

0191 BF Exxon 1/15/1983 Beechey Pt. 

Gravel Is. Diesel 0.12 

Fuel truck spilled 

diesel as it climbed a 

40 degree ramp to 

island 

Sorbents used and contaminated gravel 

removed 0.12 

0191 BF Exxon 1/23/1983 Beechey Pt. 

Gravel Is. 

Hydraulic 

Fluid 2.50 Hydraulic line on 

backhoe broke 

1 gallon in water. Boom deployed with 

sorbents, Contaminated gravel removed 2.50 

0191 BF Exxon 8/29/1983 Beechey Pt. 

Gravel Is. 

Hydraulic 

Fluid 0.20 Hydraulic line on backhoe broke 

Spill contained on island surface. Sorbents 

used and contaminated gravel removed. 0.25 

0196 BF Shell 8/30/1983 Ice Road to 

Tern Island 

Hydraulic 

Fluid 10.0 Broken hydraulic line 

on rollogon Unknown Unknown 

0191 BF Exxon 2/26/1985 Beechey Pt. 

Gravel Is. 

Hydraulic 

Fluid 0.37 Hydraulic line broke Contaminated Snow Removed 0.37 

0196 BF Shell 3/1/1985 Ice Road to 

Tern Island 

Hydraulic 

Fluid 3.00 Hydraulic line broke Unknown 3.00 

0191 BF Exxon 3/2/1985 Beechey Pt. 

Gravel Is. Gasoline 0.01 Operational Spill Snow shoved into plastic bag. 0.01 

0191 BF Exxon 3/4/1985 Beechey Pt. 

Gravel Is. Waste Oil 2.00 Drum of waste oil punctured Snow recovered 2.00 

0196 BF Shell 3/4/1985 Tern Gravel 

Island Crude Oil 1.00 

Well Separator 

overflowed, crude oil 

escaped 

Line boom deployed Unknown 

0196 BF Shell 3/6/1985 Tern Gravel 

Island Crude Oil 15.00 Test burner was 

operating poorly Containment Boom deployed Unknown 

0196 BF Shell 9/24/1985 Tern Gravel 

Island Crude Oil 2.00 

Oil released from 

steam heat coil when 

Halliburton tank 

moved 

Sorbents and hand shovel used 2.00 

0191 BF Shell 10/4/1985 

Enroute to 

Tern Gravel 

Island 

Jet fuel B 800.0

0 

Wire sling broke 

during helicopter 

transport of fuel blivits

Contaminated Snow Removed. Test holes 

drilled with no fuel below snow. Unknown 

0196 BF Shell 10/29/1985 Tern Gravel 

Island Crude Oil 2.00 Test oil burner malfunction Contaminated snow removed 2.00 

0196 BF Shell 6/27/1986 Tern Gravel 

Island Crude Oil 3.00 Test oil burner malfunction 

Spray picked up with sorbents. Bladed up 

dirty snow. 2.00 

0943 87 Tenneco 1/24/1988 SSDC/MAT Gear oil 220.0 

Helicopter sling failure 

during transfer of 

drums to SSDC 

Scooped up contaminated snow and ice 220.0 

1482 109 SWEPI 7/7/1989 Explorer III 

Drillship 

Hydraulic 

fluid 10.0 Hydraulic line 

connector Sorbent pads 0.84 

1092 97 AMOCO 10/1/1991 CANMAR 

Explorer 

Hydraulic 

fluid 2.00 Hydraulic line rupture None None 

0865 87 ARCO 7/24/1993 Beaudril 

Kulluk Diesel 0.06 Residual fuel in bilge 

water None None 

0866 87 ARCO 9/8/1993 CANMAR 

Kulluk 

Hydraulic 

fluid 1.26 Seal on shale shaker failed None None 

0866 87 ARCO 9/24/1993 CANMAR 

Kulluk Fuel 4.00 Fuel transfer in rough 

weather 

3 gallons on deck of barge recovered, 

none in sea 3.00 

1597 124 ARCO 10/31/1993 CANMAR 

Kulluk Fuel 0.50 

Released during 

emptying of disposal 

caisson 

None None 

1585 124 BP Alaska 1/20/1997 Ice Road to 

Tern Island 

Diesel, 

Hydraulic 

Fluid 

10.5 Truck went through 

ice; fuel line ruptured 

Scooped up contaminated snow and ice. 

Some product entered water Unknown 

Source: USDOI, BOEMRE 2011. 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - Historical and Modeled Oil Spill Information A-7

Table A-4 Number of well control incidents with pollution per year in the Gulf of Mexico and Pacific 

OCS Regions and total OCS wells. 

Condensate/Crude Oil Spilled 

(Barrels) 

Product

-ion Drilling Workover/ Completion 

Well 

Type 

Well 

Type 

Wells 

Drilled 

Year 

Total Number of 

Incidents 

Incidents with 

Condensate/ Crude 

Oil 

Workover, 

Production, 

Completion, P&A 

Drilling 

and Development 

Total Exploration 

Total Total 

Exploration 

Development 

Unknown 

Total 

Development 

Exploration 

Total 

1956 1 0 — — 0 — 1 — 1 0 — 204 46 258 

1957 1 0 — — 0 — 1 — 1 0 — 333 58 391 

1958 2 1 0.9 — 0.9 — 1 1 — 0 1 210 65 275 

1959 1 0 — — 0 — 1 — 1 0 — 229 96 325 

1960 2 0 — — 0 1 1 1 — 0 — 290 138 428 

1961 0 0 — — 0 — — — — 0 — 351 133 484 

1962 1 0 — — 0 — 1 — 1 0 — 385 159 544 

1963 1 0 — — 0 — 1 1 — 0 — 400 209 609 

1964 7 3 10,280 100 10,380 4 3 2 1 0 — 507 234 742 

1965 5 2 0.9 1688 1,688.9 1 4 1 3 0 — 648 194 842 

1966 2 2 0.9 0.9 1.8 — 1 — 1 0 1 628 299 973 

1967 2 1 0.9 — 0.9 0 — — — — 2 638 321 988 

1968 8 0 — — 0 1 6 2 4 — 1 735 358 1094 

1969 3 3 — 82,500.9 82,500.9 0 3 1 2 0 — 731 254 993 

1970 3 2 118,000.0 — 118,000.0 1 1 — 1 0 1 756 248 1006 

1956-

1970 39 14 128,283.60 84,289.80 212,573.40 8 25 9 16 0 6 7,045 2,812 9,952 

Major Regulatory Changes to Outer Continental Shelf Lands Act 

1971 6 2 460 — 460 2 2 1 1 0 2 620 285 909 

1972 6 2 2 0.9 2.9 1 4 2 2 — 1 608 309 917 

1973 3 1 0.9 0.9 0 3 2 1 — — 569 321 890 

1974 6 2 275 — 275 2 2 1 1 — 2 512 355 869 

1975 7 1 0.9 — 0.9 — 5 4 1 — 2 569 334 904 

1976 6 0 — — 0 1 5 1 4 — — 851 317 1169 

1977 10 1 2 — 2 1 4 3 1 — 5 975 398 1373 

1978 12 1 0.9 — 0.9 — 8 4 4 — 4 935 361 1298 

1979 5 2 1.8 1.8 — 5 4 1 — — 895 420 1316 

1980 8 1 1 — 1 2 4 3 1 — 2 943 412 1356 

1981 10 5 66.7 0.9 67.6 1 3 1 2 — 6 1012 400 1412 

1982 9 2 1.8 — 1.8 — 5 1 4 — 4 970 457 1427 

1983 12 1 — 2 2 — 10 5 5 — 2 872 458 1330 

1984 5 0 — — 0 — 4 3 1 — 1 862 663 1525 

1985 6 1 50 — 50 0 4 3 1 — 2 783 574 1361 

1986 2 0 — — 0 — 1 — 1 — 1 517 296 813 

1987 8 2 61 — 61 3 2 2 — — 3 534 439 973 

1988 4 1 4.5 — 4.5 1 2 1 1 — 1 510 584 1094 

1989 12 0 — — 0 3 7 4 3 0 2 572 489 1061 

1990 7 3 17.5 — 17.5 0 3 1 1 1 4 638 521 1159 

1991 8 1 — 0.8 0.8 — 6 3 3 0 2 483 350 833 

1992 3 1 — 100 100 — 3 3 — — — 376 229 605 

1993 4 0 — — 0 — 4 1 3 — — 645 365 1010 

1994 1 0 — — 0 — — — — — 1 686 438 1124 

1995 1 0 — — 0 — 1 0 1 — — 784 395 1179 

1996 4 0 — — 0 — 2 1 1 — 2 805 462 1267 

1997 5 0 — — 0 — 4 1 3 — 1 932 549 1481 

1998 9 3 2.6 1.62 4.22 3 3 2 1 — 3 665 495 1161 

1999 5 1 125 — 125 — 3 1 2 — 2 676 371 1048 

2000 9 3 0.02 200.5 200.52 — 8 6 2 — 1 950 443 1396 

2001 10 1 1 — 1 2 5 2 3 — 3 867 411 1278 

2002 6 3 350.505 — 350.505 2 3 1 2 1 654 310 964 

2003 5 1 10 — 10 2 2 0 1 1 1 557 354 911 

2004 6 4 2.5 22.06 24.56 1 3 3 — — 2 569 363 932 

2005 4 0 — — 0 — 4 1 3 — — 482 355 841 

2006 2 2 10 24.5 34.5 — 1 1 — — 1 375 414 789 

2007 8 — — — — 2 2 2 4 328 300 630 

2008 9 0 — — 0 3 4 1 3 2 304 267 571 
2012 Shell Camden Bay EP EA 

A-8 Oil Spill Analysis - Historical and Modeled Oil Spill Information

Condensate/Crude Oil Spilled 

(Barrels) 

Product

-ion Drilling Workover/ Completion 

Well 

Type 

Well 

Type 

Wells 

Drilled 

Year 

Total Number of 

Incidents 

Incidents with 

Condensate/ Crude 

Oil 

Workover, 

Production, 

Completion, P&A 

Drilling 

and Development 

Total Exploration 

Total Total 

Exploration 

Development 

Unknown 

Total 

Development 

Exploration 

Total 

2009 6 2 27.94 — 27.94 1 1 1 4 179 147 338 

2010 4 1 — TBD TBD 3 1 1 0 181 80 267 

1971-

2010* 253 51 1,472.87 355.98 1,828.85 36 143 77 64 2 74 26,245 15,491 41,781 

Notes: Wells drilled columns include hydrocarbon, sulfur and salt wells. The total column includes core tests and relief wells

in addition to exploration and development wells; therefore the total column may be slightly higher than the sum of 

the development and exploration wells columns for some years. 

 TBD - the final volume for the Deepwater Horizon that occurred on 4/20/2010 has not been determined by BOEMRE. 

 The 1971-2010 spill volume totals for the columns showing Drilling and Total Exploration and Development do not 

include the volume for the Deepwater Horizon incident that occurred on 4/20/2010. 

EA baseline, then (2) well control incident rates from exploration and development drilling including 

the DWH event, and finally (3) oil spills associated with well control incidents from exploration 

drilling including the DWH event (USDOI, BOEMRE, AIB, 2011). 

Exploratory and Development/Production Operations From 1971-2009. There were 249 well 

control incidents during exploratory and development/production operations on the OCS (this 

includes incidents associated with exploratory and development drilling, completion, workover, plug 

and abandon, and production operations). During this period, 41,514 wells were drilled on the OCS 

and 15.978 billion barrels (Bbbl) of oil were produced. Of the 249 well control incidents that occurred 

during this period, 50 resulted in the spillage of condensate/crude oil ranging from <1 bbl to 450 bbls. 

The total spilled from these 50 incidents was 1,829 bbls. This volume spilled was approximately 

0.000011447% of the volume produced during this period. 

In 2010, four well control incidents occurred, including the DWH event. Although a final spillage 

volume from the DWH event has not been determined by BOEMRE, the current estimate from 

Lubchenco et al. (2010) is 4.9 million bbls. The three other well control incidents that occurred in 

2010 did not result in the spillage of condensate/crude oil. 

Development and Exploration Well Drilling From 1971-2010. There were a total of 41,781 wells 

drilled in the OCS comprising of 40,565 wells in the Gulf of Mexico, 1,086 wells in the Pacific 

Region, 46 wells in the Atlantic Region and 84 wells in the Alaska Region. Of these, 26,245 were 

development wells, 15,491 were exploration wells and 43 were core tests or relief wells. The overall 

drilling well control incident rate is 1 well control incident per 292 wells drilled, compared to 1 well 

control incident per 410 development wells drilled, and 1 well control incident per 201exploration 

wells drilled. These well control incident rates include all well control incidents related to drilling 

operations whether they spilled oil or not. 

Exploration Well Drilling From 1971-2010. Industry has drilled 223 exploration wells in the Pacific 

OCS, 46 in the Atlantic OCS, 15,138 in the Gulf of Mexico OCS, and 84 in the Alaska OCS, for a 

total of 15,491 exploration wells. During this period, there were 77 well control incidents associated 

with exploration drilling. Of those 77 well control incidents, 14 resulted in crude, condensate and oil 

in drilling mud spills ranging from 0.5 bbl to 200 bbls, for a total 354 bbls, excluding the estimated 

volume from the DWH event. From 1971-2010 one well control incident resulted in a spill volume of 

1,000 bbls or more and that was the DWH event. 

A-1.3.2.2. OCS and North Sea Well Control Incident Duration 

This section summarizes information from well-control incidents that occurred during drilling from 

1992 through 2006 on the OCS and includes all well-control incidents from drilling, even if no 

pollution occurred to the environment (Izon, Danenberger, and Mayes, 2007). Overall, the 1992-2006 

period saw an improvement (decrease) in well-control-incident duration. Like the previous study 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - Well-Control Incidents on the OCS and Canadian Beaufort A-9

(Danenberger, 1993), a significant number of well-control-incident events were of short duration. 

During the current study, 49% of the well-control incidents stopped flowing in 24 hours or less, 

compared with 57% during the previous study. In the current study, 41% lasted between 1 and 7 days, 

compared with 26% during the previous study. There were fewer well-control incidents that lasted 

more than 7 days. The well-control incident with the longest duration during the current study period 

was 11 days, compared with more than 30 days in the previous period (Izon, Danenberger, and 

Mayes, 2007). 

The SINTEF blowout database was used to plot the duration of offshore blowouts in the U.S. and 

North Sea from 1980-2003. Ninety-six percent of offshore blowouts were 30 days or less in duration 

and 84% were 5 days or less in duration (Shell Offshore Inc. 2011c). 

A-1.3.2.3. Alaska North Slope Well Control Incident Information 

The blowout record for the Alaska North Slope remains the same as reported previously in USDOI, 

MMS (2003) and summarized herein. Of the 10 blowouts, 9 were gas and 1 was oil. The oil blowout 

in 1950 resulted from drilling practices that are no longer used. A third study confirmed that no crude 

oil spills ≥100 bbl from blowouts occurred from 1985-1999 (Hart Crowser, Inc., 2000). The 

remaining blowouts released dry gas or gas condensate only, resulting in minimum environmental 

impact (NRC, 2003). 

Scandpower (2001) used statistical blowout frequencies modified to reflect specific field conditions 

and operative systems at Northstar in the Beaufort Sea. This report concludes that the blowout 

frequency for drilling the oil-bearing zone is 1.5 x 10–5 per well drilled (all wells). This compares to 

a statistical blowout frequency of 7.4 x 10–5 per well (for an average development well). This same 

report estimates that the frequency of oil quantities per well drilled for Northstar for a spill >130,000 

bbl is 9.4 x 10-7 per well. 

A-1.3.3. Historical Exploration Well-Control Incidents on the OCS and Canadian 

Beaufort. 

Thirty-five (35) exploration wells were drilled between 1982 and 2003 in the U.S. Chukchi and 

Beaufort seas. Historically, no exploration drilling blowouts occurred as a result of the Chukchi Sea 

and Beaufort Sea OCS exploration drilling, nor have any occurred from the approximately 84 

exploration and 14 deep stratigraphic test wells drilled within the Alaska OCS. 

One exploration drilling blowout of gas has occurred on the Canadian Beaufort. Up to 1990, 85 

exploratory wells were drilled in the Canadian Beaufort Sea, and one shallow-gas blowout occurred. 

A second incident was not included at the Amaluligak wellsite with the Molikpaq drill platform. This 

resulted in a gas flow through the diverter, with some leakage around the flange. The incident does 

not qualify as a blowout by the definition used in other databases and, therefore, was excluded 

(Devon Canada Corporation, 2004). 

From 1971-2010 industry has drilled approximately 223 exploration wells in the Pacific OCS, 46 in 

the Atlantic OCS, 15,138 in the Gulf of Mexico OCS, and 84 in the Alaska OCS, for a total of 15,491 

exploration wells. From 1971-2010, there were 77 well-control incidents associated with exploration 

drilling. Of those 77 well-control incidents, 14 resulted in drilling mud with oil or synthetic oil, crude 

or condensate oil spills. With the exception of the DWH event of 4.9 million barrels, spill sizes 

ranged from 0.5 bbl to 200 bbl. (Table A-3). One OCS spill (large and very large) has occurred from 

1971-2010 during temporary abandonment of an exploration well. Therefore, approximately 15,000 

exploration wells have been drilled, one crude oil spill (large and very large) occurred during 

temporary abandonment and 13 small spills resulted in drilling mud oil, crude or condensate reaching 

the environment from well-control incidents during exploration drilling (Table A-3). 

A-1.3.4. Fault Tree Modeled Exploration Well-Control Incident Frequencies. 

Bercha (2006, 2008) developed an oil-spill occurrence fault-tree model to estimate the oil-spill rates 

associated with exploration, development and production for Arctic OCS locations. The information 

from Bercha (2006, 2008) was used in the USDOI MMS (2006, 2008) oil-spill analyses in the 
2012 Shell Camden Bay EP EA 

A-10Oil Spill Analysis - Worldwide Well Control Incident Spills Greater than or Equal to 150,000 Barrels

Beaufort Sea which concluded approximately 1/3 of a large spill (≥1,000 bbl) was estimated to occur 

over the exploration and development life of the lease sale which included drilling 12 exploration and 

delineation wells . 

Because limited historical spill data for the Arctic exist, Bercha incorporated Gulf of Mexico and 

Pacific OCS and North Sea data and modified the existing base data using fault trees to arrive at oilspill frequencies for future exploration, development, and production scenarios. For offshore 

exploration drilling, Bercha (2008) used historical oil well blowout statistics derived from Holand 

(1997) for non-Arctic drilling operations and Scandpower’s (2001) blowout frequency assessment for 

Northstar to estimate the expected size and frequency distribution of spills. Bercha reported the 

historical spill frequency for non-Arctic exploration well drilling as 3.42 x 10-4 per well for a blowout 

≥150,000 bbl (23,848 m3

). 

Where historical statistics are limited, it is possible to add variability in the fault tree, through a 

Monte Carlo simulation, to reduce the uncertainty in the fault tree analysis. To model the historical 

data variability for Arctic exploration well blowouts, Bercha applied a numerical simulation approach 

to develop the probability distribution for blowouts of 150,000 bbl (23,848 m3

) or greater, and arrived 

at a frequency ranging from a low of 1.5 x 10-4 per well to a high of 6.97 x 10-4 per well. The 

expected value for a blowout of this size was computed to be 3.94 x 10-4 per well (Bercha 2008). To 

address causal factors associated with blowouts, Bercha applied adjustments for improvements to 

logistics support and drilling contractor qualifications that resulted in lower predicted frequencies for 

Arctic drilling operations. No fault-tree analysis or unique Arctic effects were applied as a 

modification to existing spill causes for exploration, development, or production drilling frequency 

distributions. For exploration wells drilled in analogous water depths to planned Beaufort Sea wells 

(30-60 m), Bercha (2008) the estimated, adjusted expected value frequency is 6.12 per 10-4 per well 

for a blowout sized between 10,000 bbl (1,590 m3

) and 149,000 bbl (23,689 m3) and 3.54 x 10-4 per 

well for a blowout >150,000 bbl (23,848 m3

). 

The adjusted frequencies discussed above were applied in a fault tree model to estimate the rate of 

large and very large oil spills. Both the historical non-Arctic frequency distributions and spill causal 

distributions were modified to reflect specific effects of the Arctic setting, and the resultant fault tree 

model was evaluated using Monte Carlo simulation to adequately characterize uncertainties treated as 

probability distribution inputs (described above) to the fault tree. Using the spill rates derived from 

the fault tree analysis the BOEMRE estimated approximately 1/3 of a large spill over exploration and 

development life of a lease sale. 

A-1.3.5. Historical Worldwide Well Control Incident Spills Greater than or Equal to 

150,000 Barrels. 

Very large spills happen very infrequently, and there are limited data for use in our statistical analysis 

and predictive efforts. The chance of a very large spill occurring is very low. Five of the six well 

control-incident events ≥1,000 bbl in the OCS database occurred between 1964 and 1970 (Table A3). The sixth OCS well control incident resulting in a large spill was the DWH event. Although no 

official volume has been determined by BOEMRE it is clear from the spill volume estimates that the 

Deepwater Horizon exceeds the threshold of a VLOS; the current estimate is 4.9 million bbls and is 

greater than 150,000 barrel threshold for a VLOS (Lubchenco et al. 2010; McNutt et al. 2011). 

Internationally, from 1965 through 2010, seven offshore oil well control incidents, resulting in an oil 

spill of greater than or equal to 150,000 bbl, were identified from the peer reviewed or “gray” 

literature (Table A-5). One of the well control incidents was the result of military action. There were 

roughly 1.066 trillion barrels of oil produced worldwide from 1965–2010 (British Petroleum, 2011). 

The BOEMRE compares numbers of spills to overall production because the number of exploration 

wells worldwide is not readily available. Using the 6 spills which were not a result of war, these data 

provide an approximate rate of about 1 very large oil spill worldwide for every 533 Bbbl of oil 

produced. Using international data increases the size of the data set and is more likely to capture rare 

events. However, it assumes that non-US events are relevant to US events to the extent that 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - Small Oil Spills A-11

technology, maintenance, operational standards and other factors are equal; but this is not likely to be 

the case (especially in cases of military action). 

Table A- 5 Historical Very Large Oil Spills from Offshore Well Control Incidents 1965-2010. 

Name Company Spill 

Source Activity Location Oil Begin End 

(Days) Duration 

Bbls Source 

Deep 

Water 

Horizon/ 

Macondo 

MC 252 

BP Expl. Well 

Temporary 

Abandonment 

U.S. OCS, 

Gulf of 

Mexico 

Crude 4/20/ 

2010

7/15

/ 

201

0 

87 4,900,000 

McNutt et al. 

2011. National Oil 

Spill Commission 

2011. 

Ixtoc PEMEX Expl. Well Drilling 

Mexico, 

Gulf of 

Mexico 

Crude 6/3/ 

1979

3/23

/198

0

295 3,500,000 

OSIR, 1998; Etkin, 

2009; Fingas, 

2000; USDOC, 

NOAA, 1992. 

Dubai Dev. 

Well Drilling 1973 2,000,000 Gulf Canada 

Resources Inc 

Nowruz 

Oil Field 

No. 3 

Well* 

Iranian 

Offshore Oil Platform Production Iran, 

Persian Gulf Crude 2/4/ 

1983

9/18

/198

3

224 1,904,762 

OSIR, 1998; Etkin, 

2009; Fingas, 

2000; USDOC, 

NOAA, 1992. 

Abkatun 

91 PEMEX Prod. 

Well Workover 

Mexico, 

Gulf of 

Mexico, Bay 

of Campeche

10/ 

23/ 

1986

15 247,000 

OSIR, 1998; Etkin, 

2009; Fingas, 

2000; 

Ekofisk 

Bravo 

Platform 

B14 

Phillips 

Petroleum Prod. Well Workover 

Norway, 

North Sea, 

Ekofisk Oil 

Field 

Crude 4/22/

1977

4/30

/197

7

8 202,381 

OSIR, 1998; Etkin, 

2009; Fingas, 

2000; USDOC, 

NOAA, 1992. 

Funiwa 

No. 5 Well 

Nigerian 

National 

Petroleum 

Prod. Well Drilling 

Nigeria, 

Niger Delta/

Atlantic 

Ocean 

Crude 1/17/

1980

2/1/

198

0

14 200,000 

OSIR, 1998; Etkin, 

2009; Fingas, 

2000; USDOC, 

NOAA, 1992. 

Note: * Military attack-related events; cells with no data means the information is not readily available in the open literature. 

Source: USDOI, BOEMRE, (2011) compiled from cited references 

A-1.4. Oil-Spill Analysis Framework. 

There are three potential size categories of oil spills in connection with exploratory operations in this 

proposed action: (1) a large spill (≥1,000 bbl) from exploration operations; (2) a very large spill 

(≥150,000 bbl) from a well-control incident; and (3) a small spill (<1,000 bbl) from exploration 

operations. Historical and modeling oil spill data demonstrates that the probability of a large spill 

occurring during exploration is low and, therefore, this EA does not analyze the impacts of large 

spills from exploration operations. The occurrence of a very large spill resulting from a well-control 

incident is similarly very low. Nonetheless, this EA incorporates by reference the BOEMRE’s prior 

analyses of the impacts of a large and very large oil spill. See discussion in Section 5.0 of this EA. It 

is likely a small spill could occur during exploration operations and oil spill analysis scenario further 

includes small oil spill factors. 

A-1.4.1. Small Oil Spills. 

This section provides the analysis framework of a small oil spill used for the determination of impacts 

in this EA. Historical Beaufort Sea and Chukchi Sea OCS exploration spill data suggest that the most 

likely cause of an oil spill during exploration could be operational, such as a hose rupture, and the 

spill could be relatively small. For purposes of analysis, a 48-bbl fuel-transfer spill was chosen as the 

size spill in the small category, based on historical experience in the Beaufort and Chukchi OCS and 

OCS oil-spill analysis. It is estimated to last less than 3 days on the surface of the water, based on the 

SINTEF Oil Weathering Model calculations. In terms of timing, a small spill from the operations 

could happen at any time from July to October during exploration operations. Conservatively, we 

assume that the vessel would not retain any of the 48 bbl of diesel fuel and depending on the time of 

year, a small spill reaches the following environments: 
2012 Shell Camden Bay EP EA 

A-12 Oil Spill Analysis - Small Oil Spills

 vessel and then the water 

 open water or open water and ice 

The analysis of a small spill examines the weathering of the estimated small spill. In our weathering 

analysis, we estimate the following fate of the diesel fuel without cleanup. Table A- 6 summarizes the 

results we estimate for the fate and behavior of diesel fuel in our analysis of the effects of oil on 

environmental and social resources. 

We outline our assumptions for a small spill to provide a consistent analysis of small oil spill impacts 

by resource. We base the analysis of effects from small oil spills on the following assumptions: 

 One small spill occurs. 

 The spill size is 48 bbl. 

 The oil type is diesel fuel. 

 All the oil reaches the environment; the vessel or facility absorbs no oil. 

 The spill starts within Launch Area 15. 

 There is no cleanup or containment. Pollution prevention, containment and cleanup is 

analyzed separately as mitigation. 

 The spill could occur at any time of the exploration operations (July–October). 

 The spill weathering is as we show in Table A- 5, and the spill lasts less than 3 days on the 

water. 

 The time and chance of contact from an oil spill are calculated from an oil-spill-trajectory 

model 

 The chance of contact is analyzed from the location where it is highest when determining 

effects. 

Modeling Simulations of Oil Weathering. 

To judge the effect of a small oil spill, we estimate information regarding how much oil evaporates, 

how much oil is dispersed, and how much oil remains after a certain time period. We derive the 

weathering estimates of diesel fuel oil from modeling results from the SINTEF Oil Weathering Model 

Version 3.0 (Reed et al., 2005) for up to 30 days. Table A-6 summarizes the results we estimate for 

the fate and behavior of a 48-bbl diesel fuel spill. This estimate is slightly more conservative than the 

estimate in the EIA Table 2.10-2 which used the ADIOS model and a water temperature 2 degrees 

higher. Both models provide a reasonable estimated range of the fate and behavior of diesel fuel 

under slightly different environmental conditions. Based on modeling simulations and response 

experience, a small, 48-bbl diesel fuel oil spill will be localized and short term. 

Table A- 6 Fate and Behavior of a Hypothetical 48-Barrel Diesel Fuel Oil Spill. 

Summer Spill1

Time After Spill in Hours 1 2 3 6 12 24 48 

Oil Remaining (%) 96 91 84 65 31 4 0 

Oil Naturally Dispersed (%) 3 7 12 28 57 79 83 

Oil Evaporated (%) 1 2 4 7 12 17 17 

Thickness (mm) 0.7 0.5 0.5 0.3 0.1 0.1 0 

Notes: Calculated with the SiINTEF oil-weathering model Version3.0 of Reed et al. (2005) and assuming diesel fuel no 2. 

 1 Summer (July through September), 12-knot wind speed, 2 degrees Celsius, 0.4-meter wave height. 

A-1.4.2. This EA tiers to Previous Analysis of Very Large and Large Accidental Oil 

Spills. 

After the Exxon Valdez oil spill in 1989, the BOEMRE, Alaska OCS Region analyzed very large 

spills in several OCS locations; five of which were in the Beaufort Sea (USDOI MMS, 1990a, b, 

1991, 1995a, b, 1996, 1998, 2002, 2003a, b; USDOI, BLM and MMS, 1998, 2003; USDOI, BLM, 

2005). The chance of a very large spill (≥150,000) is very low, but its potential effects were analyzed 

in Beaufort Sea Multiple-Sale EIS, Section IV.I Low-Probability, Very Large Oil Spill to which this 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - Hydrocarbon Spill Transport and Trajectory Analysis A-13

EA tiers. The spill scenario was based on a 15,000-bbl daily flow-rate for 15 days totaling 225,000 

bbl. In the unlikely event of a very large accidental oil spill, the potential for major impacts exist as 

was identified. There are no site-specific anomalies that differentiate the trajectory analysis results of 

a very large spill release in LA12, previously analyzed, from one in LA15, and the oil spill contacts 

are statistically similar. 

The chance of a large (≥1,000 bbl) spill is low, but the potential consequences were analyzed in 

USDOI, MMS (2003) section IV.C.; USDOI, MMS (2006); and section 4.4 USDOI, MMS (2008). 

Based on OCS median spill sizes, the MMS estimated a 1,500-bbl diesel or crude oil spill from a 

facility or a 4,600 -bbl crude oil spill from a pipeline for purposes of analyzing a large spill size 

(Anderson and LaBelle, 2000). The conditional probabilities estimated by the Oil-Spill Risk Analysis 

(OSRA) model (expressed as percent chance) of a spill ≥1,000 bbl contacting environmental resource 

areas or land segments within a given time frame from launch areas (LA1-18) and pipeline segments 

(P1-11) assuming a spill occurs are discussed in USDOI, MMS (2003, 2004, 2006). In the unlikely 

event of a large accidental oil spill, there is potential for major impacts as identified in previous 

analyses (USDOI, MMS, 2003, 2008) and discussed in Section 5.0 of this EA. 

A-1.4.3. Hydrocarbon Spill Transport and Trajectory Analysis. 

The previously referenced large and very large oil spill analyses considered surface releases. 

Subsurface releases are estimated to rise to the surface in moderate water depths (<100m) in a short 

period of time and within 1000-2000m of the release site (Daling et al., 2003). The proposed action 

area water depths are relatively shallow (<40m). A subsurface release or a surface release would be 

represented by LA15 for Shell Offshore Inc.’s proposed action. 

Launch Area 15 Conditional Probabilities. The conditional probabilities to environmental resource 

areas and land segments (expressed as percent chance) from a spill originating in LA 15 (USDOI, 

MMS, 2003a: Tables A2-1-A2-54 and A2-73-A2-90) are statistically representative of the lease 

blocks cited in the Shell EP. The chance of a large spill contacting, assuming a large spill occurs, is 

summarized specifically for the LA15 and is inclusive in the conditional probability discussions in 

USDOI, MMS (2003a, 2004, 2006) cited above. The estimated conditional probabilities do not factor 

in pre-booming or spill response; these are considered mitigation, and is analyzed and discussed as 

such in the impact sections of each resource. A successful or partially successful spill response would 

reduce the chance of spill contact or make contact nonexistent. 

Probabilities in the following discussion, unless otherwise noted, are summer or winter conditional 

probabilities estimated by the OSRA model (expressed as percent chance) of a spill ≥1,000 bbl 

contacting environmental resource areas (ERAs) or land segments (LSs) within a given timeframe 

from LA15 assuming a spill occurs (USDOI, MMS, 2003a: herein summarized as Tables A-7 and A8). 

Summer 3 Days. The OSRA model estimates a <0.5-28% chance of a spill ≥1,000 bbl contacting 

ERAs 29-37 (mean distance from coast of bowhead whale migration corridor). The chance of 

contacting ERAs 56-58, 80, and 84 (ice/sea segments) is <0.5-55%. The chance of contacting ERA6 

(Cross and No Name Islands) is <0.5 %. The chance of contacting ERA 4 (Cross Island ERA) is 1%. 

The chance of contacting ERA43 (Nuiqsut Subsistence Area) is 1%. The chance of contacting ERAs 

9, 11, or 12 (Stockton, Maguire, Flaxman Islands) is<0.5-1%. The chance of contacting individual 

LSs is <0.5 except for LS42 (Point Hopson & Sweeney, Staines River) and 43 (Brownlow Point, 

Canning River), which have a 1% chance of contact. The chance of contacting grouped land segment 

(GLS) 138 (Arctic National Wildlife Refuge LSs 43-51) is 1%. 

Summer 10 Days. The OSRA model estimates a <0.5-32% chance of a spill ≥1,000 bbl contacting 

ERAs 29-37 (mean distance from coast of migration corridor). The chance of contacting ERA6 

(Cross and No Name Islands) is 1%. The chance of contacting barrier islands ERAs 3-16 is <0.5-2%. 

The chance of contacting ERA43 (Nuiqsut Subsistence Area) is 4%. The chance of contacting 

individual LSs 39-46 is 1-2%. The chance of contacting GLS 138 (Arctic National Wildlife Refuge) 

is 6%. 
2012 Shell Camden Bay EP EA 

A-14 Oil Spill Analysis - Hydrocarbon Spill Transport and Trajectory Analysis

Summer 30 Days. The OSRA model estimates a <0.5-34% chance of a spill ≥1,000 bbl contacting 

ERAs 29-37 (mean distance from coast of migration corridor). The chance of contacting barrier 

islands ERAs 3-16 is 1-5%. The chance of contacting ERA44 (Kaktovik Subsistence Area) is 12%. 

The chance of contacting ERA69 (Harrison Bay/Colville Delta) is <0.5-16%. The chance of 

contacting ERA3 (Thetis and Jones Islands) is <0.5-23%. The chance of contacting individual LSs 

37-49 is <0.5-4%. The chance of contacting GLS 138 (Arctic National Wildlife Refuge) is 15%. 

Winter 3 Days. The OSRA model estimates a <0.5-7% chance of a spill ≥1,000 bbl contacting ERAs 

29-37 (mean distance from coast of migration corridor). The chance of contacting ERAs 56-58, 80, 

and 84 (ice/sea segments) is <0.5-51%. The chance of contacting ERA79 is 2%. The chance of 

contacting barrier islands (ERAs 3-16) is <0.5%. The chance of contacting ERAs 43-44 (Nuiqsut or 

Kaktovik Subsistence Area) is <0.5%. The chance of contacting all individual LSs is <0.5. The 

chance of contacting GLS 138 (Arctic National Wildlife Refuge) is <0.5%. 

Winter 10 Days. The OSRA model estimates a <0.5-7% chance of a spill ≥1,000 bbl contacting 

ERAs 29-37 (mean distance from coast of migration corridor). The chance of contacting barrier 

islands (ERAs 3-16) is <0.5%. The chance of contacting ERA43 (Nuiqsut Subsistence Area) is <0.5% 

and ERA44 (Kaktovik Subsistence Area) is <0.5-3%. The chance of contacting ERA69 (Harrison 

Bay/Colville Delta) is <0.5-1%. The chance of contacting ERA3 (Thetis and Jones Islands) is <0.5-

3%. The chance of contacting individual LSs 46 (Arey Island, Barter Island), 47 (Kaktovik), or 48 

(Griffin Point, Oruktalik Lagoon) is <0.5-1%. The chance of contacting GLS 138 (Arctic National 

Wildlife Refuge) is <0.5-7%. 

Winter 30 Days. The OSRA model estimates a <0.5-8% chance of a spill ≥1,000 bbl contacting 

ERAs 29-37 (mean distance from coast of migration corridor). The chance of contacting ERA6 

(Cross and No Name Islands) is <0.5%. The chance of contacting ERAs 15-16 (Arey and Barter 

Islands, Bernard, Jago and Tapkaurak Spits) is <0.5-3%. The chance of contacting ERA43 (Nuiqsut 

Subsistence Area) is <0.5-1%. The chance of contacting ERA44 (Kaktovik Subsistence Area) is <0.5-

4%. The chance of contacting ERA69 (Harrison Bay/Colville Delta) is <0.5-2%. The chance of 

contacting ERA3 (Thetis and Jones Islands) is <0.5-3%. The chance of contacting individual LSs 46 

(Arey Island, Barter Island), 47 (Kaktovik), or 48 (Griffin Point, Oruktalik Lagoon) is <0.5-2%. The 

chance of contacting GLS 138 (Arctic National Wildlife Refuge) is <0.5-11%. 

Table A- 7 Annual, Summer, and Winter Conditional Probabilities (Expressed as Percent Chance) that 

an Oil Spill Starting at LA15 Will Contact a Certain Land Segment or Group of Land Segments Within 

3, 10 or 30 Days Assuming a Spill Occurs, Beaufort Sea Sales 186, 1 

Annual Summer Winter 

ID Land Segment Name 3 

Days 

10 

Days 

30 

Days

3 

Days 

10 

Days 

30 

Days 

3 

Days 

10 

 Days 

30 

 Days 

37 Milne Point, Simpson Lagoon : : : : : 2 : : : 

38 Kuparuk River : : : : : 1 : : : 

39 Point Brower, Prudhoe Bay : : : : 1 1 : : : 

41 Bullen Point, Point Gordon, Reliance Pt : : : : 1 1 : : : 

42 Point Hopson, & Sweeney, Staines River : 1 1 1 2 2 : : 1 

43 Brownlow Point, Canning River : 1 1 1 2 3 : : 1 

44 Collinson Point Konganevik Point : : : : 1 1 : : : 

45 Anderson Point, Sadlerochit River : : 1 : 1 2 : : : 

46 Arey Island, Barter Island, : : 1 : 1 2 : : : 

47 Kaktovik : : 1 : 1 4 : : : 

48 Griffin Point, Oruktalik Lagoon : : 1 : : 2 : : : 

49 Angun Pt., Beaufort Lagoon : : : : : 1 : : : 

ID Grouped Land Segment Name 3 

Days 

10 

Days 

30 

Days

3 

Days 

10 

Days 

30 

Days 

3 

Days 

10 

 Days 

30 

 Days 

Teshekpuk Lake Special Area (NPR-A) : : : : 1 : : 1 

Arctic National Wildlife Refuge : 2 5 1 6 15 : 1 2 

Notes: ** = Greater than 99.5 percent; : = less than 0.5 percent; LA = Launch Area, Rows with all values less than 0.5 

percent are not shown. 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - Hydrocarbon Spill Transport and Trajectory Analysis A-15

Table A- 8 Annual, Summer, and Winter Conditional Probabilities (Expressed as Percent Chance) that 

an Oil Spill Starting at LA15 Will Contact a Certain Environmental Resource Area Within 3, 10, and 30 

Days, Beaufort Sea Sales 186, 195, and 202. 

Annual Summer Winter 

ID Environmental Resource Area Name 3 

Days 

10 

Days 

30 

Days

3 

Days 

10 

Days 

30 

Days 

3 

Days 

10 

Days 

30 

Days

— Land 1 3 8 2 10 23 : 1 3 

3 Thetis and Jones Islands : : 1 : 1 3 : : : 

4 Cottle & Return Islands, West Dock : : 1 : 1 3 : : : 

5 Midway Islands : : 1 : 1 2 : : : 

6 Cross and No Name Islands : : 1 : 1 3 : : : 

7 Endicott Causeway : : : : 1 1 : : : 

8 McClure Islands : 1 1 : 2 3 : : 1 

9 Stockton Islands : 1 1 1 2 3 : : 1 

11 Maguire Islands : 1 1 1 2 2 : : : 

12 Flaxman Island : 1 1 1 2 3 : : : 

13 Barrier Islands : : 1 : 1 2 : : : 

14 Anderson Point Barrier Island : : : : 1 1 : : : 

15 Arey and Barter Islands, Bernard Spit : 1 2 : 2 5 : : : 

16 Jago and Tapkaurak Spits : : 1 : 1 5 : : : 

17 Angun and Beaufort Lagoons : : : : : 1 : : : 

28 Beaufort Spring Lead 10 : : 1 : : : : : 2 

31 Ice/Sea Segment 3 : : : : : 1 : : : 

32 Ice/Sea Segment 4 : 1 2 : 1 5 : : 1 

33 Ice/Sea Segment 5 2 4 5 5 9 13 1 2 2 

34 Ice/Sea Segment 6 12 14 14 28 32 34 7 7 8 

35 Ice/Sea Segment 7 : 1 3 1 5 10 : : 1 

36 Ice/Sea Segment 8 : : 1 : 1 5 : : : 

37 Ice/Sea Segment 9 : : : : : 1 : : : 

43 Nuiqsut Subsistence Area : 1 3 1 4 8 : 1 1 

44 Kaktovik Subsistence Area : 1 3 5 12 : : : 

54 Ice/Sea Segment 16a : : 3 : : 2 : : 3 

55 Ice/Sea Segment 17 : 3 11 2 7 : 3 12 

56 Ice/Sea Segment 18a 14 29 34 12 22 27 14 32 37 

57 Ice/Sea Segment 19 52 59 61 55 63 66 51 58 60 

58 Ice/Sea Segment 20a : 6 15 1 10 21 : 5 12 

59 Ice/Sea Segment 21 : : 3 : : 6 : : 2 

61 Ice/Sea Segment 23 : : : : : 1 : : : 

67 Ice/Sea Segment 16b : : 2 : : 2 : : 2 

69 Harrison Bay/Colville Delta : : : : : 1 : : : 

70 ERA 3 : : 2 : : 2 : : 2 

71 Simpson Lagoon : : 1 : 1 3 : : : 

72 Gwyder Bay : : : : : 1 : : : 

74 Cross Island ERA 1 2 4 1 4 8 : 2 2 

75 Water over Boulder Patch 1 : 1 1 : 1 2 : : 1 

76 Water over Boulder Patch 2 : 1 1 : 2 3 : : 1 

77 Foggy Island Bay : : : : 1 1 : : : 

78 Mikelson Bay : : : : : 1 : : : 

79 ERA 4 3 5 6 5 9 11 2 3 4 

80 Ice/Sea Segment 18b 7 14 16 12 22 27 5 11 12 

81 Simpson Cover : : : : 1 1 : : : 

82 ERA 5 1 3 5 2 9 14 : 1 2 

83 Kaktovik ERA : 2 5 1 5 13 : 1 2 

84 Ice/Sea Segment 20b : 4 8 : 10 21 : 2 4 

85 ERA 6 : : : : : 1 : : : 

Notes: ** = Greater than 99.5 percent; : = less than 0.5 percent; LA = Launch Area, Rows with all values less than 0.5 

percent are not shown. 

Assuming a spill occurs, the chance of a large spill contacting the group of land segments 

representing Arctic National Wildlife Refuge ranges from 1 percent during summer to <0.5 percent 

during winter within 3 days from LA15. The SINTEF Oil Weathering Model estimates that within 

approximately 48 hours a small 48-bbl diesel fuel spill will evaporate and disperse. Based on the 

weathering characteristics it is likely 48-bbl diesel fuel spill would dissipate before reaching the land 

segments representing Arctic National Wildlife Refuge. Lease Stipulation 6, pre-booming 

requirements for fuel transfers, provides further mitigation to reduce the chance of an oil spill 
2012 Shell Camden Bay EP EA 

A-16 Oil Spill Analysis - References

contacting the land segments representing Arctic National Wildlife Refuge. This stipulation provides 

for booming during fuel transfers ensuring a 48-bbl diesel fuel spill would be contained, localized and 

cleaned up. Shell’s, Alaska fuel transfer - operating condition and procedure, also addresses weather 

conditions permissive for fuel transfer and spill response, so not to prevent the deployment of spill 

containment boom and oil recovery vessels from carrying out an effective response in the event of a 

spill. 

Given the: (1) low chance of a large spill contacting land segments within ANWR, assuming one 

occurs; (2) the low chance of a 48-bbl diesel fuel spill persisting for 3 days; and (3) the likely 

containment and cleanup of a 48-bbl diesel fuel spill (because of the requirements of Lease 

Stipulation 6 and Shell’s Alaska fuel-transfer operating conditions and procedures), the grouped land 

segments, representing the Arctic National Wildlife Refuge, are not estimated to be contacted from a 

48-bbl diesel fuel spill occurring at the Torpedo or Sivulliq drill sites. 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - References A-17

A-1.5. References. 

Anderson, C.M. and R.P. LaBelle. 2000. Update of Comparative Occurrence Rates for Offshore Oil 

Spill. Spill Science and Technology 65/6:303-321. 

Bercha Group, Inc. 2006. Alternative Oil Spill Occurrence Estimators and their Variability for the 

Beaufort Sea - Fault Tree Method. OCS Study MMS 2006-061. Anchorage, AK: USDOI, MMS, 

Alaska OCS Region, 136 pp. plus appendices. 

Bercha Group, Inc. 2008. Alternative Oil Spill Occurrence Estimators and their Variability for the 

Beaufort Sea - Fault Tree Method. OCS Study MMS 2008-035. Anchorage, AK: USDOI, MMS, 

Alaska OCS Region, 322 pp. plus appendices. 

British Petroleum. BP Statistical Review of World Energy 2011. London: BP; 2011; 

http//www.bp.com/centres/energy2002/2001inreview.asp. 

Daling, P. S.; Moldestad, M.; Johansen, O.; Lewis, A., and Rodal, J. 2003. Norwegian Testing of 

Emulsion Properties at Sea - The importance of oil type and release conditions. Spill Science and 

Technology. 8(2):123-136. 

DeCola, E. International Oil Spill Statistics 2000. Arlington, MA: Cutter Information Corp.; 2001 70 

pp. 

Devon Canada Corporation. 2004. Devon Beaufort Sea Exploration Drilling Program. Devon Canada 

Corporation, Calgary Alberta, Canada. 

Etkin, D.S. 2009. Analysis of U.S. Oil Spillage. API Publication 356, Washington, D.C. American 

Petroleum Institute. 

Fingas, M. 2000. The Basics of Oil Spill Cleanup. Lewis Publishers, Boca Raton, FL. 

Gulf Canada Resources, Inc. 1982. Analysis of Accidents in Offshore Operations Where 

Hydrocarbons Were Lost. Canada; 1982(Beaufort E.I.S. Support Document). 

Hart Crowser Inc. 2000. Estimation of Oil Spill Risk from Alaska North Slope, Trans Alaska Pipeline 

and Arctic Canada Oil Spill Data Sets. OCS Study, MMS 2000-007. Anchorage Alaska: USDOI, 

MMS, Alaska OCS. 

Holand, P. 1997. Offshore Blowouts Causes and Control. Houston, TX: Gulf Publishing Company. 

Izon, D., E.P. Danenberger, and M. Mayes. 2007. Absence of Fatalities in Blowouts Encouraging in 

MMS Study of OCS Incidents 1992-2006. Drilling Contractor July/August: 84-89. 

Lubchenco J, McNutt M, Lehr B, Sogge M, Miller M, Hammond S, Conner W. 2010. Deepwater 

Horizon/BP Oil Budget: What happened to the oil? Silver Spring, MD: National Oceanic and 

Atmospheric Administration. Available at 

http://www.noaanews.noaa.gov/stories2010/PDFs/OilBudget_description_%2083final.pdf. 

McNutt, M.; Camilli, R.; Guthrie, G. Hsieh H.; Labson, V.; Lehr, B. Maclay D.; Ratzel, A., and 

Sogge, M. 2011 Assessment of Flow Rate Estimates for the Deepwater Horizon / Macondo Well 

Oil Spill Flow Rate Technical Group report to the National Incident Command, Interagency 

Solutions Group. Washington, D.C.: U.S. Department of Interior. Available at 

http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=security/getfile&PageID=237763. 

National Oil Spill Commission. 2011. Deep Water the Gulf Oil Disaster and the Future of Offshore 

Drilling Report to the President. Washington, D.C. National Commission on the BP Deepwater 

Horizon Oil Spill and Offshore Drilling. 

National Research Council (NRC). 2003. Oil and the Sea III, Inputs, Fates and Effects. Washington, 

DC: The National Academies Press, 265 pp. 

Oil Spill Intelligence Report (OSIR). 1997. International Oil Spill Statistics. Cutter Information Corp. 

Oil Spill Intelligence Report. 
2012 Shell Camden Bay EP EA 

A-18 Oil Spill Analysis - References

Oil Spill Intelligence Report (OSIR). 1998. Oil Spills from Production and Exploration Activities. 

Vol II no. 8. Cutter Information Corp, 4 pp. 

.Scandpower. 2001. Blowout Frequency Assessment of Northstar. 27.83.01/R1. Prepared for BP 

Exploration (Alaska). Kjeller, Norway: Scandpower, 40 pp. plus appendices. 

Reed, M., Ekrol, N., Daling, P., Johansen, O., and Ditlevsen, M. K. 2005a. SINTEF Oil Weathering 

Model User's Manual Version 3.0. Trondheim, Norway: SINTEF Applied Chemistry, 39 pp. 

Shell Offshore Inc. 2011a. Revised Outer Continental Shelf Lease Exploration Plan Camden Bay, 

Alaska, Anchorage, AK. Shell Offshore Inc 

Shell Offshore Inc. 2011b. Appendix F. Environmental Impact Analysis. In: Revised Outer 

Continental Shelf Lease Exploration Plan Camden Bay, Alaska, Anchorage, AK. Shell Offshore 

Inc 

Shell Offshore Inc, 2011c. Beaufort Sea Regional Exploration Oil Discharge Prevention and 

Contingency Plan. Revision 1, May 2011 Anchorage, AK. Shell Offshore Inc.. 

USDOC, NOAA, 1992. Oil Spill Case Histories 1967-1991; Summaries of Significant U.S. and 

International Spills .Report no. HMRAD 92-11. Seattle, WA: USDOC, NOAA, Hazardous 

Materials Response and Assessment Division. 

USDOI, BLM. 2005. Northeast NPR-A final Amended Integrated Activity Plan/EIS. BLM/AK/PL05/006+1610+930. Anchorage, AK: USDOI, BLM 

USDOI, BLM and MMS. 1998. Northeast National Petroleum Reserve-Alaska Final Integrated 

Activity Plan/ Final Environmental Impact Statement. BLM/AK/PL-98/016+3130+930. 

Anchorage AK: USDOI, BLM and MMS. 

 USDOI, BLM and MMS. 2003. Northwest National Petroleum Reserve-Alaska Final Integrated 

Activity Plan/Environmental Impact Statement. BLM/AK/PL-04/002+3130+930. Anchorage, 

AK: USDOI, BLM and MMS, 3 Vols. 

 USDOI, BOEMRE. 2011a. Chukchi Sea Planning Area Oil and Gas Lease Sale 193 in the Chukchi 

Sea Alaska Revised Draft Supplemental EIS. OCS EIS/EA, MMS 2010-0034. Anchorage, AK: 

USDOI, BOEMRE, Alaska OCS Region 

USDOI, BOEMRE, 2011b. Worst case discharge (WCD) model for Shell Offshore Inc 2011 Camden 

Bay exploration plan: Internal memorandum dated 27 June 2011 from Regional Supervisor for 

Resource Evaluation to Regional Supervisor for Leasing and Environment, XX p. 

USDOI, BOEMRE, AIB. 2011c. Well control incident information for Supplemental EI, Sale 193. 

Email from Melinda Mayes to Fred King RSLE and Mike Routhier, NEPA Coordinator. April 4, 

2011. 

USDOI, MMS. 1990a. Beaufort Sea Planning Area Oil and Gas Lease Sale 124, Final Environmental 

Impact Statement. OCS EIS/EA, MMS 90-0063. Anchorage, AK: USDOI, MMS, Alaska OCS 

Region. 

USDOI, MMS. 1990b. Chukchi Sea Oil and Gas Lease Sale 126 Final Environmental Impact 

Statement. OCS EIS/EA, MMS 90-0095. Anchorage, AK: USDOI, MMS, Alaska OCS Region. 

USDOI, MMS. 1991. Navarin Basin Oil and Gas Lease Sale 107 Final Environmental Impact 

Statement. OCS EIS/EA, MMS 91-0008. Anchorage, AK: USDOI, MMS, Alaska OCS Region. 

USDOI, MMS. 1995a. Cook Inlet Planning Area Oil and Gas Lease Sale 149 Final Environmental 

Impact Statement. OCS EIS/EA, MMS 95-0066. Anchorage, AK: USDOI, MMS, Alaska OCS 

Region., 2 Vols. 

USDOI, MMS. 1995b. Gulf of Alaska/Yakutat Planning Area Oil and Gas Lease Sale 158 Draft 

Environmental Impact Statement. 1 Volume. Anchorage, AK: USDOI, MMS, Alaska OCS 

Region. 
2012 Shell Camden Bay EP EA 

Oil Spill Analysis - References A-19

USDOI, MMS. 1996. Beaufort Sea Planning Area Oil and Gas Lease Sale 144 Final Environmental 

Impact Statement. OCS EIS/EA, MMS 96-0012. 2 Volumes. Anchorage, AK: USDOI, MMS, 

Alaska OCS Region. 

USDOI, MMS. 1998. Beaufort Sea Planning Area Oil and Gas Leas Sale 170 Final EIS. OCS 

EIS/EA, MMS 98-0007. Anchorage, AK: USDOI, MMS, Alaska OCS Region. 

USDOI, MMS. 2002. Liberty Development and Production Plan, Final Environmental Impact 

Statement. OCS EIS/EA, MMS 2002-019. Anchorage, AK: USDOI, MMS, Alaska OCS Region, 

3 Vols. 

USDOI, MMS. 2003a. Beaufort Sea Planning Area Sales 186, 195, and 202 Oil and Gas Lease Sale 

Final EIS. OCS EIS/EA, MMS 2003-001. Anchorage, AK: USDOI, MMS, Alaska OCS Region. 

USDOI, MMS. 2003b. Cook Inlet Planning Area Oil and Gas Lease Sales 191 and 199 Final EIS. 

OCS EIS/EA, MMS 2003-055. Anchorage, AK: USDOI, MMS, Alaska OCS Region. 

USDOI, MMS. 2004. Proposed Oil and Gas Lease Sale 195 Beaufort Sea Planning Area 

Environmental Assessment. OCS EIS/EA MMS 2004-028. Anchorage, AK: USDOI, MMS, 

Alaska OCS Region. 

USDOI, MMS. 2006. Proposed OCS Lease Sale 202 Beaufort Sea Planning Area Environmental 

Assessment. OCS EIS/EA MMS 2006-001. Anchorage, AK: USDOI, MMS, Alaska OCS 

Region. 

USDOI, MMS. 2007 Shell Offshore Inc. Beaufort Sea Exploration Plan Beaufort Sea OCS-Y-1743, 

1805, 1807, 1808, 1809,1817, 1828, 1834, 1841, 1842,1845, and 1849. OCS EIS/EA MMS 2009-

009Anchorage, AK: USDOI, MMS, Alaska OCS Region. 

USDOI, MMS. 2008. Beaufort Sea and Chukchi Sea Planning Areas Oil and Gas Lease Sales 209, 

212, 217 and 221 Draft EIS. OCS EIS/EA, MMS 2008-0055. Anchorage, AK: USDOI, MMS, 

Alaska OCS Region. 

USDOI, MMS. 2009. Environmental Assessment: Shell Offshore, Inc. 2010 Outer Continental Shelf 

Lease Exploration Plan Camden Bay, Alaska. OCS EIS/EA MMS 2009-052. Anchorage, AK: 

USDOI, MMS, Alaska OCS Region. 
2012 Shell Camden Bay EP EA 

A-20 Oil Spill Analysis - References

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APPENDIX B 

LEVEL OF EFFECTS DEFINITIONS AND ABBREVIATIONS
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i

Appendix B 

Table of Contents 

B. Level of Effect Definitions .......................................................................................................... B-1

B-1. Air Quality ......................................................................................................................... B-1

B-2. Water Quality ..................................................................................................................... B-2

B-3. Lower Trophics .................................................................................................................. B-3

B-4. Fish ..................................................................................................................................... B-3

B-5. Marine and Coastal Birds ................................................................................................... B-5

B-6. Marine Mammals ............................................................................................................... B-6

B-7. Sociocultural Systems ........................................................................................................ B-7

B-8. Subsistence ......................................................................................................................... B-8

B-9. Economy ............................................................................................................................ B-8

B-10. Public Health ...................................................................................................................... B-9

B-11. Archaeology ..................................................................................................................... B-10

B-12. Reference ......................................................................................................................... B-10
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2012 Shell Camden Bay EP EA 

Level of Effects - Air Quality B-1

B. LEVEL OF EFFECT DEFINITIONS 

The terms negligible, minor, moderate, and major are used to describe the relative degree or 

anticipated level of effect of an action on a specific resource. Following each term listed below for a 

specified resource are the general characteristics used to determine the anticipated level of effect. For 

each term, best professional judgment was used to evaluate the best available data concerning the 

affected resource. 

The absence of a significant effect does not equate to “no effect.” As shown in the four-category 

scale, and in the numerous analyses that BOEMRE has undertaken, effects from activities can be 

adverse and noticeable before they reach the significance threshold. Furthermore, in the cumulative 

effects analysis, BOEMRE analyzes the combined effects of projected activities with other actions, 

because BOEMRE recognizes that effects that individually do not reach this significance threshold 

may exceed that significance threshold when considered collectively. 

B-1. Air Quality 

The levels of effect applied to the air quality analysis are based on the results of two levels of 

analyses, the emission inventory, and if required, the more rigorous ambient air analysis based on 

computer dispersion modeling. A thorough investigation of the applicable federal and state 

regulations upon which these levels of effect are based is provided in Appendix D, Air Quality. 

Significance Threshold 

Emissions cause an increase in pollutants over an area of at least a few tens of square kilometers that 

exceeds half the increase permitted under the Prevention of Significant Deterioration criteria or the 

National Ambient Air Quality Standards for nitrogen dioxide, sulfur dioxide, or particulate matter less 

than 10 microns in diameter; or exceeds half the increase permitted under the National Ambient Air 

Quality Standards for carbon monoxide or ozone. 

Level of Effects 

Negligible 

 Emissions are shown to be de minimis; and 

 All provisions of the CAA are met and the Proposed Action is compliant to the Alaska 

State Implementation Plan (SIP); and 

 No potential exists for adverse air quality effects. 

Minor 

 Emissions constitute either a minor or a major source; and 

 If a major source, an ambient air analysis was conducted for comparison to the appropriate 

Significant Impact Levels (SILs); and 

 SILs are not exceeded; and 

 No further analysis is required; and 

 All provisions of the Clean Air Act (CAA) are met and the Proposed Action is compliant 

to the Alaska SIP; and 

 No potential exists for adverse air quality effects. 

Moderate 

 Emissions constitute a major source; and 

 An ambient air analysis was conducted for comparison to the appropriate SILs; and 

 At least one of the SILs is exceeded; and 

 Further analysis was conducted to show compliance to the air quality standards; and 
2012 Shell Camden Bay EP EA 

B-2 Level of Effects - Water Quality

 None of the National Ambient Air Quality Standards (NAAQS) or the Alaska Ambient Air 

Quality Standards (AAQS) is equaled or exceeded; and 

 All provisions of the CAA are met and the Proposed Action is compliant to the Alaska 

SIP; and 

 No potential exists for adverse air quality effects. 

Major 

 Emissions constitute a major source; and 

 An ambient air analysis was conducted for comparison to the appropriate SILs; and 

 At least one of the SILs is exceeded; and 

 Further analysis was conducted to show compliance to the air quality standards; and 

 At least one of the NAAQS or the Alaska AAQS is equaled or exceeded; and 

 Provisions of the CAA are not met and the Proposed Action is not compliant to the Alaska 

SIP; and 

 Potential for adverse air quality effects exist. 

B-2. Water Quality 

The impact levels used throughout this analysis are based on the four-level classification scheme for 

biological and physical resources outlined in the Cape Wind Energy Project Draft EIS (USDOI, 

MMS, 2008). 

Level of Effects 

Negligible 

 No measurable impacts. 

Minor 

 Most impacts to water quality could be avoided with proper mitigation. 

 If impacts occur, the water quality would recover completely without any mitigation once 

the impacting agent is eliminated. 

Moderate 

 Impacts to water quality are unavoidable. 

 The viability of the water quality is not threatened although some impacts may be 

irreversible 

 The water quality would recover completely if proper mitigation is applied during the life 

of the proposed action or proper remedial action is taken once the impacting agent is 

eliminated. 

Major 

 Impacts to water quality are unavoidable. 

 The viability of the water quality may be threatened. 

 The water quality would not fully recover even if proper mitigation is applied during the 

life of the proposed action or remedial action is taken once the impacting agent is 

eliminated. 
2012 Shell Camden Bay EP EA 

Level of Effects - Lower Trophics 

B-3

B-3. Lower Trophics 

Significance Threshold 

An adverse impact that results in a decline in abundance and/or change in distribution requiring three 

or more generations for the indicated population to recover to its former status. 

Level of Effects 

Negligible: 

 No measurable impacts. Population-level effects are not detectable. 

 Localized, short-term disturbance or habitat effect experienced during one season that is 

not anticipated to accumulate across multiple seasons. 

 No population level impacts to reproductive success or recruitment are anticipated. 

 Mitigation measures are implemented fully and effectively or are not necessary. 

Minor: 

 Population-level effects are not detectable. 

 Widespread annual or chronic disturbances or habitat effects not anticipated to accumulate 

across 1 year, or localized effects that are anticipated to persist for more than 1 year. 

 Mitigation measures may be implemented on some, but not all, impacting activities, 

indicating that some adverse effects are avoidable. 

 Unmitigatable or unavoidable adverse effects are short term and localized. 

Moderate: 

 Disturbances could occur, but not on a scale resulting in population-level effects. 

 Widespread annual or chronic disturbances or habitat effects could persist for more than 1 

year and up to a decade. 

 Widespread implementation of mitigation measures for similar activities may be effective 

in reducing the level of avoidable adverse effects. 

 Unmitigatable or unavoidable adverse effects are short term and widespread, or long term 

and localized. 

Major 

 Disturbances occur that result in measurable population-level effects. 

 Widespread seasonal, chronic, or effects from subsequent seasons are cumulative and are 

likely to persist for more than 1 decade. 

 Mitigation measures are implemented only for a small portion of similar impacting 

activities, but more widespread implementation for similar activities could be more 

effective in reducing the level of avoidable adverse effects. 

 Unmitigatable or unavoidable adverse effects are widespread and long lasting. 

B-4. Fish 

Significance Threshold 

An adverse impact that results in a decline in abundance and/or change in distribution requiring three 

or more generations for the indicated population to recover to its former status. 

Level of Effects 

Negligible: 

 No measurable impacts. Population-level effects are not detectable. 
2012 Shell Camden Bay EP EA 

B-4 Level of Effects - Marine and Coastal Birds 

 Localized, short-term disturbance or habitat effect experienced during one season that is 

not anticipated to accumulate across multiple seasons. 

 No mortality or impacts to reproductive success or recruitment are anticipated. 

 Mitigation measures are implemented fully and effectively or are not necessary. 

Minor: 

 Population-level effects are not detectable. Temporary, nonlethal adverse effects to some 

individuals. 

 Widespread annual or chronic disturbances or habitat effects not anticipated to accumulate 

across 1 year, or localized effects that are anticipated to persist for more than 1 year. 

 Low mortality levels may occur, measurable in terms of individuals or <1% of the local 

post-breeding fish populations. 

 Mitigation measures may be implemented on some, but not all, impacting activities, 

indicating that some adverse effects are avoidable. 

 Unmitigatable or unavoidable adverse effects are short term and localized. 

Moderate: 

 Mortalities or disturbances could occur, but not on a scale resulting in population-level 

effects. 

 Widespread annual or chronic disturbances or habitat effects could persist for more than 1 

year and up to a decade. 

 Some mortality could occur but remains limited to a number of individuals insufficient to 

produce population-level effects. 

 Widespread implementation of mitigation measures for similar activities may be effective 

in reducing the level of avoidable adverse effects. 

 Unmitigatable or unavoidable adverse effects are short term and widespread, or long term 

and localized. 

Major 

 Mortalities or disturbances occur that have measureable and thus significant populationlevel effects. 

 The action may adversely affect an endangered or threatened species or its habitat in a way 

that has been deemed to be critical under the Endangered Species Act of 1973. 

 For fishes, the anticipated mortality is estimated or measured in terms of tens of thousands 

of individuals or >20% of a local breeding population and/or >5% of a regional population, 

which may produce short-term, localized, population-level effects. 

 Widespread seasonal, chronic, or effects from subsequent seasons are cumulative and are 

likely to persist for more than 1 decade. 

 Mitigation measures are implemented only for a small portion of similar impacting 

activities, but more widespread implementation for similar activities could be more 

effective in reducing the level of avoidable adverse effects. 

 Unmitigatable or unavoidable adverse effects are widespread and long lasting. 
2012 Shell Camden Bay EP EA 

Level of Effects - Marine and Coastal Birds 

B-5

B-5. Marine and Coastal Birds 

Significance Threshold 

Threatened and Endangered Species: An adverse impact that results in a decline in abundance and/or 

change in distribution requiring one or more generation for the indicated population to recover to its 

former status. 

All other Marine and Coastal Birds: An adverse impact that results in a decline in abundance and/or 

change in distribution requiring three or more generations for the indicated population to recover to 

its former status. 

Level of Effects 

Negligible 

 Localized short-term disturbance or habitat effect experienced during one season that is not 

anticipated to accumulate across one year. 

 No mortality is anticipated. 

 Mitigation measures implemented fully and effectively or are not necessary. 

Minor 

 Widespread annual or chronic disturbances or habitat effects not anticipated to accumulate 

across one year, or localized effects that are anticipated to persist for more than 1 year. 

 Anticipated or potential mortality is estimated or measured in terms of individuals or <1% 

of the local post-breeding population. 

 Mitigation measures are implemented on some, but not all, impacting activities, indicating 

that some adverse effects are avoidable. 

 Unmitigatable or unavoidable adverse effects are short-term and localized. 

Moderate 

 Widespread annual or chronic disturbances or habitat effects anticipated to persist for more 

than one year, but less than a decade. 

 Anticipated or potential mortality is estimated or measured in terms of tens or low 

hundreds of individuals or <5% of the local post-breeding population, which may produce 

a short-term population-level effect. 

 Mitigation measures are implemented for a small proportion of similar impacting 

activities, but more widespread implementation for similar activities likely would be 

effective in reducing the level of avoidable adverse effects. 

 Unmitigatable or unavoidable adverse effects are short-term but more widespread. 

Major 

 Widespread annual or chronic disturbance or habitat effect experienced during one season 

that would be anticipated to persist for a decade or longer. 

 Anticipated or potential mortality is estimated or measured in terms of hundreds or 

thousands of individuals or <10% of the local post-breeding population, which could 

produce a long-term population-level effect. 

 Mitigation measures are implemented for limited activities, but more widespread 

implementation for similar activities would be effective in reducing the level of avoidable 

adverse effects. 

 Unmitigatable or unavoidable adverse effects are widespread and long lasting. 
2012 Shell Camden Bay EP EA 

B-6 Level of Effects - Marine Mammals 

B-6. Marine Mammals 

Significance Threshold 

Threatened and Endangered Species: An adverse impact that results in a decline in abundance and/or 

change in distribution requiring one or more generation for the indicated population to recover to its 

former status. 

All other Marine Mammals: An adverse impact that results in a decline in abundance and/or change 

in distribution requiring three or more generations for the indicated population to recover to its former 

status. 

Level of Effects 

Negligible: 

 Localized, short-term disturbance or habitat effect experienced during one season that is 

not anticipated to accumulate across multiple seasons. Temporary, nonlethal adverse 

effects to a few individuals are possible. 

 May cause brief behavioral reactions such as temporary avoidances of or deflections 

around an area. No mortality or population-level effects are anticipated. 

 The action is not anticipated to affect an endangered or threatened species or critical 

habitat under the Endangered Species Act of 1973. 

 Mitigation measures are implemented fully and effectively or are not necessary. 

 Unmitigatable or unavoidable adverse effects are difficult to measure or observe. 

Minor: 

 Localized, disturbance or habitat effects experienced during one season may accumulate 

across subsequent seasons, but not over one year. 

 Temporary, nonlethal adverse effects to some individuals. May cause behavioral reactions 

such as avoidances of or deflections around a localized area. Mortality or population-level 

effects are not anticipated. 

 The action may adversely affect an endangered or threatened species or critical habitat 

under the Endangered Species Act of 1973. 

 Mitigation measures are fully implemented or are not necessary. 

 Unmitigatable or unavoidable adverse effects are short term and localized. 

Moderate: 

 Widespread annual or chronic disturbances or habitat effects could persist for more than 1 

year and up to a decade. 

 Mortalities or disturbances could occur, but would be below the estimated Potential 

Biological Removal1

 (PBR). Population-level effects are not anticipated. 

 The action is likely to adversely affect an endangered or threatened species or modify 

critical habitat under the Endangered Species Act of 1973. 

 Widespread implementation of mitigation measures for similar activities may be effective 

in reducing the level of avoidable adverse effects. 

 Unmitigatable or unavoidable adverse effects are short term and widespread, or long term 

and localized. 

Major 

 Widespread seasonal or chronic effects from subsequent seasons are cumulative and are 

likely to persist for more than 1 decade. 
2012 Shell Camden Bay EP EA 

Level of Effects - Marine Mammals 

B-7

 Mortalities or disturbances could occur at or above the estimated Potential Biological 

Removal (PBR), which could be a population-level effect. 

 The action may adversely affect an endangered or threatened species or critical habitat 

under the Endangered Species Act of 1973, but would not necessarily jeopardize the 

continued existence of an ESA-listed species. 

 Mitigation measures are implemented only for a small portion of similar impacting 

activities, but more widespread implementation for similar activities could be more 

effective in reducing the level of avoidable adverse effects. 

 Unmitigatable or unavoidable adverse effects are widespread and long lasting. 

B-7. Sociocultural Systems 

Sociocultural systems include social organization, cultural values, and institutional arrangements. 

The level of significance effect would be reached at the high level. The level of effects used for 

sociocultural systems is as follows: 

Significance Threshold 

Chronic disruption of sociocultural systems occurs for a period of more than two years, with a 

tendency toward the displacement of existing social patterns. 

Level of Effects 

Negligible 

 Periodic disruption of social organization, cultural values, and institutional arrangements 

occurs without displacement of existing social patterns. 

Minor 

 Disruption of social organization, cultural values, and institutional arrangements occurs for 

a period of less than one year without a tendency toward displacement of existing social 

patterns. 

Moderate 

 Chronic disruption of social organization, cultural values, and institutional arrangements 

occurs for a period of one to two years without a tendency toward displacement of existing 

social patterns. 

Major 

 Chronic disruption of social organization, cultural values, and institutional arrangements 

occurs for a period of more than two years with a tendency toward displacement of 

existing social patterns. 
2012 Shell Camden Bay EP EA 

B-8 Level of Effects - Economy

B-8. Subsistence 

Significance Threshold 

Adverse impacts which disrupt subsistence activities, or make subsistence resources unavailable, 

undesirable for use, or only available in greatly reduced numbers, for a substantial portion of a 

subsistence season for any community. 

Level of Effects 

Negligible 

 Subsistence resources could be periodically affected with no apparent effect on subsistence 

harvests. 

Minor 

 Adverse impacts to subsistence activities are of an accidental and/or incidental nature and 

limited to a short-term. 

Moderate 

 Adverse impacts which disrupt subsistence activities, or make subsistence resources 

unavailable, undesirable for use, or only available in greatly reduced numbers, for a 

substantial portion of a subsistence season for any community. 

Major 

 Adverse impacts resulting in one or more important subsistence resources becoming 

unavailable, undesirable for use, or available only in greatly reduced numbers for any 

community. 

B-9. Economy 

The effects levels used for this analysis focus of the impacts associated with the proposed activities 

on socioeconomic systems, including employment, personal income, and revenues accruing to the 

local, state, and federal government. 

Significance Threshold 

Economic effects that would cause important and sweeping changes in the economic well-being of 

the residents or the area or region. Local employment is increased by 20% or more for at least 5 years. 

Level of Effects 

Negligible 

 No measurable effects beyond short term, periodic impacts. 

Minor

 Adverse impacts to the affected activity or community are unavoidable without proper 

mitigation. 

 Impacts would not disrupt the normal or routine functions of the affected activity or 

community. Economic systems would be impacted for a period of up to 1 year. 

 Once the impacting agent is eliminated, the affected activity or community will return to a 

condition with no measurable effects from the proposed action without any mitigation. 

Moderate

 Impacts to the affected activity or community are unavoidable. Proper mitigation would 

reduce impacts substantially during the life of the project. 
2012 Shell Camden Bay EP EA 

Level of Effects - Public Health B-9

 Effects on economic systems would be unavoidable for a period longer than 1 year. 

 The affected activity or community would have to adjust somewhat to account for 

disruptions due to impacts of the project. 

 Once the impacting agent is eliminated, the affected activity or community will return to a 

condition with no measurable effects from the proposed action if proper remedial action is 

taken. 

Major

 Impacts to affected community are unavoidable. 

 Proper mitigation would reduce impacts somewhat during the life of the project. 

 The affected activity or community would experience unavoidable disruptions to a degree 

beyond what is normal. 

 Once the effect producing agent is eliminated, the affected activity or community may 

retain measurable effects of the proposed action indefinitely, even if remedial action is 

taken. 

B-10. Public Health 

Level of Effects 

Negligible 

 Infrequent minor acute health problems, not requiring medical attention. 

 No measurable effects on normal or routine community functions. 

 No long-term consequences for Public Health or well being. 

Minor

 Public Health affected, but the effects would not disrupt normal or routine community 

functions for more than one week. 

 Effects would not occur frequently. 

 Effects would not affect large numbers of individuals. 

 Effects could be avoided with proper mitigation. 

Moderate

 Adverse effects on Public Health occurring for brief periods of time that do not result in or 

incrementally contribute to deaths or long-term disabilities. 

 Effects can be prevented, minimized, or reversed with proper mitigation. 

 Effects could occur more frequently than minor events, but would not be frequent. 

Major

 Effects on Public Health would be unavoidable and would contribute to the development 

of disabilities, chronic health problems, or deaths. 

 Alternatively, occurrence of minor health problems with epidemic frequency. 

 Effective mitigation might minimize the adverse health outcomes but would not be 

expected to reverse or eliminate the problem. 
2012 Shell Camden Bay EP EA 

B-10 Level of Effects - Archaeology

B-11. Archaeology 

Level of Effects 

Negligible 

 This category equates to No Historic Properties Affected as defined by 36 CFR 

800.4(d)(1), the Code of Federal Regulations that promulgates Section 106 of the National 

Historic Preservation Act of 1966 as amended. 

Minor

 This category equates to a finding of No Historic Properties Affected when the Agency 

identifies a potential conflict within an Area of Potential Effect due to the presence of a 

geomorphological feature and revises the plan to avoid it prior to consultation with the 

State Historic Preservation Officer. 

Moderate

 This category equates to a finding of No Adverse Effect as defined by 36 CFR 800.5(b) 

when the SHPO identifies a conflict that requires a change in plan to avoid effects on an 

Historic Property as defined by 36 CFR 800.16(l)(1&2). 

Major

 This category equates to a finding of Adverse Effect as defined by 36 CFR 800.5(C) 

requiring mitigation and a Memorandum of Agreement. 

B-12. Reference 

USDOI, MMS. 2008. Cape Wind Energy Project Draft Environmental Impact Statement. OCS 

EIS/EA MMS 2007-024. Herndon, VA: USDOI, MMS. 

Notes: 

 

1

 Marine mammal stock management is often based on a theoretical concept called Potential Biological 

Removal (PBR). The PBR is defined as the maximum number of animals, not including natural mortalities, 

which may be removed from a marine mammal stock while allowing that stock to reach or maintain its 

optimum sustained population. An optimum sustained population is defined as the number of animals which 

will result in the maximum productivity of the population or the species, keeping in mind the carrying 

capacity of the habitat and the health of the ecosystem. For example, as the bowhead whale population 

continues to grow, it continues to approach its carrying capacity. Contemporary population ecology suggests 

that at carrying capacity, a stable population is achieved when mortality equals productivity. 

 The PBR is calculated as the product of the minimum population estimate, one-half the theoretical 

productivity rate, and a “recovery factor”. For example, the current estimate for the rate of increase for the 

bowhead whale stock (3.3%) should not be used as an estimate of maximum productivity because the 

population is currently being harvested and because the population has recovered to population levels where 

the growth is expected to be significantly less than maximum productivity. For the Western Arctic bowhead 

whale stock, the population size is estimated to be 9,472 (estimated in 2001), the theoretical productivity rate 

is 0.2, and the recovery factor is 0.5. The PBR is generally only used by the NMFS to guide decisions 

regarding the allowable removal of individual animals from a stock. 

 The conceptual PBR is used in the level of effects to identify a threshold whereby maximum population 

growth is sustained or not. If an anticipated effect could result in a loss of whales that exceeded the PBR, 

this would be inferred to be a population-level effect. In reality, given the conservative values used to derive 

the PBR, the loss of marine mammals that exceeded calculated PBR could be entirely consistent with a 

stable population. 
APPENDIX C 

2012 BEAUFORT SEA CUMULATIVE EFFECTS

 
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i

Appendix C 

Table of Contents 

C. CUMULATIVE EFFECTS ......................................................................................................... C-1

C-1. Cumulative Effects Defined ............................................................................................... C-1

C-2. Impact Sources ................................................................................................................... C-1

C-2.1. Marine Vessel Traffic ........................................................................................... C-1

C-2.2. Aircraft Traffic ...................................................................................................... C-2

C-2.3. Oil and Gas Related Activities .............................................................................. C-2

C-3. Miscellaneous Associated Activities .................................................................................. C-2

C-3.1. Other Vessel Traffic .............................................................................................. C-2

C-3.2. Scientific Research ................................................................................................ C-2

C-3.3. Reasonable and Foreseeable Planned Activities ................................................... C-3

C-3.4. Climate Change and Ocean Acidification ............................................................. C-4

C-4. References .......................................................................................................................... C-5

 
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2012 Shell Camden Bay EP EA 

Cumulative Effects - Impact Sources C-1

C. CUMULATIVE EFFECTS 

The scope of this assessment includes the incremental impact from the action alternatives plus the 

aggregate effects of other activities that are known to occur or that can be reasonably expected to 

occur at the same time as and in the vicinity of the proposed action, and which have a potential to 

affect the same resources as the proposed action. 

The cumulative effects from biotic and abiotic factors that include past OCS activities plus current 

and reasonable foreseeable future activities in the Arctic OCS and adjacent areas were analyzed in the 

2008 Arctic Multiple Sale Draft EIS (USDOI, MMS, 2008, pgs. 4-1 – 4-13). That analysis is 

incorporated by reference, summarized below, updated to consider the years 2012 through 2015 and 

reflect the anticipated activities which would occur during the period of the proposed action. 

C-1. Cumulative Effects Defined 

The Council on Environmental Quality (CEQ) Regulations defines cumulative effects at 40 CFR 

1508: 

Sec. 1508.7 Cumulative impact. 

"Cumulative impact" is the impact on the environment which results from the incremental 

impact of the action when added to other past, present, and reasonably foreseeable future 

actions regardless of what agency (Federal or non-Federal) or person undertakes such other 

actions. Cumulative impacts can result from individually minor but collectively significant 

actions taking place over a period of time. 

Sec. 1508.8 Effects. 

"Effects" include: 

(a) Direct effects, which are caused by the action and occur at the same time and place. 

(b) Indirect effects, which are caused by the action and are later in time or farther removed in 

distance, but are still reasonably foreseeable. Indirect effects may include growth inducing 

effects and other effects related to induced changes in the pattern of land use, population 

density or growth rate, and related effects on air and water and other natural systems, 

including ecosystems. 

Effects and impacts as used in these regulations are synonymous. Effects includes ecological 

(such as the effects on natural resources and on the components, structures, and functioning of 

affected ecosystems), aesthetic, historic, cultural, economic, social, or health, whether direct, 

indirect, or cumulative. Effects may also include those resulting from actions which may have 

both beneficial and detrimental effects, even if on balance the agency believes that the effect 

will be beneficial. 

C-2. Impact Sources 

The main sources of introduced activities contributing to cumulative impacts affecting the Alaska 

OCS during the duration of the proposed activity are: (1) marine vessel traffic; (2) aircraft traffic; (3) 

oil and gas activities in federal and state waters; and (4) miscellaneous associated activities. 

C-2.1. Marine Vessel Traffic 

Marine vessels are expected to be the greatest contributors of anthropogenic sound introduced to the 

Beaufort Sea during the timeframe of the proposed activities. Sound levels and frequency 

characteristics of vessel sound energy underwater generally are related to vessel size and speed. 

Larger vessels generally emit more sound than smaller vessels. Vessels underway with a full load, or 

vessels pushing or towing loaded non-powered vessels, generate more sound than unladen vessels. 

While the primary sources of marine vessel sounds are propulsion engines, generators, bearings, and 

other mechanical components which transmit sound into the water through the vessel hull, the highest 

level of sound pressure introduced into the water from an underway marine vessel originates from 
2012 Shell Camden Bay EP EA 

C-2 Cumulative Effects - Miscellaneous Associated Activities

cavitation associated with spinning propellers. Fathometers and other vessel navigation and 

operations equipment also generate underwater sounds. 

Marine vessel traffic in the project area, other than that associated with the proposed activities, is 

expected to include vessels used for fishing and hunting, icebreakers, Coast Guard vessels, supply 

ships and barges with their associated towing vessels. During ice-free months (June- October), barges 

are used for supplying local communities, Alaskan Native villages, and the North Slope oil-industry 

complex at Prudhoe Bay with larger items that cannot be transported by commercial air carriers. 

Usually, one large fuel barge and one supply barge visit the coastal villages each year during the icefree period. 

C-2.2. Aircraft Traffic 

Air traffic has increased in recent years, mostly in response to increased activity in academic and 

commercial ventures. These activities will continue to be an aspect of anthropogenic effects to the 

Arctic environment. Categories of aircraft traffic in the Arctic include both fixed wing and helicopter 

flights for the pursuit of various research programs and marine mammal monitoring, cargo flights for 

supplies to villages and commercial ventures including oil and gas related activities, regional and 

inter-village transport of passengers, air-ambulance and search and rescue emergency flights, general 

aviation for purpose of sport hunting and fishing or flightseeing activities, and multi-governmental 

military flights. 

Specific activities that could affect an increase in air traffic and air emissions and lead to increased 

effects on native subsistence hunting activities and marine mammal and bird behavior over the 

proposed project area include the helicopter flights for transport of crews and supplies to and from the 

rigs and support vessels for oil and gas related activities, and flights conducted for marine mammal 

observations such as those required by BOWFEST, COMIDA, and other reasonably foreseeable 

research activities. 

C-2.3. Oil and Gas Related Activities 

Reasonably foreseeable future activities associated with current and ongoing oil and gas projects, 

including marine sea lifts and activities at West Dock in Prudhoe Bay are expected to remain at the 

current level for the duration of the proposed action. Recent trends of development-related vessel 

traffic indicate that traffic begins in July, peaks in August, and rapidly declines to a sporadic level by 

October (Shell, 2011b: Table 4.2-2.) 

C-3. Miscellaneous Associated Activities 

C-3.1. Other Vessel Traffic 

Overall vessel traffic within the proposed exploration drilling area is expected to be limited and 

consistent with the level of traffic observed in recent years. Most vessel traffic is expected to consist 

of barges, with their associated towing / pushing vessels, transiting through the area within 12.5 mi 

(20 km) off the coast, during open water conditions (Shell, 2011b: 4-131). With the reduction in ice 

cover and increase in open water season, cumulative vessel traffic in the region due to military, 

tourism, and foreign shipping interests may increase (Arctic Marine Shipping Assessment, 2005) 

C-3.2. Scientific Research 

A sizable scientific research effort conducted by governmental, non-governmental and educational 

organizations operating from marine vessels and aircraft occurs every year in the Beaufort Sea. The 

programs conducted by these organizations are expected to continue through the period of the 

proposed action. Marine environmental baseline studies include deployment of oceanographic 

equipment for collecting water and sediment samples, and use of nets and trawls for collection of 

phytoplankton, zooplankton, benthic invertebrate, pelagic invertebrate, and fish sampling. Also 
2012 Shell Camden Bay EP EA 

Cumulative Effects - Reasonable and Foreseeable Planned Activities C-3

continuing will be observations of marine and coastal birds and marine mammals using standardized 

survey transect methods and passive acoustic monitoring. Metocean buoy and acoustic wave and 

current meters will continue to be deployed for studies of physical oceanography and climate studies. 

Previous environmental assessments, such as the environmental assessment for Shell’s Beaufort Sea 

marine research program, describe techniques used and the effects of these programs in detail 

(BOEMRE, 2010, OCS EIS/EA MMS 2010-022). 

Ongoing activities in the general Beaufort and Chukchi Sea regions also include the multinational 

efforts carried out by the Pacific Arctic Group (PAG). The PAG is a group of institutes having a 

Pacific perspective on Arctic science. Organized under the International Arctic Science Committee 

(IASC), the PAG mission is to serve as a Pacific Arctic regional partnership to plan, coordinate, and 

collaborate on science activities of mutual interest to the Arctic region. Some, but not all, of these 

activities could coincide in time and space with the proposed exploration plan activities. The 

Diversified Biological Observatory is is a multi-national cooperative effort coordinated by the PAG, 

with the USA, Canada, Russia, Japan, China, and Korea contributing cruise data from past, ongoing, 

and planned research programs. Programmatical sampling includes continuation of collections from 

prior and existing research stations, including BOEMRE and MMS funded projects. Focus is on four 

geographical research areas within the Bering Sea, Bering Strait, Chukchi Sea, and Beaufort Sea. 

Science includes synthesis of multi-disciplinary studies including physical oceanography, marine 

chemistry, biological oceanography and marine biology (primary productivity, zooplankton, 

phytoplankton, ice algae, epontic, pelagic, and benthic collections), and marine mammal and marine 

bird observations. (http://pag.arcticportal.org/) 

C-3.3. Reasonable and Foreseeable Planned Activities 

Shell Chukchi Sea Proposed Exploration Plan beginning in 2012 

Shell has proposed multiple-well exploration drilling on leases in the Chukchi Sea during the period 

of the proposed activities in the Beaufort Sea. Shell proposes using dedicated and independent drilling 

and support vessels for the Chukchi Sea and Beaufort Sea operations (with some commonly shared 

secondary oil spill response resources). Weather, ice, and other environmental conditions at the 

specific locations would ultimately dictate the sequence of Shell’s operations. The proposed Chukchi 

Sea exploration program envisions “drilling up to six exploration wells in one prospect located 64 

miles (103km) offshore and 410 (600 km) west of the Torpedo and Sivulliq prospects in the Beaufort 

Sea” (Shell, 2011b: pp. 4-128). 

The proposed Beaufort Sea and Chukchi Sea project areas are more than 400 mi apart. Discharges 

and emissions associated with drilling at the two project areas would not overlap in space. Sound 

generated during transition from the Beaufort Sea to the Chukchi Sea (site-abandonment operations, 

transit, MLC construction, setting anchors, and drilling) would be continuous at varying sound levels 

but the sound generated from the various project stages would not overlap in space. Because of the 

travel time for migrating species between the locations of the two operations, some individual animals 

could be exposed to sound from both drilling operations. 

Bowhead Whale Feeding Ecology Study (BOWFEST). August – September 2012. NOAA 

Fisheries and National Marine Mammal Laboratory. The BOWFEST (NMML, 2011a) is a multiyear 

BOEMRE-funded study which was started in 2007 that focuses on late summer oceanography and 

prey densities relative to whale distribution over continental shelf waters within 100 miles north and 

east of Point Barrow, Alaska. Aerial surveys conducted by the National Marine Mammal Laboratory 

(NMML), acoustic monitoring, and boat-based surveys provide information on the spatial and 

temporal distribution of bowhead whales in the study area. Oceanographic sampling helps identify 

sources of zooplankton prey available to whales on the shelf and the association of this prey with 

physical characteristics (hydrography, currents) which may affect mechanisms of plankton 

aggregation. Results of this research program may help explain summer occurrences of bowheads in 
2012 Shell Camden Bay EP EA 

C-4 Cumulative Effects - References

the Western Beaufort Sea (U.S. waters), well west of the typical summer feeding aggregations in the 

Canadian Beaufort Sea. Increased understanding of bowhead behavior and distribution is needed to 

minimize potential impacts from petroleum development activities. 

Chukchi Sea Acoustic Oceonographic Zooplankton (CHAOZ). July – September, 2012. CHAOZ 

goals are to conduct passive acoustic/biological/biophysical surveys of whales, their prey, and their 

environment in the Bering, Chukchi, and Beaufort Seas for three field seasons, 2010-2012. The 

objective of the research is to conduct passive acoustic monitoring studies and oceanographic 

sampling to determine abundance, migratory patterns, acoustic ecology, and foraging ecology of 

cetaceans and their prey. In addition, biological and population studies of large whales will be 

continued by deploying radio and satellite transmitters on whales, conducting photo-identification, 

and biopsy sampling. Research transects are to be carried out from Wainwright, Icy Cape, Point Lay, 

Cape Lisburne, and Point Hope into the Chukchi and Bering Seas for deployment of accoustic and ice 

buoys, CTD casts, zooplankton sampling, and collection of marine mammal observation data. 

Chukchi Sea Offshore Monitoring in Drilling Area (COMIDA). Mid-June - October, 2012. 

NOAA Fisheries and National Marine Mammal Laboratory. NE Chukchi Sea aerial cetacean survey. 

COMIDA (NMML, 2011b) is a project in the northeastern Chukchi Sea designed to understand the 

distribution and relative abundance of cetaceans using aerial surveys during the open-water (ice-free) 

months, from mid-June to the end of October. Surveys follow standard line-transect protocols. Flights 

begin and end in Barrow, AK. The science team flies in either a De Havilland Twin Otter Series 300 

or Aero Commander 690A fixed wing aircraft at altitudes between 1000-1500' and 100-110kts speed. 

Surveys are flown every day, weather permitting. 

C-3.4. Climate Change and Ocean Acidification 

Climate change is an ongoing factor in the consideration of cumulative environmental effects on the 

Arctic region (NOAA, 2011). It has been implicated in changing weather patterns, changes in the 

classification and seasonality of ice cover, and the timing and duration of phytoplankton blooms in 

the Beaufort Sea. These changes have been attributed to rising CO2 levels in the atmosphere and 

corresponding increases in the CO2 levels of the waters of the world’s oceans. These changes have 

also led to the phenomena of ocean acidification (IPCC, 2007). This phenomena is often called a 

sister problem to climate change, because they are both attributed to human activities that have 

resulted in increased CO2 levels in the atmosphere. Ocean acidification in high latitude seas is 

happening at a more advanced rate compared to other areas of the ocean. The capacity of the Arctic 

Ocean to uptake CO2 is expected to increase in response to increased levels as a result of climate 

change (Bates and Mathis, 2009). This is due to the loss of sea ice that increases the open water 

surface area of the Arctic seas. Exposure of cooler surface water lowers the solubility, or saturation of 

calcium carbonate within the water, which in turn leads to lower available levels of the minerals 

needed by shell-producing organisms (Fabry et al., 2009). 
2012 Shell Camden Bay EP EA 

Cumulative Effects - References C-5

C-4. References 

Arctic Marine Shipping Assessment. 2005. http://www.arctic.gov/publications/AMSA/

current_marine_use.pdf 

Bates, N.R., and Mathis, J.T., 2009, The Arctic Ocean marine carbon cycle; evaluation of air-sea CO2 

exchanges, ocean acidification impacts and potential feedbacks, Biogeosciences Discussions 6.

pp. 6695-6747. http://www.biogeosciences-discuss.net/6/6695/2009/bgd-6-6695-2009-print.pdf 

BOEMRE 2012 Shell Revised Exploration Plan for the Chukchi Sea http://alaska.boemre.gov/

ref/ProjectHistory/2012_Shell_CK/2012x_.HTM 

CHAOZ (Chukchi Sea Acoustic Oceanographic Zooplankton) http://alaska.boemre.gov/ess/

ongoingStudies/Ongoing_studies.pdf 

COMIDA. 2011. (Chukchi Offshore Monitoring in Drilling Area) 

http://alaska.boemre.gov/ess/ongoingStudies/Ongoing_studies.pdf 

Fabry, V.J.; McClintock, J.B.; Mathis, J.T.; Grebmeier, J.M., 2009, Ocean acidification at high 

latitudes: the bellwether. Oceanography, 22(4) 160-171. 

Intergovernmental Panel on Climate Change (IPCC) 2007. Climate Change 2007: Synthesis Report. 

Contribution of Working Groups I, II and III to the Fourth Assessment Report of the 

Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri, R.K and Reisinger, 

A. (eds.)]. IPCC, Geneva, Switzerland, 104 pp. http://www.ipcc.ch/ 

NMML (National Marine Mammal Laboratory). 2011a. Cetacean Assessment & Ecology Program 

BOWFEST Survey Project: Preliminary Data. http://www.afsc.noaa.gov/NMML/cetacean/

bwasp/flights_BOWFEST.php 

NMML (National Marine Mammal Laboratory). 2011b. Cetacean Assessment & Ecology Program 

COMIDA Survey Project: Preliminary Data. http://www.afsc.noaa.gov/NMML/cetacean/

bwasp/flights_COMIDA.php 

Pacific Arctic Group (PAG). 2011. http://pag.arcticportal.org/ 

USDOC, NOAA. State of the Climate Global Analysis. 2011. http://www.ncdc.noaa.gov/sotc/global/ 
2012 Shell Camden Bay EP EA 

C-6 Cumulative Effects - References

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APPENDIX D 

AIR QUALITY
2012 Shell Camden Bay EP EA 

ii 

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2012 Shell Camden Bay EP EA 

Air Quality - Summary of sections iii

Appendix D 

Table of Contents 

D. Air Quality..........................................................................................................................................D-1

D-1. Regulatory Overview................................................................................................................D-3

D-1.1. Lead .............................................................................................................................D-5

D-1.2. Nitrogen Dioxide (NO2) ..............................................................................................D-5

D-1.3. Ozone...........................................................................................................................D-5

D-1.4. Particulate Matter (PM10 and PM2.5)............................................................................D-5

D-1.5. Sulfur Dioxide (SO2) ...................................................................................................D-5

D-1.6. OCS Air Regulations...................................................................................................D-6

D-1.7. Definitions ...................................................................................................................D-6

D-1.8. Air Operating Permits..................................................................................................D-8

D-1.8.1. Kulluk Permits ...............................................................................................D-8

D-1.8.2. Discoverer Permit..........................................................................................D-9

D-2. NEPA Air Quality Analysis....................................................................................................D-10

D-3. Air Quality Levels of Effect ...................................................................................................D-12

D-3.1. CAA Title V Requirements .......................................................................................D-12

D-3.2. PSD Requirements.....................................................................................................D-13

D-3.3. Defining the Four Levels of Effect............................................................................D-14

D-3.3.1. Negligible Level of Effect ...........................................................................D-15

D-3.3.2. Minor Level of Effect..................................................................................D-16

D-3.3.3. Moderate Level of Effect.............................................................................D-16

D-3.3.4. Major Level of Effect ..................................................................................D-17

D-4. References: .............................................................................................................................D-18

List of Figures 

Figure D-1 Map of the project area showing the extent of the 25-mile boundary for 40 CFR 

Part 55 Air Regulations. ......................................................................................... D-6 

List of Tables 

Table D-1 Summary of sections in the EA providing information relevant to the overall 

assessment of air quality conditions and impacts. .................................................. D-1

Table D-2 Summary of Shell documents providing information relevant to the overall 

assessment of air quality conditions and impacts. .................................................. D-2

Table D-3 Kulluk Air Operating Permit Application and Associated Documents .................. D-2

Table D-4 Discoverer Permit and Associated Documents ...................................................... D-3

Table D-5 Alaska and National Ambient Air Quality Standards............................................. D-4

Table D-6 Prevention of Significant Deterioration (PSD) Analysis. Comparison of pollutant 

concentrations, associated only with the Proposed Action, to the PSD SILS for 

the COA Class II area........................................................................................... D-11
2012 Shell Camden Bay EP EA 

iv 

Table D-7 Ambient Air Analysis. Comparison of pollutant concentrations associated with 

the Proposed Action, together with the background concentrations onshore, to 

the NAAQS and Alaska AAQS............................................................................ D-11
2012 Shell Camden Bay EP EA 

Air Quality - Summary of sections D-1 

D. AIR QUALITY 

The information provided in this appendix supplements the discussion of air quality conditions and 

impacts contained in the Environmental Assessment (EA) of the Shell Offshore Inc. (Shell) Revised 

Exploration Plan (EP) Outer Continental Shelf Lease Exploration Plan, Camden Bay, Alaska, (2011 

Camden Bay EP). Information provided in several sections of the EA contributes to the overall 

assessment of air quality, including discussions of climate, meteorology, and the impact of oil spills on 

local air quality. The location and content of the relevant sections are summarized in Table D-1. 

Table D-1 Summary of sections in the EA providing information relevant to the overall assessment of air quality 

conditions and impacts. 

EA Section, Title, and Summary 

1.3 Statutory Framework 

 1.3.5 Clean Air Act (1990 CAA) 

History of the CAA and an overview of air operating permits required for stationary pollutant sources, particularly for 

sources on the OCS. 

2.3 Description of Alternative 2 – The Proposed Action 

 2.3.1 Overview 

Status of the air quality permits required for the Kulluk and Discoverer along with the other major permits required before 

the Proposed Action can proceed. 

 2.3.4 Drillship, Support Vessels, and Aircraft

 Physical description of the drillships and marine vessels proposed for the EP; includes aircraft. 

 2.3.6 Emissions

Description of the types of emissions expected from the drillships, Kulluk and Discoverer, and the role of the support 

vessels; description of the emission reduction measures proposed for each of the drillships, including BACT and ORR. 

3.0 Affected Environment 

 3.1.1 Climate Change 

Overview of past, current, and future changes in the climate over the Arctic that could impact several local natural 

resources, including air quality. 

 3.1.2 Expected Weather Conditions at the Drill Sites

Description of the seasonal weather conditions expected at the proposed drill sites; includes wind, precipitation, and 

temperature information. 

 3.2.1 Air Quality

Description of the existing local air quality conditions, including the adjacent onshore area; description of the OCS air 

regulations relevant to the Proposed Action 

4.2 Alternative 2 – The Proposed Action 

 4.2.1 Air Quality

Evaluation of the direct and indirect effects of the Proposed Action on air quality conditions; includes the emission 

inventories for the Kulluk and the Discoverer; includes a discussion of GHG and the evaluation of potential cumulative 

impacts. 

5.7 Large Oil Spill Effects 

 Air Quality section describes the potential air quality impacts from a large oil spill.

5.8 Very Large Oil Spill Effects

Air Quality section briefly describes the potential air quality impacts from a very large oil spill.

Notes: 1990 CAA is the Clean Air Act Amendments of 1990. 

 OCS refers to the Alaskan Outer Continental Shelf. 

 EP refers to the Shell Offshore Inc. (Shell) Revised Exploration Plan (EP) Outer Continental Shelf 

Lease Exploration Plan, Camden Bay, Alaska 

 BACT is Best Available Control Technology 

 ORR is owner-requested restrictions to emissions 

 GHG refers to greenhouse gases. 

In addition to the information provided in this EA, the Shell Offshore Inc. (Shell) Revised Outer 

Continental Shelf Lease Exploration Plan, Camden Bay, Alaska, (2011 Camden Bay EP) provides an 

examination of air quality conditions and impacts. The analysis is supplemented by information in the 

Environmental Impact Analysis (EIA) (2011 Camden Bay EIA), attached to the EP as Appendix F, and 

provides a thorough air quality analysis. Further, information regarding the inventory of emissions, 

computer modeling, and results of the ambient air analysis is included in the air operating permits 

submitted by Shell to Environmental Protection Agency (EPA) Region 10 in Seattle. The review of air 
2012 Shell Camden Bay EP EA 

D-2 Air Quality - Summary of Shell documents

quality impacts in this EA examined and relied on the information in the Shell documents, which are 

summarized below in Table D-2 through Table D-4. Table D-2 summarizes Shell documentation that is 

relevant to the air quality assessment. 

Table D-2 Summary of Shell documents providing information relevant to the overall assessment of air quality 

conditions and impacts. 

Shell Exploratory Plan and EIA Documents and Relevant Sections 

Shell Revised Outer Continental Shelf Lease Exploration Plan, Camden Bay, Beaufort Sea, Alaska, May 2011 (2011 Camden Bay 

EP)

The main body of the 2011 Camden Bay EP provides air quality information in two sections, Section 7.0 and Section 13. In 

Section 7.0, Shell presents the physical characteristics of the sources proposed for the EP, provides the emission limitation 

measures, discloses the annual emission inventories, and provides the results of the ambient air analysis for both the Kulluk

and the Discoverer. Section 13.0 provides the same type of emission information as given in Section 7.0, but for the support 

vessels and aircraft. 

Section 7.0 

Section 13.0 

Table 7.a-2 

Table 7.a-3 

Table 7.a-8 

Table 7.e-1 

Table 7.f-1 

Table 7.f-2 

Table 7.f-3 

Table 7.f-4 

Table 13.a-3 

Table 13.b-1 

Table 13.b-2 

Appendix F 

Air Emissions Information, including distance to shore 

Support Vessels and Aircraft Information 

Projected Hourly Emissions from the Kulluk (Individual Source) and Support Vessels (Source 

Groups) 

Vessel Source Group Annual Maximum Emissions [Kulluk] 

Annual Potentials to Emit for the Discoverer Emission Units and Associated Fleet 

BOEMRE Exemption Results 

Summary of Maximum Estimated Concentrations 

Summary of Maximum Impacts at the Nearest Villages on the Beaufort Sea Coast 

Summary of Impacts on Air Quality 

Summary of Maximum Modeled Impacts – Beaufort Sea 

Aircraft Flights and Frequency 

Kulluk Support Vessel Source Group Annual Maximum Emissions 

Discoverer Support Vessel Source Group Annual Maximum Emissions 

Environmental Impact Analysis (EIA) (see below) 

Shell Environmental Impact Analysis (EIA) Revised Outer Continental Shelf Lease Exploration Plan, Camden Bay, Beaufort Sea, 

Alaska, May 2011 (2011 Camden Bay EIA)

In addition to the sections listed below, an evaluation of air emissions on other natural resource categories, such as sea ice,

water quality, fish, birds, mammals, whales, and lower trophic organisms, are included in the EIA: 

Section 1.5.6 

Section 2.8 

Section 3.1 

Section 4.1.2 

Section 4.2.3 

Section 4.4 

Table 2.2-6 

Table 2.8-1 

Table 2.8-2 

Table 3.1.7-1 

Table 3.1.7-2 

Clean Air Act 

Air Emissions 

Climate and Meteorology, including Section 3.1.7, Air Quality 

Air Quality 

Cumulative Impacts, Air Quality 

Analysis of the Probability of a Large or Very large Oil Spill and Potential Impacts; subsection, 

Impacts of a Very Large Oil Spill (discusses air quality) 

Aircraft Flights and Frequency 

Kulluk Annual Potentials to Emit 

Discoverer Annual Potentials to Emit 

National and Alaska AAQS and Representative Shoreline Baseline Concentrations 

Reported Air Quality Values – Badami Monitoring Station 

Shell proposes two potential drill platforms for the EP, each with differing emissions signatures. Table 

D-3 summarizes the Drill Vessel Kulluk's air quality documentation. Kulluk is not self propelled. 

Table D-3 Kulluk Air Operating Permit Application and Associated Documents 

Air Sciences Inc., Shell Alaska Outer Continental Shelf (OCS) Beaufort and Chukchi Seas Exploratory Drilling Program: Kulluk 

Floating Drilling Platform – Air Quality Impact Modeling Protocol, January 20, 2010; including Appendix A, the emission calculations.

This document is the air operating permit modeling protocol for the emission inventory and ambient air analysis for the 

Kulluk in both the Chukchi and Beaufort seas. Also provided is a photograph of the floating platform. None of the tables 

from this document were used because the data was later updated. 

Air Sciences Inc., Supplement to EPA OCS Operating Permit Application – Shell Beaufort Sea, Alaska Exploratory Drilling Program: 

Conical Drilling Unit Kulluk, February 28, 2011 

Tables from this permit were not used because the data was updated. See below. 

Air Sciences Inc., OCS Permit Applications Conical Drilling Unit Kulluk Beaufort Sea, March 29, 2011

The original permit, dated February 28, 2011, was declared incomplete by U.S. Environmental Protection Agency (EPA) 

and this supplement was submitted. Shell is awaiting a reply to this submittal. The permit must be approved as a 

condition of the approval of the EA. 

Air Sciences Inc., Engineering Calculations, April 28, 2011 

This is an EXCEL spreadsheet provided to BOEMRE, see tab [BOEMRE_Tables], [GHGTable], [SCR-NH3 emis] 
2012 Shell Camden Bay EP EA 

Air Quality - Regulatory Overview D-3

The drill ship M/V Discoverer may be used in lieu of the Kulluck. Table D-4 summarizes the Drill Ship 

Discoverer's air quality documentation. 

Table D-4 Discoverer Permit and Associated Documents 

ENVIRON, Outer Continental Shelf Pre-Construction Air Permit Application, Frontier Discoverer Beaufort Sea Exploration Drilling 

Program, prepared for Shell Offshore, Inc., Revised January 2010 

This is the revised permit. Emissions of at least one pollutant were shown to be greater than 250 tons per year, requiring 

a Prevention of Significant Deterioration (PSD) permit application. 

EPA, Statement of Basis for Proposed OCS PSD Permit No. R10OCS/PSD-AK-2010-01, February 17, 2010 

EPA, OCS PSD Permit to Construct, Permit Nbr: R10OCS/PSD-AK-2010-01, Issuance Date: April 9, 2010; this permit is for the 

Discoverer in the Beaufort Sea. 

Air Sciences Inc., Discoverer Drillship Impact Evaluation for SO2 and NO2 using AERMOD – Chukchi and Beaufort Seas, Shell 

Alaska Exploratory Drilling Program, March 18, 2011; including Attachment A, the emission calculations; this would be considered 

the modeling protocol for the Discoverer air quality analysis. 

Based on comments on the previous air operating permit submitted for the Discoverer, Shell prepared a supplemental 

analysis of the new one-hour SO2 and NO2 standards. 

Table 2-6 

Table 3-9 

Annual Maximum Emissions for Each Source Group 

Summary of maximum Modeled Impacts – Beaufort Sea [1-hour NO2 and 1-hour SO2 only] 

Air Sciences Inc., Technical Memorandum to Shell, AERMOD Air Quality Impact Analysis for NO2, SO2, PM2.5, PM10, CO, and NH3 – 

Discoverer Drillship, May 19, 2011; including Attachment A, the emission calculations 

This technical memorandum is a supplement to the March 18 and April 29, 2011, AERMOD Impact Reports. The 

memorandum provides updated ambient air analysis data for the Discoverer for both the Chukchi and Beaufort seas. The 

permit application was under remand at the time of the preparation of this EA. The permit must be approved as a 

condition of the approval of the EA. 

 

Table 2-6 (Revised) 

Table 1 

Table 3 

Table 5 

Annual Maximum Emissions for Each Source Group (Discoverer) 

Beaufort Sea Background Data Sources and use of Background Data 

Summary of Maximum Modeled Impacts – Beaufort Sea 

Summary of maximum Impacts at the Nearest Villages on the Beaufort Coast 

D-1. Regulatory Overview 

The outside air, referred to in the regulations as ambient air, becomes polluted when harmful gases and 

particles build up in concentrations sufficient to directly or in indirectly cause measurable damage to 

human health, wildlife, or property (Monks, Granier, & Stohl et al., 2009). Thus, emissions of pollutants 

and the buildup of pollutant concentrations are regulated under local, state, and federal regulations. 

This assessment of air quality is prepared pursuant to the National Environmental Policy Act (NEPA, 

1969) and is regulated primarily by the requirements of the Clean Air Act (CAA, 1990). The ambient air 

in Alaska is further regulated through the state’s Air Quality Management Program contained in the State 

Implementation Plan (ADEC, 2010c). When a proposed federal action is expected to cause emissions of 

any of the pollutants regulated under the CAA, the environmental review must contain an assessment of 

air quality. The assessment should include a description of existing conditions of sufficient scope and 

depth to discern the baseline characteristics of air quality over the project area. The assessment should 

also include an analytical evaluation of the projected emissions under each alternative considered in the 

environmental assessment. The project in the Beaufort Sea proposes the operation of a drillship and 

various support vessels, which require burning of fossil fuels to operate. Operation of the ships’ engines 

will create emissions of regulated pollutants, thus this environmental review requires consideration of 

emissions from the proposed project. 

The condition of air quality is measured and reported in the environmental review relative to established 

criteria, or standards, that define the normal concentration of specific pollutants in the ambient air. Under 

the CAA, the Environmental Protection Agency (EPA) is responsible for establishing and maintaining the 

National Ambient Air Quality Standards (NAAQS) (National Primary and Secondary Ambient Air 

Quality Standards, 2010), which limit concentrations of the following potentially harmful air pollutants, 

known as the criteria pollutants: 

 Carbon monoxide (CO) 

 Lead (Pb) 

 Nitrogen dioxide (NO2) 
2012 Shell Camden Bay EP EA 

D-4 Air Quality - Regulatory Overview

 Ozone 

 Particulate matter (PM2.5 and PM10) 

 Sulfur dioxide (SO2) 

For each of these pollutants, the EPA establishes primary standards intended to protect public health, and 

secondary standards for the protection of other aspects of public welfare, such as preventing materials 

damage, preventing crop and vegetation damage, and assuring good visibility. Each state establishes 

standards similar to the NAAQS and publishes the standards in the State Implementation Plan (SIP). 

State standards may be more stringent than the NAAQS and could include additional pollutants. The 

Alaska Department of Environmental Conservation (ADEC) established ambient air quality standards for 

Alaska, which are published in the Alaska SIP (ADEC State Implementation Plan, 2010). A summary of 

the Alaska AAQS and the NAAQS is provided in Table D-5. The table defines the standards in terms of 

pollutant concentrations, stated either in parts per million (ppm), micrograms per cubic meter (g/m3

), or 

in milligrams per cubic meter (mg/m3

). 

Table D-5 Alaska and National Ambient Air Quality Standards. 

Pollutant Averaging 

Period Alaska AAQS National NAAQS (Primary and/or Secondary Standards) 

8-hour 10 mg/m3 10 mg/m3 Primary Only Carbon Monoxide (CO) 

1-hour 40 mg/m3

 40 mg/m3 Primary Only 

Rolling 3-month 0.15 g/m3 0.15 g/m3

 (2008 Standard) Both 

Lead 

Calendar Quarter Not Applicable 1.5 g/m3

 (1978 Standard) Both 

Annual 100 g/m3

 100 g/m3 Both 

Nitrogen Dioxide (NO2) 

1-hour NA 0.1 ppm (2010 Standard) Primary Only 

8-hour 

(2008 Standard) 0.075 ppm 0.075 ppm Both 

8-hour 

(1997 Standard) Not Applicable 0.08 ppm Both Ozone 

1-hour Not Applicable 0.12 ppm Both 

Annual 15.0 g/m3

 15.0 g/m3 Both 

Particulate Matter (PM2.5) 

24-hour 35 g/m3

 35 g/m3 (2006 Standard) Both 

Particulate Matter (PM10) 24-hour 150 g/m3 150 g/m3 Both 

Annual 80 g/m3

 80 g/m3 Primary Only 

24-hr 365 g/m3

 365 g/m3 Primary Only 

30-minute 50 g/m3 Not Applicable 

3-hour 1300 g/m3

 1300 g/m3 Secondary Only 

Sulfur Dioxide 

(SO2) 

1-hour Not Applicable 0.075 ppm (2010 Standard) Primary Only 

Ammonia (NH3) 8-hour 2.1 mg/m3 Not Applicable 

Sources: Alaska Department of Environmental Conservation (ADEC). Ambient Air Quality Standards. 18 ACC 

§50.010, 2010. 

 EPA. National Primary and Secondary Ambient Air Quality Standards. 40 CFR Part 50.4 – 50.13. 

Each air quality standard is subject to limitations, such as restrictions on how many times during a 

calendar year a standard may be violated and still comply with the standard. These limitations are 

provided in the federal regulations at 40 CFR Part 50.4-50.13, National Ambient Air Quality Standards; 

for the State of Alaska, the limitations are stated in the Alaska Administrative Code (AAC), Title 18, 

Chapter 50, Air Quality Control. Several of the NAAQS have been recently established or revised. The 

relevant EPA code revisions are listed in the following sections that include explanations of the revisions 

and implications to the Proposed Action. 
2012 Shell Camden Bay EP EA 

Air Quality - Lead D-5

D-1.1. Lead 

The EPA updated the lead standard in 2008 to add a rolling three-month average of 0.15g/m3

(73 FR 66964, 11/12/2008). The existing 1978 standard, 1.5 μg/m3

 as a quarterly average, remains in 

effect for some areas previously designated nonattainment for the older standard, and until the appropriate 

SIPS to attain or maintain the 2008 standard are approved. The 1978 quarterly average is not listed in the 

Alaska SIP as a standard; however, ADEC submitted a request in April 2010 to amend Alaska’s State Air 

Quality Control Plan, as part of the SIP, to adopt the NAAQS for lead (ozone, and PM2.5 are also 

included); approval of the Alaska amendment by EPA is pending (ADEC, 2010c). 

Lead is not a pollutant considered in the air quality impacts analysis for this EA because lead is not a 

pollutant resulting from burning diesel fuel. The criteria pollutants of concern for the Proposed Action 

are CO, PM, NOX, and SOX. 

D-1.2. Nitrogen Dioxide (NO2) 

The EPA final rule for the new one-hour standard was published in February 2010 (75 FR 6474, 

2/9/2010). The annual average concentration standard for nitrogen dioxide is sometimes stated as 

0.053 ppm (40 CFR Part 50.22(c)). For the purpose of the emission inventory in this analysis, emissions 

of nitrogen oxides (NOX) are conservatively considered to be entirely composed of NO2. Shell 

demonstrated in the ambient air analysis included the operating permits that emissions from the Proposed 

Action would comply with this new standard (Shell, 2011b). 

D-1.3. Ozone 

The EPA has made several adjustments in recent years to the standard for ozone. The EPA proposed a 

revision to the 2008 eight-hour standard and has delayed the final rule until July 29, 2011. The final rule 

is proposed to be an annual standard within the range of 0.060 to 0.070 ppm (73 FR 16436, 3/28/2008; 

75 FR 2938, 1/19/2010; Kelly, 2010). The ADEC submitted a request in April 2010 to amend Alaska’s 

State Air Quality Control Plan, as part of the SIP, to adopt the NAAQS for ozone (lead and PM2.5 are also 

included). Approval by EPA is pending. Ozone is not specifically addressed in the air quality assessment 

because ozone is not a pollutant emitted directly from any source. Rather, ozone is formed in the 

atmosphere in the presence of precursor pollutants, nitrogen oxides (NOX) and volatile organic 

compounds (VOC) and sunlight. Thus the levels of NOX and VOC are an indication of potential ozone 

development. The air quality analysis for the Proposed Action includes the projected emissions of NOX

and VOC (Shell, 2011a; Shell, 2011d). 

D-1.4. Particulate Matter (PM10 and PM2.5) 

The newest standard for PM2.5 is the 24-hour average concentration set at 35 g/m3

 (71 FR 61144, 

10/17/2006). The ADEC submitted a request in April 2010 to amend Alaska’s State Air Quality Control 

Plan, as part of the SIP, to adopt the NAAQS for PM2.5 (lead and ozone are also included). Approval by 

EPA is pending. Shell demonstrated in the ambient air analysis included the operating permits that 

emissions from the Proposed Action would comply with this new standard (Shell, 2011a; Shell, 2011d). 

D-1.5. Sulfur Dioxide (SO2) 

The EPA updated the SO2 standards to include a primary one-hour average of 0.75 ppm; at the same time 

EPA revoked both the primary annual and 24-hour standards, effective August 23, 2010 (75 FR 35520, 

6/22/2010). However, the two revoked standards will stay in effect for an interim time until the required 

SIPs are approved, and also for one year after the new designations are made. This will serve the antibacksliding goals of the CAA. The three-hour standard for SO2 is sometimes stated as 0.5 ppm 

(40 CFR Part 50.59a). For the purpose of the emission inventory in this analysis, emissions of sulfur 

oxides (SOX) are conservatively considered to be entirely composed of SO2. Shell demonstrated in the 

ambient air analysis included the operating permits that emissions from the Proposed Action would 

comply with this new standard (Shell, 2011a; Shell, 2011d). 
2012 Shell Camden Bay EP EA 

D-6 Air Quality - OCS Air Regulations

D-1.6. OCS Air Regulations 

Sources of emission on the Alaskan OCS must be evaluated against the requirements of 40 CFR Part 55, 

referred to as the OCS Air Regulations. The OCS Air Regulations establish the air pollution control 

requirements for OCS sources and procedures for implementation and enforcement of the requirement, 

consistent with Section 328(a)(1) of the CAA. 

For OCS facilities located within 25 miles (40 km) of the state seaward boundary, the air quality 

regulations would be the same as if the facility was located onshore and thus subject to the ADEC air 

quality regulations, published at 18 AAC 50. The extent of the 25-mile boundary is illustrated in Figure 

D-1, showing the proposed drill sites are well within the 25-mile boundary. 

Figure D-1 Map of the project area showing the extent of the 25-mile boundary for 40 CFR Part 55 Air Regulations. 

D-1.7. Definitions 

The following definitions are developed from 40 CFR Part 55.2, and are modified as they would apply 

directly to the Alaskan OCS in the Beaufort and Chukchi seas. The definitions are helpful in describing 

the methods and procedures of the air quality assessment. 

Attainment area – a geographical area where EPA defines the air quality as a clean resource, and pollutant 

concentrations are as good as or better than the NAAQS or the Alaska AAQS. An area may be an 

attainment area for one pollutant and a nonattainment area for others. 

BACT – Best Available Control Technology; any Prevention of Significant Deterioration (PSD) permit 

would be required to use BACT to reduce emissions. 
2012 Shell Camden Bay EP EA 

Air Quality - Definitions D-7

Corresponding Onshore Area (COA) – the onshore area that is geographically closest to the OCS source, 

and applies when the proposed location of the source would be located within 25 miles of Alaska’s threemile seaward boundary. 

De minimis – being so small as to be negligible, as when defined relative to the CAA General Conformity 

Rule (40 CFR part 93.153(c)). A Latin expression meaning “little things.” 

Design concentration – the translation of the emission inventory to pollutant concentrations, with the 

background concentrations added to the project-related concentration values to disclose total maximum 

concentrations. 

Exploratory OCS source – a temporary source on the Alaskan OCS conducted for the sole purpose of 

gathering information. This includes an EP intended to determine the characteristics of the reservoir and 

may involve the extraction of oil and gas. 

Federal waters – those waters located outside the three-mile Submerged Lands Act boundary. 

Major stationary source is defined distinctly depending on the location of the source and the attainment 

status of the associated COA. 

1. PSD rules apply on the state and federal level, only in an attainment area for sources with the 

potential to emit (PTE) of 250 tons per year or more, and only for emissions of NO2, PM10, and 

SO2 (40 CFR Part 52.21(b)(1)(a)). A source that is major for VOC or NOX shall be considered 

major for ozone. 

2. Title V rules for the OCS apply regardless of the attainment status, and apply on the state and 

federal level. Fugitive emissions are not subject to Title V for OCS sources. A major source 

under Title V has the PTE 100 tons per year of any regulated pollutant. Regulated pollutants 

include all the criteria pollutants regulated under the NAAQS; and the Alaska AAQS adds 

reduced sulfur compounds and ammonia. Precursor emissions of VOC are also included 

because VOC is regulated under the general conformity rule (40 CFR Part 93), and VOC are 

related to the definition for a major source of ozone in 40 CFR Part 52.21. 

New OCS source – an Alaskan OCS source not already existing and does not include an action proposing 

modifications for an existing source. The following regulations apply to new OCS stationary sources: 

1. Prevention of Significant Deterioration (PSD) rules apply under 40 CFR 52.21, when the 

source is located beyond 25 miles of Alaska’s three-mile seaward boundary, and applies inside 

the boundary when PSD rules already apply on the COA. The PSD rules apply when the COA 

is designated as attainment; otherwise NSR rules would apply to nonattainment and 

maintenance areas. The North Slope Borough of Alaska is designated as attainment and is 

subject to the PSD rules when the source has the PTE 250 tons per year or more. Alaska adopts 

the rules in 40 CFR Part 52, Subpart C, Air Programs, according to Class designation; and the 

North Slope Borough is a Class II area. Any PSD permits must be approved and issued before 

construction may begin on the project; thus PSD permits are also referred to as pre-construction 

air permits. 

2. Title V of the CAA for the OCS: The federal Title V rule applies to the OCS under 40 CFR 71 

(outside the OCS Part 70 applies for Title V permits), whether or not the source is located 

beyond 25 miles of Alaska’s three-mile seaward boundary, and applies inside the boundary 

where the Title V rule already applies on the COA. Title V air permits are issued by states 

under 40 CFR Part 70 and EPA regional offices issue Title V permits under 40 CFR Part 71 in 

Indian country and in other situations, such as for the OCS. 

Nonattainment area – a geographic area identified by the EPA as not meeting either the NAAQS or the 

Alaska AAQS for one or more of the regulated pollutants. 

OCS source – any equipment, activity, or facility which: 
2012 Shell Camden Bay EP EA 

D-8 Air Quality - Air Operating Permits

1. Emits or has the PTE any air pollutant; 

2. Is regulated or authorized under the Outer Continental Shelf Lands Act (“OCSLA”) 

(43 U.S.C. §1331 et seq.); and 

3. Is located on the OCS or in or on waters above the OCS. This definition shall include marine 

vessels only when they are: 

a. Permanently or temporarily attached to the seabed, erected on the seabed, and used for the 

purpose of exploring, developing or producing resources from the seabed (Section 4(a)(1) 

of OCSLA (43 U.S.C. §1331 et seq.)); or 

b. Physically attached to an OCS facility, in which case only the stationary sources aspects of 

the vessels will be regulated. 

ORR – owner-requested restrictions to emissions applied to operational use and mechanical devices. 

Potential emissions – the maximum emissions of a pollutant from an OCS source operating at its design 

capacity. Any physical or operational limitation on the capacity of a source to emit a pollutant, including 

air pollution control equipment (such as BACT) and restrictions on hours of operation or on the type or 

amount of material combusted, stored, or processed (such as ORR), shall be treated as a limit on the 

design capacity of the source if the limitation is federally enforceable. Emissions from vessels servicing 

or associated with an OCS source shall be considered direct emissions from such a source while at the 

source, and while en-route to or from the source when within 25 miles of the source, and is referred to as 

the PTE for an OCS source. 

Significant Impact Levels (SILs) – ambient air increments caused by a major stationary source, in areas 

designated as Class I, II, or III; increase in pollutant concentration over the baseline concentration; the 

SILs are the maximum allowable increase, measured in micrograms per cubic meter. 

D-1.8. Air Operating Permits 

Air operating permits issued by EPA and ADEC will ensure that emission levels caused by the 2011 

Camden Bay EP will remain low enough to prevent harm to human health and the environment under all 

operating scenarios. Shell’s permit applications include an emission inventory and ambient air analysis 

(dispersion modeling) that include the worst-case highest hourly, enforceable emission rates from the 

Kulluk or Discoverer and its support vessels. (2011 Camden Bay EIA, p 4-5). The CAA regulations 

require certain facilities that emit criteria pollutants or hazardous substances to obtain a permit 

establishing limits on the types and amounts of emissions, governing operating parameters for pollution 

control and monitoring devices, and monitoring and record-keeping requirements. Refer to the definitions 

in this appendix for a major stationary source, new OCS sources, and potential emissions. In this case, 

EPA Region 10 will issue the air permits for the Kulluk and Discoverer. Refer to EA Section 1.3.5, Clean 

Air Act, for more information about air operating permits. 

D-1.8.1. Kulluk Permits 

Shell applied for three air operating permits in the revised application submitted to EPA Region 10 on 

March 29, 2011. The permit application requests a federal Title V permit and two Alaska state permits, 

one a state Title V permit, and second, a state minor source permit. A federal or state PSD permit is not 

necessary because the Kulluk would not have the PTE 250 tons per year of any PSD-related pollutant; the 

Kulluk, therefore, is not considered a major source under the PSD rule on either the federal or state level 

(18 AAC 50.306). Shell has requested concurrent review and consolidation of the permits so that just one 

permit is issued, if approved. The issuance of the permit is required before construction, and is a condition 

of approval of this EA, because the permit includes the Alaska minor permit, which is a pre-construction 

permit. The implementation of BACT strategies and compliance with other provisions of each permit are 

intended to ensure that air emissions are minimized. In the permit application, results of computer 

modeling of the Kulluk operation indicate none of the NAAQS or Alaska AAQS would be equaled or 

exceeded. 
2012 Shell Camden Bay EP EA 

Air Quality - Discoverer Permit D-9

CAA Title V Permit. A Title V air operating permit is required for a stationary source with actual or 

limited PTE 100 tons per year or more of any of the regulated pollutants. The projected emissions 

inventory of Kulluk operations, given in Section 4.2.1.1 Table 10, shows annual emissions would exceed 

the 100-tons-per-year threshold for NOX, and CO. As such, Shell is required to obtain a Part 71 permit 

from EPA Region 10 (40 CFR Part 71). The requirement for a CAA Title V permit includes the 

requirement to conduct an ambient air analysis (dispersion modeling) to compare results to the NAAQS 

and the Alaska AAQS (40 CFR Part 71.2, Definitions, Applicable Requirement (13)). 

Alaska Title V Permit. Shell must obtain a Title V permit from the State of Alaska consistent with the 

federal requirements under 40 CFR Part 71(18 AAC 50.326); essentially the same as a federal Title V 

permit. In essence, the State of Alaska does not have a “Title V” program. Rather, the rules of the federal 

Title V program under Part 71 are adopted into the Alaska Administrative Code (18 AAC 50.40(j)). The 

agency with jurisdiction depends on the location of the source on the OCS. Sources located outside the 

three-mile Submerged Lands Act boundary are considered to be in federal waters. The Proposed Action is 

located, at the least, 16 miles from shore. Thus, the Alaska Title V permit is subject to the approval of 

EPA Region 10 (18 AAC 50.326(k)) rather than ADEC. Shell has requested in the permit application that 

EPA Region 10 consolidate the federal Part 71 permit and the Alaska Title V permit into a single permit 

to facilitate the notice, and the comment process. 

Alaska Minor Permit. The need for an Alaska Title V permit does not exempt a stationary source from 

the requirement for a minor pre-construction permit under 18 AAC 50.502. Alaska requires a preconstruction minor permit when a stationary source exceeds the thresholds given in 18 AAC 50.502(c)(1) 

(see also 18 AAC 50.502(a)(2)). Projected emissions caused by operation of the Kulluk would exceed the 

limits for emissions of PM10 and NOX. As such, a minor permit is required; and because the Kulluk would 

be located in federal waters, the jurisdiction for the approval and issuance of the minor permit rests with 

EPA Region 10. Shell has requested in the permit application that EPA process the Alaska minor permit 

and the Alaska Title V permit concurrently. The Alaska pre-construction minor permit is driving the 

requirement for issuance of the permit prior to construction. Any approval of the 2011 Camden Bay EP 

by the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) will be 

conditional until all air operating permits for the Kulluk are issued, as required. Under the conditional 

approval, the Application for Permit to Drill (APD) cannot be approved by BOEMRE, and 

commencement of activities will not be authorized, until receipt of all necessary permits and 

authorizations. The permit application and all associated documentation related to the Kulluk air operating 

permit are available online at: yosemite.epa.gov/r10/airpage.nsf/Permits/Kullukap/ 

D-1.8.2. Discoverer Permit 

The EPA Region 10 provided Shell with a PSD Permit to Construct No. R10CS/PSD-AK-0901 for the 

Discoverer, which would cover the planned exploration in Camden Bay, should Shell decide to use the 

Discoverer for drilling. The permit was remanded to the EPA in December 2010 for revision. The EPA 

has revised the permit based on additional information provided by Shell. The draft permit is subject to a 

30-day public comment period, as well as a public hearing, before EPA can issue the final permit. The 

EPA began accepting public comments on July 6, 2011, and will accept public comments through August 

5, 2011. The final permit, if approved, will be issued after comments from the pubic and key stakeholders 

are reviewed and considered. Any approval of the 2011 Camden Bay EP by the BOEMRE will be 

conditional until all air operating permits for the Discoverer are issued, as required. Under the 

conditional approval, the APD cannot be approved by BOEMRE, and commencement of activities will 

not be authorized, until receipt of all necessary permits and authorizations. The permit application and all 

associated documentation related to the Discoverer air operating permit are available online at: 

www.epa.gov/region10/pdf/permits/shell/discoverer_beaufort_draft_revised_2011_permit_070111.pdf. 
2012 Shell Camden Bay EP EA 

D-10 Air Quality - NEPA Air Quality Analysis

D-2. NEPA Air Quality Analysis 

In the course of preparing the air operating permits, Shell conducted an analysis of emissions for the 

Kulluk and for the Discoverer, which includes all the marine support vessels associated with each 

drillship. The analysis included computer modeling, which was conducted according to the protocols 

submitted to EPA by Shell for the Kulluk (Shell, 2010) and for the Discoverer (Shell, 2011b). The 

analysis and air quality modeling conducted by Shell was required for the application of a PSD permit for 

the Discoverer, and for the Title V and pre-construction permits for the Kulluk. The air quality assessment 

required for this NEPA environmental review by the BOEMRE is distinct from the requirements for an 

air permit application and relies, in part, on the emission inventory and the ambient air analysis 

(dispersion analysis) conducted by Shell for the permit applications. However, the finding by BOEMRE 

for air quality impacts in this EA is a finding based on the BOEMRE independent review of air quality 

impacts and not a finding on the permits. The emission inventory includes the following pollutants for 

compliance with the NEPA guidelines, Alaska regulations, and includes greenhouse gases: 

 Nitrogen oxides (NOX) 

 Fine particulate matter (PM2.5) 

 Coarse particulate matter (PM10) 

 Carbon monoxide (CO) 

 Sulfur oxides (SOX) 

 Volatile organic compounds (VOC) 

 Lead (Pb) 

 Ammonia (NH3) 

 Reduced sulfur compounds (RSC) 

 Carbon dioxide equivalent emissions (CO2e) 

The emission inventories for both the drillships Kulluk and Discoverer are provided in EA Section 

4.2.1.1, Table 10 and Table 11. The emission inventory was translated into an ambient air analysis 

through computer dispersion modeling using the EPA AERMOD model. The dispersion analysis was 

conducted for the NAAQS and Alaska AAQS, and includes: 

 Nitrogen dioxide (NO2) 

 Fine particulate matter (PM2.5) 

 Coarse particulate matter (PM10) 

 Carbon monoxide (CO) 

 Sulfur dioxide (SO2) 

 Ammonia (NH3) 

The results of the dispersion analysis are provided in the application documents for the air operating 

permits for the Kulluk (Shell, 2011d), and for the Discoverer, (Shell, 2011a). Two analyses were 

conducted, one to initially compare the project-only emissions to the federal and Alaska PSD SILs 

(incremental increase thresholds), and one to compare the design concentrations to the NAAQS and the 

Alaska AAQS should any of the SILs be exceeded. The results of the analyses are provided in Table D-6 

and Table D-7. 
2012 Shell Camden Bay EP EA 

Air Quality - NEPA Air Quality Analysis D-11

Table D-6 Prevention of Significant Deterioration (PSD) Analysis. Comparison of pollutant concentrations, associated 

only with the Proposed Action, to the PSD SILS for the COA Class II area. 

Pollutant and 

Averaging Period 

Project Pollutant Concentrations 

(g/m3) 

Pollutant and Kulluk Discoverer 

Averaging Period

PSD 

Increments Nuiqsut Deadhorse Kaktovik Other1/ Deadhorse Kaktovik 

Nitrogen Dioxide 

(NO2) Annual 25 0.1 0.2 0.2 0.1 0.03 0.1 

Coarse Particulate 

Matter (PM10)

2/ 24-hour 30 0.3 0.6 1.5 0.1 0.1 0.3 

3-hour 512 4.8 5.2 8.1 1.0 0.7 2.0 

Sulfur Dioxide (SO2) 24-hour 91 2.7 2.9 4.2 0.6 0.4 1.3 

Annual 20 0.5 0.6 0.9 0.1 0.1 0.3 

Note: SILs are Significant Impact Levels, or maximum allowable increases (40 CFR 55.21(c), for Class II 

areas. 

 COA is Corresponding Onshore Area (40 CFR Part 55.2). 

Sources: Shell Offshore Inc., February 28, 2011, Supplement to EPA Outer Continental Shelf (OCS) 

Operating Permit Application [Kulluk], prepared by Air Sciences Inc., Table 3-11, Summary of 

Maximum Impacts at the Nearest Villages on the Beaufort Coast, p. 64. 

 Shell Offshore Inc., May 19, 2011, AERMOD Air Quality Impact Analysis of NO2, SO2, PM2.5, PM10, 

CO, and NH3 – Discoverer Drillship: Supplement to March 18 and April 29, 2011, AERMOD Impact 

Reports, Technical Memorandum prepared by Tim Martin, Air Sciences Inc., Table 5, Summary of 

Maximum Modeled Impacts at the Nearest Villages on the Beaufort Coast, p.17. 

 Shell Offshore Inc., March 18, 2011. Discoverer Drillship Impact Evaluation for SO2 and NO2 Using 

AERMOD, Table 3-9 Summary of Maximum Modeled Impacts – Beaufort Sea, p. 60. 

 40 CFR Part 52.21(c) Prevention of Significant Deterioration of Air Quality, for Class II areas. 

1/ As represented by 50 km from nearest leases, defined in Shell Offshore Inc., March 18, 2011. 2/ 40 CFR Part 52.21(c) includes a threshold for PM10 annual arithmetic mean. This standard has been revoked by EPA on 

December 18, 2006 (71 FR 61144, dated 10/17/2006); as such, ambient air computer modeling was not conducted for this 

standard. 

Shell prepared an emission inventory and conducted a dispersion analysis for operations using the 

drillship Kulluk, and alternately, for the drillship Discoverer. Both analyses were folded into the 

application documents for the air operating permits. The BOEMRE thoroughly reviewed and evaluated 

the methods and results of the analyses prepared by Shell to ensure the accuracy and credibility of the 

results. Refer to Section 1.3.5, Clean Air Act, for further information about the air operating permits. 

The results of the PSD analysis show concentrations of pollutants associated solely with the Proposed 

Action would be less than, and therefore compliant with, the maximum incremental increases allowed 

under the PSD rules under 40 CFR Part 52.21(d). The incremental increases reflect pollutant 

concentrations without regard or inclusion of the existing background concentrations. 

Table D-7 Ambient Air Analysis. Comparison of pollutant concentrations associated with the Proposed Action, 

together with the background concentrations onshore, to the NAAQS and Alaska AAQS. 

Pollutant Concentrations (μg/m3) 

Design Concentrations 

Pollutant and 

Averaging Period NAAQS and Alaska AAQS

Kulluk Discoverer

1-hour 188 108.7 81.6 

Nitrogen Dioxide (NO2) 

Annual 100 4.0 4.8 

24-hour 35 14.0 19.2 

Fine Particulate Matter (PM2.5) 

Annual 15 2.4 3.5 

Coarse Particulate Matter (PM10) 24-hour 150 75.7 65.8 

Sulfur Dioxide (SO2) 1-hour 196 36.5 35.0 
2012 Shell Camden Bay EP EA 

D-12 Air Quality - Air Quality Levels of Effect

Pollutant Concentrations (μg/m3) 

Design Concentrations 

Pollutant and 

Averaging Period NAAQS and Alaska AAQS

Kulluk Discoverer

3-hour 1300 27.4 24.8 

24-hour 365 15.0 10.1 

Annual 80 4.0 3.8 

1-hour 40000 3,019.0 2,240.0 Carbon Monoxide (CO) 

8-hour 10000 1,576.0 1,215.0 

Ammonia (NH3) 8-hour 2100 6.6 1.0 

Sources: Shell Offshore Inc., February 28, 2011, Supplement to EPA Outer Continental Shelf (OCS) Operating 

Permit Application [Kulluk], prepared by Air Sciences Inc., Table 3-9, Summary of Maximum Modeled 

Impacts, p. 61. 

 Shell Offshore Inc., May 19, 2011, AERMOD Air Quality Impact Analysis of NO2, SO2, PM2.5, PM10, 

CO, and NH3 – Discoverer Drillship: Supplement to March 18 and April 29, 2011, AERMOD Impact 

Reports, Technical Memorandum prepared by Tim Martin, Air Sciences Inc., Table 3, Summary of 

Maximum Modeled Impacts – Beaufort Sea, p.15. 

The results of the ambient air analysis for both drillships show concentrations of pollutants, including 

background emissions (design concentrations), would be less than the maximum ceiling allowed by the 

NAAQS and the Alaska AAQS, defined under 40 CFR Part 50 and 18 AAC 50.010, required under the 

Clean Air Act Section 176(c)(1), and compliant with provisions of the NEPA and the Alaska SIP. 

D-3. Air Quality Levels of Effect 

The levels of effect applied to the air quality analysis are based on the results of two levels of analyses, 

the emission inventory, and if required, the more rigorous ambient air analysis based on computer 

dispersion modeling. Further, the levels of effect consider whether the Proposed Action is: 

 Temporary or permanent; 

 Located within or beyond 25 miles from the Alaska seaward boundary (25-mile threshold); 

 Adjacent to a COA that is designated attainment or nonattainment; and 

 Associated with a COA that is designated as a Class I, Class II, or Class III area. 

The levels of effect are first defined by applying threshold values to the emission inventory. The emission 

inventory is the first step in assessing the potential for adverse impacts to air quality due to a proposed 

federal action. While the inventory is not intended to define the severity of the impact, the character of the 

emission inventory can provide insight to the potential for future impacts. An inventory that demonstrates 

emissions that equal or exceed established thresholds can initiate further more rigorous analyses that will 

provide the ‘hard look’ required under NEPA (Robertson v. Methow Valley Citizens Council, 1989). 

Inherent in the hard look provision is the necessity to consider and investigate the relevant issues using 

the most appropriate expertise and methodology available. Thus, BOEMRE applied thresholds provided 

in the long-established EPA guidelines for air operating permits, the PSD permit and the Title V permit. 

The OCS Air Regulations require air operating permits under 40 CFR Part 55.6, Permit Requirements, 

and include Clean Air Act (CAA) Title V permits and PSD permits. 

D-3.1. CAA Title V Requirements 

The requirement for a Title V permit for an OCS source is found at 40 CFR Part 55.6(c)(3), which 

invokes the rules under 40 Part 71. The Part 71 Title V permit program is intended to document a state’s 

major sources of stationary emissions regardless of the attainment status of the geographical area. A Part 

71 permit is required for projects with stationary sources proposed on the OCS regardless of whether the 

project is located within or beyond the 25-mile threshold. The Part 71 permit is an enforceable permit 

issued by the EPA after the source has begun to operate. Under Part 71, a permit is required when a 

stationary source has the PTE 100 tons or more of any regulated pollutant, including VOCs 
2012 Shell Camden Bay EP EA 

Air Quality - Air Quality Levels of Effect D-13

(42 USC 7602(j); 42 USC 7661a(b)(3)(B)(ii)(I, II, & III)). Thus, for the purpose of the BOEMRE air 

quality levels of effect, a proposed action that has the PTE less than 100 tons per year of any regulated 

pollutant would be considered a negligible source. In summary, a Title V Part 71 air operating permit on 

the Alaska OCS applies under the following conditions: 

 Attainment or nonattainment area 

 Obtain after construction 

 Within or beyond the 25-mile boundary on the OCS adjacent to the North Slope Borough 

 Federal EPA authority (EPA has authority on the OCS, whereas the Part 70 Title V is 

authorized by the state agency; Part 70 is nearly identical to Part 71) 

 Major stationary source has emissions equal to or greater than 100 tons per year 

 Applies to all regulated criteria and precursor pollutants 

D-3.2. PSD Requirements 

The EPA requires operating permits for new and modified stationary sources, referred to as preconstruction permits. A pre-construction permit is enforceable and must be obtained before construction 

on the federal action commences. This permit program is promulgated under the New Source Review 

rules (NSR), where NSR applies to areas of nonattainment and PSD rules apply to the attainment areas. 

The PSD permit program is intended to limit the amount of pollution emitted from a major stationary 

source to the best extent possible and reasonable in an area with otherwise clean air. On the OCS, a PSD 

permit may be required when the location of the proposed action is either within or beyond the 25-mile 

threshold (40 CFR Part 55.13(d)). 

A project sponsor will apply for a PSD permit when a stationary source on the OCS has the PTE 250 tons 

or more of any regulated pollutant, including VOCs, even after BACT and ORR are applied 

(40 CFR 52.21(b)(1)(i)(b)). Thus, an action proposed on the OCS that creates a new stationary source 

with the PTE 250 tons per year or more of any criteria or precursor pollutant is defined as a major source. 

Under the rules for a PSD major source, an ambient air analysis is necessary to compare results to SILs 

defined in the PSD rule. 

The EPA establishes SILs for pollutant concentrations under the 40 CFR Part 52.21 PSD rule. The SILs 

apply in much the same way as the emission thresholds apply to the emission inventory, except SILs are 

expressed in pollutant concentrations, such as parts per million (ppm) or micrograms per cubic meters 

(g/m3

), and are the result of computer dispersion modeling. Referred to as ambient air incremental 

increases, the SILs are applied according to the classification of the Proposed Action’s COA, such as 

Class I, Class II, or Class III. Alaska’s North Slope Borough is a Class II area (i.e. not a wildlife refuge) 

(40 CFR Part 52.21(c)Class II). The SILs applicable to the Alaskan OCS adjacent to the Beaufort and 

Chukchi seas are provided in Table D-6. 

Should the PSD dispersion analysis show that the maximum concentration of these pollutants, attributable 

solely to the Proposed Action, is greater than the SILs, additional analysis is necessary to determine if 

design concentrations would equal or exceed the NAAQS or the Alaska AAQS. The NAAQS and Alaska 

AAQS are given earlier in Table D-7. 

For the purpose of the BOEMRE air quality levels of effect, a proposed action that has the PTE 250 tons 

per year or more of any regulated pollutant would be considered a major source, as under the PSD rules. 

In summary, a Part 52.21 PSD air pre-construction permit for stationary sources on the Alaska OCS 

applies under the following conditions: 

 Attainment or unclassified area 

 Obtain before construction begins (pre-construction) 

 Within or beyond the 25-mile threshold on the OCS adjacent to the North Slope Borough 
2012 Shell Camden Bay EP EA 

D-14 Air Quality - Air Quality Levels of Effect

 Federal EPA authority 

 Major stationary source has emissions equal to or greater than 250 tons per year 

 Requires BACT and/or owner-requested restrictions (ORR) 

 Applies to all New Source Review (NSR) regulated pollutants, which are NO2, PM10, and SO2

 Incorporates the Alaska air quality control rules, which adds emissions of ammonia (NH3) and 

reduced sulfur compounds (RSC) 

 Public comment procedures are required 

D-3.3. Defining the Four Levels of Effect 

Assigning levels of effect to impacts from air emissions on the OCS is limited to four categories, 

negligible, minor, moderate, and major. Generally with air quality assessments, the objective is to 

determine whether or not the proposed action would have the potential to violate federal and state air 

quality standards, meaning the NAAQS and the State AAQS, and thereby demonstrate noncompliance 

with the CAA. Such an action could not be approved by a federal agency. Therefore, assigning 

parameters to the levels of effect first considered two scenarios, compliant and noncompliant federal 

actions. 

Assigning more than one level of effect to a noncompliant outcome would be redundant, as a 

noncompliant action cannot go forward. There are no levels of noncompliance severity, the action simply 

is or is not compliant to the CAA. Consequently, BOEMRE considers only the major level of effect to 

reflect a noncompliant action. A major effect would be defined as a federal action that causes emissions 

that would increase pollutant concentrations to a level that would equal or exceed the NAAQS or the 

Alaska AAQS, which would also be noncompliant to the CAA Section 176(c)(1). By setting the major 

level of effect as a non-complying federal action, there are three remaining levels available to define the 

severity of actions that have an impact, but are ultimately compliant actions. 

To define and assign compliant levels of effect, applicability parameters of the well-established federal 

and Alaska OCS permitting programs were used. When reviewing the various air-permitting programs, 

the potential for adverse air quality impacts are first assessed relative to the emission inventory. Where 

the Title V threshold of potential significance is 100 tons per year, the threshold is 250 tons per year 

under the PSD rules. In both cases, when the action has the PTE less than 100 tons per year, the source is 

not considered a major source. A sensitivity analysis of NOX emissions was conducted to discern the 

effect of limiting emissions to just 100 tons for a season of operations on the Alaska OCS, which is 

approximately 120 days per year. Emissions of NOX were used in the analysis because NOX is the 

limiting pollutant from the operation of drillships and marine vessels, NOX is a pollutant regulated by the 

NAAQS and the Alaska AAQS, and NOX is a PSD regulated pollutant. The highest level of emissions 

resulting from marine vessels operating on the OCS is usually NOX. The sensitivity analysis showed that 

if the vessels proposed for the Discoverer EP (Shell, 2011c) were to operate until the emissions of NOX

reached 100 tons, the operation could continue for only 35 days. This is about 30 percent of the time 

needed to complete the 2011 Camden Bay EP, when drilling only one well would require 34 to 44 days. 

Therefore, a threshold of 100 tons (uncontrolled) is considered by BOEMRE to be a reasonable threshold 

to define a small project. Generally, a negligible level of effect would imply an impact of little importance 

and of so little consequence as to warrant the slightest amount of attention. Indeed, the CAA defines de 

minimis emissions as a project that causes emissions that are less than 100 tons per year in the 

40 CFR Part 93 General Conformity Rule (40 CFR 93.153). As such, the BOEMRE will consider de 

minimis emissions to be negligible for purposes of air quality levels of effect for operations on the OCS. 

Although no ambient air analysis would likely be conducted for such a small project, the emissions would 

be presumed to conform to the Alaska SIP and comply with the NAAQS and the Alaska AAQS. The 

action would be considered compliant to the CAA Section 176(c)(1). 
2012 Shell Camden Bay EP EA 

Air Quality - Air Quality Levels of Effect D-15

The PSD rule considers federal actions to be major stationary sources only when the action causes 

controlled emissions that would exceed 250 tons per year. Therefore, a minor source should capture 

projects with the maximum PTE 100 tons per year or more, but less than 250 tons per year, with or 

without the application of BACT or ORR. It follows that a major source would capture all remaining 

possibilities, which would be projects with the maximum PTE more than 250 tons per year, even with the 

application of BACT and ORR. However, there are scenarios where regardless of whether the action has 

the PTE greater than 250 tons per year of any regulated pollutant, the ambient air analysis (dispersion 

modeling) shows the NAAQS and the Alaska AAQS would be met, ultimately resulting in a compliant 

action. At the same time, there could be instances where actions with emissions below 250 tons per year 

would not meet the air quality standards. Therefore, a second level of analysis was used as a threshold, 

which is the ambient air analysis. 

Depending on the type of air operating permit required under the regulations, the air operating permit may 

include an ambient air analysis, which requires computer dispersion modeling. The results of the ambient 

air analysis can be used to compare project impacts to thresholds that may indicate the potential for 

adverse air quality impacts. The PSD permit program provides Significant Incremental Levels (SIL) for 

three pollutants, which are presented in Table D-6. The SILs depend on the EPA-designated class-level of 

the COA. When the ambient air analysis for these three pollutants shows concentrations below these 

levels, no further analysis is required under PSD; the action is presumed to comply with all the NAAQS 

and the Alaska AAQS. However, should the action exceed these thresholds, further analysis is necessary 

to model all the criteria pollutants to ensure compliance to the full set of air quality standards. Thus, 

actions that exceed the SILs, regardless of the emission inventory, would require additional analysis, and 

would be considered the more severe scenario. In all cases and levels of effect, there would be measurable 

emissions that are unavoidable. Based on this methodology, the following levels of effect are defined for 

air quality impacts and are summarized in Appendix B, Level of Effects Definitions and Abbreviations. 

D-3.3.1. Negligible Level of Effect 

The negligible level of effect reflects a proposed action with de minimis emissions. The proposed action is 

considered a negligible emission source and no further analysis is required. The proposed action is 

presumed to conform to all provisions of the CAA. 

 New sources of air emissions are unavoidable; the proposed action would have maximum 

uncontrolled potential to emit (PTE) emissions that are less than 100 tons per year for any 

regulated criteria or precursor pollutant; as such, the Proposed Action is defined as a negligible 

emission source, and the emissions are de minimis, and 

 Maximum PTE emissions might reflect an inventory reduced by the application of BACT, 

proposed ORR, and other additional controls, if required under state and federal air operating 

and pre-construction permit regulations, and 

 If dispersion modeling was conducted, projected maximum pollutant concentrations 

attributable solely to the proposed action would be less than the PSD SILs, which reflect the 

maximum allowable incremental increase for NO2, PM10, and SO2 for the class level 

designated for the COA; further, the design concentrations (total maximum concentrations 

including background concentrations) are less than any applicable NAAQS or AAAQS, and 

 Annual emissions are presumed compliant with the plans and milestones included in the 

Alaska Air Quality Control Plan, including the Alaska SIP, and 

 Project emissions are presumed to not have the potential to cause or contribute to a violation of 

any NAAQS or AAAQS that defines healthful air quality, and 

 The federal action is considered compliant with the relevant provisions of the Clean Air Act 

1990 Amendments, including Title I, Section 176(c)(1), Limitations on Certain Federal 

Assistance, Title I, Part C, Prevention of Significant Deterioration of Air Quality, and Title III, 

Section 328, Air Pollution from Outer Continental Shelf Activities. 
2012 Shell Camden Bay EP EA 

D-16 Air Quality - Air Quality Levels of Effect

D-3.3.2. Minor Level of Effect 

The minor level of effect reflects a proposed action with emissions that could define a minor or a major 

source of emissions. If the emissions constitute a major source, an ambient air analysis was conducted for 

comparison to the appropriate SILs. The proposed action does not exceed the SILs and no further analysis 

is required. The proposed action is presumed to conform to all provisions of the CAA. 

 New sources of air emissions are unavoidable and either: 

1) The proposed action would have maximum uncontrolled PTE emissions that are more than 

100 tons per year, but less than 250 tons per year, for any regulated criteria or precursor 

pollutant; as such, the proposed action is defined as a minor emission source, or 

2) The uncontrolled PTE emissions equal or exceed 250 tons per year for any criteria or 

precursor pollutant, and maximum controlled PTE emissions are reduced for all pollutants 

to less than 250 tons per year through the application of BACT, ORR, and/or other 

additional controls, as may be required under state and federal air operating and preconstruction permit requirements, and the proposed action is defined as a minor emission 

source, or 

3) The maximum controlled PTE emissions exceed 250 tons per year even with the 

application of BACT, ORR, and/or other additional controls, as may be required under state 

and federal air operating and pre-construction permit requirements, and the proposed action 

is defined as a major emission source, and 

 An ambient air analysis (dispersion modeling) was conducted to project maximum pollutant 

concentrations attributable solely to the proposed action; the pollutant concentrations would be 

less than the PSD SILs, which reflect the maximum allowable incremental increase for NO2, 

PM10, and SO2 for the class level designated for the COA; no further analysis is required, and 

 Annual emissions are presumed compliant with the plans and milestones included in the 

Alaska Air Quality Control Plan, including the Alaska SIP, and 

 Project emissions are presumed to not have the potential to cause or contribute to a violation of 

any NAAQS or Alaska AAQS that defines healthful air quality, and 

 The federal action is considered compliant with the relevant provisions of the Clean Air Act 

1990 Amendments, including Title I, Section 176(c)(1), Limitations on Certain Federal 

Assistance, Title I, Part C, Prevention of Significant Deterioration of Air Quality, and Title III, 

Section 328, Air Pollution from Outer Continental Shelf Activities. 

D-3.3.3. Moderate Level of Effect 

The moderate level of effect reflects a proposed action with emissions that define a major source of 

emissions. An ambient air analysis was conducted for comparison to the appropriate SILs. The proposed 

action exceeds at least one of the SILs and further analysis was required to show compliance to the air 

quality standards. The additional analysis shows none of the air quality standards are exceeded. As such, 

the proposed action is shown to conform to all provisions of the CAA. 

 New sources of air emissions are unavoidable; the proposed action would have maximum 

controlled PTE emissions that equal or exceed 250 tons per year for at least one of the 

regulated criteria or precursor pollutants; as such, the proposed action is defined as a major 

source, and 

 The application of BACT, proposed ORR, and other additional controls, as may be required 

under state and federal air operating and pre-construction permit requirements, would not 

successfully reduce all pollutants to a level below 250 tons per year, and 

 An ambient air analysis (dispersion modeling) was conducted to project maximum pollutant 

concentrations attributable solely to the proposed action; the pollutant concentrations would 
2012 Shell Camden Bay EP EA 

Air Quality - References D-17

equal or exceed at least one of the PSD SILs for NO2, PM10, or SO2 for the class designation of 

the COA, and 

 Further analysis shows the design concentrations would not exceed any of the applicable 

NAAQS or Alaska AAQS, and 

 Annual emissions are compliant with the plans and milestones included in the Alaska Air 

Quality Control Plan, including the Alaska SIP, and 

 Project emissions were shown to not have the potential to cause pollutant concentrations that 

would equal or exceed any of the NAAQS or the Alaska AAQS that define healthful air 

quality, and 

 The federal action is shown to be compliant with the relevant provisions of the CAA, including 

Title I, Section 176(c)(1), Limitations on Certain Federal Assistance, Title I, Part C, Prevention 

of Significant Deterioration of Air Quality, and Title III, Section 328, Air Pollution from Outer 

Continental Shelf Activities. 

D-3.3.4. Major Level of Effect 

The major level of effect reflects a proposed action with emissions that define a major source of 

emissions. An ambient air analysis was conducted for comparison to the appropriate SILs. The proposed 

action exceeds at least one of the SILs and further analysis was required to show compliance to the air 

quality standards. The additional analysis shows at least one of the air quality standards is exceeded. As 

such, the proposed action does not conform to the provisions of the CAA. A project such as this cannot be 

approved by a federal agency. 

 New sources of air emissions are unavoidable; the proposed action would have maximum PTE 

emissions that equal or exceed 250 tons per year for at least one of the regulated criteria or 

precursor pollutants; as such, the proposed action is defined as a major source, and 

 The application of BACT, proposed ORR, and other additional controls, as may be required 

under state and federal air operating and pre-construction permit requirements, would not 

successfully reduce all pollutants to a level below 250 tons per year, and 

 An ambient air analysis (dispersion modeling) was conducted to project maximum pollutant 

concentrations attributable solely to the proposed action; the pollutant concentrations would 

equal or exceed at least one of the PSD SILs for NO2, PM10, or SO2 for the class designation of 

the COA; and 

 Additional analysis shows the design concentrations would exceed at least one of the 

applicable NAAQS or Alaska AAQS, and 

 Annual emissions are not compliant with the plans and milestones included in the Alaska Air 

Quality Control Plan, including the Alaska SIP, and 

 Project emissions were shown to have the potential to cause pollutant concentrations that 

would equal or exceed one or more of the NAAQS and/or one of the Alaska AAQS that define 

healthful air quality, and 

 The federal action is shown to be non-compliant with the relevant provisions of the CAA, 

including Title I, Section 176(c)(1), Limitations on Certain Federal Assistance, Title I, Part C, 

Prevention of Significant Deterioration of Air Quality, and Title III, Section 328, Air Pollution 

from Outer Continental Shelf Activities.
2012 Shell Camden Bay EP EA 

D-18 Air Quality - References

D-4. References: 

Alaska Department of Environmental Conservation (ADEC). 2010a. Ambient Air Quality Standards. 18 

ACC §50.010. 

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