OCS EIS/EA 

MMS 2009-052 

Environmental Assessment 

Shell Offshore Inc. 

2010 Outer Continental Shelf Lease Exploration Plan 

Camden Bay, Alaska 

Beaufort Sea Leases OCS-Y-1805 and 1941 

Prepared by

Office of Leasing and Environment 

Alaska OCS Region

October 2009 
Contents 

1.0 PURPOSE AND NEED 1 

1.1 Purpose of the Proposed Action 1 

1.2 Previous Applicable NEPA Analyses and Biological Opinions 2 

1.3 Statutory Framework 3

2.0 PROPOSED ACTION AND ALTERNATIVE 9 

2.1 Background 9 

2.2 Alternatives 9 

Alternative 1 – Proposed Action 9

 Alternative 2 – No Action 9

 2.3 Description of the Proposed Action 9 

 2.3.1 Overview 9

2.3.2 Drill Sites and Operating Environment 11

 Seafloor Conditions at the Drill Sites 12

 Expected Weather Conditions at the Drill Sites 13

 Expected Ice Conditions at the Drill Sites 14

 2.3.3 Drillship, Support Vessels, and Aircraft 14

 2.3.4 Discharges and Waste Management 15

 2.3.5 Emissions 17

 2.3.6 Sound Generation 18

 2.3.7 Local Hire 20

 2.3.8 Analysis of Accidental Oil Spills 20

 2.3.9 Oil Spill Prevention and Contingency Planning 21

 2.3.10 Compliance with Lease Stipulations 21

 2.3.11 Other Mitigation 27

3.0 DESCRIPTION OF THE ENVIRONMENT AND ANALYSIS OF ENVIRONMENTAL 

CONSEQUENCES 31 

3.1 Introduction 31 

3.2 Alternative 1: Biological Resources 32 

3.2.1 Levels of Effects and Existing Environment for Biological Resources 32

3.2.2 Proposed Action Mitigation for Biological Resources 43

 3.2.3 Effects Analysis for Biological Resources 45

 3.2.4 Overall Conclusion on Effects to Biological Resources 53

 3.2.5 Additional Mitigation for Biological Resources 53

3.3 Alternative 1: Subsistence Activities, Employment, and Community 

 Health 55 

3.3.1 Levels of Effects and Existing Environment for Subsistence Activities 56

3.3.2 Proposed Action Mitigation for Subsistence Activities 59

3.3.3 Effects Analysis for Subsistence Activities 59

3.3.4 Overall Conclusion on Effects to Subsistence Activities 61

3.3.5 Additional Mitigation for Subsistence Activities 61

3.3.5 Employment 62

3.3.6 Community Health 63

3.4 Alternative 1: Air Quality 64 

3.5 Alternative 1: Water Quality 65 

3.6 Alternative 2 – No Action Alternative 67 
3.7 Cumulative Effects 67 

3.7.1 Background 67

3.7.2 Cumulative Effects Under Shell’s Beaufort Sea and Chukchi Sea EPs 68

3.7.3 Other Cumulative Activities and Effects 69

3.7.4 Overall Conclusion on Cumulative Effects 71

4.0 CONSULTATION, AND COORDINATION 73 

 4.1 Public Review of the Exploration Plan 73 

 4.2 Government-to-Government Consultation 74 

 4.3 Endangered Species Act Consultation 74 

 4.4 Marine Mammal Protection Act 75 

 4.5 Essential Fish Habitat Consultation 75 

5.0 REVIEWERS AND PREPARERS 77 

6.0 REFERENCES 79 

7.0 FIGURES 87 

Appendix A. Analysis of Accidental Oil Spills 
 1

1.0 PURPOSE AND NEED 

1.1 Purpose of the Proposed Action 

Shell Offshore Inc. (Shell) submitted to the Minerals Management Service (MMS) an Exploration Plan 

(EP) (2010 Outer Continental Shelf Lease Exploration Plan, Camden Bay, Alaska, dated June 2009; 

deemed submitted August 10, 2009; amended September 18, 2009) (Shell Offshore Inc., 2009a) to 

conduct exploration drilling to evaluate the oil and gas resource potential of two of the company’s Outer 

Continental Shelf (OCS) leases north of Point Thompson near Camden Bay in the U.S. Beaufort Sea. 

Shell acquired these 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 proposes to drill two exploration wells on these leases during the July-October 2010 open-waterdrilling season. One well would be drilled on each of 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 6610, OCS-Y-1941) (Figures 1-1 and 1-2). The drilling operations would be conducted 

using the M/V Frontier Discoverer (Discoverer), a modern drillship that has been retrofitted and ice 

reinforced for operations in Arctic OCS waters. The wells would be drilled consecutively. Shell has 

indicated the Torpedo prospect is their primary target and would be drilled first, if ice conditions permit. 

Shell has submitted the EP under MMS operating regulations at 30 CFR 250 Subpart B. In support of the 

EP, Shell submitted an environmental impact analysis (EIA) (Shell Offshore Inc., 2009b), a revised 

Beaufort Sea Regional oil discharge prevention and contingency plan (ODPCP) for the 2010 drilling 

program (Shell Offshore Inc., 2009c), 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 EP, a project-specific Plan of Cooperation (POC) to 

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

Health, Safety, Security, and Environment (HSSE) Awareness Programs, and other information as 

required MMS regulations and by lease stipulations. 

The MMS has completed technical and environmental review of the 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), we have prepared an EA to determine whether the proposed 

action may result in significant effects (40 CFR 1508.27) that could trigger the CEQ criteria for 

preparation of an environmental impact statement (EIS) and to assist MMS planning and decisionmaking. 

In keeping with CEQ regulations at 40 CFR 1506.5(a),(b) (see below) and the intent of MMS operating 

regulations at 30 CFR 250.227, we have reviewed, evaluated, and verified the information and analysis 

provided in Shell’s EIA, which we used to prepare this EA. A list of MMS staff responsible for 

reviewing, evaluating, and verifying the information submitted by Shell is in Section 4 of this EA. 
 2

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 and Biological Opinions 

The National Environmental Policy Act (NEPA) mandates that Federal agencies conduct an 

environmental review of certain Federal projects. The NEPA review is required 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 MMS has completed numerous NEPA reviews of Arctic OCS activities. In recent years, these NEPA 

reviews relevant to the proposed activities 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, 2008) 

(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). 

• Environmental Assessment – Proposed Oil & Gas Lease Sale 202, Beaufort Sea Planning Area 

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

2006a) (hereafter “Sale 202 EA”). 

• Environmental Assessment – Proposed Oil & 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”). 

These documents are on the MMS website at http://www.mms.gov/alaska/ref/EIS_EA.htm. Relevant 

sections of these documents are summarized and incorporated by reference in this EA. This EA tiers 

from the Beaufort Sea Multiple-Sale EIS. 

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

following documents: 

• Environmental Assessment and 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 
 3

(USDOC, NOAA, NMFS, 2007a). 

• 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). 

(http://www.mms.gov/alaska/ref/BioOpinions/2008_0717_bo.pdf) 

• FWS Biological Opinion for Mineral Management Service’s Proposed Beaufort Sea Natural Gas 

and Oil Lease Sale 186 (USDOI, FWS, 2002).

(http://www.mms.gov/alaska/ref/EIS%20EA/BeaufortMultiSaleFEIS186_195_202/2003_001vol

4.pdf) 

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

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

(http://www.mms.gov/alaska/ref/BioOpinions/2009_0903_BO4BFCK.pdf) 

• Shell Offshore Inc. 2010 Outer Continental Shelf Lease Exploration Plan, Camden Bay, Alaska, 

dated June 2009 (Shell Offshore Inc., 2009a) 

(http://www.mms.gov/alaska/ref/ProjectHistory/Shell_BF/2009_final_EP_camden_bay.pdf) 

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. 

Outer Continental Shelf Lands Act and MMS Operating Regulations 

The OCSLA establishes a four-stage process for exploration and development of the OCS: (1) a five-year 

leasing program for the OCS; (2) individual lease sales; (3) exploration; and (4) development and 

production. The MMS conducts appropriate NEPA review at each stage. 

The MMS is responsible for regulating and monitoring the oil and gas operations on the Federal OCS. 

The MMS 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 MMS for review and approval. Supporting information includes environmental information, 

archeological report, 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 MMS has completed both technical and environmental review of activities proposed in Shell’s EP, 

including evaluation for geohazards and manmade hazards, archeological resources, endangered species, 

sensitive biological features, water and air quality, oil-spill response, and other uses of the OCS. 

The MMS 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 2.3.10 of this EA. 

The MMS 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 
 4

and meaning of regulations by explaining MMS’ intent of requirements. A listing of the Alaska Region’s 

NTLs is published on the Alaska Region website at: http://www.mms.gov/alaska/regs/NTLs.htm. 

Shell is not proposing to use any new or unusual technology (Shell Offshore Inc., 2009a:Section 2c). 

Shell must conduct operations in accordance with MMS’ comprehensive and stringent regulations for 

safety and pollution prevention, which generally are requirements for 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 MMS will not approve an APD until all conditions of EP approval have been met. 

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 inter-agency 

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 MMS to ensure that measures to protect endangered and threatened species are 

implemented and followed. 

The MMS formally consulted 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 MMS formally reinitiated consultation with FWS on the potential effects of OCS oil and gas leasing 

and exploration in the Beaufort and Chukchi Seas. 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 onto 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. 

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

Take Statement (ITS) from NMFS and FWS. 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 MMS has received ITSs from both NMFS and FWS. 

Marine Mammal Protection Act 

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

mammals. The NMFS has jurisdiction over whales and seals, including the bowhead whale, gray whale, 
 5

beluga whale, minke whale, humpback whale, harbor porpoise, bearded seal, ringed seal, ribbon seal, and 

spotted seal. The FWS has jurisdiction over the polar bear and Pacific walrus. 

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, kill or collect, or attempt to harass, hunt, 

capture, kill or collect.” 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 Service 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 sets for the permissible methods of taking 

and requirements pertaining to the mitigation, monitoring, and reporting of such takings. 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 7, 2009; 

Shell Offshore Inc., 2009a:Appendix E) and a Letter of Authorization (LOA) from FWS (dated May 7, 

2009; Shell Offshore Inc., 2009a:Appendix F) as part of their exploration program. 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 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 2.3.11 of this EA. 

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 they are conducted consistent with the 

State’s approved plan. The Alaska Coastal Management Program (ACMP) implements the CZMA and 

requires 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. The ACMP Coastal Project 

Questionnaire and Certification Statement are necessary for the Alaska Department of Natural Resources, 

Division of Coastal and Ocean Management coordination and review. A copy of Shell’s Coastal Project 

Questionnaire and Certification Statement is included as Section 15 of the EP (Shell Offshore Inc., 

2009a:Section 15). As part of MMS’ review process, the EP and supporting environmental information 

were sent to the ACMP for consistency-certification review and response. 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 consistency concurrence from the State of Alaska. 

Clean Air Act 

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

Environmental Protection Agency (EPA) and the States to carry out programs to ensure attainment of the 
 6

National Ambient Air Quality Standards (NAAQS). The CAA regulations at 40 CFR Part 50 require 

certain facilities that emit criteria pollutants (nitrogen dioxide, sulfur dioxide, small-diameter particulate 

matter, ozone, carbon monoxide, and lead) 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. 

MMS regulations at 30 CFR 250.218 and 250.303 require detailed air quality information to be submitted 

with an EP. On September 4, 2009, MMS required Shell to amend the EP to fully meet MMS regulatory 

requirements for air quality information. Shell submitted additional information in an amendment to the 

EP on September 18, 2009. 

Shell submitted a Prevention of Significant Deterioration (PSD) permit application to EPA on May 29, 

2009, for emissions from the Discoverer and from support vessels. Issuance of the EPA permit would 

authorize air emissions from the proposed activities and sets emission limitations and other provisions to 

ensure that the permitted emissions will have no adverse effect on public health, and all health-based 

NAAQS will be met. Shell must implement best available control technology (BACT) and comply with 

provisions of the required air quality permits. 

The MMS finding on air emissions is pursuant to MMS regulatory requirements and not a finding on the 

EPA PSD permit. The MMS has reviewed and assessed the air emissions information submitted by Shell. 

The air emissions information meets MMS regulatory requirements in 30 CFR 250.218, 250.224, and 

250.225, and was assessed under 30 CFR 250.218 and 250.303. 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 PSD permit. 

The MMS air quality regulations at 30 CFR 250.302, 250.303, and 250.304 were promulgated as 

mandated by section 5(a)(8) of OCSLA. The 1990 Clean Air Act Amendments (CAAA) directed the 

EPA to regulate air emissions from OCS sources located offshore of States along the Pacific, Arctic, and 

Atlantic coasts, and along the Gulf Coast off the State of Florida to the east of longitude 87o30'W. The 

applicable part of the statute is Section 328 of the CAA (42 U.S.C. §7627). Section 328(a)(1) states in 

part: “The authority of this subsection shall supersede section 5(a)(8) of the Outer Continental Shelf 

Lands Act (OCSLA) but shall not repeal or modify any other Federal, State, or local authorities with 

respect to air quality.” The EPA promulgated implementing regulations at 40 CFR 55 on September 4, 

1992. Thus, EPA has jurisdiction regarding air quality permits on the Alaska OCS. 

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 AKG-28-0000) 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). 
 7

Shell has submitted Notices of Intent (NOIs) to EPA requesting authorization for the Discoverer to 

discharge liquid wastes regulated under the NPDES General Permit at the Torpedo (lease block 6610) and 

Sivulliq (lease block 6658) drill sites (NOIs dated May 7, 2009; Shell Offshore Inc., 2009a:Appendix C). 

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. 

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 MMS 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 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 oil-spill estimates, a worst-case oil-spill scenario, and modeling results. 

Cultural Resource Regulations 

The Archaeological Resource requirements are contained in MMS 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-A02 and NTL 05-A03. 

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 Multiple-Sale 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, MMS 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). 
 8

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

Shell’s proposed drill sites. The MMS forwarded this finding to the SHPO and received concurrence 

from SHPO on October 2, 2009. 

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). 

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, oceanbottom-survey cables). The USCG developed regulations (33 CFR 151) that implement provisions of the 

NABPCA 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.” Shell’s proposed activities must comply with the Coast Guard 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. In addition, the Beaufort Sea poses harsh and frigid environmental conditions that are 

believed to impose major and difficult challenges to invasive species that might be introduced into the 

region’s waters by vessels or equipment. Therefore, the likelihood of introducing invasive species from 

the proposed activities is considered to be very low, and this issue is not considered further in this EA. 
 9

2.0 PROPOSED ACTION AND ALTERNATIVE 

2.1 Background

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

prospect, near the Camden Bay area of the Beaufort Sea OCS Planning Area (Figures 1-1 and 1-2). 

Twelve exploration wells have been drilled in the immediate vicinity of Shell’s proposed exploration 

wells. Nine of the twelve wells were drilled during the open-water period using floating drilling units. 

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 MMS 

regulations (30 CFR 250.115). The MMS estimated the reservoir contains 100-200 million barrels of oil 

(USDOI, MMS, 2006b, Beaufort Sea Planning Area (Alaska) – Province Summary, 2006 Oil and Gas 

Assessment)

(http://www.mms.gov/alaska/re/reports/2006Asmt/BSGA/Beaufort%20Sea%20Province%20Summary2006%20Assessment.pdf). 

2.2 Alternatives 

Alternative 1 –Proposed Action 

The proposed action is to drill two exploration wells on oil and gas leases Shell acquired in Federal 

Beaufort Sea OCS lease sales in 2005 and 2007. One well would be drilled on each lease into two 

distinct oil and gas prospects named by Shell as “Sivulliq” and “Torpedo.” Shell proposes a single season 

of exploration drilling activities at two drill sites during the months of July through October 2010. Shell’s 

proposed activities include a mid-drilling-season break in activities to avoid conflicts with the fall 

subsistence bowhead whale hunts of the villages of Kaktovik and Nuiqsut. 

Shell would drill from the M/V Frontier Discoverer (Discoverer). The Discoverer has state-of-the-art 

drilling and well-control equipment. The Discoverer would be supported by additional vessels for ice 

management, anchor handling, crew transport and supplies, and spill response. Additional vessels would 

implement Shell’s marine mammal monitoring and mitigation plan and support scientific research efforts. 

Shell states that all of the vessels are ice-class and specifically equipped for operating in Arctic waters. 

Alternative 2 – No Action 

Under this alternative, MMS would disapprove Shell’s proposed exploration drilling activities. This 

alternative would delay or preclude Shell from evaluating the potential hydrocarbon resources of two 

leases acquired under OCS Lease Sales 195 and 202. 

2.3 Description of the Proposed Action 

2.3.1 Overview 

Shell’s proposal, as detailed in the EP (Shell Offshore Inc., 2009a), is to use a single drillship, the 

Discoverer, to complete a single season of exploration drilling activities at two offshore locations near the 

Camden Bay area in the Beaufort Sea. A single well would be drilled on each of two distinct oil and gas 

prospects named by Shell as “Sivulliq” and “Torpedo.” Shell’s proposed activities would be conducted 

during the summer open-water season. Arctic waters are inaccessible to floating drilling units for up to 

nine months of the year because of pack ice. The Sivulliq drill site is 16 mi offshore in 107 ft of water. 
 10

The Torpedo drill site is 22 mi offshore in 120 ft of water. Each drill site has been surveyed by Shell and 

determined not to contain any shallow hazards or archaeological and historical resources. 

The activities are planned to begin on or about July 10, 2010. Shell’s plans include a mid-drilling-season 

break in activities to accommodate fall subsistence bowhead whaling. All operations would be suspended 

beginning August 25 and all vessels, including the drillship, would proceed from the project area to the 

northwest and remain north of latitude 71.25° N. and west of longitude 146.4° W. during the bowhead 

whale hunts (Figure 1-1) or would leave the Beaufort Sea entirely. Activities may be resumed after 

completion of the subsistence hunts and extend through October 31, 2010, depending on ice and weather. 

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

would commence. The Sivulliq well would take approximately 34 days to drill. The Torpedo well would 

take approximately 40 days to drill. Each well would be plugged and abandoned in accordance with 

MMS requirements upon completion of drilling. 

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

lease and permit requirements. The MMS 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 MMS 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 AKG-28-0000 impose limitations on 

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

authorization for the Discoverer to discharge liquid wastes regulated under the NPDES General 

Permit at the Torpedo (lease block 6610) and Sivulliq (lease block 6658) drill sites (NOIs dated 

May 7, 2009; Shell Offshore Inc., 2009a:Appendix C). 

• Air Quality Permit under the Clean Air Act from the EPA. The EPA’s air quality permits limit 

and regulate air emissions to protect ambient air quality. Shell submitted an application for a 

Prevention of Significant Deterioration (PSD) permit for their 2010 exploration program to the 

EPA on May 29, 2009. 

• Incidental Harassment Authorization (IHA) from NMFS regulating the incidental non-lethal 

harassment of protected species under the Marine Mammal Protection Act (MMPA) Shell has 

applied for an IHA from NMFS (dated May 7, 2009; Shell Offshore Inc., 2009a:Appendix E). 

• 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 7, 2009; 

Shell Offshore Inc., 2009a:Appendix F). 

• 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. 

• Coastal Consistency Concurrence under the CZMA from the State of Alaska, certifying that 

Shell’s proposed activities are consistent with the enforceable standards of the Alaska Coastal 

Management Program (ACMP), including the enforceable standards of the North Slope Borough 

Coastal Management District. A copy of Shell’s Coastal Project Questionnaire and Certification 

Statement is in the EP (Shell Offshore Inc., 2009a:Section 15.0). Concurrent with MMS’ review 
 11

process, the EP and supporting environmental information were sent to the State for consistencycertification review and response. 

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 has proposed an environmental orientation program (Shell Offshore Inc., 2009a:Section 

11.0) that informs Shell personnel and contractors regarding applicable laws and compliance 

obligations (Lease Stipulation 2, Sales 195 and 202); 

• Marine Mammal Monitoring and Mitigation Plan (4MP) (Shell Offshore Inc., 2009a:Appendix J) 

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) (Shell Offshore Inc., 2009a:Appendix B) 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); and 

• Shell’s Alaska Fuel Transfer Operating Conditions and Procedures (Shell Offshore Inc., 

2009a:Section 9.0, Attachment 9.0-4) (Lease Stipulation 6, 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. 

2.3.2 Drill Sites and Operating Environment 

Shell proposes exploration drilling on lease OCS-Y-1805 at planned drill site Sivulliq N, and on lease 

OCS-Y-1941 at planned drill site Torpedo H (Figures 1-1 and 1-2). The Sivulliq drill site and the 

Torpedo drill site 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 107 ft (33 m) at Sivulliq and 120 ft (37 m) at Torpedo. The seafloor at both of these 

locations has been extensively ice gouged. 

The Sivulliq N (Flaxman Island NR06-04 Official Protraction Diagram block 6658) drill site is located at 

latitude 70 ̊23’29.5814” N., longitude 145 ̊58’52.5284” W. 

• 16 miles (26 km) north of Point Thompson 

• 47 mi (75 km) from Cross Island 

• 60 mi (97 km) from West Dock 

• 58 mi (93 km) from Deadhorse 

• 60 mi (97 km) from Kaktovik 

• 118 mi (190 km) from Nuiqsut 

The Torpedo H (Flaxman Island NR06-04 Official Protraction Diagram block 6610) drill site is located at 

latitude 70 ̊27’01.6193” N., longitude 145 ̊49’32.0650” W. 

• 22 mi (35 km) north of Point Thompson 

• 50 mi (81 km) from Cross Island 

• 64 mi (103 km) from West Dock 

• 64 mi (103 km) from Deadhorse 

• 55 mi (89 km) from Kaktovik 

• 125 mi (201 km) from Nuiqsut 
 12

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. 

Seafloor Conditions at the Drill Sites

The MMS 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 EP (Shell Offshore Inc., 2009a:Section 3). 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 (Hammerhead) and in 

the proximity of 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 

• Ice gouging 

• Buried channels 

• Seafloor obstructions 

• Surficial sediments 

• Permafrost 

• Faulting 

• Seismicity 

• Shallow gas 

• Gas hydrates 

• Water column anomalies 

• Archaeological features 

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-A005). 

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

MMS 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. 
 13

The supplemental Fugro report assessed the following shallow-hazards parameters: Manmade 

infrastructure 

• Seafloor conditions 

• Stratigraphy and structure 

• Permafrost 

• Shallow gas 

• Gas Hydrates 

Sivulliq Prospect. Based on the assessments of 1985-1986 and the 2007 shallow hazards survey data, the 

planned Sivulliq N drill site is determined to be free of manmade and geologic risks. The more recent 

shallow hazards results for the Sivulliq N drill site did not identify any shallow hazards or constraints other 

than ice gouging. The installation of a mudline cellar (MLC) at the Sivulliq N drill site 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). The wellhead equipment would thereby be protected from the 

maximum anticipated ice-keel scour. 

The MMS has reviewed the data and reports and concurs with Shell’s findings that no shallow hazards 

occur at the proposed Sivulliq N drill site. The MMS concurs with Shell’s finding that there are no 

indications of historic sites or prehistoric archaeological resources at the proposed Sivulliq N drill site. The 

MMS also reviewed the seafloor survey for potential seafloor habitat and benthic communities. No unique 

seafloor habitat or benthic communities were identified at the proposed Sivulliq N drill site. 

Torpedo Prospect. Drill site Torpedo H was studied during the shallow-hazards surveys conducted in 

2007-2008 by Geo LLC. The shallow hazards surveys identified no manmade or geologic risks. The more 

recent shallow hazards results for the Torpedo H drill site did not identify any shallow hazards or constraints 

other than ice gouging. The installation of a MLC at the Torpedo H drill site 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 4.1 ft (1.3 m). The wellhead equipment would thereby be protected from the maximum anticipated 

ice-keel scour. 

The MMS has reviewed the data and reports and concurs with Shell’s findings that no shallow hazards 

occur at the proposed Torpedo H drill site. The MMS concurs with Shell’s finding that there are no 

indications of historic sites or prehistoric archaeological resources at the proposed Torpedo H drill site. 

The MMS 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 H drill site. 

Expected Weather Conditions at the Drill Sites

The Beaufort Sea coastal winds usually are easterly and strongly influenced by channeling due to the 

Brooks Range to the south. In the eastern portion of the Beaufort Sea around Barter Island, westerly 

winds become more frequent in the summer and fall months (USDOI, MMS, 2007a); however, the most 

prevalent wind direction within the project area during the drilling season of July through October is 

easterly to northeasterly (USDOI, MMS, 2003). Average wind speed at the Barter Island area is about 11 

mph (10 knots) during the summer months (WRCC, 2009). A multiyear meteorological study, including 

stations at Badami, Endicott, Northstar, Cottle Island, and Milne Pointe, provides a data trend for the 

months of July through October. The average wind speed from 2001 to 2005 was approximately 15.5 

mph (13 knots) with the average low around 9.5 mph (8 knots) and the average high around 41 mph (37 

knots) (Veltkamp, B. and J.R. Wilcox, 2007). 
 14

The lack of natural wind barriers results in unrestricted winds in the Alaskan Arctic. Gusting winds are 

more frequent between September and November. Along the coast, gale-force winds (greater than 39 

mph [34 knots]) are frequent, and wind velocities of hurricane strength (greater than 74 mph [64 knots]) 

have been recorded for this region. Although rare in April, May, and June, occasional high-wind events 

and sudden storms have been reported (USDOI, MMS, 2007a). An analysis of high-wind events in 

Barrow from 1955-2000 indicates that the extreme winds in the fall have decreased slightly and the winds 

in the summer have increased slightly (Lynch et al., 2004). With little warning, sudden and extreme 

storms can occur in the Alaskan Beaufort Sea (J. Ningeak in USDOI, MMS, 1990c). (See also USDOI, 

MMS, 2003, 2004, 2006a, and 2008.) 

Expected Ice Conditions at the Drill Sites 

The sea-ice descriptions in Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008) and the Shell EIA 

(Shell Offshore Inc., 2009b) 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 to 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. 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. In 2008 and 2009, Shell deployed buoys near the project area. 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 becoming much less in the arctic 

summer (Figure 2-1) and slightly less in winter, and the decline in sea-ice extent is increasing. The 

thickness of arctic ice is decreasing. 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. It generally is 

thought 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, MMS, 2003, 2004, 2006a, and 2008.) 

2.3.3 Drillship, Support Vessels, and Aircraft 

Shell would conduct drilling operations using the Discoverer and the latest drilling technologies and 

techniques. The Discoverer is a modern drillship retrofitted for operating in Arctic OCS waters. The 

Discoverer has state-of-the-art drilling and well-control equipment. The drillship Discoverer would be 

attended by a minimum of six vessels that would be used for ice management, anchor handling, oil spill 

response, refueling, resupply, and servicing. The ice management vessels would consist of an icebreaker 

and an anchor handler. The icebreaker would be located at a distance of several miles or more away from 

the drill site. The vessel would be supported by an auxiliary ice management vessel that would also serve 

as anchor handling vessel. A berthing vessel would stay on site. The oil spill response (OSR) vessels 

would include an ice-capable oil spill response barge (OSRB) and associated tug, a tank vessel for storage 

of any recovered liquids, and associated smaller workboats. The OSRB, supported by its own tug vessel 

with a full complement of crew and spill-response equipment, would be staged near the Discoverer. 

The other support vessels and aircraft would be deployed to the site as needed. A re-supply ship would 

travel from West Dock to the drilling vessel as needed. Additional vessels would implement Shell’s 

marine mammal monitoring program (4MP) (Shell Offshore Inc., 2009a:Appendix J) and support 

scientific research efforts. There would be two flights per day by a support helicopter from the shore base 

to the drill site. An aircraft would be used for overflights for 4 hours per day, 4 days per week. 
 15

Table 2.2-1 in the EIA (Shell Offshore Inc., 2009b) lists the specifications of the drilling and support 

vessels Shell is proposing to use. In addition, Shell provides estimates for trip frequency and duration for 

each vessel and aircraft (Shell Offshore Inc., 2009a:Appendix E, Table 1-1). Shell states that all support 

vessels would be ice-class and specifically equipped for operating in arctic waters. 

The Discoverer is a true floating drilling vessel (drillship), which means it mobilizes under its own 

power. The Discoverer is a 514 ft (156 m) moored drillship with drilling equipment on a turret. The 

Discoverer is winterized for service in the arctic offshore environment. It can be moved off the drill site 

in a matter of hours with the help of its anchor handler. It is a self-contained drilling unit with full 

accommodations for a crew of up to 124 persons (quarters, galley, and sanitation facilities). 

The Discoverer would have approximately 74 total drilling days in the project area. Drilling days for the 

Torpedo H drill site are estimated at 40 days. Drilling days for the Sivulliq N drill site are estimated at 34 

days. The days onsite for the Torpedo and Sivulliq drill sites include five days for constructing the MLC, 

one day to set anchors, one day to remove anchors, and one day to move. Transit speed of the Discoverer

is 8 knots. 

Shell’s Critical Operations and Curtailment Plan (COCP) (Shell Offshore Inc., 2009a:Section 9.0 b) 

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. 

Helicopter traffic is planned to both prospect sites. Most personnel transfers and some logistics support 

of the drilling program would be by helicopter. Helicopters would be used for crew changes. Work 

rotations would be based on 28-day shifts. Helicopter trip frequency is estimated at two to three trips per 

week. The shorebase at Deadhorse airport would have bunks for 50 people. At the shorebase, there 

would be a regular staff of ten persons, plus approximately 20 aircraft personnel. 

During Government-to-Government meetings held by MMS in 2007, an inland helicopter route was 

identified as a measure to lessen potential interference with subsistence caribou hunting along the coast. 

Shell has incorporated this measure in their proposed activities. 

Fixed-wing aircraft would be used for marine mammal monitoring. Aerial monitoring would enhance the 

monitoring of vessel-based marine mammal observers (MMOs) and acoustic monitoring. Shell’s aerial 

monitoring program is described in the 4MP (Shell Offshore Inc., 2009a:Appendix J). 

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

comply with flight restrictions imposed by the Sale 195 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. 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. 

Figure 2-2 depicts the helicopter routes to both drill sites. From the Mary Sachs Entrance, the boat and 

helicopter flight paths are direct to Torpedo or to Sivulliq. The vessel route to Torpedo prospect site 

would follow the helicopter route, but it is not shown on the figure to avoid confusion (i.e., two dashed 

lines with different colors along the same path). 

2.3.4 Discharges and Waste Management 

The general NPDES permit AKG-28-0000 (EPA, 2006) for the offshore areas of Alaska, including the 

Beaufort Sea, authorizes discharges from oil and gas exploration facilities. The Arctic general permit 
 16

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

requirements and other conditions. The EPA regulations (40 CFR 125.122) require a determination that 

the permitted discharge will not cause unreasonable degradation to the marine environment. The 

Discoverer is permitted under the NPDES for the Beaufort and would be the sole drilling vessel used for 

exploration. Under the NPDES General Permit AKG-28-0000, eleven separate effluent streams are 

allowed for the Discoverer. Each effluent stream, and the associated projected amount of discharge, is 

listed in Table 4.1.7-1 of the EIA. 

Shell would use water-based drilling fluids. Shell estimates that 2,761 and 2,881 barrels (bbl) of waterbased drilling muds, respectively, would be used at the Sivulliq N and Torpedo H drill sites. Drilling 

fluid volumes and chemistry would comply with NPDES General Permit conditions. 

During the 2010 drilling season, the Discoverer would be used to construct the MLCs, set casing, and 

drill up to two wells each to total depth. Shell would recycle drilling muds (e.g., use those muds on 

multiple wells), to the extent practicable based on operational considerations (e.g., mud 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 discharged into marine waters in conformance with NPDES permit conditions. Shell’s EIA 

indicates that up to 1,500 bbl of drilling cutting and fluids would be stored on board the drillship, if 

feasible (Shell Offshore Inc., 2009b:Table 2.3.2-1 footnote). At the end of the season, excess water-based 

fluid, approximately 1,500 bbl (238 m3

), would be pre-diluted to a 30:1 ratio with seawater and then 

discharged into marine waters in conformance with NPDES permit conditions. In the event the storage 

space for drill cuttings is exceeded on the Discoverer, the NPDES Arctic General Permit allows for 

discharge of drill cuttings and used drilling fluids to ambient waters of the Beaufort Sea at each drill site. 

Wastes include cement slurry, drainage waters, and domestic wastewaters. Certain discharges are made 

through the drillship’s disposal caisson (Shell Offshore Inc., 2009b:Table 4.1.7-1). The base of the 

discharge caisson while drilling is 19.6 ft (6.0 m) below mean sea level. 

Cement would be used to set the steel casing in the wellbore and to plug the well after it has been drilled 

to depth. Drainage waters include rainfall landing on the deck surfaces of the drillship, and wash-down 

water generated when cleaning portions of the deck. Domestic wastewaters include gray water, which is 

effluent from showers, laundry, and liquid galley wastes, and black water from treated sewage. Cement 

slurry, drainage waters, and black water are discharged (after sanitation treatment) according to the 

conditions and limitations of the NPDES General Permit. 

The volumes of liquid/fluid, slurry, and cuttings expected to be generated and the rates at which they 

would be discharged are indicated in Tables 2.3.2-1 and 2.3.2-2 of the EIA. 

A list of the components that may be added to the drilling fluid is summarized in Table 2.3.2-3 of the 

EIA. The component list and the associated volumes account for drilling needs at various depths from the 

MLC to total depth for both the Sivulliq N and Torpedo H wells. 

The discharge from the water cooling unit is expected to be 2.5  ̊F (1.4  ̊C) above ambient temperature. 

Seawater temperature is expected to reach ambient temperature within 450 ft (137 m) of the drillship. 

Solid wastes (trash) would be segregated and disposed of or recycled at approved disposal or recycling 

facilities on land. Solid food wastes would be incinerated onboard. Shell would use either the Oxbow 

Landfill in the greater Prudhoe Bay area or would contract the services of Phillips Service in Anchorage. 
 17

Hazardous waste and used oil would be stored onboard in approved containers and then transferred by 

boat to an approved disposal site. 

2.3.5 Emissions 

Emissions from the Discoverer and support vessels would be authorized through an air quality permit 

issued by EPA under the Clean Air Act (CAA). 

The activities described in the EP are defined as temporary facilities under 30 CFR 250.302. Shell has 

committed to applying emission reduction measures in their proposed activities. Shell’s BACT measures 

are equivalent to the BACT requirements in the EPA proposed Chukchi Sea Permit Number 

R10OCS/PSD-AK-09-01 for the Discoverer. As the agency with jurisdiction over air quality on the 

Alaska OCS, EPA will include final BACT requirements upon promulgation of a permit for Shell’s 

Beaufort Sea operations. The MMS will not approve an APD and commencement of activities will not be 

authorized until Shell’s receipt of the required air quality permit. The MMS has determined that Shell’s 

emission reduction measures achieve BACT required under MMS regulations for temporary OCS 

facilities. The modeling described under MMS regulations at 30 CFR 250.303(e) is to determine whether 

projected emissions may trigger the need for emission controls. For temporary facilities, the required 

emission controls are BACT (30 CFR 250.303(h)). With BACT incorporated in the proposed activities, it 

is not necessary for modeling to be performed to determine whether BACT is needed (30 CFR 250.303(a) 

states: “the lessee shall comply with the requirements of this section as necessary). 

Shell’s BACT and emission reduction measures (Shell Offshore Inc., 2009b:Section 4.1.6) include: 

• The primary generators on the Discoverer would be retrofitted with selective catalytic reduction 

devices to reduce NOx emissions by over 90 percent; and with catalytic oxidation devices to 

reduce CO, VOCs, and fine particulate matter by at least 60 percent. 

• All remaining engines on the Discoverer would either be Tier 3 (low emissions) or would be 

retrofitted with closed crankcase ventilation and would have improved maintenance to minimize 

emissions. 

• Maximum sulfur content of diesel fuel combusted by the support vessels would be limited to a 

maximum of 0.19 percent by weight; and the maximum sulfur content of diesel fuel combusted 

by the Discoverer would be limited to 0.0015 percent by weight. 

• Limiting the MLC compressors to 2 of the 3 while the Discoverer is occupying a drill site, and 

only using emergency equipment during emergencies. 

• Limiting daily cementing, logging, and cranes to 30 percent of combined engine capacity 

• The Discoverer may occupy drill sites, in aggregate, a maximum of 168 calendar days and any 

one drill site a maximum of 84 calendar days during any year. 

The drillship Discoverer would be attended by a minimum of six vessels that would be used for ice 

management, anchor handling, spill response, refueling, resupply, and servicing. The primary sources of 

the emissions by the Discoverer drillship and support vessels would be combustion engines including the 

vessel engines, generators, compressors, draw works, and pumps. Emission units on the Discoverer 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. 

All emission units on the Discoverer would use diesel with sulfur content at or below 15 parts per million. 

The six main generator engines on the Discoverer would be equipped with selective catalytic reduction 

systems (SCR) to reduce emissions of NOx as well as CO and VOC. The air compressor engines would 
 18

meet EPA Tier 3 emission standards. The hydraulic power units, cranes, cementing, and logging units 

would have catalytic diesel particulate filters to reduce emissions of volatile organics, carbon monoxide, 

and hydrocarbon particulate matter. The operator would manage the power of the generators so that the 

average load over the lifetime of the project would not exceed 80%. The compressors, hydraulic power 

units, and cranes are assumed to operate a maximum of 63 days for the season. The incinerator would 

operate a maximum of 12 hours per day. The sulfur content of all engines on the Discover, except the 

propulsion engines, would be limited to 15 parts per million. The sulfur content of fuel used by support 

vessels would be 0.19%. 

Ice-management activity accounts for more than 90 percent of support vessels’ emissions; thus, total 

emissions would be lower in favorable ice conditions. The remainder of emissions would be generated 

from the production of electricity, compressed air, and hydraulic pressure to support drilling; incineration 

of solid waste; and as a low-volume deliberate by-product (“ammonia” slip) from air pollution control 

equipment to reduce oxides of nitrogen. Emissions generated from the proposed activities would include 

nitrogen oxides (NOx), carbon monoxide (CO), sulfur dioxide (SO2), small-diameter particulate matter 

such as PM10 and PM2.5, and lead (Pb). The project would generate lesser quantities of volatile organic 

compounds (VOCs), hazardous air pollutants (HAPs), and ammonia, as well as CO2. 

Shell performed air quality modeling using the ISC-PRIME model in a screening mode using the range of 

meteorological parameters in SCREEN3. While this model is not on EPA’s list of recommended models, 

MMS finds the ISC-PRIME is sufficiently conservative to be used in lieu of the Offshore and Coastal 

Dispersion (OCD) model. There are insufficient data available to apply the OCD model, which requires a 

long-term record of offshore wind speed and direction, air temperature, and sea-surface temperature. The 

ISC-PRIME model is intended for modeling land-based emissions. With the range of meteorological 

input data that were used by Shell, the ISC-PRIME model is likely to result in higher modeled 

concentrations. Moreover, dispersion over land is more limited than over water because of lighter winds 

and a more stable atmosphere. The MMS considers the ISC-PRIME model acceptable to use in the 

screening mode. 

Estimates of the total annual potential emissions for the Discoverer and support vessel sources are 

provided in Table 2.3.3-1 of the EIA (Shell Offshore Inc., 2009b). Support-vessel emissions are included 

only when the vessel is within 25 mi (40 km) of the drillship. The project total annual HAPs are 

estimated at about one ton per year, which is below the EPA 25-ton per year major source threshold. 

Although there would be 122 possible drilling days between June 10 and October 31, 2010, Shell’s 

modeling of project emissions are based on a maximum 168-day drilling season. 

Shell also performed a cumulative impact analysis by including emissions from existing sources over a 

wide area. Concentrations were within the PSD Class II incremental limits and the national ambient air 

quality standards. 

2.3.6 Sound Generation 

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) 

Sounds generated by the Discoverer have not yet been directly measured and noise propagation 

measurements are not yet available. However, measurements of sounds from a similar drillship, Northern

Explorer II, were performed at two different times and locations in the Beaufort Sea (Miles et al., 1987; 

Green, 1987). During acoustic data collection, there was a support vessel idling in the vicinity of the drill 

rig (Miles et al., 1987; Green, 1987). These measurements provide source levels for modeling noise 
 19

propagation from the Discoverer. Source levels for the Discoverer were estimated based on its similarity 

to the Northern Explorer II. The Northern Explorer II was used as a proxy source for the Discoverer. A 

comparison of the key specifications for the two drillships is provided in Table 5-1 of Shell’s Application 

for NMFS IHA (Shell Offshore Inc., 2009a:Appendix E). 

In 2007, JASCO modeled sound-level radii for the Northern Explorer II for the two locations, the Sivulliq 

B site (now withdrawn) and Sivulliq N site. The Shell’s sound modeling is summarized in Shell’s IHA 

and LOA applications (Shell Offshore Inc., 2009a:Appendixes E and F, respectively). 

Modeled sound-level radii indicate that the sound from the Discoverer would not exceed the 180 dB 

“safety” radius for cetaceans specified by NMFS (USDOC, NOAA, NMFS, 2007a). The ≥160-dB radius 

for the drillship was modeled to be 172 ft (52.5 m); the ≥120-dB radius was modeled to be 4.6 mi (7.4 

km). The NMFS uses the 160-dB rms isopleth to indicate where Level B harassment begins for acoustic 

sources (USDOC, NOAA, NMFS, 2007a). The area estimated to be exposed to ≥160 dB around the 

Discoverer operating at either of the planned drill sites is ~0.01 km2

. Sound verification would be 

conducted soon after the Discoverer is onsite and at the beginning of drilling. Sound radii will be 

adjusted based on the field measurements. 

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 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 Discoverer is onsite and before 

drilling commences. 

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) (Richardson et al., 1989, citing Green, 1985). 

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 
 20

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 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, it would fly directly north 

to its destination. As a result of community input during Government-to-Government meetings held by 

MMS for Shell’s 2007 EP, the inland helicopter route was developed to mitigate potential interference 

with subsistence caribou hunting along the coast. 

2.3.7 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 Inupiat 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. 

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. 

2.3.8 Analysis of Accidental Oil Spills 

For purposes of this EA analysis, no large spills (≥1,000 bbl) or very large (≥150,000 bbls) crude oil spills 

are estimated, based on calculations and analyses (Appendix A), from the proposed exploration drilling 

activities. (Note that MMS’ definition of a large spill (>1,000 bbl) used in this analysis is different from 

the definition of large spill (>48 bbl) used in the EIA.) This estimate is based on: (1) the low rate of OCS 

exploratory drilling well-control incidents spilling fluids per well drilled; (2) since 1971 no large spills 

have occurred from exploratory drilling well-control incidents while drilling more than 14,000 wells; (3) 

the low number of exploration wells being drilled from this proposal; (4) no crude oil would be produced; 

and (5) the history of exploration spills on the Arctic OCS, all of which have been small, as documented 

in EA Appendix A. 

Based on the points listed above, the most likely size spill that might occur would be a small (<1,000 bbl) 

spill. For purposes of analysis, we chose a 48-bbl fuel-transfer spill, as identified in Shell’s Beaufort Sea 
 21

ODPCP (Shell Offshore Inc., 2009c) Summary of Potential Discharges, for a representative spill size in 

MMS’ small category. A summary of the potential discharges is shown in Appendix A Table A-1 and 

analyzed Appendix A of this EA. 

To judge the effect of a 48-bbl diesel-fuel oil spill, we estimate how much oil would evaporate, how much 

oil would be dispersed, and how much oil would remain after a certain time period. A 48-bbl diesel-fuel 

spill could evaporate and disperse in less than 3 days (EA Appendix A Table A-4). 

The SINTEF model fate and behavior 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 of fuel barges or vessels prior to transfer operations would be used in accordance with MMS 

lease stipulations, USCG requirements, and Shell’s operating procedures. Response equipment and 

trained personnel deploy recovery equipment for the control and removal of product 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. 

2.3.9 Oil Spill Prevention and Contingency Planning 

As required by both Federal and State regulations, Shell has developed and would implement a 

comprehensive ODPCP (Shell Offshore Inc., 2009c) 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 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 vessel (OSRV) 

would be staged in the vicinity of the drilling vessel when critical drilling operations into hydrocarbonbearing zones are underway and possess sufficient capacity to provided containment, recovery, and 

storage for the initial operational period. 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. Additionally, an oil-spill-response barge (OSRB) would arrive 

at the drill site with sufficient capacity relieving the OSRV to offload recovered fluids. Skimming and 

lightering operations would be conducted on a 24-hour-rotation basis (one OSRV or OSRB skimming 

while the other transits and lighters its recovered fluids to the OST). Additional personnel may be 

transported via helicopter or vessel from a land- or vessel-based staging area. 

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 using the AES-RO Response Tactics Manual as defined in the ACS Technical Manual. 

2.3.10 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 stipulations is on the MMS website 
 22

http://www.mms.gov/alaska/cproject/beaufortsale/Sale202/FNOS/FNOS202package.htm. The MMS’ 

analysis of the effectiveness of the stipulations can be found 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 MMS 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 N and Torpedo H drill sites in 2006, 

2007, and 2008 did not identify any special benthic communities at these drill sites. Hard-bottom 

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 

MMS 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 Offshore Inc., 2009a: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 EIA 

(Shell Offshore Inc., 2009b:Section 16.0). 

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 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 
 23

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 must submit a final 2010 orientation program to MMS for 

review prior to approval of an APD. 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 

• Brief history of land claims 

• Formation of regional corporations, and 

region within which Shell is working 

• History of the North Slope 

• Cultural diversity 

• Comparison of cultural values of 

Alaskan Natives vs. non-Natives 

• Patterns of language 

• Communication skills and body 

language 

• Guidelines on cultural artifacts 

• Local community values and customs 

• Whaling

Shell’s Health, Safety, Security, and Environment (HSSE) Awareness Program addresses the following: 

• Shell’s HSSE Commitment 

• Intervention policy 

• Journey Management requirements 

• Personal Protective Equipment 

requirements 

• General Alaska Venture Hazards, such 

as earthquakes and volcanoes 

• Medical emergencies 

• Security 

• North Slope Safety requirements 

• Shell Alaska Venture Standards and 

Procedures 

o Cold Climate Work Standard 

o Firearms Use in Wildlife 

Confrontations 

o Procedure for Vessel-to-Vessel 

Personnel Transfers 

• Incident Reporting 

• Environmental Awareness 

o Endangered Species Act (ESA) – 

Major Provisions 

o Endangered and threatened species 

o MMPA of 1972 

o Marine mammal interactions 

o Sensitive Habitats on the North 

Slope 

o Wildlife interactions 

o Prohibited activities of hunting, 

trapping, and fishing 

o Environmental requirements for air, 

spills, and waste 

o Environmental training 

Stipulation No. 3 - Transportation of Hydrocarbons 

This stipulation is not applicable to the activities described in the EP. 
 24

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 Actions: Shell submitted a copy of their Marine Mammal Monitoring and Mitigation Plan (4MP), 

which is also included in Shell’s application for an IHA (Shell Offshore Inc., 2009a:Appendix E). 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 MMS has determined that the level and scope of the 2010 

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 

mitigative 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 2010 drilling 

program. Aerial monitoring, designed primarily for detecting cetaceans, would be used to identify any 

large-scale distributional changes of cetaceans relative to the activities and add to the existing database on 

the abundance and distribution of observed species. 

Acoustic Recorders: 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 Offshore Inc., 2009a:Appendixes E and F, 

respectively). 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 2010 drilling season. The sound data would enable Shell to refine sound-level thresholds 
 25

and use the thresholds to more accurately define marine mammal take estimates. 

Sound Source Verification: Field measurement 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 MMS 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 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. 

Shell’s Plan of Cooperation (POC) (Shell Offshore Inc., 2009a:Appendix B 2010 Plan of Cooperation, 

Camden Bay, Alaska) identifies the measures Shell has developed and would implement during its 

proposed 2010 exploration drilling program to minimize any adverse effects on the availability of marine 

mammals for subsistence uses. The POC details Shell’s communications and consultations with local 

communities concerning its proposed 2010 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 is also provided below. Table 4.2-1 of Appendix B of the EP provides a list of public meetings 

attended by Shell as it developed its POC (Shell Offshore Inc., 2009a:Appendix B). Attachment B of 

Appendix B of the EP 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 

Offshore Inc., 2009a:Appendix B). Attachment B of Appendix B also includes copies of the sign-in 

sheets from the meetings and the presentation materials used at the meetings (Shell Offshore Inc., 

2009a:Appendix B). The MMS concludes that methods of proposed operations, safeguards and 

mitigation measures detailed in the 2010 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 proposed 2010 Camden Bay exploration drilling program (and proposed Chukchi 

Sea exploration drilling program), Shell engaged in an active consultation program with both Federal and 
 26

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 subsistence communities that were consulted regarding Shell’s 2010 proposed activities include 

Barrow, Kaktovik, Wainwright, Kotzebue, Kivalina, Point Lay, and Point Hope. Beginning in early 

January 2009, 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. 

Shell presented the proposed project to the NWAB Assembly on January 27, 2009; to the NSB Assembly 

on February 2, 2009; and to the NSB and NWAB Planning Commissions on March 25, 2009. Meetings 

were also scheduled with representatives from the AEWC, and presentations on proposed activities were 

given to the Iñupiat Community of the Arctic Slope and the Native Village of Barrow. 

Shell attempted to meet individually with Whaling Captains and hold a community meeting in Nuiqsut; 

however, the scheduled meeting was cancelled per the Mayor’s request. Shell subsequently sent 

correspondence to all post office box holders in Nuiqsut on February 26, 2009, indicating its willingness 

to visit and have dialogue on the proposed plans. 

Shell began meeting with stakeholders specifically on the 2010 Camden Bay EP in July 2009. Shell plans 

to hold additional consultation meetings in May 2010 with the affected communities and subsistence user 

groups, the NSB, and NWAB to discuss the mitigation measures included in the EP and POC. Shell also 

plans to conduct post-operation consultations with the various subsistence stakeholder groups. 

The POC may be supplemented to reflect additional engagements with local subsistence users and any 

additional or revised mitigation measures that are adopted as a result of those engagements. 

In addition, Shell has publically stated it is committed to a Conflict Avoidance Agreement process and 

has demonstrated this by making efforts to negotiate an agreement every year it has planned activities. 

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 oil-spill-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 Attachment 9.0-4 in EP Section 9.0 (Shell Offshore Inc., 2009a:Section 9.0). The fueltransfer 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, 

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. 
 27

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. 

Although the proposed drill sites are not within the area where Lease Stipulation No. 7 applies, Shell’s 

Bird Strike Avoidance and Lighting Plan, Camden Bay, Alaska (lighting plan) (Shell Offshore Inc., 

2009a:Appendix G) outlines Shell’s bird strike avoidance strategy for drilling operations near Camden 

Bay for 2010. Emphasis is on the prevention of bird strikes into the drillship by threatened spectacled 

eiders (Somateria fischeri) and Steller’s eiders (Polysticta stelleri). Given that the planned exploration 

drilling is outside the area where a lighting plan is required by MMS, 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 and the cause is believed to be at least in part due to lighting of the drillship, then 

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. 

2.3.11 Other Mitigation 

Some of the additional mitigation measures Shell has adopted and would implement during its 2010 

exploration drilling operations are presented below. Shell presented their planned mitigation measures to 

community leaders and subsistence users starting 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, 2010, with a suspension of all operations beginning August 25, 

2010, for the Nuiqsut (Cross Island) and Kaktovik subsistence bowhead whale hunts. The Discoverer and 

support vessels would leave the project area and would return to resume activities after the Nuiqsut (Cross 

Island) and Kaktovik subsistence bowhead whale hunts conclude. Activities would extend through 

October 31, 2010, 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: 
 28

• To minimize impacts to marine mammals and subsistence activities, the drillship and support 

vessels traversing north through the Bering Straight would transit through the Chukchi Sea along 

a route that allows for the highest degree of safety regarding ice conditions and sea states. Those 

vessels that can safely travel outside of the polynya zone would do so. If it is necessary for any 

vessel to move into the polynya zone, Shell would notify the local communities of any changes in 

transit routes. 

• Shell has developed a Communication Plan and would implement the plan before initiating 

exploration drilling operations to coordinate activities with local subsistence users as well as 

Village Whaling Associations to minimize the risk of interfering with subsistence activities, and 

keep current as to the timing and status of the bowhead whale migration, as well as the timing and 

status of other subsistence hunts. The Communication Plan includes procedures for coordination 

with Communication and Call Centers to be located in coastal villages along the Chukchi and 

Beaufort seas during Shell’s proposed activities in 2010.

• Shell would employ local Subsistence Advisors from the North Slope subsistence communities to 

provide consultation and guidance regarding the whale migration and subsistence hunt. There 

would be a total of nine subsistence advisor-liaison positions (one per village, including 

Shishmaref and Kivalina), to work approximately 8 hrs/day and 40 hrs/week through Shell’s 2010 

exploration project. The subsistence advisor would advise ways to minimize and mitigate 

potential 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; and advising how to avoid subsistence 

conflicts. Shell is developing a subsistence advisor handbook to specify position work tasks in 

more detail. In the EP, Shell indicates that this handbook would be completed before 

commencement of operations. The MMS will direct Shell to include, in its training material and 

handouts, instructions for the Subsistence Advisors to call MMS is there are issues that are not 

being resolved to the satisfaction of the Subsistence Advisor. The MMS will also notify the 

communities that MMS can be contacted directly. 

• 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 it would fly directly north to its 

destination. The specified inland helicopter route is intended to mitigate potential interference 

with caribou subsistence hunting along the coast. 

Protection of Marine Mammals 

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 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 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 Offshore Inc., 2009a:Appendix J). 
 29

Shell’s Aerial Survey Program described in the 4 MP (Shell Offshore Inc., 2009a:Appendix J) 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 would not exceed the 180 dB “safety” radius for 

cetaceans specified by NMFS (USDOC, NOAA, NMFS, 2007a). Additionally, these modeled results 

indicate a relatively small “zone of disturbance” of approximately 172 ft (52.5 m) around the drillship 

where sound may reach levels above 160 dB. The NMFS uses the 160-dB rms isopleth to indicate where 

Level B harassment begins for acoustic sources (USDOC, NOAA, NMFS, 2007a). 

Aerial monitors would record data on observable effects, if any, to migrating whales (e.g., the distance 

between the operations and the whale(s)).regulatory reporting requirements. 

In compliance with MMS’ Information to Lessees (ITL) clause (k) for OCS Lease Sales 195 and 202, 

Shell provided a plan to mitigate potential effects to polar bears, Pacific walrus, and grizzly bears (Shell 

Offshore Inc., 2009a:Appendix F Polar Bear, Pacific Walrus, and Grizzly Bear Avoidance and Human 

Encounter/Interaction Plan). 

In addition, Shell would implement the following measures to further minimize disturbance to marine 

mammals (Shell Offshore Inc., 2009b:Section 4.3.3): 

• A marine mammal monitoring protocol; 

• Aircraft will not operate within 1,500 ft (457 m) of whale groups; 

• Aircraft and vessels would not operate within 0.5 mi (800 m) of walrus or polar bears when 

observed on land or ice; 

• Vessel speed to be reduced during inclement weather conditions to avoid collisions with marine 

mammals; 

• When within 900 ft (274 m) of marine mammals, vessels will reduce speed, avoid separating 

member from a group and avoid multiple course changes; 

• Vessel speed will be reduced during inclement weather conditions to reduce the potential for 

collisions with marine mammals; and 

• A polar bear culvert trap would be established for oil-spill response needs near Point Thompson 

or Kaktovik prior to drilling. 

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: 
 30

• 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 Offshore Inc., 

2009a: Section 9.0) 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 icethreat 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 Offshore Inc., 2009a: Section 9.0), 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 well-control 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 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 

Offshore Inc., 2009a: Section 9.0) in the extremely unlikely event of a well-control 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 Offshore Inc., 

2009a: Section 9.0), 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.

Shell also may enter into agreements with other operators to coordinate and/or cooperate in monitoring, 

scheduling, or other aspects of the program to minimize impacts, maximize returns (in the form of 

information gathered), and share costs. 
 31

3.0 DESCRIPTION OF THE ENVIRONMENT AND ANALYSIS 

OF ENVIRONMENTAL CONSEQUENCES 

3.1 Introduction 

The area in which Shell proposes to conduct exploratory drilling operations is located offshore of Point 

Thompson in the Camden Bay area of the Beaufort Sea OCS. The potential effects of exploratory drilling 

activities in the Beaufort Sea Planning Area were assessed in recent MMS NEPA documents. The 

areawide descriptions of the environmental and analyses of potential effects were included the Beaufort 

Sea Multiple-Sale EIS for OCS Lease Sales 186, 195, and 202 (USDOI, MMS, 2003), which was updated 

in the 2004 EA for Sale 195 (USDOI, MMS, 2004), and updated further in the Sale 202 EA (USDOI, 

MMS, 2006a). This EA tiers from the Beaufort Sea Multiple-Sale EIS. Relevant information and 

analyses in these documents are summarized and incorporated by reference in this EA, as needed. The 

Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008) provides MMS’ most recent description of the 

environment and analysis of the potential effects of Arctic OCS activities. Portions of the Arctic 

Multiple-Sale Draft EIS are summarized and incorporated by reference. 

In 2006, Shell submitted an EP to conduct exploration activities similar to, but larger in scope than, the 

activities in the current proposed action. In 2007, MMS completed an EA and issued a FONSI for the 

Shell Offshore Inc., 2007-2009 Beaufort Sea Exploration Plan (USDOI, MMS, 2007b). In 2007, NMFS 

completed an EA and issued a FONSI 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). The environmental 

documentation for the prior plan is incorporated by reference in this EA where applicable. 

The 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) provides a comprehensive description of the physical, geographical, and 

biological environment; the description and biology of the marine mammal species under NMFS’ 

jurisdiction; and analysis of the potential effects of OCS activities on marine mammals species under 

NMFS’ jurisdiction. 

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

Seismic Surveys and Exploratory Drilling (USDOI, FWS, 2009) provides a comprehensive description of 

the physical, geographical, and biological environment; the description and biology of the ESA-listed 

species under FWS’ jurisdiction; and analysis of the potential effects of OCS activities on ESA-listed 

under FWS’ jurisdiction. 

Additional information on the environment at the proposed drill sites and on the potential effects of the 

proposed activities on environmental resources is provided in the EIA (Shell Offshore Inc., 

2009a:Appendix H; also cited as Shell Offshore Inc., 2009b), Shell’s IHA application to NMFS dated 

May 7, 2009 (Shell Offshore Inc., 2009a:Appendix E); and Shell’s LOA application to FWS (Shell 

Offshore Inc., 2009a:Appendix F). 

Information from the above documents has been reviewed, summarized, updated, and incorporated, as 

needed and appropriate, in this EA. Relevant sections of the above documents are cited, summarized, and 

incorporated by reference, as appropriate. 
 32

3.2 Alternative 1: Biological Resources

The environmental conditions at the proposed drill sites as described in Shell’s EIA do not deviate from 

the general conditions described in Beaufort Sea Multiple-Sale EIS (USDOI, MMS, 2003). There are no 

indications from recent studies or site-specific information that the prospect areas differ from what was 

generally described in Beaufort Sea Multiple-Sale EIS (USDOI, MMS, 2003). No sensitive seafloor 

biological communities or habitats have been identified at the proposed drill sites. 

3.2.1 Levels of Effects for Biological Resources 

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 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. 

• For mammals or birds, mortality is not anticipated. 

• For fishes, 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 population-level effects. For 

whales, mortality might occur above the estimated Potential Biological Removal (PBR). 

• 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. 
 33

Screening Analysis for Potentially Affected Biological Resources 

The mechanisms of effects to biological resources from the proposed activities during the July-October 

operational timeframe in the vicinity of the project area are expected to be the same as those analyzed in 

the Beaufort Sea Multiple-Sale EIS (USDOI, MMS, 2003). The analyses in the Beaufort Sea MultipleSale EIS and Shell’s EIA (Shell Offshore Inc., 2009b) were reviewed to determine expected level of 

effects form the types of activities proposed in the EP and the presence or absence of biological resources 

during the July-October operational timeframe in the vicinity of the project area. Tables 3.2.1-1, 3.2.1-2, 

and 3.2.1-3 below indicate the expected impact levels of the proposal on the biota in the vicinity of the 

Torpedo and Sivulliq prospects based on the analyses in the Beaufort Sea Multiple-Sale EIS and Shell’s 

EIA. The expected levels of effects indicated in the following tables apply only to effects. This first step 

in the screening analysis assumes that all species are present. The expected presence or absence of 

considered species is considered in the “Presence and Habitat Use Analysis” below. For more detailed 

analyses, refer to MMS 2003-001(USDOI, MMS 2003) and Shell EIA (Shell Offshore Inc., 2009b). The 

likelihood of large hydrocarbon spills occurring was analyzed in and summarized in EA Section 2.3.8 and 

EA Appendix A and determined not to be a reasonably foreseeable outcome of the proposed action. 

Screening for Potential Effects on Mammals 

Table 3.2.1-1. Effects analysis determinations for mammal species that may occur in the vicinity of the project area. 

Effects are described as NG = negligible, MN = minor, MO = moderate, MJ = major, and * = effect after mitigation. 

Determinations were based on existing analyses in USDOI, MMS (2003), and Shell Offshore Inc. (2009b), and 

incorporated more recent information from other sources, as appropriate. Species Vessel Traffic Vessel Noise Aircraft Traffic Aircraft Noise Drilling Noise Icebreaking/Ice Management 

Vessel Mooring 

and MLC 

Construction 

Drill Cuttings 

and Drilling Mud 

Discharges 

Other Permitted 

Discharges 

Hydrocarbon 

Small Liquid 

Spills 

Air Pollutant 

Emissions 

Cumulative 

Effects 

Marine Mammals 

Bearded Seal NG* NG NG NG NG NG NG NG NG NG* NG NG* 

Beluga Whale MN* MN NG NG NG MN NG NG NG NG NG MN 

Bowhead Whale MN* MN NG NG MN MN NG NG NG NG NG MN 

Gray Whale MN* MN NG NG NG MN NG NG NG NG NG MN 

Harbor Porpoise NG NG NG NG NG MN NG NG NG NG NG MN 

Humpback Whale MN* MN NG NG MN NG NG NG NG NG NG MN 

Killer Whale NG NG NG NG NG NG NG NG NG NG NG NG 

Narwhal MN* MN NG NG NG NG NG NG NG NG NG MN 

Pacific Walrus NG* NG NG* MN* NG NG NG NG NG NG* NG MN* 

Polar Bear MN* MN MN* MN NG MN NG NG NG NG* NG MN* 

Ribbon Seal NG* NG NG NG NG NG NG NG NG NG* NG NG* 

Ringed Seal NG* NG NG NG NG NG NG NG NG NG* NG NG* 

Spotted Seal NG* NG NG NG NG NG NG NG NG NG* NG NG* 

Terrestrial Mammals 

Central Arctic Caribou 

Herd NG NG NG* NG* NG NG NG NG NG NG* NG NG* 

Porcupine Caribou Herd NG NG NG* NG* NG NG NG NG NG NG* NG NG* 

Grizzly Bear NG NG NG* NG* NG NG NG NG NG NG NG NG 

Other Furbearers NG NG NG* NG* NG NG NG NG NG NG NG NG 
 34

The Beaufort Sea Multiple-Sale EIS (USDOI, MMS, 2003:Section IV.C.4.a(2)(a)2) concluded that 

“Drilling-mud disposal will not affect the major prey, zooplankton, or fish or their habitats.” Suspended 

solids discharged from the drillship are expected to produce a plume with acute toxicity levels out to 

about 60 ft (20 m). More than 90% of solids are expected to precipitate out of the water column within 

650 ft (200 m) from the discharge point (Shell Offshore Inc., 2009b). Assuming uniform mixing, a 

maximum 2.5o

F increase in water temperature is expected in the plume out to a distance of 450 ft (137 m) 

from the discharge point (EA Section 2.3.4). Shell (Shell Offshore Inc., 2009b) acknowledges strong, 

stable stratification of the thermocline occurs at the project locations during the summer. Deeper, colder 

strata could resist mixing with the warmer discharge from the disposal caisson, forcing the discharged 

water to disperse in the upper layers of the thermocline over a much larger area than predicted. Still, the 

area of potential disturbance is expected to remain small. Thus the thermal, chemical, and particulate 

disturbances are expected to reflect the small spatial area of the modeled discharge plume. 

Waterborne contaminates associated with the discharge plume may affect marine vertebrates through 

ingestion or filtration. Because of the relatively small discharge plume and the plume’s proximity to the 

drillship, we expect mobile invertebrates, fishes, marine mammals, and birds to avoid the area affected by 

the discharge plume, thereby avoiding exposure. With the exceptions of fourhorn sculpin and arctic 

flounder, Arctic marine fishes are migratory and are not considered to be residents at the proposed drill 

sites (USDOI, MMS, 2003; Shell Offshore Inc., 2009b). Benthic organisms under the discharge plume 

are most likely to be exposed to drill cuttings and other heavy materials. The likelihood of marine 

mammals or birds ingesting benthic organisms or fishes contaminated by discharges associated with the 

proposed activities is very low. Marine mammals or birds that feed on benthic invertebrates, sculpin, or 

flounder in the project area might ingest some organisms with very low levels of contamination. Impacts 

related to discharges are expected to be minor and localized. No population-level effects are expected for 

any species that occur in the proposed activity areas. Because no species are expected to experience 

measureable population-level effects from any discharges or temperature changes related to the proposed 

action, we conclude that there should be a negligible level of effects for drill cuttings and drilling mud 

discharges, and other permitted discharges listed in EIA Tables 3.2.1-1 thru 3.2.1-3. 

Anthropogenic sound in the marine environment can affect marine mammals. The Beaufort Sea 

Multiple-Sale EIS (USDOI, MMS, 2003:Sections IV.C.5.a(1)(a) and IV.C.7.a(2)(a)1)c) concluded: 

• Overall, bowhead whales exposed to noise-producing activities such as vessel and aircraft traffic, 

drilling operations, seismic surveys, and construction activities most likely would experience 

temporary, nonlethal effects. 

• The primary sources of noise and disturbance of ringed, bearded and spotted seals; polar bears; 

and beluga and gray whales would come from the air and marine traffic associated with Beaufort 

Sea oil development. 

• Boat traffic or icebreakers (for offshore platforms in the Far Zone) could briefly (few days) 

disturb some marine mammals within a lead system and may temporarily interrupt the 

movements of beluga and gray whales and seals or temporarily displace some animals when 

vessels pass through an area. However, there is no evidence to indicate that vessel traffic would 

block or delay marine mammal migrations. 

Modeled sound radii indicate that the sound associated with the proposed drilling operations from the 

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, and the 120-dB sound level is modeled to occur at 4.6 mi (7.4 km) (see EA 

Section 2.3.6). During summer, bowhead whales may be found feeding throughout the Beaufort Sea and 

belugas primarily follow the continental shelf break and the ice edge. During the fall westward migration 
 35

starting in late August/early September, belugas and bowhead whales migrate through the U.S. Beaufort 

Sea in a corridor that extends to at least 100 mi (161 km) offshore (Figures 3-1 and 3-2). Considering the 

limited size of the area potentially affected by the proposed activities relative to the total area of the 

Beaufort Sea OCS, MMS expects no measureable population-level effects for most marine mammals. 

Consequently drilling sounds in the marine environment are expected to result in a negligible level of 

effects to most marine mammals, other than cetaceans, in the vicinity of the project area. 

Vessel traffic related to the proposed activities would be limited to summer and autumn. Ice-management 

activities are likely to occur throughout the drilling period and icebreaking activities could occur during 

Shell’s departure from the project area in late autumn. 

Screening for Potential Effects on Birds, Benthic and Pelagic Invertebrates 

Because of the distance between the proposed drill sites and any breeding, brood rearing, or preferred 

foraging habitat for birds and the localized area of potential disturbance related to the proposed activities, 

nearshore aggregations of birds are not expected to be affected. Because of the distance from colonies, 

nesting, and brood-rearing areas and because water depths in the project area render the substrate and 

benthic invertebrates unusable by some species, the occurrence of waterfowl and seabirds (jaegers, gulls, 

terns, etc.) in the vicinity of the proposed activities is expected to be sporadic and very low density. 

Table 3.2.1-2 identifies bird-ship collisions as the only measureable source of impact to spectacled eiders 

and long-tailed ducks. Consequently, only spectacled eiders and long-tailed ducks will be analyzed 

further in this document and only in the context of bird-ship collisions. The effects analyses for 

exploratory drilling evaluated in Beaufort Sea Multiple-Sale EIS (USDOI, MMS, 2003), the Sale 202 EA 

Table 3.2.1-2. Effects analysis determinations for avian species and invertebrates that may occur in the vicinity of the 

project area. Effects are described as NG = negligible, MN = minor, MO = moderate, MJ = major, and * = effect after 

mitigation. Determinations were based on existing analyses in USDOI, MMS (2003) and Shell Offshore Inc. (2009b), 

and incorporate more recent information from other sources, as appropriate. Species Vessel Traffic Vessel Noise Aircraft Traffic Aircraft Noise Drilling Noise Icebreaking MLC Construction Vessel Mooring and Drill Cuttings and Drilling Mud Discharges 

Other Permitted 

Discharges 

Small Liquid 

Hydrocarbon Spills 

Air Pollutant 

Emissions 

Bird - Ship Collisions 

Cumulative Effects 

Birds 

Common Eiders NG NG NG NG NG NG NG NG NG NG* NG MN* MN 

Gulls, Jaegers, Terns NG NG NG NG NG NG NG NG NG NG* NG NG NG 

King Eiders NG NG NG NG NG NG NG NG NG NG* NG MN* MN 

Long-tailed Ducks NG NG NG NG NG NG NG NG NG NG* NG MN* MN* 

Pacific Loon NG NG NG NG NG NG NG NG NG NG* NG NG NG 

Red-throated Loon NG NG NG NG NG NG NG NG NG NG* NG NG NG 

Scoter Spp. NG NG NG NG NG NG NG NG NG NG* NG NG NG 

Spectacled Eiders NG NG NG NG NG NG NG NG NG NG* NG MN* MN* 

Steller's Eiders NG NG NG NG NG NG NG NG NG NG* NG MN* MN* 

Yellow-billed Loon NG NG NG NG NG NG NG NG NG NG* NG NG NG 

Invertebrates 

Benthic and Pelagic 

Invertebrates 

NG NG NG NG NG NG NG NG NG NG NG NG NG 
 36

(USDOI, MMS, 2006a), and Shell’s EIA (Shell Offshore Inc., 2009b) are incorporated by reference. 

As noted in Table 3.2.1-2 below, all bird species, excepting eiders and long-tailed ducks, are expected to 

experience negligible levels of direct, indirect, and cumulative effects from the proposed action because 

few if any are expected to occur in the project area within the zones of measureable levels of noise, 

temperature changes, water depths, or discharges. 

Screening for Potential Effects on Fishes 

Marine, anadromous, and diadromous fishes that could occur in the vicinity of the proposed drilling 

locations are noted in Table 3.2.1-3. There are no known key reproductive, or feeding areas within a 

reasonable distance of the proposed Torpedo and Sivulliq drill sites. The progeny of arctic ciscos 

spawning in Northern Canada are sometimes carried west into the central and western Beaufort Sea by 

ocean currents, and in doing so, might be affected by the proposed action. However Arctic ciscos use 

nearshore habitats to grow to maturity so any smolt swept into the OCS waters have a lower likelihood of 

survival. Moreover each prospect is a relatively tiny point in the Beaufort Sea with a very limited area of 

potential effects to fishes, so any impacts to Arctic cisco smelt that may occur are expected to affect only 

an infinitesimally small percentage of the overall population. Consequently, a negligible level of effects 

determination was made for these populations. 

Presence and Habitat Use Analyses 

Tables 3.2.1-4, 3.2.1-5, and 3.2.1-6 below provide species population estimates, the status of each species 

under the ESA, the number of individuals expected to occur near the project, and habitat preferences. 

Table 3.2.1-3. Effects analysis determinations for fish species that may occur in the vicinity of the project area. 

Effects are described as NG = negligible, MN = minor, MO = moderate, MJ = major, and * = effect after 

mitigation. Determinations were based on existing analyses in USDOI, MMS (2003) and Shell Offshore Inc. 

(2009b), and incorporate more recent information from other sources, as appropriate. Species Vessel Traffic Vessel Noise Aircraft Traffic Aircraft Noise Drilling Noise Icebreaking MLC Construction Vessel Mooring and Drill Cuttings and Drilling Mud Discharges Other Permitted Discharges 

Small Liquid 

Hydrocarbon Spills 

Air Pollutant 

Emissions 

Cumulative Effects 

Fishes 

Arctic Char NG NG NG NG NG NG NG NG NG NG NG NG 

Arctic Cisco NG NG NG NG NG NG NG NG NG NG NG NG 

Arctic Cod NG NG NG NG NG NG NG NG NG NG NG NG 

Arctic Flounder NG NG NG NG NG NG NG NG NG NG NG NG 

Broad Whitefish NG NG NG NG NG NG NG NG NG NG NG NG 

Capelin NG NG NG NG NG NG NG NG NG NG NG NG 

Chum Salmon NG NG NG NG NG NG NG NG NG NG NG NG 

Dolly Varden NG NG NG NG NG NG NG NG NG NG NG NG 

Fourhorn Sculpin NG NG NG NG NG NG NG NG NG NG NG NG 

Humpback Whitefish NG NG NG NG NG NG NG NG NG NG NG NG 

Least Cisco NG NG NG NG NG NG NG NG NG NG NG NG 

Pink Salmon NG NG NG NG NG NG NG NG NG NG NG NG 

Saffron Cod NG NG NG NG NG NG NG NG NG NG NG NG 
 37

Ribbon seals, narwhals, killer whales, harbor porpoises, and humpback whales are rarely documented in 

the Beaufort Sea, and any sightings are believed to lie outside the species’ expected range. For this 

reason, they are considered anomalous occurrences and are not analyzed further. Available scientific 

information indicates that species such as Pacific walrus, spotted seals, gray whales, Steller’s eiders, 

spectacled eiders, and salmon are not expected to occur in large numbers in the vicinity of this project. 

Presence and Habitat Use Analyses for Mammals 

Table 3.2.1-4. Population information and habitat use for marine and terrestrial mammal species that may be exposed to the effects of 

the proposed action. ESA Status: N = not listed, C = candidate, T = threatened, E = endangered, and S = species of concern. 

Anticipated Number of Exposures: * = speculative number based on general biological assumptions.

Species Population Size 

Anticipated Number/Max. 

Population Density of 

Individuals at Project Site

ESA 

Status

Area Habitat Preferences During Open Water Season

(information sources are USDOI, MMS (2003) and Shell EIA (2009) 

unless otherwise noted) 

Marine Mammals 

Bearded Seal 

Unreliable estimate of 250,000 - 

300,000 in Bering/Chukchi/ Beaufort 

Seas as reported in Angliss and 

Allen, 2009. 

3 or 0.0362 seals/km2 at 160 dB 

(NMFS, 2007) or 76 at 

> 120 dB and 13 at > 160 dB 

(Shell, 2009b). 

C Over continental shelf with 70% - 90% ice cover and between 20 and 

100 nautical miles offshore. May remain near ice, or in open waters. 

Beluga Whale 

39,258 Bering/Chukchi /Beaufort 

Seas as reported in Angliss and 

Allen, 2009. 

1 or 0.0135 belugas/km2 at 

160 dB (NMFS, 2007) or 157 

at > 120 dB and 41 at > 160 dB 

(Shell, 2009b). 

N 

Usually follow lead systems and nearshore areas in spring migration. 

Summer habitat use is segregated with older males using the continental 

shelf break and heavy ice, while females with young prefer shallower 

water over the shelf. Belugas migrate westward along the shelf during 

their fall migration. 

Bowhead Whale 10,545 Western Arctic Stock as 

reported in Angliss and Allen, 2009. 

488 or 0.0256 bowheads/km2 at 

160 dB (NMFS, 2007) or 1,994 at 

> 120 dB and 20 at > 160 dB 

(Shell, 2009b). 

E 

Feeding over deep water and in shallow waters in U.S. Beaufort Sea. 

May be found feeding near drill site locations. Spring migration into 

U.S. Beaufort Sea is typically farther offshore, north of proposed drill 

sites. The drill sites are in the fall migration path. 

Gray Whale 18,813 Eastern Pacific/Stock as 

reported in Angliss and Allen, 2009. 

1 or 0.0001 gray whales/km2 at 

160 dB (NMFS, 2007) or 5 at 

> 120 dB and 5 at > 160 dB 

(Shell, 2009b). 

N Waters over continental shelf. 

Harbor Porpoise 48,215 Bering/Chukchi Seas as 

reported in Angliss and Allen, 2009. 

1 or 0.0002 porpoises /km2 at 160 

dB (NMFS, 2007). N Considered rare and extralimital. 

Humpback Whale 961 Pacific/Bering Seas as reported 

in Angliss and Allen, 2009. 0 (extralimital) E Considered rare and extralimital. 

Killer Whale <314 Bering Sea as reported in 

Angliss and Allen, 2009. 0 (extralimital) N Open water and ice front, some coastal areas. Not known to use Beaufort 

Sea. 

Narwhal <5 0 (extralimital) Considered rare and extralimital. Prefer deeper waters over continental 

shelf breaks. Sometimes accompany beluga whales. 

Pacific Walrus Unreliable Estimates <5 C Uncommon in area. Usually forage over continental shelf. 

Polar Bear 20,000 - 25000 worldwide (FWS 

2009) Biological Opinion) 0 (USDOI, FWS, 2009) T 

Areas of sufficient sea ice cover North of the project location from July 

thru October. Some may be in open water transiting between sea ice and 

the coast. Females with young, and sub adults may occur onshore. 

Ribbon Seal 

Unreliable estimate of 90,000 – 

100,000 in Bering/Chukchi Seas as 

reported in Angliss and Allen, 2009. 

0 (extralimital) N Pelagic waters in the Bering and Chukchi Seas. Individuals have been 

rarely documented in Beaufort Sea. 

Ringed Seal 

Unreliable estimate of 249,000 in 

Bering, and Chukchi Seas as reported 

in Angliss and Allen, 2009. 

42 or 0.7094 seals/km2

 at 

160 dB (NMFS, 2007) or 1,486 at 

> 120 dB and 263 at > 160 dB 

(Shell, 2009b). 

C Shallow waters over continental shelf. 

Spotted Seal 

Unreliable estimate of 59,214 

Bering/Chukchi Seas as reported in 

Angliss and Allen, 2009. 

1 or 0.0149 seals/km2

 at 160 dB 

(NMFS, 2007) or 6 at > 120 dB 

and 5 at > 160 dB (Shell, 2009b). 

C Seasonal visitor to Beaufort Sea. Shallow waters over continental shelf. 

Terrestrial 

Mammals 

Central Arctic 

Caribou Herd 31,857 Alaska 0 N Coastal areas are used for insect relief.(Griffith et al. 2002) 

Porcupine Caribou 

Herd 110,000-115,000 ANWR/Yukon 0 N 

Most caribou from the Porcupine herd calve near the coast in May/June, 

moving back into the Brooks Range Foothills in July (Griffith et al., 

2002, Caikoski, 2008). 

Grizzly Bear Mostly stable at 269 bears in GMU 

26C (Lenart, 2007) 0 N Ubiquitous throughout Game Management Unit 26C in low densities. 

Other Furbearers Variable. None are reported to be in 

any danger. (Szepanski, 2007) 0 N Ubiquitous throughout Game Management Unit 26C in low to moderate densities (Szepanski, 2007). 
 38

Angliss and Allen (2009) characterize the population estimates for ice seals (ringed, ribbon, bearded, and 

spotted seals) as unreliable or tentative, and ice seal populations are known to be in the tens to hundreds 

of thousands for each species across the Arctic. Ice seals are associated with sea ice for all or part of the 

year. Although some species of ice seals tend to remain near the ice edge during the summer months, 

they frequently occur regularly in open water, particularly during the summer. Because Shell’s sitespecific seafloor surveys and biological studies indicate there are no unique features in this project area of 

special significance to marine mammals, MMS determined that additional population studies of these 

species are not required for this site-specific analysis. 

Typical cetacean and pinnipeds species briefly visiting the project area during the proposed time period of 

operations are expected to be migrating or feeding bowhead whales; ringed and bearded seals; and the 

occasional gray whale, walrus, spotted seal, or pod of beluga whales. The project area lies in migration 

corridor for the fall migration of bowhead and beluga whales and to the west of Camden Bay. 

Presence and Habitat Use Analyses for Birds 

Table 3.2.1-5. Population information and habitat use for avian species that may occur in the vicinity of the proposal area. ESA 

Status: N = not listed, C = candidate species, T = threatened species, and E = endangered species. 

Species Population Size

 

Anticipated 

Number/Max. Population 

Density of Individuals at 

Project Site

ESA Status

Area Habitat Preferences During Open Water Season

(information sources are MMS (2003) and Shell EIA (2009) 

unless otherwise noted)

Birds 

Common Eiders 1,936 on Alaska's North Slope 

(Dau and Larned, 2007). 

0.13/km2

 (Fischer and Larned, 

2004; Fischer, Tiplady, and 

Larned, 2002) 

N 

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 (Fischer and Larned, 2004) 

Gulls, Jaegers, 

Terns 

Trend Data and various 

population indices (Larned et al. 

2009) 

0.02/km2

 (Fischer and Larned, 

2004; Fischer, Tiplady, and 

Larned, 2002) 

N Varies with food availability near the water surface. 

King Eiders 

12,000 (Larned and Balogh, 1997; 

Larned et al., 2001). 12,896 

Larned, Stehn, and Platte (2006). 

0 (Flint et al. 2001; Fischer, 

Tiplady, and Larned, 2002) N 

Water depths <20 m (Fischer and Larned, 2004)). between the 

Colville River and Prudhoe Bay, southeast of Teshekpuk Lake and a 

large area near Atqasuk (Larned, Stehn, and Platte, 2006) 

Long-tailed Ducks 116,400 (Sea Duck Joint Venture, 

2003). 

0.12/km2

 (Fischer and Larned, 

2004; Fischer, Tiplady, and 

Larned, 2002) 

N 

Water depths <66 m (Robertson and Savard, 2002)..Most long-tailed 

ducks migrate within 45 km of shore (roughly along the 20-m 

isobath), infrequent observations of long-tailed ducks in pelagic 

waters occur in late September (Divoky, 1987).

Pacific Loon 31,699 (Larned et al., 2009) 

0.05/km2

 (Fischer and Larned, 

2004; Fischer, Tiplady, and 

Larned, 2002) 

N Water depths <46 m (Lehtonen, 1970). Most common in 

< 20-m depths (Johnsgard, 1987) 

Red-throated Loon 2,425 (Larned et al., 2009) 0 N Prefer shallow nearshore waters. (Johnsgard, 1987) 

Scoter Spp. 

0.08/km2

 (Fischer and Larned, 

2004; Fischer, Tiplady, and 

Larned, 2002) 

N Forage in 6-30 ft of water (Bellrose, 1980) 

Shorebirds Variable 0 N Shorelines, lagoons, bays, estuaries, river deltas 

Spectacled Eiders 33,587 on Alaska’s Arctic Coastal 

Plain (Stehn et al., 2006 1 (USDOI, FWS, 2009) T 

Lovvorn, et al (2000) indicated spectacled eiders prefer water depths 

40-60 m. The USDOI, FWS (2006) determined they prefer depths 

to 30.5 m and mostly migrate over the 20-m isobath. Based on 

telemetry data for molt migration in the Chukchi Sea, male 

spectacled eiders migrate an average of 35 km offshore, and females 

fly an average of 60 km offshore. 

Steller's Eiders 576 (Stehn and Platte, 2009). 

<1 (USDOI, FWS, 2009; Flint 

et al., 2001); expected 

densities were 0.0045 

birds/km2

 (USDOI, FWS, 

2007). 

T 

Range extends to Prudhoe Bay. Prefer foraging in nearshore water 

depths down to 9 m (USDOI, FWS, 2002). Not known to occur east 

of Deadhorse, AK. They mostly migrate over the 20-m isobath 

(USDOI, FWS, 2006). The greatest breeding densities on the North 

Slope occur near Barrow (Quakenbush et al., 2002); although they 

do not breed every year when present (Suydam, 1997a). 

Yellow-billed Loon 

4,892 as reported in Shell 

(2009b). <5000 (Earnst et al., 

2005). 

0 (Fischer, Tiplady, and 

Larned, 2002) C 

Most nesting occurs in NPR-A. Nearshore areas and wetlands. 

Fisher and Larned (2004) found most using water depths 

< 32 ft (10 m) (Johnsgard, 1987) 
 39

Post-breeding spectacled eider drakes using the Beaufort Sea migrate within 7 km of the coast (median 

distance; Troy, 2003; Petersen, Larned, and Douglas, 1999) enroute to molting areas in the Chukchi Sea 

or Russia. Movement between North Slope breeding areas and the primary molting area in Ledyard Bay 

typically takes several weeks, indicating several stops along the way in the Beaufort and Chukchi seas. 

The physiological importance of the stops during this extended migration is undetermined, but these stops 

could be very important to molt timing and survival during and after the molt. Smith Bay appears to be a 

site of concentrated use by female eiders (Troy, 2003) in the Beaufort Sea. 

Paired male Steller’s eiders depart the North Slope after the nest is initiated in mid- to late June. Because 

Steller’s eiders occur in such low numbers on the North Slope, it is difficult to observe large migrations 

by males after nest initiation or post-nesting females and young-of-the-year, as is the case with king and 

common eiders. It might be reasonable to expect that their movements would be loosely bounded by the 

distance of ice from shore and the water depth. It is unlikely that Steller’s eiders would be farther than 24 

km offshore, because the water depth would be beyond their diving capability and the males likely would 

be traveling over sea ice. Only 20 Steller’s eiders were counted during migration counts conducted from 

Point Barrow fall 2002 through spring 2004 (Suydam et al., 2008). 

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. 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). 

Satellite telemetry was used to determine that most 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 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 percent 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 middepth 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). 
 40

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 

(roughly along the 20-m isobath), 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). Most long-tailed ducks migrate within 45 

km of shore (roughly along the 20-m isobath); infrequent observations of long-tailed ducks in pelagic 

waters occur in late September (Divoky, 1987). 

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 midSeptember (Shell Offshore Inc., 2009b). 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 NPR-A, it is 

likely that there are fewer than 1,000 nesting pairs, because some of the 3,300 are non-breeders. 

Additionally, there are approximately 1,500 yellow-billed loons, presumably juvenile non-breeders 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). Because of the location of the project area in relation to their lifecycle requirements, we do 

not expect yellow-billed loons to occur in the vicinity of the proposed actions. 

Through discussions among MMS staff biologists early in the analytical process, the presence of 

shorebirds at or near the project area was determined to be highly unlikely (Schroeder, Denton, and 

Crews, 2009, pers. commun.). Consequently, a zero population density of shorebirds in the project area is 

expected, and no impacts to shorebirds are expected. Analysis of potential impacts to shorebirds is not 

further analyzed in this EA. 

Aerial surveys for bird use of offshore and coastal waters in the western Beaufort were conducted 

(Fischer and Larned, 2004) up to 62 mi (100 km) offshore for the MMS. The areas surveyed were 

between Cape Halkett and Brownlow Point in June, July, and August 1999 and 2000 and between Point 

Barrow and Demarcation Point in July 2001. About 90% of the birds observed were sea ducks; mostly 

long-tailed ducks, king eiders, and scoters. Densities of most species decreased with distance from shore 

except for king eiders, where densities were higher in deeper offshore waters. Mean distance offshore for 

king eiders was 10 mi (16.5 km), with 81% occurring more than 6.2 mi (10 km) from shore. However, 

densities of king eiders were higher in shallow (less than 32.8 ft [10 m]) and mid-depth (32.8-65.6 ft [10-

20 m]) waters between Barrow and Oliktok Point than in other study areas to the east. King eiders were 

not present in mid-depth and deep (> 65.6 ft [20 m]) waters in the eastern part of the study area, despite 

large open-water areas. The waters in the Torpedo and Sivulliq prospect areas vary from 107-128 ft 

(32.5-39 m) (Shell Offshore Inc., 2009b), putting these sites beyond the surveyed distribution and habitat 

preferences of king eiders and most other sea ducks. 

Oceanographic expeditions in the Beaufort and Chukchi seas found gulls, kittiwakes, jaegers, and terns 

far from shore and in pack ice (Harwood et al., 2005). The northernmost sightings consisted of blacklegged kittiwakes and ivory gulls 460 mi (740 km) from shore in an area of pack ice. Gulls, kittiwakes, 

and fulmars were numerous 37-62 mi (60-100 km) northwest of Barrow at the Northwind Ridge area and 

near Barrow Canyon. Likewise, gulls and kittiwakes were often found along the Chukchi Sea shelf break. 

Divoky (1983) observed the pelagic area (>20-m water depth) avian diversity consisted primarily of 

surface-feeding species (gulls, terns, phalaropes, and jaegers), with little use by diving species such as 

loons or sea ducks, except as a migratory area. The nearshore waters (<20-m water depth) hosted large 

numbers of long-tailed ducks, loons, and migrating eiders, with low densities of surface feeders relative to 

what was found in pelagic waters. 
 41

Consequently, we have concluded that most avian species are not likely to occur in the environs of either 

prospect area, at least not in any large numbers based on the results of Fisher et al. (2004) and their 

habitat-use limitations (as noted in Table 3.2.1-5) indicating their absence from the project area or 

unsuitability of the project area for their habitat preferences. Most sightings should be the occasional 

individual and not large aggregations. Of all the species analyzed, only the spectacled eiders, common 

eiders, king eiders, a few long-tailed ducks, an a few sea birds may face the potential of being impacted 

by the proposed action. However, seabirds such as gulls, terns, and jaegers fly at higher altitudes than do 

sea ducks; moreover, they are gliders, usually flying at slower speeds than do sea ducks, which fly 

quickly and at low altitudes. The slower speeds and higher altitudes used by seabirds are expected to 

provide more reaction time, allowing seabirds to avoid striking ships under most conditions. Spectacled 

eiders were included in the analysis on the premise that their habitat requirements permit their use of the 

project area, that their presence may not have been detected in previous surveys due to their scarcity, and 

the possibility that they may have been noted as “UNEI” or unknown eider in Table 28 of Fisher et al. 

(2004). The water depths in the project area are much too deep for foraging by Steller’s eiders. 

Moreover, Steller’s eiders are not known to occur regularly east of Deadhorse and Prudhoe Bay (USDOI, 

FWS, 2002). 

Presence and Habitat Use Analyses for Fishes 

No population estimates are available for the fishes listed in Table 3.2.1-6, because U.S. Beaufort Sea fish 

stocks lack the impetus of a large fishing industry that demands extensive population studies and 

monitoring by NOAA and NMFS. Although there are no population estimates, there is information 

available on the presence of fish species in various habitats. Completed studies indicate some fish 

species, such as salmon, have a very limited presence and are only in the larger river systems flowing into 

the U.S. Beaufort Sea, as shown in EIA Table 3.5.2-1 (Shell Offshore Inc., 2009b). No successful 

reproduction of these populations is documented in these studies. 

Table 3.2.1-6. Population information and habitat use for fishes species that may occur in the vicinity of the proposal area. 

ESA Status: NL = not listed, C = candidate species, T = threatened species, and E = endangered species. 

Species Population Size 

Anticipated 

Number/Max. 

Population Density 

of Individuals at 

Project Site

ESA Status

Area Habitat Preferences During Open Water 

Season

(information sources are MMS (2003) and Shell EIA (2009) 

unless otherwise noted)

Fishes 

Arctic Char No Estimates No Estimates NL Anadromous 

Arctic Cisco No Estimates Abundant NL Diadromous 

Arctic Cod No Estimates 57.9 / 1,000 m3

 NL Marine. Sea ice cover or shallow nearshore areas during icefree season. 

Arctic Flounder No Estimates 0-67 / day catch rate NL Marine. Usually in < 20-m water depth. 

Broad Whitefish No Estimates Abundant NL Diadromous. Fresh and brackish waters. 

Capelin No Estimates 8.2 per m3

 NL Marine. Shallow (< 3 m) water depth in coastal estuarine areas 

within 5 mi (8 km) from coast. 

Chum Salmon No Estimates Very low NL Anadromous 

Dolly Varden No Estimates Occasional NL Anadromous. Nearshore zones within 1,650 ft (500 m) of the 

coast. 

Fourhorn Sculpin No Estimates 0.12 per 1,000 m3

 NL Marine 

Humpback Whitefish No Estimates No Estimates NL Diadromous. Freshwater systems and coastal zones. 

Least Cisco No Estimates Low, tapering off in 

July NL Diadromous. Within 330 ft (100 m) of the coast 

Pink Salmon No Estimates Very low NL Anadromous 

Saffron Cod No Estimates Very abundant NL Marine. Cooler, deeper waters. 
 42

Because of the limited information on fish species in the Beaufort Sea Planning Area, MMS considered 

whether additional studies of fish would be necessary to determine the potential for significant effects for 

this site-specific analysis. Although information on continental-shelf fish species in the Arctic is limited 

compared to other regions of Alaska, there is sufficient information to evaluate the effects of the proposed 

action, which would include benthic habitat disturbance, noise, and turbidity. The area of benthic 

disturbance would be limited temporally and spatially. Fish species that are mobile would be able to 

avoid the disturbances in the project area and the associated temporary effects of turbidity and noise. 

Benthic disturbances from the drilling activities would likely affect few individuals of any species. Shell 

conducted extensive seafloor and shallow geologic surveys and collected shallow cores for geochemical 

and geotechnical studies. None of the site studies indicated that the seafloor environment at the proposed 

drill sites is in any way unique in the area. If during the exploration, unique benthic habitats, species, or 

communities are found, the occurrence will be reported to MMS and per the requirements of Lease 

Stipulation 1, Shell’s activities would be modified if necessary to protect those resources. Based on this 

information, MMS believes that additional fish studies are not needed at this time for adequate sitespecific analysis prior to this proposed action. 

The EIA (Shell Offshore Inc., 2009b) summarized the effects of noise on fishes in Section 4.1.12, 

explaining fishes may react to sound levels >120 dB and that drillship noise typically falls between 90 dB 

and 138 dB, depending on distance from the noise source. The EIA states that the ice-management 

vessels can produce sounds ranging from 174-184 dB, or 10-15 dB higher if actively breaking/moving 

ice. Such sound levels could motivate fishes to temporarily avoid these areas; however, no measurable 

population-level effects on fishes are anticipated from the proposed activities. The overall effect of the 

proposed activities on fishes is expected to be negligible in light of the temporary, non-lethal, effects that 

are not expected to affect fish populations in a measureable way. 

The Department of Commence approved the Arctic Fishery Plan for the U.S. Arctic in August 2009 

(NPFMS, 1990). The Salmon Fishery Management Plan for Coastal Alaska, approved in 1990 (NPFMC, 

1990) applies to the five Pacific salmon species in the Alaska Chukchi and Beaufort Seas. The Arctic 

Fishery Management Plan (2009) identifies three commercial target species: Arctic cod, saffron cod, and 

snow crab (opilio crab). The Arctic Fishery Plan also 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. The general distribution for adult and late juvenile Arctic cod essential fish habitat 

(EFH) covers the entire Arctic Fishery Plan Area, which includes both the Chukchi and Beaufort seas. 

Considering the mobility of fishes, the limited areal extent of disturbance associated with the proposed 

activities, and broad area of the Arctic cod EFH, MMS has determined the proposed activities would have 

no to negligible effects on EFH. 

Identification of Biological Resources Requiring Further Evaluation 

The data from EA Tables 3.2.1-1 thru 3.2.1-6 were analyzed for level of effects, the anticipated 

number/maximum population density of individuals at the project site, and habitat preferences. This 

information was then combined, evaluated in relation to the impact levels specified in EA Section 3.2.1, 

and the result entered into EA Table 3.2.1-7. Species that could potentially be affected by the proposed 

action are analyzed further, and those that are not at risk have been excluded from further consideration 

and analysis. Table 3.2.1-7 indicates whether or not a species was excluded from further analysis and, if 

so, the rationale for the exclusion. For some species, the level of effects are not reasonably expected to be 

more than negligible, meaning that it is extremely unlikely that any detectable population-level effects 

would result from the proposed activities. Species that could experience greater than negligible level of 

effects progress into the next level of analysis. Beluga, bowhead, and gray whales; Pacific walrus; polar 

bear; long-tailed ducks; and eiders are further analyzed. 
 43

Tables 3.2.1-4 and 3.2.1-7 indicate the project area is considered outside the range (extralimital) of one 

ice seal species and the other seal species are expected to experience a negligible level of effects from the 

proposed activities. Under the methodology used in this analysis, these species would be “screened out” 

for further analysis in this EA; however, because NMFS intends to use much of MMS’ environmental 

analysis in their NEPA compliance for MMPA authorization for the proposed activities, we have included 

these species in this evaluation. 

Both Steller’s and spectacled eiders were included in the FWS Biological Opinion (BO) (USDOI, FWS, 

2009) covering exploratory activities in the Beaufort and Chukchi seas by the petroleum industry and so 

will be further analyzed under the effects of bird strikes although there are no known breeding 

populations near the project area. 

Table 3.2.1-7. Species included and excluded from subsequent effects analysis. Species Excluded from further analysis? Exclusion Reason for Species

Excluded from 

further analysis? 

Exclusion 

Reason for 

Marine Mammals Birds 

Bearded Seal N ESA Scoter Spp. Y LE

Beluga Whale N -- Common Eiders Y LE

Bowhead Whale N -- Gulls, Jaegers, Terns Y LE 

Gray Whale N -- King Eiders Y LE 

Harbor Porpoise Y EO Long-tailed Ducks N -- 

Humpback Whale Y EO Red-throated Loon Y LE

Killer Whale Y EO/LE Pacific Loon Y LE

Narwhal Y EO Shorebirds Y LE 

Pacific Walrus N -- Spectacled Eiders N -- 

Polar Bear N -- Steller's Eiders N -- 

Ribbon Seal Y EO/LE Yellow-billed Loon Y LE 

Ringed Seal N ESA Fishes 

Spotted Seal N ESA Arctic Char Y LE 

Terrestrial Mammals Arctic Cisco Y LE 

Central Arctic Caribou Herd Y LE Arctic Cod Y LE 

Porcupine Caribou Herd Y LE Arctic Flounder Y LE 

Grizzly Bears Y LE Broad Whitefish Y LE 

Other Furbearers Y LE Capelin Y LE 

EXCLUSION CRITERIA Chum Salmon Y LE 

N = No. Species has not been 

excluded from further analysis in this 

EA. Dolly Varden Y LE 

Y = Yes. Species has been excluded 

from further analysis Fourhorn Sculpin Y LE 

EO = Extralimital Occurrence. Humpback Whitefish Y LE 

LE = Negligible Level of Effects 

(between July and October in the vicinity of 

the proposed action). Least Cisco Y LE 

 ESA =Analysis because of ESA 

status or Pending ESA review Pink Salmon Y LE 

 Saffron Cod Y LE 
 44

3.2.2 Proposed Action Mitigation for Biological Resources 

Shell incorporated extensive mitigation in their proposed activities to lessen or alleviate the impacts 

associated with exploratory drilling on wildlife species. These measures are summarized in EA Sections 

2.3.9 and 2.3.10. Shell describes their proposed mitigation measures in EP Appendix E (IHA application 

to NMFS); EP Appendix F (LOA application to FWS including Shell’s Polar Bear, Pacific Walrus, and 

Grizzly Bear Avoidance and Encounter Interaction Plan); EP Appendix G (Bird Strike Avoidance and 

Lighting Plan); and EP Appendix J (Marine Mammal Monitoring and Mitigation Plan. These proposed 

mitigations are in addition to or may be amended by measures required under MMPA authorizations and 

the ESA consultations administered by NMFS and the FWS. Shell’s mitigation measures related to 

discharges, emissions, and spills are summarized in EA Section 2.3.4, EA Section 2.3.11, and Shell’s 

ODPCP. The mitigation measures from the EP listed below are pertinent to species protection and are 

assumed in the analyses. 

Vessel Traffic and Noise 

• Shell will not operate vessels within 0.5 mi (800 m) of polar bears. 

• To minimize impacts on marine mammals and subsistence-hunting activities, the drillship and support 

vessels traversing north through the Bering Strait will transit through the Chukchi Sea along a route that 

allows for the highest degree of safety regarding ice conditions and sea states. 

• Marine Mammal Observers (MMOs) shall be posted on ships to ensure that support vessel activities do not 

disturb marine mammal resources or the subsistence hunt of those resources. 

• The MMOs will 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. 

• For vessels in transit, if a marine mammal is sighted from a vessel within its relative safety radius, the Shell 

vessel will reduce activity (e.g., reduce speed and/or change course) and sound energy level to ensure the 

animal is not exposed to sound above the safety level for that species. Full activity will 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. 

• When within 900 ft (274 m) of marine mammals, vessels will reduce speed, avoid separating members 

from a group, and avoid multiple course changes. 

• Vessels will not operate within 0.5 mi (800 m) of walrus. 

• Vessel speed to be reduced during inclement weather conditions to avoid collisions with marine mammals. 

• When within 1,000 ft (300 m) of walrus in water, vessels will reduce speed and avoid multiple changes of 

direction. 

Aircraft Traffic and Noise 

• Shell will implement flight restrictions prohibiting aircraft from flying within 1,000 ft (330 m) (horizontal 

distance) 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. 

• Aircraft shall not operate below 1,500 ft (457 m), unless the aircraft is engaged in marine mammal 

monitoring, approaching, landing or taking off, or unless engaged in providing assistance to a whaler or in 

poor weather (low ceilings) or any other emergency situations. 

• Aircraft engaged in marine mammal monitoring shall not operate below 1,500 ft (457 m) in areas of active 

whaling; such areas to be identified through communications with the Com Centers. Aircraft will not 

operate within 1500 ft (457 m) of whale groups. 

• 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 directly south of its offshore destination, at which 

point it shall fly directly north to its destination. 

• Helicopters primarily will fly direct routes (except to avoid severe weather), which will reduce the spatial 

area potentially disturbed. Planned routes also avoid areas of known polar bear dens. 

• Aircraft and vessels will not operate within 0.5 mi (800 m) of walrus or polar bears when observed on land 

or ice. When polar bears are seen by aircraft, the aircraft will use alternative routes to avoid disturbing the 

bear. 
 45

• Regular overflight surveys and support vessel surveys for marine mammals will be conducted to monitor 

prospect areas. 

• Mitigation to reduce bird disturbances will include flight path selection, flight altitudes, and flight timing to 

avoid those times that large concentrations of birds are present in the vicinity of the Deadhorse airport or 

the drillship. 

• The helicopter flight path will be along the coastline at 1,500 ft (457 m) altitude approximately 5 mi (8 km) 

from the coastline to a point at which the helicopters will turn and fly generally perpendicular to the 

coastline, past Point Thompson, through the Mary Sachs Entrance, and on to the drill site, reducing 

disturbances to nearshore birds and by overflights of any barrier island. 

Drilling Noise 

• Anchored vessels, including the drilling vessel, will remain at anchor and continue ongoing operations if 

approached by a marine mammal. An approaching animal not exhibiting avoidance behavior is assumed to 

be curious and not harassed. The anchored vessel will remain in place and continue ongoing operations to 

avoid a flight or alarm response from the animal elicited by suddenly changing sound-energy conditions. 

Bird-Ship Collisions 

• Installing shading and directing light inward and downward to living and work structures to minimize light 

radiating from the drillship. Shell is planning to reduce or shade light output from: 

o Derrick lights, deck lighting, doorway and stairway lighting, and pipe rack lighting – lights will be 

shaded to direct light downward and inward and/or the wattage reduced. 

o Crane boom lights – lights will remain unshielded for safety during crane operations. 

o Heliport lighting – lights will be dimmed or shut off when not in use. 

o Escape pod lighting – lights will be dimmed when not in use. 

o Navigation and clearance lights – no changes will be made due to safety concerns. 

o Lights from windows – shades will be used during darkness. 

• Where applicable, replacing some lights with “ClearSky” light technology to reduce the amount of red light 

output. ClearSky lighting emits fluorescent light with a unique light spectrum without the long-wavelength 

(red) components. This technology is produced by Philips Lighting. Studies indicate that removing the 

long wavelength components of the spectrum reduces the visual and orientation impact on birds 

(Marquenie, 2007). 

• Conducting an assessment of the movements of bird flocks in the proximity of the drillship using the radar 

equipment available onboard the drillship. One aspect of the assessment will be to monitor and compare 

bird movements during periods of good and poor visibility. Radar will be used to perform bird-movement 

monitoring, because visual observations may not be possible during periods of poor visibility, such as at 

night or during foggy conditions. 

• Shell has committed to a bird-strike monitoring program that record and report bird strikes and conditions 

under which they occur (e.g., vessel lighting configuration), providing the FWS with data for risk 

assessment of bird strikes related to operational activities, weather conditions, and response of eiders and 

other migratory birds to drillship lighting. 

Operations 

• Solid food wastes will be incinerated onboard the drillship, eliminating the wastes as a potential attractant 

for polar bears. 

3.2.3 Effects Analysis for Biological Resources 

Only species that may experience potential effects with a magnitude greater than negligible (see Section 

3.2.1) are further analyzed in this document. The following analyses scrutinize the effects of impacts 

rated minor, moderate, or major. More in-depth analyses can be found in Beaufort Sea Multiple-Sale EIS 

(USDOI, MMS, 2003) the Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008). Additional information 

can also be found in the Sale 195 and Sale 202 EAs (USDOI, MMS, 2004, 2006a). We have determined 

that no unique or noteworthy resources or seafloor habitats occur in the vicinity of the proposed drill sites. 
 46

Aircraft Traffic and Noise 

Richardson et al. (1995a) document reactions of ringed seals concealed in subnivean (below snow on ice) 

lairs varied with aircraft altitude and lateral distance (Kelly, Quakenbush, and Rose, 1986). The noise in 

a ringed seal den is reduced by snow (Cummings, Holliday, and Bonnet, 1983); however, radio-telemetry 

indicated some seals left the ice when a helicopter was at an altitude of 1,000 ft (<305 m) within a 1.25-

mi (2-km) lateral distance. Counts of ringed seal calls in water suggests that seal abundance in one area 

subjected to low-flying aircraft and other disturbances was similar to that in less disturbed areas (Calvert 

and Stirling, 1985). The proposed activities would occur during the open-water season after seals have 

pupped and molted, fast ice has melted away, and flowing ice has retreated north and away from the 

project area. Shell has incorporate measures to reduce the likelihood of impacts to marine mammals 

including restricting aircraft to above 1,500 ft (457 m), unless the aircraft is engaged in marine mammal 

monitoring, approaching, landing or taking off; and conducting regular aerial and vessel surveys to 

monitor for marine mammals prospect areas (see EA Section 3.2.2). Therefore, we conclude aircraft 

traffic and noise would have a negligible level of effect on ice seals. 

Although most polar bears attempt to remain offshore on the pack ice during the ice-free season, an 

increasing number are observed on the coast as loss of sea ice and availability of whale carcasses 

continue. As reported in USDOI, FWS (2009), repeated overflights by helicopters could disturb polar 

bears; however, behavioral reactions by non-denning polar bears are expected be brief with no long-term 

impacts on individuals and no impacts on the population. Shell has incorporate measures to reduce the 

likelihood of impacts to marine mammals including restricting aircraft to above 1,500 ft (457 m), unless 

the aircraft is engaged in marine mammal monitoring, approaching, landing or taking off; helicopter 

routes planned avoid areas of known polar bear dens; use of alternative routes when polar bears are seen 

by aircraft to avoid disturbing the bears, and specifying that aircraft will not operate within 0.5 mi (800 

m) of polar bears when observed on land or ice (see EA Section 3.2.2). Therefore, we conclude aircraft 

traffic and noise would have a negligible level of effect on polar bears 

Few Pacific walrus are known to use the project area or the central and eastern Beaufort Sea. While a few 

walrus might occur near the project area, they would likely be in the water, foraging on the seafloor, or 

swimming along the water surface. Shell has committed to maintaining a 1,500 ft altitude for aircraft 

flying in support of the proposed activities. Because of the 1,500 ft altitude, a lack of sea ice, and the low 

numbers of Pacific walrus expected in the project, a minor level of effect on Pacific walrus is expected 

form the proposed activities. 

Vessel Traffic and Noise 

A startle response of belugas was observed in a study by Fraker, Sergeant, and Hoek (1978), in which 

vessels moved 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 

Greenridge, 1996). Such reactions are not expected in the relatively shallow waters of the project area 

(USDOI, MMS, 2003; Shell Offshore Inc., 2009b), 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. 

Bowhead whales react to the approach of vessels at greater distances than they react to most other 

activities. Most bowheads exhibit avoidance of vessel traffic, although reactions are less dramatic to 

slower moving vessels and vessels that are not approaching the animals directly (NMFS, 2008). 

According to Richardson and Malme (1993), most bowheads begin to swim rapidly away when vessels 
 47

approach rapidly and directly. Avoidance usually begins when a rapidly approaching vessel is 1-4 km 

(0.62-2.5 mi) away. A few whales may react at distances from 5-7 km (3.1-4.3 mi), and a few whales 

may not react until the vessel is <1 km (<0.62 mi) away. Received noise levels as low as 84 dB re 1 μPa 

or 6 dB above ambient may elicit strong avoidance of an approaching vessel at a distance of 4 km (2.5 

mi) (Richardson and Malme, 1993) (USDOI, MMS, 2008, incorporated by reference). 

In the Canadian Beaufort Sea, bowheads observed in vessel-disturbance experiments 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). Vessel disturbance during these 

experimental conditions temporarily disrupted activities and sometimes disrupted social groups, when 

groups of whales scattered as a vessel approached. 

In their analysis of Shell’s 2007-2009 EP, NMFS determined that bowhead whale reactions to icebreaking 

and non-icebreaking ice management are expected to be variable. Generally, bowheads are expected to 

avoid areas of active icebreaking and ice management by 1.2-15.5 mi (2-25 km) (USDOC, NOAA, 

NMFS, 2008). 

Bogoslovskaya, Votrogov, and Sememova (1981) observed avoidance behaviors by gray whales when 

vessels came within 980 ft (300 m), but saw no reaction to vessels further away. In a study by Schulberg, 

Show, and Van Schoik (1989), many gray whales showed no deflection or change of behavior until 

vessels came within 98 ft (30 m). Underwater sound also may cause whales to avoid vessels moving 

within their immediate area, and gray whales are expected to exhibit avoidance of vessels in close 

proximity (USDOI, MMS, 2008, incorporated by reference). 

Shell measures for protection of biological resources (EA Section 3.2.2), include specific measures to 

minimize adverse effects to cetacean from vessels related to the proposed action. Therefore, we conclude 

that vessel traffic and noise from the proposed action are expected to result in negligible effects on any 

cetaceans in the project area. 

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, 

2009). Shell has submitted and committed to the measures in their Polar Bear, Pacific Walrus, and 

Grizzly Avoidance and Human Encounter/Interaction Plan (Shell Offshore Inc., 2009a:Appendix F). In 

addition, Shell has incorporate measures to reduce the likelihood of impacts to polar bears (EA Section 

3.2.2), include vessels will not operate within 0.5 mi (800 m) of polar bears and when within 900 ft (274 

m) of marine mammals, vessels will reduce speed, avoid separating members from a group, and avoid 

multiple course changes. Therefore, impacts to polar bears from vessel traffic associated with the 

proposed drilling operations are expected to be minor. 

Walrus may avoid moving vessels, with most reactions occurring within 0.29 mi (0.46 km) (Richardson 

et al., 1995a) or they may approach vessels out of curiosity. Shell has submitted and committed to the 

measures in their Polar Bear, Pacific Walrus, and Grizzly Avoidance and Human Encounter/Interaction 

Plan (Shell Offshore Inc., 2009a:Appendix F). Shell’s measures for protection of biological resources 

(EA Section 3.2.2), including a 0.5 mi (800 m) exclusion zone around observed walrus for vessels in 

transit, are expected to reduce contacts with and minimize adverse effects to walrus. Because of the 

timing of the project, the low number of walrus expected to occur in the central Beaufort Sea, and Shell’s 

commitment to avoid walrus, vessel traffic and noise from the proposed action are expected to result in 

negligible effects on Pacific walrus. 
 48

Richardson (1995a) found that vessel noise does not seem to strongly affect pinnipeds (seals, sea lions, 

fur seals, and walrus) that are already in the water. Richardson went on to explain that seals on haulouts 

sometimes respond strongly to the presence of vessels and at other times appear to show considerable 

tolerance of vessels, and (Brueggeman et al., 1992; as reported in Richardson, 1995a) observed ringed 

seals hauled out on ice pans displaying short-term escape reactions when a ship approached within 1⁄4 - 1⁄2 

mile. We expect the proposed mitigations (i.e. 800-m buffers, etc.) to lessen the impacts of vessel traffic 

on seals for the duration of the project to a negligible level of effect. 

The impact of vessel traffic on marine mammals is expected to be transient and localized. A minor level 

of effects on belugas, bowhead, gray whales, and polar bears is expected from vessel traffic and noise 

associated with the proposed activities. Negligible effects are expected for ice seals and walrus, because 

the proposed activities would occur during the open-water season when any seals or walrus using the area 

should be loafing, foraging, or transiting through the area. Very few walrus are known to use the central 

Beaufort Sea. 

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, as cited in Shell Offshore 

Inc., 2009b) 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 lowfrequency sounds associated with drilling activities is not expected to occur (Gales, 1982, as cited in Shell 

Offshore Inc., 2009b). 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 (Gales, 1982, as 

cited in Shell Offshore Inc., 2009b). 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., 1995b). 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 et al., 1998). Brewer et al. (1993, as cited in USDOI, MMS, 2008) observed belugas 

within 2.3 mi (3.7 km) of the drilling unit Kulluk during drilling. The more detailed discussion of this 

information provided in the USDOI, MMS (2008) Arctic Multiple-Sale Draft EIS is incorporated by 

reference. Some beluga whales may avoid the area in the vicinity of the drilling operations because of 

noise; however the effect is expected to be negligible.

Bowhead reaction to drillship-operation noise is 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., 1985a; Richardson and Malme, 1993). On several occasions, whales were 

well within the zone where drillship noise should be clearly detectable by them. In other cases, bowheads 

may avoid drillships and their support vessels at 20-30 km (see below and 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 bowheads than mobile noise sources. Most 

observations of bowheads tolerating noise from stationary operations are based on opportunistic sightings 

of whales near ongoing oil-industry operations, and it is not known whether more whales would have 

been present in the absence of those operations. Other cetaceans seem to habituate somewhat to 

continuous or repeated noise exposure when the noise is not associated with harmful events, implying that 

bowheads may habituate to certain, non-threatening noises. 
 49

The distance at which bowheads may react to drillships is difficult to gauge, because some bowheads 

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 bowheads within 9.5 km (5.9 mi) of the drillship, and few were observed within 15 km 

(9.3 mi). The study concluded that bowheads appeared to avoid the offshore drilling operation during 

their fall migration in 1986. 

In another study, Richardson et al. (1995b) 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. 

The disparity in results from these two studies indicate that variable responses of bowhead whales to 

drilling activities have been noted since at least 1987. 

Richardson et al. (1995b) 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 

significant, leading the MMS to conclude that drilling activity should have a minor level of effects on 

bowhead whales. Moreover, offshore drilling operations have occurred in the Beaufort Sea over the past 

several decades. In this time, the Western Arctic Stock of bowhead whales has concurrently increased to 

a number (10,545) estimate that may approach the bowhead whale carrying capacity of the Beaufort and 

Chukchi seas (Allen and Angliss, 2009). 

The effects of offshore drilling on ringed seals in the Beaufort Sea were investigated in the past (Frost and 

Lowry, 1988; Moulton et al., 2003). Frost and Lowry (1988) concluded that local ringed seal populations 

were less dense within a 2-nautical mile buffer of manmade islands and offshore wells that were being 

constructed in 1985-1987. Moulton et al. (2003) found less marked differences in ringed seal densities on 

the same locations to be higher in years 2000 and 2001 after a period of habituation. Conceptually, it 

appears that ringed seals may be somewhat disturbed by drilling operations for a period of time, until the 

activity has been completed. Adult ringed seals eventually seem to habituate to long-term effects of 

drilling, artificial island construction, and continuous operations that cumulatively created a much greater 

level of disturbance than what we expect from this project. This project will produce continuous sounds 

for about 74 days before the drilling convoy leaves the project area to “possibly” return after whaling has 

concluded. Because of the short duration of the proposed activities, nondescript site characteristics, and 

the observed effects of offshore drilling on seals, we do not anticipate measureable population level 

effects to occur. Consequently, a negligible level of effects is expected to result from drilling noise. 

By withdrawing from the project area from August 25 until after completion of Nuiqsut’s and Kaktovik’s 

subsistence bowhead whaling, Shell would avoid potential impacts to a portion of the migrating Western 

Arctic bowhead whale population. 
 50

The effects of drilling noise from the proposed activities on bowhead whales is expected to be minor, 

possibly resulting in some temporary deviations in migratory path in the vicinity of drilling operations. 

Some beluga whales and seals may avoid drilling operations, but the impacts are expected to be very brief 

and negligible. 

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, 2008, incorporated by reference). 

Brewer et al. (1993) reported that in fall 1992, migrating bowhead whales avoided an icebreakeraccompanied drillship by 25+ km. The ship was icebreaking almost daily. Richardson et al. (1995a) 

noted that in 1987, bowheads also avoided another drillship with little icebreaking. Response distances 

may vary, depending on icebreaker activities and sound-propagation conditions. Based on models in 

earlier studies, Miles, Malme, and Richardson (1987) predicted that bowhead whales likely would 

respond to the sound of icebreakers at distances of 2-25 km (1.24-15.53 mi) from the icebreakers. That 

study predicts roughly half of the bowhead whales show avoidance response to an icebreaker underway in 

open water at a range of 2-12 km (1.25-7.46 mi) when the sound-to-noise ratio is 30 dB. The study also 

predicts that roughly half of the bowhead whales would show avoidance response 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. (1995b) concluded that exposure to a single playback of variable icebreaker sounds can 

cause statistically, but probably not biologically, significant effects on movements and behavior of 

migrating whales in the lead system during the spring migration east of Point Barrow. The study 

indicated the predicted response distances for bowheads around an actual icebreaker would be highly 

variable; however, for typical traveling bowheads, 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 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 

should not be the case in this proposal because the proposed action is for the ice-free season. However, 

infrasounds (sound at a range of frequencies below that of human hearing) that may be associated with 

icebreakers were not adequately represented in playback transmissions. Bowhead whales likely can hear 

or detect infrasounds (Richardson et al., 1995b). 

Richardson et al. (1995b: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. (1995b: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 
 51

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 bowhead whales 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 this project lead the MMS to conclude that icebreaking and ice-management activities are 

expected to have a minor level of effect on the bowhead whale population in the Beaufort Sea. The 

response of gray whales to icebreaking and ice-management activities is expected to be similar to that of 

bowhead whales. 

Polar bears are known to run from sources of noise and the sight of icebreakers. During the open-water 

season, most polar bears remain offshore on the pack ice 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, 2009b). Polar bears may be 

temporarily drawn to or avoid icebreaker traffic with a minor level of effects. 

Reeves (1998) noted that some ringed seals have been killed by icebreakers moving through fast-ice 

breeding areas, and that the passing icebreakers could have far-reaching effects on the stability of large 

areas of sea ice; however this project would occur during the open-water season after sea ice retreats well 

north of the project area and the fast ice has melted way. Moreover, the pupping and molting seasons for 

all ice seals end well in advance of the project timeframe. Few seals are expected to be in the area or 

exposed to the proposed activities. Consequently, a negligible level of effect should arise from 

icebreaking activities. 

Walrus near moving icebreakers exhibited avoidance behavior in a monitoring project during drilling in 

the Chukchi Sea (Brueggeman et al., 1990). During icebreaking, walrus moved 12-16 mi (20-25 km) 

from the operations to areas where sound energy levels approached ambient levels (USDOI, MMS, 2008, 

incorporated by reference). 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 (Shell Offshore Inc., 2009b). 

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, we expect a negligible level of effect on Pacific walrus. 

Impacts to beluga, bowhead, and gray whales from icebreaking and ice-management activities associated 

with the proposed action are not expected to exceed a minor level of effect. Impacts to ice seals, polar 

bears, and Pacific walrus from icebreaking activity associated with the proposed action are expected to be 

negligible. 

Bird-Strikes (Collisions) 

Marine birds risk collisions with vessels at night due to attraction and subsequent disorientation from 

high-intensity lights. Sea ducks are particularly vulnerable to collisions with vessels, primarily because 

they tend to fly quickly and low over the water. Johnson and Richardson (1982) documented that 88% of 

eiders migrating to molting areas along the Beaufort Sea coast flew below an estimated 10 m (32 ft), and 
 52

over 50% flew below 5 m (16 ft). Eiders leaving the North Slope travel day or night. Movement rates 

(birds/hour) did not differ between night and day, but movement rates and velocities were higher on 

nights with good visibility (Day et al., 2004). A number of factors may reduce the height at which eiders 

migrate, including wind speed and direction, weather (i.e., fog or rain), and lighting (day vs. night) 

conditions (Day et al., 2005). 

Day, Prichard, and Rose (2005) completed a 4-year study of bird migration and collision avoidance at 

Northstar Island. The authors used bird radar to assess the reaction of migrating eiders and other birds to 

collision-avoidance lights located on the production structure. The authors reported that the lights were 

not so strong that they disrupted eider migration, but the eiders did slow down and diverted their flight 

paths from the island. 

Thirty common eiders, 6 king eiders, and 13 long-tailed ducks were killed due to collisions with Northstar 

and Endicott islands in the Alaskan Beaufort Sea during fall migrations in 2001-2004 (Day et al., 2005). 

This total was collected over a relatively narrow window (80 days total spread over 4 years) of the fall 

migration and, thus, probably underestimates total collision loss during fall migration. The greatest 

potential for collision impacts occurs where structures are in nearshore or coastal areas where birds, 

particularly eiders and long-tailed ducks, are known to migrate. 

The risk of bird strikes by Steller’s and spectacled eiders on the drillship and support vessels is very low 

and the impacts from such events are anticipated to be negligible because few, if any, threatened eiders 

are expected to be present in the project area during the drilling period. Using a generic strike rate of 0.4 

spectacled strikes per well year (USDOI, MMS, 2003), we calculated that as many as 0.16 spectacled 

eiders (calculated as = 0.40 (spectacled eider strike rate) x 0.4 years (duration of exploration) x 1 (number 

of operating drillships) might be taken during Shell's planned single-year drilling season. The strike rate 

is an estimate based on eider populations and data collected from 1 year at a single location and 

previously used in the FWS BOs (USDOI, FWS, 2002 and 2009 ) and in the Beaufort Sea Multiple-Sale 

EIS (USDOI, MMS, 2003). We rounded the value of 0.16 spectacled eiders up to a whole number value 

of 1. The water depths in the project area range between 32 and 40 m, placing both locations outside of 

the spectacled and Steller’s eider maximum diving/foraging depths of 30.5 and 9 m, respectively. 

Moreover, the locations are too far offshore and in water depths too deep (>30 m) to interfere with the 

coastal flight paths of most eider species. While most king and common eiders nest in the Canadian 

Arctic Archipelago the sheer numbers of migrating birds passing by the project area could result in some 

collisions. The risk of collisions would be highest if the drillship and associated vessels are in the area of 

the 20-m isobath during fall migration; however, as stated previously, the proposed drill sites are in 

deeper waters (Shell Offshore Inc., 2009b), putting them outside of the water depths preferred as 

migration routes by king and common eiders. Also the fall migration of common eider females and their 

young to molting areas occurs between late August and Early September, a time when the drillship and 

associated support vessels plans to depart the area, greatly reducing potential collision risks to common 

eiders. A no jeopardy determination by the FWS (USDOI, FWS, 2009) was completed, indicating a 

negligible to minor level of effect on spectacled and Steller’s eiders is expected to result from the 

proposed action. 

Long-tailed ducks are prone to collisions with structures and vessels, and they frequently venture farther 

from shore. The diving capacity of long-tailed ducks would allow them to forage on the seafloor on both 

project locations so that vessels conducting exploratory drilling could pose a threat to long-tailed ducks, 

especially if the vessels were using high-intensity work lights while operating during darkness or 

inclement weather. Shell’s preventative measures (Shell Offshore Inc., 2009a:Appendix G) are expected 

to mitigate the impacts to a negligible level. 
 53

3.2.4 Overall Conclusion on Effects to Biological Resources 

With the mitigation included in the proposed activities, a low number of avian mortalities could occur, but 

those numbers would be insufficient to measurably affect any bird populations, even those ESA-listed 

species (USDOI, FWS, 2009). The water depths in the project area place the area outside of the 

spectacled and Steller’s eider maximum diving/foraging depths. The water depths in the project area are 

within diving capacity of long-tailed ducks; thus, long-tailed may occur in the project area. Support 

vessels using high-intensity work lights while operating during darkness or inclement weather could pose 

a threat to long-tailed duck. Shell’s lighting measures (Shell Offshore Inc., 2009a:Appendix G) are 

expected to mitigate the impacts to a negligible level. No population-level effects to marine or coastal 

birds are expected from the proposed activities. 

Any polar bears, seals, or walrus in the proposed project area would be transiting open water and unlikely 

to remain in the area. We conclude that a few polar bears, Pacific walrus, ringed seals, and bearded seals 

may be negligibly affected by drilling. We expect Shell’s Polar Bear, Pacific Walrus, and Grizzly Bear 

Avoidance and Human Encounter/Interaction Plan (Shell Offshore Inc., 2009a:Appendix F) to greatly 

lessen the impacts of vessel and ice-management traffic on any walrus and polar bears. No populationlevel effects to polar bears, seals, or walrus are expected from the proposed activities. 

During July, August, and September, the project locations are expected to be mostly ice-free; thus the 

need for icebreaking or ice management should be infrequent once the vessels reach the project site. The 

presence of an icebreaker is a safety precaution in the event of an anomalous ice-related occurrence, and 

to assist the drillship in exiting the area if large amounts of ice pose a navigational hazard. We expect a 

few beluga, gray, and bowhead whales may experience short-term effects up to a moderate level of effect 

from ice-management activities and any necessary icebreaking activities. Individual beluga and bowhead 

whales are expected to avoid areas with sound levels greater than 100 dB during sound-generating 

activities, displaying a great deal of variation in their avoidance distances and the degree of their 

reactions. No population-level effects to beluga, gray, and bowhead whales are expected from the 

proposed activities. 

We conclude that no population-level effects to bird, mammal, or fish species are anticipated as a result of 

the proposed exploration drilling or support activities such as icebreaking; waste, sediment and water 

discharges; aircraft traffic and noise; vessel noise and traffic; mooring and MLC construction; air 

pollution; or small liquid hydrocarbon spills. With the mitigations incorporated in the proposed activities, 

most species occurring in the vicinity of the Torpedo and Sivulliq prospects are expected to be affected 

negligibly or at most to a minor level. Moreover, the exploration activities and impacts expected as a 

result of this proposal do not present substantially different circumstances from those anticipated in the 

prior EIS to which this EA tiers. The impacts from exploration drilling activities, particularly those 

involving threatened and endangered species, have been fully analyzed in prior environmental documents 

(USDOI, MMS, 2003, 2006a; USDOI, FWS 2006b, 2009). 

3.2.5 Additional Mitigation for Biological Resources 

Recommended Additional Mitigation 

• All vessels should maintain cruising speed not to exceed 9 knots while transiting the Beaufort Sea. This 

measure would reduce the risk of ship-whale collisions. 

• The Marine Mammal Observers on vessels underway in the Beaufort Sea should monitor the ocean waters 

near the ship for surfacing whales. If a surfacing whale is observed within 300 ft (100 m) of the ship, the 
 54

ship should disengage propellers to avoid potential propeller injury to the whale (prop strike) and, to a 

lesser degree, collision. Propellers should remain disengaged until the whale moves beyond 300 ft (100 m) 

from the ship. Safety of the vessel and its personnel shall take precedence over this measure. 

Mitigation Considered and Not Recommended 

• If the aerial monitoring detects 12 or more bowhead whales or 4 bowhead whale cow/calf pairs 

within an acoustically-verified 120-dB monitoring zone, Shell must reduce sound pressure levels 

in the drilling area. (As stated in EA Sections 2.3.11 and Shell EP Appendix J 4MP, Shell’s 

proposed activities already incorporate aerial monitoring around the drillship.) 

The MMS considered this mitigation measure, because NMFS required a similar measure in the 2007 

IHA for Shell’s 2007-2009 Beaufort Sea EP. The NMFS measure was intended to reduce potential 

impacts to bowhead whales to the lowest level practicable. 

Disturbance or behavioral effects to marine mammals from underwater sound may occur after the 

exposure to sound at distances greater than the “safety” radii (Richardson et al., 1995a). The NMFS 

assumed that marine mammals exposed to underwater pulsed sound levels ≥160 dB rms have the 

potential to be disturbed behaviorally. Safety and disturbance zones for marine mammals around 

continuous sound sources, such as drilling operations, have not been well established by the NMFS. 

In their EA for Shell’s 2007-2009 Beaufort Sea EP (USDOC, NOAA, NMFS, 2007a), NMFS stated: 

Based upon the findings of two workshops (HESS, 1998; Gentry, 1999), NMFS provides 

guidance for the establishment of "safety radii" for marine mammals around acoustic sources. 

The safety radii are customarily defined by NMFS as the distances within which received pulse 

levels are >180 dB re 1 microPa (rms) for cetaceans and >190 dB re 1 microPa (rms) for 

pinnipeds. These safety criteria are based on an assumption that lower received levels will not 

injure these animals or impair their hearing abilities, but that higher received levels might have a 

potential for such effects. 

The NMFS 2007 EA (USDOC, NOAA, NMFS, 2007) cites preliminary information from a 2006 

Canadian seismic survey on the behavior of a tagged bowhead whale to support the requirement for a 

120-dB mitigation zone. Later analysis of this information (Citta et al., undated poster presentation) 

clearly documented a single interaction with an active seismic vessel and concluded that the interaction 

only temporary disrupted the whale’s behavior. Both MMS and NMFS concluded that the cited 

information is not applicable to exploration drilling activities. 

There are almost two decades of history for exploration drilling in the Beaufort Sea. From 1981 to 2002, 

30 wells were drilled in the Beaufort Sea. Seven of these wells were drilled in the Camden Bay area, with 

another five wells completed nearby. Two of these historic wells were on the Sivulliq prospect. The 

available scientific information shows that the Western Arctic Stock bowhead whale population has 

increased at an annual rate of 3.4-3.5% over the last few decades during which the 30 wells were drilled 

in the Beaufort Sea. It is well established that the population rate increase exhibited by the population is 

indicative of a healthy marine stock (Angliss and Allen, 2009). 

The MMS concludes that the best available science does not indicate that the 120 dB mitigation 

requirement is warranted. 
 55

As summarized in Richardson (1995) and Richardson and Malme (1993): 

Bowheads seem most responsive when the sound level increases or when a noise source first 

starts up, e.g., when a boat is rapidly approaching, during a brief playback experiment, or when 

migrating whales are swimming toward a noise source. Although limited, the data suggest that 

stationary industrial activities producing continuous noise, e.g. stationary drillships and dredges, 

result in less dramatic reactions by bowheads than do moving sound sources, particularly ship.... 

Some other cetaceans seem to habituate partially to continuous or repeated noise exposure when 

the noise is not associated with pursuit, hunting or other harmful events (e.g., Jones and Swartz 

1984, Watkins 1986, Atkins and Swartz 1989). This along with habituation phenomena in other 

animals (Thorpe 1963), suggests that bowheads will habituate to certain noises that they learn are 

non-threatening. 

Richardson and Malme (1993) stated that “many comments in literature indicate baleen whales may react 

most strongly to changing, or increasing noise levels (Miles, Malme, and Richardson, 1987).” Changing 

or perhaps shutting down the noise output from a drillship may actually elicit a more profound response 

from passing bowheads than would a continuous level of noise. The additional level of protection to 

bowheads from this measure would be at best slight. 

• Implement and monitor bubble curtain technology to greatly alleviate the propagation of noise in 

the water column, greatly lessening the impacts of drilling noise on cetaceans and pinnipeds. 

The MMS does not believe that the low levels of potential effects of the drilling activities, as planned, 

would justify a need for such mitigation. 

Additional Background: The sound-reduction potential of a bubble train curtain is supported by some 

research and bubble curtains may have promise in relation to attenuation of seismic airgun sound 

propagation. A recent paper (Ayers, Jones, and Hannay, 2009) estimated transmission loss of airgun 

array sounds by about 21 dB for plane sound waves incident perpendicular to a bubble curtain. Since 

airguns are not part of the proposed activities, the degree of effectiveness such mitigation would bring to 

the proposed activities is unknown. Introducing such mitigation for this project could potentially impart 

noise variability and effects that would otherwise not occur. 

3.3 Alternative 1: Subsistence Activities, Employment, and 

Community Health 

Subsistence activities are a central element in the NSB socioeconomic system. The socioeconomic 

composition of the NSB is a blend of traditional subsistence activities; State, Federal and Native 

corporation services and jurisdictions with unique benefits and pressures that are a part of life in the 

Arctic. The following sections of the EA addresses specific components of these socioeconomic 

resources that are most relevant to the communities of Kaktovik and Nuiqsut: subsistence, employment, 

and community health. Kaktovik is a coastal community 60 mi (96.5 km) from the project area. Nuiqsut 

is 118 mi (201 km) west of the project area and about 20 mi (32 km) inland from the coast along the 

Colville River. Cross Island, from which Nuiqsut hunters base their bowhead whaling activities, is 47 mi 

(75 km) southwest of the project area. Concerns regarding short- or long-term effects the proposed 

project may have on the biological species upon which the local residents depend for subsistence will be 

found in the appropriate sections describing the biology, water quality, or air quality of this 

Environmental Assessment. For example, concerns about bowhead whale deflection, effects on coastal 

fish habitats, sensitivity of beluga whale to noise, effects of air emissions on human health and the like are 

beyond the scope of the subsistence analysis and are addressed in the appropriate sections in this EA. 
 56

3.3.1 Levels of Effects and Existing Environment for Subsistence Activities

Subsistence activities are assigned the highest cultural values by the Iñupiaq Eskimo of the North Slope 

and provide a sense of identity in addition to being an important economic pursuit. Subsistence is viewed 

by Alaskan Natives not just as an activity that is imbedded in the culture; it is viewed as the very culture 

itself (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 about the North Slope Iñupiaq 

Eskimo communities. 

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, 2008; EDAW/AECOM, 2007). Although bowhead whaling traditions are 

unquestionably significant, harvest of other wild resources, including caribou, fish, avian species, and 

other marine mammals also 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. 

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 withdraw north to lat. 71o

 (Figure 1-1) 

in the Beaufort Sea and would only resume after Kaktovik and Nuiqsut have completed fall bowhead 

whaling. Shell may continue until October 31. Alternatively, Shell may leave the Beaufort Sea 

altogether by August 25. 

The discussion below 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 the Sivulliq and Torpedo prospects present the potential to 

affect subsistence users at two Iñupiat communities: Nuiqsut, which lies 118 mi southwest of the leases, 

and Kaktovik, which lies 60 mi southeast of the leases. Barrow lies 298 mi west of the proposed project 

area. Cross Island, from which Nuiqsut whalers launch their bowhead whale hunt, is 47 mi (75 km) 

southwest of the proposed project. 

Shell proposes to drill two wells, one at the Torpedo prospect and one at the Sivulliq prospect. Shell 

proposes to mobilize by July 10, 2010, when sea ice is generally not as extensive as in the spring, 

reducing the likelihood of requiring the use of the icebreaker and after most bowhead whales have 

migrated eastward to feed. Regular crew rotation and ancillary support would be provided by helicopters 

flown from Deadhorse. 

Shell’s helicopters would fly a prescribed route previously agreed to with local residents of Nuiqsut and 

Kaktovik during MMS’ 2007 Government-to-Government meetings 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 (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 (about 6 weeks). When 

drilling is suspended on August 25, the borehole would be plugged and abandoned per MMS 
 57

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, 2010, depending on ice and weather. 

Levels of Effects for Subsistence 

In evaluating the potential adverse effects from OCS activities, MMS examines both the magnitude and 

duration of disruption. For the site-specific analysis in this EA, we used the following four categories of 

impact levels ranging from negligible to high: 

Negligible: 

Periodic, short-term effects that have no consequent effects to subsistence resources or harvests as 

the lowest level of effect. 

Minor: 

One or more subsistence resources would be affected for up to 1 year (1 harvest season), but none 

of these resources would become unavailable, undesirable for use, or experience population 

reductions. 

Moderate: 

Although one of more subsistence resources would be unavailable, undesirable for use, or 

experience population reductions for a period up to 1 year (1 harvest season), with subsistence 

harvests being affected for that period, the affected subsistence resources and harvests would be 

expected to recover completely if proper mitigation is applied or proper remedial action is taken 

once mitigation is implemented. 

High: 

The affected subsistence resources and harvests would not be expected to fully recover, even if 

proper mitigation is applied during the life of the proposed action, or even if proper remedial 

action is taken once the impacting agent is eliminated. 

High levels of effects would be considered to be significant impacts. 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 

MMS has undertaken, effects from activities can be adverse and noticeable before they reach the 

significance threshold. Furthermore, in the cumulative effects analysis, MMS analyzes the combined 

effects of projected activities with other actions, because MMS recognizes that effects that individually do 

not reach this significance threshold may exceed that significance threshold when considered collectively. 

Nuiqsut 

This discussion focuses on the subsistence activities, related subsistence resources, and subsistence 

distribution levels that generally occur during the period of Shell’s proposed operation in the Beaufort 

Sea, from mid-July through October 31, with a self-imposed withdrawal from the area and suspension of 

activity from August 25 until Nuiqsut and Kaktovik have completed bowhead whaling. 

Summer Months (July-August): During summer, the people of Nuiqsut harvest 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 (Galginaitis et al., 

1984). Residents stated that the best caribou hunting took place in summer, and coastal areas are the most 

productive for caribou hunting. People prefer the use of boats to access caribou, because the capacity of a 

boat is sufficient for hauling the meat back to the village. Although seal is not a preferred meat for 
 58

human consumption, people use the oil as a condiment. 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). These activities occur more than 100 mi from the drill sites. 

Late Summer through early Autumn (August 25-end of September): Bowhead whaling takes 

precedence over any other subsistence activity, and occurs only in the fall. The 2008 Cross Island 

bowhead whale hunting season started earlier than any other, with the first crew arriving on August 29, 

and lasted for 14 days, including days set aside for traveling, butchering, weather days, and scouting days. 

The captains agreed to stop whaling on September 9, because the four landed whales were considered 

enough. Whale strikes occurred at an average distance of 10.5 km (6.5 mi) from Cross Island. The 

shorter 2008 season compares with the 21-day season in 2006 and the 27-day season in 2005. Over the 

past 7 years of reported monitoring (2001-2008), the majority of the bowhead whales have been harvested 

in the northeast quadrant off Cross Island (Impact Assessment Inc., 2009a). 

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 (Impact Assessment Inc., 2009a). Although, because of to scheduling and logistical 

conflicts, it is not currently expedient for Nuiqsut hunters to hunt beluga and polar bear at Cross Island, it 

does not mean that the people have abandoned these subsistence resources, and they may resume using 

them in the future (Sverre Pedersen, 2009, pers. commun.). 

Late Autumn-Early Winter (end of bowhead whale hunt through October 31): When people again 

mobilize after the bowhead whale hunt, they direct their subsistence efforts inland to hunt caribou, moose, 

and avian species, and to fish. By this time, the caribou have migrated away from the coast, and the 

whitefish runs are strong. In a typical year, Nuiqsut residents expend their greatest effort fishing under 

the ice of the river channels to catch cisco and small whitefish (Impact Assessment Inc., 1990a). 

Kaktovik 

Summer Months (July-August): During summer, the people of Kaktovik engage in community-based 

subsistence fishery. Most households gillnet at beach sites on Barter Island near Kaktovik, 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. 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 fish in summer (Pedersen and Linn, 2005). 

Caribou also are a significant resource taken during the summer months. A peak harvest time is in July, 

when hunters selectively hunt fat bulls along the coast. Over a 4-year period, researchers determined that 

the summer hunt represented about 40% of caribou taken on an annual basis. During the years of 

systematic harvest documentation, caribou were taken as far west as the Canning River. Traditional 

caribou hunting grounds were delineated on maps by Kaktovik residents for researchers. Close to onethird of the depicted area lay west of the Canning River (Pedersen and Coffing, 1984; Coffing and 

Pedersen, 1985). Additional resources harvested in the summer include waterfowl and seal (Impact 

Assessment Inc., 1990b). 

Late Summer through early Autumn (August 25-end of September): As at Nuiqsut, the bowhead 

whaling effort takes precedence over any other subsistence activity, and occurs only in the fall. Although 

the Nuiqsut 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. 
 59

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 drill sites. 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, 2009:Map 64). 

The Shell EIA (Shell Offshore Inc., 2009b) describes 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. 

Late Autumn-Early Winter (End of Bowhead Whale hunt through October 31): As at Nuiqsut, 

when people again mobilize after the bowhead whale hunt, they direct their subsistence efforts inland to 

hunt caribou, moose, Dall sheep, and avian species, and to fish. In the fall/winter, the people fish inland 

under river ice using nets, mainly catching Dolly Varden, Arctic cisco, and some lake trout (Impact 

Assessment Inc, 1990b; Pedersen and Lind, 2005; Pedersen and Coffing, 1984). 

Barrow 

The Iñupiat of Barrow harvest bowhead whale in the fall of each year. Their hunt is localized around 

Point Barrow, and tends to run later than the Cross Island whale hunt season, occasionally lasting into 

October (Burwell and Newbury, no date). 

3.3.2 Proposed Action Mitigation Measures for Subsistence Activities 

Shell incorporated extensive mitigation in their proposed activities to lessen or alleviate the impacts 

associated with exploratory drilling on subsistence activities. The most important of these is the complete 

suspension of activity and withdrawal from the project area several days prior to the traditional start of the 

bowhead whale hunt. Work would not resume on-site until after Kaktovik and Nuiqsut captains terminate 

the hunt. Another important mitigation measure is committing to a flight pattern crossing overland in an 

area that receives the least amount of use by Nuiqsut and Kaktovik subsistence users during the summer 

months, and stating that helicopters would fly at an altitude of between 1,500 and 1,000 feet, weather 

permitting. These measures are summarized in Sections 2.3.10 and 2.3.11 of this EA. Shell describes 

their proposed migration measures in EP (Shell Offshore Inc., 2009a:Appendix B (Plan of Cooperation), 

Appendix E (IHA application to NMFS), Appendix F (LOA application to FWS, and Appendix J (Marine 

Mammal Monitoring and Mitigation Plan)). Shell’s mitigation measures related to discharges, emissions, 

and spills are summarized in EA Section 2.3.4, EA Section 2.3.11, and Shell’s ODPCP (Shell Offshore 

Inc., 2009c). 

3.3.3 Effects Analysis for Subsistence Activities

The areas of subsistence use by the communities of Nuiqsut or Kaktovik are discussed in EA Section 

3.3.1 above. No documented subsistence activities have occurred at the proposed offshore drill sites (S.R. 

Braund and Assocs., 2009). 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 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. 
 60

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 

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 into 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 

inland away from the coast. 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 (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 to minor, as long as Shell alters the flight path 

from the interior to closer to the coast and maintains an altitude of 1,000-1,500 ft, deploys from 

Deadhorse, and drills only the 2 prospects about 20 mi offshore, ceasing operations by October 31, 2010. 

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 oil-spill analysis has determined that 

there is a low chance for an accidental small oil spill that likely would be operational in nature. For the 

purpose of this analysis, a 48-bbl fuel transfer spill was chosen. A 48-bbl diesel spill would evaporate 

and disperse in less than 3 days. As required by Lease Stipulation 6, oil-spill containment booms would 

be deployed during any refueling activity, and would contain a small oil spill if one should occur. 
 61

The perception that oil-spill contamination of subsistence foods, particularly marine mammals or fish, 

might be of concern to the Iñupiat at Nuiqsut and Kaktovik in terms of potential effects on health. 

Because subsistence activities do not occur in the vicinity proposed drilling and any associated spill 

source and because no fuel transfer is expected during transit between the Beaufort and Chukchi seas, the 

short- and long-term effects of the analyzed small spill on subsistence activities are expected to be 

negligible to minor. 

If Shell relocates to the Chukchi, they would do so either at the end of August before the bowhead whale 

hunt or between mid- to late September after the bowhead whale hunt. This would result in an immediate 

cessation of helicopter flights from Deadhorse. As can be seen from reviewing the above analysis, 

helicopter flights have a greater potential to have adverse effects on subsistence hunting than drilling 

operations at the proposed drill sites. Vessel noises would not be discernable from shore or nearshore 

waters, where subsistence hunting for seals occurs. Therefore, relocating the operation from the Beaufort 

Sea to the Chukchi Sea would have a nonexistent to negligible effect on short- and long-term subsistence 

hunting at Nuiqsut and Kaktovik. 

3.3.4 Overall Conclusion on Effects to Subsistence Resources 

With the mitigation incorporated by Shell, effects on subsistence undertaken by Nuiqsut and Kaktovik 

residents are expected to be negligible. Mitigation measures include: 

• Complete removal from the drill site from August 25 until after Nuiqsut and Kaktovik whaling 

captains have completed their 2010 bowhead whale hunts; coordination and consultation with a 

single point of contact, the Subsistence Advisor hired in each community. 

• Adherence to communication protocols; use of marine mammal observers on-board vessels; crew 

rotation and air freight handled out of Deadhorse; 

• Helicopter flights from Deadhorse to the proposed drill sites at an altitude of 1,000-1,500 ft in 

altitude except landing, take-off, and during poor weather. 

• Helicopter flights running eastward inland away from the coast until suspending work August 25. 

• Helicopter flights running eastward north, closer to the coast if resuming work after the bowhead 

whale hunt. 

• Helicopter flight path following a prescribed route crossing the coast about 10 mi west of the 

mouth of the Canning River. 

• Deploying booms each time refueling occurs to contain any small fuel spill. 

Mitigation measures may not alleviate the perception that a small oil spill or regulated wastewater 

discharge might contaminate subsistence resources, particularly marine mammals or fish that could 

concern the Iñupiat of Nuiqsut and Kaktovik in terms of potential effects on health (EA Section 3.7, 

below). However, this analysis demonstrates that due to the short duration of the proposed activity, 

which would last from 6-12 weeks, the proposed project poses no more than a negligible effect to 

subsistence activities, as long as the above mitigation measures are followed. Moreover, the exploration 

activities and impacts expected as a result of this proposal do not present substantially different 

circumstances from those anticipated in the prior EIS to which this EA tiers. The impacts from 

exploration drilling to subsistence activities have been fully analyzed in prior environmental documents 

(USDOI, MMS, 2003, 2006a). 
 62

3.3.5 Additional Mitigation for Subsistence Resources 

Recommended Additional Mitigation 

• If Shell resumes exploration drilling in the Beaufort Sea after the bowhead whale hunt, Shell must meet 

with the communities of Kaktovik and Nuiqsut to ascertain if it would be preferable to relocate the 

helicopter route closer to the coast or offshore to avoid localities where subsistence harvest is taking place. 

Before August 25, the helicopter route is directed inland on the eastward leg to avoid effects on 

subsistence. After the fall bowhead whale hunt, the subsistence activities of the Iñupiat of Nuiqsut and 

Kaktovik move from the coast to the interior, with both groups using the foothills south of Deadhorse. 

Relocating the helicopter route away from seasonally used subsistence activity areas could reduce impacts 

to subsistence harvesters and effects on inland subsistence activities in the remote likelihood that bad 

weather required flights to travel at a lower altitude. 

3.3.6 Employment 

This analysis focuses on the sociocultural effects of local employment associated with the proposed 

activities on Nuiqsut, Kaktovik and, to a lesser extent, Barrow. 

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 oilindustry-related jobs on the North Slope. 

Changes in local employment may affect community sociocultural systems. The levels of effects for 

impacts to sociocultural systems are defined below. 

Negligible: 

Periodic, short-term effects with no measurable effects on normal or routine community 

functions, the lowest level of effect. 

Minor: 

Sociocultural systems being affected for a period up to 1 year, but effects would not disrupt 

routine community functions and could be avoided with proper mitigation. 

Moderate: 

Effects on sociocultural systems would be unavoidable for a period longer than 1 year. Affected 

normal or routine community functions would have to adjust somewhat to account for impact 

disruptions, but they would be expected to 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: 

Effects on sociocultural systems would be unavoidable, and normal or routine community 

functions would experience disruptions to a degree beyond what is normally acceptable. Once 

the impacting agent is eliminated, affected community functions may retain measurable effects, 

even if proper remedial action is taken. 

Shell’s proposed exploration drilling would offer employment to a small number of local NSB residents. 

The MMO program would employ local Inupiat 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. 

Although the number of local residents employed for the proposed activities is expected to be small and 

the effect to be negligible at the community level, qualitatively the loss of employment due to delay or 
 63

deferral of exploration during the 2010 season would be significant to individual at risk of losing his or 

her job. 

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 so are expected to have a 

negligible effect on economy of Kaktovik, Nuiqsut, and Barrow. 

3.3.6 Community Health 

The health and welfare of the residents of the NSB is a primary concern in any activity, and Shell’s 

commitment to the review and analysis of project activities affirms this is a priority. The project activities 

are offshore, of limited duration, and would be performed according to all applicable statutes and 

regulations from a number of Federal, State, and local jurisdictions and agencies. This project would 

have no adverse impact on the health of NSB residents, and specifically the communities of Kaktovik 

and Nuiqsut. 

The following analysis addresses the factors most likely to affect community health. 

All activities associated with the EP would be staged from existing infrastructure located in Deadhorse, 

Prudhoe Bay, and West Dock areas. Goods and services would be obtained from local village 

contractors, when available, during the duration of the project. These business interactions are not 

expected to adversely affect community health. Please refer to EA Section 3.3.6 on local hire for 

additional discussion. 

The air quality for the Beaufort Sea Planning Area is considered to be relatively pristine with 

concentrations of regulated air pollutants well within the National Ambient Air Quality Standards 

(NAAQS) and State of Alaska ambient air quality standards (18 AAC 50). The EPA air permit 

requirements are intended to ensure that Shell’s emission levels remain low enough to prevent harm to 

human health and the environment at all operating scenarios, including the worst-case highest hourly, 

enforceable emission rate from the Discoverer and its support vessels. By demonstrating compliance 

with the applicable NAAQS, AAAQS, and PSD increment standards at the edge of the Discoverer, in the 

immediate vicinity of its support vessels, and at the Beaufort Sea shoreline, the air quality impact analysis 

prepared for Shell’s EPA permit application shows that Shell would not have a significant adverse impact 

at the nearest villages along the Beaufort Sea coast, Nuiqsut and Kaktovik. Please refer to EA Section 3.4 

on air quality for additional discussion. 

Emissions from the proposed Shell exploration activities are not expected to significantly deteriorate the 

existing good air quality of the Beaufort Sea and adjacent coastal areas of the North Slope. Air quality 

impacts from the proposed activities are expected to be negligible to minor and short term. Therefore, 

emissions from the proposed activities are not expected to have any effect on the health of the nearest 

coastal villages. 

Existing water quality of the OCS is good due to the remoteness, active ecological system, and the limited 

presence of human (anthropogenic) inputs. Existing contaminants occur at very low levels in arctic 

waters and sediments and do not pose an ecological risk to marine organisms in the OCS (USDOI, MMS, 

2008). Anthropogenic water discharges potentially can effect changes in local marine water quality, such 

as impeding or changing existing natural properties and processes, increasing sedimentation, higher water 

temperature, lower dissolved oxygen, degradation of aquatic habitat structure, and loss of fish and other 

aquatic populations. Please refer to Section 3.5 on water quality for additional discussion. 
 64

The impact of NPDES-permitted discharges associated with Shell’s project is expected to be negligible 

and temporary. Main discharges include sanitary and domestic wastes. Minor discharges include noncontact cooling water, ballast water, desalination wastes, and deck drainage. Increases in turbidity and 

biological and chemical oxygen demand are expected near the discharge site, but the effects are expected 

to be temporary and minor, and have no effect on marine mammals and fishes or associated subsistence 

harvests. These effects would be limited to within 330 ft (100 m) of the discharge location. Therefore, 

discharges from the proposed activities are not expected to have any effect on the health of the nearest 

coastal villages. 

3.4 Alternative 1: Air Quality 

The air quality for the Beaufort Sea Planning Area is considered to be relatively pristine with 

concentrations of regulated air pollutants well within the National Ambient Air Quality Standards 

(NAAQS) and State of Alaska ambient air quality standards (18 AAC 50). Because concentrations of 

criteria pollutants are far less than Federal and State standards, the North Slope and adjacent offshore area 

are classified as an attainment area under the Clean Air Act. 

Air quality at the proposed drill sites is within the NAQQS and State of Alaska ambient air quality 

standards (AAAQS). The applicable NAAQS and Prevention of Significant Deterioration (PSD) 

increment standards are presented in EIA Table 4.2.2-1 (Shell Offshore Inc., 2009b). The EPA requires 

Shell to demonstrate compliance with these standards near the single drillship and not at the shoreline. 

The primary sources of the emissions by the Discoverer drillship and support vessels would be 

combustion engines including the vessel engines, generators, compressors, draw works, and pumps. 

Emissions generated from the proposed exploration activities would include nitrogen oxides (NOx), 

carbon monoxide (CO), sulfur dioxide (SO2), small-diameter particulate matter such as PM10 and PM2.5, 

and lead (Pb). The project would also generate lesser quantities of volatile organic compounds (VOCs), 

hazardous air pollutants (HAPs), ammonia, and CO2. 

Most of the emissions would be generated from the combustion of diesel fuel for power production from 

the movement of the ice-management and OSR vessels. Ice-management vessel activity would account 

for more than 90% of support vessels’ emissions; thus, total emissions would be lower in favorable ice 

conditions. 

Shell’s ambient air quality impact analysis is based on the worst-case, short-term, enforceable emissions 

rate for NOx, SO2, PM10, and PM2.5. The analysis has been conducted over the highest hourly emission 

rate for all the project emission units from the Discoverer and its support vessels. Shell’s analysis used a 

conservative meteorological screening data set, background ambient concentration data, and a 

conservative screening dispersion model, each of which received the informal approval of EPA modeling 

staff. Shell’s analysis also included the contribution of emissions from nearby sources. By demonstrating 

compliance with the applicable NAAQS, AAAQS, and PSD increment standards at the edge of the 

Discoverer, in the immediate vicinity of its support vessels, and at the Beaufort Sea shoreline, the 

preliminary air quality impact analysis prepared for Shell’s EPA permit application shows that Shell 

would not have a significant adverse impact at the nearest villages along the Beaufort Sea coast, Nuiqsut 

and Kaktovik. 

The EPA air permit requirements are intended to ensure that Shell’s emission levels remain low enough to 

prevent harm to human health and the environment at all operating scenarios, including the worst-case 

highest hourly, enforceable emission rate from the Discoverer and its support vessels. Emissions from 

the proposed Shell exploration activities are not expected to significantly deteriorate the existing good air 
 65

quality of the Beaufort Sea and adjacent coastal areas of the North Slope. Air quality impacts from the 

proposed activities are expected to be negligible to minor and short term. 

Although EPA has not established regulations for greenhouse gases/carbon dioxide (GHG/CO2) 

emissions control, EPA recently proposed a regulation for large sources of >25,000 tons CO2 equivalent 

per year to report annual GHG emissions beginning in the 2010 reporting year (EPA, 2009). The 

proposed exploration activities may exceed the 25,000-ton CO2-equivalent reporting threshold, depending 

on the required level of ice-management activity to keep the Discoverer and its crew safe from hazardous 

sea-ice conditions. Shell’s preliminary CO2 emissions inventory indicates the Discoverer CO2 emissions 

would be less than the 25,000 tons per year threshold with the combined Discoverer and support vessels 

CO2 emissions approaching almost 60,000 tons per year. The projected CO2 emissions for Discoverer

and its support vessels combined would account for approximately 0.1% of the Alaska 2005 total 

statewide estimated GHG of 53 million tons and 0.4% of the Alaska 2005 Statewide oil and gas industry 

estimated GHG of 15 million tons. The projected CO2 emissions from the proposed exploration activities 

would be negligible in comparison to the Alaska 2005 total statewide and Alaska oil and gas industry 

GHG/CO2 emissions. 

3.5 Alternative 1: Water Quality 

Water quality is a term used to describe the chemical, physical, and biological characteristics of water, 

usually in respect to its suitability for a particular purpose. The constituents of water in the marine 

environment mainly are composed of naturally occurring substances derived from the atmospheric, 

terrestrial, and other aquatic (freshwater and marine) environments. However, the constituents may 

include manmade substances and a few naturally occurring ones at toxic concentrations—pollutants. 

Potential impacts to water quality may occur as a result of the permitted discharges from vessels and 

drillships. Several factors at the time of discharge can play a role in how water quality is affected: 

hydrological conditions, depth at which the discharge is made, rate of the discharge, composition of the 

discharge, and concentration of contaminants. 

The general NPDES permit AKG280000 (EPA, 2006) for the offshore areas of Alaska, including the 

Beaufort Sea, authorizes discharges from oil and gas exploration facilities. The Arctic general permit 

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

requirements and other conditions. The EPA regulations (40 CFR 125.122) require a determination that 

the permitted discharge will not cause unreasonable degradation to the marine environment. 

Unreasonable degradation of the marine environment means: (1) significant adverse changes in 

ecosystem diversity, productivity, and stability of the biological community within the area of discharge 

and surrounding biological communities; (2) threat to human health through direct exposure to pollutants 

or through consumption of exposed aquatic organisms; or (3) loss of aesthetic, recreational, scientific, or 

economic values, which is unreasonable in relation to the benefit derived from the discharge. 

Shell acknowledges that intense, stable density stratification develops in the Beaufort Sea, including the 

prospect areas, during the summer ((Shell Offshore Inc., 2009b). The profile for temperature and salinity 

near the Sivulliq Prospect indicates a very sharp thermocline with a gradient exceeding 2o

C at 

approximately 16 m depth (EIA:Table 3.2-5). The profile for temperature and salinity near the Torpedo 

Prospect, indicates two thermoclines with gradients exceeding 2o

C; the first thermocline is at 3-5 m depth 

and the second at approximately 21 m depth (EIA:3.2-6). In addition, a strong halocline is seen at 5-8 m 

depth near the Torpedo Prospect with a gradient of more than two salinity units (EIA:3.2-6). 
 66

Both modeling and field studies have shown that discharged drilling fluids are diluted rapidly in receiving 

waters (Ayers, Sauer, and Steubner, 1980: Ayers, et al., 1980; Brandsma et al., 1980; NRC, 1983; 

O’Reilly et al., 1989; Nedwed, Smith, and Brandsma, 2004; Smith, Brandsma, and Nedwed, 2004; Neff, 

2005). The dilution rate is strongly affected by the discharge rate; the NPDES General Permit limits the 

discharge of cuttings and fluids to 750 bbl/hr (89 m3

/hr). 

Suspended solids discharged from the drillship are expected to produce a plume with acute toxicity levels 

out to about 60 ft (20 m). More than 90% of solids are expected to precipitate out of the water column 

within 650 ft (200 m) from the discharge point (Shell Offshore Inc., 2009b). Assuming that uniform 

mixing would occur, a maximum 2.5o

F increase in water temperature is expected in the plume out to a 

distance of 450 ft (137 m) from the discharge point (EA Section 2.3.4). 

The dilution rates used in Shell’s analysis appear to use the entire water column as the receiving volume. 

Strong stratification could severely inhibit vertical mixing in the water column so discharges to the upper 

layer could be retained in the upper 20 m of water. Deeper, colder strata could resist mixing with the 

warmer discharge from the disposal caisson, forcing the discharged water to disperse in the upper layers 

of the thermocline over a much larger area than predicted. Still, the area of potential disturbance is 

expected to remain small. Strong winds and storm events can disrupt such stratification, facilitating 

mixing. Stratification would be quickly reestablished when winds relax. Overall, the thermal, chemical, 

and particulate disturbances are expected to reflect the small spatial area of the modeled discharge plume. 

The discharges listed in Shell EIA Table 4.1.7-1 (Shell Offshore Inc., 2009b) have associated stipulations 

and effluent limitations that are defined within the general NPDES Permit. The stipulations and effluent 

limitations are designed to ensure that State water quality standards and criteria are not exceeded and that 

wastewater treatment processes used are the best available, allowing for technology and economic limits. 

Although the general permit requires that commingled discharges are subject to “the most stringent 

effluent limitations for each individual discharge,” aggregate effects from the combination of multiple 

types of discharge could be more severe than for the individual discharges. 

Of the eleven identified project discharge streams, Shell has determined that three of the discharge 

streams have the potential to affect water quality: 1) spent drilling fluids; 2) cuttings from water-based 

intervals; and 3) excess cement. These discharges would be regulated under the general NPDES Permit 

to meet the water quality standards at the point of discharge. 

The release of existing sediments and drilling muds has the potential to temporarily increase total 

suspended solids (TSS) in the water column, which can decrease the amount of light penetrating the water 

column. A full discussion of the sediment plume created by drilling activities is discussed in Shell EIA 

Section 4.1.8. Shell EIA Table 4.1.7-2 (Shell Offshore Inc., 2009b) shows modeled TSS in the water 

column around the discharge point. 

Localized impacts on temperature, salinity, and pH are possible, especially under certain conditions. 

Heavy metals are not a major concern in the water column because, although they may accumulate in 

sediments over time, many of the elements of concern (e.g., chromium, mercury, barium) are present in 

insoluble forms and are unlikely to migrate from sediments into the water column. 

Increases in turbidity and biological and chemical oxygen demand are expected near the discharge site. 

These effects on water quality are expected to be limited to within 330 ft (100 m) of the discharge 

location and be short term and temporary. 

The discharge from the water-cooling unit is expected to be 2.5  ̊F (1.4  ̊C) above the ambient temperature 

and is expected to reach an ambient temperature within 450 ft (137 m) of the drillship. The temperature 
 67

effect is expected to be short term and temporary. 

Diesel and free oil would cause mostly surface impacts; detectable quantities of oil on the water surface 

would be a violation of the general NPDES permit and a result of an unintentional release. Total aromatic 

hydrocarbons (TAHs) are soluble in the water column, and would be present in detectable concentrations 

only if a violation (unintentional release) of the general NPDES permit occurred. Localized impacts from 

Biochemical Oxygen Demand, fecal coliform, and TSS (total suspended solids; turbidity) may be 

realized, but only if the general NPDES permit is violated. 

A small fuel spill (48 bbl or less), such as a spill during a refueling operation, is the most likely spill 

scenario during the proposed activities (EA Section 2.3.8 and Appendix A). Nearly 100% of such a fuel 

spill is estimated to evaporate or disperse to very low levels within 48 hours. Light refined products, such 

as diesel, are narrow-cut fractions that have low viscosity and spread rapidly into thin sheens. Based on 

the viscosity of the diesel fuel to be used by Shell, the maximum area of the sea with diesel on the surface 

in an uncontained 48-bbl spill (i.e., no pre-booming) would be about 20-200 acres (0.1-0.8 km2), 

depending on sea state and weather conditions. 

The constituents of these oils are light to intermediate in molecular weight and can be readily degraded by 

aerobic microbial oxidation. Diesel is so light that it is not possible for the oil to sink and pool on the 

seafloor. Diesel dispersed in the water column can adhere to suspended sediments, but this generally only 

occurs in coastal areas with high TSS loads (NRC, 2003), and this would not be expected to occur at the 

drill sites to any appreciable degree. Diesel oil in the water column is readily and completely degraded by 

naturally occurring microbes, generally in 1-2 months. 

Discharges from Shell’s proposed activities would occur over relatively short periods of time (weeks). 

Impacts to water quality from permitted discharges are expected to be localized and short term. Because 

the discharges would be regulated through Section 402 of the CWA, to ensure compliance with state 

water-quality standards, impacts to water quality are expected to be temporary and minor. 

Water column effects from a small spill likely would be restricted to a small area and have a duration of 

less than 1 week. Effects would be minimized by booming during refueling, which would reduce the 

surface area of a spill and allow for recovery. Therefore, effects of any small spill on water quality would 

be expected to be minor and short term. 

3.6 Alternative 2 

Under Alternative 2 (No Action), Shell’s EP would be disapproved, and the proposed exploration 

activities would not occur. Disapproval of the EP could result in the delay or elimination of activities and 

potential impacts. Disapproval of the EP could result in lost opportunities for discovery and production 

of oil and gas resources and any associated economic benefits. 

Under Alternative 2, no impacts to the physical environment or biological resources would occur from the 

proposed activities. No impacts to the subsistence activities would occur from the proposed activities. 

The potential economic benefits for local North Slope residents described in EA Section 3.3.4 above 

would not be realized.
 68

3.7 Cumulative Effects 

3.7.1 Background 

Cumulative impacts can result from individually minor but collectively significant actions taking place 

over time. The scope of the cumulative impacts for this analysis is the incremental impact from the 

proposed exploration activities plus the aggregate effects of other activities that are known or reasonably 

expected to occur in the same timeframe (July-October 2010) and in the vicinity of the proposed 

activities, and to have potential effects on the same environmental resources 

The cumulative effects from OCS activities plus past, current, and reasonable foreseeable activities in the 

Arctic OCS and adjacent areas have been assessed in several recent MMS NEPA documents. Cumulative 

effects analyses were included the Beaufort Sea Multiple-Sale EIS for OCS Lease Sales 186, 195 and 202 

(USDOI, MMS, 2003), which was updated in the 2004 EA for Sale 195 (USDOI, MMS, 2004) and 

updated further in the Sale 202 EA (USDOI, MMS, 2006a). The level and types of activities proposed in 

Shell’s EP (Shell Offshore Inc., 2009a) are within the range of activities described and evaluated in the 

Beaufort Sea Multiple-Sale EIS and EA’s for Sales 195 and 202. 

In 2007, MMS completed an EA and issued a FONSI for the Shell’s 2007-2009 Beaufort Sea Exploration 

Plan (USDOI, MMS, 2007b). In 2007, NMFS completed an EA and issued a FONSI 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, 2007). Both EA’s included cumulative analysis for Shell’s proposed 2007-

2009 exploration activities. The Arctic Multiple-Sale Draft EIS (USDOI, MMS, 2008) provides MMS’s 

most recent cumulative analysis of the potential effects of Arctic OCS activities. 

The analysis below incorporates information from the documents cited by reference, and updates 

information as needed. 

The main sources of cumulative impacts associated with this EP are: (1) vessel traffic; (2) aircraft traffic; 

(3) oil and gas activities in federal and state waters; and (4) miscellaneous associated activities. 

Shell does not intend to conduct exploratory seismic surveys in the Beaufort Sea OCS during the 2010 

open-water season. The MMS is unaware of any industry plans to conduct exploration seismic surveys or 

site clearance activities in the vicinity of Shell’s Camden Bay exploration drilling operations during 2010. 

3.7.2 Cumulative Effects under Shell’s Beaufort Sea and Chukchi Sea EPs 

Shell has proposed exploration drilling in 2010 on their leases in both the Beaufort and Chukchi Seas. 

Shell proposes using the same drillship and support vessels for both operations. Weather and/or ice 

conditions in the Chukchi and Beaufort seas, as well as conditions at the specific proposed drilling 

locations, would ultimately dictate Shell’s operations. Given (1) the short open-water-drilling season for 

Arctic operations, even assuming Shell encounters no adverse weather and/or ice conditions or other 

unanticipated delays; (2) Shell’s commitment to cease activities by October 31 in both the Beaufort and 

Chukchi seas; (3) Shell’s commitment to suspend exploratory drilling activity in the Beaufort Sea during 

the Kaktovik and Nuiqsut bowhead whale subsistence hunts; and the time required to transit between the 

Beaufort Sea and Chukchi Sea project areas, Shell could not drill more than three of the proposed wells in 

the Beaufort and Chukchi seas combined (Shell, Letter to Secretary of the Interior Salazar dated June 24, 

2009). 
 69

The proposed Beaufort Sea and Chukchi Sea project areas are more than 400 mi apart. The MMS 

estimates a minimum of 48 hours (2 days) to plug and abandon a well. Shell estimates 1 day to retrieve 

the anchors prior to the drillship moving off site. The transit speed of the Discoverer is 8 knots (9.2 

mph); therefore, about 2 days would be required to transit between the Beaufort Sea project area and the 

Chukchi Sea project area. Shell estimates 5 days for construction of the MLC at a drill site, and 1 day to 

set anchor before drilling could begin. Based on this information, there would be at least 11 days between 

the end of drilling operations in one project area and the commencement of drilling operations in the other 

project area. 

Discharges and emissions associated with drilling at the two project areas would not overlap in time or 

space. Sound generated during transition form the Beaufort Sea to the Chukchi Sea (site-abandonment 

operations, transit, MLC constructing, setting anchors, and drilling) would be continuous at varying sound 

levels but the sound from various stages would not overlap in time or space. 

Sound generated from Shell’s proposed 2010 exploration drilling activities in the Chukchi Sea could not 

occur simultaneously with sound from the proposed Camden Bay EP because the same vessels, including 

the drillship, would be used for both drilling operations. Sound from the two exploration drilling 

operations would be separated in time and space and would not cumulatively affect the same resources. 

Because of the time required for transition of the drillship from one project area to the other, which is 

longer than the travel time for migrating species, the same animals would not be expected to be exposed 

to sound from both drilling operations and individual animals would not be expected to be exposed to 

long periods of sound from the vessels in transit. 

Effects related to proposed activities under the two EPs would not be cumulative because of the distance 

between the proposed Beaufort Sea and Chukchi Sea project areas and the limited areal and temporal 

extent of impacting factors associated with the proposed activities. Because of time required for 

transition between drilling operations and associated sound, discharges, and emissions at one project area 

and those beginning in the other project area, individual migrating animals are not expected to 

sequentially encounter operations in both seas. 

The oil-spill analysis has determined that there is a low chance for an accidental small oil spill Shell’s 

proposed activities in both the Beaufort and Chukchi seas. Therefore, if a small spill occurred in both 

seas, they would be separated by time and space. A small oil spill likely would be operational in nature, 

such as a hose rupture. For the purpose of this analysis, a 48-bbl fuel-transfer spill was chosen, and it is 

anticipated that it would last less than 3 days on the surface of the water. Booms would be on site and 

predeployed, if a small oil spill should occur, to contain the spill in a localized area to facilitate cleanup. 

A 48-bbl diesel spill would evaporate and disperse in less than 3 days. The short- and long-term effects 

on subsistence activities are considered to be low to insignificant because subsistence activities are not 

performed in the vicinity of the proposed drilling, or any associated spill; however, the perception that oilspill contamination of subsistence foods, particularly marine mammals or fish, might be of concern to the 

Iñupiat of Nuiqsut and Kaktovik in terms of potential effects on health. As described in the oil-spill 

analysis section, there is no likelihood of fuel-transfer spills occurring during vessel transit from the 

Beaufort to the Chukchi seas because there would be no refueling during transit. 

3.7.2 Other Cumulative Activities and Effects 

Vessels are expected to be the greatest anthropogenic contributors to 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, and those underway with a full load, or those pushing or towing a load, 

are noisier than unladen vessels. The primary sources of sounds are engines, bearings, and other 

mechanical parts. The sound from these sources reaches the water through the vessel hull. Other than 
 70

during icebreaking activities, the loudest sounds from vessels are made by the spinning propellers. 

Navigation and other vessel-operation equipment also generate subsurface sounds. 

Other than vessels associated with the proposed activities, vessel traffic in the project area is expected to 

include vessels used for fishing and hunting, icebreakers, Coast Guard vessels, and supply ships and 

barges. Vessel traffic in the project area is expected to be limited. Most vessels are expected to transit 

through the Camden Bay area within 12.5 mi (20 km) of the coast. During ice-free months (JuneOctober), barges are used for supplying the local communities, Alaskan Native villages, and the North 

Slope oil-industry complex at Prudhoe Bay with larger items that cannot be flown in on commercial air 

carriers. Usually, one large fuel barge and one supply barge visit the villages per year and one barge per 

year traverses through the Arctic Ocean to the Canadian Beaufort Sea. 

Vessel strikes with marine mammals in the Arctic Ocean are rare, in part because overall vessel traffic in 

the Alaska Beaufort Sea is very limited. The potential transit of the vessels, including the drillship, from 

Camden Bay to a proposed Chukchi Sea drill site would not substantially increase the risk of vessel 

strikes to marine mammals or birds because of the slow speed of the vessels, mitigation measures in 

Shell’s 4MP (Shell Offshore Inc., 2009a:Appendix J), and mitigation measures in Shell’s Lighting Plan 

(Shell Offshore Inc., 2009a:Appendix G). 

The proposed exploration drilling activities are short term, and potential effects other than noise are 

expected to be short-term and highly localized. Ice management is expected to be the greatest sound 

energy source during the proposed activities. The proposed activities would occur only during the openwater season and ice-management activities would occur only as necessary. Noise associated with the 

proposed activities is expected to have some adverse impacts on marine mammals. With mitigation 

measures incorporated in the activities proposed in Shell’s EP, no effects or negligible to minor adverse 

effects to coastal and marine birds, marine mammals, and fish are expected. The incremental contribution 

to cumulative impacts from the proposed activities on biological resources is expected negligible. 

With the mitigation incorporated by Shell, subsistence activities undertaken by Nuiqsut and Kaktovik 

residents are expected to receive at most negligible effects, and the incremental contribution to 

cumulative impacts from the proposed activities on subsistence for Nuiqsut and Kaktovik residents is 

expected to be negligible. 

Ice conditions and subsistence hunting are expected to have a greater impact on migration and survival of 

belugas, bowhead whales, and walrus than vessel traffic (USDOI, MMS, 2003). A minor level of effect 

on these marine mammals is expected from vessel traffic and noise associated with the proposed action. 

Sources of emissions in the area are generators in villages, transportation, and industrial sources at 

existing oil production facilities onshore and in State waters. During spring and winter, winds transport 

pollutants from industrial Europe and Asia across the Arctic Ocean to arctic Alaska (Rahn and Glen, 

1982). These pollutants cause a phenomenon called arctic haze. 

Shell anticipates operating a single drillship in the Beaufort Sea in 2010. The applicable NAAQS and 

PSD increment standards are presented in Shell EIA Table 4.2.2-1 (Shell Offshore Inc., 2009b). The EPA 

requires Shell to demonstrate compliance with these standards near the single drillship and not at the 

shoreline. Shell performed cumulative emissions modeling by including emissions from existing sources 

over a wide area. The modeling results indicate that concentrations of emissions from the cumulative 

sources would be within the PSD Class II incremental limits and the national ambient air quality 

standards. 

Any emissions generated from Shell’s proposed 2010 exploration drilling activities in the Chukchi Sea 
 71

could not occur simultaneously with emissions from the proposed Beaufort Sea exploration activities (the 

same vessels, including the drillship, would be used for both drilling operations if both EP’s were to be 

approved). Emissions from the two exploration drilling operations would be separated in time and space 

and would not cumulatively affect the same resources. The anticipated emissions are expected to be well 

below NAAQS and AAAQS at the shoreline as a result of distance from shore, permit restrictions, and 

dispersion. Air quality impacts from the proposed activities are expected to be negligible to minor and 

short term. The incremental contribution to cumulative impacts on air quality from the proposed EP 

activities is expected to be negligible. 

Any discharges generated from Shell’s proposed 2010 exploration drilling activities in the Chukchi Sea 

could not occur simultaneously with emissions from the proposed Beaufort Sea exploration activities (the 

same vessels, including the drillship, would be used for both drilling operations if both EP’s were to be 

approved). Discharges from the two exploration drilling operations would be separated in time and space 

and would not cumulatively affect the same resources. Discharges from the proposed activities are 

expected to be localized and short term. Because the discharges would be regulated through Section 402 

of the CWA, to ensure compliance with State water quality standards, impacts on water quality are 

expected to be temporary and minor. The incremental contribution to cumulative impacts to water quality 

from the proposed activities is expected to be negligible. 

Climate change (Arctic warming) is an observable phenomenon in the Beaufort Sea area. Many scientists 

attribute this climate change, at least partly, to emissions of greenhouse gases (GHG). The exploration 

drilling and support activities proposed in Shell’s EP are sources of GHG emissions. The projected GHG 

emissions from the proposed exploration activities would be insignificant in comparison to the Alaska 

total Statewide and Alaska oil and gas industry GHG emissions. The proposed activities would 

contribute a negligible amount to overall GHG emissions into the planet’s atmosphere. 

3.7.4 Overall Conclusion Cumulative Effects 

In conclusion, negligible to minor incremental contributions to cumulative effects are expected from the 

exploration drilling activities as proposed in Shell’s 2010 Camden Bay EP. 
 73

4.0 Consultation and Coordination 

4.1 Public Review of the Exploration Plan 

Pursuant to 30 CFR 250.232, MMS is required to submit a copy of the EP to the Governor of Alaska and 

the State coastal management agency for review and comment. On August 11, 2009, copies of the EP 

were sent to the Governor of Alaska and to the Office of Project Management and Permitting, which is 

the State’s coastal management agency. The Office of the Commissioner, Alaska Department of Natural 

Resources (DNR), submitted the Sate of Alaska’s comments on the EP (dated August 31, 2009). The 

DNR states, “The State of Alaska fully supports Shell’s efforts to conduct exploratory drilling in the 

Beaufort Sea. With this plan, Shell has voluntarily taken an action that constitutes a significant reduction 

in the planned exploration effort that is in direct response to input they have received from North Slope 

residents, the North Slope Borough (NSB), and whaling groups.” 

By letter dated July 1, 2009, the MMS notified the Mayor of the NSB; the Mayors of Kaktovik, Nuiqsut, 

and Barrow; the Presidents of the Native Villages of Kaktovik, Nuiqsut, and Barrow Inupiat Traditional 

Government; the Inupiat Community of the Arctic Slope (ICAS); and the Alaska Eskimo Whaling 

Commission (AEWC) that Shell’s proposed EP was anticipated to be submitted in July. The MMS 

acknowledged the short regulatory review schedule, offered to meet with each party, and notified that 

parties that MMS would be contacting their offices directly to arranging a meeting with them to discuss 

the EP. No request for a meeting was made. 

Interest by stakeholders in Shell’s proposal is high. Even before the EP was deemed submitted, MMS 

received requests for the preliminary draft proposal. The MMS provided copies of the preliminary draft 

EP and received comments on the document. 

It is MMS policy and practice to distribute the EP to other Federal and State agencies, local and Tribal 

governments and the AEWC. On August 11 and 12, 2009, MMS distributed copies of the EP to the 

Mayor of the NSB; the NSB Wildlife and Planning Departments; communities and Native Villages of 

Kaktovik, Nuiqsut, and Barrow; ICAS; and AEWC. Copies of the EP were provided to FWS, NMFS, 

EPA, the Army Corps of Engineers, the U.S. Coast Guard, and the National Park Service. Copies of the 

EP were sent to Alaska State agencies, including the Department of Natural Resources, the Department of 

Environmental Conservation, and the Alaska Oil and Gas Conservation Commission. A notification letter 

on the availability of the EP for review was sent to third parties who previously had expressed interest in 

the project. Comments were requested by August 31 based on the 21-calendar-day comment period 

established by 30 CFR 250.232. 

On August 11, 2009, MMS posted the EP to the MMS Alaska website at 

http://www.mms.gov/alaska/ref/ProjectHistory/Shell_BF/2009_final_EP_camden_bay.pdf. The MMS 

provided email notification about the posting of the EP to the MMS website to NSB, communities, tribes, 

and AEWC to facilitate the review process. 

The MMS received comment letters on the EP from NSB, ICAS, AEWC, the Native Village of Point 

Hope, DNR, and consortium of environmental advocacy organizations. The comments were reviewed by 

MMS and considered in the completing the regulatory, technical, and environmental reviews of the EP. 

The MMS arranged Government-to-Government meetings with the federally recognized Native Alaskan 

tribal governments during the week of August 31, 2009 (see also EA Section 4.3 below). These meetings 

were held to provide an opportunity for the local Alaskan Native tribal governments to discuss their 

comments and concerns about Shell’s proposed exploration drilling activities with MMS. 
 74

4.2 Government-to-Government Consultation 

Executive Order 13175, Consultation and Coordination with Indian Tribal Governments, requires Federal 

Agencies to consult with Tribal governments on Federal matters that significantly or uniquely affect their 

communities. In January 2001, a USDOI Alaska Regional Government-to-Government policy was 

signed by all the USDOI Alaska Regional Directors, including the MMS Alaska Regional Director. 

The MMS has held multiple Government-to-Government consultation meetings with the Federally 

recognized Alaskan Native tribal governments of the North Slope to discuss the OCS program, leasing, 

and potential OCS activities. These meeting provide an opportunity for the tribes to provide Traditional 

Knowledge to MMS and to discuss concerns and questions with MMS. The meetings also provide MMS 

an opportunity to inform the local tribal governments about MMS activities and processes. Governmentto-Government consultation meetings were held in conjunction with the Beaufort Sea Multiple-Sale EIS 

and the Sales 195 and 202 prelease and NEPA processes. 

On August 11-12, 2009, MMS sent copies of the EP by Federal Express to ICAS and the tribal 

governments of Native Villages of Barrow, Nuiqsut, and Kaktovik and offered to conduct Governmentto-Government consultation, if requested. In addition, in an August 11 e-mail, MMS informed the parties 

that the EP was being sent and specifically offered to conduct Government-to-Government meetings on 

the EP. The MMS contacted the tribal governments and ICAS by email and phone to arrange for 

Government-to-Government meetings. Meetings were held with the Native Village of Barrow on August 

31, ICAS on September 1, and the Native Village of Nuiqsut on September 2. No other Government-toGovernment consultations were requested. 

4.3 Endangered Species Act Consultation 

Section 7(a)(2) of the Endangered Species Act (ESA) requires each Federal Agency to ensure that any 

action that 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 MMS consults with FWS 

and NMFS for listed species under each Service’s jurisdiction. For ESA consultation on proposed lease 

sales, MMS specifically requests incremental Section 7 consultation. Regulations at 50 CFR 402.14 (k) 

allow consultation on part of the entire action as long as that step does not violate section 7(a)(2), there is 

a reasonable likelihood that the entire action will not violate section 7(a)(2), and the agency continues 

consultation with respect to the entire action, obtaining a biological opinion (BO) for each step. Thus, at 

the lease sale stage, MMS consults on the early lease activities (seismic surveying, ancillary activities, 

and exploration drilling) to ensure that activities under any leases issued will not result in jeopardy to a 

listed species or cause adverse modification of designated critical habitat. 

Consultation with NMFS for the Shell’s proposed exploration activities is covered by the July 17, 2008, 

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) (http://www.mms.gov/alaska/ref/BioOpinions/2008_0717_bo.pdf). 

Consultation with FWS for the Shell’s proposed exploration activities is covered by the September 3, 

2009, BO for Beaufort and Chukchi Sea Program Area Lease Sales and Associated Seismic Surveys and 

Exploratory Drilling (USDOI, FWS, 2009) 

(http://www.mms.gov/alaska/ref/BioOpinions/2009_0903_BO4BFCK.pdf). 
 75

4.4 Marine Mammal Protection Act 

Shell has applied for an Incidental Harassment Authorization (IHA) from NMFS (dated May 7, 2009; 

Shell Offshore Inc., 2009a:Appendix E) and a Letter of Authorization from FWS (dated May 7, 2009; 

Shell Offshore Inc., 2009:Appendix F) as part of their exploration program. For this EP, Shell has 

incorporated the mitigation measures from their 2007 exploration drilling IHA from NMFS, as well as 

other 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. 

4.5 Essential Fish Habitat Consultation 

The MMS consults on essential fish habitat (EFH) with NMFS at the lease sale stage. The most recent 

EFH consultation for OCS exploration activities in the Beaufort Sea was conducted concurrently with the 

preparation and public review of the Arctic Multiple-Sale Draft EIS. The MMS received NMFS’ 

conservation recommendations in a letter dated June 26, 2009. 
 77

5.0 Reviewers and Preparers 

In keeping with the intent of CEQ regulations (40 CFR 1506.5(a),(b)) that acceptable work by an 

applicant not be redone but it be verified by the agency, we have reviewed, evaluated, and verified the 

information and analysis provided in Shell’s EIA, which we used to prepare this EA. Further as required 

by 40 CFR 1506.5(a),(b), we have provided the names of the MMS staff responsible for the review of 

Shell’s EP and supporting information and analysis, and preparation of this EA. 

Christy Bohl Oil Spill Program Administrator 

Chris Campbell Sociocultural Specialist 

Douglas Choromanski Geologist, Office of Field Operations 

Cleve Cowles Regional Supervisor, Office of Leasing and Environment 

Deborah Cranswick Supervisory Environmental Specialist 

Christopher Crews Wildlife Biologist 

Heather Crowley Oceanographer/Water Quality 

Kathleen Crumrine Petroleum Engineer 

John Goll Regional Director, Alaska OCS Region 

Thomas Gleave Physical Scientist/Air Quality 

Daniel Hartung Regulatory Analyst 

Dirk Herkhof Air Quality Specialist 

Randy Howell Industry Specialist 

James Lusher Engineer 

Kyle Monkelien Petroleum Engineer 

Caryn Smith Oceanographer/Oil spill Risk Analysis 

Jeffrey Walker Regional Supervisor, Field Operations 
 79

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 87

7.0 FIGURES 

Figure 1-1 Proposed Action Locations (Shell Offshore Inc., 2009a:Figure 1-1). 

Figure 1-2 Figure 1-2. Proposed Drillsite Locations (Shell Offshore Inc., 2009b:Figure 2.1-1). 

Figure 2-1 Mean September Sea Ice Extents 1982-2007 at 5-Year Increments (Shell Offshore Inc., 

2009b: Figure 3.2-1). 

Figure 2-2 Proposed Action Locations and Support Vessel and Aircraft Travel Routes (Shell 

Offshore Inc., 2009a:Figure 13-2). 

Figure 3-1 Beluga Whale Sightings 1979-2007 (Shell Exploration Inc., 2009b:Figure 3.7-4). 

Figure 3-2 Bowhead Whale Sightings 1979-2007 (Shell Exploration Inc., 2009b:Figure 3.8-2). 
89

Figure 1-1. Proposed Action Locations (Shell Offshore Inc., 2009a; Figure 1-1). 
90

 Figure 1-2. Proposed Drillsite Locations (Shell Offshore Inc., 2009b; Figure 2.1-1). 
91

Figure 2-1. Mean September Sea Ice extents 1982-2007 at 5-Year Increments (Shell Offshore Inc., 2009b; Figure 3.
92

Figure 2-2. Proposed Action Locations and Support Vessel and Aircraft Travel Routes (Shell Offshore Inc., 2009a
93

 Figure 3-1. Beluga Whale Sightings 1979-2007 (Shell Exploration Inc. 2009b, Figure 3.7-4). 
94

Figure 3-2. Bowhead Whale Sightings 1979-2007 (Shell Exploration Inc. 2009b, Figure 3.8-2). 
 

Appendix A 

Analysis of Accidental Oil Spills 
A-1 

1.0 Oil-Spill Analysis and Scenario Framework of Accidental 

Oil Spills in this Environmental Assessment.

This section describes the results of the oil-spill analysis. It analyzes the potential discharges, their 

likelihood, and the outlines the scenario framework chosen for the impact analysis of accidental oil spills. 

The vessel, drilling, and fuel-transfer activities in the Exploration Plan (EP) were evaluated for 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 undesirable consequence. This document tiers from the oil-spill analysis in the 

Beaufort Sea Multiple-Sale EIS (USDOI, MMS, 2003) and Sales 195 and 202 EAs (USDOI, MMS, 2004, 

2006), and incorporates by reference the most recent information on well-control incidents and fault-tree 

information from the Beaufort Sea Oil and Gas Lease Sales (Sales 209 and 217) (USDOI, MMS, 2008) 

and Shell Offshore Inc. (2009) Environmental Impact Analysis. Brief summaries, where relevant, are 

provided below; the information is updated and augmented by new material as needed. 

The section below starts with the summary of estimated impact-producing factors (size, source, duration, 

weathering characteristics) from accidental oil spills used in this Environmental Assessment (EA) 

analysis. The remainder of this Appendix provides the supporting information for the estimated impactproducing factors used for accidental oil-spill analysis in this EA. 

1.1 Summary: Estimated Accidental Spills by Size Categories. 

For purposes of this EA analysis, no large or very large crude or diesel oil spills are estimated from 

exploration activities based on a review of potential discharges, historical spill and modeling data, and 

likelihood of occurrence. This estimate is based on the low rate of exploratory drilling well-control 

incidents per well drilled spilling fluids, modeled exploratory drilling well-control incidents, and the 

history of exploration spills on the Arctic OCS and Canadian Beaufort Sea discussed below. It is possible 

that a small spill could occur and is reasonably foreseeable. For purposes of analysis, we chose a 48-bbl 

fuel-transfer spill for the small spill size, as identified in Shell’s Beaufort Sea Oil Discharge Prevention 

and Contingency Plan (ODPCP) summary of potential discharges. 

1.1.1 Summary: Small Spills (<1,000 bbl) from Exploration Operations.

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. The largest exploration spill was approximately 20 bbl (Section 1.3.1). For purposes of 

analysis, a 48-bbl fuel-transfer spill was chosen as the small spill size, and it is estimated to last less than 

3 days on the surface of the water, based on weathering calculations. This EA analyzes the impacts of 

such a small spill in each of the EA sections on 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 fuel-transfer spill.

1.1.2 Summary: Large Spills (≥1,000 bbl) from Exploration Operations. 

For purposes of Shell’s proposed exploration drilling program during the 2010 open-water season, OCS 

historical crude and condensate spill data demonstrates that a large spill is too remote and speculative an 

occurrence to be considered a reasonably foreseeable occurrence of Shell’s proposed exploration project. 

No oil will be produced. All wells will be permanently plugged and abandoned in accordance with MMS 
A-2 

requirements on completion of drilling. Since 1971, no large spills have occurred from well-control 

incidents while drilling approximately 14,000 OCS exploration wells. All fuel-storage tanks will be 

internal to the drillship, and should an internal storage tank rupture internally, it is unlikely a large diesel 

fuel spill would reach water. 

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 not a reasonably foreseeable event in connection with the exploration activities set 

forth in Shell’s EP, and therefore, this EA does not analyze the impacts of such a worst-case scenario. 

The MMS 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). 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. Thus, 

MMS 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 1.4.2 below). 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 wellcontrol during drilling. Shell’s ODPCP demonstrates that access to sufficient equipment and personnel 

needed to respond to a well blowout flow rate of 5,500 barrels of oil per day (bopd) for 30-34 days. 

1.2 Oil-Spill Potential Discharge Review. 

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. 

Using information from the potential discharges, the MMS reviewed and considered available 

information regarding the small, large, and very large spill-size estimates and the likelihood of the 

potential discharges, to determine a reasonably foreseeable spill analysis to evaluate the potential impact 

producing factors of an accidental oil spill for this EA. 

Table A-1 shows the Shell’s ODPCP summary of potential discharges (Shell EIA Table 4.1.19-1) with 

the MMS spill-size categories listed in the left-hand column. The summary of potential discharges was 

divided into MMS’s three spill-size categories: (1) small (≤1,000 barrels (bbl); (2) large (≥ 1,000 bbl); 

and (3) very large (≥150,000 bbl). Within each spill-size category, the estimated potential discharge size 

is considered the representative size for that size category. A 48-bbl diesel-transfer spill is in the small 

spill category, a 1,555-bbl diesel-fuel tank-rupture spill is in the large spill category, and the blowout 

worst-case discharge of 287,100 bbl is in the very large spill category. The paragraph below describes 

why and how Shell calculated the worst-case discharge. 

1.2.1 Worst-Case Discharge Calculation for the Oil Discharge Prevention and 

Contingency Plan. 

The MMS and State of Alaska regulations set forth how the volume for a Worst Case Discharge (WCD) 

calculation is determined for oil-spill-response planning. The WCD volume and storage capacities are 

calculated to address MMS and Alaska Department of Environmental Conservation (ADEC) need to 

determine the adequacy of the company’s spill-response capabilities. The MMS requires (30 CFR 
A-3 

254.47(b) Determining the volume of oil of your worst case discharge scenario) the WCD to be based 

upon the daily volume possible from an uncontrolled blowout flowing for 30 days. The ADEC 

regulations (18 AAC 75.434) establish the Response Planning Standard (RPS) of 5,500 bbl (874 cubic 

meters [m3

]) of oil per day for the duration of 15 days for an exploration facility. The daily flow rate for a 

blowout is based on the ADEC response planning standard of 5,500 bbl per day. The MMS reviewed 

results from wells drilled in the area and concluded that the 5,500 bbl/day standard is appropriate; 

therefore, MMS concurs with using this standard for this EP. To meet both agencies’ response-planning 

requirements, the WCD volume was calculated using ADEC’s volume requirement of 5,500 bopd (874 

m3

) and MMS’s duration requirement of 30 days (30 CFR 254.47(b)) totaling 165,000 bbl (26,233 m3). 

To determine the storage capacity requirements based on ADEC guidance, an emulsion factor of 1.54 and 

a percentage of free water (20 percent) have been added to the initial RPS of 165,000 bbl (26,233 m3

) for 

a total storage volume of 287,100 bbl (45,645 m3

). 

The MMS regulations at 30 CFR 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 drilling a relief well in up 

to 34 days (with a resulting total spill volume of 187,000 bbl). To meet both agencies’ response-planning 

requirements, the WCD volume has been calculated using ADEC’s volume requirement of 5,500 bopd 

(874 m3

) and Shell’s blowout scenario based on drilling a relief well in 34 days for a total of 187,000 bbl 

(29,703m3

). To determine the storage capacity requirements based on ADEC guidance, an emulsion 

factor of 1.54 and a percentage of free water (20 percent) have been added to the initial RPS of 187,000 

bbl (29,703 m3

) for a total storage volume of 325,380 bbl (45,645 m3). 

Table A-1. Summary of Potential Discharges and Relation to MMS Spill Categories for Oil-Spill 

Analysis.

MMS SpillSize 

Categories Type Cause Product Size Duration Prevent Potential Discharge

Small Transfer 

from 

fuel barge 

to drill rig 

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 Diesel 

Tank 

Tank rupture Diesel 1,555 bbl Minutes to 

hours 

The diesel tanks are internal to each 

drilling vessel rather than deck-mounted, 

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 Blowout Uncontrolled 

flow at the 

mudline 

Crude oil 287,100 – 

325,380 bbl 

including 

emulsion and 

free water 

30-34 days 

(refer to 

ODPCP 

Page 1-26) 

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. 

ODPCP Section 2.1.8 

Drilling a relief well (ODPCP Page 1-26) 
A-4 

1.3 Historical and Modeled Oil Spills 

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 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. 

1.3.1 Historical Refined and Crude Spills from Exploration Operations on the 

Beaufort and Chukchi Outer Continental Shelf and Canadian Beaufort. 

The MMS estimates the chance of a large (≥1,000 bbl) oil spill from 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-2 shows the exploration spills on 

the Beaufort Sea and Chukchi Sea OCS. All the explorations spills on the Beaufort Sea and Chukchi Sea 

OCS have been small, with the largest spill approximately 20 bbl. Based on the historical 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 MMS 

estimates a small spill is a reasonably forseeable scenario during exploratory drilling in the Beaufort Sea. 

These small spills often are onto containment on vessels, platforms, facilities, or gravel islands, or onto 

ice, and may be cleaned up. 

Table A-2 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 this proposal 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. 

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 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 

recent years very few well-control-incident events have resulted in spilled oil, and the volumes spilled 

often are small. All five of the well-control-incident events ≥1,000 bbl in the OCS database occurred 

between 1964 and 1970 (Table A-3). Following the Santa Barbara well-control incident in 1969, 

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. 

From 1971-2007, 228 exploration and development well-control incidents occurred, on the OCS while 

drilling approximately 38,000 wells and producing 15 billion barrels (Bbbl) of oil (Table A-3). This 

includes all well-control incidents, whether they caused pollution or not. From 1971-2007, 35 of those 

228 well-control incidents from exploration and development wells resulted in spills of crude or 

condensate, with the amount of oil spilled ranging from <1 bbl to 350 bbl in any one individual spill. The 

total volume spilled from the 35 well-control incidents is approximately 1,800 bbl. The crude and 

condensate volume spilled from well-control incidents was approximately 0.00001% of the volume 
A-5 

produced. There were no spills ≥1,000 bbl from exploration and development well-control incidents in 

the last 37 years on the OCS. 

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. This information is compared with the previous study conducted for drilling 

well-control incidents that occurred from 1971 through 1991 (Izon, Danenberger, and Mayes, 2007). This 

information shows a downward trend in the number of drilling well-control incidents per well drilled 

from 1992-2006 compared to 1971-1991. 

The data analyzed was incident reports submitted by OCS oil and gas operators and from MMS accident 

investigation reports. Between 1992 and 2006, 39 well-control incidents occurred, compared with 87 

during the time period of the previous study (1971-1991). Overall, the rate of drilling well-control 

incidents per well drilled improved during the period. The current 15-year study period had a drilling 

well-control incident rate of one for every 387 wells drilled, compared with a rate of one well-control 

incident for every 246 wells drilled during the previous study period. 

Overall, the current period saw an improvement (decrease) in well-control-incident duration. Like the 

previous study, 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 U.S. Gulf of Mexico OCS blowout frequencies, as reported by Holand (1997), range from 5.9 x 10-3

blowouts per well drilled for exploratory drilling to 3.9 x10-3 blowouts per well for development. As 

Holand’s exploration blowout frequencies included blowouts of all types, the frequencies for a blowout 

resulting in oil reaching the environment are significantly less. Of the total blowouts reported by Holand 

(1997), gas releases accounted for 77% of the total of blowouts, gas/liquid mixtures 14%, and 

uncontrolled liquid flows involved 3%. 

Izon, Danenberger, and Mayes (2007) report a well-control-incident rate for exploration well drilling of 

one for every 297 wells drilled, for a frequency of 3.4 x 10-3. The development well drilling rate is one 

for every 470 wells drilled, for a frequency of 2.1 x 10-3 (Izon, Danenberger, and Mayes, 2007). Both the 

exploration and development well-control incident drilling frequencies reflect a decline in well-control 

incidents over recent years. Again, these blowout frequencies included blowouts of all kinds and 

frequencies for a blowout resulting in oil reaching the environment are significantly less. 

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. 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-6 

Table A-2. Exploration Spills on the Beaufort Sea and Chukchi Sea OCS. Lease No. 

Sale 

Area 

Operator Date Time 

24 Hr 

Facility Substance Amt. 

(Gal)

Cause of Spill Response 

0344 71 Sohio 7/22/1981 11:00 Mukluk I 

sland 

Diesel 0.50 Leaking line on portable fuel trailer Sorbents use

gravel remov

0344 71 Sohio 7/22/1981 14:00 Mukluk Island Diesel 1.00 Overfilled fuel tank on equipment Sorbents use

gravel remov

0280 71 Exxon 8/7/1981 Beaufort Sea I Hydraulic Fluid 1.00 Broken hydraulic line on ditch witch. Fluid picked u0280 71 Exxon 8/8/1981 Beaufort Sea I Trans. Fluid 0.25 Overfilling of transmission fluid. Fluid picked u0280 71 Exxon 1/11/1982 Beaufort Sea I Hydraulic Fluid 0.50 Broken hydraulic line. Fluid picked u0280 71 Exxon 1/11/1982 Alaska Beaufort Sea I Diesel 3.00 Overfilled catco 90-3 tank. Fluid picked u0280 71 Exxon 1/17/1982 Beaufort Sea I Diesel 1.00 Tank on catco 90-14 overfilled. Fluid picked u0280 71 Exxon 1/21/1982 Beaufort Sea I Hydraulic Fluid 0.25 Broken hydraulic line on ditch witch. Fluid picked u0371 71 Amoco 3/16/1982 N/A Sandpiper Gravel Island Unknown 1.00 Seeping from Gravel Island. Sorbent pads0849 87 Union Oil 9/4/1982 14:00 Canmar Explorer II Unknown 1.00 Transfer of test tank from drillship to barge. None 0871 87 Shell 

Western 

9/5/1982 18:55 Canmar Explorer II Light Oil 0.50 Washing down cement unit, drains not plumbed to oil/water 

seperator. 

None 

N/A 87 Shell 9/14/1982 19:00 Canmar II Drillship Diesel 30.00 Tank vent overflowed during fuel transfer. Deployed sor0191 BF Exxon 11/11/1982 10:00 Beechey Pt. Gravel Is. Lube Oil 1.00 Loader tipped over lube oil drum Oil cleaned u

gravel remov

0191 BF Exxon 1/15/1983 10:00 Beechey Pt. Gravel Is. Diesel 0.12 Fuel truck spilled diesel as it climbed a 40 degree ramp to 

island 

Sorbents useremoved 

0191 BF Exxon 1/23/1983 9:00 Beechey Pt. Gravel Is. Hydraulic Fluid 2.50 Hydraulic line on backhoe broke 1 gallon in wa

sorbents, Con

0191 BF Exxon 8/29/1983 6:30 Beechey Pt. Gravel Is. Hydraulic Fluid 0.20 Hydraulic line on backhoe broke Spill containe

used and con

0196 BF Shell 8/30/1983 Ice Road to Tern Island Hydraulic Fluid 10.0 Broken hydraulic line on rollogon Unknown 0191 BF Exxon 2/26/1985 17:30 Beechey Pt. Gravel Is. Hydraulic Fluid 0.37 Hydraulic line broke Contaminated 0196 BF Shell 3/1/1985 1:30 Ice Road to Tern Island Hydraulic Fluid 3.00 Hydraulic line broke Unknown 0191 BF Exxon 3/2/1985 Beechey Pt. Gravel Is. Gasoline 0.01 Operational Spill Snow shoved 0191 BF Exxon 3/4/1985 Beechey Pt. Gravel Is. Waste Oil 2.00 Drum of waste oil punctured Snow recove0196 BF Shell 3/4/1985 15:30 Tern Gravel Island Crude Oil 1.00 Well Separator overflowed, crude oil escaped Line boom de0196 BF Shell 3/6/1985 16:30 Tern Gravel Island Crude Oil 15.00 Test burner was operating poorly Containment 0196 BF Shell 9/24/1985 16:00 Tern Gravel Island Crude Oil 2.00 Oil released from steam heat coil when Halliburton tank 

moved 

Sorbents and 

0191 BF Shell 10/4/1985 8:45 Enroute to Tern Gravel 

Island 

Jet fuel B 800.00 Wire sling broke during helicopter transport of fuel blivits Contaminated 

drilled with no 

0196 BF Shell 10/29/1985 14:00 Tern Gravel Island Crude Oil 2.00 Test oil burner malfunction Contaminated 0196 BF Shell 6/27/1986 13:30 Tern Gravel Island Crude Oil 3.00 Test oil burner malfunction Spray picked 

snow. 

0943 87 Tenneco 1/24/1988 13:00 SSDC/MAT Gear oil 220.0 Helicopter sling failure during transfer of drums to SSDC Scooped up c1482 109 SWEPI 7/7/1989 3:00 Explorer III Drillship Hydraulic fluid 10.0 Hydraulic line connector Sorbent pads 1092 97 AMOCO 10/1/1991 2:00 CANMAR Explorer Hydraulic fluid 2.00 Hydraulic line rupture None 0865 87 ARCO 7/24/1993 Beaudril Kulluk Diesel 0.06 Residual fuel in bilge water None 0866 87 ARCO 9/8/1993 18:30 CANMAR Kulluk Hydraulic fluid 1.26 Seal on shale shaker failed None 0866 87 ARCO 9/24/1993 CANMAR Kulluk Fuel 4.00 Fuel transfer in rough weather 3 gallons on d

sea 

1597 124 ARCO 10/31/1993 CANMAR Kulluk Fuel 0.50 Released during emptying of disposal caisson 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 c

product enter
A-7 

Table A-3. Number of Well-Control Incidents with Pollution per Year in the Gulf of Mexico and Pacific OCS Regions. 

f Condensate/Crude Oil 

Spilled (Barrels) 

Production Drilling Workover/ 

Completion 

Well 

Type 

Well 

Type 

Wells 

Drilled 

Year 

Total Number of 

Incidents 

I ncidentswith 

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 — 198 44 242 

1957 1 0 — — 0 — 1 — — 1 — 311 55 366 

1958 2 1 Minimal — Minimal — 1 — — 1 1 198 62 260 

1959 1 0 — — 0 — 1 — — 1 — 225 95 320 

1960 2 0 — — 0 1 1 — — 1 — 285 134 419 

1961 0 0 — — 0 — — — — 0 — 340 127 467 

1962 1 0 — — 0 — 1 — — 1 — 368 156 524 

1963 1 0 — — 0 — 1 — — 1 — 379 202 581 

1964 8 3 10,280# 100 10,380 5 3 — — 3 — 493 218 711 

1965 5 2 1.688 1,688 1 4 — — 4 — 637 178 815 

1966 2 2 Minimal Minimal Minimal — 1 — — 1 1 604 280 884 

1967 2 1 Minimal — Minimal 0 — — — — 2 611 297 908 

1968 8 0 — — 0 1 6 — — — 1 679 310 989 

1969 3 3 — 82,500 82,500 1 2 — 1 1 — 630 233 863 

1970 3 3 83,000 — 83,000 1 1 — — 1 1 652 217 869 

56-70 40 15 93,280 84,288 177,568 10 24 0 1 17 6 6,610 2,608 9,218 

Major Regulatory Changes to Outer Continental Shelf Lands Act 

1971 6 2 460 — 460 2 2 1 1 — 2 573 264 837 

1972 6 1 2 — 2 1 4 2 2 — 1 577 301 878 

1973 3 0 0 — 0 — 3 2 1 — — 550 308 858 

1974 6 2 275 — 275 3 2 1 1 — 1 494 344 838 

1975 7 0 0 — 0 — 5 4 1 — 2 541 326 867 

1976 6 0 — — 0 1 5 1 4 — — 810 295 1105 

1977 9 1 2 — 2 1 4 3 1 — 4 888 352 1240 

1978 11 0 0 — 0 — 7 3 4 — 4 864 324 1188 

1979 5 0 0 — 0 — 5 4 1 — — 811 351 1162 

1980 8 1 1 — 1 2 4 3 1 — 2 835 367 1202 

1981 10 4 64 — 64 1 3 1 2 — 6 907 354 1261 

1982 9 0 0 — 0 — 5 1 4 — 4 862 412 1274 

1983 12 1 — 2 2 — 10 5 5 — 2 781 399 1180 

1984 5 0 — — 0 — 4 3 1 — 1 773 598 1371 

1985 6 1 50 — 50 0 4 3 1 — 2 682 536 1218 

1986 2 0 — — 0 — 1 — 1 — 1 460 272 732 

1987 8 2 61 — 61 3 2 2 — — 3 464 420 884 

1988 4 1 5 — 5 1 2 1 1 — 1 460 571 1031 

1989 12 0 — — 0 3 7 2 3 2 * 2 524 471 995 

1990 7 3 18 — 18 0 3 1 2 — 4 580 504 1084 

1991 8 1 — 0.8 0.8 — 6 2 2 2* 2 457 334 791 

1992 3 1 — 100 100 — 3 3 — — — 347 223 570 

1993 4 0 — — 0 — 4 1 3 — — 593 357 950 

1994 1 0 — — 0 — — — — — 1 621 427 1048 

1995 1 0 — — 0 — 1 1 — — — 710 388 1098 

1996 4 0 — — 0 — 2 1 1 — 2 726 453 1179 

1997 5 0 — — 0 — 4 1 3 — 1 859 540 1399 

1998 7 3 1.5 — 4.2 2 2 1 1 — 3 643 497 1140 

1999 5 1 125 — 125 — 3 1 2 — 2 664 371 1035 

2000 9 3 — 200.5 200.5 — 8 5 3 — 1 936 443 1379 

2001 10 1 1 — 1 2 5 1 4 — 3 853 411 1264 

2002 6 1 350 # — 350 2 3 1 2 — 1 633 309 942 

2003 5 2 10 — 10 2 2 1 1 — 1 539 354 893 

2004 5 3 2.5 16.4 18.9 — 2 2 — — 3 554 362 916 

2005 4 0 — — 0 — 4 3 1 — — 457 355 812 

2006 2 0 10 — 10 — 1 1 — — 1 350 414 764 

2007 7 1 2 2 4 316 300 616 

71-07 228 35 1,438.00 319.70 1,760.40 27 134 70 60 4 67 23,694 14,307 38,001 

Source: USDOI, MMS, Accident Investigation Board (2008). Notes: 1. Databases and incident reports frozen as of August 4, 

2008; 2007 data not finalized, 2. # = hurricane-related; * sulphur blowouts. 
A-8 

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 98 exploration and 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 1971-2007, industry has drilled approximately 172 exploration wells in the Pacific OCS, 51 in the 

Atlantic OCS, 14,006 in the Gulf of Mexico OCS, and 98 in the Alaska OCS, for a total of 14,307 

exploration wells. From 1971-2007, there were 70 well-control incidents during exploration drilling. Of 

those 70 well-control incidents, four resulted in crude or condensate oil spills of 200, 100, 11, and 0.8 bbl, 

respectively (Table A-3). No large spills (≥1,000 bbl) have occurred from 1971-2007 during exploration 

drilling. Therefore, approximately 14,000 exploration wells have been drilled, and four small spills 

resulted in crude or condensate reaching the environment from well-control incidents during exploration 

drilling (Table A-3). 

1.3.4 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 oil and gas operations for Arctic OCS locations. The information from Bercha (2006, 

2008) was used in the USDOI MMS (2006, 2008) oil-spill analyses in the Beaufort Sea. 

Because limited historical spill data for the Arctic exist, Bercha modified the existing base data using 

fault trees to arrive at oil-spill 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 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

). 

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 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

). 
A-9 

1.3.5 Historical Worldwide Very Large Spills from Well-Control Incidents. 

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. The largest spill from a wellcontrol incident in Federal OCS waters is 80,000 bbl, approximately half the size of the starting value of 

the very large category, and it occurred in 1969. One other spill >50,000 bbl has happened since offshore 

drilling began in the United States. All five of the well-control-incident events ≥1,000 bbl in the OCS 

database occurred between 1964 and 1970 (Table A-3). Following the Santa Barbara well-control 

incident in 1969, amendments to the OCS Lands Act and implementing regulations significantly 

strengthened safety, inspection, and pollution-prevention requirements for OCS offshore activities. Wellcontrol training, redundant pollution-prevention equipment, and subsurface safety devices are among the 

provisions that were adopted in the regulatory program. Since 1970, no OCS well-control incidents 

≥1,000 bbl have occurred. 

Because there have been no spills greater than 150,000 bbl in U.S. waters, the MMS looked elsewhere for 

data on spills of that size or larger. Therefore, we evaluated worldwide data to estimate the chance of 

very large spills occurring (USDOI, MMS, 2002). The spill information used was based on spills from 

other countries that do not have the regulatory standards that are enforced on the U.S. OCS. In addition, 

some drilling practices used elsewhere either are not practiced here or are against outer continental shelf 

regulations. An exploration well called IXTOC is in Mexican waters and not on the Gulf of Mexico 

OCS. For IXTOC, the blowout came about because the operator lost circulation in the well and decided 

to remove the drill pipe from the well prior to re-establishing circulation and not keeping the well full as 

the drill pipe was removed. Under MMS regulations, an operator would not be allowed to remove the 

drill string without ensuring that the well is under control and sufficient mud volume is kept in the well. 

Internationally from 1979 through 1996, five oil-well blowouts greater than or equal to 10 million gal. 

(238,000 bbl) have occurred (Cutter Information Corp., 1997; DeCola, 2000). Five of the blowouts >10 

million gal. mostly were the result of either war or drilling practices that oil companies do not now use 

and may not use under MMS regulations in the United States. During this same time period, there were 

roughly 470 Bbbl of oil produced worldwide (British Petroleum, 2001). These data provide a rate of 

about 0.01 blowouts ≥10 million gal. per billion barrels produced. 

1.4 Oil-Spill Analysis Framework.

There are three potential size categories of oil spills in connection with exploratory work in this proposed 

action: (1) a large spill (≥1,000 bbl) from operations; (2) a very large spill (≥150,000 bbl) from a wellcontrol incident; and (3) a small spill (<1,000 bbl). Historical and modeling data demonstrates that the 

probability of a large spill occurring during exploration is insignificant 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 is similarly improbable. Nonetheless, this EA incorporates by reference the 

MMS’s prior analyses of the impacts of a large and very large oil spill. See discussion in Section 1.4.2 

below. It is likely a small spill could occur during exploration activities. 

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 and oil-spill analysis. It is estimated to last less than 3 days on the surface of 

the water, based on weathering calculations. In terms of timing, a small spill from the operations could 

happen at any time from July to October during exploration operations. We assume that the vessel would not 

retain any oil. We assume that, depending on the time of year, a small spill reaches the following 

environments: 
A-10 

• vessel and then the water 

• open water or open water and ice 

The analysis of a small spill examines the weathering of the estimated spill. In our weathering analysis, we 

estimate the following fate of the diesel fuel without cleanup. Tables A-4 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 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. 

• 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. Containment and cleanup is analyzed separately as mitigation. 

• The spill could occur at any time of the operations (July–October). 

• The spill weathering is as we show in Table A-4, 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-4 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 EP Table 4.1.19-3 

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 oil spill will be localized and short 

term. 

Table A-4. 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 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 

Note: For the EA the small spill size is a 48-bbl diesel spill 

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. 

1.4.2 Previous Analysis of Very Large and Large Accidental Oil Spills.

The chance of a very large spill (≥150,000) is very low, but its potential effects were analyzed in USDOI, 

MMS (2003) 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 was identified in USDOI, MMS (2003). There are no sitespecific anomalies that differentiate a very large spill release in LA12, previously analyzed, from one in 

LA15, and the oil spill contacts are statistically similar. No new major effects from a very large spill are 

identified from this proposal. 
A-11 

The chance of a large (≥1,000) 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, the 

potential for major impacts exist from a large accidental oil spill as identified in previous analyses 

(USDOI, MMS, 2003, 2008). No new major effects from a large spill are identified from this proposal. 

Launch Area 15 Conditional Probabilities. The conditional probabilities (expressed as percent 

chance) from LA 15 (USDOI, MMS, 2003: 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 (2003, 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, 2003: herein summarized as Tables A-5 and A-6). 

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%.

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%.
A-12 

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-5. 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, 195, and 202. 

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.
A-13 

Table A-6. 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.
A-14 

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 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 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, 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 the requirements of Lease Stipulation 6 and the 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 H or Sivulliq N 

drill sites. 

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A-15 

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