Revised Outer Continental Shelf Lease Exploration Plan Chukchi Sea, Alaska 

Shell Gulf of Mexico Inc. May 2011 

Revised Chukchi Sea Exploration Plan Errata 

(In response to a request for additional information from the 

Bureau of Ocean Energy Management dated October 28, 2011.) 

 
Revised Outer Continental Shelf Lease Exploration Plan Chukchi Sea, Alaska 

Shell Gulf of Mexico Inc. May 2011 

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Shell Exploration & Production 

November 9, 2011

U.S Department of the Interior Shell

Bureau of Ocean Energy Management 3601 C Street, Suite 1000

Alaska Outer Continental Shelf Region Anchorage, AK 99503

Attn: David Johnston Tel. (907) 646-7112 

3801 Centerpoint Drive, Suite 500 Email susan.childs@shell.com

Anchorage, AK, 99503-5820 Internet http://www.shell.com

RE: 2

nd Set of Responses to Requests for Additional Information, dated October 28, 2011, for 

the revised Chukchi Sea Exploration Plan

Dear Mr. Johnston:

On October 28, 2011 Shell Gulf of Mexico Inc. (Shell) received a second request for additional 

information (RFAI) from the Bureau of Ocean Energy Management (BOEM) containing 17 

RFAIs regarding the revised Chukchi Sea Exploration Plan (EP). On November 4, 2011, Shell 

provided responses to 15 of 17 RFAIs. This letter responds to the remaining two RFAIs (#1 and 

#3), plus responds to BOEM’s clarification request of these RFAIs also dated November 4, 2011. 

In BOEM’s clarification request of November 4, 2011, BOEM suggests that, in the context of 

communications between the agency and Shell, Shell and Air Sciences agreed to conduct air 

emission dispersion analysis modeling, and then submit same to BOEM. Shell apologizes if 

there was some confusion on this issue. Based on the assumptions below, the total non-OCS 

source emissions from the marine vessels are significantly less than the permitted OCS source 

emissions, and those emissions will be dispersed at lower concentrations over a wider area than 

the emissions evaluated for the permitted OCS source. Therefore, it is Shell’s view that such 

modeling is not necessary to assess the impacts of any of the additional, de minimis air emissions 

from those sources that are the subject of this RFAI, nor does Shell believe that such analysis 

would add materially to the existing data set related to project air emissions or would alter the 

conclusion in the Environmental Impact Assessment (EIA) for the revised Chukchi Sea EP that 

there will be no significant environmental impacts resulting from project related air emissions. 

Shell’s response to BOEM RFAIs, #1 and #3 from October 28th follows the assumptions below. 

Our response should be used for the purpose of assessing air emissions beyond those specifically 

evaluated in the context of the permit review for the OCS source (e.g., EPA air permit review)

and in the Chukchi EIA, and is based on the following assumptions:

Vessels

 Figure 2.3-1 of the revised Chukchi Sea Environmental Impact Analysis (EIA; or Figure 

13.e-1 of the revised Chukchi Sea EP) shows the approximate marine vessel route 

proposed for mobilization and demobilization to the Burger Prospect. 
BOEM 

November 9, 2011

Page 2

 Marine vessels (see Table 2.2-4 of the revised Chukchi Sea EIA), other than the offshore 

supply vessels (OSVs), the oil spill response tanker (OST), and the shallow landing water 

craft, would complete only one round-trip traverse (approximately 300 miles per roundtrip) of the marine vessel route shown in Figure 2.3-1, and remain stationary for the 

remainder of the drilling season.

 OSVs (there are two proposed; see Table 2.2-4 of the revised Chukchi Sea EIA) would 

conduct 17 round-trips, divided equally between the two OSVs.

 The OST will complete one round trip of the marine vessel route shown in the revised 

Chukchi Sea EIA (Figure 2.3-1), and in addition will transit beyond the Burger Prospect 

to a location more central between Shell’s proposed Camden Bay and Chukchi Sea 

exploration drilling programs, outside of the Chukchi Sea Program area where it will 

remain for the exploration drilling season.

As described in Shell’s Chukchi Sea EIA (Section 4.1.1 – Direct and Indirect Impacts, Air 

Quality) the emissions from the project OCS source (see Section 7; revised Chukchi Sea EP, and 

Section 2.8; Chukchi Sea EIA) will have a negligible effect on air quality due to the low quantity 

of emissions and the distance over which dispersion will occur. With regard to impacts to North 

Slope villages, any additional emissions from non-OCS sources, spread over a much greater area 

(over 300 miles of round-trip travel distances versus the OCS source diameter of 50 miles) will 

add a trivial impact to the OCS source impacts and the combined impacts will also be negligible. 

Shell’s response to the remainder of BOEM’s clarification request letter on November 4th

follows.

Aircraft

 Offshore Helicopter Transport

o Assume use of the Sikorsky S-92 aircraft or Eurocopter EC-225 helicopter, as 

described in Table 13.a-3 of the revised Chukchi Sea EP and Table 2.2-4 of the 

Chukchi Sea EIA.

o Assume taxi out time of 10 minutes, taxi in time of 7 minutes with no auxiliary 

power unit (APU).

o Assume use of a gasoline fuel truck (10 minutes) only. The service truck will be 

the van assumed under Surface Vehicles. 

o Number of landing and take offs (LTOs) assumed is sufficient for estimating 

purposes.

o Anticipated number of search and rescue training flights is 3-4 per week, with an 

estimated duration of 2.5 hours per flight.

 Fixed-Wing Aircraft

o Assume taxi out time of 10 minutes, taxi in time of 7 minutes with no APU.

o Assume use of a gasoline fuel truck (10 minutes) only. The service truck will be 

the van assumed under Surface Vehicles.

o There are no aircraft flights associated with sound source surveys.

o There are no “marine mammal strike prevention” flights. Marine mammal 

observer (MMO) flights are planned daily in a de Havilland Twin Otter (DHC-6) 

aircraft daily along a saw-tooth pattern along the Chukchi Sea coastline. 

However, none of these flights will reach the boundary of the Chukchi Sea 
BOEM 

November 9, 2011

Page 3

Program area shown in Figure 1, Volume I of the 2011 Final Supplemental 

Environmental Impact Statement for the Chukchi Sea Lease Sale 193 Planning 

Area. 

o None of the US Coast Guard (USCG) flights referenced in the section entitled 

Aircraft on page 3-173 of the EIA would be conducted in support of Shell’s 

proposed activities. Available information on the USCG flights was provided in 

the subject section of the EIA to give the reader an idea of other uses of the 

Chukchi Sea as is routine done in NEPA style documents. Based on BOEM’s 

clarification letter (e.g., boundary of Chukchi Sea Program area), Shell assumes 

that emissions from these fixed-wing flights are not required.

Surface Vehicles

 Assumptions in BOEM’s clarification letter on equipment, frequency and distance of 

vehicle trips are sufficient for estimating purposes; however, considering safety of road 

conditions and the brevity of trips, Shell driving policies will not allow for a vehicle 

speed as rapid as 35 miles per hour as estimated in BOEM’s letter.

If there are any questions or comments, please contact me at (907) 646-7112 or at 

Susan.Childs@shell.com or Pauline Ruddy at (907) 771-7243 or e-mail

Pauline.Ruddy@shell.com.

Sincerely,

Susan Childs

AK Venture Support Integrator, Manager

Shell Exploration & Production 

November 14, 2011

U.S Department of the Interior Shell

Bureau of Ocean Energy Management 3601 C Street, Suite 1000

Alaska Continental Shelf Region Anchorage, AK 99503

Attn: David Johnston, Regional Supervisor for Leasing and Plans Tel. (907) 646-7112 

3801 Centerpoint Drive, Suite 500 Email susan.childs@shell.com

Anchorage, AK, 99503-5820 Internet http://www.shell.com

RE: 3

rd Set of Responses to Requests for Additional Information, dated October 28, 2011, for 

the revised Chukchi Sea Exploration Plan

Dear Mr. Johnston:

On October 28, 2011 Shell Gulf of Mexico Inc. (Shell) received a second request for additional 

information (RFAI) from the Bureau of Ocean Energy Management (BOEM) containing 17 

RFAIs regarding the revised Chukchi Sea Exploration Plan (EP). On November 4, 2011, Shell 

provided responses to 15 of 17 RFAIs. Also on November 4th, Shell received from BOEM a 

clarification request on the content of our pending responses to the remaining two RFAIs (#1 and 

#3). On November 9, 2011 Shell responded to RFAI’s #1 and #3, plus responded to BOEM’s 

November 4th clarification request. Shell received a second request for clarification on 

November 10, 2011 regarding the same RFAIs (#1 and #3), for which we have prepared the 

following response (i.e., 3rd set of responses to October 28th RFAIs).

Economy. Please see Attachment 1 to this letter, in which Shell addresses the content of the 

expansion of this RFAI as described in BOEM’s November 10th letter. Shell’s response fully 

addresses the content of the expanded RFAI. However, as noted in attached, Shell will not 

provide estimated annual income ranges for the positions that will be filled as a part of its 

exploration program, as that information is confidential. 

Sound. Shell provides the outstanding references/reports plus appendices on the enclosed CD. 

Shell has responded fully to this request, and notes that agency representatives with the former 

Minerals Management Service/BOEM have been contributing review participants of the Joint 

Monitoring Program Draft/Final Comprehensive Reports since Shell began contributing its 

activities to these reports in 2006. Last, the 2006-2007 Joint Monitoring Program Final 

Comprehensive Report is available on the National Marine Fisheries Service, Office of Protected 

Services website http://www.nmfs.noaa.gov/pr/pdfs/permits/arctic_seismic_report.pdf.

Air Quality. Please see Attachment 2 to this letter for the Chukchi Sea non-OCS vessel 

emissions inventory calculations. This attachment should be used for the purpose of assessing 

air emissions beyond those specifically evaluated in the context of the permit review for the OCS 

source (e.g., EPA air permit review) and in the Chukchi Environmental Impact Analysis. The 

assumptions used for vessel emissions are the same as those in Shell’s previous correspondence 

with BOEM on November 9th. When utilizing the emissions data provided in Attachment 2, it is 
BOEM 

November 14, 2011

Page 2

important to note that the emissions from vessels operating more than 25 miles from the 

Discoverer during drilling operations will be dispersed over a large area because the vessels are 

expected to be moving during the activities in question, with the result that the impact of these 

emissions at any one location would be negligible. To the extent that any of the vessels would 

be stationary for any extended period of time outside the 25 mile area, they would be anchored 

and not using their propulsion engines, minimizing emissions and emissions impacts. 

Based on conversations with BOEM following receipt of its November 10th letter, Shell will be 

finished shortly with printing final copies of the revised Chukchi Sea EP and is prepared to 

deliver to BOEM.

If there are any questions or comments, please contact me at (907) 646-7112 or at 

Susan.Childs@shell.com or Pauline Ruddy at (907) 771-7243 or e-mail

Pauline.Ruddy@shell.com.

Sincerely,

Susan Childs

AK Venture Support Integrator, Manager

Attachments/Enclosure

Attachment 1 – Shell Economy Response

Attachment 2 – Chukchi Sea Non-OCS Vessel Emissions

Enclosure – Chukchi Sea RFAI References CD
Attachment 1

Shell Response

The model developed by Northern Economics (2009) for its analysis of the economic impacts of future oil 

and gas exploration and development activities in the Chukchi Sea indicates an estimated 1,355 total new 

direct full-time and seasonal jobs in Alaska will be created in the first season of exploration drilling 

operations (2011) with approximately $54 million in new payroll, and an estimated 1,307 total new direct 

full-time and seasonal jobs in Alaska will be created in a second season of exploration operations (2012)

with approximately $52 million in new payroll. A copy of the spreadsheet resulting from the model, and 

indicating how these estimates were derived, is attached (Attachment 1a). These estimates are based on 

the same kinds of exploration activities as proposed in the revised Chukchi Sea Exploration Plan and can 

be considered a representative estimation of anticipated impacts from the activities in the plan. These 

estimates of the number of jobs that might be created include only direct jobs, not indirect or induced 

jobs. The estimated new revenues for the North Slope Borough from these exploration drilling scenarios 

for the Chukchi Sea are approximately $1.7 million in the first year and $1.6 million in the second year 

(Attachment 1a).

Although Shell’s proposed exploration drilling program has potential benefits to the greater U.S. 

economy, the Study Area for the Environmental Impact Analysis was established in Chapter 3 as the 

Chukchi Sea Lease Sale 193 Area and adjacent Alaska coastal waters and coastline, with particular focus 

on the Chukchi Sea villages of Barrow, Wainwright, Point Lay, and Point Hope. Socioeconomic 

resources and conditions were described in detail only for these four villages and to a lesser degree for the 

North Slope Borough and for the Northwest Arctic Borough. Therefore, analysis of potential project 

effects on socioeconomics is restricted to these areas. Estimates of the amount of direct employment that 

might occur on the North Slope as a result of Shell’s exploration drilling program are provided below in 

Table 1. These opportunities for employment can be compared to employment rates provided in Section 

3.11.3 of Shell’s EIA.

Table 1. Estimated number of North Slope jobs that may be created annually by Shell’s exploration drilling program, 

and the number of jobs that may be filled by North Slope residents.

Job Type Total 

Number 

of Jobs

Jobs Filled by NSB Residents Employment

Percent

of Total Jobs

Number 

of Jobs

MMO 140 40 56 full time / seasonal

Subsistence Advisor 10 100 10 full time / seasonal

Community Liaison 6 100 4 part time / year-round

Communication and Call Centers 20 100 20 full time / seasonal

Village OSR Responders 30 100 30 full time / seasonal

Contingency Responders 170 30 51 full time / seasonal

Shorebase Staff 30 75 23 full time / seasonal

All 486 -- 196 --

Note: Annual income ranges for the individual positions identified in Table 1 will not be 

provided, as that information is confidential.

Literature Cited

Northern Economics. 2009. Economic analysis of future offshore oil and gas development: Beaufort 

Sea, Chukchi Sea, and North Aleutian Basin. Report prepared by Northern Economics, 
Anchorage, AK in association with the Institute of Social and Economic Research, University of 

Alaska, Anchorage, for Shell Exploration and Production, Anchorage, AK. 136 pp.

Attachment 1a

Northern Economics Exploration Data v1
Attachment 1a Northern Economics Exploration Data v1 - Through 2014

Page 1

Direct Impacts of Exploration Activities

Area/Item

Chukchi Sea 2008 2009 2010 2011 2012 2013 2014

Total Full-time and Seasonal Jobs in Alaska 243 231 233 1,355 1,307 1,259 1,259

Total Annual Average Employment in Alaska 95 95 112 580 561 543 543

Property Tax Revenues

Local (NSB) $ - $ - $ 1,850,000 $ 1,726,667 $ 1,603,333 $ 1,480,000 $ 1,356,667

State $ - $ - $ 150,000 $ 140,000 $ 130,000 $ 120,000 $ 110,000

Beaufort Sea 2008 2009 2010 2011 2012 2013 2014

Total Full-time and Seasonal Jobs in Alaska 65 2,219 1,155 2,022 1,823 2,784 2,011

Total Annual Average Employment in Alaska 18 650 340 572 530 773 566

Property Tax Revenues

Local (NSB) $ - $ 1,850,000 $ 1,726,667 $ 1,603,333 $ 1,480,000 $ 1,356,667 $ 1,233,333

State $ - $ 150,000 $ 140,000 $ 130,000 $ 120,000 $ 110,000 $ 100,000

ADOLWD Wages and Salaries in 2007: Oil and Gas 

Extraction and Mining Support Activities $ 93,180

Estimated Wages and Salaries 2008 2009 2010 2011 2012 2013 2014

Chukchi Sea $ 8,827,894 $ 8,827,894 $ 10,426,018 $ 54,002,974 $ 52,279,231 $ 50,555,488 $ 50,555,488

Beaufort Sea $ 1,709,909 $ 60,539,850 $ 31,687,737 $ 53,278,541 $ 49,393,200 $ 72,019,012 $ 52,754,894
Attachment 1a Northern Economics Exploraiton Data v1 - through 2014

Page 2 - Metadata

1 Numbers cited in the paragraph write-up come from columns E and F (2011 and 2012), which are the first two years of 

exploratory drilling in the NE scenarios. Rows are 5, 6, 9 and 24.

2 The attached data describe exploration activity results from the 2009 study of statewide impacts (NEI, 2009). In this 

report, the exploration activities for the Beaufort Sea scenario are shown on page 15 and on page 27 for the Chukchi Sea 

scenario.

3 Labor income was not reported in that study. The attached data provides an estimate of annual wages and salaries associated 

with the direct jobs only. We simply took the average annual wage and salary for the oil and gas extraction sector and the 

oilfield support services sector from the AK Department of Labor data for 2007 and multiplied this wage rate by the annual 

average employment.

4 The attached data gives the estimated property tax revenues (local and state government) associated with the on-shore 

exploration shorebase which was in the scenario for both the Beaufort and Chukchi.

5 There are other government revenues from 2009 to 2019 (before production) but these are the lease revenues - rental 

payments for the 8(g) acreage. These are not necessarily tied to exploration activities and so are not included in the attached 

data.

6 All the $ values in the attached data are expressed in fixed 2007 dollars.
Attachment 2

PROJECT TITLE: BY:

Air Sciences Inc. Shell Offshore, Inc. R. Steen

PROJECT NO: PAGE: OF: SHEET:

180-20-4 1 1 VesselEmis

ENGINEERING CALCULATIONS SUBJECT: DATE:

Chukchi Sea Non-OCS Vessel Emissions November 9, 2011

Total Fuel Burn Chukchi Sea

Mobilization 

Vessel Name

Assumed 

Transit Speed 

(knots)

NM from 

Program 

Area 

Boundary to 

Drilling Site 

(approximate

Fuel Burn 

(gallons/day) Days to Site

Fuel Burn to 

Site 

(gal/season) Days

Fuel Burn 

(gallons/day)

AH/Towing 

Fuel Burn 

(gal/season)

Resupply 

Trips

Resupply RT 

Transit Days 

(@ 9 knots)

Fuel Burn 

(gallons/day)

Resupply 

Fuel Burn 

(gal/season)

Anchor Handler 9 150 1,183 0.7 822 9 1,420 12,781 NA

Ice Management Vessel 9 150 1,376 0.7 956 3 688 1,720 NA

OSV 9 150 3,936 0.7 2,733 3 4,723 11,808 8.5 1.5 3,936 50,184

OSV 9 150 3,936 0.7 2,733 3 4,723 11,808 8.5 1.5 3,936 50,184

Nanuq 9 150 5,800 0.7 4,028 NA NA

Shallow Water Landing Craft 9 150 1,500 0.7 1,042 NA NA

OST 9 150 8,400 0.7 5,833 NA NA

OSR Barge and Tug 9 150 3,408 0.7 2,367 NA NA

Containment Barge & Tug 9 150 3,408 0.7 2,367 NA NA

Discoverer 9 150 8,400 0.7 5,833 NA NA

Total 28,713 38,117 100,368

Total

Vessel Name Days

Fuel Burn 

(gallons/day)

Fuel Burn 

(gal/season)

Assumed 

Transit Speed 

(knots)

NM from 

Drilling Site 

to Prog Area 

Boundary 

(approximate

Fuel Burn 

(gallons/day)

Days to 

Program 

Area 

Boundary

Fuel Burn 

from Site 

(gal/season)

IM/AH

Total Fuel 

Burn 

(gal/season)

Other Vessels 

Total Fuel 

Burn 

(gal/season)

Total Fuel 

Burn

(gal/season)

Anchor Handler 0 0 9 150 1,183 0.7 822 14,424 14,424

Ice Management Vessel 54 688 37,153 9 150 1,376 0.7 956 40,784 40,784

OSV 9 150 3,936 0.7 2,733 67,459 67,459

OSV 9 150 3,936 0.7 2,733 67,459 67,459

Nanuq 9 150 5,800 0.7 4,028 8,056 8,056

Shallow Water Landing Craft 9 150 1,500 0.7 1,042 2,083 2,083

OST 2 8,400 12,600 9 150 8,400 0.7 5,833 24,267 24,267

OSR Barge and Tug 100 1,704 170,400 9 150 3,408 0.7 2,367 175,133 175,133

Containment Barge & Tug 100 1,704 170,400 9 150 3,408 0.7 2,367 175,133 175,133

Discoverer 9 150 8,400 0.7 5,833 11,667 11,667

Total 390,553 28,713 55,209 531,256 586,465

Notes:

Anchor Handling (AH) assumed to be within 25-mile radius for entire season

Ice Management (IM) assumed to be within 25-mile radius for 46 days so 54 days remain of a 100-day season (best estimate)

AH is assumed to take 3 days per well.

Shallow water landing craft will most likely already be on the North Slope.

The Discoverer will propel itself to the drilling location.

Barge & tug combinations emissions assumed at 50% power during drilling and outside 25-mile radius

OST traverses the program area twice per season (300 NM).

Emission factors provided below are from the EPA permit application

Values in blue are input, values in black are calculated

Emissions

Emission Factors Emissions

IM/AH other vessels IM/AH other vessels Total

Pollutant lb/gallon lb/gallon ton/season ton/season ton/season

NOx 0.05 0.59 1.38 156.72 158

PM 0.008 0.041 0.22 10.89 11

SO2 0.00021 0.00021 0.01 0.06 0

CO 0.023 0.1046 0.63 27.78 28

VOC 0.004 0.0188 0.11 4.99 5

CO2e 22.5 22.5 621.1 5,976.63 6,598

Conversion

2000 lb/ton

Anchor Handling/Towing Resupply

During Drilling-Not Resupply Demobilization