UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field Operations (MS 5231)

Public Information copy of DOCD

Control # - R-05746

Type - Revised Development Operations Coordinations Document

Lease(s) - OCS-G07975 Block - 934 Mississippi Canyon Area

Operator - Shell Offshore Inc.

Wells A-8 and A-9

DP SEMISUBMERSIBLE

Attached is a copy of the subject plan for public comments on issues that

should be addressed in an Environmental Assessment.

It has been deemed submitted as of this date and is under review for approval.

Michelle Griffitt

Plan Coordinator

G07975/MC/934

G07975/MC/934 2635 FNL, 3326 FEL

2819 FNL, 3365 FEL G07975/MC/934

G07975/MC/934 WELL/A-8

WELL/A-9 Botm Lse/Area/Blk Surface Location Surf Lse/Area/Blk Site Type/Name Description -

Rig Type - Subject: From: January 16, 2013

### Shell Offshore Inc

. P. O. Box 61933 New Orleans, LA 70161

- 1933 United States of America Tel +1 504 425 7215

Fax +1 504 425 6747 Email sylvia.bellone@shell.com



### Public Information Copy

Plan R-5746

November 20 , 2012

Ms. Liz Peuler, Chief Bureau of Ocean Energy Management Office of Field Operations

1201 Elmwood Park Boulevard New Orleans, LA 70123-2394

Attn: Plans Section

–

GM 1053C

SUBJECT: Revised Development Operations Coordination Document (N-6234 & S-7405) Mississippi Canyon Block 935 Unit No. 754 395016 Mississippi Canyon Block 934, OCS-G 7975 Mississippi Canyon Block 935, OCS-G 7976

Offshore Louisiana

Dear Ms. Peuler:

In compliance with 30 CFR 550.221 and NTLs 2008-G04 and 2009-G27, giving Development Plan guidelines, Shell Offshore Inc. (Shell) requests your approval of this Revised Development Operations Coordination Document (DOCD) to move the surface locations of wells A8 and A9 greater than 500‟ and to change rig
type. The Atwood Condor is contracted to be in Shell‟s flee t in May 2013 and this will be the first project for the rig.

Should you have any questions or require additional information, please contact Tracy Albert at 504.425.4652

or tracy.albert@shell.com

.

Sincerely,

Sylvia A. BelloneREVISIONS TABLE:

Date of Request Plan Section What was Corrected Date Resubmitted

12/5/2012 Section 7

Section 13

Section 17 Revised table 7B

Added word “ two ”

Added LA CZM 12/6/2012

## SHELL OFFSHORE INC.

Revised Development Operations Coordination Document

for



## Mississippi Canyon Block 935 Unit No. 754395016 Mississippi Canyon Block 934, OCS-G 7975 Mississippi Canyon Block 935, OCS-G 7976



# PUBLIC INFORMATION COPY

November 2012

PREPARED BY:



## Tracy W. Albert Regulatory Specialist

504.425.7215

tracy.albert@shell.comDEVELOPMENT OPERATIONS COORDINATION DOCUMENT

MISSISSIPPI CANYON BLOCK 935 UNIT

– NO

. 754395016 MISSISSIPPI CANYON BLOCK 934, OCS-G 7975 MISSISSIPPI CANYON BLOCK 935, OCS-G 7976

TABLE OF CONTENTS

SECTION 1: PLAN CONTENTS

SECTION 2: GE NERAL INFORMATION

SECTION 3: GEOLOGICAL AND GEOPHYSICAL

SECTION 4: HYDROGEN SULFIDE - H 2 S

SECTION 5: MINERAL RESOURCE CONSERVATION

SECTION 6: BIOLOGICAL, PHYSICAL AND SOCIOECONOMIC INFORMATION

SECTION 7: WASTE AND DISCHARGE INFORMATION

SECTION 8: AIR EMISSION INFORMATION

SECTION 9: OIL SPILL INFORMATION

SECTION 10: ENVIRONMENTAL MONITORING

SECTION 11: LEASE STIPULATIONS

SECTION 12: ENVIRONMENTAL MITIGATION MEASURES

SECTION 13: RELATED FACILITIES AND OPERATIONS INFORMATION

SECTION 14: SUPPORT VESSELS AND AIRCRAFT

SECTION 15: ONSHORE SUPPORT FACILITIES INFORMATION

SECTION 16: SULPHUR OPERATIONS

SECTION 17: COASTAL ZONE MANAGEMENT ACT INFORMATION

SECTION 18: ENVIRONMENTAL IMPACT ANA LYSIS

SECTION 19: ADMINISTRATIVE INFORMATIONACRONYMS AND ABBREVIATIONS

ADIOS Automated Data Inquiry for Oil Spills
APD Application for Permit to Drill

bbl barrel
BOEM Bureau of Ocean Energy Management
BOEMRE Bureau of Ocean Energy Management,

Regulation and Enforcement BOPD barrels of oil per day (bbl/day)
BSEE Bureau of Safety and Environmental

Enforcement
CFR Code of Federal Regulations

CH 4 methane

CO carbon monoxide

CO 2 carbon dioxide
DOCD Development Operations Coordination

Document DPS distinct population segment

EFH Essential Fish Habitat
EIA Environmental Impact Analysis
EIS Environmental Impact Statement

EFL Electrical flying lead
ESA Endangered Species Act

FAD fish-attracting device
GMFMC Gulf of Mexico Fishery Management

Council

H 2 S hydrogen sulfide

HAPC Habitat Area of Particular Concern
HFL Hydraulic flying leads
IPF impact-producing factor

MARPOL International Convention for the

Prevention of Pollution from Ships

MC Mississippi Canyon

MMC Marine Mammal Commission

MMPA Marine Mammal Protection Act

MM S Minerals Management Service
MWCC Marine Well Containment Company
NAAQS National Ambient Air Quality Standards
NEPA National Environmental Policy Act

NMFS National Marine Fisheries Service
NOAA National Oceanic and Atmospheric

Administration

NO 2 nitrogen dioxide

NO

x nitrogen oxides
NPDES National Pollutant Discharge Elimination

System

NPS National Park Service

NRC National Research Council
NTL Notice to Lessees and Operators
NWR National Wildlife Refuge

OCS Outer Continental Shelf

OCSLA Outer Continental Shelf Lands Act
OSAT Operational Science Advisory Team
OSRA Oil Spill Risk Analysis
OSRP Oil Spill Response Plan
PAH polycyclic aromatic hydrocarbon

PM particulate matter PSD Prevention of Significant Deterioration
ROV remotely operated vehicle
SBM synthetic-based mud
SEA Site-Specific Environmental Assessment

Shell Shell Offshore Inc.

SO 2 sulfur dioxide

SO

x sulfur oxides

SFL Steel flying leads
SWSS Sperm Whale Seismic Study
TLP tension leg platform

U.S.C. United States Code

USCG U.S. Coast Guard
USDOI U.S. Department of the Interior
USEPA U.S. Environmental Protection Agency

USFWS U.S. Fish and Wildlife Service

VOC volatile organic compound
WCD worst case discharge
WCEP Whooping Crane Eastern Partnership
WMA Wildlife Management AreaSECTION 1: PLAN CONTENTS

A. DESCRIPTION, OBJECTIVES & SCHEDULE

Shell Offshore Inc. (Shell) is submitting this Revised DOCD ( DOCD /plan) for Mississippi Canyon Blocks 934,

OCS -G 7975. These wells were originally included in Plan S-7405 (Mississippi Canyon Block 935, OCS- G 7976) and we are requesting approval to move the surface locations of wells A8 and A9 greater than 500‟

and to a difference lease in the unit

, as well as change rig type from a moored rig to a dynamically positioned (DP) semi-submersible. The well(s) will be drilled and completed in accordance with 30 CFR 250.1721. If the wells are unsuccessful, they will be permanently plugged and abandoned in accordance with the Bureau of Safety and Environmental Enforcement (BSEE) regulations.

The drilling activities are planned to commence on or about May 2013 and last approximately 141 days to drill and complete each well

. The timeframe for these drilling activities is an estimate based on the best available information regarding downhole conditions likely to be encountered while drilling each well and are not

intended to be a limitation.

The lease area is 61 statute miles from the nearest shoreline, 1 01 statute miles from the onshore support base at Port Fourchon, Louisiana and 88 statute miles from the helicopter base at Boothville, Louisiana. Water depths at the well sites range from 3,600‟ to 3,900 ‟ (Attachment 1A).

The proposed rig, The Atwood Condor (Condor) is a DP semi-submersible; a self-contained drilling vessel with accommodations for a crew which include quarters, galley and sanitation facilities. The rig will comply with the requirements in the Interim Final Rules. The drilling activities will be supported by the support vessels and aircraft as well as onshore support facilities as listed in Sections 14 and 15 of this plan. Shell has employed or contracted with trained personnel to carry out its exploration activities. Shell is committed to local hire, local contracting and local purchasing to the maximum extent possible. Shell personnel and contractors ar e experienced at operating in the Gulf of Mexico and are well versed in all Federal and State laws regulating operations. Shell‟s employees and contractors share Shell‟s deep commitment to operating in a safe and environmentally responsible manner.

Shell, through its parent and affiliate corporations, has extensive experience safely exploring for oil and gas in the Gulf of Mexico. Shell will draw upon this experience in organizing and carrying out its planned MC 934 drilling program. Shell believes that the best way to manage blowouts is to prevent them from happening. Significant effort goes into the design and execution of wells and into building and maintaining staff competence. In the unlikely event of a spill, Shell‟s Regional Oil Spill Response P lan (OSRP) is designed to contain and respond to a spill that meets or exceeds the worst case discharge (WCD) as detailed in Section 9 of this plan. The WCD does not take into account potential flow mitigating factors such as well bridging, obstructions in wellbore, reservoir barriers, or early intervention. We continue to invest in research and development to improve safety and reliability of our well systems. All operations will be conducted in accordance with applicable federal and state laws, regulations and lease and permit requirements. Shell will have trained personnel and monitoring programs in place to ensure such compliance.

B. WELL LOCATIONS AND JUMPER/FLYING LEADS INSTALLATION

See attached location plat (Attachments 1B) and BOEM forms (Attachments 1C through 1E).

A dynamically positioned intervention vessel will be used to install the jumper and flying leads. One side of the jumper will connect to an existing spare hub on the Europa manifold while the other side will connect to the newly installed EA-8 tree. Likewise, the electrical flying leads (EFLs) and Steel Flying Lead (SFL) will connect the newly installed tree to existing spare slots on the Europa Subsea Electric Hydraulic Distribution Assembly. A Hydraulic Flying Lead (HFL) will connect the newly installed tree directly to the manifold to control the manifold branch valves for this new well. Attachment 1F shows the Europa subsea field layout.C. RIG SAFETY AND POLLUTION FEATURES

The rig (Atwood Condor or similar) will comply with all of the regulations of the American Bureau of Shipping (ABS), International Maritime Organization (IMO) and the United States Coast Guard (USCG). All drilling operations will be conducted under the provisions of 30 CFR, Part 250, Subpart D and other applicable regulations and notices, including those regarding the avoidance of potential drilling hazards and safety and pollution prevention control. Such measures as inflow detection and well control, monitoring for loss of circulation and seepage loss and casing design will be our primary safety measures. Primary pollution prevention measures are contaminated and non-contaminated drain system, mud drain system and oily water processing. The Atwood Condor has a SOPEP plan and for actual spills, six (6) SOPEP kits are on deck in key areas. Additionally, the Condor has Operating Procedures and Job Safety Analysis for any fuel, base oil or

SBM transfers.

DRAIN SYSTEM POLLUTION FEATURES

Drains are provided on the Rig in all spaces and on all decks where water or oil can accumulate. The drains are divided into two categories, non-contaminated and contaminated. All deck drains are fitted with a removable strainer plate to prevent debris entering the system.

Deck Drainage from rainfall, rig washing, deck washing, and runoff from curbs and gutters, including drippans and work areas, are discharged depending on if it came into contact with the contaminated or noncontaminated areas of the Rig.

1) Non-contaminated Drains

Non-contaminated drains are designated as drains that under normal circumstances do not contain hydrocarbons, and can be discharged directly overboard. These are mostly located around the main deck and outboard in places where it is unlikely that hydrocarbons will be found.

Drains within 50 feet of a designated chemical storage area which uses the weather deck as a primary containment means shall be designated “normally plugged.” An adequate number of drains around the rig shall be designated as “normally open” to allow run -off of rain water. Normally open drains shall have a plug located in a conspicuous area near the drain which can be easily installed in the event of a spill.

The rig‟s drain plug program consist at a minimum of a weekly check of all deck drains leading to the sea to verify that their status is as designated If normally open they shall verify that the drain is open and that the plug is available in the area. If normally closed they shall verify that the plug is securely installed in the

drain.

In the event a leak or spill is observed, the event shall be contained (drain plug installation and / or spill kit deployment as appropriate) and reported immediately.

Rig personnel shall ensure that the perimeter kick-plates on weather decks are maintained and drain plugs

ar e in place as needed to ensure a proper seal.

2) Contaminated Drains

Contaminated drains are designated as drains that contain hydrocarbons and cannot be discharged overboard. When oil-based mud is used for drilling it will be collected in portable tanks and sent to shore for processing.

3) Oily Water Processing

Oily water is collected in an oily water tank. It must be separated and not pumped overboard until oil content

is < 15 ppm. The separated oil is pumped to a dirty oil tank and has to be sent ashore for disposal. On board the MODU, an oil record log will be kept according to instructions included in the log. Any and all pollution pans are subjected to a sheen test before being pumped out. If the water passes the sheen test then it ispumped over board. If it does not pass the sheen test then the water/oil mixture is pumped to a dirty oil tank

and sent to shore for disposal. All waste oil that is sent in to be disposed of is recorded in the MODU‟s oil log

book.

All discharges will be in accordance with applicable EPA NPDES permits. See Section 18 of this Plan.

4) Lower Hull Bilge System

• The main bilge system is designed to drain the pontoons. There are Gould‟s electrically driven, self priming centrifugal pumps - one for each main pump room. The aux pumps can be pump out with the bilge pump but has to be lined up manually from the main pump room.

• Bilge water is pumped overboard after a sheen test has been completed.

• The pontoon bilge pumps are operable from the Bridge, and have audible and visual bilge alarms set for high and low levels.

• Portable submersible pumps are carried onboard the rig to service all column void spaces and are also used for emergency bilge pump in the event of the main pump room flooding.

• Alternate means of pumping the bilges in each pontoon pump room include the use of:

• The ballast system emergency bilge valve which is operated from the control panel.

• Portable submersible pumps

• Emergency bilge suction line connected directly to the ballast manifold. (Main Pump rooms only)

The Bilge pumps are manual/automatic type pumps. They are equipped with sensors that give a high and a high -high alarm. They are set to a point at which the water gets to a certain point they will automatically turn on to pump water out in order to keep flooding under control. The pumps are also capable of being put in manual mode in which they can be turned on by hand.

5) Emergency Bilge System

Main ballast pumps may also be used for emergency bilge pumping directly from the pump rooms via remotely actuated direct bilge suction valves on the ballast system. These valves will operate in a fully flooded compartment. The ballast pumps can be supplied from the emergency switchboard.

6) Oily Water Drain/Separation System

Oily water/engine room bilge water is collected in an oily water tank. It must be separated and not pumped

overboard until oil content is < 15 ppm. The separated oil is pumped to a dirty oil tank and has to be sent ashore for disposal. On board all drilling Units, an oil record log has to be kept according to instructions included in the log. The rig floor has two skimmer tanks and each is subjected to a sheen test before pumping overboard to ensure environmental safety. All three anchor winch windlasses have skimmer ta nks and are subjected to sheen tests before discharge as well.

7) Drain, Effluent and Waste Systems

• The rig‟s drainage system is designed in line with our environmental and single point discharge policies. Drains are either hazardous, i.e. from a hazardous area as depicted on the Area Classification drawings,

or non-hazardous drains from nonhazardous areas.

• To prevent migration of hazardous materials and flammable gas from hazardous to non-hazardous areas, the drainage systems are segregated.

• The rig‟s drainage system ties into oily water separators that take out elements in the drainage that could harm the environment. This is part of rig contractor ‟s initiative to be good stewards of the environment. The oily water separators divide the drainage system into these sections:

8) Rig Floor Drainage

The rig floor has been outfitted with a Facet International MAS 34-3 separator. The separator has coalescent plates that remove the solids from the drainage, and the remaining drainage goes to a skimmer tank. From the skimmer tank it is drained to one of the column dirty oil tank systems where it is then sent through 2 separators and cleaned further to reduce oil content to less than 15 ppm.9) Columns #3 & 4

The drains on the decks and machinery spaces are separated at mid ship and directed to either the #3 or #4 columns. The separators in these columns go through three cycles of circulation and remove oil to < 15 ppm, then discharge the clean product to sea.

10) Main Engine Rooms

• The engine rooms have their own drainage and handling system. The engine rooms are outfitted with a dirty oil tank and the drainage in the tank is processed through the separator, the waste from the separator goes back to the dirty oil tank and the clean water (< 15ppm) goes overboard.

• The locations and models of the separators are as follows:

• Column #3

–

Westfalia WSD- 18

• Column #4

–

Westfalia WSD- 18

• Drill Floor

–

Facet International MAS 34-3

11) Helideck Drains

The helideck has a dedicated drainage system around its perimeter to drain heli-fuel from a helicopter incident. The fuel can be diverted to the designated heli-fuel recovery tank which is located under the

helideck structure.

Operating configurations are as follows:

 The overboard piping valves and hydrocarbons take on valves are closed and locked. To unlock overboard or take on valves a permit has to be filled out.

 The oily water collection tank overflow valve is closed.

 The drill floor drains are lined-up to the drill floor skimmer tank. The skimmer tanks have a high alarm which sounds by means of an air horn. Before tanks are pumped out a sheen test is performed. Water is pumped out the skimmer tanks down the shunt line. The oil containment side is pumped out into 550 gal tote tanks.

 The BOP test area drains are normally lined-up to drain overboard.

 The oily water separator continuously circulates the oily water collection tank. Waste oil is discharged into the waste oil tank and oily water is re-circulated back into the oily water collection tank. Clean water is pumped overboard, which is controlled and monitored by the oil content detector, set at 15

ppm.
 The solids control system is capable of being isolated for cuttings collection.

 The bilge system is normally pumped directly overboard after a sheen test has been performed.

 The engine dirty oil sump can be drained down to the Port column oily water separator which discharges water overboard from the water side and oil is pumped out into a 550 gallon tote tank on the containment side. There is a high audible alarm on the ballast control panel.

D. Storage Tanks - Atwood Condor (or similar)

Tank Name Tank Number of Total Contents

Capacity (bbls) Tanks Capacity (bbls) Gravity (API)

Fuel Oil Storage 4,418 4 17,672 3 3 °

Fuel Oil Storage 3,787 1 3, 787 3 3 °

Fuel Oil Storage 234 6 1,404 3 3 °

Lube Oil 28 4 112 22. 3°

Lube Oil 41 2 82 22. 3°

Waste Oil 325 1 325 6. 5°

Waste Oil 49 1 49 6. 5°E. Pollution Prevention Measures

Pursuant to NTL 2008-G04 the proposed operations covered by this plan do not require Shell to specifically address the discharges of oils and greases from the rig during rainfall or routine operations. Nevertheless, Shell has provided this information as part of its response to 1(c) above.

F. Additional Measures

 Health, safety, and environment (HSE) are the primary topics in pre-tour and pre-job safety meetings. The discussion around no harm to people or environment is a key mindset. All personnel are reminded daily to inspect work areas for safety issues as well as potential pollution issues.

 All tools that come to and from the rig have their pollution pans inspected and cleaned, and plug installation confirmed prior to leaving the dock and prior to loading on the boat.

 Preventive maintenance of rig equipment includes visual inspection of hydraulic lines and reservoirs

on a routine scheduled basis.

 All pollution pans on rig are inspected daily.

 Containment dikes are installed around all oil containment, drum storage areas, fuel vents, and fuel storage tanks.

 All used oil and fuel is collected and sent to shore for recycling.

 Direct overboard drains on the rig are checked regularly to verify drain plugs are installed.

 All trash containers are checked and emptied daily, and trash containers are kept covered. Trash is collected in a compactor and shipped to shore for disposal.

 The rig is involved in a recycling program for cardboard, plastic, paper, glass, and aluminum.

 Fuel hoses are changed on an annual basis.

 Spill prevention fittings are installed on all liquid take-on hoses.

 Shell has obtained International Organization for Standardization (ISO) 14001 certification.

 Shell will use low-sulfur fuel to reduce air pollutant impacts.

G. Description of Previously Approved Lease Activities

Wells A1, A2 and A4 were previously drilled to MC 934.Attachment 1A Bathymetry and Surface LocationsAttachment 1B

Bottom Hole Locations

Proprietary DataAttachment 1C



### U. S. Department of the Interior OMB Control Number: 1010-0151 

### Bureau of Ocean Energy Management OMB Approval Expires: 12/ 31 /2014



### OCS PLAN INFORMATION FORM

General Information

Type of OCS Plan: Exploration Plan (EP) X DOCD

Company Name: Shell Offshore Inc. BOEM Operator Number: 0689

Address: P. O. Box 61933 Contact Person: Tracy Albert

New Orleans, LA 70161

- 1933 Phone Number: (504) 728

- 4652

E

- Mail Address: tracy.albert@shell.com

Lease(s): G 7975 & 7976 Area: MC Block(s): 934 & 935 Project Name (If Applicable): Europa

Objective(s): X Oil Gas Sulphur Salt Onshore Base: Fou r chon and

Boothville Distance to Closest Land (Miles): 61



### Description of Proposed Activities (Mark all that apply)

Exploration drilli ng X Development drilling



### X Well completion Installation of production platform

Well test flaring (for more than 48 hours) Installation of production facilities

Installation of caisson or platform as well protection structure Installation of satell ite structure



### X Installation of subsea wellheads and/or manifolds X Commence production

Installation of lease term pipelines Other (Specify and describe) Pipeline appurtenance

Have you submitted or do you plan to submit a Conservation Information Docu ment to accompany this plan? X Yes No

Do you propose to use new or unusual technology to conduct your activities? Yes X No

Do you propose any facility that will serve as a host facility for deepwater subsea development? Yes X No

Do you propose any a ctivities that may disturb a BOEM

- designated high

- probability archaeological area? X Yes No

Have all of the surface locations of your proposed activities been previously reviewed and approved by BOEM ? Yes X No


### Tentative Schedule of Proposed Activities

Proposed Activity Start Date End Date No. of Days

Drill well A8 5 /1/2013 8 /1 5 /2013 106

Complete well A8 8/15/2013 9/ 19 /201 3 35

Installation of jumper, fly leads 10/21/2013 10/28/2013 7

Drill well A 9 9/19/2013 1/3/2014 106

Commence production Well A8 12/1/2013

Complete well A 9 1/3/2014 2/7/2014 35

Commence production Well A9 2/8/2014



### Description of Drilling Rig Description of Production Platform

Jackup Drillship Caisson Tension leg platform

Gorilla Jackup Platform rig Well protector Compliant tower

Semisubmersible Submersible Fixed platform Guyed tower

X DP Semisubmersible Other (Attach Description) Subsea manifold Floating production system

Drilling Rig Name (If Known): Atwood Condor or similar Spar Other (Attach Description)



### Description of Lease Term Pipelines

From (Facility/Area/Block) To (Facility/Area/Block) Diameter (Inches) Length (Feet)



### Europa Hub MC 934 Well A8 MC 934 5” ID 80’

Europa Hub MC 934 Well A9 MC 934 5” ID 73’

Form BOEM- 0137 (December 2011-Supercedes all previous editions of form BOEM-0137 which may not be used.)

### Attachment 1D

OCS PLAN INFORMATION FORM (CONTINUED)

Include one copy of this page for each proposed well/structure

Proposed Well/Structure Location

Well or Structure Name/N umber (If renaming well or structure, reference previous name): A 8 Subsea Completion

Anchor Radius (if applicable) in feet: NA X Yes No

Surface Location Bottom

- Hole Location (For Wells)

Lease No. OCS

- G 7975

Area Name Mississippi Canyon

Block No

. 934

Blockline

Departures (in feet) N/S Departure: 263 4 .66 FNL

E/W Departure 3326.24 FEL

Lambert X

- Y

coordinates X: 852,033.76

Y: 10,182,485.34

Latitude/

Longitude Latitude 28°02’ 16.06”

Longitude

- 89°26’39.78”

TVD (Feet): MD (Feet): Water Depth (Feet): 3, 875 ’



### Anchor Locations for Drilling Rig or Construction Barge ( If anchor radius supplied above, not necessary)

Anchor Name

or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on

Seafloor

Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. 2501 et seq.) requires us to inform you that
BOEM collects this information as part of an applicant’s Exploration Plan or Development Op erations Coordination Document submitted for
BOEM approval. We use the information to facilitate our review and data entry for OCS plans. We will protect proprietary data according to the
Freedom of Information Act and 30 CFR 550.197. An agency may not con duct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Management and Budget Control Number. Responses are mandatory ( 43 U.S.C. 1334).
The public reporting burden for this for m is included in the burden for preparing Exploration Plans and Development Operations Coordination
Documents. We estimate that burden to average 600 hours with an accompanying EP, or 700 hours with an accompanying DPP or DOC D, including the time for revie wing instructions, gathering and maintaining data, and completing and reviewing the forms associated with subpart
B. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Off icer, Bureau of

O cean Energy Management, 381 Elden Street, Herndon, VA 20170.

Form BOEM- 0137 (December 2011-Supercedes all previous editions of form BOEM-0137 which may not be used.)

### Attachment 1E

OCS PLAN INFORMATION FORM (CONTINUED)

Include one copy of this page for each proposed well/structure

Proposed Well/Structure Location

Well or Structure Name/Number (If renaming well or structure, reference previous name): A9 Subsea Completion

Anchor Radius (if applicable) in feet: NA X Yes No

Surface Location Bottom

- Hole Location (For Wells)

Lease No. OCS

- G 07975

Area Name Mississippi Canyon

Block No. 934

Blockline

Departures (in feet) N/S Departure:

2819 FNL
E/W Departure

3365 FEL

Lambert X

- Y

coordinates X: 851,995

Y: 10,182,301

Latitude/

Longitude Latitude 28°02’14.2320

Longitude 89°26’40.1710

TVD (Feet): MD (Feet): Water Depth (Feet): 3, 875 ’



### Anchor Locations for Drilling Rig or Construction Barge ( If anchor radius supplied above, not necessary)

Anchor Name

or No. Area Block X Coordinate Y Coordinate Length of Anchor Chain on

Seafloor

Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. 2501 et seq.) requires u s to inform you that
BOEM collects this information as part of an applicant’s Exploration Plan or Development Operations Coordination Document sub mitted for
BOEM approval. We use the information to facilitate our review and data entry for OCS plans. We wil l protect proprietary data according to the
Freedom of Information Act and 30 CFR 550.197. An agency may not conduct or sponsor, and a person is not required to respond to, a collection
of information unless it displays a currently valid Office of Manageme nt and Budget Control Number. Responses are mandatory (43 U.S.C. 1334).
The public reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operation s Coordination
Documents. We estimate that burden to averag e 600 hours with an accompanying EP, or 700 hours with an accompanying DPP or DOCD,
including the time for reviewing instructions, gathering and maintaining data, and completing and reviewing the forms associa ted with subpart
B. Direct comments regarding t he burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Bureau of
Ocean Energy Management, 381 Elden Street, Herndon, VA 20170.

Form BOEM- 0137 (December 2011-Supercedes all previous editions of form BOEM- 0137 which may not be used.)Attachment 1F - Europa Subsea Field LayoutSECTION 2 : GENERAL INFORMATION

A. Application and Permits

Application/Permit Issuing Agency Status Rig Movement Report USCG, MWA & NGA Pending Coastal Zone Management State of Louisiana N/A

B. Drilling Fluids

See Section 7, Tables 7A and 7B for this information.

C. Production

Type Average Production Rate Peak Production

Rate Life of

Reservoir

Oil Proprietary Data

Gas

D. Oil Characteristics

Condensate Cha racteristic Analytical Methodologies Should Be Compatible With:
1. Gravity (API) 41.84 ASTM D4052 2. Flash Point (oC) < ASTM D93/IP 34 3. Pour Point (oC) <

- 26 oC ASTM D97 4. Viscosity (Centipoise at 25 o C) ASTM D445

5. Wax Content (wt %) Pre cipitate with 2

- butanon/dichloromethane (1 to 1 volume) at

- 10 o C 6. Asphaltene Content (wt %) 0.02 IP

- Method 143/84 7. Resin Content (wt %) 2.52 Jokuty et al., 1996 8. Boiling point distribution including, for

each fraction, the percent volume or w eight

and the boiling point range in o C ASTM D2892 (TBP distillation) or ASTM D2887/5307

9. Sulphur (wt %) 0.99 ASTM D4294

Note: If the distillation information in Item No. 8 in the above table is not available, the GOMR may accept the asphaltenes, and resins; and total BTEX (ppm) using analytical methods compatible with the Hydrocarbon Groups methodology found in Jokuty et al., 1996).

All in wt% Topped Basis SARA (Topped Basis) All in wt %

Well # Saturates Aromatics Resin Asphaltenes A5 H sand ( API # 6081741068 ) 62.2 31.8 6.0 0.05Identify the oil you analyze. Refer to the following sample chart.

Oil from one well Oil from more than one well sampled on a facility Oil from a pipeline system

·Area/Block ·MMS platform

·API Well No. ·Comp letion perforation

interval

· BOEM ‟s reservoir name ·Sample date ·Sample No.(if more than one is taken) ·Area/Block

· BSEE platform ID ·Field/Unit ·Sample date ·Sample No. (if more than one is taken) ·Listing of API Well Nos. ·Storage tank ID No. (if sampled at a storage tank) ·Pipeline segment number ·For each pipeline that feeds into the system, the ID codes for the closest upstream LACT units and/or facility measurement points ·Storage tank ID No. (if sampled at a storage tank)

Sample Detail

Area/Block MC934

BSEE Platform OCS

- G 7975

API Well No. A5
Completion Perforation 18,252' MD

BOEM Reservoir Name
Sample Date 6

- Sep

- 2005

2B Oil Characteristics I Sand If DOCD is offshore Florida, a new surface facility in water deeper than 400 meter s (1,312‟), or one in any water depth that supports subsea development in water depths greater than 400 meters (1,312‟) complete the following two tables:

Provide the estimated chemical and physical characteristics of the oils that will be handled, stored, or transported on/by the facility.

Oil Characteristic Analytical Methodologies Should Be Compatible With:
1. Gravity (API) 28.8 ASTM D4052 2. Flash Point (oC < ASTM D93/IP 34 3. Pour Point (oC)

- 26 oC ASTM D97 4. Viscosity (Centipoise at 25 o C) ASTM D445

5. Wax Content (wt %) Precipitate with 2

- butanon/dichloromethane (1 to 1 volume) at

- 10 o C 6. Asphaltene Content (wt %) 3.97 IP

- Method 143/84 7. Resin Content (wt %) 6.19 Jokuty et al., 1996 8. Boiling po int distribution including, for

each fraction, the percent volume or weight

and the boiling point range in o C ASTM D2892 (TBP distillation) or ASTM D2887/5307

9. Sulphur (wt %) 3.29 ASTM D4294

Note: If the distillation information in Item No. 8 in the above table is not available, the GOMR may accept the following information in lieu of Items Nos. 5, 6, 7, and 8: weight percent total of saturates, aromatics, waxes, asphaltenes, and resins; and total BTEX (ppm) using analytical methods compatible with the Hydrocarbon Groups methodology found in Jokuty et al., 1996).All in wt% Topped Basis SARA (Topped Basis) All in wt %

Well # Saturates Aromatics Resin Asphaltenes

A1 (API # 6081740835 ) 20.09 58.35 14.1 10.7

Identify the oil you analyze. Refer to the following sample chart.

Oil from one well Oil from more than one well sampled on a facility Oil from a pipeline system

·Area/Block

· BSEE platform

·API Well No. ·Completion perforation

interval

· BSEE ‟s reservoir name ·Sample date ·Sample No.(if more than one

is taken) ·Area/Block

· BSEE platform ID ·Field/Unit ·Sample date ·Sample No. (if more than one is taken) ·Listing of API Well Nos. ·Storage tank ID No. (if sampled at a storage tank) ·Pipeline segment number ·For each pipeline that feeds into the system, the ID codes for the closest upstream LACT units and/or facility measurement points ·Storage tank ID No. (if sampled at a storage tank)

Sample Detail

Area/Block MC934

BSEE Platform OCS

- G

- 7975

API Well No. A1
Completion Perforation 16,353' MD

BSEE R eservoir Name
Sample Date 5

- Mar

- 2000

E. New Or Unusual Technology

There are no new or unusual technology associated with this Plan.

F. Bonding

The bond requirement for the activities proposed in this DOCD are satisfied by an area-wide bond furnished and maintained according to 30 CFR Part 256, subpart I; NTL No. 2000-G16, Guideline for General Lease Surety Bonds;” and National NTL No. 2008

- N07, “Supplemental Bond Procures.”

G. Oil Spill Financial Responsibility (OSFR)

Shell Offshore Inc. (Shell), BOEM Op erator Number 0689, has demonstrated oil spill financial responsibility for the facilities proposed in the DOCD according to 30 CFR part 253, and NTL No. 2008- N05, “Guidelines for Oil Spill Financial Responsibility for Covered Facilities.”

H. Deepwater well control statement

Shell Offshore Inc. (S hell), BOEM Operator Number 0689, has the financial capability to drill a relief well and conduct other emergency well control operations.

I. Suspension of Production

Lease is held by unit production from the Mississippi Canyon Block 935 Unit No. 754395016.J. Blowout scenario

This section was provided and approved by BOEM in Plan S-7405. The wells proposed in this plan are part of the Mississippi Canyon Block 935 Unit No. 754395016. The WCD for wells A8 and A9 do not exceed the WCD that was submitted and approved for Well A7 in Plan S-7405.

This Section 2j was prepared by Shell Offshore Inc. (Shell) pursuant to the guidance provided in the Bureau of Ocean Energy Management (BOEM) Notice to Lessees (NTL) No. 2010-N06 with respect to blowout and worst case discharge scenario descriptions.

Shell focuses on an integrated, three-pronged approach to a blowout, including prevention, intervention, containment and recovery. Shell believes that the best way to manage blowouts is to prevent them from happening. Significant effort goes into the design and execution of wells and into building and maintaining staff competence with the goal of safe and environmentally sound well construction. Shell continues to invest independently in Research and Development (R&D) to improve safety and reliability of our well systems. Shell intends to comply with all applicable laws, regulations,

rules and Notice to Lessees.

Shell is a founding member of the Marine Well Containment Company (MWCC) and will have access to an integrated subsea well control and containment system that can be rapidly deployed through the MWCC. MWCC is a non-profit organization that owns, manages, and provides fully trained crews and operates the subsea containment system during a response. The near term containment response capability will include lessons learned and equipment used in the Macondo response. Shell is investing in R&D to improve containment systems. Also, Shell is a member of Clean Caribbean America (CCA), Marine Spill Response Corporation (MSRC), Clean Gulf Associates (CGA), and OSRL/EARL to provide the resources necessary to respond to a spill as outlined in our Regional Oil Spill Response Plan (OSRP).

The Worst Case Discharge (WCD) blowout scenario for Europa is calculated for the MC-935 A7 holesection with all potentially producible hydrocarbons sands, commingled based on the guidelines outlined in NTL No. 2010-N06 along with subsequent Frequently Asked Questions (FAQ). The WCD does not take into account potential flow mitigating factors such as well bridging, obstructions in wellbore, reservoir barriers, or early intervention.

Uncontrolled blowout (volume first day) 207,677 bbl
Uncontrolled blowout rate (first 30-days average daily rate) 134,011 bopd
Duration of flow (days) based on relief well 96 days
Total volume of spill (bbls) for 96 days 6.3 MMBO

Table 1 Worst Case Discharge Summary

The Europa field is a subsea development in the deepwater Gulf of Mexico tied back to the Mars TL P via two 8” flow lines with a total capacity of 60,000 BOPD. It is located on a three -block BOEM unit 18 miles southwest of the Mars platform. The subsea system is located in 3,875 feet of water.

The Europa field production began in early 2000 as a three-well development. The Phase 1 development focused on the upper sands. The phase 2 development added wells to the sands. Currently there are five Europa producers.

1) Purpose

Pursuant to 30 CFR 250.213(g), 250.219, 250.250, and NTL No. 2010-N06, this document provides a blowout scenario description, further information regarding any potential oil spill, the assumptions and calculations used to determine the WCD and the measures taken to firstly enhance the ability to prevent a blowout and secondly to respond and manage a blowout scenario if it were to occur. These calculations are based on best technical estimates of subsurface parameters that are derived from the Europa development wells and seismic. These parameters are better than or consistent with theestimates used by Shell to justify the investment. Therefore, these assumed parameters were used to

calculate the WCD. They do not reflect probabilistic estimates.

2) Background

This attachment has been developed to document the additional information requirements for Exploration Plans as requested by NTL No. 2010-N06 in response to the explosion and sinking of the Mobile Offshore Drilling Unit (MODU) Deepwater Horizon and the resulting subsea well blowout and recovery operations of the exploration well at the MC-252 Macondo location.

3) Information Requirements

a) Blowout scenario

Each hole-section was considered as a possible candidate for the worst case discharge scenario. The simulated blowout modeled results in unrestricted flow from the well at the seafloor, which represents the WCD (no restrictions in wellbore, failure/loss of the subsea BOP, and a blowout to the seabed).

b) The greatest discharge potential identified is the hole-section with all potentially producible hydrocarbons sands commingled. The worst case discharge rate is 207,677 bopd (average of the first 24 hours).

c) Total volume and maximum duration of the potential blowout

Duration of flow (days) 96 days total duration to drill relief well
(18 rig mob, 50 spud to base of
sand, 28 ranging).
Total volume of spill (bbls) 6.3 MMBO based on 96 days flowing.

Note: From MBAL model

Table 2 Estimated Duration and Volume of a Potential Blowout

Category DOCD
Type of Activity Drilling
Facility Location (area/block) MC

- 935
Facility Designation MODU
Distance to Nearest Shoreline (miles) 61 Statute miles
Uncontrolled blowout (volume first day) 207,700 bbl

Uncontrolled blowout rate
(first 30-days average daily rate) 134,011 bopd

Table 3 Estimated Flow Rates of a Potential Blowout

There is usually a decline in the discharge rate as time proceeds, which is illustrated by the differences between the first 24-hour volume and 30-day average rate. At very short times, e.g. during the first 24 hours, the pressure profile in the reservoir changes from the moment when a well first starts flowing to a pseudo-steady state pressure profile with time, and as a result the rate declines. At somewhat longer time scales, effects such as reservoir voidage and the impact of boundaries can cause the rate to drop continuously with production. Simulation and material balance models can include these effects and form the basis of the NTL No. 2010-N06 calculations for 24-hour and 30-day rates as well as maximum

duration volumes.

d) Assumptions and calculations. This data was provided and approved in Plan S-7405.e) Potential for the well to bridge over

Mechanical failure/collapse of the borehole in a blowout scenario is influenced by several factors including in-situ stress, rock strength, and fluid velocities at the sand face. Given the substantial fluid velocities inherent in the WCD, and the scenario as defined where the formation is not supported by a cased and cemented wellbore, it is possible that the borehole may fail/collapse/bridge over within the span of a few days, significantly reducing the outflow rates. However, this WCD scenario does not include any bridging.

f) Likelihood for intervention to stop the blowout.

Safety of operations is our top priority. Maintaining well control at all times to prevent a blowout is the key focus of our operations. This is derived from robust standards, well design, prudent operations, competency of personnel, and strong HSE focus. Collectively, these constitute a robust system making blowouts extremely rare events.

Intervention Devices: Notwithstanding these facts, the main scenario for recovery from a blowout event is via intervention with the BOP attached to the well. There are built in redundancies in the BOP system to allow activation of selected components with the intent to seal off the well bore. As a minimum, the Shell contracted rig fleet in the GOM will have redundancies meeting the Drilling Safety Rule with respect to Remotely Operated Vehicle (ROV) hot stab capabilities, a deadman system, and an autoshear system. The rig also has 2 shearing rams in the BOP for added redundancy. Also, the rig is equipped with a deadman system and an autoshear system.

Containment: The experience of gaining control over the Macondo well has resulted in a better understanding of the necessary equipment and systems for well containment. As a result, industry and government are better equipped and prepared today to contain an oil well blowout in deepwater. Shell is further analyzing these advances and incorporating them into its comprehensive approach to help prevent and, if needed, control another deepwater control incident.

Should the interventions at the well not be possible, specialized equipment can be used to connect to a riser stub, damaged connector, casing stub or to the sea floor and allow the well to be shut-in to contain the blowout. The subsea containment assembly and other specialized connection devices will be available from the Marine Well Containment Company (MWCC). If full shut-in, following capping is not possible because of well integrity issues, the well can be flowed with back-pressure maintained via the MWCC specialized well flow equipment.

Shell is investing in Research and Development activities on its own to identify additional containment components and equipment that will potentially increase the range of applications and effectiveness for equipment similar to that of MWCC, and systems that can be deployed more effectively in the water column that resemble “tents or capture domes”, an d enhance well shut-in capability.

g) Availability of a rig to drill a relief well and rig package constraints

Blowout intervention can be conducted from an ROV equipped vessel, the existing drilling rig or from another drilling rig. Shell has an active portfolio of well operations in the GOM which will be supported by a total of four to six MODU rigs in 2012

– 2015 timeframe. The dynamically positioned rigs under contract, the Noble Danny Adkins and the Bully 1, will be the preferred rigs for blowout intervention work. However, moored rigs can also be used in some scenarios. Additionally, in the event of a blowout, there is the distinct possibility that other non-contracted rigs in the GOM could be utilized whether for increased expediency or better suitability. All efforts will be made at the time to secure the appropriate rig. Shell‟s current contracted rigs capable of operating at Europa water depths and reservoir depths are in the following table:Rig Name Rig Type

Deepwater Nautilus moored semi-submersible
Noble Jim Thompson moored semi-submersible
Noble Danny Adkins dynamically positioned semi-submersible
Bully 1 dynamically positioned drill ship
Noble Globetrotter I dynamically positioned drill ship

Table 4 Shell Contracted Rigs Capable at Europa.

Future modifications may change the rig‟s capability. Rig capabilities need to be assessed on a work scope specific basis.

h) Time taken to contract a rig, move it onsite, and drill a relief well

Relief well operations will immedi ately take priority and displace any activity from Shell‟s contracted rig fleet. The list of rigs capable of operating at Europa is tabled above. It is expected to take an average of 14 days to safely secure the well that the rig is working on up to the point the rig departs location, and an additional 4 days transit to mobilize to the relief well site depending on distance to the site. The relief well will take approximately 50 days to drill down to the last casing string above the blowout zone, plus approximately 28 days for precision ranging activity to intersect the blowout well bore. Total time to drill a relief well would be 96 days for the Europa well.

If a moored rig is chosen to conduct the relief well operations, anchor handlers would be prioritized to prepare mooring on the relief well site while the rig is being mobilized. This mooring activity is not expected to delay initiation of relief well drilling operations. Shell has three deepwater anchor handlers, the Laney, Dino, and Ross Chouest, on long term contract to support its moored rigs.

It is not possible to drill relief wells from any existing platforms due to distances of over fifteen miles to the discovery.

i) Measures proposed to enhance ability to prevent blowout and to reduce likelihood of

a blowout.

Shell believes that the best way to manage blowouts is to prevent them from happening. Detailed below are the measures employed by Shell with the goal of no harm to people or the environment. The Macondo incident has highlighted the importance of these practices. The lessons learned from the investigation are, and will continue to be, incorporated into our operations.

Standards: Shell‟s well design and operations adhere to internal corporate standards, the Code of Federal Regulations, and industry standards. A robust management of change process is in place to handle un-defined or exception situations. Ingrained in the Shell standards for well control is the philosophy of multiple barriers in the well design and operations on the well.

Risk Management: Shell believes that prevention of major incidents is best managed through the systematic identification and mitigation process (Safety Case). The safety case requirement is ingrained into Shell‟s Health, Security, Safety, Environment, and Social Performance Control Framework. All Shell contracted rigs in the GOM have been operating with a Safety Case and will continue to do so. A Safety Case requires both the owner and contractors to systematically identify the risks in drilling operations and align plans to mitigate those risks; an alignment which is critical before drilling begins.

Well Design Workflow: The Well Delivery Process (WDP) is a rigorous internal assurance process with defined decision gates. The WDP leverages functional experts (internal and external) to examine the well design at the conceptual and detailed design stages for robustness before making a recommendation to the management review board. Shell‟s involvement in global deepwater drilling, starting in the GOM in the m id

- 1980‟s, provides a significant depth and breadth of internal drilling and operational expertise. Third party vendors and rig contractors are involved in all stages of the planning, providing their specific expertise. A Drill the Well On Paper (DWOP) exercise is conducted with rigpersonnel and vendors involved in execution of the well. This forum communicates the well plan, and

solicits input as to the safety of the plan and procedures proposed.

Well and rig equipment qualification, certification, and quality assurance: All rigs will meet all applicable rules, regulations, and Notice to Lessees. Shell works closely with rig contractors to ensure proper upkeep of all rig equipment, which meets or exceeds the strictest of Shell, industry, or regulatory requirements. Well tangibles are governed by our internal quality assurance/control standards and industry standards.

MWD/LWD/PWD Tools: Shell intends to use these tools at Europa. The MWD/LWD/PWD tools are run on the drill string so that data on subsurface zones can be collected as the well advances in real time instead of waiting until the drill string is pulled to run wireline logs. Data from the tools are monitored and interpreted real time against prognosis to provide early warning of abnormal pressures to allow measures to be taken to progress the well safely.

Mud Logger: Mud logging personnel continually monitor returning drilling fluids for indications of hydrocarbons, utilizing both a hot wire and a gas chromatograph. An abrupt increase in gas or oi l carried in the returning fluid can be an indication of an impending kick. The mud logger also monitors drill cuttings returned to the surface in the drilling fluid for changes in lithology that can be an indicator that the well has penetrated or is about to penetrate a hydrocarbon-bearing interval. Mud logging instruments also monitor penetration rate to provide an early indication of drilling breaks that show the bit penetrating a zone that could contain hydrocarbons. The mud logging personnel are in close communication with both the drilling foreman and Shell representative to report any observed anomalies so appropriate action can be taken.

Remote Monitoring: The Real Time Operating Center has been used by Shell to complement and support traditional rig-site monitoring since 2003. Well site operations are lived virtually by onshore teams consisting of geoscientists, petrophysicists, well engineers, and 24/7 monitoring specialists. The same real time well control indicators monitored by the rig personnel are watched by the monitoring specialist for an added layer of redundancy.

Competency and Behavior: A structured training program for Well Engineers and Foreman is practiced, which includes internal professional examinations to verify competency. Other industry training in well control, such as by International Association of Drilling Contractors (IADC) and International Well Control Forum (IWCF) are also mandated. Progressions have elements of competency and Shell continues to have comprehensive internal training programs. The best systems and processes can be defeated by lack of knowledge and/or improper values. We believe that a combination of HSE tools (e.g. stop work, pre-job analysis, behavior based safety, DWOPs, audits), management HSE involvement and enforcement (e.g. compliance to life saving rules) have created a strong safety culture in our operations.

j) Measures to conduct effective and early intervention in the event of a blowout.

The response to a blowout is contained in our Well Control Contingency Plan (WCCP) which is a specific requirement of our internal well control standards. The WCCP in turn is part of the wider emergency response framework within Shell that addresses the overall organization response to an emergency situation. Resources are dedicated to these systems and drills are run frequently to test preparedness (security, medical, oil spill, and hurricane). This same framework is activated and tested during hurricane evacuations, thereby maintaining a fresh and responsive tea m.

The WCCP specifically addresses implementing actions at the emergency site that will ensure personnel safety, organizing personnel and their roles in the response, defining information requirements, establishing protocols to mobilize specialists and pre-selecting sources, and developing mobilization plans for personnel, material and services for well control procedures. The plan references individual activity checklists, a roster of equipment and services, initial information gathering forms, a generic description of relief well drilling, strategy and guidelines, intervention techniques and equipment, site safety management, exclusion zones, and re-boarding.As set forth in 3f of this document, Shell is currently analyzing recent advances in containmen t

technology and equipment and will incorporate them as they become available and is a founding

member of MWCC.

k) Arrangements for drilling a relief well

The size of the Shell contracted rig fleet in the GOM from 2012-2015 ensures that there is adequate well equipment (e.g. casing and wellhead) available for relief wells. Rigs and personnel will also be readily available within Shell, diverted from their active roles elsewhere. Resources from other operators can also be leveraged should the need arise. Generally, relief well plans will mirror the blowout well, incorporating any learning on well design based on root cause analysis of the blowout. A generic relief well description is outlined in the WCCP.

l) Assumptions and calculations used in approved or proposed OSRP

Shell has designed a response program (Regional OSRP) based upon a regional capability of responding to a range of spill volumes, from small operational spills up to and including the WCD from an exploration well blowout. Shell‟s prog ram is developed to fully satisfy federal oil spill planning regulations. The Regional OSRP presents specific information on the response program that includes a description of personnel and equipment mobilization, the incident management team organization, and the strategies and tactics used to implement effective and sustained spill containment and recovery operations.SECTION 3 : GEOLOGICAL AND GEOPHYSICAL INFORMATION

A. Geological description

Proprietary Data

B. Structure Contour Map(s)

Proprietary Data

C. Interpreted 2D and/or 3D Seismic line(s)

Proprietary Data

D. Geological Structure Cross-section(s)

Proprietary Data

E. Shallow Hazards Report

Shallow Hazards Report, Blocks 891, 934, and 935, Mississippi Canyon Area, Gulf of Mexico, prepared by Fugro McClelland, report #0201-0841, November 4, 1990. Deep-Towed Side Scan Sonar and Sub-Bottom Profiler data, Sparker data was previously submitted.

Shell Exploration and Production Archaeological and Hazard Report, Blocks 890-979, Mississippi Canyon Area, U.S. Gulf of Mexico, prepared by C&C Technologies, July, 2012, Project 100231. AUV data consisting of side scan sonar and sub-bottom profiler was previously submitted.

Archaeological Assessment, Proposed Well Site and Anchor Locations, Blocks 890, 891, 934, & 935, Mississippi Canyon Area, Gulf of Mexico, Fugro Geoservices, report 2405-1366, November 8, 2005. Deep-Towed Side Scan Sonar and Sub-Bottom Profiler was previously submitted.

F. Shallow Hazards Assessment

See Section 6 for full shallow hazards and chemo assessment.

G. High-resolution seismic lines

Proprietary Data. ESRs can be found in Section 6.

H. Stratigraphic Column and Time versus Depth Table:

Proprietary DataSECTION 4: HYDROGEN SULFIDE (H 2 S)

A. Concentration

0 ppm.

B. Classification

Based on 30 CFR 550.215, Shell requests that the Regional Supervisor, Field Operations, determine the zones in the proposed drilling operations in this plan are classified as an area where the absence

of H 2 S has been confirmed.

C. H 2 S Contingency Plan

According to NTL 2008-G04 this is not applicable to this plan.

D. Modeling Report

We do not anticipate to encounter or handle H 2 S at concentrations greater than 500 parts per million (ppm) and therefore have not included modeling for H 2 S.SECTION 5: MINERAL RESOURCE CONSERVATION INFORMATION

A. Technology and reservoir engineering practices and procedures

Proprietary Data

B. Technology and recovery practices and procedures

Proprietary Data

C. Reservoir Development

Proprietary DataSECTION 6: BIOLOGICAL, PHYSICAL, AND SOCIOECONOMIC INFORMATION

A. Chemosynthetic Communities Report

Reports and Data: Previously submitt ed

Shallow Hazards 

### :

Shallow Hazards Report, Blocks 891, 934, and 935, Mississippi Canyon Area, Gulf of Mexico, prepared by Fugro McClelland, report # 0201-0841, November 4, 1990. Deep-Towed Side Scan Sonar and Sub-Bottom Profiler data, Sparker data.

Ar chaeological:

Shell Exploration and Production Archaeological and Hazard Report, Blocks 890-979, Mississippi Canyon Aera, U.S. Gulf of Mexico, prepared by C&C Technologies, July, 2012, Project 100231. AUV data consisting of side scan sonar and sub-bottom profiler

Archaeological Assessment, Proposed Well Site and Anchor Locations, Blocks 890, 891, 934, & 935,Mississippi Canyon Area, Gulf of Mexico, Fugro Geoservices, report 2405-1366, November 8, 2005. DeepTowed Side Scan Sonar and Sub-Bottom Profiler.

Proposed Locations and Coordinates:

Proposed

Location X Coordinate Y Coordinate FNL/FSL FEL/FWL Water Depth

MC 934 A

- 8 852033.76 10182485.34 263 4 .66‟ FNL 3326.24‟ FEL 3875

MC 934 A

- 9 851995.00 10182301.00 2819.00‟ FNL 3365.00‟ FEL 3875

Site Assessment, MC 934, Proposed Location A-8

Mississippi Canyon 934, Proposed Location A-8 is located in a water depth of approximately 3875 feet. There is no evidence of seafloor and near-surface faulting, slumping, amplitudes or fluid expulsion features within 2000 feet of MC 934, Proposed Location A- 8.

The stratigraphy at the site of MC 934, Proposed Location A-8 consists of:

• Unit 1 (Seafloor – 371„BML) consists of normal marine drape, hemipelagic mud and muddy mass transport deposits ( MTD‟s). • Unit 2 (371‟ – 649‟ BML) consists of 278‟ of muddy MTD‟s • Unit 3 (619‟ – 1158‟ BML) consists of 509‟ of MTD‟s with a thin sand package • Unit 4 (1158‟ – 1591‟ BML) consists of 433/ of MTD‟s, conformable turbidites with some silty sections

• Unit 5 (1591‟ – 1903‟ BML) consists of 312‟ of muddy channel system that has mostly eroded “Blue

Unit” • Unit 6 (1903‟ – 2497‟ BML) consists of 594‟ of muddy MTD‟s with silty sand at the base • Unit 7 (2497‟ – 2726‟BML) consists of Muddy MTD‟s and confo rmable turbidites • Unit 8 (2726‟ – 3637‟ BML) consists of 911‟ of regional MTD‟s with sands and silts • Unit 9 (3637‟ – 4475‟ BML) consists of 838‟ of muddy MTD‟s and conformable turbidites with some thin sand packages.

Shallow Water Flow Potential:

Low Potential

– Seafloor

– 649‟ BML

Moderate Potential

– 649‟

– 1903‟ BML Moderately Low Potential

– 1903‟

– 2497‟ BML

Low Potential

– 2497‟

– 4475‟ BMLShallow Gas Potential:

Low Potential

– Seafloor

– 4475‟ BML

Chemo Assessment, MC 934, Proposed Location A- 8

Mississippi Canyon 934, Proposed Location A-8 is located in a water depth of approximately 3875 feet. There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 12000‟ of MC 934, Propo sed Location A-8. This location will not disturb any high-density areas of benthic

communities. (See Attachment 6A.)

The following table consisting of 5 targets is a listing of marine avoidance zones identified within 2000‟ of MC 934, Proposed Location A- 8:

Avoidance

Zone Number Avoidance Central X

Coordinate Central Y

Coordinate Distance from

Prop Loc A

- 8 Direction from

Prop Loc A

- 8

999 100‟ 851619.02 10182629.61 439.12 Southeast

1111 100‟ 852834.07 10182390.00 805.97 Northwest

935 100‟ 851201.66 10182595.67 839.38 Southeast

1133 100‟ 853112.40 10182743.67 1109.14 Southwest

1141 100‟ 853240.60 10183144.34 1375.04 Southwest

The following table consisting of 30 targets, is a listing of barrels identified within 2000‟ of MC 934, Proposed

Location A- 8:

Avoidance

Zone Number Avoidance Central X

Coordinate Central Y

Coordinate Distance from

Prop Loc A

- 8 Direction from

Prop Loc A

- 8

980 50‟ 851506.46 10182573.12 534.56 Northwest

1001 50‟ 851696.28 10182069.09 535.87 Northwest

981 50‟ 851516.56 101 82325.08 541.46 Southeast

973 50‟ 851465.40 10182421.19 571.97 Southwest

972 50‟ 851463.70 10182240.74 620.32 Northeast

969 50‟ 851441.45 10182671.66 620.92 Northwest

1101 50‟ 852755.67 10182564.28 726.21 Southwest

951 50‟ 851292.38 10182882.96 841.28 Northeast

1007 50‟ 851737.19 10183287.59 855.31 Southeast

938 50‟ 851222.80 10182762.64 857.06 Northwest

1117 50‟ 852929.23 10182409.19 898.70 Northeast

1115 50‟ 852899.54 10182212.13 907.86 Northeast

937 50‟ 851221.82 10182901.20 912.24 Southeast

1 136 50‟ 853130.85 10182852.83 1157.00 Northwest

877 50‟ 850696.13 10182321.85 1347.58 Northwest

1096 50‟ 852649.11 10181257.73 1373.20 Southwest

1145 50‟ 853282.34 10183088.31 1386.55 Northeast

856 50‟ 850491.55 10182377.29 1545.99 Northeast

960 50‟ 8 51391.16 10183940.64 1590.86 Northeast

1163 50‟ 853695.48 10182275.07 1674.97 Southeast

849 50‟ 850405.10 10181839.82 1751.92 Northwest

845 50‟ 850373.58 10181875.65 1768.59 Northwest

908 50‟ 850890.65 10183836.73 1770.02 Southeast

1178 50‟ 853865.72 10182464.77 1832.08 Southwest

1181 50‟ 853925.37 10182472.00 1891.66 Northeast

1079 50‟ 852421.02 10184355.33 1909.67 Northwest

1023 50‟ 851846.31 10180571.81 1922.69 Southwest

1008 50‟ 851737.61 10180572.66 1935.47 Northeast

932 50‟ 851120.16 1018074 8.44 1962.52 Southeast

882 50‟ 850739.17 10183968.55 1968.72 NorthwestShell‟s “Waste Barrel Avoidance and Release Response in the Mississippi Canyon Area” is included at the end

of this section in the plan.

Conclusion:

Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR‟s), ESR‟s with amplitudes applied, AUV data consisting of Side Scan Sonar and Sub

Bottom Profiler, MC 934, Proposed Location A-8 appears suitable for the planned activity.

Site Assessment, MC 934, Proposed Location A-9

Mississippi Canyon 934, Proposed Location A-9 is located in a water depth of approximately 3875 feet. There is no evidence of seafloor and near-surface faulting, slumping, amplitudes or fluid expulsion features within 2000 feet of MC 934, Proposed Location A- 9.

The stratigraphy at the site of MC 934, Proposed Location A-9 consists of:

• Unit 1 (Seafloor – 371„BML) consists of normal marine drape, hemipelagic mud and muddy mass transport deposit s (MTD‟s). • Unit 2 (371‟ – 649‟ BML) consists of 278‟ of muddy MTD‟s • Unit 3 (619‟ – 1158‟ BML) consists of 509‟ of MTD‟s with a thin sand package • Unit 4 (1158‟ – 1591‟ BML) consists of 433/ of MTD‟s, conformable turbidites with some silty sections • Unit 5 (1591‟ – 1903‟ BML) consists of 312‟ of muddy channel system that has mostly eroded “Blue

Unit” • Unit 6 (1903‟ – 2497‟ BML) consists of 594‟ of muddy MTD‟s with silty sand at the base • Unit 7 (2497‟ – 2726‟BML) consists of Muddy MTD‟s and co nformable turbidites • Unit 8 (2726‟ – 3637‟ BML) consists of 911‟ of regional MTD‟s with sands and silts • Unit 9 (3637‟ – 4475‟ BML) consists of 838‟ of muddy MTD‟s and conformable turbidites with some thin sand packages.

Shallow Water Flow Potential:

Low Potential

– Seafloor

– 649‟ BML

Moderate Potential

– 649‟

– 1903‟ BML Moderately Low Potential

– 1903‟

– 2497‟ BML

Low Potential

– 2497‟

– 4475‟ BML

Shallow Gas Potential:

Low Potential

– Seafloor

– 4475‟ BML

Chemo Assessment, MC 934, Proposed Location A- 9

Mississippi Canyon 934, Proposed Location A-9 is located in a water depth of approximately 38 75 feet. There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 12000‟ of MC 934, Propo sed Location A-9. This location will not disturb any high-density areas of benthic communities. (See Attachment 6B.)

The following table consisting of 5 targets is a listing of marine avoidance zones identified within 2000‟ of MC 934, Proposed Location A- 9:

Avoidance

Zone Number Avoidance Central X

Coordinate Central Y

Coordinate Distance from

Prop Loc A

- 9 Direction from

Prop Loc A

- 9

999 100‟ 851619.02 10182629.61 499.35 Southeast

1111 100‟ 852834.07 10182390.00 843.78 Southwest

935 100‟ 851201.66 1 0182595.67 846.30 Southeast

1133 100‟ 853112.40 10182743.67 1201.89 Southwest

1141 100‟ 853240.60 10183144.34 1504.24 SouthwestThe following table consisting of 29 targets, is a listing of barrels identified within 2000‟ of MC 934, Proposed

Location A- 9:

Avoidance

Zone Number Avoidance Central X

Coordinate Central Y

Coordinate Distance from

Prop Loc A

- 9 Direction from

Prop Loc A

- 9

1001 50‟ 851696.28 10182069.09 378.17 Northeast

981 50‟ 851516.56 10182325.08 479.05 Southeast

972 50‟ 851463.70 10 182240.74 534.71 Northeast

973 50‟ 851465.40 10182421.19 543.07 Southeast

980 50‟ 851506.46 10182573.12 559.21 Southeast

969 50‟ 851441.45 10182671.66 666.19 Southeast

1101 50‟ 852755.67 10182564.28 804.94 Southwest

938 50‟ 851222.80 10182762.64 899.6 7 Southeast

1115 50‟ 852899.54 10182212.13 908.90 Northwest

951 50‟ 851292.38 10182882.96 912.33 Southeast

1117 50‟ 852929.23 10182409.19 940.47 Southwest

937 50‟ 851221.82 10182901.20 978.80 Southeast

1007 50‟ 851737.19 10183287.59 1019.72 Southeast

1096 50‟ 852649.11 10181257.73 1231.37 Northwest

1136 50‟ 853130.85 10182852.83 1262.80 Southwest

877 50‟ 850696.13 10182321.85 1299.04 Southeast

856 50‟ 850491.55 10182377.29 1505.38 Southeast

1145 50‟ 853282.34 10183088.31 1509.01 Southwest

849 50‟ 850405.10 10181839.82 1655.44 Northeast

845 50‟ 850373.58 10181875.65 1676.28 Northeast

1163 50‟ 853695.48 10182275.07 1700.68 Northwest

1023 50‟ 851846.31 10180571.81 1735.57 Northeast

960 50‟ 851391.16 10183940.64 1747.30 Southeast

1008 50‟ 851737. 61 10180572.66 1747.40 Northeast

932 50‟ 851120.16 10180748.44 1782.07 Northeast

1178 50‟ 853865.72 10182464.77 1877.87 Southwest

908 50‟ 850890.65 10183836.73 1891.57 Southeast

860 50‟ 850536.23 10181062.48 1913.62 Northeast

1181 50‟ 853925.37 101824 72.00 1937.93 Southwest

Shell‟s “Waste Barrel Avoidance and Release Response in the Mississippi Canyon Area” is included at the end of this section in the plan.

Conclusion:

Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR‟s), ESR‟s with amplitudes applied, AUV data consisting of Side Scan Sonar and Sub

Bottom Profiler, MC 934, Proposed Location A-9 appears suitable for the planned activity.

Processing Platform

Mississippi Canyon Block 807 (Mars) Platform x = 924,373 3630' FNL y = 10,229,010 5653' FWL

The Mars TLP will serve as the processing platform for the Mississippi Canyon Block 934/ 935 subsea wells. The MC 807 platform is located in a water depth of approximately 2, 950 ‟ . A fault with seafloor expression is 1, 450 ‟ west of this site. There is no evidence of fluid expulsion associated with this fault. None of the MC 935 Unit wells will be drilled from the MC 807 platform site for MC 935 Unit objectives.Proposed New Seafloor Hardware

Mississippi Canyon 934, Proposed Pile 2 & Jumpers X = 851,860.26 Y = 10,182,417.67

MC 934, Proposed Pile 2 is located in a water depth of approximately 3875 feet. There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 250 feet of MC 934. Proposed Pile 2 will not disturb any high-density areas of benthic communities.

There are no sonar targets identified within 250 feet of MC 934, Proposed Pile 2.

Conclusion:

Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR‟s), ESR‟s with amplitudes applied, AUV data consisting of Side Scan Sonar and Sub

Bottom Profiler, MC 934, Proposed Pile 2 appears suitable for the planned activity.

B-F:

Pursuant to NTL No. 2008-G04 the proposed operations covered by this plan do not involve operations impacting the following: Topographic features map, Topographic features statement (shunting), Live bottoms, (Pinnacle Trend) map, Live bottoms (low relief) map, potentially sensitive biological features map.

G. Remotely Operated Vehicle (ROV) Monitoring Plan

Mississippi Canyon Block 934 is located in Grid 13, which has adequate ROV coverage so in accordance with the provisions of NTL No. 2008-G06, Remotely Operated Vehicle Surveys in Deepwater, we are not proposing to run an ROV survey.

H. Threatened and Endanger Species Information

There are 5 species of sea turtles that may be found in the Gulf of Mexico (see table). No critical habitat for these species has been designated in the Gulf of Mexico.

Common Name Scientific Name T/E Status

Hawksbill Turtle Eretmochelys imbricata E

Green Turtle Chelonia mydas T
Kemp's Ridley Turtle Lepidochely s kempii E

Leatherback Turtle Dermochelys coriacea E
Loggerhead Turtle Caretta caretta TThere are 28 species of marine mammals that may be found in the Gulf of Mexico (see table). Of the species

listed as Endangered, only the Sperm whale is commonly found in the project area. No critical habitat for these species has been designated in the Gulf of Mexico.

Common Name Scientific Name T/E Status
Atlantic Spotted Dolphin Stenella frontalis

Blainville's Beaked Whale Mesoplodon densirostris

Blue Whale Balaenoptera musculus E
Bottlenose Dolphin Tursiops truncatus
Bryde's Whale Balaenoptera edeni
Clymene Dolphin Stenella clymene

Cuvier's Beaked Whale Ziphius cavirostris
Dwarf Sperm Whale Kogia simus

False Killer Whale Pseudorca crassidens

Fin Whale Balaenoptera physalus E
Fraser's Dolphin Lagenodelphis hosei

Gervais' Beaked Whale Mesoplodon europaeus
Humpback Whale Megaptera novaeangliae E

Killer Whale Orcinus orca

Melon

- headed Whale Peponocephala electra

Minke Whale Balaenopte ra acutorostrata
Northern Right Whale Eubalaena glacialis
Pantropical Spotted Dolphin Stenella attenuata
Pygmy Killer Whale Feresa attenuata
Pygmy Sperm Whale Kogia breviceps
Risso's Dolphin Grampus griseus
Rough

- toothed Dolphin Steno bredanens is

Sei Whale Balaenoptera borealis E

Short

- finned Pilot Whale Globicephala macrorhynchus
Sowerby's Beaked Whale Mesoplodon bidens
Sperm Whale Physeter macrocephalus E
Spinner Dolphin (Long

- snouted) Stenella longirostris
Striped Dolphin Stenella c oeruleoalba

I. Archaeological Report

Mississippi Canyon Block 934 has been identified as having a high probability of archeological features in accordance with NTL 2008-G20. An Archeological Assessment Report was previously submitted to BOEM on December 15, 2005 and updated April 25, 2006 in connection with our Revised DOCD R-4234 approved November 1, 2005. Shell will comply with NTL 2005-G07.

J. Air and Water Quality Information

Pursuant to NTL No. 2008-G04 the proposed operations covered by this plan do not require Shell to provide additional information relating to air and water quality information. For specific information relating to air and water quality information please refer to the EIA, Attachment 18.

K. Socioeconomic Information

Pursuant to NTL No. 2008-G04 the proposed operations covered by this plan do not require Shell to provide additional information relating to socioeconomic information. For specific information relating to socioeconomic information please refer to the EIA, Attachment 18.

# OLYMPUS Host – MARS “B” Development

MISSISSIPPI CANYON BLOCK 807



# Waste Barrel Avoidance and Release
Response in the Mississippi Canyon

Area

Project OLYMPUS Host – MARS “B” Development

Document Title Waste Barrel Avoidance and Release Response in the Mississippi Canyon Area

Document Number MRB-100-HX-0505-0000002-000

Document Revision REV 2

Version Code Not Applicable

Document Status Issued for Review

EIS Discipline / Document Type Hazard Analysis Report

Originator / Author Robert Kuehn

Classification Restricted

ECCN EAR 99

Issue Date 10/20/10

Revision History is shown on next pageDocument Number -Rev Page 2 of 8

RESTRICTED 

### REVISION HISTORY

Rev # Date of

Issue Issue Description Originator Reviewer Approver

2 10/20/10 Formalized existing

document into Document Mgmt

program RB Kuehn RB Kuehn Nilesh Popat

SummaryDocument Number -Rev Page 3 of 8

RESTRICTED 

### Contents

PURPOSE ....................................................................................................................... ..... 4

REVISION HISTORY ....................................................................................................... 4

BACKGROUND ................................................................................................................. 4

N ORMAL 

### O PERATIONS 

### ....................................................................................................... 5

D ECONTAMINATION OF 

### E QUIPMENT 

### ................................................................................... 6

### Waste Barrel Avoidance and Release Re sponse in the Mississippi Canyon Area

10/20/10 REV 2

4 of 8 

# Purpose

This document provides expectations and guida nce for avoiding, and responding to a release of the contents of, a seafloor waste barrel. The pr ocedures below describes Shell’s expectations for routine barrel avoidance, data management, and response to inadvertent release of barrel

contents.



# Applicability

This document applies to all ROV, anchor and other operations which could cause a seafloor barrel rupture.

Changes to this procedure must be approved by BOEMRE. 1



# Revision History

Date Person Revision 12/16/08 RBKuehn Incorporated comments from MMS 2 and issued as final. 8/16/10 RBKuehn Incorporated comment from BOEMRE 3 to include New Orleans District manager in the notification of Step 2 of the section Barrel Impact Reporting.

Also revised all relevant references to MMS as BOEMRE

10/20/10 RBKuehn 3⁄4 In Background, added in summary of suspected materials disposed at the site, based on research of the site in public records.
3⁄4 In section on Equipment Decontamination- Decon Procedure:

o clarified what types of detergents are preferred/allowed, using the NPDES Vessel General Permit as a guide.

o Expanded on appropriate PPE and other personnel precautions

o Noted a need for secondary containment as appropriate

Significant changes to the text are shown in yellow shade.
3⁄4 Added page numbers and cleaned up format.

3⁄4 Issued as REV 2



# Background

Various projects will be carried out in an area of the Miss issippi Canyon known to contain

barrels of chemical waste.

1 Per MMS approval of West Bor eas Supplemental Ex ploration Plan, MS 5231 December 16, 2008 Control No. S-07273, Lease(s) OCS-G07957, Block 762, Mississippi Canyon Area OCS-G07962, Block 806, Mississippi Canyon Area

2 Per MMS approval of West Bor eas Supplemental Ex ploration Plan, MS 5231 December 16, 2008 Control No. S-07273, Lease(s) OCS-G07957, Block 762, Mississippi Canyon Area OCS-G07962, Block 806, Mississippi Canyon Area

3 Per BOEM approval of the Supplement to the Conceptual DWOP for Mars B project, 8/12/10, MS 5220

### Waste Barrel Avoidance and Release Re sponse in the Mississippi Canyon Area

10/20/10 REV 2

5 of 8 • The barrels were discharged in this ar ea in the 1970’s under government approved permits.

• The content, and its toxicity, of each indivi dual barrel is not known. However, there are records of a wide range of i ndustrial waste materials that we re disposed in the barrels including chlorinated hydrocarbons and liquid metal salts. Below is a summary of the

barrel contents based on available records.

1. Metallic sodium and calcium; calcium oxide, sodium oxide, and inert salts. 4



### 2. 80-90% dichlorobutene, 20% organic high-boilers, and 1% quaternary ammonium salts. “Other wastes produ ced from the manufacture of fungicides

and herbicides”. 5



### • Within the area there are/could be many hundred s of waste barrels. Ma ny of the barrels may have released their contents over time. However, an unknown numb er of barrels still look intact, and they may or may not still contai n their original conten t. Also, as some of

the barrels contained metal based solid wast e, some of the barrels that no longer look intact may still contain some waste.

• Extensive sonar surveys of the area exist and are available for planning purposes.



# Potential Hazards

Although there are no records of any issues rega rding the barrels during the many years of Oil and Gas operations in the Mississippi Canyon area, the following potential hazards exist:

• Personnel exposure or equipment damage due to adherence of waste chemicals to recovered subsea equipment

• Equipment damage from sodium exposur e to water (very vigorous reaction).



# Normal Operations

For normal operations, all contractors and Shell employees must meet the following expectations:

1. Shell’s over-arching policy is to avoid barrel contact.

2. Press releases making any reference to the ch emical waste or barre ls, or any incidents involving any chemical waste or barrels, will require the ex press written permission from

4 EPA Permit Application No. 730D009E from Ethyl Co rp, March 1, 1977, Public Notice April 20, 1977,

5 Chapter 5 “Ocean Discharge” in the book Assessing Potentia l Ocean Pollutants, A Report of the Study Panel on Assessing Potential Ocean Pollutants. National Academy of Sciences, Wash ington DC, 438 pp. This document details DuPont’s application to dispose of the following at the ocean disposal site

### Waste Barrel Avoidance and Release Re sponse in the Mississippi Canyon Area

10/20/10 REV 2

6 of 8 Shell.

3. All recorded video material is confidential and the property of Shell (standard contract provision).

If during normal ROV operations there is a discovery of any potential archaeological resource (i.e., cannot be definitiv ely identified as waste barrel/b arrel remnant, modern debris, or refuse), any seafloor-disturb ing activities in its proximity, must be stopped, the discovery must be reported to Dr. Chris Horrell at 504-736-2796, and further in structions must be obtained before proceeding.

4. Equipment Placement/Stand-off Distance

4.1. A safe stand-off distance from the waste barr els is considered 10m (33ft). Care must be taken that flexible components (e.g. ROV te ther, anchor lines, seismic cables) are controlled as well (e.g. don’t drag through a barrel field).

4.2. If a seafloor action will genera te cuttings or debris, increa se the stand-off distance as

needed to avoid debris c ontact with nearby barrels.

4.3. Do not investigate any barrels or remainders of barrels. Remain the minimum stand-off of 10m (33ft) at all times.

4.4. Survey the anchor/pile/export locations with an ROV to ensure barrel avoidance.

4.5. Record the (approximate) location of any chem ical waste barrel seen, if feasible, without getting closer than the 10m (33ft) stand-off distance.

5. Contact the Shell EP Company Environmental Du ty Phone for any questions or concerns. 1-

504-390-1330

6. Decontamination of Equipment: In the event of contact with a barrel contents decontaminate equipment per Decontamination of Equipment below.

7. Make reports of barre l contact/rup ture per Barrel Release Reporting below.



# Decontamination of Equipment

1. General In the unlikely case that contact is suspected or has been made with any wastes from a barrel, appropriate action needs to be taken to guarantee the topside safety of personnel handling the equipment (e.g. ROV, anchor lines, etc). 

## It is left solely to the judgment of the Person-in-Charge of the equipment/vessel to determine if it is necessary to abandon all or part of the equipment on the sea floor.

2. Decon Procedure

### Waste Barrel Avoidance and Release Re sponse in the Mississippi Canyon Area

10/20/10 REV 2

7 of 8 Based on various factors 6 

### , Shell recommends the following:

2.1. Use the ocean to “wash” the equipment (e.g. fl y an ROV for at least an hour at depth high enough above sea floor to prevent umbili cal dragging or other disturbance of the sea floor). For other equipment, provide any movement through the water column that’s possible, again avoi ding seafloor dragging.

2.2. Retrieve the equipment to the surface, but do not bring onboard if feasible.

2.3. Hose the equipment off befo re retrieving onto the vessel . Use as high a water flow as

is available/safe. CAUTION - detergent/soap may be used BUT in as low a quantity as practicable to minimize foam. Only non-toxic and phosphate free cleaners and detergents may be used. Furthermore, cleaner s and detergents should not be caustic or only minimally caustic and should be biodegradable 7



### .

2.4. Avoid physical contact with the equipment, and keep the equipment off the vessel at this point..

2.5. Dunk the equipment back in the sea and “w ash” the equipment for approximately 15

minutes.

2.6. Retrieve the equipment to the surface. Before recovering, visually inspect the equipment, umbilical, cable surfaces with binoculars for signs of corrosion,
discoloration, air reac tion such as fuming/smoking, or any other signs of chemical contact. Rewash and dunk the equipment as needed.

2.7. Retrieve the equipment onto the back d eck. Monitor the equipment and surrounding storage area for indications of chemical contamination (corrosion, discoloration, air reaction such as fuming/smoking, etc). Estab lish secondary containment as necessary to collect any potentially contaminated drips.

2.8. Only essential personnel should be allowed near the equipment, once retrieved on the

back deck.

2.9. While performing cleaning operations on th e equipment, involving contact with potentially contaminated surfaces, persona l protective equipment must be worn including, but not limited to: safety eye goggl es, safety clothing su ch as coverall and

6 Shell assumes, for purposes of this decontamination guidance, that:

• The most toxic material identified in the disposal area’s permit s and other available documents is involved . However Shell ca nnot guarantee there are not other toxic materials present than t hose identified in the permits and other documents.

• It is assumed that the materials do not chemically interact with the materials of the ROV, its tools and equipment.

7 The NPDES General Permit for Discharges Incidental to the Normal Operation of a Vessel provides insight into managing any washing. Also, EPA provides the following definitions: “Non-toxic” soaps, cleaners, and detergents means these materials which do not exhibit potentially harmful characteristics as defined by the Consumer Product Safety Commission regulati ons found at 16 CFR Chapter II, Subchapter C, Part 1500. “Phosphate Free” soaps, cleaners, and detergents m eans these materials which contain, by weight, 0.5% or less of phosphates or derivatives of phosphates.

### Waste Barrel Avoidance and Release Re sponse in the Mississippi Canyon Area

10/20/10 REV 2

8 of 8 aprons, Nitrile type chemi cal resistant industrial-safe ty gloves, and PVC boots.

2.10. Wash hands thoroughly and take a shower after performing cl eaning operations on the equipment.

2.11. Avoid drinking liquids or eating food in the work area.

2.12. If contamination is still suspected, consult with the Shell representatives/management for further actions including additiona l washing, abandonment on the seafloor, segregated storage on the boat, wrapping the equipment partially or fully in plastic sheeting, etc.

2.13. Document all actions an d results in a log.



# Barrel Impact Reporting

1. Initial reporting:

1.1. Equipment operator is to inform the Shell onsite representative and the Shell operations supervisor on duty.

1.2. The Shell onsite representative or the Shell operations supervisor will call the SEPCO Environmental Duty Engineer at 1-504-390-1330. As a back-up, call 337- 281-0783 (Rob Kuehn).

• The call should be made at the earliest convenience.

• Be prepared to report the lat/long of the ruptured barrel (not the surface location) and water depth.

2. The SEPCO Environmental Duty Engineer will call

• the regulatory Affairs Duty Phone 504-782-7823,

• Mr. Broussard of the BOEMRE (504-736-3245) and

• BOEMRE New Orleans District Manager

to report the event. The call should include the lat/long and any circ umstances of note.

3. Follow-up Reporting The SEPCO Environmental Duty Engineer or Rob Kuehn follows up with an email to

Mr. Broussard of BOEMRE.

The BOEMRE have requested submission of a copy of whatever relevant video is available for the event period. No dedicated video survey is required for a barrel rupture (i.e. just be prepared to submit whatever video was obtained as normal part of the activities). BOEM has agreed we can submit any video after the project is completed.Attachment 6A

– ESR for Well A8Attachment 6B

– ESR for Well A9SECTION 7 : WASTE AND DISCHARGE INFORMATION

A. Projected Generated WastesB. Projected Ocean Discharges

C. Modeling Report

Not applicable to this Plan.SECTION 8: AIR EMISSIONS INFORMATION

A. Emissions Worksheet and Screening Questions

Screening Questions for DOCD’s Yes No

Is any calculated Complex Total (CT) Emission amount (in tons) associated with your proposed exp loration activities more than 90% of the amounts calculated using the following formulas: CT = 3400D 2/3 for CO, and CT = 33.3D for the other air pollutants (where D = distance to shore in miles)? X

Do your emission calculations include any emission redu ction measures or modified

emission factors? X

Does or will the facility complex associated with your proposed development and production activities process production from eight or more wells? X

Do you expect to encounter H 2 S at concentrations greater than 20 parts per million (ppm)? X

Do you propose to flare or vent natural gas in excess of the criteria set forth under 250.1105(a)(2) and (3)? X

Do you propose to burn produced hydrocarbon liquids? X Are your proposed development and production ac tivities located within 25 miles

from shore? X

Are your proposed development and production activities located within 200

kilometers of the Breton Wilderness Area? X

B. If you answer no to all of the above screening questions from the appropriate table, provide:

(1) Summary information regarding the peak year emissions for both Plan Emissions and Complex Total Emissions, if applicable. This information is compiled on the summary form of the two sets of worksheets. You can submit either these summary forms or use the

format below. You do not need to include the entire set of worksheets.

Air Pollutant Plan

Emission Amounts (tons) Calculated

Exemption

Amounts (tons) Calculated

Complex Total

Emission

Amounts (tons)

Carbon monoxide CO

Particulate matter (PM) Sulphur dioxide (SO 2 ) Nitrogen oxides (NO

x ) Volatile organic compounds (VOC)

(2) Contact: Tracy Albert, 504.425.4652. Tracy.albert@shell.com

### Atwood Condor

- Fuel Limit Basis

jbm

- 11/15/12

Step 1

- Determine typical operating loads The Atwood Condor has eight main engines. With no weather conditions present and no heavy currents (i.e., steady

- state conditions), the Condor utilizes roughly 30

- 40 cubic meters of fuel a day with 4 engines out of 8 total online with about 35% load on the engines.

See e

- mail provided from Atwood for basis: See attached email

Step 2

- Identify Safety Factors and Overall Load Factor Since minimal data is available for the Atwood Condor (newly built rig only recently put into operation), appropriate safety factors are utilized in conjunction with the data provided in Step 1.

Description Value Notes

PTE Fuel Use (g al/day) 62931 The Atwood Condor is equipped with 8 main engines at 6786 hp each. The PTE fuel use is then estimated using the AQR conversion factor of 0.0483 gal/hp

- hr.

Operating Load

- From Step 1 35% Note this is based on only 4 of 8 engines operating

.

Proposed Operating Load

- Across all 8 Main Engines 40% By applying the load evenly across all 8 engines, this should provide for conservative emission estimates. And additional 5% load was applied to the engine

as well.

Proposed Campaign Average Da ily Fuel Use (gal/day) 25172 Calculated Value

- PTE fuel use * Proposed Operating Load

2013 Equivalent Campaign Total MODU Fuel Use (MMgals) 6.17 Calculated Value

- Proposed Campaign Average Daily Fuel Use * Campaign Days

### Step 3

- Other Ves sel Fuel Loads

Description Value Notes

Proposed Operating Loads 50% Shell policy restricts D/P to < 50% near rig. When in standby away from rig but within 25 miles load will be < 50% (conserve fuel). When transiting through field (25 nm), trave ling at economical speeds.

2013 Equivalent Campaign Total Vessel Fuel Use (MMgals) 1.78 Sum of the product of each vessel daily fuel use and the number of campaign days

Additional Notes

1

- Operating loads are campaign specific and ma y change in future AQRs depending on the future fuel usage tracking. Fuel levels depicted in this AQR does not restrict Shell from using a different value in future AQRs.

2

- If tracked fuel usage associated with this activity indicates emissions may exceed the approved emissions, Shell will submit revised AQR

calculations.

3

- Calendar

- Year 2014 is below the BOEM exemption threshold using the 100% load conditions. As such, Shell is not including fuel usage records for Calendar

- Year 2014.

### Fr om: Michael Morrow [mmorrow@atwd.com]

Sent: Wednesday, November 14, 2012 12:35 PM

To: McMenis, Jeffrey B SEPCO-UAS/E/USOFF

Cc: Wullie Strachan; Sorgard, Eirik SIEP-PTW/DGO Subject: FW: Rig Environmental Questionnaire - Atwood Condor

Categories: AQRs

Jeff,

As discussed on the phone, see the below concerning the average fuel consume during a normal

situation on the Condor.

With no weather conditions present and no heavy currents, we are burning roughly 30-40 cubic meters of fuel a day with 4 engines out of 8 total online with about 35% load on the engines.

Let us know if you would like the values for a different situation or scenario.

Kind Regards,

MICHAEL MORROW 

### ● ● Operations Engineer

– Atwood Condor

Houston: Cell: (+1) 281- 203 -9454 Houston: Office: (+1) 281-749- 7806 mmorrow@atwd.com www.atwd.com

From: Condor RMS

Sent: Tuesday, November 13, 2 012 7:44 PM

To: Michael Morrow Subject: FW: Rig Environmental Questionnaire - Atwood Condor



### Mike,

FYI

Regards, Gordon Hynes Maintenance Supervisor

Atwood Condor

Office +1 281 749-8664

E-mail condor_rms@atwd.com

From: Condor Chief Engineer

Sent: Tuesday, November 13, 2012 6:19 PM

To: Condor RMS Subject: RE: Rig Environmental Questionnaire - Atwood Condor



### Gordon,

Looking back at the reports with no weather conditions present and no heavy currents, we are burning roughly 30-40 cubic meters of fuel a day with 4 engines online with about 35% load on the engines.

Regards,

### Matt

Atwood Condor Condor_Chief@atwd.com

www.atwd.com

From: Condor RMS

Sent: Tuesday, November 13, 2012 8:53 AM

To: Condor Chief Engineer Subject: FW: Rig Environmental Questionnaire - Atwood Condor



### Matt,

Maybe you can calculate this up tonight?

Thanks

Regards, Gordon Hynes Maintenance Supervisor

Atwood Condor

Office +1 281 749-8664

E-mail condor_rms@atwd.comCOMPANY Shell Offshore Inc.

AREA Mississippi Canyon

BLOCK 934

LEASE OCS

- G

- 7975

PLAT FORM MODU

WELL A8, A9

COMPANY

CONTACT Jeff McMenis

TELEPHONE NO. 504

- 425

- 6021

REMARKS SEPCO Env File Name

- Europa_AQR_DOCD_Condor_111612.xlsxCOMPANY A REA BLOCK LEASE PLATFORM WELL

Shell Offshore

Inc. Mississippi

Canyon 934 OCS

- G

- 7975 MODU A8, A9

Emitted Substance

Year

PM SOx NOx VOC CO

2013 58.04 33.28 1995.28 59.86 435.33

2014 23.60 13.53 811.14 24.33 176.98

Al lowable 2031.30 2031.30 2031.30 2031.30 52686.43SECTION 9 : OIL SPILL INFORMATION

A. Oil Spill Response Planning

All the proposed activities and facilities in this plan will be covered by the Regional OSRP filed by Shell Offshore Inc. (0689) in accordance with 30 CFR 250. An update to the Regional OSRP was filed with the BSEE October 26, 2010, March 15, 2011, May 31, 2011, July 6, 2011 and August 1, 2011, January, February and March 2012 and July 2012, and is pending approval. An updated OSRP Certification in accordance with 30 CFR 254.2 was accepted by the BSEE in July 2012.

Spill Response Sites:

Primary Response Equipment Location Preplanned Staging Location(s)

Venice, LA; Houma, LA; Pascagoula, MS;

Fort Jackson, LA Fourchon, LA; Pascagoula, MS; Fort Jackson, LA; Venice, LA

OSRO Information:

The names of the oil spill removal organizations (OSRO‟s) under contract include Clean Gulf Associates (CGA), Marine Spill Response Company (MSRC), Clean Caribbean America (CCA), and OSRL/EARL.

Worst Case Scenario Determination:

Drilling Production

Category Regional OSRP DOCD Regional OSRP DOCD

Type of Activity Subsea
Drilling Europa A7
Drilling Production >10

miles to shore Production >10

miles to shore

Facility Location (area/block) MC 391 MC 935 MC 807 MC 935

Facility Designation Subsea well 1 ◊ Subsea well #A7 Subsea well A A7

Distance to Nearest Shoreline (miles) 70 61 53 61

Volume
Storage tanks (total)
Flowlines (on facility)
Pipelines
Uncontrolled blowout (volume per day)

Total Volume N/A
N/A
N/A
416,414* BOPD

416,414 BOPD N/A
N/A
N/A

20 7,677** BOPD
207,677** BOPD 11,163 Bbls

100 Bbls
1,604 Bbls
446,000*** BOPD
458,867 Bbls 0 Bbls

100 Bbls

8,679 Bbls

1 9

, 250 BOPD
28,029 Bbls

Type of Oil(s)

- (crude oil, condensate,
diesel) Crude oil Crude oil Crude Oil Crude Oil

API Gravity(s) 26o 37.5 o 26o 37.5o
*24 hour rate (391,808 BOPD 30 day average)
**24 hour rate ( 134,011 BOPD 30 day average rate)
***24 hour rate (359,500 BOPD 30 day average rate)

◊ This well was reviewed and accepted by BOEM on July 10, 2012 during the drilling of the well. The 30- day average was updated in update to the OSRP July 2012

Since Shell Offshore Inc. has the capability to respond to the appropriate worst-case spill scenario included in its regional OSRP, filed with the BSEE October 26, 2010 and updated March 15, 2011, May 31, 2011, July 6, 2011 and August 1, 2011, January, February, March and July 2012 and is pending approval, and since the worst-case scenario determined for our Plan does not replace the appropriate worst-case scenario in our regional OSRP, I hereby certify that Shell Offshore Inc. has the capability to respond, to the maximum extent practicable, to a worst-case discharge, or a substantial threat of such a discharge, resulting from the activities proposed in our DOCD.B. Oil Spill Response Discussion

1. Volume of the Worst Case Discharge

Please refer to Section 2J of this plan.

2. Trajectory Analysis

Trajectories of a spill and the probability of it impacting a land segment have been projected utilizing information in the BOEMRE Oil Spill Risk Analysis Model (OSRAM) for the Central and Western Gulf of Mexico available on the BSEE website using 30 day impact. Offshore areas along the trajectory between the source and land segment contact could be impacted. The land segment contact probabilities are shown in Table 9.C.1.

Area/Block

MC 935 OCS

G 7976 Launch

Area Land Segment Contact %

> 10 Miles

from Shoreline

MC 93 5 58 GALVESTON, TX JEFFERSON, TX CAMERON, LA VERMILION, LA IBERIA, LA TERREBONNE, LA LA FOURCHE, LA JEFFERSON, LA PLAQUEMINES, LA ST. BERNARD, LA OKALOOSA, FL 1

1

3

2

1

3

3

1

8

1

1

Table 9.C.1 Probability of Land Segment Impact

3. Resource Identification

The locations identified in Table 9.C.1 are the highest probable land segments to be impacted using the BOEM Oil Spill Risk Analysis Model (OSRAM). The environmental sensitivities are identified using the appropriate National Oceanic and Atmospheric Administration (NOAA) Environmental Sensitivity Index (ESI) maps for the given land segment. ESI maps provide aconcise summary of coastal resources that are at risk if an oil spill occurs nearby. Examples of atrisk resources include biological resources (such as birds and shellfish beds), sensitive shorelines (such as marshes and tidal flats), and human-use resources (such as public beaches and parks).

In the event an oil spill occurs, ESI maps can help responders meet one of the main response objectives: reducing the environmental consequences of the spill and the cleanup efforts. Additionally, ESI maps can be used by planners to identify vulnerable locations, establish protection priorities, and identify cleanup strategies.

The following is a list of resources of special economic or environmental importance that potentially could be impacted by the WCD scenario.

Onshore/Nearshore: Plaquemines Parish is identified as the most probable impacted Parish within the Gulf of Mexico for the Worst Case Discharge. Plaquemines Parish has a total area of 2,429 square miles of which, 845 square miles of it is land and 1,584 square miles is water. Plaquemines Parish includes two National Wildlife Refuges and one Wildlife Management Area including the Breton National Wildlife Refuge, the Delta National Wildlife Refuge, and the Pass a Loutre Wildlife Management Area. Key ESI maps for Plaquemines Parish and the legend are shown in Figures 9.C.1, 9.C.2, 9.C.3, 9.C.4, and 9.C.5.Offshore: An offshore spill may require an Essential Fishing Habitat (EFH) Assessment. This

assessment would include a description of the spill, analysis of the potential adverse effects on EFH and the managed species; conclusions regarding the effects on the EFH; and proposed mitigation, if applicable.

Significant pre-planning of joint response efforts was undertaken in response to provisions of the National Contingency Plan (NCP). Area Contingency Plans (ACPs) were developed to provide a well coordinated response to oil discharges and other hazardous releases. The One Gulf Plan is specific to the Gulf of Mexico to advance the unity of policy and effort in each of the Gulf Coast ACPs. Strategies used for the response to an oil spill regarding protection of identified resources

are detailed in the One Gulf Plan and relevant Gulf Coast ACP.

4. Worst Case Discharge Response

Shell will make every effort to respond to the Worst Case Discharge as effectively as possible.

Applied Science Associates (ASA) conducted a deepwater blowout simulation to better determine subsurface and surface evaporation and dispersion rates. Below is a table outlining the applicable evaporation and dispersion quantities.

Mississippi Canyon Block 935 Calculations

(BBLS)

i. 30 Day Average WCD = 134, 011

ii. Subsurface dispersion

– 25% (Water Depth = ~3,800‟)

- 33,600

i ii. REMAINING WCD AFTER SUBSURFACE DISPERSION 101,000

iv. Surface dispersion and evaporation

– 25%

- 25,200

TOTAL REMAINING ~75,800 bbls

Table 9.D.1 Oil Remaining After Subsurface and Surface Dispersion

Shell has contracted OSROs to provide equipment, personnel, materials and support vessels as well as temporary storage equipment to be considered in order to cope with a WCD spill. Under adverse weather conditions, major response vessels and Transrec skimmers are still effective and safe in sea states of 6-8 ft. If sea conditions prohibit safe mechanical recovery efforts, then natural dispersion and airborne chemical dispersant application (visibility & wind conditions permitting) may be the only safe and viable recovery option.

MSRC OSRV 8 foot seas

V OSS System 4 foot seas Expandi Boom 6 foot seas, 20 knot winds Dispersants Winds more than 25 knots, Visibility less than 3 nautical miles, or Ceiling less than 1,000 feet.

Table 9.D.2 Operational Limitations of Response Equipment

Upon notification of the spill, Shell would request a partial or full mobilization of contracted resources, including, but not limited to, skimming vessels, oil storage vessels, dispersant aircraft, subsea dispersant, shoreline protection, wildlife protection, and containment equipment. Following is a list of the contracted resources including de-rated recovery capacity, personnel, and estimated response times (procurement, load out, travel time to the site, and deployment). The Incident Commander or designee may contact other service companies if the Unified Command deems such services necessary to the response efforts.Subsea Control and Containment: Shell, as a founding member of the MWCC, will have

access to the IRCS that can be rapidly deployed through the MWCC. The IRCS is designed to contain oil flow in the unlikely event of an underwater well blowout, and is designed, constructed, tested, and available for rapid response. Shell‟s specific containment response for

MC 935 will be addressed in Shell‟s NTL10 submission at the time the APD is submitted.

Mechanical Recovery (skimming): Response strategies include skimming utilizing available OSROs Oil Spill Response Vessels (OSRVs), Oil Spill Response Barges (OSRBs), ID Boats, and Quick Strike OSRVs. There is a combined de-rated recovery rate capability of approximately 865,993 barrels/day. Temporary storage associated with the identified skimming and temporary storage equipment equals approximately 836,574 barrels.

De

- rated Recovery Rate (bopd) Storage (bbls)

Offshore Re covery 749,000 607,750

Offshore Storage 211,500

Nearshore Recovery 116,993 17,324

Total 865,993 836,574

Table 9.D.3 Mechanical Recovery Combined De-Rated Capability

Table 9.D.4 Offshore On-Water Recovery Activation List Table 9.D.5 Offshore On-Water Storage Activation List Table 9.D.6 Nearshore On-Water Recovery Activation List

Oil Storage: The strategy for transferring, storing and disposing of oil collected in these recovery zones is to utilize two 150,000-160,000 ton (dead weight) tankers mobilized by Shell (or any other tanker immediately available). The recovered oil would be transferred to Motiva‟s Norco, LA storage and refining facility, or would be stored at Delta Commodities, Inc. Harvey, LA facility.

Aerial Surveillance: Aircraft can be mobilized to detect, monitor, and target response to oil spills. Aircraft and spotters can be mobilized within hours of an event.

Table 9.D.7 Aerial Surveillance Activation List

Aerial Dispersant: Depending on proximity to shore and water depth, dispersants may be a viable response option. If appropriate and approved, 4 to 5 sorties from three DC- 3‟s can be made within the first 12 hour operating day of the response. These aerial systems could disperse approximately 7,704 to 9,630 barrels of oil per day. Additionally, 3 to 4 sorties from the BE90 King Air and 3 to 4 sorties from the Hercules C-130A within the first 12 hour operating day of the response could disperse 4,600 to 6,100 barrels of oil per day. For continuing dispersant operations, the CCA‟s Ae rial Dispersant Delivery System (ADDS) would be mobilized. The ADDS has a dispersant spray capability of 5,000 gallons per sortie.

Table 9.D.8 Offshore Aerial Dispersant Activation List

Vessel Dispersant: Vessel dispersant application is another available response option. If appropriate, vessel spray systems can be installed on offshore vessels of opportunity using inductor nozzles (installed on fire-water monitors), skid mounted systems, or purpose-built boom arm spray systems. Vessels can apply dispersant within the first 12-24 hours of the response and continually as directed.

Table 9.D.9 Offshore Boat Spray Dispersant Activation List

Subsea Dispersant: Shell has contracted with Wild Well Control for a subsea dispersant package. Subsea dispersant application has been found to be highly effective at reducing the amount of oil reaching the surface. Additional data collection, laboratory tests and field tests will help in facilitating the optimal application rate and effectiveness numbers. For planning purposes, The system has the potential to disperse approximately 24,500 to 34,000 barrels of oil per day.Table 9.D.10 Subsea Dispersant Package Activation List

In -Situ Burning: Open-water in-situ burning (ISB) also may be used as a response strategy, depending on the circumstances of the release. ISB services may be provided by the primary OSRO contractors. If appropriate conditions exist and approvals are granted, one or multiple ISB task forces could be deployed offshore. Task forces typically consist of two to four fire teams, each with two vessels capable of towing fire boom, guide boom or tow line with either a handheld or aerially-deployed oil ignition system. At least one support/safety boat would be present during active burning operations to provide logistics, safety and monitoring support. Depending upon a number of factors, up to 4 burns per 12-hour day could be completed per ISB fire team. Most fire boom systems can be used for approximately 8-12 burns before being replaced. Fire intensity and weather will be the main determining factors for actual burns per system. Although the actual amount of oil that will be removed per burn is dependent on many factors, recent data suggests that a typical burn might eliminate approximately 750 barrels. For planning purposes and based on the above assumptions, a single task force of four fire teams with the appropriate weather and safety conditions could complete four burns per day and remove up to ~12,000 bbls/day. In-situ burning nearshore and along shorelines may be a possible option based on several conditions and with appropriate approvals, as outlined in Section 19, In-situ Burn Plan (OSRP). In-situ burning along certain types of shorelines may be used to minimize physical damage where access is limited or if it is determined that mechanical/manual removal may cause a substantial negative impact on the environment. All safety considerations will be evaluated. In addition, Shell will assess the situation and can make notification within 48 hours of the initial spill to begin ramping up fire boom production through contracted OSRO(s). There are potential limitations that need to be assessed prior to ISB operations. Some limitations include atmospheric and sea conditions; oil weathering; air quality impacts; safety of response workers; and risk of secondary fires.

Table 9.D.11 In -Situ Burn Equipment Activation List

Shoreline Protection: If the spill went unabated, shoreline impact in St. Bernard or Plaquemines Parish, LA would depend upon existing environmental conditions. Nearshore response may include the deployment of shoreline boom on beach areas, or protection and sorbent boom on vegetated areas. Strategies would be based upon surveillance and real time trajectories provided by The Response Group that depict areas of potential impact given actual sea and weather conditions. Strategies from the New Orleans, Louisiana Area Contingency Plan, The Response Group and Unified Command would be consulted to ensure that environmental and special economic resources would be correctly identified and prioritized to ensure optimal protection. The Response Group shoreline response guides depict the protection response modes applicable for oil spill clean-up operations. Each response mode is schematically represented t o show optimum deployment and operation of the equipment in areas of environmental concern. Supervisory personnel have the option to modify the deployment and operation of equipment allowing a more effective response to site-specific circumstances.

Table 9.D.12 Shoreline Protection and Wildlife Support List

Wildlife Protection: If wildlife is threatened due to a spill, the contracted OSRO‟s have resources available to Shell, which can be utilized to protect and/or rehabilitate wildlife. The resources under contract for the protection and rehabilitation of affected wildlife are in the following table:

Table 9.D.12 Shoreline Protection and Wildlife Support List

Estimated Time for Spill Response and to Contain to the Maximum Extent Possible:

According to Table 9.D.4, it is estimated that the first spill response equipment will arrive on scene in approximately 11 hrs from notification. Shell‟s estimate, based on the anticipated worst case discharge scenario, is that we can have dedicated, contracted oil spill recovery equipment with adequate response capacity based on the equipment‟s Estimated Daily Response Capacity (EDRC) on site within 22 hours which includes mechanical oil recovery and storage. Shell will continue to ramp up additional on-water mechanical recovery resources as well as deploy aerial dispersant and in-situ burn resources as needed and as approved under the supervision of the USCG Captain of the Port (COTP) and the Regional Response Team (RRT).Additionally, in the event of a sustained well control event, Shell will deploy a capping stack and

can be in position to commence capping and containment operations in an estimated 10-14 days.

This is Shell‟s best estimates with full recognition that times to respond and effectiveness can be affected by uncontrollable factors such as weather and sea state.

C. Modeling Report

Not applicable to this plan.Figure 9.C.1 Environmental Sensitivity Index Map LegendFigure 9.C.2 South Pass ESI MapFigure 9.C.3 Garden Island Pass ESI Map.

Figure 9.C.4 Pass a Loutre West ESI MapFigure 9.C.5 Main Pass ESI MapSECTION 10 : ENVIRONMENTAL MONITORING INFORMATION

A. Monitoring Systems

A rig based Acoustic Doppler Current Profiler (ADCP) is used to continuously monitor the current beneath the rig. Metocean conditions such as sea states, wind speed, ocean currents, etc. will also be continuously

monitored.

B. Incidental takes

No incidental takes are anticipated. Although marine mammals may be seen in the area, Shell does not believe that its operations proposed under this plan will result Shell implements the mitigation measures and monitors for incidental takes of protected species according to the following notices to lessees and operators from the BOEM/BSEE:

NTL 2012 -BSEE-G01 “Marine Trash and Debris Awareness and Elimination”

NTL 2012-Joint-G01 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”

NTL 2012-Joint-G02 “Implementation of Seismic Survey Mitigation Measures & Protected Species Observer Program”

C. Flower Garden Banks National Marine Sanctuary

This block is not located in the Flower Garden Banks National Marine Sanctuary.

SECTION 11 : LEASE STIPULATIONS INFORMATION

OCS -G 7975 is not a part of any Biological Sensitive Area, Shipping Fairway, or located in a Military Warning Area. It has been designated as having a high potential for containing archeological properties; see section 6 of this plan for additional information.

SECTION 12 : ENVIRONMENTAL MITIGATION MEASURE INFORMATION

A. Impacts to Marine and coastal environments

The proposed action will implement mitigation measures required by laws and regulations, including all applicable Federal & State requirements concerning air emissions, discharges to water, and solid waste disposal, as well as any additional permit requirements and Shell policies. Project activities will be conducted in accordance with the Regional Oil Spill Response Plan. The EIA in Section 18 of this plan discusses impacts and mitigation measures.

B. Incidental Takes

We do not anticipate any incidental takes related to the proposed operations. Shell implements the mitigation measures and monitors for incidental takes of protected species according to the following notices to lessees and operators from BOEM/BSEE:

NTL 201 2-BSEE-G01 “Marine Trash and Debris Awareness and Elimination”

NTL 2012-Joint-G01 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”

NTL 2012-Joint-G02 “Implementation of Seismic Survey Mitigation Measures & Protected Species Observ er Program”SECTION 13 : RELATED FACILITIES

AND OPERATIONS INFORMATION

Plans are to drill, complete and produce two new subsea wells. The new wells will be located at the existing manifold in MC 934. The oil will be commingled in the Europa manifold located in MC 934. It will then be transported 18 miles through an 8" x 12" pipe- in - pipe (pip) flowline system for processing at the existing Mars TLP in MC 807.

Only drilling, completion, and subsea tie back activities will take place at this subsea location (MC 934) using a DP Rig for drilling and tree installation and a dynamically positioned intervention vessel for jumper, HFL, SLF, and EFL installation.

The new wells will be controlled from the Mars TLP through the existing Europa electro-hydraulic

um bilicals. The umbilicals will be utilized to deliver chemical and water-based hydraulic control fluid to the subsea wells and flowlines as well as to provide for multiplexed electrical control and monitoring of the subsea system.

No expansion of the existing Mars TLP is anticipated as a result of the addition of these wells. There will be minor control system modifications to accommodate the new well within the existing Europa control

scheme.

Transportation System

Oil Export

Oil is exported from the Mars Platform via an 18", 41 mile pipeline to West Delta 143 platform. From the WD 143 platform oil is transported through a 24", 55-mile pipeline to Fourchon, La.

Gas Export

Gas is exported from the Mars Platform via a 14", 41-mile pipeline to the West Delta 143 platform. From the WD 143 platform gas is transported through a 30" pipeline to the Venice Gas Plant for processing.

Produced liquid hydrocarbons transportation vessels

Not applicable.SECTION 14 : SUPPORT VESSELS AND AIRCRAFT INFORMATION

A. General

Type Maximum Fuel Tank Storage Capacity Maximum No. In Area at Any Time Trip Frequency or

Duration

Jumper Installation Vessel 9,000 bbls. 1 1 0 days Supply Boats 9,750 bbls. 1 Twice weekly Stand by Vessel 500 bbls. 1 Daily

Crew Boats 1,040 bbls. 1 Twice Weekly Helicopters 22 bbls. 2 10 per week

B. Diesel Oil Supply Vessels

Size of Fuel Supply

Vessel Capacity of Fuel Supply

Vessel Frequency of Fuel

Transfers Route Fuel Supply Vessel Will

Take

280 foot length 100,000 gals. 1 per wee k Port Fourchon to MC 93 4

C. Drilling Fluids Transportation

According to NTL 2008-G04, this information in only required when activities are proposed in the

State of Florida.

D. Solid and Liquid Wastes Transportation

See Section 7, Table 7B.

E. Vicinity Map

See Attachment 14A for Vicinity Map.Attachment 14A

– Vicinity MapSECTION 15 : ONSHORE SUPPORT FACILITIES INFORMATION

A. General

Name Location Existing/New/Modified

C Port Port Fourchon, LA Existing

Boothville H eliport Boothville , LA Existing

The onshore support bases for water and air transportation will be the existing terminals in Boothville and Fourchon, Louisiana. The Fourchon boat facility is operated by Shell and is located on Bayou Lafourche, south of Leeville, LA approximately 3 miles from the Gulf of Mexico. The existing onshore air support base in Boothville, LA is located at 38963 Hwy. 23, Boothville,

LA 70041.

B. Support Base Construction or Expansion

This project will not cause support base construction or expansion.

C. Support Base Construction or Expansion Timetable

Based on B above, this is not applicable to this Plan.

D. Waste Disposal

See Section 7, Table 7B.

SECTION 16 : SULPHUR OPERATIONS INFORMATION

Information regarding Sulfur Operations Information is not included in this RDOCD as we are not proposing sulphur operations.SECTION 17 : COASTAL ZONE MANAGEMENT ACT (CZMA) INFORMATION

LOUISIANA

COASTAL ZONE MANAGEMENT

CONSISTENCY CERTIFICATION

EXPLORATION PLAN Type of Plan

MISSISSIPPI CANYON BLOCKS 934

Area and Blocks

OCS-G 7975

Lease Number



### The proposed activities described in detail in this Plan will comply with Louisiana's State and Local Coastal Resources Management Act of 1978, Coastal Resources Program and Coastal Area Management Enforceable Policies.

We have considered all of Louisiana's Enforceable Policies in making this certification of consistency.

SHELL OFFSHORE INC. Operator



### ____________________________________________

Sylvia Bellone Certifying Official

11/01/2012

DateSECTION 18: ENVIRONMENTAL IMPACT ANALYSIS (EIA)

REVISED DEVELOPMENT OPERATIONS COORDINATION DOCUMENT

Mississippi Canyon Block 934 (OCS-G 7975)

Offshore Louisiana

November 2012

Prepared for:

Shell Offshore Inc.

P.O. Box 61933 New Orleans, Louisiana 70161 Telephone: (504) 425 -6021

Prepared by:

CSA International, Inc.

8502 SW Kansas Avenue Stuart, Florida 34997 Telephone: (772) 219-3000Introduction

Project Summary

Shell Offshore Inc. (Shell) is submitting a Revised Development Operations Coordination Document (DOCD) for Mississippi Canyon (MC) Block 934. Shell‟s Initial DOCD for the MC 935 Unit (including MC 890, 891, 934, and 935) was approved by the Minerals Management Service (MMS, now Bureau of Ocean Energy Management [BOEM]) on July 1, 1998 (Plan Control No. N-6234). Shell submitted a Supplemental DOCD on March 23, 2010 (Plan Control No. S-7405) with a revision to the DOCD submitted February 14, 2011.

Under this DOCD, Shell plans to drill, complete, and produce from two subsea wells, A8 and A9. The surface locations are in MC 934. New wellheads, trees, and jumpers and flying leads, will be installed to facilitate production from the new wells to an existing Europa manifold located in

MC 934. Production will then be transported 18 miles (29 km) through the existing flowline system to the existing Mars A tension leg platform (TLP) in MC 807.

Only drilling, completion, and subsea tie back activities are included in this DOCD. The new wells will be controlled from the Mars TLP through a step-out of existing Europa umbilicals. No expansion of the existing Mars TLP is anticipated as a result of the addition of these wells. There will be minor control system modifications to accommodate the new wells within the existing Europa control scheme. Non-anchored vessels will be used for jumper and flying lead

installation.

The lease area is 61 miles (98 km) from the nearest shoreline, 101 miles (163 km) from the onshore support base at Port Fourchon, Louisiana, and 88 miles (142 km) from the helicopter base at Boothville, Louisiana. All miles in this Environmental Impact Analysis (EIA) are statute miles. Water depth at the wellsites is approximately 3,875 ft (1, 181 m).

The Atwood Condor

or a similar dynamically positioned semisubmersible rig will be used for drilling. Drilling of the wells is expected to commence during the second quarter of 2013. The average time to drill and complete a well will be approximately 141 days.

Purpose of the EIA

This EIA was prepared pursuant to the requirements of the Outer Continental Shelf Lands Act (OCSLA), 43 U.S.C. §§ 1331-1356, as well as regulations including 30 CFR 550.242(s) and 550.261. The EIA is a project- and site- sp ecific analysis of Shell‟s planned activities under this DOCD. On October 1, 2011, the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) reorganized into two separate agencies: BOEM and Bureau of Safety and Environmental Enforcement (BSEE). Shell understands that the BOEM will review this EIA and prepare a Site-Specific Environmental Assessment (SEA) for the project. This EIA complies with guidance provided in existing Notices to Lessees and Operators (NTLs) issued by the former MMS and BOEMRE, including NTL 2008-G04. Throughout this EIA, when existing guidance and general agency activities are referred to, “BOEM” is meant to subsume the former agencies and to represent the continuous regulatory entity now called BOEM. The former agency names (MMS and BOEMRE) are used when referring to particular historical documents published under those names. In addition, until NTLs are reissued under BOEM and/or BSEE, the EIA will refer to the former BOEMRE as BOEM when addressing NTLs issued by BOEMRE or MMS.

The EIA presents data, analyses, and conclusions to support BOEM reviews as required by the National Environmental Policy Act (NEPA) and other relevant federal laws, including theEndangered Species Act (ESA) and Marine Mammal Protection Act (MMPA). It also identifies some of the mitigation measures Shell will implement in connection with the planned activities.

The EIA is a project-specific analysis that focuses on the impacts of a specific plan. This EIA addresses the impact-producing factors (IPFs), resources, and impacts associated with the activities proposed in this DOCD. The EIA also analyzes the potential environmental impacts of the revised blowout scenario and worst case discharge (WCD) information.

The MMS, BOEMRE, and BOEM have performed numerous environmental evaluations of oil and gas activities on the Gulf of Mexico Outer Continental Shelf (OCS). Potential impacts were analyzed at a broader level in the Programmatic Environmental Impact Statement (EIS) for the OCS Oil and Gas Leasing Program (MMS, 2007a; BOEM, 2012a) and in multi-lease-sale EISs for the Western, Central, and Eastern Gulf of Mexico Planning Areas (MMS, 2001, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b).

These studies generated critical data and advanced the large body of existing knowledge on the Gulf of Mexico OCS. They analyze potential impacts on the natural environment, the socioeconomic effects of exploration and development activities, and other regional resources. Numerous technical studies address the likely trajectory of spilled oil, the effects of underwater noise on threatened and endangered species, and other IPFs. The studies inform agency decision-making on lease offerings, mitigation measures and lease stipulations, operational requirements, and permit restrictions. This substantial body of work which, in part, forms the basis for the evaluation presented here, will allow the BOEM and other regulatory agencies to evaluate Shell‟s DOCD and ensure that oil and gas exploration and development activitie s are performed in an environmentally sound manner, with minimal impacts on the environment. Shell has incorporated these comprehensive environmental analyses by reference and built on them with project- and site-specific analyses, where applicable.

OCS Regulatory Framework

The regulatory framework for OCS activities in the Gulf of Mexico was summarized by

MMS (2010). Under the OCSLA, the U.S. Department of the Interior (USDOI) is responsible for the administration of mineral exploration and development of the OCS. Within the USDOI, the BOEM and BSEE are charged with the responsibility of managing and regulating the development of OCS oil and gas resources in accordance with the provisions of the OCSLA. The BSEE offshore regulations are in 30 CFR Parts 250, 251, 252, 254, 256, 270, and 282. The BOEM offshore regulations are in 30 CFR Parts 550, 551, 552, 556, 559, 560, 570, 580, 581, 582, and 585.

In implementing its responsibilities under the OCSLA and NEPA, the BOEM consults numerous federal departments and agencies that have authority to govern and maintain ocean resources pursuant to other federal laws. Among these are the U.S. Coast Guard (USCG), U.S. Environmental Protection Agency (USEPA), U.S. Fish and Wildlife Service (USFWS), and the National Oceanic and Atmospheric Administration (NOAA) through the National Marine Fisheries Service (NMFS). Federal regulations establish consultation and coordination processes with federal, state, and local agencies (e.g., the ESA, MMPA, Coastal Zone Management Act of 1972, and the Magnuson-Stevens Fishery Conservation and Management Act).

NTLs are formal documents issued by the BOEM and BSEE that provide clarification, description, or interpretation of a regulation or standard. Table 1 lists and summarizes the NTLs applicable

to this EIA.

Oil Spill Prevention and Contingency Planning

Shell submitted an update to the Gulf of Mexico Regional Oil Spill Response Plan (OSRP) to the BSEE as a fundamental component of the planned drilling program that certifies Shell‟s capabilityto respond to the maximum extent practicable to a WCD (see DOCD Section 7 ). The OSRP demonstrates Shell‟s capabilities to rapidly and effectively manage oil spills that may result from drilling operations. Despite the extremely low likelihood of a large oil spill occurring during the project, Shell has designed its response program based upon a regional capability of responding to a range of spill volumes that increase from small operational spills to a WCD from a well blowout. Shell‟s progra m is intended to meet the response planning requirements of the relevant coastal states and federal oil spill planning regulations. The OSRP includes information regarding Shell‟s regional oil spill organization and dedicated response assets, potential sp ill risks, and local environmental sensitivities. The OSRP presents specific information on the response program that includes a description of personnel and equipment mobilization, the incident management team organization, and the strategies and tactics used to implement effective and sustained spill containment and recovery operations.

EIA Organization

The EIA is organized into Sections A through I corresponding to the information required by

NTL 2008 -G04, which provides guidance regarding information required by 30 CFR Part 550 for DOCDs. The main impact-related discussions are in Section A (Impact-Producing Factors) and

Section C (Impact Analysis).Table 1. Notices to Lessees and Operators (NTLs) that are applicable to this Environmental Impact Analysis (EIA).

NTL Title Summary

2012

- N06 Guidance to Owners and

Operators of Offshore Facilities

Seaward of the Coast Line
Concerning Regional Oil Spill
Response Plans Provides clarification, guidance, and information for preparation of
regional Oil Spill R esponse Plans. Recommends description of response strategy for worst case discharge (WCD) scenarios to ensure capability to respond to oil discharges is both efficient and

effective.

2012

- JOINT

- G01 Vessel Strike Avoidance and

Injured/Dead Protected Speci es Reporting Recommends protected species identification training;

recommends that vessel operators and crews maintain a vigilant watch for marine mammals and slow down or stop their vessel to
avoid striking protected species; and requires operators to rep ort sightings of any injured or dead protected species.

2012

- BSEE

- G01 Marine Trash and Debris

Awareness and Elimination Instructs operators to exercise caution in the handling and disposal of small items and packaging materials; requires the posting of pl acards at prominent locations on offshore vessels and
structures; and mandates a yearly marine trash and debris awareness training and certification process.

2011

- JOINT

- G01 Revisions to the List of OCS Blocks

Requiring Archaeological Resource
Surveys and Reports Provides new information on which Outer Continental Shelf (OCS)
blocks require archaeological surveys and reports and line spacing required in each block. This NTL augments NTL 2005

- G07.

2010

- N10 Statement of Compliance with

Applicable Regulation s and

Evaluation of Information
Demonstrating Adequate Spill
Response and Well Containment

Resources Informs operators using subsea blowout preventers (BOPs) or surface BOPs on floating facilities that applications for well
permits must include a statement signed by an authorized company official stating that the operator will conduct all activities
in compliance with all applicable regulations, including the increased safety measures regulations (75 FR 63346). Informs
operators that the BOEM will be evalu ating whether each operator has submitted adequate information demonstrating that it has
access to and can deploy containment resources to promptly respond to a blowout or other loss of well control.

2010

- N06 Information Requirements for

Exploration Plans , Development
and Production Plans, and
Development Operations

Coordination Documents on the

OCS Rescinds the limitations set forth in NTL 2008

- G04 regarding a blowout scenario and worst case discharge (WCD) scenario, and
provides guidance regarding the in formation required in blowout

scenario and WCD scenario descriptions.

2009

- G40 Deepwater Benthic Communities Guidance for avoiding and protecting high

- density deepwater benthic communities (including chemosynthetic and deepwater
coral communities) from da mage caused by OCS oil and gas activities in water depths greater than 984 ft (300 m). Prescribes separation distances of 2,000 ft (610 m) from each mud and cuttings discharge location and 250 ft (76 m) from all other

seafloor disturbances.

2009

- G39 Biol ogically Sensitive Underwater

Features and Areas Guidance for avoiding and protecting biologically sensitive features and areas (i.e., topographic features, pinnacles,

low

- relief live bottom areas, and other potentially sensitive biological features) when conducting OCS operations in water depths less than 984 ft (300 m) in the Gulf of Mexico.

2008

- G04 Information Requirements for

Exploration Plans and
Development Operations

Coordination Documents Guidance on the information requirements for OCS plans,

inc luding EIA requirements and information regarding compliance with the provisions of the Endangered Species Act and Marine

Mammal Protection Act.

2005

- G07 Archaeological Resource Surveys

and Reports Provides guidance on regulations regarding archaeological discoveries, specifies requirements for archaeological resource surveys and reports, and outlines options for protecting
archaeological resources.A. Impact-Producing Factors

Table 2 is a matrix of IPFs and potentially affected environmental resources adapted from

Form BOEM- 142. An “X” indicates that an IPF could reasonably be expected to affect a certain resource, and a dash (

-- ) indicates no impact or negligible impact. Where there may be an effect, an analysis is provided in Section C . Potential IPFs for the proposed activity are listed below and briefly discussed in the following subsections:

Drilling rig presence (including noise and lights); Physical disturbance to the seafloor; Air pollutant emissions; Effluent discharges; Water intake; Onshore waste disposal; Marine debris; Support vessel and helicopter traffic; and

Accidents.

A.1 Drilling Rig Presence (including noise and lights)

The wells will be drilled using the Atwood Condor or a similar dynamically positioned semisubmersible rig. The rig will be on site for an estimated 141 days per well. Non-anchored vessels will be on site for jumper and flying lead installation for brief intervals. Offshore support vessels will be used during the drilling program and there will likely be at least one vessel in the field at all times. The physical presence of a drilling rig in the ocean can attract pelagic fishes and other marine life, as discussed in Section C.5.1

.

A semisubmersible rig maintains buoyancy using ballasted, watertight pontoons located below the sea surface. The operating deck is located above the tops of passing waves. Structural columns connect the pontoons and operating deck. When the rig moves its location, the pontoons are de-ballasted so that the rig can float on the sea surface. The Atwood Condor uses thrusters to hold or adjust its position.

Drilling operations produce noise that includes strong tonal components at low frequencies, including infrasonic frequencies in at least some cases (MMS, 2000). Drilling noise from semisubmersibles is not particularly intense and is strongest at low frequencies, averaging

10 to 500 Hz (Richardson et al., 1995). From a semisubmersible, sound and vibration are transmitted to the water either through the air or the risers (MMS, 2000). Drilling rigs also maintain exterior lighting for navigational and aviation safety in accordance with federal regulations.

### Table 2. Matrix of impact-producing factors and affected environmental resources. X = potential impact; dash (

-- ) = no impact or negligible

impact.

Environmental Resources Impact

- producing Factors

Drilling Rig Presence (incl. noise & lights) Physical

Disturbance to Seafloor Air Pollutant

Emissions Effluent

Discharges Water

Intake Onshore

Waste Disposal Marine

Debris Support

Vessel/Helo Traffic Accidents

Small Fuel Spill Large Oil

Spill Physical/Chemical Environment Air quality

-- -- X

-- -- -- -- -- X (6) X (6) Water quality

-- -- -- X

-- -- -- -- X (6) X (6)

Seafloor Habitats and Biota

Soft bottom benthic communities

-- X

-- X

-- -- -- -- -- X (6) High

- density deepwater benthic communities

-- -- (4)

-- -- (4)

-- -- -- -- -- X (6) Designated topographic features

-- -- (1)

-- -- (1)

-- -- -- -- -- -- Pinnacle trend area live bottoms

-- -- (2)

-- -- (2)

-- -- -- -- -- -- Eastern Gul f live bottoms

-- -- (3)

-- -- (3)

-- -- -- -- -- -- Threatened, Endangered, and Protected Species and Critical Habitat Sperm whale (endangered) X (8)

-- -- -- -- -- -- X (8) X (6,8) X (6,8) Florida manatee (endangered)

-- -- -- -- -- -- -- X (8)

-- X (6,8)

En dangered mysticete whales

-- -- -- -- -- -- -- -- -- -- Non

- endangered marine mammals (protected) X

-- -- -- -- -- -- X X (6) X (6) Sea turtles (endangered/threatened) X (8)

-- -- -- -- -- -- X (8) X (6,8) X (6,8) Piping Plover (threatened)

-- -- -- -- -- -- -- -- -- X (6) Whooping Crane (endangered)

-- -- -- -- -- -- -- -- -- X (6) Gulf sturgeon (threatened)

-- -- -- -- -- -- -- -- -- X (6) Beach mice (endangered)

-- -- -- -- -- -- -- -- -- X (6)

Coastal and Marine Birds Marine and pelagic birds X

-- -- -- - - -- -- X X (6) X (6) Shorebirds and coastal nesting birds

-- -- -- -- -- -- -- X

-- X (6)

Fisheries Resources Pelagic communities and ichthyoplankton X

-- -- X X

-- -- -- X (6) X (6)

Essential Fish Habitat X

-- -- X X

-- -- -- X (6) X (6) Archaeological Res ources Shipwreck sites

-- -- (7)

-- -- -- -- -- -- -- X (6) Prehistoric archaeological sites

-- -- (7)

-- -- -- -- -- -- -- X (6)

Coastal Habitats and Protected Areas

Beaches

-- -- -- -- -- -- -- -- -- X (6) Wetlands and seagrass beds

-- -- -- -- -- -- -- X

-- X (6) Coastal wildlife refuges and wilderness areas

-- -- -- -- -- -- -- -- -- X (6)

Socioeconomic and Other Resources Recreational and commercial fishing X

-- -- -- -- -- -- -- X (6) X (6) Public health and safety

-- -- -- -- -- -- -- -- X (6) X (6)

E mployment and infrastructure

-- -- -- -- -- -- -- -- X (6) X (6)

Recreation and tourism

-- -- -- -- -- -- -- -- X (6) X (6)

Land use

-- -- -- -- -- -- -- -- -- X (6)

Other marine uses

-- -- -- -- -- -- -- -- -- X (6)

### Table 2 Footnotes and Applicability:

(1 ) Activities that may affect a marine sanctuary or topographic feature. Specifically, if the well, platform site, or any anchors will be on the seafloor within the following: (a) 4-mi zone of the Flower Garden Banks, or the 3-mi zone of Stetson Bank; (b) 1,000-m, 1-mi, or 3-mi zone of any topographic feature (submarine bank) protected by the Topographic Features Stipulation attached to an Outer Continental Shelf (OCS) lease; (c) Essential Fish Habitat (EFH) criteria of 500 ft from any no-activity zone; or (d) Proximity of any submarine bank (500-ft buffer zone) with relief greater than 2 m that is not protected by the Topographic Features Stipulation attached to an OCS lease.

 Not applicable. The lease is not within the given ranges (buffer zone) of any marine sanctuary, topographic feature, or no-activity zone. There are no submarine banks in the

lease block.

(2) Activities with any bottom disturbance within an OCS lease block protected through the Live Bottom (Pinnacle Trend) Stipulation attached to an OCS lease.

 The Live Bottom (Pinnacle Trend) Stipulation is not applicable to the lease area.

(3) Activities within any Eastern Gulf OCS block where seafloor habitats are protected by the Live Bottom (Low-Relief) Stipulation attached to an OCS lease.

 The Live Bottom (Low-Relief) Stipulation is not applicable to the lease area.

(4) Activities on blocks designated by the BOEM as being in water depths 300 m or greater.

 No impacts on high-density deepwater benthic communities are anticipated because no features indicative of high-density chemosynthetic communities or coral communities are located within 2,000 ft (610 m) of mud or cuttings discharge locations. A dynamically positioned semisubmersible rig will be used; therefore, seafloor disturbances due to anchoring will not

occur.
(5) Exploration or production activities where H 2 S concentrations greater than 500 ppm might be

encountered.

 DOCD Section 4 contains Shell‟s request for classification as an area absent of H 2 S.

(6) All activities that could result in an accidental spill of produced liquid hydrocarbons or diesel fuel that you determine would impact these environmental resources. If the proposed action is located a sufficient distance from a resource that no impact would occur, the EIA can note that in a sentence

or two.

 Accidental hydrocarbon spills could affect the resources marked (X) in the matrix, and impacts are analyzed in Section C

. (7) All activities that involve seafloor disturbances, including anchor emplacements, in any OCS block designated by the BOEM as having high-probability for the occurrence of shipwrecks or prehistoric sites, including such blocks that will be affected that are adjacent to the lease block in which your planned activity will occur. If the proposed activities are located a sufficient distance from a shipwreck or prehistoric site that no impact would occur, the EIA can note that in a sentence or two.

 No impacts on archaeological resources are expected. The lease area is on the list of archaeology survey blocks (BOEM, 2012c ). The geohazards and archaeological assessments indicate multiple sonar contacts in the lease area, but none are interpreted to be historic shipwrecks. The lease is beyond the 60-m depth contour, so prehistoric archaeological sites are not likely. A dy namically positioned semisubmersible rig will be used; therefore, seafloor disturbances due to anchoring will not occur.

(8) All activities that you determine might have an adverse effect on endangered or threatened marine

mammals or sea turtles or their critical habitats.

 IPFs that may affect marine mammals, sea turtles, or their critical habitats include drilling rig presence and emissions, support vessel and helicopter traffic, and accidents. See Section C

. (9) Production activities that involve transportation of produced fluids to shore using shuttle tankers or barges. Not applicable.A.2 Physical Disturbance to the Seafloor

Semisubmersible rigs like the Atwood Condor do not use anchors for holding or stabilization during drilling operations. There will be minimal disturbance to the seafloor and soft bottom communities during positioning of the wellbore and blowout preventers. Physical disturbance of the seafloor will be limited to the proximal area where the wellbore penetrates the substrate, where mud and drill cuttings will be deposited.

Non-anchored vessels will be used for jumper and flying lead installation. There will be no anchoring impacts, but placement of the subsea equipment on the seafloor will directly disturb a small area of seafloor estimated to be less than 1 ac (0.4 ha). Jumpers will be installed within MC 934 to link the A8 and A9 wells to the existing Europa manifold in MC 934.

A.3 Air Pollutant Emissions

Estimates of air pollutant emissions are provided in DOCD Section 8 . Offshore air pollutant emissions will result from operations of the drilling rig, as well as service vessels and helicopters. These emissions occur mainly from combustion of diesel fuel. Primary air pollutants typically associated with OCS activities are suspended particulate matter (PM), sulfur oxides (SO

x ), nitrogen oxides (NO

x ), volatile organic compounds (VOCs), and carbon monoxide (CO).

The Air Quality Emissions Report (see DOCD Section 8 ) prepared in accordance with BOEM requirements shows that the projected emissions from emission sources associated with the proposed activities meet the BOEM exemption criteria and are therefore exempt from further air quality review pursuant to 30 CFR 550.303(d).

A.4 Effluent Discharges

Effluent discharges from the semisubmersible rig are summarized in DOCD Section 7 . Support vessel discharges are expected to be in accordance with USCG regulations and, as applicable, the National Pollutant Discharge Elimination System (NPDES) Vessel General Permit, and therefore are not expected to cause significant impacts on water quality. Discharges from the semisubmersible rig will be in compliance with and monitored as required by the NPDES permit (GMG290000).

A synthetic-based mud (SBM) system will be used for drilling activities after the marine riser is installed that allows recirculation of the SBM fluids and cuttings. Unused or residual SBM will be collected and transported to Port Fourchon, Louisiana, for recycling. SBM cuttings will be discharged overboard via a downpipe below the water surface, after treatment that complies with the NPDES permit limitations for SBM fluid retained on cuttings. The estimated volume of SBM cuttings to be discharged is provided in DOCD Section 7

.

Well treatment fluids, completion fluids, and workover fluids may be discharged overboard via a downpipe below the water surface, after treatment that complies with NPDES permit limitations for these fluids. Other effluent discharges expected to be in accordance with the NPDES permit may include excess cement, non-contact cooling water, treated sanitary and domestic wastes, deck drainage, desalination unit brine, uncontaminated fire water, and ballast water.

A.5 Water Intake

Seawater will be drawn from several meters below the ocean surface for various services, including firewater and once-through non-contact cooling of machinery on the drilling rig ( DOCD Table 7a ).

Section 316(b) of the Clean Water Act requires NPDES permits to ensure that the location, design, construction, and capacity of cooling water intake structures reflect the best technologyavailable to minimize adverse environmental impact from impingement and entrainment of aquatic organisms. The current general NPDES Permit No. GMG290000 specifies requirements for new facilities for which construction was commenced after July 17, 2006, with a cooling water intake structure having a design intake capacity of greater than 2 million gallons of water per day, of which at least 25% is used for cooling purposes. The Atwood Condor meets the

app licability criteria for a “new, non

- fixed” facility as defined by the NPDES permit and therefore is subject to the cooling water intake permit requirements. Affected water intakes are expected to be in compliance with the design, monitoring, and recordkeeping requirements of the NPDES permit.

A.6 Onshore Waste Disposal

Wastes generated during development activities are tabulated in DOCD Secti on 7

. Non-hazardous trash and debris and non-recyclable waste will be transported to Republic BFI in Louisiana. Recyclable trash and debris will be recycled at Omega Waste Management in Patterson, Louisiana, or at ARC of New Iberia, Louisiana. Hazardous waste such as paints, solvents, and unused chemicals will be disposed of at Safety Kleen Systems, Inc. in Denton, Texas. Used oil will be sent to Omega Waste Management in Patterson, Louisiana, or ARC of New Iberia, Louisiana for recycling. At the onshore facilities, wastes will be recycled or disposed of according to applicable regulations.

A.7 Marine Debris

Trash and debris released into the marine environment can harm marine animals through entanglement and ingestion. Shell will adhere to the International Convention for the Prevention of Pollution from Ships (MARPOL 73/78) An nex V requirements, USEPA and USCG regulations, and BSEE regulations and NTLs regarding solid wastes. BSEE regulations at 30 CFR 250.300(a) and (b)(6) prohibit operators from deliberately discharging containers and other similar materials (e.g., trash and debris) into the marine environment, and 30 CFR 250.300(c) requires durable identification markings on equipment, tools and containers (especially drums), and other material. USCG and USEPA regulations require operators to become proactive in avoiding

ac cidental loss of solid waste items by developing waste management plans, posting informational placards, manifesting trash sent to shore, and using special precautions such as covering outside trash bins to prevent accidental loss of solid waste. Shell complies with NTL

2012 -BSEE-G01, which instructs operators to exercise caution in the handling and disposal of small items and packaging materials, requires the posting of placards at prominent locations on offshore vessels and structures, and mandates a yearly marine trash and debris awareness training and certification process. Shell‟s compliance with applicable laws, regulations, and NTL

2012 -BSEE-G01 will avoid significant impacts on the environment.

A.8 Support Vessel and Helicopter Traffic

Shell will use existing shorebased facilities at Port Fourchon and Boothville, Louisiana, for onshore support for water and air transportation, respectively. No terminal expansion or construction is planned at either location.

The supply base at Port Fourchon is operated by Shell and located on Bayou Lafourche, approximately 3 miles (5 km) from the Gulf of Mexico. There will likely be at least one support vessel in the field at all times during drilling activities. The supply vessels will normally move to the project area via the most direct route from the shorebase. Helicopters transporting personnel and small supplies will normally take the most direct route of travel between the helicopter base and the lease area when air traffic and weather conditions permit. Helicopters typically maintain a minimum altitude of 700 ft (213 m) while in transit offshore, 1,000 ft (305 m) over unpopulated areas or across coastlines, and 2,000 ft (610 m) over populated areas and sensitive habitats such as wildlife refuges and park properties. Additional guidelines andregulations specify that helicopters maintain an altitude of 1,000 ft (305 m) within 300 ft (91 m) of marine mammals (BOEM, 2012a).

A.9 Accidents

A.9.1 Types of Accidents Evaluated

The analysis in this EIA focuses on two types of potential accidents:

a small fuel spill, which is the most likely type of spill during OCS development activities; and an oil spill resulting from an uncontrolled blowout. A blowout resulting in a large oil spill is an extremely rare event, an d the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures detailed in DOCD Section 2j

.

The following subsections summarize assumptions about the sizes and fates of these spills as well as Shell‟s spill res ponse plans. Impacts are analyzed in Section C

.

The lease sale EIS (MMS, 2007b) analyzes three other types of accidents: chemical spills, vessel collisions, and loss of well control. These accidents are discussed briefly in Section A.9.4

.

A.9.2 Small Fuel Spill

Spill Size . According to the analysis in BOEM (2012b), the most likely type of small spill (<1,000 barrels [bbl]) as a result of OCS activities is a minor diesel fuel spill. Historically, most diesel spills have been <1 bbl, and this size is predicted to be the most common in ongoing and future OCS activities in the Western and Central Gulf of Mexico Planning Areas (BOEM, 2012b). The median size for spills <1 bbl is <0.024 bbl, and the median size for spills of 1 to 10 bbl is 3 bbl (BOEM, 2012b). For this analysis, a small diesel fuel spill of 3 bbl is assumed. Operational experience suggests that the most likely cause of such a spill would be a hose rupture resulting in the loss of the contents of a fuel transfer hose, which is less than 3 bbl.

Spill Fate . The fate of a small fuel spill in the lease area would depend on meteorological and oceanographic conditions at the time, as well as the effectiveness of spill response activities. However, given the open ocean location of the lease area, the duration of a small spill and the opportunity for impacts to occur would be very brief.

The water-soluble fractions of diesel are dominated by two- and three-ringed polycyclic aromatic hydrocarbons (PAHs), which are moderately volatile (National Research Council [NRC], 2003). The constituents of these oils are light to intermediate in molecular weight and can be readily degraded by aerobic microbial oxidation. Diesel‟s density is such that it will not sink to the seafloor. Diesel dispersed in the water column can adhere to suspended sediments, but this generally occurs only in coastal areas with high-suspended solids loads (NRC, 2003) and would not be expected to occur to any appreciable degree in offshore waters of the Gulf of Mexico. Diesel oil is readily and completely degraded by naturally occurring microbes (NOAA, 2006).

The fate of a small diesel fuel spill was estimated using NOAA‟s Automated Data Inquiry for Oil Spills 2 (ADIOS2) model. This model uses the physical properties of oils in its database to predict the rate of evaporation and dispersion over time, as well as changes in the density, viscosity, and water content of the product spilled. It is estimated that over 90% of a small diesel spill would be evaporated or naturally dispersed within 24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha) depending on sea state and weather

conditions.

The ADIOS2 results, coupled with spill trajectory information discussed below for a large spill,

in dicate that a small fuel spill would not affect coastal or shoreline resources. The lease area is 61 miles (98 km) from the nearest shoreline (Louisiana). Modeling results discussed belowindicate that a spill in the lease area would have a 4% probability of contacting the nearest Louisiana shoreline (Plaquemines Parish) within 10 days after a spill. Slicks from spills are expected to persist for relatively short periods of time ranging from minutes (<1 bbl) to hours (<10 bbl) to a few days (10 to 1,000 bbl) and rapidly spread out, evaporate and disperse into the water column. Because of the distance of these potential spills on the outer continental shelf and the lack of persistence, it is unlikely that they would make landfall prior to dissipation (BOE M, 2012b).

Spill Response . In the unlikely event of a fuel spill, response equipment and trained personnel would be available to ensure that spill effects are localized and would result only in short-term, localized environmental consequences. DOCD Section 9b provides a detailed discussion of Shell‟s response to a spill.

A.9.3 Large Oil Spill

A large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures detailed in DOCD Section 2j . Blowouts are rare events and most do not result in oil spills (BOEM, 2012a).

Spill Size . Shell has calculated a WCD for this DOCD using the requirements prescribed by

NTL 2010 -N06. The WCD is 207,700 bbl for the first day with a 30-day average of 134,011 barrels of oil per day (BOPD). The detailed analysis of this calculation can be found in

DOCD Section 2j . The WCD scenario for this DOCD, in terms of both initial and the sustained rates, has a low probability of being realized. Some of the factors that are likely to reduce rates and volumes, which are not included in the WCD calculation, include, but are not limited to, obstructions or equipment in the wellbore, well bridging, and early intervention such as

containment.

Shell has a robust system in place to prevent blowouts. Included in DOCD Sections 2j and 9b is Shell‟s response to NTL 2010 -N06, which includes descriptions of measures to prevent a blowout, reduce the likelihood of a blowout, and conduct effective and early intervention in the event of a blowout. Shell will also comply with NTL 2010 -N10 and the Final Drilling Safety Rule, which specify additional safety measures for OCS activities.

Spill Trajectory . The fate of a large oil spill in the lease area would depend on meteorological and oceanographic conditions at the time. The Oil Spill Risk Analysis (OSRA) model is a computer simulation of oil spill transport that uses realistic data for winds and currents to predict spill fate. The OSRA report by Ji et al. (2004) provides conditional contact probabilities for shoreline segments.

The results for Launch Area 58 (the launch area nearest to the lease area) are presented in

Table 3 . The model predicts no shoreline contacts within 3 days. After 10 days, three Louisian a parishes may be contacted. After 30 days, 11 counties and parishes from Texas to the Florida Panhandle may be contacted. Plaquemines Parish, Louisiana, has the greatest probability of shoreline contact, with a 4% and 8% chance within 10 and 30 days, respectively.

### Table 3. Conditional probabilities of a spill in the lease area contacting shoreline segments
(From: Ji et al., 2004). Values are conditional probabilities that a hypothetical spill in
the lease area (represented by OSRA Launch Area 58) could contact shoreline
segments within 3, 10, or 30 days.

Shoreline Segment County or Parish and State Conditional Probability of Contact a (%) 3 Days 10 Days 30 Days

C10 Galveston, TX

-- -- 1

C12 Jefferson, TX

-- -- 1

C13 Cameron, LA

-- -- 3

C14 Vermilio n, LA

-- -- 2

C15 Iberia, LA

-- -- 1

C17 Terrebonne, LA

-- 1 3

C18 Lafourche, LA

-- 2 3

C19 Jefferson, LA

-- -- 1

C20 Plaquemines, LA

-- 4 8

C21 St. Bernard, LA

-- -- 1

C28 Okaloosa, FL

-- -- 1

a Conditional probability refers to the probability of contact within the stated time period, assuming that a spill has
occurred (

-- indicates less than 0.5%).

The OSRA model does not evaluate the fate of a spill over time periods longer than 30 days, nor does it predict the fate of a release that continues over a period of weeks or months. Also as noted by Ji et al. (2004), the OSRA model does not take into account the chemical composition or biological weathering of oil spills, the spreading and splitting of oil spills, or spill response activities. The model does not assume a particular spill size but has generally been used by BOEM to evaluate contact probabilities for spills greater than 1,000 bbl.

Weathering . Following an oil spill, several physical, chemical, and biological processes, collectively called weathering, interact to change the physical and chemical properties of the oil, and thereby influence its harmful effects on marine organisms and ecosystems. The most important weathering processes include spreading, evaporation, dissolution, dispersion into the water column, formation of water- in -oil emulsions, photochemical oxidation, microbial degradation, adsorption to suspended PM, and stranding on shore or sedimentation to the seafloor (NRC, 2003).

Weathering decreases the concentration of oil and produces changes in its chemical composition, physical properties, and toxicity. The more toxic, light aromatic and aliphatic hydrocarbons are lost rapidly by evaporation and dissolution from the slick on the water surface. Evaporated hydrocarbons are degraded rapidly by sunlight. Biodegradation of oil on the water surface and in the water column by marine bacteria removes first the n-alkanes and then the light aromatics from the oil. Other petroleum components are biodegraded more slowly. Photooxidation attacks mainly the medium and high molecular weight PAHs in the oil on the water surface.

Spill Response . Shell is a founding member of the Marine Well Containment Company (MWCC) and has access to an integrated subsea well control and containment system that can be rapidly deployed through the MWCC. The MWCC is a non-profit organization that assists with the subsea containment system during a response. The near-term containment response capability will be specifically addressed in Shell‟s NTL 2010-N10 submission at the time an Application for Permit to Drill (APD) is submitted and will include equipment and services available to Shell through MWCC‟s development of near -term capability and other industry sources. Shell is a member of Clean Caribbean & Americas, Marine Spill Response Corporation, Clean Gulf Associates, and Oil Spill Response Limited, organizations that are committed to providing the resources necessary to respond to a spill as outlined in Shell‟s OSRP.Mechanical recovery capabilities are addressed in the OSRP. The mechanical recovery response equipment that could be mobilized to the spill location in normal and adverse weather conditions is included in the Offshore On-Water Recovery Activation List in the OSRP.

Chemical dispersion capabilities are also readily available from resources identified in the OSRP. Available equipment for surface and subsea application of dispersants, response times, and support resources are identified in the OSRP.

Open-water in situ

burning may also be used as a response strategy, depending on the circumstances of the release. If appropriate conditions exist and approval from the Unified Command is received, one or multiple in situ burning task forces could be deployed offshore.

See DOCD Section 9b for a detailed description of spill response measures.

A.9.4 Other Accidents Not Analyzed in Detail

The lease sale EIS (MMS, 2007b) discusses three other types of accidents: chemical spills, vessel collisions, and loss of well control. These accidents are discussed briefly below. No hydrogen sulfide (H 2 S) is expected at this site, and no other site-specific issues have been identified for this DOCD. The analysis in the lease sale EIS for these topics is incorporated by reference.

Chemical Spill . Chemicals are used in drilling and producing operations to achieve technical goals in the drilling process, improve the efficiency and safety of drilling, and protect associated equipment. Chemicals used during drilling include surfactants, bentonite clays, olefins, inorganic salts, glycols, polymers, barite, and calcium carbonate. Supplies are renewed on a regular basis by transfer in containers from supply boats (Boehm et al., 2001). In addition to chemicals used in drilling fluids, the following chemicals are likely to be used on the rig: ethylene glycol (blowout prevention control fluid, used in closed cooling loops for crane and main engines and brake coolers), cement (used to cement casing in place), solvents (used in painting operations), hydraulic fluids (used in cranes and other hydraulic rig equipment), lubricating oil and grease (used in reciprocating and electrical equipment), and sodium hypochlorite (dilute, used as laundry bleach and disinfectant).

A study of environmental risks of chemical products used in OCS activities determined that only two chemicals could potentially affect the marine environment in the concentrations typically used: zinc bromide and ammonium chloride (Boehm et al., 2001). The project addressed by this DOCD does not anticipate the use of either zinc bromide or ammonium chloride. Most other chemicals are either nontoxic or used in small quantities (BOEM, 2012b). No significant impacts are expected from chemical spills.

Vessel Collisions . As summarized in MMS (2007b) and BOEM (2012b), vessel collisions occasionally occur during routine operations. Most collision mishaps are the result of service vessels colliding with platforms or vessel collisions with pipeline risers. About 10% of these collisions have caused spills of diesel fuel or chemicals (BOEM, 2012b). Shell will comply with USCG and BOEM-mandated safety requirements to minimize the potential for vessel collisions.

Loss of Well Control . A loss of well control is the uncontrolled flow of a reservoir fluid that may result in the release of gas, condensate, oil, drilling fluids, sand, or water. Loss of well control is a broad term that includes minor to serious well control incidents, while blowouts are considered to be a subset of more serious incidents with greater risk of oil spill or human injury (MMS, 2007b). Loss of well control may result in the release of oil. Shell has a robust system in place to prevent loss of well control. Included in this DOCD is Shell‟s response to NTL 2010 -N06, which includes descriptions of measures to prevent a blowout, reduce the likelihood of a blowout, and conduct effective and early intervention in the event of a blowout. Shell will also comply withNTL 2010 -N10 and the Final Drilling Safety Rule, which specify additional safety measures for

OCS activities. See DOCD Sections 2j and 9b for further information.

H 2 S Release

. DOCD Section 4 contains Shell‟s request for classification as an area absent of

H 2 S.

B. Affected Environment

The lease area is in the north-central Gulf of Mexico, 61 miles (98 km) from the nearest shoreline, 101 miles (163 km) from the onshore support base at Port Fourchon, Louisiana, and 88 miles (142 km) from the helicopter base at Boothville, Louisiana.

Water depth in MC 934 at the proposed A8 and A9 wellsites is approximately 3,875 ft (1,181 m) and there is no evidence of seafloor or near-surface faulting, slumping, amplitudes, or fluid expulsion features within 12,000 ft (3,658 m) of both wellsites (Fugro McClelland, 1990; C&C Technologies, Inc., 2012). The side-scan sonar survey identified 36 sonar contacts within 2,000 ft (610 m) of A8 and A9. Five contacts are listed as marine avoidance zones, and 30 as simple debris or possibly barrels that are not archaeologically significant. Shell‟s procedure “Waste Barrel Avoidance and Release Response in the Mississippi Canyon Area,” which has been previously approved by MMS and BOEM [1] applies to operations that could cause a disturbance of

a seafloor barrel. Shell‟s over

‐ arching policy is to avoid barrel contact. In the unlikely case that contact is suspected or has been made with any wastes from a barrel, the plan specifies actions to be taken for the topside safety of personnel handling the equipment. The plan also outlines barrel impact reporting procedures. According to the survey results, the proposed wellsite locations appear suitable for the planned activities.

A detailed description of the regional affected environment is provided in recent EISs (MMS, 2007b; BOEM, 2012b), including meteorology, oceanography, geology, air and water quality, benthic communities, threatened and endangered species, biologically sensitive resources, archaeological resources, socioeconomic conditions, and other marine uses. These regional descriptions are based on extensive literature reviews and are incorporated by reference. General background information is presented below, and brief descriptions of each potentially affected resource are presented in Section C , including site-specific and/or new information if

available.

The local environment in the lease area is not known to be unique with respect to physical/chemical, biological, or socioeconomic conditions. Baseline environmental conditions in the lease area are expected to be consistent with the regional description of continental slope locations evaluated in recent lease sale EISs (MMS, 2001, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b,d ).

[1] MMS approval of West Boreas Supplemental Exploration Plan, MS 5231 December 16, 2008, Control No. S-07273, Mississippi Canyon Area Block 762, Lease OCS-G 07957; Mississippi Canyon Area Block 806, Lease OCS-G 07962 and BOEM approval of the Supplement to the Conceptual Deepwater Operations Plan for Mars B project, August 12, 2010, MS 5220.C. Impact Analysis

This section analyzes the potential direct and indirect impacts of routine activities and accidents; cumulative impacts are discussed in Section C.9

.

Impacts have been analyzed extensively in multi-lease-sale EISs for the Western, Central, and Eastern Gulf of Mexico Planning Areas (MMS, 2001, 2007b, 2008) as well as the final EIS for the Western and Central Gulf of Mexico Planning Areas (BOEM, 2012b). Site-specific issues are addressed in this section as appropriate.

C.1 Physical/Chemical Environment

C.1.1 Air Quality

Due to the distance from shorebased pollution sources, offshore air quality is expected to be good. The attainment status of federal OCS waters is unclassified because there is no provision in the Clean Air Act for classification of areas outside state waters (MMS, 2007b).

In general, ambient air quality on coastal counties along the Gulf of Mexico is relatively good (BOEM, 2012a). As of July 20, 2012, Louisiana, Mississippi, Alabama, and Florida coastal counties and parishes are in attainment of the National Ambient Air Quality Standards (NAAQS) for all criteria pollutants (USEPA, 2012). One coastal metropolitan area in Texas (Houston-Galveston-Brazoria) is a nonattainment area for 8-hour ozone.

Winds in the region are driven by the clockwise circulation around the Bermuda High (MMS, 2007b). The Gulf of Mexico is located to the southwest of this center of circulation, resulting in a prevailing southeasterly to southerly flow, which is conducive to transporting emissions toward shore. However, circulation is also affected by tropical cyclones (hurricanes) during summer and fall and by extratropical cyclones (cold fronts) during winter.

IPFs potentially affecting air quality are air pollutant emissions and two types of accidents: a small fuel spill and a large oil spill.

Impacts of Air Pollutant Emissions

Air pollutant emissions are the only routine IPF likely to affect air quality. Offshore air pollutant emissions will result from the operation of the drilling rig as well as helicopters and service vessels. These emissions occur mainly from combustion or burning of diesel fuel. Primary air pollutants typically associated with OCS activities are suspended PM, SO

x , NO

x , VOCs, and CO.

Due to the distance from shore, routine operations in the project area are not expected to impact air quality along the coast. As noted in the lease sale EISs (MMS, 2007b; BOEM, 2012b), emissions of air pollutants from routine activities in the Gulf of Mexico Central Planning Area are projected to have minimal impacts on onshore air quality because of the prevailing atmospheric conditions, emission heights, emission rates, and the distance of these emissions from the

coastline.

The Air Quality Emissions Report (see DOCD Section 8 ) prepared in accordance with BOEM requirements shows that the projected emissions from emission sources associated with the proposed activities meet the BOEM exemption criteria. This DOCD is therefore exempt from further air quality review pursuant to 30 CFR 550.303(d).

The Breton Wilderness Area, which is part of the Breton National Wildlife Refuge (NWR), is designated under the Clean Air Act as a Prevention of Significant Deterioration (PSD) Class I airquality area. The BOEM coordinates with the National Park Service (NPS) and the USFWS if emissions from proposed projects may affect the Breton Class I area. The lease area is approximately 100 miles ( 161 km) from the Breton Wilderness Area. Shell does not anticipate impact on the Class I area but will comply with emissions requirements as directed by the BOEM.

Impacts of a Small Fuel Spill

Potential impacts of a small spill on air quality are expected to be consistent with those analyzed and discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). The probability of a small spill would be minimized by Shell‟s preventative measures during routine operations, including fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the extent and duration of air quality impacts from a small spill would not be significant.

A small fuel spill would likely affect air quality near the spill site by introducing VOCs through evaporation. The ADIOS2 model (see Section A.9.2 ) indicates that more than 90% of a small diesel spill would be evaporated or dispersed within 24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha) depending on sea state and weather

conditions.

A small fuel spill would not affect coastal air quality because the spill would not be expected to make landfall or reach coastal waters prior to breaking up (see Section A.9.2 ).

Impacts of a Large Oil Spill

Potential impacts of a large oil spill on air quality are expected to be consistent with those analyzed and discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b).

A large oil spill would likely affect air quality by introducing VOCs through evaporation from the slick. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Additional air quality impacts could occur if response measures included in situ burning of the floating oil. Burning would generate a plume of black smoke and result in emissions of NO

x , SO

x , CO, and PM, as well as greenhouse gases.

Due to the lease area location (61 miles [98 km] from the nearest shoreline), most air quality impacts would occur in offshore waters. Depending on the spill trajectory and the effectiveness of spill response measures, coastal air quality could also be affected. Based on the OSRA modeling predictions ( Table 3 ), Plaquemines Parish, Louisiana is the coastal area most likely to

be affected.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in

DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on air quality are expected.

C.1.2 Water Quality

Deepwater areas in the Gulf of Mexico are relatively homogeneous with respect to temperature, salinity, and oxygen (MMS, 2007b). IPFs potentially affecting water quality are effluent discharges and two types of accidents: a small fuel spill and a large oil spill.Impacts of Effluent Discharges

Discharges of treated SBM cuttings will produce temporary, localized increases in suspended solids in the water column around the drilling rig. In general, turbid water can be expected to extend between a few hundred meters and several kilometers down current from the discharge point (NRC, 1983; Neff, 1987). NPDES permit limitations and requirements are expected to be met. After discharge, SBM retained on cuttings would be expected to adhere tightly to the cuttings particles and, consequently, would not produce much turbidity as the cuttings sink through the water column (Neff et al., 2000). There will be no persistent impacts on water quality in the lease area, according to analyses in the most recent Final EIS (BOEM, 2012b).

Treated sanitary and domestic wastes may have a slight transient effect on water quality in the immediate vicinity of these discharges. NPDES permit limitations and requirements are expected to be met and little or no impact on water quality is anticipated.

Deck drainage includes effluents resulting from rain, deck washings, and runoff from curbs, gutters, and drains, including drip pans in work areas. Rainwater that falls on uncontaminated areas of the drilling rig will flow overboard without treatment. However, rainwater that falls on the drilling rig deck and other areas such as chemical storage areas and places where equipment is exposed will be collected and oil and water separated to meet NPDES permit requirements. Negligible impact on water quality is anticipated.

Other discharges from the semisubmersible rig expected to be in accordance with the NPDES permit, such as desalination unit brine and uncontaminated cooling water, fire water, and ballast water, are expected to be diluted rapidly and have little or no impact on water quality.

Support vessels will discharge treated sanitary and domestic wastes. These will have a slight effect on water quality in the immediate vicinity of the discharges. Support vessel discharges are subject to USCG regulations and, as applicable, the NPDES Vessel General Permit, and therefore are not expected to cause significant impacts on water quality.

Impacts of a Small Fuel Spill

Potential impacts of a small spill on water quality are expected to be consistent with those analyzed and discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). The probability of a small spill would be minimized by Shell‟s preventative measures during routine operations, including fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the extent and duration of water quality impacts from a small spill would not be significant.

A small fuel spill in offshore waters would increase the concentrations of petroleum hydrocarbons and their degradation products. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. However, it is estimated that more than 90% of a small diesel spill would be evaporated or dispersed within 24 hours (see Section A.9.2 ). The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha) depending on sea state and weather

conditions.

Th e water-soluble fractions of diesel are dominated by two- and three-ringed PAHs, which are moderately volatile (NRC, 2003). The constituents of these oils are light to intermediate in molecular weight and can be readily degraded by aerobic microbial oxida tion. Diesel‟s density is such that it will not sink and pool on the seafloor. Diesel dispersed in the water column can adhere to suspended sediments, but this generally occurs only in coastal areas with high -suspended solid loads (NRC, 2003) and would not be expected to occur to any appreciabledegree in offshore waters of the Gulf of Mexico. Diesel oil is readily and completely degraded by naturally occurring microbes (NOAA, 2006).

A small fuel spill would not affect coastal water quality because the spill would not be expected

to make landfall or reach coastal waters prior to breaking up (see Section A.9.2 ).

Impacts of a Large Oil Spill

Potential impacts of a large oil spill on water quality are expected to be consistent with those analyzed and discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). A large spill would likely affect water quality by producing a slick on the water surface and increasing the concentrations of petroleum hydrocarbons and their degradation products. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Most of the oil would be expected to form a slick at the surface, although observations following the Macondo spill indicate that plumes of submerged oil droplets can be produced when subsea dispersants are applied at the wellhead (Camilli et al., 2010; Hazen et al., 2010; Joint Analysis Group, 2010a,b,c). A report by Kujawinski et al. (2011) indicates that chemical components of subsea dispersants used during the Macondo spill persisted for up to two months and were detectable up to

186 miles (300 km) from the wellsite at a water depth of 3,280 to 3,937 ft (1,000 to 1,200 m). While dispersants were detectable in 353 of the 4,114 total water samples, concentrations in the samples were significantly below the chronic screening level for dispersant (BOEM, 2012d).

Once oil enters the ocean, a variety of physical, chemical, and biological processes act to disperse the oil slick. These processes include spreading, evaporation of the more volatile constituents, dissolution into the water column, emulsification of small droplets, agglomeration sinking, microbial modification, photochemical modification, and biological ingestion and excretion (NRC, 2003). Marine water quality would be temporarily affected by the dissolved components and small oil droplets that do not rise to the surface or are mixed down by surface turbulence. Dispersion by currents and microbial degradation removes the oil from the water column or dilutes the constituents to background levels.

A large oil spill could result in a release of gaseous hydrocarbons that could affect water quality. During the Macondo spill, large volumes of methane (CH 4 ) were released, causing localized oxygen depletion as methanotrophic bacteria rapidly metabolized the hydrocarbons (Joye et al., 2011; Kessler et al., 2011). However, a broader study of the deepwater Gulf of Mexico found that although some stations showed slight depression of dissolved oxygen concentrations relative to climatological background values, the findings were not indicative of hypoxia (<2.0 mg/L) (Operational Science Advisory Team [OSAT], 2010). Stations revisited around the Macondo wellhead in October 2010 showed no measurable oxygen depressions (OSAT, 2010).

Due to the lease area location (61 miles [98 km] from the nearest shoreline), most water quality impacts would occur in offshore waters. Depending on the spill trajectory and the effectiveness of spill response measures, coastal water quality could be affected. Based on the OSRA modeling predictions ( Table 3 ), nearshore waters and embayments of Plaquemines Parish are the most likely coastal areas to be affected.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures detailed in

DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on water quality are expected.C.2 Seafloor Habitats and Biota

Water depth at the proposed well surface locations is approximately 3,875 ft (1,181 m). See

DOCD Section 6a for further information.

According to the BOEM (2011), existing information for the deepwater Gulf of Mexico indicates that the seafloor is composed primarily of soft sediments; hard bottom communities are rare. MC 934 is within deepwater Grid 13 where remotely operated vehicle (ROV) coverage of the seafloor is considered adequate to characterize the area (BOEM, 2011).

C.2.1 Soft Bottom Benthic Communities

Data from the Northern Gulf of Mexico Continental Slope Habitats and Benthic Ecology study (Wei, 2006; Rowe and Kennicutt, 2009) can be used to describe typical benthic communities in

the area. Table 4 summarizes data from two nearby stations in similar water depths. Sediments at these two stations were predominantly clay (53% [MT-3]; 45.5% [MT-4]) and silt (42% [MT-3]; 45.5% [MT-4]).

Table 4. Benthic community data from stations near the lease area and in similar water depths

sampled during the Northern Gulf of Mexico Continental Slope Habitats and Benthic Ecology Study (From: Wei, 2006; Rowe and Kennicutt, 2009).

Station Location

Relative to

Lease Area Water

Depth (m) Abundance

Meiofauna (individuals/m 2 ) Macroinfauna

(individuals/m 2 ) Megafauna

(individuals/ha)

MT3 15 mi NNE 987 885,995 4,924 1, 034

MT4 21 mi SE 1,401 246,058 3,262 1,548

Meiofaunal and megafaunal abundance from Rowe and Kennicutt (2009); macroinfaunal abundance from Wei (2006).

Meiofauna (animals passing through a 0.5-mm sieve but retained on a 0.062-mm sieve) densities in water depths representative of the lease area typically range from about 250,000 to 650,000 individuals/m 2 (Rowe and Kennicutt, 2009). Nematodes, nauplii, and harpacticoid copepods were the three dominant groups in the meiofauna, accounting for about

90% of total abundance.

The benthic macroinfauna is characterized by small mean individual sizes and low densities, both of which are a reflection of the meager primary production in Gulf of Mexico surface waters (Wei, 2006). Densities decrease exponentially with water depth. Based on an equation presented by Wei (2006), macroinfaunal densities in the water depth of the wellsites are expected to be about 2,800 individuals/m 2 , or lower than the values in Table 4

.

Polychaetes are typically the most abundant macroinfaunal group on the northern Gulf of Mexico continental slope, followed by amphipods, tanaids, bivalves, and isopods. Wei (2006) recognized four depth-dependent faunal zones (1 through 4), two of which are divided horizontally. The lease area is in Zone 2E, which consists of stations on the mid Texas-Louisiana Slope ranging in depth from 625 to 1,828 m (2,050 to 5,997 ft). The five most abundant species in Zone 2E were the polychaetes Litocorsa antennata

, Aricidea suecica

, Tharyx marioni

, and Paralacydoni

a paradoxa and the bivalve Heterodonta sp.

Megafaunal density from nearby stations MT-3 and MT-4 was 1,034 and 1,548 individuals/ha, respectively ( Table 4 ). Densities of 300 to 2,000 individuals/ha were reported from other stations in a similar depth range. Common megafauna included motile groups such as decapods,ophiuroids, holothurians, and demersal fishes, as well as sessile groups such as sponges and

anemones.

Bacteria are the foundation of deep-sea chemosynthetic communities (Ross et al., 2012) and are an important component in terms of biomass and cycling of organic carbon (Cruz-Kaegi, 1998). Bacterial biomass at the depth range of the lease area typically is about 1 to 2 grams of carbon per square meter (g C m

− 2 ) in the top 6 inches (15 cm) of sediments (Rowe and Kennicutt, 2009).

IPFs potentially affecting benthic communities are physical disturbance, effluent discharges (drilling mud and cuttings), and a large oil spill resulting from a well blowout at the seafloor. A small fuel spill would not affect benthic communities because the diesel fuel would float and dissipate on the sea surface.

Impacts of Physical Disturbance to the Seafloor

In water depths such as those that are encountered in the lease area, dynamically positioned semisubmersibles disturb the seafloor only around the wellbore (surface hole location) where the bottom template and blowout preventer are located. Depending upon the specific well configuration, this area is generally about 0.62 ac (0.25 ha) (BOEM, 2012b).

The areal extent of these impacts from a dynamically positioned drilling rig will be small compared to the lease area itself. Soft bottom communities are ubiquitous along the northern Gulf of Mexico continental slope (Gallaway et al., 2003; Rowe and Kennicutt, 2009). Physical disturbance to the seafloor during this project will have no significant impact on soft bottom benthic communities on a regional basis.

Impacts of Effluent Discharges

Drilling mud and cuttings are the only effluents likely to affect benthic communi ties. During initial well interval(s) before the marine riser is set, cuttings and seawater- based “spud mud” will be released at the seafloor. Excess cement slurry will also be released at the seafloor during casing installation for the riserless portion of the drilling operations. Cement slurry components typically include cement mix and some of the same chemicals used in water-based drilling mud (Boehm et al., 2001). The main impacts will be burial and smothering of benthic organisms within several meters to tens of meters around the wellbore. Soft bottom sediments disturbed by cuttings, drilling mud, and cement slurry will eventually be recolonized through larval settlement and migration from adjacent areas. Because some deep-sea biota grow and reproduce slowly, recovery may require several years.

Discharges of treated SBM cuttings from the rig may affect benthic communities, primarily within several hundred meters of the wellsites. The fate and effects of SBM cuttings have been reviewed by Neff et al. (2000), and monitoring studies have been conducted in the Gulf of Mexico by Continental Shelf Associates, Inc. (2004, 2006). In general, cuttings with adhering SBM tend to clump together and form thick cuttings piles close to the drillsite. Areas of SBM cuttings deposition may develop elevated organic carbon concentrations and anoxic conditions (Continental Shelf Associates, Inc., 2006). Where SBM cuttings accumulate and concentrations exceed approximately 1,000 mg/kg, benthic infaunal communities may be adversely affected due to both the toxicity of the base fluid and organic enrichment (with resulting anoxia) (Neff et al., 2000). Infaunal numbers may increase and diversity may decrease as opportunistic species that tolerate low oxygen and high H 2 S predominate (Continental Shelf Associates, Inc., 2006). As the base synthetic fluid is decomposed by microbes, the area will gradually return to pre-drilling conditions. Disturbed sediments will be recolonized through larval settlement and migration from adjacent areas.The areal extent of impacts from drilling discharges will be small; the typical effect radius is 1,640 ft (500 m) around each wellsite. For the two surface locations in this development-drilling program, the total impact area would be 388 ac (157 ha). In light of the proximity of the proposed wells to each other, the overall impact area could be reduced. Soft bottom communities are ubiquitous along the northern Gulf of Mexico continental slope (Gallaway, 1988; Gallaway et al., 2003; Rowe and Kennicutt, 2009). Impacts from drilling discharges during this project will have no significant impact on soft bottom benthic communities on a regional basis.

Impacts of a Large Oil Spill

The most likely effects of a subsea blowout on benthic communities would be within a few hundred meters of the wellsites. The MMS (2007b) estimates that a severe subsurface blowout could resuspend and disperse sediments within a 984-ft (300-m) radius. While coarse sediments (sands) would probably settle at a rapid rate within 1,312 ft (400 m) from the blowout site, fine sediments (silts and clays) could be resuspended for more than 30 days and dispersed over a much wider area. Previous studies characterized surface sediments in the vicinity of the site as about 50% clay and 45% silt (Rowe and Kennicutt, 2009).

Previous analyses (MMS, 2007a, 2008) concluded that oil spills would be unlikely to affect benthic communities beyond the immediate vicinity of the wellhead (i.e., due to physical impacts of a blowout) because the oil would rise quickly to the sea surface directly over the spill location. However, during the Macondo spill, subsurface plumes were reported at a water depth of about 3,600 ft (1,100 m), extending at least 22 miles (35 km) from the wellsite and persisting for more than a month (Camilli et al., 2010). The subsurface plumes apparently resulted from the use of dispersants at the wellhead (Joint Analysis Group, 2010c). Chemical components of subsea dispersants used during the Macondo spill persisted for up to two months and were detected up to 186 miles (300 km) from the wellsite at a water depth of 3,280 to 3,937 ft (1,000 to 1,200 m) (Kujawinski et al., 2011). However, estimated dispersant concentrations in the subsea plume were below levels known to be toxic to marine life. While the behavior and impacts of subsurface plumes are not well known, a subsurface plume could contact the seafloor and affect benthic communities beyond the 984-ft (300-m) radius estimated by MMS (2007a, 2008), depending on its extent, trajectory, and persistence. This contact could result in smothering and/or toxicity to benthic organisms. The affected area would be recolonized by benthic organisms over a period of months to years (NRC, 2003).

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in

DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mit igate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on soft bottom communities are expected.

C.2.2 High-Density Deepwater Benthic Communities

As defined by NTL 2009 -G40, high-density deepwater benthic communities are features or areas that could support high-density chemosynthetic communities, high-density deepwater corals, or other associated high-density hard bottom communities. Chemosynthetic communities were discovered in the central Gulf of Mexico in 1984 and have been studied extensively (MacDonald, 2002). Deepwater coral communities are also known from numerous locations in the Gulf of Mexico (Brooke and Schroeder, 2007; CSA International, Inc., 2007). These communities occur almost exclusively on authigenic carbonates created by chemosynthetic communities, and on shipwrecks. The nearest known chemosynthetic community site is located approximately 28 miles (45 km) west of the lease area in MC 969 (Brooks et al., 2009).The chemosynthetic community assessment by Fugro McClelland (1990) and C&C Technologies, Inc. (2012) did not identify features that could support high-density deepwater benthic communities within 2,000 ft (610 m) of the proposed drilling mud/cuttings discharge locations.

IPFs potentially affecting high-density deepwater benthic communities are effluent discharges (drilling mud and cuttings), and a large oil spill from a well blowout at the seafloor. A small fuel spill would not affect benthic communities because the diesel fuel would float and dissipate on

the sea surface.

Impacts of Effluent Discharges

The chemosynthetic community assessment included in this DOCD, based on the reports by Fugro McClelland (1990) and C&C Technologies, Inc. (2012), did not identify features that could support high-density deepwater benthic communities within 2,000 ft (610 m) of the proposed drilling mud/cuttings discharge locations. Monitoring programs on the Gulf of Mexico continental slope have shown that benthic impacts from drilling discharges typically are concentrated within about 1,640 ft (500 m) of the wellsites, although detectable deposits may extend beyond this distance (Continental Shelf Associates, Inc., 2004, 2006; Neff et al., 2005). If high-density deepwater communities are associated with the more distant expulsion features and mud volcanoes identified in the hazards survey, significant impacts on these communities will be avoided because of the distance from the discharge location.

Impacts of a Large Oil Spill

Previous analyses (MMS, 2007a, 2008) concluded that oil spills would be unlikely to affect benthic communities beyond the immediate vicinity of the wellhead (i.e., due to physical impacts of a blowout) because the oil would rise quickly to the sea surface directly over the spill location. However, during the Macondo spill, subsurface plumes were reported at a water depth of about 3,600 ft (1,100 m), extending at least 22 miles (35 km) from the wellsite and persisting for more than a month (Camilli et al., 2010). The subsurface plumes apparently resulted from the use of dispersants at the wellhead (Joint Analysis Group, 2010c). Chemical components of subsea dispersants used during the Macondo spill persisted for up to two months and were detectable up

to 186 miles (300 km) from the wellsite at a water depth of 3,280 to 3,937 ft (1,000 to 1,200 m) (Kujawinski et al., 2011). However, estimated dispersant concentrations in the subsea plume were below levels known to be toxic to marine life. While the behavior and impacts of subsurface plumes are not well known, a subsurface plume could have the potential to contact high -density deepwater benthic communities beyond the 984-ft (300-m) radius estimated by MMS (2007a, 2008), depending on its extent, trajectory, and persistence. Potential impacts on sensitive resources would be an integral part of the decision and approval process for the use of dispersants. The chemosynthetic community assessment by Fugro McClelland (1990) and C&C Technologies, Inc. (2012) did not identify high-density deepwater benthic communities within 2,000 ft (610 m) of the proposed drilling mud/cuttings discharge locations. Potential impacts of oil on high-density deepwater benthic communities are discussed in MMS (2007b) and BOEM (2012b ).Although chemosynthetic communities live among hydrocarbon seeps, natural seepage occurs at a relatively constant low rate compared with the potential rates of oil release from a blowout. In addition, seep organisms require unrestricted access to oxygenated water at the same time as exposure to hydrocarbon energy sources (MacDonald, 2002). Oil droplets or oiled sediment particles could come into contact with chemosynthetic organisms or deepwater corals. As discussed by MMS (2007b), impacts could include loss of habitat, biodiversity, and live coral coverage; destruction of hard substrate; change in sediment characteristics; and reduction or loss of one or more commercial and recreational fishery habitats. Sublethal effects could be long lasting and affect the resilience of coral colonies to natural disturbances (e.g., elevated water temperature and diseases) (BOEM, 2012d).

The potential for a spill to affect deepwater corals was observed during an October 2010 survey of deepwater coral habitats in water depths of 4,600 ft (1,400 m) approximately 7 miles (11 km) southwest of the Macondo wellhead. Much of the soft coral observed in a location measuring about 50 by 130 ft (15 by 40 m) was covered by a brown flocculent material (BOEMRE, 2010) with signs of stress, including varying degrees of tissue loss and excess mucous production (White et al., 2012). Researchers concluded, based on hopanoid petroleum biomarker analysis of the flocculent material, that it contained oil from the Macondo spill. The injured and dead corals were in an area where a subsea plume of oil had been documented during the spill in June 2010. The deepwater coral at this location showed signs of tissue damage that was not observed elsewhere during these surveys or in previous deepwater coral studies in the Gulf of Mexico. The team of researchers concluded that the observed coral injuries likely resulted from exposure to the subsurface oil plume (White et al., 2012). The study location is about 75 miles (120 km) northeast of the activities discussed in this EIA. There would not likely be cumulative impacts to those corals even in the unlikely event of a large spill associated with the activities discussed in

this EIA

.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in

DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Potential impacts on sensitive resources would be an integral part of the decision and approval process for the use of dispersants. Therefore, no significant spill impacts on deepwater benthic communities are expected.

C.2.3 Designated Topographic Features

The lease blocks are not within or near a designated topographic feature or a no-activity zone as identified in NTL 2009-G39. The nearest designated topographic feature stipulation block is

MC 316 , located 41 miles (66 km) north of the lease area.

There are no IPFs associated with either routine operations or accidents that could cause impacts to designated topographic features due to the distance from the lease area.C.2.4 Pinnacle Trend Area Live Bottoms

The lease area is not covered by the Live Bottom (Pinnacle Trend) Stipulation. As defined by

NTL 2009 -G39, the nearest pinnacle trend blocks are located about 104 miles (167 km) northeast of the lease area, along the shelf edge south of Alabama.

There are no IPFs associated with either routine operations or accidents that could cause impacts to pinnacle trend area live bottoms due to the distance from the lease area.

C.2.5 Eastern Gulf Live Bottoms

The lease area is not covered by the Live Bottom (Low-Relief) Stipulation, which applies to Gulf of Mexico Eastern Planning Area leases in water depths of 328 ft (100 m) or less. The nearest blocks covered by the live bottom stipulation, as defined by NTL 2009-G39, are about 140 miles (226 km) northeast of the project area.

There are no IPFs associated with either routine operations or accidents that could cause impacts

to eastern Gulf live bottom areas due to the distance from the lease area.

C.3 Threatened, Endangered, and Protected Species and Critical Habitat

This section discusses species listed as endangered or threatened under the ESA. In addition, it includes all marine mammal species in the region, which are protected under the MMPA.

Endangered or threatened species that may occur in the project area and/or along the northern

Gulf Coast are listed in Table 5 . The table also indicates the location of designated critical habitat in the Gulf of Mexico. Critical habitat is defined as (1) specific areas within the geographical area occupied by the species at the time of listing, if they contain physical or biological features essential to conservation, and those features may require special management considerations or protection; and (2) specific areas outside the geographical area occupied by the species if the agency determines that the area itself is essential for conservation. The NMFS has jurisdiction over ESA-listed cetaceans and fishes in the Gulf of Mexico. The USFWS has jurisdiction over ESA-listed birds and the Florida manatee. These two agencies share federal jurisdiction over sea turtles, with NMFS having lead responsibility at sea and USFWS on nesting

beaches.

The sperm whale and five species of sea turtles are the only endangered or threatened species likely to occur at or near the lease area. No critical habitat has been designated for these species

in the Gulf of Mexico.

Five endangered mysticete whales (blue whale, fin whale, humpback whale, North Atlantic right whale, and sei whale) also have been reported from the Gulf of Mexico but are considered rare or extralimital there (Würsig et al., 2000). No critical habitat has been designated for these species

in the Gulf of Mexico.

### Table 5. Federally listed endangered and threatened species in the lease area and along the

northern Gulf Coast.

Species Scientific Name Status Potential Presence Critical Habitat Designated in

Gulf of Mexico Lease

Area Coastal

Marine Mammals Sperm whale Physeter macrocephalus E X

-- None

Florida manatee Trichechus manatus latirostris E

-- X Florida (Peninsular)

Blue whale Balaenoptera musculus E X a

-- None

Fin whale Balaenoptera physalus E X a

-- None Humpback whale Megaptera novaeangliae E X a

-- None North Atlantic right whale Eubalaena glacialis E X a

-- None

Sei whale Balaenoptera borealis E X a

-- None

Sea Turtles Loggerhead turtle Caretta caretta T, E b X X None

Green turtle Chelonia mydas T, E c X X None

Leatherback turtle Dermochelys coriacea E X X None

Hawksbill turtle Eretmochelys imbricata E X X None Kemp‟s ridley turtle Lepidochelys k empii E X X None

Birds

Piping Plover Charadrius melodus T

-- X Coastal Texas, Louisiana, Mississippi, Alabama, and Florida (Panhandle)

Whooping Crane Grus americana E

-- X Coastal Texas (Aransas National Wildlife Refuge)

Fishes

Gulf sturgeon Acipenser oxyrinchus desotoi T

-- X Coastal Louisiana, Mississippi, Alabama, and Florida (Panhandle)

Terrestrial Mammals Beach mouse (Alabama, Choctawhatchee,

Perdido Key, St. Andrew) Peromyscus polionotus E

-- X Alabama and Florida (Panhandle) beachesAbbreviations: E = Endangered; T = Threatened.
a The blue, fin, humpback, North Atlantic right, and sei whales are rare or extralimital in the Gulf of Mexico and are
unlikely to be present in the lease area.
b The loggerhead turtle is composed of nine distinct population segments (DPS) that are considered “species.” The
only DPS that may occur in the project area (Northwest Atlantic DPS) is listed as threatened ( 76 FR 58868; September 22, 2011).
c The green sea turtle is threatened, except for the Florida breeding population, which is listed as endangered.

Coastal endangered or threatened species include the Florida manatee, Piping Plover, Whooping Crane, Gulf sturgeon, and four subspecies of beach mouse. Critical habitat has been designated for all of these species as indicated in Table 5 and discussed in individual sections.

Two other coastal species (Bald Eagle and Brown Pelican) discussed by MMS (2007b) and BOEM (2012b) are no longer listed as endangered or threatened; these species are discussed in

Section C.4.2

, Shorebirds and Coastal Nesting Birds

.

There are no other endangered animals or plants in the Gulf of Mexico that are reasonably likely to be affected by either routine or accidental events. Other species occurring at certain locations in the Gulf of Mexico such as the smalltooth sawfish ( Pristis pectinata ), elkhorn coral (

Acropora palmata ), staghorn coral ( Acropora cervicornis ), and Florida salt marsh vole ( Microtus pennsylvanicus dukecampbelli ) are remote from the lease area and highly unlikely to be

affected.



### C.3.1 Sperm Whale (Endangered)

The only endangered marine mammal likely to be present at or near the project area is the sperm whale ( Physeter macrocephalus ). Resident populations of sperm whales occur within the Gulf of Mexico. A species description is presented in a recent lease sale EIS (MMS, 2007b). Gulf of Mexico sperm whales are classified as an endangered species and a “strategic stock” (defined as a stock that may have unsustainable human-caused impacts) by NMFS (Waring et al., 2012). No critical habitat for the sperm whale has been designated in the Gulf of Mexico.

The distribution of sperm whales in the Gulf of Mexico is correlated with mesoscale physical features such as eddies associated with the Loop Current (Jochens et al., 2008). Sperm whale populations in the north-central Gulf of Mexico are present there throughout the year (Davis et al., 2000). Results of a multi-year tracking study show female sperm whales typically concentrated along the upper continental slope between the 656- and 3,280-ft (200- and 1,000-m) depth contours (Jochens et al., 2008). Male sperm whales were more variable in their movements and were documented in water depths greater than 9,843 ft (3,000 m). Generally, groups of sperm whales sighted in the Gulf of Mexico during the MMS-funded Sperm Whale Seismic Study (SWSS) consisted of mixed-sex groups comprising adult females and immatures, and groups of bachelor males. Typical group size for mixed groups was 10 individuals (Jochens et al., 2008). SWSS results show that sperm whales transit through the vicinity of the lease area. Movements of satellite-tracked individuals suggest that this area of the Gulf continental slope is within the home range of the Gulf of Mexico population (within the

95% utilization distribution) (Jochens et al., 2008).

IPFs potentially affecting sperm whales include drilling rig presence, noise, and lights; support vessel and helicopter traffic; and two types of accidents

– a small fuel spill and a large oil spill. Effluent discharges are likely to have negligible impacts on sperm whales due to rapid dispersion, the small area of ocean affected, the intermittent nature of the discharges, and the mobility of these marine mammals. Compliance with NTL 2012-BSEE-G01 will minimize the potential for marine debris-related impacts on sperm whales.Impacts of Drilling Rig Presence, Noise, and Lights

Noise from routine drilling activities has the potential to disturb sperm whales. Sperm whales appear to have good low-frequency hearing, but the available data do not indicate a consistent response to anthropogenic noise (Jochens et al., 2008). Noise associated with drilling is relatively weak in intensity, and an i ndividual animal‟s noise exposure would be transient. There are other OCS facilities and activities near the lease area, and the region as a whole has a large number of similar sources. Due to the limited scope, duration, and geographic location of drilling activities, this project would represent a small temporary contribution to the overall noise regime.

NMFS analyzed the potential for impacts of drilling-related noise on sperm whales in its Biological Opinion for the Five-Year Oil and Gas Leasing Program in the Central and Western Planning Areas of the Gulf of Mexico (NMFS, 2007). The analysis noted that drilling rigs show low sound source levels and concluded that drilling is not expected to produce amplitudes sufficient to cause hearing or behavioral effects in sperm whales; therefore, these effects are insignificant (NMFS, 2007).

Although offshore lighting and presence of drilling rigs and OCS vessels were considered potential factors affecting sperm whales, NMFS‟s 2007 Biological Opinion and recent lease sale EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b) did not identify these as IPFs for sperm whales. Therefore, no significant impacts are expected.

Impacts of Support Vessel and Helicopter Traffic

Support vessel traffic has the potential to disturb sperm whales. There is also a risk of vessel strikes, which are identified as a threat in the recovery plan for this species (NMFS, 2010a). Data concerning the frequency of vessel strikes are presented in the lease sale EIS (MMS, 2007b).

To reduce the potential for vessel strikes, the BOEM has issued NTL 2012 -JOINT-G01, which recommends protected species identification training and that vessel operators and crews maintain a vigilant watch for marine mammals and slow down or stop their vessel to avoid striking protected species, and requires operators to report sightings of any injured or dead protected species. When whales are sighted, vessel operators and crews are required to attempt to maintain a distance of 300 ft (91 m) or greater whenever possible. Vessel operators are required to reduce vessel speed to 10 knots or less, when safety permits, when mother/calf pairs, pods, or large assemblages of cetaceans are observed near an underway vessel. Compliance

with this NTL will minimize the likelihood of vessel strikes as well as reduce the chance for disturbing sperm whales.

NMFS (2007) analyzed the potential for vessel strikes and harassment of sperm whales in its Biological Opinion for the Five-Year Oil and Gas Leasing Program in the Central and Western Planning Areas of the Gulf of Mexico (NMFS, 2007). With implementation of the mitigation

measures in NTL 2012 -JOINT-G01, NMFS concluded that the likelihood of collisions between vessels and sperm whales would be reduced to insignificant levels. NMFS concluded that the observed avoidance of passing vessels by sperm whales is an advantageous response to avoid a potential threat and is not expected to result in any significant effect on migration, breathing, nursing, breeding, feeding, or sheltering to individuals, or have any consequences at the level of the population. With implementation of the vessel strike avoidance measures requirement to maintain a distance of 295 ft (90 m) from sperm whales, NMFS concluded that the potential for harassment of sperm whales would be reduced to discountable levels.

Helicopter traffic also has the potential to disturb sperm whales. Smultea et al. (2008) documented responses of sperm whales offshore Hawaii to fixed wing aircraft flying at an altitude of 800 ft (245 m). A reaction to the initial pass of the aircraft was observed during three (12%) of 24 sightings. All three reactions consisted of a hasty dive and occurred at less than 1,180 ft (360 m) lateral distance from the aircraft. Additional reactions were seen when aircraft circledcertain whales to make further observations. Based on other studies of cetacean responses to sound, the authors concluded that the observed reactions to brief overflights by the aircraft were short-term and probably of no long-term biological significance.

Helicopters maintain altitudes above 700 ft (213 m) during transit to and from the offshore working area. In the event that a whale is seen during transit, the helicopter will not approach or circle the animal(s). In addition, guidelines and regulations specify that helicopters maintain an altitude of 1,000 ft (305 m) within 300 ft (91 m) of marine mammals (BOEM, 2012a,b). Although whales may respond to helicopters (Smultea et al., 2008), NMFS (2007) and BOEM (2012a) concluded that this altitude would minimize the potential for disturbing sperm whales. Therefore, no significant impacts are expected.

Impacts of a Small Fuel Spill

Potential spill impacts on marine mammals including sperm whales are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b) and the Biological Opinion for the Five-Year Oil and Gas Leasing Program in the Central and Western Planning Areas of the Gulf of Mexico (NMFS, 2007). Oil impacts on marine mammals are discussed by Geraci and St. Au bin (1990). For this DOCD there are no unique site-specific issues with respect to spill impacts on these

animals.

The probability of a fuel spill will be minimized by Shell‟s preventative measures during routine operations including fuel transfer. In th e unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts on sperm whales. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

A small fuel spill in offshore waters would produce a slick on the water surface and increase the concentrations of petroleum hydrocarbons and their degradation products. The extent an d persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Section A.9.2 discusses the likely fate of a small fuel spill and indicates that over 90% would be evaporated or dispersed naturally within

24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha), depending on sea state and weather conditions.

Direct physical and physiological effects of exposure to diesel fuel could include skin irritation, inflammation, or necrosis; chemical burns of skin, eyes, and mucous membranes; inhalation of toxic fumes; ingestion of oil directly or via contaminated prey; and stress from the activities and noise of response vessels and aircraft (Marine Mammal Commission [MMC], 2011). However, due to the limited areal extent and short duration of water quality impacts from a small fuel spill, as well as the mobility of sperm whales, no significant impacts would be expected.

Impacts of a Large Oil Spill

Potential spill impacts on marine mammals including sperm whales are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b) and by the NMFS (2007). Oil impacts on marine mammals are discussed by Geraci and St. Aubin (1990). For this DOCD, there are no unique site-specific issues with respect to spill impacts on these animals.

Impacts of oil spills on sperm whales can include direct impacts from oil exposure, as well as indirect impacts due to response activities and materials (e.g., vessel traffic, noise, and dispersants) (MMC, 2011). Direct physical and physiological effects can include skin irritation, inflammation, or necrosis; chemical burns of skin, eyes, and mucous membranes; inhalation of toxic fumes; ingestion of oil (and dispersants) directly or via contaminated prey; and stress from the activities and noise of response vessels and aircraft. Complications of the above may lead todysfunction of immune and reproductive systems, physiological stress, declining physical condition, and death. Behavioral responses can include displacement of animals from prime habitat, disruption of social structure, changing prey availability and foraging distribution and/or patterns, changing reproductive behavior/productivity, and changing movement patterns or migration (MMC, 2011).

Studies have shown that the cetacean epidermis functions as an effective barrier to noxious substances found in petroleum (Geraci and St. Aubin, 1985). Unlike other mammals, penetration of such substances in cetacean skin is impeded by tight intercellular bridges, the vitality of the superficial cells, the thickness of the epidermis, and the lack of sweat glands and hair follicles. In addition, cetacean skin is free from hair or fur, which in other marine mammals not found in the Gulf of Mexico (e.g., pinnipeds and otters) tend to collect oil and/or tar.

In the event of a large spill, the level of vessel and aircraft activity associated with spill response could disturb sperm whales and potentially result in vessel strikes, entanglement, or other injury or stress. Response vessels would operate in accordance with NTL 2012 -JOINT-G01 to reduce the potential for striking or disturbing these animals.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on sperm whales are expected.

C.3.2 Florida Manatee (Endangered)

Most of the Gulf of Mexico manatee population is located in peninsular Florida (USFWS, 2001). Manatees regularly migrate farther west of Florida in the warmer months (Wilson, 2003) into Alabama and Louisiana coastal environs, with some individuals traveling as far west as Texas (Fertl et al., 2005). A species description is presented in a recent lease sale EIS (MMS, 2007b) and in the recovery plan for this species (USFWS, 2001).

IPFs potentially affecting manatees include support vessel and helicopter traffic and a large oil spill. A small fuel spill in the lease area would be unlikely to affect manatees, as the lease area is approximately 61 miles (98 km) from the nearest shoreline (Louisiana). As explained in

Section A.9.2 , a small fuel spill would not be expected to make landfall or reach coastal waters prior to breaking up. Compliance with NTL 2012 -BSEE-G01 will minimize the potential for marine debris-related impacts on manatees. Consistent with the analysis in BOEM (2012a), impacts of routine project-related activities on the manatee would be negligible.

Impacts of Support Vessel and Helicopter Traffic

Support vessel traffic has the potential to disturb manatees, and there is also a risk of vessel strikes, which are identified as a threat in the recovery plan for this species (USFWS, 2001).

To reduce the potential for vessel strikes, the BOEM has issued NTL 2012-JOINT-G01, which recommends protected species identification training and that vessel operators and crews maintain a vigilant watch for marine mammals and slow down or stop their vessel to avoid striking protected species, and requires operators to report sightings of any injured or dead protected species. Compliance with NTL 2012-JOINT-G01 will minimize the likelihood of vessel strikes, and no significant impacts on manatees are expected.

Helicopter traffic, if present, also has the potential to disturb manatees. Rathbun (1988) reported that manatees were disturbed more by helicopters than by fixed-wing aircraft; however, the helicopter was flown at relatively low altitudes of 66 to 525 ft (20 to 160 m). Helicopters used in support operations maintain a minimum altitude of 700 ft (213 m) while in transitoffshore, 1,000 ft (305 m) over unpopulated areas or across coastlines, and 2,000 ft (610 m) over populated areas and sensitive habitats such as wildlife refuges and park properties. In addition, guidelines and regulations specify that helicopters maintain an altitude of 1,000 ft (305 m) within 300 ft (91 m) of marine mammals (BOEM, 2012a,b). This mitigation measure will minimize the potential for disturbing manatees, and no significant impacts are expected.

Impacts of a Large Oil Spill

The OSRA results summarized in Table 3 predict that some Texas, Louisiana, and Florida shorelines could be contacted by a spill within 30 days. There is no critical habitat designated in

th ese areas, and the number of manatees potentially present is a small fraction of the population in peninsular Florida.

In the event that manatees were exposed to oil, effects could include direct impacts from oil exposure, as well as indirect impacts due to response activities and materials (e.g., vessel traffic, noise, and dispersants) (MMC, 2011). Direct physical and physiological effects can include skin irritation, inflammation, or necrosis; chemical burns of skin, eyes, and mucous membranes; inhalation of toxic fumes; ingestion of oil (and dispersants) directly or via contaminated prey (or contaminated vegetation, in the case of manatees); and stress from the activities and noise of response vessels and aircraft. Complications of the above may lead to dysfunction of immune and reproductive systems, physiological stress, declining physical condition, and death. Behavioral responses can include displacement of animals from prime habitat, disruption of social structure, changing prey availability and foraging distribution and/or patterns, changing reproductive behavior/productivity, and changing movement patterns or migration (MMC, 2011).

In the event that a large spill reached coastal waters where manatees were present, the level of vessel and aircraft activity associated with spill response could disturb manatees and potentially result in vessel strikes, entanglement, or other injury or stress. Response vessels would operate in accordance with NTL 2012-JOINT-G01 to reduce the potential for striking or disturbing these animals, and therefore no significant impacts are expected.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on manatees are expected.

C.3.3 Endangered Mysticete Whales

Five endangered mysticete whales (blue whale, fin whale, humpback whale, North Atlantic right whale, and sei whale) also have been reported from the Gulf of Mexico but are considered rare or extralimital there (Würsig et al., 2000). No critical habitat has been designated for these species

in the Gulf of Mexico.

Due to the rare occurrence of these whales in the Gulf of Mexico, it is unlikely that any endangered mysticete would come into contact with any project activities, either routine operations or accidents.

Mysticete whales were not included as affected species in the Biological Opinion for the Five-Year Oil and Gas Leasing Program in the Central and Western Planning Areas of the Gulf of Mexico (NMFS, 2007). Potential impacts analyzed in recent lease sale EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b,d) are incorporated by reference. If any of these whales were present in the area, potential impacts would be the same as those discussed below in

Section C .3.4

.C.3.4 Non-Endangered Marine Mammals (Protected)

In addition to the seven endangered species that have been cited previously, 22 additional species of marine mammals may be found in the Gulf of Mexico, including 2 species of mysticete whales, the dwarf and pygmy sperm whales, 4 species of beaked whales, and 14 species of delphinids (see DOCD Section 6h ). All marine mammals are protected species under the MMPA. The most common non-endangered cetaceans in the deepwater environment are odontocetes such as the pantropical spotted dolphin, spinner dolphin, and Clymene dolphin. A brief summary is presented below, and additional information on these groups is presented in a recent lease sale EIS (MMS, 2007b).

Mysticete whales . Two species of non-endangered mysticete whales are known from the Gulf of

Mexico: the Bryde‟s whale ( Balaenoptera edeni ) and minke whale ( Balaenoptera acutorostrata ). The Bryde‟s whale ( Balaenoptera edeni ) has been sighted most frequently along the 328-ft (100- m) isobath (Davis and Fargion, 1996; Davis et al., 2000). Most sightings have been made in the DeSoto Canyon region and off western Florida, although there have been some in the west-central portion of the northeastern Gulf. The minke whale is considered rare in the Gulf of

Me xico, with the only confirmed records coming from strandings (Würsig et al., 2000). Based on the available data, it is possible that Bryde‟s whales could occur in the lease area.

Dwarf and pygmy sperm whales . At sea, it is difficult to differentiate dwarf sperm whales ( Kogia sima

) from pygmy sperm whales ( Kogia breviceps ), and sightings are often grouped together as “ Kogia spp.” Both species have a worldwide distribution in temperate to tropical waters. In the Gulf of Mexico, both species occur primarily along the continental shelf edge and in deeper waters off the continental shelf (Mullin et al., 1991; Mullin, 2007; Waring et al., 2012). Either species could occur in the lease area.

Beaked whales . Four species of beaked whales are known from the Gulf of Mexico. They are Blainville‟s beaked whale ( Mesoplodon densirostris ), Cuvier‟s beaked whale ( Ziphius cavirostris ), Sowerby‟s beaked whale ( Mesoplodon bidens ), and Gervais‟ beaked whale ( Mesoplodon

europaeus

). Stranding records in the Gulf of Mexico s uggest that Gervais‟ beaked whale is the most common and Sowerby‟s beaked whale is extralimital. Due to the difficulties of at -sea identification, beaked whales in the Gulf of Mexico are identified either as Cuvier‟s beaked whales or are grouped into an undifferentiated complex ( Mesoplodon spp. and Ziphius

spp.). In the northern Gulf of Mexico, they are broadly distributed in waters greater than 3,281 ft (1,000 m) over lower slope and abyssal landscapes (Davis et al., 2000). Any of these species could occur in the lease area (Waring et al., 2012).

Delphinids . Fourteen species of delphinids are known from the Gulf of Mexico, including Atlantic spotted dolphin ( Stenella frontalis ), bottlenose dolphin ( Tursiops truncatus

), Clymene dolphin ( Stenella clymene

)

, false killer whale ( Pseudorca crassidens ), Fraser‟s dolphin ( Lagenodelphis

hosei ), killer whale ( Orcinus orca ), melon-headed whale ( Peponocephala electra ), pantropical spotted dolphin ( Stenella attenuata ), pygmy killer whale ( Feresa attenuata ), short- fin ned pilot whale ( Globicephala macrorhynchus ), Risso‟s dolphin ( Grampus griseus ), rough-toothed dolphin ( Steno bredanensis

), spinner dolphin ( Stenella longirostris ), and striped dolphin ( Stenella

coeruleoalba

). The most common non-endangered cetaceans in the deepwater environment are the pantropical spotted dolphin, spinner dolphin, and Clymene dolphin. However, any of these species could occur in the lease area (Waring et al., 2012).

IPFs potentially affecting non-endangered marine mammals include drilling rig presence, noise, and lights; support vessel and helicopter traffic; and two types of accidents (a small fuel spill and a large oil spill). Effluent discharges are likely to have negligible impacts on marine mammals due to rapid dispersion, the small area of ocean affected, the intermittent nature of thedischarges, and the mobility of marine mammals. Compliance with NTL 2012-BSEE-G01 will minimize the potential for marine debris -related impacts on marine mammals.

Impacts of Drilling Rig Presence, Noise, and Lights

Noise from routine drilling activities has the potential to disturb marine mammals. Most odontocetes (toothed whales and dolphins) use higher frequency sounds than those produced by OCS drilling activities (Richardson et al., 1995). Noise associated with drilling is relatively weak in intensity, and an individual animal‟s noise exposure would be transient. There are other OCS facilities and activities near the lease area, and the region as a whole has a large number of similar sources. Due to the limited scope, duration, and geographic extent of drilling activities, this project would represent a small temporary contribution to the overall noise regime, and any short-term impacts are not expected to be biologically significant to marine mammal populations.

Drilling rig lighting and presence are not identified as IPFs for marine mammals in recent lease sale EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b,d). Therefore, no significant impacts are expected.

Impacts of Support Vessel and Helicopter Traffic

Support vessel traffic has the potential to disturb marine mammals, and there is also a risk of vessel strikes. Data concerning the frequency of vessel strikes are presented in the lease sale EIS (MMS, 2007b). To reduce the potential for vessel strikes, the BOEM and BSEE have issued

NTL 2012 -JOINT-G01, which recommends protected species identification training and that vessel operators and crews maintain a vigilant watch for marine mammals and slow down or stop their vessel to avoid striking protected species, and requires operators to report sightings of any injured or dead protected species. Vessel operators and crews are required to attempt to maintain a distance of 300 ft (91 m) or greater when whales are sighted and 150 ft (45 m) when small cetaceans are sighted. When cetaceans are sighted while a vessel is underway, vessels must attempt to remain parallel to the animal‟s course and avoid excessive speed or abrupt changes in direction until the cetacean has left the area. Vessel operators are required to reduce vessel speed to 10 knots or less when mother/calf pairs, pods, or large assemblages of cetaceans are observed near an underway vessel, when safety permits. Compliance with this NTL will

minimize the likelihood of vessel str ikes as well as reduce the chance for disturbing marine mammals, and therefore no significant impacts are expected.

Aircraft traffic also has the potential to disturb marine mammals (Würsig et al., 1998). However, while flying offshore, helicopters maintain altitudes above 700 ft (213 m) during transit to and from the working area. In addition, guidelines and regulations specify that helicopters maintain an altitude of 1,000 ft (305 m) within 300 ft (91 m) of marine mammals (BOEM, 2012a,b). This altitude will minimize the potential for disturbing marine mammals, and no significant impacts are expected (BOEM, 2012a,b).

Impacts of a Small Fuel Spill

Potential spill impacts on marine mammals are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b ), and oil impacts on marine mammals in general are discussed by Geraci and St. Aubin (1990). For this DOCD, there are no unique site-specific issues with respect to spill impacts on these animals.

The probability of a fuel spill will be minimized b y Shell‟s preventative measures during fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP is expected to mitigate and reduce the potential for impacts on marine mammals. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.A small fuel spill in offshore waters would produce a slick on the water surface and increase the concentrations of petroleum hydrocarbons and their degradation products. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Section A.9.2 discusses the likely fate of a small fuel spill and indicates that over 90% would be evaporated or dispersed naturally within

24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha), depending on sea state and weather conditions.

Direct physical and physiological effects of exposure to diesel fuel could include skin irritation, inflammation, or necrosis; chemical burns of skin, eyes, and mucous membranes; inhalation of toxic fumes; ingestion of oil directly or via contaminated prey; and stress from the activities and noise of response vessels and aircraft (MMC, 2011). However, due to the limited areal extent and short duration of water quality impacts from a small fuel spill, as well as the mobility of marine mammals, no significant impacts would be expected.

Impacts of a Large Oil Spill

Potential spill impacts on marine mammals are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b) and by Geraci and St. Aubin (1990). For this DOCD, there are no unique site-specific issues.

Impacts of oil spills on marine mammals can include direct impacts from oil exposure, as well as indirect impacts due to response activities and materials (e.g., vessel traffic, noise, and dispersants) (MMC, 2011). Direct physical and physiological effects can include skin irritation, inflammation, or necrosis; chemical burns of skin, eyes, and mucous membranes; inhalation of toxic fumes; ingestion of oil (and dispersants) directly or via contaminated prey (or contaminated vegetation, in the case of manatees); and stress from the activities and noise of response vessels and aircraft. Complications of the above may lead to dysfunction of immune and reproductive systems, physiological stress, declining physical condition, and death. Behavioral responses can include displacement of animals from prime habitat, disruption of social structure, changing prey availability and foraging distribution and/or patterns, changing reproductive behavior/productivity, and changing movement patterns or migration (MMC, 2011).

In the event of a large spill, the level of vessel and aircraft activity associated with spill response could disturb marine mammals and potentially result in vessel strikes, entanglement, or other injury or stress. Response vessels would operate in accordance with NTL 2012 -JOINT-G01 to reduce the potential for striking or disturbing these animals, and therefore no significant impacts are expected. A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention

measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of

Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on marine mammals are expected.

C.3.5 Sea Turtles (Endangered/Threatened)

As listed in DOCD Section 6h , five species of endangered or threatened sea turtles may be found near the lease area. Endangered species are the leatherback ( Dermochelys coriacea ), Kemp's ridley ( Lepidochelys kempii ), and hawksbill ( Eretmochelys imbricata ) turtles. The distinct population segment (DPS) of loggerhead turtle ( Caretta caretta ) that occurs in the Gulf of Mexico is listed as threatened, although other DPSs are endangered. The green turtle ( Chelonia mydas ) is listed as threatened, except for the Florida breeding population, which is listed as endangered. Species descriptions are presented in a recent lease sale EIS (MMS, 2007b).

Leatherbacks and loggerheads are the most likely species to be present near the lease area as adults. Green, hawksbill, and Kemp‟s ridley turtles are typically inner shelf and nearshorespecies, unlikely to occur near the lease area as adults. Hatchlings or juveniles of any of the sea turtles may be present in deepwater areas, including the lease area, where they may be

associated with Sargassum and other flotsam.

All five sea turtle species in the Gulf of Mexico are migratory and use different marine habitats according to their life stage. These habitats include high-energy beaches for nesting females and emerging hatchlings and pelagic convergence zones for hatchling and juvenile turtles. As adults, green, hawksbill, and loggerhead turtles forage primarily in shallow, benthic habitats. Leatherbacks are the most pelagic of the sea turtles, feeding primarily on jellyfish.

Sea turtle nesting in the northern Gulf of Mexico can be summarized by species as follows:

Loggerhead turtles

–

Loggerheads nest in significant numbers along the Florida Panhandle and, to a lesser extent, from Texas through Alabama (MMS, 2007b). The nearest significant nesting area of loggerhead turtles is found in Louisiana, on beaches within the Breton NWR;

Green and leatherback turtles

– Green and leatherback turtles infrequently nest on Florida Panhandle beaches (Florida Fish and Wildlife Conservation Commission, 2011); Kemp‟s ridley turtles – The main Kemp‟s ridley nesting site is Rancho Nuevo beach, T amaulipas, Mexico (NMFS et al., 2011). Approximately 200 Kemp‟s ridley turtles nested on Texas beaches in 2009 (Sea Turtle Restoration Project, 2011). Kemp‟s ridley turtles typically do not nest anywhere near the project area, although there have been oc casional reports of Kemp‟s ridleys nesting in Alabama (Share the Beach, 2010); and

Hawksbill turtles

–

Hawksbills typically do not nest anywhere near the project area.

IPFs potentially affecting sea turtles include drilling rig presence, noise, and lights; support vessel and helicopter traffic; and two types of accidents - a small fuel spill and a large oil spill. Effluent discharges are likely to have negligible impacts on sea turtles due to rapid dispersion, the small area of ocean affected, and the intermittent nature of the discharges. Compliance with

NTL 2012 -BSEE-G01 will minimize the potential for marine debris-related impacts on sea turtles.

Impacts of Drilling Rig Presence, Noise, and Lights

Offshore drilling activities produce a broad array of sounds at frequencies and intensities that may be detected by sea turtles (Geraci and St. Aubin, 1987). Potential impacts may include behavioral disruption and temporary or permanent displacement from the area near the sound source. Certain sea turtles, especially loggerheads, may be attracted to offshore structures (Lohoefener et al., 1990) and, thus, may be more susceptible to impacts from sounds produced during routine operations. Helicopters and service vessels may also affect sea turtles due to machinery noise and/or visual disturbances. The most likely impacts would be short-term behavioral changes such as diving and evasive swimming, disruption of activities, or departure from the area. Due to the limited scope, duration, and geographic extent of drilling activities, these short-term impacts are not expected to be biologically significant to sea turtle populations.

Artificial lighting can disrupt the nocturnal orientation of sea turtle hatchlings (Witherington, 1997; Tuxbury and Salmon, 2005). However, hatchlings may rely less on light cues when they are offshore than when they are emerging on the beach (Salmon and Wyneken, 1990). NMFS (2007) concluded that the effects of lighting from offshore structures on sea turtles are insignificant.

Impacts of Support Vessel and Helicopter Traffic

Support vessel traffic has the potential to disturb sea turtles, and there is also a risk of vessel strikes. Data show that vessel traffic is one cause of sea turtle mortality in the Gulf of Mexico (Lutcavage et al., 1997). While adult sea turtles are visible at the surface during the day and in clear weather, they can be difficult to spot from a moving vessel when resting below the watersurface, during nighttime, or during periods of inclement weather. To reduce the potential for vessel strikes, the BOEM and BSEE have issued NTL 2012 -JOINT-G01, which recommends protected species identification training and that vessel operators and crews maintain a vigilant watch for sea turtles and slow down or stop their vessel to avoid striking protected species, and requires operators to report sightings of any injured or dead protected species. When sea turtles are sighted, vessel operators and crews are required to attempt to maintain a distance of 150 ft (45 m) or greater whenever possible. Compliance with this NTL will minimize the likelihood of vessel strikes as well as reduce the chance for disturbing sea turtles (NMFS, 2007).

Helicopter traffic also has the potential to disturb sea turtles. However, while flying offshore, helicopters maintain altitudes above 700 ft (213 m) during transit to and from the working area. This altitude will minimize the potential for disturbing sea turtles, and no significant impacts are expected.

Impacts of a Small Fuel Spill

Potential spill impacts on sea turtles are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b) and by the NMFS (2007) in its Biological Opinion for the Five-Year Oil and Gas Leasing Program in the Central and Western Planning Areas of the Gulf of Mexico. For this DOCD, there are no unique site-specific issues with respect to spill impacts on these

animals.

The probability of a fuel spill will be minimized by Shell‟s preventative measures during fuel transfer. In the unlikely event of a spill, implem entation of Shell‟s OSRP is expected to mitigate and reduce the potential for impacts on sea turtles. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

A small fuel spill in offshore waters would produce a slick on the water surface and increase the concentrations of petroleum hydrocarbons and their degradation products. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Section A.9.2 discusses the likely fate of a small fuel spill and indicates that over 90% would be evaporated or dispersed naturally within

24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha), depending on sea state and weather conditions.

Direct physical and physiological effects of exposure to diesel fuel could include skin irritation, inflammation, or necrosis; chemical burns of skin, eyes, and mucous membranes; inhalation of toxic fumes; ingestion of oil directly or via contaminated prey; and stress from the activities and noise of response vessels and aircraft (MMS, 2007b; NMFS, 2010b; BOEMRE, 2011; BOEM, 2012b). However, due to the limited areal extent and short duration of water quality impacts from a small fuel spill, no significant impacts would be expected.

A small fuel spill in the lease area would be unlikely to affect sea turtle nesting beaches because the lease area is 61 miles (98 km) from the nearest shoreline (Louisiana). As explained in

Section A.9.2 , a small fuel spill would not be expected to make landfall or reach coastal waters prior to breaking up.

Impacts of a Large Oil Spill

Impacts of oil spills on sea turtles can include direct impacts from oil exposure, as well as indirect impacts due to response activities and materials (e.g., vessel traffic, noise, and dispersants). Direct physical and physiological effects can include skin irritation, inflammation, or necrosis; chemical burns of skin, eyes, and mucous membranes; inhalation of toxic fumes and smoke (e.g.,

from in situ burning of oil); ingestion of oil (and dispersants) directly or via contaminated food;and stress from the activities and noise of response vessels and aircraft. Complications of the above may lead to dysfunction of immune and reproductive systems, physiological stress, declining physical condition, and death. Behavioral responses can include displacement of animals from prime habitat, disruption of social structure, changing food availability and foraging distribution and/or patterns, changing reproductive behavior/productivity, and changing
movement patterns or migration (MMS, 2007b; NMF S, 2010c). In the unlikely event of a spill, implementation of Shell‟s OSRP is expected to mitigate and reduce the potential for these types
of impacts on sea turtles. DOCD Section 9b provides detail on spill response measures.

Studies of oil effects on loggerheads in a controlled setting (Lutcavage et al., 1995) suggest that
sea turtles show no avoidance behavior when they encounter an oil slick, and any sea turtle in an affected area would be expected to be exposed. Sea turtles‟ diving behaviors also p ut them at risk. Sea turtles rapidly inhale a large volume of air before diving and continually resurface over time, which may result in repeated exposure to volatile vapors and oiling (NMFS, 2007).

The OSRA results summarized in Table 3 predict that some shorelines that support sea turtle nesting could be contacted within 10 to 30 days. The nearest nesting area of loggerhead turtles is found in St. Bernard Parish, Louisiana, on beaches within the Breton NWR. This area has a contact probability of 1% after 30 days.

Spilled oil reaching sea turtle nesting beaches could have effects on nesting sea turtles and egg development (NMFS, 2007). An oiled beach could affect nest site selection or result in no nesting at all (e.g., false crawls). Upon hatching and successfully reaching the water, hatchlings are subject to the same types of oil spill exposure hazards as adults. Hatchlings that contact oil residues while crossing a beach can exhibit a range of effects, from acute toxicity to impaired movement and normal bodily functions (NMFS, 2007).

In the event of a large spill, the level of vessel and aircraft activity associated with spill response could disturb sea turtles and potentially result in vessel strikes, entanglement, or other injury or stress. Response vessels would operate in accordance with NTL 2012 -JOINT-G01 to reduce the potential for striking or disturbing these animals, and therefore no significant impacts are expected.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on sea turtles are expected.

C.3.6 Piping Plover (Threatened)

The Piping Plover ( Charadrius melodus ) is a migratory shorebird that overwinters along the southeastern U.S. and Gulf of Mexico coasts. This threatened species is in decline as a result of hunting, habitat loss and modification, predation, and disease (USFWS, 2003). Critical overwintering habitat has been designated, including beaches in Texas, Louisiana, Mississippi, Alabama, and Florida ( Figure 1 ). Piping Plovers inhabit coastal sandy beaches and mudflats, feeding by probing for invertebrates at or just below the surface. They use beaches adjacent to foraging areas for roosting and preening (USFWS, 2010a). A species description is presented in a recent lease sale EIS (MMS, 2007b).A large oil spill is the only IPF potentially affecting Piping Plovers. There are no IPFs associated with routine project activities that could affect these birds. A small fuel spill in the lease area would be unlikely to affect Piping Plovers because a small fuel spill would not be expected to make landfall or reach coastal waters prior to breaking up (see explanation in Section A.9.2 ).

### Figure 1. Location of selected environmental features in relation to the lease area.Impacts of a Large Oil Spill

The lease area is 69 miles (112 km) from the nearest shoreline inhabited by Piping Plovers. The

OSRA results summarized in Table 3 predict that Texas, Louisiana, and Florida shorelines designated as critical habitat for the wintering Piping Plover could be contacted by a spill within

30 days. Plaquemines Parish, Louisiana, which has the highest probability of contact for the

10 -day and 30-day intervals (4% and 8%, respectively)

, includes Piping Plover critical habitat.

Plovers could become externally oiled while foraging on oiled shores or be exposed internally through ingestion of oiled intertidal sediments and prey (MMS, 2007b). Plovers congregate and feed along tidally exposed banks and shorelines, following the tide out and foraging at the water‟s edge. It is possible that some deaths of Piping Plovers could occur, especially if spills occur during winter months when plovers are most common along the coastal Gulf or if spills contacted critical habitat. Impacts could also occur from vehicular traffic on beaches and other activities associated with spill cleanup. Shell has extensive resources available to protect and rehabilitate wildlife in the event of a spill reaching the shoreline, as detailed in the OSRP.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In th e unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on Piping Plovers are expected.

C.3.7 Whooping Crane (Endangered)

The Whooping Crane ( Grus americana ) is an omnivorous wading bird and an endangered species. There are three wild populations in North America (National Wildlife Federation, 2012). One population winters along the Texas coast at Aransas NWR and summers at Wood Buffalo National Park in Canada. This population represents the majority of the world‟s population of free-ranging Whooping Cranes and reached a record population of 278 at Aransas/Wood Buffalo National Park in August 2011 (Whooping Crane Eastern Partnership [WCEP], 2012). A non-migrating population has been re-introduced in central Florida, and another re-introduced population summers in Wisconsin and migrates to the southeastern U.S. for the winter. Whooping Cranes breed, migrate, winter, and forage in a variety of habitats, including coastal marshes and estuaries, inland marshes, lakes, ponds, wet meadows and rivers, and agricultural fields (USFWS, 2007). About 22,240 ac (9,000 ha) of salt flats on Aransas NWR and adjacent islands comprise the principal wintering grounds of the Whooping Crane. Aransas NWR is designated as critical habitat for the species ( Figure 1 ). A species description is presented in recent lease sale EISs (MMS, 2007b, 2012b).

A large oil spill is the only IPF that could potentially affect Whooping Cranes due to the distance

from Aransas NWR.

Impacts of a Large Oil Spill

A large oil spill is has a low probability of affecting Whooping Cranes because the lease area is approximately 427 miles (687 km) from its critical habitat (Aransas NWR, Texas) and the likelihood of contact with the habitat is extremely low (BOEM, 2012b).

In the event of oil exposure, Whooping Cranes could become externally oiled while foraging in oiled areas or internally exposed to oil through ingestion of contaminated shellfish, frogs, and fishes. It is possible that some death of Whooping Cranes could occur. Shell has extensive resources available to protect and rehabilitate wildlife in the event of a spill reaching the shoreline, as detailed in the OSRP.A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spil l, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on Whooping Cranes are expected.

C.3.8 Gulf Sturgeon (Threatened)

The Gulf sturgeon (

Acipenser oxyrinchus desotoi ) is a threatened fish species that inhabits major rivers and inner shelf waters from the Mississippi River to the Suwannee River, Florida (Barkuloo, 1988; Wakeford, 2001). An anadromous fish that migrates from the sea upstream into coastal rivers to spawn in freshwater, it historically ranged from the Mississippi River to Charlotte Harbor, Florida (Wakeford, 2001). Today, this range has contracted to encompass major rivers and inner shelf waters from the Mississippi River to the Suwannee River, Florida. Populations have been depleted or even extirpated throughout this range by fishing, shoreline development, dam construction, water quality changes, and other factors (Barkuloo, 1988; Wakeford, 2001). These declines prompted the listing of the Gulf sturgeon as a threatened species in 1991. The best known populations occur in the Apalachicola and Suwannee Rivers in Florida (Carr, 1996; Sulak and Clugston, 1998), the Choctawhatchee River in Alabama (Fox et al., 2000), and the Pearl River in Mississippi/Louisiana (Morrow et al., 1998). Critical habitat in the Gulf extends from Lake Borgne, Louisiana (St. Bernard Parish), to Suwannee Sound, Florida (Levy County) (NMFS, 2010d) ( Figure 1 ). A species description is presented in a recent lease sale EIS (MMS, 2007b) and in the recovery plan for this species (USFWS and Gulf States Marine Fisheries Commission, 1995).

A large oil spill is the only IPF potentially affecting Gulf sturgeon. There are no IPFs associated with routine project activities that could affect this species. A small fuel spill in the lease area would be unlikely to affect Gulf sturgeon because a small fuel spill would not be expected to make landfall or reach coastal waters prior to breaking up (see explanation in Section A.9.2 ).

Impacts of a Large Oil Spill

Potential spill impacts on Gulf sturgeon are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b) and by the NMFS (2007) in its Biological Opinion for the Five-Year Oil and Gas Leasing Program in the Central and Western Planning Areas of the Gulf of Mexico. For this DOCD, there are no unique site-specific issues with respect to this species.

The lease area is about 127 miles (205 km) from the nearest Gulf sturgeon critical habitat. OSRA modeling ( Table 3 ) predicts that a spill in the lease area has a 1% probability of contacting coastal areas inhabited by Gulf sturgeon within 30 days.

In the event of oil reaching Gulf sturgeon habitat, the fish could be affected by direct ingestion, ingestion of oiled prey, or the absorption of dissolved petroleum products through the gills. Based on the life history of this species, subadult and adult Gulf sturgeon would be most vulnerable to a marine oil spill, and would be vulnerable only during winter months (from September 1 through April 30) when this species is foraging in estuarine and marine habitats (NMFS, 2007).

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well c ontrol and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. Shell has extensive resources available to protect coastal and estuarine wildlife and habitats in the event of a spill reaching the shoreline, as detailed in the OSRP.

DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on Gulf sturgeon are expected.C.3.9 Beach Mice (Endangered)

Four subspecies of endangered beach mouse ( Peromyscus polionotus ) occur on the barrier islands of Alabama and the Florida Panhandle. They are the Alabama, Choctawhatchee, Perdido Key, and St. Andrew beach mouse. Critical habitat has been designated for all four subspecies; Figure 1 shows the critical habitat combined for all four subspecies. Species descriptions are provided in a recent lease sale EIS (MMS, 2007b).

A large oil spill is the only IPF potentially affecting subspecies of beach mouse. There are n o IPFs associated with routine project activities that could affect these animals due to the distance from shore and the lack of onshore support activities near their habitat.

Impacts of a Large Oil Spill

Potential spill impacts on beach mice are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). For this DOCD, there are no unique site-specific issues with respect to these species.

The lease area is about 175 miles (281 km) from the nearest beach mouse critical habitat. OSRA modeling predicts that a spill in the lease area would not contact beach mouse critical habitat within 30 days. In the event of oil contacting these beaches, beach mice could experience several types of direct and indirect impacts. Contact with spilled oil could cause skin and eye irritation and subsequent infection; matting of fur; irritation of sweat glands, ear tissues, and throat tissues; disruption of sight and hearing; asphyxiation from inhalation of fumes; and toxicity from ingestion of oil and contaminated food. Indirect impacts could include reduction of food supply, destruction of habitat, and fouling of nests. Impacts could also occur from vehicular traffic and other activities associated with spill cleanup.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on beach mice are expected.

C.4 Coastal and Marine Birds

C.4.1 Marine and Pelagic Birds

A variety of seabirds may occur in the pelagic environment of the project areas (Clapp et al., 1982a,b, 1983; Peake, 1996; Hess and Ribic, 2000). Seabirds spend much of their lives offshore over the open ocean, except during breeding season when they nest along the coast. In addition, other birds such as waterfowl, marsh birds, and shorebirds may occasionally be present over open ocean areas. No endangered or threatened bird species are likely to occur at the project area due to the distance from shore. For a discussion of shorebirds and coastal nestin g birds, see Section C.4.2

.

Seabirds of the northern Gulf of Mexico were surveyed from ships during the GulfCet II program. Hess and Ribic (2000) reported that terns, storm-petrels, shearwaters, and jaegers were the most frequently sighted seabirds in the deepwater area. From these surveys, four ecological categories of seabirds were documented in the deepwater areas of the Gulf: summer migrants (shearwaters, storm petrels, boobies); summer residents that breed in the Gulf (Sooty Tern, Least Tern, Sandwich Tern, Magnificent Frigatebird); winter residents (gannets, gulls, jaegers); and permanent resident species (Laughing Gull, Royal Tern, Bridled Tern) (Hess and Ribic, 2000).

Common seabird species include Wilson‟s Storm -Petrel ( Oceanites oceanicus ), Magnificent Frigatebird ( Fregata magnificens ), Northern Gannet ( Morus bassanus ), Masked Booby( Sula dactylatra ), Brown Booby ( Sula leucogaster ), Cory‟s Shearwater ( Calonectris diomedea ), Greater Shearwater ( Puffinus gravis ), and Audubon Shearwater ( Puffinus lherminieri ). Seabirds are distributed Gulf-wide and are not specifically associated with the lease area.

Relationships with hydrographic features were found for several seabird species, possibly due to effects of hydrography on nutrient levels and productivity of surface waters where birds forage. GulfCet II did not estimate bird densities; however, Powers (1987) indicates that seabird densities over the open ocean typically are <10 birds/km 2

.

Trans-Gulf migrant birds including shorebirds, wading birds, and terrestrial birds may also be present in the lease area. Migrant birds may use offshore structures and platforms for resting, feeding, or as temporary shelter from inclement weather (Russell, 2005). Some birds may be attracted to offshore structures because of the lights and the fish populations that aggregate

around these structures.

IPFs potentially affecting marine and pelagic birds include drilling rig presence, noise, and lights; support vessel and helicopter traffic; and two types of accidents - a small fuel spill and a large oil spill. Effluent discharges are likely to have negligible impacts on the birds due to rapid dispersion, the small area of ocean affected, the intermittent nature of the discharges, and the mobility of these animals. Compliance with NTL 2012-BSEE-G01 will minimize the potential for marine debris-related impacts on birds.

Impacts of Drilling Rig Presence, Noise, and Lights

Birds that frequent platforms may be exposed to contaminants including air pollutants and routine discharges, but significant impacts are unlikely due to rapid dispersion of effluents and air pollutants. Birds migrating over water have been known to strike offshore structures, resulting in death or injury (Wiese et al., 2001; Russell, 2005). Mortality of migrant birds at tall towers and other land-based structures has been reviewed extensively, and the mechanisms involved in platform collisions appear to be similar. In some cases, migrants simply do not see a part of the platform until it is too late. In other cases, navigation may be disrupted by noise (Russell, 2005). On the other hand, offshore structures are suitable stopover habitats for most trans-Gulf migrant species, and most of the migrants that stop over on platforms probably benefit from their stay, particularly in spring (Russell, 2005).

A study in the North Sea indicated that platform lighting causes circling behavior in various birds, especially on cloudy nights; a pparently the birds‟ geomagnetic compass is upset by the red part of the spectrum from the lights currently in use (Poot et al., 2008). The numbers varied greatly, from none at all to some tens of thousands of birds per night per platform, with an apparent effect radius of up to 3 miles (5 km). A study in the Gulf of Mexico also noted the phenomenon, but did not recommend mitigation (Russell, 2005). Factors to consider in evaluating this impact in the Gulf of Mexico would include the lower incidence of cloudy and foggy days in the Gulf of Mexico versus the North Sea. Impacts on populations of seabirds and trans-Gulf migrant birds may be adverse but are not expected to be significant (BOEM, 2012b).

Impacts of Support Vessel and Helicopter Traffic

Support vessels and helicopters are unlikely to significantly disturb pelagic birds in open, offshore waters. It is likely that individual birds would experience, at most, only short-term behavioral disruption, and the impact would not be significant.

Impacts of a Small Fuel Spill

Potential spill impacts on marine birds are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). For this DOCD, there are no unique site-specific issues with respect to spill impacts on these animals.The probability of a fuel spill will be minimized by Shell‟s preventative measures during routi ne operations including fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts on marine and pelagic birds. DOCD Section

9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

A small fuel spill in offshore waters would produce a slick on the water surface and increase the concentrations of petroleum hydrocarbons and their degradation products. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Section A.9.2 discusses the likely fate of a small fuel spill and indicates that over 90% would be evaporated or dispersed naturally within

24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha), depending on sea state and weather conditions.

Birds exposed to oil on the sea surface could experience direct physical and physiological effects including skin irritation; chemical burns of skin, eyes, and mucous membranes; and inhalation of toxic fumes. Due to the limited areal extent and short duration of water quality impacts from a small fuel spill, secondary impacts due to ingestion of oil via contaminated prey or reductions in prey abundance are unlikely. Due to the low densities of birds in open ocean areas, the small area affected, and the brief duration of the surface slick, no significant impacts on marine and pelagic birds would be expected.

Impacts of a Large Oil Spill

Potential spill impacts on marine and pelagic birds are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). For this DOCD, there are no unique site-specific issues with respect to spill impacts on these animals.

Pelagic seabirds could be exposed to oil from a spill at the project area. Hess and Ribic (2000) reported that terns, storm-petrels, shearwaters, and jaegers were the most frequently sighted seabirds in the deepwater Gulf of Mexico (>656 ft [>200 m]). Powers (1987) indicates that seabird densities over the open ocean typically are <10 birds/km 2 . The number of pelagic birds that could be affected in open, offshore waters would depend on the extent and persistence of

the oil slick.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measure s as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on marine and pelagic birds are expected.

C.4.2 Shorebirds and Coastal Nesting Birds

Threatened and endangered bird species (Piping Plover and Whooping Crane) are discussed in

Section C.3 . Various species of non-endangered birds are also found along the northern Gulf Coast, including diving birds, shorebirds, marsh birds, wading birds, and waterfowl. Gulf Coast marshes and beaches also provide important feeding grounds and nesting habitats. Species that breed on beaches, flats, dunes, bars, barrier islands, and similar habitats include the Sandwich Tern, Wilson‟s Plover, Black Skimmer, Forster‟s Tern, Gull -Billed Tern, Laughing Gull, Least Tern, and Royal Tern (USFWS, 2010b). Additional information is presented in recent lease sale EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b ).

The Brown Pelican ( Pelecanus occidentalis ) was delisted from federal endangered status in 2009 (USFWS, 2010c). However, this species is listed as a species of greatest conservation need by the State of Mississippi (Mississippi Department of Wildlife, Fisheries and Parks, 2011) and as aspecies of special concern by the State of Florida (Florida Fish and Wildlife Conservation Commission, 2011). Brown Pelicans inhabit coastal habitats and forage within both coastal waters and waters of the inner continental shelf. Aerial and shipboard surveys, including GulfCet and GulfCet II, indicate that Brown Pelicans do not occur over deep offshore waters (Fritts and Reynolds, 1981; Peake, 1996; Hess and Ribic, 2000). Nearly half the southeastern population of Brown Pelicans lives in the northern Gulf Coast, generally nesting on protected islands (USFWS, 2010b).

IPFs potentially affecting shorebirds and coastal nesting birds include support vessel and helicopter traffic and a large oil spill. Compliance with NTL 2012-BSEE-G01 will minimize the potential for marine debris-related impacts on shorebirds.

Impacts of Support Vessel and Helicopter Traffic

Support vessels and helicopters will transit coastal areas near Port Fourchon and Boothville, Louisiana, where shorebirds and coastal nesting birds may be found. These activities could periodically disturb individuals or groups of birds within sensitive coastal habitats (e.g., wetlands that may support feeding, resting, or breeding birds).

Vessel traffic may disturb some foraging and resting birds. Flushing distances vary among species and individuals (Rodgers and Schwikert, 2002). The disturbances will be limited to flushing birds away from vessel pathways; known distances are from 65 to 160 ft (20 to 49 m) for personal watercraft and 75 to 190 ft (23 to 58 m) for outboard-powered boats (Rodgers and Schwikert, 2002). Flushing distances may be similar or less for the support vessels to be used for Shell‟s project, and some species such as gulls are attracted to boats. Support vessels will not approach nesting or breeding areas on the shoreline, so nesting birds, eggs, and chicks will not be disturbed. Vessel operators will use designated navigation channels and comply with posted speed and wake restrictions while transiting sensitive inland waterways. Due to the limited scope, duration, and geographic extent of drilling activities, any short-term impacts are not expected to be biologically significant to coastal bird populations.

Aircraft traffic can cause some disturbance to birds onshore and offshore. Responses are highly dependent on the type of aircraft, the bird species, the activities that animals were previously engaged in, and previous exposures to overflights (Efroymson et al., 2000). Helicopters seem to cause the most intense responses over other human disturbances for some species (Bélanger and Bédard, 1989). However, Federal Aviation Administration Advisory Circular No. 91

- 36D recommends that pilots maintain a minimum altitude of 2,000 ft (610 m) when flying over noise-sensitive areas such as wildlife refuges, parks, and areas with wilderness characteristics. This is greater than the distance (slant range) at which aircraft overflights have been reported to cause behavioral effects on most species of birds studied (Efroymson et al., 2000). With these guidelines in effect, it is likely that individual birds would experience, at most, only short-term behavioral disruption.

Impacts of Large Oil Spill

The OSRA results summarized in Table 3 predict that shorelines of Texas, Louisiana, and Florida that include habitat for shorebirds and coastal nesting birds could be affected within 30 days.

Studies being performed after the Macondo spill provide additional information regarding impacts on species of coastal and shorebirds that may be affected in the event that a large oil spill reached coastal habitats. Although the Macondo spill had direct and indirect impacts to coastal and marine birds, it is premature to conclude impacts over a long period (BOEM, 2012b). Impacts to birds from the Macondo spill are being studied as part of the Natural Resource Damage Assessment, but results have not yet been released.A blowout resulting in a large oil spill is an extremely rare event, and the probability of such a n event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on shorebirds and coastal nesting birds are expected.

C.5 Fisheries Resources

C.5.1 Pelagic Communities and Ichthyoplankton

Biggs and Ressler (2000) reviewed the biology of pelagic communities in the deepwater environment of the northern Gulf of Mexico. The biological oceanography of the region is dominated by the influence of the Loop Current, whose surface waters are among the most oligotrophic in the world‟s oceans. Superimposed on this lo w-productivity condition are productive “hot spots” associated with entrainment of nutrient -rich Mississippi River water and mesoscale oceanographic features. Anticyclonic and cyclonic hydrographic features play an important role in determining biogeographic patterns and controlling primary productivity in the northern Gulf of Mexico (Biggs and Ressler, 2000).

Most fishes inhabiting shelf or oceanic waters of the Gulf of Mexico have planktonic eggs and larvae (Ditty, 1986; Ditty et al., 1988; Richards et al., 1989, 1993). Pelagic eggs and larvae become part of the planktonic community for various lengths of time (10 to 100 days, depending on the species) (MMS, 2007b). A study by Ross et al. (2012) on mid-water fauna to characterize vertical distribution of mesopelagic fishes in selected deepwater areas in the Gulf of Mexico substantiated high species richness, but general domination by relatively few families and species.

IPFs potentially affecting pelagic communities and ichthyoplankton include drilling rig presence, noise, and lights; effluent discharges; water intakes; and two types of accidents -a small fuel spill and a large oil spill.

Impacts of Drilling Rig Presence, Noise, and Lights

The drilling rig, as a floating structure in the deepwater environment, will act as a fish-attracting device (FAD). In oceanic waters, the FAD effect would be most pronounced for epipelagic fishes such as tunas, dolphin, billfishes, and jacks, which are commonly attracted to fixed and drifting surface structures (Holland et al., 1990; Higashi, 1994; Relini et al., 1994). This FAD effect could possibly enhance the feeding of epipelagic predators by attracting and concentrating smaller fish species. Because the drilling rig is a single, temporary structure, impacts on fish populations, whether beneficial or adverse, are considered minor.

Impacts of Effluent Discharges

Discharges of treated SBM cuttings will produce temporary, localized increases in suspended solids in the water column around the drilling rig. In general, turbid water can be expected to extend between a few hundred meters and several kilometers down current from the discharge point (NRC, 1983; Neff, 1987). NPDES permit limitations and requirements are expected to be

met.

Treated sanitary and domestic wastes may have a slight effect on the pelagic environment in the immediate vicinity of these discharges. These wastes may have elevated levels of nutrients, organic matter, and chlorine, but will be diluted rapidly to undetectable levels within tens to

hundr eds of meters from the source. Minimal impacts on water quality, plankton, and nekton are anticipated.Deck drainage may have a slight effect on the pelagic environment in the immediate vicinity of these discharges. Deck drainage from contaminated areas will be passed through an oil and water separator prior to release, and discharges will be monitored for visible sheen. The discharges may have slightly elevated levels of hydrocarbons but will be diluted rapidly to undetectable levels within tens to hundreds of meters from the source. Minimal impacts on water quality, plankton, and nekton are anticipated.

Other discharges in accordance with the NPDES permit, such as desalination unit brine and uncontaminated cooling water, fire water, fracturing fluids, and ballast water, are expected to be diluted rapidly and have little or no impact on water column biota.

Impacts of Water Intakes

Seawater will be drawn from several meters below the ocean surface for various services including firewater and once-through non-contact cooling of machinery on the drilling rig ( DOCD Table 7a ). Section 316(b) of the Clean Water Act requires NPDES permits to ensure that the location, design, construction, and capacity of cooling water intake structures reflect the best technology available to minimize adverse environmental impact from impingement and entrainment of aquatic organisms. The current general NPDES Permit No. GMG290000 specifies requirements for new facilities for which construction was commenced after July 17, 2006, with a cooling water intake structure having a design intake capacity of greater than 2 million gallons of water per day, of which at least 25% is used for cooling purposes. The Atwood Condor meets the applicability criteria for a “new, non

- fixed” facili ty as defined by the NPDES permit and therefore is subject to the cooling water intake permit requirements. Affected water intakes are expected to be in compliance with the design, monitoring, and recordkeeping requirements of the NPDES permit.

Impacts of a Small Fuel Spill

Potential spill impacts on fisheries resources are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b). For this DOCD, there are no unique site-specific issues with respect to spill impacts.

The probability of a fu el spill will be minimized by Shell‟s preventative measures during routine operations including fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts on pelagic communities, including ichthyoplankton. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

A small fuel spill in offshore waters would produce a slick on the water surface and increase the concentrations of petroleum hydrocarbons and their degradation products. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Section A.9.2 discusses the likely fate of a small fuel spill and indicates that over 90% would be evaporated or dispersed naturally within

24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha), depending on sea state and weather conditions.

A small fuel spill could have localized impacts on phytoplankton, zooplankton, ichthyoplankton, and nekton. Due to the limited areal extent and short duration of water quality impacts, a small fuel spill would be unlikely to produce detectable impacts on pelagic communities.

Impacts of a Large Oil Spill

A large oil spill could affect water column biota including phytoplankton, zooplankton, ichthyoplankton, and nekton. A large spill that persisted for weeks or months would be morelikely to affect these communities. While adult and juvenile fishes may actively avoid a large spill, planktonic eggs and larvae would be unable to avoid contact. Eggs and larvae of fishes in

th e upper layers of the water column are especially vulnerable to oiling; certain toxic fractions of spilled oil may be lethal to these life stages. Impacts would be potentially greater if local scale currents retained planktonic larval assemblages (and the floating oil slick) within the same water

mass.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in

DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on pelagic communities and ichthyoplankton are expected.

C.5.2 Essential Fish Habitat

Essential Fish Habitat (EFH) is defined as those waters and substrate necessary to fish for spawning, breeding, feeding, and growth to maturity. Under the Magnuson-Stevens Fishery Conservation and Management Act, as amended, federal agencies are required to consult on activities that may adversely affect EFH designated in Fishery Management Plans developed by the regional Fishery Management Councils.

The Gulf of Mexico Fishery Management Council (GMFMC) has prepared Fishery Management Plans for corals and coral reefs, shrimps, stone crab, spiny lobster, reef fishes, coastal migratory pelagic fishes, and red drum. In 2005, the EFH for these managed species was redefined in Generic Amendment No. 3 to the various Fishery Management Plans (GMFMC, 2005). The EFH for most of these GMFMC-managed species is on the continental shelf in waters shallower than

600 ft (183 m). The shelf edge is the outer boundary for coastal migratory pelagic fishes, reef fishes, and shrimps. EFH for corals and coral reefs includes some shelf-edge topographic features on the Texas-Louisiana OCS, the nearest of which is located 42 miles (68 km) north of

the lease area.

EFH has been identified in the deepwater Gulf of Mexico for highly migratory pelagic fishes, which occur as transients in the lease area. Species in this group, including tunas, swordfishes, billfishes, and sharks, are managed by NMFS. Highly migratory species with EFH at or near the lease area include the following (NMFS, 2009):

Atlantic bluefin tuna (spawn, eggs, larvae) Skipjack tuna (spawn) Yellowfin tuna (all) Swordfish (all) Blue marlin (juveniles, adults) White marlin (juveniles) Whale shark (all) Longfin mako shark (all) Oceanic whitetip shark (all) Atlantic yellowfin tuna (all) Bigeye thresher shark (all)

Research indicates the central and western Gulf of Mexico may be important spawning habitat for Atlantic bluefin tuna, and NMFS (2009) has designated a Habitat Area of Particular Concern (HAPC) for this species. The HAPC covers much of the deepwater Gulf of Mexico, including the lease area ( Figure 1 ). The areal extent of the HAPC is approximately 15,000 mi 2 (300,000 km 2 ). The prevailing assumption is that Atlantic bluefin tuna follow an annual cycle of foraging in June through March off the eastern United States and Canadian coasts, followed by migration to the Gulf of Mexico to spawn in April, May, and June (NMFS, 2009).

Other HAPCs have been identified in the Gulf of Mexico by the GMFMC (2005). These include the Florida Middle Grounds, Madison-Swanson Marine Reserve, Tortugas North and South Ecological Reserves, Pulley Ridge, and several individual reefs and banks of the northwestern Gulf of Mexico( Figure 1 ). The nearest of these is Jakkula Bank, located 129 miles (207 km) west of the lease

area.

Routine IPFs potentially affecting EFH and fisheries resources include drilling rig presence, noise, and lights; effluent discharges; and water intakes. In addition, two types of accidents

– a small fuel spill and a large oil spill may potentially affect EFH and fisheries resources.

Impacts of Drilling Rig Presence, Noise, and Lights

The drilling rig, as a floating structure in the deepwater environment, will act as an FAD. In oceanic waters, the FAD effect would be most pronounced for epipelagic fishes such as tunas, dolphin, billfishes, and jacks, which are commonly attracted to fixed and drifting surface structures (Holland et al., 1990; Higashi, 1994; Relini et al., 1994). This FAD effect would possibly enhance feeding of epipelagic predators by attracting and concentrating smaller fish species. Any impacts on EFH for highly migratory pelagic fishes are considered minor.

Impacts of Effluent Discharges

Other effluent discharges affecting EFH by diminishing ambient water quality include drilling mud and cuttings, treated sanitary and domestic wastes, deck drainage, and miscellaneous discharges such as desalination unit brine and uncontaminated cooling water, fire water, fracturing fluids, and ballast water. Impacts on water quality have been discussed previously. No significant impacts on EFH for highly migratory pelagic fishes are expected from these discharges.

Impacts of Water Intakes

As noted previously, cooling water intake will cause entrainment and impingement of plankton, including fish eggs and larvae (ichthyoplankton). Due to the limited scope, duration, and geographic extent of drilling activities, any short-term impacts on EFH for highly migratory pelagic fishes are not expected to be biologically significant.

Impacts of a Small Fuel Spill

Potential spill impacts on EFH are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b). For this DOCD, there are no unique site-specific issues with respect to spill impacts.

The probability of a fuel spill will be minimized by Shell‟s preventative measures during routine operations including fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts on EFH. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

A small fuel spill in offshore waters would produce a slick on the water surface and increase the concentrations of petroleum hydrocarbons and their degradation products. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time and the effectiveness of spill response measures. Section A.9.2 discusses the likely fate of a small fuel spill and indicates that over 90% would be evaporated or dispersed naturally within

24 hours. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha), depending on sea state and weather conditions.

A small fuel spill could have localized impacts on EFH for highly migratory pelagic fishes, including tunas, swordfishes, billfishes, and sharks. These species occur as transients in the lease area. A spill would also produce short-term impact on water quality in the HAPC for spawning Atlantic bluefin tuna, which covers much of the deepwater Gulf of Mexico. The affected area would represent a negligible portion of the HAPC, which covers 114,793 mi 2
(297,312 km 2 ) of the Gulf of Mexico.A small fuel spill would not affect EFH for corals and coral reefs; the nearest coral EFH is

Sackett Bank, located 42 miles (68 km) north of the lease area. A small fuel spill would float and dissipate on the sea surface and would not contact these features.

Impacts of a Large Oil Spill

Potential spill impacts on EFH are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b). For this DOCD , there are no unique site-specific issues with respect to EFH.

An oil spill in offshore waters would temporarily increase hydrocarbon concentrations on the water surface and potentially the subsurface as well. Given the extent of EFH designations in the Gulf of Mexico (GMFMC, 2005; NMFS, 2009), some impact on EFH would be unavoidable.

A large spill could affect the EFH for many managed species including shrimps, stone crab, spiny lobster, corals and coral reefs, reef fishes, coastal migratory pelagic fishes, red drum, and highly migratory pelagic fishes. It would result in adverse impacts on water quality and water column biota including phytoplankton, zooplankton, ichthyoplankton, and nekton. In coastal waters, sediments could be contaminated and result in persistent degradation of the seafloor habitat for managed demersal fish and invertebrates.

The lease area is within the HAPC for spawning Atlantic bluefin tuna (NMFS, 2009). A large spill could temporarily degrade the HAPC due to increased hydrocarbon concentrations in the water column, with the potential for lethal or sublethal impacts on spawning tuna and their offspring. Potential impacts would depend in part on the timing of a spill, as this species migrates to the Gulf of Mexico to spawn in April, May, and June (NMFS, 2009).

The nearest feature designated as EFH for corals is located 42 miles (68 km) north of the lease area. An accidental spill would be unlikely to reach or affect this feature. Near-bottom currents in the region are expected to flow along the isobaths (Nowlin et al., 2001) and typically would not carry a plume up onto the continental shelf edge.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . I n the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on EFH are expected.

C.6 Archaeological Resources

C. 6.1 Shipwreck Sites

MC 934 is on the list of archaeological survey blocks (BOEM, 2012c). The archaeological surveys conducted by C&C Technologies, Inc. (2012) and Fugro GeoServices, Inc. (2005) detected unidentified sonar targets within the survey area that were classified as modern debris and are not recommended for investigation on the basis of archaeological potential.

Avoidance radii of 100 ft (30 m) will be established around five marine avoidance zones identified near A8 and A9. An additional 31 sonar contacts, which may be dumped waste barrels, were deemed to be not archaeologically significant. An avoidance radius of 50 ft (15 m) will be

observed around these contacts.

Because there are no historic shipwreck sites in the lease area (see DOCD Section 6 ), there are no routine IPFs that are likely to affect these resources. A small fuel spill would not affect shipwrecks in adjoining blocks because the oil would float and dissipate on the sea surface. The impact of a large oil spill that could contact shipwrecks in other areas is considered below a level

of concern.Impacts of a Large Oil Spill

There are no known historic shipwrecks in the lease area and a large oil spill would not result in any impact on archaeological resources. A spill entering shallow coastal waters could conceivably contaminate an undiscovered or known historic shipwreck site. The OSRA modeling summarized

in Table 3 predicts that Texas, Louisiana, and Florida shorelines could be contacted by a spill within 30 days.

Previous analyses (MMS, 2007a, 2008) concluded that oil spills would be unlikely to affect archaeological sites beyond the immediate vicinity of the wellhead (i.e., due to physical impacts of a blowout) because the oil would rise quickly to the sea surface directly over the spill location. However, during the Macondo spill, subsurface plumes were reported at a water depth of about 3,600 ft (1,100 m), extending at least 22 miles (35 km) from the wellsite and persisting for more than a month (Camilli et al., 2010). The subsurface plumes apparently resulted from the use of dispersants at the wellhead (Joint Analysis Group, 2010c). While the behavior and impacts of subsurface plumes are not well known, a subsurface plume could contact shipwreck sites beyond the 984-ft (3 00 -m) radius estimated by MMS (2007a, 2008), depending on its extent, trajectory, and persistence.

As noted by MMS (2007b), should an oil spill contact a coastal historic site, such as a fort or a lighthouse, the major impact would be a temporary, reversible visual impact from oil contact and contamination of the site and its environment. However, more recent studies suggest that the impacts could be longer term and not easily reversible (BOEM, 2012b).

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures.

C.6.2 Prehistoric Archaeological Sites

With a water depth of approximately 3,875 ft (1,181 m), the wellsites are well beyond the 197-ft (60-m) depth contour used by the BOEM as the seaward extent for prehistoric archaeological site potential in the Gulf of Mexico. Because prehistoric archaeological sites are not found in the lease area, the only relevant IPF is a large oil spill that would reach coastal waters within the

197 -ft (60-m) depth contour.

Impacts of a Large Oil Spill

Because prehistoric archaeological sites are not found in the lease area, they would not be affected by the physical effects of a subsea blowout. The MMS (2007b) estimates that a severe subsurface blowout could resuspend and disperse sediments within a 984-ft (300-m) radius.

Along the northern Gulf Coast, prehistoric sites occur frequently along the barrier islands and mainland coast and along the margins of bays and bayous (MMS, 2007b). The OSRA modeling

summarized in Table 3 predicts that Texas, Louisiana, and Florida shorelines could be contacted by a spill within 30 days. A spill reaching a prehistoric site along these shorelines could coat fragile artifacts or site features and compromise the potential for radiocarbon dating organic materials in a site (although other dating methods are available and it is possible to decontaminate an oiled sample for radiocarbon dating). If appropriate measures are not in place, coastal prehistoric sites could also be damaged by spill cleanup operations (e.g., by destroying fragile artifacts and disturbing the provenance of artifacts and site features).

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an

event will be minimized b y Shell‟s well control and blowout prevention measures as detailed in

DOCD Section 2J . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigateand reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on archaeological resources are expected.

C.7 Coastal Habitats and Protected Areas

Coastal habitats in the northern Gulf of Mexico that may be affected by oil and gas activities are described in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b,d) and in a literature review by Collard and Way (1997). Sensitive coastal habitats are also tabulated in the OSRP. Coastal habitats inshore of the project area include barrier beaches and dunes, wetlands, and submerged seagrass beds. Generally, most of the northern Gulf is fringed by barrier beaches, with wetlands and/or submerged seagrass beds occurring in sheltered areas behind the

barrier islands and in estuaries.

Due to the distance from shore, there are no IPFs associated with routine activities that are likely to affect beaches and dunes, wetlands, seagrass beds, coastal wildlife refuges, wilderness areas, or any other managed or protected coastal area. The support bases at Port Fourchon and Boothville are not located in a wildlife refuge or a wilderness area. Potential impacts of support vessel traffic are briefly addressed below.

A small fuel spill in the lease area would be unlikely to affect coastal habitats because it would not be expected to make landfall or reach coastal waters prior to breaking up (see explanation in

Section A.9.2 ).

Impacts of Support Vessel Traffic

For OCS activities in general, support operations, including the crew boat and supply boats, may have a minor incremental impact on coastal habitats. Over time with a large number of vessel trips, vessel wakes can erode shorelines along inlets, channels, and harbors. Support operations, including the crew boat and supply boats as detailed in DOCD Section 14 , may have a minor incremental impact on coastal habitats or protected areas. Impacts will be minimized by following the speed and wake restrictions in harbors and channels.

Impacts of a Large Oil Spill

Potential spill impacts on coastal habitats are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012a,b,d). Coastal habitats inshore of the project area include barrier beaches and dunes, wetlands, and submerged seagrass beds. For this DOCD, there are no unique site-specific issues with respect to coastal habitats.

The OSRA results summarized in Table 3 predict that shorelines of Texas, Louisiana, and Florida could be affected within 30 days. Plaquemines Parish, Louisiana has the highest probability of contact for the 10-day and 30-day intervals (4% and 8%, respectively). Two other Louisiana parishes (Terrebonne and Lafourche) may be contacted within 10 days. After 30 days,

11 counties or parishes may be contacted from Galveston, Texas, to Okaloosa County in the

Florida Panhandle.

The shorelines within the geographic range predicted by the OSRA modeling include extensive barrier beaches and wetlands, with submerged seagrass beds occurring in sheltered areas behind the barrier islands and in estuaries. NWRs and other protected areas along the coast are

discussed in the lease sale EIS (MMS, 2007b) and Shell‟s OSRP. Coastal wildlife refuges, wilderness areas, and state and national parks within the geographic range of the potential shoreline contacts after 30 days include the following:

Brazoria NWR

Galveston Island State Park Apffel Park Seawolf Park

Old Fort Travis ParkAtkinson Island Wildlife Management Area (WMA)

Ft. Anahuac Park

Anahuac NWR

McFaddin NWR Candy Abshier WMA

Atkinson Island WMA

Sea Rim State Park Murphree WMA

Texas Point NWR

Sabine NWR

Cameron Prairie NWR

La Cassine NWR

Little Pecan NA

Peveto Woods NA

Lower Neches WMA

Rockefeller WMA and Game Preserve Paul J. Rainey WMA

Marsh Island WMA Cypremort Point State Park Shell Keys NWR Atchafalaya Delta WMA Mandalay NWR Isles Dernieres Barrier Islands Refuge

Pointe-aux-Chenes WMA

Wisner State WMA

Grand Isle State Park

Salvador WMA

Jean Lafitte National Historical Park and

Preserve
Lafitte Woods NA

Delta NWR

Pass-a-Loutre WMA

Breton NWR
St. Bernard State Park

Biloxi WMA Bayou Sauvage NWR
Gulf Islands National Seashore Pensacola Bay Surface Water Improvement and Management Area Choctawhatchee Bay Surface Water Improvement and Management AreaThe OSRA results in Table 3 include only shoreline segments with contact probabilities greater

than 0.5% within 30 days; other coastal areas could be affected at lower contact probabilities within 30 days, or from a spill persisting for more than 30 days. Additional NWRs and managed wildlife areas occur along the Gulf Coast. These areas include habitats such as barrier beach and dune systems, wetlands, and submerged seagrass beds that support diverse wildlife, including endangered or threatened species.

The level of impacts from oil spills on coastal habitats depends on many factors, including the oil characteristics, the geographic location of the landfall, and the weather and oceanographic conditions at the time (MMS, 2007b). Oil that makes it to beaches may be either liquid weathered oil, an oil-and-water mousse, or tarballs (MMS, 2007b). Oil is generally deposited o n beaches in lines defined by wave action at the time of landfall. Oil that remains on the beach will thicken as its volatile components are lost. Thickened oil may form tarballs or aggregations that incorporate sand, shell, and other materials into its mass. Tar may be buried to varying depths under the sand. On warm days, both exposed and buried tarballs may liquefy and ooze. Oozing may also serve to expand the size of a mass as it incorporates beach materials. Oil on beaches may be cleaned up manually, mechanically, or both. Some oil can remain on the beach at varying depths and may persist for several years as it slowly biodegrades and volatilizes.

Coastal wetlands are highly sensitive to oiling and can be significantly impacted because of the

inh erent toxicity of hydrocarbon and non-hydrocarbon components of the spilled substances (Mendelssohn, 2012). The MMS (2007b) predicted that for every 50 bbl of oil contacting wetlands, approximately 6.7 ac (2.7 ha) of wetland vegetation will experience dieback. Thirty percent of these damaged wetlands are assumed to recover within 4 years, and 85% within

10 years. About 15% of the contacted wetlands are expected to be converted permanently to open-water habitat. The critical concentration of oil is that concentration above which impacts to wetlands will be long-term and recovery will take longer than two growing seasons, and which causes plant mortality and some permanent wetland loss. Critical concentrations of various oils are expected to vary broadly for wetland types and wetland plant species. Louisiana wetlands are assumed to be more sensitive to oil contact than elsewhere in the Gulf because of high cumulative stress (MMS, 2007b). In addition to the direct impacts of oil, cleanup activities in marshes may accelerate rates of erosion and retard recovery rates (MMS, 2007b).

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on coastal habitats are expected.

C.8 Socioeconomic and Other Resources

C.8.1 Recreational and Commercial Fishing

The main commercial fishing activity in deep waters of the northern Gulf of Mexico is pelagic longlining for tunas, swordfishes, and other billfishes (Continental Shelf Associates, Inc., 2002). Pelagic longlining has occurred historically in the project area, primarily during spring and

summer.

It is unlikely that any commercial fishing activity other than longlining occurs at or near the project area. Benthic species targeted by commercial fishers occur on the upper continental slope, well inshore of the project area. Royal red shrimp ( Pleoticus robustus ) are caught by trawlers in water depths of about 820 to 1,804 ft (250 to 550 m). Tilefishes (primarily

Lo phalotilus chamaeleonticeps ) are caught by bottom longlining in water depths from about

540 to 1,476 ft (165 to 450 m) (Continental Shelf Associates, Inc., 2002). The proposed project is in approximately 3,875 ft (1,181 m) of water. No conflict with commercial fishing activity is expected to occur.

Most recreational fishing activity in the region occurs in water depths less than 656 ft (200 m) (Continental Shelf Associates, Inc., 1997, 2002). In deeper water, the main attraction to recreational fishers would be petroleum platforms in offshore waters of Texas and Louisiana.The only routine IPF potentially affecting fisheries is drilling rig presence (including noise and

lights). Two types of potential accidents are also addressed below

– a small fuel spill and a large oil spill.

Impacts of Drilling Rig Presence

There is a slight possibility of pelagic longlines becoming entangled in the drilling rig. For example, in January 1999 a portion of a pelagic longline snagged on the acoustic Doppler current profiler of a drillship working in the Gulf of Mexico (Continental Shelf Associates, Inc., 2002). The line was removed without incident. Generally, longline fishers use radar and are aware of offshore structures and ships when placing their sets. Therefore, little or no impact on pelagic longlining is expected.

No adverse impacts on fishing activities are anticipated. Other factors such as effluent discharges are likely to have negligible impacts on commercial or recreational fisheries due to rapid dispersion, the small area of ocean affected, and the intermittent nature of the discharges.

Impacts of a Small Fuel Spill

The probability of a fuel spill will be minimized by Shell‟s preventative measures during routine operations including fuel transfer. In th e unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

Pelagic longlining activities in the lease area, if any, could be interrupted in the event of a small fuel spill. The area of the sea surface with diesel fuel on it would range from 1.2 to 12 ac (0.5 to 5 ha), depending on sea state and weather conditions. Fishing activities could be interrupted due to the activities of response vessels operating in the lease area. A small fuel spill would not affect coastal water quality because the spill would not be expected to make landfall or reach coastal waters prior to breaking up (see Section A.9.2 ).

Impacts of a Large Oil Spill

Potential spill impacts on fishing activities are discussed in recent EISs (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b,d). For thi s DOCD , there are no unique site-specific issues with respect to this activity.

Pelagic longlining activities in the lease area and other fishing activities in the northern Gulf of Mexico could be interrupted in the event of a large oil spill. A spill may or may not result in fishery closures, depending on the duration of the spill, the oceanographic and meteorological conditions at the time, and the effectiveness of spill response measures. A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts.

DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on fishing activities are expected.

C.8.2 Public Health and Safety

There are no IPFs associated with routine operations that are expected to affect public health and safety. Impacts of a small fuel spill and a large oil spill are addressed below.

Impacts of a Small Fuel Spill

The probability of a fuel spill will be minimized by Shell‟s preventative measures during routine operations including fuel transfer. I n the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts. DOCD Section 9b provides detail on spill

response measures.

A small fuel spill would not have impacts on public health and safety because it would likely affect only a small area of the open ocean 61 miles (98 km) from the nearest shoreline and nearly all of the diesel fuel would evaporate or disperse naturally within 24 hours. Response crews would be equipped with appropriate safety equipment to avoid injury and health effects. A small fuel spill would not be expected to make landfall or reach coastal waters prior to breakingup ( see Section A.9.2 ).

Impacts of a Large Oil Spill

In the event of a large spill from a blowout, the main safety and health concerns are those of the offshore personnel involved in the incident and those responding to the spill. The proposed activities will be covered by the OSRP, and, in addition, the drilling rig maintains a Shipboard Oil Pollution Emergency Plan as required under MARPOL 73/78.

Depending on the spill rate and duration, the physical/chemical characteristics of the oil, the meteorological and oceanographic conditions at the time, and the effectiveness of spill response measures, the public could be exposed to oil on the water and along the shoreline, through skin contact or inhalation of VOCs. Crude oil is a highly flammable material, and any smoke or vapors from a crude oil fire can cause irritation. Exposure to large quantities of crude oil may pose a

health hazard.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on public health and safety are expected.

C.8.3 Employment and Infrastructu re

There are no IPFs associated with routine operations that are expected to affect employment and infrastructure. The project involves drilling with support from existing shorebased facilities in Louisiana. No new or expanded facilities will be constructed, and no new employees are expected to move permanently into the area. The project will have a negligible impact on socioeconomic conditions such as local employment, existing offshore and coastal infrastructure (including major sources of supplies, services, energy, and water), and minority and lower income groups. Impacts of a small fuel spill and a large oil spill are addressed below.

Impacts of a Small Fuel Spill

The probability of a fuel spill will be minimized by Shell‟s preventative measures dur ing routine operations including fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts. DOCD Section and 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

A small fuel spill that is dissipated within a few days would have little or no economic impact, as the spill response would use existing facilities, resources, and personnel.

Impacts of a Large Oil Spill

Potential socioeconomic impacts of an oil spill are discussed in recent EISs (MMS, 2007b, 2008; BOEM, 2012b,d). For this DOCD, there are no unique site-specific issues with respect to employment and coastal infrastructure. A large spill could cause several types of economic impacts: extensive fishery closures could put fishermen out of work; temporary employment could increase as part of the response effort; adverse publicity could reduce employment in coastal recreation and tourism industries; and OCS drilling activities, including service and support operations that are an important part of local economies, could be suspended.

The lease area is 61 miles (98 km) from the nearest shoreline. Based on the OSRA modeling predictions ( Table 3 ), Texas, Louisiana, and Florida coastal areas are the most likely to be contacted by a spill.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an

event will be min imized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on employment and infrastructure are expected.C.8.4 Recreation and Tourism

There are no known recreational uses of the lease area. Recreational resources and tourism in coastal areas would not be affected by routine activities due to the distance from shore. Compliance with NTL 2012-BSEE-G01 will minimize the chance of trash or debris being lost overboard from the drilling rig and subsequently washing up on beaches.

Impacts of a Small Fuel Spill

The probabilit y of a fuel spill will be minimized by Shell‟s preventative measures during routine operations including fuel transfer. In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the potential for impacts. DOCD Section 9b provides detail on spill response measures. Given the open ocean location of the lease area, the duration of a small spill and opportunity for impacts to occur would be very brief.

A small fuel spill in the lease area would be unlikely to affect recreation and tourism. There are no known recreational or tourism activities occurring in the lease area, and as explained in

Section A.9.2 , a small fuel spill would not be expected to make landfall or reach coastal waters prior to breaking up.

Impacts of a Large Oil Spill

Potential impacts of an oil spill on recreation and tourism are discussed in recent EISs (MMS, 2007b, 2008; BOEM, 2012b). For this DOCD , there are no unique site-specific issues with respect to these impacts.

Impacts on recreation and tourism would vary depending on the duration of the spill and its fate including the effectiveness of response measures. A large spill that reached coastal waters and shorelines could adversely affect recreation and tourism by contaminating beaches and wetlands,

re sulting in negative publicity that encourages people to stay away. Based on OSRA modeling as

summarized in Table 3 , Plaquemines Parish, Louisiana, is the area most likely to be contacted by a spill. However, shorelines from Galveston, Texas, to the Florida Panhandle could be contacted. The shorelines along Galveston, Texas, include popular beaches and recreational sites.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implementation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on recreation and tourism are expected.

C.8.5 Land Use

Land use along the northern Gulf Coast is discussed in recent lease sale EISs (MMS, 2007b, 2008; BOEM, 2012b,d). There are no routine IPFs potentially affecting land use. The project will use existing onshore support facilities in Louisiana. The land use at the existing shorebase sites is industrial. The project will not involve new construction or changes to existing land use and, therefore, will not have any impacts. Levels of boat and helicopter traffic, as well as demand for goods and services including scarce coastal resources, will represent a small fraction of the level of activity occurring at the shorebases.

A large oil spill is the only relevant accident IPF. A small fuel spill would not have impacts on land use, as the response would be staged out of existing shorebases and facilities.

Impacts of a Large Oil Spill

The initial response for a large oil spill would be staged out of existing facilities, with no effect on land use. A large spill could have limited temporary impacts on land use along the coast if additional staging areas were needed. For example, during the Macondo spill, 25 temporary staging areas were established in Louisiana, Mississippi, Alabama, and Florida for spill response and cleanup efforts (BOEM, 2012b). In the event of a large spill in the lease area, similar temporary staging areas could be needed. These areas would eventually return to their original use as the response is demobilized.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed inDOCD Section 2j . In the unlikely event of a spill, implemen tation of Shell‟s OSRP will mitigate

and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on land use are expected.

C.8.6 Other Marine Uses

The lease area is not located within any US CG -designated fairway or shipping lane. MC 934 is not in a designated Military Warning Area. Shell will comply with BOEM requirements and lease stipulations to avoid impacts on uses of the area by military vessels and aircraft.

The archaeological surveys conducted by C&C Technologies, Inc. (2012) and Fugro GeoServices, Inc. (2005) detected unidentified sonar targets within the survey areas that were classified as modern debris or possibly barrels. Shell‟s procedure “Waste Barrel Avoidance and Release

Res ponse in the Mississippi Canyon Area,” which has been previously approved by MMS and BOEM applies to operations that could cause a disturbance of a seafloor barrel. Shell‟s

over

‐ arching policy is to avoid barrel contact. In the unlikely case that contact is suspected or has been made with any wastes from a barrel, the plan specifies actions to be taken for the topside safety of personnel handling the equipment. The plan also outlines barrel impact reporting procedures.

There are no IPFs from routine project activities that are likely to affect shipping or other marine uses. Physical disturbance to existing wells, flowlines, and umbilicals will be prevented by a

152 -m (500-ft) avoidance zone established around these features. A large oil spill is the only relevant accident IPF. A small fuel spill would not have impacts on other marine uses, as the spill and response activities would be mainly within the lease area and the duration would be brief.

Impacts of a Large Oil Spill

An accidental spill would be unlikely to significantly affect shipping or other marine uses. The lease block is not located within any USCG-designated fairway or shipping lane. In the event of a large spill requiring numerous response vessels, coordination would be required to manage the vessel traffic for safe operations. Shell will comply with BOEM requirements and lease stipulations to avoid impacts on uses of the area by military vessels and aircraft.

A blowout resulting in a large oil spill is an extremely rare event, and the probability of such an event will be minimized by Shell‟s well control and blowout prevention measures as detailed in DOCD Section 2j . In the unlikely event of a spill, implement ation of Shell‟s OSRP will mitigate and reduce the impacts. DOCD Section 9b provides detail on spill response measures. Therefore, no significant spill impacts on other marine uses are expected.

C.9 Cumulative Impacts

For purposes of NEPA, cumulative imp act is defined as “the impact on the environment which results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes su ch other actions” (40 CFR 1508.7). Any single activity or action may have a negligible impact(s) by itself, but when combined with impacts from other activities in the same area and/or time period, substantial impacts may result.

Prior Studies . Prior to the lease sales, MMS prepared a multisale EIS in which it analyzed the environmental impact of activities that might occur in the multi-lease-sale area. The MMS also recently analyzed the cumulative impacts of OCS development activities similar to those planned in this DOCD in several documents. The level and types of activities planned in Shell's DOCD are within the range of activities described and evaluated in the Final EIS for Gulf of Mexico OCS Oil and Gas Lease Sales 2007-2012: Western Planning Area Sales 204, 207, 210, 215, and 218, and Central Planning Area Sales 205, 206, 208, 213, 216, and 222 (MMS, 2007b), as updated by a 2012 Final Supplemental EIS for Gulf of Mexico OCS Oil and Gas Lease Sales 2012-2017: Western Planning Area Lease Sales 229, 233, 246, and 248 and Central Planning Area Lease Sales 227, 231, 235, 241 and 247 (BOEM, 2012b). Past, present, and reasonably foreseeable activities were identified in the cumulative effects scenario of these documents, which are incorporated by reference. The proposed action will not result in any additional impacts beyond those evaluated in the Multisale and Final EISs (MMS, 2007b; BOEM, 2012b).Description of Activities Reasonably Expected to Occur in the Vicinity of Project Area . Other

exploration and development activities may occur in the vicinity of lease block MC 934. Shell does not anticipate other projects in the vicinity of the project area beyond the types of projects analyzed in the Multisale and Supplemental EIS (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b).

Cumulative Impacts of Activities in the DOCD . The MMS (2007b) multi-lease-sale EIS and BOEM (2012b) Final EIS included a lengthy discussion of cumulative impacts, which analyzed the environmental and socioeconomic impacts from the incremental impact of the 11 proposed lease sales, in addition to all activities (including non-OCS activities) projected to occur from past, proposed, and future lease sales during the 40-year period of 2007 to 2046 (see MMS, 2007b; BOEM, 2012b). The EIS considered exploration, delineation, and development wells; platform installation; service-vessel trips; and oil spills. The EIS examined the potential cumulative effects on each specific resource for the entire Gulf of Mexico.

The level and type of activi ty proposed in Shell‟s DOCD are within the range of activities described and evaluated in the recent multi-lease-sale EISs. This EIA incorporates and builds on these analyses by examining the potential impacts on physical, biological, and socioeconomic

re sources from the work planned in this DOCD, in conjunction with the other reasonably foreseeable activities expected to occur in the Gulf of Mexico. Thus, for all impacts, the incremental contribution of Shell‟s proposed actions to the cumulative impacts analysis in these prior analyses is not significant.

C.9.1 Cumulative Impacts to Physical/Chemical Resources

The work planned in this DOCD is limited in geographic scope and duration, and the impacts on the physical/chemical environment will be correspondi ngly limited.

Air Quality

. Emissions from pollutants into the atmosphere from activities are not projected to have significant effects on onshore air quality because of the prevailing atmospheric conditions, emission rates and heights, and resulting pollutant concentrations. As the BOEM found in the

multi-lease- sale EISs, the incremental contribution of activities similar to Shell‟s proposed activities to the cumulative impacts is not significant and will not cause or contribute to a violation of national ambient air quality standard (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). In addition, the cumulative contribution to visibility impairment is also very small (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b). As mentioned in previous sections, projected emissions meet the BOEM exemption criteria and would not contribute to cumulative impacts on air quality.

Climate Change . Carbon dioxide (CO 2 ) and CH 4 emissions from the project would constitute a small incremental contribution to greenhouse gas emissions from all OCS activities. According to the EIS (MMS, 2007a), estimated CO 2 emissions from all OCS activities in the 2007- 2012 leasing program are about 0.08% to 0.016% of the global CO 2 emissions from fossil fuel combustion. Greenhouse gas emissions may contribute to climate change, with important effects on temperature, rainfall, frequency of severe weather, ocean acidification, and sea level rise (Intergovernmental Panel on Climate Change, 2007). In the Gulf of Mexico, sea level rise is an important issue due to the ongoing losses in coastal wetlands, particularly in coastal Louisiana. Greenhouse gas emissions from the DOCD represent a negligible contribution to the total greenhouse gas emissions from reasonably foreseeable activities in the Gulf of Mexico area and would not significantly alter any of the climate change impacts evaluated in the previous EISs. Globally, Shell is working to reduce greenhouse gas emissions by increasing the efficiency of its operations, establishing a substantial capability in CO 2 capture and storage, and continuing to research and develop technologies that increase efficiency and reduce emissions in hydrocarbon production. In 2010, Shell met a voluntary target set in 1998 for direct greenhouse gas emissions from its facilities to be at least 5% lower than the comparable 1990 level (Shell, 2011). Shell‟s ongoing efforts to reduce greenhouse gas emissions should offset any incremental

contribution from the DOCD.

Water Quality . Shell‟s project will result in some minor wat er quality impacts due to the NPDES-permitted discharge of SBM cuttings, treated sanitary and domestic wastes, excess cement, non-contact cooling water, deck drainage, desalination unit brine, uncontaminated fire water and ballast water. These effects are expected to be minor (localized to the area within a few hundred meters of the drilling rig), and temporary (lasting only hours longer than thedisturbance or discharge). Any cumulative effects to water quality are expected to be negligible.

Archaeological Resources . MC 934 is on the list of archaeology survey blocks (BOEM, 2012c). Archaeological assessments by C&C Technologies, Inc. (2012) and Fugro GeoServices, Inc. (2005) indicated the presence of 31 sonar contacts and 5 marine avoidance zones in the lease area, which will be avoided by 100 ft (30 m) and 50 ft (15 m), respectively. Also, the lease area is well beyond the 197-ft (60-m) depth contour used by the BOEMRE as the seaward extent for prehistoric archaeological site potential in the Gulf of Mexico. Therefore, Shell‟s operations will have no cumulative impacts on historic shipwrecks or prehistoric archaeological resources.

New Information . New information included in the most recent Supplemental and Final EISs (BOEMRE, 2011; BOEM, 2012b) has been incorporated into the EIA, where applicable.

C.9.2 Cumulative Impacts to Biological Resources

The work planned in this DOCD is limited in geographic scope and duration, and the impacts on biological resources will be correspondingly limited.

Seafloor Habitats and Biota . Effects on seafloor habitats and biota from discharges of drilling mud and cuttings are expected to be minor and limited to a small area. Areas that may support high -density deepwater benthic communities will be avoided as required by NTL 2009 -G40. Soft bottom communities are ubiquitous along the northern Gulf of Mexico continental slope, and theextent of benthic impacts during this project is insignificant regionally. As noted in the multilease-sale EISs, the incremental contribut ions of activities similar to Shell‟s proposed activities to the cumulative impacts is not significant (MMS, 2007b, 2008; BOEMRE, 2011; BOEM, 2012b).

Threatened, Endangered, and Protected Species . Threatened and endangered species reasonably likely to occur in the lease area include the sperm whale and five species of sea turtles. Potential impact sources include drilling rig presence including noise and lights; marine debris; and support vessel and aircraft traffic. Potential effects for these species would be limited and temporary, and would be reduced by Shell‟s compliance with BOEM -required mitigation measures including NTLs 2012 -BSEE-G01 and 2012-JOINT-G01. No significant cumulative impacts are expected.

Coastal and Marine Birds . Birds may be exposed to contaminants including air pollutants and routine discharges, but significant impacts are unlikely due to rapid dispersion. Shell‟s compliance with NTL 2012-BSEE-G01 will minimize the likelihood of debris-related impacts on birds. Support vessel and helicopter traffic may disturb some foraging and resting birds; however, it is likely that individual birds would experience, at most, only short-term behavioral disruption.

Due to the limited scope, duration, and geographic extent of drilling activities, collisions or other adverse effects are unlikely, and no significant cumulative impacts are expected.

Fisheries Resources . Exploration and production structures occur in the MC lease blocks proposed for the drilling activities. The additional effect of the proposed drilling activity would be negligible.

Coastal Habitats . Due to the distance of the wellsites from shore, routine activities are not expected to have any impacts on beaches and dunes, wetlands, seagrass beds, coastal wildlife refuges, wilderness areas, or any other managed or protected coastal area. The support bases at Port Fourchon and Boothville are not in wildlife refuge or wilderness areas. Support operations, including the crew boat and supply boats, may have a minor incremental impact on coastal habitats. Over time with a large number of vessel trips, vessel wakes can erode shorelines along inlets, channels, and harbors. Impacts will be minimized by following the speed

and wake restrictions in harbors and channels.

New Information

. New information included in the most recent Supplemental and Final EISs (BOEMRE, 2011; BOEM, 2012b) has been incorporated into the EIA, where applicable.

C.9.3 Cumulative Impacts to Socioeconomic Resources

The work planned in this DOCD is limited in geographic scope and duration, and the impacts on socioeconomic resources will be correspondingly limited.The multi-lease-sale and supplemental and final EISs analyzed the cumulative impacts of oil and

gas exploration and development in the lease area, in combination with other impact-producing activities, on commercial fishing, recreational fishing, recreational resources, historical and archaeological resources, land use and coastal infrastructure, demographics, and environmental justice (MMS, 2007b; BOEMRE, 2011; BOEM, 2012b). The BOEM also analyzed the economic impact of oil and gas activities on the Gulf states, finding only minor impacts in most of Texas, Mississippi, Alabama, and Florida, more significant impacts in parts of Texas, and substantial impacts on Louisiana.

Shell‟s proposed activities will have negligible cumulative impacts on socioeconomic resources. There are no IPFs associated with routine operations that are expected to affect public health and safety, employment and infrastructure, recreation and tourism, land use, or other marine uses. Due to the distance from shore, it is unlikely that any recreational fishing activity is occurring in the project area, and it is unlikely that any commercial fishing activity other than longlining occurs at or near the project area. The project will have negligible impacts on fishing

activities.

New Information . New information included in the most recent Supplemental and Final EISs (BOEMRE, 2011; BOEM, 2012b) has been incorporated into the EIA, where applicable.

D. Environmental Hazards

D.1 Geologic Hazards

The shallow hazards assessment included in this DOCD, based on the shallow hazards reports by Fugro McClelland (1990) and C&C Technologies, Inc. (2012), concludes that the wellsites are free of any major geological hazards and are suitable for the proposed activities. There are no fluid expulsion features or faults within 2,000 ft (600 m) of the well proposed locations based on results of a high-resolution geophysical survey consisting of frequency-enhanced three-dimensional seismic, enhanced surface renderings, autonomous underwater vehicle surveys, and side-scan sonar.

See DOCD Section 6a for supporting geological and geophysical information.

D.2 Severe Weather

Under most circumstances, weather is not expected to have any effect on the proposed activities. Extreme weather, including high winds, strong currents, and large waves, was considered in the design criteria for the drilling rig. High winds and limited visibility during a severe storm could disrupt communication and support activities (vessel and helicopter traffic) and make it necessary to suspend some activities on the drilling rig for safety reasons until the storm or weather event passes. In the event of a hurricane, procedures in Sh ell‟s Hurricane Evacuation Plan would be

followed.

D.3 Currents and Waves

A rig-based acoustic Doppler current profiler will be used to continuously monitor the current beneath the rig. Metocean conditions such as sea states, wind speed, ocean currents, etc. will also be continuously monitored. Under most circumstances, physical oceanographic conditions are not expected to have any effect on the proposed activities. Strong currents (e.g., caused by Loop Current eddies and intrusions) and large waves were considered in the design criteria for the drilling rig. High waves during a severe storm could disrupt support activities (i.e., vessel and helicopter traffic) and make it necessary to suspend some activities on the drilling rig for safety reasons until the storm or weather event passes.

E. Alternatives

No formal alternatives were evaluated in this EIA. However, various technical and operational options, including the location of the wellsites and the selection of a drilling unit, were considered by Shell in developing the proposed action. There are no other reasonable alternatives toaccomplish the goals of this project.

F. Mitigation Measures

The proposed action includes numerous mitigation measures required by laws, regulations, and BOEM lease stipulations and NTLs. The project will comply with applicable federal, state, and local requirements concerning air pollutant emissions, discharges to water, and solid waste disposal. Project activities will be conducted under Shell‟s OSRP and will include the measures

described in DOCD Section 2f

.

G. Consultation

No persons or agencies were consulted regarding potential impacts associated with the proposed activities during the preparation of this EIA.

H. Preparers

The EIA was prepared at the direction of Shell Offshore Inc. by its contractor, CSA International, Inc. Contributors included the following:

Tracy Albert (Regulatory Specialist, Regulatory Consultants of LA, LLC ); Jeffrey McMenis (Environmental Engineer, Shell Exploration & Production Co.); Mark Koper (Well Development Team Lead, Shell Exploration & Production Co.); Megan Henley (Drilling Engineer, Shell Exploration & Production Co.); June Mire, Ph.D. (Senior Ecologist and Project Manager, Tetra Tech EM, Inc.); Carlyle Kalloo (Senior Scientist, CSA International, Inc.); John Thompson (Senior Scientist, CSA International, Inc.); Neal Phillips, Ph.D. (Senior Scientist, CSA International, Inc.); Deborah Fawcett (Project Scientist II, CSA International, Inc.); Stephen Viada (Senior Scientist, CSA International, Inc.); Keith VanGraafeiland (GIS/Remote Sensing Specialist, CSA International, Inc.); and Danielle Johnson (Technical Editor, CSA International, Inc.).

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University Press, College Station, TX. 232 pp.SECTION 19 : ADMINISTRATIVE INFORMATION

A. Exempted Information Description (Public Information Copies Only)

The following attachments were excluded from the public information copies of this plan:

1b. OCS Plan Information form

– Bottom hole locations & proposed total depth

2c. Production Information 3a. Geologic Description 3b. Structure Contour Maps 3c. Interpreted 2D or 3D seismic line(s) 3d. Cross Section(s) 3g. Top hole prognosis and power spectrum diagram

4b. H 2 S Classification Information

5. Mineral Resource Conservation information

B. Bibliography

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Shell Exploration and Production Archaeological and Hazard Report, Blocks 890-979, Mississippi Canyon Area, U.S. Gulf of Mexico, prepared by C&C Technologies, July, 2012, Project 100231. AUV data consisting of side scan sonar and sub-bottom profiler.

Archaeological Assessment, Proposed Well Site and Anchor Locations, Blocks 890, 891, 934, & 935,Mississippi Canyon Area, Gulf of Mexico, Fugro Geoservices, report 2405-1366, November 8, 2005. DeepTowed Side Scan Sonar and Sub-Bottom Profiler.

Shell OSRP