UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)

Plans Section, Office of Field 

Operations (MS 5231)

Public Information copy of Exploration Plan

Control # - N-09821

Type - Initial Exploration Plan

Lease(s) - OCS-G21817 Block - 768 Green Canyon Area

OCS-G34557 Block - 724 Green Canyon Area

Operator - Anadarko Petroleum Corporation

Drill, Complete Wells GC 724 A, AA, AAA

Not Found

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.

Tonya Jez

Plan Coordinator

Description -

Rig Type -

Subject:

From:

September 12, 2014
INITIAL EXPLORATION PLAN 

N-9821 

ANADARKO PETROLEUM 

CORPORATION 

GREEN CANYON BLOCK 724 

OCS-G 34557 

PUBLIC COPY 

RECORD OF CHANGE LOG 

Submission 

Type 

Date Sent to 

BOEM 

Summary of 

Submission 

Page 

Numbers 

Initial 07/09/2014 Submit Initiall EP All 

Amendment 07/30/2014 Add additional shorebase 6 

Final version of EP 08/22/2014 Final copy of plan with 

all revisions included 

All 

Record of Change 

Log 

08/22/2014 Record of Change Log 1 

 
 

PUBLIC 

INITIAL EXPLORATION PLAN 

GREEN CANYON BLOCK 724 

OCS-G 34557 

OFFSHORE, LOUISIANA

 

Anadarko Petroleum Corporation 

1201 Lake Robbins Drive 

The Woodlands, Texas 77380 

Contact: Jill Fowler 

jill.fowler@anadarko.com 

(832) 636-1554 

1 – Hard Copy Confidential 

1 – CD Confidential 

1 – Hard Copy Public Information 

2 – CDs Public Information

July, 2014 
 

INITIAL EXPLORATION PLAN 

LEASES OCS-G 34557 

GREEN CANYON BLOCK 724 

 A. Plan Contents 

 B. General Information 

 C. Geological, Geophysical 

D. Hydrogen Sulfide Information 

 E. Biological, Physical and Socioeconomic Information 

F. Wastes and Discharge Information 

 G. Air Emissions Information 

 H. Oil Spill Information 

I. Environmental Monitoring Information 

 J. Lease Stipulations 

 K. Support Vessels and Aircraft Information 

 L. Onshore Support Facilities Information 

M. Coastal Zone Management Act Information 

N. Environmental Impact Analysis 

O. Administrative Information 
 

A 

PLAN CONTENTS

(a) Plan Information Form 

Under this Initial Exploration Plan (EP), Anadarko Petroleum Corporation (Anadarko) proposes to drill 

and complete three wells total in Green Canyon (GC) Block 724. 

The wells will be drilled using either a Dynamically Positioned (DP) Drillship or DP Semisubmersible 

drilling rig. Drilling and completion operations for the proposed well locations will utilize a Subsea BOP 

stack. OCS Plan Information Form BOEM-137 is enclosed as Attachment A-1. 

(b) Location 

Enclosed as Attachment A-2 is a well location plat at a scale of 1 inch = 2000 feet that depicts the 

surface location and water depth of the proposed well. 

(c) Safety and Pollution Prevention Features 

Safety features on the drilling unit will include well control, pollution prevention, safe welding 

procedures, and blowout prevention equipment as described in Title 30 CFR Part 250, Subparts C, D, E, 

G and O; and as further clarified by BOEM Notices to Lessees, and applicable regulations of the 

Environmental Protection Agency and the U.S. Coast Guard. The appropriate life rafts, life jackets, ring 

buoys, etc., as prescribed by the U.S. Coast Guard, will be maintained on the facility at all times. 

(d) Storage Tanks and Production Vessels 

The Green Canyon Block 724 wells will be drilled with a DP drillship/ DP semisubmersible unit. 

Type of Facility Type Of Storage 

Tank 

Tank 

Capacity 

Number 

Of Tanks 

Total 

Capacity 

Fluid 

Gravity 

(Api) 

Total Capacity 

of all Tanks 

for Rig Type 

Drillship 

Fuel Oil Storage 

Tank 5,514 bbls 2 11,028 bbls No. 2 Diesel 12 tanks total= 

62,874 bbls 

Fuel Oil Storage 

Tank 12,458 bbls 2 24,916 bbls No. 2 Diesel 

Fuel Oil Storage 

Tank 12,065 bbls 2 24,130 bbls No. 2 Diesel 

Fuel Oil Settling 

Tanks 640 bbls 2 1,280 bbls No. 2 Diesel 

Fuel Oil Service 

Tanks 480 bbls 3 1,440 bbls No. 2 Diesel 

Fuel Oil 

Emergency 

Generator Tank 

80 bbls 1 80 bbls No. 2 Diesel 

DP Semi Fuel Oil Hull 

Tanks 

4,541 bbls 2 9,082 bbls No. 2 Diesel 7 tanks total= 

16,689 bbls 

 Fuel Oil Hull 

Tanks 

3,392 bbls 2 6,784 bbls No. 2 Diesel 
 

 Fuel Oil Deck Day 

Tank 

629 bbls 1 629 bbls No. 2 Diesel 

 Fuel Oil Deck 

Settling Tank 

164 bbls 1 164 bbls No. 2 Diesel 

 Fuel Oil 

Emergency 

Generator 

30 bbls 1 30 bbls No. 2 Diesel 

(e) Pollution Prevention Measures 

The drilling rig utilized for these operations will comply with all applicable regulations regarding 

pollution prevention and control. The rig has a Shipboard Oil Pollution Emergency Plan 

(SOPEP), which is reviewed and approved annually by the American Bureau of Shipping (ABS). 

The SOPEP is provided to assist employees in dealing with an unexpected discharge of oil. Its 

primary purpose is to set in motion the necessary actions to stop or minimize the discharge of oil 

and to mitigate its effects. Effective planning ensures that the necessary actions are taken in a 

structured, logicalm and timely manner. 

Pollution prevention measures include installation of curbs, gutters, drip pans, and drains on deck 

areas to collect all contaminants and debris. Most deck drains and some of the joints at the edge 

of the rig floor go overboard or into the moonpool, respectively. To prevent ocean discharge 

from the drains there is a dedicated drip pan under the rotary table. The pipe racks, mud pump 

room, sack store, and drill floor drains go to a holding tank, which is served by a dedicated oily 

water separator. The well test area, engine room, and other major machinery spaces drains all go 

to slops tanks, which are served by a large general-service, oily water separator. The containment 

devices are temporary. They are not meant for permanent storage of waste. On the rare occasion 

that they contain wastes, they are pumped, mopped, or cleaned within a short period of time. The 

chances of damage to a containment structure during such time as it contains wastes are 

exceedingly small. 

(f) Additional Pollution Prevention Measures 

No additional measures are proposed under this plan. The activities proposed in this plan are not 

located offshore Florida.

(g) Description of Previously Approved Lease Activities 

Anadarko has no previously approved well locations in Green Canyon Block 724. 
U.S. Department of the Interior OMB Control Number: 1010-0151

Bureau of Ocean Energy Management OMB Approval Expires: 12/31/14

 

OCS PLAN INFORMATION FORM 

General Information 

Type of OCS Plan: Exploration Plan (EP) Development Operations Coordination Document (DOCD) 

Company Name: BOEM Operator Number: 

Address: Contact Person: 

Phone Number: 

E-Mail Address: 

If a service fee is required under 30 CFR 550.125(a), provide the Amount paid Receipt No. 

Project and Worst Case Discharge (WCD) Information

Lease(s): Area: Block(s): Project Name (If Applicable): 

Objective(s) Oil Gas Sulphur Salt Onshore Support Base(s): 

Platform/Well Name: Total Volume of WCD: API Gravity: 

Distance to Closest Land (Miles): Volume from uncontrolled blowout: 

Have you previously provided information to verify the calculations and assumptions for your WCD? Yes No 

If so, provide the Control Number of the EP or DOCD with which this information was provided 

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

Do you propose to use a vessel with anchors to install or modify a structure? Yes No 

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

Description of Proposed Activities and Tentative Schedule (Mark all that apply) 

Proposed Activity Start Date End Date No. of Days 

Drill and Complete Well Location A

Drill and Complete Well Location AA 

Description of Drilling Rig Description of Structure 

Jackup Drillship Caisson Tension leg platform

Gorilla Jackup Platform rig Fixed platform Compliant tower 

Semisubmersible Submersible Spar Guyed tower

DP Semisubmersible Other (Attach Description) 

Drilling Rig Name (If Known): 

Floating production 

system 

Other (Attach Description) 

Description of Lease Term Pipelines 

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

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 1 of 4
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): 

Previously reviewed under an approved EP or 

DOCD? 

Yes No 

Is this an existing well 

or structure? 

Yes No If this is an existing well or structure, list the 

Complex ID or API No. 

Do you plan to use a subsea BOP or a surface BOP on a floating facility to conduct your proposed activities? Yes No 

WCD info For wells, volume of uncontrolled 

blowout (Bbls/day): 

For structures, volume of all storage and 

pipelines (Bbls): 

API Gravity of 

fluid 

Surface Location Bottom-Hole Location (For Wells) Completion (For multiple completions, 

enter separate lines) 

Lease No. OCS OCS OCS 

OCS 

Area Name 

Block No. 

Blockline 

Departures 

(in feet)

N/S Departure: F____ L N/S Departure: F____ L N/S Departure: F____ L 

N/S Departure: F____ L 

N/S Departure: F____ L 

E/W Departure: F____ L E/W Departure: F____ L E/W Departure: F____ L 

E/W Departure: F____ L 

E/W Departure: F____ L 

Lambert XY 

coordinates 

X: X: X: 

X: 

X: 

Y: Y: Y: 

Y: 

Y: 

Latitude/ 

Longitude

Latitude Latitude Latitude 

Latitude 

Latitude 

Longitude Longitude Longitude 

Longitude 

Longitude 

Water Depth (Feet): MD (Feet): TVD (Feet): 

Anchor Radius (if applicable) in feet: 

MD (Feet): 

MD (Feet): 

MD (Feet): 

TVD (Feet): 

TVD (Feet): 

TVD (Feet): 

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 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

 

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 2 of 4
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): 

Previously reviewed under an approved EP or 

DOCD? 

Yes No 

Is this an existing well 

or structure? 

Yes No If this is an existing well or structure, list the 

Complex ID or API No. 

Do you plan to use a subsea BOP or a surface BOP on a floating facility to conduct your proposed activities? Yes No 

WCD info For wells, volume of uncontrolled 

blowout (Bbls/day): 

For structures, volume of all storage and 

pipelines (Bbls):

API Gravity of 

fluid

Surface Location Bottom-Hole Location (For Wells) Completion (For multiple completions, 

enter separate lines) 

Lease No. OCS OCS OCS

OCS

Area Name 

Block No. 

Blockline

Departures 

(in feet)

N/S Departure: F____ L N/S Departure: F____ L N/S Departure: F____ L

N/S Departure: F____ L 

N/S Departure: F____ L 

E/W Departure: F____ L E/W Departure: F____ L E/W Departure: F____ L 

E/W Departure: F____ L 

E/W Departure: F____ L 

Lambert XY

coordinates 

X: X: X: 

X:

X:

Y: Y: Y:

Y:

Y:

Latitude/

Longitude

Latitude Latitude Latitude 

Latitude

Latitude

Longitude Longitude Longitude 

Longitude

Longitude

Water Depth (Feet): MD (Feet): TVD (Feet): 

Anchor Radius (if applicable) in feet: 

MD (Feet): 

MD (Feet): 

MD (Feet): 

TVD (Feet): 

TVD (Feet): 

TVD (Feet): 

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 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 2 of 4

GC 724 "AA" x

x n/a

x

G 21817

Green Canyon

768

107'FNL

5489'FWL

2,299,892.78

9,884,053.02

27.22362735

90.97026812

5257'

N/A

n/a
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): 

Previously reviewed under an approved EP or 

DOCD? 

Yes No 

Is this an existing well 

or structure? 

Yes No If this is an existing well or structure, list the 

Complex ID or API No. 

Do you plan to use a subsea BOP or a surface BOP on a floating facility to conduct your proposed activities? Yes No 

WCD info For wells, volume of uncontrolled 

blowout (Bbls/day): 

For structures, volume of all storage and 

pipelines (Bbls):

API Gravity of 

fluid

Surface Location Bottom-Hole Location (For Wells) Completion (For multiple completions, 

enter separate lines) 

Lease No. OCS OCS OCS

OCS

Area Name 

Block No. 

Blockline

Departures 

(in feet)

N/S Departure: F____ L N/S Departure: F____ L N/S Departure: F____ L

N/S Departure: F____ L 

N/S Departure: F____ L 

E/W Departure: F____ L E/W Departure: F____ L E/W Departure: F____ L 

E/W Departure: F____ L 

E/W Departure: F____ L 

Lambert XY

coordinates 

X: X: X: 

X:

X:

Y: Y: Y:

Y:

Y:

Latitude/

Longitude

Latitude Latitude Latitude 

Latitude

Latitude

Longitude Longitude Longitude 

Longitude

Longitude

Water Depth (Feet): MD (Feet): TVD (Feet): 

Anchor Radius (if applicable) in feet: 

MD (Feet): 

MD (Feet): 

MD (Feet): 

TVD (Feet): 

TVD (Feet): 

TVD (Feet): 

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 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

X = Y = 

Form BOEM- 0137 (December 2011- Supersedes all previous editions of this form which may not be used.) Page 2 of 4

GC 724 "AAA" x

x n/a

x

G 21817

Green Canyon

768

8'FNL

3168'FWL

2,299,967.93

9,884,167.99

27.22394019

90.97003120

5257'

N/A

n/a

 

B 

GENERAL INFORMATION 

(a) Applications and Permits 

Prior to beginning exploration operations the following application(s) will be submitted for approval: 

Application/Permit Issuing Agency Status 

Permits to Drill BSEE Bureau of Safety and Environmental 

Enforcement (BSEE) 

To be submitted 

(b) Drilling Fluids 

Type of Drilling Fluid Estimated Volume Per Well 

Water-based (NaCl saturated, seawater, 

freshwater, barite) for Pump and Dump 

16,000 bbls per well**

Synthetic-based (internal olefin, ester) 10,000 bbls per well

Oil-based NA 

**The actual volume ordered out will be an estimated 16,000 bbls/well of mud. Once on location this volume will 

be cut back and mixed with seawater to different desired mud weights which will increase the volume that is 

discharged at the seafloor. The estimated volume that will be discharged at the seafloor will be approximately 

40,000 bbls/well (NOTE: there will be three wells drilled for a total of 120,000 bbls). 

(c) New or Unusual Technology 

Anadarko does not propose to use any new or unusual technology to drill the well proposed in this plan. 

(d) Bonding Statement 

The bond requirements for the activities and facilities proposed in this EP are satisfied by an area-wide 

bond furnished and maintained according to 30 CFR part 256, subpart I; NTL No. 2000-G16, “Guidelines 

for General Lease Surety Bonds,” and National NTL No. 2008-N07, “Supplemental Bond Procedures”. 

(e) Oil Spill Financial Responsibility (OSFR) 

Anadarko Petroleum Corporation (Company Number 00981) has demonstrated oil spill financial 

responsibility for the facilities proposed in this EP according to 30 CFR Part 253, and NTL No. 2008-

N05, “Guidelines for Oil Spill Financial Responsibility for Covered Facilities”. 

(f) Deepwater Well Control Statement 

Anadarko Petroleum Corporation (Company Number 00981) has the financial capability to drill a relief 

well and conduct other emergency well control operations if required. 

(g) Blowout Scenario

Anadarko prepared this blowout scenario pursuant to guidance provided in NTL No. 2010-N06. The 

Green Canyon 724 “A” (GC 724 #1) is addressed in this blowout scenario since it is the location with the 

highest potential worst case discharge (WCD) rate for Green Canyon Block 724. A similar approach 

would be taken in the event of a blowout for the wells covered under this plan. Based on NTL No. 2010-
 

N06 guidance, the maximum hydrocarbon discharge for Green Canyon Block 724 is calculated to be 

201,530 BOPD.

Purpose 

This information provides a generic blowout scenario, additional information regarding any potential oil 

spill, the measures Anadarko Petroleum will take to prevent a blowout, and if necessary, promptly 

respond to manage a blowout scenario if one occurs. The following information is pursuant with 30 CFR 

250.213(g), 250.219, 250.250 and NTL No. 2010-N06. 

Background 

This information has been developed to document the additional information requirements for 

Exploration Plans as requested by NTL No. 2010-N06. . 

INFORMATION REQUIREMENTS

Blowout Scenario 

The GC 724 #1 well will be drilled to the sand objective, as outlined in the Geological and Geophysical 

Information section of this Plan, utilizing a MODU rig with a marine riser and subsea BOP. 

The Blowout Scenario assumes the well has reached its objective TD and a hydrocarbon influx occurs 

from the objective and ancillary intervals, followed by a well control event. The subsea BOP and marine 

riser fail, and a blowout occurs at the seabed. The WCD scenario assumes 12-1/4” open-hole across the 

objective intervals and 13-5/8” casing back to the mudline, as per the attached wellbore schematic 

(Attachment H-1). The WCD scenario assumes simultaneous flow from the objective zones. 

Estimated Flow Rate of the Potential Blowout 

Category Initial EP 

Type of Activity Drilling 

Facility Location (area/block) Green Canyon Block 724 

Facility Designation MODU 

Distance to Nearest Shoreline (miles) 122 

Uncontrolled Blowout (volume per day) 201,530 bbls 

Type of Fluid(s) Crude Oil 

a) Potential for the well to bridge over: 

Mechanical collapse of the reservoirs in the open-hole section of the wellbore was not considered. 

b) Measures to enhance the ability to conduct effective and early intervention in the event of a 

blowout: 

The likelihood of surface intervention to stop a blowout is high and based on the following 

equipment specific to the MODU that has been contracted to do this drilling program: 

 ROV Secondary BOP Control System: The BOP is confirmed to have a ROV Intervention 

Panel and circuits that have the following attributes: 

 Hot stab is capable of closing one set of:

- Blind-Shear Rams (one set)
 

- Pipe Rams (one set)

- Unlatch the Lower Marine Riser Package 

 ROV hot stab to be function tested in conjunction with the Stump test and tested at the 

same rate and pressure as the pump installed on the ROB used by the rig. 

 BOP panels also can be operated by an ROV from an independent supply boat in the 

event of a loss-of-rig scenario 

 Deadman/Autoshear Function: The rig is equipped with an automated sequence that closes 

the blind shear rams in the event of any of the following scenarios: 

 Inadvertent disconnect of the LMRP 

 Loss of both hydraulic pressure and electrical supply from the surface BOP control 

system

No human interface is required once these systems are armed. 

c) Availability of a rig to drill a relief well: 

Per the preliminary Mutual Aid agreements that are being worked between E&P Operators in the 

Gulf of Mexico, Anadarko will select from the best rig option available in the Gulf of Mexico fleet 

if and when it is required for relief well work. As of March 30, 2014, there were over 20 

additional rigs capable of operating under these conditions in the Gulf of Mexico. A rig that could 

be used to drill a relief well is the Transocean Discoverer Clear Leader, which is a drillship 

capable of drilling in 12,000’ of water without any constraints. The rig is currently under contract 

to Chevron and is on location in Keathley Canyon 829 working on the Buckskin Prospect. 

There are no nearby platforms from which to drill a relief well. It is not feasible to drill a relief 

well from land. 

d) Rig constraints: 

A rig capable of drilling in 5,500’ of water with at least a 10k Stack is required for any relief well 

operation. The Transocean Discoverer Clear Leader drillship meets these requirements. 

e) Time taken to mobilize a rig and drill a relief well: 

An estimate of 7–21 days is required to suspend operations on a deepwater GOM well and begin 

drilling the relief well. This assumes 0–14 days to suspend current operations on an existing well 

and 7 days to mobilize and be ready to spud the relief well. The estimated time to drill the relief 

well is 85 days, for a total estimated time of 92–106 days from time of blowout to finishing the 

relief well. 
 

f) Assumptions and calculations used in approved or proposed Oil Spill Response Plan:

 The Merlin reservoir simulator and Avalon nodal analysis programs were used to estimate the 

WCD for this well. Supporting input data can be found on Data Sheets 1, 2, and 3, and 

Merlin and Avalon files are included as Electronic Attachments 1 and 2. At the seafloor, the 

estimated worst case discharge for the well is 201,530 BOPD based on the objective sand 

intervals. 

 The maximum total volume during a blowout could potentially be 21,362,180 bbls assuming 

106 days for the maximum duration of a blowout, multiplied by the worst case daily 

uncontrolled blowout volume of 201,530 bbls. 

g) Measures taken to reduce the likelihood of a blowout: 

 Well Design: Anadarko utilizes a systematic well design process for the planning and 

construction of a well operation. This process taps into the vast depth of experience 

Anadarko possesses in the Deep Water drilling arena and involves a multi-team peer review 

of the well design, shallow hazards, and formation pressure hazards expected during drilling. 

This process minimizes the potential for an unplanned well control event that could lead to a 

blowout. This process will also include a Registered Professional Engineer review and 

approval of the final casing design and cementing program. 

A detailed pre-drill assessment of formation pressure provided by Anadarko’s Geological and 

Geophysical team, along with third-party consultants, allows for a mud program that provides 

an overbalanced mud weight for the safe drilling of the well. For an exploration well, this 

may also include taking formation pressures to confirm the actual formation pressure during 

the well construction process to minimize the risk of an unplanned well control event. The 

pore pressure environment is understood due to the nearby offset wells. 

The well construction process also requires a systematic review and management acceptance 

of the start-up preparation work for the rig and crews and the third-party technical audit work 

on the rig and the rig’s well control equipment. This measures the rig’s ability to handle an 

unplanned well control event, and it provides assurance the rig can successfully mitigate a 

loss of well control event and prevent it from becoming a blowout scenario. 

 Barrier Philosophy: For all well designs, Anadarko requires and uses a redundant barrier 

philosophy, which is two independent tested barriers including one mechanical barrier, across 

each flow path during well operations. 

For the final casing string (or liner if it is the final string), there shall be two mechanical 

barriers in addition to cement inside the wellbore. 

It is also standard practice to perform pressure tests, in accordance with the law, to confirm 

integrity on all relevant barriers. 
 

In addition, all intermediate and production casing strings returned to the wellhead will be 

locked down prior to proceeding with subsequent wellbore construction. 

 BOP and Well Control Equipment: The rig will have an 18-3/4” 15k psi BOP with 

primary and secondary BOP control systems. The BOP will have been completely 

recertified, compliant to OEM specifications, by a qualified third-party. Prior to 

commencement of operations, an independent third-party will verify the subsea BOP is 

designed for the specific equipment on the rig and the specific well design. [250.416(f)] 

 BOP and Well Control Equipment Testing: To ensure effectiveness of the BOP and well 

control equipment, a testing program will be conducted prior to running the BOP and then 

during the well operations. This testing program will provide compliance with current 

federal regulations for pressure and function testing. It will also provide periodic assurance 

on the performance of both primary and secondary BOP control systems including actual 

interface operations with the ROV and ROV panel. 

 Well Control Training and Drills: Anadarko requires key nominated onshore and offshore 

positions, including rig contractor personnel, hold a WellCAP or equivalent well control 

training certificate, renewed every two years for the type of floating drilling operation being 

conducted. Anadarko also monitors compliance for its personnel with the federal regulations 

and Sub-Part O for well control training. 

A comprehensive program of well control drills will be conducted offshore to ensure 

readiness to identify and manage a well control situation; thereby minimizing the potential for 

a well control event to lead to a blowout scenario.

h) Arrangements for drilling a relief well: 

 Anadarko maintains a master agreement with Wild Well Control, Inc. for advice, 

management, engineering, well kick pre- and post-modeling, and resource support for an 

unplanned loss-of-well-control event. Wild Well Control, Inc. will be contacted and 

mobilized, if required, to support Anadarko’s operational team, both at onshore and offshore 

locations. 

 The conceptual relief well design is similar to the design of the GC 724 #1 well with respect 

to identical casing weights, grades, and setting points. A site clearance letter has been 

prepared that includes an assessment of the specific seafloor and subsurface hazards for an 

area within a 2,000 ft radius of the primary location, within which a relief well could be 

drilled. There is negligible potential for high-density chemosynthetic or other benthic 

communities within this 2,000 ft radius. Depending on the nature of the blowout scenario, 

well geometry, and total depth required to intersect the blowout, previously submitted surface 

locations and/or additional surface locations will be submitted and reviewed to determine the 
 

most appropriate location of the relief well. 

 Anadarko’s philosophy is to carry adequate inventory in stock to drill a complete well(s) 

from surface to TD. Back-up long-lead equivalent to the original well design will be carried 

in stock to allow a rapid response. This includes a spare deepwater subsea wellhead system, 

the large OD casing (36”, 28”, 22”, 18”, 16”), and required connectors. Smaller OD casing 

(13-5/8”, 11-7/8”, and 9-7/8”) is considered widely available on the ground in the GOM and 

would be resourced out of existing inventory or from suppliers as required. 

 Existing service agreements are in place for support services, including drilling fluids, casing 

running, cementing, ROVs, solids control, mud logging, directional drilling, LWD/MWD, 

logging, boats, and helicopters. 

 Specialist services for range finding to drill the relief well in close proximity to the original 

wellbore at the reservoir depth will be provided through Vector Magnetics, LLC. Sperry 

Drilling/Halliburton and Schlumberger have in-house personnel to supplement Vector 

Magnetics, LLC, under our existing directional drilling agreements.
 

C 

GEOLOGICAL AND GEOPHYSICAL INFORMATION 

(a) Geological Description 

Discussions regarding geologic information are considered proprietary and have been omitted from this 

public copy of the EP, along with the attachments. 

(b) Structure Contour Maps 

Current structure maps drawn to the top of each productive hydrocarbon sand showing the entire lease 

block, the surface locations of each well and locations of geological cross-sections, are enclosed as 

Attachment C-1.

(c) Interpreted 2-D and/or 3-D Seismic Lines 

Interpreted seismic lines are enclosed as Attachment C-2.

(d) Geological Structure Cross-Sections 

Interpreted geological structure cross-sections showing the location and depth of each proposed well are 

enclosed as Attachment C-3.

(e) Shallow Hazards Report 

A Shallow Hazards Report prepared by Fugro GeoServices, Inc. was previously submitted with the Initial 

Exploration Plan for Green Canyon Block 768, which covers the proposed well’s surface locations. 

(f) Shallow Hazards Assessment 

Shallow Hazards Site Clearance Letters for the proposed well’s surface locations in Green Canyon Block 

768 are enclosed as Attachment C-4. 

Since the wells have a surface location with 500’ of the previously approved GC 768 BB well (drilled as 

the GC 768 #004), the three wells proposed under this plan will utilize the Site Clearance Letter from the 

GC 768 BB location. 

(g) High-resolution Seismic Lines 

High resolution seismic lines are enclosed as Attachment C-5.

(h) Stratigraphic Column 

A generalized stratigraphic column depicting the wells from the seafloor to total depth is included as 

Attachment C-6. 

(i) Time Vs. Depth Tables 

The proposed activities under this EP are not considered to be in areas where there is no well control. 

Therefore, a seismic travel time versus depth table is not required per NTL No. 2008-G04. 




















 

D 

HYDROGEN SULFIDE INFORMATION 

The GC 724 wells will only penetrate supra-salt sections previously penetrated by four of the GC 

768 wells (within approximately 250’ of the surface location of proposed well) and had no 

recorded amounts of Hydrogen Sulfide. The objective interval has been penetrated by all of the 

Ticonderoga Field wells mentioned above, the closest being the Kerr McGee (Anadarko) GC 

768-3 (API # 608114050200) well at a distance of 2,500’. None of these penetrations 

encountered any Hydrogen Sulfide within the aforementioned section. Since no (H2S) was 

encountered in any of these wells we request the area be classified as a "zone where the 

absence of H2s has been confirmed.” 
 

E 

 BIOLOGICAL, PHYSICAL, AND SOCIOECONOMIC INFORMATION 

(a) Chemosynthetic Communities Report 

The seafloor disturbing activities proposed in this plan are in approximately 5,257’of water. The wells 

will be drilled with a DP Drillship or DP Semisubmersible drilling unit. 

Maps 

A map prepared using 3-D seismic data to depict bathymetry, seafloor and shallow geological 

features, and surface location of the proposed well is included in Section A. 

Analysis 

Features or areas that could support high-density chemosynthetic communities are not located 

within 2000 feet of each proposed muds and cuttings discharge location. 

Features or areas that could support high-density chemosynthetic communities are not located 

within 250 feet of any seafloor disturbances. 

(b) Topographic Features Map 

The proposed activities are not within 1,000 feet of a no-activity zone or within the 3-mile radius 

zone of an identified topographic feature. Therefore, no map is required per NTL No. 2008-G04. 

(c) Topographic Features Statement (Shunting) 

Anadarko does not plan to drill more than two wells from the same surface location within the 

Protective Zone of an identified topographic feature. Therefore, the topographic features 

statement required by NTL No. 2008-G04 is not applicable. 

(d) Live Bottoms (Pinnacle Trend) Map 

The activities proposed in this plan are not within 200 feet of any pinnacle trend feature with 

vertical relief equal to or greater than 8 feet. Therefore, no map is required per NTL No. 2008-

G04. 

(e) Live Bottoms (Low Relief) Map 

The activities proposed in this plan are not within 100 feet of any live bottom low relief features. 

Therefore, no map is required per NTL No. 2008-G04. 

(f) Potentially Sensitive Biological Features 

The activities proposed in this plan are not within 200 feet of any potentially sensitive biological 

features. Therefore, no map is required per NTL No. 2008-G04. 
 

(g) Remotely Operated Vehicle (ROV) Monitoring Survey Plan 

Green Canyon Block 724 is located within Deepwater Grid Area 10. This grid is considered to 

have “adequate ROV survey coverage”, and therefore, under the guidance set out in NTL No. 

2008-G06, a Remotely Operated Vehicle Monitoring Survey Plan is not required. 

(h) Threatened and Endangered Species Information 

Under Section 7 of the Endangered Species Act (ESA) all federal agencies must ensure that any 

actions they authorize, fund, or carry out are not likely to jeopardize the continued existence of a 

listed species, or destroy or adversely modify its designated critical habitat. 

In accordance with the 30 CFR 250, Subpart B, effective May 14, 2007, and further outlined in 

Notice to Lessees (NTL) 2008-G04, lessees/operators are required to address site-specific 

information on the presence of federally listed threatened or endangered species and critical 

habitat designated under the ESA and marine mammals protected under the Marine Mammal 

Protection Act (MMPA) in the area of proposes activities under this plan. 

Currently there are no designated critical habitats for the listed species in the Gulf of Mexico 

Outer Continental Shelf; however, it is possible that one or more of these species could be seen 

in the area of our operations. The following table reflects the Federally-listed endangered and 

threatened species in the lease area and along the northern Gulf coast: 
 

pecies Scientific Name Status 

Potential Presence Critical Habitat Designated in 

Gulf of Mexico Lease Area Coastal 

Marine Mammals 

Sei whale Balaenoptera borealis E Xa -- None 

Blue whale Balaenoptera musculus E Xa -- None 

Fin whale Balaenoptera physalus E Xa -- None 

North Atlantic right whale Eubalaena glacialis E Xa -- None 

Humpback whale Megaptera novaeangliae E Xa -- None 

Sperm whale Physeter macrocephalus E X -- None 

West Indian manatee Trichechus manatus latirostris E -- X Florida (Peninsular) 

Sea Turtles 

Loggerhead turtle Caretta caretta T X X None 

Green turtle Chelonia mydas T, Eb X X None 

Leatherback turtle Dermochelys coriacea E X X None 

Hawksbill turtle Eretmochelys imbricata E X X None 

Kemp’s ridley turtle Lepidochelys kempii 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)

Smalltooth sawfish Pristis pectinata E -- X Southwest Florida and the 

Florida Keys 

Invertebrates

Elkhorn coral Acropora palmata E -- X Flower Garden Banks 

Terrestrial Mammals 

Beach mice (Alabama, 

Choctawhatchee, 

Perdido Key, St. Andrew) 

Peromyscus polionotus E -- X Alabama and Florida 

(Panhandle) beaches 

Abbreviations: 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 green sea turtle is threatened, except for the Florida breeding population, which is listed as endangered.

The Environmental Impact Analysis in Section N of this plan further discusses potential impacts and mitigation 

measures related to threatened and endangered species. 

(i) Archaeological Report 

Green Canyon Block 724 is not located in an area designated as having high archaeological potential and, as such, 

an Archaeological Report is not required per NTL No. 2011-JOINT-G01. However, an Archaeological Report 

prepared by Fugro Geoservices, Inc covering the proposed Green Canyon Block 724 well’s surface locations in 

Green Canyon Block 768 was previously submitted along with the Supplemental Exploration Plan Control No. S7604. The survey was conducted in accordance with the latest guidelines established by the BOEMRE in 2011. 

(j) Air and Water Quality Information

This EP does not propose activities for which the State of Florida is an affected State. Therefore, the discussion 

required per NTL 2008-G04 is not applicable to this EP. 
 

(k) Socioeconomic Information 

The activities proposed in this plan are not located offshore Florida. Therefore, socioeconomic information required 

per NTL 2008-G04 is not applicable to this EP. 
 

F 

WASTE AND DISCHARGE INFORMATION 

The following estimates were prepared utilizing Anadarko’s experience with similar drilling operations. 

Estimated maximum discharge rates are reflected below. Projected amounts may vary during the course 

of drilling and/or completion operations. 

(a) Projected Generated Wastes 

Type of Waste Composition Projected Amount Treatment/Storage/Disposal 

Synthetic-based 

drilling fluids 

Synthetic-based drilling 

muds 

10,000 bbls/well Re-use and/or transport to shore in 

DOT approved containers to 

Fourchon, Louisiana and on to 

base/transfer station. If recycled, 

returned to vendor (Bariod or MI). 

Cuttings wetted with 

synthetic-based fluids 

Cuttings coated with 

synthetic drilling 

muds/fluids, including 

drilled out cement 

2,000 bbls/well Treated and discharge overboard 

*Note, an estimated 5-10% of cuttings 

may be transported to shore in tanks 

and/or cutting boxes and on to the 

base/transfer station if oil still 

remains. 

Water-based drilling 

fluids 

Water based drilling 

muds (NaCl saturated, 

seawater, freshwater, 

barite) 

40,000 bbls/well** Discharge overboard or at seafloor 

Cuttings wetted with 

water-based fluids 

Cuttings coated with 

water-based drilling 

muds/fluids 

2,000 bbls/well Discharge overboard 

Chemical product 

waste (well treatment 

fluids) 

Ethylene glycol 

Methanol 

1,500bbls total 

375 bbls total 

Transport to shore in DOT approved 

containers to Fourchon, Louisiana for 

pick up. 

Completion Fluids Brine, spent acid, prop 

sand, debris 

3,000 bbls/well Transport to shore in DOT approved 

containers to Fourchon, Louisiana and 

on to Newpark Base. 

Non-pollutant 

completion fluids 

Low density uninhibited 

completion brines 

5,000 bbls/well Discharge overboard 

Workover fluids Brine, spent acid, prop 

sand, debris 

3,000 bbls/well Transport to shore in DOT approved 

containers to Fourchon, Louisiana and 

on to Newpark Base. 

Trash and debris Refuse generated during 

operations 

750 bbls total Transport to shore in disposal bags by 

vessel to shorebase for pickup by 

municipal operations. 

Sanitary Wastes* Treated human body 

waste 

2,250,000 gals total Chlorinate and discharge overboard 

Domestic Waste* Gray water 2,250,000 gals total Chlorinate and discharge overboard 

Deck drainage Platform washings and 

rainwater 

1,575,000 bbls total Treat for oil and grease and discharge 

overboard 

Produced water N/A N/A N/A 

Desalinization Unit Seawater 157,500 bbls total Discharge overboard 

Wash water Drill water (fresh) 22,500 bbls total Discharge overboard 

Blowout preventer 

fluid 

Blend (3% Stack Magic 

& Filtered Fresh Water) 

59,464 gals total Discharge at seafloor 

Ballast water Seawater 47,650 m3/year Discharge overboard 

Bilge water Seawater 142,650 bbls total Discharge overboard through 15 ppm 

equipment 

Excess cement at the 

seafloor*** 

Nitrified cement slurry 1,500 bbls/well Discharge at seafloor 
 

Fire water Seawater 137,142 bbls/day/well Discharge overboard 

Cooling water Seawater 137,142 bbls/day/well Discharge overboard 

Produced Sand N/A N/A N/A 

Used oil Excess oil from engines 1,613 bbls total Transport in DOT approved containers 

to shore for recycling 

*The rig is designed for maximum personnel capacity of 200 people. The discharge rates are based off of maximum personnel 

capacity but will generally not have this many personnel onboard during drilling and/or completion operations. 

**The actual volume ordered out will be an estimated 16,000 bbls/well of mud. Once on location this volume will be cut back 

and mixed with seawater to different desired mud weights which will increase the volume that is discharged at the seafloor. The 

estimated volume that will be discharged at the seafloor will be approximately 40,000 bbls/well (NOTE: there will be three wells 

drilled for a total of 120,000 bbls). 

(b) Projected Ocean Discharges

Type of Waste Total Amount to be 

Discharged 

Discharge Rate Discharge Method 

Sanitary Wastes* 2,250,000 gals total 25 gals per person daily Chlorinate and discharge overboard 

Domestic waste* 2,250,000 gals total 25 gals per person daily Chlorinate and discharge overboard 

Deck drainage 1,575,000 bbls total 3500 bbls/day Treat for oil and grease and discharge 

Blowout preventer fluid 59,464 gals total 925 gals/week/well; 

Vents on a weekly basis 

Discharge at seafloor 

Desalinization Unit 157,500 bbls total 350 bbls/day Discharge overboard 

Wash water 22,500 bbls total 50 bbls/day Discharge overboard 

Ballast water 47,650 m3/year Not continuous Discharge overboard 

Bilge water 142,650 bbls total 317 bbls/day Discharge overboard through 15 ppm 

equipment 

Excess cement at the 

seafloor** 

4,500 bbls total 20 bbls/min Discharge at seafloor 

Fire water 61,713,900 bbls total 137,142 bbls/day Discharge overboard 

Cooling water 61,713,900 bbls total 137,142 bbls/day Discharge overboard 

Cuttings wetted with Waterbased fluids** 6,000 bbls total 1,000 bbls/hr max Discharge overboard 

Water-based drilling 

fluids** 

120,000 bbls total** 1,000 bbls/hr max Discharge at seafloor or overboard 

Cuttings wetted with 

Synthetic-based fluids** 

8,000 bbls total NA Treated and discharge overboard 

*Note, an estimated 5-10% of 

cuttings may be transported to shore 

in tanks and/or cutting boxes and on 

to the base/transfer station if oil still 

remains. 

Non-pollutant completion 

fluids 

15,000 bbls total 100 bbl/hour Discharge overboard 

*The rig is designed for maximum personnel capacity of 200 people. The discharge rates are based off of maximum personnel 

capacity but will generally not have this many personnel onboard during drilling and/or completion operations. 

**The actual volume ordered out will be an estimated 16,000 bbls/well of mud. Once on location this volume will be cut back 

and mixed with seawater to different desired mud weights which will increase the volume that is discharged at the seafloor. The 

estimated volume that will be discharged at the seafloor will be approximately 40,000 bbls/well (NOTE: there will be three wells 

drilled for a total of 120,000 bbls). 

 (c) Modeling Report 

The proposed activities under this plan do not meet the U.S. Environmental Protection Agency 

requirements for an individual NPDES permit. Therefore, modeling report requirements per NTL No. 

2008-G04 is not applicable to this EP. 
 

G 

AIR EMISSIONS INFORMATION 

(a) Screening Questions 

Screening Questions for EP’s Yes No 

Is any calculated Complex Total (CT) Emission amount (in tons) associated with your 

proposed exploration activities more than 90% of the amounts calculated using the 

following formulas: CT = 3400D2/3 for CO, and CT = 33.3D for the other air pollutants 

(where D = distance to shore in miles)? 

No 

Do your emission calculations include any emission reduction measures or modified 

emission factors? 

Yes 

Are your proposed exploration activities located east of 87.5 W longitude? No 

Do you expect to encounter H2S at concentrations greater than 20 parts per million (ppm)? No 

Do you propose to flare or vent natural gas for more than 48 continuous hours from any 

proposed well? 

 No 

Do you propose to burn produced hydrocarbon liquids? No 

(b) Emissions Worksheets 

Air emission worksheets have been prepared utilizing the maximum horsepower rating from an Anadarko 

contracted DP drillship, the Noble Bob Douglas. The Noble Bob Douglas has six main engines. The 

average number of engines on-line at once will be four engines. Rigs typically do not operate at maximum 

horsepower capacity or engine load, therefore Anadarko has opted to calculate the plan emission amounts 

based on the total horsepower rating and 50% average engine load. A different rig may be utilized (DP 

drillship or DP semi-submersible); but the horsepower rating, average engine load, and air emissions will 

be equal to, or less than, the calculated plan emission amounts shown on the following pages. Air 

emission worksheets are enclosed as Attachment G-1. 

(c) Summary Information 

The following tables summarize information regarding the peak year emissions generated from the Plan 

Emissions and Complex Total Emissions: 

If drilled with a DP Drillship or DP Semi (Horsepower equal to or less than the Noble Bob Douglas): 

Air Pollutant Plan Emission 

Amounts1

 (tons)

Calculated 

Exemption 

Amounts2

 (tons)

Calculated Complex 

Total Emission 

Amounts3 (tons)

Particulate matter (PM) 69.91 4062.60 N/A 

Sulphur dioxide (SO2) 320.73 4062.60 N/A 

Nitrogen oxides (NOx) 2405.32 4062.60 N/A 

Volatile organic compounds (VOC) 73.90 4062.60 N/A 

Carbon monoxide (CO) 535.98 83634.50 N/A 

The air emission calculations were calculated by: 

Jill Fowler 

Regulatory Analyst 

(832) 636-1554 

jill.fowler@anadarko.com 
EXPLORATION PLAN (EP)

AIR QUALITY SCREENING CHECKLIST

OMB 

COMPANY Anadarko Petroleum Corporation

AREA Green Canyon

BLOCK 724 & 768LEASE OCS-G 34557 & 21817

PLATFORMWELL A, AA, AAA

COMPANY CONTACT Jill FowlerTELEPHONE NO. 832-636-1554

REMARKS Drill and complete 3 wells total

FORM BOEM-0138 (December 2011 - Supersedes all previous versions of this form which may not be used). Page 1 of 8
EMISSIONS FACTORS

Fuel Usage Conversion Factors Natural Gas Turbines Natural Gas Engines Diesel Recip. Engine RE

SCF/hp-hr 9.524 SCF/hp-hr 7.143 GAL/hp-hr 0.0483 AP42 

Equipment/Emission Factors units PM SOx NOx VOC CO RENG Turbines gms/hp-hr 0.00247 1.3 0.01 0.83 AP42 3.2-NG 2-cycle lean gms/hp-hr 0.00185 10.9 0.43 1.5 AP42 NG 4-cycle lean gms/hp-hr 0.00185 11.8 0.72 1.6 AP42 NG 4-cycle rich gms/hp-hr 0.00185 10 0.14 8.6 AP42 Diesel Recip. < 600 hp. gms/hp-hr 1 1.468 14 1.12 3.03 AP42 Diesel Recip. > 600 hp. gms/hp-hr 0.32 1.468 11 0.33 2.4 AP42 Diesel Boiler lbs/bbl 0.084 2.42 0.84 0.008 0.21 AP42 1.3NG Heaters/Boilers/Burners lbs/mmscf 7.6 0.593 100 5.5 84 P42 1.4-1, 1NG Flares lbs/mmscf 0.593 71.4 60.3 388.5 AP42 1Liquid Flaring lbs/bbl 0.42 6.83 2 0.01 0.21 AP42 1.3-Tank Vapors lbs/bbl 0.03 E&P FFugitives lbs/hr/comp. 0.0005 API SGlycol Dehydrator Vent lbs/mmscf 6.6 La. DGas Venting lbs/scf 0.0034

Sulphur Content Source Value Units

Fuel Gas 3.33 ppm

Diesel Fuel 0.4 % weight

Produced Gas( Flares) 3.33 ppm

Produced Oil (Liquid Flaring) 1 % weight

FORM BOEM-0138 (December 2011 - Supersedes all previous versions of this form which may not be used). Page 2 of 8
EMISSIONS CALCULATIONS 1ST YEAR

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Anadarko Petroleum CorGreen Canyon 724 & 768 OCS-G 34557 & 21817 A, AA, AAA Jill Fowler 832-636-1554 

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

DRILLING PRIME MOVER>600hp diesel 64370 1554.5355 50% 37308.85 24 60 22.69 104.07 779.81 23.39 170.14 16.33 

PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 BURNER diesel 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 AUXILIARY EQUIP<600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

3 trips/week VESSELS>600hp diesel(crew) 14805 715.0815 17161.96 6 26 10.44 47.87 358.71 10.76 78.26 0.81 2 trips/week VESSELS>600hp diesel(supply) 9266 447.5478 10741.15 6 17 6.53 29.96 224.51 6.74 48.98 0.33 

VESSELS>600hp diesel(tugs) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

FACILITY DERRICK BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 INSTALLATION MATERIAL TUG diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(crew) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 VESSELS>600hp diesel(supply) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 MISC. BPD SCF/HR COUNTTANK- 0 0 0 0.00 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 WELL TEST GAS FLARE 625000 24 0 0.37 44.63 37.69 242.81 

2014 YEAR TOTAL 39.65 182.27 1407.66 78.58 540.20 17.48 

EXEMPTION 

CALCULATION

DISTANCE FROM LAND IN 

MILES 4062.60 

122.0

Average 

Engine 

Load %

FORM BOEM-0138 (December 2011 - Supersedes all previous versions of this form which may not be used). Page 3 of 8
EMISSIONS CALCULATIONS 1ST YEAR

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Anadarko Petroleum CorGreen Canyon 724 & 768 OCS-G 34557 & 21817 A, AA, AAA Jill Fowler 832-636-1554 

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

DRILLING PRIME MOVER>600hp diesel 64370 1554.5355 50% 37308.85 24 240 22.69 104.07 779.81 23.39 170.14 65.33 

PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 BURNER diesel 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 AUXILIARY EQUIP<600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

3 trips/week VESSELS>600hp diesel(crew) 14805 715.0815 17161.96 6 103 10.44 47.87 358.71 10.76 78.26 3.22 2 trips/week VESSELS>600hp diesel(supply) 9266 447.5478 10741.15 6 69 6.53 29.96 224.51 6.74 48.98 1.35 

VESSELS>600hp diesel(tugs) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

FACILITY DERRICK BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 INSTALLATION MATERIAL TUG diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(crew) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 VESSELS>600hp diesel(supply) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 MISC. BPD SCF/HR COUNTTANK- 0 0 0 0.00 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 WELL TEST GAS FLARE 625000 24 4 0.37 44.63 37.69 242.81 

2015 YEAR TOTAL 39.65 182.27 1407.66 78.58 540.20 69.91 

EXEMPTION 

CALCULATION

DISTANCE FROM LAND IN 

MILES 4062.60 

122.0

Average 

Engine 

Load %

FORM BOEM-0138 (December 2011 - Supersedes all previous versions of this form which may not be used). Page 3 of 8
EMISSIONS CALCULATIONS 1ST YEAR

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKS

Anadarko Petroleum CorGreen Canyon 724 & 768 OCS-G 34557 & 21817 A, AA, AAA Jill Fowler 832-636-1554 

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR 

Diesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/D

Burners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM 

DRILLING PRIME MOVER>600hp diesel 64370 1554.5355 50% 37308.85 24 150 22.69 104.07 779.81 23.39 170.14 40.83 

PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 PRIME MOVER>600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 BURNER diesel 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 AUXILIARY EQUIP<600hp diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

3 trips/week VESSELS>600hp diesel(crew) 14805 715.0815 17161.96 6 64 10.44 47.87 358.71 10.76 78.26 2.00 2 trips/week VESSELS>600hp diesel(supply) 9266 447.5478 10741.15 6 43 6.53 29.96 224.51 6.74 48.98 0.84 

VESSELS>600hp diesel(tugs) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

FACILITY DERRICK BARGE diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 INSTALLATION MATERIAL TUG diesel 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 

VESSELS>600hp diesel(crew) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 VESSELS>600hp diesel(supply) 0 0 0.00 0 0 0.00 0.00 0.00 0.00 0.00 0.00 MISC. BPD SCF/HR COUNTTANK- 0 0 0 0.00 

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 WELL TEST GAS FLARE 625000 24 2 0.37 44.63 37.69 242.81 

2016 YEAR TOTAL 39.65 182.27 1407.66 78.58 540.20 43.68 

EXEMPTION 

CALCULATION

DISTANCE FROM LAND IN 

MILES 4062.60 

122.0

Average 

Engine 

Load %

FORM BOEM-0138 (December 2011 - Supersedes all previous versions of this form which may not be used). Page 3 of 8
SUMMARY

COMPANY AREA BLOCK LEASE PLATFORM WELLAnadarko Petrol Green Canyon 724 & 768 OCS-G 34557 & 21817 A, AA, AAA

Emitted Substance

Year

 PM SOx NOx VOC CO

2014 17.48 80.19 600.89 18.03 131.102015 69.91 320.73 2405.32 73.90 535.982016 43.68 200.39 1502.57 45.95 333.432017 0.00 0.00 0.00 0.00 0.002018 0.00 0.00 0.00 0.00 0.002019 0.00 0.00 0.00 0.00 0.002020 0.00 0.00 0.00 0.00 0.002021 0.00 0.00 0.00 0.00 0.002022 0.00 0.00 0.00 0.00 0.002023 0.00 0.00 0.00 0.00 0.00

Allowable 4062.60 4062.60 4062.60 4062.60 83634.50

FORM BOEM-0138 (December 2011 - Supersedes all previous versions of this form which may not be used). Page 8 of 8
 

H

OIL SPILL INFORMATION 

(a) Oil Spill Response Planning 

(i) OSRP Information 

All the proposed activities and facilities in this EP are covered by the Regional Oil Spill 

Response Plan (OSRP) approved on September 25, 2013 for Anadarko Petroleum Corporation 

and its subsidiaries, Anadarko US Offshore Corporation and Anadarko E&P Company L.P. 

(Company Numbers 00981, 02219 and 00148, respectively) in accordance with 30 CFR Part 

254. 

(ii) Spill Response Sites 

Primary Response Equipment Location(s) Preplanned Staging Location(s) 

Houma, Louisiana 

Harvey, Louisiana 

Venice, Louisiana 

Lake Charles, Louisiana 

Galveston, Texas 

Fourchon, Louisiana 

Harvey, Louisiana 

Venice, Louisiana 

Cameron, Louisiana 

Galveston, Texas 

(iii) OSRO Information 

Anadarko maintains a contract with Clean Gulf Associates (CGA) for spill response equipment. 

Various equipment locations are staged throughout the Gulf of Mexico. CGA equipment can be 

referenced on their website: http://www.cleangulfassoc.com/. Personnel would be obtained from 

the Marine Spill Response Corporation’s (MSRC) STARS network, including a supervisor to 

operate the equipment. 

In addition Anadarko has a contract with the Marine Spill Response Corporation (MSRC) for 

spill response equipment. MSRC stages equipment throughout the Gulf of Mexico and has 

recently completed a large expansion of its resources, with particular focus on deepwater. The expansion 

is known as “Deep Blue”. MSRC capabilities and a complete equipment listing are available online at: http://www.msrc.org/. 

Anadarko is also a member of the Marine Well Containment Company (MWCC), which 

provides access to containment response capabilities and includes subsea dispersant injection 

equipment. 
 

(iv) Worst-Case Scenario Determination 

Category Regional OSRP EP 

Type of Activity Exploratory Exploratory 

Facility Location 

(area/block) GC 683 GC 724 

Facility Designation GC 683 “G” GC 724 “A” 

Distance to Nearest 

Shoreline 120 miles 122 miles 

 Storage Tanks (total) N/A N/A 

 Flowlines (on facility) N/A N/A 

 Pipelines N/A N/A 

 Uncontrolled Blowout 410,000 bopd* 201,530 BOPD

Type of Oil(s) Oil Oil 

API Gravity 28.9o 30.9o -32.2o

*The volume denoted in the Regional OSRP is higher than the NTL No. 2010-N06 (403,608 bopd) calculations approved 

under EP Plan Control No. S-7623. Anadarko elected to denote a higher volume in the Regional OSRP for planning 

purposes to demonstrate equipment response capabilities per previous discussions with Mr. Mike Tolbert. 

Anadarko has determined that the worst-case scenario from the activities proposed in this Initial 

EP do not supersede the worst-case scenario for Green Canyon Block 683. 

Since Anadarko has the capability to respond to the worst-case spill scenario included in our 

Regional OSRP, and since the worst-case scenarios determined for our EP do not replace the 

worst-case scenario in our Regional OSRP last approved on September 25, 2013, I hereby certify 

that Anadarko 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 

EP. 

(b) Worst-Case Discharge Volume Assumptions 

Worst-case discharge (WCD) calculations and assumptions within this section utilized guidelines 

and requirements pursuant with NTL No. 2010-N06. The following information summarizes the 

WCD scenario and assumptions for Green Canyon Block 724: 

Discussions regarding geologic information are considered proprietary and have been omitted 

from this public copy of the EP, along with the attachments. 

 (c) Oil Spill Response Discussion

For the purpose of NEPA analysis, the largest spill volume originating from the proposed 

activity would be an uncontrolled blowout of the well during drilling operations at 201,530 

BOPD with an API gravity of 30.9o

 -32.2o. A discussion of the blowout scenario from this 

proposed activity is included within this Initial EP in accordance with NTL No. 2010-N06. 
 

Land Segment and Resource Identification Modeling

Trajectory of a spill and the probability of its impacting a land segment have been projected 

utilizing information in the Oil Spill Risk Analysis Model (OSRAM) for the Central Gulf of 

Mexico. Additional information may be referenced in the “Oil-Spill Risk Analysis: Contingency 

Planning Statistics for Gulf of Mexico OCS Activities” (OCS Report MMS 2004-026), using the 

average conditional probability for 3, 10, and 30 day impacts. 

Green Canyon Block 724 is located within Launch Area 45. According to the BOEMRE 

OSRAM, the trajectory indicates a 4% probability of potential impact to the shoreline in 

Cameron Parish, Louisiana. The results are shown in Table H-2. 

Cameron Parish is identified as the most probable potential impacted parish or county within the 

Gulf of Mexico for this operation. Cameron Parish is located in Louisiana and includes Cameron 

Prairie National Wildlife Refuge (NWR), East Cove Unit (a part of the Cameron Prairie NWR), 

Lacassine NWR, and Sabine NWR. 

Response 

Anadarko will make every effort to respond to the worst-case discharge as effectively as 

possible. Response equipment available to respond to the worst-case discharge and the estimated 

time of a spill response from oil spill detection to equipment deployment on-site is included in 

Table H-3. The table estimates individual times needed for procurement, load out, travel time to 

the site and deployment. In the event of an actual incident equipment and times can vary. 

For the purpose of response scenario discussion, an uncontrolled blowout of the well would be 

considered the largest potential spill volume at 201,530 BOPD. An ADIOS weathering model 

was run based on a similar type of oil expected to be produced from this well. Based on this 

information, approximately 16% (32,245 bbls) of the initial volume would be 

evaporated/dispersed within 24 hours. 

If approved and appropriate, 4 sorties (8,000 gallons) from the Basler aircraft and 8 sorties 

(9,600 gallons) from two DC-3 aircrafts could disperse approximately 7,540 barrels of oil. 

If the conditions are appropriate, and the necessary approvals and permits have been obtained, 

in-situ burning may be utilized. Based on in-situ burn operations during Deepwater Horizon, 

approximately 5% (10,267 bbls) of the total initial worst case discharge could be burned. 

Although unlikely in a spill lasting thirty (30) days, potential shoreline impact in Cameron 

Parish, Louisiana could occur depending on environmental conditions (wind, currents and 

temperature) at the time of an incident. Nearshore response may include the use of shoreline 

boom on beach areas, or protection/sorbent boom on vegetated areas. Surveillance and real time 

trajectories would aide in determining the most appropriate strategies to respond to a spill. 

Table H.3 provides an example of offshore and nearshore equipment, response times, and 

personnel to respond to a spill of 169,285 bbls, which is the estimated amount that would remain 
 

considering natural evaporation/dispersion at 24 hours. This amount could be further reduced 

through the application of aerial and subsea dispersants, and in-situ burning provided such 

applications/actions were approved. 

Anadarko’s contingency plan for dealing with this worst-case discharge would be to activate its 

Spill Management Team and equipment resources as described in its Gulf of Mexico Regional 

Oil Spill Response Plan (OSRP) and provide continuous support for the duration of the event. 

Response resources are activated and supplemented according to need. These resources would 

remain engaged in the response until the incident is deemed complete or until released by 

Unified Command. 

Anadarko is also a member of the Marine Well Containment Company (MWCC), which 

provides access to containment response capabilities and includes subsea dispersant injection 

equipment. 

In the event of a blowout, Anadarko may: 

 1. Evacuate personnel, if necessary. Deploy emergency responders in an effort to preserve 

human life, if necessary. 

 2. Assess the damage and attempt to stop the flow at the source, if safe to do so, to reduce 

the amount of oil discharged. 

 3. Notify agencies. 

 4. Assess the amount of oil that has been spilled and calculate additional potential of oil 

flow. A continuous aerial surveillance program would be used to assess the growth of the 

slick and the volume of oil on the water. Observations of the size of the slick on the 

water, combined with observations at the source, would be used to provide a constant 

update. Additional potential to release fuel from the remaining tanks onboard the 

dynamically positioned (DP) semi-submersible drilling rig would be determined by 

marine surveyors. Operations and Unified Command would continue to assess the 

adequacy of response equipment capacities based on this continually updated mass 

balance. 

 5. Convene the Spill Management Team (SMT). Organize Unified Command and establish 

objectives and priorities. 

 6. Monitor the oil spill with aerial surveillance and obtain trajectories. If oil is seaward 

bound, going away from land, discuss additional strategies with Unified Command. 

 7. If oil is moving in the direction of a shoreline and weather conditions are favorable, 

request approval to utilize dispersants. 

 a. Prior to commencing application operations, conduct an on-site survey in consultation 

with natural resource specialists to determine if any threatened or endangered species 
 

are present in the projected application area or otherwise at risk from dispersant 

application. 

 b. Upon approval, mobilize one Basler aircraft and two DC-3 aircrafts from Houma, with 

surveillance aircraft and spotter. Mobilize MSRC contracted aircraft(s) if needed. 

Rotate aircraft, spraying the leading edge of the spill and working back to the source. 

Monitor/sample for effectiveness (USCG SMART Team). Truck additional 

dispersants from CGA/MSRC stockpile to Houma, if necessary. 

 c. Dispersants are most effective when applied as soon after discharge as possible, since 

weathering of the oil decreases dispersant effectiveness. The estimated window of 

opportunity for most effective use of dispersants is within 48-72 hours post-release. 

The oil may still be dispersible after 72 hours on the water surface, but the 

effectiveness of dispersant use would likely be diminished after the oil has been on the 

water for more than three days. Ultimately, the USCG SMART monitoring protocol 

will be used to determine whether or not dispersant operations are effective. 

 d. Once the CGA HOSS barge is on location and in the skimming mode, dispersants 

would only be used if required and approved. 

 8. Deploy offshore mechanical oil containment and recovery equipment. Attempt to recover 

as much oil at sea as possible, utilizing: 

 a. The CGA HOSS barge, will be positioned in a stationary mode, will be situated downwind and down-current from location for long-duration, high-volume skimming. 

Based on average travel times, the HOSS barge could be on location within 

approximately 31 hours of the release. The de-rated skimming capacity of the HOSS 

barge is 43,000 bbls per day. However, only the oil encountered by a skimmer can be 

recovered. In order to maximize oil encounter rate, boom will be deployed in a 

V-configuration in front of the HOSS barge to funnel oil to the skimmers. If 

necessary, temporary barges can be activated to support continuous skimming 

operations. (These barges arrive on-site at approximately the same time as the HOSS 

barge.) For an on-going release, multiple barges are deployed to provide for 

continuous off-loading of skimmer storage vessels and shuttling of recovered oil to an 

onshore waste handling facility. Sufficient barges are available to provide enough 

temporary storage for continuous recovery operations. 

 b. CGA’s Fast Response Units (FRU) would arrive on-scene between approximately 

17-25 hours of the initial release. These skimmers operate downstream of the HOSS 

barge and are used to recover pockets and streamers of oil that may move past the 

large stationary skimmer. Each FRU has 200 barrels of on-board storage. Approval 

will be requested to decant water after gravity separation, through a hose forward of 

the skimmer, to optimize temporary storage capacity. A 42" Boom will be utilized to 

concentrate oil so that it is thick enough to be skimmed. 
 

 9. Dispersants, Fast Response Units (FRU), Oil Spill Response Vessels (OSRV or R/V) 

would typically work daylight hours only. The HOSS barge can operate continuously, 

including night operations. Available technology will be considered such as remote 

sensing devices that will enable 24 hour surveillance, trajectories, and planning. All 

response vessels are designed to be able to remain offshore continuously throughout the 

response. Even if sea conditions prohibit effective skimming, these resources would 

remain offshore until skimming operations could be commenced again. Safety would 

remain the first priority. 

 10. Prepare Site-Specific Waste Management Plan, Site Safety Plan, Decontamination Plans, 

Communications and Medical Plans. 

 11. If oil becomes a threat to any shoreline, data from the aerial surveillance, weather reports, 

and trajectories would be used to direct onshore teams to deploy protection/containment 

boom with reference to Area Contingency Plans and in coordination with State and 

Federal On-Scene Coordinators. 

 a. Implement pre-designated strategies. 

 b. Identify resources at risk in spill vicinity. 

 c. Develop/implement appropriate protection tactics. 

 12. Establish Site-Specific Wildlife Rescue and Rehabilitation Plan. 

The following types of additional support may be required for a blowout lasting 120 days. 

 Additional Oil Spill Removal Organization (OSRO) personnel to relieve equipment 

operators 

 Vessels for supporting offshore operations 

 Field safety personnel 

 Continued surveillance and monitoring of oil movement 

 Helicopter, video cameras 

 Infra red (night time spill tracking) capabilities, X-band radar 

 Barge to transport recovered oil from offshore skimming system, and temporary 

storage barges to onshore disposal sites that are identified in Area Contingency Plans 

(ACP) 

 Logistics needed to support equipment: 

- Staging areas 

- Parts, trailers, and mechanics to maintain skimmers and boom 

- Fueling facilities 

- Decontamination stations 

- Dispersant stockpile transported from Houston to Houma or other potential 

command post locations 

- Communications equipment and technicians 

 Logistics needed to support responder personnel 

- Medical aid stations 
 

- Safety personnel

- Food 

- Berthing 

- Additional clothing/safety supplies 

- Decontamination stations 

Louisiana CZM Containment Response Information 

Anadarko has the capability to respond and contain, to the maximum extent practicable as 

defined in 30 CFR 254.6 and 30 CFR 250.26(d)(1), to the estimated worst case discharge (WCD) 

associated with the proposed activity within 30 days. Deployment time for surface containment 

equipment is subject to availability and location, weather conditions, potential security zones 

around the spill site, and site/well specific assessment data. Personnel safety is always first and 

foremost. Refer to further details on equipment and timing provided in Section H–Oil Spill 

Information and Table H-3 of the EP. 

The potential WCD will be further evaluated during the Application for Permit to Drill (APD) 

process, including the Well Containment Screening Tool (WCST) and associated subsea 

containment plan for enhanced planning purposes. 

There will be no new or unusual technology deployed that has not been previously deployed for 

Gulf of Mexico oil spill prevention, control, and/or cleanup. 
 

Table H-1 

Worst Case Discharge Calculation 

(Based on Blowout during Drilling Operations)

Calculations for Uncontrolled Blowout> 10 miles from shore: Block 724 

 i. Type of Oil (crude, condensate, diesel) Crude 

 ii. API Gravity 30.9o -32.2o

 iii. EP Location Used for NTL No. 2010-N06 WCD for GC 724 IEP GC 724 “A” 

 iv. Largest Anticipated WCD Rate during blowout 201,530 BOPD

 v. WCD Total for Drilling Operations for GC 724 (> 10 miles from shore): 201,530 BOPD
 

Table H-2 

Trajectory by Land Segment 

Following are the average conditional probabilities (expressed as percent chance) that an oil spill starting at a 

particular launch area will contact a land segment as included in the BOEMRE Oil Spill Risk Analysis Model 

(OSRAM) for the Central Gulf of Mexico. This information can be found on the BOEMRE website using 3/10/30 

day potential impact, as applicable. The results are listed below. 

Area/Block OCS-G Launch 

Area Land Segment and/or Resource 

Conditional Probability (%) 

3 

days 

10 

days 

30 

days 

Green Canyon 

Block 724 

Drilling 

(122miles from 

shore) 

G34557 LA 45 

Central 

Planning 

Area 

Calhoun, TX 

Matagorda County, TX 

Brazoria County, TX 

Galveston County, TX 

Jefferson County, TX 

Cameron Parish, LA 

Vermilion Parish, LA 

Iberia, LA 

Lafourche Parish, LA 

Terrebonne Parish, LA 

Plaquemines Parish, LA 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

-- 

1 

1 

1 

2 

1 

4 

2 

1 

1 

2 

2 
Table H-3 

WCD Scenario Drilling Activities – Based on a single well uncontrolled blowout (122 miles from shore) Green Canyon Block 724 201,530 BOPD (initial volume) 169,285 BOPD (after evaporation/dispersion) API Gravity 30.9o -32.2o

Offshore Equipment from Spill Detection to Equipment Deployment Response Time: Green Canyon Block 

Spill Team Area Responders (STARS) called out by Marine Spill Response Corporation (MSRC) Vessel of Opportunity=VOO EMS=Enterprise Marine Services K-Sea=K-Sea Operating Partnership 


Nearshore Equipment from Spill Detection to Equipment Deployment Response Time: Green Canyon Bloc
*Some equipment may be used offshore up to approximately 25 miles from shore 
 

H-3 (continued) 

Operational Limitations of Response Equipment 

 HOSS Barge–8 foot seas 

 Fast Response Unit (FRU)–8 foot seas 

 Oil Spill Response Vessel (OSRV and R/V)–4 foot seas 

 Boom–3 foot seas, 20 knot winds 

 Dispersants–winds more than 25 knots, visibility less than 3 nautical miles or ceiling less than 

1,000 feet 
 

I 

Environmental Monitoring and Environmental Mitigation Measures 

(a) Monitoring 

If required, Anadarko will monitor loop currents per NTL 2005-G05. 

Anadarko subscribes to Wilkins Weather Service which provides real-time weather 

conditions such as tropical depressions, storms and/or hurricanes entering the Gulf. 

(b) Incidental Takes 

Although marine mammals may be seen in the area, Anadarko does not believe that its 

operations proposed under this EP will result in the harassment, capture, collection or 

killing of any mammals covered by the Marine Mammal Protection Act. 

Anadarko will operate in accordance with applicable regulations, including: 

NTL No. 2012-G02 – “Implementation of Seismic Survey Mitigation Measures and 

Protected Species Observer Program” 

BSEE NTL No. 2012-G01 “Marine Trash and Debris Awareness and Elimination”, and 

JOINT NTL No. 2012-G01 “Vessel Strike Avoidance and Injured/Dead Protected 

Species Reporting” 
 

J 

LEASE STIPULATIONS INFORMATION 

Lease Sale # 222: 

Military Area: Green Canyon Block 724 is located within Military Warning Area W-92. 

Anadarko will contact the Naval Air Station, Air Operations Department, New Orleans, 

Louisiana in order to coordinate and control the electromagnetic emissions during these 

proposed operations. 
 

K 

Support Vessels and Aircraft Information 

(a) General 

Type Max. Total Fuel Tank 

Storage Capacity 

Max. No. in Area at 

any Time 

Trip Frequency or 

Duration 

Supply Vessel 336,227 gallons 1 2 trips/week 

Helicopter 735.3 gallons 1 10 trips/week 

Crew Vessel 50,000 gallons 1 3 trips/week 

Tug Boats N/A N/A N/A 

(b) Diesel Oil Supply Vessels 

Fuel for the rig will be transported via a supply vessel as follows: 

a. Size of fuel supply vessel: 230 feet 

b. Carrying capacity of fuel supply vessel: 336,227 gallons 

c. Frequency that fuel supply vessel will visit the facilities: twice per week 

d. Routes the fuel supply vessel will use to travel between 

the onshore support base and proposed facility: 

6 miles from Port Fourchon to the mouth of 

Bayou Lafourche, then approximately 133 miles 

to GC 724. 

(c) Vicinity Map 

A vicinity map is included in this section as Attachment K-1. 

(d) Produced Liquid Hydrocarbons Transportation Vessels 

Produced liquid hydrocarbons from future flow tests on wells in Green Canyon Block 724 will be 

transported by barge. Flow tests will not exceed 48 hours/well without further approval. 

Transport Method Vessel Capacity Average Volume to be Loaded 

(per transfer) 

No. of Transfers 

(Yearly Average) 

Barge 50,000 to 130,000 

bbls 

Proprietary Info 1 

(e) Summary of Method to Transfer Liquid Hydrocarbons to the Transporting Vessel 

Production from the well will be routed through portable surface well test equipment and safety 

controls aboard the rig. Gas will be flared and liquids (oil & water) will be collected in US Coast 

Guard approved tanks and a barge. The well will be produced / cleaned up and measured using 

various meters through portable surface well test equipment including a separator. A three phase 

separator will be used to analyze water cut if present. All liquids (hydrocarbons and water) will 

then be transferred to a coast guard approved barge via tested & approved petroleum transfer 

hose. We will have a Safe Breakaway Coupling (KLAW) installed between the hoses connecting 
 

the barge-end and the rig-end. If this device parts the KLAW is designed to contain all fluids 

from both hoses.

(e) Solid and Liquid Wastes Transportation

Type of 

Waste 

Composition Total 

Projected 

Amount 

Rate Transport 

Method 

Name/Location of 

Facility 

Disposal 

Method 

Syntheticbased 

drilling 

fluid or 

mud 

Syntheticbased drilling 

muds 

30,000 bbls 10,000 bbls/well Re-use 

and/or 

transport to 

shore in 

DOT 

approved 

containers. 

Waste - Port Fourchon, 

LA and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station. If 

recycled, returned to 

vendor (Bariod or MI). 

Re-used and/or 

recycled; if can’t 

be reused and/or 

recycled the waste 

is disposed of at 

Newpark (injection 

disposal facility) or 

USLL (landfarm). 

Cuttings 

wetted with 

syntheticbased muds 

Cuttings coated 

with synthetic 

drilling muds, 

including 

drilled out 

cement 

300-600 bbls 100-200 

bbls/well* 

*An estimated 

5-10% of cuttings 

may be 

transported to 

shore 

Re-use 

and/or 

transport to 

shore in 

DOT 

approved 

containers. 

Waste - Port Fourchon, 

LA and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station. If 

recycled, returned to 

vendor (Bariod or MI). 

Re-used and/or 

recycled; if can’t 

be reused and/or 

recycled the waste 

is disposed of at 

Newpark (injection 

disposal facility) or 

USLL (landfarm). 

Chemical 

product 

waste (well 

treatment 

fluids) 

Ethylene 

glycol 

Methanol 

1,500 bbls 

375 bbls 

100 bbls/month 

25 bbls/month 

Transport to 

shore in 

DOT 

approved 

containers 

for pick up 

Chemwaste in Sulphur, 

LA and Veolia Port 

Arthur, TX or to Newpark, 

Port Arthur as nonhazardous waste. 

Can be returned to 

vendor and/or used 

at another facility; 

MEG is solidified 

and disposed of in 

a landfill. 

Methanol is 

incinerated or used 

for fuels blending. 

Completion 

fluids 

Brine, spent 

acid, prop 

sand, debris 

9,000 bbls 3,000 bbls/well Transport to 

shore in 

DOT 

approved 

containers 

and/or vessel 

tanks for 

pick up 

Sent to Port Fourchon, LA 

and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station 

Unused brine can 

be returned to 

vendor and/or 

stored for use on 

another job. Used 

brine and spent 

acid is transferred 

to Newpark's 

Processing & 

Transfer facility 

for injection. 

Workover 

fluids 

Brine, spent 

acid, prop 

sand, debris 

9,000 bbls 3,000 bbls/well Transport to 

shore in 

DOT 

approved 

containers 

and/or vessel 

tanks for 

pick up

Sent to Port Fourchon, LA 

and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station 

Unused brine can 

be returned to 

vendor and/or 

stored for use on 

another job. Used 

brine and spent 

acid is transferred 

to Newpark's 

Processing & 

Transfer facility 

for injection. 
 

Trash and 

debris 

Refuse 

generated 

during 

operations 

750 bbls 50 

bbls/month/well 

Transport to 

shore in 

disposal bags 

by vessel to 

shorebase for 

pickup by 

municipal 

operations 

Recycled Material in 

ARC, New Iberia, LA. 

Trash disposed of at 

SWDI landfill. 

Recycled and/or 

disposed in 

landfill. 

Used oil Excess oil from 

engines 

1,613 bbls 430 bbls/120 

days/well 

Transport in 

DOT 

approved 

containers to 

shore for 

pick up 

American Recovery 

Fourchon, LA 

Recycled 

*Total amount assumes drilling & completing 3 wells with 450 Total No. of Days
Green Canyon Blocks 724 and 768 

Environmental Impact Analysis for Initial Exploration Plan 

CSA‐Anadarko‐FL‐14‐2716‐01‐REP‐01‐Ver01

Figure 1. Location of Green Canyon Blocks 724 and 768 offshore of the coast of Louisiana.
 

L 

ONSHORE SUPPORT FACILITIES INFORMATION

(a) General 

Per NTL No. 2008-G04, the following tables reflect the onshore facilities Anadarko may utilize 

to provide supplies and service support for the activities proposed in this EP. 

Name Primary Location(s) Existing/New/Modified 

Anadarko Service Base Fourchon, Louisiana Existing 

Anadarko Service Base (Helicopter base) Houma, LA Existing 

Name *Alternate Locations Existing/New/Modified 

Anadarko Service Base Galveston, TX Existing 

Anadarko Service Base Cameron, LA Existing 

Anadarko Service Base Lake Charles, LA Existing 

Anadarko Service Base Houma, LA Existing 

Anadarko Service Base Pascagoula, MS** Existing 

*In the unlikely event Anadarko’s primary service base cannot be utilized Anadarko will exercise the use of an alternate 

service base during drilling and/or completion operations.

**Helicopter base only 

(b) Support Base 

No support base construction or expansion is planned for these activities. 

(c) Waste Disposal 

Disposed wastes describe those wastes generated by the proposed activity that are disposed of by 

means other than by release into the water of the GOM at the site where they are generated. 

These wastes can be disposed of by offsite release, injection, encapsulation, or placement at either 

onshore or offshore permitted locations for the purposes of returning them back to the 

environment. 

Type of 

Waste 

Composition Total 

Projected 

Amount 

Rate Transport 

Method 

Name/Location of 

Facility 

Disposal 

Method 

Syntheticbased 

drilling 

fluid or 

mud 

Syntheticbased drilling 

muds 

30,000 bbls 10,000 bbls/well Re-use 

and/or 

transport to 

shore in 

DOT 

approved 

containers. 

Waste - Port Fourchon, 

LA and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station. If 

recycled, returned to 

vendor (Bariod or MI). 

Re-used and/or 

recycled; if can’t 

be reused and/or 

recycled the waste 

is disposed of at 

Newpark (injection 

disposal facility) or 

USLL (landfarm). 
 

Cuttings 

wetted with 

syntheticbased muds 

Cuttings coated 

with synthetic 

drilling muds, 

including 

drilled out 

cement 

300-600 bbls 100-200 

bbls/well* 

*An estimated 

5-10% of cuttings 

may be 

transported to 

shore 

Re-use 

and/or 

transport to 

shore in 

DOT 

approved 

containers. 

Waste - Port Fourchon, 

LA and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station. If 

recycled, returned to 

vendor (Bariod or MI). 

Re-used and/or 

recycled; if can’t 

be reused and/or 

recycled the waste 

is disposed of at 

Newpark (injection 

disposal facility) or 

USLL (landfarm). 

Chemical 

product 

waste (well 

treatment 

fluids) 

Ethylene 

glycol 

Methanol 

1,500 bbls 

375 bbls 

100 bbls/month 

25 bbls/month 

Transport to 

shore in 

DOT 

approved 

containers 

for pick up 

Chemwaste in Sulphur, 

LA and Veolia Port 

Arthur, TX or to Newpark, 

Port Arthur as nonhazardous waste. 

Can be returned to 

vendor and/or used 

at another facility; 

MEG is solidified 

and disposed of in 

a landfill. 

Methanol is 

incinerated or used 

for fuels blending. 

Completion 

fluids 

Brine, spent 

acid, prop 

sand, debris 

9,000 bbls 3,000 bbls/well Transport to 

shore in 

DOT 

approved 

containers 

and/or vessel 

tanks for 

pick up 

Sent to Port Fourchon, LA 

and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station 

Unused brine can 

be returned to 

vendor and/or 

stored for use on 

another job. Used 

brine and spent 

acid is transferred 

to Newpark's 

Processing & 

Transfer facility 

for injection. 

Workover 

fluids 

Brine, spent 

acid, prop 

sand, debris 

9,000 bbls 3,000 bbls/well Transport to 

shore in 

DOT 

approved 

containers 

and/or vessel 

tanks for 

pick up

Sent to Port Fourchon, LA 

and on to Newpark 

Fourchon Transfer Station 

#1 & #2. Newpark 

Transfer Station Morgan 

City. Newpark Transfer 

Station Port Arthur. USLL 

Galveston and Fourchon 

Transfer Station 

Unused brine can 

be returned to 

vendor and/or 

stored for use on 

another job. Used 

brine and spent 

acid is transferred 

to Newpark's 

Processing & 

Transfer facility 

for injection. 

Trash and 

debris 

Refuse 

generated 

during 

operations 

750 bbls 50 

bbls/month/well 

Transport to 

shore in 

disposal bags 

by vessel to 

shorebase for 

pickup by 

municipal 

operations 

Recycled Material in 

ARC, New Iberia, LA. 

Trash disposed of at 

SWDI landfill. 

Recycled and/or 

disposed in 

landfill. 

Used oil Excess oil from 

engines 

1,613 bbls 430 bbls/120 

days/well 

Transport in 

DOT 

approved 

containers to 

shore for 

pick up 

American Recovery 

Fourchon, LA 

Recycled 

*Total amount assumes drilling & completing 3 wells with 450 Total No. of Days 
 

M 

COASTAL ZONE MANAGEMENT ACT INFORMATION 

 

TEXAS COASTAL MANAGEMENT PROGRAM 

The following is an evaluation that includes findings relating the coastal effects of the proposed 

activities and associated facilities to the relevant enforceable policies of the Texas’ Coastal 

Management Program (TCMP), Title 31, Part 16, Chapter 501, Subchapter B:

(Category 2) 

Construction, Operation & Maintenance of Oil & Gas Exploration & Production 

Facilities 

No operations are proposed in or near any critical areas. The proposed activities are explorative in 

nature, so no facility construction is proposed. The proposed activities are located approximately 

235 miles from the Texas shoreline; therefore we expect no adverse impacts to CNRAs or beach 

access and use rights of the public. All activities shall be conducted in a manner that minimizes 

significant impacts to coastal resources. No adverse effects to Texas’ coastal area are expected in 

association with the proposed activities. 

(Category 3) 

Discharges of Wastewater and Disposal of Waste from Oil and Gas Exploration and 

Production Activities 

No discharge of wastewater or disposal of waste from the proposed activities will occur in the 

Texas’ coastal zone; therefore no impact to Texas’ coastal waters is expected. 

(Category 4) 

Construction and Operation of Solid Waste Treatment, Storage, and Disposal 

Facilities 

No construction of solid waste facilities or expansion of existing facilities in the coastal zone are 

proposed in the attached plan, therefore, no adverse effects on any features of Texas’ coastal cone 

are expected. 

(Category 5) 

Prevention, Response, and Remediation of Oil Spills 

The proposed activities will be covered under an approved Regional Oil Spill Response Plan. The 

plan is in place, practiced, and updated as necessary. The best practical techniques shall be 

utilized to prevent the release of pollutants or toxic substances into the environment. All involved 

vessels and facilities are designed to be capable of prompt response and adequate removal of 

accidental discharges of oil. In addition, the proposed activities are 235 miles from shore; 

therefore no damages to natural resources are expected as the result of an unauthorized discharge 

of oil into coastal waters. 

(Category 6) 

Discharge of Municipal and Industrial Waste Water to Coastal Waters 

No discharges from the proposed activities will occur in coastal waters. The proposed activities 

are 235 miles from shore; therefore there will be no effect on coastal waters. 
 

(Category 8) 

Development in Critical Areas 

None of the proposed activities will occur in a critical area; therefore no effects to Texas’ coastal 

zone are expected. The activity will not jeopardize the continued existence of species listed as 

endangered or threatened, and will not result in likelihood of the destruction or adverse 

modification of a habitat determined to be a critical habitat under the Endangered Species Act. 

The activity will not cause or contribute to violation of any applicable surface water quality 

standards. The activity will not violate any requirement imposed to protect a marine sanctuary. 

(Category 9) 

Construction of Waterfront Facilities and Other Structures on Submerged lands 

No waterfront facilities or other structures are proposed on submerged lands in the Texas coastal 

zone, therefore the proposed activities are not expected to have any adverse impacts on 

submerged lands. 

(Category 10) 

Dredging and Dredged Material Disposal and Placement 

No dredging or disposal/placement of dredged material is proposed; therefore no adverse effects 

to coastal waters, submerged lands, critical areas, coastal shore areas, or Gulf beaches are 

expected. 

(Category 11) 

Construction in the Beach / Dune System 

The proposed activities do not include any construction projects in critical dune areas or areas 

adjacent to or on Gulf beaches, therefore, no impact to Texas’ beach or dune systems are 

expected. 

(Category 15) 

Alteration of Coastal Historic Areas 

The proposed activities do not include any alteration or disturbance of a coastal historic area; 

therefore, no impacts are expected to adversely affect any historical, architectural, or 

archaeological site in Texas’ coastal zone. 

(Category 16) 

Transportation 

The proposed activities do not include any transportation construction projects within the coastal 

zone; therefore, no impacts to Texas’ coastal zone are expected. 

(Category 17) 

Emission of Air Pollutants 

The proposed activities shall be carried out in conformance with applicable air quality laws, 

standards, and regulations. Emissions from the proposed activities are not expected to have 

significant 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 
 

proposed activities will occur approximately 235 miles from shore and will be within the 

exemption limits set by BOEM, therefore, no impacts to Texas’ coastal zone is expected. 

(Category 18) 

Appropriations of Water 

The proposed activities do not include the impoundment or diversion of state water, therefore, no 

impacts to Texas’ coastal zone is expected. 

(Category 20) 

Marine Fishery Management 

The proposed activities are located approximately 235 miles from shore and are not expected to 

have any effect on marine fishery management or fishery migratory patterns within waters in the 

coastal zone of Texas. 

(Category 22) 

Administrative Policies 

The necessary information for applicable agencies to make an informed decision on the proposed 

activities has been provided In conclusion, all activities shall be consistent with Texas’ coastal 

management program and shall comply with all relevant rules and regulations. No activities are 

planned within any critical areas. Activities will be carried out avoiding unnecessary conflicts 

with other uses of the vicinity. 

 

MISSISSIPPI COASTAL ZONE MANAGEMENT ACT INFORMATION 

As authorized by the Federal Coastal Zone Management Act (CZMA), The State of 

Mississippi developed a Coastal Management Program (CMP) to allow for the review of 

proposed Federal license and permit activities affecting any coastal use or resources, in or 

outside of the Mississippi Coastal Zone. 

The OCS related oil and gas exploratory and development activities having potential 

impact on the Mississippi Coastal Zone are based on the location of the proposed 

facilities, access to those sites, best practical techniques for drilling locations, drilling 

equipment guidelines for the prevention of adverse environmental effects, effective 

environmental protection, emergency plans and contingency plans. 

Below are goals identified by the State of Mississippi and our comments and/or 

corresponding cross references: 

Goal 1: To provide for reasonable industrial expansion in the coastal area and to 

ensure the efficient utilization of waterfront industrial sites so that suitable sites are 

conserved for water dependent industry. 

The activities proposed in this plan are based out of Fourchon, Louisiana. The activities 

will not provide any industrial expansion on the coastal area of Mississippi. Therefore 

Mississippi coastal areas will be conserved for water dependent industry. 

Goal 2: To favor the preservation of the coastal wetlands and ecosystems, except 

where a specific alteration of specific coastal wetlands would serve a higher public 

interest in compliance with the public purposes of the public trust in which the 

coastal wetlands are held. 

Goal 2 is addressed in Section N, Environmental Impact Analysis. The nearest proposed 

activities will be 200 miles from the Mississippi coast. 

Goal 3: To protect, propagate and conserve the state’s seafood and aquatic life in 

connection with the revitalization of the seafood industry of the State of Mississippi. 

Goal 3 is addressed in Section N, Environmental Impact Analysis. Little impact to the 

seafood industry can be expected due to the activities occurring 200 miles from the 

Mississippi coast. 

Goal 4: To conserve the air and waters of the state, and to protect, maintain and 

improve the quality thereof for public use, for the propagation of wildlife, fish and 

aquatic life, and for domestic, agricultural, industrial, recreational and other 

legitimate beneficial uses. 

Goal 4 is addressed in Section B, General Information, Section G, Air Emissions 

Information, and Section N, Environmental Impact Analysis. 
 

Goal 5: To put to beneficial use to the fullest extent of which they are capable the 

water resources of the state, and to prevent the waste, unreasonable use, or 

unreasonable method of use of water. 

The activities proposed in this plan are based in Fourchon, Louisiana. As such, 

Mississippi’s water resources should not be impacted by the proposed activities. 

Activities occurring at the sites in the OCS will be conducted in accordance with our 

Regional Oil Spill Response Plan referenced in Section H of this plan. 

Goal 6: To preserve the state’s historical and archaeological resources, to prevent 

their destruction, and to enhance these resources wherever possible. 

Goal 6 is addressed in Section E, Biological, Physical and Socioeconomic Information, 

and Section N, Environmental Impact Analysis. 

Goal 7: To encourage the preservation of natural scenic qualities in the coastal area. 

Goal 7 is addressed in Section F, Waste Discharges Information, Section H, Oil Spill 

Information, Section G, Air Emissions Information, and Section N, Environmental 

Impact Analysis. 

Goal 8: To assist local governments in the provision of public facilities services in a 

manner consistent with the coastal program. 

As the proposed activities are located 200 miles from the Mississippi coast and are based 

out of a shorebase in Fourchon, Louisiana, local governments should not be affected. 

 

N

ENVIRONMENTAL IMPACT ANALYSIS 
Environmental Impact Analysis

INITIAL EXPLORATION PLAN

for

Green Canyon Blocks 724 and 768

(OCS-G 21814 and OCS-G 21817)

Offshore Louisiana

July 2014

CSA-Anadarko-FL-14-2716-01-REP-01-FIN

Prepared for:

Jill Fowler

Regulatory Analyst

Anadarko Petroleum Corporation

1201 Lake Robbins Drive

The Woodlands, Texas 77380

Telephone: (832) 636-1554

Prepared by:

CSA Ocean Sciences Inc.

8502 SW Kansas Avenue

Stuart, Florida 34997

Telephone: (772) 219-3000
ENVIRONMENTAL IMPACT ANALYSIS

INITIAL EXPLORATION PLAN FOR

GREEN CANYON BLOCKS 724 AND 768

(OCS-G 21814 AND OCS-G 21817)

OFFSHORE LOUISIANA

DOCUMENT NO. CSA-ANADARKO-FL-14-2716-01-REP-01-FIN

VERSION DATE DESCRIPTION PREPARED BY: REVIEWED BY: APPROVED BY:

01 7/3/14 Initial draft for review MJT JH, NK, LR MJT

FIN 7/9/14 Final MJT NK MJT

Next Review Due Date: Next Review By:

The electronic PDF version of this document is the Controlled Master Copy at all times. A printed copy is considered 

to be uncontrolled and it is the holder’s responsibility to ensure that they have the current revision. 

Controlled copies are available on the Management System network site or on request from the 

Document Production team.
Contents

Page

List of Tables................................................................................................................v

List of Figures...............................................................................................................v

Acronyms and Abbreviations......................................................................................vi

Introduction ................................................................................................................1

A. Impact-Producing Factors .......................................................................................5

A.1 Drilling Rig Presence (Including Noise and Lights)..........................................................................5

A.2 Physical Disturbance to the Seafloor..............................................................................................5

A.3 Air Pollutant Emissions...................................................................................................................8

A.4 Effluent Discharges.........................................................................................................................8

A.5 Water Intake...................................................................................................................................8

A.6 Onshore Waste Disposal.................................................................................................................9

A.7 Marine Debris.................................................................................................................................9

A.8 Support Vessel and Helicopter Traffic ............................................................................................9

A.9 Accidents ......................................................................................................................................10

A.9.1 Types of Accidents Evaluated ...........................................................................................10

A.9.2 Small Fuel Spill ..................................................................................................................10

A.9.3 Crude Oil Spill (Worst Case Discharge) .............................................................................11

A.9.4 Other Accidents Not Analyzed in Detail............................................................................15

B. Affected Environment...........................................................................................17

C. Impact Analysis.....................................................................................................19

C.1 Physical/Chemical Environment...................................................................................................19

C.1.1 Air Quality .........................................................................................................................19

C.1.2 Water Quality....................................................................................................................21

C.2 Seafloor Habitats and Biota..........................................................................................................23

C.2.1 Soft Bottom Benthic Communities...................................................................................23

C.2.2 High-Density Deepwater Benthic Communities...............................................................26

C.2.3 Designated Topographic Features....................................................................................28

C.2.4 Pinnacle Trend Area Live Bottoms....................................................................................28

C.2.5 Eastern Gulf Live Bottoms.................................................................................................28

C.3 Threatened, Endangered, and Protected Species and Critical Habitat........................................29

C.3.1 Sperm Whale (Endangered)..............................................................................................31

C.3.2 West Indian Manatee (Endangered).................................................................................35

C.3.3 Endangered Mysticete Whales.........................................................................................36

C.3.4 Non-Endangered Marine Mammals (Protected)..............................................................36

C.3.5 Sea Turtles (Endangered/Threatened) .............................................................................40

C.3.6 Piping Plover (Threatened)...............................................................................................43

C.3.7 Whooping Crane (Threatened).........................................................................................44

C.3.8 Gulf Sturgeon (Threatened)..............................................................................................46

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page iii

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Contents

(Continued)

Page

C.3.9 Beach Mice (Endangered).................................................................................................47

C.3.10 Smalltooth Sawfish (Endangered).....................................................................................47

C.3.11 Elkhorn Coral (Threatened)...............................................................................................48

C.4 Coastal and Marine Birds..............................................................................................................49

C.4.1 Marine Birds......................................................................................................................49

C.4.2 Shorebirds and Coastal Nesting Birds...............................................................................51

C.5 Fisheries Resources ......................................................................................................................53

C.5.1 Pelagic Communities and Ichthyoplankton ......................................................................53

C.5.2 Essential Fish Habitat........................................................................................................55

C.6 Archaeological Resources.............................................................................................................58

C.6.1 Shipwreck Sites.................................................................................................................58

C.6.2 Prehistoric Archaeological Sites........................................................................................59

C.7 Coastal Habitats and Protected Areas..........................................................................................60

C.8 Socioeconomic and Other Resources...........................................................................................62

C.8.1 Recreational and Commercial Fishing ..............................................................................62

C.8.2 Public Health and Safety ...................................................................................................64

C.8.3 Employment and Infrastructure .......................................................................................65

C.8.4 Recreation and Tourism....................................................................................................66

C.8.5 Land Use............................................................................................................................67

C.8.6 Other Marine Uses............................................................................................................67

D. Environmental Hazards.........................................................................................68

D.1 Geologic Hazards..........................................................................................................................68

D.2 Severe Weather............................................................................................................................68

D.3 Currents and Waves .....................................................................................................................68

E. Alternatives ..........................................................................................................69

F. Mitigation Measures.............................................................................................69

G. Consultation .........................................................................................................69

H. Preparers..............................................................................................................69

I. References.............................................................................................................69

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page iv

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
List of Tables

Table Page

1 Notices to Lessees and Operators (NTLs) applicable to this Environmental Impact 

Analysis (EIA)...........................................................................................................................3

2 Matrix of impact-producing factors and environmental resources .......................................6

3 Conditional probabilities of a spill in the lease area contacting shoreline segments 

based on the 30-day Oil Spill Risk Analysis (OSRA) (From: Ji et al., 2004)............................12

4 Conditional probabilities of a spill in the lease area contacting shoreline segments 

based on the 120-day Oil Spill Risk Analysis (OSRA).............................................................13

5 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 (Adapted from: Wei, 2006; Rowe and Kennicutt, 2009)...........24

6 Federally listed endangered and threatened species that could potentially occur in 

the lease area and along the northern Gulf Coast ...............................................................30

7 Wildlife refuges, wilderness areas, and state and national parks within the 

geographic range of the potential shoreline contacts after 30 days based on OSRA 

modeling ...............................................................................................................................61

List of Figures

Figure Page

1 Location of Green Canyon Blocks 724 and 768 offshore of the coast of Louisiana ...............2

2 Bathymetric map of the lease area showing the surface hole locations of the 

proposed wellsites................................................................................................................18

3 Location of selected environmental features in relation to the lease areas of 

interest..................................................................................................................................45

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page v

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Acronyms and Abbreviations

ac acre

ADIOS2 Automated Data Inquiry for Oil Spills 2

Anadarko Anadarko Petroleum Corporation

bbl barrel

BHL bottom hole location

BOEM Bureau of Ocean Energy Management

BOEMRE Bureau of Ocean Energy Management, 

Regulation and Enforcement

BOP blowout preventer

B.P. before present

BSEE Bureau of Safety and Environmental 

Enforcement

CFR Code of Federal Regulations

CH4 methane

CO carbon monoxide

CO2 carbon dioxide

CGA Clean Gulf Associates

DP dynamically positioned

DPS distinct population segment

EEZ Exclusive Economic Zone

EFH Essential Fish Habitat

EIA Environmental Impact Analysis

EIS Environmental Impact Statement

EP Exploration Plan

ESA Endangered Species Act

FAD fish aggregating device

FR Federal Register

GC Green Canyon

GMFMC Gulf of Mexico Fishery Management 

Council

GPS global positioning system

H2S hydrogen sulfide

ha hectare

HAPC Habitat Area of Particular Concern

HOSS high-volume open sea skimmer

IPF impact-producing factor

MARPOL International Convention for the 

Prevention of Pollution from Ships

MMC Marine Mammal Commission

MMPA Marine Mammal Protection Act

MMS Minerals Management Service

MSRC Marine Spill Response Corporation

MWCC Marine Well Containment Company

NAAQS National Ambient Air Quality 

Standards

NMFS National Marine Fisheries Service

NMS National Marine Sanctuary

NOAA National Oceanic and Atmospheric 

Administration

NO2 nitrogen dioxide

NOx nitrogen oxides

NPDES National Pollutant Discharge 

Elimination System

NPS National Park Service

NRDA Natural Resource Damage Assessment

NTL Notice to Lessees and Operators

NWR National Wildlife Refuge

OCS Outer Continental Shelf

OSAT Operational Scientific Advisory Team

OSRA Oil Spill Risk Analysis

OSRP Oil Spill Response Plan

PAH polycyclic aromatic hydrocarbon

PM particulate matter

PSD Prevention of Significant Deterioration

SBM synthetic-based mud

SHL surface hole location

SOx sulfur oxides

SWSS Sperm Whale Seismic Study

USCG U.S. Coast Guard

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

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page vi

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Introduction

Anadarko Petroleum Corporation (Anadarko) is submitting an Initial Exploration Plan (EP) for

Green Canyon (GC) Blocks 724 (GC 724) and 768 (GC 768). Under the EP, Anadarko proposes to 

drill and complete three wells: GC 724 A, GC 724 AA, and GC 724 AAA. All wells will have their 

surface hole locations (SHLs) in GC 768 and bottom hole locations (BHLs) in GC 724. This 

Environmental Impact Analysis (EIA) provides information on potential impacts of Anadarko’s 

proposed activities based on the SHLs.

The lease area is 122 miles (196 km) from the nearest shoreline, 135 miles (217 km) from the 

onshore support base at Port Fourchon, Louisiana, and 160 miles (258 km) from the helicopter 

base at Houma, Louisiana (Figure 1). Water depths at the wellsites are between 1,573 and 

1,695 m (5,160 to 5,560 ft). The drilling rig has not yet been determined but will be a 

dynamically positioned (DP) drillship or semisubmersible rig. It is anticipated that drilling 

operations for the exploratory wells covered in the EP will require 150 days for completion, but 

a firm schedule as not yet been established.

This EIA was prepared for submittal to the Bureau of Ocean Energy Management (BOEM) in 

accordance with applicable regulations, including 30 Code of Federal Regulations (CFR) 

550.212(o) and 550.227. This EIA is a project- and site-specific analysis of Anadarko’s planned 

activities under the EP. This EIA complies with guidance provided in existing Notices to Lessees 

and Operators (NTLs) issued by the former Minerals Management Service (MMS) and Bureau of 

Ocean Energy Management, Regulation and Enforcement (BOEMRE), including NTLs 2008-G04

and 2014-G03. Potential impacts have been analyzed at a broader level in the Programmatic 

Environmental Impact Statement (EIS) for the Outer Continental Shelf (OCS) Oil and Gas Leasing 

Program (MMS, 2007a; BOEM, 2012a) and in multi-lease-sale EISs for the Western and Central 

Gulf of Mexico Planning Areas (MMS, 2007b; BOEM, 2012b,c, 2013). The analyses from those 

documents are incorporated here by reference.

All the proposed activities and facilities discussed in the EP are covered by the Sub-Regional Oil 

Spill Response Plan (OSRP) last approved on 15 April 2013 for Anadarko and its subsidiaries, 

Anadarko U.S. Offshore Corporation and Anadarko E&P Company L.P. (Company Numbers 

00981, 02219, and 00148, respectively), in accordance with 30 CFR Part 254.

The OSRP details Anadarko’s plan to rapidly and effectively manage oil spills that may result 

from drilling and production operations. Anadarko has designed its spill response program 

based on a regional capability of response to spills ranging from small operational spills to a 

worst case discharge (WCD) from a well blowout. Anadarko’s spill response program meets the 

response planning requirements of the relevant coastal states and applicable Federal oil spill 

planning regulations. The OSRP also includes information regarding Anadarko’s regional oil spill 

organization and dedicated response assets, potential spill risks, and local environmental 

sensitivities. It describes personnel and equipment mobilization, incident management team 

organization, and an overview of actions and notifications to be taken in the event of a spill.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 1

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Figure 1. Location of Green Canyon Blocks 724 and 768 offshore of the coast of Louisiana.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 2

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
This EIA is organized into Sections A through I corresponding to the information required by 

NTL 2008-G04. The main impact-related discussions are in Section A (Impact-Producing Factors) 

and Section C (Impact Analysis). Table 1 lists and summarizes the NTLs applicable to this EIA.

Table 1. Notices to Lessees and Operators (NTLs) applicable to this Environmental Impact 

Analysis (EIA).

NTL Title Summary

2014-G04 Military Warning and Water 

Test Areas

Provides contact links to individual command 

headquarters for the military warning and water 

test areas in the Gulf of Mexico. Lease stipulations 

require lessees or designated operators to enter 

into an agreement with the appropriate individual 

military command headquarters concerning the 

control of electromagnetic emissions and use of 

boats and aircraft in the applicable warning area or 

water test area before commencing such traffic.

BOEM-2014-G03 Extension of Prior Notices to 

Lessees

Extends the effective date of NTLs 2008-G04 and 

2008-G05 until 30 June 2014.

BSEE-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 Response Plans. 

Recommends description of response strategy for 

worst case discharge scenarios to ensure capability 

to respond to oil spills is both efficient and 

effective.

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 placards at 

prominent locations on offshore vessels and 

structures; and mandates a yearly training and 

certification process for marine trash and debris 

awareness.

2012-JOINT-G01

Vessel Strike Avoidance and 

Injured/Dead Protected Species 

Reporting

Recommends protected species identification 

guides be carried on all Gulf of Mexico petroleum 

vessels and that vessel operators and crews 

maintain a vigilant watch for marine mammals. 

Vessels are to slow down or stop to avoid striking 

protected species, and operators are required to 

report sightings of any injured or dead protected 

species.

2011-JOINT-G01

Revisions to the List of Outer 

Continental Shelf (OCS) Blocks 

Requiring Archaeological 

Resource Surveys and Reports

Provides new information of which OCS blocks 

require archaeological surveys and reports; 

identifies required survey line spacing in each block. 

This NTL augments NTL 2005-G07.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 3

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Table 1. (Continued).

NTL Title Summary

2010-N10

Statement of Compliance with 

Applicable Regulations 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 Federal Register [FR] 63346). Informs operators 

that the Bureau of Ocean Energy Management will 

be evaluating 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 WCD scenario 

and provides guidance regarding the information 

required in blowout scenario and WCD scenario 

descriptions.

2009-G40 Deepwater Benthic 

Communities

Provides guidance for avoiding and protecting 

high-density deepwater benthic communities 

(including chemosynthetic and deepwater coral 

communities) from damage caused by OCS oil and 

gas activities in water depths greater than 300 m 

(984 ft). Prescribes separation distances of 610 m 

(2,000 ft) from each mud and cuttings discharge 

location and 76 m (250 ft) from all other seafloor 

disturbances.

2009-G39 Biologically Sensitive 

Underwater Features and Areas

Provides 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 300 m 

(984 ft) in the Gulf of Mexico.

2008-G04

Information Requirements for 

Exploration Plans and 

Development Operations 

Coordination Documents

Provides guidance on information requirements for 

OCS plans, including EIA requirements and 

information regarding compliance with the 

provisions of the Endangered Species Act and 

Marine Mammal Protection Act.1

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.

1 NTL extended on 30 June 2014 until 31 December 2014.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 4

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
A. Impact-Producing Factors

Table 2 is a matrix of impact-producing factors (IPFs) and potentially affected environmental 

resources adapted from Form BOEM-0142. 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 sections.

• 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

• Accidents

A.1 Drilling Rig Presence (Including Noise and Lights)

The wells proposed in this EP will be drilled using either a DP drillship or a DP semisubmersible 

rig. DP drilling rigs use a global positioning system (GPS), specific computer software, and 

sensors in conjunction with their own propellers and thrusters to maintain position. The precise 

location of the vessel is monitored by vessel operators using satellite navigation. Thrusters 

positioned at various locations around the vessel’s hull are activated as needed to maintain 

position. This process, known as station-keeping, allows operations at sea in locations at which 

mooring or anchoring is impractical or not feasible.

The drilling rig for the three wells proposed in the EP will be on site for an estimated 150 days

per well, but a firm schedule has not yet been established. The physical presence of the drilling 

rig in the ocean can attract pelagic fishes and other marine life, as discussed in Section C.5.1.

Drilling operations produce noise that includes strong tonal components at low frequencies, and 

in some cases, infrasonic frequencies (MMS, 2000). Drilling noise from DP drilling vessels is not 

particularly intense and is strongest at low frequencies, averaging 10 to 500 Hz 

(Richardson et al., 1995). From a drilling rig, sound and vibration paths to the water flow either 

through the air or through the risers (MMS, 2000). Drilling rigs also maintain exterior lighting for 

navigational and aviation safety in accordance with applicable Federal safety regulations.

A.2 Physical Disturbance to the Seafloor

In water depths of 600 m (1,969 ft) or greater, DP drilling vessels disturb a small area of the 

seafloor around the wellbore (SHL) where the bottom template and blowout preventer (BOP) 

are located. Depending on the specific well configuration, this area is generally 0.25 hectares

(ha), or approximately 0.62 acres (ac) (MMS, 2007a).

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Table 2. Matrix of impact-producing factors and environmental resources.

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

Oil Spill 

(WCD)

Physical/Chemical Environment

Air quality and greenhouse gases -- -- X(9) -- -- -- -- -- 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 Gulf 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)

West Indian manatee (endangered) -- -- -- -- -- -- -- X(8) -- X(6,8)

Endangered 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)

Smalltooth sawfish (endangered) X(6)

Beach mouse (endangered) -- -- -- -- -- -- -- -- -- X(6)

Elkhorn coral (threatened) -- -- -- -- -- -- -- -- -- X(6)

Coastal and Marine Birds

Marine 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 Resources

Shipwreck sites -- --(7) -- -- -- -- -- -- -- X(6)

Prehistoric archaeological sites -- --(7) -- -- -- -- -- -- -- X(6)

Coastal Habitats and Protected Areas

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

Wetlands and seagrass beds -- -- -- -- -- -- -- -- -- 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)

Employment and infrastructure -- -- -- -- -- -- -- -- -- X(6)

Recreation and tourism -- -- -- -- -- -- -- -- -- X(6)

Land use -- -- -- -- -- -- -- -- -- X(6)

Other marine uses -- -- -- -- -- -- -- -- -- X(6)

X indicates potential impact; dash (--) indicates no impact or negligible impact; numbers refer to table footnotes; Helo = helicopter; WCD = worst case discharge.

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Table 2 Footnotes and Applicability to this Drilling Program:

Footnotes are numbered to correspond to entries in Table 2; applicability to this case is noted by a bullet point 

following the footnote.

(1) Activities that may affect a marine sanctuary or topographic feature. Specifically, if the well, rig site, or any 

anchors will be on the seafloor within the following:

(a) 4-mile zone of the Flower Garden Banks or the 3-mile zone of Stetson Bank;

(b) 1,000-m, 1-mile, or 3-mile 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 or near any marine sanctuary, topographic feature, or no-activity 

zone. There are no submarine banks in the blocks.

(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 400 m or greater.

• No impacts on high-density deepwater benthic communities are anticipated. There are no features 

indicative of high-density chemosynthetic communities or coral communities within 610 m (2,000 ft) of 

any drilling mud/cuttings discharge location (Fugro GeoServices, Inc., 2003).

(5) Exploration or production activities where hydrogen sulfide (H2S) concentrations greater than 500 parts per 

million (ppm) might be encountered. 

• Anadarko is requesting Green Canyon Blocks 724 and 768 be classified as a zone in which the absence of

H2S has been confirmed.

(6) All activities that could result in an accidental spill of produced liquid hydrocarbons or diesel fuel that would

potentially 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 potential 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 not listed in BOEM’s (2012d)

Archaeology Survey Blocks. The lease area is well beyond the 60-m depth contour used by BOEM as the 

seaward extent for prehistoric archaeological site potential in the Gulf of Mexico. No archaeological 

resources were detected in the project area during the archaeological surveys (Fugro GeoServices, Inc., 

2003). A dynamically positioned drilling vessel or 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, 

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.

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A.3 Air Pollutant Emissions

Air pollutant emissions are calculated in EP Section G and are estimated to be insignificant. 

Offshore air pollutant emissions will result from drilling rig operations as well as service vessels 

and helicopters. These emissions occur mainly from combustion of diesel fuel. The combustion 

of fuels occurs in diesel-powered generators, pumps, or motors and from lighter fuel motors. 

Primary air pollutants typically associated with OCS activities are suspended particulate matter 

(PM), sulfur oxides (SOx), nitrogen oxides (NOx), volatile organic compounds (VOCs), and carbon 

monoxide (CO).

The Air Quality Emissions Report prepared in accordance with BOEM requirements

demonstrates that the projected emissions are below exemption levels set by the applicable 

regulations in 30 CFR 550.303. Based on this and the distance from shore, it can be concluded 

that the emissions will not significantly affect the air quality of the onshore area for any of the 

criteria pollutants. No further analysis or control measures are required.

A.4 Effluent Discharges

Effluent discharges are summarized in EP Section F. All offshore discharges will be in accordance 

with requirements of the National Pollutant Discharge Elimination System (NPDES) General 

Permit No. GMG290000 issued by the U.S. Environmental Protection Agency (USEPA). Any 

discharges will be in compliance with the permit terms and monitored as required by the 

permit.

Water-based drilling muds and cuttings will be released at the seafloor during initial well-drilling 

intervals in which the marine riser that enables the return of muds and cuttings to the surface 

vessel has not been set. Excess cement slurry also will be released at the seafloor during casing 

installation for the riserless portion of the drilling operations. Synthetic-based drilling muds 

(SBMs) will be collected on the rig after riser emplacement and either reused by the vendor or 

transported to Port Fourchon, Louisiana, for recycling and disposal at an approved facility. 

Cuttings wetted with SBMs will be discharged to the seafloor in accordance with the NPDES 

permit.

Other effluents that will be discharged in accordance with the NPDES permit will include excess 

cement, non-contact cooling water, treated sanitary and domestic wastes, deck drainage, 

desalination unit brine, uncontaminated freshwater and seawater, and ballast water.

A.5 Water Intake

Seawater will be drawn from the ocean for once-through, non-contact cooling of machinery on 

the drilling rig. 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 NPDES General Permit No. GMG290000 does 

not specify requirements for existing facilities (those that started construction before 

16 July 2006). The drilling vessel ultimately selected for this project will be in compliance with 

all cooling water intake structure requirements.

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A.6 Onshore Waste Disposal

Wastes generated during drilling are tabulated in EP Section F. A total of approximately

750 barrels (bbl) of trash will be generated over the life of the project. Trash will be transported 

to shore in disposal bags for final disposal by municipal operators in accordance with applicable 

regulations.

A.7 Marine Debris

Anadarko will comply with all regulations relating to solid wastes handling and disposal, 

including the International Convention for the Prevention of Pollution from Ships 

(MARPOL 73/78) Annex V requirements and USEPA, U.S. Coast Guard (USCG), and BOEM 

regulations. For example, BOEM regulations 30 CFR 250.300(a) and (b)(6) prohibit operators 

from deliberately discharging containers and other similar materials (i.e., trash and debris) into 

the marine environment, and 30 CFR 250.300(c) requires durable identification markings on 

equipment, tools, containers (especially drums), and other material. The USEPA and 

USCG regulations require operators to be proactive in avoiding accidental 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. In addition to the regulations in 30 CFR 250, the Bureau of Safety 

and Environmental Enforcement (BSEE) issued 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 training and certification process for marine trash and debris awareness.

A.8 Support Vessel and Helicopter Traffic

Anadarko will use existing shorebase facilities at Port Fourchon, Louisiana, for onshore support 

for vessel activities. Air transportation (helicopters) will be based at facilities in Houma, Louisiana. 

No terminal expansion or construction is planned at either location.

The project will be supported by one crew vessel and one supply vessel. The crew vessel will 

make three round-trips per week and the supply vessel will make two round-trips per week

between Port Fourchon and the drilling rig. The boats typically will move to the project area via 

the most direct route from the shorebase.

A helicopter will make an estimated 10 round-trips per week between the drilling rig and the 

heliport in Houma. The helicopter will be used to transport personnel as well as small supplies 

and will normally take the most direct route of travel between the heliport and the lease area 

when air traffic and weather conditions permit. Helicopters typically maintain a minimum 

altitude of 213 m (700 ft) while in transit offshore, 305 m (1,000 ft) over unpopulated areas or 

across coastlines, and 610 m (2,000 ft) over populated areas and sensitive habitats such as 

wildlife refuges and park properties. Additional guidelines and regulations specify that 

helicopters maintain an altitude of 305 m (1,000 ft) within 91 m (300 ft) of marine mammals 

(BOEM, 2012a).

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A.9 Accidents

A.9.1 Types of Accidents Evaluated

The analysis in this EIA focuses on two potential accidents:

• a small fuel spill, which is the most likely type of spill during OCS exploration activities; and

• a large oil spill, up to and including the WCD for this EP, which is an oil spill resulting from an 

uncontrolled blowout.

The following subsections summarize assumptions about the sizes and fates of these spills, as 

well as Anadarko’s spill response plans. Impacts are analyzed in Section C.

MMS (2007b) and BOEM (2012a,b, 2013) analyzed three other types of accidents: chemical 

spills, vessel collisions, and loss of well control. These types of accidents are discussed briefly in 

Section A.9.4.

A.9.2 Small Fuel Spill

Spill Size. According to the analyses in MMS (2007b) and BOEM (2012a), the most likely type of 

small spill (<1,000 bbl) resulting from OCS activities is a minor diesel fuel spill. Historically, most 

diesel spills have been ≤1 bbl, and this is predicted to be the most common size in ongoing and 

future OCS activities in the Western and Central Gulf of Mexico Planning Areas. As the spill size 

increases, the incident rate declines dramatically (MMS, 2007b; 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, 2012a). 

For this analysis, a small diesel fuel spill of 3 bbl is used. Operational experience suggests that 

the most likely cause of such a spill would be a hose rupture resulting in a loss of contents

(<3 bbl of fuel) of the fuel transfer hose.

Spill Fate. The fate of a small fuel spill in the lease area would depend on meteorological and 

oceanographic conditions at the time of the spill, as well as the effectiveness of spill response 

activities. However, given the open ocean location of the lease area and response actions, it is 

expected that impacts from a small spill would be minimal (BOEM, 2012b).

The water-soluble fractions of diesel are dominated by two- and three-ringed polycyclic 

aromatic hydrocarbons (PAHs), which are moderately volatile (National Research Council, 

2003a). The constituents of these oils are light to intermediate in molecular weight and can be 

readily degraded by aerobic microbial oxidation. Due to its low density, diesel 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 (National Research 

Council, 2003a) 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 (National Oceanic and Atmospheric Administration [NOAA], 2006).

For the purposes of this EIA, 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 spilled product. Based on 

model results, it is estimated that more than 90% of a small diesel spill would evaporate or 

disperse within 24 hours. The area of sea surface exhibiting floating diesel fuel during this 

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24-hour period would range from 0.5 to 5 ha (1.2 to 12 ac), depending on sea state and weather 

conditions.

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

indicate that a small fuel spill would not have any impacts on coastal or shoreline resources. 

The lease area is 122 miles (196 km) from the nearest shoreline. Modeling results indicate that 

a spill in the lease area would have a 5% or lower probability of reaching coastal areas of 

Louisiana within 10 days following a spill. By that time, essentially 100% of a small fuel spill 

would have dispersed or evaporated through natural processes, without taking into account 

Anadarko’s response measures. 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 (BOEM, 2012b). Because 

of the distance of these potential spills on the OCS and their lack of persistence, it is unlikely 

that a spill would make landfall prior to dissipation (BOEM, 2012b).

Spill Response. In the unlikely event that shipboard prevention procedures fail to avoid a fuel 

spill, response equipment and trained personnel would be activated so that any spill effects 

would be localized and result only in short-term environmental consequences. EP Section 9b

provides a detailed discussion of Anadarko’s response to a spill.

A.9.3 Crude Oil Spill (Worst Case Discharge)

Spill Size. In accordance with requirements of NTL 2010-N06, Anadarko has estimated a WCD 

for the EP of 201,530 bbl of oil per day based on a hypothetical blowout from GC 724-A.

An estimated 7 to 21 days would be required to suspend operations on a deepwater Gulf of 

Mexico well, mobilize to a relief well location, and begin drilling the relief well. This assumes 

0 to 14 days to suspend current operations on an existing well and 7 days to mobilize and be 

ready to spud the relief well. The estimated duration of time required to drill the relief well is 

85 days, for an estimated total of 92 to 106 days from time of blowout to completion of the 

relief well.

The maximum total volume during a blowout could be 21,362,180 bbl, assuming 106 days for 

the maximum duration of a blowout multiplied by the worst case daily uncontrolled blowout 

volume of 201,530 bbl/day. The detailed analysis of this calculation can be found in 

EP Section H.

Historically, blowouts are rare events and most do not result in oil spills. Holand (1997) 

estimated a probability of 0.0021 for a deep drilling blowout during exploration drilling based on 

U.S. Gulf of Mexico data. The International Association of Oil & Gas Producers (2010) conducted 

an updated analysis using the SINTEF1 database and estimated a blowout frequency of 

0.0017 per exploratory well for non-North Sea locations. As noted by MMS (2007b), from 1992 

to 2005, half of blowouts lasted less than half a day, and less than 10% of blowouts resulted in 

spilled oil. BOEM is in the process of updating these spill frequency estimates to include the 

Macondo oil spill that occurred in Mississippi Canyon Block 232 in 2010; however, significant 

changes to the spill rates for the entire OCS are not anticipated (BOEM, 2012a). According to 

BSEE’s Final Drilling Safety Rule (75 Federal Register [FR] 63365) issued following the Macondo 

1 Stiftelsen for industriell og teknisk forskning (Foundation for Scientific and Industrial Research, Norwegian Institute of 

Technology)

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spill, the baseline risk of a catastrophic blowout is estimated to be once every 26 years. 

Included in EP Section H are Anadarko’s calculations and information as required by 

NTL 2010-N06, including 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. Anadarko 

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 of the spill. The Oil Spill Risk Analysis (OSRA) model is 

a computer simulation of oil spill transport that uses realistic data for winds and currents to 

estimate spill trajectory. The OSRA report by Ji et al. (2004) provides conditional contact 

probabilities for shoreline segments in the Gulf of Mexico. The results for Launch Area 45 

(where the lease area is located) are presented in Table 3. The model predicts a 0% chance of 

shoreline contact within 10 days of a spill. Shoreline contact is predicted within 30 days for 

shorelines ranging from Calhoun, Texas, to Plaquemines Parish, Louisiana. The probability of 

shoreline contact within 30 days is highest in Cameron, Louisiana (4%).

Table 3. Conditional probabilities of a spill in the lease area contacting shoreline segments 

based on the 30-day Oil Spill Risk Analysis (OSRA) (From: Ji et al., 2004). Values are 

conditional probabilities that a hypothetical spill in the lease area (represented by 

OSRA Launch Area 45) could contact shoreline segments within 3, 10, or 30 days.

Shoreline 

Segment County or Parish and State Conditional Probability of Contact1 (%)

3 Days 10 Days 30 Days

C07 Calhoun, Texas -- -- 1

C08 Matagorda, Texas -- -- 1

C09 Brazoria, Texas -- -- 1

C10 Galveston, Texas -- -- 2

C12 Jefferson, Texas -- -- 1

C13 Cameron, Louisiana -- -- 4

C14 Vermillion, Louisiana -- -- 2

C15 Iberia, Louisiana -- -- 1

C16 St. Mary, Louisiana --

C17 Terrebonne, Louisiana -- -- 2

C18 LaFourche, Louisiana -- -- 1

C19 Jefferson, Louisiana -- -- --

C20 Plaquemines Parish, Louisiana -- -- 2

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

occurred (-- indicates <0.5%).

The original OSRA modeling runs reported by Ji et al. (2004) did not evaluate the fate of a spill 

over time periods exceeding 30 days, nor did they estimate the fate of a release that continues 

over a period of weeks or months. As noted by Ji et al. (2004), the OSRA model does not 

consider the chemical composition or biological weathering of oil spills, the spreading and 

splitting of oil spills, or spill response activities. The model does not specify a particular spill size 

but has been used by BOEM to evaluate contact probabilities for spills greater than 1,000 bbl.

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BOEM (2012b) conducted additional OSRA modeling to simulate a spill that continued for 

90 consecutive days, with each trajectory tracked for 120 days during each of the four seasons. 

The spatial resolution was limited, with five hypothetical launch points in the Central and 

Western Gulf of Mexico Planning Areas. These launch points were deliberately located in areas 

identified as having a high possibility of containing large oil reserves. The launch point most 

appropriate for modeling a spill in the lease area is Launch Point 3. The 120-day OSRA results 

for Launch Point 3 are presented in Table 4.

Table 4. Conditional probabilities of a spill in the lease area contacting shoreline segments 

based on the 120-day Oil Spill Risk Analysis (OSRA). Values are conditional 

probabilities that a hypothetical spill in the lease area could contact shoreline 

segments within 120 days (Modified from: BOEM, 2012b, Appendix C).

Season Winter Spring Summer Fall

Days 3 10 30 120 3 10 30 120 3 10 30 120 3 10 30 120

County or Parish, State Conditional Probability of Contact1 (%)

Cameron, TX -- -- -- 2 -- -- -- -- -- -- -- 2 -- -- -- 2

Willacy, TX -- -- -- 3 -- -- -- -- -- -- -- 2 -- -- -- 3

Kenedy, TX -- -- -- 8 -- -- -- 1 -- -- -- 9 -- -- -- 5

Kleberg, TX -- -- 1 6 -- -- -- -- -- -- -- 4 -- -- 1 6

Nueces, TX -- -- 1 6 -- -- -- -- -- -- -- 2 -- -- 1 2

Aransas, TX -- -- -- 5 -- -- -- 1 -- -- -- 3 -- -- -- 2

Calhoun, TX -- -- 1 6 -- -- -- -- -- -- -- 6 -- -- 1 4

Matagorda, TX -- -- 2 17 -- -- 3 4 -- -- -- 11 -- -- 1 6

Brazoria, TX -- -- 3 12 -- -- 1 3 -- -- 2 8 -- -- 1 5

Galveston, TX -- -- 3 10 -- -- 3 6 -- -- 2 5 -- -- 1 4

Jefferson, TX -- -- 1 4 -- -- 7 9 -- -- 1 1 -- -- -- 2

Cameron, LA -- -- 1 4 -- -- 11 12 -- 1 1 4 -- -- -- 4

Vermilion, LA -- -- 1 2 -- -- 5 6 -- 1 1 2 -- -- -- --

Iberia, LA -- -- -- 1 -- -- 4 4 -- -- -- -- -- -- -- --

Terrebonne, LA -- 1 2 3 -- 4 12 14 -- -- -- 2 -- -- -- --

Lafourche, LA -- -- 1 1 -- 2 8 10 -- -- 1 2 -- -- -- --

Jefferson, LA -- -- -- 1 -- -- 2 2 -- -- 1 1 -- -- -- --

Plaquemines, LA -- -- -- 1 -- 2 10 12 -- -- 1 2 -- -- -- --

Jackson, MS -- -- -- -- -- -- 1 1 -- -- -- -- -- -- -- --

Baldwin, AL -- -- -- -- -- -- 1 1 -- -- -- -- -- -- -- --

Bay, FL -- -- -- -- -- -- -- 1 -- -- -- -- -- -- -- --

Franklin, FL -- -- -- 1 -- -- -- -- -- -- -- -- -- -- -- --

Monroe, FL -- -- -- -- -- -- -- -- -- -- -- 1 -- -- -- 1

Miami-Dade, FL -- -- -- -- -- -- -- -- -- -- -- 1 -- -- -- --

State Coastline Conditional Probability of Contact1 (%)

Texas -- -- 12 78 -- -- 14 24 -- -- 6 54 -- -- 4 41

Louisiana -- 1 6 14 -- 9 52 60 -- 1 4 13 -- -- -- 6

Mississippi -- -- -- -- -- -- 1 1 -- -- -- -- -- -- -- --

Alabama -- -- -- -- -- -- 1 1 -- -- -- -- -- -- -- --

Florida -- -- -- 1 -- -- 1 4 -- -- -- 2 -- -- -- 2

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

occurred (-- indicates <0.5%).

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For this launch point, potential shoreline contacts after 120 days range from Cameron County, 

Texas (at the Texas/Mexico border) to Miami-Dade County in southeastern Florida. Based on 

statewide contact probabilities after 120 days, Texas and Louisiana shorelines have the highest 

likelihood of contact during all four seasons, with Louisiana having higher probabilities in spring 

(60%) and Texas having higher probabilities during all other seasons (ranging from 41% to 78%). 

The modeling predicts a 1% probability of a spill contacting Alabama and Mississippi shorelines, 

but only during spring. The modeling predicts that Florida shorelines could be contacted in any 

season, with statewide probabilities ranging from 1% to 4%. Based on the 120-day trajectories, 

counties or parishes with more than 10% contact probability during any season include

Matagorda, Brazoria, Galveston, and Cameron Counties in Texas and Terrebonne, Lafourche,

and Plaquemines Parishes in Louisiana.

OSRA is a preliminary risk assessment model. In the event of an actual oil spill, real-time 

monitoring and trajectory modeling would be conducted using current and wind data available 

from the rigs and permanent production structures in the area. Satellite and aerial monitoring 

of the plume and real-time trajectory modeling using wind and current data would continue on 

a daily basis to help position equipment and human resources throughout the duration of any 

major spill or uncontrolled release.

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, 

influencing potential effects to 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 particulate matter, and stranding on shore or sedimentation to the 

seafloor (National Research Council, 2003a).

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 a 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 alkanes and then the light 

aromatics from the oil. Other petroleum components are biodegraded more slowly. 

Photo-oxidation attacks mainly the medium and high molecular weight PAHs in the oil on the 

water surface.

Spill Response. BOEM has issued NTLs following the Macondo spill that clarify additional oil spill 

prevention and response planning requirements. These NTLs are summarized in Table 1.

Anadarko’s Sub-Regional OSRP was last approved on 25 September 2013. The OSRP provides a 

detailed plan for Anadarko to respond to rapidly and effectively manage oil spills that may result 

from drilling and production operations. The OSRP contains detailed information on 

"Quick Response" procedures, including:

• responsibilities of all Anadarko and contract personnel to report any observed discharge 

from known or unknown sources;

• procedures to locate and determine the size of a discharge; and

• contact information for alerting the spill management team, complete with names, phone 

numbers, and locations.

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In the event of a WCD, Anadarko has access to surface and subsea response/containment 

capabilities that could be implemented through various organizations under contract. 

Anadarko’s primary spill response equipment provider is Clean Gulf Associates (CGA).

CGA has four skimming vessels capable of operating in shallow waters, nearshore areas, and 

offshore areas. These vessels have oleophilic brush pack skimming systems operating in troughs 

built into the hulls; below-deck storage; and marine electronics packages including marine, 

aircraft, and company-frequency radios, radar, moving map plotters, GPS, satellite phones, and 

depth finders. CGA also offers nine Fast Response Systems staged throughout the Gulf of 

Mexico available for offshore use.

The CGA high-volume open sea skimmer (HOSS) barge consists of a skimming system built into 

an oil recovery barge. There are four 1,000-bbl recovered oil storage tanks built into the hull 

where oil can be separated and offloaded. Skimming operations are conducted from the control

room overlooking the skimmer deck. The estimated daily recovery capacity for the HOSS barge 

is approximately 43,000 bbl.

CGA is currently adding to its equipment stockpile and has acquired 11 sets of Koseq skimming 

arms and two Aqua Guard skimmers. In addition, an x-band radar/infrared tracking system is 

installed on the HOSS barge. Additional CGA equipment can be referenced online at

http://www.cleangulfassoc.com/equipment.

Anadarko also has a contract with the Marine Spill Response Corporation (MSRC) for additional 

spill response equipment. MSRC has a dedicated fleet for the Atlantic/Gulf of Mexico region and 

additional available equipment staged throughout the U.S. MSRC equipment staged throughout 

the Gulf of Mexico includes 7 oil spill response vessels, 2 fast response vessels, 5 oil spill 

response barges, 5 platform supply vessels, and 15 shallow water barges. Various equipment is 

outfitted with x-band radar and infrared technology for detecting surface oil.

MSRC expanded its resources and capability in the Gulf of Mexico with particular focus on deep

water, known as "Deep Blue." Additional MSRC capabilities and a complete equipment listing 

are available online at http://www.msrc.org/.

Anadarko is a member of the Marine Well Containment Company (MWCC). In the event of an 

incident, MWCC can provide a 15,000-psi single ram capping stack and dispersant injection 

capability. MWCC can install and operate the interim containment system, including subsea 

flowlines, manifolds, and risers. The interim system is engineered to be used in depths up to 

3,048 m (10,000 ft) and has the capacity to contain 60,000 bbl of liquid per day (and 120 million 

standard cubic feet per day of gas) with potential for expansion.

See EP Section H for a detailed description of Anadarko’s site-specific spill response measures

for this plan.

A.9.4 Other Accidents Not Analyzed in Detail

BOEM (2012b) discusses other types of accidents, including chemical spills, pipeline failures, 

vessel collisions, and loss of well control. The information from the EIS on these topics remains 

valid and is incorporated by reference into this document. These accidents along with a 

hydrogen sulfide (H2S) release are discussed briefly in the following subsections. There are no 

other site-specific issues for the drilling of the wells proposed in this EP.

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Chemical Spills. Chemicals are stored and used to condition drill muds, as well as during 

production activities and well completions, stimulations, and workover procedures. A study of 

environmental risks of chemical products used in OCS activities determined that only two 

chemicals could potentially affect the marine environment: zinc bromide and ammonium 

chloride (Boehm et al., 2001). The risk of a chemical spill is very low, and most chemicals are 

either nontoxic or used in small quantities (BOEM, 2012a,b). No significant impacts are 

expected from chemical spills.

Riser Disconnect SBM Spills. There is the potential for an SBM spill due to a riser disconnect 

(BOEM, 2012a,b). In the event of an SBM spill, there would be short-term, localized impacts on 

water quality, and the potential for localized benthic impacts due to SBM deposition on the 

seafloor. Benthic impacts would be similar to those described in Section C.2.1.

Vessel Collisions. BOEM data show that from 1996 to 2009 there were 226 OCS-related 

collisions. Most collision mishaps are the result of service vessels colliding with platforms or 

vessel collisions with pipeline risers. Approximately 10% of vessel collisions with platforms in 

the OCS resulted in diesel spills, and in several collision incidents, fires resulted from 

hydrocarbon releases. To date, the largest diesel spill associated with a collision occurred in 

1979 when an anchor-handling vessel collided with a drilling platform in the Main Pass lease

area, spilling 1,500 bbl of diesel fuel. Diesel fuel is the product most frequently spilled, but oil, 

natural gas, corrosion inhibitor, hydraulic fluid, and lube oil also have been released as the result 

of vessel collisions. Human error accounted for approximately half of all reported vessel 

collisions from 2006 to 2009. As summarized by MMS (2007b) and BOEM (2012b), vessel 

collisions occasionally occur during routine operations. Some of these collisions have caused 

spills of diesel fuel or chemicals. Anadarko will comply with all 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 very minor up to the most 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 synthetic drilling 

fluid or loss of oil. Not all loss of well control events result in blowouts (BOEM, 2012a,b, 2013). 

In addition to the potential release of gas, condensate, oil, sand, or water, the loss of well 

control can also resuspend and disperse bottom sediments (BOEM, 2012b). BOEM 

(2012a,b, 2013) noted that most OCS blowouts have resulted in the release of gas.

Anadarko has a robust system in place to prevent loss of well control. Measures to prevent a 

blowout, reduce the likelihood of a blowout, and conduct effective and early intervention in the 

event of a blowout are described in the NTL 2010-06 package submitted with the EP, as required

by BOEM. The potential for a loss of well control event will be minimized by adhering to the 

requirements of applicable regulations such as the Final Drilling Safety Rule and NTL 2010-N10, 

which specify additional safety measures for OCS activities.

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H2S Release. The wells proposed in the EP will test the Pliocene and Pleistocene sections of the 

subbottom geological formation. The proposed GC 724 A well will only penetrate sections that 

have been previously penetrated by four of the GC 768 wells within approximately 250 ft of the 

surface location of proposed well, and had no recorded amounts of H2S. Therefore, Anadarko is 

requesting that the area for the wells proposed in the EP be classified as a zone in which the 

absence of H2S has been confirmed.

B. Affected Environment

The lease area is in the central Gulf of Mexico, 122 miles (196 km) from the nearest shoreline, 

135 miles (217 km) from the onshore support base at Port Fourchon, Louisiana, and 160 miles

(258 km) from the helicopter base at Houma, Louisiana (Figure 1). Based on the site clearance 

surveys conducted by Fugro GeoServices, Inc. (2003), water depths at the wellsites range from 

1,573 to 1,695 m (5,160 to 5,560 ft) (Figure 2).

The seafloor surrounding the proposed wellsites is smooth and stable, with one seafloor fault 

south of and within approximately 1,300 ft of the proposed surface location. Seafloor gradients 

are less than 1 degree (Fugro GeoServices, Inc., 2003). Several existing structures are present 

near the proposed locations, including three existing wells, two 6-inch pipelines, an umbilical, 

and numerous cables. No areas of high seafloor amplitude occur within 610 m (2,000 ft) the 

proposed well locations. No areas with the potential for high-density deepwater benthic or 

chemosynthetic communities were identified by Fugro GeoServices, Inc. (2003) within 610 m 

(2,000 ft) of the proposed wellsites.

A detailed description of the regional affected environment, 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 is provided in MMS (2007b) and BOEM (2012a,b, 2013). 

These regional descriptions remain valid and are incorporated by reference. Brief descriptions 

of each potentially affected resource, including site-specific and/or new information if available,

are presented in Section C.

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Figure 2. Bathymetric map of the lease area showing the surface hole locations of the proposed wellsites.

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C. Impact Analysis

This section analyzes the potential direct and indirect impacts of routine activities and accidents. 

Impacts have been analyzed extensively in multi-lease-sale EISs for the Western and Central Gulf 

of Mexico Planning Areas (MMS, 2007b; BOEM, 2012b, 2013). The information in these 

documents is incorporated by reference. Potential site-specific issues are addressed in this 

section.

C.1 Physical/Chemical Environment

C.1.1 Air Quality

There are no site-specific air quality data for the project area due to the distance from shore. 

Because of the distance from shore-based pollution sources and the lack of sources offshore, air 

quality at the wellsites 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 (BOEM, 2012a).

In general, ambient air quality of coastal counties along the Gulf of Mexico is relatively good 

(BOEM, 2012b). As of 5 December 2013, Louisiana, Mississippi, Alabama, and Florida Panhandle 

coastal counties and parishes are in attainment of the National Ambient Air Quality Standards 

(NAAQS) for all criteria pollutants (USEPA, 2013). One coastal metropolitan area in Texas 

(Houston-Galveston-Brazoria) is a nonattainment area for 8-hour ozone. One coastal 

metropolitan area in Florida (Tampa) is a nonattainment area for lead based on the 

2008 standard.

As noted earlier, based on calculations made pursuant to applicable regulations, emissions from 

drilling activities are not expected to be significant because they are below exemption levels. 

Therefore, the only potential effects to air quality would be from routine air pollutant emissions, 

a small fuel spill, and a large oil spill.

BOEM has reexamined the analysis for air quality presented by MMS (2007b, 2008) based on 

additional information and in consideration of the Macondo oil spill event. No substantial new 

information was found that would alter the potential impacts on air quality presented in 

BOEM (2012b).

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 drilling rig operations, helicopters, and service vessels. These 

emissions occur mainly from combustion or burning of diesel fuel. The combustion of fuels 

occurs primarily in diesel-powered generators, pumps, or motors as well as from lighter fuel 

motors. Primary air pollutants typically associated with OCS activities are suspended PM, SOx, 

NOx, VOCs, and CO. Emissions of pollutants into the atmosphere from these activities are not 

projected to have significant effects on onshore air quality because of the prevailing 

atmospheric conditions, anticipated emission rates, anticipated heights of emission sources, and 

the resulting anticipated pollutant concentrations. The incremental contribution to cumulative 

impacts from activities similar to Anadarko’s proposed activities is not significant and will not 

cause or contribute to a violation of NAAQS (MMS, 2007b, 2008). Since BOEM completed the 

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lease sale EISs, the USEPA has adopted a new short-term NAAQS for nitrogen dioxide (NO2). The 

standard has not yet been implemented in the Gulf Coast states, but given the levels of 

expected emissions and the distance of the project from shore, emissions from the activities 

described in Anadarko’s proposed EP are not likely to contribute to violations of any NAAQS 

onshore.

Greenhouse gas emissions contribute to climate change, with important impacts on 

temperature, rainfall, frequency of severe weather, ocean acidification, and sea level rise 

(Intergovernmental Panel on Climate Change, 2007, 2014). Greenhouse gas emissions from this 

proposed project 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 Programmatic EIS (BOEM, 2012a). Carbon 

dioxide (CO2) and methane (CH4) emissions from the project would constitute a small 

incremental contribution to greenhouse gas emissions from all OCS activities. According to

recent Programmatic and OCS lease sale EISs (BOEM, 2012a,b), estimated CO2 emissions from 

OCS oil and gas sources represent 0.4% of the U.S. total. All OCS activities combined contribute 

approximately 0.005% to total global CO2 emissions. Because of the distance from shore, 

routine operations in the project area are not expected to have any impact on air quality 

conditions along the coast, including nonattainment areas. As noted in MMS (2007b), emissions 

of air pollutants from routine activities in the Central and Western Gulf of Mexico Planning 

Areas 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 EP Section G) prepared in accordance 

with BOEM requirements shows that the projected emissions are below exemption levels; 

therefore, according to 30 CFR 550.303, the emissions will not significantly affect the air quality 

of the onshore area for any of the criteria pollutants. No further analysis or control measures 

are required.

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 air 

quality area. BOEM is required to notify the National Park Service (NPS) and U.S. Fish and 

Wildlife Service (USFWS) if emissions from proposed projects may affect the Breton Class I area.

Additional review and mitigation measures may be required for sources within 186 miles 

(300 km) of the Breton Class I area that exceed emission limits agreed upon by the administering 

agencies (NPS, 2010). The lease area is approximately 186 miles (300 km) from the Breton

Wilderness Area, and no air quality impacts on the Wilderness Area are expected. Anadarko will 

comply with all BOEM requirements regarding air emissions.

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 MMS (2007b) and BOEM (2012a,b, 2013). The probability of a small spill would 

be minimized by Anadarko’s preventative measures during routine operations, including fuel 

transfer. In the unlikely event of a spill, implementation of Anadarko’s OSRP could reduce the

potential impacts. EP Section H includes a detailed discussion of the spill response measures

that would be employed. 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.

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A small fuel spill would 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 evaporate or disperse within 24 hours. The sea surface area with diesel fuel 

on it would range from 0.5 to 5 ha (1.2 to 12 ac), 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 natural dispersion (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 by MMS (2007b) and BOEM (2012a,b, 2013).

A large oil spill could 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. Real-time wind and 

current data from the project area would be available at the time of a spill and would be used to 

assess the fate and effects of VOCs released. 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 NOx, SOx, CO, and PM as well as greenhouse gases.

However, in situ burning would occur only if authorized by the USEPA.

Due to the lease area’s distance from the nearest shoreline, most air quality impacts would 

occur in offshore waters with minimal chances to affect onshore air quality.

C.1.2 Water Quality

There are no site-specific water quality data for the lease area. Due to the lease location in 

deep, offshore waters, water quality is expected to be good, with low levels of contaminants. 

As noted in MMS (2007b), deepwater areas in the northern Gulf of Mexico are relatively 

homogeneous with respect to temperature, salinity, and oxygen. Kennicutt (2000) noted that 

the deepwater region has little evidence of contaminants in the dissolved or particulate phases 

of the water column. However, there are localized occurrences of natural seepage of oil, gas, 

and brines in near-surface sediments and up through the water column.

The lease area is located approximately 187 miles (301 km) from the Macondo spill site in 

Mississippi Canyon Block 232. Based on the general circulation pattern observed in the Gulf of 

Mexico and in satellite imagery, the surface slick from that discharge extended over the GC lease 

area during the spill, and local water quality may have been affected.

IPFs that could affect water quality are effluent discharges and two types of accidents – a small 

fuel spill and a large oil spill.

Impacts of Effluent Discharges

In general, turbid water can be expected to extend between a few hundred meters and several 

kilometers down current from the discharge point for water-based drilling muds and cuttings. 

SBMs will be collected on the rig and either reused by the vendor or transported to 

Port Fourchon, Louisiana, for recycling and disposal at an approved facility. Cuttings wetted 

with SBMs will be discharged to the seafloor at the drillsite in accordance with the NPDES 

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permit. All NPDES permit limitations and requirements will be met. There will be no persistent 

impacts on water quality in the lease area (National Research Council, 1983; Neff, 1987;

Neff et al., 2000).

Treated sanitary and domestic wastes, including those from support vessels, may have a 

transient effect on water quality in the immediate vicinity of these discharges. All NPDES permit 

limitations and requirements as well as USCG regulations (as applicable) will be met; therefore, 

little or no impact on water quality is anticipated.

Deck drainage includes all 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 will be separated to meet NPDES permit 

requirements. Based on adherence to permit limits and applicable regulations, little or no 

impact on water quality is anticipated.

Other discharges in accordance with the NPDES permit, such as desalination unit brine and 

uncontaminated cooling water, fire water, and ballast water, are expected to dilute rapidly,

resulting in little or no impact 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 MMS (2007b) and BOEM (2012a,b, 2013). The probability of a small 

spill would be minimized by Anadarko’s preventative measures during routine operations 

including fuel transfer. In the unlikely event of a spill, implementation of Anadarko’s OSRP could

potentially help mitigate and reduce the impacts. EP Section H provides detail on spill response 

measures in addition to the summary information provided in this EIA. 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 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. However, it is estimated that more 

than 90% of a small diesel spill would evaporate or disperse within 24 hours (see Section A.9.2). 

The sea surface area with diesel fuel on it would range from 0.5 to 5 ha (1.2 to 12 ac), depending 

on sea state and weather conditions.

The water-soluble fractions of diesel are dominated by two- and three-ringed PAHs, which are 

moderately volatile (National Research Council, 2003a). The constituents of these oils are light 

to intermediate in molecular weight and can be readily degraded by aerobic microbial oxidation. 

Because the density of diesel is less than the density of seawater, diesel 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 (National Research 

Council, 2003a) 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).

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

to make landfall or reach coastal waters due to both response efforts that would be undertaken 

as well as natural attenuation (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 MMS (2007b) and BOEM (2012a,b, 2013). A large spill would 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 new information from the Macondo spill indicates 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). However, subsea 

dispersants would be applied only after approval from the USEPA. Small droplets in the water 

may adhere to suspended sediments and be removed from the water column (Operational 

Scientific Advisory Team [OSAT], 2010).

Recent analyses of the full set of samples associated with the Macondo spill have confirmed that 

the application of subsurface dispersants resulted in subsurface hydrocarbon plumes 

(Spier et al., 2013). A report by Kujawinski et al. (2011) indicates that chemical components of 

subsea dispersants used during the Macondo spill persisted for up to 2 months and were 

detected up to 186 miles (300 km) from the wellsite in water depths of 3,280 to 3,937 ft 

(1,000 to 1,200 m). Although dispersants were detected by laboratory analysis in 353 of the 

4,114 water samples, concentrations were significantly below the chronic screening level for 

dispersants (BOEM, 2012b).

Because of the lease area’s distance from the nearest shoreline, it is expected that most water 

quality impacts would occur in offshore waters, especially in the event of a spill lasting less than 

30 days (Table 4). The 30-day OSRA modeling (Table 3) indicates a 4% conditional probability of 

contact in Cameron, Louisiana within 30 days. A very low conditional probability of contact 

(1% to 2%) is predicted by the 30-day OSRA for other shorelines between Calhoun, Texas and 

Plaquemines Parish, Louisiana.

C.2 Seafloor Habitats and Biota

Water depths at the proposed wellsites range from 1,573 to 1,695 m (5,160 to 5,560 ft). The 

site clearance surveys conducted by Fugro GeoServices, Inc. (2003) identified no hazards at the 

seafloor that preclude the proposed wellsites from exploratory drilling. There is no evidence of

high-density deepwater benthic or chemosynthetic communities within 610 m (2,000 ft) of the 

proposed wellsites (Fugro GeoServices, Inc., 2003).

C.2.1 Soft Bottom Benthic Communities

There are no site-specific benthic community data from the lease area. However, 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 that occur at 

similar water depths elsewhere in the region. Table 5 summarizes data collected at nearby 

stations in water depths similar to the proposed drilling area.

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Table 5. 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 (Adapted from: Wei, 2006; Rowe and Kennicutt, 2009).

Station Water Depth

(m)

Abundance

Meiofauna

(individuals/m2)

Macroinfauna

(individuals/m2)

Megafauna

(individuals/ha)

NB2 1,530 168,276 1,700 570

NB3 1,875 165,245 1,342 191

Meiofaunal and megafaunal abundances from Rowe and Kennicutt (2009); macroinfaunal abundance from 

Wei (2006).

Densities of meiofauna (animals passing through a 0.5-mm sieve but retained on a 

0.062-mm sieve) in water depths representative of the lease area (1,573 to 1,695 m) typically 

range from approximately 100,000 to 300,000 individuals/m2 (Rowe and Kennicutt, 2009). 

Nematodes, nauplii (crustacean larvae), and harpacticoid copepods were the three dominant 

meiofaunal groups, accounting for approximately 90% of total abundance.

The benthic macroinfauna is characterized by small mean individual sizes and low densities, 

both of which reflect the meager primary production in Gulf of Mexico surface waters 

(Wei, 2006). Based on an equation presented by Wei (2006) in which densities decrease 

exponentially with water depth, macroinfaunal densities in the water depths of the lease area 

are expected to be approximately 2,119 individuals/m2

; however, actual densities are unknown 

and pften highly variable.

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 located in Zone 3W, which contains the most complex 

bathymetric features in the northern Gulf of Mexico, including the Alaminos Canyon, basin sites, 

non-basin sites, and the base of the Sigsbee Escarpment. The five most abundant species in 

Zone 3W were the polychaetes Paraonella monilaris, Tachytrypane sp. A, and Levinsenia 

uncinata and the bivalves Heterodonta sp. B and Heterodonta sp. C (Wei, 2006).

Megafaunal densities from nearby stations ranged from 191 to 570 individuals/ha (Table 5). 

Common megafauna included motile groups such as decapods, ophiuroids, holothurians, and 

demersal fishes as well as sessile groups such as sponges and anemones.

Bacteria also 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 

0.5 to 1.5 g C/m2 in the top 15 cm (6 in.) of sediments (Rowe and Kennicutt, 2009).

IPFs potentially affecting benthic communities are physical disturbance to the seafloor, effluent 

discharges (drilling muds 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.

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Impacts of Physical Disturbance to the Seafloor

In water depths such as those encountered in the lease area, the areal extent of seafloor 

impacts will be small compared to the lease area itself. DP drilling vessels disturb the seafloor 

only around the wellbore where the bottom template and BOP are located. Depending on the 

specific well configuration, this area is generally 0.25 ha (0.62 ac) per well.

Soft bottom communities are ubiquitous along the northern Gulf of Mexico continental slope 

(Gallaway, 1988; Gallaway et al., 2003; Rowe and Kennicutt, 2009), and impacts from the 

physical disturbance of the seafloor during this project likely will have no significant impact on 

soft bottom benthic communities in the region.

Impacts of Effluent Discharges

Drilling muds and cuttings are the only effluents that are likely to affect benthic communities. 

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 muds (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 muds, and cement slurry will eventually be recolonized 

through larval settlement and migration from adjacent areas. Because some deepsea biota 

grow and reproduce slowly, recovery may require several years for the area within meters to 

tens of meters of the wellbore.

Discharges of washed SBM cuttings from the rig may affect benthic communities, primarily 

within several hundred meters of the wellsite. 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, washed cuttings with 

adhering SBMs 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 in 

concentrations of approximately 1,000 mg/kg or higher, 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 H2S 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. Soft bottom communities are 

ubiquitous along the northern Gulf of Mexico continental slope (Gallaway, 1988; Gallaway et al., 

2003; Rowe and Kennicutt, 2009). Drilling discharges during this project likely will have no 

significant impact on soft bottom benthic communities in the region.

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 wellsite. MMS (2007b) estimated that a severe subsurface blowout 

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could resuspend and disperse sediments within a 300-m (984-ft) radius. While coarse sediments 

(sands) would probably settle at a rapid rate within 400 m (1,312 ft) of the blowout site, fine 

sediments (silts and clays) could be resuspended for more than 30 days and dispersed over a 

much wider area. Based on previous studies, surface sediments at the project area are assumed 

to largely be silt and clay (Rowe and Kennicutt, 2009).

Discussions in MMS (2007a, 2008) and BOEM (2013) indicated 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 in water depths

of approximately 1,100 m (3,600 ft), 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 subsea dispersants at the wellhead (Joint Analysis Group, 2010c; 

Spier et al., 2013). 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 300-m 

(984-ft) radius estimated by MMS (2007a, 2008), depending on its extent, trajectory, and 

persistence (Spier et al., 2013). This contact could result in smothering or toxicity to benthic 

organisms. The affected area likely would be recolonized by benthic organisms over a period of 

months to years (National Research Council, 2003a).

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 chemosynthetic communities, deepwater corals, and other associated 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; Brooks et al., 2012). These communities occur 

almost exclusively on authigenic carbonates created by chemosynthetic communities.

Monitoring programs on the Gulf of Mexico continental slope have shown that benthic impacts 

from drilling discharges typically are concentrated within approximately 500 m (1,640 ft) of the 

wellsite, although detectable deposits may extend beyond this distance (Continental Shelf 

Associates, Inc., 2004, 2006; Neff et al., 2005). In water depths such as those encountered in 

the project area, DP drilling vessels disturb the seafloor only around the wellbore (SHL) where 

the bottom template and BOP are located. Depending on the specific well configuration, this 

area is approximately 0.25 ha (0.62 ac) per well.

The site clearance surveys of the proposed wellsites did not identify any features that could 

support high-density deepwater benthic or chemosynthetic communities within 610 m (2,000 ft)

of the proposed drilling mud/cuttings discharge locations (Fugro GeoServices, Inc., 2003). The 

nearest known chemosynthetic community site is approximately 31 miles (50 km)

north-northeast of the project area in GC Block 287. The nearest identified deepwater coral 

communities are located 12 miles (20 km) west-southwest of the project area in GC Block 852.

The only IPF identified for this project that could affect high-density deepwater benthic 

communities is 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. 

Physical disturbance and effluent discharge are not considered IPFs for deepwater benthic 

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communities because these communities are not expected to be present near the proposed 

wellsites.

Impacts of a Large Oil Spill

Previous analyses (MMS, 2007a, 2008; BOEM, 2012a) 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 approximately 1,100 m (3,600 ft), 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 subsea dispersants at the wellhead (Joint Analysis Group, 

2010c). 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 300-m (984-ft) radius estimated by MMS (2007a, 2008), depending on its extent, trajectory, 

and persistence (Spier et al., 2013). Oil plumes that contact sensitive benthic communities 

before degrading could potentially impact the resource (BOEM, 2012b). Potential impacts on 

sensitive resources would be an integral part of the decision and approval process for the use of 

dispersants, and such approval would be obtained from the USEPA prior to the use of 

dispersants.

The biological effects and expected fate of the oil remaining in the Gulf of Mexico from the 

blowout are still unknown due to the depth and magnitude of the event. Hazen et al. (2010) 

reported changes in plume hydrocarbon composition with distance from the source. Incubation 

experiments with environmental isolates demonstrated faster than expected hydrocarbon 

biodegradation rates at 5°C. Based on these results, Hazen et al. (2010) suggested the potential 

exists for intrinsic bioremediation of the oil plume in the deep water column without substantial 

oxygen drawdown.

Potential impacts of oil on high-density deepwater benthic communities are discussed in 

MMS (2007b). Although chemosynthetic communities live among hydrocarbon seeps, natural 

seepage is very consistent and occurs at low rates compared to the potential rates of oil release 

from a blowout. In addition, seep organisms also 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, 2012a).

The potential for a spill to affect deepwater corals is indicated by preliminary findings from an 

October 2010 survey of deepwater coral habitats near the Macondo spill site (BOEMRE, 2010). 

Government and academic researchers were working at a site 1,400 m (4,600 ft) deep and 

approximately 7 miles (11 km) southwest of the Macondo wellhead when they observed dead 

and dying corals with sloughing tissue and discoloration. Much of the soft coral observed in an 

area measuring approximately 15 by 40 m (50 by 130 ft) was covered by what appeared to be a 

brown flocculent substance. Of 40 large corals, 90% were heavily affected, showing dead or

dying parts and discoloration. Another site 400 m (1,312 ft) farther away had a colony of stony 

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corals similarly affected and partially covered with a similar brown substance. Based on 

hopanoid petroleum biomarkers from the brown flocculent substance, researchers concluded 

that the colony 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. Corals 

elsewhere in the Gulf of Mexico outside the area affected by the plume did not appear to be 

experiencing higher mortality. The research team concluded that the observed coral injuries 

likely resulted from exposure to the subsurface oil plume (White et al., 2012). Apparent 

recovery of some affected areas by March 2012 correlated negatively with the proportion of the 

coral covered with flocculent in late 2010 (Hsing et al., 2013).

C.2.3 Designated Topographic Features

The 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 is Ship Shoal South in 

Ewing Bank Block 947, 54 miles (87 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. A small 

fuel spill would float and dissipate on the surface and would not reach these seafloor features.

In the event of an oil spill from a well blowout, a surface slick would not contact these seafloor 

features. If a subsurface plume were to occur, impacts on these features would be unlikely due 

to the distance and the difference in water depth. Near-bottom currents in the region are 

predicted to flow along the isobaths (Nowlin et al., 2001) and typically would not be expected to 

carry a plume up onto the continental shelf edge.

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 Stipulation Block is Main Pass Block 290, located 203 miles 

(327 km) northeast of the lease area.

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. A small 

fuel spill would float on the surface and would not reach these seafloor features.

In the event of an oil spill from a well blowout, a surface slick would not contact these seafloor 

features. If a subsurface plume were to occur, impacts on these features would be unlikely due 

to the distance and the difference in water depth. Near-bottom currents in the region are 

predicted to flow along the isobaths (Nowlin et al., 2001) and typically would not be expected to 

carry a plume up onto the continental shelf edge.

C.2.5 Eastern Gulf Live Bottoms

The lease area is not covered by the Live Bottom (Low-Relief) Stipulation, which pertains to 

seagrass communities and low-relief hard-bottom reef within the Eastern Gulf of Mexico

Planning Area blocks in water depths of 100 m (328 ft) or less and portions of Pensacola and 

Destin Dome Area blocks in the Central Gulf of Mexico Planning Area. The nearest block 

covered by the Live Bottom Stipulation, as defined by NTL 2009-G39, is Destin Dome Block 573,

located 243 miles (390 km) northeast of the lease area.

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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. A small fuel 

spill would float and dissipate on the surface and would not reach these seafloor features.

In the event of an oil spill from a well blowout, a surface slick would not contact these seafloor 

features. If a subsurface plume were to occur, impacts on these features would be unlikely due 

to the distance and the difference in water depth. Near-bottom currents in the region are 

predicted to flow along the isobaths (Nowlin et al., 2001) and typically would not be expected to 

carry a plume up onto the continental shelf.

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

This section discusses species listed as endangered or threatened under the Endangered Species 

Act (ESA). In addition, it includes all marine mammal species in the region, which are protected 

under the Marine Mammal Protection Act (MMPA).

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

Gulf Coast are listed in Table 6. The table also indicates the location of critical habitat 

(if designated 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 National Marine Fisheries Service (NMFS) has jurisdiction for ESA-listed 

cetaceans, sea turtles in the marine environment, and fishes in the Gulf of Mexico. The USFWS 

has jurisdiction for ESA-listed birds, the West Indian manatee, and sea turtles on their nesting 

beaches.

As mandated by the ESA, MMS consulted NMFS and the USFWS on possible and potential 

impacts from the proposed leasing in the Gulf of Mexico on endangered/threatened species and 

their designated critical habitat (MMS, 2007a,b). A Biological Assessment was prepared for each 

consultation. The formal ESA consultation with NMFS was concluded with receipt of the 

Biological Opinion on 3 July 2007 (NMFS, 2007). The Biological Opinion concludes that the 

proposed lease sales and associated activities in the Five-Year Leasing Plan for Western and 

Central Planning Areas 2007-2012 are not likely to jeopardize the continued existence of 

threatened and endangered species under NMFS jurisdiction or destroy or adversely modify 

designated critical habitat. The informal ESA consultation with the USFWS was concluded with a 

letter dated 14 September 2007. The USFWS concurred with MMS’s determination that 

proposed actions of the Five-Year Leasing Plan were not likely to adversely affect 

endangered/threatened species or designated critical habitat under USFWS jurisdiction. 

Following the Macondo spill, BOEMRE requested to reinitiate an ESA consultation with both 

NMFS and the USFWS on 30 July 2010. NMFS responded with a letter to BOEMRE on 

24 September 2010, and the USFWS responded with a letter to BOEMRE on 27 September 2010. 

At present, NMFS and the USFWS have placed the consultation process on hold because they 

feel the environmental baseline information needs to be updated for the post-Macondo spill 

environment based on the results of the Natural Resource Damage Assessment (NRDA) process. 

The NRDA data have yet to be released, and the existing consultation remains in effect

(BOEM, 2012b). The existing consultation recognizes that BOEM-required mitigation and other 

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reasonable and prudent measures should reduce the likelihood of impacts from all 

BOEM-authorized activities in the Gulf of Mexico.

Coastal endangered or threatened species that may occur along the northern Gulf Coast include 

the West Indian 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 6

and are discussed in individual sections.

Table 6. Federally listed endangered and threatened species that could potentially occur 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

Sei whale Balaenoptera borealis E Xa -- None

Blue whale Balaenoptera musculus E Xa -- None

Fin whale Balaenoptera physalus E Xa -- None

North Atlantic right whale Eubalaena glacialis E Xa -- None

Humpback whale Megaptera novaeangliae E Xa -- None

Sperm whale Physeter macrocephalus E X -- None

West Indian manatee Trichechus manatus 

latirostris E -- X Florida (Peninsular)

Sea Turtles

Loggerhead turtle Caretta caretta T X X Proposedb

Green turtle Chelonia mydas T, Ec X X None

Leatherback turtle Dermochelys coriacea E X X None

Hawksbill turtle Eretmochelys imbricata E X X None

Kemp’s ridley turtle Lepidochelys kempii 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)

Smalltooth sawfish Pristis pectinata E -- X Southwest Florida and the 

Florida Keys

Invertebrates

Elkhorn coral Acropora palmata Td -- X Flower Garden Banks

Terrestrial Mammals

Beach mice (subspecies: 

Alabama, Choctawhatchee, 

Perdido Key, St. Andrew)

Peromyscus polionotus E -- X Alabama and Florida 

(Panhandle) beaches

Abbreviations: E = endangered; T = threatened. a The sei, blue, fin, North Atlantic right, and humpback whales are rare or extralimital in the Gulf of Mexico and are 

unlikely to be present in the lease area. b In September 2011, the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS) listed 

nine distinct population segments (DPS) of loggerhead turtles under the Endangered Species Act. The Northwest 

Atlantic Ocean DPS was designated as threatened (76 FR 58868). NMFS and the USFWS have proposed to 

designate critical habitat for this DPS, including beaches in Jackson County, Mississippi; Baldwin County, Alabama; 

and Bay, Gulf, and Franklin Counties in the Florida Panhandle, as well as several counties in southwest Florida and 

the Florida Keys (78 FR 18000). c The green sea turtle is threatened, except for the Florida breeding population, which is listed as endangered. d In December 2013, NMFS proposed to redesignate elkhorn coral as endangered (77 FR 73220).

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Two other coastal species (bald eagle and brown pelican) discussed in MMS (2007b) and 

BOEM (2012b) are no longer federally listed as endangered or threatened. These are discussed

in Section C.4.2.

There are five sea turtle and six marine mammal species known to occur within OCS and slope 

waters of the Gulf of Mexico that are currently listed as endangered and threatened by the ESA. 

The listed sea turtles include the leatherback turtle, Kemp's ridley turtle, hawksbill turtle, 

loggerhead turtle, and green turtle. Listed marine mammal species include one odontocete 

(sperm whale) and five mysticetes (blue whale, fin whale, humpback whale, North Atlantic 

right whale, and sei whale) (Pritchard, 1997; Würsig et al., 2000). No critical habitat has been 

designated for these species in the Gulf of Mexico.

The sperm whale and five species of sea turtles are the only endangered or threatened species 

likely to occur in or near the lease area. No critical habitat has been designated for these 

species in the Gulf of Mexico. However, critical habitat has been proposed for the loggerhead 

turtle as discussed in Section C.3.5.

The five endangered mysticetes listed previously also have been reported to occur in 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.

C.3.1 Sperm Whale (Endangered)

The only endangered marine mammal likely to be present in 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 MMS (2007b). Gulf of Mexico sperm 

whales are classified as an endangered species and a "strategic stock" by NMFS (Waring et al., 

2013). A "strategic stock" is defined by the MMPA as a marine mammal stock that meets the 

following criteria:

• The level of direct human-caused mortality exceeds the potential biological removal level;

• Based on the best available scientific information, is in decline and is likely to be listed as a 

threatened species under the ESA within the foreseeable future; or

• Is listed as a threatened or endangered species under the ESA, or is designated as depleted 

under the MMPA.

No critical habitat for the sperm whale has been designated in the Gulf of Mexico.

In 2013, NMFS conducted a status review to consider designating the Gulf of Mexico population 

of the sperm whale as a distinct population segment (DPS) under the ESA. The designation 

would list the Gulf of Mexico population as a separate endangered or threatened population 

that is "significant to the species and faces additional unique threats to its survival." On 

13 November 2013, NMFS concluded that the designation of a Gulf of Mexico DPS for sperm 

whales is not warranted (78 FR 68032).

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 200- and 1,000-m (656- and 

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3,280-ft) depth contours (Jochens et al., 2008). Male sperm whales were more variable in their 

movements and were documented in water depths greater than 3,000 m (9,843 ft). 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 immature

whales, and groups of bachelor males. Typical group size for mixed groups was 10 individuals 

(Jochens et al., 2008). A review of sighting reports from seismic mitigation surveys in the 

Gulf of Mexico conducted over a 6-year period found a mean group size for sperm whales of 

2.5 individuals (Barkaszi et al., 2012). In these mitigation surveys, sperm whales were the most 

common cetacean encountered (Barkaszi et al., 2012). 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 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.

Current threats to sperm whale populations worldwide are discussed in a final recovery plan for 

the sperm whale (NMFS, 2010a). Threats are defined as "any factor that could represent an 

impediment to recovery," and include fisheries interactions, anthropogenic noise, vessel 

interactions, contaminants and pollutants, disease, injury from marine debris, research, 

predation and natural mortality, direct harvest, competition for resources, loss of prey base due 

to climate change and ecosystem change, and cable laying. In the Gulf of Mexico, impacts from 

many of these threats are identified as either low or unknown (BOEM, 2012b).

Impacts of Drilling Rig Presence, Noise, and Lights

Noise generated from the drilling rig and from routine drilling activities may be audible to sperm 

whales and so has the potential to disturb individuals near the lease area. The drilling rig used 

during the proposed activity will be located within a deepwater, open ocean environment and 

will remain stationary during drilling operations. Sounds generated by the rig and by drilling 

operations will be generally continuous (with some variability in sound level, considering 

thruster activity). This analysis assumes that the continuous nature of sounds produced by the 

drilling rig will provide individual whales with cues relative to the direction and relative distance 

(sound intensity) of the sound source, and the fixed position of the drilling rig will provide 

multiple options for active avoidance of potential physical impacts. NMFS analyzed the 

potential for impacts of drilling-related noise on sperm whales in its Biological Opinion for the 

Gulf of Mexico Oil and Gas Activities: Five-Year Leasing Plan for Western and Central Planning

Areas 2007-2012 (NMFS, 2007). The analysis noted that semisubmersible drilling rigs emit 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).

In addition, there are other OCS facilities and activities near the lease area, and the region as a 

whole has a large number of similar noise sources. Drilling-related noise associated with this 

project will contribute to an increase in the ambient noise environment of the Gulf of Mexico, 

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but it is not expected in amplitudes sufficient to cause either hearing or behavioral effects to 

sperm whales.

Drilling rig lighting and rig presence are not identified as IPFs for sperm whales (MMS, 2007b; 

BOEM, 2012a,b,c, 2013; NMFS, 2007).

Impacts of Support Vessel and Helicopter Traffic

Support vessel traffic has the potential to disturb sperm whales, and 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 MMS (2007b). To reduce the 

potential for vessel strikes, BSEE and BOEM 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 91 m (300 ft) 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 of disturbing sperm 

whales.

NMFS (2007) analyzed the potential for vessel strikes and harassment of sperm whales. 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 population level. With implementation of the vessel strike 

avoidance measures requirement to maintain a distance of 91 m (300 ft) 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 a fixed-wing aircraft flying at an 

altitude of 245 m (800 ft). A reaction to the initial pass of the aircraft was observed during 3 of 

24 sightings (12%). All three reactions consisted of a hasty dive and occurred at less than 

360 m (1,180 ft) lateral distance from the aircraft. Additional reactions were seen when the 

aircraft circled certain 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.

While flying offshore in the Gulf of Mexico, helicopters maintain altitudes above 213 m (700 ft) 

during transit to and from the working area. In the event that a whale is seen during transit, the 

helicopter will not approach or circle the animal. Although responses are possible 

(Smultea et al., 2008), NMFS (2007) and BOEM (2012d) concluded that this altitude would

minimize the potential for disturbing sperm whales. Therefore, no significant impacts are 

expected.

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Impacts of a Small Fuel Spill

Potential spill impacts on marine mammals, including sperm whales, are discussed in 

MMS (2007b), NMFS (2007), and BOEM (2012a,b,c, 2013). Oil impacts on marine mammals are 

discussed by Geraci and St. Aubin (1990). For this EP, there are no unique site-specific issues 

with respect to spill impacts on these animals that were not analyzed in the previous 

documents.

The probability of a fuel spill will be minimized by Anadarko’s preventative measures during 

routine operations, including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could mitigate and lessen the potential for impacts on sperm whales. 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 more than 90% would evaporate or disperse naturally 

within 24 hours. The sea surface area with diesel fuel on it would range from 0.5 to 5 ha 

(1.2 to 12 ac), 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 aircrafts (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 are expected.

Impacts of a Large Oil Spill

Potential spill impacts on marine mammals, including sperm whales, are discussed in 

MMS (2007b), NMFS (2007), and BOEM (2012a,b,c, 2013). For this EP, 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 aircrafts. The level of impact of oil exposure 

depends on the amount, frequency, and duration of exposure; route of exposure; and type or 

condition of petroleum compounds or chemical dispersants (Waring et al., 2013). 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 or patterns, changing reproductive behavior/productivity, and changing 

movement patterns or migration (MMC, 2011). Ackleh et al. (2012) hypothesized that sperm 

whales may have temporarily relocated away from areas near the Macondo spill in 2010.

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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.

C.3.2 West Indian Manatee (Endangered)

Most of the Gulf of Mexico manatee population is located in peninsular Florida (USFWS, 2001). 

Manatee sightings in Louisiana have increased as the species extends its presence farther west 

of Florida in the warmer months (Wilson, 2003). A species description is presented in

MMS (2007b), BOEM (2013), and the recovery plan for this species (USFWS, 2001).

IPFs that could affect 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 due to the distance from 

the nearest shoreline. As explained in Section A.9.2, a small fuel spill would not be expected to 

make landfall or reach coastal waters prior to natural dispersion. Compliance with 

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

Impacts of Support Vessel and Helicopter Traffic

Support vessel traffic has the potential to disturb manatees, and there is 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, BSEE and BOEM 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 this NTL will minimize the likelihood of vessel strikes, and no significant 

impacts on manatees are expected.

Helicopter traffic also has the potential to disturb manatees. Rathbun (1988) reported that 

manatees were disturbed more by helicopters than by fixed-wing aircrafts; however, the 

helicopter was flown at relatively low altitudes of 20 to 160 m (66 to 525 ft). Helicopters used in 

support operations maintain a minimum altitude of 213 m (700 ft) while in transit offshore, 

305 m (1,000 ft) over unpopulated areas or across coastlines, and 610 m (2,000 ft) 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 305 m (1,000 ft) 

within 91 m (300 ft) 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

In the event that manatees are 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 

vegetation; 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, change in prey 

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availability and foraging distribution or patterns, change in reproductive behavior/productivity, 

and change in movement patterns or migration (MMC, 2011).

In the event that a large spill reaches coastal waters where manatees are 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.

C.3.3 Endangered Mysticete Whales

Five endangered mysticetes (blue whale, fin whale, humpback whale, North Atlantic right whale, 

and sei whale) 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.

Because these whales rarely occur in the Gulf of Mexico and the limited scope and duration of 

the project, it is highly unlikely that any endangered mysticete would come into contact with 

project activities, either routine operations or accidents. NMFS did not include any of these 

mysticetes as affected species in its Biological Opinion (NMFS, 2007). Potential impacts are 

analyzed in MMS (2007b) and BOEM (2012a,b,c, 2013), and those analyses are incorporated by 

reference. If any of these whales were present in the area, potential impacts would be the same 

as those discussed in Section C.3.4.

C.3.4 Non-Endangered Marine Mammals (Protected)

Excluding the seven endangered species that have been cited previously, there are 22 additional 

species of marine mammals that may be found in the Gulf of Mexico, including 2 species of 

mysticetes, dwarf and pygmy sperm whales, 4 species of beaked whales, and 14 species of 

delphinids. 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 in the following subsections, and additional information on these groups is presented 

in MMS (2007b) and BOEM (2012a,b,c, 2013).

Mysticete Whales. Two species of non-endangered mysticetes are known to occur in the Gulf of 

Mexico. The Bryde’s whale (Balaenoptera edeni) has been sighted most frequently along the 

100-m (328-ft) 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 

(Balaenoptera acutorostrata) is considered rare in the Gulf of Mexico, 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., 2013). 

Either species could occur in the lease area.

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Beaked whales. Four species of beaked whales are known to occur in the Gulf of Mexico: 

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 suggest that Gervais’ beaked 

whale is the most common and Sowerby’s 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 water depths greater than 

1,000 m (3,281 ft) over lower slope and abyssal landscapes (Davis et al., 2000). Any of these 

species could occur in the lease area (Waring et al., 2013).

Delphinids. Fourteen species of delphinids are known to occur in the Gulf of Mexico: Atlantic 

spotted dolphin (Stenella frontalis), Clymene dolphin (Stenella clymene), pantropical spotted 

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

coeruleoalba), bottlenose dolphin (Tursiops truncatus), false killer whale (Pseudorca crassidens), 

killer whale (Orcinus orca), pygmy killer whale (Feresa attenuata), melon-headed whale

(Peponocephala electra), short-finned pilot whale (Globicephala macrorhynchus), Risso’s dolphin

(Grampus griseus), Fraser’s dolphin (Lagenodelphis hosei), and rough-toothed dolphin

(Steno bredanensis). Any of these species could occur in the lease area (Waring et al., 2013).

The most common non-endangered cetaceans in the deepwater environment are the

pantropical spotted dolphin, spinner dolphin, and Clymene dolphin.

Bottlenose Dolphins. The bottlenose dolphin (Tursiops truncatus) is a common inhabitant of the 

northern Gulf of Mexico, particularly within continental shelf waters. There are two ecotypes of 

bottlenose dolphins, a coastal form and an offshore form, which are genetically isolated from 

each other (Waring et al., 2013). The offshore form of the bottlenose dolphin may occur within 

the lease area. Inshore populations of coastal bottlenose dolphins in the northern Gulf of 

Mexico are separated into 37 geographically distinct population units, or stocks, for 

management purposes by NMFS (Waring et al., 2013). NMFS has proposed to classify the 

Gulf of Mexico Northern Coastal Stock, Western Coastal Stock, and all 32 of the Bay, Sound, and 

Estuarine Stocks as strategic stocks (Waring et al., 2013).

The strategic stock designation in this case was based primarily on the occurrence of an 

"unusual mortality event" of unprecedented size and duration that has affected these stock 

areas. The unusual mortality event began in February 2010 and, as of June 2014, the event was 

still considered to be ongoing (NOAA, 2014; Waring et al., 2013). Carmichael et al. (2012) 

hypothesized that the unusual number of bottlenose dolphin strandings in the northern Gulf of 

Mexico during this time may have been associated with environmental perturbations including 

sustained cold weather and the Macondo spill in 2010 as well as large volumes of cold 

freshwater discharge in the early months of 2011. Schwacke et al. (2014) reported that one 

year after the Macondo spill, many dolphins in Barataria Bay, Louisiana, showed evidence of 

disease conditions associated with petroleum exposure and toxicity.

IPFs that could affect 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 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.

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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 generated during drilling operations is 

generally continuous and fixed in location. Noise intensity associated with these operations is 

relatively weak. Stronger noise levels will occur during thruster use in dynamic positioning. 

Thruster noise impacts would be expected at greater distances than vessel noise alone 

(LGL Ecological Research Associates, Ltd., 2006) but are dependent on variables relating to 

thruster type and usage. It is expected that marine mammals within or near the lease area 

would be able to detect the presence of the drilling rig and avoid exposure to higher energy 

sounds, particularly within an open ocean environment.

Some odontocetes have shown increased feeding activity around lighted platforms at night 

(Todd et al., 2009). Even temporary drilling rigs present an attraction to pelagic food sources 

that may attract both cetaceans and sea turtles. Therefore, prey congregation could pose an 

attraction to protected species that exposes them to higher levels or longer durations of noise 

that might otherwise be avoided. There are other OCS facilities and activities near the lease 

area, and the region as a whole has a large number of similar sources. Species in the northern 

Gulf of Mexico have been exposed to noise from anthropogenic sources for a long period of 

time and over large geographic areas and likely do not represent a naïve population with regard 

to sound (National Research Council, 2003b). Due to the limited duration of drilling activities, 

this project would represent a temporary contribution to the overall noise regime within the 

lease area, and potential impacts are expected to be biologically insignificant to marine mammal 

populations.

Drilling rig lighting and rig presence are not identified as IPFs for marine mammals

(MMS, 2007b, 2008; BOEM, 2012a,b, 2013).

Impacts of Support Vessel and Helicopter Traffic

Support vessel traffic has the potential to disturb marine mammals, and there is a risk of vessel 

strikes. Data concerning the frequency of vessel strikes are presented in MMS (2007b). To 

reduce the potential for vessel strikes, BSEE and BOEM 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 

91 m (300 ft) or greater when whales are sighted and 45 m (150 ft) 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 NTL 2012-JOINT-G01 will 

minimize the likelihood of vessel strikes 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 213 m (700 ft) during transit to and 

from the working area. In addition, guidelines and regulations specify that helicopters maintain 

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an altitude of 305 m (1,000 ft) within 91 m (300 ft) of marine mammals (BOEM, 2012a,b). 

Maintaining 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 MMS (2007b) and

BOEM (2012a,b, 2013). Oil impacts on marine mammals in general are discussed by Geraci and 

St. Aubin (1990). For this EP, 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 Anadarko’s preventative measures during 

routine operations, including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP is expected to lessen the potential for impacts on marine mammals. 

EP Section H provides detail on spill response measures, along with a summary of those 

measures in this EIA. Given the open ocean location of the lease area, the limited duration of a 

small spill and response efforts, it is expected that any impacts would be brief and minimal.

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 more than 90% would evaporate or disperse naturally 

within 24 hours. The sea surface area with diesel fuel on it would range from 0.5 to 5 ha 

(1.2 to 12 ac), 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 are expected.

Impacts of a Large Oil Spill

Potential spill impacts on marine mammals are discussed in MMS (2007b) and

BOEM (2012a,b, 2013). For this EP, 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 

aircrafts. 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, change in 

prey availability and foraging distribution or patterns, change in reproductive 

behavior/productivity, and change in movement patterns or migration (MMC, 2011).

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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.

C.3.5 Sea Turtles (Endangered/Threatened)

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. In September 2011, 

NMFS and the USFWS listed nine DPSs for loggerhead turtles (Caretta caretta) under the ESA. 

The Northwest Atlantic Ocean DPS, which includes the Gulf of Mexico was designated as 

threatened (76 FR 58868), although other DPSs are endangered. In March 2013, the USFWS 

proposed to designate critical habitat for this DPS including beaches in Jackson County, 

Mississippi; Baldwin County, Alabama; and Bay, Gulf, and Franklin Counties in the Florida 

Panhandle, as well as several counties in southwest Florida and the Florida Keys (78 FR 18000). 

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 BOEM (2012a, 

2013).

Leatherback and loggerhead turtles 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 nearshore 

species, unlikely to occur near the lease area as adults. Hatchlings or juveniles of any of the sea 

turtle species 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. 

Leatherback turtles are the most pelagic of the sea turtles, feeding primarily on jellyfish.

Sea turtle nesting on the northern Gulf of Mexico coast can be summarized by species as 

follows:

• Loggerhead turtles – Loggerhead turtles nest in significant numbers along the Florida 

Panhandle (Florida Fish and Wildlife Conservation Commission, 2014a) and, to a lesser 

extent, from Texas through Alabama (NMFS and USFWS, 2008). 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, 2014b,c);

• Kemp’s ridley turtles – The main nesting site of Kemp’s ridley turtles is Rancho Nuevo Beach 

in Tamaulipas, Mexico (NMFS et al., 2011). Approximately 150 Kemp’s ridley turtles nested 

on Texas beaches in 2013 (Sea Turtle Restoration Project, 2013). Kemp’s ridley turtles 

typically do not nest anywhere near the project area, although there have been occasional 

reports of Kemp’s ridleys nesting in Alabama (Share the Beach, 2014); and

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• Hawksbill turtles – Hawksbill turtles typically do not nest anywhere near the project area

(USFWS, 2013).

IPFs that could affect 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 loggerhead turtles, may be attracted to offshore 

structures (Lohoefener et al., 1990) and, thus, may be more susceptible to impacts from sounds 

produced during routine operations. 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 and short duration 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

Noise generated from support vessel traffic has the potential to disturb sea turtles, and there is 

a risk of vessel strikes. Data show that vessel strike 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 water surface, during nighttime, or during periods of inclement weather. To reduce 

the potential for vessel strikes, BSEE and BOEM 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 

45 m (150 ft) 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).

Noise generated from support helicopter traffic also has the potential to disturb sea turtles. 

However, while flying offshore, helicopters maintain altitudes above 213 m (700 ft) during 

transit to and from the working area. This altitude will minimize the potential for disturbing sea 

turtles, and no significant impacts are expected.

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Impacts of a Small Fuel Spill

Potential spill impacts on sea turtles are discussed in MMS (2007b), NMFS (2007), and

BOEM (2012a,b, 2013). For this EP, 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 Anadarko’s preventative measures during 

routine operations, including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP is expected to minimize potential impacts on sea turtles. EP Section H

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 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 of the spill, as well as the effectiveness of spill response measures. Section A.9.2

discusses the likely fate of a small fuel spill and indicates that more than 90% would evaporate 

or disperse naturally within 24 hours. The sea surface area with diesel fuel on it would range 

from 0.5 to 5 ha (1.2 to 12 ac), 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 aircrafts (MMS, 2007b; NMFS, 2010b; BOEM, 2012a,b, 2013). 

However, due to the limited areal extent and short duration of water quality impacts from a 

small fuel spill, no significant impacts are expected.

A small fuel spill in the lease area would be unlikely to affect sea turtle nesting beaches due to 

the distance from nearest shoreline. As explained in Section A.9.2, a small fuel spill would not 

be expected to make landfall or reach coastal waters prior to natural dispersion.

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 aircrafts. 

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, change in food 

availability and foraging distribution or patterns, change in reproductive behavior/productivity, 

and change in movement patterns or migration (NOAA, 2010; NMFS, 2010c). In the unlikely 

event of a spill, implementation of Anadarko’s OSRP is expected to minimize the potential for 

these types of impacts on sea turtles. EP Section H provides detail on spill response measures.

Studies of oil effects on loggerhead turtles 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 put 

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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 30-day OSRA results summarized in Table 3 estimate that Louisiana and Texas shorelines 

that support limited sea turtle nesting could be contacted within 30 days (1% to 4%). The 

120-day OSRA (Table 4) modeling predicts the probability of contacting Alabama and Florida 

Panhandle shorelines that support significant loggerhead sea turtle nesting is 1% or less.

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.

The extent and scope of the Macondo spill represents new information not assessed in the 

existing ESA Section 7 consultation under the current Five-Year Program. As a result of this new 

information, BOEMRE reinitiated ESA Section 7 consultation on the existing Gulf of Mexico lease 

sale EIS with NMFS and the USFWS on 30 July 2010. NMFS responded with a letter to BOEMRE 

on 24 September 2010, and the USFWS responded with a letter to BOEMRE on 

27 September 2010. However, NMFS and the USFWS have placed the consultation process on 

hold pending the results of the NRDA post-Macondo spill data review, which has yet to be 

released. The existing consultation currently remains in effect (BOEM, 2012b).

Based on additional information and in consideration of the Macondo spill, BOEM (2012b)

reexamined the impacts analyses presented in MMS (2007b, 2008) for the five sea turtle species 

that inhabit the Gulf of Mexico based on additional information and in consideration of the 

Macondo spill. No new information was found that would alter the potential impacts on sea 

turtles described in previous EISs. In most foreseeable cases, exposure to hydrocarbons 

persisting in the sea following the dispersal of an oil slick will result in sublethal impacts 

(e.g., decreased health, reproductive fitness, and longevity; and increased vulnerability to 

disease) to sea turtles.

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 3). Piping plovers inhabit coastal sandy beaches and mudflats, 

feeding by probing for invertebrates at or just below the surface. They use beaches adjacent to 

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foraging areas for roosting and preening (USFWS, 2010a). A species description is presented in 

MMS (2007b) and BOEM (2013).

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 natural dispersion (see explanation in 

Section A.9.2).

Impacts of a Large Oil Spill

The lease area is 122 miles (196 km) from the nearest shoreline that is designed as critical 

habitat for Piping Plovers (Figure 3). The 120-day OSRA results summarized in Section A.9.3

(Table 4) predict that during the spring, there is a 14% probability that an oil spill from the lease 

area would reach a shoreline designated as critical habitat for the Piping Plover within 120 days. 

Piping Plovers could physically oil themselves while foraging on oiled shores or secondarily 

contaminate themselves through ingestion of oiled intertidal sediments and prey (MMS, 2007b). 

Piping 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. Anadarko has extensive resources 

available to protect and rehabilitate wildlife in the event of a spill reaching the shoreline, as 

detailed in the OSRP.

C.3.7 Whooping Crane (Threatened)

The Whooping Crane (Grus americana) is an omnivorous wading bird and an endangered 

species. There are three wild populations in North America (Whooping Crane Eastern 

Partnership [WCEP], 2013). 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 

270 at Aransas NWR in December 2008 (WCEP, 2013). 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). Approximately 

9,000 ha (22,240 ac) of salt flats on Aransas NWR and adjacent islands make up the principal 

wintering grounds of the Whooping Crane. Aransas NWR is designated as critical habitat for the 

species (Figure 3). A species description is presented in a recent lease sale EIS (MMS, 2007b).

A large oil spill (WCD) is the only IPF potentially affecting Whooping Cranes. A small fuel spill in 

the lease area would be unlikely to affect Whooping Cranes due to the distance from Aransas 

NWR. As explained in Section A.9.2, a small fuel spill would not be expected to make landfall or 

reach coastal waters prior to natural dispersion.

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Figure 3. Location of selected environmental features in relation to the lease areas of interest. EFH = Essential Fish Habitat; HAPC = Habitat 

Area of Particular Concern; NMS= National Marine Sanctuary.

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Impacts of a Large Oil Spill

The lease area is 344 miles (553 km) from the nearest shoreline that is designed as critical 

habitat for Whooping Cranes (Figure 3). The 120-day OSRA results summarized in Section A.9.3

(Table 4) predict that during the winter, there is a 5% probability that an oil spill from the lease 

area would reach a shoreline designated as critical habitat for the Whooping Crane within 

120 days. Whooping Cranes could physically oil themselves while foraging in oiled areas or 

secondarily contaminate themselves through ingestion of contaminated shellfish, frogs, and 

fishes (MMS, 2007b). It is possible that some deaths of Whooping Cranes could occur, especially 

if spills occur during winter months when Whooping Cranes are most common along the Texas 

coast if the spill contacts their critical habitat in Aransas NWR. Impacts could also occur from 

vehicular traffic on beaches and other activities associated with spill cleanup. Anadarko has 

extensive resources available to protect and rehabilitate wildlife in the event of a spill reaching 

the shoreline, as detailed in the OSRP.

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). 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, 2010b) (Figure 3). A species description is presented in

MMS (2007b) and in the recovery plan for this species (USFWS et al., 1995).

A large oil spill is the only IPF that could affect Gulf sturgeon. There are no IPFs associated with 

routine project activities that could affect these fish. 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 natural dispersion (see explanation in Section A.9.2).

Impacts of a Large Oil Spill

Potential spill impacts on Gulf sturgeon are discussed in MMS (2007b), NMFS (2007), and 

BOEM (2012a,b, 2013). For this EP, there are no unique site-specific issues with respect to this 

species.

The lease area is approximately 232 miles (374 km) from the nearest Gulf sturgeon critical 

habitat. The 120-day OSRA modeling (BOEM, 2012b) predicts that a spill in the lease area has 

1% or less probability of contacting any coastal areas inhabited by Gulf sturgeon within 

120 days.

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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, sub-adult and adult Gulf sturgeon would be most 

vulnerable to an estuarine or marine oil spill, and likely would be vulnerable only from 

1 September through 30 April when the species is foraging in estuarine and shallow marine 

habitats (NMFS, 2007).

C.3.9 Beach Mice (Endangered)

Four subspecies of endangered beach mice (Peromyscus polionotus) occur on the barrier islands 

of Alabama and the Florida Panhandle: the Alabama, Choctawhatchee, Perdido Key, and 

St. Andrew beach mice. Critical habitat has been designated for all four subspecies; Figure 3

shows the combined critical habitat for all four subspecies. Species descriptions are provided in 

MMS (2007b) and BOEM (2013).

A large oil spill is the only IPF that could affect beach mice. There are no IPFs associated with 

routine project activities that could affect these animals due to the distance from shore and the 

lack of any onshore support activities near their habitat. A small fuel spill in the lease area 

would not affect beach mice because a small fuel spill would not be expected to make landfall or 

reach coastal waters prior to natural dispersion (see Section A.9.2).

Impacts of a Large Oil Spill

Potential spill impacts on beach mice are discussed in MMS (2007b, 2008) and

BOEM (2012a, 2013). For this EP, there are no unique site-specific issues with respect to these 

species that were not analyzed in these documents.

Beach mouse critical habitat is 271 miles (436 km) from the lease area. The 120-day 

OSRA modeling summarized in Section A.9.3 predicts that a spill in the lease area has a 1% or 

lower probability of reaching either the Alabama or Florida shorelines inhabited by beach mice 

within 120 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. However, any such impacts are unlikely due to the distance from 

shore and response actions that would occur in the event of a spill.

C.3.10 Smalltooth Sawfish (Endangered)

Smalltooth sawfish (Pristis pectinata) are found in the tropical and subtropical Atlantic Ocean. 

In the Western Atlantic, they have historically ranged from New York to Brazil, including the Gulf 

of Mexico and Caribbean Sea. Smalltooth sawfish primarily occur in estuarine and coastal 

habitats such as bays, lagoons, and rivers. The smalltooth sawfish was listed as endangered

under the ESA on 1 April 2003. Its critical habitat consists of two units – the Charlotte Harbor 

Estuary Unit, which comprises approximately 89,621 ha (221,459 ac) of coastal habitat, and the 

Ten Thousand Islands/Everglades Unit, which comprises approximately 250,506 ha (619,013 ac)

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of coastal habitat. The two units are located along the southwestern coast of Florida between 

Charlotte Harbor and Florida Bay.

A large oil spill is the only IPF potentially affecting smalltooth sawfish. There are no IPFs 

associated with routine project activities that could affect these fish. A small fuel spill in the 

lease area would be unlikely to affect smalltooth sawfish because a small fuel spill would not be 

expected to make landfall or reach coastal waters prior to natural dispersion (see Section A.9.2).

Impacts of a Large Oil Spill

Potential spill impacts on smalltooth sawfish are similar to those discussed for other coastal and 

estuarine species in MMS (2007b), NMFS (2007), and BOEM (2012a, 2013). For this EP, there 

are no unique site-specific issues with respect to smalltooth sawfish.

In the event of oil reaching smalltooth sawfish habitat, the fish could be affected by direct 

ingestion, ingestion of oiled prey, or the absorption of dissolved petroleum products through 

the gills.

C.3.11 Elkhorn Coral (Threatened)

Elkhorn coral (Acropora palmata) is found primarily in shallow waters with temperatures ranging 

between 26°C and 30°C (79°F and 86°F) and significant water movement. Elkhorn coral was 

once one of the most abundant coral species in waters ranging from 1 to 5 m (3.3 to 16 ft) deep

in tropical and subtropical waters. In the northern Gulf of Mexico, elkhorn coral has been found 

within the coral cap region of the Flower Garden Banks National Marine Sanctuary

(Flower Garden Banks National Marine Sanctuary [NMS], 2014). The nearest critical habitat is 

designated in the Florida Keys.

NMFS has recently proposed to change the designation of elkhorn coral and staghorn coral 

(Acropora cervicornis) from threatened to endangered (77 FR 73220). Five other Atlantic corals 

are proposed for endangered listing: pillar coral (Dendrogyra cylindrus), boulder star coral 

(Montastraea annularis), mountainous star coral (Montastraea faveolata), cactus coral 

(Mycetophyllia ferox), and star coral (Montastraea franksi). Two Atlantic species, Lamarck's 

sheet coral (Agaricia lamarcki) and elliptical star coral (Dichocoenia stokesii), are proposed for 

listing as a threatened species. None of these species other than elkhorn coral are reported to 

occur in the northern Gulf of Mexico (Flower Garden Banks NMS, 2014) and the nearest 

populations are in the Florida Keys.

There are no IPFs associated with routine project activities that could affect this species in the 

northern Gulf of Mexico. A small fuel spill would not affect elkhorn coral colonies because the 

oil would float and dissipate on the sea surface. Thus, a large oil spill is the only relevant IPF.

Impacts of a Large Oil Spill

A large oil spill would be unlikely to reach elkhorn coral critical habitat in the Florida Keys 

(Monroe County, Florida) or coral reefs at the Flower Garden Banks. The 120-day 

OSRA modeling (Table 4) predicts the probability of contacting the Florida Keys is 1% or lower. 

A spill would be highly unlikely to reach the Flower Garden Banks. A surface slick would not 

contact corals on the seafloor. If a subsurface plume were to occur, impacts on the banks would 

be unlikely due to the distance and the difference in water depth. Near-bottom currents in the 

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region are predicted to flow along the isobaths (Nowlin et al., 2001) and typically would not 

carry a plume up onto the continental shelf edge.

C.4 Coastal and Marine Birds

C.4.1 Marine Birds

Marine birds include seabirds and other species that may occur in the pelagic environment of 

the project area (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 nesting 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 Gulls, Royal Terns, Bridled Terns) (Hess and 

Ribic, 2000). The GulfCet II study did not estimate bird densities; however, Powers (1987) 

indicated that seabird densities over the open ocean typically are <10 birds/km2

.

The distributions and relative densities of seabirds within the deepwater areas of the Gulf of 

Mexico, including the project area, vary temporally (i.e., seasonally) and spatially. In GulfCet II 

studies, species diversity and density varied by hydrographic environment and by the presence 

and relative location of mesoscale features such as Loop Current eddies that may enhance

nutrient levels and productivity of surface waters where these seabird species forage 

(Hess and Ribic, 2000).

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 rigs 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 that could affect 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 rigs may be exposed to contaminants including air pollutants and routine 

discharges, but significant impacts are unlikely due to rapid dispersion. 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 rig collisions appear to be 

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similar. In some cases, migrants simply do not see a part of the rig until it is too late to avoid it. 

In other cases, navigation may be disrupted by noise (Russell, 2005). However, offshore 

structures are suitable stopover habitats for most trans-Gulf migrant species, and most of the 

migrants that stop over on rigs probably benefit from their stay, particularly in spring 

(Russell, 2005). Due to the limited scope and short duration of drilling activities described in this 

EP, any impacts on populations of either seabirds or trans-Gulf migrant birds from activities 

described in this EP are not expected to be significant.

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 MMS (2007b) and

BOEM (2012a,b,c, 2013). For the EP, 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 Anadarko’s preventative measures during 

routine operations, including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could reduce the potential for impacts on marine and pelagic birds. 

EP Section H 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 more than 90% would evaporate or disperse naturally 

within 24 hours. The sea surface area with diesel fuel on it would range from 0.5 to 5 ha 

(1.2 to 12 ac), 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 pelagic birds 

are expected.

Impacts of a Large Oil Spill

Potential spill impacts on marine and pelagic birds are discussed in MMS (2007b) and

BOEM (2012a,b,c, 2013). For this EP, there are no unique site-specific issues with respect to spill 

impacts on these animals.

BOEM has reexamined the analyses for coastal and marine birds presented in 

MMS (2007b, 2008) and determined that no new information was found that would alter the 

potential impacts on marine and pelagic birds (BOEM, 2012b).

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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 (>200 m [>656 ft]). Powers (1987) indicated that 

seabird densities over the open ocean typically are <10 birds/km2

. The number of pelagic birds 

that could be affected in open offshore waters would depend on the extent and persistence of 

the oil slick.

Data following the Macondo spill provide relevant information about the species of pelagic birds 

that may be affected in the event of a large oil spill. Birds that have been treated for oiling 

include several pelagic species such as the Northern Gannet, Magnificent Frigatebird, and 

Masked Booby (USFWS, 2011). The Northern Gannet is among the species with the largest 

numbers of birds affected by the spill.

C.4.2 Shorebirds and Coastal Nesting Birds

Threatened and endangered bird species (Piping Plover and Whooping Crane) have been 

discussed previously in Sections C.3.6 and C.3.7. 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 MMS (2007b) and BOEM (2012a, 2013).

The Brown Pelican (Pelecanus occidentalis) was delisted from Federal endangered status in 

2009 (USFWS, 2010c). However, this species remains on the Louisiana list of Endangered 

Species (State of Louisiana Department of Wildlife and Fisheries, 2013), is listed as a species of 

greatest conservation need by the State of Mississippi (Mississippi Department of Wildlife, 

Fisheries and Parks, 2005), and is listed as a species of special concern by the State of Florida 

(Florida Fish and Wildlife Conservation Commission, 2014d). 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 in 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).

The Southern Bald Eagle (Haliaeetus leucocephalus) was delisted from its threatened status in 

the lower 48 states on 28 June 2007. The Bald Eagle is a terrestrial raptor widely distributed 

across the southern U.S., including coastal habitats along the Gulf of Mexico. The Gulf Coast is 

inhabited by both wintering migrant and resident Bald Eagles (Johnsgard, 1990; Ehrlich 

et al., 1992).

IPFs that could affect shorebirds and coastal nesting birds include support vessel and helicopter 

traffic and a large oil spill. A small fuel spill in the lease area would be unlikely to affect 

shorebirds or coastal nesting birds, due to the lease area’s distance from the nearest shoreline. 

As explained in Section A.9.2, a small fuel spill would not be expected to make landfall or reach 

coastal waters prior to natural dispersion. Compliance with NTL 2012-BSEE-G01 will minimize 

the potential for marine debris-related impacts on shorebirds.

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Impacts of Support Vessel and Helicopter Traffic

Support vessels and helicopters will transit coastal areas near Port Fourchon and Houma, 

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 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 20 to 49 m (65 to 160 ft) for personal 

watercrafts and 23 to 58 m (75 to 190 ft) for outboard-powered boats (Rodgers and Schwikert, 

2002). Flushing distances may be similar or less for the support vessels to be used for 

Anadarko’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 disturbances to nesting birds, eggs, 

and chicks are not expected. 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 and short duration 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, bird species, 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 610 m (2,000 ft) 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

Coastal birds can be exposed to oil as they float on the water surface, dive during foraging, or 

wade in oiled coastal waters. Oiled birds can lose the ability to fly, dive for food, or float on the 

water, which could lead to drowning (USFWS, 2010d). Oil interferes with the water repellency 

of feathers and can cause hypothermia in the right conditions. As birds groom themselves, they 

can ingest and inhale the oil on their bodies. Scavengers such as Bald Eagles and gulls can be 

exposed to oil by feeding on carcasses of contaminated fish and wildlife. While ingestion can kill 

animals immediately, more often it results in lung, liver, and kidney damage, which can lead to 

death. Bird eggs may be damaged if an oiled adult sits on the nest.

As noted previously, the Brown Pelican was recently removed from the Federal endangered 

species list. Brown Pelicans are especially at risk from direct and indirect impacts from spilled oil 

within inner shelf and inshore waters, such as embayments. The range of this species is 

generally limited to these waters and surrounding coastal habitats. Brown Pelicans feed on 

mid-size fish that they capture by diving from above ("plunge diving") and then scooping the fish 

into their expandable gular pouch. This behavior makes them susceptible to plumage oiling if 

they feed in areas with surface oil or an oil sheen. They may also capture prey that has been 

physically contaminated with oil or has ingested oil. Issues for Brown Pelicans include direct 

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contact with oil, disturbance from cleanup activities, and long-term habitat contamination. The 

Bald Eagle also may be at risk from direct and indirect impacts from spilled oil. This species 

often captures fish within shallow water areas (snatching prey from the surface or wading into 

shallow areas to capture prey with their bill) and so may be susceptible to plumage oiling and, as 

with the Brown Pelican, they may also capture prey that has been physically contaminated with 

oil or has ingested oil.

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, the surface waters of which are among the 

most oligotrophic in the world’s oceans. Superimposed on this low-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 midwater 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 

aggregating 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; 

MMS, 2000, 2007b, 2008). The 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

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 should dilute rapidly to undetectable levels within tens to 

hundreds of meters from the source. Minimal impacts on water quality, plankton, and nekton 

are anticipated.

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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 should dilute 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, and ballast water, are expected to dilute rapidly and 

have little or no impact on water column biota.

Impacts of Water Intakes

Seawater will be drawn from the ocean for once-through, non-contact cooling of machinery 

on the drilling rig. The drilling rig ultimately chosen for this project will be in compliance with all 

cooling water intake requirements. The intake of seawater for cooling water will entrain 

plankton. The low intake velocity should allow most strong-swimming juvenile fishes and 

smaller adults to escape entrainment or impingement. However, drifting plankton would not be 

able to escape entrainment with the exception of a few fast-swimming larvae of certain 

taxonomic groups. The entrained organisms may be stressed or killed, primarily through 

changes in water temperature during the route from cooling intake structure to discharge 

structure and through mechanical damage (turbulence in pumps and condensers). Due to the 

limited scope and short duration of drilling activities, any short-term impacts of entrainment are 

not expected to be biologically significant to plankton or ichthyoplankton populations.

Impacts of a Small Fuel Spill

Potential spill impacts on fisheries resources are discussed in MMS (2007b) and

BOEM (2012a,b, 2013). For this EP, there are no unique site-specific issues with respect to spill 

impacts.

The probability of a fuel spill will be minimized by Anadarko’s preventative measures during 

routine operations including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could mitigate the potential for impacts on pelagic communities, including 

ichthyoplankton. EP Section H 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 more than 90% would evaporate or disperse naturally 

within 24 hours. The sea surface area with diesel fuel on it would range from 0.5 to 5 ha 

(1.2 to 12 ac), depending on sea state and weather conditions.

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A small fuel spill could have localized impacts on phytoplankton, zooplankton, 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

Potential spill impacts on pelagic communities and ichthyoplankton are discussed in 

BOEM (2012a,b,c, 2013). For this EP, there are no unique site-specific issues.

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 more 

likely 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. Fish eggs and larvae are 

especially vulnerable to oiling because they inhabit the upper layers of the water column, and 

they will die if exposed to certain toxic fractions of spilled oil. Impacts could be greater if 

local-scale currents retained planktonic larval assemblages (and the floating oil slick) within the 

same water mass.

C.5.2 Essential Fish Habitat

Essential Fish Habitat (EFH) is defined as the 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.

BOEM (2012b) has reexamined the analysis for fish resources and EFH presented in 

MMS (2007a,b) in consideration of the Macondo event. No substantial new information was 

found that would alter the impact conclusions for fish resources and EFH presented in 

MMS (2007a,b).

The Gulf of Mexico Fishery Management Council (GMFMC) has prepared Fishery Management 

Plans for corals and coral reefs, shrimps, 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 

183 m (600 ft). 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 located approximately 88 miles (142 km) northwest of the lease area.

Highly migratory pelagic fishes, which occur as transients in the lease area, are the only 

remaining group for which EFH has been identified in the deepwater Gulf of Mexico. Species in 

this group, including tunas, swordfishes, billfishes, and sharks are managed by NMFS. Highly 

migratory species with EFH in or near the lease area include the following species and life stages 

(NMFS, 2009):

• Atlantic bluefin tuna (spawn, eggs, 

larvae, adults)

• Bigeye thresher shark (all)

• Bigeye tuna (juveniles, adults)

• Blue marlin (juveniles, adults)

• Longfin spearfish (juveniles, adults)

• Longfin mako shark (all)

• Oceanic whitetip shark (all)

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• Sailfish (adults)

• Silky shark (all)

• Skipjack tuna (spawn, adults)

• Swordfish (larvae, juveniles, adults)

• Tiger shark (adults)

• Whale shark (all)

• White marlin (juveniles, adults)

• Yellowfin tuna (spawn, juveniles, 

adults)

Research indicates the central and western Gulf of Mexico may be important spawning habitat 

for Atlantic bluefin tuna (Thunnus thynnus), 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 3). The areal extent of the HAPC is approximately 

300,000 km2 (115,830 mi2

). The prevailing assumption is that Atlantic bluefin tuna follow an 

annual cycle of foraging in June through March off the eastern U.S. and Canadian coasts, 

followed by migration to the Gulf of Mexico to spawn in April, May, and June (NMFS, 2009).

On 27 May 2011, after an extensive scientific review, NOAA announced that Atlantic bluefin 

tuna currently do not warrant species protection under the ESA. However, NOAA did classify 

the bluefin tuna as a species of concern, effectively placing the species on a watch list as the 

agency awaits new data on the impact of a stricter international management regimen.

An amendment to the original EFH Generic Amendment was finalized in 2005 (GMFMC, 2005). 

One of the most significant proposed changes in this amendment reduced the extent of EFH 

relative to the 1998 Generic Amendment by removing the EFH description and identification 

from waters between 100 fathoms and the seaward limit of the Exclusive Economic Zone (EEZ). 

The Highly Migratory Species Fisheries Management Plan was amended in 2009 to update 

EFH and HAPC to include the bluefin tuna spawning area (NMFS, 2009).

NTLs 2009-G39 and 2009-G40 provide guidance and clarification of regulations for biologically 

sensitive underwater features and areas and benthic communities that are considered EFH 

(MMS, 2009a,b). A new EFH consultation has been initiated between BOEM’s Gulf of Mexico 

Region and NOAA’s Southeastern Region. Some EFH requirements may change with the new 

agreement. Until the new agreement is in place, the 1999 Programmatic Consultation with the 

elements described previously will be followed (BOEM, 2012b).

Other HAPCs have been identified 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 3). The nearest HAPC is the Jakkula Bank, located approximately 62 miles (99 km) from

the project area.

IPFs that could affect EFH 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 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; MMS, 2000, 2007b, 2008). 

The FAD effect would possibly enhance feeding of epipelagic predators by attracting and 

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concentrating smaller fish species. Because the drilling rig is a single, temporary structure, 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 

muds and cuttings, treated sanitary and domestic wastes, deck drainage, and miscellaneous 

discharges such as desalination unit brine and uncontaminated cooling water, fire water, 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 and short duration 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 MMS (2007b) and BOEM (2012a,b,c, 2013). For 

this EP, there are no unique site-specific issues with respect to spill impacts.

The probability of a fuel spill will be minimized by Anadarko’s preventative measures during 

routine operations, including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could help diminish the potential for impacts on EFH. EP Section H 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 more than 90% would evaporate or disperse naturally 

within 24 hours. The sea surface area with diesel fuel on it would range from 0.5 to 5 ha 

(1.2 to 12 ac), 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 bluefin tuna, which covers much of the deepwater Gulf of Mexico. The affected area 

would represent a negligible portion of the HAPC, which covers approximately 115,830 mi2 

(300,000 km2) of the Gulf of Mexico.

A small fuel spill would likely not affect EFH for corals and coral reefs, the nearest of which is 

located approximately 88 miles (142 km) from the project 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 MMS (2007b) and BOEM (2012a,b, 2013). For 

this EP, there are no unique site-specific issues with respect to EFH.

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An oil spill in offshore waters would temporarily increase hydrocarbon concentrations on the 

water surface and potentially in 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, spiny lobster, 

reef fishes, coastal migratory pelagic fishes, and red drum. It would result in adverse impacts on 

water quality and water column biota including phytoplankton, zooplankton, and nekton. In 

coastal waters, sediments could be contaminated and result in persistent degradation of the 

seafloor habitat for managed demersal fish and shellfish species.

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. Potential impacts 

would depend in part on the timing of a spill, as the species migrates to the Gulf of Mexico to 

spawn in April, May, and June (NMFS, 2009).

The topographic features located 88 miles (142 km) from the lease area are designated as 

EFH under the corals and coral reefs management plan. An accidental spill would be unlikely to 

affect this area, because a surface slick would not reach these features due to their depth.

C.6 Archaeological Resources

C.6.1 Shipwreck Sites

The lease area is not on the list of OCS blocks with a high potential for historic shipwrecks 

(BOEM, 2012d). Numerous sonar contacts were noted during the archaeological survey (Fugro 

GeoServices, Inc., 2003), but none were interpreted to be shipwrecks. Anadarko will abide by 

the applicable requirements of NTL 2005-G07, which stipulate that work be stopped at the 

project site if any previously undetected archaeological resource is discovered after work has 

begun until appropriate surveys and evaluations have been completed.

Because there are no known shipwreck sites in the lease area, there are no routine IPFs that are 

likely to affect shipwrecks. Impacts of a large oil spill are the only IPFs considered. A small fuel 

spill would not affect shipwrecks because the oil would float and dissipate on the sea surface.

Impacts of a Large Oil Spill

MMS (2007b) estimated that a severe subsurface blowout could resuspend and disperse 

sediments within a 300-m (984-ft) radius. Because there are no historic shipwrecks in the lease 

area, this impact would not be relevant.

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 

approximately 1,100 m (3,600 ft), 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 subsea dispersants at the wellhead (Joint Analysis Group, 2010c). 

While the behavior and impacts of subsurface plumes are not well known, a subsurface plume 

could have the potential to contact shipwreck sites beyond the 300-m (984-ft) radius estimated 

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by MMS (2007a, 2008), depending on its extent, trajectory, and persistence (Spier et al., 2013). 

If oil from a subsea spill should come into contact with wooden shipwrecks on the seafloor, it 

could adversely affect their condition or preservation. Should there be any indication that 

potential shipwreck sites could be affected, in accordance with NTL 2005-G07, Anadarko will 

immediately halt operations, take steps to ensure that the site is not disturbed in any way, and 

contact the BOEM Regional Supervisor, Leasing and Environment, within 48 hours of its 

discovery. Anadarko would cease all operations within 305 m (1,000 ft) of the site until the 

Regional Supervisor provides instructions on steps to take to assess the site’s potential historic 

significance and protect it.

A spill entering shallow coastal waters could conceivably contaminate an undiscovered 

shipwreck site. 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.

C.6.2 Prehistoric Archaeological Sites

Available evidence suggests that sea level in the northern Gulf of Mexico was at least 91 m 

(300 ft), and possibly as much as 130 m (427 ft), lower than present sea level during the period 

20,000 to 17,000 years before present (B.P.) (Nelson and Bray, 1970). Sea level in the northern 

Gulf reached its present stand around 3,500 years B.P. (Pearson et al., 1986).

During periods that the continental shelf was above sea level, the area was open to habitation 

by prehistoric peoples. The advent of early man into the Gulf of Mexico region is currently 

accepted to be approximately 12,000 years B.P. (Aten, 1983). The sea-level curve for the 

northern Gulf of Mexico proposed by Coastal Environments, Inc. suggests that sea level 

12,000 years B.P. would have been approximately 45 to 60 m (148 to 197 ft) below present-day 

sea level (Coastal Environments, Inc., 1977, 1982). On this basis, the continental shelf 

shoreward of the 45- to 60-m (148- to 197-ft) bathymetric contours has potential for prehistoric 

sites dating after 12,000 years B.P. Because of inherent uncertainties in both the depth of sea 

level and the entry date of prehistoric man into North America, MMS adopted the 60-m (197-ft) 

water depth as the seaward extent for archaeological site potential in the Gulf of Mexico region.

With water depths ranging from approximately 1,573 to 1,695 m (5,160 to 5,560 ft), the project

area is well beyond the 60-m (197-ft) depth contour used by BOEM as the seaward extent for 

prehistoric archaeological site potential in the Gulf of Mexico. Numerous sonar contacts were 

identified during the archaeological survey conducted by Fugro GeoServices, Inc. (2013), but 

none were interpreted to be shipwrecks or of archeological significance. Because prehistoric 

archaeological sites are not found in the lease area, the only relevant IPF is a large oil spill. 

A small fuel spill would not affect prehistoric archaeological resources because the oil would 

float and dissipate on the sea surface.

Impacts of a Large Oil Spill

Because prehistoric archaeological sites are not found in the lease area, they would not be 

impacted by the physical effects of a subsea blowout. MMS (2007b) estimated that a severe 

subsurface blowout could resuspend and disperse sediments within a 300-m (984-ft) 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). If a spill did reach a 

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prehistoric site along these shorelines, it 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). Coastal prehistoric sites also could be damaged by spill cleanup operations 

(e.g., by destroying fragile artifacts and disturbing the provenance of artifacts and site features).

C.7 Coastal Habitats and Protected Areas

Coastal habitats in the northeastern Gulf of Mexico that may be affected by oil and gas activities 

are described in MMS (2007b) and BOEM (2012a,b,c, 2013), and are tabulated in the OSRP. 

Coastal habitats inshore of the project area include barrier beaches and dunes, wetlands, and 

submerged seagrass beds. Most of the northeastern Gulf is fringed by barrier beaches, with 

wetlands and submerged seagrass beds occurring in sheltered areas behind the barrier islands 

and in estuaries.

Due to the distance from shore, the only IPF associated with routine activities in the lease area 

that could affect beaches and dunes, wetlands, seagrass beds, coastal wildlife refuges, 

wilderness areas, or any other managed or protected coastal area relate to support vessel 

traffic. The support bases at Port Fourchon and Houma, Louisiana, are not in wildlife refuges or 

wilderness areas. 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 due to the lease 

area’s distance from the nearest shoreline. As explained in Section A.9.2, a small fuel spill

would not be expected to make landfall or reach coastal waters prior to natural dispersion.

Impacts of Support Vessel Traffic

For OCS activities in general, support operations, including crew boats 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 crew boats and supply boats as detailed in EP Section K, 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 MMS (2007b) and

BOEM (2012a,b,c, 2013). Coastal habitats inshore of the project area include barrier beaches 

and dunes, wetlands, and submerged seagrass beds. For this EP, there are no unique 

site-specific issues with respect to coastal habitats.

The 30-day OSRA modeling (Table 3) indicates that Calhoun, Texas is the area most likely to be 

contacted in the event of a spill in the lease area. However, the 120-day OSRA modeling 

summarized in Table 4 predicts potential shoreline contacts ranging from Cameron County, 

Texas, to Miami-Dade County, Florida, within 120 days.

The shorelines within the geographic range predicted by the 120-day OSRA modeling (Table 4) 

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 MMS (2007b), BOEM (2012b), and Anadarko’s OSRP. Coastal 

and near coastal wildlife refuges, wilderness areas, and state and national parks within the 

geographic range of the potential shoreline contacts after 30 days are presented in Table 7.

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Table 7. Wildlife refuges, wilderness areas, and state and national parks within the geographic 

range of the potential shoreline contacts after 30 days based on OSRA modeling.

County or Parish, State Wildlife Refuge, Wilderness Area, or

State/National Park

Terrebonne, Louisiana

Atchafalaya Delta WMA

Mandalay NWR

Isles Dernieres Barrier Islands Refuge

Point Au Chein WMA

Lafourche, Louisiana

Point Au Chein WMA

Wisner WMA

Plaquemines, Louisiana

Salvador WMA

Jean Lafitte National Historical Park and Preserve

Delta NWR

Pass A Loutre WMA

Breton NWR

St. Bernard State Park

Iberia, Louisiana

Marsh Island WMA

Cypremort Point State Park

Shell Keys NWR

Vermillion, Louisiana

Rockefeller WMA

Paul J. Rainey WMA

Cameron, Louisiana

Sabine NWR

Cameron Prairie NWR

Lacassine NWR

Little Pecan Island Preserve

Peveto Woods Bird Sanctuary

Lower Neches WMA

Rockefeller WMA

Jefferson, Texas

McFaddin NWR

Sea Rim State Park

Texas Point NWR

Murphree WMA

Galveston, Texas

Brazoria NWR

Galveston Island State Park

Apfell Park

Seawolf Park

Old Fort Travis Park

Atkinson Island WMA

Ft. Anahuc Park

Anahuc NWR

McFaddin NWR

Candy Abshier WMA

Atkinson Island WMA

Brazoria, Texas

San Bernard NWR

Peach Point WMA

Brazoria NWR

Christmas Bay State Park

Christmas Bay Coastal Preserve

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Table 7. (Continued).

County or Parish, State Wildlife Refuge, Wilderness Area, or

State/National Park

Matagorda, Texas

Aransas NWR

Mad Island WMA

Big Boggy NWR

San Bernard NWR

Calhoun, Texas

Mission-Aransas National Estuarine Research Reserve

Aransas NWR

Matagorda Island State Park

Guadalupe Delta WMA

Welder Flats Coastal Reserve

NWR = National Wildlife Refuge; WMA = Wildlife Management Area.

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 on 

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.

Wetlands are highly sensitive to oiling. MMS (2007b) predicted that for every 50 bbl of oil 

contacting wetlands, approximately 2.7 ha (6.7 ac) of wetland vegetation will experience 

dieback. Thirty percent of these damaged wetlands are assumed to recover within 4 years, and 

85% within 10 years. Approximately 15% of the contacted wetlands are expected to be 

converted permanently to open-water habitat. The critical concentration of oil is the

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, which have been reported to require from years to decades following a spill 

(MMS, 2007b; BOEM, 2012b).

C.8 Socioeconomic and Other Resources

C.8.1 Recreational and Commercial Fishing

BOEM has reexamined the analysis for recreational and commercial fishing presented in 

MMS (2007b, 2008) based on additional information and in consideration of the Macondo spill.

No new information was found that would alter the potential impacts on commercial fishing

(BOEM, 2012b, 2013).

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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.

Longline gear consists of monofilament line deployed from a moving vessel and generally 

allowed to drift for 4 to 5 hours (Continental Shelf Associates, Inc., 2002). As the mainline is put 

out, baited leaders and buoys are clipped in place at regular intervals. It takes 8 to 10 hours to 

deploy a longline and approximately the same time to retrieve it. Longlines are often set near 

oceanographic features such as fronts or downwellings, with the aid of sophisticated onboard 

temperature sensors, depth finders, and positioning equipment. Vessels typically are 10 to 30 m 

(33 to 98 ft) long, and their trips last from 1 to 3 weeks. The main Gulf of Mexico homeports for 

longlining vessels are in Louisiana (Dulac and Venice) and Florida (Destin, Madeira Beach, and 

Panama City).

It is unlikely that any commercial fishing activity other than longlining will occur in 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 approximately 250 to 550 m (820 to 1,804 ft). Tilefishes 

(primarily Lophalotilus chamaeleonticeps) are caught by bottom longlining in water depths from 

approximately 165 to 450 m (540 to 1,476 ft) (Continental Shelf Associates, Inc., 2002).

Most recreational fishing activity in the region occurs in water depths less than 200 m (656 ft) 

(Continental Shelf Associates, Inc., 1997, 2002). In deeper water, the main attraction to 

recreational fishers would be petroleum rigs offshore Texas and Louisiana. Due to the distance 

from shore, it is unlikely that recreational fishing activity is occurring in the lease area.

The only routine IPF potentially affecting fisheries is drilling rig presence (including noise and 

lights). Two types of potential accidents are also addressed – a small fuel spill and a large oil 

spill.

Impacts of Drilling Rig Presence, Noise, and Lights

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.

Because it is unlikely that any recreational fishing activity is occurring in the project area, no 

adverse impacts 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 Anadarko’s preventative measures during 

routine operations including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could potentially mitigate and reduce the potential for impacts. EP Section H

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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 sea surface area with diesel fuel on it would range from 0.5 to 5 ha (1.2 to 12 ac),

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 natural dispersion (see Section A.9.2).

Impacts of a Large Oil Spill

Potential spill impacts on fishing activities are discussed in MMS (2007b) and

BOEM (2012a,b, 2013). For this EP, 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. Data following the 

Macondo spill provide information about the maximum potential extent of fishery closures in 

the event of a large oil spill in the Gulf of Mexico (NMFS, 2010d). At its peak on 12 July 2010, 

closures encompassed 217,821 km2 (84,101 mi2

), or 34.8% of the U.S. Gulf of Mexico EEZ.

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 in the following 

subsections.

Impacts of a Small Fuel Spill

The probability of a fuel spill will be minimized by Anadarko’s preventative measures during 

routine operations including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could potentially alleviate the potential for impacts. EP Section H provides

detail on spill response measures.

A small fuel spill would not have any impacts on public health and safety because it would affect 

only a small area of the open ocean 122 miles (196 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 natural 

dispersion (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 drilling rig 

maintains a Shipboard Oil Pollution Emergency Plan as required under MARPOL 73/78.

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Depending on the spill rate and duration, the physical/chemical characteristics of the oil, 

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, including 

skin contact or breathing VOCs. Crude oil is a highly flammable material, and any smoke or 

vapors from a crude oil fire can cause irritation, and in large quantities may pose a health 

hazard.

Data from the Macondo spill provide relevant information about the types of health issues that 

may occur in the event of a large oil spill (Centers for Disease Control and Prevention, 2010a). 

Wildlife cleaning and rehabilitation workers have reported concerns including scrapes and cuts, 

itchy or red skin or rash, and symptoms of headache or feeling faint, dizzy, or fatigued. Hand, 

shoulder, or back pain was reported by some wildlife-cleaning workers as well. Personnel 

working on offshore vessels or providing direct oversight to offshore vessels, including 

USCG personnel, civilian contractors, and other responders who were exposed to oil and 

dispersants, had a 7 to 12 times higher prevalence of upper respiratory symptoms and cough 

than those not exposed (Centers for Disease Control and Prevention, 2010b). Another potential 

occupational hazard for spill response workers in general was heat stress from work in a hot and 

humid environment. Initial symptoms from cleanup workers who sought medical care in 

Louisiana were typical of acute exposure to hydrocarbons or H2S (e.g., headaches, dizziness, 

nausea, vomiting, cough, respiratory distress, and chest pain) (Solomon and Janssen, 2010).

C.8.3 Employment and Infrastructure

There are no IPFs associated with routine operations that are expected to affect employment 

and infrastructure. The project involves drilling with support from existing shorebase 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 in the following 

subsections.

Impacts of a Small Fuel Spill

The probability of a fuel spill will be minimized by Anadarko’s preventative measures during 

routine operations including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could potentially mitigate and reduce the potential for impacts. EP Section H

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 MMS (2007b) and

BOEM (2012a,b,c, 2013). For this EP, there are no unique site-specific issues with respect to 

employment and coastal infrastructure. A large spill could cause economic impacts in several 

ways: it could result in extensive fishery closures that put fishermen out of work; it could result 

in temporary employment as part of the response effort; it could result in adverse publicity that 

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affects employment in coastal recreation and tourism industries; and it could result in another 

suspension of OCS drilling activities, including service and support operations that are an 

important part of local economies.

In addition to the analyses presented in MMS (2007b, 2008) and BOEM (2012b), a study 

explored the economic impacts of the Macondo spill on oil and gas industry employment due to 

suspension of deepwater drilling (Inter-Agency Economic Report, 2010). The study indicates 

that during the moratorium, the number of oil industry workers in the Gulf of Mexico fell by 

approximately 2,000 and may have indirectly caused a temporary loss of 8,000 to 12,000 jobs 

along the Gulf Coast. Total spending by drilling operators is estimated to have declined by 

$1.8 billion over a 6-month period; this direct reduction in spending affected employment in the 

industries that supply the Gulf drilling industry and in all other industries affected by declines in 

consumer and business spending (Inter-Agency Economic Report, 2010).

C.8.4 Recreation and Tourism

BOEM has reexamined the analyses for recreation and tourism presented in MMS (2007b, 2008) 

based on additional information and in consideration of the Macondo oil spill event. No new 

information was found that would alter the potential impacts on recreation and tourism 

(BOEM, 2012b, 2013).

There are no known recreational uses of the lease area. Recreational resources and tourism in 

coastal areas would not be affected by any 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 probability of a fuel spill will be minimized by Anadarko’s preventative measures during 

routine operations including fuel transfer. In the unlikely event of a spill, implementation of 

Anadarko’s OSRP could potentially help mitigate and reduce the potential for impacts. 

EP Section H 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 natural dispersion.

Impacts of a Large Oil Spill

Potential impacts of an oil spill on recreation and tourism are discussed in MMS (2007b) and

BOEM (2012a,b,c, 2013). For this EP, 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, resulting in negative publicity that encourages people to stay away. The 30-day OSRA 

modeling summarized in Table 3 indicates that Cameron, Louisiana is the area most likely to be 

contacted in the event of a spill in the project area. However, the 120-day OSRA model predicts 

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a chance for oil to contact shorelines ranging from Cameron County, Texas, to Miami-Dade 

County, Florida. 

In addition to the analysis presented in MMS (2007b) and BOEM (2012a,b,c, 2013), recent and 

ongoing studies have explored the economic impacts of the Macondo spill including tourism and 

"brand" damage (IEM, 2010; Oxford Economics, 2010). The U.S. Travel Association has 

estimated the economic impact of the Macondo spill on tourism across the Gulf Coast over a 

3-year period at $22.7 billion (Oxford Economics, 2010).

C.8.5 Land Use

Land use along the northern Gulf Coast is discussed in MMS (2007b) and BOEM 

(2012a,b,c, 2013). There are no routine IPFs that could affect 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 any 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 IPF. A small fuel spill would not have any 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, temporary 

staging areas were established in Louisiana, Mississippi, Alabama, and Florida for spill response 

and cleanup efforts. 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.

C.8.6 Other Marine Uses

The lease area is not located within any USCG-designated fairway or shipping lane. The 

proposed wellsites are located within Military Warning Area W-92. Anadarko will comply with 

BOEM requirements and lease stipulations to avoid impacts on uses of the area by military 

vessels and aircrafts.

Fugro GeoServices, Inc. (2003) reported that existing infrastructure is present near the proposed 

locations including three existing wells, two 6-inch pipelines, an umbilical, and numerous cables 

noted during analysis of the 3D seismic data.

There are no IPFs from routine project activities that are likely to affect other marine uses of the 

lease area. A large oil spill is the only relevant accident-related IPF. A small fuel spill would not 

have any impacts on other marine uses because spill response activities would be mainly within 

the lease area and the duration would be brief.

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Impacts of a Large Oil Spill

An accidental spill would be unlikely to significantly affect shipping or other marine uses. In the 

event of a large spill requiring numerous response vessels, coordination would be required to 

manage the vessel traffic for safe operations. Anadarko will comply with BOEM requirements 

and lease stipulations to avoid impacts on uses of the area by military vessels and aircraft.

In the event of a large spill requiring numerous vessels in the area, coordination would be 

required to ensure that no anchoring or seafloor-disturbing activities occur near the existing 

wells and pipelines.

D. Environmental Hazards

D.1 Geologic Hazards

Fugro GeoServices, Inc. (2003) reported that the highly irregular seafloor in the southern minibasin in western portion of Block 768 may represent a zone of potential modern seafloor 

instability associated with seafloor faulting and salt withdrawal. They have reported that 

although large-scale slope failure is unlikely during temporary exploratory drilling, when 

planning production and development facilities, the potential for seafloor instability should be 

considered. The proposed wellsites were found to be free of significant geological hazards and 

were considered suitable for the proposed activities (Fugro GeoServices, Inc., 2003). See 

EP Section C 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 rigs under consideration for this project. 

High winds and limited visibility during a severe storm could disrupt 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 

as outlined in the Hurricane Evacuation Plan would be adhered to.

D.3 Currents and Waves

Metocean conditions such as sea states, wind speed, and ocean currents will 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 under 

consideration for this project. 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.

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E. Alternatives

No formal alternatives were evaluated in this EIA for the EP. However, various technical and 

operational options, including the location of the wellsites and the selection of a drilling unit, 

were considered by Anadarko in developing the proposed action.

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 all applicable Federal, State, 

and local requirements concerning air pollutant emissions, discharges to water, and solid waste 

disposal. All project activities will be conducted under guidance by Anadarko’s OSRP and will 

include the measures described in EP Section H.

G. Consultation

No persons or agencies were consulted during the preparation of this EIA.

H. Preparers

This EIA was prepared by CSA Ocean Sciences Inc. Contributors included:

• M. John Thompson (Senior Scientist);

• John M. Tiggelaar II (Project Scientist);

• Heidi Etter (Project Scientist);

• Neal Phillips (Senior Scientist);

• Keith VanGraafeiland (Geospatial Manager);

• Kevin Noack (Geospatial Coordinator);

• Kristen L. Metzger (Library and Information Services Director); and 

• Natalie Kraft (Technical Editor).

I. References

Ackleh, A., G.E. Loup, J.W. Loup, B. Ma, J.J. Newcomb, N. Pal, N.A. Sidorovskaia, and C. Tiemann. 2012. Assessing 

the Deepwater Horizon oil spill impact on marine mammal population through acoustics: Endangered sperm 

whales. J. Acoust. Soc. Am. 131(3): 2,306-2,314.

Aten, L.E. 1983. Indians of the upper Texas coast. New York, NY: Academic Press. 370 pp.

Barkuloo, J.M. 1988. Report on the conservation status of the Gulf of Mexico sturgeon, Acipenser oxyrinchus 

desotoi. U.S. Department of the Interior, U.S. Fish and Wildlife Service, Panama City, FL. 33 pp.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 69

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Barkaszi, M.J., M. Butler, R. Compton, A. Unietis, and B. Bennet. 2012. Seismic survey mitigation measures and 

marine mammal observer reports. U.S. Dept. of the Interior, Bureau of Ocean Energy Management, Gulf of 

Mexico OCS Region, New Orleans, LA. OCS Study BOEM 2012-015. 53 pp.

Bélanger, L. and J. Bédard. 1989. Responses of staging Greater Snow Geese to human disturbance. J. Wildl.

Manage. 53:713-719.

Biggs, D.C. and P.H. Ressler. 2000. Water column biology, pp. 141-187. In: Continental Shelf Associates, Inc. 

Deepwater Program: Gulf of Mexico Deepwater Information Resources Data Search and Literature Synthesis. 

Volume I: Narrative Report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA. OCS Study MMS 2000-049.

Boehm, P., D. Turton, A. Raval, D. Caudle, D. French, N. Rabalais, R. Spies, and J. Johnson. 2001. Deepwater 

program: Literature review, environmental risks of chemical products used in Gulf of Mexico deepwater oil 

and gas operations. Volume I: Technical report. U.S. Department of the Interior, Minerals Management 

Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2001-011. 326 pp.

Brooke, S. and W.W. Schroeder. 2007. State of deep coral ecosystems in the Gulf of Mexico region: Texas to the 

Florida Straits, pp. 271-306. In: S.E. Lumsden, T.F. Hourigan, A.W. Bruckner, and G. Dorr (eds.), The State of 

Deep Coral Ecosystems of the United States. NOAA Tech. Memo. CRCP-3. Silver Spring, MD. 365 pp.

Brooks, J.M., C. Fisher, H. Roberts, E. Cordes, I. Baums, B. Bernard, R. Church, P. Etnoyer, C. German, E. Goehring, 

I. McDonald, Harry Roberts, T. Shank, D. Warren, S. Welsh, and G. Wolff. 2012. Exploration and research of 

northern Gulf of Mexico deepwater natural and artificial hard-bottom habitats with emphasis on coral 

communities: Reefs, rigs, and wrecks — “Lophelia II” Interim report. U.S. Dept. of the Interior, Bureau of 

Ocean Energy Management, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study BOEM 2012-106. 

135 pp.

Bureau of Ocean Energy Management (BOEM). 2012a. Outer Continental Shelf Oil and Gas Leasing Program: 

2012-2017. Final Programmatic Environmental Impact Statement. U.S. Department of the Interior, Bureau of 

Ocean Energy Management. OCS EIS/EA BOEM 2012-030.

Bureau of Ocean Energy Management (BOEM). 2012b. Gulf of Mexico OCS Oil and Gas Lease Sales: 2012-2017. 

Western Planning Area Lease Sales 229, 233, 238, 246, and 248. Central Planning Area Lease Sales 227, 231, 

235, 241, and 247. Final Environmental Impact Statement. U.S. Department of the Interior, Bureau of Ocean 

Energy Management, Gulf of Mexico OCS Region. OCS EIS/EA BOEM 2012-019. 3 vol.

Bureau of Ocean Energy Management (BOEM). 2012c. Gulf of Mexico OCS Oil and Gas Lease Sale: 2012. Central 

Planning Area Lease Sale 216/222. Final Supplemental Environmental Impact Statement. U.S. Department of 

the Interior, Bureau of Ocean Energy Management, Gulf of Mexico OCS Region, New Orleans, LA. OCS EIS/EA 

BOEM 2012-058. 2 vol.

Bureau of Ocean Energy Management (BOEM). 2012d. Archaeology Survey Blocks. Website accessed on 

11 April 2014. http://www.boem.gov/Environmental-Stewardship/Archaeology/surveyblocks-pdf.aspx.

Bureau of Ocean Energy Management (BOEM). 2013. Gulf of Mexico OCS Oil and Gas Lease Sales: 2013-2014.

Western Planning Are Lease Sale 233. Central Planning Area 231. Final Supplemental Environmental Impact 

Statement. U.S. Department of the Interior, Bureau of Ocean Energy Management, Gulf of Mexico 

OCS Region. OCS EIS/EA BOEM 2013-0118.

Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE). 2010. Federal & Academic 

Scientists Return from Deep-sea Research Cruise in Gulf of Mexico: Scientists Observe Damage to Deep-sea 

Corals. Online news dated 4 November 2010. Website accessed 17 January 2014. 

http://www.noaanews.noaa.gov/stories2010/20101104_coralcruise.html

Camilli, R., C.M. Reddy, D.R. Yoerger, B.A.S. Van Mooy, M.V. Jakuba, J.C. Kinsey, C.P. McIntyre, S.P. Sylva, and 

J.V. Maloney. 2010. Tracking hydrocarbon plume transport and biodegradation at Deepwater Horizon. 

Science 330(6001):201-204.

Carmichael, R.H., W.M. Graham, A. Aven, G.Worthy, and S. Howden. 2012. Were multiple stressors a ‘perfect 

storm’ for northern Gulf of Mexico bottlenose dolphins (Tursiops truncatus) in 2011? Website accessed 

26 March 2014 at: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0041155.

Carr, A. 1996. Suwannee River sturgeon, pp. 73-83. In: M.H. Carr (ed.), A Naturalist in Florida. Yale University 

Press, New Haven, CT.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 70

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Centers for Disease Control and Prevention. 2010a. Deepwater Horizon Response: NIOSH Health Hazard 

Evaluation. Website accessed 17 January 2014, updated 24 August 2011 at: 

http://www.cdc.gov/niosh/topics/oilspillresponse/gulfspillhhe.html.

Centers for Disease Control and Prevention. 2010b. Health Hazard Evaluation of Deepwater Horizon Response 

Workers, HETA 2010-0115. Interim Report #6A. 11 pp. Website accessed 25 March 2014 at: 

http://www.cdc.gov/niosh/hhe/pdfs/interim_report_6.pdf.

Clapp, R.B., R.C. Banks, D. Morgan-Jacobs, and W.A. Hoffman. 1982a. Marine birds of the southeastern United 

States and Gulf of Mexico. Part I. Gaviiformes through Pelicaniformes. U.S. Fish and Wildlife Service, Office of 

Biological Services, Washington, D.C. FWS/OBS-82/01. 637 pp.

Clapp, R.B., D. Morgan-Jacobs, and R.C. Banks. 1982b. Marine birds of the southeastern United States and Gulf of 

Mexico. Part II. Anseriformes. U.S. Fish and Wildlife Service, Office of Biological Services, Washington, D.C. 

FWS/OBS-82/20. 492 pp.

Clapp, R.B., D. Morgan-Jacobs, and R.C. Banks. 1983. Marine birds of the southeastern United States and Gulf of 

Mexico. Part III. Charadriiformes. U.S. Fish and Wildlife Service, Office of Biological Services, Washington, 

D.C. FWS/OBS-83/30. 853 pp.

Coastal Environments, Inc. 1977. Cultural Resources Evaluation of the Northern Gulf of Mexico Continental Shelf. 

Prepared for the U.S. Department of the Interior, National Park Service, Office of Archaeology and Historic 

Preservation, Interagency Archaeological Services, Baton Rouge, LA. 4 vol.

Coastal Environments, Inc. 1982. Sedimentary Studies of Prehistoric Archaeological Sites. Prepared for the 

U.S. Department of the Interior, National Park Service, Division of State Plans and Grants, Baton Rouge, LA.

Continental Shelf Associates, Inc. 1997. Characterization and trends of recreational and commercial fishing from 

the Florida panhandle. U.S. Department of Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA. USGS/BRD/CR-1997-0001 and OCS Study MMS 97-0020. 333 pp.

Continental Shelf Associates, Inc. 2002. Deepwater Program: Bluewater fishing and OCS activity, interactions 

between the fishing and petroleum industries in deepwaters of the Gulf of Mexico. U.S. Department of the 

Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study 

MMS 2002-078.

Continental Shelf Associates, Inc. 2004. Final Report: Gulf of Mexico Comprehensive Synthetic Based Muds 

Monitoring Program. Report prepared for SBM Research Group, Houston, TX. October 2004. 3 vol.

Continental Shelf Associates, Inc. 2006. Effects of oil and gas exploration and development at selected continental 

slope sites in the Gulf of Mexico. Volume II: Technical report. U.S. Department of the Interior, Minerals 

Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2006-045.

Cruz-Kaegi, M.E. 1998. Latitudinal variations in biomass and metabolism of benthic infaunal communities. 

Ph.D. dissertation, Texas A&M University, College Station, TX.

CSA International, Inc. 2007. Characterization of northern Gulf of Mexico deepwater hard-bottom communities 

with emphasis on Lophelia coral. U.S. Department of the Interior, Minerals Management Service, Gulf of 

Mexico OCS Region, New Orleans, LA. OCS Study MMS 2007-044. 169 pp. + app.

Davis, R.W. and G.S. Fargion. 1996. Distribution and abundance of cetaceans in the north-central and western 

Gulf of Mexico: Final report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA. 

Davis, R.W., J.G. Ortega-Ortiz, C.A. Ribic, W.E. Evans, D.C. Biggs, P.H. Ressler, J.H. Wormuth, R.R. Leben, K.D. Mullin, 

and B. Würsig. 2000. Cetacean habitat in the northern Gulf of Mexico, pp. 217-253. In: R.W. Davis, 

W.E. Evans, and B. Würsig (eds.), Cetaceans, sea turtles, and seabirds in the northern Gulf of Mexico: 

Distribution, abundance and habitat associations. Volume II: Technical report. U.S. Geological Survey, 

Biological Resources Division, USGS/BRD/CR-1999-0006 and U.S. Department of the Interior, Minerals 

Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2000-003. 346 pp.

Ditty, J.G. 1986. Ichthyoplankton in nerItic waters of the northern Gulf of Mexico off Louisiana: Composition, 

relative abundance, and seasonality. Fish. Bull. 84(4):935-946.

Ditty, J.G., G.G. Zieske, and R.F. Shaw. 1988. Seasonality and depth distribution of larval fishes in the northern 

Gulf of Mexico above 26°00’N. Fish. Bull. 86:811-823.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 71

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Efroymson, R.A., W.H. Rose, S. Nemeth, and G.W. Suter II. 2000. Ecological risk assessment framework for low 

altitude overflights by fixed-wing and rotary-wing military aircraft. Report prepared by Oak Ridge National 

Laboratory, Oak Ridge, TN. ORNL/TM-2000/289: ES-5048.

Ehrlich, P.R., D.S. Dobkin, and D. Wheye. 1992. Birds in Jeopardy: The Imperiled and Extinct Birds of the United 

States and Canada, including Hawaii and Puerto Rico. Stanford University Press, Palo Alto, CA. 261 pp.

Florida Fish and Wildlife Conservation Commission. 2014a. Loggerhead nesting in Florida. Website accessed 

5 May 2014 at: http://myfwc.com/research/wildlife/sea-turtles/nesting/loggerhead/.

Florida Fish and Wildlife Conservation Commission. 2014b. Green turtle nesting in Florida. Website accessed 

5 May 2014 at: http://myfwc.com/research/wildlife/sea-turtles/nesting/green-turtle/.

Florida Fish and Wildlife Conservation Commission. 2014c. Leatherback nesting in Florida. Website accessed 

5 May 2014 at: http://myfwc.com/research/wildlife/sea-turtles/nesting/leatherback/.

Florida Fish and Wildlife Conservation Commission. 2014d. Florida's endangered and threatened species.

Website accessed 25 March 2014 at: 

http://myfwc.com/media/1515251/Threatened_Endangered_Species.pdf.

Flower Garden Banks National Marine Sanctuary. 2014. Cnidarian species. Website accessed 5 May 2014, 

updated 10 February 2014 at: http://flowergarden.noaa.gov/about/cnidarianlist.html.

Fox, D.A., J.E. Hightower, and F.M. Paruka. 2000. Gulf sturgeon spawning migration and habitat in the 

Choctawhatchee River system, Alabama-Florida. Trans. Am. Fish. Soc. 129:811-826.

Fritts, T.H. and R.P. Reynolds. 1981. Pilot study of the marine mammals, birds, and turtles in OCS areas of the 

Gulf of Mexico. U.S. Department of the Interior, Fish and Wildlife Service, Biological Services Program. 

FWS/OBS-81/36.

Fugro GeoServices, Inc. 2003. Shallow Hazard Assessment, Gulf of Mexico, Green Canyon Blocks GC 723, 724, 768,

& Vicinity, Wellsite GC 768 BB Site Clearance Letters. Fugro Report Nos. 2402-2004 to 27.2012-2582.

Fugro GeoServices, Inc. 2013. Archaeological Assessment, Block 852-854, 897, & 898, DeSoto Canyon Area, Gulf 

of Mexico. Report No. 2413-059.

Gallaway, B. (ed.). 1988. Northern Gulf of Mexico Continental Slope Study, Final report: Year 4. Volume II: 

Synthesis report. Final report submitted to the U.S. Department of the Interior, Minerals Management 

Service, New Orleans, LA. Contract No. 14-12-0001-30212.

Gallaway, B.J., J.G. Cole, and R.G. Fechhelm. 2003. Selected Aspects of the Ecology of the Continental Slope Fauna 

of the Gulf of Mexico: A Synopsis of the Northern Gulf of Mexico Continental Slope Study, 1983-1988. 

U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. 

OCS Study MMS 2003-072.

Geraci, J.R. and D.J. St. Aubin. 1987. Effects of offshore oil and gas development on marine mammals and turtles, 

pp. 587-617. In: D.F. Boesch and N.N. Rabalais (eds.), Long Term Environmental Effects of Offshore Oil and 

Gas Development. Elsevier Applied Science Publ. Ltd., London and New York.

Geraci, J.R. and D.J. St. Aubin. 1990. Sea Mammals and Oil: Confronting the Risks. Academic Press, San Diego.

Gulf of Mexico Fishery Management Council. 2005. Generic Amendment Number 3 for addressing Essential Fish 

Habitat Requirements, Habitat Areas of Particular Concern, and adverse effects of fishing in the following 

Fishery Management Plans of the Gulf of Mexico: Shrimp fishery of the Gulf of Mexico, United States waters 

red drum fishery of the Gulf of Mexico, reef fish fishery of the Gulf of Mexico coastal migratory pelagic 

resources (mackerels) in the Gulf of Mexico and South Atlantic, stone crab fishery of the Gulf of Mexico, spiny 

lobster in the Gulf of Mexico and South Atlantic, coral and coral reefs of the Gulf of Mexico. Gulf of Mexico 

Fishery Management Council, Tampa, FL.

Hazen, T.C., E.A. Dubinsky, T.Z. DeSantis, G.L. Andersen, Y.M. Piceno, N. Singh, J.K. Jansson, A. Probst, S.E. Borglin, 

J.L. Fortney, W.T. Stringfellow, M. Bill, M.S. Conrad, L.M. Tom, K.L. Chavarria, T.R. Alusi, R. Lamendella, 

D.C. Joyner, C. Spier, J. Baelum, M. Auer, M.L. Zemla, R. Chakraborty, E.L. Sonnenthal, P. D’haeseleer, 

H.N. Holman, S. Osman, Z. Lu, J.D. Van Nostrand, Y. Deng, J. Zhou, and O.U. Mason. 2010. Deep-sea oil plume 

enriches indigenous oil-degrading bacteria. Science 330(6001):204-208.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 72

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Hess, N.A. and C.A. Ribic. 2000. Seabird ecology, pp. 275-315. In: R.W. Davis, W.E. Evans, and B. Würsig (eds.), 

Cetaceans, sea turtles, and seabirds in the northern Gulf of Mexico: Distribution, abundance and habitat 

associations. Volume II: Technical report. U.S. Geological Survey, Biological Resources Division, 

USGS/BRD/CR-1999-0006 and U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA. OCS Study MMS 2000-003. 346 pp.

Higashi, G.R. 1994. Ten years of fish aggregating device (FAD) design and development in Hawaii. 

Bull. Mar. Sci. 55(2-3):651-666.

Holand, P. 1997. Offshore Blowouts: Causes and Control. Gulf Publishing Co., Houston, TX.

Holland, K.R., R.W. Brill, and R.K.C. Chang. 1990. Horizontal and vertical movements of yellowfin and bigeye tuna 

associated with fish aggregating devices. Fish. Bull. 88:493-507.

Hsing, P.-Y., B. Fu, E.A. Larcom, S.P. Berlet, T.M. Shank, A.F. Govindarajan, A. J. Lukasiewicz, P.M. Dixon, and 

C.R. Fisher. 2013. Evidence of lasting impact of the Deepwater Horizon oil spill on a deep Gulf of Mexico coral 

community. Elementa: Science of the Anthropocene 1: 000012. Website accessed 26 March 2014 at: 

http://www.elementascience.org/article/info%3Adoi%2F10.12952%2Fjournal.elementa.000012.

IEM. 2010. A Study of the Economic Impact of the Deepwater Horizon Oil Spill. Prepared for Greater 

New Orleans, Inc. October 2010. Website accessed 25 March 2014.

http://gnoinc.org/wp-content/uploads/Economic_Impact_Study_Part_I_-_Full_Report.pdf.

http://gnoinc.org/wp-content/uploads/Economic_Impact_Study_Part_II_-_Moratoria_FINAL.pdf.

http://gnoinc.org/wp-content/uploads/Economic_Impact_Study_Part_III_-_Public_Perception_FINAL.pdf.

Inter-Agency Economic Report. 2010. Estimating the effects of the deepwater drilling moratorium on the Gulf 

coast economy. Website accessed 25 March 2014.

http://www.esa.doc.gov/Reports/estimating-economic-effects-deepwater-drilling-moratorium-gulf-coast-economy.

Intergovernmental Panel on Climate Change. 2007. Climate Change 2007: Synthesis Report. Contribution of 

Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate 

Change. Geneva, Switzerland. 104 pp.

Intergovernmental Panel on Climate Change. 2014. Climate Change 2014: Impacts, Adaptation and Vulnerability. 

Yokohama, Japan. http://www.ipcc.ch/report/ar5/wg2/.

International Association of Oil & Gas Producers. 2010. Risk assessment data directory: Blowout frequencies. 

OGP Report No. 434-2. Website accessed 25 March 2014. http://www.ogp.org.uk/pubs/434-02.pdf.

Ji, Z.-G., W.R. Johnson, C.F. Marshall, and E.M. Lear. 2004. Oil-Spill Risk Analysis: Contingency Planning Statistics 

for Gulf of Mexico OCS Activities. U.S. Department of the Interior, Minerals Management Service, Gulf of 

Mexico OCS Region. OCS Report MMS 2004-026.

Jochens, A., D. Biggs, K. Benoit-Bird, D. Engelhaupt, J. Gordon, C. Hu, N. Jaquet, M. Johnson, R. Leben, B. Mate, 

P. Miller, J. Ortega-Ortiz, A. Thode, P. Tyack, and B. Würsig. 2008. Sperm whale seismic study in the Gulf of 

Mexico: Synthesis report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA. OCS Study MMS 2008-006. 341 pp.

Johnsgard, P.A. 1990. Hawks, Eagles, and Falcons of North America; Biology and Natural History. Smithsonian 

Institute Press, Washington. 403 pp.

Joint Analysis Group. 2010a. Joint Analysis Group (JAG) review of preliminary data to examine subsurface oil in 

the vicinity of MC252#1 May 19 to June 19, 2010. Website accessed 25 March 2014. 

http://gomex.erma.noaa.gov/layerfiles/7229/files/JAG_Data_Report_2_Subsurface%20Oil_Final.pdf.

Joint Analysis Group. 2010b. Joint Analysis Group (JAG) review of R/V Brooks McCall data to examine subsurface 

oil. Website accessed 25 March 2014. 

http://www.noaa.gov/sciencemissions/PDFs/JAG_Report_1_BrooksMcCall_Final_June20.pdf.

Joint Analysis Group. 2010c. Joint Analysis Group (JAG) review of preliminary data to examine oxygen levels in the 

vicinity of MC252#1 May 8 to August 9, 2010. Website accessed 25 March 2014. 

http://www.noaa.gov/sciencemissions/PDFs/JAG_Oxygen_Report%20%28FINAL%20090410%29.pdf.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 73

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Kennicutt, M.C. II. 2000. Chemical Oceanography, pp. 123-139. In: Continental Shelf Associates, Inc. Deepwater 

Program: Gulf of Mexico deepwater information resources data search and literature synthesis. Volume I: 

Narrative report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 

New Orleans, LA. OCS Study MMS 2000-049.

Kujawinski, E.B., M.C. Kido Soule, D.L. Valentine, A.K. Boysen, K. Longnecker, and M.C. Redmond. 2011. Fate of 

dispersants associated with the Deepwater Horizon oil spill. Environ. Sci. Technol. 45(4): 1298-1306. Website 

accessed 28 March 2014. http://pubs.acs.org/doi/abs/10.1021/es103838p.

LGL Ecological Research Associates, Ltd. 2006. Assessment of the effects of underwater noise from the proposed 

Neptune LNG Project - Supplementary Biological Effects Report to Ecology and Environment, Inc. LGL Report 

No. 4200-2a, 8 August 2006. 11 pp.

Lohoefener, R., W. Hoggard, K. Mullin, C. Roden, and C. Rogers. 1990. Association of sea turtles with petroleum 

platforms in the north-central Gulf of Mexico. U.S. Department of the Interior, Minerals Management Service, 

Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 90-0025. 90 pp.

Lutcavage, M.E., P.L. Lutz, G.D. Bossart, and D.M. Hudson. 1995. Physiologic and clinicopathologic effects of crude 

oil on loggerhead sea turtles. Arch. Environ. Contam. Toxicol. 28:417-422.

Lutcavage, M.E., P. Plotkin, B. Witherington, and P.L. Lutz. 1997. Human impacts on sea turtle survival, 

pp. 387-409. In: P.L. Lutz and J.A. Musick (eds.), The Biology of Sea Turtles. CRC Press, Boca Raton, FL.

MacDonald, I.R. (ed.). 2002. Stability and Change in Gulf of Mexico Chemosynthetic Communities. Volume II: 

Technical Report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 

New Orleans, LA. OCS Study MMS 2002-036. 456 pp.

Marine Mammal Commission (MMC). 2011. Assessing the long-term effects of the BP Deepwater Horizon oil spill 

on marine mammals in the Gulf of Mexico: A statement of research needs. Website accessed 25 March 2014. 

http://www.mmc.gov/reports/workshop/pdf/longterm_effects_bp_oilspil.pdf.

Minerals Management Service (MMS). 2000. Gulf of Mexico Deepwater Operations and Activities: Environmental 

Assessment. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 

New Orleans, LA. OCS EIS/EA MMS 2000-001.

Minerals Management Service (MMS). 2007a. Outer Continental Shelf Oil & Gas Leasing Program: 

2007-2012 Final Environmental Impact Statement. U.S. Department of the Interior, Minerals Management 

Service, Herndon, VA. OCS EIS/EA MMS 2007-003. April 2007.

Minerals Management Service (MMS). 2007b. Gulf of Mexico OCS Oil and Gas Lease Sales: 2007-2012. Western 

Planning Area Sales 204, 207, 210, 215, and 218; Central Planning Area Sales 205, 206, 208, 213, 216, and 222. 

Final Environmental Impact Statement. U.S. Department of the Interior, Minerals Management Service, Gulf 

of Mexico OCS Region. OCS EIS/EA MMS 2007-018. April 2007.

Minerals Management Service (MMS). 2008. Gulf of Mexico OCS Oil and Gas Lease Sales: 2009-2012; Central 

Planning Area Sales 208, 213, 216, and 222; Western Planning Area Sales 210, 215, and 218. Final 

Supplemental Environmental Impact Statement. U.S. Department of the Interior, Minerals Management 

Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS EIS/EA MMS 2008-041. September 2008.

Minerals Management Service (MMS). 2009a. NTL No. 2009-G39: Biologically Sensitive Underwater Features and 

Areas. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, 

New Orleans, LA. 

Minerals Management Service (MMS). 2009b. NTL No. 2009-G40: Deepwater Benthic Communities. 

U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA.

Mississippi Department of Wildlife, Fisheries and Parks. 2005. Appendix VIII: Mississippi’s species of greatest 

conservation need by ecoregion, pp. 375-380. In: Mississippi's Comprehensive Wildlife Conservation Strategy 

2005-2015, Version 1. Website accessed 11 April 2014 at: http://www.mdwfp.com/media/63792/cwcs.pdf.

Morrow, J.V., Jr., J.P. Kirk, K.J. Killgore, H. Rugillio, and C. Knight. 1998. Status and recovery of Gulf sturgeon in the 

Pearl River system, Louisiana-Mississippi. N. Am. J. Fish Manage. 18:798-808.

Mullin, K., W. Hoggard, C. Roden, R. Lohoefener, C. Rogers, and B. Taggart. 1991. Cetaceans on the upper 

continental slope in the north-central Gulf of Mexico. OCS Study/MMS 910027. U.S. Department of the 

Interior, Minerals Management Service, Gulf of Mexico OCS Regional Office, New Orleans, LA. 108 pp.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 74

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Mullin, K.D. 2007. Abundance of cetaceans in the oceanic Gulf of Mexico based on 2003-2004 ship surveys. 

Available from: National Marine Fisheries Service, Southeast Fisheries Science Center, Pascagoula, MS. 26 pp.

National Marine Fisheries Service. 2007. Endangered Species Act, Section 7 Consultation – Biological Opinion. 

Gulf of Mexico Oil and Gas Activities: Five-Year Leasing Plan for Western and Central Planning Areas 

2007-2012. 29 June 2007.

National Marine Fisheries Service. 2009. Final Amendment 1 to the Consolidated Atlantic Highly Migratory 

Species Fishery Management Plan Essential Fish Habitat. Highly Migratory Species Management Division, 

Office of Sustainable Fisheries, Silver Spring, MD. June 2009. Website accessed 25 March 2014 at: 

http://www.nmfs.noaa.gov/sfa/hms/EFH/Final/FEIS_Amendment_Total.pdf.

National Marine Fisheries Service (NMFS). 2010a. Final Recovery Plan for the Sperm Whale 

(Physeter macrocephalus). Office of Protected Resources, Silver Spring, MD. December 2010. Website 

accessed 25 March 2014 at: 

http://www.nmfs.noaa.gov/pr/pdfs/recovery/final_sperm_whale_recovery_plan_21dec.pdf.

National Marine Fisheries Service. 2010b. Gulf sturgeon (Acipenser oxyrinchus desotoi). Website accessed 

17 January 2014, updated 27 February 2013. http://www.nmfs.noaa.gov/pr/species/fish/gulfsturgeon.htm

National Marine Fisheries Service (NMFS). 2010c. Sea turtles, dolphins, and whales and the Gulf of Mexico oil 

spill. Website accessed 25 March 2014; updated 13 December 2013 at: 

http://www.nmfs.noaa.gov/pr/health/oilspill.htm.

National Marine Fisheries Service (NMFS). 2010d. Deepwater Horizon/BP oil spill: size and percent coverage of 

fishing area closures due to BP oil spill. Website accessed 25 March 2014 at: 

http://sero.nmfs.noaa.gov/deepwater_horizon/size_percent_closure/index.html

National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS). 2008. Recovery Plan for the 

Northwest Atlantic Population of the Loggerhead Sea Turtle (Caretta caretta), Second Revision. Website 

accessed 25 March 2014 at: http://www.nmfs.noaa.gov/pr/pdfs/recovery/turtle_loggerhead_atlantic.pdf.

National Marine Fisheries Service, U.S. Fish and Wildlife Service, and Secretaría de Medio Ambiente y Recursos 

Naturales (SEMARNAT). 2011. Bi-National Recovery Plan for the Kemp‘s Ridley Sea Turtle 

(Lepidochelys kempii), Second Revision. 

http://www.nmfs.noaa.gov/pr/pdfs/recovery/kempsridley_revision2.pdf

National Oceanic and Atmospheric Administration (NOAA). 2006. Fact Sheet: Small Diesel Spills 

(500-5,000 gallons). NOAA Scientific Support Team, Hazardous Materials Response and Assessment Division, 

National Oceanic and Atmospheric Administration. Seattle, WA. 2 pp.

National Oceanic and Atmospheric Administration (NOAA). 2010. Oil and Sea Turtles. Biology, Planning and 

Response. Website accessed 25 March 2014 at: 

http://response.restoration.noaa.gov/sites/default/files/Oil_Sea_Turtles.pdf.

National Oceanic and Atmospheric Administration (NOAA). 2014. 2010-2014 Cetacean Unusual Mortality Event in 

Northern Gulf of Mexico. Website accessed 30 June 2014, updated 24 June 2014 at: 

http://www.nmfs.noaa.gov/pr/health/mmume/cetacean_gulfofmexico.htm.

National Park Service. 2010. Breton Wilderness 300 km Radius. Website accessed 25 March 2014 at:

http://www2.nature.nps.gov/air/Permits/ARIS/docs/bretMap300.pdf.

National Research Council. 1983. Drilling Discharges in the Marine Environment. National Academy Press, 

Washington, DC. 180 pp.

National Research Council. 2003a. Oil in the Sea III: Inputs, Fates, and Effects. National Academies Press, 

Washington, DC. 182 pp. + app.

National Research Council. 2003b. Ocean Noise and Marine Mammals. Ocean Studies Board, National Academies 

Press, Washington, DC. 204 pp.

Neff, J.M. 1987. Biological effects of drilling fluids, drill cuttings and produced waters, pp. 469-538. 

In: D.F. Boesch and N.N. Rabalais (eds.), Long-Term Effects of Offshore Oil and Gas Development. Elsevier 

Applied Science Publishers, London.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 75

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Neff, J.M., S. McKelvie, and R.C. Ayers, Jr. 2000. Environmental impacts of synthetic based drilling fluids. 

Prepared by Robert Ayers & Associates, Inc. U.S. Department of the Interior, Minerals Management Service, 

Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2000-064. 118 pp.

Neff, J.M., A.D. Hart, J.P. Ray, J.M. Limia, and T.W. Purcell. 2005. An assessment of seabed impacts of 

synthetic-based drilling-mud cuttings in the Gulf of Mexico. 2005 SPE/EPA/DOE Exploration and Production 

Environmental Conference, 7-9 March 2005, Galveston, Texas, USA. SPE 94086.

Nelson, H.F. and E.E. Bray. 1970. Stratigraphy and History of the Holocene Sediments in the Sabine-High Island 

Area, Gulf of Mexico. In: Morgan, J.P. (ed.) Deltaic Sedimentation; Modern and Ancient. Special Publn. 

No. 15. Tulsa, OK: SEPM.

Nowlin, W.D., Jr., A.E. Jochens, S.F. DiMarco, R.O. Reid, and M.K. Howard. 2001. Deepwater Physical 

Oceanography Reanalysis and Synthesis of Historical Data: Synthesis Report. U.S. Department of the Interior, 

Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2001-064. 

528 pp.

Operational Science Advisory Team. 2010. Summary report for sub-surface and sub-sea oil and dispersant 

detection: Sampling and monitoring. Prepared for Paul F. Zukunft, U.S. Coast Guard Federal On-Scene 

Coordinator, Deepwater Horizon MC252. December 17, 2010. 

http://www.restorethegulf.gov/sites/default/files/documents/pdf/OSAT_Report_FINAL_17DEC.pdf.

Oxford Economics. 2010. Potential impact of the Gulf oil spill on tourism. Report prepared for the U.S. Travel 

Association. Website accessed 25 March 2014 at: 

http://www.ustravel.org/sites/default/files/page/2009/11/Gulf_Oil_Spill_Analysis_Oxford_Economics_710.pdf.

Peake, D.E. 1996. Bird surveys, pp. 271-304. In: R.W. Davis and G.S. Fargion (eds.), Distribution and abundance of 

cetaceans in the north-central and western Gulf of Mexico, Final report. Volume II: Technical report. 

Prepared by the Texas Institute of Oceanography and the National Marine Fisheries Service. U.S. Department 

of the Interior, Minerals Management Service, Gulf of Mexico OCS Region Office, New Orleans, LA. OCS Study 

MMS 96-0027. 357 pp.

Pearson, C.E., D.B. Kelley, R.A. Weinstein, and S.W. Gagliano. 1986. Archaeological investigations on the Outer 

Continental Shelf: A study within the Sabine River valley, offshore Louisiana and Texas. U.S. Department of 

the Interior, Minerals Management Service, Reston, VA. OCS Study MMS 86-0119. 314 pp.

Powers, K. 1987. Seabirds, pp. 194-201. In: J.D. Milliman and W.R. Wright (eds.), The Marine Environment of the 

U.S. Atlantic Continental Slope and Rise. Jones and Bartlett Publ., Inc. Boston/Woods Hole, MA. 275 pp.

Pritchard, P.C.H. 1997. Evolution, phylogeny, and current status, pp. 1-28. In: Lutz, P.L. and J.A. Musick (eds.), The

Biology of Sea Turtles. Boca Raton, FL: CRC Press. 

Rathbun, G.B. 1988. Fixed-wing airplane versus helicopter surveys of manatees. Mar. Mamm. Sci. 4(1):71-75.

Relini, M., L.R. Orsi, and G. Relini. 1994. An offshore buoy as a FAD in the Mediterranean. Bull. Mar. Sci. 

55(2-3):1,099-1,105.

Richards, W.J., T. Leming, M.F. McGowan, J.T. Lamkin, and S. Kelley-Farga. 1989. Distribution of fish larvae in 

relation to hydrographic features of the Loop Current boundary in the Gulf of Mexico. Rapp. P.-v. Reun. 

Cons. Int. Explor. Mer. 191:169-176.

Richards, W.J., M.F. McGowan, T. Leming, J.T. Lamkin, and S. Kelley. 1993. Larval fish assemblages at the Loop 

Current boundary in the Gulf of Mexico. Bull. Mar. Sci. 53(2):475-537.

Richardson, W.J., C.R. Greene, Jr., C.I. Malme, and D.H. Thomson. 1995. Marine Mammals and Noise. Academic 

Press, San Diego. 576 pp.

Rodgers, J., Jr, and S. Schwikert. 2002. Buffer Zone Distances to Protect Foraging and Loafing Waterbirds from 

Disturbances by Personal Watercraft and Outboard-Powered Boats. Conserv. Biol. 16:216-224.

Ross, S.W., A.W.J. Demopoulos, C.A. Kellogg, C.L. Morrison, M.S. Nizinski, C.L. Ames, T.L. Casazza, D. Gualtieri, 

K. Kovacs, J.P. McClain, A.M. Quattrini, A.Y. Roa-Varón, and A.D. Thaler. 2012. Deepwater Program: Studies of 

Gulf of Mexico lower continental slope communities related to chemosynthetic and hard substrate habitats: 

U.S. Geological Survey Open-File Report 2012-1032. 301 pp.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 76

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
Rowe, G.T. and M.C. Kennicutt II. 2009. Northern Gulf of Mexico Continental Slope Habitats and Benthic Ecology 

Study. Final Report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA. OCS Study MMS 2009-039. 456 pp.

Russell, R.W. 2005. Interactions between migrating birds and offshore oil and gas platforms in the northern 

Gulf of Mexico: Final Report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico 

OCS Region, New Orleans, LA. OCS Study MMS 2005-009. 348 pp.

Salmon, M. and J. Wyneken. 1990. Do swimming loggerhead sea turtles (Caretta caretta) use light cues for 

offshore orientation? Mar. Freshw. Behav. Phy. 17(4): 233-246.

Schwacke, L.H., C.R. Smith, F. I. Townsend, R.S. Wells, L.B. Hart, B.C. Balmer, T.K. Collier, S. De Guise, M.M. Fry,

L.J. Guillette, Jr., S.V. Lamb, S.M. Lane, W.E. McFee, N.J. Place, M.C. Tumlin, G.M. Ylitalo, E.S. Zolman, and 

T.K. Rowles. 2014. Health of Common Bottlenose Dolphins (Tursiops truncatus) in Barataria Bay, Louisiana, 

following the Deepwater Horizon Oil Spill. Environ. Sci. Technol. 48 (1): 93-103. Website accessed 

26 March 2014 at: http://pubs.acs.org/doi/abs/10.1021/es403610f.

Sea Turtle Restoration Project. 2013. Kemp’s ridley protection campaign. Website accessed 11 April 2014 at:

http://blog.seaturtles.org/section.php?id=41.

Share the Beach. 2014. Nesting season statistics. Website accessed 11 April 2014. 

http://www.alabamaseaturtles.com/nesting-season-statistics/

Smultea, M.A., J.R. Mobley, Jr., D. Fertl, and G.L. Fulling. 2008. An unusual reaction and other observations of

sperm whales near fixed wing aircraft. Gulf. Carrib. Res. 20:75-80.

Solomon, G.M. and S. Janssen. 2010. Health Effects of the Gulf Oil Spill. JAMA 304(10):1,118-1,119.

Spier, C., W.T. Stringfellow, T.C. Hazen, and M. Conrad. 2013. Distribution of hydrocarbons released during the 

2010 MC252 oil spill in deep offshore waters. Environmental Pollution 173: 224-230.

State of Louisiana Department of Wildlife and Fisheries. 2013. Species by parish list. Website accessed 

11 April 2014 at: http://www.wlf.louisiana.gov/wildlife/species-parishlist?order=field_com_name_value&sort=asc&tid=All&type_1=All.

Sulak, K.J. and J.P. Clugston. 1998. Early life history stages of Gulf sturgeon in the Suwannee River, Florida. 

Trans. Am. Fish. Soc. 127:758-771.

Todd, V. L. G., W.D. Pearse, N.C. Tregenza, P.A. Lepper, and I.B. Todd. 2009. Diel echolocation activity of harbour 

porpoises (Phocoena phocoena) around North Sea offshore gas installations. ICES J. Mar. Sci., 66: 734–745.

Tuxbury, S.M. and M. Salmon. 2005. Competitive interactions between artificial lighting and natural cues during 

seafinding by hatchling marine turtles. Biol. Conserv. 121: 311-316.

U.S. Environmental Protection Agency. 2013. The green book nonattainment areas for criteria pollutants. 

Website accessed 11 April 2014; updated 5 December 2013 at: http://www.epa.gov/air/oaqps/greenbk.

U.S. Fish and Wildlife Service (USFWS). 2001. Florida manatee recovery plan (Trichechus manatus latirostris), 

Third Revision. U.S. Fish and Wildlife Service, Southeast Region, Atlanta, GA.

U.S. Fish and Wildlife Service (USFWS). 2003. Recovery plan for the Great Lakes Piping Plover (Charadrius 

melodus). Fort Snelling, Minnesota. September 2003.

U.S. Fish and Wildlife Service (USFWS). 2007. International Recovery Plan: Whooping Crane (Grus americana), 

Third Revision. Albuquerque, New Mexico. March 2007.

U.S. Fish and Wildlife Service (USFWS). 2010a. All about piping plovers. Website accessed 25 March 2014 at:

http://www.fws.gov/plover/facts.html.

U.S. Fish and Wildlife Service (USFWS). 2010b. Beach-nesting Birds of the Gulf. Website accessed 25 March 2014 

at: http://www.fws.gov/home/dhoilspill/pdfs/DHBirdsOfTheGulf.pdf.

U.S. Fish and Wildlife Service (USFWS). 2010c. Find endangered species. Website accessed 25 March 2014 at:

http://www.fws.gov/endangered/.

U.S. Fish and Wildlife Service (USFWS). 2010d. Effects of oil on wildlife and habitat. Website accessed 

25 March 2014 at: http://www.fws.gov/home/dhoilspill/pdfs/DHJICFWSOilImpactsWildlifeFactSheet.pdf.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 77

CSA-Anadarko-FL-14-2716-01-REP-01-FIN
U.S. Fish and Wildlife Service (USFWS). 2011. FWS Deepwater Horizon Oil Spill Response. Bird Impact Data and 

Consolidated Wildlife Reports. Deepwater Horizon Bird Impact Data from the DOI-ERDC NRDA Database 

12 May 2011. Website accessed 25 March 2014 at: 

http://www.fws.gov/home/dhoilspill/pdfs/Bird%20Data%20Species%20Spreadsheet%2005122011.pdf.

U.S. Fish and Wildlife Service. 2013. Hawksbill sea turtle (Eretmochelys imbricata). Website accessed 

25 March 2014 at: http://www.fws.gov/northflorida/SeaTurtles/Turtle%20Factsheets/hawksbill-sea-turtle.htm.

U.S. Fish and Wildlife Service, Gulf States Marine Fisheries Commission, and National Marine Fisheries Service. 

1995. Gulf Sturgeon Recovery/Management Plan. 170 pp. Website accessed 25 March 2014 at: 

http://www.nmfs.noaa.gov/pr/pdfs/recovery/sturgeon_gulf.pdf.

Wakeford, A. 2001. State of Florida conservation plan for Gulf sturgeon (Acipencer oxyrinchus desotoi). Florida 

Marine Research Institute Technical Report TR-8. St. Petersburg, FL.

Waring, G.T., E. Josephson, K. Maze-Foley, and P.E. Rosel (eds.). 2013. U.S. Atlantic and Gulf of Mexico Marine 

Mammal Stock Assessments – 2012. NOAA Tech. Memo. NMFS NE 223. 419 pp.

Wei, C.-L. 2006. The bathymetric zonation and community structure of deep-sea macrobenthos in the northern 

Gulf of Mexico. M.S. thesis, Texas A&M University. Website accessed 11 April 2014 at:

http://repository.tamu.edu/handle/1969.1/4927.

White, H.K., P. Hsing, W. Cho, T.M. Shank, E.E. Cordes, A.M. Quattrini, R.K. Nelson, R. Camilli, A.W.J. Demopoulous, 

C.R. German, J.M. Brooks, H.H. Roberts, W. Shedd, C.M. Reddy, and C.R. Fisher. 2012. Impact of the 

Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico. Proc. Nat. Acad. Sci. 

109(50):20,303-20,308. Website accessed 25 March 2014 at: 

http://www.pnas.org/content/early/2012/03/23/1118029109.full.pdf+html?sid=56e8cdfe-2830-43f8-9d08-

8eca0efd27e2.

Whooping Crane Eastern Partnership. 2013. Whopping Crane Numbers 2002 thru 2013. Website accessed 

25 March 2014 at: http://www.bringbackthecranes.org/technicaldatabase/recovery/wc_nos_02to11.html.

Wiese, F.K., W.A. Montevecchi, G.K. Davoren, F. Huettmann, A.W. Diamond, and J. Linke. 2001. Seabirds at risk 

around offshore oil platforms in the north-west Atlantic. Mar. Poll. Bull. 42(12):1,285-1,290.

Wilson, J. 2003. Manatees in Louisiana. Louisiana Conservationist. July/August 2003. 7 pp. Website accessed 

25 March 2014 at: http://www.lamer.lsu.edu/pdfs/Manatees_LaConservArticle.pdf.

Witherington, B.E. 1997. The problem of photopollution for sea turtles and other nocturnal animals, pp. 303-328. 

In: J.R. Clemmons and R. Buchholz (eds.), Behavioral Approaches to Conservation in the Wild. Cambridge 

University Press, Cambridge, England.

Würsig, B., S.K. Lynn, T.A. Jefferson, and K.D. Mullin. 1998. Behaviour of cetaceans in the northern Gulf of Mexico 

relative to survey ships and aircraft. Aquat. Mamm. 24: 41-50.

Würsig, B., T.A. Jefferson, and D.J. Schmidly. 2000. The Marine Mammals of the Gulf of Mexico. Texas A&M 

University Press, College Station, TX. 232 pp.

Green Canyon Blocks 724 and 768 July 2014

Environmental Impact Analysis for Initial Exploration Plan Page 78

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