### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 110 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 111 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 112 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 113 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 114 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 115 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 116 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 117 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 118 © The Response Group 6/2011 Revision 7

### Exxon Mobil Corporation **Regional Oil Spill Response Plan – Offshore Operations**  Appendix H Worst Case Discharge Scenarios

© The Response Group 6/2011 Revision 7 

### Appendix H – 119 © The Response Group 6/2011 Revision 7Page 35 

### SECTION 10 : Environmental Monitoring Information

Monitoring Systems

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



### Incidental Takes

No incidental takes are anticipated. ExxonMobil implements the mitigation measures and monitors for incidental takes of protected species according to the following notices to lessees and operators from the Minerals Management Service:

NTL 2007- G03 “Marine Trash and Debris Awareness and Elimination”

NTL 2007-G04 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”



### Flower Garden Banks National Marine Sanctuary

The operations proposed in this REP will not be conducted within the Protective Zones of the Flower Garden Banks and
Stetson Bank.



### SECTION 11 : Lease Stipulations Information

Lease OCS- G 2144 7 is not part of a Biological Sensitive Area, known Chemosynthetic Area, or Shipping Fairway. It is not on the list of areas that the BOEM has identified as having a high probability for archeological resources.

 Stipulation 8: Protected Species This Lease Stipulation assigned to Keathley Canyon Block 919 is to reduce the potential taking of federally protected species (e.g., sea turtles, marine mammals, Gulf sturgeon and other listed species). See Sections 6 and Section 12 of this REP.

 Marine Protected Species
BOEM has issued Notice to Lessees NTL 2007- G02 “Implementation of Seismic Mitigation Measures and Protected Species Observer Program”, NTL 2007

- G04 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting” and NTL 2007

- G03 “Marine Trash and Debris Awareness and Elimination” to reference measures to minimize or avoid potential adverse impacts to protected species (sea turtles, marine mammals, gulf sturgeon, and other federally protected species). See

Sections 6 and Section 12 of this REP.Page 36 

### SECTION 12 : Environmental Mitigation Measure Information

Impacts to Marine and Coastal Environments

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



### Incidental Takes

We do not anticipate any incidental takes related to the proposed operations. ExxonMobil implements the mitigation measures and monitors for incidental takes of protected species according to the following notices to lessees and operators from the Minerals Management Service:

NTL 2007- G03 “Marine Trash and Debris Awareness and Elimination”

NTL 2007- G04 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”

Note: ROV Mitigation was placed in the approval of Plan S-7330 to take ROV surveys for the next well drilled in the field. ExxonMobil has complied with this mitigation while drilling well F (Hadrian 5) in 2011.



### SECTION 13 : Related Facilities and Operations Information

Information regarding Related Facilities and Operations Information, transportation systems, & produced liquid hydrocarbon transportation vessels are not included in this REP as such information is only necessary in the case of DOCDs.Page 37 

### SECTION 14 : Support Vessels and Aircraft Information

General

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

Duration

Crew Boats 8,000 2 Twice per week

Offshore Support Vessels 120,000 3 Twice per week

Tug Boats 100,000 2 Once per rig move

Helicopter 764 1 Once per day



### Diesel Oil Supply Vessels

Size of Fuel Supply
Vessel Capacity of Fuel

Supply Vessel Frequency of Fuel
Transfers Route Fuel Supply Vessel Will
Take

280 foot length 100,000 gals. 1 week Port Fourchon to KC 919



### Drilling Fluids Transportation

This information is only required for Eastern Gulf of Mexico.



### Solid and Liquid Wastes Transportation

See Table 7B.



### Vicinity Map

See Attached.

### Lund East Breaks Atwater Valley Garden Banks

Keathley Canyon Alaminos Canyon Henderson Mississippi Canyon

Lloyd Ridge Destin Dome

De Soto Canyon

Lund South Amery Terrace Florida Plain Mobile

Figure 14 

# Vicinity Map - Block Keathley Canyon 919

Fourchon Range: 237mi

Bearing 27 Nearest Shoreline

Range: 21 6 mi

Bearing 1 9Page 38 

### SECTION 15 : Onshore Support Facilities Information

General

Name Location Existing/New/Modified

Fourchon Port Fourchon, LA Existing

The proposed surface disturbances in Keathley Canyon Block 919 for this Plan will be located approximately 216 miles from the nearest Louisiana shoreline, and approximately 237 miles from the onshore support base. ExxonMobil will use the Port Fourchon existing dock as support base. The Fouchon facility is located on Bayou Lafourche, south of Leesville, LA approximately 3 miles from the Gulf of Mexico.



### Support Base Construction or Expansion

This Section does not apply to this EP as ExxonMobil does not plan to construct a new onshore support base or expand an existing one to accommodate the activities proposed in this EP.



### Support Base Construction or Expansion Timetable

This Section does not apply to this EP as ExxonMobil does not plan to construct a new onshore support base or expand an existing one to accommodate the activities proposed in this EP.



### Waste Disposal

See Tables 7A and 7B.



### Air emissions

Not required by BOEMRE GOM.



### Unusual solid and liquid wastes

Not required by BOEMRE GOM.Page 39 

### SECTION 16 : Sul ph ur Operations Information

Information regarding Sul ph ur Operations is not included in this REP as such information is only necessary in the case of

DOCDs.Page 39 

### SECTION 17 : Coastal Zone Management Act (CZMA) Information

LOUISIANA

COASTAL ZONE MANAGEMENT

CONSISTENCY CERTIFICATION

Revised EXPLORATION PLAN Type of Plan

KEATHLEY CANYON BLOCK 919 (OCS-G 21447)

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

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

EXXON MOBIL CORPORATION

Operator

_____________________________________________

Bryan L. Chapman Certifying Official

08 / 29 /201 1 DatePage 40 

### SECTION 17 : Coastal Zone Management Act (CZMA) Information

LOUISIANA

COASTAL ZONE MANAGEMENT

CONSISTENCY CERTIFICATION

Revised EXPLORATION PLAN Type of Plan

KEATHLEY CANYON BLOCK 919 (OCS-G 21447)

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

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

EXXON MOBIL CORPORATION

Operator

_____________________________________________

Bryan L. Chapman Certifying Official

08 / 29 /201 1 DatePage 41 

### Section 18 - Environmental Impact Analysis (EIA)

A. Impact-Producing Factors

This Environmental Impact Analysis (EIA) evaluates the potential impacts of exploratory drilling in Keathley Canyon (KC) Block 919. The activities proposed in this Plan will be a DP semi-submersible (rig).

Water depths in KC 919 range from about 6,900 to 7,400 ft. The lease is approximately 216 statute miles from the nearest shoreline (Louisiana). The air onshore support base for helicopters will be located in Port Fourchon, Louisiana, and the marine onshore support base for the work and crew boats will be the C-Port base in Port Fourchon, Louisiana. No new facilities or workers will be needed for the proposed activities. Helicopters and boats will move supplies and personnel between the offshore and onshore locations. Helicopters will make approximately 30 round trips per month. Work boats will make approximately 15 round trips per month, and crew boats will make approximately 5 round trips per month. Helicopters and boats will normally take the most direct route, traffic and weather conditions permitting.

Table 1 is a matrix of impact-producing factors (IPFs) and potentially affected environmental resources. The table is based on the matrix provided by the Minerals Management Se rvice (MMS). An “X” in a table cell indicates that an IPF could affect a certain resource, and a dash (

-- ) indicates no impact or negligible impact. Where there may be an effect, an analysis is provided in EIA Section B . For those cells that are footnoted, a statement has been provided after the table as to the applicability of the proposed operations.

The following IPFs applicable to the proposed activity have been identified:

 Rig presence, noise, and lights;

 Air pollutant emissions (from rig, support vessels, and helicopters);

 Effluent discharges (drilling fluids and cuttings, sanitary and domestic wastes, deck drainage, etc.);

 Marine debris;

 Support vessel and helicopter traffic; and

 Accidents (oil spills).

Physical disturbance to the seafloor was determined not to be a relevant IPF for the proposed action because a DP semi will be used, with no anchoring or rig emplacement on the seafloor. This IPF was included in the matrix, but all of the entries in the column indicate no impact.Page 42 

### Table 1 . Matrix of impact-producing factors and environmental resources.

Environmental Resources Impact

- Producing Factors

Rig Presence, Noise, and Lights Air

Pollutant
Emissions (rig, support vessels, and helicopters) Effluent Discharges

(drilling fluids and cuttings, sanitary and domestic wastes, deck drainage, etc.) Physical Disturbances to the Seafloor a Marine

Debris Support

Vessel and Helicopter
Traffic Accidents

(oil spills)

Site

- specific at Offshore Location Designated topographic features

-- -- -- (1)

-- (1)

-- -- -- (1)

Pinnacle trend area live bottoms

-- -- -- (2)

-- (2)

-- -- -- (2)

Eastern Gulf live bottoms

-- -- -- (3)

-- (3)

-- -- -- (3) Chemosynthetic communities

-- -- -- -- (4)

-- -- -- Water quality

-- -- X

-- -- -- X
Fisheries X

-- -- -- -- -- X
Marine mammals X(8)

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

Sea turtles X(8)

-- -- -- X X X(8) Air quality

-- X(9)

-- -- -- -- X Shipwreck sites (known/potential)

-- -- -- -- (7)

-- -- -- Prehistoric archaeological sites

-- -- -- -- (7)

-- -- -- Vicinity of Offshore Location

Essential fish habitat X

-- X

-- -- -- X(6) Marine and pelagic birds X

-- -- -- X

-- X Public health and safety

-- -- -- - - -- -- -- (5)

Coastal and Onshore
Beaches

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

Wetlands

-- -- -- -- -- -- -- (6) Shore birds and coastal nesting birds

-- -- -- -- -- X

-- (6) Coastal wildlife refuges

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

Wilderness areas

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

Other Resources

Non

- chemosynthetic benthic communities

-- -- X

-- -- -- X Pelagic communities X

-- X

-- -- -- X

a This column is included for completeness; however, because a DP semi-submersible (rig) will be used, there will be no anchoring. Table Footnotes and Applicability:

(1) Activities that may affect a marine sanctuary or topographic feature. Specifically, if the well or platform site or any anchors will be on the seafloor within the: (a) 4-mile zone of the Flower Garden Banks, or the 3-mile zone of Stetson Bank; (b) 1000 -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.

– This footnote does not apply because the lease is not within or near any marine sanctuary, topographic feature, or no-activity zone. There are no submarine banks in the lease. There will be no anchoring in the lease.

(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.Page 43 (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.

(4) Activities on blocks designated by the MMS as being in water depths 400 m or greater.

– The lease is in water depths greater than 400 m, but the chemosynthetic community review indicates that there are no areas that could support high-density chemosynthetic communities within 1,500 ft of the proposed surface locations. There will be no anchoring.

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

– This footnote is not applicable to the proposed activities because H 2 S concentrations greater than 500 ppm are not expected to be encountered.

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

– Accidental spills could affect the resources marked (X) in the matrix, and impacts are analyzed in EIA Section B . Due to spill response measures, weathering, and the distance from shore, impacts on coastal resources and biota are highly unlikely.

(7) All activities that involve seafloor disturbances, including anchor emplacements, in any OCS block designated by the MMS 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.

– The lease is not on the BOEMRE list of blocks determined to have a high probability of archaeological resources. Moreover, there will be no anchoring. Therefore, no impacts on historic or prehistoric sites are expected.

(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 endangered or threatened marine mammals, sea turtles, or their critical habitats include rig presence, noise, and lights; marine debris; support vessel and helicopter traffic; and accidents. Impacts are analyzed in EIA Section B

.

(9) Production activities that involve transportation of produced fluids to shore using shuttle tankers or barges.

– This footnote is not applicable. The proposed activity does not involve transportation of produced fluids using shuttle tankers or barges.Page 44



### B. Analysis

B.1 Site-Specific at Offshore Location

B.1 .1 Designated Topographic Features

There are no IPFs that could cause impacts to designated topographic features. The block is not within or near a BOEMRE-designated topographic feature or no-activity zone. The nearest designated topographic feature is over 100 miles away.

An oil spill is unlikely to occur during the proposed activities. Because of spill response measures described in the ExxonMobil Corporation Gulf of Mexico Regional Oil Spill Response Plan (OSRP) as well as natural weathering processes, significant quantities of oil would be unlikely to reach the vicinity of any topographic feature. Since the crests of designated topographic features in the northern Gulf are at least 10 m below the sea surface, concentrated oil would not be expected to reach their sessile biota. No impacts would be expected.



### B.1.2 Pinnacle Trend Area Live Bottoms

There are no IPFs that could cause impacts to pinnacle trend live bottoms. The Live Bottom (Pinnacle Trend) Stipulation does not apply to the lease. The pinnacle trend is located along the shelf edge offshore of the Mississippi River delta, several hundred miles from the lease area.

An oil spill is unlikely to occur during the proposed activities. Because of spill response measures described in the Regional OSRP as well as natural weathering processes, significant quantities of oil would be unlikely to reach the vicinity of the pinnacle trend area. Further, since the crests of pinnacle features are more than 50 m below the sea surface, concentrated oil would not be expected to reach their sessile biota. No impacts would be expected.



### B.1.3 Eastern Gulf Live Bottoms

There are no IPFs that could cause impacts to low-relief Eastern Gulf live bottoms. The nearest Eastern Gulf live bottom areas as defined by MMS stipulation (Eastern Planning Area leases in water depths of 100 m or less) are several hundred miles from the project area.

An oil spill is unlikely to occur during the proposed activities. Because of spill response measures described in the Regional OSRP as well as natural weathering processes, significant quantities of oil would be unlikely to reach the vicinity of Eastern Gulf live bottom areas. Further, since these are low-relief features on the seafloor, concentrated oil would not be expected to reach these communities. No impacts would be expected.



### B.1.4 Chemosynthetic Communities

The chemosynthetic community review indicates that there are no areas that could support high-density chemosynthetic communities within 457 m (1,500 ft) of the proposed surface locations. There will be no anchoring and there are no IPFs likely to cause impacts to chemosynthetic communities. It is possible that undiscovered chemosynthetic communities exist in nearby lease blocks. However, a subsurface spill (e.g., a blowout) would be unlikely to affect benthic communities beyond a few hundred meters from the wellsite. Therefore, no impacts on chemosynthetic communities would be expected.



### B.1.5 Water Quality

IPFs potentially affecting water quality include:

 Effluent discharges; and

 Accidents (oil spills).A-IMPACT-PRODUCING FACTORSPage 45 Effluent Discharges . Effluents to be discharged will include water-based drilling fluids and associated cuttings; cuttings with adhering synthetic drilling fluids; sanitary and domestic wastes; deck drainage;
de salinization unit brine, and uncontaminated bilge and ballast water. Since all routine discharges from the rig will be made in accordance with the general National Pollutant Discharge Elimination System (NPDES) permit issued by the U.S. Environmental Protection Agency (USEPA), they are not expected to cause significant impacts to water quality. Discharges of sanitary and domestic wastes from support vessels will be in accordance with U.S. Coast Guard (USCG) regulations and also would not cause significant impacts on water quality.

Accidents (oil spills) . It is unlikely that an oil spill would occur from the proposed activities. If a spill were to occur, marine water quality would be temporarily affected by the dissolved components and small oil droplets. Spill response measures detailed in the Regional OSRP as well as natural weathering processes would remove the oil from the water column and dilute the constituents to background levels.



### B.1.6 Fisheries

The main commercial fishing activity in deepwaters of the northern Gulf of Mexico is pelagic longlining for tuna, swordfish, and other billfishes (Continental Shelf Associates, Inc., 2002). While most recreational fishing activity occurs in depths less than about 200 m, deepwater petroleum platforms attract considerable recreational fishing activity offshore of Louisiana and Texas.

IPFs potentially affecting fisheries include:

 Rig presence, noise, and lights; and

 Accidents (oil spills).

Rig Presence, Noise, and Lights . Rig presence is the only routine IPF that may have an impact on commercial fishing. There is a slight possibility of pelagic longlines becoming entangled in the rig; however, longline fishers use radar and generally are aware of offshore structures when placing their sets. Therefore, little or no impact on pelagic longlining is expected. Other routine 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.

Accidents (oil spills) . In the event of a large oil spill, fishing activities near the project area could be temporarily disrupted. The area affected would be relatively small, and the duration presumably would be a few days. Due to spill response measures and natural weathering processes, little or no disruption of fishing activities in coastal waters would be expected.



### B.1.7 Marine Mammals

The only endangered marine mammal likely to be present near the project area is the sperm whale (Davis et al., 2000). Five endangered baleen whales (northern right whale, blue whale, fin whale, sei whale, and humpback whale) have been reported from the northern Gulf but are either extralimital or uncommon (Jefferson and Schiro, 1997) and are not discussed further. Another endangered marine mammal, the West Indian manatee, is a coastal species that does not occur in or near the project area, although manatees occasionally occur in Louisiana and Texas coastal waters during summer months. The most common nonendangered cetaceans in the deepwater environment are odontocetes such as pantropical spotted dolphin, spinner dolphin, and clymene dolphin. Other odontocetes that may be present include dwarf and pygmy sperm whales, four species of beaked whales, and 14 species of dolphins and porpoises (Jefferson and Schiro, 1997).

IPFs potentially affecting marine mammals include:

 Rig presence, noise, and lights;

 Marine debris;

 Support vessel and helicopter traffic; and

 Accidents (oil spills).

Other factors such as effluent discharges are likely to have negligible impacts on marine mammals due to rapid dispersion, the small area of ocean affected, and the intermittent nature of the discharges.

Rig Presence, Noise, and Lights . The behavior of marine mammals could be affected by noise and light emitted from the rig, as well as the presence of fish populations associated with the rig. Drilling-related noise is of relatively low frequency (Richardson et al., 1995). The sperm whale appears to have good low frequencyPage 46

hearing, but the available data do not indicate a consistent response to anthropogenic noise (National Marine Fisheries Service [NMFS], 2001). The other marine mammals commonly seen in deepwater are odontocetes, which have their best hearing in high frequencies and are less likely to be disturbed by low frequency noise. Little is known of the effects of offshore structures and activities on marine mammals, but in any case, such effects would likely consist of short-term behavioral changes and would not be expected to harm the animals.

Marine Debris . Ingestion of, or entanglement with, accidentally discarded debris can kill or injure marine mammals. The disposal of solid waste from drilling rigs and vessels is prohibited by the MMS and the USCG under MARPOL regulations. In addition, MMS has issued Notice to Lessees (NTL) 2003-G11, which instructs operators to exercise caution in the handling and disposal of small items and packaging materials, requires posting of placards at prominent locations on offshore vessels and structures, and requires a marine trash and debris awareness training and certification process. Compliance with this NTL and any related MMS requirements is assumed to be effective in minimizing the potential for debris-related impacts on marine
mammals.

Support Vessel and Helicopter Traffic . Vessel and helicopter traffic may startle or disturb marine mammals. Reactions may range from apparent indifference to evasive moves (e.g., turns, diving, etc.) (Ric hardson et al., 1995). Many of the reactions of marine mammals to vessel traffic appear to be primarily a result of noise, though there may be visual or other cues as well.

There is a small risk of a supply or crew boat striking a sperm whale. To reduce the potential for vessel strikes, the MMS has issued NTL 2003-G10, which recommends protected species identification training, specifies ways for vessel operators and crews to avoid vessel strikes, and requires operators to report sightings of any injured or dead protected species. Compliance with this NTL and any related MMS requirements is assumed to be effective in minimizing the likelihood of vessel strikes.

Accidents (oil spills) . The sperm whale is the only endangered marine mammal likely to come into contact with an oil spill at the project area. Sperm whales are widely distributed in the Gulf of Mexico, but concentrations occur in the Mississippi Canyon area south of the Mississippi River Delta (Davis et al., 2000). Common nonendangered cetaceans in the deepwater environment, such as pantropical spotted dolphin, spinner dolphin, and clymene dolphin, also could come into contact with spilled oil. However, the total area of a slick would be small relative to the available deepwater habitat. Oil exposure would not persist in the open ocean, and the animals could avoid oiled areas. Although individual marine mammals may be affected if exposed to oil, no significant population-level impacts on any marine mammal species would be expected.

The West Indian manatee occasionally occurs in Louisiana, Texas, and other northern Gulf states during summer months. It is assumed that natural weathering processes and spill response measures as detailed in the Regional OSRP would remove most or all of the spilled oil before it could contact manatee habitats. The historical spill data and trajectory/risk calculations referenced in a recent Environmental Impact Statement (EIS) (MMS, 2002) indicate there is little risk of contact or impact to the coastline or associated environmental resources. Therefore, no significant impacts on manatees are expected.



### B.1.8 Sea Turtles

Five species of endangered or threatened sea turtles may be found near the project area. Endangered species are the leatherback, Kemp's ridley, and hawksbill sea turtles. The loggerhead sea turtle is a threatened species. The green sea turtle is listed as threatened, except for the Florida breeding population, which is listed as endangered. Leatherbacks and loggerheads are the most likely turtles to be present as adults near the project area. Green, hawksbill, and Kemp’s ridley turtles are typically inshore species that are unlikely to occur near the project area as adults. Hatchlings or juveniles of any of the sea turtles may be present in deepwater areas, where they may be associated with sargassum and other flotsam.

Loggerhead turtles nest in significant numbers along the Florida Panhandle and to a limited extent in other northern Gulf coast states. Green turtles infrequently nest on Florida Panhandle and Alabama beaches. Very few leatherback nests have been documented along the northern Gulf coast (e.g., Florida Panhandle). Kemp’s ridley turtles nest mainly near Rancho Nuevo in northeastern Mexico and also in South Texas (Padre and Mustang Islands). Hawksbill turtles do not nest anywhere near the project area. Due to the distance from shore, nesting beaches are highly unlikely to be affected by the project.Page 47 IPFs potentially affecting sea turtles include:

 Rig presence, noise, and light s;

 Marine debris;

 Support vessel and helicopter traffic; and

 Accidents (oil spills).

Other factors such as 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.

Rig Presence, Noise, and Lights . Little is known of how turtles may respond to noise from offshore drilling activities. Helicopters and service vessels also may affect sea turtles due to machinery noise and/or visual disturbances. The most likely impacts would be short-term behavioral changes such as diving and evasive swimming, disruption of activities, or departure from the area.

Turtle hatchlings may be attracted to brightly lit offshore platforms, where they may be subject to increased predation by birds and fishes that are also attracted to offshore structures. However, NMFS (2001) states that attraction to offshore platforms is unlikely to appreciably reduce the reproduction, numbers, or
distribution of sea turtles in the wild.

Marine Debris . Ingestion of, or entanglement with, accidentally discarded solid debris can kill or injure sea turtles (Lutcavage et al., 1997). Some adult sea turtles such as loggerheads and leatherbacks may ingest plastic debris. The disposal of solid waste from drilling rigs and vessels is prohibited. Also, MMS has issued NTL

2003 -G11, which instructs operators to exercise caution in the handling and disposal of small items and packaging materials, requires posting of placards at prominent locations on offshore vessels and structures, and requires a marine trash and debris awareness training and certification process. Compliance with this NTL and any related MMS requirements is assumed to be effective in minimizing the potential for debris-related impacts
on sea turtles.

Support Vessel and Helicopter Traffic . There is a chance of collision between service vessels and sea turtles. While adult 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 or during nighttime or periods of inclement weather. To reduce the potential for vessel strikes, the MMS has issued NTL 2003-G10, which recommends protected species identification training, specifies ways for vessel operators and crews to avoid vessel strikes, and requires operators to report sightings of any injured or dead protected species. Compliance with this NTL and any related MMS requirements is assumed to be effective in minimizing the likelihood of striking sea
turtles.

Accidents (oil spills) . Sea turtles could be affected by an oil spill in offshore waters. Leatherbacks and loggerheads are the most common adult turtles in offshore waters and the most likely to be affected. They are regularly sighted within deepwater areas. In addition, juvenile turtles of any species may be found within convergence zones in deepwater areas. While some turtles may come into contact with spilled oil, the total area affected would be small relative to the available deepwater habitat, and the viability of sea turtle populations as a whole would not likely be threatened.

It is assumed that most or all of the spill volume would be removed due to weathering and spill response measures prior to reaching turtle nesting beaches. The historical spill data and trajectory/risk calculations referenced in a recent EIS (MMS, 2002) indicate there is little risk of contact or impact to the coastline or associated environmental resources. Therefore, no significant impacts on turtle nesting beaches would be expected.



### B.1.9 Air Quality

There are no site-specific air quality data for the project area. The attainment status of Federal OCS waters is unclassified due to the lack of representative air quality data. Due to the distance from shore-based pollution sources, offshore air quality is expected to be good.

IPFs potentially affecting air quality include:

 Air pollutant emissions; and

 Accidents.Page 48 Air Pollutant Emissions . Routine offshore air pollutant emissions will result from rig operations and from helicopters and service vessels. These emissions occur mainly from combustion or burning of fuels and natural gas and from venting or evaporation of hydrocarbons. The combustion of fuels occurs primarily on diesel-powered generators, pumps, or motors and from lighter fuel motors. Air pollutants associated with OCS activities are nitrogen oxides, carbon monoxide, sulfur oxides, volatile organic compounds, and suspended particulate matter.

Due to the distance from shore, routine operations in the project area will have no impact on air quality conditions along the coast. Based on the air quality screening in EP Appendix G , no detailed analysis of emissions is required by MMS.

Accidents (oil spills) . An oil spill would affect air quality in the vicinity of the oil slick by introducing volatile organic compounds through evaporation. The emissions would not last long due to rapid volatilization of hydrocarbons. Evaporation is greatest within the first 24 hours. The extent and persistence of impacts would depend on the meteorological and oceanographic conditions at the time. Little or no impact on air quality in coastal areas would be expected.



### B.1.10 Shipwreck Sites (known or potential)

There are no IPFs that are likely to cause impacts to shipwreck sites. There will be no anchoring around the wellsites, and the lease is not on the MMS list of blocks determined to have a high probability of archaeological resources. Therefore, no impacts on shipwreck sites are expected. Further, due to natural weathering processes and spill response measures as detailed in the Regional OSRP, it is highly unlikely that significant quantities of oil from a spill in the project area would reach coastal areas and contaminate shipwreck sites.



### B.1.11 Prehistoric Archaeological Sites

There are no IPFs that are likely to cause impacts to prehistoric archaeological sites. There will be no anchoring around the wellsites, and the lease is not on the MMS list of blocks determined to have a high probability of archaeological resources. Therefore, no impacts on prehistoric archaeological resources are expected. Further, due to natural weathering processes and spill response measures as detailed in the Regional OSRP, it is highly unlikely that significant quantities of oil from a spill in the project area would reach coastal areas and contaminate prehistoric sites.



### B.2 Vicinity of

Offshore Location

B.2.1 Essential Fish Habitat

The Gulf of Mexico Fishery Management Council (GMFMC) has prepared fishery management plans (FMPs) identifying EFH for corals and coral reefs, shrimp, stone crab, spiny lobster, reef fishes, coastal pelagic fishes, and red drum, none of which occur in waters overlying the lease area.

Another group of exploited species, the highly migratory pelagic fishes, are managed by NMFS. NMFS (1999) defined EFH for managed highly migratory species, which include 10 shark, 3 tuna, and single swordfish species of concern. These species may occur as transients in the project area. EFH includes most of the substrate and water column of the Gulf of Mexico where the managed species commonly occur. Although billfishes are now managed as highly migratory species, there were no EFH designations given in NMFS (1999).

Sp atially limited EFH called habitat areas of particular concern (HAPC) have been identified in the Gulf of Mexico by the GMFMC. These include the Flower Garden Banks National Marine Sanctuary, Florida Middle Grounds, Florida Keys National Marine Sanctuary, and Dry Tortugas (Fort Jefferson National Monument). The nearest of these, the Flower Garden Banks, is about 80 miles from the lease area.

IPFs potentially affecting EFH include:

 Rig presence, noise, and lights;

 Effluent discharges; and

 Accidents (oil spills).Page 49 Rig Presence, Noise, and Lights . The rig will attract fishes, particularly epipelagic fishes such as tunas, dolphin, billfishes, and jacks (e.g., Holland et al., 1990; Higashi, 1994). This effect could enhance feeding of epipelagic predators by attracting and concentrating smaller fish species. Because the rig is a single, temporary structure, impacts on EFH, whether beneficial or adverse, are considered minor.

Effluent Discharges . Discharges of water-based drilling fluids and associated cuttings will produce temporary, localized increases in suspended solids in the water column around the rig. Turbid water will persist for minutes to a few hours during and after each discharge and will have a negligible impact on EFH. Other effluent discharges such as sanitary and domestic wastes, deck drainage, desalinization unit brine, and uncontaminated bilge and ballast water will have negligible impacts on ambient water quality. No significant impacts on EFH are expected from these discharges.

Accidents (oil spills) . An oil spill in offshore waters would produce a slick and temporarily increase hydrocarbon concentrations. Given that EFH includes most of the substrate and water column of the Gulf of Mexico where highly migratory managed species commonly occur, some impact on EFH would be unavoidable. However, the area affected would be a small percentage of the EFH in the Gulf of Mexico, and the duration would be brief (few hours to a few days).

A large spill could affect biota including phytoplankton, zooplankton, and nekton. Eggs and larvae of fishes will die if exposed to certain toxic fractions of spilled oil. Most of the fishes inhabiting shelf or oceanic waters of the Gulf of Mexico have planktonic eggs and larvae. However, due to the wide dispersal of early life history stages of fishes in the surface waters of the Gulf of Mexico, an oil spill is not expected to have significant impacts at the population level.



### B.2.2 Marine and Pelagic Birds

A variety of seabirds such as terns, storm-petrels, shearwaters, and jaegers occur in the deepwater environment (Peake, 1996; Hess and Ribic, 2000). Powers (1987) indicates that seabird densities over the open ocean typically are <10 birds/km 2 . Seabirds spend much of their lives offshore over the open ocean, except during breeding season when they nest along the coast. Other birds such as waterfowl, marsh birds, and shore birds may occasionally be present over open ocean areas, but no endangered or threatened birds are likely to occur at the project area due to the distance from shore. EIA Section B.3.3 discusses Shore Birds and Coastal Nesting Birds.

IPFs potentially affecting marine and pelagic birds include:

 Rig presence, noise, and lights;

 Marine debris; and

 Accidents.

Other factors such as effluent discharges are likely to have negligible impacts on marine birds due to rapid dispersion, the small area of ocean affected, and the intermittent nature of the discharges.

Rig Presence, Noise, and Lights . Pelagic seabirds and trans-Gulf migrant birds may be present at the project area. Birds may use offshore drilling rigs and platforms for resting, feeding, or as temporary shelter from inclement weather (Russell, 2001). Some birds may be attracted to offshore structures because of the lights and the fish populations that aggregate around these structures. Birds that frequent platforms may be exposed to contaminants including air pollutants and routine discharges, but significant impacts are unlikely due to rapid dispersion of effluents. Birds migrating over water at night have been known to strike offshore structures, resulting in death or injury (Russell, 2001; Wiese et al., 2001).

Marine Debris . Debris lost overboard from offshore operations can injure or kill birds that ingest or become entangled in it. MMS regulations and Federal law prohibit disposal of trash and debris in the ocean. In addition, MMS has issued NTL 2003-G11, which instructs operators to exercise caution in the handling and disposal of small items and packaging materials, requires posting of placards at prominent locations on offshore vessels and structures, and requires a marine trash and debris awareness training and certification process. Compliance with this NTL and any related MMS requirements is assumed to be effective in minimizing the potential for debris-related impacts on birds.

Accidents (oil spills) . Pelagic seabirds could be exposed to oil from a spill at the project area. Presumably, birds such as terns, storm-petrels, shearwaters, and jaegers would be the most likely to be present, but in lowPage 50

densities. Due to these low densities and the relatively small percentage of deepwater habitat that would be affected by a spill, total numbers of birds affected would be small, and no significant population-level impacts on any bird species would be expected.



### B.2.3 Public Health and Safety

There are no IPFs associated with routine operations that are expected to affect public health and safety.

In the event of a major spill, the main safety and health concerns are those of the offshore personnel responding to the spill. The proposed activities will be covered by the Regional OSRP, and in addition, the rig maintains a Shipboard Oil Pollution Emergency Plan as required under MARPOL. Based on the spill volumes,

we athering rates, and response measures as detailed in the Regional OSRP, it is expected that most or all of the spilled oil would be removed before reaching coastal waters or shorelines. Therefore, no impacts on public health and safety would be expected.



### B.3 Coastal and Onshore

Coastal habitats in the northeastern Gulf of Mexico that may be affected by oil and gas activities are described in a recent Gulf EIS (MMS, 2002). Sensitive coastal habitats are also tabulated in the Regional OSRP. Coastal habitats inshore of the project area include barrier beaches and dunes, wetlands, and submerged seagrass beds. Generally, most of the northern Gulf is fringed by barrier beaches, with wetlands and/or submerged seagrass beds occurring in sheltered areas behind the barrier islands and in estuaries.



### B.3.1 Beaches

There are no IPFs associated with routine activities that could affect beaches due to the distance from
shore.

Accidents (oil spills) . A large oil spill is unlikely, and it is assumed that most or all of the spill volume would be removed due to weathering and spill response measures, as detailed in the Regional OSRP, before reaching the coast. The historical spill data and trajectory/risk calculations referenced in a recent EIS (MMS, 2002) indicate there is little risk of contact or impact to the coastline or associated environmental resources. Therefore, no significant impacts on beaches are expected.



### B.3.2 Wetlands

Coastal wetlands are unlikely to be affected by any routine IPF due to the distance from shore. Support operations including crew boats and supply boats may have a minor incremental impact on coastal wetlands. Over time with a large number of vessel trips, vessel wakes can erode shorelines along inlets, channels, and harbors. Impacts are assumed to be minimized by following the speed and wake restrictions in harbors and
channels.

Accidents (oil spills) . A large oil spill is unlikely, and it is assumed that most or all of the spill volume would be removed due to weathering and spill response measures, as detailed in the Regional OSRP, before reaching the coast. The historical spill data and trajectory/risk calculations referenced in a recent EIS (MMS, 2002) indicate there is little risk of contact or impact to the coastline or associated environmental resources. Therefore, no significant impacts on wetlands are expected.



### B.3.3 Shore Birds and Coastal Nesting Birds

Bird species of concern in inshore waters or onshore areas include the bald eagle, brown pelican, piping plover, and western snowy plover. Various species of nonendangered birds are also found along the northern Gulf coast, including diving birds, shore birds, marsh birds, wading birds, and waterfowl (MMS, 2002).

IPFs potentially affecting shore birds and coastal nesting birds include:

 Support vessel and helicopter traffic; and

 Accidents (oil spills).Page 51 Support Vessel and Helicopter Traffic . Due to the distance from shore, the only routine IPF that may affect shore birds and coastal nesting birds is support operations. Support vessels and helicopters will transit coastal areas in Louisiana where shore birds and nesting birds may be found. Helicopter and vessel traffic could periodically disturb individuals or groups of birds within sensitive coastal habitats (e.g., wetlands that may support feeding, resting, or breeding birds). However, existing mitigation measures requiring aircraft to maintain minimum altitudes over sensitive habitats such as wildlife refuges and park properties would minimize any potential impacts. Similarly, vessel operators are required to use designated navigation channels and comply with posted speed and wake restrictions while transiting sensitive inland waterways. With these measures in effect, it is likely that individual birds would experience at most only short-term, behavioral disruption.

Accidents (oil spills) . Coastal bird species could be affected if a large oil spill reached coastal waters and shorelines. Brown pelicans typically do not venture offshore of the inner continental shelf. Piping plovers or western snowy plovers could encounter the spill only if it reached coastal habitats. A spill would not be expected to contact or otherwise impact bald eagles unless contamination and subsequent cleanup activities occurred near eagle nesting or roosting sites. However, it is assumed that most or all of the spill volume would be removed due to weathering and response measures, as detailed in the Regional OSRP, prior to reaching coastal waters. The historical spill data and trajectory/risk calculations referenced in a recent EIS (MMS, 2002) indicate there is little risk of contact or impact to the coastline or associated environmental resources. Therefore, no significant impacts on shore birds or coastal nesting birds are expected.



### B.3.4 Co astal Wildlife Refuges

Coastal national wildlife refuges (NWRs) include Breton, Delta, and Shell Keys in Louisiana and Anahuac, Aransas, Big Boggy, Brazoria, McFaddin, San Bernard, Texas Point in Texas. In addition, there are various state wildlife management areas and private refuges in coastal areas.

Due to the distance from shore, there are no IPFs associated with routine activities that are likely to affect coastal wildlife refuges.

Accidents (oil spills) . A large spill is unlikely, and it is assumed that most or all of the spill volume would be removed due to weathering and spill response measures, as detailed in the Regional OSRP, before reaching the coast. The historical spill data and trajectory/risk calculations referenced in a recent EIS (MMS, 2002) indicate there is little risk of contact or impact to the coastline or associated environmental resources. Therefore, no significant impacts on coastal wildlife refuges are expected.



### B.3.5 Wilderness Areas

There are no IPFs associated with routine activities that are likely to affect wilderness areas in Louisiana, Texas, or other coastal states.

Accidents (oil spills) . A large spill is unlikely, and it is assumed that most or all of the spill volume would be removed due to weathering and spill response measures, as detailed in the Regional OSRP, before reaching the coast. The historical spill data and trajectory/risk calculations referenced in a recent EIS (MMS, 2002) indicate there is little risk of contact or impact to the coastline or associated environmental resources. Therefore, no significant impacts on coastal wilderness areas are expected.



### B.4 Other resources

B.4.1 Non -Chemosynthetic Benthic Communities

Benthic communities in the project area are expected to consist of soft bottom infauna and epifauna. No chemosynthetic communities are expected in the lease area (see Section B.1.4 ). Drilling activities and anchoring will affect a small area of seafloor around the wellsite. Disturbed bottom sediments will be recolonized through larval settlement and migration from adjacent areas. Because some deepsea biota grow and reproduce slowly, recovery may require several years.

Water depths are approximately 2,226 m (7,304 ft) at the surface location for KC 919 -1 and KC 919 -2, and approximately 2,219 m (7,279 ft) at the surface location for KC 919 -3. Therefore, the wellsites fall within thePage 52

Upper Abyssal Zone (1,650 to 2,250 m) defined by Gallaway (1988). Macroinfaunal densities for this depth are likely to be about 3,000 individuals/m 2 (Rowe and Kennicutt, 2002). There are no individual dominant species in the deepsea macroinfauna, but polychaetes are the most abundant and diverse group (Pequegnat et al., 1990). Meiofauna and microbiota are also important components of the deepsea benthos. Rowe (2000) indicates that little information is available on either group for the deep Gulf. A deep Gulf of Mexico benthos program is now underway that expands upon the depth range and geographic coverage of the previous MMS continental slope study (Rowe and Kennicutt, 2002).

Under NTL 2003-G03, the MMS requires remotely operated vehicle (ROV) surveys in deepwater blocks in the Central and Western Planning Areas. If required by the MMS, an ROV survey will be conducted as specified under this NTL. ROV surveys provide information about the extent of drilling-related impacts on deepwater
benthic communities.

The IPFs potentially affecting benthic communities are

 Effluent discharges; and

 Accidents (seafloor blowout).

Effluent Discharges . Cuttings associated with both water-based and synthetic drilling fluids will be discharged from the rig. All discharges will be in accordance with the NPDES general permit. Cuttings from synthetic drilling fluid systems tend to clump together and form cuttings piles close to the discharge point (Neff et al., 2000). Where these cuttings accumulate in concentrations of about 1,000 mg/kg or higher, benthic infaunal communities may be adversely affected (Neff et al., 2000). Some benthic organisms will be buried or smothered by cuttings accumulations. Infaunal numbers may increase, and diversity may decrease as opportunistic species that tolerate low oxygen and high H 2 S predominate. Neff et al. (2000) estimated the area affected around a drilling rig on the Gulf of Mexico continental slope to be about 1 hectare (10,000 m 2 ), or about 0.04 percent of a lease block. As the base synthetic fluid is decomposed by microbes, the area will gradually return to pre-drilling conditions. Disturbed soft bottom sediments will be recolonized through larval settlement and migration from adjacent areas.

Accidents (seafloor blowout) . A seafloor blowout resulting in an oil spill could affect benthic communities within a few hundred meters of the wellsite. While some oil could initially adhere to surface sediments surrounding the wellsite, resulting in smothering and/or toxicity to benthic organisms, most of the oil is assumed to rise rapidly through the water column. The physical impacts of a seafloor blowout are also a
consideration. The MMS (2002) estimates that a seafloor blowout could resuspend and disperse sediments within a 300-m radius. While coarse sediments (sands) would probably settle at a rapid rate near the blowout site, fine sediments (silts and clays) could be resuspended for more than 30 days and dispersed over a much wider area. Surface sediments at the project area are assumed to be largely silt and clay. The affected area would be recolonized by benthic organisms over a period of months to years.



### B.4.2 Pelagic Communities

IPFs potentially affecting pelagic communities include:

 Rig presence, noise, and lights;

 Effluent discharges; and

 Accidents (oil spills).

Rig Presence, Noise, and Lights . The rig will attract epipelagic fishes such as tunas, dolphin, billfishes, and jacks (e.g., Holland et al., 1990; Higashi, 1994). This effect might enhance feeding of epipelagic predators by attracting and concentrating smaller fish species. Because the rig is a single, temporary structure, impacts on fish populations, whether beneficial or adverse, are considered minor.

Effluent Discharges . Discharges of drilling muds and associated cuttings are likely to have little or no impact on pelagic biota due to the low toxicity and rapid dispersion of these discharges (National Research Council, 1983; Neff, 1987; Hinwood et al., 1994). Other effluent discharges in accordance with the NPDES permit, such as sanitary and domestic wastes, deck drainage, desalinization unit brine, and uncontaminated bilge and ballast water, are expected to be diluted and mixed rapidly with ambient waters and would have little or no impact on water column biota.

Accidents (oil spills) . A large spill could affect water column biota including phytoplankton, zooplankton, and nekton. While adult and juvenile fishes may actively avoid a large spill, the planktonic eggs and larvaePage 53

would be unable to avoid contact. Eggs and larvae of fishes will die if exposed to certain toxic fractions of spilled oil. Most fishes inhabiting shelf or oceanic waters of the Gulf of Mexico have planktonic eggs and larvae. However, due to the wide dispersal of early life history stages of fishes in the Gulf of Mexico, a large spill would not be expected to have significant impacts at the population level.



### C. Impacts on Proposed Activities

A shallow hazards assessment was prepared in accordance with Appendix C of NTL 2003 -G17, and

NTL 98 -20. The analysis concluded that the drillsites are free of any major constraints to drilling.

Under most circumstances, meteorological and oceanographic conditions are not expected to have any effect on the proposed activities. Extreme weather, including high winds, strong currents, and large waves, has been taken into account in the design criteria for the rig. High winds, waves, and limited visibility during a severe storm could disrupt support activities (vessel and helicopter traffic) and might make it necessary to suspend some activities for safety reasons until the storm or weather event passes.



### D. Alternatives

Various technical and operational options have been considered in developing the proposed action, including the selection of a drilling unit, the selection of drilling fluids, and the drilling locations required to meet the objectives. No formal alternatives to the proposed action were evaluated.



### E. Mitigation Measures

The proposed action does not involve any mitigation measures other than those required by laws and regulations, including all applicable Federal, State, and local requirements concerning air emissions, discharges to water, and solid waste disposal, as well as any additional permit requirements. All project activities will be conducted under the ExxonMobil Corporation Gulf of Mexico Regional OSRP.

Note: Mitigation placed on Plan S-7330 approval letter

-- "In accordance with Notice to Lessees and Operators No.

2008 -G06, conduct the two Remotely Operated Vehicle surveys you proposed in your plan. The first survey will be for the first well location approved under this plan which is actually drilled. The post-drilling survey can be conducted at the time you are preparing to leave this location. Submit both your survey reports within 60 days after the rig leaves the well location." ExxonMobil drilled KC 919 Location F (Hadrian 5) and has complied with this mitigation.

ExxonMobil will not implement any mitigation measures to avoid, diminish, or eliminate potential environmental resources, other than those required by regulation and policy.



### F. Consultation

No persons or agencies were consulted during the preparation of this EIA.Page 54



### G. References

The following references were used in preparing the EIA.

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.

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 hab itat 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.
Gallaway, B. (ed.). 1988. Northern Gulf of Mexico continental slope study, final report: Year 4. Vol. II: Synthesis Report. Final report submitted to the Minerals Management Service, New Orleans, LA. Contract No. 14

- 12

- 0001

- 30212.

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.

Hinwood, J.B., A.E. Potts, L.R. Denis, J.M. Carey, H. Houridis, R.J. Bell, J.R. Thomson, P. Boudreau, and A.M. Ayling. 1994. Drilling activities, pp. 126 -206. In: J.M. Swan, J.M. Neff, and P.C. Young (eds.), Environmental Implications of Offshore Oil and Gas Development in Australia. The Findings of an Independent Scientific Review. Australian Petroleum Exploration Association (APEA) and Energy Research and Development Corporation (ERDC). Christopher Beck Books, Queensland, Australia. ISBN 0 908277 17 2.

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.

Jefferson, T.A. and A.J. Schiro. 1997. Distribution of cetaceans in the offshore Gulf of Mexico. Mammal Rev. 27(1):27- 50.

Lutcavage, M.E., P. Plotkin, B. Witherington, and P.L. Lutz. 1997. Human Impacts on sea turtle survival, pp. 387 -410. In: P.L. Lutz and J.A. Musick (eds.), The Biology of Sea Turtles. CRC Press, Boca Raton, FL. 432 pp.

Minerals Management Service. 2002. Gulf of Mexico OCS oil and gas lease sales: 2003-2007. Final Environmental Impact Statement. Central Planning Area Sales 185, 190, 194, 198, and 201; Western Planning Area Sales 187, 192, 196, and 200. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS EIS/EA MMS 2002-052.

National Marine Fisheries Service. 1999. Fishery Management Plan for Atlantic tunas, swordfish, and sharks, Volume II. National Marine Fisheries Service, Division of Highly Migratory Species, Office of Sustainable Fisheries, Silver Spring, MD. 302 pp.

National Marine Fisheries Service. 2001. Endangered Species Act, Section 7 Consultation, Gulf of Mexico OCS Lease Sale 181. Appendix B in: Gulf of Mexico OCS Oil and Gas Lease Sale 181, Eastern Planning Area. Final Environmental Impact Statement. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS EIS/EA MMS 2001-051.

National Research Council. 1983. Drilling Discharges in the Marine Environment. National Academy Press, Washington,

DC. 180 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.

Neff, J.M., S. McKelvie, and R.C. Ayers, Jr. 2000. Environmental impacts of synthetic based drilling fluids. Report 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.Page 55

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.

Pequegnat, W., B. Gallaway, and L. Pequegnat. 1990. Aspects of the ecology of the deep-water fauna of the Gulf of Mexico. American Zoologist 30:45- 64.

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.

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.

Rowe, G.T. 2000. Non-seep benthos, pp. 189 -207. 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.

Rowe, G.T. and M.C. Kennicutt II. 2002. Deepwater Program: Northern Gulf of Mexico Continental Slope Habitat and Benthic Ecology. Year 2: Interim Report. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, Louisiana. OCS Study MMS 2002-063. 158 pp.

Russell, R.W. 2001. Platforms for research: The “migration over the Gulf” project, pp. 395

- 398. In: M. McKay, J. Nides,
and D. Vigil (eds.), Proceedings: Twentieth Annual Gulf of Mexico Information Transfer Meeting, December 2000. U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2001

- 082. 464 pp.

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.



### H. List of Preparers

This EIA was prepared by the following Consultant:

Neil Phillips, Senior Scientist
Continental Shelf AssociatesPage 56 

### SECTION 19 : Administrative Information

Exempted Information Description (Public Information Copies Only)

The following attachments were excluded from the public information copies of this plan:

 Section 1: OCS Plan Information form

– Bottom hole locations & proposed total depth

 Section 2: Blowout Scenario

– confidential information for NTL 2010 N06 calculation

 Section 3: Geologic Description

 Section 3: Structure Contour Maps

 Section 3: Interpreted 2D or 3D seismic line(s)

 Section 3: Cross Section(s)

 Section 3: Shallow Hazards Report

 Section 3: Shallow Hazards Assessment

– confidential data

 Section 3: High-Resolution Seismic Lines & Top Hole Progs

 Section 3: Stratigraphic Column with Time vs. depth table



### Bibliography

 Gardline Surveys Inc. Geohazards Report No. 8796 for KC874, 875, 918, and 919, June 2011

 Fugro Geoservices site specific geophysical survey in Keathley Canyon Block 919, August 2008.

 Sassen et al., 1994

 Exxon Mobil Corporation Regional Oil Spill Response Plan - Offshore Operations, Appendix H, July 2011

 OCS EIA/ EA MMS 2007- 059

 Geraci and St Aubin, 1980

 Laist et al, 2001

 CSA Environmental Impact Analysis for Keathley Canyon, 2004