Draft	Environmental	

Assessment

BSEE	BOP/Well	Control	Proposed	Rule	– AA11

4/8/2015
1

1. INTRODUCTION

1.1 Background and Overview

The Department of the Interior is mandated under the Outer Continental Shelf Lands Act 

(OCSLA) to manage the orderly leasing, exploration, development, and production of mineral 

resources on the Federal Outer Continental Shelf (OCS). The Secretary of the Interior oversees 

the OCS oil and gas program and is required to balance orderly resource extraction with 

protection of human safety and marine and coastal environments. 

The BSEE proposes to revise portions of existing regulatory subparts concerning offshore 

operations, incorporate certain industry standards, and create a new subpart, 30 CFR 250, 

Subpart G – Well Operations and Equipment, in order to consolidate existing regulations 

concerning common equipment and operations covering drilling, completions, workovers, and 

decommissioning on the OCS. This proposed rulemaking would create new subpart G, which 

would focus on blowout preventer (BOP) requirements, including incorporation of the latest 

industry standard document on BOPs, API Standard 53, Blowout Prevention Equipment Systems 

for Drilling Wells – Fourth Edition (2012). This proposed rule would address and implement 

multiple recommendations from the various Deepwater Horizon (DWH) investigations and invite 

public comment. Additional discussion on the background of this rulemaking is included in the 

preamble of the Notice of Proposed Rulemaking, Blowout Preventer Systems and Well Control, 

RIN 1014-AA11 (Docket ID: BSEE-2012-0016).

This environmental assessment (EA) discusses the purposes of and need for this proposed 

rulemaking, alternatives to this proposed rulemaking, and this proposed rulemaking’s reasonably 

foreseeable environmental impacts in order to determine whether an Environmental Impact 

Statement (EIS) should be prepared. This EA was prepared in accordance with the Council on 

Environmental Quality (CEQ) regulations implementing the National Environmental Policy Act 

(NEPA). BSEE welcomes any comments on this EA and on any other documents associated 

with these proposed regulations. 

1.2 Purpose and Need

The purpose of the proposed Federal action is to amend and update regulations under 30 CFR 

Part 250 regarding oil and gas well-control operations on the OCS, including those concerning 

BOP systems. Ensuring the integrity of the wellbore and maintaining control over well pressure 

and fluids during operations are critical aspects of ensuring human safety and protecting the 

environment. In particular, BOP systems can be the last defense against an uncontrolled 

discharge of oil or volatile gas into the environment. The proposed rule is needed to ensure that 

BSEE’s regulations governing OCS oil and gas well operations, including drilling, completions, 

workovers, and decommissioning, require technology and practices that enhance safety and 

environmental protection.

Following the April 20, 2010 DWH explosion, blowout, and oil spill, multiple entities initiated 

investigations to determine the causes of the event and to make recommendations to reduce the 

likelihood of a similar event in the future.
2

The investigative bodies included:

• Department of the Interior and U.S. Coast Guard Joint Investigation Team

• National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling

• Chief Counsel for the National Commission on the BP Deepwater Horizon Oil Spill and 

Offshore Drilling

• National Academy of Engineering

• Chemical Safety Board 

Each investigation outlined several recommendations to improve offshore safety. The 

requirements in this proposed rule are based, in part, on recommendations from these 

investigations.

The proposed rule includes reforms in the areas of well design, well control, casing, cementing, 

real-time well monitoring, and subsea containment. It also incorporates guidance from several 

Notices to Lessees and Operators (NTLs) and revises existing regulations related to drilling, 

workover, completion, and decommissioning operations to enhance safety and environmental 

protection. Many of the changes proposed in this rulemaking are designed specifically to 

improve wellbore integrity and well control in order to prevent incidents involving loss of well 

control.

2. PROPOSED ACTION AND ALTERNATIVES

This EA evaluates three alternatives, including a No Action Alternative, for amending and 

updating regulations under 30 CFR Part 250 regarding oil and gas well-control operations on the 

OCS, including those concerning BOP systems.

2.1 Alternative 1: No Action Alternative

This alternative would forgo any changes to the 30 CFR Part 250 regulations that apply to 

blowout preventer systems and other well-control practices. BSEE would continue to rely on 

existing regulations in combination with permit conditions, Deepwater Operations Plans 

(DWOPs), operator prudence, and industry standards.

2.2 Alternative 2: Preferred Alternative and Proposed Action

The proposed action is the promulgation of the proposed rule entitled Oil and Gas and Sulphur

Operations on the Outer Continental Shelf – Oil and Gas Blowout Preventer Systems and Well 

Control, which would modify and/or consolidate the existing requirements under 30 CFR Part 

250 Subparts A, B, D-G, P, and Q, to include 89 new or revised sections that would impose new 

requirements and incorporate new or improved industry standards. By improving safety, this rule 

has the potential to reduce the number and/or severity of oil spills on the OCS and, as a result,

reduce the environmental impacts of oil spills on the OCS.

In summary, the proposed rulemaking would improve well control through the following:
3

1. Incorporate industry standards related to improving wellbore integrity and well control. 

Although the industry generally follows the published standards, compliance with those 

standards is not enforceable unless they are incorporated into regulations. Incorporating 

standards into regulations makes those standards requirements. The proposed rule would 

incorporate the following industry standards: 

a. American Petroleum Institute (API) Standard 53, Blowout Prevention Equipment 

Systems for Drilling Wells, 4th Edition;

b. American National Standards Institute (ANSI)/API Specification (Spec.) 11D1, 

Packers and Bridge Plugs, 2nd Edition;

c. API Recommended Practice (RP) 17H, Remotely Operated Tools and Interfaces on 

Subsea Production Systems, 1st Edition;

d. API RP 2RD, Design of Risers for Floating Production Systems (FPSs) and TensionLeg Platforms (TLPs), 1st Edition;

e. ANSI/API Spec. 6A, Specification for Wellhead and Christmas Tree Equipment, 19th

Edition;

f. ANSI/API Spec. 16A, Specification for Drill-through Equipment, 3rd Edition;

g. API Spec. 16C, Specification for Choke and Kill Systems, 1st Edition;

h. API Spec. 16D, Specification for Control Systems for Drilling Well Control 

Equipment and Control Systems for Diverter Equipment, 2nd Edition;

i. ANSI/API Spec. 17D, Design and Operation of Subsea Production Systems – Subsea 

Wellhead and Tree Equipment, 2nd Edition; and

j. ANSI/API Spec. Q1, Specification for Quality Programs for the Petroleum, 

Petrochemical and Natural Gas Industry, 8th Edition.

2. Revise the requirements for DWOPs to require free-standing hybrid risers (FSHR) for use 

with floating production, storage, and offloading (FPSO) units. The proposed rule would 

require the operator to provide additional information and to submit additional 

documentation on a proposed FSHR. This additional detail and documentation would 

include the following:

a. Detailed descriptions and drawings of the FSHR and its buoy and tether system;

b. Information on the design, fabrication, and installation of the FSHR and its buoy and 

tether system, including pressure ratings, fatigue life, and yield strengths;

c. A description of how the operator complied with API RP 2RD, Recommended 

Practice for Design of Risers for Floating Production Systems (FPSs) and Tension 

Leg Platforms (TLPs);

d. Detailed information regarding the tether system used to connect the FSHR to a 

buoyancy air can;

e. Descriptions of the monitoring system and a monitoring plan to monitor the pipeline 

FSHR and tether for fatigue, stress, and any other abnormal condition (e.g., 

corrosion) that may negatively impact the riser or tether; and

f. Documentation that the tether system and connection accessories for the pipeline 

FSHR have been certified by an approved classification society or equivalent, and 

verified by the Certified Verification Agent (CVA), as currently required by BSEE. 
4

3. Revise sections currently in existing 30 CFR Part 250 subpart D – Oil and Gas Drilling 

Operations to include the following requirements:

a. Submittal of equivalent circulating density (ECD) for wellbore fluid with the 

Application for Permit to Drill. The ECD is the effective fluid density exerted by a 

circulating fluid against the formation that takes into account the pressure drop in the 

annulus. The ECD is an important parameter in avoiding kicks and losses, 

particularly in wells that have a narrow window between the fracture gradient and 

pore pressure. This information is necessary for proper well drilling design and for 

BSEE to better review the drilling program.

b. Improved safe drilling margin requirements. The planned safe drilling margins would 

be required to be between the proposed drilling fluid weights and the estimated pore 

pressures, and the lesser of estimated fracture gradients or casing shoe pressure 

integrity test. The safe drilling margins would need to ensure that:

1. The static downhole mud weight is greater than the estimated pore pressure;

2. Static downhole mud weight is a minimum of one-half pound per gallon below 

the lesser of the casing shoe pressure integrity test or the lowest estimated 

fracture gradient;

3. The ECD is below the lesser of the casing shoe pressure integrity test or the 

lowest estimated fracture gradient; and 

4. Related hole behavior (e.g., pressures, influx/loss of fluids, and fluid types) is 

considered when determining the pore pressure and lowest estimated fracture 

gradient for a specific interval. 

c. A wellhead description that includes the type of wellhead and liner hanger systems 

and a descriptive schematic. The descriptive schematic would include pressure 

ratings, dimensions, valves, load shoulders, and locking mechanisms, if applicable. 

d. Adequate casing or liner centralization to help ensure proper cementation.

e. For operations using a subsea BOP or a surface BOP on a floating facility, the 

operator would be required to demonstrate the ability to control or contain a blowout 

event at the sea floor. The operator must have access to, and the ability to deploy, all 

equipment necessary to regain control of the well. Source Control and Containment 

Equipment (SCCE) means the capping stack, cap and flow system, containment 

dome, and/or other subsea and surface devices, equipment, and vessels whose 

collective purpose is to control a spill source and stop the flow of fluids into the 

environment or to contain fluids escaping into the environment.

4. Revise provisions in 30 CFR Part 250 subparts E and F to include requirements for:

a. Adherence to newly incorporated API Spec. 11D1, Packers and Bridge Plugs, 2nd

Edition;

b. Production packer setting depth to allow for a sufficient column of weighted fluid for 

hydrostatic control of the well; and
5

c. A description, with calculations, of how the production packer setting depth was 

determined.

5. Revise provisions currently in existing 30 CFR Part 250 subpart Q to include requirements

for packer and bridge plug design, casing bridge plugs, and decommissioning applications 

and reports, including the requirement that all packers and bridge plugs would have to 

comply with API Spec. 11D1, Packers and Bridge Plugs, 2nd Edition.

6. Create new Subpart G, and move common existing requirements from subparts D, E, F, and 

Q into this new subpart. This would create consistency among the requirements related to 

well operations (drilling, completion, workover, and decommissioning); i.e., regardless of 

the type of operation being performed, the same basic requirements would apply. Included 

within this section, BSEE would revise the existing 7-day BOP pressure testing interval for 

well workovers and decommissioning operations to be consistent with the 14-day interval

for drilling and completions. 

7. Include additional or revised requirements in new Subpart G, such as the following:

a. Rig and equipment movement reports for Mobile Offshore Drilling Units (MODUs), 

platform rigs, snubbing units, wire-line units used for non-routine operations, and 

coiled tubing units;

b. Real-time monitoring by onshore personnel of the BOP system, fluid handling system 

of the rig, and downhole conditions. Having the real-time data available to onshore 

personnel would increase the level of oversight throughout operations. Onshore 

personnel could review data and help rig personnel better conduct operations in a safe 

manner. Also, onshore personnel would be able to assist the rig crew in identifying 

and evaluating abnormalities or unusual conditions while conducting operations. 

This section would require that BSEE be provided access to the real-time monitoring 

facility, upon request. 

c. BOP requirements for the following:

i. Design and manufacture/quality assurance;

ii. Accumulator system capabilities and calculations;

iii. BOP and remotely operated vehicle capabilities such as: the remotely operated 

vehicle would have to be able to perform critical BOP functions, including 

opening and closing each shear ram, choke and kill side outlet valves, all pipe 

rams, and the Lower Marine Riser Platform disconnect under Maximum 

Anticipated Surface Pressure (MASP) conditions;

iv. BOP shearing functions, including the installation of shear rams that center 

drill pipe during shearing operations, and two shear rams, one of which must 

be capable of sealing the wellbore under MASP after shearing;

v. Increased maintenance and inspection requirements and qualifications and 

training for personnel that work on BOPs;

vi. Failure reporting procedures per API standards, within timeframes specified 

by BSEE;
6

vii. Third-party verification of the design, maintenance, inspection, testing, and 

repair of BOP systems and equipment; and

viii. Additional submittals to BSEE including up-to-date schematics of the BOP 

and BOP control systems.

8. Incorporate guidance from several Notices to Lessees into a new subpart for the following:

a. Global positioning systems (GPS) for MODUs, which would provide a robust and 

reliable means of monitoring the position and tracking the path, in real-time, of 

MODUs or jack-up rigs that may move during a severe storm;

b. Ocean Current Monitoring, which would provide ocean current data needed for 

planning, designing, and operating MODUs, floating production platforms, and

ancillary equipment, and ensure the sharing of ocean current data to develop a better 

understanding of ocean currents and bathymetry;

c. Alternate Compliance in Safety Systems for Subsea Production Operations, which 

would allow the use of the Barrier Concept as the basis for using procedures or 

equipment in the safety systems for subsea production operations;

d. Dropped Objects Plan for floating MODUs, which would help avoid prolonged 

damage to subsea infrastructure and aid the response of operators and BSEE to a 

dropped object;

e. Standard Reporting Period for Well Activity Reports (WARs), which clarifies when 

to submit the WARs (Form BSEE-0133) and accompanying Form BSEE-0133S, 

Open Hole Data Report; and

f. Information to be included in WARs and End of Operation Reports, including:

i. information describing the operations conducted, any abnormal or significant 

events that affect the permitted operation;

ii. verbal approvals;

iii. the wells as-built drawings;

iv. casing fluid weights;

v. shoe tests;

vi. test pressures at surface conditions; and 

 vii. status of the well at the end of the reporting period.

2.3 Alternative 3: Proposed Action Plus Change in Frequency of Pressure 

Testing from 14 to 21 Days

This alternative would promulgate the requirements contained within the proposed rule with a 

change to the required frequency of BOP pressure testing from the existing regulatory

requirements (i.e., once every 7 or 14 days depending upon the type of operation) to once every 

21 days for all operations.
7

2.4 Alternatives Considered but not Carried Forward for Further Analysis

1. BSEE also considered another alternative that would eliminate certain proposed requirements 

in the following provisions of the proposed rulemaking (as described in part 2.2 above), 

which could result in small increases in vessel traffic and in associated environmental 

consequences (as discussed in part 4.2 below): 

 § 250.462 What are the source control requirements?

 § 250.734 What are the requirements for a subsea BOP system?

Compliance with those proposed provisions could require some additional vessel traffic to 

and from OCS well sites (e.g., to ensure that SCCE and BOP equipment meet the proposed 

new requirements), and exclusion of those provisions could avoid the potentially negligible 

adverse environmental effects (e.g., increased air emissions, noise levels) that could result 

from additional vessel traffic. Exclusion of those provisions could also result in some 

potential cost savings for OCS operators. However, exclusion of those provisions under such 

an alternative would substantially reduce the potential beneficial environmental 

consequences that would result from Alternative 2 (and Alternative 3) and would fall far 

short of achieving the main purpose and need of the proposed rule; i.e., to prevent loss of 

well control and prevent or minimize potentially catastrophic oil spills. 

2. Additionally within § 250.734, BSEE considered including requirements for industry that 

would be associated with the installation of technology capable of severing any components 

of the drill string (excluding drill bits). Including such a severing requirement would provide 

additional protection against the potential loss of well control by requiring that operators 

install supplemental technology that ensures all components of a drill string, including those 

components that cannot be sheared with current shear rams, could be severed in an 

emergency to allow the well to be safely shut-in, thereby reducing the risk of a loss of well 

control. BSEE provides extensive and robust discussion of severing in the preamble of the 

rulemaking, including seeking input on whether such a provision should be included in the 

final rule. Although these requirements were not included within the proposed regulatory

text, BSEE nonetheless considered them and determined that they would not result in 

operational changes and would likely have no adverse environmental impacts as a 

result. Given this analysis, BSEE determined that a separate alternative was not needed to 

assess the impacts of including this requirement in the final rule. 

3. AFFECTED ENVIRONMENT

The vast majority of active OCS oil and gas operations take place in the Gulf of Mexico OCS 

region, while fewer but still significant operations are conducted in the Pacific OCS region

(BOEM 2012). Although there is relatively little current operational activity in the Alaska OCS 

region, especially in the Arctic areas of that region, there is the potential for significant future 

operations in that region. Moreover, the environment and ecosystems in the Arctic areas and 

other parts of the Alaska region are particularly sensitive (BOEM 2012). Thus, while the coastal 

and marine environments of the Pacific and Gulf of Mexico regions are proportionally most 

relevant to this proposed rulemaking in the near term, this EA also considers the potential 
8

impacts of the proposed action on the Arctic OCS. Descriptions of baseline environmental and 

socioeconomic conditions of the Gulf of Mexico, Pacific, and Alaska OCS planning areas may

be found in the BOEM 2012-2017 OCS Oil and Gas Leasing Program programmatic 

environmental impact statement (BOEM 2012) and the Minerals Management Service 

programmatic environmental impact statement for alternative energy development and 

alternative use of facilities on the OCS (MMS 2007).

In these regions, an oil spill following a loss of well control could affect: 

 Air quality;

 Water quality;

 Marine and terrestrial mammals;

 Marine and coastal birds;

 Sea turtles;

 Fish and shellfish;

 Coastal, nearshore, and seafloor habitats;

 Areas of special concern, including essential fish habitat;

 Sociocultural systems and environmental justice;

 Population, employment, and regional income;

 Tourism and recreation;

 Commercial and recreational fisheries;

 Subsistence hunting and fishing;

 Land use and existing infrastructure; and

 Archeological resources.

4. ENVIRONMENTAL CONSEQUENCES

4.1 Alternative 1: No Action Alternative

Adopting the No Action alternative would mean that the proposed revisions to 30 CFR Part 250 

would not be incorporated into federal regulation, and thus the intended benefits of the 

rulemaking would not be realized. The underlying purpose of the proposed rulemaking is to 

enhance the safety of oil and gas operations on the OCS, thereby reducing the likelihood of a loss 

of well control and a discharge of oil into the environment. This, in turn, would also reduce the 

likelihood of potential injury, loss of life, and environmental and socioeconomic impacts.

Conversely, under the No Action Alternative, no reduction would be expected in the likelihood 

of a loss of well control and any subsequent discharge of oil. A loss of well control during well 

operations on an OCS facility can cause human injury or loss of life, as well as adverse economic 

and environmental impacts. The volume of oil resulting from a worst case discharge at a well 

may exceed volumes from other potential spill sources, such as pipelines or vessels (BOEM 

2012). For example, a spill from a pipeline at or near the seafloor is accessible for repairs, and 
9

the flow into the pipeline can be shut-in. In contrast, a loss of well control and a failure of the 

BOP system may result in the discharge of gas, condensate, oil, sand, or water that is more 

difficult to contain and shut-in, potentially compromising safety and resulting in a significant oil 

spill.

A catastrophic oil spill resulting from a loss of well control and BOP failure can affect a variety

of biological, socioeconomic, and sociocultural resources over extensive coastal and offshore 

areas. Impacts that may occur include:

 Air Quality: Impacts on air quality may result from the emission of pollutants from the 

oil and from in situ burning, and from the dispersant mist resulting from the application 

of chemical dispersants on the oil (BOEM 2012). Evaporation of spilled oil also would 

cause increases in volatile organic compounds (VOCs). The magnitude and extent of any

air quality impacts would depend on the size, location, and duration of the spill, and on 

local meteorological conditions such as wind speed and direction. Spreading of spilled 

oil and action by wind, waves, and currents would act to disperse and thus reduce VOC 

concentrations. Over time, air quality would return to pre-spill conditions. The in situ

burning of spilled oil would generate a plume of black smoke and emissions of nitrogen 

oxides1(NOx), sulfur dioxide (SO2), carbon monoxide (CO), and particulate matter2

(PM10, and PM2.5) that would temporarily affect air quality. Smoke from burning crude 

oil also would contain polycyclic aromatic hydrocarbons (PAHs). After the burn, air 

quality would return to pre-burn conditions.

 Water Quality: An oil spill will adversely affect water quality by introducing 

hydrocarbons into the water column. Weathering processes that transform oil, such as 

volatilization, emulsification, dissolution, chemical oxidation, photo-oxidation, and 

microbial oxidation, may reduce water quality impacts of oil spills (NRC 2003; NOAA 

2005). Because oil is generally less dense than water, it would tend to float on the sea 

surface, and lighter oil fractions containing BTEX3 would evaporate from the surface 

and, therefore, would not be a continuing source of potential water contamination.

Following a spill, light crude oils can lose as much as 75% of their initial volume to 

evaporation as the lighter components (e.g., BTEX) change from the liquid to the gas 

phase; medium-weight crude oils can lose as much as 40% (NRC 2003b). In the event of 

a spill occurring under ice cover, oil would be trapped and essentially remain unchanged 

until ice breakup occurred and the ice began to melt. The volatile compounds from such 

a spill would be more likely to freeze into the ice within hours to days, rather than 

dissolve or disperse into the water below the ice.

The impacts on water quality will depend upon the type of oil spilled; the size, location, 

and duration of the spills; weather conditions in the spill area; and remediation activities. 

Small spills would likely result in short-term, localized impacts, while impacts from large 

spills could persist for an extended period of time (BOEM 2012). The potential for more 

 

1 The combination of nitrogen oxide (NO) and nitrogen dioxide (NO2) is referred to as NOx.

2

PM10 and PM2.5 refer to particulate matter of 10 micrometer and 2.5 micrometer mean aerodynamic diameter, or 

less, respectively.

3 BTEX refers to a mixture of benzene, toluene, ethyl benzene, and xylene.
10

widespread and long-term water quality impacts may be expected to be greater in 

Alaskan waters, especially under ice-cover conditions. On the Alaska OCS, winter 

conditions (e.g., complete ice cover and extremely cold conditions) could substantially

complicate spill response, given current spill control and remediation technologies. The 

speed of natural recovery in the Alaska OCS, as compared to GOM waters, could be 

slowed by the persistence of oil in cold water temperatures and under ice cover. 

Additional effects on water quality would occur from response and cleanup vessels, in 

situ burning of oil, dispersant use, discharges and seafloor disturbance from relief well 

drilling, and activities on shorelines associated with cleanup, booming, beach cleaning, 

and monitoring (BOEM 2012).

 Marine and Terrestrial Mammals: Oil spills may result in the direct and indirect 

exposure of mammals and their habitats to oil (BOEM 2012, NOAA 2012). Marine 

mammals can be exposed to chemicals in oil or dispersants in several ways, such as 

internal exposure (by consuming oil or contaminated prey, or inhaling volatile oil and 

dispersant-related compounds); external exposure (by swimming in oil or dispersants,

and having oil or dispersants directly on the skin and body); and maternal transfer of 

contaminants to embryos. Fouling of fur of some species (e.g., sea otter, polar bear, and 

fur seal) could affect thermoregulation and reduce survival. Terrestrial species may be 

exposed if a spill reaches their terrestrial and aquatic habitats. When oil reaches land, it 

can severely impact coastal and estuarine habitats such as marshes, mudflats, mangrove 

stands, and beaches (BOEM 2012, NOAA 2012). Terrestrial mammals that use these 

habitats (such as beach mice in the GOM) are at risk from direct fouling by the oil, as 

well as exposure via consumption of prey contaminated by the oil spill. The magnitude 

of effects to marine and terrestrial mammals from oil spills would depend on the location, 

magnitude, duration, timing, and volume of the spills; the habitats affected by the spills 

(e.g., marine, coastal, and estuarine habitats); and the species exposed. Overall, impacts 

on marine mammals from an oil spill could include physical injury or death; behavior 

disturbances; lethal or sublethal toxic effects; and loss of reproductive, nursery, feeding, 

and resting habits (BOEM 2012). Specifically, in Alaska, the greatest risk to marine 

mammals would be associated with large spills reaching rookeries and haul out locations 

where large numbers of individuals could be exposed and population-level impacts could 

occur (BOEM 2012).

Response activities, such as collecting and burning oil at sea, skimmer operations, boom 

deployment, the use of dispersants, berm construction, and boat traffic also could directly 

injure marine mammals or cause behavioral changes. Terrestrial habitats used by some

species may be negatively impacted by response activities, such as shoreline cleanup 

efforts, placement of booms, and siting of land-based staging areas (BOEM 2012).

In addition, the discharge of condensate, oil, sand, or water from a loss of well control 

could result in increased turbidity and concentrations of total suspended solids in the 

water column, which could displace marine mammals from the drill sites and could 

adversely affect habitat and prey within and around the drill site. Such an effect could be 

of particular concern in the Arctic and other areas of the Alaska OCS. In the Arctic, 

subsistence hunters, who rely on traditional ecological knowledge, have expressed 
11

concern that whales, particularly migrating bowhead whales, are capable of detecting the 

odors from discharges and will avoid areas where these discharges occur, which in turn 

would significantly impact subsistence whale hunting (BOEM 2012).

 Marine and Coastal Birds: Birds may be exposed to, and affected by, oil or dispersants 

in a number of ways (BOEM 2012, NOAA 2012). External exposure may occur if the 

birds swim or dive through floating oil, or utilize oiled beaches and marshes. External 

exposure results in the oiling of feathers, and oiled birds can lose the ability to fly, dive

for food, or float on the water, which can lead to drowning. Oiling of feathers interferes 

with the water repellency of feathers and can lead to hypothermia. Internal exposure may

occur through the incidental ingestion of oil as the birds preen and try to clean their 

feathers, through ingestion of contaminated food and media, and through inhalation of 

volatile oil-related compounds. Maternal transfer of contaminants from exposed adult 

females to embryos and eggs may also occur. Internal exposure may result in a variety of 

lethal and sublethal physiological, metabolic, developmental, and behavioral effects. 

Internal exposure may lead to reduced survival and reproductive success (e.g., reduced

hatching of eggs and survival of hatchlings) (BOEM 2012, NOAA 2012).

The magnitude and ecological importance of any effects to marine and coastal birds 

would depend upon the size, location, duration, and timing of the spill; the species and 

life stages of the exposed birds; and the size of the local bird population (BOEM 2012). 

Exposure to spills in deep water would be largely limited to pelagic birds. Spills that 

reach coastal habitats could affect the greatest variety and number of birds, including 

shorebirds, waterfowl, wading birds, gulls, and terns. Spills reaching onshore locations 

have the greatest potential for affecting the greatest number of birds, especially if a spill 

occurs in or reaches an area where birds have congregated and are carrying out important 

activities (such as nesting, molting, and staging areas for some waterfowl and 

shorebirds).

 Sea Turtles: Oil spills may expose one or more sea turtle life stages to oil or its 

weathering products (BOEM 2012, NOAA 2012). Internal exposure may occur through 

the incidental ingestion of oil, feeding on contaminated food, or inhaling volatile oil and 

dispersant-related compounds, as well as maternal transfer from exposed adults to eggs. 

External exposure may occur as juveniles and adults swim in oil or dispersants which 

then adhere directly to the skin and body, while eggs and hatchlings may be exposed if 

nest sites become oiled. Exposed hatchlings, juveniles, and adults may incur a variety of 

lethal or sublethal effects. Oil reaching nests may reduce egg hatching and hatchling 

survival and inhibit hatchling access to water, while the presence of oil on nesting 

beaches may affect nest site access and use by adult turtles (BOEM 2012, NOAA 2012).

The magnitude of effects from an oil spill will depend on the location, timing, duration, 

and volume of the spill; the environmental settings of the spills; and the species and life 

stages of sea turtle exposed to the spills. A catastrophic spill could affect the greatest 

number of individuals, life stages, and habitats, and result in major impacts to the 

affected species and potentially lead to population-level effects (BOEM 2012). In 

addition to chemical exposure, response activities such as the use of dispersants, 
12

collecting and burning oil at sea, skimmer operations, boom deployment, berm 

construction, and onshore equipment use and increased light at night on or near nesting 

beaches, could directly injure sea turtles, block access to turtle nesting beaches, and/or 

cause behavioral changes. Furthermore, BSEE recognizes that most species of

potentially impacted sea turtles are listed under Endangered Species Act, and BSEE

considered this when evaluating the potential impacts described above. 

 Fish and Shellfish: Fish and shellfish may be exposed to oil and dispersants through a 

variety of pathways, including direct dermal contact (e.g., swimming through oil and 

dispersants or waters with elevated dissolved hydrocarbon concentrations and other 

constituents), ingestion (e.g., feeding on contaminated food and filter-feeding in 

contaminated water), and respiration (e.g., elevated dissolved contaminant concentrations 

in water passing over the gills). Recent results from studies looking at potential

synergetic effects of dispersants in oil exposure have suggested that the dispersants make 

it easier to move hydrocarbons across membranes, and thus may enhance exposure (see 

BOEM 2012, NOAA 2012).

Hydrocarbons can have a range of effects on fish depending on the concentration, the 

length of exposure, and the life history stage of the fish involved (BOEM 2012, NOAA 

2012). Exposure to an oil spill could affect fish populations by causing mortality of eggs, 

larvae, juveniles, or adults; triggering abnormal development; impeding the access of 

migratory fishes (e.g., salmon and herring) to spawning habitat; altering behaviors; 

displacing individuals from preferred habitat; reducing or eliminating prey populations 

available for consumption; impairing feeding, growth, or reproduction; causing adverse 

physiological responses; increasing susceptibility to predation, parasitism, diseases, or 

other environmental perturbations; and increasing or introducing genetic abnormalities.

Water quality changes resulting from an oil spill can also adversely affect habitat quality

and quantity for fish and shellfish. A catastrophic spill has the potential to cause the loss 

of a year class, affecting future stock populations. 

A large oil spill in Alaskan waters may have greater ecological consequences than a 

comparable spill in temperate areas because oil is likely to persist longer in Alaska due to 

the colder water temperatures (BOEM 2012). In addition, in the Alaska OCS region in 

winter, fish must contend with reduced light, seasonal darkness, prolonged low 

temperatures and ice cover, and scarcer food resources, which affect primary and 

secondary productivity. Thus, most of a fish’s yearly energy needs must be satisfied

during the brief Arctic summer, and an uncontrolled discharge of oil in such areas during 

the summer drilling season could have even greater effects than in other regions where 

seasonal differences in environmental conditions do not affect food resources and 

productivity as dramatically as in the Arctic.

 Coastal, Nearshore, and Seafloor Habitats: Oil and dispersants are transported on the 

surface of the water column by wind and currents. For oil to become incorporated into 

bottom sediment, oil particles must either weather to a dense asphaltic material that can 

then sink, or absorb or adhere to heavier particles and sink. Such particles may include

marine detritus (non-living particulate organic material) or inorganic sediment (e.g., 
13

sediment particulate introduced to the Gulf from the Mississippi River). Oil that has been

deposited onshore and mixed with sand and sediment may be resuspended and washed 

back out via tidal action, eventually settling to the bottom (BOEM 2012, NOAA 2012).

Coastal, nearshore, and benthic habitats exposed to an oil spill may incur minor to major 

impacts associated with reduction in habitat quality and service (e.g., loss of use as 

spawning grounds, reduced ability to provide food resources) and secondary impacts to 

the biota that rely on affected services. The magnitude of potential impacts to exposed

habitats would depend on a variety of factors, including the location, size, timing, and 

duration of the spill; the specific type of habitat exposed; the effectiveness of remediation 

efforts; existing environmental conditions (e.g., vegetation, substrate type, ice cover); and 

natural localized erosion and deposition patterns. The effects of small spills would 

generally be localized and relatively short-term. In the event of a large or catastrophic 

spill, however, habitats over a much greater geographic area may be affected and may

incur more severe impacts where oil is concentrated. In some cases, full recovery of 

oiled habitats could take many years, and habitats such as coastal wetlands may not fully 

recover even following remediation (BOEM 2012, NOAA 2012).

 Areas of Special Concern, Including Essential Fish Habitat: Areas of Special Concern 

include Marine Protected Areas, National Marine Sanctuaries, and National Seashores, 

Reserves, and Refuges (see BOEM 2012). Areas of Special Concern also include 

military use areas and areas designated as essential fish habitat (EFH). An oil spill 

reaching sensitive coastal habitats could affect national parks, national wildlife refuges,

national estuarine research reserves, or national estuary program sites (BOEM 2012). 

Impacts could result from both oiling of the shoreline and mechanical damage during the 

cleanup process. Potential effects include reduced ecological services, impacts to 

habitats and resident biota, and reduced human use (e.g., subsistence use, recreation and 

tourism, commercial and recreational fisheries, and military training). The magnitude of 

the potential effects would depend on the location, size, duration, and timing of a spill; 

type of area affected (national seashore vs. military training area); the weather conditions 

at the time of the spill; the nature and effectiveness of response operations; and other 

environmental conditions (e.g., wave conditions or presence of sea ice) at the time of the 

spill (BOEM 2012).

 Sociocultural Systems and Environmental Justice: Humans can be affected by an oil spill 

through contact with the contaminants (via inhalation, skin contact, or intake of 

contaminated foods); through reduced availability of subsistence resources; through 

interference with subsistence harvest patterns; and by stress due to fears of long-term 

implications of the spill. Physiological effects may include a variety of respiratory

symptoms; irritation of the eyes and mucous membranes; and increased incidence of 

headaches, nausea, and dizziness. 

Low-income and minority populations, and especially Native Alaskan communities on 

the Arctic coast, could be affected to a greater extent than the general population because 

of their dietary reliance on marine mammals and wild coastal resources, their reliance on 

these resources for other subsistence purposes such as sharing and bartering, their limited 
14

flexibility in substituting wild resources with those purchased, and their spiritual and 

cultural beliefs and practices. Thus, any significant environmental impacts on fish and 

mammal subsistence resources from oil spills would have major sociocultural impacts,

primarily associated with disruption of subsistence activities (BOEM 2012).

 Population, Employment, and Regional Income: The immediate impact of a large oil 

spill may include the loss of employment and income, reduced property values, increased 

cost of public service provision, and possible shortages of commodities or services. 

Longer-term impacts could affect commercial and recreational fisheries, and/or tourism if 

these activities were to suffer due to the real or perceived impacts of the spill. 

Expenditures associated with potential spill response and cleanup activities could create 

short-term employment and income in some parts of the affected coastal region(s) 

(BOEM 2012).

 Tourism and Recreation: Potential impacts on recreation and tourism resulting from an 

oil spill would likely include direct impacts (e.g., oil contamination of a beach), access 

restrictions to a particular area (e.g., no diving or fishing while cleanup is being 

conducted), and aesthetic impacts. These impacts could persist for several months or 

longer, pending cleanup completion and any required habitat restoration. The extent and 

duration of impacts would depend on the location, size, duration, and timing of the spill 

and associated cleanup activities, and on the effectiveness of response operations. 

Because oiled coastal sediments are often removed via mechanical means, such shoreline 

activity would effectively close the area to public use for the duration of cleanup 

operations. If restoration is required (i.e., to restore the proper beach profile), additional 

time may be required before public access is allowed (BOEM 2012).

 Commercial and Recreational Fisheries: The effects of oil spills on commercial and 

recreational fisheries would depend on the location, timing, duration, and volume of 

spills, in addition to other environmental factors. Small spills would be unlikely to have 

a large effect before dilution and weathering reduced concentrations and therefore would 

not have long-term effects on commercial and recreational fisheries. If a large oil spill 

were to occur, commercial and recreational fisheries could incur costlier and more longterm effects. The potential for oil-soaked fishing gear and potentially contaminated fish 

may reduce commercial and recreational fishing efforts. Very large spills could also 

indirectly affect fisheries by degrading habitats that are critical for the survival of target 

species, but would only be serious if they led to severe declines in target species 

populations. Highly mobile fish species (tunas, sharks, and billfish) could move away

from surface oil spills in deep water, disrupting fishing efforts (BOEM 2012, NOAA 

2012).

 Land Use and Existing Infrastructure: A large oil spill could at least temporarily alter 

land use in areas where the spill contacts the shore, but may not result in long-term 

changes (BOEM 2012). There could be an immediate but temporary change in existing 

land use at the impacted areas associated with beach closures, coastal access restrictions, 

and restrictions on visitation, hunting, and fishing during spill containment and cleanup, 

as well as during any post-spill habitat restoration efforts. The magnitude and duration of
15

impacts would depend upon the location, size, timing, and duration of the spill and the 

existing land use at the spill location.

 Archeological Resources: Oil spills could affect coastal historic and prehistoric 

archeological resources and could result in an unavoidable loss of information and 

physical damage of oiled artifacts and sites (BOEM 2012). The level of this impact 

would depend on the significance and uniqueness of the information lost. Prehistoric 

sites in all regions occur frequently along the mainland coast and barrier islands, and 

along the margins of estuaries, bays, and lagoons; thus, any spill that contacts these areas 

could involve a potential impact on a prehistoric site.

4.2 Alternative 2: Preferred Alternative and Proposed Action

The potential environmental consequences of a loss of well control discussed above in 

Alternative 1 also apply to Alternative 2. However, due to the additional safety and reliability

provisions in Alternative 2, the likelihood and/or severity of a loss of well control and discharge 

of hydrocarbons under Alternative 2 is expected to be less than that under Alternative 3 and 

further less than that under Alternative 1. Accordingly, over time, the resulting adverse human 

health, socioeconomic, and environmental effects described in section 4.1 above would be 

expected to be less under Alternative 2 than under Alternative 3, and further less than under 

Alternative 1, due to fewer incidents of loss of well control.

Implementing certain provisions of the proposed rule has the potential to lead to environmental 

impacts. For example, implementing the proposed SCCE requirements may lead to an increase 

in vessel traffic required to support such capabilities and to the potential environmental 

consequences of such traffic; e.g., any increase in vessel traffic may lead to some additional air 

emissions and increased noise levels (BOEM 2012). However, BSEE estimates that any increase 

in vessel traffic would be de minimis due to operators scheduling routine operations in 

conjunction with these requirements in order to optimize time and minimize costs. 

Consequently, any increase in vessel traffic resulting from the provisions of the proposed 

regulations requiring SCCE would be a minor fraction of ongoing traffic levels in each of the 

three BSEE OCS regions. (For example, the 2012-2017 OCS Leasing Program estimated traffic 

of 300-600 vessels/week in support of routine operations in the Gulf of Mexico) (BOEM 2012). 

Since any additional SCCE-related vessel traffic would represent a very small incremental 

increase over routine vessel traffic, it would have negligible effects on the potential 

environmental consequences, such as air emissions and noise levels. However, we welcome 

comments on the potential impacts of the proposed provisions on any of the regions. 

BSEE has also examined whether the proposed reduction in BOP testing frequency for workover 

and decommissioning operations— from once every 7 days to once every 14 days—potentially

could lead to an increase in the likelihood of a loss of well control, and an increase in the 

associated potential environmental impacts, should the reduced testing lead to a BOP failing to 

operate properly when actually needed. On the other hand, reducing the BOP testing frequency

for workovers and decommissioning potentially could increase equipment durability somewhat,

through a reduction of the number of times the BOP is subjected to repetitive testing during those 
16

operations. Increased durability might partially offset the potential risk that the equipment will 

not perform properly when needed due to decreased testing frequency. 

In addition, any potential increase in the risk that a BOP would fail to operate properly when 

needed could be offset to some degree because reducing the frequency of BOP testing could 

reduce the risk of potential environmental consequences (such as a non-catastrophic oil spill) 

directly related to performance of the tests themselves. For example, each time such a test is 

performed, there is some risk that an error could occur or that some piece of equipment could 

fail; reducing the frequency of such tests (and, thus, the number of tests) would decrease the 

number of possible opportunities for such hazards to occur. 

Of importance, the proposed testing interval of 14 days for workover and decommissioning 

operations simply brings those activities into alignment with the 14-day testing interval that has 

long been required for all other well operations (e.g., drilling and completions). Given the 

extensive experience with a 14-day BOP testing requirement for those well operations, BSEE 

does not expect that aligning the workover and decommissioning BOP testing interval with the 

testing interval for all other operations would result in a heightened risk of the loss of well 

control or entail other significant environmental consequences. 

Many of the other changes proposed in Alternative 2 are designed specifically to improve 

wellbore integrity and well control, with the intent of preventing incidents involving loss of well 

control. Although it is not possible to estimate the level of reduction in BOP failure rates that 

could result with adoption of the proposed rulemaking, implementation of Alternative 2 is 

expected to reduce the likelihood of well control incidents and spills (catastrophic or otherwise)

compared to the likelihood under Alternative 3 and to reduce such likelihood even further 

compared to Alternative 1. Adoption of Alternative 2 is expected to benefit environmental 

health to a greater degree than Alternative 1 through the avoidance of potential adverse effects

associated with losses of well control and discharges of hydrocarbons that might otherwise 

occur.

4.3 Alternative 3: Proposed Action Plus Change in Frequency of Pressure 

Testing from 14 to 21 Days

This alternative would promulgate the requirements contained within the proposed rule but

would change the required frequency of BOP pressure testing from the existing regulatory

requirements (i.e., once every 7 or 14 days depending upon the type of operation) to once every

21 days for all operations. The only variation from Alternative 2 would be the longer interval 

between BOP pressure tests. This variation could potentially affect the risk of a loss of well 

control and discharge of hydrocarbons, as compared to Alternatives 1 and 2, in several ways. 

Due to the additional safety and reliability provisions in Alternative 3, the likelihood of a loss of 

well control and discharge of hydrocarbons (e.g., from failure of a BOP to operate correctly 

when needed to prevent a blowout) under Alternative 3 is lower than that under Alternative 1. 

However, as compared to Alternative 2, the reduced frequency of BOP testing under Alternative 

3 potentially could increase the likelihood of a loss of well control and catastrophic discharge of 

hydrocarbons (and an increase in the associated potential environmental impacts) should the 
17

reduced testing lead to a BOP failing to operate properly when actually needed. On the other 

hand, reduced pressure testing frequency potentially could increase equipment durability

somewhat, through a reduction of the number of times the BOP is subjected to repetitive testing, 

and thus might partially offset the potential risk that the equipment will not perform properly 

when needed.

In addition, under Alternative 3, the potential increase in the risk that a BOP would fail to 

operate properly when needed, due to decreased testing frequency, could be offset to some 

degree because reducing the frequency of BOP testing could reduce the risk of potential 

environmental consequences directly related to performance of the tests themselves (as 

discussed under Alternative 2). In the preamble to the proposed rule, BSEE has requested 

additional information on these issues associated with testing frequency, operational safety, and 

equipment durability. Overall, however, based on our existing data, the potential positive 

consequences of reduced testing frequency under Alternative 3 do not outweigh (as compared to 

Alternative 2) the potential increased risk and related consequences of a blowout and 

catastrophic oil spill that might occur if a BOP fails to operate, when needed, as a result of 

reduced testing.

5. REFERENCES

API - American Petroleum Institute.

American Petroleum Institute, 2012. API Standard 53, Blowout Prevention Equipment Systems 

for Drilling Wells - Fourth Edition (November)

BSEE, 2015. Oil and Gas and Sulphur Operations in the Outer Continental Shelf – Blowout 

Preventer Systems and Well Control, Initial Regulatory Impact Analysis, RIN: 1014-AA11.

BOEM - Bureau of Ocean Energy Management.

Bureau of Ocean Energy Management, 2012. Outer Continental Shelf Oil and Gas Leasing 

Program: 2012-2017, Final Programmatic Environmental Impact Statement. OCS EIS/EA, 

BOEM 2012-030. U.S. Department of the Interior, Bureau of Ocean Energy Management, 

Herndon, Virginia.

MMS – Minerals Management Service.

Minerals Management Service, 2007. Programmatic Environmental Impact Statement for 

Alternative Energy Development and Production and Alternate Use of Facilities on the Outer 

Continental Shelf, Final Environmental Impact Statement. OCS EIS/EA MMS 2007-046. U.S. 

Department of the Interior, Minerals Management Service, Herndon, Virginia.

NOAA - National Oceanographic and Atmospheric Administration.

NOAA, 2005. Trajectory Analysis Handbook. Office of Response and Restoration, Hazardous 

Materials Response Division, Seattle, Wash. Available at http://response.restoration.noaa.gov.
18

NOAA, 2012. Natural Resource Damage Assessment Status Update for the Deepwater Horizon 

Oil Spill, April. Electronically available at: http://www.gulfspillrestoration.noaa.gov/wpcontent/uploads/FINAL_NRDA_StatusUpdate_April2012.pdf. 

NRC - National Research Council.

NRC, 2003. Oil in the Sea III: Inputs, Fates, and Effects, Committee on Oil in the Sea: Inputs, 

Fates, and Effects, Ocean Studies Board and Marine Board, Divisions of Earth and Life Studies 

and Transportation Research Board, National Academies Press, Washington, D.C.