# Deepwater Horizon Oil Spill: Selected Issues for Congress

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URL: https://www.frixlaw.com/law-library/documents/crs%3AR41262

## Record

- **Collection:** Congressional research report
- **Document type:** CRS Report
- **Published:** July 31, 2010
- **Citation:** R41262

## Text

Deepwater Horizon Oil Spill:
Selected Issues for Congress
Curry L. Hagerty, Coordinator
Specialist in Energy and Natural Resources Policy
Jonathan L. Ramseur, Coordinator
Specialist in Environmental Policy
July 31, 2010

Congressional Research Service
7-5700
www.crs.gov
R41262

CRS Report for Congress
Prepared for Members and Committees of Congress

Deepwater Horizon Oil Spill: Selected Issues for Congress

Summary
On April 20, 2010, an explosion and fire occurred on the Deepwater Horizon drilling rig in the
Gulf of Mexico. This resulted in 11 worker fatalities, a massive oil release, and a national
response effort in the Gulf of Mexico region by the federal and state governments as well as BP.
Based on estimates from the Flow Rate Technical Group, which is led by the U.S. Geological
Survey, the 2010 Deepwater Horizon spill is the largest oil spill in U.S. waters. The oil spill
damaged natural resources, causing some regional economic impacts. In addition, questions have
been raised as to whether offshore regulation of oil exploration has kept pace with the
increasingly complex technologies needed to explore and develop deeper waters.
Crude oil washed into some marshes and estuaries and onto beaches in Louisiana, Mississippi,
and Alabama. Oil killed some wildlife, and efforts are underway to treat oil-coated birds. The
most immediate economic impact of the oil spill has been on the Gulf fishing industry:
commercial and recreational fishing have faced extensive prohibitions within the federal waters
of the Gulf exclusive economic zone. The fishing industry, including seafood processing and
related wholesale and retail businesses, supports over 200,000 jobs with related economic activity
of $5.5 billion. Other immediate economic impacts include a decline in tourism. On the other
hand, jobs related to cleanup activities could mitigate some of the losses in the fishing and
tourism industry.
The Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE), formerly
known as the Minerals Management Service (MMS), and the U.S. Coast Guard are the primary
regulators of drilling activity. The Coast Guard generally overseas the safety of systems at the
platform level of a mobile offshore drilling unit. The Environmental Protection Agency (EPA) has
multiple responsibilities, with a representative serving as the vice-chair of the National Response
Team and Regional Response Teams. The Federal Emergency Management Administration
(FEMA) has responsibilities with respect to the economic impacts of the spill; its role so far has
been primarily that of an observer, but that may change once the scope of impacts can be better
understood.
BOEMRE/MMS is also the lead regulatory authority for offshore oil and gas leasing, including
collection of royalty payments. Its regulations generally require that a company with leasing
obligations demonstrate that proposed oil and gas activity conforms to federal laws and
regulations, is safe, prevents waste, does not unreasonably interfere with other uses of the outer
continental shelf, and does not cause impermissible harm or damage to the human, marine, or
coastal environments. Further attention to the internal organization of BOEMRE/MMS is an
ongoing legislative and regulatory focus.
Several issues are developing for Congress as a result of the Deepwater Horizon incident.
Questions include: What lessons should be drawn from the incident? What technological and
regulatory changes may be needed to meet risks peculiar to drilling in deeper water? How should
Congress distribute costs associated with a catastrophic oil spill? What interventions, if any, may
be necessary to ensure recovery of Gulf resources and amenities? What does the Deepwater
Horizon incident imply for national energy policy, and the trade-offs between energy needs, risks
of deepwater drilling, and protection of natural resources and amenities? This report provides an
overview of selected issues related to the Deepwater Horizon incident and is not intended to be
comprehensive. This report will not be updated.

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Deepwater Horizon Oil Spill: Selected Issues for Congress

Contents
Introduction ................................................................................................................................1
Setting: Oil and Gas Recovery in the Gulf of Mexico ..................................................................2
Offshore Oil and Gas Drilling Technology.............................................................................2
Methane Hydrates in the Gulf of Mexico...............................................................................4
Weather and Ocean Currents in the Gulf of Mexico ...............................................................5
Biological Resources of the Gulf of Mexico ..........................................................................6
Federal Statutory Framework ......................................................................................................6
OCS Leasing.........................................................................................................................7
Oil Spill Response ................................................................................................................7
National Contingency Plan..............................................................................................8
Role of the Secretary of Homeland Security ....................................................................9
National Response Framework........................................................................................9
Oil Spill Liability ................................................................................................................ 10
Limits (or Caps) to Liability.......................................................................................... 11
Loss of Liability Limit .................................................................................................. 11
Oil Spill Liability Trust Fund ........................................................................................ 12
OPA Compensation and Claims Process .............................................................................. 12
Federal Regulatory Framework ................................................................................................. 13
Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE,
Formerly MMS)............................................................................................................... 14
Wells............................................................................................................................. 15
Platforms ...................................................................................................................... 15
Equipment and Facilities ............................................................................................... 16
Role of U.S. Coast Guard.................................................................................................... 16
The International Maritime Organization (IMO)............................................................ 17
Classification Societies ................................................................................................. 17
Oil Spill Response Issues .......................................................................................................... 18
Use of Dispersants .............................................................................................................. 18
Louisiana Protective Berm Project ...................................................................................... 20
Relief Wells ........................................................................................................................ 22
What Are Relief Wells? ................................................................................................. 22
Examples of Relief Wells Being Used to Stop Blowouts................................................ 23
Relief Well Policies....................................................................................................... 24
Issues for Further Consideration.................................................................................... 25
Response Vessels and the Jones Act..................................................................................... 27
Investigations and Commissions ............................................................................................... 27
Environmental and Economic Impacts ...................................................................................... 28
Environmental Impacts ....................................................................................................... 28
Natural Resource Damage Assessment and Compensation............................................. 29
Environmental Recovery............................................................................................... 30
Economic Impacts............................................................................................................... 30
Natural Resources and Related Economic Activity ........................................................ 30
Impact on Oil and Natural Gas Prices ............................................................................ 32
Possible Impacts on Shipping........................................................................................ 34
Labor Issues.............................................................................................................................. 34

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Safety and Health of OCS Workers...................................................................................... 34
Oil and Gas Industry Safety Statistics.................................................................................. 35
Coast Guard Oversight of OCS Safety................................................................................. 37
Technical Competence .................................................................................................. 37
Regulatory Issues .......................................................................................................... 37
IMO Convention Issues................................................................................................. 38
Reorganization of BOEMRE/MMS........................................................................................... 39
Establishment of the Minerals Management Service............................................................ 40
Administrative Reorganization by Secretary Salazar............................................................ 41
Call for Organic Legislation ................................................................................................ 43
Agency Reorganization Legislation During the 111th Congress ............................................ 43
FEMA Issues ............................................................................................................................ 45
Federal Duplication/Federal Coordination ........................................................................... 45
Exxon Valdez....................................................................................................................... 46
Recent Regional Disaster History........................................................................................ 47
Conclusion................................................................................................................................ 47

Figures
Figure 1. The Loop Current .........................................................................................................6
Figure 2. Cumulative Dispersant Application in Gulf Oil Spill................................................... 20
Figure 3. Image of Two Relief Wells Being Drilled by BP to Plug the Deepwater Horizon
Well ....................................................................................................................................... 23
Figure 4. Gulf of Mexico Fishery Closure ................................................................................. 31

Contacts
Author Contact Information ...................................................................................................... 49

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Introduction
On April 20, 2010, the Deepwater Horizon oil drilling rig—under contract to BP, the leaseholder
of the tract approximately 50 miles offshore of Louisiana—was nearing completion of a
deepwater oil well when an explosion occurred. An apparent equipment failure, perhaps of the
blowout protector, at the wellhead released oil and natural gas; explosions and fire on the oil rig
killed 11 of the crew, and the rig sank within days. In the aftermath, the oil spill became the
largest in U.S. waters. Based on estimates from the Flow Rate Technical Group, which is led by
the U.S. Geological Survey, it appears this oil spill would eclipse the 1989 Exxon Valdez spill
several times over.1 Crude oil has been washing into estuaries and onto beaches in Louisiana,
Mississippi, and Alabama; affected fishing and shrimping areas in the Gulf of Mexico have been
closed.
The former Minerals Management Service (MMS), now known as the Bureau of Ocean Energy
Management, Regulation, and Enforcement (BOEMRE), in the Department of the Interior (DOI)
is responsible for leasing the tract to BP.2 (Because the name change is relatively recent, hereafter
in this report this agency will be referred to as BOEMRE/MMS.) The U.S. Coast Guard oversees
the fitness of the rig and efforts to control the leak. The Environmental Protection Agency (EPA)
has multiple responsibilities, with a representative serving as the vice-chair of the National
Response Team and Regional Response Teams. The Federal Emergency Management
Administration (FEMA) has responsibilities with respect to the economic impacts of the spill; its
role so far has been primarily that of an observer, but that may change once the scope of impacts
can be better understood. Information about the Deepwater Horizon rig, its drilling operations,
and the federal response to the oil spill is available from numerous sources, including
BOEMRE/MMS and the Coast Guard, the two agencies with lead federal roles in governing
response efforts. As the lessee of the area in which the offshore facility is located, BP is
responsible for capping the leak and paying for removal costs.
Issues such as worker safety, economic and environmental impacts, and oil and gas leasing for
exploration and development are the focus of congressional attention at this time. The incident
has triggered numerous congressional hearings, including those investigating the causes of the
blowout; impacts of the spill; liability for damages; and the administrative process of leasing and
regulatory requirements concerning health, safety, and environmental protection in drilling.
Secretary Ken Salazar of DOI initiated changes in the administration of offshore oil drilling by
splitting MMS functions into three new bureaus, one to conduct leasing, one to enforce safety and
environmental requirements, and one to handle revenues. Congress will be evaluating this
reorganization and examining the adequacy and effectiveness of statutes governing leasing and
oil spills, including the Outer Continental Shelf Lands Act of 1953, as amended (OCSLA), and
the Oil Pollution Act of 1990 (OPA).
This report provides an initial overview of Deepwater Horizon-related issues for Congress, and
refers readers to in-depth CRS reports on specific issues. Congressional readers with questions
1
For up-to-date estimates of the spill rate, see the most recent press releases from the Department of the Interior, at
http://www.doi.gov/news/index.cfm/.
2
Secretarial Order 3302, issued June 18, 2010, changed the name of the Minerals Management Service to the Bureau
of Ocean Energy Management, Regulation, and Enforcement (BOEMRE). The name change was effective
immediately.

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about an issue discussed in this report should contact the experts listed in CRS Report R40883,
Oil Spill in the Gulf of Mexico: CRS Experts.

Setting: Oil and Gas Recovery in the Gulf of Mexico
Sediments buried deep below the seafloor in the Gulf of Mexico host large quantities of oil and
gas that have been the target of exploration activities for decades. Most of the undiscovered oil
and gas on the U.S. outer continental shelf (OCS) is thought to occur in the Gulf, particularly in
the central and western regions. The central and western Gulf account for about 48% of the
undiscovered technically recoverable resource (UTRR)3 for oil and about 50% of the UTRR for
natural gas in the entire U.S. OCS, according to the Department of the Interior.4 (In comparison,
Alaska accounts for about 31% of the UTRR for oil and gas in the OCS.)
Recent attention has focused on oil and gas resources underlying deep water in the Gulf (i.e.,
deeper than 1,000 feet), because that is where the largest resource potential exists and where the
majority of OCS leases are held. 5 Since 2006, there has been a 44% increase in proven deepwater
discoveries in the Gulf, even though most of the deepwater leases are as yet undrilled. (For
example, 272 of nearly 1,900 ultra-deepwater leases—those at a water depth greater than 5,000
feet—were drilled between 1996 and 2007.) Deepwater and ultra-deepwater exploration and
development have been the focus of OCS oil and gas development in recent years, and the
potential for new and large discoveries in that part of the Gulf has been viewed as key to slowing
or stopping the decline in OCS oil and gas reserves. (For a more complete discussion of OCS oil
and gas issues, see CRS Report R40645, U.S. Offshore Oil and Gas Resources: Prospects and
Processes, by Marc Humphries, Robert Pirog, and Gene Whitney.)

Offshore Oil and Gas Drilling Technology6
In comparison with nearshore oil and gas activities, deepwater and ultra-deepwater exploration
and production require technologies that can withstand high pressures and low temperatures at the
seafloor, and require the operator to control the process remotely from a surface vessel thousands
of feet above the actual well. Seawater temperatures are lower in these waters (for example, at
5,000 feet deep in the Gulf, the seafloor water temperature is about 40o F, or 4.4o C); and
pressures are greater (at 5,000 feet deep the seafloor pressure is about 2,500 psi). Consequently,
equipment and operations at the seafloor are accessible only by remotely operated vehicles
(ROVs). Drilling technologies built to withstand the harsher conditions in deep water and ultradeep water are complicated, difficult to repair, and expensive. In addition, long lengths of pipe, or
marine “riser,” extending from the seafloor to the drill rig, are needed, requiring a large and
complex surface platform to conduct operations through the longer pipe. One of the most
common types of drilling platforms for deep water and ultra-deep water is a semisubmersible rig,
3

The undiscovered technically recoverable resource (UTRR) is an estimate of the volume of oil or natural gas that is
likely to be recovered using currently available technologies without considering price. UTRR changes as available
technology changes, but not as price changes.
4
Statement of Steven C. Allred, DOI/MMS, January 25, 2007.
5
Thirty-five percent of active OCS leases are in water depths of less than 200 meters, while 51% of active OCS leases
are in water depths of 1,000 meters and deeper.
6
Prepared by Peter Folger, Specialist in Energy and Natural Resources Policy.

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which has an upper and lower hull. During the drilling operation, the lower hull is filled with
water, partially submerging the rig but leaving the upper hull floating above the drill site. 7
Transocean’s Deepwater Horizon rig was a semisubmersible platform, kept in place above the
drill site by a dynamic positioning system (i.e., not permanently anchored to the seafloor) and
connected to the well by the marine riser.8
During drilling operations, the drill bit and drill pipe (or drill string) extend through the riser from
the drill platform and through a subsea drilling template—essentially a large metal box embedded
in the seafloor—into the marine sediments and rocks down to the hydrocarbon-bearing zone. A
special fluid called drilling mud (a mixture of water, clay, barite, and other materials) is circulated
down to the drill bit and back up to the drilling platform. The drilling mud, which has higher
viscosity and density than water, serves several purposes: it lubricates the drill bit, helps convey
rock cuttings from the drill bit back to the surface, and exerts a column of weight down the hole
to control pressure against a possible blowout. A blowout can occur if the subterranean pressure
encountered down the hole exceeds the pressure exerted by the weight of the drill assembly and
drilling mud. The Deepwater Horizon rig experienced a blowout on April 20, 2010, and the role
of the drilling fluid is under investigation.
Drilling a deepwater or ultra-deepwater well is a multi-step process. At different stages the drill
string is removed and steel casing is inserted into the wellbore, telescoping down from the
largest-diameter casing at the top of the well to the smallest diameter at the bottom. Casing
serves, among other things, to stabilize the wellbore, prevent the formation from caving in,
maintain control of fluid pressure, and prevent crossflow of fluids from one part of the formation
to another. The bottommost interval of casing, usually called the production casing, is inserted
through the interval in the formation containing hydrocarbons that the operator wishes to produce.
The casing is cemented in place over various intervals; cement is injected between the well casing
and the surrounding rock. In addition, cement may be injected into intervals of the casing itself
when the well is to be temporarily or permanently plugged. 9 At the Deepwater Horizon well,
Halliburton (as a contractor for BP) had finished cementing the final production casing string
about 20 hours before the blowout on April 20, according to congressional testimony. 10
As a last line of defense against a blowout, a blowout preventer (BOP) is installed at the seafloor
and connected to the marine riser. The BOP is essentially a system of valves designed to be closed
in the event of anomalous wellbore pressure (such pressure is sometimes referred to as a “kick”).
At the depth and pressures encountered by the Deepwater Horizon well, BOEMRE/MMS
regulations require at least four such valves, or rams, which must be remote-controlled and
hydraulically operated during offshore operations.11 During the Deepwater Horizon blowout, all
of the rams on the BOP failed to close properly.
7

For a more detailed description of drilling rigs, see http://www.naturalgas.org/naturalgas/extraction_offshore.asp.
For specifications about the Deepwater Horizon, see http://www.deepwater.com/fw/main/Deepwater-Horizon56C17.html?LayoutID=17.
9
For example, in the Deepwater Horizon well, casing intervals spanned nine different diameters, from 36-inch
diameter casing at the top of the well, to 7-inch diameter casing at the bottom, according to congressional testimony.
Also, the witness stated that there was no continuous cement column throughout the entire wellbore. Testimony by Tim
Probert, President, Global Business Lines and Chief Health, Safety, and Environmental Officer, Halliburton, hearing to
review current issues related to offshore oil and gas development, U.S. Congress, Senate Committee on Energy and
Natural Resources, 111th Cong., 2nd sess., May 11, 2010.
10
Testimony by Tim Probert, Halliburton, May 11, 2010.
11
30 C.F.R. § 250.442.
8

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BOPs can have backup systems that would attempt to engage the rams in case of loss of direct
communication to the drilling vessel at the surface. One type of backup system, referred to as a
“deadman switch,” is intended to operate automatically if communication to the surface is
disrupted. A second type of backup system, referred to as an “autoshear,” would automatically
activate one of the rams if the lower marine riser pipe disconnected. Another form of backup
system includes the use of remotely operated vehicles (ROVs), controlled from the surface, which
can operate control panels on the BOP itself at the seafloor. In the Deepwater Horizon incident,
the BOP was reportedly equipped with a deadman switch12 and an autoshear device, and ROVs
were used to attempt to activate the BOP after the blowout occurred. These systems appear to
have failed to fully engage the BOP.

Methane Hydrates in the Gulf of Mexico13
At the temperatures and pressures of deepwater and ultra-deepwater drilling in the Gulf of
Mexico, solid methane hydrates can occur. They constitute a potential natural gas resource as well
as a possible risk to exploration activities. In a methane hydrate, frozen water molecules form a
cage-like structure around molecules of methane, the primary component of natural gas. In 2007,
BOEMRE/MMS released an estimate of methane hydrate resources in the Gulf with a mean value
of 21,000 trillion cubic feet, although the report noted that the amount of hydrate commercially
recoverable using current technology is likely just a fraction of that resource. 14 Methane hydrates
also present a significant hazard for drilling and production operations.15 Offshore drilling
operations that disturb methane hydrate-bearing sediments could fracture or disrupt the bottom
sediments and compromise the wellbore, pipelines, rig supports, and other equipment involved in
oil and gas production from the seafloor.16 Decreases in pressure and/or increases in temperature
can cause a solid methane hydrate to dissociate and rapidly release large amounts of gas into the
wellbore during a drilling operation. (For a more detailed discussion of methane hydrates, see
CRS Report RS22990, Gas Hydrates: Resource and Hazard, by Peter Folger.)
Methane hydrates also have interfered with attempts to divert oil and gas from the Deepwater
Horizon blowout. When BP first attempted to lower a steel “cofferdam” over the leaking riser
pipe to intercept the oil and gas and divert it to the surface, methane hydrates formed and clogged
valves and piping leading to the surface. This occurred because methane gas from the wellbore
encountered cold seawater at 5,000 feet below the ocean surface, and methane converted from a
gas to solid methane hydrate. Methane hydrates are stable at that depth and temperature.

12

According to testimony by Steve Newman, President and CEO of Transocean Ltd., in response to questions during
the House Committee on Energy and Commerce, Subcommittee on Oversight and Investigations, Inquiry Into the
Deepwater Horizon Gulf Coast Oil Spill, hearing, 111th Cong., May 12, 2010.
13
Prepared by Peter Folger, Specialist in Energy and Natural Resources Policy.
14
U.S. Department of the Interior, Minerals Management Service, Resource Evaluation Division, “Preliminary
Evaluation of In-Place Gas Hydrate Resources: Gulf of Mexico Outer Continental Shelf,” OCS Report MMS 2008-004
(February 1, 2008), at http://www.mms.gov/revaldiv/GasHydrateFiles/MMS2008-004.pdf.
15
Timothy S. Collett and Scott R. Dallimore, “Detailed Analysis of Gas Hydrate Induced Drilling and Production
Hazards,” Proceedings of the Fourth International Conference on Gas Hydrates, Yokohama, Japan, April 19-23, 2002.
16
George J. Moridis and Michael B. Kowalsky, “Geomechanical Implications of Thermal Stresses on Hydrate-Bearing
Sediments,” Fire in the Ice, Methane Hydrate R&D Program newsletter, Winter 2006.

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Weather and Ocean Currents in the Gulf of Mexico17
Oil and gas operations in the Gulf of Mexico face severe weather hazards, namely hurricanes
during the summer and fall, that could disrupt operations and possibly cause leaks and spills from
drilling rigs and production platforms. For example, disruptions to oil and gas operations
occurred in 2005 during Hurricanes Katrina and Rita. As a result of the hurricanes, approximately
600,000 gallons were spilled from offshore oil platforms and associated pipelines in the Gulf. 18
Hurricanes and the Gulf Oil Spill
A hurricane in the Gulf could have significant consequences for the oil spill’s impacts. The National Hurricane Center
(NHC) recently predicted an “active to extremely active” hurricane season in the Atlantic Ocean and Gulf. The
season began June 1 and extends through November 30 (a NOAA FAQ website notes that the season’s termination
date has gradually extended over time). Although past hurricanes (e.g., Katrina in 2005) have led to oil spills, a
hurricane interacting with a pre-existing, significant oil spill would be an unprecedented event.
Movement of oil would depend greatly on the track, wind speed, and size of a hurricane, and other factors in the
evolution of the storm. The ultimate effects would be uncertain: some effects could be beneficial, others disastrous.
High winds and seas are expected to mix and weather the oil, which can help accelerate biodegradation processes
and dispersion. However, barrier islands that normally protect coastal wetlands from oil may be overtopped or
destroyed by winds and water. Furthermore, heavy winds and storm surges could push oil further inland into areas
that would not normally become oiled. Even after oil stops flowing from the Deepwater Horizon site, hurricanestrength winds could stir up oil that has penetrated sediments, thus releasing oil and causing renewed impacts on
plants and wildlife.
In addition, as Hurricane Alex recently demonstrated, a hurricane could impede response efforts, requiring vessels
and personnel to abandon oil containment and recovery activities.
Sources: National Oceanic and Atmospheric Administration, “NOAA Expects Busy Atlantic Hurricane Season,”
NOAA News, May 27, 2010, at http://www.noaanews.noaa.gov/stories2010/20100527_hurricaneoutlook.html; NOAA
FAQ website, at http://www.aoml.noaa.gov/hrd/tcfaq/G1.html; NOAA, “NOAA’s Oil Spill Response, Hurricanes and
the Oil Spill,” May 27, 2010, at http://www.nhc.noaa.gov/pdf/hurricanes_oil_factsheet.pdf.

Winds and currents in the Gulf of Mexico also affect how oil will migrate away from the source
of the spill. One key oceanographic feature of the Gulf that could possibly transport an oil spill
into the Gulf Stream and up the Atlantic seaboard is called the Loop Current. The Loop Current is
a clockwise flow that joins together the Yucatan Current to the south with the Florida Current to
the east and flows through the Florida Straits. The Florida Current feeds into the Gulf Stream (see
Figure 1). The position of the Loop Current is not static but varies over time in the Gulf. Its
variability, combined with the location, size, and duration of an oil spill, will determine whether
the Loop Current could entrain the spilled oil and how much oil it could transport toward the
Florida Current. There is also the possibility that part of the Loop Current could break off and
form a separate, temporary “anticyclonic” (i.e., clockwise-moving) ring, which could keep
entrained oil circulating within the Gulf rather than connecting with the Florida Current.19 In
addition to the complicated flow pattern in the Loop Current, it is not clear how the Deepwater
Horizon oil spill—which not only occurs at the surface but extends from the seafloor through the
entire water column—might become entrained into the current and where it might migrate.
17

Prepared by Peter Folger, Specialist in Energy and Natural Resources Policy.

18

For more information about oil spills generally, see CRS Report RL33705, Oil Spills in U.S. Coastal Waters:
Background and Governance, by Jonathan L. Ramseur.
19
E-mail from Robert H. Weisberg , Professor of Physical Oceanography, and colleagues, College of Marine Science,
University of South Florida, May 19, 2010.

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Figure 1.The Loop Current

Source: The Cooperative Institute for Marine and Atmospheric Studies, University of Miami Rosenstiel School,
at http://oceancurrents.rsmas.miami.edu/atlantic/loop-current.html. Modified by CRS.
Notes: The arrows indicate the direction and magnitude of the current velocity. The Loop Current is shown by
black arrows surrounded by white.

Biological Resources of the Gulf of Mexico20
The Gulf of Mexico is home to productive, diverse, and valuable living natural resources. Some
major features of the U.S. Gulf include barrier islands, coastal wetlands, beaches, and coral reefs.
The combined coastline of these areas, including islands and inland areas, is 47,000 miles. The
coastal and ocean resources of the region provide commercial, recreational, ecological, historical,
educational, and aesthetic benefits to local communities and the nation. Coastal wetlands and
estuaries are nursery areas for many species, including those that support commercial fisheries,
such as shrimp, oysters, and blue crab, and those that support recreational fishing, such as
snappers, groupers, and drum. Attributes such as warm weather, white sand beaches, and seafood
restaurants make the Gulf a popular tourist destination. Major tourist-related businesses include
eating and drinking establishments, hotels and lodging, and amusement and recreation services.

Federal Statutory Framework
The development of offshore oil, gas, and other mineral resources in the United States is subject
to a number of interrelated legal regimes, including international, federal, and state law.
International law provides a framework for establishing national ownership or control of offshore
20

Prepared by Harold F. Upton, Analyst in Natural Resources Policy.

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areas, and U.S. domestic law has, in substance, adopted these internationally recognized
principles. U.S. domestic law further defines U.S. ocean resource jurisdiction and ownership of
offshore minerals, dividing regulatory authority and ownership between the states and the federal
government based on the resource’s proximity to the shore. Below is a broad summary of the
framework.21

OCS Leasing22
The basis for most federal regulation is the Outer Continental Shelf Lands Act (OCSLA),23 which
provides a system for offshore oil and gas exploration, leasing, and ultimate development. The
OCSLA establishes broad five-year planning periods for offshore leasing across the U.S. OCS as
well as other processes for leasing, development, and production. It also authorizes the
administration of health and safety requirements. All of these are administered by
BOEMRE/MMS.24 The OCSLA further provides for judicial review of agency actions alleged to
be in violation of federal law, including violations of the act itself, its implementing regulations,
and the terms of any permit or lease.25
Governance of offshore minerals and oil and gas development in the U.S. OCS is bifurcated
between state and federal law. States generally have primary authority in the 3-geographical-mile
area extending from their coasts pursuant to the Submerged Lands Act, with some exceptions. 26
Laws governing oil and gas development in state waters vary significantly from state to state. The
federal government and its comprehensive regulatory regime govern those minerals located under
federal waters, which extend from the states’ offshore boundaries to at least 200 nautical miles
from the shore.

Oil Spill Response27
The Oil Pollution Act of 1990 (OPA, P.L. 101-380) and the Clean Water Act (CWA)28 are the
primary federal statutes governing the federal response to oil spills. As amended by OPA, Section
311(d)29 of the Clean Water Act authorized the President to develop a National Oil and Hazardous
Substances Pollution Contingency Plan (National Contingency Plan or NCP) to specify the
federal response actions and authorities related to an oil spill. 30 Although the NCP is the operative

21

See CRS Report RL33404, Offshore Oil and Gas Development: Legal Framework, by Adam Vann.
Prepared by Adam Vann, Legislative Attorney.
23
43 U.S.C. § 1331 et seq.
24
As noted above, MMS is in the process of reorganization into three bureaus (the Bureau of Ocean Energy
Management, the Bureau of Safety and Environmental Enforcement, and the Office of Natural Resource Revenue)
pursuant to Secretarial Order No. 3299 issued by Secretary of the Interior Ken Salazar on May 19, 2010.
25
43 U.S.C. § 1349.
26
U.S.C. § 1301(b).
27
Prepared by Jonathan L. Ramseur, Specialist in Environmental Policy.
28
33 U.S.C. §§ 1251-1387.
29
33 U.S.C. § 1321(d).
22

30
The first NCP was prepared in 1968 after U.S. policymakers observed the British government’s response to a 37million-gallon oil tanker spill (Torrey Canyon) off the coast of England. See EPA, “National Contingency Plan
Overview,” at http://www.epa.gov/emergencies/content/lawsregs/ncpover.htm.

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framework for oil spill response, other frameworks and authorities may play a role in the Gulf
spill response.

National Contingency Plan
The NCP establishes the National Response System (NRS), a multitiered and coordinated
national response strategy for addressing oil spills and releases of hazardous substances. The NCP
is codified in federal regulation at 40 C.F.R. Part 300. Subpart D specifically addresses response
to oil spills.31 Oil spill response actions required under the regulations of the NCP are binding and
enforceable, per the enforcement authorities of the OPA and the CWA.
Key components of the NRS include:
•

National Response Team (NRT). This team is composed of representatives from
the federal departments and agencies assigned roles in responding to oil spills.
The U.S. Coast Guard, in the Department of Homeland Security (DHS), chairs
the NRT when a response is being mounted to a spill in a coastal region.
According to statements by the Administration, the Secretary of DHS, Janet
Napolitano, is leading the NRT in response to the Gulf spill.32

•

Regional Response Teams (RRTs). RRTs are composed of regional
representatives of each NRT member agency, state governments, and local
governments. The Coast Guard leads the relevant RRT during responses to oil
spills in coastal zone. The Gulf spill involves Regions IV and VI.33

•

Area Committees (ACs). These include qualified personnel from federal, state,
and local agencies. The primary function of each AC is to prepare an Area
Contingency Plan (ACP) for its designated area.

•

On-Scene Coordinator (OSC). The OSC directs the response efforts and
coordinates all other efforts at the scene. In general, Coast Guard Captains of the
Port serve as OSCs for their particular area.34

As amended by OPA, the CWA provides the President with the authority to ensure that an oil spill
is effectively removed and actions are taken to prevent further discharge from the source.35
Executive Order 12777 (signed by President George H. W. Bush on October 18, 1991) delegated
response authority in the coastal zone to the Coast Guard OSC. The OSC is broadly empowered
to direct and coordinate all response and recovery activities of federal, state, local, and private
entities (including the responsible party), and will draw on resources available through the
appropriate ACPs and RRTs.36
31
Subpart E addresses response to hazardous substances, which is beyond the scope of this report. The Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) is the statute that authorizes response to
hazardous substances. Combined, CERCLA, OPA, and the CWA provide the statutory authority for the NCP as a
whole.
32
See e.g., http://www.whitehouse.gov/deepwater-bp-oil-spill/.
33
Information and documents from these regions can be accessed via the NRT website at http://nrt.org/.
34
The corresponding role for spills in EPA’s jurisdiction is the Remedial Project Manager (RPM).
35
33 U.S.C. § 1321(c).
36
The Oil Pollution Act of 1990 (P.L. 101-180) strengthened and clarified the federal government’s role in oil spill
response and cleanup. OPA Section 4201 amended Section 311(c) of the CWA to provide the President with authority
(continued...)

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In addition, the OSC determines the level of cleanup required. Although the federal government
must consult with designated trustees of natural resources and the governor of the state affected
by the spill, the decision that cleanup is completed and can be ended rests with the OSC. States
may require further work, but without the support of federal funding.37

Role of the Secretary of Homeland Security
The Secretary of the Department of Homeland Security (DHS) may be involved in an oil spill
response either through her/his lead role in the department in which the Coast Guard operates38 or
as the “principal federal official for domestic incident management.” This latter role was
established in Homeland Security Presidential Directive (HSPD) 5.39 The Secretary’s role will
depend on the nature and magnitude of the incident, but in most cases, the role will likely be
minimal.
For the Gulf oil spill, Secretary Napolitano is coordinating the federal response activities. A
specific role the Secretary has assumed in this regard is leading the NRT (discussed above). In
addition, on April 29, 2010, Secretary Napolitano classified the event as a Spill of National
Significance (SONS).40 This designation does not provide additional funding or authority, but
allows for the appointment of a National Incident Commander (NIC), whose role is to coordinate
strategic communications, national policy, and resource support, and to facilitate collaboration
with key parts of the federal, state, and local governments. On the same day, Secretary Napolitano
named Coast Guard Admiral Thad Allen as the NIC.41

National Response Framework
The National Response Framework (NRF) is the federal government’s broader administrative
mechanism that is intended to coordinate the array of federal response plans.42 As such, the NRF
provides the administrative policies and guiding principles for a unified response from all levels
of government, and all sectors of communities, to all types of hazards through the combined
scope of the various federal response plans that it incorporates. However, the NRF itself is not an
(...continued)
(delegated to the USCG or EPA) to perform cleanup immediately using federal resources, monitor the response efforts
of the responsible party, or direct that party’s cleanup activities.
37
OPA § 1011.
38
The Coast Guard was transferred to DHS in 2003.
39

The White House, Management of Domestic Incidents, Homeland Security Presidential Directive - 5, Washington,
DC, February 28, 2003, http://www.fas.org/irp/offdocs/nspd/hspd-5.html.
40
The predecessor to the National Response Framework—the National Response Plan (NRP)—contained a similarsounding phrase, “Incident of National Significance.” This term caused significant confusion and was subsequently
eliminated in the NRF. For more information, see Department of Homeland Security, National Response Framework:
Frequently Asked Questions, at http://www.fema.gov/pdf/emergency/nrf/NRF_FAQ.pdf.
41
The authority for the SONS classification and NIC designation is found specifically in the NCP regulations at 40
CFR Section 300.323. However, this section authorizes the Commandant of the Coast Guard to classify a spill as a
SONS and to name a NIC. It is unclear whether the DHS Secretary was employing the authority provided by HSPD 5
to take these actions.
42
Authority for the creation of the NRF emanates from numerous sources. FEMA has described the NRF as being
guided by 15 “principal emergency authorities,” 48 other statutory authorities and regulations, 17 executive orders, and
20 presidential directives. U.S. Department of Homeland Security, Federal Emergency Management Agency, National
Response Framework: List of Authorities and References, January 2008.

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operational plan that dictates a step-by-step process for responding to a specific type of hazard,
nor is the NRF a binding and enforceable regulation like the NCP.43
The NRF contains 15 “emergency support functions” (ESFs), which coordinate the capabilities
and resources of various federal departments and agencies, state and local governments, and
certain private-sector and nongovernmental organizations. ESF #10—Oil and Hazardous
Materials Response—provides federal support in response to an actual or potential discharge
and/or uncontrolled release of oil or hazardous materials.44 In some cases, the ESFs point to
existing response frameworks and authorities. Such is the case with ESF #10, which identifies the
NCP as the operative structure for oil spill response. According to the DHS, ESF #10 has not been
activated in response to the Gulf spill.45 Regardless, the NCP is the operative framework, with or
without ESF #10 activation.

Oil Spill Liability46
OPA liability provisions apply to any discharge of oil, or threat of discharge, from a vessel (e.g.,
oil tanker) or facility (e.g., offshore oil rig)47 to navigable waters, adjoining shorelines, or the
exclusive economic zone of the United States (i.e., 200 nautical miles beyond the shore).48
Responsible parties, including owners/operators of vessels or facilities and/or lessees of offshore
facilities,49 are liable50 for oil spill removal costs and for a range of other costs, including:
•

injuries to natural resources (e.g., fish, animals, plants, and their habitats);

•

loss of real personal property (and resultant economic losses);

•

loss of subsistence use of natural resources;

•

lost government revenues resulting from destruction of property or natural
resource injury;

•

lost profits and earnings resulting from property loss or natural resource injury;
and

•

costs of providing extra public services during or after spill response.51

43

For more on the NRF, see CRS Report RL34758, The National Response Framework: Overview and Possible Issues
for Congress, by Bruce R. Lindsay.
44
Emergency Support Function #10—Oil and Hazardous Materials Response Annex, available at
http://www.fema.gov/emergency/nrf/index.htm.
45
Per telephone conversation with DHS personnel (July 13, 2010).
46
Prepared by Jonathan L. Ramseur, Specialist in Environmental Policy, and James E. Nichols, Law Clerk.
47
The definition of “facility” is broadly worded and includes pipelines and motor vehicles. 33 U.S.C. § 2701(9).
48
Under OPA, the terms “liable” and “liability” are “construed to be the standard of liability which obtains under
section 311 of the [Clean Water Act].” Courts have interpreted Section 311 of the Clean Water Act as imposing strict
liability on parties responsible for the discharge of oil or other hazardous substances into the waters of the United
States. See United States v. New York, 481 F.Supp. 4 (D.N.Y. 1979).
49
See 33 U.S.C. § 2701(32).
50
Responsible parties have several defenses from liability (33 U.S.C. 2703): act of God, act of war, and act or omission
of certain third parties. These defenses are analogous to those of the Superfund statute (the Comprehensive
Environmental Response, Compensation, and Liability Act, or CERCLA, commonly known as Superfund, P.L. 96-510)
enacted in 1980 for releases of hazardous substances. See 42 U.S.C. § 9607(b).
51
OPA § 1002(b)(2).

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Compared to the pre-OPA liability framework, OPA significantly increased the range of covered
damages. 52 Moreover, a responsible party is now liable (subject to the limits discussed below) for
all cleanup costs incurred not only by a government entity but also by a private party.53

Limits (or Caps) to Liability
With some exceptions (identified below), the liability of the responsible party is limited or capped
for each “incident.”54 Liability limits differ based on the source of the oil spill: some limits are
simple dollar amounts; in other cases liability is unlimited for cleanup costs, but there are limits
on other damages.
Mobile offshore drilling units (MODUs), like the Deepwater Horizon unit (owned by
Transocean), are first treated as tank vessels for purposes of liability caps. Based on the
Deepwater Horizon unit’s gross tonnage, its liability cap would be approximately $65 million
(per the National Pollution Funds Center).55 If removal and damage costs exceed this liability cap,
a MODU is deemed to be an offshore facility for the excess amount.56 Offshore facilities, like the
Gulf well leased to BP, have their liability capped at “all removal costs plus $75 million.”
The National Pollution Funds Center described the liability for this incident as follows:
The lessee of the area in which the offshore facility is located is clearly a responsible party for
the reported discharge below the surface from the well, an offshore facility. The OPA liability
limit, if it applies, is all removal costs plus $75 million. The owner of the MODU would also be a
tank vessel responsible party for any oil discharge on or above the surface of the water. The
MODU liability limit, if it applies, as a tank vessel, is approximately $65 million. If the OPA oil
removal costs and damages resulting from the discharge on or above the water exceed this
liability amount the MODU is treated as an offshore facility for the excess amount. In that case
the lessee of the area in which the offshore facility is located would be a liable responsible party
up to the offshore liability limit amount of all removal costs plus $75 million.57 (emphasis added
by CRS)

Loss of Liability Limit
Liability limits do not apply if the incident was “proximately caused” by “gross negligence or
willful misconduct” or “the violation of an applicable Federal safety, construction, or operating
regulation.” If one of these circumstances is determined to have occurred, liability would be
52

Congress recognized that “there is no comprehensive legislation in place that promptly and adequately compensates
those who suffer other types of economic loss as a result of an oil pollution incident.” U.S. Congress, House Committee
on Merchant Marine and Fisheries, report accompanying H.R. 1465, Oil Pollution Prevention, Removal, Liability, and
Compensation Act of 1989, H.Rept. 101-242, Part 2, 101st Cong., 1st sess., p. 31.
53
OPA § 1002(b)(1).
54
“Incident” means any occurrence or series of occurrences having the same origin, involving one or more vessels,
facilities, or any combination thereof, resulting in the discharge or substantial threat of discharge of oil. 33 U.S.C.
§ 2701(14).
55
See National Pollution Funds Center, “Oil Pollution Act Liabilities for Oil Removal Costs and Damages as They
May Apply to the Deepwater Horizon Incident” (undated).
56
33 U.S.C. § 2704(b).
57
See National Pollution Funds Center, “Oil Pollution Act Liabilities for Oil Removal Costs and Damages as They
May Apply to the Deepwater Horizon Incident” (undated).

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unlimited. In addition, the responsible party must report the incident and cooperate with response
officials to take advantage of the liability caps. According to the National Pollution Funds Center,
liability limits are “not usually well defined until long after response,” and litigation may be
required to resolve the issue. 58

Oil Spill Liability Trust Fund
Before the passage of OPA, federal funding for oil spill response was widely considered
inadequate, 59 and damage recovery was difficult for private parties.60 To help address these issues,
Congress established the Oil Spill Liability Trust Fund (OSLTF). Although Congress created the
OSLTF in 1986,61 Congress did not authorize its use or provide its funding until after the Exxon
Valdez incident.
The OSLTF is a federally administered trust fund that may be used to pay costs related to federal
and state oil spill removal activities, costs incurred by federal, state, and Indian tribe trustees for
natural resource damage assessments, and unpaid damages claims. 62 The fund is financed by a
per-barrel tax on crude oil received at U.S. refineries and on petroleum products imported into the
United States for consumption.63

OPA Compensation and Claims Process64
OPA established a compensation and claims process for removal costs and the costs/damages
identified above. 65 In general, claims for removal costs and damages must be presented first to the
responsible party (i.e., BP).66 If the party to whom the claim is presented denies all liability, or if
the claim is not settled by payment within 90 days after the claim was presented, the claimant
may elect either to initiate an action in court against the responsible party or to present the claim
directly to the OSLTF.67
The OSLTF managers are limited in the amount of payments that may be awarded for each
incident.68 Under current law, the per-incident cap is $1 billion. Some are now arguing that
58

National Pollution Funds Center, FOSC Funding Information for Oil Spills and Hazardous Materials Releases, April
2003, p. 4.
59
Cynthia Wilkinson et al., “Slick Work: An Analysis of the Oil Pollution Act of 1990,” Journal of Energy, Natural
Resources, and Environmental Law, 12 (1992), p. 188.
60
U.S. Congress, House Committee on Merchant Marine and Fisheries, report accompanying H.R. 1465, Oil Pollution
Prevention, Removal, Liability, and Compensation Act of 1989, H.Rept. 101-242, Part 2, 101st Cong., 1st sess., p. 35.
61
Omnibus Budget Reconciliation Act of 1986 (P.L. 99-509).
62

33 U.S.C. § 2712. The standards and procedural requirements for claims filed against the fund are set forth in the
USCG’s OPA regulations. See 33 C.F.R. §§ 136.1 through 136.241.
63
26 U.S.C. §§ 4611(a)(1) and (2). The Oil Spill Liability Trust Fund is also financed by a per-barrel tax on domestic
crude oil “used in or exported from the United States.” 26 U.S.C. § 4611(b)(1)(A).
64
Prepared by Jonathan L. Ramseur, Specialist in Environmental Policy.
65
OPA § 1013 (33 U.S.C. 2713). Implementing regulations are found in 33 C.F.R. Part 136.
66
33 U.S.C. § 2713(a). Under OPA, the term “claim” means “a request, made in writing for a sum certain, for
compensation for damages or removal costs resulting from an [oil spill] incident.” 33 U.S.C. § 2701(3).
67
33 U.S.C. § 2713(c). Claims for removal costs must be presented within six years after the date of completion of all
removal activities related to the oil spill incident. 33 U.S.C. § 2712(h)(1).
68
“Incident” means any occurrence or series of occurrences having the same origin, involving one or more vessels,
(continued...)

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increasing the per-incident cap would reduce the risk that parties (private citizens and
governments) would not be fully compensated for losses associated with an oil spill. Statements
from OPA’s legislative history suggest that drafters intended the fund to cover “catastrophic
spills.”69 However, $1 billion today does not have the same value as it did in 1990, when OPA
was enacted. Although OPA requires the President to issue regulations to adjust liability limits at
least every three years,70 an analogous provision for the per-incident cap does not exist. As a point
of reference, if the $1 billion figure had been adjusted for inflation, it would be approximately
$1.6 billion in today’s dollars.
On June 16, 2010, the President announced that BP had agreed to set aside $20 billion to pay
economic damage claims to people and businesses that have been affected by the oil spill. The
claims will be processed by an independent claims facility administered by Kenneth Feinberg. An
accompanying factsheet stated that the facility will develop and publish standards for claims. 71 As
of the date of this report, these standards are not yet available. It is uncertain whether these
standards will mirror OPA’s liability framework or to what degree they may differ. Further, it is
uncertain how the independent claims facility will interact with the existing claims process or if
the facility is simply a means by which BP is complying with the process. 72
Although the $20 billion fund established by BP may render the per-incident cap a moot issue for
the 2010 Gulf spill, a subsequent catastrophic spill could threaten the current per-incident cap
threshold. As a reference point, the 1989 Exxon Valdez spill tallied approximately $2 billion in
cleanup costs and $1 billion in natural resource damages in 1990 dollars. These combined figures
equate to approximately $5 billion in today’s dollars and would not include the wider array of
claims for which responsible parties are now liable.

Federal Regulatory Framework
Regulations to implement federal statutes are promulgated by numerous federal authorities and
vastly outnumber federal statutes. The bases for relevant federal regulation in this instance are,
among other statutes, OCSLA73 and the OPA. 74 The sheer number of regulations from these
statutes and from other federal laws complicates the description of the regulatory framework.
Frequently, case law, international measures, or other legal actions define the regulatory
parameters that apply to the Deepwater Horizon events. The roles of the lead federal regulators,
BOEMRE/MMS and the U.S. Coast Guard, are outlined below.

(...continued)
facilities, or any combination thereof, resulting in the discharge or substantial threat of discharge of oil. 33 U.S.C. §
2701(14).
69
U.S. Congress, House Committee on Merchant Marine and Fisheries, report accompanying H.R. 1465, Oil Pollution
Prevention, Removal, Liability, and Compensation Act of 1989, H.Rept. 101-242, part 2, 101st Cong., 1st sess., p. 36.
70
33 U.S.C. § 2704(d)(4).
71
See http://www.whitehouse.gov/the-press-office/fact-sheet-claims-and-escrow.
72
See http://www.bp.com/sectiongenericarticle.do?categoryId=9033791&contentId=7062345.
73
43 U.S.C. § 1331 et seq.
74
33 U.S.C § 2701.

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Bureau of Ocean Energy Management, Regulation, and
Enforcement (BOEMRE, Formerly MMS)75
BOEMRE/MMS is the agency within the Department of the Interior with lead regulatory
authority for offshore oil and gas leasing. Regulatory authority in the OCS encompasses resource
assessment and development, operational safety, and environmental considerations.
BOEMRE/MMS regulations generally require that a company with leasing obligations
demonstrate that proposed oil and gas activity conforms to federal laws and regulations, is safe,
prevents waste, does not unreasonably interfere with other uses of the OCS, and does not cause
impermissible harm or damage to the human, marine, or coastal environments.
Three types of regulatory authority govern OCS lease obligations: prescriptive requirements
generally codified in the Code of Federal Regulations, performance-based goals, and consensusbased technical standards. BOEMRE/MMS regulations cover a wide range of equipment,
procedures, and certifications. BOEMRE/MMS lease stipulations and regulations refer to maps,
communications, and contingencies such as hurricanes and other emergencies. Many of the rules
governing OCS exploration, development, and production are published in the Code of Federal
Regulations.76 The major statutes that govern the leasing process are discussed in the “OCS
Leasing” section.
Once the agency has issued a lease for oil and gas exploration and development rights, a lessee or
operator may submit an application to explore for oil and gas resources. Approval of the
exploration plan by the BOEMRE/MMS regional office is a prerequisite for drilling. After the
exploration phase, if the lessee decides to further develop the area governed by the lease, the
lessee must submit another application, typically a Development and Production Plan or a
Development Operations Coordination Document, for review and approval by BOEMRE/MMS.
In water depths greater than 400 meters (1,312 ft.), a lessee would also submit a Deepwater
Operations Plan and a Conservation Information Document. If a lessee seeks to use nonconventional production or completion technology such as floating or subsea production systems,
BOEMRE/MMS may provide a different approval process. The agency is responsible for
approving applications for a permit to drill (APDs), and subsequent BOEMRE/MMS approvals
are typically required for further drilling actions to sidetrack, bypass, or deepen a well.
It is difficult to determine at what stage in the BOEMRE/MMS approval process applicants
typically address financial assurances, precautionary actions to control development operations,
compliance with design criteria, and compliance with casing and cementing requirements.
Furthermore, it is difficult to determine the agency’s approval process for diverter and blowout
preventer systems in various exploration and development plans. Federal risk assessments are
typically conducted at numerous stages of the exploration and development planning process and
typically depend on risk assessments conducted at a previous stage in the leasing process.
Congress is interested in when risk assessments are conducted, and hearings are underway to
focus on the various stages of the BOEMRE/MMS leasing process. How the agency enforces
regulations and assesses financial penalties for violations, and how it would suspend or shut down
operations under certain conditions, have been raised as concerns since April 20, 2010.
75

Prepared by Curry L. Hagerty, Specialist in Energy and Natural Resources Policy.
See Code of Federal Regulations (30 C.F.R. Chapter 2, Minerals Management Service, Department of the Interior;
40 C.F.R., Protection of the Environment).
76

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Phases of the OCS leasing process undergo review under the National Environmental Policy Act
(NEPA),77 unless specifically excluded. Generally speaking, NEPA requires an agency to consider
the environmental impacts of its actions and prepare a document describing its analysis.
BOEMRE/MMS prepared four documents describing its environmental analysis related to the BP
lease: an environmental impact statement (EIS) for the five-year plan for all OCS leasing; an EIS
for the combined lease sales in the western and central Gulf of Mexico; an environmental analysis
for Lease Sale 206; and a categorical exclusion for the exploration plan for activity on the
Mississippi Canyon block 252.
A categorical exclusion (CE) may be used under NEPA when an agency has determined that a
type of project does not have significant impacts. A CE can be used unless certain exceptions—
typically referred to as extraordinary circumstances—exist, such as the presence of endangered
species or an archeological site. BOEMRE/MMS guidance provides that many exploration plans
in the Gulf can be categorically excluded from further NEPA review. (For a more comprehensive
discussion, see CRS Report R41265, The 2010 Oil Spill: MMS/BOEMRE and NEPA, by Kristina
Alexander.)

Wells
The operator is required, pursuant to provisions contained in 30 C.F.R. 250, to submit an APD
and obtain approval for it. BOEMRE/MMS reviews applications for drilling wells. Once a permit
is approved, the lessee is required to take precautions to keep all exploratory well drilling under
control at all times. There is increased interest in what constitutes compliance with “best available
and safest technology” (BAST) to address pressure conditions during drilling operations, and in
the potential for uncontrolled well flow. 78 According to federal regulations, operators in the Gulf
must use BAST whenever practical on all exploration, development, and production operations. 79
However, the regulations also state that, “[i]n general, we consider your compliance with
[BOEMRE/MMS] regulations to be the use of BAST.” The language of the regulation in effect
defines BAST as whatever complies with the agency’s regulation. Some observers question
whether the regulations preclude a more effective approach to BAST.

Platforms
The lessee typically designs, fabricates, installs, uses, inspects, and maintains platforms and
structures on the OCS to assure their structural integrity for the conduct of operations at specific
locations.80 BOEMRE/MMS program personnel typically use certified verification agents to
provide third-party expertise and technical input in the verification process. After installation,
platforms are required to be inspected. 81

77

42 U.S.C. § 4321 et seq.
Specific requirements for sundry notices for well workovers, completions, and abandonments are detailed in
Subparts D-G of 30 C.F.R. Chapter II.
79
30 C.F.R. 250.107.
80
30 C.F.R. 250.901-904.
81
30 C.F.R. 250.912.
78

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Equipment and Facilities
Equipment used on the OCS is regulated to assure the safety and protection of the human, marine,
and coastal environments. Surface- and subsurface-controlled safety valves and locks must
conform to federal requirements.82 Facilities also have requirements concerning electrical
systems, flow lines, engines, and firefighting systems.83

Role of U.S. Coast Guard84
The Coast Guard regulates certain activities at mobile offshore drilling units (MODUs) such as
the Deepwater Horizon. The Coast Guard generally overseas the safety of systems at the platform
level of a MODU, as opposed to the sub-platform drilling systems overseen by BOEMRE/MMS.
The areas of Coast Guard oversight include a MODU’s hull structure, navigation equipment,
lifesaving equipment, and fire protection equipment and structures; the safety of the electrical
system; and the safety and health of workers as they perform their routine tasks. The Coast Guard
is to conduct an initial review of a unit before it is allowed to operate. Once a MODU is
operating, the Coast Guard is to conduct a full survey of the rig every two years and an interim
inspection annually.
The Coast Guard’s regulatory framework for MODUs resembles that for ships calling at U.S.
ports. The “checklist” the Coast Guard uses when inspecting a MODU depends on its “flag” or
country of registration. Like ships engaged in international trade, MODUs on the OCS can be
registered in foreign countries. The Deepwater Horizon was registered in the Marshall Islands.85
Registering a rig or ship in the Marshall Islands or another “flag of convenience” (FOC) country
(Panama, Liberia, and the Bahamas are other common ones) provides tax and other economic
advantages. FOCs are also referred to as “open registries” or “international registries” because
they do not require that a vessel be owned or crewed by citizens of the flag state.86 For these
reasons, the world shipping fleet is predominantly flagged in these countries. According to the
regulatory compliance manager of the Deepwater Horizon, since MODUs can potentially be
moved around the world, international registries provide more flexibility as to where repairs can
be performed, the citizenship of the crew, and the timing of inspections. 87 Foreign-flagged rigs
either must meet the design, equipment, and operating standards of the flag state, provided the
Coast Guard determines they are equivalent to or more stringent than U.S. standards
(promulgated at 46 C.F.R. parts 108 and 109), or they must meet the design and equipment
standards contained in the International Maritime Organization (IMO) Code for the Construction
82

30 C.F.R. 250.801.
The safety-system devices are tested by the lessee at specified intervals and must be in accordance with numerous
certifications including API RP 14 C, Appendix D, and other measures.
84
Prepared by John Frittelli, Specialist in Transportation Policy.
83

85
This ship registry began in 1988 partly as a result of political instability in Panama and Liberia at the time. American
interests were instrumental in its creation, as is the case with the Panamanian, Liberian, and other ship registries. The
corporate headquarters of the Marshall Islands registry is located in Reston, VA, and the corporate headquarters of the
Liberian registry is located in Vienna, VA.
86
Elizabeth R. DeSombre, Flagging Standards: Globalization and Environmental, Safety, and Labor Regulations at
Sea (Cambridge, MA: MIT Press, 2006).
87
Oral and written testimony of Warren Weaver, Manager of Regulatory Compliance, Transocean, Ltd. before the
House Committee on Transportation and Infrastructure, Subcommittee on the Coast Guard and Maritime
Transportation, hearing on Foreign Vessel Operations in the U.S. Exclusive Economic Zones, June 17, 2010.

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and Equipment of MODUs (2009 MODU Code, adopted by Resolution A.1023(26)).88 The
Deepwater Horizon was inspected and found to be in compliance with the MODU code. 89

The International Maritime Organization (IMO)
The IMO is a U.N. body that has established international standards for the safety, security, and
prevention of pollution from ships. Its first convention, the International Convention for the
Safety of Life at Sea (SOLAS), was adopted in response to the Titanic disaster.90 The MODU
code was developed, beginning in the 1970s, to provide for a level of safety on MODUs
equivalent to that provided by SOLAS for ships. Countries must ratify IMO conventions and
enforce their requirements. The United States is a signatory to most IMO conventions, including
the MODU IMO convention. 91 Like the Coast Guard’s regulatory oversight, the IMO MODU
code does not address the drilling-related equipment of an oil rig.

Classification Societies
The offshore oil industry has also adopted classification societies as an institution of shipping
oversight. Classification societies are independent organizations that inspect a ship or oil rig and
certify that it meets the construction requirements and standards for its intended purpose. They
inspect only the physical elements of a rig, not the qualifications of the crew or how it is operated.
Inspections are performed during the construction phase as well as throughout the operating life
of a unit and become more thorough as the unit ages. Ship and oil rig owners pursue certification
from these societies for mortgage, insurance, and marketing reasons. Deepwater Horizon was
certified mostly by the American Bureau of Shipping (ABS), but also by Det Norske Veritas
(DNV).92 The Coast Guard checks for certification from approved classification societies when
inspecting both foreign and U.S.-flagged vessels or rigs.
Some have questioned the credibility of classification societies, because the societies are paid by
vessel owners. Classification societies typically have a for-profit side of their business, selling
technical expertise to vessel owners, and they compete with each other.93 They date back to the
mid-18th century, when insurers would hire ex-sea captains to survey ships. 94 Their pragmatic
knowledge of ships was useful for insurers assessing risk. Eventually, ex-captains were replaced
by naval engineers and technicians and standards were formalized in writing. For marketing
reasons, shipbuilders found it advantageous to build their ships to these standards and therefore
sought and paid for classification. Thus, from an insurer’s or banker’s perspective, a classification
society had a conflict of interest if it was being paid by a ship’s owner. In response, insurers and
banks began creating a separate method of inspection as their confidence in classification
societies eroded. Some of the classification societies established a trade association in 1969 to set
88

See http://www.imo.org/, and search under “MODU” for a brief description.
The Deepwater Horizon was built in 2001 and thus the 1989 version of the MODU code was applicable.
90
The convention has been updated since then.
91
See http://www.imo.org/, and select “status of conventions by country.”
92
The Deepwater Horizon’s record of certification and inspection can be viewed at http://cgmix.uscg.mil/PSIX/
PSIXSearch.aspx, searching under the vessel name or its number: 8764597.
93
“Quality Stem to Stern: The Changing Role of Classification Societies,” Marine Technology and SNAME News, vol.
34, no. 3 (July 1997).
94
Philippe Boisson, “Classification Societies and Safety at Sea: Back to Basics to Prepare for the Future,” Marine
Policy, vol. 18, no. 5 (1994), pp. 363-377.
89

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industry practices to address these concerns.95 In 2004, Congress required that the Coast Guard
not accept certifications by classification societies that are not a member of this trade association
or that have not been approved by the Coast Guard under specified criteria.96

Oil Spill Response Issues
Use of Dispersants97
Dispersants are chemical agents that include surfactants, solvents, and other compounds. By
reducing the connection (referred to as an interfacial tension) between oil and water, dispersants
enhance the breakup of an oil slick into small oil droplets that mix with the water column. Oil
spill dispersants do not reduce the amount of oil entering the environment; instead, dispersants
alter the physical properties of oil, changing its transport, fate, and potential effects.98
In general, the decision to use dispersants poses trade-offs for oil spill responders. The objective
of dispersant use is to minimize the amount of surface oil that reaches shoreline habitats, where it
threatens a wide range of wildlife and organisms. The downside is that dispersants increase the
exposure to oil of organisms living in the water column. As stated in a 2005 National Research
Council study, “[d]ispersant application thus represents a conscious decision to increase the
hydrocarbon load (resulting from a spill) on one component of the ecosystem (e.g., water column)
while reducing the load on another (e.g., coastal wetland).”99
Section 311(d) of the Clean Water Act (33 U.S.C. 1251 et seq.) requires EPA, in cooperation with
the states, to prepare a schedule of dispersants, other chemicals, and other spill-mitigating devices
and substances. The Product Schedule100 includes dispersants and other chemical or
bioremediation products that may be authorized for use on oil discharges in accordance with the
procedures set forth in the National Contingency Plan (NCP).
EPA may add products to the NCP Product Schedule after companies submit specific data to the
agency. Data requirements include results from effectiveness and toxicity testing. Although EPA
reserves the right to verify testing data (and to require additional information), the regulations do
not establish a toxicity threshold for placement on the schedule. A decision that a product is
eligible for listing on the Product Schedule does not constitute EPA approval of the product.
As part of their oil spill response preparations, Regional Response Teams (RRTs) and Area
Committees address the desirability of using dispersants and other oil control agents in particular
situations. Planners consider the potential sources and types of oil that might be spilled, the
existence and location of environmentally sensitive resources that might be impacted by spilled
95

The International Association of Classification Societies (IACS).
The Coast Guard and Maritime Transportation Act of 2004 (P.L. 108-293, § 413). The Coast Guard issued a notice
of proposed rulemaking on April 23, 2010; 75 Fed. Reg. 21212.
97
Prepared by Jonathan L. Ramseur, Specialist in Environmental Policy.
98
For a more comprehensive discussion, see National Research Council, Oil Spill Dispersants: Efficacy and Effects
(National Academies Press, 2005).
99
Ibid.
100
EPA, National Contingency Plan Product Schedule, May 2010, http://www.epa.gov/emergencies/docs/oil/ncp/
schedule.pdf.
96

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oil, available product and storage locations, the availability of equipment and adequately trained
operators, and the available means to monitor product application and effectiveness. Regional
Contingency Plans and Area Contingency Plans may preauthorize dispersants and the specific
contexts in which products should and should not be used, and many regions/areas have done so,
including those in the Gulf.101 Before authorizing dispersant use in an area without a
preauthorization plan, an On-Scene Coordinator must (1) seek and receive “concurrence” with the
RRT representative from EPA and representatives from states with jurisdiction, and (2), when
practicable, consult with trustees from the Departments of Commerce and the Interior.
An unprecedented volume of dispersants (at least for U.S. waters) has been applied to the oil spill
in the Gulf. While dispersants have proven effective in breaking up the oil on the surface,
numerous questions remain regarding the fate of the dispersed oil and the chemical dispersants.
Moreover, the application of undersea dispersants is essentially experimental. 102 Many have
raised questions about the toxicity of the dispersant BP has been using in the Gulf. Although it is
on the NCP schedule, other dispersants are listed as both more effective and less toxic. 103
On May 20, 2010, EPA and the Coast Guard directed BP to evaluate available, preapproved
dispersants for toxicity and effectiveness.104 On May 22, BP responded by (generally) concluding
that the dispersant being used (COREXIT) continued to be the best option.105 On May 26, 2010,
EPA and the Coast Guard directed BP to “eliminate the surface application of dispersants. In rare
cases when there may have to be an exemption, BP must make a request in writing to the FOSC
[the Coast Guard OSC] … to justify the use of surface application. The FOSC must approve the
request and volume of dispersant prior to initiating surface application” (emphasis added).106
When this directive was made, BP had applied a reported 700,000 gallons of dispersants to the
surface waters. Since the directive, responders have applied an additional (approximately)
300,000 gallons on the surface, at a fairly consistent daily rate (Figure 2). However, as of July 16,
data indicated that July 6 was the last surface application. For up-to-date information from EPA,
see http://www.epa.gov/bpspill; for more current dispersant application data, see
http://www.deepwaterhorizonresponse.com.

101

See Figure 2-1 in National Research Council, Oil Spill Dispersants: Efficacy and Effects (National Academies Press,
2005).
102
Nancy Kinner (co-director of the Coastal Response Research Center), testimony before the House Committee on
Transportation and Infrastructure, May 19, 2010.
103
More information is available at EPA’s website, at http://www.epa.gov/bpspill/dispersants.html.
104
See http://www.epa.gov/bpspill/dispersants/bp-hayward-dhs-epa.pdf.
105
See http://www.epa.gov/bpspill/dispersants/5-21bp-response.pdf.
106
See http://www.epa.gov/bpspill/dispersants/directive-addendum3.pdf.

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Figure 2. Cumulative Dispersant Application in Gulf Oil Spill
1,200,000
1,000,000

Gallons

800,000
600,000
400,000
200,000

Surface Application

7/
9/
10

4/
23
/1
0
4/
30
/1
0
5/
7/
10
5/
14
/1
0
5/
21
/1
0
5/
28
/1
0
6/
4/
10
6/
11
/1
0
6/
18
/1
0
6/
25
/1
0
7/
2/
10

0

Subsurface Application

Source: Prepared by CRS with data from daily “Current Operations” updates, available at
http://www.deepwaterhorizonresponse.com.
Notes: Data for some days were not available. In these instances, the volume for the previous day was used.

Louisiana Protective Berm Project107
On May 11, 2010, the U.S. Army Corps of Engineers (Corps) received a request from the state of
Louisiana’s Coastal Restoration and Protection Authority (LCRPA) for an emergency permit to
construct a project of approximately 86 miles of sand berms in order to protect Louisiana’s barrier
islands and coastal wetlands from damage by the Deepwater Horizon oil spill. 108 Supporters of
the plan to construct the protective berms (including federal agencies and nongovernmental
entities) argue that the project is a promising means to mitigate the effects of the oil spill in
Louisiana. They note that the urgent situation associated with the oil spill requires that the project
move forward with maximum speed and regulatory flexibility. These observers contend that,
combined with other natural barriers in the Gulf, strategically placed berms of relatively small
size and minimal cost will protect large areas of coastline and wetland habitat from oil pollution.
Some have expressed doubts regarding the barrier project. Specifically, agency and
nongovernmental stakeholders have questioned the feasibility and effectiveness of the barriers.109
Further, some scientists—including those from the National Oceanic and Atmospheric
107

Prepared by Charles V. Stern, Analyst in Natural Resources Policy.

108

Under 33 C.F.R. § 325(b), authorization (through a permit) by the Corps of Engineers is required to conduct certain
regulated activities within waters of the United States. This requirement is maintained during emergencies, although the
Corps has modified procedures to expedite permit processing during an emergency under 33 C.F.R. § 235.2(e)(4).
109
One of the main critiques associated with feasibility of the project is timing. By some estimates, even if construction
is initiated immediately, it would not be complete until the end of the calendar year. Additionally, questions have been
raised as to the ability of the berms to withstand tidal fluctuations and storms, including hurricanes.

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Administration (NOAA), the U.S. Geological Survey (USGS), and the Fish and Wildlife Service
(FWS)—have expressed preliminary concerns about the potential of the barriers to disrupt tidal
currents and ocean circulation patterns, and to have other long-term environmental impacts.110
These observers note the unprecedented nature of large-scale berm construction of this type, and
advocate for a significant degree of caution moving forward on this project.
The original request by LCPRA proposed to construct 86 miles of berms standing 6 feet above the
mean high water line in and around areas near Louisiana barrier islands in the Gulf. The plan
called for the berms to be built largely from dredge and fill materials taken from nearby areas
(including some barrier islands), and to leave open certain deepwater channels for tidal influx.
The State of Louisiana estimated the preliminary cost of this plan to be $350 million. After
subsequent discussions between LCPRA and the Corps, the state submitted a new permit request
that revised the location from which certain borrowed materials would be taken, as well as the
coverage areas of the berms themselves. The revised request was submitted on May 14, 2010, and
circulated by the Corps for interagency comment on May 17, 2010.111 This revised version of the
plan requested 128 miles of barriers over 19 separate areas (also known as reaches). Construction
of the revised plan was estimated to take six to nine months, and no cost estimate was provided
for this version of the plan.
Following interagency coordination and submission of comments, the Corps partially approved
the LCPRA request on May 27, 2010. The Corps permit noted that approval of the project did not
eliminate the need for a number of other associated requirements, including an FWS Special Use
Permit, a Louisiana Coastal Use Permit, and approval from BOEMRE/MMS to dredge certain
offshore borrow sites.
The Corps approved six reaches (four reaches to the west of the Mississippi River Delta, and two
reaches to the east) of the revised request by the state.112 The final Corps environmental analysis
noted that the state’s proposal was not selected in its entirety because of its potential to increase
tidal circulation and reduce pathways for the oil to be flushed back out to sea.113 Additionally, the
Corps highlighted concerns with the longevity of the structures and the timing of construction.
The Corps concluded that the selected six reaches would offer the greatest immediate benefits
without adverse environmental impact. The Corps noted that subsequent construction decisions
may be based on monitoring of the initial structures.
Responsibility for financing and construction of the approved reaches of berm is an ongoing
concern. In early June, National Incident Commander Thad Allen announced that the federal
government would direct BP to pay for all six reaches approved by the Corps.114 BP announced
support for this decision and estimated the cost for construction of the approved plan to be $360
110

Concerns with the barriers are noted in the final permitting documents at http://155.76.147.200/news/
Emergency%20Permit%20Documents%20Compressed%20FINAL.pdf. Additionally, Admiral Allen noted the initial
concerns of Dr. Jane Lubchenco, NOAA Administrator, with the barriers at a press conference on June 2, 2010. See
http://www.deepwaterhorizonresponse.com/go/doc/2931/581707/.
111
The request was revised in part because the original proposal for a coastal restoration project did not qualify under
Corps emergency authorization procedures.
112
The original request’s 19 reaches of berm included 15 reaches to the west of the Mississippi River Delta and four
reaches to the east.
113
See environmental analysis by the Corps at http://155.76.147.200/news/
Emergency%20Permit%20Documents%20Compressed%20FINAL.pdf, pp. 88-89.
114
See http://www.deepwaterhorizonresponse.com/go/doc/2931/585863/.

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million. 115 Notably, while BP has agreed to make payments based on project milestones, it has
also stated that it will not manage project construction or assume any liability associated with the
project. 116
Congress may consider what role, if any, the federal government should play in construction,
upkeep, and monitoring of the Barrier Island Project. Responsibility for management of the
barriers’ construction has not been formalized, although National Incident Commander Thad
Allen has previously asserted that the state will have primary responsibility.117 Additionally, it is
unclear who will assume ownership and liability of the barriers after they are constructed, and
over what period of time the barriers will be maintained. Maintenance and monitoring
requirements could result in additional costs beyond the original construction estimates, and BP
has not indicated whether it will accept any additional responsibility for these elements. Finally, it
is unclear whether other states in the Gulf region intend to pursue similar barrier strategies in
response to the oil spill, and whether federal decisions on the Louisiana project would apply to
these and other future efforts.

Relief Wells118
On May 2, 2010, 12 days after the Deepwater Horizon drill rig exploded and caught fire, BP
began drilling the first of two relief wells, with the goal of intersecting the Deepwater Horizon
well near the bottom and plugging it with heavy mud and cement. At the request of the Obama
Administration, BP began drilling a second relief well on May 16 to provide a second chance at
plugging the well if the first relief well failed. Both wells are being drilled vertically and then
turned at an angle to intercept the Deepwater Horizon well just above the oil- and gas-producing
reservoir at about 18,000 below sea level. (See Figure 3.) As of June 13, 2010, the first relief well
had reached 13,973 feet and had begun to drill at an angle of 35 degrees; the second relief well
had reached 9,022 feet and was still drilling vertically. BP and the Administration estimate that it
will take several months, possibly until August, for the first relief well to reach the target area.119

What Are Relief Wells?
A relief well is drilled and constructed similarly to an exploration well but for a different purpose.
Instead of drilling to intersect a petroleum-bearing horizon and to produce oil and gas, a relief
well is drilled to intersect an out-of-control well that suffered a blowout. The relief well is guided
to the blown-out well and drilled into the existing well casing, and then heavy drilling mud and
cement are injected into the well to form a permanent plug. The plug is intended to prevent oil
and gas from flowing from the petroleum-bearing reservoir into the wellbore of the blown-out
well and up to the surface.
115

In light of questions raised about the original cost estimate by the state of Louisiana for the larger project during the
interagency comment period, BP appears to have used a more conservative estimate for the six reaches approved by the
Corps.
116
See http://www.bp.com/genericarticle.do?categoryId=2012968&contentId=7062613.
117
See, for example, June 2 press briefing by Admiral Thad Allen, at http://www.deepwaterhorizonresponse.com/go/
doc/2931/581707/.
118
Prepared by Peter Folger, Specialist in Energy and Natural Resources.
119
Deepwater Horizon Response site, Ongoing Response Timeline, at http://www.deepwaterhorizonresponse.com/
posted/2931/updated_timeline_June_10.594723.pdf. Greg Bluestein and Jason Dearen, “Spill Relief Well Draws
Scrutiny,” Associated Press, June 13, 2010., at http://news.yahoo.com/s/ap/20100613/ap_on_bi_ge/
us_gulf_oil_spill_relief_wells.

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Figure 3. Image of Two Relief Wells Being Drilled by BP to Plug the
Deepwater Horizon Well

Source: BP, modified by CRS.
Notes: Relief well 1 had reached a depth of 13,973 feet below sea level and relief well 2 had reached 9,022 feet
as of June 13, 2010. Numbers listed next to the trace of the relief well locations indicate the diameter of casing
at that point (e.g., CSG-36 indicates 36-inch diameter casing).

Examples of Relief Wells Being Used to Stop Blowouts
On June 3, 1979, more than 30 years prior to the Deepwater Horizon disaster, the Ixtoc I
exploration well blew out in the Bay of Campeche, Mexico, resulting in a rig fire and subsequent
sinking of the rig into 167 feet of water in the southern Gulf of Mexico. According to NOAA, the
blowout resulted in the release of 10,000 to 30,000 barrels of oil per day until the leak was
stopped on March 23, 1980, 290 days later.120 According to reports, two relief wells were drilled
to intersect the well near the petroleum-bearing reservoir after other attempts to cap the well on
the seafloor failed. Relief well Ixtoc 1A was spudded121 in the middle of June and relief well Ixtoc
1B was spudded in the middle of July.122 Ixtoc 1A reached the petroleum-bearing reservoir in the
120

National Oceanic and Atmospheric Administration, National Ocean Service, Office of Response and Restoration,
Incident News, at http://www.incidentnews.gov/incident/6250.
121
To “spud” a well means to start drilling into the sediments and rock.
122
Arne Jernelöv and Olof Lindén, “Ixtoc I: A Case Study of the World’s Largest Oil Spill,” Ambio, vol. 10, no. 6
(1981).

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second week of February, approximately eight months after relief well drilling began. Mud
pumped through the relief wells finally stopped the uncontrolled leak in Ixtoc 1 five weeks
later.123
On August 21, 2009, a drill rig operating in the Montara oil field about 140 miles northwest of the
northern Australian coastline suffered a blowout and uncontrolled release of oil on the seafloor in
water approximately 240 feet deep. It is still unclear how much oil was leaking per day, although
the rig operator initially estimated that about 400 barrels per day were being released into the
ocean. Other reports indicate that as many as 2,000 barrels per day were leaking. 124 A relief well
was drilled to intersect the original well near the petroleum-bearing reservoir approximately
13,000 feet below the ocean bottom. After multiple attempts, mud injected into the leaking well
finally stopped the leak on November 3, about 10 weeks after the initial blowout.125 A
commission appointed by the Australian Minister for Resources and Energy is investigating the
blowout, and is expected to release a report soon.126

Relief Well Policies
Relief wells are mentioned in several places in federal regulations that govern offshore oil and
gas development for the U.S. OCS, which includes the U.S. Gulf of Mexico.127 Under 30 C.F.R.
§ 250.213, an exploration plan (EP) approved by BOEMRE/MMS for oil and gas operations in
the OCS must show that a company has or will have the financial capability to drill a relief well
or conduct other emergency well control operations. The EP must also indicate the availability of
a rig to drill a relief well, and an estimate of the time it would take to drill a relief well. Under 30
C.F.R. § 250.243, a company’s development and production plan, or development operations
coordination documents, must also contain the same information: financial capability, rig
availability, and estimated time to drill a relief well. The current regulations do not indicate that a
drill rig must be on-site and ready to drill a relief well if a blowout occurs.
An exhaustive review of regulations governing relief wells in other countries is beyond the scope
of this report. However, news reports have frequently cited Canadian policies regarding relief
wells.128 An issue for Canada that is not pertinent to the Gulf of Mexico is offshore drilling in
regions where sea ice covers the ocean surface during the colder months, and the possible need to
drill a relief well during the months when the sea is ice-free (a so-called “same-season” relief
well). For example, if an offshore well suffers a blowout and uncontrolled leak at the end of the
drilling season, a relief well drilled to curtail the blowout may not have sufficient time to reach
the well and inject mud and cement before the winter ice forms and causes drilling operations to
cease. The “same-season” relief well issue is of concern to offshore drilling in the Beaufort Sea
(which also borders parts of Alaska), but may not necessarily be an issue for offshore drilling off
the coasts of Newfoundland, Labrador, or Nova Scotia.
123

Ibid.
Keith Bradsher, “Relief Well Was Used to Halt Australian Spill,” New York Times, May 2, 2010.
125
Ibid.
126
See http://www.montarainquiry.gov.au/index.html for more information on the Montara oil spill.
127
See 30 C.F.R. § 250 for the regulations covering oil and gas operations in the OCS.
124

128
See, for example, Greg Bluestein and Jason Dearen, “Spill Relief Well Draws Scrutiny,” Associated Press, June 13,
2010; and Peter Overby, “BP Sought to Ease Canada’s Policy on Relief Wells,” NPR, June 3, 2010, at
http://www.npr.org/templates/story/story.php?storyId=127381814.

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According to the Canadian National Energy Board, which governs offshore drilling in the
Beaufort Sea, the regulations require project-specific contingency plans that must include all
measures to respond to an emergency situation with an offshore well. 129 The Beaufort Sea
regulations contain a definition for relief well (“a well drilled to assist in controlling a blow-out in
an existing well”), but do not contain language specifically requiring a relief well as part of the
contingency plan. 130 Offshore drilling in Canada is also governed regionally by joint federalprovincial agreements, and regulated under the Canada-Newfoundland and Labrador Offshore
Petroleum Board and the Canada-Nova Scotia Offshore Petroleum Board.131 In a letter to the
editor of the Ottawa Citizen, the chairs of the Canada-Newfoundland and Labrador Offshore
Petroleum Board, the Canada-Nova Scotia Offshore Petroleum Board, and the National Energy
Board wrote:
The new drilling and production regulations state that companies are required to provide
contingency plans describing how they plan to mitigate the effects of any reasonably foreseeable
event that might compromise safety or environmental protection, which absolutely would include
mitigating the effects of a blowout. Relief wells are a proven method of regaining well control
and none of the regulatory boards would authorize companies to conduct any drilling or
production activities if the contingency plans did not adequately address the drilling of a relief
well.132

In response to some statements that relief well regulations have been relaxed under the current
Canadian government, Christian Paradis, Minister of Natural Resources for Canada, wrote:
Drilling program guidelines pertaining to relief wells have remained the same since 1990. These
guidelines specifically address the issue of relief wells, and explicitly state that “operators are
expected to identify an alternate drilling installation for relief well purposes and provide a
description of its operating capability, its location, contractual commitments, and state of
readiness.” The adequacy of these arrangements constitutes a crucial aspect of the board’s
decision of whether or not to issue an authorization to drill in the first place. 133

Issues for Further Consideration
Establishing a new policy for relief wells has captured the interest of the Administration and
Congress. In response to a question about requiring oil companies to drill relief wells
simultaneously to the production of oil, National Incident Commander Thad Allen stated that it
would be a legitimate point to be raised and put in front of the national commission on the BP oil
spill established by President Obama.134 On June 15, 2010, Senator Lautenberg introduced S.
3492, the Emergency Relief Well Act, that would require the concurrent drilling of at least one
129

E-mail from Sarah Kiley, Communications Officer, National Energy Board (Canada), June 11, 2010.
Under the Canada Oil and Gas Drilling and Production Regulations, Part 2—Management System, Application for
Authorization and Well Approvals, Application for Authorization, the application for authorization “shall be
accompanied by … contingency plans, including emergency response procedures, to mitigate the effects of any
reasonably foreseeable event that might compromise safety or environmental protection.” See http://laws.justice.gc.ca/
PDF/Regulation/S/SOR-2009-315.pdf.
131
E-mail from Sarah Kiley, Communications Officer, National Energy Board (Canada), June 11, 2010.
132
Max Ruelokke, Diana Dalton, and Gaétan Carron, “Address Relief Wells,” Ottawa Citizen, June 11, 2010.
133
Christian Paradis, “Drilling Guidelines on Relief Wells the Same,” Ottawa Citizen, June 14, 2010.
130

134
White House Press Briefing by Press Secretary Robert Gibbs and National Incident Commander Admiral Thad
Allen, June 7, 2010, at http://www.whitehouse.gov/the-press-office/press-briefing-press-secretary-robert-gibbs-andnational-incident-commander-admiral.

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relief well whenever a new exploratory or development well is drilled. A requirement to drill a
relief well concurrently with a new exploratory or development well would raise a number of
safety and economic issues for offshore drilling.
A rationale for drilling a relief well concurrently with drilling and exploration or development
well would be to shorten the time, possibly by months for deep wells, between a blowout and
when a leak is plugged. For example, the two relief wells now being drilled to intercept the
Deepwater Horizon well are expected to take several months to reach the target zone. Plugging a
well in days or weeks instead of months could prevent large quantities of oil and gas from leaking
from a blown-out well that otherwise would leak over the time it takes to drill a relief well. The
actual drilling and completion of a relief well, however, would likely require the same or even
greater attention to safety so as not to experience a similar blowout while drilling into the same
geological formation. Thus drilling a relief well is not a risk-free proposal, and a possibility
would still exist for anomalous gas “kicks”135 in the well and for a blowout if the gas kicks are not
prevented or controlled.
Drilling a relief well with the same equipment needed for an exploration and development well,
such as semi-submersible drilling platforms, marine risers, casing, cement, and blowout
preventers, would likely mean that the cost to drill an exploration or development well would rise
significantly compared to current practices. Whether costs would double—twice the wells
required compared to current practices—is unclear, and might depend on whether a
simultaneously drilled relief well could ultimately also be used for exploration, development, or
production in the same oil and gas field.
For deepwater and ultra-deepwater drilling requiring semisubmersible rigs or drill ships capable
of drilling 4,000 feet or more below the seabed, the average daily rate for the drill rigs exceeds
$400,000 per day.136 The time to drill and complete a well depends on water depth and how deep
the petroleum-bearing reservoir lies beneath the seabed. Deeper water and deeper reservoirs
require more time to drill. For example, BP began drilling the Deepwater Horizon well in 5,000
feet of water on October 21, 2009. BP halted operations on November 28 because of damage to
the rig caused by Hurricane Ida, resumed drilling on February 3, 2010, and was nearing
completion of the well at a depth of 18,000 below sea level on April 20 when the blowout and fire
occurred. Total time drilling until the disaster was approximately 114 days. Assuming drill rig
costs of $400,000 per day, the Deepwater Horizon well rig costs were approximately $45 million
when the April 20 accident occurred. Presumably, costs to drill a concurrent relief well would be
approximately the same. Currently there are 31 drill rigs operating in 5,000 feet or deeper waters
in the U.S. Gulf of Mexico.137
An option to have a drill rig “standing by” but not actually drilling a relief well unless the
exploration or development well experienced a blowout might be less costly than drilling two
concurrent wells. If a blowout occurred, then the relief well would be positioned to begin drilling
immediately. During the Deepwater Horizon incident, 12 days elapsed before the first relief well
was spudded. Nevertheless, the Deepwater Horizon relief wells will take months to drill, so

135

A “kick” is the flow of reservoir fluids into the wellbore during drilling operations.
Rigzone, Offshore Rig Day Rates, at http://www.rigzone.com/data/dayrates/.
137
As reported by Rigzone, Offshore Rig Search, at http://www.rigzone.com/data/advanced_search.asp, as of June 17,
2010.
136

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whether the time saved—and quantity of oil leaked—would be worth the expense of keeping a
drilling operation on “stand-by” is another challenging policy issue.

Response Vessels and the Jones Act138
A law commonly known as the Jones Act requires that cargo transported between any two U.S.
points be transported by a U.S.-built, -owned, and -documented vessel (requiring a U.S. crew). 139
This law applies to oil spill response vessels, such as skimmers, operating within 3 miles of the
U.S. coastline. The law does not apply to response vessels outside the 3-mile limit, and as of June
15, 2010, 15 foreign-flagged vessels were engaged in oil spill cleanup activities.140 Within the
3-mile limit, foreign oil spill response vessels can be used if there is an inadequate supply of U.S.
oil spill response vessels and the foreign country has a reciprocal agreement with the United
States.141 The U.S. Maritime Administration is responsible for checking on the availability of U.S.
vessels if a waiver is requested and in one instance with regard to the current spill found that U.S.
vessels were available to perform the task.142 Some contend that the Jones Act is hindering
cleanup efforts by delaying or preventing foreign offers of assistance, while others contend that
many U.S. oil spill response vessels are sitting idle. The National Incident Command Center has
stated that no offers of foreign assistance have been declined because of the Jones Act.143
Dredging must also be performed by U.S. vessels, and thus this requirement would be applicable
to the Louisiana Protective Berm Project.144 For vessels not considered to be oil spill response
vessels, a Jones Act waiver could be obtained pursuant to 46 U.S.C. § 501, which also requires a
determination that not enough U.S. vessels are available.

Investigations and Commissions145
Several investigations and commissions have been initiated to look into various issues
surrounding the Deepwater Horizon incident. For the most part, these examinations are still in
their early stages.
•

The President directed the Secretary of the Interior to provide a study of current
safety measures for OCS activities. Made available on May 27, 2010,146 the
study—Increased Safety Measures for Energy Development on the Outer

138

Prepared by John Frittelli, Specialist in Transportation Policy.
46 U.S.C. § 55102.
140
Coast Guard press release dated June 15, 2010, at http://www.deepwaterhorizonresponse.com/go/doc/2931/660195.
141
46 U.S.C. § 55113.
139

142

Written testimony of David T. Matsuda, Acting Maritime Administrator, before the Subcommittee on the Coast
Guard and Maritime Transportation, House Committee on Transportation and Infrastructure, hearing on Foreign Vessel
Operations in the U.S. Exclusive Economic Zones, June 17, 2010.
143
National Incident Command, “Jones Act Fact Sheet,” June 18, 2010, at http://www.deepwaterhorizonresponse.com/
posted/2931/MARAD_revised_Jones_Act_Fact_Sheet.670991.pdf.
144
46 U.S.C. §§ 55109, 55110.
145
Prepared by Jonathan L. Ramseur, Specialist in Environmental Policy.
146
The May 27 study is available at http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=security/getfile&
PageID=33598.

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Continental Shelf—was the first of several formal investigatory measures related
to the Deepwater Horizon accident and oil spill.
•

The Secretaries from the Departments of the Interior and Homeland Security
directed the Coast Guard and BOEMRE/MMS to conduct a joint investigation.
The objective of the investigation is to develop conclusions and
recommendations as they relate to the Deepwater Horizon explosion and loss of
life on April 20, 2010.147

•

President Obama established the Bipartisan National Commission on the BP
Deepwater Horizon Oil Spill and Offshore Drilling. The commission is tasked
with providing recommendations on how to prevent—and mitigate the impact
of—any future spills that result from offshore drilling. The commission’s first
meeting was on July 12.

Many companies (including BP), trade groups, and industry standards organizations are
conducting internal reviews. The focus of private-sector investigations tends to include testing the
use of blowout preventers and other procedures, as well as testing other safety, communications,
and operational procedures.

Environmental and Economic Impacts
Oil spills can cause significant harm to living organisms that inhabit ocean and coastal areas and
may result in significant costs to businesses and the public. Coastal areas may be especially
vulnerable because of oil stranding in wetlands and other coastal ecosystems. Oil coating, and
absorption or ingestion of oil, result in direct mortality and sublethal effects that reduce the fitness
of organisms. For example, oil can coat small animals and plants that inhabit shoreline areas and
suffocate them. The uptake of dissolved components of oil may be toxic for fish, shellfish, and
other invertebrates and plankton. Birds and fur-bearing marine mammals are among the most
vulnerable species. When coated by oil, they lose protection and body heat maintained by their
feathers and fur, and they may also ingest oil when preening. Coastal habitats may require years
or decades to recover from lethal levels of oil exposure. 148

Environmental Impacts149
When natural resources are affected by oil spills, services that benefit the public may be damaged.
Services can be divided into different categories, depending on the nature of the benefits they
provide:150
•

Supporting services—processes that provide the foundation for all ecosystem
services, such as nutrient cycling and primary production.

147

More information is available at http://www.restorethegulf.gov/investigation.shtm.
CRS Report R41311, The Deepwater Horizon Oil Spill: Coastal Wetland and Wildlife Impacts and Response, by M.
Lynne Corn and Claudia Copeland.
149
Prepared by Harold F. Upton, Analyst in Natural Resources Policy.
150
Walter Reid et al., Millennium Ecosystem Assessment: Ecosystems and Human Well-being (Washington, DC: Island
Press, 2005).
148

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•

Provisioning services—direct material benefits that humans receive from the
products of ecosystems, such as food (fisheries), timber, and genetic resources.

•

Regulating services—indirect benefits provided by natural systems, such as
retaining and purifying of water in wetlands or mitigation of natural hazards
(e.g., storms) by coastal marshes and mangrove forests.

•

Cultural services—a broad category that includes the general values humans
place on natural areas. Benefits may be gained through direct use, such as
recreational activities (recreational fishing and swimming), or through the value
placed by the public on the continued existence of natural resources, including
aesthetic values, bequest or generational values, and community and spiritual
connections to natural resources.

Natural Resource Damage Assessment and Compensation
OPA addresses natural resource damages and the restoration of resources that are injured and
services that are lost as the result of an oil spill. Designated federal, state, tribal, and sometimes
foreign trust agencies are responsible to act on behalf of the public. OPA directs trustees to
undertake two main actions: (1) return injured natural resources to their baseline condition (the
condition that existed prior to the spill), and (2) recover compensation for interim losses.
Restoration actions focus on returning natural resources to the baseline level with as much
certainty and as quickly as possible. Compensation includes actions to address interim losses of
natural resources and services until resources have recovered. Compensatory actions provide
services of the same type and quality and of comparable value as those lost or injured. Damage
assessment is required to quantify the extent of injuries to natural resources and to determine the
type and amount of restoration and compensatory actions needed. The process of recovery can be
broken down into three main phases:151
•

Pre-assessment phase—determines whether natural resource injuries have
occurred or are expected and whether to continue to the next phase.

•

Restoration planning phase—evaluates potential injuries to natural resources.
This phase includes an assessment of the nature and extent of natural resource
injuries and development of plans for restoring the resource and compensating
the public for interim losses.

•

Restoration phase—the final restoration plan is presented to responsible parties
to implement or fund the plan. This provides the opportunity for settlement of
damages claims without litigation. However, OPA authorizes trustees to bring
civil action for damages.

In addition, natural resource impacts may disrupt business activity, especially sectors that depend
directly (or indirectly) on natural resources and the environment. Direct economic losses may
accrue from the closure of fishing grounds, effects on port operations, or the loss of tourist-related
business. Unlike natural resource damages, which are considered by the appropriate natural
resources trustees, costs to businesses are submitted as claims by the third parties that suffer the
loss (as discussed above in “OPA Compensation and Claims Process”).
151

Department of Commerce, “Natural Resource Damage Assessments; Final Rule,” 61 Fed. Reg. 441-442, January 5,
1996.

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Environmental Recovery
NOAA regulations state that recovery means the return of injured natural resources and services
to baseline. 152 Defining the baseline condition of the ecosystem is often hindered by limited
scientific understanding of physical and biological processes in coastal and marine areas, natural
variability of marine systems, and a paucity of related scientific data. These factors are coupled
with uncertainties about acute and chronic effects of oil on marine organisms. In the face of these
uncertainties, it is possible that questions related to restoration and compensation will arise,
including basic questions about what constitutes ecosystem recovery and when it has occurred.

Economic Impacts
Natural Resources and Related Economic Activity153
Natural resource-dependent sectors of the Gulf coastal economy that have been affected by the oil
spill include commercial and recreational fisheries and the tourist industry. In 2008, the Gulf
fishing industry landed 1.274 billion pounds of fish and shellfish with a dockside value of $659
million. 154 When related processor, wholesale, and retail businesses are included, the Gulf
seafood industry supports over 200,000 jobs with related income impacts of $5.5 billion.155 The
top commercial species in terms of value are shrimp ($367 million), menhaden ($64 million),
oysters ($59 million), and blue crab ($38 million).156 Recreational fisheries also make significant
contributions to the region’s economy. In 2008, recreational anglers took 25.4 million fishing trips
and spent over $12 billion on equipment and trips in the Gulf region. 157 Some of the most popular
recreational species include snappers, several types of drum, sheepshead, and Spanish mackerel.
Recreational fisheries support businesses such as charters and bait and tackle shops, and services
such as restaurants and hotels. In 2000, 21.9 million people visited Gulf beaches and accounted
for 177.2 million beach days.158 The tourist industry contributed 620,000 jobs and over $9 billion
in wages to the Gulf region. On the other hand, jobs related to cleanup activities could mitigate
some of the losses in the fishing and tourism industry.
Immediate economic injuries of the oil spill have been incurred by the Gulf of Mexico fishing
industry. As of July 14, 2010, NOAA had closed 83,927 square miles of the Gulf to commercial
and recreational fishing (Figure 4).159 This is approximately 35% of the federally managed waters
of the Gulf exclusive economic zone. 160 Portions of Louisiana, Alabama, Mississippi, and Florida
state waters have also been closed. These areas are some of the richest fishing grounds in the Gulf
for major commercial species such as shrimp, blue crab, and oysters. Fishermen have filed claims
152

Ibid., p. 441.
Prepared by Harold F. Upton, Analyst in Natural Resources Policy.
154
National Marine Fisheries Service, U.S. Department of Commerce, Fisheries Economics of the United States, Silver
Spring, MD, 2008, http://www.st.nmfs.noaa.gov/st5/publication/econ/2008/FEUS%202008%20ALL.pdf.
155
Ibid.
156
Ibid.
157
Ibid.
158
Brent Ache, David Bylsma, and Kristen Crossett, et al., The Gulf of Mexico at a Glance, National Ocean Service,
NOAA, A Tool for the Gulf of Mexico Alliance and the American Public, Washington, DC, 2008,
http://gulfofmexicoalliance.org/pdfs/gulf_glance_1008.pdf.
159
See http://sero.nmfs.noaa.gov/deepwater_horizon_oil_spill.htm.
160
The exclusive economic zone includes the area between 3 and 200 nautical miles from shore.
153

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with BP for economic injuries, and claims are being paid out to individuals on a monthly basis.
As the supplies of Gulf oysters, shrimp, and crabs have decreased, prices for these items have
increased. Imports of shrimp are likely to increase to substitute for lost domestic production.161
The seafood industry is also very concerned with consumers’ perceptions of Gulf seafood and
potential effects on demand for Gulf seafood products. To ensure seafood safety, NOAA and FDA
are monitoring fish caught just outside closed areas and testing them for oil compounds.
Bookings and trips for recreational fishing charters have decreased, especially in Louisiana, and
sportfishing tournaments have been cancelled.
Figure 4. Gulf of Mexico Fishery Closure
(as of July 14, 2010, unchanged from July 12, 2010))

Source: NOAA, http://sero.nmfs.noaa.gov/deepwater_horizon_oil_spill.htm.
Notes: For more recent closing announcements, see NOAA’s website, at http://sero.nmfs.noaa.gov/
deepwater_horizon_oil_spill.htm.

Oil has reached many central Gulf of Mexico beaches, and visits to these areas have decreased
significantly. Cancellations have also been reported for areas that are still clear of oil. Tourism
officials are concerned that reporting on the spill has contributed to negative perceptions of the
entire Gulf region. To counter these perceptions, BP has funded tourism promotion programs in
Alabama, Mississippi, and Florida.
161

The United States imports 90% of the shrimp it consumes.

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Impact on Oil and Natural Gas Prices162
The Deepwater Horizon incident has had limited immediate impact on oil and natural gas supply
and prices because production has not been significantly disrupted.163 Longer-term impacts are
uncertain and depend at least in part on policy and regulatory responses, which may affect the
production of offshore oil and natural gas.
At the time of the incident, the oil and gas formation was still being explored, and was not yet in
the production phase of the project.164 Stopping production activity near the spill location for
safety reasons has so far resulted in a relatively small reduction in energy supply. MMS reported
that five offshore platforms were evacuat

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3AR41262. Public record. Not legal advice.
