The 2010 Oil Spill: MMS/BOEMRE and NEPA

The 2010 Oil Spill: MMS/BOEMRE and NEPA

The 2010 Oil Spill: MMS/BOEMRE and NEPA
Kristina Alexander
Legislative Attorney
March 2, 2011
Congressional Research Service
7-5700
www.crs.gov
R41265
CRS Report for Congress
P
repared for Members and Committees of Congress

The 2010 Oil Spill: MMS/BOEMRE and NEPA

Summary
On April 20, 2010, an exploratory oil well in the Gulf of Mexico exploded, killing 11 people and
causing the worst oil spill in American history. The oil well was on a tract leased by BP, having
obtained a lease and the relevant permits from the federal government. Under relevant federal
law, federal actions that may have adverse environmental effects are required to be reviewed for
potential environmental harm under the National Environmental Policy Act (NEPA). This report
will review those environmental procedures. While there are additional environmental obligations
imposed on Outer Continental Shelf (OCS) drilling by other acts, this report will not review those
requirements.
Multiple environmental reviews were conducted by the Minerals Management Service (MMS) at
each stage of OCS development. (MMS was reorganized in May 2010, and the relevant office for
the environmental reviews is the Bureau of Ocean Energy Management, Regulation, and
Enforcement (BOEMRE). This report will refer to MMS for actions before the reorganization and
BOEMRE going forward.) For the particular well in question, MMS addressed the environmental
impacts on four occasions, including two full environmental impact statements, an environmental
assessment, and a categorical exclusion. The fact that MMS categorically excluded the
exploration plan from a NEPA analysis is controversial, since that is the first step in which
drilling would be conducted. It appears MMS followed its internal procedure for NEPA reviews
in the western and central areas of the Gulf of Mexico by employing a categorical exclusion for
an exploration plan. However, that procedure has never been reviewed by a court to see if it is
consistent with the law or whether an exception to the categorical exclusion may apply in this
case. Had this project occurred in a different geographical area, including the eastern area of the
Gulf of Mexico, it likely would have undergone a higher level of environmental scrutiny.
Following a White House report suggesting that BOEMRE review its NEPA exclusions,
BOEMRE announced it would not apply the categorical exclusion used in the Gulf until its
review was complete.
Congress has addressed the issue of MMS/BOEMRE categorical exclusions in proposed
legislation. In the 112th Congress, bills have been introduced that would require either a full
environmental impact statement (H.R. 52 (Connolly)), or at least an environmental assessment
(H.R. 501, §§ 208, 215 (Markey)) for exploration, development, and production plans. Both
would change the 30-day deadline for approval of exploration plans. Another proposed NEPA
change would prevent the act from applying to testing oil spill prevention, response, or mitigation
technology in Arctic waters and bar judicial review (S. 203 (Begich)). In the 111th Congress, the
Consolidated Land, Energy, and Aquatic Resources Act of 2010 (CLEAR) (H.R. 3534) would
have required certain levels of environmental reviews for exploration, development, and
production plans, and it would have changed the 30-day statutory deadline for approving
exploration plans to 90 days.

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The 2010 Oil Spill: MMS/BOEMRE and NEPA

Contents
Background and Context ............................................................................................................. 1
NEPA.......................................................................................................................................... 1
MMS/BOEMRE NEPA Reviews........................................................................................... 3
The 2007-2012 Outer Continental Shelf Oil and Gas Leasing Program.................................. 4
The EIS for the 5-year Plan ................................................................................................... 4
The EIS for 11 Gulf of Mexico Lease Sales ........................................................................... 6
Adequacy of the Environmental Review of the Multiple Lease Sales ............................... 8
Lease Sale 206 Environmental Assessment.......................................................................... 10
Categorical Exclusion for the Exploration Plan.................................................................... 11
Adequacy of the Environmental Review of the Exploration Plan ................................... 14
The Council on Environmental Quality Report on MMS and NEPA .............................. 16
Congressional Attention to Categorical Exclusions ........................................................ 17
Conclusion................................................................................................................................ 18

Appendixes
Appendix A. Background Facts................................................................................................. 19
Appendix B. MMS Categorical Exclusions ............................................................................... 21
Appendix C. The MMS Categorical Exclusion Review Process ................................................. 24

Contacts
Author Contact Information ...................................................................................................... 27

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The 2010 Oil Spill: MMS/BOEMRE and NEPA

Background and Context
On April 20, 2010, an exploratory oil well in the Gulf of Mexico exploded, killing 11 people and
causing the worst spill in United States history at approximately 4.1 million barrels (bbl).1 It was
capped in mid-July. The oil well was on a tract leased by BP, having obtained an oil and gas lease
and the relevant permits from the federal government. The spill was at the Mississippi Canyon
Block 252, which is one block obtained by BP under Lease Sale 206. Under applicable federal
law, federal actions that may have adverse environmental effects are required to be reviewed for
potential environmental harm under the National Environmental Policy Act (NEPA). Additional
environmental obligations are imposed by the Outer Continental Shelf Lands Act (OCSLA),2
Endangered Species Act,3 Marine Mammal Protection Act,4 and the Coastal Zone Management
Act5 but will not be examined within this report. Rather, this report focuses on the environmental
analyses conducted by the Minerals Management Service (MMS) and their compliance with
NEPA. MMS was reorganized in May 2010,6 and the relevant successor office is the Bureau of
Ocean Energy Management, Regulation, and Enforcement (BOEMRE). This report will refer
to MMS for events prior to the reorganization.
NEPA
NEPA states that for all “major Federal actions significantly affecting the quality of the human
environment” federal agencies shall prepare a “detailed statement” of “the environmental impact
of a proposed action, any adverse environmental effects which cannot be avoided should the
proposal be implemented, [and] alternatives to the proposed action.”7 Agencies must comply to
“the fullest extent possible.”
MMS/BOEMRE of the Department of the Interior is the federal agency charged with overseeing
oil and gas exploration of the Outer Continental Shelf (OCS). MMS issued the lease to and
approved the exploration plan of BP for the oil well that caused the spill. Under NEPA
terminology, MMS/BOEMRE is the lead agency for any environmental reviews.8

1 Department of the Interior Press Release, Flow Rate Group Provides Preliminary Best Estimate Of Oil Flowing from
BP Oil Well (May 27, 2010). Available at http://www.doi.gov/news/pressreleases/Flow-Rate-Group-Provides-
Preliminary-Best-Estimate-Of-Oil-Flowing-from-BP-Oil-Well.cfm. Estimates were revised from 5,000 bbl a day to
62,000 bbl a day, decreasing toward the end of the leak to 53,000 bbl. An estimated total of 4.1 million bbl were
released into the Gulf (4.9 million bbl leaked, but 800,000 bbl captured before it leaked into the Gulf). See Official Site
of the Deepwater Horizon Unified Command, at http://www.deepwaterhorizonresponse.com/go/doc/2931/840475.
2 43 U.S.C. §§ 1331 – 1356a. For analysis of the OCSLA, see CRS Report RL33404, Offshore Oil and Gas
Development: Legal Framework, by Adam Vann.
3 16 U.S.C. §§ 1531 – 1544. See Section 1536 for consultation obligations of federal agencies.
4 16 U.S.C. §§ 1361 – 1384. See Section 1371(a)(5)(A) for incidental takes of marine mammals.
5 16 U.S.C. §§ 1451 – 1456. See Section 1456(c) for federal actions affecting coasts.
6 Secretarial Order 3299 (May 19, 2010), available at http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=
security/getfile&PageID=32475.
7 42 U.S.C. § 4332. The act also requires consideration of “(iv) the relationship between local short-term uses of man’s
environment and the maintenance and enhancement of long-term productivity, and (v) any irreversible and irretrievable
commitments of resources.”
8 As referenced above, MMS was reorganized, effective May 19, 2010. Secretary of the Interior Order No. 3299.
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NEPA includes three types of environmental reviews with different levels of scrutiny into the
environmental effects of an action. The goal of the reviews is for an agency to be able to
demonstrate that it has taken an appropriately hard look at the environmental consequences of its
planned activity.9 The environmental review is also supposed to involve the public.10 The most
comprehensive review is concluded by an environmental impact statement (EIS). It is required by
NEPA for all agency actions that will significantly affect the environment. An EIS should
demonstrate that the agency considered a reasonable range of alternatives that took a hard look at
the environmental consequences of a proposed action. An EIS also requires extensive public
involvement, including a public comment period for a draft EIS and consideration of those
comments in the final document.
Where an action may not have significant effects, or when an agency is unsure of the degree to
which an action may have significant impacts, a review called an environmental assessment (EA)
is conducted. An EA also requires consideration of alternatives to the action and a review of the
effects, but it is intended to be an abbreviated review. The public comment period is limited and
could occur only upon completion of a final document.
The third type of review is for actions that agencies have pre-determined have no significant
impact, typically because an agency routinely conducts the activity. This type of review is a
categorical exclusion (CE, sometimes known as a Cat Ex). Technically, it means a formal review
is not required because the agency has already determined that the environmental consequences
of the action will not be significant.11 Agencies prepare lists of CEs and may exclude a particular
action if it is on that list. The decision to invoke a CE for a project must be documented in some
way.12 CEs are not allowed when there are extraordinary circumstances surrounding a proposed
action, which generally include the presence of endangered species or significant resources of
some type, such as archeological sites. This is consistent with the purpose of CEs—they do not
apply when there could be a significant environmental impact.
Aside from the interpretive case law, the requirements for NEPA reviews can be found in two
places: the regulations issued by the Council on Environmental Quality (CEQ);13 and within
agency-specific regulations or guidelines. Generally speaking, the CEQ regulations provide the
foundation for NEPA compliance, while the agency guidelines provide for more specific
application to the circumstances of a particular agency. In the case of MMS/BOEMRE, NEPA
procedures are found within the Department of the Interior agency-wide NEPA guidelines in the
Departmental Manual (DM),14 as well as in MMS guidelines within the DM.15

9 Kleppe v. Sierra Club, 427 U.S. 390, 410 n.21 (1976) (the role of a court is to ensure than an agency took a “hard
look” at the environmental consequences); National Audubon Society v. Department of the Navy, 422 F.3d 174, 185
(4th Cir. 2005) (a hard look “encompasses a thorough investigation into the environmental impacts of an agency’s
action and a candid acknowledgement of the risks that those impacts entail”); Idaho Conservation League v. Mumma,
956 F.2d 1508, 1519 (9th Cir. 1992) (courts review whether an EIS “contains a reasonably thorough discussion of the
significant aspects of the probable environmental consequences”); Natural Resources Defense Council, Inc. v. Morton,
458 F.2d 827, at 838 (D.C. Cir. 1972) (an environmental review complies with NEPA “so long as the officials and
agencies have taken the ‘hard look’ at environmental consequences mandated by Congress”).
10 40 C.F.R. § 1506.6. See California v. Block, 590 F.2d 753 (9th Cir. 1982) (informed public participation is a goal of
NEPA).
11 40 C.F.R. § 1508.4.
12 California v. Norton, 311 F.3d 1162 (9th Cir. 2002).
13 40 C.F.R. part 1500.
14 516 DM 1-15, available at http://206.131.241.18/app_DM/index.cfm?fuseaction=searchDM&keyword=
(continued...)
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MMS/BOEMRE NEPA Reviews
MMS/BOEMRE’s summary of its OCS program indicates there are four different stages at which
it performs an environmental review for OCS leasing.16 The summary indicates what type of
environmental review is typically done at each stage. Those stages, and the typical environmental
reviews, are
• develop a 5-year program—EIS;
• plan for a specific lease sale—EIS;
• approve the exploration plan—EA; and
• approve development and production plan—EIS.
The four stages are based on the OCSLA.17
Records indicate that MMS conducted four separate environmental reviews related to the oil well
known as Mississippi Canyon Block 252, including two EISs, one EA, and a CE. These four
documents relate to the first three stages described above; two reviews were conducted at the
lease sale stage, and the development and production stage had not been reached. Mississippi
Canyon Block 252 was at the exploration stage. Briefly, those four documents are as follows:
• April 2007: MMS issued an EIS for the OCS Five Year Leasing Program, the
2007-2012 Outer Continental Shelf (OCS) Oil and Gas Leasing Program. This
document considered environmental impacts related to off shore drilling, not just
within the Gulf of Mexico, but for the two other areas in which off shore drilling
is conducted: around Alaska and along the Atlantic coast.
• April 2007: MMS issued an EIS for the lease sale in the western and central
portion of the Gulf of Mexico.
• October 2007: MMS issued an EA for Lease Sale 206, which included
Mississippi Canyon Block 252, finding no new significant impact. This
document was intended by MMS to supplement the other environmental reviews,
which is why instead of the accepted NEPA terminology of “finding of no
significant impact” (FONSI) it referred to no “new” significant impacts.
• April 2009: MMS issued a CE for the exploration plan that authorized BP to
begin exploratory drilling on its site.
Additionally, two other environmental reviews were conducted that relate to drilling in the Gulf.
Both were programmatic environmental assessments, meaning they were designed to consider
broad impacts from a type of federal action and not just the impacts from one action.
Programmatic environmental reviews are viewed as an efficient way to consider impacts without

(...continued)
516%20DM%201-15.
15 516 DM 15.
16 A copy of this is available at http://www.boemre.gov/PDFs/5BOEMRE_Leasing101.pdf.
17 43 U.S.C. § 1344—5-year plan; 43 U.S.C. § 1337(a)—lease sale; 43 U.S.C. § 1340—exploration plan; and 43 U.S.C.
§ 1351—development and production.
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creating redundant reviews.18 In July 2004, MMS announced completion of a programmatic EA
that evaluated potential impacts of geological and geophysical testing in the Gulf.19 That testing
included seismic testing. A different programmatic EA was announced in March 2005 for
Structure-Removal Operations in the Gulf,20 which typically involve the use of explosives.
The 2007-2012 Outer Continental Shelf Oil and Gas Leasing
Program
In February 2006, and again in August 2006, MMS sought comments on its proposed 5-year lease
plan for 2007-2012 that would expand OCS leasing areas. The proposed plan addressed 21 OCS
areas, including two in the Gulf of Mexico.21 An EIS for this plan was prepared, and the final 5-
year Plan EIS was completed in April 2007.22 The 2007-2012 OCS Oil and Gas Leasing Program
became effective on July 1, 2007. However, a federal court of appeals determined that MMS had
not complied with all of the environmental requirements, and the program was returned to MMS
for revision.23 A preliminary revised 5-year plan was announced in March 2010.24
The EIS for the 5-year Plan
The EIS for the 5-year Plan for 2007-201225 describes its scope as being regional and
programmatic, and it also describes the assumptions made when evaluating the environmental
effects of the proposed action. It divides the environmental effects based on the three
geographical areas within the 5-year Plan: Gulf of Mexico, Atlantic, and Alaska. Different
assumptions are made for each area, and the environmental effects are premised on that. One
assumption for the Gulf of Mexico is the scale of oil spills that could be expected to occur.26 The
estimates were made for potential spills during production and transportation, and do not appear
to consider oil spills at the exploration stage. A large oil spill, according to the 5-year Plan EIS,
would be one of 1,000 barrels (bbl) or greater. Based on historical modeling, MMS calculated a
probable large oil spill from a platform to be 1,500 bbl and 4,600 bbl from a pipeline.27 The spill
from the current Mississippi Canyon exploration well is categorized as a platform-related spill,

18 40 C.F.R. § 1500.4: “Agencies shall reduce excessive paperwork by ... (i) using program, policy, or plan
environmental impact statements and tiering from statements of broad scope to those of narrower scope, to eliminate
repetitive discussions of the same issues.”
19 MMS, Geological and Geophysical Exploration for Mineral Resources on the Gulf of Mexico Outer Continental
Shelf - Final Programmatic Environmental Assessment, MMS 2004-054 (July 2004). 69 Fed. Reg. 45851 (July 30,
2004).
20 MMS, Structure-Removal Operations on the Gulf of Mexico Outer Continental Shelf Programmatic Environmental
Assessment, MMS 2005-013 (February 2005). 70 Fed. Reg. 9965 (March 1, 2005).
21 71 Fed. Reg. 50457, 50458 (Aug. 25, 2006).
22 72 Fed. Reg. 24326 (May 2, 2007).
23 Center for Biological Diversity v. U.S. Department of the Interior, 563 F.3d 466 (D.C. Cir. 2009).
24 75 Fed. Reg. 16833 (April 2, 2010). Available at http://www.boemre.gov/5-year/2007-2012FEIS.htm. On that same
date, MMS announced intent to prepare an EIS for the next 5-year plan, from 2012 to 2017. 75 Fed. Reg. 16828 (April
2, 2010).
25 MMS, Outer Continental Shelf Oil & Gas Leasing Program: 2007-2012, Final Environmental Impact Statement
MMS 2007-003 (hereinafter 5-year Plan EIS). Available at http://www.boemre.gov/5-year/2007-2012FEIS.htm.
26 5-year Plan EIS, Ch. IV, pp. IV-28 – IV-31.
27 5-year Plan EIS, Ch. IV, pp. IV-29.
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even though the leak occurred far below the surface of the water. The 5-year Plan EIS estimates
that the Gulf of Mexico wells would produce 4 to 8 billion bbl of oil and have nine large oil spills
(four from pipelines; four from platforms; and one from a tanker).28 These numbers are for
deepwater and near-shore drilling combined. Approximately 75% of the leasing activity is
planned for deepwater.
The programmatic environmental effects for the preferred alternative for the Gulf Coast included
impacts on the following: air and water quality; mammals and birds; fish, fisheries, and fish
habitat; sea turtles; coastal and seafloor habitats; areas of special concern; socioeconomic
impacts; archeological resources; tourism and recreation; and land use.29 Some protected
resources in the area include the following endangered species:
• Northern Right Whale,
• Blue Whale,
• Fin Whale,
• Sei Whale,
• Humpback Whale,
• Sperm Whale,
• West Indian Manatee,
• Leatherback turtle,
• Green turtle,
• Hawksbill turtle,
• Kemp’s Ridley turtle,
• Loggerhead turtle,
• Gulf Sturgeon,
• Whooping crane,
• Piping plover,
• Alabama beach mouse,
• Choctawhatchee beach mouse,
• St. Andrew beach mouse, and
• Perdido Key beach mouse.
The baseline data described above largely influence the discussion of environmental impacts
within this EIS. The data contemplate four platform spills across the entire 40-year lease term
(and not just the five years of the 5-year Plan) that would produce spills of approximately 1,500
bbl each, and only three of those spills would be in deepwater. Accordingly, the analysis of the
effects from the spills is limited to considering how a 1,500 bbl spill could affect the

28 5-year Plan EIS, Table IV-4.
29 5-year Plan EIS, Ch. IV, pp. IV-33 – IV-102.
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environment. There is no extrapolation or other hypothesis for what would happen if the spill
were larger. Based on the assumptions of limited spill quantities, the conclusion for the
environmental consequences tends to be in one of two camps: one, that the magnitude of harm
would depend on the timing and quantity of the oil spill (see, for example, Coastal Waters,
Marine Waters, Marine Mammals, Marine and Coastal Birds, Essential Fish Habitat, Sea Turtles);
or two, that because a deepwater spill is calculated to be at 1,500 bbl, it is unlikely to reach areas
where significant impacts could occur (see, for example, Marine and Coastal Birds, Terrestrial
Mammals, Coastal Barrier Beaches, Sea turtle nesting, Seafloor Habitat and Live Bottom and
Pinnacle Areas).
Environmental groups argued that the agency failed to take a hard look at the environmental
consequences of its action. Limiting the size of a potential spill could limit the size of impacts
that are reviewed. However, the court that reviewed this matter, the D.C. Circuit Court of
Appeals,30 has determined that challenges to the sufficiency of that NEPA process for the 5-year
plan could not be reviewed.31 The court said that the 5-year Plan NEPA review had “not yet
reached that ‘critical stage’ where an ‘irreversible and irretrievable commitment of resources’ has
occurred that will adversely affect the environment.”32 The court suggested that the appropriate
time for such claims would be at the leasing stage. Accordingly, this ruling bars any challenge to
the 5-year Plan NEPA review.
This position is consistent with other courts that have reviewed NEPA challenges of multiple
stage administrative programs. The Second Circuit has held that a federal action, in that case an
administrative hearing involving Mobil Oil, is not subject to NEPA until that point where there
might be irreversible and irretrievable commitments of resources.33 Similarly, the D.C. Circuit
held that a Forest Service procedure for identifying areas for oil and gas leases was not ripe
because it could prove unnecessary if no leases were ever issued.34 No irreversible or irretrievable
commitment of resources had been made.
The EIS for 11 Gulf of Mexico Lease Sales
In April 2007, MMS also completed the EIS for the 11 lease sales for the Gulf of Mexico, the
Multisale EIS.35 For the lease sales, the MMS divided the Gulf of Mexico into three regions:
western (the Texas coast); central (the coasts of Louisiana, Mississippi and Alabama); and eastern
(the Florida coast). Eleven lease sales were planned for the western and central areas and none for

30 43 U.S.C. § 1349(c)(1) gives this court exclusive jurisdiction for review of OCSLA leasing program approvals. This
exclusive jurisdiction has been found to apply only to OCSLA claims and not to NEPA claims related to OCSLA
approval. See Get Out Oil, Inc. v. Andrus, 477 F. Supp. 40, 42 (C.D. Cal. 1979).
31 Center for Biological Diversity v. U.S. Department of the Interior, 563 F.3d 466 (D.C. Cir. 2009).
32 Center for Biological Diversity v. U.S. Department of the Interior, 563 F.3d 466, 480 (D.C. Cir. 2009).
33 Mobil Oil Corp. v. FTC, 562 F.2d 170, 173 (2d Cir. 1977) (finding that certain adjudicatory proceedings were not
subject to NEPA because the final order was still speculative).
34 Wyoming Outdoor Council v. U.S. Forest Service, 165 F.3d 43 (D.C. Cir. 1999). See also Conner v. Burford, 848
F.2d 1441 (9th Cir. 1988) (holding that no EIS was required where lease was issued forbidding surface occupancy (and
therefore oil drilling)).
35 MMS, Gulf of Mexico OCS Oil and Gas Lease Sales: 2007-2012; Western Planning Area Sales 204, 207, 210, 215,
and 218; Central Planning Area Sales 205, 206, 208, 213, 216, and 222; Final Environmental Impact Statement, MMS
2007-018 (April 2007) (hereinafter Multisale EIS). Available at http://www.gomr.boemre.gov/homepg/regulate/
environ/nepa/nepaprocess.html.
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the eastern area.36 A number of leases could be issued within each of the 11 lease sales, typically
over 300, based on the amount of resources an area is estimated to produce. For more details on
the facts underlying the western and central lease sales, see Appendix A.
The Multisale EIS evaluated the environmental impacts from routine operations as well as
accidents such as oil spills. It reviewed all of the different steps involved in extracting oil—
seismic testing, exploratory drilling, development and production, transportation, and removing
structures at the end of the lease.
Blowouts and other spills were evaluated, first, on the probability of such events occurring, and
then analyzing the probable resulting environmental effects. Like the 5-year Plan EIS, the
Multisale EIS used historical data as the basis for the size of an oil spill. According to MMS, the
most likely size of an oil spill that was greater than 1,000 bbl would be 4,600 bbl.37 However,
MMS states that large oil spills (meaning spills greater than 1,000 bbl) are “low-probability
events.”38
MMS used modeling to see how a 4,600 bbl spill would dissipate when on the surface. (Although
it studied both surface and subsurface spills, MMS noted that subsurface spills would behave the
same as surface spills once they reached the top.) MMS found that natural weathering would
dissipate 32% to 74% of the slick; between 30% and 32% would be lost to the atmosphere via
evaporation; and about 2% to 42% would be lost into the water column via natural dispersion.39
No modeling was done on a larger spill.
The Multisale EIS did consider the possibility of a larger offshore spill for the leases, although it
did not analyze impacts from such a spill. It found that a spill larger than 10,000 bbl had greater
than a 99% chance of occurring during the 40-year period.40 A mean number of spills of that size
was estimated between 11 and 13 for that time period.41 MMS analyzed the environmental effects
of a spill of 4,600 bbl, the “most likely size of a spill greater than 1,000 bbl.”42
In general, the probability of an offshore oil spill greater than 1,000 bbl (but not larger than 4,600
bbl) reaching an environmentally sensitive resource was found to be small, ranging from less than
0.5% (for example, reaching Gulf communities, listed beach mice, or Gulf Sturgeon habitat), but
greater for other resources (for example, the probability of such a spill reaching waters used by
coastal sea turtles ranged from 6% to 35%, while the odds of a spill reaching sea turtle nesting
and mating habitat were 4%).43 Thus, an offshore spill larger than 1,000 bbl was not found to be a
significant environmental impact.

36 Approximately 5.8 million acres located in the southeastern part of the Central Planning Area (CPA) are not included
in the lease sale area, despite being opened to leasing by the Gulf of Mexico Energy Security Act of 2006 after years of
leasing moratoria in appropriations acts. 71 Fed. Reg. 35258 (June 27, 2007).
37 Multisale EIS, p. 4-232.
38 Multisale EIS, p. 4-228. Ninety-four percent of all spills in the Gulf were found to be less than 1 bbl, contributing 5%
by volume to all spills. Multisale EIS, p. 4-235.
39 Multisale EIS, p. 4-233.
40 Multisale EIS, p. 4-75.
41 Id.
42 Multisale EIS, p. 4-232.
43 Multisale EIS, p. 4-243.
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The Multisale EIS includes a discussion of blowouts as a Loss of Well Control (LWC), of which a
blowout is the most severe form. Most LWC events were found to last half a day.44 Therefore,
MMS concluded impacts to marine water quality were not estimated to be significant.45 However,
it is noted that the noise from a blowout explosion could injure marine mammals, depending on
their proximity.46
Adequacy of the Environmental Review of the Multiple Lease Sales
It could be questioned whether the review within the Multisale EIS was comprehensive enough to
satisfy a court that MMS fully complied with NEPA. The act requires “a detailed statement” on
“any adverse environmental effects which cannot be avoided should the proposal be
implemented.”47 A court could consider the adequacy of not reviewing the environmental effects
of spills over 10,000 bbl when MMS calculated a greater than 99% probability that such a spill
would occur. On the other hand, the court could find that reviewing spills of 4,600 bbl met
NEPA’s standards. There is no court decision reviewing this document.
NEPA requires an agency to consider the environmental consequences of its actions during the
development of a proposal.48 Courts apply the “rule of reason” to see if the document is
sufficient. One court described that review as finding whether an EIS “contains a reasonably
thorough discussion of the significant aspects of the probable environmental consequences.”49 In
general, courts have held that the goals of NEPA are satisfied when an EIS “sets forth sufficient
information to enable the decision-maker to consider fully the environmental factors involved.”50
In the case of OCS leases, courts have accepted that there are staged analyses with different
degrees of scrutiny matching the different OCSLA steps. In a suit challenging an EIS prepared for
one lease sale in the Arctic,51 the plaintiffs argued that the NEPA analysis was flawed because it
significantly underestimated the amount of oil that might be spilled.52 The Ninth Circuit held that
they were “least troubled by what may seem to be incomplete or speculative data at the lease sale
stage,” noting that prior to exploration “an oil spill risk analysis can never be more than
speculative.”53 The court’s comfort with the data was based on the fact that OCSLA had tiered
analyses: “the amount and specificity of information necessary to meet NEPA requirements varies
at each of OCSLA’s stages.”54 It referred to the U.S. Supreme Court decision regarding the tiered
environmental analysis of OCSLA, Secretary of the Interior v. California.55 In that case, which

44 Multisale EIS, p. 4-239.
45 Multisale EIS, p. 4-260.
46 Multisale EIS, p. 4-275.
47 42 U.S.C. § 4332(2)(C)(ii).
48 Kleppe v. Sierra Club, 427 U.S. 390, 410 (1976).
49 Idaho Conservation League v. Mumma, 956 F.2d 1508, 1519 (9th Cir. 1992).
50 County of Suffolk v. Dept. of the Interior, 562 F.2d 1368 (2d Cir. 1977) (holding that an EIS for OCS drilling
proposal was not inadequate).
51 The Multisale EIS for the Gulf reviewed 11 lease sales.
52 Tribal Village of Akutan v. Hodel, 869 F.2d 1185 (9th Cir. 1988).
53 Id. at 1192.
54 Id.
55 Secretary of the Interior v. California, 464 U.S. 312 (1984) (holding that an adverse effects analysis under the CZMA
was not required at the lease sale stage).
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did not consider NEPA, the Supreme Court said that a lease sale on its own “does not directly
mandate further activity that would raise an oil spill problem,” and therefore, there was no need to
perform a CZMA environmental analysis at that point.56 The Supreme Court and the Ninth Circuit
predicated their decisions on the fact that the desired environmental review could occur at a later
stage in the OCSLA process.
Other courts have considered the argument that an environmental document at the lease sale stage
should have considered the potential effects of a larger spill, ultimately rejecting that claim.57 In a
dispute in the Ninth Circuit, the NEPA document had discussed impacts from spills exceeding
1,000 barrels and those exceeding 10,000 barrels for OCS drilling in the Arctic. The plaintiff
wanted consideration of spills of greater than 100,000 bbl, based on the Amoco Cadiz spill of 1.6
million barrels in 1978, and the 3.5 million bbl exploratory well blowout in the Gulf of Mexico in
Mexican waters in 1979. The district court held that plaintiff had not made its argument well,
failing to show how impacts from a 100,000 bbl spill would be different from those discussed for
a 10,000 bbl spill. Additionally, the court noted that an EIS does not have to consider every
possible impact: “The rule of reason applicable to environmental impact statements does not
require an inquiry into every conceivable situation that may occur no matter how remote or
speculative it may be.”58
The Ninth Circuit agreed with the conclusion of the district court, but for different reasons. It
found that the tiered environmental reviews under the OCSLA would mean that as drilling
became more likely, the impacts of a 100,000 bbl spill may be considered. The lease sale stage
was a preliminary stage, according to the court: “Further information about the probability and
location of a 100,000 barrel spill will become available as lessees survey their tracts, or test them,
or plan for production and development.”59
While NEPA requires consideration of a range of alternatives, it does not require consideration of
a worst case scenario, such as another 3.5 million bbl spill.60 An earlier version of the CEQ
regulations did require such an evaluation when an agency had “incomplete or unavailable
information” regarding the effects of an action. In that case, an agency was required to “include a
worst case analysis and an indication of the probability or improbability of its occurrence.”61 In
general, courts have held that an EIS “is not required to discuss every conceivable consequence of
an agency’s actions. Under the rule of reason, the environmental impact statement is not required
to consider alternatives or consequences that are only speculative or are too remote.”62 It would

56 Secretary of the Interior v. California, 464 U.S. 312, 317 (1984).
57 Village of False Pass v. Watt, 565 F. Supp. 1123 (D.C. Alaska 1983), aff’d sub nom., Village of False Pass v. Clark,
733 F.2d 605 (9th Cir. 1984).
58 Village of False Pass v. Watt, 565 F. Supp. 1123, 1147 (D.C. Alaska 1983).
59 Village of False Pass v. Clark, 733 F.2d 605, 616 (9th Cir. 1984).
60 Robertson v. Methow Valley Citizens Council, 490 U.S. 332 (1989); Sierra Club v. Sigler, 695 F.2d 957 (5th Cir.
1983) (holding the Corps of Engineers did not have to consider the worst case scenario of a tanker losing all of its cargo
when considering the impacts of a dredging permit basing its holding in significant part on a now-revised CEQ
regulation).
61 40 C.F.R. § 1502.22(b) (revised in 1986). The current regulations require an agency to prepare a statement regarding
unavailable information that includes reasonably foreseeable significant adverse impacts, which is defined as including
“impacts which have catastrophic consequences, even if their probability of occurrence is low, provided that the
analysis of the impacts is supported by credible scientific evidence.”
62 Grazing Fields Farm v. Goldschmidt, 626 F.2d 1068, 1074 (1st Cir.1980).
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be up to a court to consider whether a blowout spill from Lease Sale 206 was too remote and
speculative for MMS to consider in its environmental review.
Lease Sale 206 Environmental Assessment
The third environmental review in the OCS process is the environmental assessment (EA)
prepared for Lease Sale 206 in the Gulf (Lease Sale 206 EA).63 The oil spill occurred in
Mississippi Canyon Block 252 of this lease sale. MMS prepared environmental assessments for
other particular lease sales in the western and central Gulf, such as Lease Sale 207, although a
Supplemental EIS was prepared for Lease Sale 224 in the eastern Gulf.
Typically, an EA leads to one of two conclusions: discovery of a significant impact and then
preparation of an EIS, or a finding of no significant impact (FONSI). MMS terms its EAs
differently. It issues an EA-FONNSI, meaning finding of no new significant impact, reflecting the
tiered environmental analyses for the OCS process. Lease Sale 206 EA recognizes that it “tiers off
the Multisale EIS and incorporates much of the material by reference.”64 According to MMS, new
information related to the lease sale was discovered, but did not change the conclusions reached
within the Multisale EIS.65
The EA appears to back off some of the environmental impacts considered in the EIS. It states
that because activity was overestimated, the environmental impacts “may have been
overstated.”66 While new information was considered within the EA, MMS found it supports the
conclusions made in the Multisale EIS, and so no new conclusions are made within the EA.67 The
Lease Sale 206 EA refers to the Multisale EIS review of spills greater than 1,000 bbl.68 No
reference to larger spills was found, such as a 4,600 bbl spill. In fact, oil spills were discussed in
more general terms throughout the document than in either of the EISs, which were incorporated
by reference.
No legal challenge to the Lease Sale 206 EA has been found. However, challenges to other EAs
for OCS drilling have been found for EAs issued for particular lease sales in the Arctic. Courts
have found EAs should be used in these circumstances to determine whether “the new
circumstance must present a seriously different picture of the environmental impact of the
proposed project from what was previously envisioned.”69 If those different impacts are found, an
EIS or Supplemental EIS is warranted. A federal district court considered whether a Supplemental
EIS should have been prepared three years after conclusion of a multisale EIS for the Arctic
region, instead of an EA. It found that the multisale EIS in that case had considered scenarios that

63 MMS, Proposed Gulf of Mexico OCS Oil and Gas Lease Sale 206; Central Planning Area; Environmental
Assessment, MMS 2007-059 (Oct. 2007) (hereinafter Lease 206 EA). Available at http://www.gomr.boemre.gov/PDFs/
2007/2007-059.pdf.
64 EA FONNSI, introduction.
65 EA FONNSI, p. 1.
66 Lease 206 EA, p. 14.
67 Lease 206 EA, p. 18.
68 Lease 206 EA, p. 24.
69 Sierra Club v. Froehlke, 816 F.2d 205, 210 (5th Cir. 1987); North Slope Borough v. Minerals Management Service,
No. 3:07-cv-0045-RRB, *2 (D. Alaska April 12, 2007); Oregon Natural Resources Council v. Devlin, 776 F. Supp.
1440, 1449 (D. Ore. 1991).
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included the new data addressed by the EA.70 As this conclusion is fact-specific, it cannot be used
to predict whether a court may reach the same decision regarding the Lease Sale 206 EA.
Categorical Exclusion for the Exploration Plan
The final environmental document to date for the Mississippi Canyon Block 252 oil well is a
categorical exclusion for the exploration plan (EP) submitted by BP (EP CE). As discussed above,
a categorical exclusion may be used by an agency when a category of actions has been
determined to have no significant effect on the environment either individually or cumulatively.71
The CEQ regulations provide that any procedures allowing CEs must also include “extraordinary
circumstances” for when a CE would not apply.72
In 1986, MMS issued its list of categories of activities excluded from further NEPA review within
the DOI Departmental Manual.73 The list was revised in 2004. The Departmental Manual states
that a CE does not apply if “the action qualifies as an exception under Appendix 2 of 516 DM.” A
copy of the MMS categorical exclusions and the exceptions is available as Appendix B to this
report.74
MMS recorded its decision to invoke a categorical exclusion for the BP EP in a Categorical
Exclusion Review (CER) with Analysis and included reviews for specific environmental harms.
The CE process begins when a leaseholder (in this case BP) submits an exploration plan for MMS
approval.75 MMS reviews the plan to see if it fits any of the published categorical exclusions. The
agency must also see whether any exceptions to those CEs apply. The decision must be
documented. MMS uses forms that include check lists to document the CERs.
Under 43 U.S.C. § 1340(c), MMS is required to approve an exploration plan within 30 days of
submission. The Secretary of the Interior, in testimony before the Senate Committee on
Environment and Public Works, asked Congress to extend this deadline to 90 days.76 This may
suggest that a CE for the exploration plan was invoked because MMS had only 30 days to
complete an environmental review. However, MMS prepares EAs (which require more analysis
than a CE) for exploration plans that are not in the western or central Gulf of Mexico.77

70 North Slope Borough v. Minerals Management Service, No. 3:07-cv-0045-RRB, *2 (D. Alaska April 12, 2007).
71 40 C.F.R. § 1508.4.
72 40 C.F.R. § 1508.4.
73 The Federal Register notice announcing these CEs refers to them as being functions transferred from the Geological
Survey (GS) and the Bureau of Land Management (BLM) to the MMS upon its establishment. 51 Fed. Reg. 1855 (Jan.
15, 1986).
74 It is also available at http://206.131.241.18/app_DM/act_getfiles.cfm?relnum=3625.
75 In practice, multiple versions of an EP may be submitted, such as an initial EP, or an amended EP. The CER for BP
shows separate reviews were conducted for archaeological resources, chemosynthetic communities, and what was
referred to as a NEPA (1) determination. Copies of these documents (either the I-EP (Initial Exploration Plan) with a
NEPA final date of April 15, 2009, or the A-EP (Amended Exploration Plan) with a NEPA final date of April 3, 2009)
are available from the author.
76 Senate EPW Hearing, Federal Response to the Recent Oil Spill in the Gulf of Mexico (May 18, 2010).
77 For example, MMS prepared an EA for an exploration plan in the Arctic that was rejected by a court and ultimately
withdrawn by the agency. Alaska Wilderness League v. Kempthorne, 548 F.3d 815 (9th Cir. 2008), withdrawn and
vacated as moot 559 F.3d 916 (9th Cir. 2009), and superseded sub nom. Alaska Wilderness League v. Salazar, 571 F.3d
859 (9th Cir. 2009) (upon rescission by MMS of the EP approval).
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Arguably, a 1976 U.S. Supreme Court decision supports the Secretary of the Interior’s position
that the deadline is too short.78 In that decision, Flint Ridge Development Co. v. Scenic Rivers
Association of Oklahoma, the Court held that a 30-day statutory deadline meant that the federal
agency could not complete an EIS, and therefore NEPA did not require it. The Court noted that
NEPA only required agencies to comply “to the fullest extent possible.” The Court considered the
fact that the 30-day deadline for the federal agency in Flint Ridge did not begin until the
submission was completed. The Ninth Circuit made a similar observation regarding the MMS 30-
day deadline for exploration plan approval, finding some flexibility in the fact that a NEPA
review could begin while the agency sought further information from an applicant.79 However,
that Ninth Circuit decision was withdrawn and vacated. Flint Ridge could be distinguished from
the Mississippi Canyon EP in that the Flint Ridge plaintiffs sought to have a full EIS prepared,
whereas for Mississippi Canyon the argument is that a CE was not enough, leaving open the
possibility that an EA would suffice within the time frame.
According to MMS, CEs are available when “the impacts from the common operations are
expected to be negligible to non-existent based upon general information gathered during past
environmental analyses.”80 This means that based on its experience, MMS has found that those
operations have at most negligible environmental impacts, and therefore, additional review is not
required.
The CER documents from MMS do not indicate which CE was used. However, it seems likely
that MMS invoked CE 15.4(C)(10), which is a CE that applies to exploration plans:
Approval of an offshore lease or unit exploration development/production plan or a
Development Operation Coordination Document in the central or western Gulf of Mexico
(30 CFR 250.2) except those proposing facilities: (1) In areas of high seismic risk or
seismicity, relatively untested deep water, or remote areas, or (2) within the boundary of a
proposed or established marine sanctuary, and/or within or near the boundary of a proposed
or established wildlife refuge or areas of high biological sensitivity; or (3) in areas of
hazardous natural bottom conditions; or (4) utilizing new or unusual technology.81
This CE appears to have been created in 1978 in guidelines for MMS’s predecessor. It is the only
CE that makes specific reference to an OCS area, or, in fact, contains any geographical
restriction. It excludes two of the four stages of OCSLA actions from further NEPA review. It
excludes both exploration plans in the western and central Gulf of Mexico and development and
production plans in those areas. In contrast, the other CEs exclude what appear to be more
general, administrative activities such as “issuance and modification of regulations, Orders,
Standards, Notices to Lessees and Operators, Guidelines, and field rules” (C)(1); “approval of
unitization agreements, pooling, or communitization agreements” (C)(4); and “approval of
suspension of operations and suspensions of productions” (C)(6).

78 Flint Ridge Development Co. v. Scenic Rivers Association of Oklahoma, 426 U.S. 776 (1976) (holding that 30 days
after filing was not enough time to complete a NEPA review and therefore one was not required).
79 Alaska Wilderness League v. Kempthorne, 548 F.3d 815 (9th Cir. 2008), withdrawn and vacated as moot, 559 F.3d
916 (9th Cir. 2009), and superseded sub nom. Alaska Wilderness League v. Salazar, 571 F.3d 859 (9th Cir. 2009) (upon
rescission by MMS of the EP approval).
80 MMS, Discussion of Categorical Exclusion Reviews (undated). A copy of this document is included as Appendix C.
81 516 DM 15.4(C)(10).
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The CE for Gulf plans could be based on the OCSLA amendments of 1978.82 Those amendments
address certain NEPA requirements, giving exemptions to activities in the Gulf of Mexico. The
relevant section of that law, Section 25 (codified at 43 U.S.C. § 1351(e)(1)), states that “at least
once the Secretary shall declare the approval of a development and production plan in any area or
region ... of the outer Continental Shelf, other than the Gulf of Mexico, to be a major Federal
action.”83 While this language contains some ambiguity as to whether the “at least once”
requirement must be used by the Secretary for all development plans or on a plan-by-plan basis,
this suggests that approval of a development and production plan in the Gulf of Mexico might
never need to be declared a major federal action (key words in NEPA to mandate preparation of
an EIS).84 No similar statutory reference to exploration plans exists, but this may be the
foundation for excluding Gulf of Mexico plans from environmental analyses at certain stages.
BP discussed a Worst Case Scenario Response in its initial EP for Mississippi Canyon Block 252,
indicating it considered a potential large-scale spill. The EP states that for exploratory wells A and
B at Block 252, the worst case scenario would be a blowout at the exploratory stage, leading to a
spill of 162,000 bbl85 of crude oil a day.86 The EP indicates that BP’s regional oil spill response
plan for a worst case scenario had been approved by MMS.87 There is no indication that MMS
conducted a NEPA review for approving the regional oil spill response plan (OSRP). This
suggests that the methods for responding to a massive spill—such as in situ burning, or chemical
dispersant—were not scrutinized for environmental impacts other than within the Multisale EIS
and the Lease Sale 206 EA, and those documents considered much smaller leaks.
Despite referring to a blowout in the context of a response plan, no blowout scenario was
included in the EP. This appears to be based on MMS policy for the area. Section 2.7 of the EP
states: “A scenario for a potential blowout of the well from which BP would expect to have the
highest volume of liquid hydrocarbons is not required for the operations proposed in this EP.”88
While MMS regulations require disclosure of a blowout scenario in EPs,89 MMS provided an

82 P.L. 95-372, § 25, 92 Stat. 659 (1978).
83 The legislative history for this amendment does not discuss why the Gulf was excepted from this provision.
However, the Conference Report suggests that the exception was for efficiency: “to limit bureaucratic redtape and
otherwise minimize delays in the search for and production of oil and gas” which had been “going on for a number of
years” in the Gulf. H. Rep. 95-1474, at 115 (Aug. 10, 1978). The Gulf exclusion was within the Senate language, while
the House had no exclusion. Id.
84 As referenced earlier in this report, MMS policy is that development and production plans undergo a full EIS.
However, the MMS allows a CE for development and production plans in the western and central areas of the Gulf of
Mexico, essentially exempting those plans from that policy. Because it was still in exploration, the Mississippi Canyon
Block had not reached the stage of development and production. It is not known whether MMS would have issued a CE
for that plan as well.
85 The EP does not indicate the measure of the spill (either in bbl or gallons). The data given here are based on the fact
that the Regional Oil Spill Response Plan (OSRP) by BP reports the worst case scenario for an exploratory well in
barrels per day. See Regional Oil Spill Response Plan, Appx. H (Rev. 6/30/09), available at
http://info.publicintelligence.net/BPGoMspillresponseplan.pdf. The data in the EP for worst case discharge do not
match that in the OSRP. The OSRP estimates a 250,000 bbl per day spill from MC 462 as the worst case discharge
from an exploratory well. It does not have any reference to MC 252. See OSRP Quick Guide Table 1 for a list of
production facilities. The EP estimates the daily volume as 300,000 bbl for MC 727, and 162,000 bbl for MC 252. MC
727 is not referenced in OSRP Table 1.
86 EP, § 7.1.
87 EP, § 7.1.
88 BP, Initial Exploration Plan, Mississippi Canyon Block 252, OCS-G 32306 (received by MMS Feb. 23, 2009)
(hereinafter EP). A copy of this document is available from the author.
89 30 C.F.R. § 250.213(g). A lawsuit challenging the DOI’s issuance of the Notice was filed in federal court. Gulf
(continued...)
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exception in a 2008 Notice to Lessees. The exception exempts OCS actions in the Gulf from
blowout scenario requirements under certain conditions.90 On June 18, 2010, this exception was
revoked by another Notice. The 2010 Notice to Lessees expressly rescinds portions of the 2008
Notice; lessees not already having approved Applications for Permit to Drill are required to
submit blowout scenarios and worst case discharge scenarios.91
Even if a blowout scenario was not prepared, it seems there would be significant amounts of oil
released if the worst case scenario of a blowout occurred, oil at quantities greater than considered
in the Multisale EIS or the Lease Sale 206 EA. However, because a CE was used for the EP,
instead of an EIS or an EA, a review of the environmental impacts for a spill of this size was not
conducted. They were not considered within the previous EISs or the EA either.
Adequacy of the Environmental Review of the Exploration Plan
No court has reviewed this categorical exclusion (516 DM 15.4(C)(10)), either to determine
whether on its face it meets the standards for a CE—actions that either individually or
cumulatively are found not to have a significant effect on the environment—or as it has been
applied to any exploration or development plan. However, the Ninth Circuit considered whether
MMS had properly used a different CE in California when approving lease suspensions. The
court found the use of that CE was not adequately justified by MMS.92 In that case 36 lease
suspensions were sought nearly 30 years after a large oil spill near Santa Barbara. Under the
OCLSA, MMS may suspend the term of a lease when a lessee is not able to begin production
within the term of the lease, thus avoiding expiration of the lease.93 The court found that there
was no documentation of the CE, and that some exceptions to a CE could have applied that MMS
did not consider. Accordingly, the court remanded the NEPA review to MMS.
It is possible a court may find that exceptions to CEs apply in the case of the EP CE, in which
case the BP CE would be invalid. (The exceptions are included as part of Appendix B.) One
exception that may apply addresses effects on ESA-listed species, meaning a CE could not be
used if an action may “have adverse effects on species listed or proposed to be listed on the List
of Endangered or Threatened Species, or have adverse effects on designated Critical Habitat for
these species.”94 All of the environmental documents address the effects of an oil spill on listed
species and the critical habitat of the Gulf Sturgeon. For example, the Lease Sale 206 EA states
that over the 40-year term of the lease, 119 loggerhead, 10 leatherback, 1 hawksbill, 13 Kemp’s

(...continued)
Restoration Network v. Salazar, No. 2:10-cv-01497 (E.D. La. filed May 18, 2010).
90 MMS, Notice to Lessee 2008-G04 (May 1, 2008). Available at http://www.gomr.mms.gov/homepg/regulate/regs/
ntls/2008NTLs/08-g04.pdf. Under this Notice, a blowout scenario is only required for OCS drilling if 1) Florida is an
affected state; 2) the activity occurs within protective zones of Flower Garden Banks or Stetson Bank; 3) activity
includes installation of surface facility at greater than 400 meters; 4) initial Development Operations Coordination
Documents (DOCDs) and supplemental DOCDs with new multiwell structures if either Texas or Louisiana is an
affected state; and 5) initial EPs if Texas is an affected state. Notice 2008 G-4, p. 6.
91 MMS, Notice to Lessee No. 2010-N06. Available at http://www.doi.gov/deepwaterhorizon/loader.cfm?csModule=
security/getfile&PageID=35724.
92 California v. Norton, 311 F.3d 1162 (9th Cir. 2002).
93 43 U.S.C. § 1334(a)(1).
94 516 DM Appx. 2, exception 2.8.
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ridley, and 38 green turtles will be killed.95 It is possible a court could find that these effects could
be considered “adverse.” Another exception to the CEs addresses actions when the impacts
cannot be known, perhaps due to the fact that the harm depends on the scale, timing, and location
of an oil spill: “2.4 - Have highly uncertain and potentially significant environmental effects or
involve unique or unknown environmental risks.”
Even if the exceptions do not apply, MMS may be required to explain in the CE why they do not.
Under accepted law, if there is substantial evidence that an exception may apply, an agency must
document why an exception to a CE does not apply in order to support the CE.96 While the CER
documents specifically address exceptions regarding archeological resources and chemosynthetic
communities, finding that neither exception applies, there is no explicit reference to any other
exception.
The fact that this project was in the Gulf of Mexico made a difference in the type of review MMS
conducted. Arguably, a heightened level of review might have reached a different conclusion as to
the probable environmental impacts. If the EP had been in the Arctic, the CE for the Gulf plans
would not apply and consideration of a blowout scenario also would have been required. Instead,
EAs are used, which must sufficiently analyze the environmental impacts of the action. When the
Ninth Circuit reviewed an EA for an exploration plan in the Beaufort Sea in the Arctic
(hereinafter the Beaufort Sea EP), it found that an EA was not adequate.97 The BP EP and the
Beaufort Sea EP are factually similar in that they result from a nearly identical set of tiered NEPA
analyses. The Beaufort Sea EP also came after an EIS for a 5-year plan (for 2002-2007), an EIS
for the multiple lease sale, and a series of EAs for particular lease sales. Like the EP CE,
endangered species were present at the planned drilling site. In the case of the Beaufort Sea EP
the court indicated experts expressed concern that the exploration plan could have significant
impacts on polar bears and whales. An EA-FONNSI was issued, meaning no new significant
impacts were found. The court held that the Beaufort Sea EA did not indicate MMS took a “hard
look” at the environmental impacts of the exploration plan since substantial questions remained
regarding the harm to wildlife and the people in the area.98 MMS revoked its approval of the EP.99
The EP CE, perhaps, could be justified as a fourth environmental review, implying that all of the
environmental impacts had been considered in the earlier, more expansive documents.
Technically, however, that is not how a CE is intended to be applied. The NEPA regulations do
not provide that CEs may be used to exclude reviews on the basis that previous analyses already
considered impacts. A CE is supposed to be invoked because the project would not have any
impacts. NEPA allows tiered environmental reviews100 when the impacts have already been
considered.
Additionally, this rationale runs counter to the OCSLA staging justification used by courts as to
why environmental reviews at the lease sale stage or earlier did not need to be in depth. Those

95 Lease 206 EA, p. 41.
96 Jones v. Gordon, 792 F.2d 821 (9th Cir. 1986).
97 Alaska Wilderness League v. Kempthorne, 548 F.3d 815 (9th Cir. 2008), vacated as moot, 571 F.3d 859 (9th Cir.
2009) (upon rescission by MMS of the EP approval).
98 Alaska Wilderness League v. Kempthorne, 548 F.3d 815, 825 (9th Cir. 2008), vacated as moot, 571 F.3d 859 (9th Cir.
2009).
99 See Alaska Wilderness League v. Kempthorne, 571 F.3d 859 (9th Cir. 2009).
100 40 C.F.R. § 1500.4(i).
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courts held that a more intense environmental review was not needed at the early stages of the
OCSLA because it would occur when actual drilling was imminent.101 For example, the
justification used by the District Court of Alaska for why a 100,000 bbl spill did not have to be
analyzed may not apply when a CE is used at the exploration stage instead of a more in-depth
analysis: “Congress has decided to allow key decisions having serious environmental
consequences to be made at the exploration and production and development stages instead of
requiring all decisions to be made at the pre-leasing and leasing stages.”102
The Ninth Circuit’s rationale for why a larger oil spill was not examined at the lease sale stage
was that environmentally significant activities did not occur then. A more thorough review would
be conducted later
by purchasing a lease, lessees acquire no right to do anything more. Under the plain language
of OCSLA, the purchase of a lease entails no right to proceed with full exploration,
development, or production ... the lessee acquires only a priority in submitting plans to
conduct those activities. If these plans, when ultimately submitted, are disapproved, no
further exploration or development is permitted.103
If no review were conducted later, this justification may not seem to be supportable. The Ninth
Circuit had suggested in another case that the exploration stage was where a spill analysis would
be most appropriate.104
The U.S. Supreme Court also emphasized the importance of administrative review of the post-
lease actions: “an OCS lease authorizes the holder to engage only in preliminary exploration;
further administrative approval is required before full exploration or development may begin.”105
It could be argued that the EP CE is the inverse result of what is supposed to happen with tiered
environmental reviews. Instead of the process described by the courts where the environmental
review becomes more exacting as the drilling becomes imminent, the opposite has happened and
no additional environmental analysis was conducted.
The Council on Environmental Quality Report on MMS and NEPA
In August 2010, CEQ issued a report on MMS/BOEMRE and its NEPA procedures for OCS
drilling.106 The report recommends that BOEMRE policies could be revised to reflect the
purposes of NEPA more closely. Many of the recommendations address issues discussed within
this report. For example, CEQ recommends that BOEMRE seek a statutory revision to OCSLA to
extend the 30-day limit for considering EPs.

101 Center for Biological Diversity v. U.S. Department of the Interior, 563 F.3d 466, 480 (D.C. Cir. 2009).
102 Village of False Pass v. Watt, 565 F. Supp. 1123 (D.C. Alaska 1983).
103 Village of False Pass v. Clark, 733 F.2d 605, 608 (9th Cir. 1984).
104 Tribal Village of Akutan v. Hodel, 869 F.2d 1185, 1192 (9th Cir. 1988).
105 Secretary of the Interior v. California, 464 U.S. 312, 321 (1984).
106 CEQ, Report Regarding the Minerals Management Service’s National Environmental Policy Act Policies, Practices,
and Procedures as They Relate to Outer Continental Shelf Oil and Gas Exploration and Development (Aug. 16, 2010)
(hereinafter CEQ Report). Available at http://www.whitehouse.gov/sites/default/files/microsites/ceq/20100816-ceq-
mms-ocs-nepa.pdf.
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It also questions the propriety of allowing CEs for exploration and drilling and production plans.
For one thing, it suggests that those CEs were developed before OCS activities were conducted at
such depths, saying that there is a “progressively more complex environment” for deepwater
operations than there was at the time of the CEs’ creation. According to an MMS report, drilling
at 1,000 feet began in the late 1970s, although drilling at 3,000 to 5,000 feet did not occur until
the late 1990s.107
Another point the CEQ Report makes is that BOEMRE should review how it perceives
“extraordinary circumstances.” Under NEPA practice, finding an extraordinary circumstance
indicates that a CE should not be used. The CEQ Report suggests that MMS was not properly
evaluating those factors, stating that BOEMRE “intends to review its interpretation of the
threshold requirement of ‘extraordinary circumstances.’”108
Additionally, the CEQ Report points to the lack of consideration of massive oil spills in any of the
environmental documents. While MMS found that a large spill had a low probability, the report
still recommends that the agency consider reasonably foreseeable impacts associated with a
catastrophic spill, despite the predicted low risk. The reasonably foreseeable impacts would
include cumulative impacts. The cumulative impacts analysis for other Gulf projects should be
different following the 4.1 million bbl spill.
On the same day as the CEQ Report was issued, the Department of the Interior announced it was
not going to use certain CEs until it completed a review of all its CEs for OCS exploration and
drilling activities.109 The directive specifically prohibits using the CE that allows exclusion of
exploration and development and production plans in the western and central Gulf (516 DM
15.4(C)(10)) if the project involves a subsea blowout preventer.
Congressional Attention to Categorical Exclusions
Congress has also focused on the use of CEs for exploration and development in the Gulf. Two
House bills would eliminate the use of CEs for exploration, development, and production plans.
H.R. 52 (Connolly) would require an EIS for those plans. It states that exploration, development,
and production plans are “major federal actions significantly affecting the quality of the human
environment.” It would also eliminate the 30-day deadline for agency response to
exploration plans.
H.R. 501 (Markey) is similar. It would require either an EA or an EIS for those three types of
plans. Section 215(3) of H.R. 501 addresses development and production plans. Section 208(g) of
H.R. 501 addresses exploration plans, extending the approval time for those plans from 30 to 90
days. In addition, it would require those plans to demonstrate the use of best available technology,
including for blowout prevention. The bill would also put into law exceptional circumstances for
when a plan can be rejected by the agency.
A third bill of the 112th Congress comes from the Senate. S. 203 (Begich) would prevent NEPA
from applying to tests of technology for spill prevention, recovery, and mitigation in Arctic

107 MMS, Deepwater Gulf of Mexico 2008: America’s Offshore Energy Future, Appx. A (CS Report MMS 2008-013).
108 CEQ Report, at 31.
109 BOEMRE Directive, Use of Categorical Exclusions in Gulf of Mexico Region (Aug. 16, 2010). Available at
http://www.doi.gov/news/pressreleases/loader.cfm?csModule=security/getfile&PageID=42011.
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waters. It does this by declaring that such testing is not a major federal action. The bill also
provides that the agency decision regarding this exclusion is exempt from judicial review.
In the 111th Congress, three bills were proposed by the House to restrict the use of CEs. H.R.
3534 (Rahall), the Consolidated Land, Energy, and Aquatic Resources Act of 2010 (CLEAR),
would have required BOEMRE approval of exploration, development, and production plans to
include either an EA or an EIS, effectively eliminating the CE for those plans.110 CLEAR would
have amended the requirement for approval of EPs from 30 days to 90 days.111 H.R. 5506
(Connolly) would have gone further than H.R. 3534 by requiring an EIS (and not an EA) for
those plans’ approval. It would have removed the 30-day deadline. H.R. 5572 (Buchanan) states
that the Department of the Interior could not exempt any OCS activity from legal requirements.
Conclusion
The exploration well blowout in the Gulf of Mexico appears to have major, and potentially
catastrophic, environmental effects. None of the environmental reviews under NEPA considered
an oil spill of this magnitude. However, it is unclear whether that violates NEPA, which has no
requirement for analysis of a worst case scenario. The use of a categorical exclusion at the
exploration stage appears to be procedurally correct under MMS policy, provided there were no
applicable exceptions. However, the legality of that CE has never been examined by a court,
which could consider whether an exemption from a NEPA review at the point where drilling is
imminent violates NEPA either because extraordinary circumstances existed in the case, or
because, in general, the tiered OCSLA process envisioned more scrutiny of environmental
consequences after the lease stage. BOEMRE has indicated it will take a closer look at its CEs
and how they are applied.

110 H.R. 3534, § 208(f).
111 H.R. 3534, § 208(b)(2).
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Appendix A. Background Facts
Source: MMS, Gulf of Mexico OCS Oil and Gas Lease Sales: Final Environmental Impact
Statement (MMS 2007-018) (April 2007).
Duration of Gulf of Mexico OCS Oil and Gas Activity—40 years (p. 4-5):
• Exploratory drilling activity can take place over an 8-year period, beginning
within one year after the lease sale.
• Development activity takes place over a 39-year period, beginning with the
installation of the first production platform and ending with the drilling of the last
development wells.
• Production of oil and gas begins by the third year after the lease sale and
continues through the 40th year.
• Final abandonment and removal activities occur in the 40th year.
Amount of oil and gas expected to be produced (p. 4-5):
Western Gulf:
• Oil = 242-423 million bbl
• Gas = 1.644-2,647 trillion cubic feet
Central Gulf:
• Oil = 776-1,292 million bbl
• Gas = 3.236-5.229 trillion cubic feet
Amount of seismic testing expected (p. 4-7):
• Western Gulf—400-800 blocks
• Central Gulf—1,000-2,000 blocks
Number of exploration and delineation wells from this lease sale expected during 40-year
period (p. 4-10):
• Western Gulf—42-66
• Central Gulf—65-96
Number of development wells from this lease sale anticipated during 40-year period
(p. 4-13):
• Western Gulf—155-221
• Central Gulf—330-468
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Number of loss of well control events (including blowouts) from this lease sale estimated
during 40-year period (p. 4-250):
• Western Gulf—1-2
• Central Gulf—2-3
Number of offshore oil spills estimated from this lease sale during 40-year period (p. 4-241):
• Western Gulf—800-1,500 spills/ 400-21,000 bbl of oil
• Central Gulf—2,700-4,500 spills/ 5,500-26,500 bbl of oil
Natural seeps of oil, annual average (1990-1999) (Table 4-12):
• Western Gulf—490,000 bbl
• Eastern Gulf112—490,000 bbl
Probability of spills greater than 10,000 bbl occurring (Table 4-15):
Western Gulf:
• Mean number of spills from all sources (facilities, pipelines, shuttle tankers)—3
• Probability of occurrence—92%-96%
Central Gulf:
• Mean number of spills from all sources (facilities, pipelines, shuttle tankers)—9
• Probability of occurrence—99+%
Historical data on offshore spills greater than 10,000 bbl in the Gulf of Mexico from 1985-
1999 (Table 4-16):
• From pipelines: 2 spills; 30,000 bbl spilled in total
• From platforms: 0 spills

112 Data not available for Central Gulf.
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Appendix B. MMS Categorical Exclusions
Source: 516 DM
15.4 Categorical Exclusions. In addition to the actions listed in the Departmental categorical
exclusions outlined in Appendix 1 of 516 DM 2, many of which the MMS also performs, the
following MMS actions are designated categorical exclusions unless the action qualifies as an
exception under Appendix 2 of 516 DM 2:
A. General.
(1) Inventory, data, and information collection, including the conduct of environmental
monitoring and nondestructive research programs.
(2) Actions for which MMS has concurrence or co-approval with another Bureau if the action is a
categorical exclusion for that Bureau.
B. Internal Program Initiatives.
(1) All resource evaluation activities including surveying, mapping, and geophysical surveying
which do not use solid or liquid explosives.
(2) Collection of geologic data and samples including geologic, paleontologic, mineralogic,
geochemical, and geophysical investigations which does not involve drilling beyond 50 feet of
consolidated rock or beyond 300 feet of unconsolidated rock, including contracts therefor.
(3) Acquisition of existing geological or geophysical data from otherwise private exploration
ventures.
(4) Well logging, digital modeling. inventory of existing wells, and installation of recording
devices in wells.
(5) Establishment and installation of any research/monitoring devices.
(6) Test or exploration drilling and downhole testing included in a project previously subject to
the NEPA process.
(7) Insignificant revisions to the approved 5-year leasing program.
(8) Prelease planning steps such as the Call for Information and Area Identification.
C. Permit and Regulatory Functions.
(1) Issuance and modification of regulations, Orders, Standards, Notices to Lessees and
Operators. Guidelines and field rules for which the impacts are limited to administrative,
economic, or technological effects and the environmental impacts are minimal.
(2) Approval of production measurement methods, facilities, and procedures.
(3) Approval of off-lease storage in existing facilities.
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(4) Approval of unitization agreements, pooling, or communitization agreements.
(5) Approval of commingling of production.
(6) Approval of suspensions of operations and suspensions of production.
(7) Approval of lease consolidation applications, lease assignments or transfers, operating rights,
operating agreements, lease extensions, lease relinquishments, and bond terminations.
(8) Administration decisions and actions and record keeping such as:
(a) Approval of applications for pricing determinations under the Natural Gas Policy Act.
(b) Approval of underground gas storage agreements from a presently or formerly productive
reservoir.
(c) Issuance of paying well determinations and participating area approvals.
(d) Issuance of drainage determinations.
(9) Approval of offshore geological and geophysical mineral exploration activities, except when
the proposed activity includes the drilling of deep stratigraphic test holes or uses solid or liquid
explosives.
(10) Approval of an offshore lease or unit exploration. development/production plan or a
Development Operation Coordination Document in the central or western Gulf of Mexico (30
CFR 250.2) except those proposing facilities: (1) In areas of high seismic risk or seismicity,
relatively untested deep water, or remote areas, or (2) within the boundary of a proposed or
established marine sanctuary, and/or within or near the boundary of a proposed or established
wildlife refuge or areas of high biological sensitivity; or (3) in areas of hazardous natural bottom
conditions; or (4) utilizing new or unusual technology.
(11) Approval of minor revisions of or minor variances from activities described in an approved
offshore exploration or development/production plan, including pipeline applications.
(12) Approval of an Application for Permit to Drill (APD) an offshore oil and gas exploration or
development well, when said well and appropriate mitigation measures are described in an
approved exploration plan, development plan, production plan, or Development Operations
Coordination Document.
(13) Preliminary activities conducted on a lease prior to approval of an exploration or
development/production plan or a Development Operations Coordination Plan. These are
activities such as geological, geophysical, and other surveys necessary to develop a
comprehensive exploration plan, development/production plan, or Development Operations
Coordination Plan.
(14) Approval of Sundry Notices and Reports on Wells.
(15) Rights-of-ways, easements, temporary use permits, and any revisions thereto that do not
result in a new pipeline corridor to shore.
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D. Royalty Functions. All functions of the Associate Director for Royalty Management including,
but not limited to, such activities as: approval of royalty payment procedures, including royalty
oil contracts; and determinations concerning royalty quantities and values, such as audits, royalty
reductions, collection procedures, reporting procedures, and any actions taken with regard to
royalty collections (including similar actions relating to net profit and windfall profit taxes).
Exceptions To Categorical Exclusions
516 DM 2 Appendix 2
The following exceptions apply to individual actions within categorical exclusions (CX).
Environmental documents must be prepared for actions which may:
2.1 Have significant adverse effects on public health or safety.
2.2 Have adverse effects on such unique geographic characteristics as historic or cultural
resources, park, recreation or refuge lands, wilderness areas, wild or scenic rivers, sole or
principal drinking water aquifers, prime farmlands, wetlands, floodplains or ecologically
significant or critical areas, including those listed on the Department’s National Register of
Natural Landmarks.
2.3 Have highly controversial environmental effects.
2.4 Have highly uncertain and potentially significant environmental effects or involve unique
or unknown environmental risks.
2.5 Establish a precedent for future action or represent a decision in principle about future
actions with potentially significant environmental effects.
2.6 Be directly related to other actions with individually insignificant but cumulatively
significant environmental effects.
2.7 Have adverse effects on properties listed or eligible for listing on the National Register of
Historic Places.
2.8 Have adverse effects on species listed or proposed to be listed on the List of Endangered
or Threatened Species, or have adverse effects on designated Critical Habitat for these
species.
2.9 Require compliance with Executive Order 11988 (Floodplain Management), Executive
Order 11990 (Protection of Wetlands), or the Fish and Wildlife Coordination Act.
2.10 Threaten to violate a Federal, State, local or tribal law or requirement imposed for the
protection of the environment.
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Appendix C. The MMS Categorical Exclusion
Review Process
Source: Minerals Management Service
A more detailed discussion of Categorical Exclusion Reviews (CERs) and the NEPA process for
review of Industry Submittals follows:
Descriptions for the “NEPA Determination Type” field under FastFacts?
The NEPA Determination Type is identified in a NEPA Determination Type Review at the
very beginning of the Categorical Exclusion Review (CER) process and it establishes the level of
NEPA analyses that should be conducted for a particular proposal. Based upon details about the
proposed action, policy, and programmatic NEPA analyses, the NEPA Determination Type could
be one of the following:
• CER with no further Analyses; i.e., finalize the CER with no additional
reviews/conditions of approval (COAs)
• CER with Analyses; i.e., continue processing/review under a CER with the
applicable protected resource reviews assigned; or
• Prepare an Environmental Assessment (EA) or an Environmental Impact
Statement (EIS)
When it’s a categorical exclusion [review] with analysis, what kind of analysis is it?
Though not a document in the same sense as an EA or EIS, the CERs ultimately consist of a
series of procedures and activity-specific reviews that are conducted and compiled so that MMS
is assured that the activity can remain Categorically-Excluded from review under an EA or EIS.
The CERs are completely digital and therefore, stored within TIMS as part of the Administrative
Record along with all documentation related to the proposed action (in this case, the EPs on
MC252) and all associated surveys/reports. Even though central and western Gulf of Mexico
drilling and production activities are Categorically-Excluded from any additional review, MMS
GOMR prepares CERs on each proposal to ensure that “extraordinary circumstances” do not
exist and to ensure that the agency has the ability to consider the best-available data/technology
on a case-by-case basis, which in turn affords real-time adaptive management of assessment
triggers, reviewing standards, and conditions of approval/mitigation.
When an exception criteria [now called an “extraordinary circumstance”] is identified
during analysis, what exactly does that mean?
An “extraordinary circumstance” (EC) is an identified condition that could exist within an action
that could be Categorically-Excluded from additional NEPA analysis. MMS has 12 ECs identified
under 43 CFR § 46.215 (see last page) that it reviews the proposed action against to determine if
any of the activities proposed by the operator may “trigger” or cause an EC condition to occur. If
an EC is identified for a proposal that cannot be avoided (either in the NEPA Determination
Review or protected resource reviews), an EA must be prepared. The EA, in turn, could result in a
Finding of Significant Impact (FOSI), which would then require preparation of an EIS.
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Detailed Discussion:
The DOI and MMS can categorically-exclude (CatEx) certain actions from further NEPA
analyses if it is determined that they would not have a significant effect on the environment
(individually or cumulatively). The MMS CatEx list is currently found in the Departmental
Manual (see 516DM15.4) and it not only contains administrative actions, but also common OCS
operations. The impacts from the common operations are expected to be negligible to non-
existent based upon general information gathered during past environmental analyses about the
type of activities, the area of the proposed action, programmatic NEPA analyses (Program/Sale
EISs/EAs), and the past actions as conducted and observed. The specific MMS operational CatEx
corresponding to the submittal of an Exploration Plan (EP) is below:

MMS Categorical Exclusion
under 516 DM 15.4
C. Permit and Regulatory Functions.
10. Approval of an offshore lease or unit exploration plan (EP), development/production plan (DPP), or a
Development Operation Coordination Document (DOCD) in the central or western Gulf of Mexico (30CFR250.2)
except those proposing facilities:
In areas of high seismic risk or seismicity, relatively untested deep water, or remote areas, or
within the boundary of a proposed or established marine sanctuary, and/or within or near the boundary of a
proposed or established wildlife refuge or areas of high biological sensitivity; or
in areas of hazardous natural bottom conditions; or
utilizing new or unusual technology.

Since the CatEx list is based upon general/historical information and generalized/programmatic
information, GOMR goes the extra step and prepares a Categorical Exclusion Review (CER) for
each action to determine if site-specific details of the proposed operations will not result in an
Extraordinary Circumstance (EC), which would require that an EA be prepared. Coordinators in
GOMR’s Environmental Compliance Section (ECS) follow a set of submittal-specific SOPs and
utilize a detailed GIS application, PMT GIS, that addresses the activity being proposed and
compares information with established business rules/EC triggers based upon the specific
resources to determine if the action should be reviewed under an Environmental Assessment (EA)
and which, if any, protected resource reviews should be assigned for the CER/EA.
When the NEPA coordinator is finished following the SOP, their NEPA Determination Review
and associated PMT GIS report will identify the Initial NEPA Determination Type, which could
include the following:
• CER with no further Analyses; i.e., finalize the CER with no additional
reviews/conditions of approval (COAs)
• CER with Analyses; i.e., continue processing/review under a CER with the
applicable protected resource reviews assigned; or
• Prepare an EA/EIS.
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All of the applicable information related to the NEPA Determination and/or any resource reviews
is recorded in the Technical Information Management System (TIMS) and the PMT GIS Report is
attached in the respective NEPA Determination Type Review. A copy of the plan/application is
provided to the NEPA Decision Maker for a concurrence review of the TIMS information and
PMT GIS Report. If the Decision Maker concurs with the coordinator, NEPA Determination
Type is also recorded in TIMS for the specified submittal. If the Chief has any questions about
the NEPA determination type, the information will be reviewed together until a decision can be
made.
Once concurrence is given, all necessary reviews are assigned to resource specialists (i.e., marine
archaeologists, benthic biologists, meteorologists, oceanographers, etc.) and tracked in TIMS.
The SME informs the NEPA Coordinator if additional information or a clarification is required
and/or when the review is completed. The completed review will note one of the following:
• The proposed action will have no impact on the protected resource.
• The proposed action requires a condition of approval (COA) to ensure that an
extraordinary circumstance (EC) will not be met/triggered.
• The proposed action may cause a significant impact and an EA is recommended.
When all of the applicable reviews are completed, the SME’s conclusions, and any suggested
conditions of approval/mitigation (if necessary), are recorded in TIMS and compiled by the NEPA
Coordinator for presentation to the NEPA Decision Maker. The NEPA decision maker will review
the findings and choose from the following Final NEPA Actions:
• CER Approved; (Action can be CatExed with no COAs—an EC will not be
triggered/occur); or
• CER Approved; (Action can be CatExed with COAs—to ensure that an EC will
not be triggered/occur);
• Prepare an EA/EIS.
43 CFR § 46.215 Categorical Exclusions: Extraordinary circumstances
Extraordinary circumstances (see paragraph 46.205(c)) exist for individual actions within
categorical exclusions that may meet any of the criteria listed in paragraphs (a) through (l) of this
section. Applicability of extraordinary circumstances to categorical exclusions is determined by
the Responsible Official.
• Have significant impacts on public health or safety.
• Have significant impacts on such natural resources and unique geographic
characteristics as historic or cultural resources; park, recreation or refuge lands;
wilderness areas; wild or scenic rivers; national natural landmarks; sole or
principal drinking water aquifers; prime farmlands; wetlands (EO 11990);
floodplains (EO 11988); national monuments; migratory birds; and other
ecologically significant or critical areas.
• Have highly controversial environmental effects or involve unresolved conflicts
concerning alternative uses of available resources [NEPA section 102(2)(E)].
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• Have highly uncertain and potentially significant environmental effects or
involve unique or unknown environmental risks.
• Establish a precedent for future action or represent a decision in principle about
future actions with potentially significant environmental effects.
• Have a direct relationship to other actions with individually insignificant but
cumulatively significant environmental effects.
• Have significant impacts on properties listed, or eligible for listing, on the
National Register of Historic Places as determined by the bureau.
• Have significant impacts on species listed, or proposed to be listed, on the List of
Endangered or Threatened Species or have significant impacts on designated
Critical Habitat for these species.
• Violate a Federal law, or a State, local, or tribal law or requirement imposed for
the protection of the environment.
• Have a disproportionately high and adverse effect on low income or minority
populations (EO 12898).
• Limit access to and ceremonial use of Indian sacred sites on Federal lands by
Indian religious practitioners or significantly adversely affect the physical
integrity of such sacred sites (EO 13007).
Contribute to the introduction, continued existence, or spread of noxious weeds or non-native
invasive species known to occur in the area or actions that may promote the introduction, growth,
or expansion of the range of such species (Federal Noxious Weed Control Act and EO
13112).Contribute to the introduction, continued existence, or spread of noxious weeds or non-
native invasive species known to occur in the area or actions that may promote the introduction,
growth, or expansion of the range of such species (Federal Noxious Weed Control Act and EO
13112).

Author Contact Information

Kristina Alexander

Legislative Attorney
kalexander@crs.loc.gov, 7-8597

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