Order Code RS20621
Updated April 19, 2005
CRS Report for Congress
Received through the CRS Web
Overview of NEPA Requirements
Pamela Baldwin
Legislative Attorney
American Law Division
Summary
The National Environmental Policy Act (NEPA) establishes national environmental
policies that apply to the federal government and also prescribes certain procedural
requirements for federal agency actions. Except as otherwise provided by Congress,
NEPA applies to all federal agency actions, although its requirements may vary
depending on the nature of the action involved. This report provides an overview of
NEPA’s requirements. This report will be updated as warranted.
General
The National Environmental Policy Act of 1969 (NEPA)1 establishes national
environmental policies that apply to the federal government as a whole and prescribes
certain procedural requirements for federal agency actions. Except as otherwise provided
by Congress, the act applies to all federal agency actions,2 including those that intersect
with private activities, e.g. through a federal permit or funding, although its requirements
may vary depending on the nature of the action involved. NEPA imposes several
obligations on federal agencies in addition to the familiar requirement to prepare
Environmental Impact Statements (EISs) in certain circumstances.3
NEPA establishes a national environmental policy that makes it the:
continuing responsibility of the Federal Government to use all
practicable means, consistent with other essential considerations of
1 Act of January 1, 1970, Pub. L. No. 91-190, 83 Stat. 852, 42 U.S.C. §§4321 et seq.
2 40 C.F.R. 1508.12 defines “Federal agency” as not meaning the Congress, the Judiciary, or the
President. Attention focuses on this regulation from time to time, e.g. when the President
established several national monuments without preparation of NEPA documents.
3 It is sometimes said that NEPA “doesn’t apply” to federal actions unless they are “significant,”
a reference to the requirement in § 102(2)(C) that an agency prepare an environmental impact
statement (EIS) for a proposed “major federal action significantly affecting the quality of the
human environment.”
Congressional Research Service ˜ The Library of Congress

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national policy, to improve and coordinate Federal plans, functions,
programs, and resources to the end that the Nation may – . . .
(2) assure for all Americans safe, healthful, productive, and
aesthetically and culturally pleasing surroundings;
(3) attain the widest range of beneficial uses of the environment
without degradation, risk to health or safety, or other undesirable and
unintended consequences; ....4
In addition to these general policies, NEPA requires all federal agencies to do certain
specific things, only one of which is the preparation of an EIS for any major federal action
significantly affecting the quality of the human environment. Among other things,
§102(2) of NEPA (42 U.S.C. §4332(2)) requires agencies to:
(A) utilize a systematic, interdisciplinary approach which will insure
the integrated use of the natural and social sciences and the
environmental design arts in planning and in decisionmaking which
may have an impact on man's environment; ...
(C) include in every recommendation or report on proposals for
legislation and other major Federal Actions significantly affecting the
quality of the human environment, a detailed statement by the
responsible official on --
(I) the environmental impact of the proposed action,
(ii) any adverse environmental effects which cannot be
avoided should the proposal be implemented,
(iii) alternatives to the proposed action,
(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 which would be involved in the proposed action
should it be implemented; ...
(E) study, develop, and describe appropriate alternatives to
recommended courses of action in any proposal which involves
unresolved conflicts concerning alternative uses of available
resources; ...
NEPA also created the Council on Environmental Quality (CEQ), which
promulgated regulations implementing NEPA.5 Each agency is expected to elaborate on
how to comply with NEPA in the context of its own duties. The CEQ regulations
emphasize communicating with the public, reducing delays, and making better decisions,
rather than producing unnecessary paperwork.6 Agencies are to integrate the NEPA
4 42 U.S.C. §4331(b). Although the enforceable requirements of NEPA are those that are
“essentially procedural” (Robertson v. Methow Valley Citizens’ Council, 490 U.S. 332, 350
(1989)), such as the preparation of environmental documents, the NEPA policy establishes goals
for agency actions.
5 40 C.F.R. §§ 1500 et seq.
6 40 C.F.R. §§ 1500.1 through 1500.5.

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reviews with other agency planning and review processes,7 and coordinate with other
federal agencies and with similar state processes when appropriate.8
NEPA Documents
The regulations require various levels of analysis of possible environmental effects,
depending on the circumstances and the likely degree of environmental impacts. At one
end of the spectrum are major federal actions that significantly affect the environment,9
regarding which EISs generally must be prepared.10 Most court cases relate to when an
EIS needs to be prepared and to the adequacy of EIS coverage.11 An EIS must discuss an
adequate range of proposed alternatives, and the direct, indirect, and cumulative effects
or impacts of each. The thoroughness with which an agency must study environmental
effects and consider alternatives is greatest if an EIS is required.12
An EIS may either be a “programmatic” EIS, which addresses the “adoption of
programs, such as a group of concerted actions to implement a specific policy or plan,”13
or a “site-specific” EIS, which analyzes the environmental impacts of a particular project.
More focused environmental documents should be “tiered” to broader ones to avoid
repeating more general analysis in the more specific documents.14
At the other end of the spectrum are categories of activities that either separately or
cumulatively are known to have no or only minor environmental effects. An agency need
not prepare formal NEPA environmental analyses with respect to these types of actions,
which are known as "categorical exclusions."15 Many departments and agencies,
especially those with land management responsibilities such as the Bureau of Land
Management in the Department of the Interior and the Forest Service in the Department
of Agriculture, have established criteria for determining categories of actions or decisions
7 40 C.F.R. § 1500.2(c).
8 40 C.F.R. § 1506.2.
9 40 C.F.R. §1501.4, and parts 1502 and 1503. Under §1508.18, the concept of "major" federal
action may be determined largely by the significance of the effects of a proposed action on the
environment: "Major Federal action includes actions with effects that may be major and which
are potentially subject to Federal control and responsibility. Major reinforces but does not have
a meaning independent of significantly (§1508.27)."
10 In some circumstances, an agency may be excused from preparing an EIS. For example, an
agency may be excused from preparing an EIS if Congress has imposed a deadline that makes
preparation of an EIS impossible. Flint Ridge Development Co. v. Scenic Rivers Ass’n. of
Oklahoma, 426 U.S. 776 (1976). Sometimes too, other agency processes may be the “functional
equivalent” of the NEPA process such that preparation of an EIS is obviated. International
Harvester Co. v. Ruckelshaus, 478 F. 2d 615, 650, n. 130 (D.C. Cir. 1973).
11 See THE NEPA LITIGATION GUIDE, Karin Sheldon and Mark Squillace, editors; American Bar
Association, 1998.
12 Mt. Lookout - Mt. Nebo Property Protection Ass’n. v. FERC, 143 F. 3d 165 (4th Cir. 1998).
13 40 C.F.R. § 1508.18(b)(3).
14 40 C.F.R. §§ 1502.20 and 1508.28.
15 40 C.F.R. §1508.4.

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that are categorical exclusions, and maintain lists of same. However, an action may
nonetheless require analysis if particular listed “extraordinary circumstances” (such as the
presence of wetlands or species listed as threatened or endangered under the Endangered
Species Act) are present, or are deemed to be so by the acting official.
An Environmental Assessment (EA), is prepared for an action that is not clearly
categorically excluded, but does not clearly require an EIS. Based on the EA, the agency
either prepares an EIS, if one appears warranted, or issues a "Finding of No Significant
Impact" (FONSI), which finding obviates further NEPA document preparation. Although
an EA is typically prepared to determine whether an EIS is necessary and the CEQ
regulations state that an assessment is not necessary if the agency has decided initially to
prepare an environmental impact statement,16 the CEQ regulations also recognize that
agencies may prepare an EA on any action at any time in order to assist agency planning
and decision-making.17
Environmental analyses are to be prepared early in the decision making process so
that they can make an important contribution to the decision making process.18
“Ultimately, of course it is not better documents but better decisions that count. NEPA’s
purpose is not to generate paper work– even excellent paperwork – but to foster excellent
action.”19
When more than one federal agency is involved in an action, the regulations provide
for the responsibilities of a “lead agency”20 and “cooperating agencies,”21 and for referral
to CEQ of disagreements among federal agencies on how to proceed with certain
decisions.22
Congress has at times directed some particular level of NEPA document preparation
– e.g., by specifying either that an EIS be or not be prepared.23 No CEQ regulation
specifically addresses NEPA compliance when Congress has precluded preparation of an
EIS. As noted, an agency may always prepare an EA to aid in decision-making and to
comply with general NEPA duties. But since an EA is principally prepared to ascertain
whether an EIS is necessary, it is not clear whether preparation of an EA would ever be
an enforceable duty if Congress precluded preparation of an EIS.
The duty under §102(2)(E) (42 U.S.C. § 4332(2)(E)) to study, develop, and describe
appropriate alternatives to recommended courses of action in any proposal which involves
16 40 C.F.R. §1501.3.
17 40 C.F.R. §1501.3(a) and (b); 1508.9.
18 40 C.F.R. § 1502.5.
19 40 C.F.R. § 1500.1(b).
20 40 C.F.R. § 1501.5.
21 40 C.F.R. § 1508.5.
22 40 C.F.R. § 1504.3.
23 See P. Baldwin, STATUTORY MODIFICATIONS OF THE APPLICATION OF NEPA, CRS Report 98-
417 A.

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“unresolved conflicts concerning alternative uses of available resources,” may be relevant
to possible agency duties aside from the EIS context.
Some courts have looked at the § 102(2)(E) requirement to study alternatives and
analyzed this duty as separate from (if usually coincidental with) the duty to prepare an
EIS, but the scope of possible duties under § 102(2)(E) is not clear. The definition of an
EA states that an EA shall include brief discussions of the need for the proposal, of
alternatives as required by section 102(2)(E), of the environmental impacts of the
proposed action and alternatives, and a listing of agencies and persons consulted.24 One
court has found that even when an agency determines that an EIS is not required, an
agency must do more to meet its duty under § 102(2)(E) than provide a perfunctory and
conclusory statement.25 However, exactly what level and form of documentation might
be required is still uncertain. At least one case questioned whether any duty to consider
alternatives existed once an agency had correctly decided that an EIS was not necessary.26
Also, it is not clear what agency "proposals" trigger the duty to consider alternatives.27
In a case interpreting § 511 of the Clean Water Act, which eliminates the duty to
prepare an EIS, plaintiffs argued that the Environmental Protection Agency (EPA) had
other duties under NEPA, such as those under §102(2)(E) to study and develop
alternatives to the proposed action, but the court held that §511 completely exempted the
relevant activities of EPA from all NEPA obligations, including those under § 102(2)(E).
However, in reaching this conclusion, the court looked to the special role of the EPA in
assisting and protecting the environment, the intent of Congress, the fact that the
processes in setting water standards were the "functional equivalent" of the NEPA
24 50 C.F.R. § 1508.9 (emphasis added).
25 Trinity Episcopal School Corp. v. Romney, 523 F.2d 88 (2d Cir. 1975), subsequently
relitigated after a new document was prepared, in Trinity Episcopal School Corp. v. Harris, 445
F. Supp. 204 (1978), Karlen v. Harris, 590 F. 2d 39 (1978) and rev'd on other grounds sub nom.
Strycker's Bay Neighborhood Council, Inc. v. Karlen, 444 U.S. 223 (1980). See 40 C.F.R. §
1508.9, which states that an EA must discuss alternatives “as required by section 102(2)(E).” In
Van Abbema v. Fornell, 807 F. 2d 633 (7th Cir. 1986), in which the Army Corps of Engineers had
completed an EA and decided that an EIS was not necessary, the court looked separately at the
adequacy of the Corps' consideration of alternatives under § 102(2)(E). Although the Corps did
undertake "a serious review of alternatives," it also had received comments specifically
challenging the information on which it had relied. The court, at 642, found that the Corps had
not taken "a hard look" at alternatives, but rather evidenced "a blind reliance on material prepared
by the applicant in the face of specific challenges raised by opponents." Therefore, the court
vacated the §404 permit and remanded. In other words, in this instance the consideration of
alternatives even in an EA when no EIS was necessary was found to be inadequate. One could
argue that this indicates that the duty to consider alternatives might exist even when an EIS is not
necessary.
26 Webb v. Gorsuch, 699 F.2d 157, 161 (4th Cir. 1983). Note, however, that the court cited only
42 U.S.C.A. §4332(C) and not (E), and hence did not discuss the definition of EA that requires
discussion of alternatives.
27 See Aertsen v. Landrieu, 637 F.2d 12 (1st Cir. 1980); Environmental Defense Fund v. Costle,
657 F.2d 275 (D.C. Cir. 1981).

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safeguards, and that an EIS would be prepared for implementing permits.28 A court might
not apply the same reasoning to statutory language eliminating an EIS in another context.
Public Participation
Although NEPA refers only to consultative and cooperative processes and to making
available the “comments” and views of federal, state, and local environmental agencies,
the NEPA regulations elaborate on and require public participation. The public
participation aspects of the NEPA process are regarded by many as a valuable aspect of
the law. Agencies must:
Provide public notice of NEPA-related hearings, public meetings,
and the availability of environmental documents so as to inform
those persons and agencies who may be interested or affected.29
The CEQ regulations specify levels of notice to the public depending on whether an
action is of national or local interest, and state that in all cases the agency must mail
notice to those who requested it regarding a particular action.30 In addition, an agency
must seek comments on draft or final EISs from certain entities and from the public,31 and
must respond to comments received.32 Other statutes and the regulations of various
departments and agencies typically elaborate on agency processes and when public
comments must be sought. The extent to which an agency eliminates NEPA document
preparation may affect opportunities for public participation in the decisions and actions
in question.
28 Municipality of Anchorage v. United States, 980 F. 2d 1320, 1329 (9th Cir. 1992). Section
511(c) states that with certain exceptions, no action of the Administrator of EPA taken under that
act "shall be deemed a major Federal action significantly affecting the quality of the human
environment within the meaning of the [NEPA]." This is language that Congress has enacted
many times.
29 40 C.F.R. §1506.6(b).
30 Ibid.
31 40 C.F.R. § 1503.1.
32 40 C.F.R. § 1503.4.

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