Order Code RS20621
Updated January 11, 2008
Overview of National Environmental Policy
Act (NEPA) Requirements
American Law Division
The National Environmental Policy Act (NEPA) establishes environmental policies
that apply to the federal government, but it is best known for imposing environmental
review procedures on federal agency actions. NEPA requires agencies to review the
potential environmental impacts of their projects, recording their review in a publicly
available document. There are three types of environmental documents, based on the
type of review: a categorical exclusion (CE), an environmental assessment (EA) and an
environmental impact statement (EIS). The act dictates procedure, not results. Agencies
are required to take a “hard look” at the environmental impacts, not to meet set
environmental standards nor to choose the project with the least environmental
consequence. This report provides an overview of NEPA’s requirements.
The National Environmental Policy Act of 1969 (NEPA)1 establishes environmental
policies that apply to the federal government, but it is best known for imposing
environmental review procedures on 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, such as through a federal permit or funding, although its
requirements vary depending on the nature of the action involved.3
Act of January 1, 1970, P.L. 91-190, 83 Stat. 852; 42 U.S.C. §§ 4321 et seq.
42 U.S.C. § 4332 (“The Congress authorizes and directs that, to the fullest extent possible... all
agencies of the Federal Government shall [do the following]”) (emphasis added). 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 a NEPA review.
There are also several judicially created exemptions for when NEPA does not apply, although
they are the exception. Some examples include appropriations, where the statute provides no
NEPA created the Council on Environmental Quality (CEQ), which promulgated
regulations implementing the act.4 The NEPA regulations emphasize communicating
with the public, reducing delays of federal projects, and making better decisions.5
Agencies are to integrate NEPA reviews with other agency planning and review
processes,6 and coordinate with other federal agencies and with similar state processes
when appropriate.7 Each agency is expected to elaborate on how to comply with NEPA
in the context of its own duties. Agencies generally issue regulations specifying their
NEPA review process.8 When more than one federal agency is involved in an action, the
regulations provide for the responsibilities of a “lead agency”9 and “cooperating
NEPA establishes goals for agency actions. It sets as a national environmental policy
that the federal government “use all practicable means” to improve and coordinate federal
actions to assure “safe, healthful, productive, and aesthetically and culturally pleasing
surroundings” and to “attain the widest range of beneficial uses of the environment
without degradation, risk to health or safety, or other undesirable and unintended
In addition to this policy, NEPA requires certain practices, including using a
“systematic, interdisciplinary approach using natural and social sciences and
environmental design in planning and decisionmaking.”12 The most significant of these
practices are the requirements in Section 102(2), which states that “for proposals for
legislation and other major Federal actions significantly affecting the quality of the human
environment” the agency must prepare a detailed environmental review discussing
(i) the environmental impact of the proposed action,
(ii) any adverse environmental effects which cannot be avoided should the proposal
(iii) alternatives to the proposed action,
discretion, and where the statutory deadline is too short.
40 C.F.R. §§ 1500 et seq. CEQ is within the Executive Office of the President with three
members appointed by the President. 42 U.S.C. § 4342. It does not have the responsibility for
enforcing NEPA requirements. Each agency oversees its own compliance with the act.
40 C.F.R. §§ 1500.1 - 1500.5.
40 C.F.R. § 1500.2(c).
40 C.F.R. § 1506.2.
See, e.g., Federal Highway Administration (FHWA) regulations at 23 C.F.R. Part 771; United
States Department of Agriculture (USDA) regulations at 7 C.F.R. Part 1b; Housing and Urban
Development (HUD) regulations at 24 C.F.R. Part 50.
40 C.F.R. § 1501.5.
40 C.F.R. § 1508.5.
NEPA § 101(b); 42 U.S.C. § 4331(b).
NEPA § 102(2); 42 U.S.C. § 4332(2).
(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. 42 U.S.C. §
These environmental reviews are to be conducted early in the decision-making process
so that they can contribute to the process and not be used to “rationalize or justify
decisions already made.”13
An environmental review under NEPA can take one of three forms: a categorical
exclusion (CE); an environmental assessment (EA); or an environmental impact statement
(EIS). For each of these, the CEQ regulations require consideration of the possible
environmental effects of an agency action. The extent of that analysis depends on the
circumstances and the likely degree of environmental impacts.
CEs are at one end of the spectrum. CEs are used for categories of actions that have
been determined not to have a significant effect on the human environment, individually
or cumulatively, and therefore, do not require further analysis.14 Typically, CEs are used
for minor actions that an agency does repeatedly and knows will have no or only minor
environmental effects. Agencies publish lists of activities that are CEs. When a project
arises that falls into a category on the list, a CE may be invoked.15 However, if an
“extraordinary circumstance” (such as wetlands or a threatened or endangered species)
is present, a CE may not be used.16 Even though a CE represents a determination that an
environmental review is not necessary, the determination still must be documented and
cannot be made after a project has begun.17
40 C.F.R. § 1502.5. See also 40 C.F.R. § 1501.2.
40 C.F.R. § 1508.4.
For example, FHWA has determined these actions are suitable for CEs: landscaping,
construction of bike and pedestrian lanes, improvements to existing truck stations (23 C.F.R. §
771.117). The Forest Service lists these CEs: closing an area during a period of extreme fire
danger, adjusting special use or recreation fees, approving a Surface Use Plan for oil and natural
gas exploration in a new field without herbicides (FSH 1909.15_31). CEs in HUD include
inspections and testing of properties for hazards or defects, purchase of tools, and approval of
foreclosure sale of HUD-held mortgages (24 C.F.R. § 50.19).
40 C.F.R. § 1508.4. Some examples of “extraordinary circumstances” include highly
controversial issues (see Fund for Animals v. Babbitt, 89 F.3d 128, 133 (2d Cir. 1996)); actions
that cumulatively may have significant effects (see Citizens for Better Forestry v. USDA, 481 F.
Supp. 2d 1059, 1089 (N.D. Cal. 2007)); and actions that may have significant effects, such as by
affecting an endangered species or an archeological site.
See Wilderness Watch and Public Employees for Environmental Responsibility v. Mainella,
375 F.3d 1085 (11th Cir. 2004) (NEPA was violated where record indicated that a categorical
exclusion was invoked only after the action had been taken); Anacostia Watershed Soc’y v.
Babbitt, 871 F. Supp. 475, 481 (D.D.C. 1994); Fund for Animals, Inc. v. Espy, 814 F. Supp. 142,
150-51 (D.D.C. 1993) (a categorical exclusion must be invoked prior to the agency action).
In the middle of the spectrum are Environmental Assessments. EAs are conducted
to determine whether an EIS is needed or a finding of no significant impact (FONSI) is
appropriate.18 EAs are intended to be concise, but are also required to consider the need
for the project, the environmental impacts of the project and its alternatives, alternatives
required by section 102(2)(E), and a list of the agencies and persons consulted.19
At the other end of the spectrum are full reviews for major federal actions that may
significantly affect the environment — EISs.20 These documents are the most complex
and have drawn the most scrutiny. The thoroughness with which an agency must study
environmental effects and consider alternatives is greatest if an EIS is required.21 An EIS
must discuss an adequate range of proposed alternatives, and the direct, indirect, and
cumulative effects or impacts of each. The required documents can be voluminous and
may take years to produce. Under NEPA, different versions of EISs are produced: DEIS
(draft EIS), which is circulated for comment; FEIS (final EIS); SEIS (supplemental EIS);
and DSEIS (draft supplemental EIS), also circulated for comment.22
Even though both EISs and EAs require reviews of environmental impacts, there is
a difference between these documents. An EA review is intended to be briefer. Its purpose
is to find whether there are significant environmental impacts. If there are significant
impacts, an EIS is developed to analyze those impacts in detail. Both documents must
review not only the impacts of the planned project, but the impacts of the alternatives.
However, there is a distinction between the review within an EA and that of an EIS. The
regulations require an EA to “include brief discussions” on the impacts of the alternatives.
In contrast, an EIS’s alternatives analysis is referred to as the “heart of the environmental
impact statement.”23 The document must “devote substantial treatment to each
alternative.”24 A successful EIS will clearly illustrate how the agency made its decision
to choose that alternative. NEPA does not require the agency to choose the most
CEs, by their nature, are extremely brief. Agencies have been encouraged to create
more CEs25 because CEs are perceived to be less of a burden on agency resources than
40 C.F.R. § 1508.9(a)(1). An EA that results in a FONSI is referred to as an EA-FONSI.
40 C.F.R. § 1508.9(b).
40 C.F.R. § 1501.4, and parts 1502 and 1503.
Mt. Lookout - Mt. Nebo Property Protection Ass’n v. FERC, 143 F.3d 165 (4th Cir. 1998).
See 40 C.F.R. § 1502.9 for a description of these different types of documents. Additionally,
the type of an EIS can vary depending on the nature of the project. A site-specific EIS is prepared
for one project. A programmatic EIS is prepared for a series of related projects. A generic EIS
is prepared for a type of project that will be repeated.
40 C.F.R. § 1502.14. The act mentions alternatives twice, in Sections 102(2)(C)(iii) and
40 C.F.R. § 1502.14(b).
See 48 Fed. Reg. 34263, 34265 (July 28, 1983) (criticizing excessive use of EAs, and
encouraging agencies to draft broadly defined criteria for CEs).
EAs or EISs.26 For example, the CEQ issued draft guidance in 2006 encouraging agencies
to designate more CEs. Additionally, three recent significant pieces of federal legislation
directed creation of CEs: the Energy Policy Act of 2005 (for projects disturbing fewer
than five acres); the Safe, Accountable, Flexible, and Efficient Transportation Equity Act:
A Legacy for Uses of 2005 (for activities using intelligent transportation infrastructure
and systems); and the Healthy Forests Restoration Act of 2003 (P.L. 108-148) (for
hazardous fuel reduction projects on federal land). Agencies update their lists of CEs
regularly. The Federal Aviation Administration, for example, added 18 CEs to its list in
2004. The Forest Service added two in February 2007.
NEPA prescribes federal agency review but does not specify public involvement in
the reviews. However, the NEPA regulations discuss 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.27
Public input is encouraged early in the process. CEQ recommends that a scoping
process be conducted for EISs and that public comment be included in the scoping
process.28 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.29 Also, draft EISs must
be made available for public comment.30 Those comments must be responded to by the
lead agency in the final version of the document.31 Court challenges to EISs must wait
until there is a final agency action. EISs are final only upon the issuance of the Record of
Public hearings are appropriate for any type of environmental document when there
is substantial controversy regarding a project or substantial interest in having a hearing.32
No public involvement in the preparation of an EA or in making a categorical
exclusion determination is specified by the CEQ regulations, although agency-specific
“Establishing, Revising, and Using Categorical Exclusions under the National Environmental
Policy Act,” 70 Fed. Reg. 54816, 54817 (September 19, 2006).
40 C.F.R. § 1506.6(b).
48 Fed. Reg. 34263 (July 28, 1983). See also Forest Service Handbook, 1909.15, ch. 30,
requiring an abbreviated scoping process for categorical exclusions.
40 C.F.R. § 1506.6(b).
40 C.F.R. § 1503.1.
40 C.F.R. § 1503.4.
40 C.F.R. § 1506.6(c)(1).
regulations may require some public notice for these determinations.33 Notably, the CEQ
regulations for these documents do not require drafts to be issued to the public.
Because NEPA does not provide a right of action, suit is brought under the
Administrative Procedure Act (5 U.S.C. §§ 706 et seq.). Like other APA cases, the court
reviews the administrative record to see if the agency acted arbitrarily or capriciously.
NEPA litigation is complicated, and just about every word in “major Federal actions
significantly affecting the quality of the human environment” has been disputed,
scrutinized, and defined by the courts. Some issues have been resolved. For example,
there is consensus that a court’s review of a NEPA document is to ensure that the agency
took a “hard look” at the environmental impacts of an action.34 Also, the courts agree that
NEPA “does not mandate particular results, but simply prescribes the necessary
process.”35 Thus, “NEPA merely prohibits uninformed — rather than unwise — agency
action.”36 Most court cases relate to when an EIS needs to be prepared and to the adequacy
of EIS coverage.37
For EAs, the contention generally is whether that document demonstrates that no EIS
is required. Sometimes this can take the form of a claim that the agency had decided that
an EIS was not required before preparing the EA, which is against the express purpose of
the document. The courts review EAs to determine whether the agency considered the
alternatives and the impacts from those alternatives.
CEs are different. They are intended to allow agencies to find that a project has no
significant effects on the environment without conducting a review, but the agency must
still assemble a record to support its decision. Disputes regarding CEs center on whether
the category was proper in the first place or whether the designation of a CE for a
particular project was appropriate. One factor in determining whether a CE was
appropriate is whether the action normally requires an EA or an EIS.38
For example, the FHWA regulations require that EAs are made available for public review, but
not comment. 23 C.F.R. § 771.119(d).
Natural Resources Defense Council v. Morton, 458 F.2d 827, 838 (D.C. Cir. 1972).
Robertson v. Methow Valley Citizens Council, 490 U.S. 332, 350 (1989).
Id. at 351.
See THE NEPA LITIGATION GUIDE, Karin Sheldon and Mark Squillace, eds. (American Bar
40 C.F.R. § 1501.4(a)(2). See, e.g., Citizens for Better Forestry v. USDA, 481 F. Supp. 2d 1059
(N.D. Cal. 2007) (rejecting agency CE for nationwide rulemaking in part because the previous
times the agency changed that rule it prepared EAs).