National Environmental Policy Act: An Overview
December 28, 2023
National Environmental Policy Act: An Overview
Introduction and Background
Major federal actions do not include nonfederal actions
Since 1970, the National Environmental Policy Act (NEPA,
with “no or minimal federal funding,” federally funded
42 U.S.C. §§ 4321 et seq.) has set forth a national policy
actions where the agency lacks oversight or control over the
with respect to environmental quality. For decades, NEPA
subsequent use of the funds, or other circumstances where
has required agencies to integrate environmental
the federal agency “does not exercise sufficient control”
considerations into planning and decisionmaking. Further,
over a project’s outcome. An agency also does not need to
NEPA’s “continuing policy” has been that the federal
document relevant impacts until a decision is final. While
government use “all practicable means and measures” to
only domestic actions are subject to the environmental
support humans and nature coexisting and to fulfill the
review process, NEPA also requires agencies to recognize
“social, economic, and other requirements” of present and
the global nature of environmental problems and
future generations. NEPA envisions a continuing
“maximize international cooperation” to prevent
responsibility for the federal government to, inter alia, treat
environmental decline.
each generation as a “trustee of the environment,” preserve
historical and cultural heritage, and allow for pleasing
For some decisions under other laws, agencies have
surroundings and high standards of living.
developed review and disclosure processes that are
functionally equivalent to the NEPA process. Courts have
NEPA is often described as a procedural law that mandates
held that if a statute provides for such a functional
environmental review of many agency actions, including by
equivalence, both procedurally and substantively, then an
requiring that agencies consider the environmental impacts
agency is exempt from producing a separate NEPA
of certain federal actions. NEPA also established the
statement.
Council on Environmental Quality (CEQ), which issues
regulations and guidance on NEPA implementation.
Consideration of Impacts
One step in the NEPA process is to determine whether the
To implement NEPA, CEQ issues broadly applicable rules
proposed action is likely to have “significant” effects that
that complement agency-specific statutes and regulations.
require an environmental impact statement (EIS). The
CEQ regulations require that an agency assess how the
effects an agency must consider and analyze include social,
NEPA process applies to an action early in its
ecological, and health impacts as well as environmental
decisionmaking process. In most cases, the NEPA analysis
justice concerns. The depth of analysis and type of
becomes part of the administrative record for the agency’s
documentation required by NEPA depends in large part on
decision or action. Agencies are also encouraged to
the extent to which anticipated impacts are expected to be
integrate NEPA reviews with other federal reviews and
significant.
permitting decisions authorized under separate authorities.
Categorical Exclusion
While NEPA prescribes the process for environmental
Many agency activities may be subject to a categorical
reviews, it does not mandate that federal agencies alter their
exclusion, which refers to a type of activity undertaken by
proposals based on those reviews. Rather, NEPA focuses on
an agency that “normally does not significantly affect the
ensuring that the agency has the information and analyses it
quality of the human environment.” If the agency
needs to make better informed decisions. In the words of
determines that a categorical exclusion applies, NEPA does
the Supreme Court, NEPA “merely prohibits uninformed—
not require an environmental assessment or EIS.
rather than unwise—agency action.”
Agencies maintain their own categorical exclusions and in
Scope of Agency Review
some cases may adopt another agency’s exclusion. When
NEPA requires agencies, prior to finalizing certain
an agency considers applying one of these categorical
decisions, to identify and evaluate the impacts of “major
exclusions to a proposal, it also decides whether site-
Federal actions significantly affecting the quality of the
specific extraordinary circumstances exist that could result
human environment.” For this requirement to apply, the
in more significant impacts than would typically be
major federal actions must occur within the United States,
anticipated and thus warrant further analysis and
and the decisions underlying the actions must be subject to
documentation. Congress can also mandate a categorical
agency discretion and a degree of control over the outcome.
exclusion by statute and specify whether the agency should
The range of federal agencies and actions subject to NEPA
consider any extraordinary circumstances. Categorical
is broad and commonly includes activities such as issuing
exclusions apply to the vast majority of agency actions that
permits and funding infrastructure.
require NEPA compliance.
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National Environmental Policy Act: An Overview
Environmental Assessment
“practicable,” an agency should issue a single document to
A second important way to determine whether an agency’s
evaluate a proposal.
proposed action is likely to have significant impacts that
require an EIS is an Environmental Assessment (EA). An
For certain larger-scale projects likely to require both an
EA helps an agency document the basis of its determination
EIS and at least one federal permit, agencies undertake
of whether any impacts are significant. NEPA states that
additional coordination through a process known as
EAs should be completed within a year and limited to 75
FAST-41. For a FAST-41 covered project, a lead agency
pages in length, excluding tables and appendices. An EA
tracks the development of each EIS and individual permit
results in the agency either conducting an EIS if impacts are
applications on an online Permitting Dashboard.
significant or issuing a Finding of No Significant Impact
(FONSI) to conclude the NEPA process.
Public Comment
During the scoping phase, a notice of intent to prepare an
Environmental Impact Statement
EIS must include a request for public comment on impacts,
Unless Congress provides otherwise, an agency must
alternatives, and information relevant to the proposed
prepare an Environmental Impact Statement (EIS) for a
action. Pursuant to Executive Order 14096, agencies
proposed action that is reasonably anticipated to result in
should also consult with communities that have expressed
significant environmental effects. The EIS is a detailed
environmental justice concerns and provide opportunities
statement that must assess reasonably foreseeable effects of
for “early and meaningful community involvement.”
a proposed action, identify “irreversible and irretrievable”
resource commitments, and consider a reasonable range of
Further, agencies generally offer draft EISs and sometimes
alternatives to the proposed action, among other criteria.
draft EAs for public comment. While agencies generally
NEPA states that an EIS should generally be completed
receive public comments when establishing a categorical
within two years and limited to 150-300 pages, excluding
exclusion, agencies typically do not solicit public comments
tables and appendices. While nonfederal actors, including
when applying a categorical exclusion to an individual
the project sponsor and state or local governments, may
project. While agencies are required to consider and
prepare documentation, the lead federal agency remains
respond to substantive comments prior to publishing a final
responsible for the content.
EIS, they are not required to change an EIS to address a
comment if they disagree with the comment received.
When an agency has completed a final EIS, including any
associated inter-agency coordination and public comment
Judicial Review
period, it issues a Record of Decision, which constitutes
Under NEPA, a project sponsor may seek judicial review if
final agency action for purposes of judicial review. EPA
an agency fails to complete its environmental review
maintains an online database of all agencies’ EISs.
process in a timely manner.
Tiering
A judicial challenge to a NEPA document, or the failure to
Agencies have the option of undertaking NEPA in stages
prepare one, on any other basis must be brought under the
through a process known as tiering. An agency may elect to
Administrative Procedure Act. Under this law, a reviewing
first consider the overall impacts of a broad program or
court evaluates whether the agency acted arbitrarily or
large geographic area by issuing a programmatic
capriciously or abused its discretion, among other things,
environmental document, which could be an EA or an EIS.
when conducting an environmental review under NEPA. As
For individual projects that are implemented under that
the courts apply this standard, they consider on a case-by-
program, NEPA review may refer back to the programmatic
case basis whether the agency has followed the appropriate
analysis and focus instead on any project-specific impacts.
NEPA procedure and adequately considered impacts. For
example, plaintiffs may allege that an agency has failed to
Process Considerations
take a hard look at a particular impact, failed to conduct the
NEPA requires agencies to follow certain processes in the
appropriate level of review, or failed to act in a timely
preparation of EAs and EISs.
manner. Courts have generally not dictated the substance of
the agency’s decision. Instead, they have enforced NEPA
Interagency Coordination
processes, such as by requiring agencies to take a “hard
When more than one agency is involved, a lead agency
look” at the consequences of proposed actions, consider
oversees the environmental review process and develops a
alternatives, identify unavoidable adverse impacts, and
schedule for completing the environmental review process
consult with other agencies and the public before making
as well as any associated permits or other authorization.
final decisions. Plaintiffs may also combine NEPA
Lead agencies may extend NEPA deadlines as
challenges with claims under statutes such as the Clean
circumstances warrant. In addition to other federal
Water Act or Endangered Species Act.
agencies, state, tribal, and local agencies may serve
alongside a federal agency as joint lead agencies. Prior to
While only a small percentage of agency actions require
preparing NEPA documentation, the lead agency must
EISs, a higher percentage of EISs get challenged in court
consult with and obtain comments from other agencies with
compared to other environmental review documents. For
jurisdiction or special expertise regarding associated
more information on judicial review and NEPA, see CRS In
impacts. Comments received from states, tribes, and local
Focus IF11932, National Environmental Policy Act:
agencies should accompany an EIS. To the extent
Judicial Review and Remedies.
https://crsreports.congress.gov
National Environmental Policy Act: An Overview
IF12560
Kristen Hite, Legislative Attorney
Disclaimer
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