National Environmental Policy Act (NEPA), United States


The National Environmental Policy Act (NEPA) (42 U.S.C. 4321-4327) was signed into law by President Richard M. Nixon Jan. 1, 1970 as the first law of the new decade. It represented a fundamental shift in United States federal government policy from a primary focus on economic development toward a more environmentally balanced approach:

“The Congress, recognizing the profound impact of man’s activity on the interrelations of all components of the natural environment…and recognizing the critical importance of restoring and maintaining environmental quality to the overall welfare and development of man…declares it is the continuing policy of the Federal government, in cooperation with State and local governments, and other concerned public and private organizations to use all practical means and measures…to promote the general welfare, to create and maintain conditions under which man and nature can exist in productive harmony, and fulfill the social, economic, and other requirements of present and future generations of Americans” (42 U.S.C. Sec. 4331).

NEPA is the briefest of all major U.S. environmental laws, approximately 5 ½ pages. It has two parts: Title I, Congressional Declaration of Policy; and Title II, Council of Environmental Quality (CEQ). The latter requires the President to issue an Annual Report to Congress, on the state of the nation’s environment (42 U.S.C. Sec. 4341), and creates a President-appointed three-member CEQ within the Executive Office of the President to:

“…interpret environmental trends and information, appraise programs and activities of the Federal Government, to be conscious of and responsive to the scientific, economic, social, aesthetic, and cultural interests of the nation, and to formulate and recommend national policies…” (42 U.S.C. Sec. 4342).

Action Forcing Policy

Policy participants and environmental historians have generally agreed that NEPA was the product of only minor debate in Congress, with limited engagement by the media and the public at large. It created no new environmental rights for citizens, and explicitly was “supplemental to those (policies and goals) set forth in existing authorizations of Federal agencies” (42 U.S.C. Sec. 4335). Many agencies and interest groups initially concluded that the law was essentially symbolic.

It took a series of early Federal court cases, such as Calvert Cliffs’ Coordinating Committee, Inc. v. Atomic Energy Commission, 44 F.2d 1109 (D.C. Cir. 1971), cert. denied, 404 U.S. 942 (1972), to establish that all federal agencies must follow NEPA, particularly 42. U.S.C. Sec. 4332. This section mandates that “all agencies of the Federal Government shall": prepare and publicly circulate a comprehensive, interdisciplinary “detailed statement” prior to making decisions that may significantly affect the environment. The statement:

  • Utilizes a systematic, interdisciplinary (natural and social sciences, with the design arts) approach;
  • Describes the environmental impact of the proposal, including unavoidable effects;
  • Identifies and analyzes alternatives to the proposal; and
  • Evaluates the relationship between short-term uses and long-term environmental maintenance an productivity, including irreversible commitment of resources.

The process of Environmental Impact Assessment (EIA), results in formal documents including full Environmental Impact Statements (EIS), and more abbreviated Environmental Assessments (EA).

These court cases clearly established that NEPA was not just of symbolic value. However the courts also concluded that NEPA is a procedural not a substantive law. It creates a transparent process of pre-decision generation and dissemination of environmental information. Final selection of the preferred alternative and its resultant impacts remains the responsibility of the lead agency, acting within its laws, procedures, and resource constraints.

Before NEPA, we could characterize much of the federal decision making as “disjointed incrementalism”. Numerous individual programs, (many development-oriented, some protecting particular components of the environment), were independently implemented with little or no communication, coordination, or analysis of long-term outcomes other than economic projections. NEPA not only requires the preparation of a “detailed statement”, it mandates inter-agency collaboration:

“Prior to making any detailed statement, the responsible Federal official shall consult with and obtain the comments of any Federal agency which has jurisdiction by law or special expertise with respect to any environmental impact involved” (42 U.S.C. Sec 4332 (2)(C)).

With NEPA, topical expertise such as habitat, aesthetics, and human health, which had been isolated in special purpose agencies, were now accessible by the development and land management agencies.

NEPA Developments Since 1970

Due to its brevity and generality, (for example no definitions of “environment”, or “major actions”), early Environmental Impact Statements were highly variable in scope, content, and quality. Following the initial court cases, the response by many agencies and their consultants was “overkill”. Rather than risk a judge determining that some relevant information was missing, documentation ballooned. It was common for a major EIS to contain hundreds of pages of arcane data. This was costly, and undermined the primary focus on informing decision makers about the environmental consequences of alternative courses of action..

In response, President Jimmy Carter issued Executive Order 11991, delegating authority to the CEQ to promulgate formal regulations binding on all federal agencies. The CEQ NEPA Regulations were enacted as 40 C.F.R. Part 1500-1508 in 1978. Aiming to “Reduce Paperwork” and “Delay” while improving decision effectiveness, the Regulations create a triage process. Minor decisions can be exempted by agencies amending their Procedures to include Categorical Exclusions. Projects with potentially significant impacts undergo a streamlined Environmental Assessment which may lead to a Finding of No Significant Impact (FONSI). Only those actions which clearly involve major impacts undergo a full EIS. The Regulations specify the contents of an EIS detail, however little is said about EAs. The roles of Lead and Cooperating agencies are articulated; and a Glossary of Terms is included.

Unlike almost any other U.S. environmental policy, since their creation neither NEPA (1970), nor the CEQ NEPA Regulations (1978) have been substantively amended. Over the intervening years, both pro-environment and anti-regulation interests have tried unsuccessfully to make changes to these policies. To keep the process current, the CEQ periodically issues “Guidelines” (non-enforceable recommended practices), on topics such as the Safe Drinking Water Act (Nov. 1976), Biodiversity (Jan. 1993), and Environmental Justice (Dec. 1997). The lack of updated centralized binding policy does not mean that the impact assessment process is obsolete. From the outset, NEPA clearly placed the primary implementation of environmental responsibility on the federal agencies (42 U.S.C. Sec. 4333). All agencies involved in NEPA have their individual agency NEPA Regulations and Procedures which are continuously revised to reflect evolving environmental and agency laws and court cases.

Major Continuing NEPA Issues

  • Lack of clarification on the content of EAs, which now constitute the majority of assessments;
  • Concern about the increased use and lack of transparency by agencies' Categorical Exclusions;
  • Continuing growth of procedural complexity of new and revised environmental laws;
  • The need to comprehensively embrace the Internet and associated information technologies.

Further Reading



Felleman, J. (2008). National Environmental Policy Act (NEPA), United States. Retrieved from


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