Understanding NEPA

October, 2021: Go here to learn about the Biden administration's proposal to restore NEPA provisions

What is NEPA?

National Environmental Policy Act (NEPA) of 1969

NEPA declares it a national policy to encourage productive and enjoyable harmony between man and the environment and promote efforts to better understand and prevent damage to ecological systems and natural resources important to the nation. Agencies are required to prepare a detailed environmental impact statement for any major federal action significantly affecting the environment. The Act also establishes the Council on Environmental Quality to review government policies and programs for conformity with NEPA.

NEPA contains this ambitious policy statement: …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 practicable means and measures, including financial and technical assistance, in a manner calculated to foster and 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.

The NEPA process

NEPA operates by imposing procedural obligations on federal agencies (and nonfederal actors enabled by federal agencies) that undertake “major Federal actions significantly affecting the quality of the human environment”. If a proposed action meets this standard, an Environmental Impact Statement (EIS) must be prepared, describing the environmental consequences of the proposed action and considering a range of alternatives. NEPA does not require that an agency choose the most environmentally benign alternative, nor does it prescribe any other substantive outcome, but it does require that an agency take a “hard look” at the environmental consequences of its actions and disclose information on these consequences to the public. For this reason, NEPA is often described as an Act that requires a procedural rather than a substantive outcome.

While NEPA itself is relatively brief, its implementing regulations are extensive. NEPA regulations, published by the Council on Environmental Quality (CEQ), include details on important dimensions of the Act including requirements regarding cumulative effects analysis, the scoping process, and content requirements of the EIS. These CEQ regulations have been interpreted to have the force of law.

A proposed agency action falls into one of three general categories relevant to NEPA. First, if an agency determines the action fits within a specific agency-identified category of proposed actions and will clearly not have significant individual or cumulative effects on the environment, it is categorically excluded from the EIS obligation (commonly referred to as a categorical exclusion or CE). Second, if, on the other hand, a proposed action will have a significant effect on the environment, an EIS is required. The third situation occurs when it is not clear whether or not an action will significantly affect the environment. In these cases where effects “may” be significant, an Environmental Assessment (EA) is prepared as a means of evaluating this question. If the EA determines that effects will be significant, an EIS is prepared. Otherwise, the agency issues a Finding of No Significant Impact (FONSI) and proceeds without further obligations under NEPA.

Proposed Agency Action

The NEPA process begins when an agency develops a proposal to address a need to take an action. The need may be something the agency identifies itself, or it may be a need to make a decision on a proposal brought to it by someone outside of the agency, for example, an applicant for a permit. Based on the need, the agency develops a proposal for action.

Determination of a Categorical Exclusion (CE)

If an agency determines the action fits within a specific agency-identified category of proposed actions and will clearly not have significant individual or cumulative effects on the environment, it is categorically excluded from the EIS obligation. Examples of CEs include issuing administrative procedures, making minor facility renovations, and reconstruction of trails. If a proposed action is included in the description provided for a listed CE, the agency must check to make sure that no extraordinary circumstances exist. Extraordinary circumstances are also set out in the agency NEPA procedures and typically include such matters as effects to endangered species, protected cultural sites, and wetlands. If the proposed action is not included in the description provided in the CE, or there are extraordinary circumstances, then the agency must choose whether to withdraw the proposed action, develop a new proposal that may qualify for application of a CE, or prepare an EA or an EIS. When the agency does not know whether significant impacts are expected, the agency will prepare an EA to determine if there are significant environmental effects. An EIS is prepared when significant environmental effects are expected to result from the proposed action.

For more information about the CE option, see this page.

Need for an Environmental Assessment (EA)

The purpose of an EA is to determine the significance of the environmental effects and to look at alternative means to achieve the agency’s objectives. The EA is intended to be a concise document that briefly provides sufficient evidence and analysis for determining whether to prepare an environmental impact statement or Finding of No Significant Impact (FONSI), aids an agency’s compliance with NEPA when no environmental impact statement is necessary, and facilitates preparation of a statement when one is necessary. The EA will include brief discussions of the need for the proposal, of alternative courses of action for any proposal which involves unresolved conflicts concerning alternative uses of available resources, of the environmental impacts of the proposed action and alternatives, and a listing of agencies and persons consulted

Finding of No Significant Impact (FONSI)

A FONSI is a document that presents the reasons why the agency concludes that there are no significant environmental impacts projected to occur upon implementation of the action. The EA is attached to the FONSI, otherwise the FONSI includes a summary of the EA.

A Notice of Intent of proposed action

The EIS process begins with publication of a Notice of Intent (NOI), stating the agency’s intent to prepare an EIS for a particular proposal. The NOI is published in the Federal Register, and it will provide some basic information on the proposed action in preparation for the scoping process.

Public Scoping Comment Period

The NOI provides a brief description of the proposed action and possible alternatives. It also describes the agency’s proposed scoping process, including any meetings and how the public can get involved. The scoping process is the best time to identify issues, determine points of contact, determine project schedules and provide recommendations to the agency. The overall goal is to define the scope of issues to be addressed in depth in the analyses that will be included in the EIS. The public is encouraged to attend meetings and submit substantive comments relating to the proposed action. This is the first opportunity for the public to let the federal agency proposing the action know that it either supports or opposed the project or plan proposal. During this important period it is also possible for the public to submit its own proposed alternatives which would assist the agency in attaining its stated goals for the proposed action. All proposed alternatives must be considered by the agency.

Release of Draft Environmental Impact Statement (EIS)

The Draft EIS represents the agency’s efforts at identifying the potential negative environmental impacts of the proposed action. One key aspect of a Draft EIS is the statement of the underlying purpose and need. Agencies draft a “Purpose and Need” statement to describe what they are trying to achieve by proposing an action. The purpose and need statement explains to the public why an agency action is necessary, and serves as the basis for identifying the reasonable alternatives available to the agency. The identification and evaluation of alternative ways of meeting the purpose and need of the proposed action is the heart of the NEPA analysis. The agency must, “objectively evaluate all reasonable alternatives, and for alternatives which were eliminated from detailed study, briefly discuss the reasons for their having been eliminated.” Reasonable alternatives are those that substantially meet the agency’s purpose and need. Agencies are also obligated to evaluate all reasonable alternatives, or a range of reasonable alternatives, in enough detail so that a reader can compare and contrast the environmental effects of the various alternatives. The agency must analyze the full range of direct, indirect and cumulative effects of the preferred alternative, if any, and of the reasonable alternatives identified in the Draft EIS.

Public review and comment period for Draft EIS

The release of the Draft EIS also includes a mandatory 30-60 day comment period which allows the public or any State or Federal agency to comment on the selection of alternative actions and the environmental analysis conducted throughout the document analyzing all potential negative environmental impacts of the proposed actions. Submission of substantive comments on the Draft EIS must be considered by the agency when moving forward with their analysis of the proposed alternatives and environmental impacts of the proposed action.

Release of Final EIS

When the public comment period delineated for the Draft EIS is finished, the agency analyzes comments, conducts further analysis as necessary, and prepares the Final EIS. In the Final EIS, the agency must respond to the substantive comments received from other government agencies and from the public. The response can be in the form of changes in the Final EIS, factual corrections, modifications to the analyses or the alternatives, new alternatives considered, or an explanation of why a comment does not require the agency’s response. During this analysis the agency will also choose its preferred alternative and lay out the potential negative environmental impacts of that proposed action.

Public review and comment period for Final EIS

When it is ready, the agency will publish the Final EIS and will also publish a Notice of Availability in the Federal Register. The Notice of Availability marks the start of a review and comment period. A minimum of 30 days must pass before the agency can make a decision on their proposed action. A comment period of 30 to 60 days is put in pace for the public and any State and Federal Agencies to comment of the proposed action alternative selected in the Final EIS. The objection period also begins with publication of the final EIS or EA.

Preparation and release of a Supplemental EIS

Sometimes a federal agency is obligated to prepare a supplement to an already existing EIS. An agency must prepare a supplement to either a Draft or Final EIS if it makes substantial changes in the proposed action that is relevant to environmental concerns, or if there are significant new circumstances or information relevant to environmental concerns and bearing on the proposed action of its impacts. An agency may also prepare Supplemental EIS if it determines that doing so will further the purposes of NEPA. A Supplemental EIS is prepared in the same way as a Draft or Final EIS, except that scoping is not required. If a supplement is prepared following a Draft EIS, the Final EIS will address both the Draft EIS and Supplemental EIS.

Objecting to the agency decision and final action

The process of objecting to Forest Service decisions has changed considerably over the years. Until 2013, the public had the right to appeal projects after the decision (ROD) was issued. The appeal would be reviewed by regional staff. If the appeal was found to have merit, the reviewing officer could affirm the appeal and the decision would be withdrawn. In most cases, the proposal would be modifed to make it lawful, and then go forward.

In 2012-2013, revisions to 36 CFR Part 218 did away with the appeals process and replaced it with the pre-decisional objection process. The new rule expanded the use of the pre-decisional objection process promulgated in 2004 for hazardous fuel reduction projects under the Healthy Forests Restoration Act (HFRA) of 2003 to include other projects and activities implementing land and resource management plans. After publication of a final EIS or EA, the public has 45 days to file a formal objection for projects not authorized under the Healthy Forests Restoration Act. For projects authorized under HFRA, the public has 30 days to file an objection.

The specifics of the objection process are available here. Also see this Forest Service memo, March 5, 2014, explicitly directing agency offices to cease publication and notification of the public for CE projects.

Today, if negotiations under the pre-decisional objection process are not fruitful, and a decision and proposed action are seen to be contrary to the law, the public now has only one option--and that is to bring a lawsuit against the federal government, something that rarely happens because of the high cost and resources necessary to do this.


Prior to 1992, response by the agency to administrative appeals of proposed Forest Service actions were not required by law. This changed in 1992 with passage of the Appeals Reform Act (ARA). The ARA required that the Forest Service “establish a notice and comment process for proposed actions and activities implementing land and resource management plans…and…modify the procedure for appeals of decisions concerning such projects.” Revisions to the ARA by the Bush Administration included limiting eligible appellants to “Individuals and organizations who submit substantive written or oral comments during the 30-day comment period for an environmental assessment, or 45-day comment period for a draft environmental impact statement,” as well as exempting projects falling under a NEPA categorical exclusion (CE) from the notice and comment procedure.

The current regulatory status that expanded changes to 36 CFR Part 218 was published in the Federal Register on March 27, 2013.

Record of Decision published

The Record of Decision (ROD) is the final step for agencies in the EIS process. The ROD is a document that states what the decision is; identifies the alternatives considered, including the environmentally preferred alternative; and discusses mitigation plans, including any enforcement and monitoring commitments. In the ROD, the agency discusses all the factors that it balanced, including any considerations of national policy, when it reached its decision on whether to, and if so how to, proceed with the proposed action. The ROD will also discuss if all practical means to avoid or minimize environmental harm have been adopted, and if not, why they were not.

Learn More

Click here for a PDF of the handbook A Citizens Guide to the NEPA – Having Your Voice Heard published by the Council on Environmental Quality (CEQ) in 2007.


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