The U.S. Fish and Wildlife Service (Service) works with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. To achieve this mission, we administer a wide variety of programs to implement environmental laws and associated regulations, including the National Environmental Policy Act (NEPA) of 1969(42 U.S.C. § 4321, et seq.), as amended.
National Environmental Policy Act Overview
The National Environmental Policy Act (NEPA) of 1969(42 U.S.C. § 4321, et seq.), sets the national policy for protection and enhancement of the human environment. This procedural statue mandates Federal agencies consider reasonably foreseeable effects of their proposed major Federal actions on the quality of the human environment during the Federal decision-making process.
The purpose of NEPA is to achieve harmony between people and the environment while achieving the social, economic and other needs of present and future generations of Americans. Pursuant to the NEPA, it is the continuing responsibility of the Federal government to use all practicable means, consistent with other national policy to improve and coordinate Federal plans, functions, programs, and resources to:
- Fulfill the responsibilities of each generation as a trustee of the environment for succeeding generations;
- Assure safe, healthful, productive, and esthetically and cultural pleasing surroundings;
- Maximize beneficial uses of the environment without degradation, risk to health or safety, or other undesirable and unintended consequences;
- Preserve historic, cultural, and natural aspects of national heritage and maintain an environment, whenever possible, that supports diversity and individual choice;
- Balance between population and resource use to allow for high standards of living and shared amenities; and
- Enhance the quality of renewable resources and maximize recycling of depletable resources.
National Environmental Policy Act Summary of Requirements
The NEPA mandates Federal agencies to assess the reasonably foreseeable effects of proposed major Federal actions, unless otherwise exempted, prior to making Federal decisions. Federal agencies must include an environmental impact statement (EIS) in their recommendations or reports on proposals for legislation and other major Federal actions significantly affecting the quality of the human environment, unless otherwise exempted. An EIS should contain:
- Reasonably foreseeable environmental effects of the proposed agency action;
- Any reasonably foreseeable adverse environmental effects which cannot be avoided should the proposal be implemented;
- A reasonable range of alternatives to the proposed agency action;
- Relationship between local short-term uses of the environment and the maintenance and enhancement of long-term productivity; and
- Any irreversible and irretrievable commitments of resources.
To achieve compliance, Federal agencies must either apply a categorical exclusion or prepare an environmental assessment (EA), or an EIS and also complete, as necessary, any required agency, Tribal, and public coordination and consultations.
Department of the Interior NEPA Regulations and Procedures
The Service follows the Department of the Interior (DOI) NEPA Implementing Regulations, 43 CFR 46 that were revised on February 24, 2026 (91 FR 8738). DOI maintains the majority of its NEPA procedures in the DOI Handbook of National Environmental Policy Act Implementing Procedures separate from the 43 CFR 46. The Handbook Appendix 1 contains DOI NEPA implementation guidance. The Handbook Appendix 2 provides bureau and office categorical exclusions as well as adopted categorical exclusions.
Three Levels of NEPA Review
Categorical exclusions are applied for major Federal actions an agency has determined do not have reasonably foreseeable significant effects on the quality of the human environment; categorical exclusions are applied typically for those actions with the least amount of reasonably foreseeable effects on the quality of the human environment.
Environmental assessments are a type of NEPA compliance documentation prepared for major Federal actions with no reasonably foreseeable significant effects and a categorical exclusion cannot be applied or for those where the significance of reasonably foreseeable effects is unknown. Environmental assessments are concise documents that typically have a minimal level of detail and analysis needed to justify either preparation of a finding of no significant impact or alternatively a decision to prepare an EIS.
Environmental impact statements must be prepared for proposed major Federal actions with a reasonably foreseeable significant effect on the quality of the human environment that cannot be mitigated to an insignificant level of reasonably foreseeable effect; EISs are typically prepared for proposed actions with the most substantive reasonably foreseeable adverse effects on the quality of the human environment and typically have more detailed documentation and analyses as compared to an EA.