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National Environmental Policy Act (NEPA)

This website is archived for historical purposes and is no longer being maintained or updated.

The Healthy Community Design Initiative, also known as the Built Environment and Health Initiative, is no longer a funded program and the information on this website is not being reviewed and updated on a regular basis.


In 1970, Congress enacted the National Environmental Policy Act (NEPA) [42 U.S.C. §4321 et seq.] to include environmental protection in federal government plans and decisions. NEPA mandates that federal agencies consider how any proposed plan or project might affect the environment. Through a process sometimes referred to as environmental impact assessment, each federal agency—often in consultation with other federal agencies—reviews the potential effect its initiatives might have on the nation’s social, economic, and natural resources. If those potential effects are tangible, the agency prepares an Environmental Assessment (EA). If on further review those effects appear significant, the agency then prepares an Environmental Impact Statement (EIS)—a more detailed analysis of the project’s environmental issues. If from the outset, however, environmental concerns appear significant, the agency can prepare an EIS without first writing an EA. Primarily at the EIS stage, federal agencies, as well as concerned state, local, and tribal governments, and private citizens can review the EIS and provide comments.

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