What Is NEPA?

The National Environmental Policy Act (NEPA) was enacted in 1969, one of many legislative and executive responses to growing concern about the condition of the environment and about what human actions were doing to it. NEPA does two major things.

First, it establishes national policy (U.S. government policy under NEPA) regarding the environment. It's important to understand this policy as a basis for correctly interpreting NEPA's action-forcing provisions.

Second, NEPA requires that agencies prepare a "detailed statement" of the environmental impacts of any "major federal action significantly affecting the quality of the human environment" (MFASAQHE). This "detailed statement" is known as an Environmental Impact Statement (EIS).

NEPA has been amended several times since its enactment, and a number of other laws have established interlocking or overlapping requirements that must be addressed in NEPA analyses.

This procedural requirement, and those that logically need to be followed in order to figure out whether an EIS is needed, are complied with by following regulations issued by the Council on Environmental Quality (CEQ). These regulations are found at 40 CFR 1500-1508 — that is, Title 40, Parts 1500-1508 of the Code of Federal Regulations.

This site provides guidance about the NEPA review process, how cultural resources should be addressed in carrying out the process, and how people concerned with cultural resources can use the process.

Proceed to the NEPA Review Process

Where Did NEPA Come From?

The origins of NEPA are similar to those of the National Historic Preservation Act (NHPA), which was enacted three years before NEPA. During the 1930s, rapid industrialization created environmental problems, which were exacerbated by World War II. After the war, programs like urban renewal, the interstate highway program, and the charge given the Corps of Engineers to dam rivers for a variety of purposes accelerated damage, as did the increasing use of toxic pesticides and fertilizers. Rachel Carson's pivotal book, Silent Spring, helped mobilize people to push for protection of the environment in a variety of ways, notably from the thoughtless acts of Federal agencies. One major result was NEPA, enacted in 1969, though it did not take effect until 1970.