National Environmental Policy Act (NEPA), the first major U.S. environmental law. Enacted in 1969 and signed into law in 1970 by President Richard M. Nixon, NEPA requires all federal agencies to go through a formal process before taking any action anticipated to have substantial impact on the environment. Part of that process requires the agencies to assess the potential environmental impact of their proposed actions in accordance with NEPA policy goals and, if necessary, to consider reasonable alternatives to those actions. The primary responsibility for overseeing implementation of NEPA rests with the Council on Environmental Quality (CEQ), which was created by the U.S. Congress as part of NEPA. The scope of NEPA is limited to agencies of the federal government. Some states have enacted similar regulations, mandating that their agencies consider environmental impact as one fact when making decisions.
There are three levels to the NEPA process. If the federal government has previously determined that some activity would have no significant effect on the environment, such activities fall into the first level, called categorical exclusion, and thus are exempt from detailed environmental analysis. For other activities that do affect the environment, at the second level federal agencies must first create a relatively brief environmental assessment (EA) that describes the anticipated environmental effects of the action and alternatives to it. If the action will result in significant environment impact, at the third level a more-detailed evaluation must be filed. Called an environmental impact statement (EIS), it describes the expected environmental effects of the action—including adverse impacts, reasonable alternatives, and any irreversible changes—and assesses both short- and long-term gains.. The EIS is reviewed by the Office of Federal Activities within the Environmental Protection Agency. Notices of EAs and EISs are published in the Federal Register, allowing the general public and any interested organizations the chance to identify issues they wish to see addressed.
The EIS process involves multiple stages, and individuals have the opportunities to comment, either in person or in writing, on draft stages of the document. In addition, if members of the public feel that the EIS has not adequately addressed their concerns, they may appeal to the head of the agency involved or file suit against the agency in federal court. NEPA has certainly increased consideration of the environmental consequences of actions taken by federal agencies. However, the EIS system is not a perfect guardian of the environment, the most obvious reason being that it does not prohibit actions that harm the environment but only requires that alternatives be considered.