The National Environmental Policy Act (NEPA) is a law first established in 1970 by the US government. This act provides a process to review actions proposed by the government that might have a negative impact on the environment. NEPA provides for exclusions to the law, requires branches of the federal government to file statements about the environmental impact of actions, and requires such statements to outline other possible courses of action.
Not every branch of the federal government must file an Environmental Impact Statement (EIS). Some actions are categorically excluded from such filing by NEPA. For example, if the forestry service wishes to conduct a controlled burning or cut down a few dangerous trees, these actions are excluded from filing.
However, if a branch of the government wants to divert a waterway, set up oil wells, or use open space area for building, it is required by NEPA that the branch file an EIS. The EIS draws on the experts to determine the environmental impact of a choice. It also usually contains an argument when environmental impact is significant as to why such impact cannot be avoided.
However, no matter how great the arguments for taking an action, NEPA makes it clear that all alternatives to the action must be listed. The Environmental Protection Agency (EPA) then reviews the EIS. It is the EPA that ultimately decides which action, if any, the branch of government or governmental agency may pursue.
NEPA defines environment as several constituent factors. The environment is the geological, biological, ecological environment, and the social structure of the government’s inhabitants. Thus actions that would destabilize an economy would also be viewed by NEPA as reason for filing an EIS.
The intent of NEPA according to the framers of the act was to promote harmony between man and his environment. However, recent changes to NEPA have weakened the act by excluding more actions from review by the Environmental Protection Agency. While some see the new definitions of exclusions as necessary, environmentalists prefer NEPA in its original form and disapprove of the recent changes.