The National Environmental Policy Act of 1969 requires that federal agencies prepare detailed analyses of any actions that significantly affect the quality of the environment. Environmental impact statements (EISs) are the result of this requirement. EIS's have been produced, since 1969, on virtually every type of activity, from oil and gas development to scientific research in Antarctica, and from protection of wildlife habitat to construction of light rail lines.
This guide lists various resources for finding environmental impact statements online and in the library.