What is an EIS?
An Environmental Impact Statement (EIS) is a comprehensive, full-disclosure document in which the proposed project's effects on the social, economic and environmental conditions are assessed. Evaluated in the EIS are impacts of all the alternatives under consideration, and the measures required to mitigate (compensate for) those impacts.
The EIS process includes a Draft EIS (DEIS), in which the selected or preferred alternative can be identified for public review and comment, and a Final EIS (FEIS), in which public comments are addressed. The EIS process is mandated by the National Environmental Policy Act of 1969 for actions by federal agencies and/or proposed projects requiring federal funds.