Guidance for environmental impact assessment

Environmental impact assessment (EIA) originated with the US National Environmental Policy Act of 1969 (NEPA) as one of several means specified for achieving NEPA's central purpose: the full incorporation of environmental considerations into the decision-making process of the federal government. Beyond EIA itself, which by its nature demands considerable use of science, NEPA requires agencies to use science in all planning and decision-making that may have an effect on the human environment. Indeed, scientific notions are pervasive in nearly every section of NEPA. In the 1970s, the use of science in EIA was addressed by scholars, court opinions, and unofficial guidelines, as the practice of EIA evolved and became a requirement of many state governments, numerous other nations, and several international agencies. Regulations issued in 1978 by the President's Council on Environmental Quality (CEQ) clarified, elaborated, and standardized how impact assessment was to be done by agencies of the federal government.