NEPA and scientific uncertainty relating to inadequate information

The National Environmental Policy Act (NEPA) was signed into law on January 1, 1970, and required, among other things, that all federal agencies assess the environmental impacts of and alternatives to proposals for major federal actions significantly affecting the quality of the human environment. Long before the promulgation of the regulations of the Counsel on Environmental Quality (CEQ), the courts developed a uniform body of law addressing the problem confronted by federal agencies lacking information as to the impacts of its proposed action. When CEQ developed its regulations in 1978, Sec. 1502.22 of these rules included a requirement for a worst-case analysis. On April 25, 1986, CEQ issued its final rule amending Section 1502.22 concerning incomplete or unavailable information. In summary, the rule now provides that if information relevant to reasonably foreseeable significant adverse impacts cannot be obtained, the agency shall include in the EIS a statement that such information is incomplete or unavailable, a statement of the relevance of the incomplete or unavailable information to evaluating the impacts, and a summary of existing credible scientific evidence that is relevant to evaluating these adverse impacts