The National Environmental Policy Act (NEPA) (1970) (42 U.S.C. §§ 4321-4347) requires all Federal agencies to include a detailed environmental impact statement in every proposal for a major Federal action (including rules) that significantly affect the quality of the human environment. The environmental impact statement must address the subjects and apply substantive criteria set forth in the Act. The Council on Environmental Quality (CEQ) has issued regulations to implement the procedural provisions of NEPA (40 CFR parts 1500-1508). Every agency with legislative rulemaking authority should have supplementary regulations establishing its procedures for assessing the need for an environmental impact statement and for preparing and obtaining comments on such statements.