§4336 Procedure for Determination of Level of Review

Summary

Agencies must decide when to do an environmental review and what type. They do not have to prepare one in four cases: if the action is not a final agency action as defined in chapter 5 of title 5; if the action is covered by a categorical exclusion (the agency’s own, another agency’s that follows section 4336c, or another law); if making the review would clearly conflict with another law; or if the action is nondiscretionary and the agency cannot take environmental factors into account. If a proposed action will likely have a significant effect on the human environment, the agency must prepare an environmental impact statement. If it will not have a significant effect, or if the effect is uncertain, the agency must prepare a short environmental assessment unless an exclusion applies. The assessment is a brief public paper explaining why there is no significant impact or why a full impact statement is needed. Agencies may use any reliable data and do not have to do new scientific research unless that research is essential to choosing among options and is not unreasonably costly or slow.