In this Memorandum, the Council on Environmental Quality provides guidance on the extent to which agencies of the Federal government are required to analyze the environmental effects of past actions when they describe the cumulative environmental effect of a proposed action.
Selected documents on the topic of Cumulative Impacts and NEPA.
June 24, 2005
May 1, 1999
The purpose of this guidance is to assist EPA reviewers of NEPA documents in providing accurate, realistic, and consistent comments on the assessment of cumulative impacts. The guidance focuses on specific issues that are critical in EPA's review of NEPA documents under Section 309 of the Clean Air Act. The guidance offers information on what issues to look for in the analysis, what practical considerations should be kept in mind when reviewing the analysis, and what should be said in EPA comments concerning the adequacy of the analysis.
January 1, 1997
This handbook presents the results of research and consultations by the Council on Environmental Quality concerning the consideration of cumulative effects in analyses prepared under the National Environmental Policy Act (NEPA). It introduces the NEPA practitioner and other interested parties to the complex issue of cumulative effects, outlines general principles, presents useful steps, and provides information on methods of cumulative effects analysis and data sources.