Since the signing of the National Environmental Policy Act (NEPA) on January 1, 1970, eighteen states have initiated their own programs of compre-hensive environmental review. These State Environ-mental Policy Acts (SEPA’s), or "NEPA equivalents, " &re generally patterned after the policies, goals, and processes established by NEPA but, at the same time, demonstrate a great deal of variability in terms of extent as well as style of implementation. They are "equivalent, " however, in the sense that they all utilize a similar tool–the environmental impact statement (EIS).