The National Environmental Policy Act (NEPA) declared the Federal government's commitment to comprehensive environmental protection. The cutting-edge of NEPA is its requirement for including an Environmental Impact Statement (EIS) for all major Federal actions significantly affecting the environment. Opinions about the effectiveness of NEPA's EIS requirement range along a continuum. On one extreme are those who view the NEPA process as essentially procedural and overshadowed by other environmental legislation which provide explicit standards of environmental protection for specific environmental values. On the other extreme are those who believe that NEPA provides substantive, comprehensive, and holistic environmental protection of all environmental values. Most of the research on NEPA and its EIS reqUirement has revolved around the act's procedural and substantive mandates. However, despite the proliferation of non-NEPA environmental legislation mandating the protection of such environmental values as air and water quality, land use, and wildlife and endangered species, very little attention has been paid to the role of the mandates and requirements of these legislation in the EIS process. This research effort characterizes the role of NEPA's EIS process in light of the mandates and requirements of this body of non-NEPA legislation to determine the extent to which it addresses the substance of environmental impact evaluation. Specifically, this research focuses on the following questions: • Is the body of non-NEPA legislation sufficiently comprehensive to cover the entire spectrum of environmental values making NEPA's EIS requirement redundant? • Does NEPA enhance the avenues for public participation in government decision-making provided by non-NEPA legislation? • Does NEPA address the impacts of large scale projects, public programs and policy decisions, and cumulative impacts in a more comprehensive manner than non-NEPA legislation? • Does NEPA enhance coordination and integration among Federal agencies in ensuring that environmental issues are addressed comprehensively? The study focuses on the civil works program of the U.S. Army Corps of Engineers (Corps). As such, all conclusions are applicable only to the Corps and are not generalized to other agencies to which NEPA's requirements apply. The study involved a literature review on the role of NEPA in Federal agency planning and decision-making and the development of five research hypotheses with respect to the questions outlined earlier. These hypotheses were then evaluated through a critical review of NEPA and of the role of NEPA and other legislation in Corps activities, and a case-study of a Corps-directed EIS of the Metropolitan Denver Water Supply System. This research effort concluded that there is a relative lack of redundence among the environmental policy and requirement provisions of NEPA and those of non-NEPA legislation—what exists is a complementary, albeit tenuous relationship. Complementary, because in theory and intent: • NEPA proclaims a national policy for all environmental values while specific legislation focus only on specific environmental values; • NEPA does not contain specific standards or requirements but draws from those contained in other legislation; • in the absence of NEPA, assessments of a project's impacts to specific environmental values would be disjointed and incomplete; • the antagonistic and synergistic impacts to various values preclude individualized assessments—such impacts may not be fully addressed in the absence of NEPA; and • NEPA's public participation mechanisms as well as its requirements to ensure coordination among agencies are necessary and complementary to the focused provisions of other legislation. Tenuous, because this complementary intent has not been fully realized in practice. While the intent of NEPA was to ensure the complete and comprehensive alignment of NEPA and non-NEPA legislation, the realities of NEPA’s implementation have brought to light a variety of obstacles. These include: • inadequate guidance on NEPA compliance with other legislation; • inadequate integration among agency planning procedures and procedures for compliance with the requirements of various legislation, and inadequate inter-agency integration mechanisms; • redundant pubic participation procedures; and • a general lack of internalization in Federal agencies of the true intent of NEPA’s national policy declaration. Recommendations to surmount these obstacles include among others: developing comprehensive guidance on NEPA compliance with other legislation; ensuring that agencies’ compliance procedures are standardized and consistent with one another; developing processes whereby NEPA's public participation procedures subsume those of other legislation; and creating a fully represented Federal task force to develop and recommend detailed options for streamlining NEPA implementation. / Ph. D.