NEPA (42 USC 4321 et seq.) requires Federal agencies to use a systematic, interdisciplinary approach to analyzing the environmental impact of major Federal Actions. This approach ensures integration of natural and social sciences in any planning and decision-making that may have an impact on the environment. In furtherance of these policies, NEPA also requires Federal agencies to prepare a detailed EIS on any major Federal action that may have a significant impact on the environment. An EIS must analyze any adverse environmental effects that cannot be avoided or mitigated, alternatives including the Proposed Action, the relationship between short-term uses and long-term productivity of the environment, and any irreversible and irretrievable commitments of resources. In 1979, the Council on Environmental Quality established uniform procedures for implementing NEPA. These regulations (40 CFR § 1500–1508) provide for the use of the NEPA process to identify and assess the alternatives to proposed actions that avoid and minimize adverse effects on the human environment. The USDOI regulations implementing NEPA are at 43 CFR Part 46.