National Environmental Policy Act
The National Environmental Policy Act (NEPA) was signed into law on January 1st, 1970 by President Richard Nixon.The preamble reads:
"To declare a national policy which will encourage productive and enjoyable harmony between man and his environment; to promote efforts which will prevent or eliminate damage to the environment and biosphere and stimulate the health and welfare of man; to enrich the understanding of the ecological systems and natural resources important to the Nation..."
The action forcing provision of the law required an Environmental Impact Statement to be written for all major federal actions. A major federal action was later defined as something that any part of the federal government could prohibit or regulate.
An Environmental Impact Statement (EIS) is a document written to aid in decision making. It explores alternatives to a proposed action, and the environmental consequences of those actions. NEPA sought to put environmental concerns on par with economic motivations and technological feasibility when making a decision that could effect the environment. Hydrological/geological, Biological/ecological and social consequences are considered.
NEPA requires that an EIS must include: the environmental impacts of the proposed action, unavoidable adverse environmental impacts, alternatives including no action, the relationship between short term uses of the environment and maintenance of long-term [ecological] productivity and any irreversible and irretrievable commitments of resources.
NEPA established the Council on Environmental Quality (CEQ) to write regulations for EIS's and advise the executive branch on environmental issues.