Governance & Policy
US National Environmental Policy Act (NEPA)
The 1970 United States law requiring federal agencies to assess the environmental effects of major actions before deciding, through environmental assessments and impact statements.
Definition
The National Environmental Policy Act, signed in 1970, requires US federal agencies to evaluate the environmental consequences of proposed major federal actions. Depending on significance, agencies prepare an environmental assessment or a full environmental impact statement, with public comment, before decisions on permits, funding and projects.
Quick reference
At a glance
- Subject
- Governance & Policy
- Editorial status
- Editorial draft
- Definition status
- Established
- Last updated
- 19 August 2026
- Also known as
- NEPA · National Environmental Policy Act of 1969
Overview
What it means
It created environmental review as a procedural discipline — and, through litigation, a powerful checkpoint on infrastructure and energy projects.
How it is used
Project sponsors schedule years for EIS processes; agencies issue categorical exclusions; courts review adequacy of analysis.
Why it matters
NEPA is the original environmental impact assessment law, the model for EIA systems in over a hundred countries.
Review
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