major federal action
major federal action. Environmental law. An undertaking by a federal agency, or one that must be approved by a federal agency, that may have a significant impact on the environment, such as constructing an aqueduct or dam, constructing a highway through wetlands, or adopting certain agency regulations. • Under the National Environmental Policy Act, a federal agency that plans to take a major federal action that may significantly affect the environment is required to prepare and file an environmental-impact statement, along with any public comments, with the Environmental Protection Agency. 40 CFR §§ 1506.9, 1508. [Cases: Environmental Law 587.]
