The three major types of actions which are exempt from NEPA procedural or documentation requirements are: 1) congressionally exempt actions, 2) emergency actions and 3) rejections of proposed actions based on statutory or regulatory authority. If an action is exempt from NEPA, then no further NEPA review is conducted. Review and compliance for other laws and regulations, however, may still be conducted.
Categorically Excluded Actions
Certain categories of actions have been determined to have an insignificant effect and generally do not require preparation of an EA or EIS. This list of categorically excluded actions is determined by the Department of the Interior and the Bureau of Land Management at a national level. If an action is categorically excluded, it is compared to a list of exceptions. The list of exceptions describe circumstances where an activity with normally insignificant effects might be considered to have significant effects. If one or more exception circumstances apply to the proposed action, the proposal may be modified so the circumstances no longer apply. If modifications are not possible, then an EA or EIS is prepared.
If no exception circumstance applies to the proposed action, the interdisciplinary team documents the project details, reviews the project for compliance with other laws and regulations, and determines if there are any special stipulations for approving the action.
Previously Analyzed Actions
If an action has been addressed in an existing NEPA document, the interdisciplinary team will review the existing NEPA document to determine if it adequately addresses the proposed action. If the proposed action is adequately addressed, the determination will be documented. If the existing document does not adequately address the proposed action, a new EA will be prepared.
Preparation of an Environmental Assessment
An interdisciplinary team is assembled to review project design, identify impacts and develop mitigation. Project design is reviewed against standard operating procedures or practices that pertain to the particular type of project. A standard operating practice for a powerline might be to use a design that prevents electrocution of large birds. Potential impacts of the action are identified after review and only necessary modification of the project. Measures to reduce the potential impacts, mitigation measures, are developed. If after modification and application of mitigation measures the residual impacts of the action are not significant, the project may be approved. If the residual impacts are significant, the project is modified further or an EIS is prepared