The role of a federal agency in the NEPA process depends on the agency's expertise and relationship to the proposed undertaking.
The agency carrying out the federal action is responsible for complying with the requirements of NEPA. In some cases, there may be more than one federal agency involved in an undertaking. In this situation, a lead agency is designated to supervise preparation of the environmental analysis. Federal agencies, together with states, tribes, or local agencies, may act as joint lead agencies.
A federal, state, tribe, or local agency having special expertise with respect to an environmental issue or jurisdiction by law may be a cooperating agency in the NEPA process. A cooperating agency has the responsibility to:
- Assist the lead agency by participating in the NEPA process at the earliest possible time.
- Participate in the scoping process.
- Develop information and prepare environmental analyses including portions of the environmental impact statement concerning which the cooperating agency has special expertise.
- Make available staff support at the lead agency's request to enhance the lead agency's interdisciplinary capabilities.
Under 40 CFR 1504 of the NEPA regulations, federal agencies may refer to the Council on Environmental Quality (CEQ) inter-agency disagreements concerning proposed federal actions that might cause unsatisfactory environmental effects. CEQ's role, when it accepts a referral, is generally to develop findings and recommendations, consistent with the policy goals of Section 101 of NEPA. The referral process consists of certain steps and is carried out within a specified period.