36 C.F.R. § 1010.11 – Preparation of an EA.

(a) When to prepare. The Trust will begin the preparation of an EA (or require it to be begun) as early as possible after it is determined by the NEPA Compliance Coordinator to be required. The Trust will provide notice of such determinations in accordance with § 1010.12. The Trust may prepare or require an EA at any time to assist planning and decision-making.
(b) Content and format. An EA is a concise public document used to determine whether to prepare an EIS. An EA should address impacts, including cumulative impacts, on those resources that are specifically relevant to the particular proposal. Those impacts should be addressed in as much detail as is necessary to allow an analysis of the alternatives and the proposal. The EA shall contain brief discussions of the following topics:
1. (1) Purpose and need for the proposed action.
2. (2) Description of the proposed action.
3. (3) Alternatives considered, including a No Action alternative.
4. (4) Environmental effects of the proposed action and the alternatives, including mitigation measures.
5. (5) Listing of agencies, organizations, and/or persons consulted.
(c) Finding of no significant impact (FONSI). If an EA is completed and the NEPA Compliance Coordinator determines that an EIS is not required, then the NEPA Compliance Coordinator shall prepare a finding of no significant impact. The finding of no significant impact shall be made available to the public by the Trust as specified in 40 CFR 1506.6.
(d) Mitigated FONSI. If an EA is completed and the NEPA Compliance Coordinator determines that an EIS is required, then prior to preparation of an EIS, the proposal may be revised in order to mitigate the impacts identified in the EA through adherence to legal requirements, inclusion of mitigation as an integral part of the proposal, and/or fundamental changes to the proposal. A supplemental EA will be prepared on the revised proposal and will result in a Mitigated Finding of No Significant Impact, preparation of an EIS, or additional revision of the proposal and a supplemental EA.