(a) An EA is required for all proposals, except those exempt from NEPA or categorically excluded under this part, and those requiring or determined to require an EIS. EAs provide sufficient evidence and analysis to determine whether to prepare an EIS or a finding of no significant impact (FONSI).

(b) In addition, an EA may be prepared on any action at any time in order to assist in planning and decision making, to aid in the Commission's compliance with NEPA when no EIS is necessary, or to facilitate EIS preparation.

(c) EAs shall be prepared in accordance with subpart C of this part and shall contain analyses to support conclusions regarding environmental impacts. If a FONSI is proposed, it shall be prepared in accordance with § 900.305.