(a) Every Commission action not specifically excluded under § 504.4 shall be subject to an environmental assessment.

(b) A notice of intent to prepare an environmental assessment briefly describing the nature of the potential or proposed action and inviting written comments to aid in the preparation of the environmental assessment and early identification of the significant environmental issues may be published in the Federal Register. Such comments must be received by the Commission no later than ten (10) days from the date of publication of the notice in the Federal Register.