(a) Under the circumstances described in this section, the FONSI must be made available for public review for 30 calendar days before a final decision is made whether to prepare an EIS and before the HUD action is taken. The circumstances are:

(1) When the proposed action is, or is closely similar to, one which normally requires the preparation of an EIS pursuant to § 50.42(b) but it is determined, as a result of an EA or in the course of preparation of a draft EIS, that the proposed action will not have a significant impact on the human environment; or

(2) When the nature of the proposed action is without precedent and does not appear to require more than an assessment.

(b) In such cases, the FONSI must be concurred in by the AS/CPD and the Program Environmental Clearance Officer. Notice of the availability of the FONSI shall be given to the public in accordance with paragraphs (a) through (d) of § 50.23.