The certification requirement with respect to an application for a license or permit shall be waived upon:
(a) Written notification from the State or interstate agency concerned that it expressly waives its authority to act on a request for certification; or
(b) Written notification from the licensing or permitting agency to the Regional Administrator of the failure of the State or interstate agency concerned to act on such request for certification within a reasonable period of time after receipt of such request, as determined by the licensing or permitting agency (which period shall generally be considered to be 6 months, but in any event shall not exceed 1 year).
In the event of a waiver hereunder, the Regional Administrator shall consider such waiver as a substitute for a certification, and as appropriate, shall conduct the review, provide the notices, and perform the other functions identified in §§ 121.13, 121.14, and 121.15. The notices required by § 121.13 shall be provided not later than 30 days after the date of receipt by the Regional Administrator of either notification referred to herein.