No decision on a proposed action shall be made or recorded by the Commission until the later of the following dates unless reduced pursuant to 40 CFR 1506.10(d), or unless required by a statutorily-prescribed deadline on the Commission action:

(a) Forty (40) days after EPA's publication of the notice described in §504.7(b) for a DEIS; or

(b) Ten (10) days after publication of EPA's notice for an FEIS.