39 C.F.R. § 776.9 – Review procedures.

(a) Early public notice. If a facility action at the contending site(s) could require construction in a wetland, public notice must be provided.
(b) Finding of no practicable alternative. The Postal Service shall avoid construction located in a wetland unless it issues a finding of no practicable alternative. The facilities organization, in conjunction with the operations organization, or, for projects within the delegated authority of the Vice President, Area Operations, the operations organization, shall make a written determination that:
1. (1) There is no practicable alternative to such construction; and
2. (2) The proposed action includes all practicable measures to minimize harm to wetlands.
(c) NEPA coordination. If either an Environmental Impact Statement or an Environmental Assessment is required under the Postal Service's National Environmental Policy Act (NEPA) regulations, the above review procedures must be incorporated into and evaluated in that document.