39 CFR § 775.3 - Responsibilities.
(a) The Chief Environmental Officer is responsible for overall development of policy regarding NEPA and other environmental policies. The officer in charge of the facilities or real estate organization is responsible for the development of NEPA policy as it affects real estate or acquisition, construction and disposal of postal facilities consistent with overall NEPA policy. Each officer with responsibility over the proposed program, project, action, or facility is responsible for compliance with NEPA as the responsible official.
(b) Postal managers will designate environmental coordinators to assist with compliance with NEPA procedures.