40 CFR § 1501.2 - Apply NEPA early in the process.
Agencies shall integrate the NEPA process with other planning at the earliest possible time to insure that planning and decisions reflect environmental values, to avoid delays later in the process, and to head off potential conflicts. Each agency shall:
(a) Comply with the mandate of section 102(2)(A) to “utilize a systematic, interdisciplinary approach which will insure the integrated use of the natural and social sciences and the environmental design arts in planning and in decisionmaking which may have an impact on man's environment,” as specified by § 1507.2.
(b) Identify environmental effects and values in adequate detail so they can be compared to economic and technical analyses. Environmental documents and appropriate analyses shall be circulated and reviewed at the same time as other planning documents.
(c) Study, develop, and describe appropriate alternatives to recommended courses of action in any proposal which involves unresolved conflicts concerning alternative uses of available resources as provided by section 102(2)(E) of the Act.
(d) Provide for cases where actions are planned by private applicants or other non-Federal entities before Federal involvement so that:
(1) Policies or designated staff are available to advise potential applicants of studies or other information foreseeably required for later Federal action.
(2) The Federal agency consults early with appropriate State and local agencies and Indian tribes and with interested private persons and organizations when its own involvement is reasonably foreseeable.
(3) The Federal agency commences its NEPA process at the earliest possible time.