NEPA and Section 106 of the National Historic Preservation Act

General Rules for NEPA-Section 106 Coordination

The Advisory Council on Historic Preservation's (ACHP's) Section 106 of the National Historic Preservation Act (NHPA) regulations (36 CFR 800) prescribes the following for the consideration of historic properties under National Environmental Policy Act (NEPA):

  • Early coordination. Federal agencies are encouraged to coordinate compliance with Section 106 and the procedures in this part with any steps taken to meet the requirements of . . . (NEPA). Agencies should consider their Section 106 responsibilities as early as possible in the NEPA process, and plan their public participation, analysis, and review in such as way that they can meet the purposes and requirements of both statutes in a timely and efficient manner. The determination of whether an action is a "major Federal action significantly affecting the quality of the human environment," and therefore requires preparation of an . . . environmental impact statement (EIS) under NEPA, should include consideration of the undertaking's likely effects on historic properties. A finding of adverse effect on a historic property does not necessarily require an EIS under NEPA. (36 CFR 800.8(a)(1))
  • Inclusion of historic preservation issues. Agency Officials should ensure that preparation of an Environmental Assessment (EA) and Finding of No Significant Impact (FONSI) and an EIS and Record of Decision (ROD) includes appropriate scoping, identification of historic properties, assessment of effects upon them, and consultation leading to resolution of any adverse effects. (36 CFR 800.8(a)(3))
  • Actions categorically excluded under NEPA. If a project, activity or program is categorically excluded from NEPA review under an agency's NEPA procedures, the Agency Official shall determine if it still qualifies as an undertaking requiring review under Section 106 pursuant to Sec. 800.3(a). If so, the Agency Official shall proceed with Section 106 review in accordance with the procedures in this subpart (36 CFR 800.8(b)).

According to the NEPA regulations, in considering whether an action may "significantly affect the quality of the human environment," an agency must consider, among other things:

  • Unique characteristics of the geographic area such as proximity to historic or cultural resources (40 CFR 1508.27(b)(3))


  • The degree to which the action may adversely affect districts, sites, highways, structures, or objects listed in or eligible for listing in the National Register of Historic Places (40 CFR 1508.27(b)(8)).

The NEPA regulations also require that:

  • To the fullest extent possible, agencies shall prepare draft environmental impact statements concurrently with and integrated with environmental impact analyses and related surveys and studies required by the National Historic Preservation Act (40 CFR 1502.25(a)).

General Recommendations for Coordination

Based on the above requirements, Section 106 review – that is, the scoping, identification, assessment, and consultation called for in 36 CFR 800.8 – should be carried out in coordination with NEPA review as follows:

  • Conduct Section 106 review when screening a project that may be categorically excluded from NEPA review to see whether "extraordinary circumstances" exist requiring further review (40 CFR 1508.4). Whether such extraordinary circumstances are found to exist based on historic property impacts will depend on the severity of the impacts and what the agency's NEPA procedures say, but even if no further review is required under NEPA, Section 106 review must be completed.
  • During preparation of any EA, conduct Section 106 review in order both to comply with Section 106 itself and in order to determine whether historic resources will be adversely affected, and if so, whether measures can be implemented to reduce adverse effects to a less than significant level. The results of the review should be reported in the FONSI if one is issued, with an explanation of how Section 106 review has resulted in avoiding significant adverse effect.
  • Section 106 review should be conducted during preparation of any EIS. Scoping, identification, and assessment of effects should be done during the analysis leading to the draft EIS (DEIS), and the results should be presented in the DEIS. Consultation to resolve adverse effects should be coordinated with public comment on the DEIS, with the results reported in the final EIS (FEIS). Any Memorandum of Agreement (MOA) developed under Section 106, or the final comments of the ACHP, should be addressed in the ROD. Unless there is some compelling reason to do otherwise, the Section 106 MOA should be fully executed before the ROD is issued, and the ROD should provide for implementation of the MOA's terms.


Note that Section 106 does not deal with impacts on all types of cultural resources, or all cultural aspects of the environment; it deals with impacts on properties included in or eligible for the National Register of Historic Places. Other authorities, such as the American Indian Religious Freedom Act (AIRFA) and Executive Order 12898, may require consideration of other cultural resource types, and NEPA itself provides for considering all aspects of the cultural environment – for example, the cultural use of natural resources. So complying with Section 106 does not guarantee that all impacts on all cultural resource types have been addressed in NEPA analysis.

"Substituting" NEPA Compliance for Section 106 Compliance

It is possible for an agency to "substitute" its NEPA review for the specific steps set forth in the Section 106 regulations, providing specific standards are met. Substitution is not allowed where a project is categorically excluded from NEPA review, and practically speaking it will probably be useful only where relatively large, complicated projects involving many alternatives are under review. If you want to consider substitution, be sure to review the standards carefully.