U.S. Army Corps of Engineers Proposes Broader Historic Preservation Review

On February 9, 2024, the U.S. Army Corps of Engineers (Corps) published a proposed rule that would amend the Corps permitting regulations to follow the National Historic Preservation Act (NHPA) implementing regulations as developed interpreted by the Advisory Council on Historic Preservation (ACHP). Specifically, the Corps proposes removing its own NHPA regulations, Appendix C from 33 CFR part 325, and replacing them with those promulgated by the ACHP at 36 CFR part 800. This change may lengthen the regulatory review process and expand the scope of the Corps’ NHPA review.


NHPA Section 106 requires federal agencies to consider the effects of their undertakings and permits for undertakings on historic properties (properties included in or eligible for the National Register of Historic Places) and to provide the ACHP a reasonable opportunity to comment on the undertaking. Pursuant to the authority granted in NHPA Section 211, the ACHP promulgated implementing regulations (36 CFR part 800) that define federal agencies’ NHPA Section 106 responsibilities. These regulations allow federal agencies to develop alternate procedures to implement NHPA Section 106 and substitute them for ACHP 36 CFR part 800 implementing regulations after consulting with and gaining approval from the ACHP.

The Corps issued its current NHPA regulations in Appendix C to 33 CFR part 325 (Appendix C) but did so without using the consultation procedures in the ACHP regulations. In the proposed rule, the Corps states that differences between Appendix C and the ACHP implementing regulations at 36 CFR part 800 have “in many cases introduced confusion resulting in debate over the extent and appropriateness of the Corps review.”

Proposed rule

The Corps proposes replacing Appendix C with 36 CFR part 800 to resolve discrepancies with the ACHP, which the Corps identifies as including the following:

  • Appendix C omits the 36 CFR part 800 Tribal and Native Hawaiian Organization consultation requirements.
  • Appendix C and 36 CFR part 800 have different definitions for the scope of activities or “undertakings” subject to NHPA Section 106 review and the scope of the review itself (“area of potential affect” under 36 CFR part 800 and “permit area” under Appendix C).
    • An “undertaking” under Appendix C includes the work, structure, or discharge that requires a permit. By contrast, ACHP’s definition of “undertaking” is broader and includes a project, activity, or program funded in whole or in part under the direct or indirect jurisdiction of a federal agency, including those carried out by or on behalf of a federal agency; those carried out with federal financial assistance; and those requiring a federal permit, license, or approval.
    • The Corps limits the scope of NHPA Section 106 review to the “permit area,” which includes jurisdictional waters under Corps statutory authority that will be directly affected by the proposed undertaking and may be expanded beyond such areas dependent on a three-part test used to determine whether the Corps should include others areas or activities. By contrast, ACHP regulations designate the scope of review to the “area of potential effects,” which encompasses the area affected by an undertaking that may directly or indirectly cause alterations in the character or use of historic properties.

If the proposed rule is finalized, the Corps could expand the number and duration of NHPA Section 106 consultations in its permitting decisions. For example, the Corps currently does not require NHPA Section 106 review in areas in which an undertaking may indirectly alter a historic property, but adoption of 36 CFR part 800 could broaden the scope of NHPA review and the time required for such review. The Corps is now soliciting comments on the proposal to remove Appendix C from 33 CFR part 325. Instructions for submitting comments are included in the publication of the proposed rule.

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