The U.S. Army Corps of Engineers (Corps) has published a notice in the Federal Register regarding their intention to change the way they look at impacts to cultural resources. Since 1990 the Corps has followed Appendix C in lieu of implementing Section 106 of the National Historic Preservation Act (NHPA). Section 106 compels all federal agencies to consider the effects of their undertakings on historic properties and cultural resources, and plays a powerful role in the Clean Water Act permitting process. Wetland Studies and Solutions, Inc. (WSSI) has been monitoring the proposed change, and our breakdown of the implications follows.

What Projects Will Be Impacted?

Construction projects that involve dredging and filling of Waters of the U.S. (WOTUS) must apply for and obtain a Clean Water Act (CWA) Section 404 permit, which triggers requirements of Section 106 of the National Historic Preservation Act (NHPA). Appendix C was implemented in 1990 to serve as a streamlined process for the Corps to evaluate, screen, and mitigate potential adverse effects to historic properties specifically within the CWA Section 404 wetland permitting process. Army Civil Works programs other than the Corps Regulatory Program, and all other federal agencies use the ACHP’s 36 CFR 800 regulations for federal agency compliance with Section 106 of the NHPA.

Processing Time and Jurisdiction Changes Could Impact Permit Applications

Perhaps most significant amongst the changes WSSI clients may see (should Appendix C be withdrawn) involve the Corps’ options to limit their jurisdiction to narrowly defined permit areas under Appendix C and more robust consultation between the Corps and tribes. Additionally, with the proposed removal of Appendix C, the Corps will need to undertake further regulatory actions to align with the NHPA’s Section 106 rules as specified in 36 CFR 800. Finally, applicants can likely expect delays in obtaining CWA Section 404 permitting during a transition period following the withdrawal of Appendix C.

When Would the Changes Happen?

Individual and General Permits (other than Nationwide Permits): Following the withdrawal of Appendix C, new applications for federal CWA Section 404 permits will likely be affected immediately. Those permit applications under consideration at the time would almost certainly be processed under Appendix C rules.

Nationwide Permits: The Corps has stated intent to continue to utilize the January 2021 regulation regarding General Condition 20 for historic properties through the issuance of the next cycle of Nationwide Permits in 2026. However, once notification occurs under General Condition 20, the Corps would then proceed using 36 CFR part 800 for Section 106 compliance.

More About the Regulation

The NHPA requires federal agencies to:

  • Evaluate the impact of their undertakings on historic resources (i.e., historic and precontact archeological sites, historic architectural resources, and indigenous/tribal cultural resources that are eligible for listing or listed in the National Register of Historic Places),
  • Afford the Advisory Council on Historic Preservation (ACHP) an opportunity to comment on such undertakings, and
  • See that any adverse effects to historic properties associated with a federal undertaking are mitigated.

A Brief History of Appendix C

 The Corps’ use of Appendix C has been controversial since its adoption in 1990. NHPA Section 106 requires federal agencies to present any alternative screening protocols and regulations concerning effects on historic or cultural resources to the ACHP for consultation, but the Corps bypassed this mandate.

Critics of Appendix C have argued that it fails to fully comply with the NHPA’s requirements, particularly regarding the level of consideration and protection afforded to historic properties and cultural resources and that it falls short in ensuring meaningful consultation with tribes and in adequately assessing and mitigating impacts. The Biden Administration and various tribal representatives have pointed out that Appendix C inadequately involves tribes in the permitting process, contrary to the increased emphasis on tribal consultation and involvement in federal actions mandated by recent executive orders and presidential directives.

Comment on the Proposed Change

The Corps’ is accepting public feedback until April 9, 2024. Comments can be sent online, by email, or by mail.

Federal eRulemaking Portal:

[email protected]
Include the docket number, COE–2023–0004, in the subject line of the message.

U.S. Army Corps of Engineers
441 G Street NW
Washington, DC 20314–1000

WSSI Can Help

If you have questions about how the withdrawal of Appendix C may impact your current and future projects that are subject to Corps review, please contact your WSSI project manager or WSSI’s Cultural Resources and Regulatory staff listed below. Our Cultural Resources and Regulatory teams work seamlessly to ensure smooth permit processing and compliance with local, state, and federal requirements for cultural resource investigation and stewardship.



  • Boyd Sipe, M.A., RPA

    Manager - Archeology

    Gainesville, VA

  • John Mullen, M.A., RPA

    Principal Archeologist/Assistant Manager

    Gainesville, VA

  • Christie Blevins, PWS, CESSWI, LEED AP

    Director - Regulatory

    Gainesville, VA