Define the area of potential effects (APE) as outlined in the regulations of Section 106 of the National Historic Preservation Act. Clarify the meaning of direct and indirect effects, discuss how to document an APE to facilitate consultation, review the potential to affect historic properties, and consider the assessment of effects. Understand the importance of definitions of APE in Section 106 and direct and indirect effects in National Environmental Policy Act (NEPA) to the coordination of these regulations.


  • The four steps of the Section 106 process
  • The importance of consultation
  • Initiating the process—defining the APE (area of potential effects)
  • Definition of effect
  • Direct effect and indirect effect
  • Recent court case (National Parks Conservation Association v. Semonite)
  • Direct effects—examples:
    • Physical
    • Visual
    • Auditory
    • Socioeconomic
  • Indirect effects—examples:
    • Reasonably foreseeable
    • Cumulative
  • How to document the APE
  • NEPA and Section 106 coordination
  • Applying the criteria of adverse effect to assess effects
  • Adverse effects—examples
  • Special situations—National Historic Landmarks
  • Case studies

Training Curriculum

75-minute, on-demand course

  • 1

    Welcome Letter

    • NPI Welcome Letter

  • 2


    • Section 106: The Meaning of Effects: Chapter 1

    • Section 106: The Meaning of Effects: Chapter 2

    • Section 106: The Meaning of Effects: Chapter 3

    • Section 106: The Meaning of Effects: Chapter 4

  • 3

    Download Course Slides

    • Section 106: The Meaning of Effects (slide deck)

  • 4

    Supplemental Materials

    • Advisory Council on Historic Preservation Memorandum, Recent court decision regarding the meaning of "direct" in Sections 106 and 110(f) of the National Historic Preservation Act, June 7, 2019

    • 36 CFR 800 - Protection of Historic Properties

    • Assessing Visual Effects on Historic Properties, Virginia Department of Historic Resources (Marc Holma, 2010)

    • The National Historic Preservation Act As amended through December 16, 2016 and Codified in Title 54 of the United States Code

    • National Parks Conservation Association v. Semonite, March 1, 2019

    • Charleston Union Pier Terminal Project, National Park Service letter to Charleston District, Corps of Engineers, September 21, 2017

    • Comparison of Visual Impact Analysis under the National Environmental Policy Act and Section 106 of the National Historic Preservation Act (Robert G. Sullivan, Mark E. Meyer, and Daniel J. O'Rourke, Visual Resource Stewardship Conference Proceedings, 2018

  • 5

    Download Video Transcript

    • Section 106: The Meaning of Effects (transcript)

  • 6

    Course Evaluation

    • NPI Evaluation



Ethel R. Eaton, Ph.D.

Ethel R. Eaton, Ph.D., policy experience working with Section 106 of the National Historic Preservation Act for the Virginia Department of Historic Resources and the Maryland Historical Trust; past excavation, teaching, and research positions at universities and museums
Full Bio/CV


This training is suitable for

  • Officials and community leaders, archaeologists, architectural historians, cultural and natural resource managers

  • Landscape and preservation architects, planners, and project managers with SHPOs, THPOs

  • Tribes, government agencies, and contractors involved in compliance requirements

Immediate Access

  • $100.00

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