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Federal Law (Section 106)

What’s it about?

Section 106 of the National Historic Preservation Act of 1966 (NHPA) requires every federal agency to “take into account” how its projects and expenditures will affect historic properties, which includes prehistoric and historic sites.

Projects include construction, rehabilitation, demolition, licenses, permits, loan guarantees, transfer of federal property, etc. State and local governments and others using federal funds are also required to comply with Section 106.

Read the law:  Section 106 Regulations (36 CFR Part 800)


 Section 106 steps


The agency determines whether its proposed action is an undertaking. An undertaking is defined as 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 agency makes determinations of eligibility and effect for the undertaking:

ELIGIBILITY: Is the site eligible for listing on the National Register of Historic Places?

Properties already listed on the National Register are, of course, “eligible.” Properties not yet listed are considered eligible if they meet the following criteria:

  • Age – 50 years old or older
  • Research potential – Sites can yield important information about prehistory or history.

If the site is 50 years old or older and has integrity, the determination would be “Eligible Historic Property.”

If there are no historic properties in the project area, or if the site is less than 50 years old, or if the site lacks integrity, the determination would be “No Historic Properties.”

EFFECT: What impact will the work will have on the site?

Effect needs to be determined only for eligible properties. There are three possible effects:

  • No Effect – Only minor changes are being proposed, e.g., planning or minor construction.
  • No Adverse Effect – More substantial changes are proposed, but they meet Secretary of the Interior Standards.
  • Adverse Effect – Work is proposed that will damage or diminish the historic integrity of the property or its research potential.

In most cases, archaeological sites receive a No Adverse Effect if the site’s value lies solely in its research potential, and the information can be preserved through appropriate research.


The agency or government consults with the State Historic Preservation Office (SHPO) on its determinations.

Consult about projects possibly affecting historic structures

Consult about projects possibly affecting archaeological resources


SHPO either concurs with the determinations or does not concur.
If SHPO concurs:

  • No Historic Property, No Effect, or No Adverse Affect: You are finished with the Section 106 Review consultation process.
  • Adverse Effect: The agency enters into a “Memorandum of Agreement” (MOA) to mitigate the adverse effect or submits a research design to mitigate adverse effects through proper recovery. The MOA is signed by the agency and SHPO. The federal agency submits the MOA to the Advisory Council, along with a description of the project and the alternatives that were considered to mitigate the “adverse effect.” The Advisory Council has 30 days to review the project and decide if it is willing to sign the MOA. Once the MOA is signed, the documentation should be completed and accepted by designated repositories before the project begins.

If SHPO does not concur: Federal agencies may make final determinations, i.e., the Keeper of the National Register of Historic Places or the Advisory Council on Historic Preservation.

Section 106 Training Opportunities

Workshops and other Section 106 training opportunities are provided by a variety of organizations.

Advisory Council on Historic Preservation

Federal Preservation Institute

National Preservation Institute

SRI Foundation

SWCA Environmental Consultants

Advisory Council on Historic Preservation web pages:

Section 106 Flowchart
Flowchart outlining the Section 106 process step-by-step.

Section 106 Citizens Guide 
Brochure that explains the Section 106 process and the public’s role within that process.

Section 106 Case Digest
A digest of current and archived prominent Section 106 cases throughout the country.

Section 106 Relation to Other Laws
Federal agencies have responsibilities under multiple laws that may influence the way they carry out their Section 106 duties; compliance with one or more of these other statutes does not substitute for compliance with ACHP’s regulations.

Nationwide Programmatic Agreements
List of Nationwide Programmatic Agreements in effect, including the FCC Programmatic Agreement.

Federal Preservation Officers
List of FPO’s and their contact information.  Every agency has an FPO who coordinates preservation programs and interaction with other agencies.

The Secretary of the Interior’s Standards and Guidelines for Archeology and Historic Preservation