Agency officials decide how to involve the public in the Section 106 process. A formal plan is not required, though one may be appropriate depending upon the scale of the undertaking and the magnitude of its effects on historic properties. An agency may use their National Environmental Policy Act public involvement procedures. Agency officials also consult with the SHPO/THPO to identify organizations and individuals with a demonstrated interest in the undertaking that will have the right to be consulting parties under the terms of the regulations. They may participate because they have a legal or economic relationship with the undertaking or affected properties or because they are concerned with the undertaking’s effects on historic properties.

Consulting parties may include local governments, Indian tribes, Native Hawaiian organizations, and applicants for Federal assistance or permits. Others may request to be consulting parties, but that decision is ultimately up to the agency officials.

If the agency determines that there is no undertaking (i.e., State funds are used instead of Federal funds and thus Section 106 is no longer applicable), or there is an undertaking but it does not have the potential to affect historic properties, the agency has no further obligations under Section 106. Agencies are strongly advised to keep appropriate records of such findings if questions are raised by members of the public or other parties at a later date.

When the agency has determined that the proposed project has the potential to impact historic properties, the agency can begin to identify properties that might be affected. At this stage in the process, though, the agency official does not need to know whether there are historic properties present.

The standard for identification is a “reasonable and good faith effort” to identify historic properties. Meeting this standard depends on previous identification work, and may include background research, a consultation, oral history interviews, a sample field investigation, and a field survey. An agency may conduct phased identification when the scope of an undertaking and its effect have not been completely defined because the undertaking includes corridors or large land areas, or access to properties is restricted. Final identification and evaluation may also be deferred if it is outlined in an agreement with the SHPO/THPO. The ACHP provides additional guidance on other program alternatives.

Federal agencies are required to apply the National Register Criteria to properties identified and to acknowledge the special expertise of Indian tribes and Native Hawaiian organizations when assessing the eligibility of a property to which they attach religious and/or cultural significance. Previous determinations of eligibility may need to be re-evaluated due to the passage of time or other factors such as a change in regulations or policy from the original determination.

Agency officials make determinations of eligibility in consultation with the SHPO/THPO. If there is disagreement or the ACHP or Secretary of Interior so requests, the agency refers the matter to the Keeper of the National Register.

If no historic properties or no effects on historic properties are found, the agency provides appropriate documentation to the SHPO/THPO and notifies the consulting parties. Members of the public do not need to receive direct notification, but FHWA must provide access to the information when requested by the public.

Once adequate documentation is received, the SHPO/THPO has 30 days to object to the determination. If the SHPO/THPO does not object within the 30-day period, this means that the agency has completed its Section 106 responsibilities.

If historic properties may be affected, the agency then assesses the adverse effects.

Examples of adverse effects include physical destruction or damage; alteration not consistent with the Secretary of the Interior’s Standards; relocation of a property; change of use or physical features of a property’s setting; visual, atmospheric, or audible intrusions; neglect resulting in deterioration; or transfer, lease, or sale of a property out of Federal ownership or control without adequate protections. If a property is restored, rehabilitated, repaired, maintained, stabilized, remediated, or otherwise changed in accordance with the Secretary’s Standards, then it will not be considered an adverse effect (assuming that the SHPO/THPO agrees).

Where properties of religious and cultural significance to Indian tribes or Native Hawaiian organizations are involved, neglect and deterioration may be recognized as qualities of those properties and thus may not necessarily constitute an adverse effect. Alteration or destruction of an archaeological site is an adverse effect, whether or not recovery of archaeological data from the site is proposed.

The SHPO/THPO may suggest changes in a project or impose conditions so that adverse effects can be avoided and thus result in a no adverse effect determination. If a SHPO/THPO does not respond to an agency finding within the 30-day review period, then the agency can consider the SHPO/THPO to be in agreement with the finding.

Agencies must retain records of their no adverse effect determinations and make them available to the public. A finding of adverse effect requires further consultation to resolve it.

The agency provides project documentation to all consulting parties at the beginning of the consultation to resolve adverse effects, and FHWA provides sufficient time and information for the public to provide meaningful comments. A new public notice is only required if all pertinent information was not provided throughout the process or if new information is available.

When resolving adverse effects without ACHP, the agency consults with the SHPO/THPO and other consulting parties to develop a Memorandum of Agreement (MOA). If this is achieved, the agreement is executed and filed with ACHP. This filing is the formal conclusion of the Section 106 process and must occur before the undertaking is approved.

If the terms of an MOA are not followed, the agency reopens the Section 106 process and brings it to suitable closure as prescribed in the regulations. The roles and responsibilities of signatories to an agreement are described, along with who is required to sign the agreement under specific circumstances. The term “signatory” refers to the ability to terminate or agree to amend the MOA. It is particularly desirable to invite signatories who assume obligations under the agreement. Once invited signatories sign a MOA, they have the same rights to terminate or amend the MOA as the other signatories. Other parties may be invited to concur in agreements, but they cannot amend or terminate an MOA.