INTRODUCTION

The objective of NCHRP Project 25-65, Preparing Successful No-Effect and No-Adverse-Effect Section 106 Determinations: A Handbook for Transportation Cultural Resource Practitioners, is to produce a handbook for cultural resources professionals at state DOTs and federal and local transportation agencies to aid in developing and effectively communicating Section 106 of the National Historic Preservation Act (NHPA) findings of No Effect and No Adverse Effect to historic properties (i.e., properties listed in or eligible for inclusion in the National Register of Historic Places (National Register)) for federally funded or approved transportation projects. The project team included staff from WSP USA, Inc. and the SRI Foundation. The federal regulations for Section 106 NHPA (i.e., 36 CFR § 800) require federal agencies, including the FHWA, to take into account the effects of its undertakings on historic properties. The formal effect determinations laid out in the Section 106 regulations are No Historic Properties Affected (36 CFR § 800.4(d)(1)), No Adverse Effect (36 CFR § 800.5(b)), and Adverse Effect (36 CFR § 800.5(a)). A finding of No Historic Properties Affected is made when no historic properties are present within a project’s area of potential effects (APE), or when historic properties are present but the undertaking will have No Effect on these properties, as defined in 36 CFR § 800.16(i), which describes an “effect” as an alteration to the characteristics of a historic property that qualify it for inclusion in or eligibility for inclusion in the National Register. A finding of No Adverse Effect is made when a project’s effects do not meet the criteria of adverse effect as defined in 36 CFR § 800.5(a)(1), or the undertaking is modified, or conditions are imposed that avoid an Adverse Effect. These Section 106 effect determinations are made by a federal agency in consultation with the appropriate SHPO or Tribal Historic Preservation Officer (THPO, if the project is on tribal lands) and the Tribe and other Section 106 consulting parties, including federally recognized Tribes and NHOs, applicants for federal funding, permits, or licenses, local governments, local historical societies, and historic preservation organizations. Documentation on these findings is also made available to the public for review and comment.

As noted, the criteria for defining an Adverse Effect are detailed in the Section 106 regulations in 36 CFR § 800.5(a)(1). As defined in the regulations, an Adverse Effect is found when a project:

may alter, directly or indirectly, any of the characteristics of a historic property that qualify the property for inclusion in the National Register in a manner that would diminish the integrity of the property’s location, design, setting, materials, workmanship, feeling or association.

In addition, adverse effects may include “reasonably foreseeable effects caused by the undertaking that may occur later in time, be farther removed in distance, or cumulative.” The FHWA Section 106 Tutorial (FHWA 2024a) and ACHP’s Handbook for Integrating National Environmental Policy Act (NEPA) and Section 106 (ACHP 2013) provide additional definitions and guidance on the meaning of indirect, and cumulative effects:

• Indirect: Effects that may change the character of the property’s use or of physical features within the property’s setting that contribute to its historic significance, or introduce visual, atmospheric, or audible elements that diminish the integrity of the property’s significant historic features.
• Cumulative: Adverse effects may include reasonably foreseeable effects caused by the undertaking that may occur later in time, be farther removed in distance, or be cumulative. [36 CFR § 800.5(a)(1)]. While the Section 106 regulations do not define “cumulative effects,” the CEQ regulation definition of “cumulative impact” is analogous and instructive.

The majority of FHWA Division Offices coordinate and work with state DOTs to assess the effects on historic properties as part of the transportation project development process. State DOTs must therefore be equipped not only to assist in making such assessments but also to assist FHWA in communicating these findings to SHPOs, THPOs, Tribes, other consulting parties, and members of the public.

This NCHRP project began with a literature review and analysis of existing Section 106 guidance, publications, and cultural resource manuals; statewide Programmatic Agreements for the Federal-Aid Transportation program; forms and tools used by state DOTs and SHPOs for making effects determinations; and current practices by transportation practitioners. This literature review and analysis was followed by an online survey of state DOTs, FHWA Division Offices, SHPOs, THPOs, local transportation organizations and private-sector firms that work for state DOTs and a sample of FPOs. Based on the results of the online survey, the project team conducted follow-up telephone interviews of a sample of the online survey respondents. Interviews were also conducted with the FPOs for FHWA and Federal Railroad Administration (FRA). The results of the literature review, online survey, and interviews were used to identify the state of the practice in terms of effective approaches to making well-reasoned and defensible determinations of No Effect and No Adverse Effect on historic properties, and effective strategies for communicating these findings to all the parties involved in the Section 106 consultation process.

As noted, the primary outcome of this NCHRP project is a handbook showcasing these successful practices and approaches. The audience for the handbook includes but is not limited to cultural resource professionals at state DOTs¹, FHWA, other transportation agencies, SHPOs, THPOs, Tribes, and private-sector firms working for transportation agencies.

This conduct of research report provides a summary of the literature review, the state of practice survey, and the interviews. The report is organized into five sections (plus References Cited) and four appendices.

• Project Approach – This section discusses each step taken to gather information and produce the handbook, including brief descriptions of the methodology used for the literature review, online survey, and interviews.
• Literature Review – This section reviews the literature on current guidance and practices for making effects determinations and documentation of these effects finding within the context of Section 106.
• State of Practice Survey – This section summarizes and discusses the findings of the online survey and follow-up telephone interviews. A summary of the case studies presented in the handbook is also provided in this section.
• Practitioner Interviews: Practices and Experiences. This section also includes a summary of several case studies.
• Summary of Findings.
• Appendices: State of Practice Survey Questionnaire (Agencies), State of Practice Survey Questionnaire (Organizations/Consultants), State of Practice Survey Questionnaire (THPOs), and List of Interviewees and Interview Questionnaires.