LITERATURE REVIEW

As described in the preceding chapter, Project Approach, an extensive literature review was conducted to identify and evaluate available information on determinations of No Effect and No Adverse Effect in existing Section 106 guidance, publications, and cultural resource manuals, statewide delegation PAs, and forms and tools available for making effects determinations. During the literature review the project team searched for resources on working with consulting parties during the Section 106 process and how consultation is used as part of assessing effects; however, no specific guidance or practices were found. As a result, the online survey and follow-up interviews of agencies, organizations, and THPOs were used to identify approaches and practices associated with engaging and working with consulting parties on effects determinations.

The following sections synthesize the results of the literature review and highlight some key resources for making determinations of No Effect and No Adverse Effect to historic properties.

• Highlights Section 106 guidance documents and dedicated cultural resource manuals produced by state DOTs and SHPOs containing specific examples and practices for assessing effects on historic properties.
• Discusses stipulations dealing with effects determinations included in recent statewide delegation transportation PAs.
• Lists useful forms and tools created by state DOTs and SHPOs for making effects determinations.
• Discusses working with consulting parties during the Section 106 process and how consultation is used as part of assessing effects.
• Presents commonalities and best practices for supporting well-reasoned and defensible determinations of No Effect and No Adverse Effect. This section includes a breakdown of each step in the Section 106 process and how they can contribute to a finding of effect as well as a discussion of findings of No Adverse Effect through the use of conditions placed on advancing a transportation project.

Some of the information and approaches identified throughout the course of this research project are from NEPA Assignment states. Information and approaches from these states are unique and customized to each of these individual states, as each of these states, under NEPA assignment, is the lead federal agency legally responsible for Section 106 compliance. It should be noted that under NEPA assignment, the legal responsibility for government to government consultation with federally recognized Tribes remains with FHWA and other federal agencies. In this report, NEPA Assignment states will be highlighted in bold in the narrative below.

SECTION 106 GUIDANCE, PUBLICATIONS, AND CULTURAL RESOURCE MANUALS

All but 13 states have a statewide delegation PA in place, but relatively few state DOTs have Section 106 guidance documents available online, either as standalone documents or as informational websites, and only four have published manuals on the implementation of their PAs (see section below on PAs).

Alaska Department of Transportation and Public Facilities (Alaska DOT) guidance on determining a finding of effect comes from the agency’s letter templates for Section 106 project submittals to SHPO. The template instructs practitioners to “provide a finding of effect for each eligible resource and for the overall project and explain the basis for the findings” (Alaska DOT 2020). The following pieces of

• If more than a few properties were evaluated, provide a table delineating the effect determinations for each property [Colorado DOT 2021:15].

Florida DOT uses a Cultural Resource Management Handbook that focuses almost exclusively on Section 106 procedures (Florida DOT 2013:8-1). The Cultural Resource Handbook includes a chapter on effects determinations and resolution of adverse effects, providing the regulatory definitions for each type of effect finding and the documentation requirements as stated in 36 CFR 800. Florida DOT does provide information on findings of No Adverse Effect based on the imposition of conditions on a project (see section below regarding findings of No Adverse Effect based on the imposition of conditions for more details). Florida DOT also has a separate handbook and quick guide on the evaluation of cumulative effects for state DOT projects subject to NEPA (Florida DOT 2012). Although this document focuses on evaluating impacts under NEPA, it offers some connections to the Section 106 process, stating, “the distinction between NEPA and other definitions [such as Section 106 of the NHPA] should also be taken into account when preparing cumulative impacts analyses that are intended to serve multiple purposes because some resource agencies define these terms differently” (Florida DOT 2012:2-7).

In 2022 Georgia DOT updated procedures on Cultural Resources: Assessment of Effects in its Environmental Procedures Guidebooks, which establishes the standards for submitting an assessment of effect for Georgia DOT undertakings (Georgia DOT 2022). Georgia DOT offers some avoidance and minimization discussion points to guide early project planning to avoid adverse effects on historic properties (Figure 1) (Georgia DOT 2022:4).

The Indiana DOT Cultural Resources Manual, Part II, Chapter 8: Assessment of Effects, details findings of No Historic Properties Affected, No Adverse Effect, and Adverse Effect and provides sample formats and guidance for documenting each finding (Indiana DOT 2022). The guidance includes a list of questions to consider when assessing the effects of a transportation project.

• Will right-of-way be acquired from the historic property?
• Will any part of the property or its contributing elements, including landscape features, be altered or removed?
• Will there be introduction of visual elements that will diminish the property’s setting and feeling?
• Will the use of the property be affected in a way that could diminish its integrity? [Indiana DOT 2022].

In most instances, Indiana DOT submits an effects report to SHPO and other consulting parties for their input on a project’s proposed effect finding prior to the release of the state’ DOTs formal finding of effect and supporting 36 CFR § 800.11 documentation. The sample format and guidance for this effects report provided by Indiana DOT outlines aspects of a historic property and changes to the setting of the property that should be included in the description of effects, both direct and indirect:

Physical Effects

• Describe the physical impacts to the property, specifically those occurring within the historic property boundaries. Describe if any contributing features will be altered or removed. Contributing features may include, but not limited to:
  • ➢ Trees/landscaping
  • ➢ Brick/limestone sidewalks/curbs
  • ➢ Light poles, signage, and other freestanding elements
  • ➢ Structures
• Specify and detail if any new elements will be introduced onto the property.
• Indicate whether any permanent or temporary right-of-way will be acquired, and specify amounts as appropriate, from the property.

Other Effects

• Describe other non-physical effects such as those that may cause visual, auditory, or atmospheric changes. Consider the following as potential indirect effects:
  • ➢ Will new roads/roadway elements/infrastructure elements be introduced where not previously existing?
  • ➢ Will existing elements, both historic and non-historic, be altered that would change the viewshed of the property?
  • ➢ Will the existing road be widened? How wide?
  • ➢ Will the existing road be elevated, depressed? If so, how high, low?
  • ➢ Will there be associated walls or barriers?
  • ➢ Will traffic increase as result of project? New/different types of traffic such as heavy trucks?
  • ➢ Will access to and from the property change? [Indiana DOT 2022].

Maine SHPO includes a “Maine Department of Transportation Specific” section in Above Ground Cultural Resource Survey Manual: Guidelines for Identification: Architecture and Cultural Landscapes (2013) that dedicates a chapter to “Findings of Effect Reports.” The chapter identifies two parts in defining an “effect,” (1) determining if there will be an effect, and (2) determining whether the effect is harmful (Maine SHPO 2013:32). Six “Points to Remember” are listed for consideration when applying the criteria of effect:

• An effect does not have to be negative to be an effect. If the undertaking will change the relevant characteristics of the property at all, it will have an effect. Therefore, even a beneficial effect is nevertheless an effect.
• However, to have an effect, the undertaking must have the potential to “alter characteristics of the

• property that may qualify [it] for inclusion in the National Register.” If the undertaking will alter the property in some other way, there may not be an effect for the purposes of Section 106. Therefore, it is critical to understand why the property is significant and what elements of the property contribute to its significance.
• The potential alteration does not have to be a certainty; as long as the undertaking may alter the relevant characteristics, it must be found to have an effect.
• All possible effects of an undertaking on historic properties are to be considered under Section 106; including visual audible effects, effects on land use, and other effects to setting, feeling and association.
• The agency should consider not only the changes that may occur at the time of the undertaking, but also those reasonably foreseeable effects that may occur later in time.
• Effects do not need to be direct and physical. For example, altering the way an eligible place of traditional cultural importance to a community, tribe, or other group it used has an effect [Maine SHPO 2013].

In July 2022 Michigan DOT produced Tips for Filling out a Section 106 Application. This document supplies agency staff and consultants with detailed guidance on appropriate terminology for a finding of effect and how to document that finding in a Section 106 application for SHPO review. The document instructs applicants to choose “ONLY ONE” of three types of effects.

• Check the “no historic properties affected” box if you can demonstrate that there are no historic properties in the APE, or the work is so limited in the vicinity of the historic property or properties it will not have any effect on any historic properties. While the [PA] exemption letter does cover a number of situations, there are many work items that may be included in a project that do not meet the exemption. Those additional work items may still have a minimal effect on historic properties.
• Check the “No Adverse Effect” box if your project has very minor impacts.
• Check the “adverse effect” box if your project has major impacts [Michigan DOT 2022:3].

Nebraska DOT’s Section 106 Guidelines provides instructions for consultants and others working within the Nebraska DOT Section 106 compliance process. Guidelines regarding effects findings for both archaeological resources and architectural resources are included as joint sections on evaluating National Register eligibility. Nebraska DOT gives some qualifying information on assessing effects on historic properties, including the statement that when determining if there is an Adverse Effect to a property, “all qualifying characteristics of a historic property shall be considered, including those that may have been identified after the original evaluation of the property’s NRHP eligibility” (Nebraska DOT 2019:6-5).

New York State DOT has numerous tools for guiding practitioners through the Section 106 process. The state DOT’s guidance document, Finding Documentation, outlines what is needed to appropriately document a finding of effect. For a finding of “No Effect” on historic properties, the document advises the user to explain why the criteria of adverse effect do not apply, or to explain why the criteria of adverse effect apply, considering any alterations to the character-defining features of the property. In addition, the document advises the user to describe any conditions to avoid adverse effects when documenting a finding of No Adverse Effect (New York State DOT 2006). Other forms and templates used by New York State DOT regarding Section 106 findings of effect include an Excel spreadsheet and letter template for reporting a finding to the FHWA.

In 2021 Ohio DOT published an online version of their Cultural Resources Manual & Guidance “designed for transportation project managers, project planners, and environmental professionals, as well as any others involved in Ohio DOT’s Project Development Process” (Ohio DOT 2021). The manual was

• be affected by clear cutting in order to provide a transmission line right-of-way.
• Rural historic districts that would be affected by the location of a transmission line through the associated landscape.
• A twentieth-century estate designed to take advantage of prominent view sheds of a ridge line on which a wind tower is proposed.
• A historic farm whose associated farmland would be impacted by the construction of a solar farm on the farmland and within the viewshed of the farm complex [Pennsylvania SHPO 2021].

When assessing potential visual effects, Pennsylvania SHPO advises practitioners to focus on topography, setting, and manmade or natural features that enhance a property’s significance and integrity; the nature and quality of the view to and from the property; and the property’s relationship to its setting (Pennsylvania SHPO 2021:8-9). Aerial imagery and photo simulations of the proposed project are also suggested.

Texas DOT issued a Standard Operating Procedure for Historic Properties Visual Impacts Assessment in 2012. The procedure defines visual impacts, properties sensitive to visual impacts, and examples of adverse visual impacts to historic properties. The agency reminds practitioners that visual effects can be beneficial or adverse to historic properties, and the procedures include a step in the assessment process to analyze the advantages and disadvantages of the undertaking and any potential alternatives (Texas DOT 2012:3). This is a highly detailed document providing information on assessing visual effects on historic properties in a transportation context. Some of the procedure’s content is excerpted below for reference.

• Texas DOT(2012:1) defines a visual impact as “1) subjective to the viewer or viewers, 2) can be beneficial to a historic property, and 3) can be adverse to a historic property.”
• “…a historic property is not sensitive to a visual impact if visual aspects of its feeling and setting are not part of what makes it eligible” (Texas DOT 2012:1).
• “When you determine the impact, you should provide a descriptive narrative of the project and impacts and provide visual aids. Visual aids may include drawings or computer renderings that show the relationship of the roadway to the historic property” (Texas DOT 2012:3).
• “In order to determine and analyze the visual impact, you must thoroughly document the resource, its present condition and integrity, and its relationship to the project area” (Texas DOT 2012:6).

STATEWIDE DELEGATION PROGRAMMATIC AGREEMENTS

Statewide Section 106 delegation PAs can serve as another source on the state of the practice for making determinations of No Effect and No Adverse Effects. The project team reviewed only PAs that were executed (signed) in 2020, 2021, and 2022. This time frame was selected because these PAs reflect the current policies and PA language and structural requirements established by the ACHP and the FHWA’s FPO for transportation delegation PAs.³

The project team examined the following nine state PAs: Arkansas, District of Columbia, Maryland, Maine, Michigan, North Carolina, South Dakota, Tennessee, and Vermont. The project team also looked

The North Carolina PA has two distinct effects determination procedures, one for findings of No Historic Properties Affected and one for cases in which the state DOT applies the criteria of adverse effect to a project in accordance with 36 CFR 800.5. In addition, the PA lays out separate procedures for applying the criteria of adverse effect to archaeological vs. historic architecture resources.

For findings of No Historic Properties Affected, the North Carolina DOT issues these findings using No Historic Properties Affected Forms that are attached to the PA. These forms are included in the project’s NEPA file, and the completion and filing of these forms completes the Section 106 review process. Completed No Historic Properties Affected Forms are provided to North Carolina SHPO annually.

When applying the criteria of adverse effect involving archaeological resources, North Carolina DOT can make a determination of No Effect and documents this determination using the No National Register of Historic Places Eligible or Listed Archaeological Sites Affected Form that is attached to the PA. The state DOT notifies the North Carolina Office of State Archaeology (OSA) of this finding. If OSA or other consulting parties do not object or do not comment on this finding within 30 days, the state DOT may proceed with the project. For findings of No Adverse Effect, the state DOT documents the finding using the No National Register of Historic Places Eligible or Listed Archaeological Sites Adversely Affected Form, which is also attached to the PA. The North Carolina DOT sends the form to OSA, and if OSA or other consulting parties do not object or do not comment on this finding within 30 days, the state DOT may proceed with the project.

For historic architectural resources, North Carolina DOT meets with SHPO staff to discuss the effects of the project. The state DOT then completes the National Register of Historic Places Eligible or Listed Historic Properties Effects Determination Form (form is also attached to the PA). The form documents the application of the criteria of adverse effect and is signed by the state DOT, SHPO staff, FHWA, and the U.S. Army Corps of Engineers (USACE) if they are involved in the project (the USACE is a signatory to the North Carolina PA). If SHPO or another consulting party proposes conditions or changes to the project that would result in a determination of No Historic Properties Affected or No Adverse Effect, and North Carolina DOT agrees to implement the conditions or changes, the state DOT documents these conditions or changes on the National Register of Historic Places Eligible or Listed Historic Properties Effects Determination Form, and no further consultation is necessary.

If North Carolina SHPO or other consulting parties object to the state DOT’s findings of No Historic Properties Affected or No Adverse Effect, SHPO or other consulting parties are to indicate the reasons for non-concurrence and will consult further to resolve the objection, either by identifying project alternatives that may result in the project’s having No Adverse Effect on historic properties or by proceeding to implement the PA’s dispute resolution stipulation.

FORMS AND TOOLS FOR MAKING EFFECTS DETERMINATIONS

A number of state DOTs and SHPOs have developed forms and other tools to obtain sufficient and standardized information for making an effects determination, in addition to documenting and communicating with consulting parties on these determinations (Table 1). State DOTs in Alaska, North Carolina, Nebraska, New Hampshire, Oregon, and Wisconsin have developed Section 106 forms for findings of effect and made them available on their websites. SHPOs in Arizona, Idaho, Indiana, Michigan, Oregon, Pennsylvania, South Carolina, and Tennessee have specific guidance or forms on findings of effect. Many of these forms are presented as merely guidance, whereas others are required as part of the Section 106 consultation package.

TABLE 1: FORMS AND TOOLS FOR MAKING EFFECTS DETERMINATIONS

Bold face denotes DOT NEPA assignment states.

Note: See also Appendix E, “Forms and Tools.”

WORKING AND ENGAGING WITH SECTION 106 CONSULTING PARTIES ON EFFECT DETERMINATIONS

Regarding consultation on effects findings, the FHWA online Section 106 tutorial states, “It is also of utmost importance to begin consultation among appropriate parties early in project development while options for project design or alternatives are still open. This will help to avoid surprises or misunderstandings that can lead to project delays and increased project costs” (FHWA 2024a).

NCHRP 25-62, “Improving the Efficiency and Consistency of Section 106 Compliance for State DOTs: Strategies for Project-Level Programmatic Agreements” (Mead & Hunt, Inc. 2021), identified two consultation strategies associated with the successful development of project-level PAs that could also apply to early and effective consultation on No Effect and No Adverse Effect determinations.

• Using effective and clear language.
• Working with Section 106 consulting parties.

Using clear and effective language when developing stipulations in a project-level PA was considered vital in avoiding misunderstandings among cultural resource practitioners, engineers, contractors, and consulting parties. Each of these parties uses different terms and communicates differently. Use of concepts and technical terms that the other parties may not understand or may interpret differently will create confusion if the terms and concepts are not discussed and/or articulated to achieve understanding by all parties. This NCHRP study suggests using unambiguous language in the context of effects findings;

2. A description of the steps taken to identify historic properties, including, as appropriate, efforts to seek information pursuant to 36 CFR § 800.4(b).
3. The basis for determining that no historic properties are present or affected.

Materials required for finding of No Adverse Effect [and Adverse Effect] are specified in 36 CFR § 800.11(e).

1. A description of the undertaking, specifying the federal involvement, and its APEs, including photographs, maps, and drawings, as necessary.
2. A description of the steps taken to identify historic properties.
3. A description of the affected historic properties, including information on the characteristics that qualify them for the National Register.
4. A description of the undertaking’s effects on historic properties.
5. An explanation of why the criteria of adverse effect were found applicable or inapplicable, including any conditions or future actions to avoid, minimize or mitigate adverse effects.
6. Copies or summaries of any views provided by consulting parties and the public.

Describing the Undertaking

Exhibit 2.8 of the California DOT Standard Environmental Reference (California DOT 2020) provides two key guidelines when describing a project:

• Describe the project concisely but with sufficient detail to ensure that a reviewer unfamiliar with the project or project area has a clear understanding of the extent of potential effects.
• Discuss all pertinent project-related activities and alternatives.

On its Section 106 Review – Project Summary Form, Ohio SHPO notes that providing a detailed description of the project is a “critical” part of the submission (Ohio SHPO 2022). Ohio SHPO qualifies that for challenging projects, such as those with effects on significant historic properties or with procedural issues, the agency should provide as much detail as possible when describing the undertaking and completing project review forms (Ohio SHPO 2022). Further, Ohio SHPO recommends that the project description be written for a “cold reader who may not be an expert in this type of project,” and the information must aid in the assessment of effects on historic properties.

Defining the Area of Potential Effects

An APE is defined in 36 CFR § 800.16(d) as

The geographic area or areas within which an undertaking may directly or indirectly cause alterations in the character or use of historic properties, if any such properties exist.

The APEs is influenced by the scale and nature of an undertaking and may be different for different kinds of effects cause by the undertaking.

Alaska DOT provides a framework for defining a project study area that is then refined to define the APE for consultation with SHPO, Tribes, and other consulting parties (Alaska DOT 2019). Further, Alaska DOT provides a description of what a study area, and ultimately the APE, should include:

The study area would include the direct footprint (i.e., project area, staging areas, and material sources) and also include adjacent/neighboring parcels/outlying areas that may experience other potential effects of the project (e.g., noise, visual, traffic changes, etc.) (Department of Transportation and Public Facilities Template for SHPO Section 106

Consultation Initiation Letters) [Alaska DOT 2019].

California guidance on defining an APE begins on page 7 of the Section 106 Primer produced by California SHPO in 2008. When defining the APE, after determining that the undertaking has potential to affect historic properties, California SHPO directs users to consider both direct and indirect effects, such as visual effects in areas in which an undertaking will be visible; audible effects in areas in which the project’s noise, if any, could be heard; sociocultural effects in areas in which the project may cause changes in land use, traffic, public access, etc.; and indirect or secondary effects of the project in the future (California SHPO 2008:8). This Section 106 Primer also identifies common mistakes when defining an APE.

• A common mistake is to identify historic properties and then determine the APE. The Section 106 regulations are very specific and require that you first determine the APE, and only after the APE has been determined should you take the necessary steps to identify historic properties.
• A common mistake is to base the APE on the location of historic properties. The APE cannot be manipulated to avoid including historic properties. Determining the APE is not intended to center on what is convenient and to avoid affecting historic properties.
• A common mistake is to equate the APE with the “footprint”, or physical boundaries, of the undertaking…Rather, you must consider how the construction will impact the neighborhood…The impacts that an undertaking may have on the surrounding area(s) are not confined to the physical boundaries of the undertaking [California SHPO 2008].

Chapter III, Section D of the Pennsylvania DOT Cultural Resources Handbook addresses defining an APE during the early project scoping process for the agency (Pennsylvania DOT 2021:22-23). Pennsylvania DOT explains that the APE should be determined after project designs have advanced through most reasonable alternatives, but early enough to allow the completion of cultural resource studies and appropriate avoidance and minimization of effects (Pennsylvania DOT 2021:23). A few considerations are presented by Pennsylvania DOT when defining an APE associated with the historic built environment:

• Consider multiple factors such as potential physical, visual, and auditory impacts.
• The APE should include all areas used for staging and temporary construction.
• Although areas used for staging and temporary construction may not be known at the time of scoping, these will need to be considered as the project develops.
• The APE must be set in relation to the project, not in relation to the above ground properties that are, or may be, present.
• The presence or absence of buildings in the viewshed does not always mean that there are no historic properties in the APE. For example, land associated with a farm whose buildings are outside the viewshed of the project may still be within the APE. In this case, it may be necessary to assess the eligibility of the entire farm to determine effects [Pennsylvania DOT 2021:23-24].

The APE for archaeological properties, as defined by Pennsylvania DOT, has both a horizontal and a vertical (depth) dimension and should include any part of the project area in which ground disturbance may occur, or where the integrity of archaeological sites may be diminished (Pennsylvania DOT 2021:24). Considerations should be given to the following factors:

• Delineating an APE that is large enough to include potential staging and temporary construction areas and to accommodate any reasonably foreseeable design changes, balanced against the costs of potentially testing too large of an area.
• Areas previously disturbed should be included in the APE if they are to be disturbed again by the

• project.
• Projects with limited vertical disturbance should consider depth of disturbance from the activity, disturbance from previous land use, degree of alteration of existing surface features, permanence of the project, and reversibility [Pennsylvania DOT 2021].

Pennsylvania SHPO (2021) outlines a two-step process for APE delineation for projects with potential visual effects: an initial APE and a refined APE. The initial APE, which considers the extent of visual effects on specific types of new construction (transmission lines, cell towers, wind towers, and solar farms), is submitted to SHPO as part of the Environmental Review initial submission in PA-SHARE. The initial APE is then refined using topography, elevation, vegetative cover and/or GIS-based modeling to include only the area from which a project might be visible. The proposed refined APE is documented/justified in a survey proposal submitted to PA-SHARE. When the survey is conducted, the refined APE is checked for accuracy.

Georgia DOT provides agency cultural resource staff and consultants with supplemental guidance to the Section 106 regulations on defining APEs, to be used on a project-by-project basis (Georgia DOT 2019:12). Separate procedures are provided for architectural resources and archaeological resources, given the varied geographic areas considered for each type of resource. Archaeological APEs are generally defined by the limits of the proposed project footprint, including the existing right-of-way (ROW) and new ROW or easements. For architectural resources, Georgia DOT directs practitioners to consider the following factors.

• Topography
• Vegetation
• Setting
• Physical Siting of a Historic Resource
• Existing/Planned Future Land Use

Washington State SHPO allows practitioners to create and submit a proposed APE to SHPO for review and comment through its digital database system, called WISAARD. Similar to other states’ digital cultural resource databases, WISAARD serves as a repository for architectural and archaeological resources and reports. Specific to WISAARD is the function to create the APE digitally as one of the first steps in the Section 106 process. A 2017 written tutorial and 2022 online tutorial are available online providing instructions for how to complete this task (Washington SHPO 2017, 2022). The instructions direct users to draw a polygon of the APE into the mapping system, indicate whether it is an “above ground” or “below ground” APE, or combined, and complete the submission with an APE consultation letter (Washington SHPO 2022).

Evaluation of National Register Eligibility and Identifying Character-Defining Features

A finding of Adverse Effect applies when “an undertaking 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” (36 CFR § 800.5(1)). To document how a project is affecting a historic property, it is critical to have a thorough understanding of each historic property’s eligibility for the National Register, its character-defining features, and what aspects of its integrity are important to convey the significance of the property.

California SHPO reminds practitioners that all properties change over time and the property must simply retain essential features or characteristics to be listed in or eligible for inclusion in the National Register (California SHPO 2008:9). Condition does not equal integrity.

Exhibit 2.8 of the California Department of Transportation (California DOT) Standard Environmental Reference (California DOT 2020) provides a detailed bulleted list of information required for the description of historic properties that are affected by an undertaking, which includes a form for recording character-defining features:

• Date of NRHP eligibility determination; date of Keeper of the National Register (Keeper) determination of NRHP eligibility, stating that it was a Keeper determination; date of SHPO concurrence with a determination of eligibility, stating that it was a consensus determination; or state that an eligibility consensus determination with SHPO is pending, as applicable.
• NRHP Criteria under which the property is listed or eligible, including a brief reason why and the level(s) and period(s) of significance.
• Brief NRHP boundary description.
• For built environment properties, description of important physical features or character-defining features (CDFs)(California DOT 2020).
• Photographs, particularly views depicting elements of the property subject to direct or indirect effects.
• Photo simulations depicting before and after conditions, if available [California DOT 2020].

California DOT SER guidance also reminds practitioners:

• The evaluation should indicate the property boundary, the period and level (local, state, or national) of significance, and a description of contributing and non-contributing features (California DOT 2020: Chapter 4, Section 4.8.4); and,
• Character-defining features…convey a property’s historic appearance and are indispensable to conveying its historic significance. They define why a property is significance…and when it was significant…These CDFs are critical in assessing integrity and, for eligible properties, determining a project’s effects [California DOT 2020: Chapter 6, Section 6.7.5.2].

Indiana DOT, in addition to including content from 36 CFR 800 and the National Register Bulletin How to Apply the National Register Criteria for Evaluation, provides some more specific direction in and reasoning behind the evaluation of historic properties in its Cultural Resources Manual (Indiana DOT 2022):

• National Register evaluations should clearly show that the NRHP criteria were applied, and that integrity was appropriately considered. Once again, it is critical to frame evaluations in these terms: Significance + Integrity = Eligibility [II.6.12].
• When assessing integrity, it is vital to understand how a property is significant and what aspects of integrity are critical for that property to convey its significance [II.6.12].
• Fully supporting the aspects of integrity that are critical to a property’s significance will help ensure that upon its review, the SHPO concurs to a project findings and recommendations [II.6.12].
• When assessing “adverse effects,” it is important to understand why the property is significant and what aspects of integrity are most critical to convey that significance [II.8.6].
• NRHP evaluations should include the following information [II.6.22-23]:
  • A detailed description of each property highlighting the CDFs of the properties.
  • Mapped location of each resource with at least two photographs.

• • Information must be sufficient to support a NRHP evaluation with photos showing material integrity as best as possible, especially if integrity issues are the main reason for not recommending a property as eligible.
  • Each property must be evaluated against the NRHP Criteria A, B, C, and D – all criteria must be specifically addressed as well as aspects of integrity.
  • Property boundary justifications with descriptions identifying contributing and non-contributing buildings and features. The boundary is particularly important if the project may have a physical impact on the property.

Pennsylvania SHPO in its Guidelines for Projects with Potential Visual Effects in Pennsylvania describes the relationship between integrity and significance and provides guidance on evaluating the visual effects of a project on property’s aspects of integrity:

Integrity is critical to the ability of a property to convey its historic significance. Therefore, when developing a survey, properties in the APE should be considered in light of the criteria for significance and aspects of integrity for which they are significant. Evaluation of whether the introduction of a new feature will adversely affect a property’s aspects of integrity is critical.

In assessing visual effects for historic properties, the criteria for significance and the aspects of integrity provide a qualitative method for determining visual effects on historic properties.

For example, integrity of setting is critical to a farm’s (farm complex and associated lands) ability to convey its agricultural significance. The introduction of a tower or a field of solar panels in the viewshed of the farmstead or the removal of associated landscape features, such as tree lines, woodlots, or field patterns, could alter integrity of setting and feeling. However, if the setting of a property is not critical to understanding its significance (resources significant for architecture alone), then the introduction of a new visual feature or removal of surrounding features may not diminish the integrity of the property [Pennsylvania SHPO 2021].

Boundaries of a Historic Property

Clear definition of historic property boundaries is critical for the assessment of project effects. According to the National Register Bulletin Defining Boundaries for National Register Properties, the selection of boundaries “is a judgement based on the nature of the property’s significance, integrity, and physical setting” (Seifert et al. 1995:2). The bulletin lists the following guidelines for selecting boundaries.

• Select boundaries to encompass but not exceed the extent of the significant resources and land areas comprising the property.
• Include all historic features of the property, but do not include buffer zones or acreage not directly contributing to the significance of the property.
• Exclude peripheral areas that no longer retain integrity due to alterations in physical conditions or setting caused by human forces, such as development, or natural forces, such as erosion.
• Include small areas that are disturbed or lack significance when they are completely surrounded by eligible resources. “Donut holes” are not allowed.
• Define a discontiguous property when large areas lacking eligible resources separate portions of the eligible resource [Seifert et al. 1995:2].

Current property lines (assessor’s parcels) are often the appropriate boundaries for built environment properties in urban and suburban areas, and sometimes for rural properties. Other kinds of boundaries may also be used, such as the original property lines from the period of significance as depicted on historical ownership maps; landscape features such as tree rows, stone walls, or roads; or adjacent modern intrusions. In situations in which the boundary does not correspond to the current legal parcel, California DOT emphasizes that the boundary description needs to provide “a clear rationale, based upon historical significance and historic integrity” (California DOT 2020:6:11).

Georgia DOT procedures call for an “Avoidance and Minimization Measures Meeting” (A3M) during which project designers, environmental experts, and historians and archaeologists meet to discuss the overall project effects (Georgia DOT 2022:3). Prior to this meeting, historic property boundaries are to be sent to the design team and conceptual designs sent back to the cultural staff. Potential impacts to resources are then identified prior to the meeting.

No Adverse Effect Findings Based on the Use of Conditions

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. In relation to the latter, the regulations state in 36 CFR § 800.5(b):

The agency official, in consultation with the SHPO/THPO, may propose a finding of No Adverse Effect when the undertaking’s effects do not meet the criteria of adverse effect or the undertaking is modified or conditions are imposed, such as the subsequent review of plans for rehabilitation by the SHPO/THPO to ensure consistency with the Secretary’s standards for the treatment of historic properties (36 CFR part 68) and applicable guidelines, to avoid adverse effects [underlined for emphasis].

The imposing of conditions on an undertaking to avoid adverse effects, as noted above, is not often conveyed in Section 106 manuals, guidebooks, and other publications by state DOTs, SHPOs, and other agencies. Georgia DOT (2022), Texas SHPO (2022), and Michigan SHPO (2020) mention the condition clause but provide no further guidance on its applicability and/or use.

Montana SHPO, in its guidance on assessing adverse effects, notes that any No Adverse Effect conditions “must directly and completely preserve the significant qualities and integrity of eligible properties” (Montana SHPO 2022).

Arizona DOT guidance on implementing the state’s Section 106 PA identifies a “Finding of No Adverse Effect with Standard Conditions” as a separate finding from No Adverse Effect (Arizona DOT 2021:30). Standard conditions for avoidance according to Arizona DOT include placement of flagging, fencing, or signage around a property to be avoided, and putting avoidance areas on construction plan sheets. Monitoring is also an element of these conditions.

California DOT provides guidance on two types of No Adverse Effect findings with conditions as defined in SER Exhibit 2.2: Concordance between Existing Section 106 Regulations and Section 106 PA:

1. FNAE-SC-ESA: Protection of historic properties from all adverse effects by designation of an Environmentally Sensitive Area (ESA); or
2. FNAE-SC-SOIS: The undertaking consists of maintenance, repairs, rehabilitation or alterations to historic properties and the work can be completed according to the Secretary of the Interior’s Standards for Treatment of Historic Properties (California DOT 2020:Exhibit 2.2, page E-2-2 – 3).

California DOT instructs practitioners to apply the criteria of adverse effect (36 CFR § 800.5(a)(1)) to each historic property and to impose conditions to avoid adverse effects if necessary.

To apply these standard conditions, property boundaries must be defined accurately, CDFs must be clearly understood, and the scope and design of the undertaking must be sufficiently developed to assess potential effects.

Florida DOT’s Cultural Resource Management Handbook includes specific examples of conditions that may be used to make a finding of No Adverse Effect.

• Place fencing or clean fill materials, as appropriate, to minimize adverse effects to a NRHP-eligible archaeological site;
• Rehabilitate the historic property in accordance with the Secretary’s Standards;
• Create an at-grade roadway instead of an elevated roadway that would significantly affect views from and toward the NRHP-listed or eligible property;
• Reroute the roadway in certain areas to go around a NRHP-listed or eligible property;
• Create an earth berm or other form of landscaped barrier to limit visual and audible intrusion into a NRHP-listed or eligible property or district;
• Redesign lanes, curb, sidewalk, and other roadway improvements to be compatible in design, scale, and materials with the existing NRHP-listed or eligible property or district. For example, reuse or match existing street paving or sidewalk paving materials (brick, hexagonal pavers, etc.);
• Retain or replant existing landscape elements (trees, shrubs, or grass) and/or other boundary elements (fences, walls, etc.) along the roadway ROW; and/or
• Use signs, street lighting, traffic lighting, etc. that will be compatible with the NRHP-listed or eligible property or district [Florida DOT 2013:8-3].

As outlined in Ohio DOT’s Cultural Resource Manual, when it is determined that an undertaking will have an Adverse Effect on historic properties, Ohio DOT, SHPO, and FHWA will begin to evaluate “measures to avoid, minimize, or mitigate the undertaking’s adverse effect” (Ohio DOT 2021). Ohio DOT explains that “the intent is to identify any measures or solutions that could be implemented so that a No Adverse Effect determination might be made, thus avoiding an Adverse Effect to historic properties” (Ohio DOT 2021). Some site/property-specific strategies to reach such a finding of No Adverse Effect (with conditions) suggested by Ohio DOT include but are not limited to the following.

• Aesthetic treatments
• Avoidance
• Informing/educating the public
• Publishing a professional paper
• Moving and re-using a historic bridge
• Alternative construction techniques
• Vibration monitoring
• Minimization of ROW take from within a NRHP boundary
• Resource protection by fencing
• Landscaping

Commonalities in Assessing and Documenting Findings of No Effect and No Adverse Effect

The literature review identified a number of commonalities in the guidance, publications, manuals, PAs, tools, and forms outlined above that support and document well-reasoned and defensible determinations of No Effect and No Adverse Effect⁴:

• Guidelines and/or manuals on Section 106 procedures that include chapters/sections on findings of No Historic Properties Affected and No Adverse Effect. These guidelines and/or manuals often provide explicit, detailed guidance for documenting determinations of No Effect and No Adverse Effect.
• Combining cultural resource inventory results, determinations of National Register eligibility, and assessment of effects in one submittal to SHPO and other consulting parties.
• Providing effects determinations for both the project as a whole (following the Section 106 regulations) and individual properties within a project’s APE.
• PAs with alternative procedures for making findings of No Effect and No Adverse Effect, that is, not following the standard process laid out in the Section 106 regulations but using a more streamlined, state-specific customized approach.

As noted, several state DOTs and SHPOs provide explicit guidance through guidelines, manuals, forms, and templates on the key elements that support and document thorough and well-reasoned determinations of No Effect and No Adverse Effect, such as descriptions of an undertaking, delineation of an APE, National Register eligibility criteria, description of historic property boundaries, and a discussion on a historic property’s CDFs and aspects of integrity.

Another commonality is the practice of combining the methods and results of historic property identification efforts with findings of effect into one submittal to SHPO and other consulting parties. Oregon and Vermont, for example, use these combined submittals. Not all SHPOs may accept this approach, however, and it is advisable for state DOTs and their consultants to discuss the appropriateness of combining the Section 106 steps into a single coordination with their respective SHPO prior to submitting the project for review.

Some state DOTs, including Alaska and Colorado, request a finding of effect for each individual historic property as well as a finding of effect for the overall project. Other states, like Colorado, also require that information on the nature of project activities within or adjacent to each historic property be included as part of the finding of effects documentation.

In terms of statewide PAs, half of the reviewed agreements provide alternative procedures for making No Effect and No Adverse Effect findings. Alternative procedures include shorter timeframes for review of findings by SHPO and other consulting parties and allowing state DOTs to make a finding of No Historic Properties Affected without SHPO concurrence or FHWA involvement. In the case of the latter, findings made without consultation are documented in an annual report or other type of reporting that is provided to SHPO and the other signatories to the PA.