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Tennessee Environmental Procedures Manual

Chapter 5: Impact Analysis

5.3 Technical Studies and Other Impact Analyses

5.3.1 Overview

Technical studies are completed both to assist in developing the location and design of a project build alternative or alternatives and to provide a comparison of environmental impacts between the no-build and build alternative(s) and between build alternatives if more than one is under consideration.

The timing for the study phases may differ depending on the project development process being utilized by TDOT for the individual project. Field or baseline studies may be completed first as part of the environmental screening process for the Context Sensitive Solutions (CSS) or Transportation Planning Report (TPR) processes. The comprehensive impact analysis would come later, with full consideration given to the identified environmental factors. If conceptual plans are generated during the pre-NEPA transportation planning process, baseline studies, fieldwork and the impact analysis may be done at the same time.

Sources for guidance on the preparation of the required NEPA analyses are discussed in the applicable sections in this chapter. Guidance is also available in FHWA's 1987 Technical Advisory 6640.8A (Technical Advisory, hereafter), which is available in Appendix D [pdf 201 kb] of this report and at http://www.environment.fhwa.dot.gov/projdev/index.asp.

The section below describes the technical studies that are needed for the NEPA analysis. For each technical study, the discussion includes the applicable regulations, who should prepare the study, overview of the study process, agency or public involvement required, and mandated review times that could affect the project schedule.

The technical studies are prepared by technical specialists within TDOT or by consultants. Environmental Division technical staff or planners will generally oversee and review consultant studies or may request studies to be completed by other TDOT offices. Once the studies are completed, Environmental Division technical staff, planners or consultants will summarize the study findings for the NEPA document.

Listed below are the technical studies described in this chapter:

  • Cultural Resources (architectural/historical and archaeological);
  • Natural Resources (threatened and endangered species, wetlands, water quality, terrestrial and aquatic resources);
  • Noise;
  • Air Quality;
  • Hazardous Materials;
  • Conceptual Stage Relocation Plan; and
  • Soils and Geology.
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5.3.2 Cultural Resources (Section 106 and Section 4(f))

5.3.2.1 Applicable Regulations

The two primary federal laws that apply to transportation projects and their impacts to cultural resources are:

  • Section 4(f) of the Department of Transportation Act; and
  • Section 106 of the National Historic Preservation Act.

Cultural resource investigations are conducted for compliance with Section 106 of the National Historic Preservation Act of 1966 (NHPA), as amended (codified as 36 CFR 800), with Section 4(f) of the Department of Transportation Act of 1966 (now codified as 23 USC 774), as well as NEPA. This section focuses on the NHPA; Section 4(f) is described in Section 5.3.9.

The Federal Interstate Highway System was initially designed and constructed in the 1950s, meaning this massive infrastructure system is now over 50 years old, the typical threshold for properties to be considered potentially "historic." In 2005, however, the Advisory Council on Historic Preservation (ACHP) adopted the "Section 106 Exemption Regarding Effects to the Interstate Highway System," which exempted the bulk of the 46,700-mile federal Interstate system from consideration as a historic property under Section 106. Also in 2005, SAFETEA-LU regulations included a provision (Section 6007) that exempts the bulk of the Interstate System from consideration as a historic property under Section 4(f). Therefore, planners are no longer required to consider the federal Interstate system as a potentially historic resource.

However, under Section 106, certain elements of the Interstate system, such as bridges, tunnels and rest areas can be excluded from this exemption if these resources are designated by FHWA as "nationally and exceptionally significant features" (ESF) and potentially eligible for the National Register. In December 2006, the FHWA published the final list of ESFs in the Federal Register. The list can be found at http://www.environment.fhwa.dot.gov/histpres/highways_list.asp. The only designated ESFs in Tennessee are the I-40 Hernando DeSoto Bridge (1973) and the I-55 Memphis & Arkansas Bridge (1949), both connecting Memphis, Tennessee, with West Memphis, Arkansas, over the Mississippi River.

Cultural resources include prehistoric and historic archaeological sites and historic bridges, buildings, structures, sites, objects, and districts. The purpose of cultural resource investigations is to consider the impact of federally funded undertakings on properties, sites, buildings, structures and objects that are listed in, or may be eligible for listing in, the NRHP. The criteria of adverse effect, the standard by which effects to historic properties are measured, are included in 36 CFR 800.

A historic property, as defined in regulation 36 CFR Section 800.16(l)(1), is any cultural resource included in, or eligible for listing in, the NRHP. A cultural resource is eligible for listing in the NRHP if it meets one or more of the four NRHP Criteria and retains sufficient integrity to convey historic significance.

National Register of Historic Places (NRHP) Eligibility Criteria

The NRHP Criteria states that the quality of significance is present in cultural resources when resources:

  1. Are associated with events that have made a significant contribution to the broad patterns of our history; or
  2. Are associated with the lives of persons significant in our past; or
  3. Embody the distinctive characteristics of a type, period, or method of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant and distinguishable entity whose components may lack individual distinction; or
  4. Have yielded, or may be likely to yield information important in prehistory or history.

In addition to significance, a property must also have integrity of location, design, setting, materials, workmanship and feeling to be eligible for listing in the NRHP. This means that not only must a resource be of sufficient age; it must also retain many of its original features and be significant under one or more of the four criteria listed above.

Typically, the following types of cultural resources are not eligible for listing in the NRHP: religious properties, moved properties, birthplaces or graves, cemeteries, reconstructed properties, commemorative properties, and properties that have achieved significance within the last 50 years. Such resources, however, may be eligible for listing in the NRHP, under special circumstances. For example, a property less than 50 years old could be eligible if it is an integral part of an eligible historic district, or it could be eligible for other reasons, which are outlined in the NRHP regulations (36 CFR 60).

Two types of cultural resources need to be identified to satisfy the requirements of Section 106 of the National Historic Preservation Act of 1966:. architectural/historical resources (e.g., above ground buildings and structures) and archaeological resources (e.g., underground sites). For federally-funded transportation projects, TDOT conducts the Section 106 required studies on behalf of FHWA.

The oversight of the archaeological and architectural/historical studies needed to satisfy Section 106 falls to the TDOT Archaeology Program Manager and the Historic Preservation Program Manager. Their staff may perform the needed studies or may contract the work to a consultant. If contracted, TDOT requires that an archaeologist be utilized to perform the archaeological survey and an architectural historian perform the architectural survey. If contracted out by TDOT, the architectural/historical and archaeological studies do not necessarily need to be done by the same firm and can be contracted separately. If contracted to a consultant, the work must be done according to TDOT cultural resource scopes of work, which can obtained from the Archaeology Program Manager and the Historic Preservation Program Manager.

The purpose of the studies is to identify architectural/historical resources or archaeological sites that are listed in or eligible for listing in the NRHP and to assess a project's effects to such resources. The first step in this process is to define the project's Area of Potential Effect (APE).

Area of Potential Effect (APE)

The geographic area or areas within which an undertaking may directly or indirectly cause changes in the character or use of historic properties, if any such properties exist. The area of potential effects is influenced by the scale and nature of an undertaking and may be different for different kinds of effects caused by the undertaking.

36 CFR 800.16 (d)

The APE will differ between architectural/historical resources and archaeological resources. For example, the architectural/historical resource APE for a highway improvement project may encompass areas that:

  1. Could be affected by noise;
  2. Could be affected by traffic increases;
  3. May have changes in access;
  4. Are within the viewshed of the proposed improvements; and
  5. Would be physically affected by the project.

Only #5 above, areas of direct physical impact, would be considered as the APE for an archaeological survey. It is important to note, however, that the archaeological APE could also include areas of construction staging, borrow areas and areas of cut and fill. In addition, construction staging areas and borrow areas could be considered to be within the APE for historic resources.

Within the framework of the Section 106 process, the impact analysis is referred to as the "determination of effect." Functional or conceptual plans, or other more detailed plans, are needed to undertake the effects assessment.

Effects determinations are made by applying the Criteria of Adverse Effects as defined in 36 CFR 800.5 to each identified NRHP listed or eligible cultural resource. This involves the consideration of several factors, including whether the project will alter the characteristics that qualify the historic property for listing in the NRHP.

In accordance with Section 106, a project can result in one of the following findings:

  • No Historic Properties Affected, indicating that a project will not affect the characteristics or qualities of an NRHP listed or eligible resource;
  • No Adverse Effect, indicating that a project has an effect on a historic resource, but that this effect does not have a negative affect to the historic characteristics or qualities of the resource; or
  • Adverse Effect, indicating that a project has a negative effect on a historic resource.

If historic resources are potentially adversely affected, TDOT must seek ways to avoid, minimize or mitigate impacts through the consultation process, which is described below.

5.3.2.2 Agency Coordination and Public Involvement

A cornerstone of the Section 106 process is the identification of the appropriate parties that need to be involved in the process of assessing effects of a proposed project to historic properties and working through the process with such parties. This "involvement" is referred to as "consultation." Additional description of the early steps in the Section 106 "consultation process," i.e., those that occur during early coordination, can be found in Section 4.3.4.2, Section 106 Initial Coordination.

Consultation is required with the Tennessee SHPO. In addition, the Advisory Council on Historic Preservation (ACHP) must be afforded a reasonable opportunity to comment on the undertaking. The Section 106 regulations also require the federal agency or its designee to consult with certain other entities and involve the public in the process of assessing a project's effects to historic resources.

The Section 106 regulations specify that federally recognized Native American tribes that may attach cultural or religious significance to properties within a project study area be given the opportunity to participate in the project as Section 106 "Consulting Parties." The Section 106 Consultation with American Indian Tribes in Tennessee manual, developed by the FHWA Tennessee Division, should be used for determining the appropriate tribes to contact for proposed projects.

TDOT must also contact local governments and, if such government elects to participate as a consulting party in the 106 process, they do so as consulting parties. As a result of TDOT's NEPA initial coordination mail-out to historical groups known to have an interest in the area or through other correspondence or meetings, additional parties may be identified and invited by the agency to serve as consulting parties. For TDOT projects, the decision regarding the designation of additional consulting parties ultimately lies with FHWA.

For some projects, Section 106 coordination may begin prior to the NEPA process and/or the mailing of initial coordination packages. For example, such coordination may occur during the TPR process.

For EA or EIS documents, the first outreach effort to the SHPO, Native American tribes, local government and parties with historic preservation interests generally occurs in the NEPA initial coordination stage. At that time, the Environmental Division cultural resource staff will prepare a special Section 106 mail-out. The Historic Preservation and Archaeology Sections maintain a list of parties with historic preservation interests, which is sorted by county, and a list of Native American tribes that are potential consulting parties in Tennessee.

The second phase of outreach occurs after technical studies have been completed. (In both the historic and archaeological areas, studies are or can be phased. If that is the case, outreach should occur after each phase). As applicable, the completed technical study will be sent by the respective TDOT Cultural Resource Program Manager to the SHPO office for review and comment. A copy of the cultural resource study, the management summary, or a pertinent study excerpt will be sent to all Section 106 consulting parties, and to the ACHP if adverse effects are identified under 36 CFR 800.

If adverse effects are found, TDOT must work with the SHPO, the ACHP if they choose to participate, and Section 106 consulting parties to identify ways to avoid, minimize or mitigate project effects. The measures agreed upon are included in a Memorandum of Agreement (MOA), which is a legally binding document and is signed, at a minimum, by the SHPO and FHWA and concurred with by TDOT. FHWA may also invite other parties to sign the MOA as concurring parties. The implementation of the measures included in an MOA is discussed in Section 9.3.1, Cultural Resources, of Chapter 9, Environmental Commitments.

5.3.2.3 Study Process for Architectural/Historical Resources

The architectural/historic study can begin as early as the environmental screening phase. The goal of the study is to identify historic resources that are listed in or eligible for listing in the NRHP and identify effects to such historic resources, pursuant to 36 CFR 800. It is undertaken either by the Historic Preservation Section or by consultants.

A records search is required to identify previously surveyed cultural resources in the proposed project corridor, to identify NRHP listed or previously determined eligible historic properties and to identify whether any properties in the project corridor are currently under consideration for nomination to the NRHP. This research can help in establishing the alignment and serves as the basis for field work to be conducted in the project corridor.

The first step in the survey process entails examination of historical records and literature with the intent to identify previously recorded resources that may be important to understanding the area's resources and can provide a historic background, or context, of the project area. The historic context provides a basis against which cultural resources may be evaluated using the NRHP Criteria of Evaluation.

Century Farms

Century Farms are designated by the Tennessee Department of Agriculture program. For properties that might have agricultural significance, the Environmental Division Historic Preservation Section or its consultant must check with the Tennessee Century Farms Program, Center for Historic Preservation at Middle Tennessee State University in Murfreesboro for contextual information on the significance of the property.

Center for Historic Preservation
MTSU, Box 80
Murfreesboro, TN 37132
615-898-2300
http://www.mtsuhistpres.org/

Once the records check is complete, a field survey is undertaken. The purpose of the architectural survey is to make an assessment concerning the presence of properties in the project vicinity that are either listed in, or eligible for listing in, the NRHP. The architectural historian will survey an area large enough to encompass all potential historic properties within the project's APE.

While it is not necessary to inventory every building or structure that is at least 50 years old in the APE, the architectural historian should inventory any potentially historic properties in the APE. If there are properties either listed in or potentially eligible for listing in the NRHP (even if they are not being affected) in the immediate vicinity of the project impact area, these should be inventoried. Two primary reasons for this are to illustrate to the public and agencies that TDOT has an awareness of the existence of the property in proximity to the project and to assist in developing project modifications and alignment shifts needed to avoid other sensitive areas (e.g., archaeology, ecology, hazardous materials).

Following the survey, the findings regarding NRHP eligibility will be compiled in a report that is submitted to the SHPO for review and concurrence. Sometimes the survey data are presented in a stand-alone report, which is submitted to the SHPO for concurrence with the NRHP eligibility findings and boundaries. At other times, the survey report is combined with the assessment of effects report.

The survey report will provide an architectural description of each inventoried property, general historical information about it, and a brief discussion of each support building (historic and modern). For each property, the report author must provide an opinion regarding its NRHP eligibility. For all listed or eligible resources, the existing or potential NRHP boundaries must be illustrated on a map. The historical/architectural survey must be coordinated with the SHPO.

The SHPO must comment on the findings of effect and the comment letter must be included in an appendix of the NEPA document. The Section 106 regulations allow 30 days for the report review to occur, however, the SHPO can respond within that 30-day period and request additional information or disagree with the report findings. This can substantially increase the review time.

If adverse effects are found, the Historic Preservation Program Manager will coordinate the effort to examine ways to avoid, minimize, or mitigate project effects with the SHPO, the ACHP if they are participating and any Section 106 consulting parties. This generally occurs after the NEPA public hearing and the selection of a preferred alternative. All measures agreed upon are included in a Memorandum of Agreement (MOA), a legally binding agreement prepared pursuant to Section 106 if properties will be adversely affected by a project. A copy of the fully executed MOA must be included in an appendix of the final NEPA document.

A copy of TDOT's guidelines for historic and architectural surveys and effect determinations is contained in the Appendix.

5.3.2.4 Study Process for Archaeological Resources

The archaeology study can begin in the environmental screening phase for a corridor study or whenever functional or more detailed conceptual plans are available. The goal of the study is to identify resources that are listed in, or eligible for listing in, the NRHP and identify effects to such resources, pursuant to 36 CFR 800. If NRHP resources are adversely affected, FHWA, TDOT, SHPO and project-specific consulting parties must examine ways to avoid those effects. If avoidance is not feasible, then TDOT or the consultant must develop a plan for minimization and mitigation of adverse effects. Typically archaeological mitigation involves excavation for the recovery of significant information. All of the measures to be taken to minimize and mitigate a project's adverse effects are stipulated in an MOA. Once approved by the FHWA and the SHPO, TDOT implements the agreed-upon measures.

The first step in the survey process entails examination of historical and archaeological records and literature with the intent to identify previously recorded resources and develop cultural/historical contexts that may be important to understanding the area's resources. The records check includes examination of the site file maps and accompanying site survey forms at the TDEC Division of Archaeology.

The second step involves field work, which is almost always undertaken by a consultant. Prior to commencing work, the consultant is required to make a good faith effort to contact landowners and must secure a permit from the TDEC Division of Archaeology. This survey will involve a visual inspection, a systematic pedestrian examination of exposed ground surfaces, and shovel testing of land having poor surface visibility. Limited deep soil sampling to ascertain whether buried archaeological deposits are present is also required. The completion of site survey forms is required for all identified archaeological sites. The data collected will be analyzed and then the findings of the literature search and field work and analysis are presented in a written report. The report must present sufficient information to allow evaluation of whether additional investigation is warranted to determine NRHP eligibility. This report will be reviewed by Environmental Division archaeologists and then, through the FHWA, sent to the project-specific consulting parties for a 30-day review period as provided in the regulations. After questions and comments about the report are addressed, a final report is prepared and distributed to the consulting parties.

The Phase I Archaeological Survey (consisting of the two steps described above) not only identifies cultural resources listed or eligible for inclusion in the NRHP, but it also identifies cultural resources requiring additional testing to evaluate their NRHP eligibility.

Between the draft and final environmental documents, if it is determined that a site or sites on the selected alignment require additional testing, it is currently TDOT's policy to attempt first to avoid the sites. The Environmental Division archaeology staff coordinates with the project planner and designer to determine whether the subject site or sites can be avoided. If it is not feasible to avoid the sites, Phase II testing of the sites identified in Phase I will occur within the proposed right-of-way limits. The Phase II work, which must be completed prior to the approval of the final environmental document, is almost always undertaken by a consultant. It focuses on excavation of 15 to 20 percent of a site's area within the right-of-way, often employing the use of heavy equipment to determine whether undisturbed archaeological deposits are present that would meet the NRHP eligibility criteria. Right-of-way will not yet have been purchased. If an amicable arrangement cannot be made with the landowner to conduct the archaeological work on the site, the process will be carried forward by TDOT's legal office.

The fieldwork includes clearing, plowing and disking the direct impact zone to enhance surface visibility and then conducting controlled surface collection and subsurface excavation. The artifacts are then analyzed in the laboratory. The Phase II findings are presented in a report, which evaluates the NRHP eligibility of the site and provides recommendations for future work. Justification must be presented for suggested mitigation measures. If a site is considered NRHP eligible and recovery of significant data is recommended, a preliminary research design and data recovery plan must be included in the report. The Phase II testing report is distributed by FHWA to the project-specific consulting parties for a 30-day review in accordance with the Section 106 regulations.

Any mitigation agreed upon will be described in an MOA, which must be included in an appendix to the NEPA document. The MOA must be fully executed and may also include agreed-upon cultural resource mitigation. Archaeological mitigation measures may involve archaeological data recovery, which is referred to as Phase III, or Recovery of Significant Data (RSI). Phase III is most often undertaken after right-of-way has been acquired. All mitigation work must be completed before FHWA will authorize construction. The SHPO must also be notified when the field work has been completed and offered the opportunity to conduct an inspection.

It is important to note that precise archaeological location data (written descriptions and maps) are not made available to the public in order to eliminate the distribution of this information to potential "treasure hunters" and to diminish the potential of looting of archaeological sites.

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5.3.3 Natural Resources

5.3.3.1 Applicable Regulations

In addition to NEPA, a number of federal and state laws pertain to the consideration and evaluation of natural resources. The list includes:

  • The Clean Water Act (CWA) 33 U.S.C. 1251 et seq. (1977)
  • The Endangered Species Act (ESA); 7 U.S.C. 136; 16 U.S.C. 1531 et.seq. (1973)
  • Fish and Wildlife Coordination Act 16 U.S.C. 661-667
  • Executive Order 11988, Floodplain Management
  • Executive Order 11990, Protection of Wetlands
  • Tennessee Non-game and Endangered or Threatened Wildlife Species Conservation Act of 1974
  • Tennessee Rare Plant Protection and Conservation Act of 1985
  • Tennessee Water Quality Control Act of 1977 (T.C.A. 69-3-101)

5.3.3.2 Study Process for Natural Resources

Ecological evaluations are conducted by consultants or by the Environmental Division's Natural Resources Office - Ecology Section. Both terrestrial and aquatic surveys must be conducted by qualified biologists. Biologists must be familiar with the regulations listed above and with the Environmental Division's current Scope of Work for Ecological Studies.

The initial step in the assessment of natural resources is a records check (the records check process is described in Section 5.2.2). The next step is a field review by a qualified biologist of all alternative alignments being considered. The field survey includes an area 250 feet on either side of the centerline of the proposed alignments. For a bridge project, the field study must include an area 150 feet on either side of the centerline of the proposed alignments, to include any area needed for temporary detours. Biologists identify the presence or absence of:

  • Streams that may be affected by construction (including those that may be crossed, those that are parallel to the alignment and may be relocated, and those that are potentially affected only by sediment in runoff);
  • Wetlands;
  • Types of plant and animal species that occur in the area;
  • Federal- and State-listed threatened and endangered species (including critical habitats);
  • Waterfowl refuges;
  • Wildlife management areas;
  • Caves;
  • Springs or seeps;
  • Sink holes; and
  • Potential mitigation sites.

Streams. Biologists examine all defined channels within the direct project impact area. They will use the TDEC approved stream determination protocols, once developed, for making any watercourse determinations. For both channels that show as "blue-lines" on USGS topographic maps and other discernible channels encountered during field surveys, the biologist determines and documents whether the channel is a stream or a wet-weather conveyance, and clearly identifies the channel as such in the Ecological Boundaries and Mitigation Memorandum.

The substrate at each stream crossing and the canopy shading percentage and tree species composition are described. Aquatic fauna and flora are noted.

Wetlands. Biologists describe the location, type, size, and characteristics of wetlands within the project impact area, including:

  • Soils;
  • Hydrology;
  • Vegetation; and
  • Functions and Value.

The total area of wetlands present and the area likely to be filled are estimated and the impacts that will result from project construction are discussed. Possible wetland mitigation sites are included in the report, as well as the type of water quality permits that may be required (Section 404, Individual or General Aquatic Resource Alteration Permits or ARAPs, see Chapter 9, Permits). Wetland determinations are made using the Level 2 routine determination method described in the 1987 USACE Wetlands Delineation Manual.

Federal- and State-Listed Species. The first step in the process of investigating threatened and endangered (T&E) species is to send a coordination letter requesting a species list to the U.S. Fish and Wildlife Service (FWS). Next, a TDOT biologist will conduct a database review of the occurrence records maintained by the TDEC Division of Natural Areas (DNA), as well as other applicable sources (such as the Tennessee Valley Authority (TVA)) to determine if there are known occurrences of state or federally listed species near a proposed project. When a species review indicates known occurrences for state listed animals near a project, the TDOT biologist shall coordinate with TWRA to address these species. TDOT biologists will provide TWRA with the list of species that were noted during the database review as well as a brief project description. TWRA personnel review this information and provide comments regarding the potential project impacts to the listed species. The TWRA may also provide direction and notes that will protect the species of concern.

When the species review indicates state listed plants are near a project, the TDOT biologist shall determine if coordination with the DNA is required and only coordinate with DNA if it is believed a listed plant may be impacted by the proposed project or if additional information is needed regarding a state listed plant. If coordination is warranted, TDOT biologists will provide DNA with the list of plant species that were noted during the database review as well as a brief project description. DNA personnel review this information and provide comments regarding the potential project impacts to the listed species. The DNA may also provide direction and notes that will protect the species of concern.

Information regarding the species review and coordination is then incorporated into the Ecological Boundaries and Mitigation Memorandum. A one-page topographical map showing the recorded locations of state or federally listed species should be included in the memorandum.

To determine the presence or absence of listed species, both terrestrial and aquatic, field reviews of the project area shall be conducted. Sufficient time should be taken at each site to reasonably determine the presence or absence of listed species and any suitable habitats.

Descriptions of any state or federally listed species or federally designated critical habitats observed during the field survey are included in the memorandum. The memorandum also documents the presence or absence of suitable habitats for state or federally listed species appearing in FWS correspondence or identified during the DNA database review. It addresses all listed species (terrestrial and aquatic) recorded within a four mile radius of the project, stating whether suitable habitat for each identified species occurs within the project impact zone and the likely project impacts on each, differentiating whether the project is likely to physically harm the identified species, whether the identified species are likely to be affected by sedimentation only, or whether the identified species are unlikely to be affected by the project. It is intended that the species review sufficiently address downstream aquatic impacts so as to meet the requirements of the Tennessee Construction General Permit for Storm Water Discharges.

If FWS provides a list of protected species in response to the request for information, or if federally protected species are located within the project impact area, a separate Biological Assessment (BA) is prepared following the guidelines issued pursuant to Section 7(c) of the Endangered Species Act. If suitable habitat for a federally listed species is present, either simple or complex field studies will be required to determine impacts. Complex studies include scuba surveys or mist-netting are usually conducted by consultants with specialized expertise and the appropriate FWS license. Occasionally, complex studies are conducted by other agencies and the results provided for inclusion in the BA.

The completed BA shall be transmitted by Environmental Division to FWS via the FHWA. The BA contains a reference to the date of the species list provided by FWS, as well as the complete project route, termini, county, and log mile description. A conclusion is made in the BA as to whether a project will have no effect on each federally listed species, or whether it may affect each species. If it is determined that the project may affect the species, a further determination is made whether the effect is likely to be adverse or not. If it is determined that the project may affect the species, TDOT immediately requests the initiation of formal consultation with FWS via the Federal action agency.

Reports. The Ecology Report, required by NEPA, is a summary of the conditions in the field. It is prepared initially as part of the planning process and is an overview of the potential alignment ecological impacts. The Ecology Report is a preliminary report that may cover several alignments and provides insight into the potential impacts a specific alignment may have on ecological resources.

The Environmental Boundaries Study and Mitigation Memorandum is developed once a single alignment is determined and is prepared prior to preparation of any necessary permit assessment or application. This memorandum ensures that species impacts and mitigation needs for the field survey are addressed and is sent to all appropriate parties within TDOT for roadway development and permit assessment and/or permit application. The memorandum describes the project setting, terrain, land use, vegetation, and terrestrial and aquatic habitats and discusses the impacts the proposed construction may have on plants, animals, streams, and wetlands. It describes the substrate at each stream crossing and the canopy along the stream banks, as well as impacts the proposed construction may have on water quality.

The memorandum highlights sensitive areas (wetlands, glades, critical habitat, natural areas, wildlife refuges, and management areas), and includes a color topographic map showing the study boundaries and labeled color photographs. Tabular formats for project data are encouraged. Sensitive areas, as well as streams and wet-weather conveyances are labeled on the topographic map in a manner consistent with the labeling protocols defined in TDOT's Mitigation Practices manual (May 2007) found at /sswmp/pdfs/Mitigation.pdf. Photos include upstream and downstream views, as well as views of the surrounding land use. For bridge projects and approach projects and widening and drain projects, photos should include views of the existing highway and its surroundings. Copies of correspondence with other agencies are included in the memorandum. If a USDA Soil Survey is available for the area, a soil map with the hydric soils and soils with hydric inclusions (highlighted) is placed in the report.

The Environmental Division staff member or consultant should identify potential onsite mitigation areas for stream and/or wetland mitigation during the field survey, and mitigation areas should be documented in the Ecological Boundaries and Mitigation Memorandum. A primary focus of the field survey should be to identify impacts and mitigation opportunities on a project well before design is completed and right-of-way obtained.

The results of the technical investigations must be summarized in the Ecological Boundaries and Mitigation Memorandum, the format of which is prescribed in Scope A of the current Scope of Work for Ecological Studies. The memorandum should be made available to the IPPT. The results of the memorandum should be incorporated into the project commitments.

Once the final alternative is selected and design plans are received, studies are usually repeated in more detail to ensure that nothing has been missed and to prepare detailed minimization and mitigation strategies and documents.

Impact, Avoidance and Minimization. If the Ecology Report is prepared as part of a Transportation Planning Report (TPR) study, the biologist provides advice and assistance to enable the TPR consultant to avoid and minimize ecological impacts, specifically those to streams, wetlands, springs, and protected species. In all other project phases, the TDOT ecology staff coordinates impact avoidance and minimization with the staff of the Environmental Division and the Design and Structures Divisions. Ecology section staff coordinates stream mitigation design with the Environmental Division's Environmental Design Group (once established) to ensure that natural channel design is considered to avoid in-lieu fees, where possible and practicable. Projects requiring complex mitigation or minimization activities require close coordination with construction staff during planning and design as well as during construction.

Deliverables. The consultant should submit two copies of the Draft Ecological Report and Ecological Boundaries and Mitigation Memorandum with color copies of the maps and photographs. After the Environmental Division Ecology Section staff reviews the draft report and memorandum, the consultant shall make any needed changes to these documents. The consultant, on written approval of the draft reports, will prepare and submit the original photographs, two hard copies, one electronic copy of the final documents with color copies of the maps and photographs. If a BA is required, the consultant should submit four hard copies and one electronic copy with color copies of maps, photographs, and the USFWS letter containing the species list. The Final Ecological Report is to be used by the planner for insertion into the NEPA document ecology section(s). The final Ecological Boundaries and Mitigation Memorandum is used to transmit more detailed ecology information internally within TDOT.

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5.3.4 Noise

Pursuant to requirements set forth by the Federal Highway Administration (FHWA), the Tennessee Department of Transportation's (TDOT's) Noise Policy, Policy on Highway Traffic Noise Abatement, provides the requirements for the evaluation of highway traffic noise and the consideration of noise abatement when noise impacts are predicted.

The purpose of these noise procedures is to provide detailed technical guidance for conducting highway traffic noise studies for federal, federal-aid and state-funded highway projects in accordance with federal regulations and TDOT's Noise Policy.

5.3.4.1 Legislation, Regulations and Policies

5.3.4.1.1 NEPA

The National Environmental Policy Act of 1969 (NEPA) established a national policy on the environment and created the Council on Environmental Quality (CEQ). The purpose of NEPA is to minimize or eliminate damage to the environment caused by actions funded or taken by the federal government. NEPA provides broad authority and responsibility for evaluating and mitigating adverse environmental effects including those resulting from highway traffic noise.

5.3.4.1.2 1970 Federal-Aid Highway Act

The Federal Aid Highway Act of 1970 (FAHA 1970) mandated that FHWA develop noise standards for identifying noise impacts and evaluating noise mitigation for federal projects. FAHA 1970 also stipulated that FHWA should not approve plans and specifications for federal projects unless the project includes adequate noise abatement measures to comply with the standards.

5.3.4.1.3 FHWA Noise Standards (23 CFR 772)

FHWA developed noise standards in response to the requirements set forth in FAHA 1970. These standards have been modified over time as summarized below:

  • 1973 - Policy and Procedures Manual (PPM) 90-2.
  • 1976 - Federal Highway Procedures Manual 7-7-3 (FHPM 773).
  • 1982 - Procedures for Abatement of Highway Traffic Noise and Construction Noise, 23 CFR 772.
  • 1997 - Procedures for Abatement of Highway Traffic Noise and Construction Noise, 23 CFR 772: Revised eligibility for Type II projects.
  • 2005 - Procedures for Abatement of Highway Traffic Noise and Construction Noise, 23 CFR 772: Revised to require FHWA's Traffic Noise Model (TNM) for highway traffic noise analyses.
  • July 13, 2010 - Procedures for Abatement of Highway Traffic Noise and Construction Noise, 23 CFR 772: Revised to add definitions and to clarify the applicability of the regulation, certain analysis requirements, and the use of Federal funds for noise abatement measures.

The purposes of the FHWA Noise Standards are to:

  • Provide procedures for noise studies and noise abatement measures to help protect public health and welfare and livability;
  • Supply noise abatement criteria (NAC); and,
  • Establish requirements for information to be given to local officials for use in the planning and design of highways.
5.3.4.1.4 FHWA Guidance

On June 12, 1995 FHWA issued a memorandum requiring states to adopt written statewide noise policies. These written state policies must be approved by FHWA and demonstrate "substantial compliance" with FHWA's noise standards contained in 23 CFR 772.

FHWA concurrently published the document, Highway Traffic Noise Analysis and Abatement: Policy and Guidance (FHWA's Guidance), to aid states in developing their policies. This guidance document was updated in 2010 to ensure consistency with the July 13, 2010 revision of 23 CFR 772.

State agencies have some flexibility in establishing their highway traffic noise policies and procedures in accordance with 23 CFR 772. However, all policies must be reviewed and approved by FHWA before they can become effective.

5.3.4.1.5 TDOT's Noise Policy

TDOT's Noise Policy, Policy on Highway Traffic Noise Abatement, was developed in accordance with 23 CFR 772 (July 13, 2010) and FHWA's Guidance (December 2010). TDOT's Noise Policy was approved by FHWA on April 19, 2011 and became effective on [insert date]. TDOT's Noise Policy outlines the process that TDOT uses to make decisions on highway traffic noise abatement and to justify the expenditure of public funds in the most cost-effective manner when addressing the total needs of the state's highway system. TDOT's Noise Policy is located at http://www.tn.gov/tdot/environment/airnoise/pdf/TDOTNoisePolicy520-01.pdf.

5.3.4.2 Qualifications Necessary to Conduct Noise Studies

Only individuals (TDOT or consultant staff) qualified in the field of highway traffic noise analysis shall conduct highway traffic noise studies for TDOT projects or local projects that will utilize federal or state funding.

In order to be qualified, the person performing the analysis must have 1) demonstrated experience in conducing highway traffic noise analyses for transportation projects in accordance with 23 CFR 772, 2) familiarity with TDOT's Noise Policy, and 3) demonstrated experience conducting noise measurements in accordance with FHWA-PD-96-046, "Measurement of Highway-Related Noise."

Qualified individuals must have successfully completed the following formal training before conducting work on TDOT noise studies:

  • Highway Traffic Noise Analysis Training; and,
  • FHWA Traffic Noise Model (TNM) Training.

TDOT may request that analysts provide documentation of the above training before or during the conduct of a noise study. TDOT may also request documentation of other noise studies that the analyst has completed.

5.3.4.3 Definitions

The following definitions are used in these Procedures.

Abatement - measures used to reduce traffic noise levels. The use of quieter pavements and the planting of vegetation are not acceptable Federal-aid noise abatement measures for Federal projects.

Ambient Noise - all-encompassing sound that is associated with a given environment.

Approach - as used in 23 CFR 772.5(g), one-hour equivalent sound levels [Leq(1h)] that are one decibel or less below the levels shown in Table 5-2.

Attenuation - reduction of the level of sound or noise.

Average Daily Traffic (ADT) - the average number of vehicles passing a specific point in a 24-hour period (vehicles per day).

A-Weighted Sound Level (dBA) - the sound level in decibels measured with a frequency weighing network corresponding to the A-scale. The A-scale tends to suppress lower frequencies (e.g. below 1,000 Hz) and best approximates the sound as heard by the human ear.

Benefited Receptor - the recipient of an abatement measure that receives a noise reduction at or above the minimum threshold of 5 dBA regardless of whether or not the receptor is "impacted."

Common Noise Environment - a g - a group of receptors within the same Activity Category in Table 5-3 that are exposed to similar noise sources and levels; traffic volumes, traffic mix and speed; and topographic features. Generally, common noise environments occur between two secondary noise sources such as interchanges, intersections or cross-roads.

Date of Public Knowledge - the date of approval of the Categorical Exclusion (CE), the Finding of No Significant Impact (FONSI), or the Record of Decision (ROD), as defined in 23 CFR 771.

Decibel (dB) - a measure used to express the relative level of a sound in comparison with a standard reference level. For traffic noise purposes, the A-weighted scale, which closely approximates the frequency response of the human ear to typical environmental sound levels, is used. The A-weighted sound level in decibels has the unit dBA.

Design Year - the future year used to estimate the probable traffic volume for which a highway is designed, typically 20 years into the future.

Design Hour Volume (DHV) - the DHV is typically the thirtieth highest hourly traffic volume for the design year, commonly twenty years from the time of construction. The DHV is given in units of vehicles per hour.

Existing Noise Level - the existing worst one-hour equivalent sound level in dBA resulting from the natural and mechanical sources and human activity present in a particular area.

Feasibility - one of two criteria (also see "reasonableness") used to evaluate a noise abatement measure. Feasibility deals with engineering considerations and the ability to achieve a 5 dB noise reduction.

First-Row - receptors directly adjacent to the highway with no intervening developed lands.

Frequent Human Use - any activity that results in prolonged human exposure to traffic noise on a regular basis over the course of a year in a given location.

Future Noise Level - the predicted worst one-hour equivalent sound level in dBA in the design year.

Impacted Receptor - a receptor that has a traffic noise impact.

Insertion Loss - the reduction in Leq(1h) at a location after a noise barrier is constructed.

K- Factor - a percentage applied to the Average Daily Traffic (ADT) to determine the Design Hour Volume (DHV).

LAeq - the A-weighted equivalent steady-state sound level that in a stated period of time contains the same acoustic energy as the time-varying sound level during the same time period.

LAeq(h) - the hourly value of LAeq.

Multifamily Dwelling - a residential structure containing more than one residence. Each residence in a multifamily dwelling shall be counted as one receptor when determining impacted and benefited receptors.

Noise - unwanted sound.

Noise Abatement Criteria (NAC) - the Noise Abatement Criteria shown in Table 5-3 of these Procedures.

Noise Barrier - a physical obstruction that is constructed between the highway noise source and the noise sensitive receptor(s) that lowers the noise level, including stand alone noise walls, noise berms (earth or other material) and combination berm/wall systems.

Noise Reduction Design Goal - the predicted minimum noise level reduction provided by the noise abatement measure. TDOT's noise reduction design goal is 7 dB and must be achieved at 60% or more of the first-row benefited receptors. If a reduction of 7 dB at 60% or more of first-row benefited receptors cannot be met, the abatement measure would not be considered reasonable.

NEPA - the National Environmental Policy Act.

Permitted - a definite commitment to develop land with an approved specific design of land use activities as evidenced by the issuance of a building permit.

Property Owner - an individual or group of individuals that holds a title, deed or other legal documentation of ownership of a property or residence.

Reasonableness - one of two criteria (also see "feasibility") used to evaluate a noise abatement measure. Reasonableness weighs the amount of required noise barrier area against the benefits that would be provided by the barrier.

Receptor - a discrete or representative location of a noise sensitive area(s), for any of the land uses listed in Table 5-3.

Residence - either a single family residence or each dwelling unit in a multifamily dwelling.

Shielding - any man-made or natural structure or barrier that provides an auditory barrier between a receptor and a roadway. For example, the top of a cut or an intervening hill.

Sound Level Meter - a device used to measure sound levels. A sound level meter is also called a sound level analyzer or dosimeter.

Statement of Likelihood - a statement provided in the environmental clearance document based on the feasibility and reasonableness analysis completed at the time the environmental document is being approved.

Substantial Construction - the granting of a building permit, prior to right-of-way acquisition or construction approval for the highway. This definition applies to Type II projects only.

Substantial Noise Increase - an increase in existing noise levels as defined in Table 5-2 of these Procedures.

Substantial Noise Reduction - a minimum reduction in traffic noise levels of at least 7 dB at the majority of impacted first-row receptors.

Traffic Noise Impacts - impacts that occur when the predicted design year traffic noise levels for the Build Alternative(s) approach or exceed the NAC or when the predicted design year traffic noise levels for the Build Alternative(s) substantially exceed the existing noise levels.

Type I Project - a project shall be considered Type I if it meets one of the following conditions:

  • (1) The construction of a highway on new location; or,
  • (2) The physical alteration of an existing highway where there is either:
    • (i) Substantial Horizontal Alteration. A project that halves the distance between the traffic noise source and the closest receptor between the existing condition to the future build condition; or,
    • (ii) Substantial Vertical Alteration. A project that removes shielding, therefore, exposing the line-of-sight between the receptor and the traffic noise source. This is done by either altering the vertical alignment of the highway or by altering the topography between the highway traffic noise source and the receptor; or,
  • (3) The addition of a through-traffic lane(s). This includes the addition of a through-traffic lane that functions as a High-Occupancy Vehicle (HOV) lane, High-Occupancy Toll (HOT) lane, bus lane or truck climbing lane; or,
  • (4) The addition of an auxiliary lane, except for when the auxiliary lane is a turn lane; or,
  • (5) The addition or relocation of interchange lanes or ramps added to a quadrant to complete an existing partial interchange; or,
  • (6) Restriping existing pavement for the purpose of adding a through-traffic lane or an auxiliary lane; or,
  • (7) The addition of a new or substantial alteration of a weigh station, rest stop, ride-share lot or toll plaza.
  • (8) If a project is determined to be a Type I project under this definition, then the entire project area as defined in the environmental document is a Type I project.

Type II Project - a Federal or Federal-aid highway project for noise abatement on an existing highway.

Type III Project - a Federal or Federal-aid highway project that does not meet the classifications of a Type I or Type II project. Type III projects do not require a noise analysis.

Worst Noise Hour - a one-hour period during the day that represents the peak noise hour.

5.3.4.4 Traffic Noise Terminology

Traffic noise levels are expressed in terms of the hourly, A-weighted equivalent sound level in decibels (dBA). A sound level represents the level of the rapid air pressure fluctuations caused by sources such as traffic that are heard as noise. A decibel is a unit that relates the sound pressure of a noise to the faintest sound the young human ear can hear. The A-weighting refers to the amplification or attenuation of the different frequencies of the sound (subjectively, the pitch) to correspond to the way the human ear "hears" these frequencies. Generally, when the sound level exceeds the mid-60 dBA range, outdoor conversation in normal tones at a distance of three feet becomes difficult. A 9-10 dB increase in sound level is typically judged by the listener to be twice as loud as the original sound while a 9-10 dB reduction is judged to be half as loud. Doubling the number of sources (i.e., vehicles) will increase the hourly equivalent sound level by approximately 3 dB, which is usually the smallest change in hourly equivalent A-weighted sound levels that people can detect without specifically listening for the change.

Because most environmental noise fluctuates from moment to moment, it is standard practice to condense data into a single level called the equivalent sound level (Leq). The Leq is a steady sound level that would contain the same amount of sound energy as the actual time-varying sound evaluated over the same time-period. The Leq averages the louder and quieter moments, but gives much more weight to the louder moments in the averaging. For traffic noise assessment purposes, Leq is typically evaluated over the worst one-hour period and is defined as Leq (1h).

The term insertion loss (IL) is generally used to describe the reduction in Leq (1h) at a location after a noise barrier is constructed. For example, if the Leq (1h) at a residence before a barrier is constructed is 75 dBA and the Leq (1h) after a barrier constructed is 65 dBA then the insertion loss would be 10 dB.

5.3.4.5 Noise Study Requirements

Per 23 CFR 772 and TDOT's Noise Policy, noise studies must be conducted for highway projects that are determined to be Type I.

5.3.4.5.1 Type I Projects

Per the definition in Section 5.3.4.3, Type I projects are proposed Federal or Federal-aid highway projects for the construction of a highway on new location or the physical alteration of an existing highway that significantly changes either the horizontal or vertical alignment or increases capacity.

A detailed noise analysis is required if the project meets the definition of a Type I project. Noise analyses are not required for projects that are Type III regardless of the level of NEPA document.

Per the definition, a project that halves the distance between the traffic noise source and the closest receptor is a Type I project. When assessing whether a project will halve the distance between the noise source and a receptor, the measured distance should be the smallest distance between the receptor and the center of the nearest travel lane.

5.3.4.5.2 Noise Impact Screening for Type I Projects

There will be cases when it is unclear whether a Type I project will result in noise impacts based on the NAC.

These cases might include widening projects on low to medium volume roads, and projects where potentially impacted land uses are located at distances where impacts would not normally be expected. In these cases, a screening analysis should be completed to determine whether a noise study is warranted.

Any Type I project that might result in impacts due to a substantial increase in sound levels requires a noise study.

The screening level steps are summarized below.

  • Determine if noise-sensitive land uses exist that might be impacted by the project. If the project will not affect noise-sensitive land uses, then a noise study is not needed.
  • If noise-sensitive land uses exist that may or may not be impacted by the project, TNM should be used with simplifying assumptions to predict whether noise impacts would be expected. If the predicted sound levels are within 5 dB of the NAC for the identified noise-sensitive land use(s), then a noise study is needed. If predicted sound levels are more than 5 dB lower than the NAC, then a noise-study is not needed.

The screening analysis should involve a review of project plans as well as aerial photography from web-based mapping sites such as Google Maps (http://maps.google.com) or Bing Maps (http://www.bing.com/maps), web-based city or county GIS sites, or data from the County Property Assessor (http://www.assessment.state.tn.us/). A site visit may be required to establish if any recent development has occurred. The municipal planning or codes department should also be contacted to determine if any building permits have been issued in the project area.

The results of the screening procedure and the conclusion that a noise study is not needed should be summarized in the environmental document along with discussions of information for local officials and construction noise per Sections 5.3.6 of these Procedures.

5.3.4.5.3 Type II Projects

TDOT is required by federal law to evaluate noise abatement for new highway construction and widening projects. However, there is no federal requirement for State DOTs to construct noise barriers along existing highways adjacent to impacted communities that were in place before the highways were built. Such stand-alone "retrofit" noise barrier projects are referred to as Type II projects. Following the completion of detailed Type II Noise Barrier Needs and Cost Assessment and Noise Barrier Prioritization Studies, TDOT initiated a Type II Noise Barrier Program in 2005.

To be eligible for a Type II noise barrier, an area must meet the following criteria:

  • The neighborhood must be located along a limited-access roadway;
  • The neighborhood must be primarily residential;
  • The majority (more than 50%) of residences in the neighborhood near the highway pre-dated the initial highway construction;
  • A noise barrier for the neighborhood must not have been previously determined to be not reasonable or not feasible as part of a new highway construction or through-lane widening study (Type I project);
  • Existing noise levels measured in the neighborhood must be above the Noise Abatement Criteria (NAC) of 66 dBA;
  • A barrier must be feasible to construct and will provide substantial noise reduction;
  • A barrier must be reasonable in accordance with TDOT's Noise Policy. A residence is considered "benefited" if the noise barrier will reduce the traffic noise by at least 5 dB; and,
  • A majority of the impacted residents (>50%) must support the construction of the noise barrier.

TDOT's Type II studies resulted in a list of eligible Type II projects. This list is available at URL http://www.tn.gov/tdot/environment/airnoise/default.htm. This list includes all of the areas that have been identified for inclusion in TDOT's Type II Program and represents TDOT's prioritized list of Type II projects.

The order in which these projects are programmed will depend on many factors including funding limitations; requirements for lane closures (particularly on urban interstates); other nearby interstate construction projects; a strong likelihood that an area will get a barrier as part of a Type I project; geographic considerations; right-of-way and utility requirements; and the need to retrofit existing bridges with noise barriers.

TDOT will review the Type II project list on an annual basis and will select projects from the list for programming based upon a comprehensive consideration of the above factors.

5.3.4.6 Noise Study Methodology and Procedures

The primary goal of conducting noise studies is to ensure that the information derived and related conclusions are accurate and pertinent to the decision-making process.

In order to facilitate this goal, noise studies should 1) accurately identify all noise-sensitive land uses that are predicted to be impacted under each Build Alternative in the design year, and 2) properly assess the noise abatement measures listed in Section 5.3.4.6.6 for impacted land uses.

This section provides the detailed framework for conducting a highway traffic noise study in Tennessee. Noise studies should include the following tasks:

  • Identification of noise-sensitive land uses: Identification of existing land uses in the project area that are sensitive to highway traffic noise;
  • Determination of existing sound levels: Measurement and/or prediction of existing worst-hour sound levels at noise-sensitive land uses to characterize the existing noise environment in the project area;
  • Determination of future sound levels: Prediction of design year worst-hour sound levels for the No-Build and Build Alternatives;
  • Determination of traffic noise impacts: Determination of traffic noise impacts based on the increase in existing sound levels and predicted design year sound levels;
  • Noise abatement evaluation: Evaluation of noise abatement measures for noise-sensitive land uses predicted to be impacted by the project;
  • Discussion of construction noise; and,
  • Provision of information for local officials.

Each of these steps and all analysis results should be thoroughly documented in a Noise Technical Report for the project. Each of these analysis steps is discussed in detail below following a discussion of TDOT's criteria for determining noise impacts.

5.3.4.6.1 Criteria for Determining Impacts

Traffic noise impacts may occur when either the predicted noise level at a receptor approaches or exceeds the NAC or when there is a substantial increase in noise as a result of the project. Both criteria are defined below.

Substantial Increase

Highway traffic noise impacts will occur if there is a substantial increase in design year noise levels above existing noise levels as shown in Table 5-2.

Noise Abatement Criteria (NAC)

Highway traffic noise impacts will also occur when the design year noise levels approach, equal, or exceed the FHWA's noise abatement criteria (NAC) shown in Table 5-3.

Table 5-2 Substantial Noise Level Increase
Existing Noise Level (dBA) (1) Predicted Design Year Noise Level Increase (dB) (2)
42 or less 15 or more
43 14 or more
44 13 or more
45 12 or more
46 11 or more
47 or more 10 or more

(1) Worst hour noise level from the combination of natural and mechanical sources and human activity.

(2) Predicted design year noise level minus existing noise level.

Noise Abatement Criteria

[Hourly A-weighted Sound Level, decibels (dB(A))]

Table 5-3 Noise Abatement Criteria
[Hourly A-weighted Sound Level, decibels (Db(A))]
Activity Category LAeq(h) Evaluation Location Activity Description
A 57 Exterior Lands on which serenity and quiet are of extraordinary significance and serve an important public need and where the preservation of those qualities is essential if the area is to continue to serve its intended purpose.
B(1) 67 Exterior Residential.
C(1) 67 Exterior Active sport areas, amphitheaters, auditoriums, campgrounds, cemeteries, day care centers, hospitals, libraries, medical facilities, parks, picnic areas, places of worship, playgrounds, public meeting rooms, public or nonprofit institutional structure, radio stations, recording studios, recreation areas, Section 4(f) sites, schools, television studios, trails, and trail crossings.
D 52 Interior Auditoriums, day care centers, hospitals, libraries, medical facilities, places of worship, public meeting rooms, public or nonprofit institutional structure, radio studios, recording studios, schools, and television studios.
E(1) 72 Exterior Hotels, motels, offices, restaurants/bars, and other developed lands, properties or activities not included in A-D, or F.
F --- --- Agriculture, airports, bus yards, emergency services, industrial, logging, maintenance facilities, manufacturing, mining, rail yards, retail facilities, shipyards, utilities (water resources, water treatment, electrical), and warehousing.
G --- --- Undeveloped lands that are not permitted.

(1) Includes undeveloped lands permitted for this activity category.
Source: 23 CFR 772, July 2010.

TDOT's Noise Policy defines "approach" as one decibel below the NAC.

The NAC are not arbitrary. The NAC are based upon noise levels associated with interference of speech communication and are a compromise between noise levels that are desirable and those that are achievable. The NAC should not be viewed as desirable noise levels and they should not be used as design goals for noise barrier construction.

5.3.4.6.2 Identification of Noise-Sensitive Land Uses

Traffic noise analysis should be performed for 1) developed lands containing noise-sensitive land uses, and for 2) undeveloped lands where noise-sensitive development is permitted.

Land uses that are sensitive to highway noise will generally be identified based on review of project plans, aerial photography from web-based mapping sites including Google Maps (http://maps.google.com) and Bing Maps (http://www.bing.com/maps), web-based city or county GIS sites, and data from the County Property Assessor (http://www.assessment.state.tn.us/).

The municipal planning or codes department should also be contacted to determine if any building permits have been issued in the project area.

For most projects, the availability of these mapping resources should eliminate the need for separate field reviews to identify noise-sensitive land uses. Unresolved questions regarding noise-sensitive land uses and other site related concerns can generally be addressed during the conduct of noise measurements.

The Noise Technical Report should include a summary of the existing land uses in the project area.

Developed Lands

Developed lands that should be identified and included in the noise study include Category A, B, C and E land uses with exterior areas of frequent human use, as well as qualifying Category D uses.

If, in TDOT's opinion, a land use within the project limits is worthy of consideration as a Category A land use, TDOT will prepare and submit a "Proposal for Justification for Designating Land Use as Category A" to the FHWA Division Office.

Category C and E land uses should be assessed to identify any areas of frequent human use. Specific locations of human use that are exposed to traffic noise on a regular basis over the course of a year would qualify as frequent human use areas that should be assessed for noise impacts.

Category C and E frequent human use areas could include exterior sitting or eating areas, playgrounds, pools or other similar locations where people may gather for extended periods. Parking lots and sidewalks are not considered to be frequent human use areas.

For campgrounds, frequent human use areas might include dedicated camp sites or picnic areas. For cemeteries, frequent human use areas might include exterior areas where services are held on a regular basis but would generally not include individual grave sites.

If a Category C land use has both exterior and interior areas of frequent human use, the exterior area should be analyzed for impact as Category C. If there are no exterior areas of frequent human use, or the exterior area is far from or physically shielded from the roadway in a manner that prevents an impact on the exterior areas, then the interior area should be analyzed for impact as Category D.

TDOT should be consulted during the conduct of the noise study if there is uncertainty regarding whether an area qualifies as a frequent human use area.

Permitted Development

Per TDOT's Noise Policy, development is deemed to be "permitted" if there is a definite commitment to develop land with an approved specific design as evidenced by the issuance of a building permit.

The noise study should include lands for which development is "permitted" at the date of public knowledge for the project. The date of public knowledge is the date that a project's final environmental document (i.e. CE, FONSI, or ROD) is approved by FHWA.

Undeveloped Lands

Category G land uses are undeveloped lands that should be addressed as part of the "Information for Local Officials" described in Section 5.3.4.6.13 of these procedures. Lands used for agriculture that are included in Category F should also be addressed the in "Information for Local Officials" section.

5.3.4.6.3 Determination of Existing Noise Levels

The determination of existing noise levels will generally be made utilizing field measurement of actual sound levels and/or the prediction of existing sound levels.

Existing noise levels should be determined using one of the following methods

  • Method 1: Measurement of Existing Noise Levels
  • Method 2: Prediction of Existing Noise Levels
  • Method 3: Measurement and Prediction of Existing Noise Levels (including validation)

The method selected for each project should consider several factors including the type of project (i.e. widening or new alignment); facility type; the extent, level of detail, and accuracy of the data available to complete noise modeling for existing conditions; the number of expected impacts; the potential need for evaluation of noise abatement measures; and the effect on the decision-making process. TDOT's Environmental Division should be consulted to determine the proper method to be used for each project

Method 1: Measurement of Existing Noise Levels

This method should be used for Type I projects involving the construction of a roadway on a new alignment. This method should also be used on Type I projects when the extent, level of detail, and/or accuracy of data for existing conditions is not sufficient to support the development of an accurate noise model for existing conditions.

All measurements should be conducted in accordance with the detailed procedures outlined later in this section. Use of these procedures will ensure that the existing worst-hour noise levels at noise-sensitive uses in the project area are accurately determined and reported.

Method 2: Prediction of Existing Noise Levels

This method could be used for projects located in areas where the existing noise environment is dominated by traffic noise from an existing highway, arterial or local road; where the number of impacts is expected to be low or the impacts will be isolated; and where conditions clearly indicate that noise abatement will not be feasible and/or reasonable. This method should not be used for projects involving interstate facilities or similar major highways. TDOT will consider whether this method should be used on a case-by-case basis.

IF TDOT determines that TNM modeling of existing conditions is necessary, then the procedures outlined in Section 5.3.4.6.4 should be used.

Method 3: Measurement and Prediction of Existing Noise Levels (including validation)

There may be some projects for which both noise measurements and modeling of existing conditions may be needed to facilitate validation of the TNM model. These projects might include large or controversial widening projects; projects where there is uncertainty as to whether impacts will occur; and projects that are likely to include reasonable and feasible noise abatement measures. TDOT will consider whether this method should be used on a case-by-case basis.

Noise Measurements

Noise measurements should be conducted in accordance with FHWA-PD-96-046, "Measurement of Highway-Related Noise" and using the procedures described below.

Noise Measurement Locations

Measurement sites should generally include exterior areas of Category B, C and E land uses.

Noise measurement sites should be selected according to the purpose of the measurement and should be representative of the area of interest, meaning that the sound level at a measurement location is representative of that location and any nearby locations.

Generally, sites should be selected that will be exposed to the highest sound levels generated by the project for each project alternative. All sites should be representative of areas of frequent human use.

Measurement sites should be clear of obstructions and the microphone should be located at least 10 feet (3 meters) from any reflective surfaces. Sites should be free of contamination by sources such as barking dogs, HVAC noise, etc.

Interior measurements are generally not needed and would only be made in situations where there are no exterior areas of frequent human use. TDOT should be consulted before interior noise measurements are conducted for any project.

Noise Measurement Data Sheets

TDOT's standard noise measurement data sheets should be used. The data sheets are available at http://www.tn.gov/tdot/environment/airnoise/default.htm.

A noise measurement data sheet should be completed for each measurement location, and copies of the noise measurement data sheets should be provided in an appendix of the Noise Technical Report.

Each noise measurement data sheet should provide a detailed site sketch including appropriate distance measurements. The following information should be noted as applicable:

  • Microphone height
  • The roadway elevation relative to the elevation of the measurement location (i.e. in cut, on fill, at-grade)
  • An indication whether the road is on a grade or at-grade
  • Type of intervening ground
  • Any surfaces or areas that could affect sound levels such as ponds, lakes, and parking areas
  • Existing structures including residences, garages, barns, commercial and industrial buildings, noise barriers and fences
  • Significant existing terrain features such as the berms, crests of hills, and drainage ditches
  • Locations and density of areas of trees and/or vegetation
  • A description of any non-traffic noise sources including aircraft and/or train operations, commercial and industrial activities, etc.
  • Calibration results
  • Wind speed and direction
  • Temperature

Field staff conducting noise measurements must wear Type III safety vests and should carry proper identification. Consultants conducting measurements should obtain a measurement explanation letter from TDOT before conducting any field work. This letter will explain the purpose of the measurements and should be provided to residents, business owners, law enforcement, etc. who inquire about the purpose of the measurements.

Equipment

Measurements should be conducted using an ANSI Type I or II sound level meter using slow time weighting.

A windscreen shall be used and should be of a type specified by the microphone manufacturer as suitable for the particular microphone.

Sound level meters should be calibrated at the beginning and end of each measurement and the results should be noted on the noise measurement data sheet.

Noise Measurement Times

Sound levels will vary by location and time of day depending on the proximity of noise-sensitive land uses to roads and other background noise sources. Additionally, sound levels can vary with changes in meteorological conditions including shifts in wind speed and direction, and changes in the vertical temperature profile.

Although long-term measurements would more fully characterize the existing noise environment, collection of long-term data at many sites requires significant time, effort and cost. In most cases, the additional data would not significantly change the conclusions regarding the number and locations of noise impacts and the associated need to consider noise abatement.

As a result, a combination of long-term and short-term noise measurements should be conducted to aid in characterizing the existing noise environment in the project area.

Long-Term Measurements

Existing sound levels should be representative of the worst noise hour. The highest traffic volume at the highest average speed usually creates the noisiest conditions. The peak traffic hour may be the worst noise hour if traffic is free-flowing. However, the worst noise hour may occur at other times of the day due to traffic congestion and changing speeds, as well as fluctuations in the number of heavy trucks throughout the day. In most cases, the worst noise hour will occur between 6:00 am and 7:00 pm.

One or more long-term measurements (8 to 12 hours) should be conducted to identify changes in sound levels throughout the day and to aid in identifying the worst noise hour. Long-term measurements should generally include the morning and/or afternoon peak periods.

The noise environment at long-term measurement sites should generally be dominated by traffic noise from the study roadway. Long-term sites should be isolated from local traffic noise sources and other sources of potential contamination.

The long-term monitor does not have to be attended during the entire course of the measurement. However, it is recommended that field staff return to the monitor site several times during the measurement period(s) to ensure that the sound level meter continues to function properly.

The number of long-term measurements will depend on the number of alternatives and the variation in sound levels throughout the day. Long-term measurements are generally not needed to establish background noise levels in areas where no significant traffic noise sources exist, such as near new roadway alignments in rural areas. Short-term measurements can generally be used to establish background sound levels in these areas.

The long-term measurement data should be recorded in one minute intervals to allow for removal of non-representative, intrusive events. After the measurement is conducted, the data should be thoroughly reviewed to ensure that the reported data is representative of traffic noise levels. One-minute periods where it is clear that recorded sound levels were influenced by random non-traffic noise sources (i.e. intermittent lawn equipment, sirens, etc.) should be eliminated.

The long-term measurement data should be used to calculate sound levels for each hour of the long-term measurement period, and to identify the worst noise hour. The long-term data should also be used to develop adjustments to apply to the short-term measurements to arrive at existing worst-hour sound levels at the short-term measurement sites.

Short-Term Measurements

Short-term measurements should be conducted during the long-term measurements at times when traffic is relatively free-flowing. The short-term measurements should be adjusted to represent worst-hour noise levels during the measurement period as described above. Short-term measurement data should be recorded in one minute intervals to allow for removal of non-representative, intrusive events.

The duration of the short-term measurement will depend on the density of traffic on the study roadway. Noise measurements near high volume roads can be of shorter duration than measurements near low volume roads. General guidance for determining the minimum duration of short-term measurements is provided in Table 5-4.

Table 5-4 Short-Term Measurement Durations
Traffic Volume (vehicle/hour/lane) Minimum Duration (minutes)
High (>1000) 15
Medium (500-1000) 20
Low (<500) 30

Meteorological Conditions

Meteorological conditions can affect sound levels and sound propagation, particularly at long distances.

Measurements should not be conducted when the wind speed(s) at the microphone exceeds 11 mph (5 m/s), regardless of wind direction. Wind speed should be monitored and reported on the noise measurement data sheet.

There is no set limit on temperature during noise measurements. However, the ambient temperature must be noted on the noise measurement data sheet.

Pavement Conditions

Noise measurements should only be conducted when road surfaces are dry. Road surfaces should also be free of extraneous material such as gravel.

Data Analysis

The measured sound level data should be imported into spreadsheet tables and any measurement intervals that are contaminated due to unrepresentative noise sources, high wind, or other factors should be eliminated.

5.3.4.6.4 Determination of Design Year Sound Levels

No-Build Alternative

For most projects, sound levels for the No-Build Alternative in the design year should be predicted by evaluating existing and design year traffic volumes on the roadway network. Background sound levels in areas that are not affected by highway traffic noise should generally not be increased.

The increase in sound level from the existing year to the design year can be estimated using the following equation.

Increase in sound level = 10 log (1+N/10)

where: N = Percent increase in traffic between existing and design year

For example, doubling the traffic on a roadway would result in a 3 dB increase in the sound level at a given receptor assuming all other conditions remain the same. Similarly, an increase in existing traffic volumes of 60% would results in an approximate 2 dB increase in sound levels. In this case, design year sound levels would be approximately 2 dB higher than existing sound levels.

If the percentage of trucks is projected to increase significantly between the existing year and the design year for the No-Build Alternative, then a more detailed analysis would be needed to determine the projected sound level increase.

Additionally, the projected No-Build traffic volumes for the design year should be reviewed to determine if the design hour volumes could be accommodated at free-low traffic conditions. If the projected traffic volumes would result in decreases in travel speeds, the traffic volumes should be analyzed to identify the percent increase in traffic volume that could be accommodated during the worst noise hour at free-flow traffic conditions.

Build Alternative(s)

Noise modeling of the Build Alternative(s) should be completed using the most recent version of the FHWA Traffic Noise Model (TNM) computer program. The program should be used to calculate design year noise levels at the noise-sensitive land uses in the project area, including the measurement sites.

In TDOT's experience, requiring detailed and accurate modeling of the Build Alternative(s) in the design year is the best way to ensure 1) the best estimates of design year sound levels for all receptors and 2) the most accurate accounting of the impacts resulting from the project.

TNM is a complex model requiring numerous inputs and modeling assumptions. As a result, TDOT developed "TDOT Guidelines for Traffic Noise Modeling Using TNM" to ensure consistency in modeling practices and enable comparison of results. The TNM Guidelines are available at:

http://www.tn.gov/tdot/environment/airnoise/default.htm.

The guidelines have been developed based on TDOT's TNM noise modeling experiences for numerous projects across the state, and are intended to provide supplementary information to analysts who are skilled in both traffic noise modeling and in the use of TNM.

The TNM model should include the following for all Build Alternatives:

  • The proposed roadway alignment including all existing and proposed ramps and intersections;
  • Local roads that contribute to the noise environment;
  • Receivers;
  • Existing noise barriers or large buildings that act as noise barriers;
  • Terrain features including intervening hills, tops of cuts, and bases of fills;
  • Rows of buildings that provide shielding; and,
  • Intervening ground zones that will affect sound propagation including parking lots and bodies of water.

All TNM runs developed for the project shall be transmitted to TDOT electronically or on a disk at the time any draft or final report is submitted.

Mapping

The following mapping should be used in the development if the TNM models as available:

TNM Roadways

The proposed roadway alignment including all existing and proposed ramps and intersections should be modeled. Local roads that contribute to the noise environment should also be modeled.

The direction of travel should be properly modeled for each TNM roadway. No more than two lanes of travel should be combined into a single TNM roadway.

The actual width of the roadway pavement should be modeled including travel lanes and shoulders. Additionally, the outside edge of pavement should be modeled as close as possible to the actual location.

All appropriate flow devices including on-ramps, stop signs, traffic signals, and toll booths should be modeled.

Traffic

Design year sound levels should be predicted for the worst-noise hour which would normally occur when the highest traffic volume can travel at the highest possible speed.

Traffic projections developed for the project typically include traffic volumes for the "design hour," which is often representative of Level of Service (LOS) C operating conditions. These design hour volumes (DHVs) should be used for the noise analysis since they represent the highest number of vehicles expected to travel on the roadway network in a given hour.

The DHVs should be modeled at the planned posted speed for the Build Alternative(s) since modeling DHVs at posted speeds provides a conservative estimate of worst-hour noise levels.

If the projected traffic volume is less than the LOS C volume. Those lesser volumes should be used. The source of the traffic data used for the TNM modeling should be documented in the Noise Technical Report.

Traffic projections for the project should also include truck projections. If the percentage of trucks for the design hour is not provided, then the percentage of trucks during the design hour should be assumed to be two-thirds of the projected percentage of trucks on a daily basis. The split between medium trucks and heavy trucks should be based on traffic classification counts if they are available. If classification counts are not available, a split should be requested from TDOT's Planning Division.

The Noise Technical Report should include a table summarizing the projected traffic volumes for each modeled TNM roadway. The traffic projections should be included in an appendix of the Noise Technical Report.

TNM Receivers

Traffic noise analysis should be preformed for Category B, C and E land uses with areas of frequent human use as well as for FHWA-approved Category A land uses. The analysis should also include qualifying Category D uses and Category G undeveloped land where development is permitted.

Receivers should be modeled at all noise measurement sites.

Category B Land Uses

For residences, receivers should typically be located in areas near the residences where frequent human use would be expected such as patios, decks, balconies, common grounds or areas such as swimming pools, playgrounds, or other appropriate locations.

Receivers should be located in areas of the property that are oriented toward the project roadway. Therefore, receivers may need to be located to represent front porch or yard locations. Generally, receivers should be located approximately 10 feet from the residence.

Often, residences will have decks that are elevated above the ground. These locations can be modeled for the purpose of identifying impacts and counting benefits. However, noise abatement will generally not be designed for these locations.

Upper story locations such as those at apartments and condominiums should be modeled for the purpose of identifying impacts and counting benefits. Noise abatement might be designed for these locations as discussed in Section 5.3.4.6.6.

A single receiver can represent more than one residential unit as long as the units would be expected to have comparable existing and design year sound levels.

Category C Land Uses

Receivers should be located at frequent human use areas of Category C land uses. Areas of frequent human use must be exposed to traffic noise on a regular basis over the course of a year. These locations might include exterior sitting or eating areas.

For campgrounds, these areas might include dedicated camp sites. For cemeteries, these areas might include exterior areas where services are held on a regular basis but would generally not include individual grave sites.

If a Category C land use has both exterior and interior areas of frequent human use, the exterior area should be analyzed for impact as Category C.

Category D Land Uses

If there are no exterior areas of frequent human use or the exterior area is far from or physically shielded from the roadway in a manner that prevents an impact on the exterior areas, then the interior area should be analyzed for impact as Category D.

Receivers should be modeled at exterior areas of these properties facing the highway. After the TNM predictions are made, interior noise levels should be estimated in accordance with FHWA's Guidance. FHWA's procedure requires that the type of building construction be identified and documented. A determination whether the building would normally operate under "closed windows" conditions should then be made. The appropriate sound level reduction from Table 5-5 for building attenuation should be applied to the predicted exterior noise level to arrive at the predicted interior noise level. This level should be compared to the NAC for Activity Category D land uses to determine if interior impacts are predicted.

Table 5-5 Building Noise Reduction Factors
Building Type Window Condition Reduction
All Open 10 dB
Light Frame Ordinary Sash (closed) 20 dB
Storm Windows 25 dB
Masonry Single Glazed 25 dB
Double Glazed 35 dB
* The windows shall be considered open unless there is firm knowledge that the windows are in fact kept closed almost every day of the year.

Source: FHWA's "Highway Traffic Noise Analysis and Abatement: Policy and Guidance."

There may be situations where it is desirable to develop noise reduction factors through the conduct of additional field measurements or more detailed acoustical analysis. TDOT will determine the need for interior measurements on a case-by-case basis.

Category E Land Uses

Receivers should be modeled at exterior frequent human use areas of Category E land uses such as exterior restaurant seating areas, pools or playgrounds.

Exterior areas of commercial properties including sidewalks and parking areas are not considered to be areas of frequent human use.

Number of Receivers

The number of modeled TNM receivers for a project should be adequate to facilitate an accurate count of the number of impacts that will result from each Build Alternative.

For a project with a large number of residences, it is not necessary to model at every residence. One receiver can represent multiple residences if the location is considered to be acoustically representative of several residences.

If noise barriers are being evaluated, enough receivers should be modeled to ensure an accurate count of the number of benefits.

A table that indicates the number of residences being modeled by each receiver should be included in the Noise Technical Report.

The analyst should exercise judgment in determining the distance at which receivers should be modeled. Consideration should be given to the distance within which impacts are expected, as well as where benefits might occur if noise abatement is evaluated.

For projects involving widening existing roads or interchange modifications, a distance of 500 to 600 feet from the road should generally be sufficient. However, the distance within which impacts might occur will often be much greater for projects involving construction of a road on a new alignment.

The analyst should be aware that unique site conditions such as a high percentage of trucks or the existence of intervening "hard" ground, such as paved areas or bodies of water, might also result in impacts at greater distances that would normally be expected.

Receiver Elevations

Receiver elevations should closely approximate actual ground elevations. The elevation datum should be Mean Sea Level (North American Vertical Datum of 1988 or National Geodetic Vertical Datum of 1929). If a different datum is used, then a discussion of the datum should be included in the Noise Technical Report.

First-floor receivers should generally be modeled 5 feet (1.5 m) above the ground and second-floor receivers should generally be modeled 15 feet (4.5 m) above the ground.

Receiver Names

Generally, receivers should be named by designating the address of the property where the receiver is located. Address information can be obtained at

http://www.assessment.state.tn.us/, http://tnmap.state.tn.us/assessment/map.aspx or various county GIS websites.

An alternative method of receiver naming is to designate the receiver as first (1), second (2), third (3) or subsequent row relative to the roadway. The relative location is then followed by a hyphen, the first two letters of the local street on which the receiver is located, and the station of the adjacent roadway being modeled. For example, a second-row receiver on Green Street near STA 335+00 would be designated as 2-GR335.

Existing noise barriers or noise barriers that are being evaluated as abatement measures should be modeled, as well as any structures that act like noise barriers such as median barriers, parapet walls and large buildings.

Median Barriers

If the future typical cross section shows that a median barrier will be constructed, the median barrier shall be modeled in TNM at the proposed location(s) and height(s).

Parapet Walls

Parapet walls should be modeled at the existing or proposed location(s) and height(s) so that the shielding from the parapet wall is included in the no-abatement sound levels.

Buildings

Buildings that cannot be accurately modeled as part of a building row should be modeled as fixed height noise barriers.

Existing Noise Barriers

Solid noise barriers that were constructed to abate noise should be modeled as fixed height noise barriers.

Privacy Fences

Privacy fences that are constructed with materials and in a manner that would be expected to reduce sound levels should be modeled in TNM. These types of fences could include solid cinder block or brick walls.

Wooden privacy fences are not typically constructed to mitigate noise and should not be modeled as noise barriers. However, these fences can provide small reductions in sound levels. If the fence is expected to remain in good condition over the lifetime of the project (i.e. 20 years in the future), then it may be appropriate to model the fence as a TNM building row as described below. However, TDOT should be consulted before a privacy fence is modeled.

Field measurements can also assist in evaluating the noise level reduction that might be provided by existing fences.

TNM Building Rows

Multiple small buildings, such as rows of houses, that act as multiple small barriers with gaps should be modeled as building rows with a uniform low transmission loss.

TNM Terrain Lines

TNM terrain lines should be used to define the terrain between TNM roadways and receivers. TNM terrain lines should be modeled where they break the line-of-sight or where they would reduce excess ground attenuation. TNM terrain lines could include:

  • The top of cut for a depressed roadway
  • The bottom of deep drainage ditches
  • The edge of fill for roadways on fill
  • Ridges of intervening hills
  • Lines of constant elevation of an intervening hill

TNM Ground Zones

Lawn should generally be specified as the default ground type for TDOT projects. Any large areas of ground type that would be expected to affect sound propagation should be modeled as TNM ground zones. Ground zones might include parking lots and lakes.

TNM Tree Zones

Tree zones should not be modeled on TDOT projects unless they meet FHWA's definition which states that tree zones should consist of long, wide regions of heavy, non-deciduous woods and undergrowth, not just individual trees or several rows of trees. The vegetation also must be sufficiently dense to completely block the view along the sound propagation path. This requires dense undergrowth as well as dense tree-top foliage. Tree zones should not be modeled unless they have this vegetative density and without TDOT's concurrence.

TNM Contours

This TNM feature should only be utilized for land-use planning activities.

Review of Design Year Sound Levels

The predicted design year sound levels for the Build Alternative(s) should be thoroughly reviewed to assess whether the predicted sound levels at each receiver are reasonable given the analyst's knowledge and understanding of the source of the traffic noise, the path between the source and the receiver, and the characteristics of the intervening terrain.

The predicted design year sound levels at the measurement locations should be compared to the existing and design year No-Build worst-hour sound levels at each measurement location to assess whether the predicted change in sound level due to the project is reasonable.

If the predicted change in noise levels due to project is significantly higher or lower than the change that the analyst would expect, then the analyst should thoroughly review the modeling for the Build Alternative to ensure that the TNM model accurately represents the design year conditions. For example, a predicted 6 dB increase in the sound level would not be expected if the traffic did not double and the roadway did not move closer to the receiver.

5.3.4.6.5 Determination of Traffic Noise Impacts

Traffic noise impacts for each Build Alternative should be identified in accordance with TDOT's Noise Policy. An impact analysis is generally not needed for the No-Build Alternative.

Each modeled receiver should be identified as not impacted, impacted based on the NAC, impacted based on substantial increase in sound levels, or impacted based on both the NAC and a substantial increase in sound levels. The information should be presented in a table in the Noise Technical Report.

The total number of impacts by Land Use Category resulting from each Build Alternative should be determined and summarized in a table in the Noise Technical Report.

If traffic noise impacts are not predicted for the Build Alternative(s) in the design year, the analysis is considered complete and noise abatement measures should not be evaluated. This determination should be stated in the Noise Technical Report.

5.3.4.6.6 Evaluation of Noise Abatement Measures

Noise abatement should be evaluated when noise impacts are predicted in the design year for the Build Alternative(s). At a minimum, TDOT will consider noise abatement in the form of a noise barrier, since barriers are generally the best available abatement measure to reduce sound levels for impacted land uses.

Earth berms are similar to noise barriers and are sometimes considered to be more aesthetically pleasing that noise barriers. However, berms require significant right-of-way that is typically not available. For example, the width of a 15-foot high berm constructed at a 2:1 slope with a top flat width of 5 feet is 65 feet plus additional width for drainage. Additionally, berms are generally not feasible where the road is in cut or on-fill. Earth berms may also be difficult to maintain. Therefore, earth berms are not feasible for most projects. As a result, berms will be evaluated in lieu of or in combination with noise barriers on a case-by-case basis.

TDOT may also consider the following noise abatement measures for Type I projects: (1) traffic management measures (e.g., traffic control devices and signing for prohibition of certain vehicles types, time-use restrictions for certain vehicle types, and exclusive lane designations); (2) alteration of horizontal and vertical alignments; (3) acquisition of property rights (either in fee or lesser interest) for construction of noise barriers; and (4) noise insulation of Category D land uses.

These measures are discussed in greater detail below. The feasibility and reasonableness of these alternative abatement measures will be assessed on a case-by-case basis.

Traffic Management Measures: Truck prohibitions and reducing speed limits can sometimes reduce sound levels. However, a 20 mile-per-hour reduction in speed is necessary for a readily noticeable (5 dB) decrease in sound levels. This sound level reduction would not be substantial. Therefore, speed reductions are not acoustically feasible for most projects.

FHWA generally does not allow restrictions of truck trailer combinations on facilities in the National Network for large trucks, except under very special circumstances and where comparable parallel facilities are available. The National Network includes most of the Interstate Highway System in Tennessee. Therefore, truck restrictions are not possible for projects involving Interstates or other routes where comparable alternative routes do not exist. Truck restrictions could be evaluated if the restriction would not conflict with the designated use of the roadway and where such restrictions would not cause increased delay or travel times to the motoring public.

Alteration of Horizontal and Vertical Alignment: For projects that involve widening of an existing facility, the modification of the horizontal and vertical alignment is generally not a feasible mitigation strategy. However, the modification of the horizontal and vertical alignment may be a feasible strategy for projects that involve the construction of a roadway on a new alignment.

Noise Insulation of Category D Land Uses: Sound insulation might be possible to mitigate predicted interior impacts of public use or nonprofit institutional structures.

Noise insulation measures might include installation of new windows; sealing windows, cracks, and other openings; and the installation of air-conditioning. However, post-installation maintenance and operational costs for noise insulation are not eligible for Federal-air funding.

Noise Reduction Design Goal

The noise abatement measure shall provide at least 7 dB noise reduction at 60% or more of the first-row benefited receptors. For impacted Category D land uses, the noise abatement measure should provide a minimum 7 dB reduction in interior noise levels for the impacted areas.

Multistory Buildings

For multiple-story, single-family houses and multi-family dwellings, noise abatement will be designed to protect the exterior ground-floor receptors when the exterior areas are at-grade or elevated above the roadway. In cases where the exterior first-floor areas (i.e., decks or porches) are elevated above the ground but are still below the grade of the roadway (i.e., first-floor decks or porches), noise abatement will generally be designed to protect those elevated first-floor areas.

If any of the upper floor exterior balconies in multi-family dwellings are benefited as a result of a noise abatement design, then these upper floor units will be included in the reasonableness analysis.

Date of Public Knowledge

Federal participation in noise abatement measures will not be considered for lands that are not permitted by the date of public knowledge of the project, and TDOT will not analyze or provide noise abatement for these lands. After the date of public knowledge, provision of noise abatement becomes the responsibility of local communities or private developers.

Trees/Vegetation

The planting of trees/vegetation is not considered as a noise abatement measure because vegetation and trees could not be constructed within the right-of-way at the depth and density required to provide a substantial noise reduction. Additionally the planting of vegetation is not acceptable Federal-aid noise abatement measures for Federal projects.

Alternative Pavements

The use of alternative pavement types is also not considered as a noise abatement measure. FHWA's policy related to tire/pavement noise is as follows:

"Pavement is sometimes mentioned as a factor in traffic noise. While it is true that noise levels do vary with changes in pavements and tires, it is not clear that these variations are substantial when compared to the noise from exhausts and engines, especially when there are a large number of trucks on the highway. Additional research is needed to determine to what extent different types of pavements and tires contribute to traffic noise.

It is very difficult to forecast pavement surface condition into the future. Unless definite knowledge is available on the pavement type and condition and its noise generating characteristics, no adjustments should be made for pavement type in the prediction of highway traffic noise levels. Studies have shown open-graded asphalt pavement can initially produce a benefit of 2-4 dBA reduction in noise levels. However, within a short time period (approximately 6-12 months), any noise reduction benefit is lost when the voids fill up and the aggregate becomes polished. The use of specific pavement types or surface textures must not be considered as a noise abatement measure."

5.3.4.6.7 Noise Barrier Design

Noise barriers should be evaluated using TNM to reduce sound levels at impacted land uses.

Noise Reduction Design Goal: Noise barriers should provide at least 7 dB noise reduction at 60% or more of the benefited first-row receptors. For impacted Category D land uses, the noise abatement measure should provide a minimum 7 dB reduction in interior noise levels for the impacted areas.

When the noise reduction design goal can be achieved, additional efforts may be made to obtain up to a 10 dB noise reduction at impacted first-row receivers.

Barrier Location: Acoustically, the most effective noise barriers are generally located close to the source (i.e. at the highway shoulder) or close to the receptor (i.e. at/near the right-of-way). The analyst should exercise judgment in determining the most effective location for a barrier. Additionally, in areas where a road transitions from cut to fill and vice versa, the barrier will likely need to transition from a location near the road to a location near the right-of-way.

Some situations may require an analysis of more than one barrier location and may require coordination with TDOT's Design Division.

Barrier Heights: Barrier heights will vary considerably depending on traffic volumes and mixes, the characteristics of the intervening ground, and the location of the road relative to the impacted receptors (i.e. cut or fill).

TNM should generally be run with an input height of 16 feet, a perturbation increment of 2 feet, and with 4 perturbations up and down.

5.3.4.6.8 Barrier Feasibility and Reasonableness

Noise abatement measures must be feasible and reasonable, as defined below. Feasibility deals with engineering considerations and the ability to achieve a 5 dB noise reduction. Reasonableness weighs the amount of required noise barrier area against the benefits that would be provided by the barrier. The viewpoints of the benefited property owners and residents will be considered by TDOT in its final decision regarding reasonableness.

Feasibility

Feasibility deals with engineering considerations and the ability to achieve a 5 dB noise reduction. In order for the noise abatement measure to be feasible, the measure should provide a minimum of 5 dB reduction in design year highway traffic noise levels for the majority of the benefited first-row receptors.

Feasibility may also be affected by: (1) topography; (2) access and utility requirements; (3) drainage; (4) safety and maintenance considerations; (5) the presence of local cross streets; and (6) noise from other sources in the area such as local roads, trains, aircraft, factories, (7) excessive height of barrier needed to reach reduction goal, etc.

A preliminary qualitative assessment should be completed to identify any major design, construction, maintenance or safety factors associated with construction of noise barriers. The factors that should be evaluated include:

  • Access to adjacent properties for non access-controlled facilities
  • Sight distance
  • Clear zone
  • Drainage
  • Utilities
  • Constructability of the barrier including issues associated with constructing noise barriers on bridges

The extent to which these issues can be assessed will depend on the project development process. The Noise Technical Report and NEPA document should indicate the type of plans upon which the noise study was based.

Noise barriers will generally not be determined to be not feasible for non-acoustic reasons during the NEPA process. Instead, non-acoustic issues that could affect the feasibility determination during the final design process should be discussed in the Noise Technical Report and NEPA document.

TDOT will assess all potential feasibility issues during the final design process for those barriers that are determined to be acoustically feasible and reasonable. Issues associated with drainage, sight distance, clear zone and utilities can generally be addressed during the final design process without affecting the feasibility and reasonableness of the noise barrier.

Barriers that are predicted to provide a minimum 5 dB IL at the majority of impacted first-row receptors should be identified as acoustically feasible.

The feasibility of providing noise abatement may be influenced by other significant noise sources in the areas including rail, aircraft, and industrial/manufacturing operations. The extent to which other significant noise sources affect acoustic feasibility will depend on the temporal nature of the noise source as well as the sound levels themselves.

In these cases, a more detailed assessment of acoustical feasibility may be needed and TDOT should be consulted. The procedures contained in the Federal Transit Administration Report Number FTA-VA-90-1003-06, "Transit Noise and Vibration Impact Assessment" should be followed in cases where acoustic feasibility may be affected by transit or rail operations.

Feasibility alone does not dictate whether a noise barrier will be built. Each noise barrier must also be "reasonable" in accordance with TDOT's Noise Policy.

Reasonableness

Noise abatement will only be assessed where noise impacts are predicted and where frequent human use occurs. Primary consideration will be given to exterior areas.

In order for a noise abatement measure to be reasonable, the required barrier area (in square feet) per benefited residence must be less than or equal to the allowable barrier area per benefited residence for that noise abatement location.

The calculated area per benefited residence is the estimated area of the barrier divided by the number of benefited residences. The number of benefited residences in each noise analysis area is determined by counting all of the residences that would receive 5 dB or more insertion loss due to construction of the barrier regardless of whether or not the residence is predicted to be impacted.

Noise abatement will generally not be considered reasonable for isolated residences due to the quantity of abatement versus the benefits provided.

The allowable barrier area per benefited residence for each noise abatement location is calculated using the following equation:

Allowable Area per Benefited Residence

     = Base Allowance _____________

     + Previous Type I Widening Allowance _____________

     + Design Year Noise Levels Allowance _____________

     + Noise Level Increase Allowance _____________

     + Noise Compatible Planning Allowance _____________

     = Total Allowable Area per Benefited Residence _____________

The value for each allowance type should be selected based on the criteria outlined in the following table:

Allowance Type Criteria Allowance in square feet
Base Allowance Residences pre-date the highway(1) or the project is on a new alignment. 1,500
Residences post-date the highway(2) but were constructed before September 16, 2005. (3) 750
Residences were constructed after September 16, 2005.(3) 250
Previous Type I Widening Allowance(4) Residences pre-date a Type I widening project on the adjacent highway. 200
Design Year Noise Levels Allowance(5) 69 or less dBA 0
70 - 74 dBA 100
75 or more dBA 200
Noise Level Increase Allowance(6)(7) 0 - 4 dBA 0
5 - 9 dBA 200
10 or more dBA 400
Noise Compatible Planning Allowance The local government of the jurisdiction in which the project will be constructed has no policies to require that noise be considered in the land development process. 0
The local government of the jurisdiction in which the project will be constructed has adopted official and enforceable policies to require that noise be considered as an integral component of the land development process. 100

(1) The majority (more than 50%) of residences existed before the original highway construction.

(2) The majority (more than 50%) of residences were constructed after the original highway construction.

(3) TDOT's previous noise policy became effective on September 16, 2005. FHWA's approval of this policy was contingent upon TDOT's completion of a public outreach program to 1) notify local jurisdictions of the changes in TDOT's new noise policy and 2) encourage them to consider noise compatible land use planning when noise-sensitive land uses are proposed adjacent to TDOT's highways. As a result, development that occurs after this date receives less consideration in the reasonableness analysis.

(4) The majority (more than 50%) of residences existed before the most recent Type I project that added through traffic lanes.

(5) Based on an average of the impacted first-row receivers' levels (design year noise levels for Type I projects and existing noise levels for Type II projects).

(6) An average of the increases from existing noise levels to design year noise levels for the Build Alternative at the impacted first-row receivers.

(7) Not applicable for Type II projects.

A table summarizing the results of the noise barrier reasonableness analysis should be provided in the Noise Technical Report and environmental document. The table should include a description of the area protected by the barrier(s), barrier length(s), average height(s), estimated barrier area, number of benefited residences, calculated area per benefited residence, allowable area per benefited residence, and whether the barrier is reasonable.

Section 772.17(b) of 23 CFR 772 (July 13, 2010) states that if a highway agency chooses to participate in a Type II noise program or to use the date of development as one of the factors in determining the reasonableness of a Type I noise abatement measure, the highway agency shall have a statewide outreach program to inform local officials and the public of (1) Noise compatible planning concepts, (2) The best estimation of the future design year noise levels for undeveloped lands or properties within the project limits, and (3) Non-eligibility for Federal-aid participation for Type II projects.

TDOT's policy dated September 16, 2005 was the result of a lengthy policy update process that was developed with close coordination with the FHWA Tennessee Division Office. As part of that policy update, TDOT committed to undertaking a public education campaign to 1) notify local jurisdictions of the changes in TDOT's new noise policy and 2) encourage them to consider noise compatible land use planning when noise-sensitive land uses are proposed adjacent to TDOT's highways. The campaign included sending more than 400 letters City and County officials of jurisdictions adjacent to TDOT's highways; presentations at Metropolitan Planning Organizations (MPOs) meetings and conferences; hosting a booth at a Tennessee Chapter of the American Planning Association (TAPA) state conference; and publishing an article regarding TDOT's Noise Policy and noise compatible land use planning. A detailed summary of the public outreach program can be obtained from the Environmental Planning Division.

Since TDOT has demonstrated compliance with Section 772.17(b) of 23 CFR 772 (July 13, 2010), the date of development is a factor in determining the Base Allowance for the reasonableness analysis as described below.

Base Allowance

If the project is located on a new alignment, then each impacted area along the new alignment should be assigned New Alignment Allowance of 1,500 square feet.

If the project involves an existing road, then a development date analysis must be completed to determine the build dates of the impacted residences or other noise-sensitive land uses. The development date analysis involves first, determining the date of original highway construction; second, determining the construction dates of the impacted receptors; and third, determining whether the majority of impacted residences 1) predated the highway, 2) postdated the highway but were constructed before September 16, 2005, or 3) were constructed after September 16, 2005. The applicable base allowance is determined based on the results of the development date analysis.

The construction dates for most of Tennessee highways can be obtained from TDOT's TRIMs database. If the road construction date is not available, a determination as to whether a land use(s) predated the highway might be possible by reviewing historical USGS mapping, GIS data, and data from the property assessor. TDOT should be consulted if a determination cannot be made using these available sources of information.

The construction dates for impacted receptors can generally be obtained from the County Property Assessor (http://www.assessment.state.tn.us/).

A table summarizing the results of the development date analysis should be included in the Noise Technical Report and detailed results should be provided in an appendix.

Previous Type I Widening Allowance

Areas where the majority (more than 50%) of residences existed before the most recent Type I project that added through traffic lanes should be assigned a Previous Type I Widening Allowance of 200 square feet.

Design Year Noise Levels Allowance

The Design Year Noise Levels Allowance is based on an average of the impacted first-row receptors' levels. Areas with average predicted future sound levels of 75 dBA or higher should be assigned a Noise Levels Allowance of 200 square feet. Areas with average predicted future sound levels between 70 and 74 dBA should be assigned a Noise Levels Allowance of 100 square feet. Areas with average predicted future sound levels of 69 dBA or lower should not be assigned a Noise Levels Allowance.

Noise Level Increase Allowance

The Noise Level Increase Allowance is based on an average of the change between existing sound levels and future sound levels for the Build Alternative(s) at the impacted first-row receptors.

Areas where the predicted change is 10 dB or more should be assigned a Build Versus Noise Levels Allowance of 400 square feet. Areas where the predicted change is between 5 and 9 dB should be assigned a Build Versus Noise Levels Allowance of 200 square feet. Areas where the predicted change is 4 dB or less should not be assigned a Build Versus Noise Levels Allowance.

Noise Compatible Planning Allowance

TDOT's Noise Policy states the following:

"TDOT and the FHWA believe that highway traffic noise should be reduced through a program of shared responsibility. Local governments should use their power to regulate land development in such a way that noise-sensitive land uses are either prohibited from being located adjacent to a highway or that the developments are planned, designed and constructed in such a way that noise impacts are minimized."

Local governments that have adopted official and enforceable policies to require that noise be considered as an integral component of the land development process will be assigned Noise Compatible Planning Allowance of 100 square feet.

C, D and E Land Uses

The reasonableness determination for Category C, D and E land uses requires the calculation of an equivalent number of residences based on the size, type and duration of the activity.

The allowable barrier area per equivalent benefited residence for each noise abatement location is determined using the reasonableness calculation provided in the previous section.

The abatement measure will be reasonable if the required barrier area (in square feet) per equivalent benefited residence is less than or equal to the allowable barrier area per equivalent benefited residence for that noise abatement location.

The number of equivalent residences is determined using the following formula:

Equivalent Residences = Number of Users x Usage

(Number of People Per Residence)

where:

Number of Users = Average Number of Users During Usage Times

Number of People Per Residence = 2.5 (Tennessee Average from Census)

Usage = (Hours Used Per Day/24 Hours) x (Days Used Per Year/365 Days)

The Number of Users, Hours Used Per Day, and Days Used Per Year should be determined by evaluating the characteristics of the individual use.

Variables that might be included in assessing the Number of Users could include the maximum capacity of the use or the number of parking spaces provided. If maximum capacities are used, these capacities should be multiplied by a Typical User Factor to arrive at the average number of users during usage times. Guidance for calculating the Number of Users for swimming pools and playgrounds is provided in the following table.

Land Use Number of Users Maximum Users Typical User Factor
Swimming Pool Maximum Users x Typical User Factor Swimming Pool Area (sq. ft.)/ 10 sf. ft(1) 10% to 50%(2)
Playground Maximum Users x Typical User Factor Playground Area (sq. ft.)/
50 sf. ft(3)
10% to 75%(4)

(1) Maximum occupancy based on Davidson County and Hamilton County swimming pool regulations that require 10 sq. ft. of swimming pool area (deck areas excluded) per person.

(2) The typical number of users would be significantly less than the maximum number of users..

(3) Based on Tennessee licensure regulations for playgrounds requiring 50 sq. ft. of area per child.

(4)School playgrounds that are used throughout the day (i.e. schools) would have higher Typical User Factors than playgrounds at other facilities (i.e. churches, libraries, etc.).

Active sports areas are not considered to be noise-sensitive since a quiet noise environment is not important for normal activities. Therefore, these areas are equivalent to one residence.

Parks will typically be comprised of several individual use areas including active sports areas, swimming pools, playgrounds, picnic areas, etc. The equivalent residences for each of these individual uses should be calculated and added to get the total number of equivalent residences for the park.

5.3.4.6.9 Views of Benefited Property Owners and Residents

Per TDOT's Noise Policy, the views of benefited property owners and residents will be considered in making final noise abatement decisions. This input will generally be received at planning, NEPA, or design public hearings or public meetings.

If a noise barrier has been determined to be both feasible and reasonable, TDOT will include a note in the public hearing or meeting advertisement indicating that noise barriers are proposed and that public comments will be solicited and received at the meeting or hearing. TDOT will also include a discussion of the noise barrier(s) in the presentation and provide a dedicated space on the comment card for noise barrier comments.

Experience on past projects has indicated that the vast majority of residents have supported TDOT's proposed noise barriers. However, there may be instances where benefited residents or property owners oppose the construction of noise barriers for various reasons including blockage of views, the loss of sunlight due to the shadow created by a noise barrier, and isolation effects.

If significant opposition exists and there is not clear support for the construction of the proposed noise barrier(s), TDOT will conduct a certified mail survey to solicit the views of the benefited residents and/or property owners that would be protected by the barrier(s). If a majority of benefited residents/property owners oppose the construction of a noise barrier, then the barrier will not be included as a "likely" noise abatement measure. Benefited residents and/or property owners that do not respond will be contacted a second time. A final determination will be made based upon the total responses received after the second survey.

Responses from residents or owners of properties that are predicted to be impacted as well as benefited will be counted as two responses. Responses from residents or owners of properties that are predicted to be benefited but not impacted will be counted as one response.

TDOT will conclude that a community desires the construction of a noise barrier unless a majority (at least 51%) of the impacted property owners and residents indicate that they do not want the proposed noise barrier.

5.3.4.6.10 Statement of Likelihood

A statement of likelihood should be included in the CE, FONSI, ROD or TEER for all abatement measures that are determined to be feasible and reasonable in the preliminary analysis.

The statement of likelihood should include the preliminary location and physical description of all likely noise abatement measures, and should indicate that final decisions regarding the construction of abatement measures will be made during the final design process for the project.

5.3.4.6.11 Funding

Third-party funding is not allowed on a Federal or Federal-aid Type I or Type II project if the noise abatement measure would require the additional funding from the third-party to be considered feasible and/or reasonable. Third-party funding is acceptable on a Federal or Federal-aid highway Type I or Type II project to make functional enhancements, such as absorptive treatment, access doors, aesthetic enhancements, to a noise abatement measure already determined feasible and reasonable.

5.3.4.6.12 Assessment of Construction Noise

Construction noise related to transportation projects should be addressed in the Noise Technical Report and in the environmental document for the project. Most projects will not require modeling or any form of construction-related noise analysis. In most cases, construction noise may be adequately addressed through a narrative discussion. The following statement should be included in the Noise Technical Report and environmental document for most projects:

"Transportation projects will result in intermittent and temporary noise above existing ambient noise levels due to construction activities. The sound levels resulting from construction activities will be a function of the types of equipment utilized, the duration of the activities, and the distances between construction activities and nearby land uses.

However, the noise increases will be temporary and will not constitute a noise impact as defined by the FHWA Noise Standards and TDOT's Noise Policy.

If TDOT's construction specifications apply to this project, construction procedures should be governed by the Standard Specifications for Road and Bridge Construction as issued by TDOT and as amended by the most recent applicable supplements. The contractor will be bound by Section 107.01 of the Standard Specifications to observe any noise ordinance in effect within the project limits. All construction equipment should be maintained, repaired and adjusted to keep it in full satisfactory condition and detoured traffic should be routed during construction so as to cause the least practicable noise impact upon noise-sensitive areas."

Large projects in urban or populated areas or controversial projects may require a more detailed assessment of construction noise. TDOT will consider the need for more detailed construction noise analyses on a case-by-case basis.

If TDOT determines that a more detailed construction noise analysis is required, the analysis scope will be developed in coordination with TDOT and will be completed in accordance with the most recent version of the FHWA Roadway Construction Noise Model (RCNM).

5.3.4.6.13 Information for Local Officials

To minimize future traffic noise impacts on currently undeveloped lands adjacent to Type I projects, TDOT will provide local officials of the jurisdiction where the highway project is located with the following:

  1. Information on noise compatible planning concepts;
  2. The best estimation of the design year noise levels on the undeveloped lands along the project at various distances from the edge of the nearest travel lane of the highway improvement; and,
  3. Information on TDOT's Type II Noise Barrier Program.

This information should be included in the "Information for Local Officials" section of the Noise Technical Report and environmental document.

Information on Noise Compatible Planning Concepts

TDOT encourages local governments with jurisdiction over undeveloped lands, as well as potential developers of these lands, to practice noise compatibility planning in order to avoid future noise impacts. The following language is included in TDOT's Noise Policy:

"TDOT and the FHWA believe that highway traffic noise should be reduced through a program of shared responsibility. Local governments should use their power to regulate land development in such a way that noise-sensitive land uses are either prohibited from being located adjacent to a highway or that the developments are planned, designed and constructed in such a way that noise impacts are minimized."

TDOT's Noise Policy states that:

"Federal participation in noise abatement measures will not be considered for lands that are not permitted by the date of public knowledge of the project and TDOT will not analyze or provide noise abatement for these lands. After the date of public knowledge, provision of noise abatement becomes the responsibility of local communities or private developers."

The Noise Technical Report templates include this language as well as references to the following FHWA guidance documents on noise compatible land use planning:

Estimates of Design Year Noise Levels

The Noise Technical Report and environmental document should include a brief discussion of the location and type of undeveloped lands the project area.

TNM should be used to predict design year sound levels at various distances from the proposed centerline of the near lane for these undeveloped areas. The analysis should be done for an at-grade condition.

The predicted sound levels should be summarized in a table and the Noise Technical Report should clearly state the following:

"The noise predictions do not represent predicted levels at every location at a particular distance back from the roadway. Sound levels will vary with changes in terrain and will be affected by the shielding of objects such as buildings. This information is being included to make local officials and planners aware of anticipated highway noise levels so that future development will be compatible with these levels."

TDOT's Type II Noise Barrier Program

The following discussion should be included in the Noise Technical Report and environmental document.

"TDOT currently has a Type II Noise Barrier Program to facilitate the construction of "retrofit" noise barriers along existing highways. To be eligible for a Type II noise barrier, an area must meet the following criteria:

  • The neighborhood must be located along a limited-access roadway;
  • The neighborhood must be primarily residential;
  • The majority (more than 50%) of residences in the neighborhood near the highway pre-dated the initial highway construction;
  • A noise barrier for the neighborhood must not have been previously determined to be not reasonable or not feasible as part of a new highway construction or through-lane widening study (Type I project);
  • Existing noise levels measured in the neighborhood must be above the Noise Abatement Criteria (NAC) of 66 dBA;
  • A barrier must be feasible to construct and will provide substantial noise reduction; and,
  • A barrier must be reasonable (barrier cost per benefited residence) in accordance with TDOT's Noise Policy. A residence is considered "benefited" if the noise barrier will reduce the traffic noise by at least 5 dB."

5.3.4.7 Noise Technical Report

The results of the noise analysis should be documented in a Noise Technical Report that should have a logical sequence and language that adequately describes the procedures used to complete the noise analysis. Tables and figures should be used to convey the study results and make the report easily understandable by both a technical reviewer and a lay person.

The Noise Technical Report should generally contain the following sections:

  1. 1.0 Executive Summary
  2. 2.0 Project Description
  3. 3.0 Criteria for Determining Impacts
    1. 3.1 Traffic Noise Terminology
    2. 3.2 Noise Abatement Criteria (NAC)
  4. 4.0 Identification of Noise-Sensitive Land Uses
  5. 5.0 Determination of Existing Sound Levels
  6. 6.0 Determination of Future Sound Levels
    1. 6.1 No-Build Alternative
    2. 6.2 Build Alternative(s)
  7. 7.0 Impact Determination Analysis, Build Alternative(s)
  8. 8.0 Noise Abatement Evaluation
    1. 8.1 Noise Barrier Feasibility
    2. 8.2 Noise Barrier Reasonableness
    3. 8.3 Views of Benefited Property Owners and Residents
    4. 8.4 Summary
  9. 9.0 Construction Noise
  10. 10.0 Information for Local Officials
  11. 11.0 Indirect and Cumulative Effects
  12. 12.0 References
  13. Appendices (as applicable):
    1. Typical Cross-Sections
    2. Noise Measurement Data Sheets and Photographs
    3. Traffic Projections
    4. TNM Plan Views
    5. Design Year Sound Levels and Impacts, Build Alternative(s)
    6. Development Date Analysis
    7. Noise Barrier Analysis Results

The PIN and state project numbers should be included on the report cover.

All TNM runs developed for the project shall be transmitted to TDOT electronically or on a disk at the time any draft or final report is submitted.

TDOT has developed templates for the preparation of Noise Technical Reports to ensure consistency between project studies. These templates should be used on all TDOT projects and will be provided upon request.

5.3.4.8 Noise Section of Environmental Document

TDOT has developed templates for CEs, EAs, EISs and TEERs to ensure consistency between project studies. The analyst conducting the noise study should use the appropriate template to develop the noise section of the NEPA environmental document.

The environmental document for the project should also include brief discussions of the public involvement process (if applicable). Projects for which an EA or EIS is being prepared should include a discussion of indirect and cumulative impacts.

5.3.4.9 Final Noise Abatement Decisions

Conditions can change during the project design process. These changes may affect the preliminary noise abatement determinations in the environmental document. Such changes could include modifications to the proposed cross-sections, shifting the alignment, and changing roadway or ramp grades.

Final decisions regarding the construction of noise barriers will be made during the final design process.

5.3.4.10 Final Noise Barrier Design

Preliminary final noise barrier designs will be developed once right-of-way plans have been completed. The preliminary final barrier designs will be incorporated into the preliminary roadway design plans. The final noise barrier design will be re-evaluated when the preliminary roadway construction plans are completed.

The factors discussed below should be considered in making final decisions regarding noise abatement.

Noise Reduction Design Goal

The noise abatement measure shall provide at least 7 dB noise reduction at 60% or more of first-row benefited receptors. For impacted Category D land uses, the noise abatement measure should provide a minimum 7 dB reduction in interior noise levels for the impacted areas.

When noise abatement measures are considered and the noise reduction design goal can be achieved, additional efforts may be made to obtain up to a 10 dB noise reduction at impacted first-row receivers.

Barrier Heights

Barrier heights will vary considerably depending on traffic volumes and mixes, the characteristics of the intervening ground, and the location of the road relative to the impacted receptors (i.e. cut or fill). Barrier heights between 10 and 20 feet are typical. Barrier heights above 20 feet will generally only be constructed in areas where the barrier location is transitioning from a location at/near the shoulder to a location at/near the right-of-way or vice versa.

Right-of-Way (ROW)

ROW needs, including access rights (air, light, view, ingress/egress), easement for construction and/or maintenance, and additional land must be considered as part of the feasibility of noise barrier construction.

Isolated pockets of land between noise barriers and access control fences and private fencing should be avoided if possible. Such areas collect litter and are difficult to access and maintain. In many cases, the noise barriers will serve to control access so that a control of access fence may not be required, particularly in locations where the noise barrier is constructed at/near the ROW.

Safety

Safety factors including maintaining adequate clear zone and sight distance are critical factors in determining whether a particular abatement scheme is viable.

Accessibility

Noise abatement measures should not affect ingress or egress from adjacent properties. Accessibility is considered in determining if the abatement measure is feasible and should be reviewed during final design.

Drainage

Drainage is an important consideration in locating and designing a noise barrier. Directing water along, under, or away from a noise barrier can be expensive and cause construction and maintenance problems.

Utilities

The location of overhead and underground utilities can affect the location and design of noise barriers. In some cases, utilities may have to be relocated so that a noise barrier can be constructed.

Ultimate Location

Noise abatement measures should be constructed to accommodate any planned widening of the facility. A noise abatement measure will not normally be constructed where the implementation of future projects would limit its useful life to less than 20 years. If noise abatement measures will be constructed at a shoulder location along a project where future widening is anticipated, then the project design should provide for salvage in the future.

Noise Reflections

Noise reflections between parallel reflective noise barriers can degrade the predicted effectiveness of the noise barriers. The amount of degradation is highly dependent on geometrics and degradations can vary significantly from location to location behind the same noise barrier.

A detailed noise reflections analysis should be completed during final noise barrier design using the "Parallel Barriers" module of TNM for all projects that involve the construction of parallel barriers on both sides of the highway.

The analysis should predict degradations at enough receivers to make a determination whether the barrier(s) should be specified as absorptive. Modeled receivers should include impacted first and second-row receivers as well as any other receivers where noise reflections could reduce the predicted barrier insertion loss.

If noise reflections are predicted to substantially degrade the predicted design year noise reductions, TDOT will specify that the barrier sections that are causing the degradations be absorptive.

Noise reflections off of a noise barrier on one side of a highway can also increase sound levels on the opposite side of the highway. In most cases, these increases are less than 3 dB which is usually the smallest change in hourly sound levels that people can detect without specifically listening for the change. However, TDOT may consider specifying single noise barriers as absorptive if there are noise-sensitive land uses of the opposite side of the road from the noise barrier.

Aesthetics

TDOT will generally solicit the views of the residents and/or owners of the impacted properties in making a determination regarding the aesthetic texture and color of the community side of the noise barrier. TDOT will select the aesthetic texture and color of the highway side of the noise barrier.

Maintainability

Noise barriers must be maintained after construction including removing or covering any graffiti that appears on both the road side and community side of noise barriers. Maintenance could be hampered if the noise barrier is constructed at a location that is difficult for maintenance crews to access. Maintenance crews must be able to access locations

5.3.4.11 Construction Noise

As discussed previously, Transportation projects will result in intermittent and temporary noise above existing ambient noise levels due to construction activities. The sound levels resulting from construction activities will be a function of the types of equipment utilized, the duration of the activities, and the distances between construction activities and nearby land uses.

One key to effectively addressing construction noise effects is proactive communication with the community. Residents and other affected property owners should be notified in advance of construction activities that will generate high noise levels including blasting and pile driving. Measures contained in TDOT's Section 107.01 of the Standard Specifications should apply to most projects. In addition to those measures, the following measures may be incorporated:

  • Inform the public in advance on construction activities that might generate particularly high noise levels.
  • Noise barriers that are included in the design plans should be constructed as early in project construction as practical.
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5.3.5 Air Quality

Transportation projects have the potential to affect air quality by changing the volume, mix, and location of motor vehicle traffic. The potential effects that a project may have on air quality must be assessed during the NEPA process.

5.3.5.1 Applicable Legislation and Regulations

5.3.5.1.1 The Clean Air Act (CAA)

The Clean Air Act (CAA) was enacted in 1970 to protect and enhance air quality and to assist state and local governments with air pollution prevention programs. The CAA established six criteria pollutants and required the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for these criteria pollutants.

The CAA was amended in 1977 to set new goals for achieving attainment of NAAQS. This amendment also required a qualitative discussion of the air quality impacts of transportation projects and any transportation control measures (TCMs) which may be used to mitigate the air quality impacts attributable to the project.

The CAA amendments (CAAA) of 1990 were intended to meet unaddressed or insufficiently addressed problems such as acid rain, ground level ozone, air toxics, and stratospheric ozone depletion. Specific criteria were established for areas that did not meet the NAAQS for each criteria pollutant. The amendments also mandated the development and implementation of State Implementation Plans (SIPs) and specific timetables for implementing mobile source emission control strategies. If the criteria are not met, EPA can impose sanctions on all or part of the state.

Criteria Pollutants

Under the Clean Air Act, EPA establishes air quality standards for six common air pollutants called "criteria" pollutants including carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM), and sulfur dioxide (SO2).

National Ambient Air Quality Standards

Under the CAA, EPA establishes primary National Ambient Air Quality Standards (NAAQS) to protect public health, including the health of sensitive populations such as people with asthma, children, and older adults. EPA also sets secondary standards to protect public welfare. This includes protecting ecosystems, including plants and animals, from harm, as well as protecting against decreased visibility and damage to crops, vegetation, and buildings.

The NAAQS for the six criteria pollutants as summarized in Table 5-3.

In January 2010, EPA proposed stricter ozone standards. To ensure EPA's decision is grounded in the best science, EPA will review scientific data provided by the Clean Air Scientific Advisory Committee (CASAC). EPA intends to set a final standard in the range recommended by CASA by the end of July 2011. The new standard is expected to be lower than the 2008 standard of 0.075 ppm.

NAAQS Designations

The CAA established three designations for areas based on ambient measured concentrations for each criteria pollutant:

  • Attainment Area: A geographic area that meets the NAAQS for the pollutant.
  • Nonattainment Area: an area that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the NAAQS for the pollutant.
  • Maintenance Area: an area with a history of nonattainment, but that is now consistently meeting the NAAQS. Maintenance areas have been re-designated by EPA from "nonattainment" to "attainment with a maintenance plan." Maintenance areas are required to have a plan to remain in attainment for at least 20 years.

Nonattainment areas may also be given classifications based on the magnitude of the area's air quality problem. Nonattainment classifications are used to specify certain regulatory requirements, establish deadlines for states to submit air quality plans, and determine when an area must be in compliance (attainment) with the NAAQS.

For ozone, the nonattainment classifications are marginal, moderate, serious, severe, and extreme. For CO and PM, the classifications are moderate and serious. Table 5-4 shows the Tennessee's non-attainment and maintenance areas.

State Implementation Plans (SIPs)

The CAA requires that each state that has areas designated as nonattainment or maintenance develop a plan for how it will attain and maintain the NAAQS. This plan is called a state implementation plan (SIP). The state must involve the public in approving the plan before it is submitted to EPA. If the EPA finds a plan unacceptable, it can promulgate and enforce a Federal Implementation Plan (FIP). The SIP elements for Tennessee are located at EPA's Region 4 SIP Page (http://www.epa.gov/region4/air/sips/).

General Conformity Rule

The General Conformity Rule established under section 176(c) of the CAA prohibits Federal entities from taking actions in nonattainment or maintenance areas that do not conform to the SIP.

The purpose of the General Conformity Rule is to:

  • Ensure that federal activities do not interfere with the budgets in the state implementation plans (SIPs);
  • Ensure that actions do not cause or contribute to new violations; and
  • Ensure the attainment and maintenance of the national ambient air quality standards (NAAQS).
5.3.5.1.2 Conformity Regulations

In November 1993, EPA promulgated two sets of regulations to ensure compliance with Section 176(c):. the Transportation Conformity Regulations and the General Conformity Regulations.

Transportation Conformity

The Transportation Conformity Regulations apply to highways and mass transit. These regulations establish the criteria and procedures for determining whether transportation plans, programs, and projects funded under title 23 U.S.C. or the Federal Transit Act conform to the SIP.

The Transportation Conformity Regulations contained in 40 CFR 96 establish the criteria and procedures for determining that transportation plans, programs, and projects that are funded under Title 23 U.S.C. or the Federal Transit Act conform with the SIP.

Transportation Conformity applies to nonattainment and maintenance areas for ozone (O3), carbon monoxide (CO), particulate matter (PM10 and PM2.5), and nitrogen dioxide (NO2). Transportation Conformity does not apply to nonattainment and maintenance areas for sulfur dioxide (SO2) and lead (Pb).

EPA's Final Conformity Rule, revised on July 1, 1999, requires state Departments of Transportation and Metropolitan Planning Organizations (MPOs) to develop Long Range Transportation Plans (LRTPs) and Transportation Improvement Programs (TIPs) that conform to the emissions budget and implemented schedule of Transportation Control Measures (TCMs) established in the SIP for air quality. The responsibility for implementing the conformity regulations falls upon the United States Department of Transportation (USDOT), through the Federal Highway Administration (FHWA) and the Federal Transit Administration (FTA).

These agencies ensure that transportation plans and programs in nonattainment and maintenance areas conform to the SIP. The policy board of each MPO makes a formal conformity determination on its transportation plans and program prior to submitting them to the USDOT for approval.

Table 5-6 National Ambient Air Quality Standards (NAAQS)
Pollutant Primary Standards Secondary Standards
Level Averaging Time Level Averaging Time
Carbon Monoxide 9 ppm (10 mg/m3) 8-hour (1) None
35 ppm (40 mg/m3) 1-hour (1)
Lead 0.15 µg/m3 (2) Rolling 3-Month Average Same as Primary
1.5 µg/m3 Quarterly Average Same as Primary
Nitrogen Dioxide 53 ppb(3) Annual
(Arithmetic Average)
Same as Primary
100 ppb 1-hour (4) None
Particulate Matter (PM10) (4) 150 µg/m3 24-hour (5) Same as Primary
Particulate Matter (PM2.5) 15 µg/m3 Annual (6)
(Arithmetic Average)
Same as Primary
35 µg/m3 24-hour (7) Same as Primary
Ozone 0.075 ppm (2008 std) 8-hour (8) Same as Primary
0.08 ppm (1997 std) 8-hour (9) Same as Primary
0.12 ppm 1-hour (10) Same as Primary
Sulfur Dioxide 0.03 ppm Annual
(Arithmetic Average)
0.5 ppm 3-hour (1)
0.14 ppm 24-hour (1)
75 ppb(11) 1-hour None

(1) Not to be exceeded more than once per year.

(2) Final rule signed October 15, 2008.

(3) The official level of the annual NO2 standard is 0.053 ppm, equal to 53 ppb, which is shown here for the purpose of clearer comparison to the 1-hour standard

(4) To attain this standard, the 3-year average of the 98th percentile of the daily maximum 1-hour average at each monitor within an area must not exceed 100 ppb (effective January 22, 2010).

(5) Not to be exceeded more than once per year on average over 3 years.

(6) To attain this standard, the 3-year average of the weighted annual mean PM2.5 concentrations from single or multiple community-oriented monitors must not exceed 15.0 µg/m3.

(7) To attain this standard, the 3-year average of the 98th percentile of 24-hour concentrations at each population-oriented monitor within an area must not exceed 35 µg/m3 (effective December 17, 2006).

(8) To attain this standard, the 3-year average of the fourth-highest daily maximum 8-hour average ozone concentrations measured at each monitor within an area over each year must not exceed 0.075 ppm. (effective May 27, 2008)

(9) (a) To attain this standard, the 3-year average of the fourth-highest daily maximum 8-hour average ozone concentrations measured at each monitor within an area over each year must not exceed 0.08 ppm.
(b) The 1997 standard - and the implementation rules for that standard - will remain in place for implementation purposes as EPA undertakes rulemaking to address the transition from the 1997 ozone standard to the 2008 ozone standard.
(c) EPA is in the process of reconsidering these standards (set in March 2008).

(10) (a) EPA revoked the 1-hour ozone standard in all areas, although some areas have continuing obligations under that standard ("anti-backsliding").
(b) The standard is attained when the expected number of days per calendar year with maximum hourly average concentrations above 0.12 ppm is < 1.

(11) Final rule signed June 2, 2010. To attain this standard, the 3-year average of the 99th percentile of the daily maximum 1-hour average at each monitor within an area must not exceed 75 ppb.

Table 5-7: Tennessee Counties NAAQS Designations(1)(2)
Area Transportation-Related Criteria Pollutants Non Transportation-Related Criteria Pollutants (3)
Ozone
(8 Hour)
PM2.5 Carbon Monoxide Sulfur Dioxide Lead
Chattanooga AL-TN-GA
Hamilton Co   N      
Knoxville TN
Anderson Co M N      
Blount Co M N      
Cocke Co. M (P-GSMP)        
Jefferson Co M        
Knox Co M N      
Loudon Co M N      
Sevier Co M        
Roane Co   N (P)      
Memphis TN-AR
Shelby Co M   M   M (P)
Nashville TN
Williamson Co         M (P)
Clarksville-Hopkinsville TN-KY
Montgomery Co M        
Benton Co       M (P)  
Fayette Co         M (P)
Humphreys Co       M (P)  
Polk Co       M  

(1) Source: US Environmental Protection Agency website: http://www.epa.gov/airquality/greenbk/. As of January 1, 2011.

(2) N = Nonattainment; M = Maintenance; (P) = Part of the county; (P - GSMNP) = the only part of Cocke County in nonattainment for ozone is the Great Smokey Mountains National Park.

(3) Transportation conformity does not apply to nonattainment and maintenance areas for sulfur dioxide (SO2) and lead (Pb).

Project-level conformity determinations must also be made for Federal highway and transit projects to demonstrate that the project is either exempt or included in a conforming transportation plan and TIP.

Additionally, projects located in CO and PM2.5 nonattainment and maintenance areas, are subject to localized "hot-spot" analysis.

General Conformity

The General Conformity Regulations apply to all other projects to ensure that other Federal actions also conform to the SIP.

5.3.5.1.3 Transportation Legislation

The Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 and subsequent legislation, including the Transportation Efficiency Act for the 21st Century (TEA 21), offer tools to help transportation decision makers carry out the CAA mandates. ISTEA strengthened the role of the MPO in transportation planning and programming while emphasizing intermodalism and the environment.

Furthermore, ISTEA linked transportation and environmental goals by providing funding flexibility and the Congestion Mitigation and Air Quality Improvement Program (CMAQ). The Safe, Accountable, Flexible, Efficient Transportation Equity Act - Legacy for Users (SAFETEA-LU) includes an expanded list of eligible CMAQ projects and revisions to some conformity and planning requirements.

5.3.5.1.4 Mobile Source Air Toxics (MSATs)

In addition to the criteria air pollutants for which there are NAAQS, EPA also regulates air toxics. Most air toxics originate from human-made sources, including on-road mobile sources, non-road mobile sources (e.g., airplanes), area sources (e.g., dry cleaners) and stationary sources (e.g., factories or refineries).

Mobile Source Air Toxics (MSATs) are a subset of the 188 air toxics defined by the CAA. The MSATs are compounds emitted from highway vehicles and non-road equipment. The EPA identified a subset of this list that FHWA labels as the six priority MSATs:

  • Benzene
  • Formaldehyde
  • Acetaldehyde
  • Diesel particulate matter/diesel exhaust organic gases
  • Acrolein
  • 1, 3-butadiene

While these MSATs are considered the priority transportation toxics, the EPA stresses that this list is subject to change and may be adjusted in future rules.

5.3.5.2 Air Quality Study Methodology and Procedures

The air quality analysis process will vary in content and scope based on the project size, geographic location, background conditions and anticipated impacts.

However, the air quality analysis for most projects will generally address the following:

  • Project-Level Conformity; and,
  • Mobile Source Air Toxics (MSATs).

Additionally, a discussion of climate change should be included for projects for which an EA or an EIS is prepared.

Standard air quality sections for project-level conformity, MSATs, and climate change are provided in the appendices of this manual.

TDOT staff can provide assistance in determining the level of air quality analysis that is needed on a project-by-project basis.

5.3.5.2.1 Project-Level Conformity

Conformity Statement

A chart showing the work flow for developing a conformity statement for TDOT projects is provided in Figure 5.1. The appropriate conformity statements to be included in the air quality technical report and NEPA document are provided in the blue document boxes.

The projects that are exempt per the Transportation Conformity Regulations are shown in Table 5-5. Traffic signal synchronization projects are also exempt from conformity per 40 CFR 93.128.

Hot-Spot Analysis

As noted in Figure 5.1, projects located in CO and PM2.5 nonattainment or maintenance areas are also subject to localized project-level hot-spot analyses to ensure that the project will not cause or contribute to violations of the NAAQS. These analyses should be conducted as described below.

If a hot-spot analysis indicates that the project would worsen air quality, FHWA will not approve the project as planned. In these situations, mitigation measures might be required and would need to be coordinated and assessed in cooperation with TDOT.

Projects in CO Nonattainment and Maintenance Areas (Shelby County Only)

A CO hot-spot analysis must be completed for non-exempt projects in CO nonattainment or maintenance areas.

As shown in Table 5-4, the only CO nonattainment or maintenance area in Tennessee is Shelby County which is a maintenance area. All other Tennessee counties are in attainment for CO.

Therefore, non-exempt projects in Shelby County are subject to CO hot-spot analyses. The analysis should be completed in accordance with the Guideline for Modeling Carbon Monoxide from Roadway Intersections published by EPA (hereafter referred to as the EPA Guideline) and the Transportation Conformity Regulations. The analysis should be completed using the EPA's CAL3QHC air quality dispersion model.

Hot-spot modeling is required for:

Projects affecting intersections that are at Level-of-Service D or worse or those that will change to Level-of-Service D or worse because of increased traffic volumes related to the project.

Figure 5.1 Mobile Source Air Toxics (MSATs) Work Flow TDOT Projects

Figure 5-1

EnlargeClick image to open a larger version of Figure 5.1 in new window [pdf 894 kb]

Hot-spot modeling is not required for a project if all intersections are predicted to operate at LOS C or better.

For projects affecting four or more intersections, a screening procedure based on traffic volumes and level of congestion should be used as described in the EPA Guideline to select the intersections for CO hot-spot modeling. If no exceedances of the CO NAAQS are predicted for the worst-case intersections, lower volume intersections can be assumed to pass the hot-spot test. This screening procedure reduces the amount of modeling required, yet still complies with the intent of the Transportation Conformity Regulations.

On December 20, 2010, EPA announced in the Federal Register that it approved the use of EPA's MOVES model for CO hot-spot analyses with a 2-year grace period. EPA also released guidance on using MOVES for CO hot-spot analysis, "Using MOVES in Project-Level Carbon Monoxide Analyses."

During the 2-year grace period, TDOT should be consulted to determined whether the CO emission factors that will be input into CAL3QHC should be determined using the most recent version of the EPA's MOBILE model or the new MOVES model.

Projects in CO Attainment Areas (All counties except Shelby County)

Generally, CO hot-spot analyses should not be conducted for projects located in CO attainment areas. However, TDOT should be consulted to determine if a CO hot-spot analysis is warranted if either of the following conditions occurs:

  • The project is a signalized intersection with a projected design year average daily traffic (ADT) volume greater than 80,000 vehicles per day and the intersection is projected to operate at Level-of-Service D or worse in the base year or the design year with the project; or,
  • The project is controversial due in part to the potential air quality impacts of the project.

TDOT will make the determination regarding whether a project is controversial.

If a CO hot-spot is required, the analysis should be conducted as described in the previous section.

If the project does not require a CO hot-spot analysis, then the NEPA document should include the following statement:

"Based on the screening procedure in the Tennessee Environmental Procedures Manual, this project does not meet the criteria requiring a CO project level hot-spot analysis and will not produce a projected violation of the CO National Ambient Air Quality Standards (NAAQS)."

Projects in PM Nonattainment and Maintenance Areas

In March, 2006, EPA published the Final Conformity Rule establishing transportation conformity requirements for analyzing the local PM air quality impacts of transportation projects (71 FR 12468). To meet statutory requirements, the Transportation Conformity Rule requires PM hot-spot analyses to be performed for "projects of air quality concern" located in PM2.5 and PM10 nonattainment and maintenance areas.

All areas in Tennessee are in attainment of the PM10 NAAQS. However, six counties listed in Table 5-4 are included in the Knoxville and Chattanooga PM2.5 nonattainment areas. Projects in these areas must be reviewed and assessed for potential local PM2.5 hot-spot impacts.

The Final Conformity Rule required qualitative PM hot-spot analysis to be performs until EPA releases guidance on how to conduct quantitative PM hot-spot analysis. At the time of the final rule, EPA and FHWA issued "Transportation Conformity Guidance for Qualitative Hot-spot Analyses on PM2.5 and PM10 Nonattainment and Maintenance Areas" for states to use in conducting the required PM2.5 hot-spot analyses for "projects of air quality concern."

EPA also stated in the final rule that quantitative PM hot-spot analyses would not be required until EPA released an appropriate motor vehicle emissions model for project-level analyses.

In December 2010, EPA announced in the Federal Register that it approved the use of the MOVES model for PM hot-spot analyses with a 2-year grace period. EPA also announced the availability of its updated PM hot-spot guidance "Transportation Conformity Guidance for Quantitative Hot-Spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas."

EPA's guidance provides information for State and local agencies to meet the PM2.5 and PM10 hot-spot analysis requirements established in the Final Conformity Rule. The guidance includes examples of projects that are most likely to be an air quality concern, as well as examples of projects that are not considered an air quality concern.

TDOT is responsible for making hot-spot determinations for all projects in PM2.5 nonattainment and areas. TDOT's Environmental Division developed a PM2.5 Hot-Spot Determination Process and Procedures document that details the hot-spot analysis process for TDOT projects. This document was reviewed and approved by the Knoxville and Chattanooga Interagency Consultations (IAC) Groups.

The PM2.5 hot-spot determination process involves classifying all federally-assisted transportation projects in PM2.5 nonattainment areas as one of the following categories:

Exempt - Projects that are exempt per the Transportation Conformity Regulations as shown in Table 5-5 and traffic signal synchronization projects under 40 CFR 93.128.

Project Not of Air Quality Concern - If a project does not meet the criteria to be classified as exempt, then TDOT will analyze traffic and land use data in accordance with Part 93.123(b) to determine if the project is of concern or not. If a project is on a new or expanded roadway that serves a significant volume of diesel truck traffic, such as a facility with greater than 125,000 AADT and 8 percent or more of the AADT is diesel truck traffic, then this may be a project of air quality concern.

Project of Air Quality Concern - If the project does not meet the requirements of either of the two preceding categories then the project will be classified as a "project of air quality concern" because it has the potential to adversely impact air quality. If TDOT determines and the IAC concurs that a project falls into this classification, then a PM2.5 Hot-Spot Analysis is required.

Projects that are exempt do not require hot-spot determinations. However, the IAC must concur with the exempt status of projects in PM2.5 nonattainment areas. TDOT routinely submits lists of exempt project to the IAC for concurrence.

TDOT must complete a hot-spot determination for all projects that are not exempt to determine if the project is of air quality concern. TDOT submits all completed hot-spot determinations to the appropriate IAC group for review and concurrence. The IAC group must concur with the hot-spot determination for each project before a conformity determination can be made for the project.

During the 2-year MOVES grace period, TDOT will coordinate with the IAC to determine whether a qualitative analysis should be completed using the EPA's 2006 guidance or whether a quantitative analysis should be completed using EPA's 2010 guidance and the MOVES model.

The air quality technical report and NEPA documents should include the applicable conformity statement and supporting documentation as outlined in Figure 5.1. As noted, TDOT will provide the IAC concurrence information for all projects.

No additional analysis or discussion beyond inclusion of the conformity statement is required for exempt projects or "projects not of air quality concern." "Projects of air quality concern" will be addressed by TDOT on a case-by-case basis.

5.3.5.2.2 Mobile Source Air Toxics (MSATs)

On February 3, 2006, the FHWA released "Interim Guidance on Air Toxic Analysis in NEPA Documents." This guidance was superseded on September 30, 2009 by FHWA's "Interim Guidance Update on Air Toxic Analysis in NEPA Documents." The guidance is located at: http://www.fhwa.dot.gov/environment/air_quality/air_toxics/.

An analysis of the potential MSAT emissions impacts of TDOT projects should be completed in accordance with FHWA's Interim Guidance. A chart showing the work flow for MSATs analysis for TDOT projects is provide in Figure 5-2.

The FHWA has developed a tiered approach for analyzing MSATs in NEPA documents. Depending on the specific project circumstances, the FHWA has identified three levels of analysis:

  • No analysis is needed for projects with no potential for meaningful MSAT effects.
  • Qualitative analysis for projects with low potential MSAT effects.
  • Quantitative analysis to differentiate alternatives for projects with higher potential MSAT effects.

The MSATs assessment should provide a description of the project and must identify the project as one of the three categories listed above. The appropriate TDOT standard MSATs section should then be used as the basis for the development of the MSATs section to be included in the air quality technical report and environmental document.

Projects that might qualify as a "project with higher potential MSAT effects" will require early coordination with TDOT and FHWA. To fall into this category, projects must:

  • Create or significantly alter a major intermodal freight facility that has the potential to concentrate high levels of diesel particulate matter in a single location; or,
  • Create new or add significant capacity to urban highways with traffic volumes where the AADT is projected to be in the range or 140,000 to 150,000, or greater, by the design year.

And also

  • Be proposed to be located in proximity to populated areas or in rural areas, in proximity to concentrations of vulnerable populations (i.e. schools, nursing homes, hospitals).

TDOT should be consulted early in the air quality analysis process on all projects that might fall into this category.

Figure 5.2 Project-Level Conformity Work Flow TDOT Projects

Figure 5-2: Project-level Conformity Work Flow TDOT Projects

EnlargeClick image to open a larger version of Figure 5.2 in new window [pdf 1.03 MB]

5.3.5.2.3 Climate Change

Climate change, also referred to as global warming, is an increase in the overall average atmospheric temperature of the earth due to the trapping of heat in the atmosphere by greenhouse gases. The primary greenhouse gas emitted by human activities in the United States is carbon dioxide (CO2), which represents approximately 85 percent of total greenhouse gas emissions.

Transportation sources contribute global warming through the burning of petroleum-based fuel. According to FHWA, transportation sources are responsible for approximately one-quarter of the greenhouse gas emissions for the United States. Automobiles and light-duty trucks account for almost two-thirds of emissions from the transportation sector and emissions have grown steadily since 1990.

FHWA is actively involved in efforts to initiate, collect, and disseminate climate-change-related research and to provide technical assistance to stakeholders. FHWA is also involved in climate change initiatives with the U.S. DOT Center for Climate Change and Environmental Forecasting. Information on FHWA research, publications, and resources related to climate change science, policies, and actions can be found on FHWA's Climate Change web site (http://www.fhwa.dot.gov/hep/climate/index.htm).

FHWA currently does not require climate change analysis for plans or projects. FHWA has stated that climate change effects should be addressed in the planning process from both mitigation and adaptation perspectives. The broad geographic scope and time scale of the planning process makes it an appropriate place to consider GHG emissions and the effects of climate change.

FHWA's Tennessee Division has requested that a discussion of the potential climate change effects be included for projects for which an EA or EIS is prepared. TDOT has developed climate change language that should be included in the Air Quality Technical Report and environmental documents for projects requiring an EIS. The template is available on TDOT's web site.

5.3.5.2.4 Construction Air Quality

Most projects will result in the temporary generation of construction-related pollutant emissions and dust that could result in short-term air quality impacts. These construction-related impacts can generally be mitigated through the implementation of Best Management Practices, which are included in TDOT's Standard Specifications for Road and Bridge Construction.

As a result, most projects will not require a construction air quality analysis but should include the following statement:

"If TDOT's construction specifications apply to this project, construction procedures shall be governed by the Standard Specifications for Road and Bridge Construction as issued by TDOT and as amended by the most recent applicable supplements. All construction equipment shall be maintained, repaired and adjusted to keep it in full satisfactory condition to minimize pollutant emissions."

Large scale construction projects located in populated areas may require a more detailed assessment of potential construction air quality impacts and possible assessment of mitigation measures. TDOT will consider the need for a more detailed construction air quality analysis for these projects on a case-by-case basis.

5.3.5.2.5 Indirect and Cumulative Impacts

The forecasted traffic volumes for most projects typically account for any redistribution of traffic that would occur as a result of the project. Therefore, the air quality analysis addresses any indirect traffic-related air quality impacts that might occur.

Additionally, the forecast traffic volumes include expected traffic growth and other planned and programmed projects in the area. As a result, the air quality analysis addresses the traffic-related cumulative air quality impacts of the project.

5.3.5.3 Air Quality Technical Report

TDOT has developed templates for use in the preparation of an Air Quality Technical Report to ensure consistency between project studies. These templates should be used on all TDOT projects and will be provided upon request.

An Air Quality Technical Report should be prepared only if the project is located in a CO or PM2.5 nonattainment or maintenance area and a hot-spot analysis was required as part of the project level conformity analysis. For all other projects, the results of the air quality analysis should be documented and summarized in the air quality section of the environmental documents as described below.

The Air Quality Technical Report should have a logical sequence and language that adequately describes the procedures used to complete the analysis. Tables and figures should be used to convey the study results and make the report easily understandable by both a technical reviewer and a lay person.

The Air Quality Technical Report will generally contain the following sections:

1.0 Introduction

2.0 Air Quality Evaluation

2.1 Transportation Conformity

2.2.1 Carbon Monoxide Hot-Spot Analysis (if applicable)

2.2.2 PM2.5 Hot-Spot Analysis (if applicable)

2.2 Mobile Source Air Toxics (MSATs)

2.3 Climate Change (for projects requiring an EIS)

2.4 Construction Air Quality

2.5 Indirect and Cumulative Impacts

3.0 Summary and Conclusions

The Air Quality Technical Report should include all applicable correspondence of agency consultation and required concurrence.

5.3.5.4 Air Quality Section of Environmental Document

The air quality section of the environmental document should generally address 1) the transportation conformity requirements for the project, including the results of any required hot-spot analyses, and 2) the potential Mobile Source Air Toxics (MSATs) effects of the project.

TDOT has developed templates for CEs, EAs, EISs and TEERs to ensure consistency between project studies. These templates should be used on all TDOT projects and will be provided upon request.

Table 5-8: Exempt Projects per 40 CFR 93.126
Safety
Railroad/highway crossing.
Hazard elimination program.
Safer non-Federal-aid system roads.
Shoulder improvements.
Increasing sight distance.
Safety improvement program.
Traffic control devices and operating assistance other than signalization projects.
Railroad/highway crossing warning devices.
Guardrails, median barriers, crash cushions.
Pavement resurfacing and/or rehabilitation.
Pavement marking demonstration.
Emergency relief (23 U.S.C. 125).
Fencing.
Skid treatments.
Safety roadside rest areas.
Adding medians.
Truck climbing lanes outside the urbanized area.
Lighting improvements.
Widening narrow pavements or reconstructing bridges (no additional travel lanes).
Emergency truck pullovers.
Mass Transit
Operating assistance to transit agencies.
Purchase of support vehicles.
Rehabilitation of transit vehicles.
Purchase of office, shop, and operating equipment for existing facilities.
Purchase of operating equipment for vehicles (e.g., radios, fareboxes, lifts, etc.).
Construction or renovation of power, signal, and communications systems.
Construction of small passenger shelters and information kiosks.
Reconstruction or renovation of transit buildings and structures (e.g., rail or bus buildings, storage and maintenance facilities, stations, terminals, and ancillary structures).
Rehabilitation or reconstruction of track structures, track, and trackbed in existing rights-of-way.
Purchase of new buses and rail cars to replace existing vehicles or for minor expansions of the fleet.
Construction of new bus or rail storage/maintenance facilities categorically excluded in 23 CFR part 771.
Air Quality
Continuation of ride-sharing and van-pooling promotion activities at current levels.
Bicycle and pedestrian facilities.
Other
Specific activities which do not involve or lead directly to construction, such as:
Planning and technical studies.
Grants for training and research programs.
Planning activities conducted pursuant to titles 23 and 49 U.S.C.
Federal-aid systems revisions.
Engineering to assess social, economic, and environmental effects of the proposed action or alternatives to that action.
Noise attenuation.
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5.3.6 Hazardous Materials

5.3.6.1 Applicable Regulations

While NEPA does not specifically mandate the completion of hazardous materials investigations, other laws do. Hazardous waste sites are regulated primarily by the Resource Conservation and Recovery Act of 1976 (RCRA) and the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). RCRA regulates the ongoing manufacture, storage, use, treatment, transportation, and disposal of hazardous substances/wastes from manufacture to final disposal. CERCLA is designed to control, clean up, and designate liability for abandoned, uncontrolled or inactive waste sites. Service stations and other underground storage tank (UST) sites are regulated by the Tennessee Petroleum Underground Storage Tank Act.

TDOT can be liable as an owner of a hazardous waste or releaser of a hazardous substance/waste if it purchases property which has been or is being contaminated with such substances, or if such substances are discovered/released during construction. The 1986 amendments to CERCLA (Superfund Amendments and Reauthorization Act of 1986 (SARA)) expanded the defenses to liability under CERCLA to provide a defense for both private and public "innocent landowners" of land upon which hazardous waste attributed to a previous owner is discovered.

Not all hazardous materials sites have negative impacts to transportation projects. "Brownfields" are abandoned, idled, or underused commercial, industrial, and institutional properties where redevelopment and reuse are complicated by light to moderate contamination from hazardous substances and wastes. These properties are most often in urban areas previously used by industrial and commercial operations that generated waste materials.

The Brownfields Economic Redevelopment Initiative, administered by the EPA, provides assistance, incentives and liability protection to States, local communities, and the private sector for the assessment, clean-up, and economic reuse of these sites. TDOT, in conjunction with FHWA, supports the Brownfields Initiative by encouraging participation in transportation projects that include the use and redevelopment of contaminated sites when appropriate.

5.3.6.2 Study Process for Hazardous Materials

Hazardous waste sites within potential transportation corridors are dealt with by:

Early identification and assessment of all potential right-of-way properties which could be contaminated with hazardous substances/wastes (also adjacent properties from which contamination could migrate);

Early coordination with Federal/State/local agencies to assess the likely degree of contamination and the scope of treatment and disposal measures needed, and;

Early determination and use of measures to avoid or minimize involvement with such properties or to cause responsible parties to undertake appropriate cleanup of the properties to be acquired.

The preferred option of dealing with hazardous waste sites is avoidance, unless the risks of proceeding can be justified. Contaminated property can cause excessive project delays, impacts, costs, and liability. However, experience with minor contamination such as limited contamination with Underground Storage Tanks (USTs), standard asbestos, etc. shows that not all contaminated property must be avoided and some can be dealt with in a relatively predictable manner.

The NEPA-level investigations for hazardous materials are usually prepared by a consultant overseen by the Hazardous Materials Coordinator in the Social and Cultural Resources Office of the Environmental Division. Sometimes, however, the investigations are part of a NEPA consultant contract. The coordinator can provide the scope of work for hazardous materials studies. The coordinator will manage all consultant studies and will ensure that the work is undertaken and completed at the appropriate time in the project development process. All hazardous materials studies will be submitted to the coordinator.

The required study is an Environmental Site Assessment (ESA), a two-phased study. The purpose of the study is to determine if hazardous materials and/or regulated substances are present within, or adjacent to, the proposed right-of-way limits. The ESA process is a phased study process used to determine if a property has been contaminated with hazardous materials and/or regulated substances. If a contaminated property is identified, avoidance, minimization, or mitigation must be considered.

The primary objectives of the ESA are:

  • To identify properties as polygons on a map with potential environmental concerns;
  • To establish a defense to CERCLA and other liabilities in the event TDOT purchases the property for right-of-way; and
  • To develop reasonable procedures to manage contaminated properties where they cannot be avoided.

The two-phased ESA process is comprised of the following levels of investigation:

  • Phase I: historical/environmental research and visual assessment; and
  • Phase II: sampling and testing, impact analysis, and mitigation development.

Draft Document - Phase I Environmental Site Assessment

All properties for each alternate analyzed in the draft environmental document should be evaluated for potential contamination. The information gathered should be sufficient to compare the scope of potential hazardous waste involvement among project alternatives and support the determination of a preferred alternative. Unless an alternative can be ruled out of consideration and unless all property required for right-of-way can be reliably prejudged to have negligible potential for contamination, the following steps will be taken to assure hazardous waste sites are identified, properly assessed, and avoided where possible:

  • Classify existing and past property uses according to the likelihood of hazardous waste contamination. To do this, existing land uses should be screened and past land uses reviewed to categorize each property according to hazardous waste risk. Some examples of high risk land uses include unregulated municipal or private dumps or landfills, waste segregation sites, waste piles, treatment plants and outfalls, oil/plastics/chemical/electrical/electronic/adhesives manufacturing plants, photo/printing/paint/plating/battery shops, automotive junkyards, metals and paper processing plants, mining/agriculture/medical supply facilities, service stations, dry cleaning and other cleaning operations, older buildings with structural asbestos or other contaminants, etc.;
  • Existing and past aerial photographs should be studied and compared to assist in identifying contaminating uses and contaminated sites/structures (e.g., ponds and lagoons, pits, depressions, fills, drums, tanks, piping, incinerators, drainages and drainage structures, nearby streambeds);
  • Title/Deed histories and other appropriate records should be reviewed;
  • Long-time local citizens and workers should be interviewed to obtain additional information about past land uses, potential contamination, and any history of hazardous wastes problems;
  • The EPA and State/local regulating or response agencies should be consulted for license permit actions and violation/enforcement/litigation actions against property owners and for general information about local hazardous waste problems such as midnight dumping, use of asbestos in buildings, and past contaminated water problems;
  • Confirm and supplement the above information with a visual site survey of all properties which could contain hazardous wastes. Additional evidence could include surface or partially buried containers, discolored soil, seeping liquids, abnormal or dead vegetation or animals, suspect odors, dead-end pipes, abnormal grading, fills, or depressions; and
  • Where appropriate, interview current owners of prospective right-of-way parcels to obtain additional information about current and past land uses and potential contamination. Close coordination with landowners is recommended in order to secure access for investigation if needed.

Final Document - Phase II Environmental Site Assessment

For the final environmental document, if avoidance is not possible, the identified potentially contaminated properties associated with the preferred alternative should be evaluated further by additional on-site investigations, including limited on-site sampling and testing of soil/water/air in order to confirm the presence of contamination and estimate its magnitude/extent and the estimated type/cost of cleanup of the confirmed sites.

The determination to conduct testing on the site should be in consultation with EPA and with the State/local regulatory agencies to assure that any sampling/testing or monitoring plan is adequate. This limited testing is key to recognizing the scope/costs/delays that are associated with the preferred alternative and allowing these to be factored into the decision to select the project alternative to be implemented. Early testing of the preferred alternative to confirm and estimate the contamination/cleanup will not only support the determination of the preferred alternative and decision of the alternative to implement but will also facilitate the expanded detailed site investigation and coordination with regulatory agencies, which closely follows in the design and right-of-way stages. In some cases, the extent of contamination problems found through this limited testing could lead to reconsideration of the preferred alternative and selection of another alternative.

The above procedures will be followed for all potentially contaminated properties to which TDOT can obtain access, and TDOT will exhaust every reasonable means to work with property owners and the regulatory agencies to gain access. If voluntary access cannot be obtained, TDOT will seek court-granted access or a limited condemnation action for investigation of potential substantially contaminated property for the preferred alternative, while still pursuing and negotiating for voluntary access. For those instances where access cannot be obtained, the procedure below will be used to estimate the extent, cleanup methods, and costs related to the potential contamination for the final environmental document and project alternative (location) decisions.

For potentially contaminated properties of the preferred alternative where access has been denied, the State will use all information available and the best professional judgment of staff experienced with hazardous waste contamination to estimate either the worst case that could reasonably be expected or the most likely case for the extent/cleanup/cost of the potential contamination. This estimate should be reliable and should take into account all related information which could help refine the estimate, such as the observed characteristics of the site, experience with similar sites in the past, existing records, interviews, previous testing by others, and testing by the State of properties adjacent to the site. The worst case or most likely case for the access-denied sites should then be combined with the results of investigation/testing of other potentially contaminated properties for the preferred alternative and summarized in the final environmental document.

Note that for projects being processed as Categorical Exclusions (CEs) that do not have comparable draft and final documents, it is expected that the appropriate testing or estimates would be made prior to final approval of the CE, to support that location decision.

Hazardous Materials Documentation Requirements

The results of a hazardous materials investigation must be thoroughly documented in the project environmental documentation and files. The draft environmental document should provide:

  • Complete documentation of all steps taken to identify hazardous materials sites;
  • A map to clearly delineate the extent of the site(s) in relation to alternative project alignments;
  • Information on the number and types of sites/structures and the extent of contamination and alternative treatment/disposal measures needed;
  • Results of coordination with EPA and State/local agencies and the public including description of the agencies' previous plans, if any, for cleanup of the site(s);
  • Sufficient information to allow a reasonable evaluation of alternatives; and
  • Justification for not avoiding the site.

The final document should, for the preferred alternative:

  • Describe the results of continuing coordination with EPA and State/local agencies and the public;
  • Document the resolution of hazardous waste issues, to the extent possible; and
  • To the extent possible, provide a detailed description of the site(s) and contamination, agreed upon treatment/disposal measures, and costs of the remedial plan.

The Phase I and Phase II Hazardous Materials studies, along with the other technical studies, will be submitted to FHWA for review concurrently with the submission of the review copies of the draft and final environmental documents.

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5.3.7 Conceptual Stage Relocation Plan

5.3.7.1 Applicable Regulations

The federal Uniform Relocation Assistance and Real Property Acquisition Policies Act, as amended, (43 CFR 24) requires that relocation assistance be made available to all displaced persons without discrimination, in order that those persons not suffer disproportionate burden as a result of projects designed for the benefit of the public as a whole.

5.3.7.2 Study Process for Relocations

The relocation study is prepared by TDOT Regional Right-of-Way staff following a request from the Environmental Division planner. Known as the Conceptual Stage Relocation Plan (CSRP), the purpose of the study is to ascertain the number and type of relocations, to determine whether comparable replacement housing is available and to determine project impacts. The number and type of relocations is one factor used in developing, refining and selecting project alternatives.

The first study phase is completed in the field. Maps are marked up to show the location of residences and businesses that the project has the potential to displace and notations are made of the estimated size of displaced buildings. If handicapped ramps are visible or minority occupants are viewed at houses that may potentially be displaced, notations are also made of this data.

Once the field work is completed, local realtors, the multiple listing service in an area, and/or local officials must be contacted to discuss potential community disruption that the displacements could cause and the availability of replacement housing.

5.3.7.3 Documentation

The data collected by either visual inspection or secondary or community sources in the field and the report that documents the relocation study must include:

  • An estimate of the number of households to be displaced, including the family characteristics (e.g., minorities, income levels, the elderly, large families, handicapped residents). At the planning stage, no direct contact is made with the occupants of properties that may be displaced. The survey is done by visual observations that note the existence of minorities, handicap ramps that indicate that disabled or elderly reside there, and property conditions that can indicate income level;
  • Identification of any divisive or disruptive effect that the displacements could have on the community, such as separation of residences from community facilities or removal of a business that is critical to the community;
  • An estimate of the possible number of businesses to be displaced (size, type, number of employees);
  • A description of replacement housing in the area, the ability to provide replacement housing for the families to be displaced, and a description of actions proposed to remedy insufficient housing, including, if necessary, use of the last resort housing provision;
  • A description of special relocation advisory services that will be necessary for identifiable unusual conditions, problems that may arise, and the possible solution to those problems;
  • Results of consultation with local officials, social agencies and community groups regarding the impacts on the community; and
  • An estimate of the time required to clear the project for construction.

FHWA has, in some instances, approved the inclusion of all of the above data in the NEPA document, in lieu of presenting it in a stand-alone report. If done as a stand-alone report, the planner will summarize the study findings for the NEPA document in the relocation section. This section must include a discussion of TDOT's relocation policy, a sample of which can be found in most approved NEPA documents or it can be obtained from the TDOT Right-of-Way Division. The relocation data may also assist in addressing the Environmental Justice Executive Order or the social or economic impact analysis conducted by the planner and described in Section 5.3.10.2. A copy of CSRP is submitted with the NEPA document to FHWA.

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5.3.8 Soils and Geology Analysis

5.3.8.1 Applicable Regulations

The soils and geology analysis is not specifically referred to in federal regulations but is needed to address the requirements of. 23 CFR Part 771, to "prepare documentation of compliance to a level appropriate to the undertaking's potential to cause significant harm to the environment." The study is also needed to assist in the location of the project.

5.3.8.2 Study Process for Soils and Geology

A preliminary soils and geology (geotechnical) study is undertaken for the NEPA document either by TDOT's Division of Materials and Tests or by a consultant. If the study is to be done by TDOT, the Environmental Division will need to make a request to the Materials and Tests Division to undertake the study.

The purpose of the study is to identify geotechnical features that may impact the project design or the environment. The study will identify the area's topography, soil types, subsurface formations, areas of unstable materials, caves, and sinkholes. In addition, special concerns, such as the existence of acid-producing rock, are identified. Recommendations are also made to address any geotechnical issues identified.

The identification of such issues may require coordination with the Design Division. Some of these issues may result in alignment shifts and others, such as the acid-producing rock, will require commitments to be made in the NEPA document as to how the material will be handled and disposed of properly. The planner will summarize the results of the study for the NEPA document and will include any agreed-upon minimization or mitigation measures. The geotechnical study should be included in the project files. In the post-NEPA design phase, in-depth geotechnical studies will be undertaken, as warranted.

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5.3.9 Sections 4(f) and 6(f) Analyses

Two federal regulations apply to projects that impact certain recreational resources: Section 6(f) of the Land and Water Conservation Fund Act of 1965 and Section 4(f) of the Department of Transportation Act of 1966, as amended. The latter also applies to other types of resources. Description of the regulations and study processes required to meet their respective regulatory requirements are provided in this section.

5.3.9.1 Section 4(f) of the Department of Transportation Act

Applicable Regulations

Section 4(f) was created when the U.S. Department of Transportation (USDOT) was formed in 1966 and was initially codified at 49 USC 1653. Amended in 1968 and again in 1983 as part of the overall re-codification of the USDOT Act, the Act applies only to federally-funded or permitted transportation projects. Now found in 49 USC 303, Section 4(f) reads:

(a) It is the policy of the United States Government that special effort be made to preserve the natural beauty of the countryside and public park and recreation lands, wildlife and waterfowl refuges, and historic sites.

(b) The Secretary of Transportation shall cooperate and consult with the Secretaries of Interior, Housing and Urban Development, and Agriculture, and with the States, in developing transportation plans and programs that include measures to maintain or enhance the natural beauty of lands crossed by transportation activities or facilities.

(c) The Secretary may approve a transportation program or project requiring the use of publicly owned land of a public park, recreation areas or wildlife or waterfowl refuge, or land of an historic site of national, State, or local significance (as determined by the Federal, State, or local officials having jurisdiction over the park, recreation areas, refuge, or site) only if,

(1) there is no prudent and feasible alternative to using that land; and

(2) the program or project includes all possible planning to minimize harm to the park, recreation area, wildlife and waterfowl refuges or historic site resulting from such use.

A provision with the same meaning is found at 23 U.S.C. 138 and applies only to FHWA actions. This regulation continues to be referred to as Section 4(f).

Section 4(f) applies to all historic sites (historic sites defined as those on or eligible for the NRHP), but only to publicly owned public parks, recreation areas, and wildlife and waterfowl refuges. It also applies only if the project impact is considered a "use" under Section 4(f). Three conditions exist under which a "use" occurs:

  1. When Section 4(f) property is acquired outright for a transportation project;
  2. When there is occupancy of property that is adverse in terms of the preservationist purposes of Section 4(f), primarily applies to historic NRHP eligible or listed resources; and
  3. When the proximity impacts of a transportation project on Section 4(f) property, even without the acquisition of the property, are so great that the purposes of the property that qualify the resource for protection are substantially impaired.

"Use" also falls into one of four types:.

  1. Fee simple - acquisition of right-of-way through direct purchase, permanently converting the property to a transportation use;
  2. Permanent easement - e.g., acquisition of an easement for maintenance or utility access;
  3. Temporary easement - e.g., an easement that is only needed on a short term basis, for construction, for example, and then is restored to its near original condition. Many conditions apply in which such an easement may not be considered a 4(f) use; and
  4. Constructive use - occurs when the project does not physically incorporate land from the resource into the project, but is so close that it severely impacts the resource's activities, and FHWA determines that the project "substantially" impairs the resource. Constructive use is the most complicated use to determine and the findings must be coordinated closely with and approved by FHWA.

Changes to Section 4(f) in SAFETEA-LU

In August 2005, Section 6009(a) of the Safe, Accountable, Flexible, and Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), made the first substantive revision to Section 4(f) since the 1966 U.S. Department of Transportation Act. Section 6009, which amended existing Section 4(f) legislation at both Title 49 U.S.C Section 303 and Title 23 U.S.C. Section 138, simplified the process and approval of projects that have only de minimis impacts on lands impacted by Section 4(f). Under the new provisions, once the USDOT determines that a transportation use of Section 4(f) property results in a de minimis impact, analysis of avoidance alternatives is not required and the Section 4(f) evaluation process is complete. Section 6009 also required the USDOT to issue regulations that clarify the factors to be considered and the standards to be applied when determining if an alternative for avoiding the use of a section 4(f) property is feasible and prudent.

On March 12, 2008 FHWA issued a Final Rule on Section 4(f), which clarifies the 4(f) approval process and simplifies its regulatory requirements. While Section 4(f) remains codified in law at Title 49 United States Code (USC) § 303 and 23 USC § 138, the regulation implementing this law has been moved from 23 CFR 771, FHWA's NEPA implementation regulation, to 23 CFR 774, in order to highlight that Section 4(f) is one of numerous social, economic, and environmental issues that must be considered under the "umbrella" of the environmental review process. In addition to being assigned a new location, the regulation has been reorganized to improve clarity and readability. The text of the final rule can be accessed on-line at http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr;sid=d2f8dcabc9b29425
cf1202dc33970a46; rgn=div2;view=text;node=20080312%3A1.19;idno=23;cc=ecfr;start=1;size=25
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De Minimis Impacts. SAFETEA-LU Section 6009(a) amended the existing Section 4(f) legislation at 23 U.S.C. 138 and 49 U.S.C. 303 to simplify the processing and approval of projects that have only de minimis impacts on lands protected by Section 4(f). Under the new provisions, once the USDOT determines that a transportation use of Section 4(f) property results in a de minimis impact, analysis of avoidance alternatives is not required and the Section 4(f) evaluation process is complete. The determination of de minimis impacts required concurrence from the officials with jurisdiction over the park, recreation area, or wildlife or waterfowl refuge, or in the case of a historic resource, concurrence from the SHPO and other consulting parties. All avoidance, minimization, mitigation, or enhancement measures that are required to be implemented as a condition of approval of the transportation program or project are incorporated as a part of the project.

FHWA issued on December 13, 2005 a memorandum (Guidance for Determining De Minimis Impacts to Section 4(f) Resources), which can be found at http://www.environment.fhwa.dot.gov/4f/index.asp. The memorandum uses the question-and-answer format to discuss the application of the de minimis impact criteria.

TDOT has developed a checklist to be used for the Determination of Section (4) De Minimis Finding, which is included in Appendix F [pdf 627 kb].

Feasible and Prudent Determination. SAFETEA-LU Section 6009 (b) required the USDOT to issue regulations that clarify the factors to be considered and the standards to be applied when determining if an alternative for avoiding the use of a Section 4(f) property is feasible and prudent. The final rule, issued on March 12, 2008, is codified in 23 CFR 774. The Final Rule defines a "feasible and prudent" avoidance alternative as one that "avoids using Section 4(f) property and does not cause other severe problems of a magnitude that substantially outweighs the importance of protecting the Section 4(f) property." The definition emphasizes that the use of Section 4(f) property is to be balanced against competing factors, with a "thumb on the scale" in favor of preserving the Section 4(f) property. The competing factors must pose the threat of severe problems or impacts. The definition describes an alternative as not feasible if it cannot be constructed on the basis of sound engineering judgment. A list of factors with a severity that may rise to the level at which an alternative would qualify as "not prudent" is included. The definition of feasible and prudent is located in section 774.17.

Interstate Highway Exemption. In the March 12, 2008 Final Rule, FHWA updated a number of existing exceptions to the Section 4(f) requirements, such as clarifying the applicability of the exception for restoration, rehabilitation, or maintenance of historic transportation facilities, and for the first time codifying several new exceptions that advance the regulation's preservation purpose. These new exceptions include:

  • The Interstate System and some of its individual elements;
  • Certain trails, paths, sidewalks, bikeways, and recreational facilities that are located within the transportation right of way; and
  • Transportation enhancement projects and mitigation activities where use of the Section 4(f) property is solely for the purpose of preserving or enhancing an activity, feature, or attribute that qualifies the property for Section 4(f) protection.

The seven 4(f) exceptions are located in 23 CFR 774.13.

With the Interstate highway exception the federal agencies are not required to consider the vast majority of the Interstate System as historic property under Section 4(f), provided the portion of the system plays an integral component of the entire system. As discussed in Section. 5.3.2.1, the only two Interstate Highway resources in Tennessee that have been designated by FHWA as "exceptionally significant features (ESF)" (from a historic perspective) are the I-40 Hernando DeSoto Bridge and the I-55 Memphis and Arkansas Bridge, both connecting Memphis with West Memphis, Arkansas.

Study Process for 4(f)

The Section 4(f) analysis and documentation will be undertaken by the planner or consultant for non-historic resources and by the cultural resource staff for an NRHP listed or eligible historic resource. Occasionally, consultants will prepare Section 4(f) evaluations for TDOT. Section 4(f) is widely acknowledged as a regulation that can be hard to interpret and implement. It is also one of the most widely litigated transportation regulations. It is very important that experienced staff or consultants either directly undertake the analysis or closely oversee it.

The 1987 FHWA Technical Advisory reprinted in Appendix D [pdf 201 kb] to this manual contains a section that provides the format and content of the required Section 4(f) Evaluation. An excellent recent 4(f) guide, developed by the Maryland State Highway Administration, entitled Section 4(f) Interactive Training, can be accessed at www.section4f.com. This guide contains a description of Section 4(f) resource types, what entails a "use," and the process for conducting a Section 4(f) analysis. On March 1, 2005, the FHWA issued the FHWA Section 4(f) Policy Paper, which replaces and rescinds the September 1987 Section 4(f) Policy Paper and subsequent memoranda and guidance issued by FHWA on Section 4(f). The 2005 Policy Paper provides updated comprehensive guidance on when and how to apply the provisions of Section 4(f) on FHWA projects. A copy of this paper is found on the FHWA website at http://www.environment.fhwa.dot.gov/projdev/4fpolicy.asp. Other information can also be found on FHWA's website.

Determining if Section 4(f) Resources are Present. The first step in the process is to identify whether Section 4(f) resources exist in the project area. Determination of applicability or non-applicability is made by the FHWA Division Office. The Division Office states whether Section 4(f) does or does not apply to a particular property and why.

There are four main categories of Section 4(f) resources:. park and recreation areas, wildlife refuges, cultural resources (historic sites), and other considerations. Parks and recreation areas must be publicly owned and open to the public, its major purpose must be for recreational activity, and it must be significant as a park or recreation area. Wildlife refuges must also be publicly owned, its major purpose must be that of a refuge, and it must be significant as a refuge.

Historic resources do not have to be in public ownership for Section 4(f) to apply. In order to qualify for protection under Section 4(f), a cultural resource must meet the following criteria:

  • It must be of National, State or local significance; and
  • If it is not on or eligible for listing on the National Register of Historic Places (NRHP), its protection must be considered appropriate by the FHWA.

The items in the group of "other considerations" may or may not be Section 4(f) resources, depending on certain conditions. Some of them may fit into multiple categories - parks and refuges, for example - while others may fit into one category or another, depending on how they're used. The list of other considerations may include:

  • Wildlife Management Areas
  • School Playgrounds
  • Fairgrounds
  • Public Multiple-Use Land Holdings
  • Wild & Scenic Rivers
  • Bodies of Water
  • Planned Facilities
  • Bikeways
  • Trails
  • Scenic Byways

A resource's Section 4(f) status is determined not by its name, but by the criteria that define it. No assumptions about the final status of any Section 4(f) resource should be made until the FHWA has reviewed and approved all documentation, including detailed records of the communication and coordination with the official with jurisdiction over the land in question. The determination of whether a Section 4(f) resource exists is based on:

  • Significance of the property;
  • Primary purpose of the land; and
  • Proposed transportation use;

Is the Resource Significant? If Section 4(f) resources exist in the study area, are the resources considered "significant"? The significance of the resource as defined by FHWA, means that in comparing the availability and function of the resource with the objectives of the community, the land in question plays an important role in meeting those objectives. Except under unusual circumstances, only historic properties on or eligible for inclusion on the National Register are protected under Section 4(f). For publicly owned land considered to be parks, recreation areas, or wildlife or waterfowl refuges, significance determinations are made as a result of a TDOT request to the agencies having jurisdiction over the land. The TDOT letter request to the agency should explain the meaning of the term "significance" for Section 4(f) purposes.

When a potential 4(f) resource is determined not to be a Section 4(f) resource after a review of its significance, the draft NEPA document should include this determination analysis.

Is there a Section 4(f) Use of the Resource? If the resource is considered significant, the second step is to determine if there is a "use" of the property as described above. This can be a "tricky" process, particularly in regard to historic resources. The Section 4(f) Policy Paper and the Section 4(f) Interactive Training provide easy-to-understand guidance that can assist with this determination. It is important to note that not all direct property takes will be considered a "use" and that even though there is no direct property take, the project's impacts might be considered a "use." Experienced staff or consultants must make this preliminary determination, which will need confirmation from FHWA.

Does a Programmatic Section 4(f) Evaluation apply? At this point, it is necessary to determine whether any of the five national Section 4(f) programmatic evaluations apply to the resource and "use" type. Certain types of actions can be processed as a "programmatic" evaluation. These are generally for projects where the "use" is considered minor, either in size or in level of effect for cultural resources. The primary advantage of the programmatic 4(f) is that it saves time, it requires only one document, has no comment period, and is approved by the FHWA Division office. Early coordination is necessary with the official having jurisdiction over the resource (e.g., the USACE if an individual permit is required, the SHPO, or other interested parties). Whether prepared by TDOT or a consultant, the document must be closely coordinated with FHWA. The content of the individual 4(f) and programmatic evaluation is similar. The five types of programmatic evaluations that have been approved for use nationwide are:

  1. Independent Bikeway and Walkway Construction Projects - can be used for constructing bikeways/walkways on parks and recreational properties;
  2. Historic Bridges - applicable for uses involving bridges that are individually eligible for the National Register of Historic Places;
  3. Minor Involvements with Historic Sites - can be used where a project involves a minor take from a property eligible for the National Register of Historic Places. No contributing elements may be demolished and the Section 106 effect determination must be "no adverse effect" or "no historic properties affected";
  4. Minor Involvements with Parks, Recreation Areas, and Wildlife and Waterfowl Refuges - applicable to minor property takes/encroachments into parks, recreation areas and wildlife/waterfowl refuges. The programmatic evaluation gives details on what constitutes "minor."; and
  5. Net Benefits - can be used where the proposed project, with mitigation, would actually result in an overall "net" benefit to the Section 4(f) property.

The two programmatic evaluations addressing minor involvements cannot be used for projects being processed as Environmental Impact Statements. The net benefits programmatic evaluation, which was published in the Federal Register on April 20, 2005, and the historic bridge programmatic, can be used with all NEPA processing options.

FHWA provides guidance on the conditions that must be met for a project to be processed as one of these five programmatic evaluations; the level of evaluation needed for avoidance alternatives, and the documentation that must be presented in support of the findings. The guidance is found at http://environment.fhwa.dot.gov/projdev/4fnspeval.asp.

The March 12, 2008 Final Rule makes it clear that the programmatic evaluation merely establishes a simpler approach to compliance for certain classes of projects and does not in itself provide an exemption to Section 4(f) requirements. The new rule specifies the process for applying an existing programmatic evaluation as well as the process for developing a new one. Requirements for programmatic evaluations are now listed in 23 CFR 774.3(d) and 774.5(c).

What is the Proposed Transportation Use of the Resource? If it is found that the project will involve a "use" from a "significant" Section 4(f) resource, then location or design alternatives must be examined that would avoid the 4(f) resource. When a project will involve a "use" from more than one Section 4(f) resource, the analysis needs to evaluate alternatives that avoid each and all 4(f) resources. Design avoidance alternatives should be in the immediate area of the property and may involve minor alignment shifts, a reduced facility (i.e., reduced cross section), use of retaining walls, or any combination of these features.

If the preferred alternative will involve a Section 4(f) use, then it must be proved that no prudent or feasible alternatives exist. This also is a complicated process. To prove that no such alternatives exist, it must be documented that "unique problems" are present when there are truly unusual factors or when the costs or community disruption reach extraordinary magnitude. According to the FHWA Section 4(f) Policy Paper:

When making a finding that an alternative is not feasible and prudent, it is not necessary to show that any single factor presents unique problems. Adverse factors such as environmental impacts, safety and geometric problems, decreased traffic service, increased costs and other problems such as these may be considered collectively. A cumulation of problems such as these may be a sufficient reason to use a 4(f) property, but only if it creates truly unique problems. In applying the standard of "unique problems," the nature, quality, and effect of the taking of the 4(f) property may be considered to show that there are truly unusual factors, or cost or community disruption of extraordinary magnitude.

The Final Rule, codified in 23 CFR 774, clarifies the factors to be considered and the standards to be applied when determining if an alternative for avoiding the use of a Section 4(f) property is feasible and prudent. Section 774.3(c) states that if the analysis concludes that there is no feasible and prudent avoidance alternative, then FHWA may approve only the alternative that causes the least overall harm in light of the statute's preservation purpose. The least overall harm is determined by balancing the following factors:

(i) The ability to mitigate adverse impacts to each Section 4(f) property (including any measures that result in benefits to the property);

(ii) The relative severity of the remaining harm, after mitigation, to the protected activities, attributes, or features that qualify each Section 4(f) property for protection;

(iii) The relative significance of each Section 4(f) property;

(iv) The views of the official(s) with jurisdiction over each Section 4(f) property;

(v) The degree to which each alternative meets the purpose and need for the project;

(vi) After reasonable mitigation, the magnitude of any adverse impacts to resources not protected by Section 4(f); and

(vii) Substantial differences in costs among the alternatives.

Once that alternative has been selected, all reasonable measures to minimize that harm or mitigate adverse impacts to the property in question must be included in the project before Section 4(f) approval can be granted.

The finding of "no prudent or feasible" alternatives can only be made by FHWA. FHWA will; however, consider agency comments.

Format for Section 4(f) Evaluation. A Section 4(f) Evaluation must be prepared if a 4(f) use is identified. The Draft Section 4(f) Evaluation is prepared during the draft NEPA document stage (EA or DEIS). The recommended format for this document is described in the Technical Advisory in Appendix D [pdf 201 kb]. For each Section 4(f) resource, the documentation must include:

  1. Proposed Action. Where a separate Section 4(f) evaluation is prepared, describe the proposed project and explain the purpose and need for the project.
  2. Section 4(f) Property. Describe each Section 4(f) resource which would be used by any alternative under consideration. The following information should be provided:

    (a) A detailed map or drawing of sufficient scale to identify the relationship of the alternatives to the Section 4(f) property;

    (b) Size (acres or square feet) and location (maps or other exhibits such as photographs, sketches, etc.) of the affected Section 4(f) property;

    (c) Ownership (city, county, state, etc.) and type of Section 4(f) property (park, recreation, historic, etc.);

    (d) Function of or available activities on the property (ball playing, swimming, golfing, etc.);

    (e) Description and location of all existing and planned facilities (ball diamonds, tennis courts, etc.);

    (f) Access (pedestrian, vehicular) and usage (approximate number of users/visitors, etc.);

    (g) Relationship to other similarly used lands in the vicinity;

    (h) Applicable clauses affecting the ownership, such as lease, easement, covenants, restrictions, or conditions, including forfeiture; and

    (i) . Unusual characteristics of the Section 4(f) property (flooding problems, terrain conditions, or other features) that either reduce or enhance the value of all or part of the property.

  3. Impacts on the Section 4(f) Property(ies). Discuss the impacts on the Section 4(f) property for each alternative (e.g., amount of land to be used, facilities and functions affected, noise, air pollution, visual, etc.). Where an alternative (or alternatives) uses land from more than one Section 4(f) property, a summary table would be useful in comparing the various impacts of the alternative(s). Impacts (such as facilities and functions affected, noise, etc.) which can be quantified should be quantified. Other impacts (such as visual intrusion) which cannot be quantified should be described.
  4. Avoidance Alternatives. Identify and evaluate location and design alternatives which would avoid the Section 4(f) property. Detailed discussions of alternatives in an EA or DEIS need not be repeated in the Section 4(f) portion of the document, but should be referenced and summarized. However, when alternatives (avoiding Section 4(f) resources) have been eliminated from detailed study, the discussion should also explain whether these alternatives are feasible and prudent and, if not, the reasons why.
  5. Measures to Minimize Harm. Discuss all possible measures that are available to minimize the impacts of the proposed action on the Section 4(f) property(ies). Detailed discussions of mitigation measures in the EA or DEIS may be referenced and appropriately summarized, rather than repeated.
  6. Coordination. Discuss the results of preliminary coordination with the public official having jurisdiction over the Section 4(f) property. Generally, the coordination should include discussion of avoidance alternatives, impacts to the property, and measures to minimize harm. In addition, the coordination with the public official having jurisdiction should include, where necessary, a discussion of significance and primary use of the property.

The conclusion that there are no feasible and prudent alternatives is not normally addressed at the draft Section 4(f) evaluation stage. Such conclusion is made only after the draft Section 4(f) evaluation has been circulated and coordinated and any identified issues adequately evaluated.

The draft Section 4(f) evaluation can be done as a stand-alone document for inclusion in an appendix of the draft NEPA document or it can be integrated into the body of the document. If included in the appendix, it must be briefly summarized and referenced in the body of the document. The FHWA will review the preliminary draft 4(f) evaluation and must provide clearance before it is circulated in the NEPA document or as a stand-alone Draft Section 4(f) Evaluation. The preliminary draft evaluation report submitted to the FHWA needs to include a description of the property, a map and the supporting information used to make the decision. The Draft Section 4(f) Evaluation must be sent to the regional office of the Department of Interior and, as appropriate, to the Forest Supervisor of affected National Forest properties.

After the draft NEPA document stage, if the selected alternative involves a Section 4(f) use, all of the information from the Draft Section 4(f) Evaluation should be included in the Final Section 4(f) Evaluation. In addition, according to the Technical Advisory, the final document must include:

  1. A discussion of the basis for concluding that there are no feasible and prudent alternatives to the use of Section 4(f) property. The supporting information must demonstrate that "there are no unique problems or unusual factors involved in the use of alternatives that avoid these properties or that the cost, social, economic and environmental impacts, or community disruption resulting from such alternatives reaches extraordinary magnitudes" (23 CFR 771.135(a)(2)). This language should appear in the document together with the supporting information.
  2. A discussion of the basis for concluding that the proposed action includes all possible planning to minimize harm to the Section 4(f) property. When there are no feasible and prudent alternatives that avoid the use of Section 4(f) property, the Final Section 4(f) Evaluation must demonstrate that the preferred alternative is the feasible and prudent alternative with the least harm on the Section 4(f) resources after considering mitigation to the Section 4(f) resources.
  3. Concluding statement as follows, "Based on the above considerations, there is no feasible and prudent alternative to the use of land from the (identify Section 4(f) property) and the proposed action includes all possible planning to minimize harm to the (Section 4(f) property) resulting from such use."

The final document must also include a summary of all formal coordination with the Department of Interior and, if appropriate, the U.S. Forest Service and copies of all relevant Section 4(f) comments received.

The Final Section 4(f) Evaluation is generally either included as a chapter in the final NEPA document or in the appendix as a stand-alone report. If included in the appendix, it must be briefly summarized and referenced in the body of the document.

5.3.9.2 Section 6(f) of the Land and Water Conservation Fund Act

Applicable Regulations

The purpose of the Land and Water Conservation Fund (L&WCF) Act of 1965 (36 CFR 59) is to "assist in preserving, developing and assuring accessibility to all citizens of the United States of America of present and future generations, such quality and quantity of outdoor recreational resources as may be available and are necessary and desirable for individual active participation." The program provides matching grants to states and local governments through the U.S. Department of Interior, National Park Service (NPS), for the acquisition and development of public outdoor recreation areas and facilities.

Section 6(f) of the Act contains provisions to protect the federal investment and the quality of resources developed with L&WCF assistance. Section 6(f) protects grant-assisted areas from conversions to other uses, and states that:

No property acquired or developed with assistance under this section shall, without the approval of the Secretary, be converted to other than public outdoor recreation uses. The Secretary shall approve such conversion only if he finds it to be in accord with the then existing comprehensive statewide outdoor recreation plan and only upon such conditions as he deems necessary to assure the substitution of other recreation properties of at least equal fair market value and reasonably equivalent usefulness and location.

For Tennessee resources developed with L&WCF grants, TDEC is responsible for compliance and enforcement of these provisions. The pertinence of Section 6(f) to transportation projects is that if a TDOT project proposes to take land from a recreational resource that has been wholly or partially developed with a L&WCF grant, the project must be coordinated with TDEC, Division of Recreational Services, Grants Program Office, and replacement land of "reasonably equivalent usefulness and location" must be found.

Study Process for 6(f)

The planner must identify whether a project will take land from any local or state parks. If any land will be taken, the project must be coordinated with the park owner, whether it is state or local government. This coordination is intended to make them aware of the potential project impacts, to get their input on the project and its impacts, to determine the significance of the resource, and to determine if there are any restrictions or covenants attached to the park land, for example, was L&WCF grant money used to develop the facility?

Once the planner receives the comments, the planner should draft and send a letter to TDEC stating that the project may take land from a park. The letter should summarize the coordination that has occurred with the entity that has jurisdiction over the park. If known, the letter should acknowledge that TDOT has been informed that L&WCF grant monies were utilized in park development. The project location, in relation to the park and its boundaries must be depicted on a map that accompanies this letter.

In its comments, TDEC will inform TDOT or confirm whether the park has been wholly or partially developed with L&WCF grant monies. The involvement could range from planning activities, to the installation of playground equipment, to the development of a new park.

If the park has been developed at any funding level with L&WCF monies, during the draft NEPA document stage, the planner must coordinate with TDEC on the issue of locating replacement land for the land to be taken, if TDEC is in agreement with proceeding with the project in that manner. The planner must work with the TDOT Right-of-Way Division staff to identify land that is suitable and to identify the monetary value of the land to be replaced and possible replacement land. TDOT must submit to TDEC one original and one copy of an appraisal report prepared by a licensed appraiser and establishing the fair market value of the property to be converted (taken). The replacement property must be of at least equal fair market value as the conversion property. The correspondence must also include documentation describing the entity responsible for the costs associated with obtaining the appraisals and the land replacement. A statement indicating that the property proposed for replacement is of reasonably equivalent usefulness and location as that being converted must also be included.

Replacement land may be adjacent to the park where land will be taken or adjacent to another state or local park. Once an agreement is reached with TDEC, the process and results are summarized in the draft NEPA document. Any commitments made are then reaffirmed in the final NEPA document.

5.3.9.3 Section 6(f) and 4(f) Differences

While Section 4(f) evaluations may encounter Section 6(f) properties, some key differences exist:

  • Section 4(f) applies only to USDOT programs and projects, while Section 6(f) applies to programs and policies of any federal agency; and
  • Mitigation is more flexible under Section 4(f). Section 6(f) requires replacement lands of equal value, location and usefulness as the impacted lands, while Section 4(f) may or may not include replacement lands.

While Section 6(f) is integral to Section 4(f) compliance if L&WCF are used, Section 4(f) is not integral to Section 6(f). Section 6(f) involvement should be discussed in the Section 4(f) Evaluation and in the separate parklands and recreational resources section of the NEPA document, if applicable.

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5.3.10 Other Impact Analyses

Other technical analyses needed for the NEPA document are described below and include:

  • Social and Community Impacts
  • Environmental Justice and Non-Discrimination
  • Economic and Business Impacts
  • Land Use Planning and Land Use Impacts
  • Farmland Impacts
  • Visual Quality Impacts
  • Traffic and Accident Impacts
  • Construction Impacts
  • Wild and Scenic Rivers Impacts
  • Floodplain Impacts
  • Pedestrian and Bicycle Considerations
  • Energy Impacts
  • Indirect and Cumulative Impacts

These impact analyses can be conducted by the Environmental Division planner and/or consultant. The analyses are done for inclusion in the NEPA document and do not generally require a stand-alone report.2. Differing levels of field work, coordination, data collection and analysis are required to substantiate or understand a project's potential impacts. The analysis can include:

  • Review of census data;
  • Use of GIS for spatially locating different types of data;
  • Using data provided by other TDOT divisions;
  • Conducting Internet searches;
  • Reviewing project plans and other mapping;
  • Obtaining and reviewing planning documents;
  • Coordination with state/federal agencies, local government, and the public; and
  • Conducting a field review of the project area.

Many tasks require a field review of the project area to enable an accurate depiction of existing conditions and impact assessment. One field review and a marked up set of plans and notes can facilitate many of the analyses needed for the NEPA document. For example, during the field review the planner can collect information for use in the environmental justice, social and community, economic and business, community facilities and land use impact analyses. If new or planned development is discovered during the field review, it is important to inform the project designer or the Project Manager. A review of approved NEPA documents, both EAs and EISs, can provide the planner with a good idea of the level of analysis needed and can suggest a possible format for presenting the analysis.

5.3.10.1 Social/Community Impacts

Applicable Regulations

Assessing community impacts is needed for practical reasons, but is also required and supported by federal regulations, policies and Executive Orders, for example:

  • Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA);
  • NEPA;
  • Title VI of the Civil Rights Act of 1964, and related statutes;
  • 23 USC 109(h), Standards (1970);
  • 23 CFR 771, Environmental Impact and Related Procedures; and
  • Executive Order 12898 on Environmental Justice.

Study Process

Community Impact Assessment (CIA) is a fluid and iterative process that occurs throughout the life of a transportation project - from planning through construction and monitoring. The basic steps of the process are:

  1. Define the project and study area
  2. Develop a community profile
  3. Analyze impacts
  4. Identify Context Sensitive Solutions
  5. Document findings

Public involvement is an integral part of each of these steps.

The level of effort involved in each step is a function of the size and complexity of the project, the level of controversy involved, and the potential for significant community impacts. If a project requires preparation of an EIS, it will also require a more detailed community impact assessment. The findings would be incorporated into the EA or EIS, a separate technical report, or both. For smaller or less controversial projects, the results might simply be documented in the project files and summarized for use in the next phase of the project. If an issue surfaces that is of considerable concern to an affected community, it should be assessed regardless of the nature of the project. This will assure that it is adequately addressed and does not stop the project later in the process. Below is a brief description of each component or step of the CIA process.

1. Define the Project and Study Area

The first step of the CIA process entails gaining an understanding of the proposed project and its potential to impact the surrounding community or communities, and defining the study area boundary for the assessment of community impacts. Having a good understanding of the proposed project and its potential to impact communities is essential to properly scope and develop the project. The Environmental Division planner or consultant should obtain information on the proposed project as early in the project development process as possible. This information should include: project purpose, project need(s), potential alternatives, logical termini, a general (order of magnitude) estimate of potential impacts, and an identification of potential community issues. Information on project history and prior planning studies associated with the project such as visioning activities, comprehensive plans, and traffic studies undertaken by communities and/or planning partners, should also be obtained. This information can be obtained through review of available project files, field reconnaissance, and interviews with project sponsors, planning partners, project stakeholders, and TDOT staff. Upon obtaining an understanding of the proposed project, boundaries for the CIA study area can be established.

The CIA study area should reflect the varied physical and social boundaries that help define the geographic limits of the community. CIA practitioners need to recognize that social impacts can occur throughout a community and are not limited in extent to those areas immediately adjacent to a proposed transportation project. The CIA study area, because of the wide-ranging nature of community impacts, may involve a broader area than the typical project study area boundaries, which are generally based on the direct physical impacts of the alternatives under consideration.

The CIA study area may include a synthesis of the following community boundaries:

  • Physical boundaries - boundaries attributable to man-made elements (bridges, roadways, buildings, etc.) or land use characteristics.
  • Natural boundaries - boundaries attributable to natural features of the landscape; such as topography, watersheds, bodies of water, wildlife habitat, and vegetative natural communities.
  • Administrative boundaries - political boundaries and boundaries attributable to such organizations as school districts and infrastructure authorities.
  • Social boundaries - boundaries attributable to ethnic concentrations, influence and extent of social, civic, and religious backgrounds.
  • Economic boundaries - boundaries attributable to areas and types of employment and commercial opportunities.

While the limits of some of these boundaries are easily identified, the interpretation of others will require input from various community stakeholders.

The CIA study area boundaries should be clearly delineated on project mapping and graphics and made available to the public in a variety of forums (plans, displays, public meetings, project websites, newsletters, etc.). The CIA study area boundaries should be periodically reassessed throughout the course of the project development process and modified, as necessary, based on community stakeholder input and/or relative to changes in the proposed action, or in the dynamics of the affected community.

Depending upon the length of the project development process, it may be necessary to reassess earlier findings to assure that the assessment is accurate or to repeat the steps to address new impacts that are identified later in the process. To streamline the process, the planner or consultant should strive to anticipate future needs and collect relevant data on all potential impacts early in the process.

2. Develop a Community Profile

The development of community baseline conditions involves the collection of qualitative and quantitative data from field observations, published agency sources, prior transportation studies, community organizations, municipal governments, and community and individual coordination activities. The documentation of community resources should not focus only on the physical location of resources, but also on the function, value, quality, and capacity of those resources. CIA is not only a collection and assessment of the physical location of resources and structures, but also the functional and social characteristics of those features as they relate to the community's "quality of life."

To adequately characterize a community, information on a wide variety of community characteristics should be collected. A list of recommended community considerations on which to base the development of community baseline conditions is discussed later in this document. In addition, it is recommended that a Community Context Audit, developed as part of TDOT's Context Sensitive Solutions initiative, should be completed during this step.

Comprehensive plans at both the municipal and county level can provide a wealth of information on communities and often include vision statements, and community goals, objectives, and values related to quality of life concerns. Comprehensive plans and other relevant planning studies, documents and ordinances should be reviewed as part of the development of baseline conditions. Public involvement during this step can include a range of activities aimed at gathering information from community stakeholders and presenting the collected baseline information to the stakeholders.

The goals of these activities are to verify that the study team has adequately identified baseline conditions and to ensure a thorough understanding of important community issues. The identification and review of baseline conditions should be performed in consultation with the MPO or RPO, local officials, and other community stakeholders. The baseline conditions should be reassessed periodically throughout the project development process and modified as necessary.

A variety of information sources can be consulted to develop the profile. These may include both primary sources, such as public meetings, interviews, or fieldwork and secondary sources, such as newspapers, minutes of public hearings, community or facility plans.

3. Analyze Impacts

Analyzing project impacts involves uncovering potential community impacts, collecting information on the nature of those impacts, and determining the relative intensity of those impacts. This analysis needs to occur for each major project alternative, including the "No-Build" scenario. Establishing the consequences of doing nothing helps to clarify what impacts can be attributed to the project and the relative magnitude of those impacts, in relation to the potential benefits. In addition, conducting this analysis for each alternative provides a meaningful basis for comparing alternatives and selecting a final alternative.

Community impact analysis addresses three general categories of impacts: direct, indirect, and cumulative. Potential impacts can be explored in a variety of ways, through evaluation of primary or secondary data, basic problem solving, discussions with knowledgeable persons, and public involvement. An effective community impact assessment requires a solid understanding of the community, direct observation of the affected area, and some research and evaluation of data. It does not, however, require or necessarily benefit from sophisticated models or many hours of technical analysis.

4. Identify Context Sensitive Solutions

In concert with the TDOT's commitment to Context Sensitive Solutions (CSS), it should be the goal of every project to develop and identify transportation improvements/solutions that are context sensitive and help the project fit more harmoniously into the community. These context sensitive solutions should be developed in collaboration with the impacted communities.

If adverse impacts are identified, potential methods to address them may be explored. Solutions to adverse impacts fall into the following four categories:

  • Avoid - Alter the project so the impact does not occur.
  • Minimize - Modify the project to reduce the severity of an impact.
  • Mitigate - Alleviate or offset an impact or replace an appropriated resource.
  • Enhance - Add a desirable or attractive feature to the project to make it fit more harmoniously into the community.

5. Document Findings

The results of the CIA are used for decision-making throughout the project development process. Therefore, it is important to document this information in a clear and concise manner for reference during the environmental and future project phases. All assessment materials (e.g., maps, analyses, public comments, survey responses, minutes of meetings, etc.) should be collected and maintained in the project file. A written summary of this material should be prepared near completion of the environmental phase, both for inclusion in the NEPA document as well as for reference as the project moves into the next phase of project development.

This written summary may be prepared for direct inclusion in the NEPA document, or a separate stand-alone report can be prepared for summarization and reference in the NEPA document. Generally a separate technical report is prepared if the complexity of the project, severity of the impacts, or quality of data justify a specialized technical report.

Guidance exists in the Technical Advisory (Appendix D [pdf 201 kb]) and several other publications, such as Community Impact Assessment: A Quick Reference for Transportation (Publication No. FHWA-PD-96-036). This publication can be viewed at http://www.ciatrans.net/CIA_Quick_Reference/Purpose.html. TDOT is also developing a stand alone Community Impact Assessment Manual.

5.3.10.2 Environmental Justice and Non-discrimination

Applicable Regulations

Title VI of the Civil Rights Act and Executive Order 12898 on Environmental Justice relate to the programs and projects of federal agencies and their impacts to minority and low-income populations.

Title VI, 42 U.S.C. 2000d et seq., was enacted as part of the landmark Civil Rights Act of 1964. It prohibits discrimination on the basis of race, color, and national origin in programs and activities receiving federal financial assistance.

Executive Order 12898 and the FHWA compliance procedures (FHWA Order 6640.23, December 2, 1998) requires identifying and addressing disproportionately high and adverse human health and environmental effects, including the interrelated social and economic effects of their programs, policies and activities on minority and low-income populations in the United States. FHWA Order 6640.23 provides the following definitions:

  • Low-Income Population means any readily identifiable group of low-income persons who live in geographic proximity, and, if circumstances warrant, geographically dispersed/transient persons (such as migrant workers or Native Americans) who would be similarly affected by a proposed FHWA program, policy, or activity.

    Low-Income means a household with income at or below the U.S. Department of Health and Human Services poverty guidelines.
  • Minority Population means any readily identifiable groups of minority persons who live in geographic proximity, and if circumstances warrant, geographically dispersed/transient persons (such as migrant workers or Native Americans) who would be similarly affected by a proposed FHWA program, policy, or activity.

    Minority means a person who is:
    • Black (having origins in any of the black racial groups of Africa);
    • Hispanic (of Mexican, Puerto Rican, Cuban, Central or South American, or other Spanish culture or origin) regardless of race;
    • Asian American (having origins in any of the original peoples of the Far East, Southeast Asia, the Indian subcontinent, or the Pacific Islands); or
    • American Indian and Alaskan Native (having origins in any of the original people of North America and who maintain cultural identification through tribal affiliation or community recognition).
  • Adverse Effects means the totality of significant individual or cumulative human health or environmental effects, including interrelated social and economic effects, which may include, but are not limited to: bodily impairment, infirmity, illness or death; air, noise, and water pollution and soil contamination; destruction or disruption of man-made or natural resources; destruction or diminution of aesthetic values; destruction or disruption of community cohesion or a community's economic vitality; destruction or disruption of the availability of public and private facilities and services; vibration; adverse employment effects; displacement of persons, businesses, farms, or nonprofit organizations; increased traffic congestion, isolation, exclusion or separation of minority or low-income individuals within a given community or from the broader community; and the denial of, reduction in, or significant delay in the receipt of benefits of FHWA programs, policies, or activities.
  • Disproportionately High and Adverse Effect on Minority and Low-Income Populations means an adverse effect that:
    • Is predominately borne by a minority population and/or a low-income population; or
    • Will be suffered by the minority population and/or low-income population and will be appreciably more severe or greater in magnitude than the adverse effect is that will be suffered by the non-minority population and/or non-low income population.

A CEQ publication entitled Environmental Justice - Guidance under the National Environmental Policy Act provides a good overview of the regulations and assessment process (http://www.epa.gov/compliance/ej/resources/policy/ej_guidance_nepa_ceq1297.pdf). Environmental Justice issues may arise at any time during NEPA and even in early project planning prior to the commencement of NEPA. TDOT must consider these issues, as appropriate, at every step of the project development process. Environmental Justice issues cover a broad range of impacts that fall under the NEPA umbrella, including impacts on the natural or physical environment and interrelated social, cultural, and economic impacts. Staff that is undertaking an assessment of whether Environmental Justice issues may be pertinent to a project should be highly sensitive to the history or circumstances of a particular community or population, the particular type of impact, and the nature of the proposed action.

FHWA provides the following guiding principles for identifying Environmental Justice issues:

  • Agencies should consider the composition of the affected area, to determine whether minority populations, low-income populations, or Indian Tribes are present in the area affected by the proposed action, and if so whether there may be disproportionately high and adverse human health or environmental effects on minority populations, low income populations or Indian tribes;
  • Agencies should consider relevant public health data and industry data concerning the potential for multiple or cumulative exposure to human health or environmental hazards, to the extent such information is reasonably available. For example, data may suggest there are disproportionately high and adverse human health or environmental effects on a minority population, low income population or Indian Tribe from the agency action. Agencies should consider these multiple or cumulative effects, even if certain effects are not within the control or subject to the discretion of the agency proposing the action;
  • Agencies should recognize the interrelated cultural, social, occupational, historical or economic factors that may amplify the natural and physical environmental effects of the proposed agency action. These factors should include the physical sensitivity of the community or population to particular impacts; the effect of any disruption on the community structure associated with the proposed action; and the nature and degree of impact on the physical and social structure of the community;
  • Agencies should develop effective public participation strategies. Agencies should, as appropriate, acknowledge and seek to overcome linguistic, cultural, institutional, geographic, and other barriers to meaningful participation, and should incorporate active outreach to affected groups; and
  • Agencies should assure meaningful representation in the process. Agencies should be aware of the diverse constituencies within any particular community when they seek community representation and should endeavor to have complete representation of the community as a whole. Agencies also should be aware that community participation must occur as early as possible for it to be meaningful.

Study Process

The data collected above for social/community impacts are combined with public outreach and a field review to determine if the project has the potential to impact low or minority populations and, if so, to determine if these impacts are disproportionate. The data utilized include race, color, national origin, age and level of income of the overall population, as well as the existence of any minority or low-income populations or communities. GIS can spatially plot the U.S. Census demographic data collected for this analysis.

In the NEPA document, the planner first presents the baseline data. The discussion of this information in the text should be accompanied by data tables. Such tables provide an easy to read overview of the data and they also provide a means for referencing the data later in the document. Then, the planner should describe community involvement and any issues identified by the community that are related to Environmental Justice. The planner must develop and present a clear statement in the NEPA document of whether the project alternative(s) will or will not involve an environmental justice issue, i.e., will it have a disproportionately high or adverse effect on minority and low-income populations?  In this assessment, it is important to recognize that impacts on such populations may be different from impacts on the general population due to a community's distinct cultural practices.

When determining whether impacts are disproportionately high and adverse, FHWA suggests that the following three factors be considered:

  1. Whether there is or will be an impact on the natural or physical environment that significantly (as defined in NEPA) and adversely affects a minority or low-income population. Such effects may include ecological, cultural, human health, economic or social when those impacts are interrelated to impacts on the natural or physical environment;
  2. Whether environmental effects are significant (as defined by NEPA) and are or may have an adverse impact on minority and low-income populations that exceeds or is likely to appreciably exceed those of the general population or other appropriate comparison group; and
  3. Whether the environmental effects occur or would occur in a minority or low-income population affected by cumulative or multiple exposures from environmental hazards.

When a disproportionately high and adverse effect on a low-income population or minority population has been identified, an analysis should be done to show how the effects are distributed within the affected community. Displaying available data spatially, through GIS, can provide an effective visualization of the distribution of impacts among the various demographic populations.

Lastly, when Environmental Justice issues are identified, TDOT should encourage members of the communities that may suffer a disproportionately high and adverse human health or environmental effects from a proposed project to develop and comment on possible alternatives as early as possible in the planning process.

5.3.10.3 Economic and Business Impacts

The economic and business impact analysis can be prepared by the planner or consultant by first creating a baseline economic profile. Data/information for this analysis can be obtained from:

  • U.S. Census (employment, income);
  • Tennessee Department of Labor (County Economic Profiles, unemployment data);
  • Local Economic Development Office, Chamber of Commerce, Planning Office;
  • Field review to locate existing and planned businesses;
  • Local government - tax base data;
  • City/County websites - may contain list of large employers and their locations and number of employees; and
  • USDA, National Agricultural Statistics Service, Census of Agriculture.

Once the baseline is established, the planner must determine the economic and business impacts. To prepare the impact analysis, the planner should address, as pertinent, the questions below:.

  • Will the project encourage businesses to move to the area, or to relocate within the area, close to or outside the area?
  • Will the project increase or diminish visibility for a commercial area of traffic-related businesses?
  • Will the project increase or decrease parking for businesses?
  • Will access changes help or harm business viability, including operating farms?
  • How will the project affect employment (e.g., will it facilitate a new industrial park and more jobs).
  • Will the project affect land/property values (e.g., changes may provide improved access to an area, thereby increasing property values or values may decline as a function of a property's proximity to the facility or as a result of a new undesirable feature).
  • Will the project spur economic development?
  • How will the project affect the tax base and property values (e.g., remove taxable property from the tax base and change property values)?

5.3.10.4 Land Use Planning and Land Use Impacts

The planner or consultant should conduct a records check, a field review and a visit to the local planning office to collect the data needed to determine the project's potential impacts to land use and whether the project is consistent with area plans. In addition, contact with the local planning office can reveal land development projects in the project area that are under consideration, in the planning stages, or are under construction. It is not unusual for such changes to have occurred in the project area after the time the project was flown for aerial photography or after the time that TDOT coordinated with local officials during the very early project development stage (e.g., at the Needs Assessment or TPR stage).

The planner should mark up a set of project plans in the field indicating land uses throughout the corridor. During this field review or by telephone, the planner should talk with city/county or development district planning staff and obtain applicable excerpts or a copy of any comprehensive plans (including the transportation element) and information on any developments that are being considered or are planned or approved in the project corridor. The planner or consultant should also ask if either zoning or subdivision regulations are in place in the project area.

Tennessee Code Annotated 6-58-106 (Public Chapter 1101, adopted in 1998) outlined the need for cities and counties to evaluate their potential growth over the next twenty years and define their responsibility to manage growth, ensure efficient use of land, and provide appropriate public service standards. The law requires each county prepare a growth plan that places parameters on growth within the county, identified as municipal urban growth boundaries, county planned growth areas, and rural areas. These delineations are based on land needs and public service capabilities of each area. The result is intended to guide growth within each county in a more efficient manner. The planner or consultant should ask if an urban growth plan has been approved and if it has, to request an Urban Growth Boundary map that outlines growth boundaries around the developed towns and cities. The boundaries are placed to depict areas where a locality believes it has the capability to serve water, sewer and other infrastructure within the next 20 years.

If the planner or consultant uncovers any planned development in the project alignment, the planner or consultant should notify the preparer of the functional plans and/or the Project Manager and discuss how the issue will be addressed.

The planner or consultant can also consult with local government and check in the field the locations of parks, recreation facilities, and community services, such as fire stations, ambulance services, schools, and hospitals.

The land use data will form the basis for the land use impact analysis conducted by the planner or consultant. The baseline land use discussion should describe:

  • The general character of land use in the area (e.g., areas of agricultural, residential, commercial or industrial uses, locations of community services). For a long corridor project, this may be done from one end to the other (e.g., The project begins in an area that is populated by small farms. As it proceeds northward, the area is populated with ca. 1970s subdivision development. The county high school is on the north side of the subdivision development on the west side of the subject roadway. At the project's northern end, the area has commercial strip development, including a large box retailer).
  • Whether there are any planned developments in the area.
  • Existing land use plans and controls, including the growth plan, if one exists.

Issues to be examined in the impact analysis discussion include:

  • Is the project consistent with the comprehensive development plan of an area, and its transportation element, if one exists?
  • Will the project cause changes in land use? Will it induce commercial development at an interchange where no development or no commercial development now exists? Will the development that would likely occur require changes to the zoning or subdivision ordinance? Will the project bypass an area lined with highway service businesses, eliminating the need for such services at that location? Will the project change a rural area to an area desirable for industrial development?
  • How will the project affect growth of an area? Is it consistent with the Urban Growth Boundary, if one exists?

5.3.10.5 Farmland Impacts

Applicable Regulations

The farmland impact assessment is undertaken by the planner during Initial Coordination and is coordinated with the state office of the Natural Resource Conservation Service (NRCS). Guidance is available on FHWA's Environmental Guidebook on the FHWA website: http://environment.fhwa.dot.gov/guidebook/chapters/v1ch5.asp.

The purpose of the Farmland Protection Policy Act of 1981 (FPPA) is to "minimize the extent to which Federal programs contribute to the unnecessary and irreversible conversion of farmland to non-agricultural usages, and to ensure that Federal programs are administered in a manner that, to the extent practicable, will be compatible with State, unit of local government, and private programs and policies to protect farmland." If farmland, as defined in the Act, is converted to non-agricultural use by a project and if there are adverse effects (as defined by NRCS when the impact rating on the AD-1006 form exceeds 160), FHWA and TDOT must examine alternatives to minimize the impacts. Pursuant to the FPPA, "farmland means prime or unique farmlands."

Six situations exist where land does not meet the FPPA definition of farmland and no coordination with NRCS is needed:

  1. Land is not farmland, either through its soil type as indicated on NRCS soils mapping as not suitable for agriculture, or through consultation with NRCS. This also applies if land needed for right-of-way is clearly not farmland (e.g., rocky and/or mountainous terrain, sand dunes). Completion of a Farmland Impact Rating Form (Form AD-1006) is not necessary;
  2. Land is urban (or within a designated Urban Growth Boundary). Completion of an AD-1006 form is not necessary;
  3. For linear development, if land has already been converted for industrial, commercial, residential or recreational activity. Completion of an AD-1006 form is not necessary;
  4. If the arrangements for borrow areas or disposal sites are not directed by TDOT, then completion of an AD-1006 form is not necessary for these activities;
  5. A state has a LESA (Land Evaluation and Site Assessment) system (which Tennessee does not have); or
  6. Farmland with low potential. Completion of the AD-1006 form is needed to make this determination, but it is not necessary to coordinate with the NRCS.

Study Process

For projects requiring coordination with the NRCS, the planner or consultant completes Parts I and III of the Form AD-1006 during initial coordination (see Chapter 4, Section 4.3.4.1). This form and the instructions for completing it can be found at NRCS's website: http://www.nrcs.usda.gov/programs/fppa/. A copy of the form is in Appendix F [pdf 627 kb]. The planner completing the form will need to utilize available plans to calculate the amount of right-of-way that may be needed from land that does not fall under the six exceptions above.

TDOT will send the AD-1006 form3, together with a copy of all maps showing the locations of project alternatives to the NRCS state office. The NRCS is required to respond within 45 days and will either complete Parts II, IV or V or mark a "No" in Part II indicating that no farmlands are involved. Part V will contain a value rating of between 0 and 100 (the higher the rating, the greater the impact). Pursuant to this Act, FHWA coordinates an assessment of the potential farmland impacts for its project with the Tennessee NRCS office through the completion of Form AD-1006.

If farmland involvement is indicated on the form by the NRCS, then TDOT must undertake the assessment needed to complete Part VI. This task will require review of aerial photographs and quad maps, or possibly even a field review. In-depth directions for this task are on the NRCS website shown above. Then, Part VII must be completed to determine the level of significance of the farmland involvement. Projects receiving a total score of less than 160 points require only minimal level of consideration for protection and no alternatives are required to be evaluated. For sites scoring 160 or higher, TDOT must consider alternatives that convert less farmland or convert farmland of lower value.

A copy of the completed AD-1006, if one is required for the project, should be included in the NEPA document. The NEPA document should summarize the steps taken to comply with the FPPA and the results of the coordination. Any steps taken to reduce the amount of farmland impacts should also be discussed.

5.3.10.6 Visual Quality Impacts

Applicable Regulations

One of the most readily recognized effects of a transportation project is its visual presence. FHWA regulations do not specifically require the inclusion of a visual impact analysis in NEPA documents. NEPA, however, states that visual effects ("esthetics") are one environmental factor that must be considered during the environmental impact analysis.

Study Process

A visual impact assessment will be prepared for the project area. FHWA's 1990 Guidance Material on the Preparation of Visual Impact Assessments is out of print and FHWA has indicated that there are no plans to reprint it. USDA Forest Service and the U.S. Department of the Interior, Bureau of Land Management (BLA) both have visual assessment methodologies that are similar to FHWA's and are acceptable to FHWA as alternative processes to undertake. The BLA Visual Resources Manual (Manual 8400 - Visual Resource Management) can be found at http://www.blm.gov/nstc/VRM/8410.html. The 1997 USDA Forest Service manual is Landscape Aesthetics: A Handbook for Scenery Management, Agriculture Handbook 701; it is currently not available online but can be requested by contacting:

USDA Forest Service Southern Region Regional Office
1720 Peachtree Street, Suite 760S
Atlanta, GA 30309
Phone: 404-347-4177 Fax: 404-347-4821

It is important to recognize that the level of visual analysis needed for the NEPA document needs to be commensurate with the scope and magnitude of a project and its impacts, as well as public concerns. In general, for an EIS when there is a potential for visual impacts, a visual impact assessment should be prepared and summarized in the NEPA document. The need for a discussion of the visual effects of a proposed project in an EA depends on the visual characteristics of the proposed project area. If the visual environment encompasses visually sensitive elements or if it is considered unique by its viewers, a visual analysis may be warranted.

The public nature of highways and their visual prominence in the environment require that visual impacts - both positive and negative - be adequately addressed and considered in project planning. Community acceptance of a project may also be strongly influenced by its visual effects.

Whether the analysis is prepared for direct insertion into the NEPA document or as a stand-alone visual impact analysis, the following visual issues should be addressed:

  • Describe the visual environment;
  • Identify the visual quality of the area. The existing landscape is considered to have a high visual quality when its setting (landforms, water, vegetation, manmade development) have striking characteristics that convey visual excellence. High visual quality can be present in natural, rural or urban settings;
  • Identify visually sensitive resources/locations. This could include, for example, areas with historic or culturally important resources, areas of recognized scenic beauty, parks, and residential areas;
  • Describe the views looking to and from the highway;
  • Describe potential visual impacts - both positive and negative. Highways will result in some degree of visual change in an area. The analysis should identify the project's level of effect on visually sensitive resources/locations based on changed views to or from the resources and the perceptions of viewers; and
  • Describe feasible measures to minimize or mitigate adverse visual impacts.

5.3.10.7 Traffic and Crash Impacts

Study Process

In most cases, the NEPA Documentation Office staff requests a traffic and crash report from the Project Planning Division, Safety Planning and Travel Data Office. A map is included with the request (Note: The Environmental Division has developed a form to request traffic and crash data). Once the information is received by the planner, it will assist with several tasks, some of which are completed by the planner and others that are completed by other TDOT offices or consultants. The information is used as follows:

  • By the planner to identify safety and/or community impacts for discussion in NEPA document;
  • By the Safety Planning and Travel Data Office or consultant to prepare a Level of Service Analysis (for the planner's discussion in the Purpose and Need and/or Alternatives Chapters of the NEPA document); and
  • By the consultant or Air and Noise Section staff for the noise impact analysis (for the planner to summarize in the impacts discussion of the NEPA document).

The traffic data received include existing, or baseline, traffic and projected traffic, with or without the project. Traffic is assigned to the local roadway network and is depicted on a map. This information can be used for both a level of service analysis and for conducting air and noise analyses.

In the traffic impact analysis, the planner needs to show how the proposed project is alleviating traffic congestion, particularly if this is included as one of the purposes of the project. In order to do this, for example, for a new roadway, a level of service analysis must be done for existing local roads currently being used, such as parallel routes. This analysis would show how these roadways operate under existing conditions, and how they will be improved under future conditions with the proposed improvements. In other words, if one of the purposes of the project is to "relieve traffic congestion", as is often the case, the document writer must objectively prove that the improvements are accomplishing this objective.

TDOT's traffic data are also included in the printouts of the crash data. The printouts include a summary sheet (or sheets), worksheets and attached computer generated data sheets. (A key/legend is required to read and understand the data sheets and can be obtained from the Safety Planning and Travel Data Office.). The summary sheet indicates the total number of crashes, and numbers of injuries and fatalities. It also contains the statewide average rate for the road type and other comparative rates. Using the data sheets, planners can also identify accident locations by log mile and accident types. These can be mapped by the planner to identify the actual accident locations. This also graphically depicts locations that have had frequent accidents, if any exist.

The crash rate analysis was prepared to identify any high crash locations by route segment. This is the first step toward identifying any problem locations. The section crash rates are based on the number of crashes on a specified section, the average daily traffic on the roadway, the time frame of analysis, and the length of the section. They are expressed in terms of crashes per one million vehicle miles. A section's crash rate is then compared to a statewide critical crash rate based in part on the Tennessee statewide average crash rate. The comparison is expressed as a ratio of the section crash rate to the critical crash rate and is referred to as the critical crash rate factor. The critical crash rate factor is the threshold above which there is a statistical certainty (at a 99.5% confidence level) that the section crash rate exceeds the average crash rate and is not mistakenly shown as higher than the average due to randomly occurring crashes. In practical terms, sections with a critical crash rate factor greater than one are considered high crash locations and are potential candidates for safety improvements.

The section crash rate is also compared directly to the statewide average crash rate provided by TDOT. Section rates that exceed the statewide average crash rate but not the critical crash rate may be problem areas, but they are not statistically proven to be higher crash areas. Therefore, this second comparison is used to identify a second tier of highway sections that may have crash problems and could be considered for safety improvements (if warranted) based on further analyses.

5.3.10.8 Construction Impacts

Study Process

The planner will prepare the analysis of a project's potential adverse construction impacts. The discussion for the NEPA document should address construction-related concerns such as, but not limited to the following:

  • Maintenance of traffic and access;
  • Employment benefits;
  • Waste disposal;
  • Utility relocation;
  • Discovery of unknown archaeological sites;
  • Erosion control;
  • Air quality; and
  • Noise.

In some of these areas, impacts will be very similar from project to project. A review of the construction impact section of previously approved NEPA documents will provide guidance on how to address each of these issues, but some projects will require more analysis to be completed in areas of concern. The construction-related commitments to avoid and minimize impacts should be outlined in the NEPA document. Several commitments are standard to TDOT and are in accordance with TDOT's Standard Specifications for Road and Bridge Construction, TDOT's Statewide Storm Water Management Program, and FHWA's Best Management Practices.

5.3.10.9 Wild and Scenic Rivers Impacts

Applicable Regulations

The planner must determine if federally-designated Wild and Scenic Rivers, or those under study for designation, are in the project area. Rivers are designated under the federal Wild and Scenic Rivers Act. According to the Act, "certain selected rivers of the Nation which, with their immediate environments, possess outstandingly remarkable scenic, recreational, geologic, fish and wildlife, historic, cultural, or other similar values, shall be preserved in free-flowing condition, and that they and their immediate environments shall be protected for the benefit and enjoyment of present and future generations."

Currently, no Tennessee rivers are under study and only one river has been designated:. the Obed Wild and Scenic River in Morgan and Cumberland Counties in East Tennessee on the Cumberland Plateau. The designated "river" includes the segment of the Obed River from the western edge of the Catoosa Wildlife Management Area to its confluence with the Emory River. It also includes Clear Creek from the Morgan County line to the confluence with the Obed River, Daddys Creek from the Morgan County line to the confluence with the Obed River and the Emory River from the confluence with the Obed River to Nemo Bridge. Over 45 miles of creeks and rivers are included in this wild and scenic river area. The list of designated and study rivers can be found at http://www.rivers.gov/wildriverslist.html.

Study Process

If a project has the potential to adversely impact the Obed River, or any rivers added to the listing for study or through designation, early coordination must be undertaken with the U.S. Department of Interior, National Parks Service. Potential effects of the project must be analyzed; adverse effects include alteration of the free-flowing nature of the river, alteration of the setting or deterioration of the water quality. If adverse effects are identified, consultation with the NPS must be undertaken to avoid or mitigate the impacts. In addition, publicly-owned waters of designated rivers are subject to Section 4(f), and public lands adjacent to designated rivers may be subject to Section 4(f). For each alternative that takes land, coordination with the NPS will provide information on the management plan, specific affected land uses and any necessary Section 4(f) coordination.

The Tennessee Scenic Rivers Act of 1968 designated scenic rivers. A list and map showing the state's 13 designated Scenic Rivers can be found at http://www.state.tn.us/environment/na/scenicrivers/. For the NEPA document, the planner should identify the existence of these rivers in the study area and describe the project's potential impacts.

5.3.10.10 Floodplain Impacts

Applicable Regulations

Protection of floodways and floodplains is required under 23 CFR 650A, which is explained in FHWA's policy guide on assessing floodplain impacts that can be found at http://www.fhwa.dot.gov/legsregs/directives/fapg/cfr0650a.htm. Protection of floodplains and floodways is also required by Executive Order 11988 Floodplain Management and USDOT Order 550.2 Floodplain Management and Protection. The intent of these regulations is to avoid or minimize highway encroachments within the 100-year (base) floodplains, where practicable, and to avoid supporting land use development which is incompatible with floodplain values. The Technical Advisory (Appendix D [pdf 201 kb]) also addresses floodplain impacts.

Study Process

A preliminary analysis is needed in the NEPA phase to determine whether a project alternative will encroach on any base (100-year) floodplain and/or regulatory floodway, and if so the "worst-case" amount of encroachment. That is, the amount of encroachment (generally in acres) if no structures are built to span part or all of an area.

The planner should work with an ecologist or engineer to undertake the level of floodplain analysis needed. The first step in the process is to consult the National Flood Insurance Program (NFIP) Flood Insurance Rate Maps (FIRM) if such maps are available for the subject community. Information of community participation in NFIP is available in the National Flood Insurance Program Community Status Book, which is available through the website of the Federal Emergency Management Agency (FEMA):. http://www.fema.gov/. The FIRM, aerial photographs, and USGS quadrangle maps are all needed to conduct the analysis.

If NFIP maps exist for a community, they must be reviewed. Frequently asked questions regarding the NFIP maps are found at the website and FEMA maps can also be viewed on-line or ordered from the FEMA flood map store. It is helpful to overlay the floodplain limits on project mapping, such as functional plans or USGS quad maps. If a highway project encroaches on the base floodplain within a NFIP-participating community, the floodplain administrator of the local government that has land use jurisdiction should be notified. Communities in the regular NFIP program generally have detailed flood insurance studies performed. In such communities, the NFIP map will be an insurance rate map and in the majority of cases, a regulatory floodway is in effect. The local floodplain administrator should also be asked to provide the planner with a copy of local floodplain regulations, if they exist. Communities in the NFIP emergency program usually have no completed flood insurance study and only limited floodplain data. For these communities the map will be a hazard boundary map, without a regulatory floodway.

The environmental document should identify the locations and sizes of floodplains. If applicable, the document should state that "no significant encroachments of the floodplain are anticipated that would result in a potential for interruption of a transportation facility which is needed for emergency vehicles or provides the community's only evacuation route; a significant risk, including property loss or hazard to life; or a significant adverse impact on the natural and beneficial floodplain values."

If an alternative results in a floodplain encroachment or supports incompatible floodplain development having significant impacts or requires a commitment to build a particular structure size or type, the NEPA document must include an evaluation and discussion of practicable alternatives to the structure or to the significant encroachment. The evaluation must also include a preliminary analysis of whether the encroachment would be consistent with or require a revision to the regulatory floodway. If a floodway revision is necessary, the final NEPA document must include evidence from FEMA and the applicable local floodplain regulatory agency that such revision would be acceptable.

A detailed floodplain study, a "Location Hydraulic Report" is undertaken by the TDOT Structures Division generally in the permitting or design phase of the project. According to the Technical Advisory, the following items should be included in the Location Hydraulic Report, which should be "commensurate" with the level of environmental risk or impact:

  • Flooding risks;
  • Impacts on natural and beneficial floodplain values;
  • Support of incompatible floodplain development (i.e., any development that is not consistent with a community's floodplain development plan);
  • Measures to minimize floodplain impacts; and
  • Measures to restore and preserve the natural and beneficial floodplain values.

5.3.10.11 Pedestrian and Bicycle Considerations

Applicable Regulations

There are growing efforts throughout the United States to improve conditions for bicycling and walking. Congress recognized this need in 1991 when it passed the Intermodal Surface Transportation Efficiency Act (ISTEA). ISTEA included a spending package that increased the responsibilities of local and state governments to plan and implement bicycle and pedestrian facilities. The funding infusion provided by ISTEA and continued by the Transportation Efficiency Act for the 21st Century (TEA-21) in turn fueled even stronger efforts to build trails and to renovate streets and roadways for bicycling and walking. Section 1202(a) of TEA-21 states that "bicycle transportation facilities and pedestrian walkways shall be considered, where appropriate, in conjunction with all new construction and reconstruction of transportation facilities, except where bicycle and pedestrian use are not permitted." That section of TEA-21 also states that "transportation plans and projects shall provide due consideration for safety and contiguous routes for bicycles and pedestrians."

In addition, 23 USC 109(n) states that the Secretary of the USDOT "shall not approve any project or take any regulatory action under this title that will result in the severance of an existing major route or have significant adverse impact on the safety for non-motorized transportation traffic and light motorcycles, unless such project or regulatory action provides for a reasonable alternate route or such a route exists."

FHWA considers non-motorized modes of transportation to be an integral part of their mission and a critical element of the local, regional and national transportation system. To varying extents, pedestrians and bicycles will be present on many transportation facilities and it was the intent of TEA-21 that all new and improved transportation facilities be planned, designed and constructed with this in mind. The passage of SAFETEA-LU has not altered the intent of TEA-21.

In March 2010, FHWA adopted a Policy Statement on Bicycle and Pedestrian Accommodation Regulations and Recommendations (http://www.dot.gov/affairs/2010/bicycle-ped.html). The purpose of the policy statement was to reflect the FHWA's support for the development of fully integrated active transportation networks to accommodate people of all ages and abilities, including people too young to drive, people who cannot drive, and people who choose not to drive. The statement reads "The DOT policy is to incorporate safe and convenient walking and bicycling facilities into transportation projects. Every transportation agency, including DOT, has the responsibility to improve conditions and opportunities for walking and bicycling and to integrate walking and bicycling into their transportation systems. Because of the numerous individual and community benefits that walking and bicycling provide - including health, safety, environmental, transportation, and quality of life - transportation agencies are encouraged to go beyond minimum standards to provide safe and convenient facilities for these modes."

With the adoption of this policy statement, FHWA encouraged states, local governments, and public and private agencies and organizations to adopt similar policy statements and to go beyond minimum design standards and requirements to create safe, attractive, sustainable, accessible, and convenient bicycling and walking networks.

Study Process

"Due consideration" of bicycle and pedestrian needs should include, at a minimum, a presumption that bicyclists and pedestrians will be accommodated in the design of new and improved transportation facilities. In the planning, design, and operation of transportation facilities, bicyclists and pedestrians should be included as a matter of routine, and the decision to not accommodate them should be the exception rather than the rule. There must be exceptional circumstances for denying bicycle and pedestrian access either by prohibition or by designing highways that are incompatible with safe, convenient walking and bicycling.

TDOT's Bicycle and Pedestrian Policy (Policy No. 530-01, adopted September 1, 2004), is "to routinely integrate bicycling and walking options into the transportation system as a means to improve mobility and safety of non-motorized traffic."

If non-motorized transportation is already a feature of a facility, the continuation of that function should be considered in project development. In addition, changes in traffic or traffic patterns may transform a pedestrian-friendly environment into one in which walking or biking residents are at risk of injury. A discussion of the results of this consideration should be included in the NEPA document. If routes are truncated or removed, replacement routes should be developed and discussed in the NEPA document.

5.3.10.12 Energy Impacts

A detailed energy analysis is needed only for large-scale projects. For most projects, the NEPA document should discuss in general terms the construction and operation requirements and conservation potential of the project alternative(s). The planner can review previously completed NEPA documents for examples of acceptable discussions.

For large-scale projects with potential substantial energy impacts, the discussion should include:

  • Direct energy impacts from energy consumed by vehicles using the facility; and
  • Indirect energy impacts from project construction and/or changes in type of vehicle usage or numbers of vehicles.

The final NEPA document should discuss any conservation measures that will be implemented as part of the preferred alternative, for example, high occupancy vehicle incentives and measures to improve traffic flow.

5.3.10.13 Indirect and Cumulative Impacts

Section 5.1.1.2 defines the concepts of indirect and cumulative impacts and provides references for analyzing these impacts. The degree to which indirect and cumulative impacts need to be evaluated in a NEPA document depends on the potential for the impacts to be significant and varies by resource, project type, geographic location and other factors. Indirect and cumulative impacts should be addressed, particularly when preparing an EA or EIS, with other agencies and the public during early coordination activities or scoping. The issue of indirect and cumulative impacts can be discussed on a resource-by-resource basis, and/or discussed in a separate section in the Impacts Chapter of the NEPA document.

Footnotes

2. In rare cases, significant issues may warrant a stand-alone study be undertaken, and its results summarized in the NEPA document.

3 The old AD-1006 was a carbon form that had two carbon copies. Generally today, a photocopy is used or a copy is printed from the Internet.

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