Final Tier 1 Environmental Impact Statement 5-1

5 Existing Conditions and Environmental Consequences

5.1 Introduction

A Tier 1 environmental review was conducted for the APRCS because FRA and FTA determined 

that the route of a future passenger rail system must first be considered in its regional context, 

as it would influence roadway networks, future planning processes, and environmental issues 

spanning portions of three counties, numerous jurisdictions, and multiple independent 

planning processes. Given the existing and projected rapid growth in and around the study 

area, it is vital to identify a preferred corridor alternative as early as feasible, so that planning 

decisions can consider a future passenger rail system, and before new development reduces 

alignment options or increases ROW acquisition costs. While this Tier 1 EIS examines a 

conceptual level of design without a specific track alignment, more detail about specific 

affected areas would be examined in Tier 2 NEPA analyses.

The Final EIS includes revisions made subsequent to the publication of the Draft EIS. 

Substantive additions or text revisions to this chapter of the EIS resulting from agency and 

public comments received on the Draft EIS during the review and comment period are 

identified by the use of underlined type.

Service development planning is also being completed as part of the development of the APRCS 

and includes the development of FRA-required conceptual site plans for passenger rail, new 

stations, and maintenance facilities. Detail about the affected areas for stations and 

maintenance facilities would be examined more closely in future Tier 2 NEPA analyses. ADOT 

has prepared the Service Development Plan (SDP) for the alternative identified by the FRA. The 

SDP will be completed and adopted by ADOT following the publication of the Final EIS and 

issuance of a FRA Record of Decision.

This chapter describes the existing social, economic, and environmental conditions within the 

two corridor alternatives which serve as a baseline for comparing the potential impacts of a 

passenger rail system with the No Build Alternative. Chapter 5, Existing Conditions and 

Environmental Consequences also identifies potential environmental consequences that could 

result from implementation of a passenger rail system, as well as types of mitigation measures 

that could be used to avoid or minimize some of the potential environmental consequences 

identified.

5.1.1 Regulatory Requirements

This Tier 1 EIS is being prepared in compliance with NEPA to analyze and disclose the potential

effects of a passenger rail system between Tucson and Phoenix. FRA is the lead federal agency 

for the EIS. ADOT is the local sponsoring agency and in 2009 received $2 million – $1 million 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-2

plus a $1 million state match – through FRA’s Capital Assistance to States – Intercity Passenger 

Rail Service Program, to prepare a Service Development Plan and the required environmental 

study. In addition to funding for these two studies, ADOT received $4,331,250 in 2011 through 

FTA’s New Starts program funds ($3,465,000 federal in an 80%-20% state match), to conduct an 

Alternatives Analysis (See the Alternatives Analysis Appendix) to be eligible to proceed with the 

FTA New Starts Project Development phase. 

ADOT could seek future funding opportunities from FTA, which provides financial and technical 

assistance to local public transit systems, as well as FRA, which provides financial assistance for 

developing and enhancing intercity rail service. Funding could also be provided by other sources

such as other USDOT grant programs, federal loan programs, local bonds, and public-private 

partnerships.

Cooperating agencies include those agencies with federal, state, or local jurisdiction by law. 

Cooperating agencies also may have special expertise or information that would assist in 

development of the analysis in an EIS, even when the agency may not have legal jurisdiction. 

FHWA and FTA are both serving as cooperating agencies, which includes responsibilities for 

sharing data and contributing to the review of the EIS. Approximately 75 parties were invited to 

serve as participating agencies, including federal, state, and local agencies. In addition, 

consultation has been initiated with 29 Native American tribes. Numerous stakeholders have 

participated in the studies and planning process, as described in Chapter 3, Public Agency 

Coordination.

In addition to complying with NEPA (42 U.S.C. § 4321 et seq.), this EIS complies with FRA's 

Procedures for Considering Environmental Impacts (Environmental Procedures) (64 FR 28545, 

May 26, 1999), Council on Environmental Quality’s (CEQ) regulations implementing NEPA (40 

CFR parts 1500-1508), and FTA’s Environmental Impact and Related Procedures (23 CFR Part 

771), for compliance with that agency’s Alternatives Analysis process.

5.1.2 Chapter Organization

In this Tier 1 EIS, the following general outline is used to summarize the analysis conducted for 

each resource. 

 Methodology and Regulatory Requirements – Summarizes the impact analysis 

methodology and the regulatory requirements for each resource, including the sources 

for the data collected and the applicable regulatory agencies.

 Existing Conditions – Describes the existing social, economic, or environmental 

conditions for each resource within the study corridor and, in some cases, the area 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-3

surrounding the corridor alternatives. Existing data are used to develop the description 

as a baseline for assessment of effects for the alternatives considered.

 Environmental Consequences – Evaluates the potential effects of building, 

implementing, and operating a passenger rail system within each of the corridor 

alternatives, beginning at the southern hub in Tucson and ending at the northern hub in 

Phoenix. This section also evaluates the potential effects of the No Build Alternative.

 Potential Mitigation Measures – Reviews potential mitigation measures, including 

avoidance and minimization appropriate for a Tier 1 EIS and lists more specific 

mitigation measures that might be identified during preparation of Tier 2 NEPA 

documents.

 Tier 2 Considerations – Identifies some of the additional studies and evaluations that 

may be required as funding becomes available and specific track alignments and rail 

station locations are developed.

Tier 2 NEPA analysis could be advanced for logical operable sections of a passenger rail system 

within the preferred corridor alternative; that is, one or more operable sections of a Tucson-toPhoenix passenger rail system could be developed as individual projects. Separate Tier 2 NEPA 

documentation would be prepared for each project identified. Preliminary design and NEPA 

documentation would be conducted in support of the Tier 2 analyses because more detailed 

information would be necessary to identify the specific resources that would be affected by 

construction and to what extent. Any such section would be required to have independent 

utility, with or without construction of other sections. The sections could be evaluated as 

logical, independent sections subject to available funding and the source of that funding. Tier 2

sections could also be combined, modified, or revisited in the future based on available 

funding.

In addition to the No Build Alternative, this Tier 1 EIS analyzes the potential effects of building 

and operating a passenger rail system within two corridor alternatives that are a mile wide. At 

this stage in project development, rather than examine specific alignments, the corridor 

analysis looks at a broader area, allowing future design and construction to avoid potential 

direct impacts while reducing the potential need to reassess the existing conditions and 

potential impacts. At the same time, the entire mile-wide corridors described under “Existing 

Conditions” in this chapter would not be affected by construction of a passenger rail system. 

Therefore, the potential impacts described in this Final Tier 1 EIS are estimated based on a 

hypothetical railroad ROW corridor, particularly where potential ground disturbance is a factor 

in the impacts analysis. The impact area used to estimate potential effects was obtained by 

adding 60 to 70 feet to either side of the 60 to 80-foot typical sections shown in Figure 4-3, 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-4

Figure 4-4, and Figure 4-5. Thus, a 200-foot wide corridor was used to allow for passenger 

stations, parking lots, and temporary impacts such as staging areas, access for construction 

vehicles and equipment, areas for stockpiling topsoil, and nurseries for relocated vegetation 

that could be used in reclaimed construction areas.

To measure the potential impacts of a hypothetical 200-foot wide corridor within the mile-wide 

corridor alternatives without a specific alignment identified, the ratio of 200 feet to the onemile (5,280 foot) corridor width was calculated, and then multiplied by the GIS-derived existing 

conditions data within the mile-wide corridor alternative, as represented in the following 

formula:

200′impact corridor

1 − mile (5,280′) corridor alternative = 0.0379

0.0379 x Existing Conditions = Estimated Impact

Because the estimated environmental consequences are representative of the mile-wide 

corridor and not calculated for a predetermined alignment, the Tier 1 analysis preserves 

flexibility for consideration of multiple alignments within the corridor identified for Tier 2 NEPA 

studies.

The resources within the natural, built, and social environment have characteristics that vary, 

and not all of the environmental resource categories in this Tier 1 EIS were analyzed using this 

method. For resources unrelated to potential ground disturbance, e.g., noise and vibration 

from train operations, air quality, and energy consumption, federal guidelines and regulations 

specify the method by which potential impacts are measured, based on established sensitivity 

distances or effect buffers. 

This Tier 1 EIS provides approximate impact quantities for environmental resources in most 

cases; however in some cases this is not possible. For example, land use data are not available 

at the same level of detail throughout the approximately 120-mile-long corridor alternatives. 

Consequently, land use impacts are addressed qualitatively to provide a consistent level of 

analysis within and between the two corridor alternatives. The individual resource sections 

describe the area reviewed and discuss whether impacts are evaluated quantitatively or 

qualitatively in each Methodology and Regulatory Requirements section.

The Corridor Aerial Atlas Appendix contains 91 maps of the corridor alternatives, with many 

environmental resources highlighted. The maps were developed using recent aerial and 

satellite high-resolution photographic imagery, and the most recent GIS data available for a 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-5

variety of environmental resources. Resource data were not digitized or field verified for this 

Tier 1 analysis.

5.1.3 Resources Eliminated from Study in the Tier 1 EIS 

Table 5-1 identifies environmental resources traditionally included in environmental studies 

that are not found within the study corridors and therefore are not analyzed in this Tier 1 EIS. 

The table includes background information regarding each resource category and provides the 

sources used to obtain this information. 

Table 5-1. Resources Eliminated from Study in the Tier 1 EIS

Resourcea Determination Rationale for Determination

Wild and Scenic Rivers Not Present No watercourses in the National Wild and Scenic 

Rivers System or congressionally approved for study 

are located within the corridor alternatives (National 

Wild and Scenic Rivers System 2012).

Navigable Rivers Not Present No navigable rivers are located within the corridor 

alternatives (Arizona Navigable Stream Adjudication 

Commission 2003). 

Outstanding Arizona 

Waters

Not Present No outstanding Arizona waters are within the 

corridor alternatives (Arizona Department of 

Environmental Quality [ADEQ] 2008).

National Natural 

Landmarks

Not Present No National Natural Landmarks are located in the 

corridor alternatives (National Park Service 2012).

a These resource lists are updated periodically. ADOT will review new issues of these lists for relevance to a project until it is constructed.

5.2 Land Use

The following assessment of land use includes a program-level (qualitative) analysis of the 

impacts of a passenger rail system on existing and future land uses within one of two 

alternative study corridors (the Yellow and Orange corridor alternatives), as well as the No Build 

Alternative. A review of the land use, transportation, environmental planning, and conservation 

elements of the general plans of the cities and counties through which the corridor alternatives 

pass was undertaken to determine if construction and operation of a passenger rail system 

would be consistent with these jurisdictions’ planned land uses and applicable goals and 

policies. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-6

5.2.1 Methodology and Regulatory Requirements

As stated earlier, this EIS complies with FRA's Procedures for Considering Environmental 

Impacts (Environmental Procedures) (64 FR 28545, May 26, 1999) and FTA’s Environmental 

Impact and Related Procedures (23 CFR Part 771). FRA’s Environmental Procedures Section 

14(n)(15) states that an EIS should assess the impacts of each alternative on local land use 

controls and comprehensive regional planning as well as on development within the affected 

environment, including, where applicable, other proposed federal actions in the area.

This Tier 1 assessment of land use impacts focuses on areas where the existing uses would be 

converted to transportation land use and, specifically, where new facilities would be 

anticipated. Changes in land use such as induced growth from an expanded transportation 

system are assessed in the indirect and cumulative effects section later in this chapter. The 

impacts on local land use controls and comprehensive regional plans would be evaluated during 

Tier 2 NEPA analysis.

The corridor alternatives are each approximately 120 miles long. While specific track 

alignments have not been determined, a 200-foot-wide ROW corridor of this length would 

occupy approximately 2,900 acres. Given the magnitude of the mile-wide corridor alternatives, 

land use data collection and analysis were accomplished using publicly available electronic GIS 

land cover and zoning data and corresponding general plans. Field surveys and ground-truthing

of existing land uses were not conducted as part of this analysis. Because alignments and 

station locations could hypothetically be located anywhere within the mile-wide corridor 

alternatives, zoning, which varies widely within the corridor alternatives, was not addressed in 

this Tier 1 EIS. For the same reason, land use impacts were not analyzed for any 200-foot ROW 

corridor, nor were Bureau of Land Management (BLM) subsurface mineral estate mining rights

(See the letter from the United States Department of the Interior (DOI) in the Agency 

Comments on the Draft Tier 1 EIS Appendix). BLM administers mineral rights beneath private 

land within the corridor alternatives. In the Tier 1 analysis, only surface land use was identified 

within the corridor alternatives. Specific affected areas would be examined in more detail in 

Tier 2 NEPA analyses to assess project-level impacts on land use, zoning, individual property 

owners, and mining rights. 

For this Tier 1 analysis, land uses are identified relative to the following categories assembled 

from land use designations defined by PAG, CAG, and MAG; and potential impacts are 

described qualitatively. 

 Agricultural/rangeland

 Commercial
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-7

 Designated open space

 Industrial

 Institutional

 Office

 Other/mixed use

 Public

 Residential

 Undevelopable

 Utilities/transportation

 Vacant (also described as undeveloped land)

5.2.2 Existing Conditions

Aerial views of the study corridors are shown in Maps 1 through 91 of the Corridor Aerial Atlas 

Appendix. While the overall Study Area encompasses Pima, Pinal, and Maricopa counties, the 

corridor alternatives run between the major city destinations of Tucson and Phoenix and 

intermediately pass through the mid-sized cities of Gilbert, Mesa, and Tempe southeast of 

Phoenix. Additional communities through which the study corridors pass include small 

economic centers or suburbs of the larger cities, including Marana, Eloy, Coolidge, Florence, 

Queen Creek, and the Census-Designated Place of San Tan Valley in Pinal County.

Undeveloped land accounts for 27 percent of the existing land use within the Yellow Corridor 

Alternative and 33 percent of the Orange Corridor Alternative. Agriculture and rangeland 

account for 24 percent and 25 percent of the Yellow and Orange corridor alternatives, 

respectively. Residential use accounts for between 11 and 14 percent of the use for the Yellow 

and Orange corridor alternatives, respectively. A mix of other uses accounts for the remaining 

percentage. Table L-1 in the Land Use Appendix provides more information on existing uses in 

the study corridors. 

Future land use within the corridor alternatives is overwhelmingly planned for residential use, 

with approximately 36 percent of each corridor alternative designated for residential

development. Designated mixed uses also account for approximately 26 percent of the future 

land use within each corridor. A mix of other planned uses accounts for the remaining 

percentage. Table L-2 in the Land Use Appendix provides more information on future land use 

in the corridor alternatives.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-8

Land ownership within the corridor alternatives is dominated by private land, including 

approximately 63,000 acres of each corridor alternative, constituting 80 percent of the Yellow 

Corridor Alternative and 76 percent of the Orange Corridor Alternative. The bulk of the 

remaining land is managed by the Arizona State Land Department, accounting for 

approximately 13,000 acres, or 17 percent, of the Yellow Corridor Alternative and 

approximately 17,000 acres, or 20 percent, of the Orange Corridor Alternative. The remaining 

percentage includes a mix of other land management agencies and owners, including federal, 

tribal, and local entities. Figure 5-1 and Figure 5-2 on the following pages illustrate land 

ownership and jurisdiction in and around the corridor alternatives. Table L-3 in the Land Use 

Appendix provides more information on land ownership within the study corridors.

A broad description of the land use within the corridor alternatives follows.

Yellow Corridor Alternative

Southern Hub to Eloy

Predominant land uses around the southern terminus near downtown Tucson include 

transportation (UP and I-10), industrial, commercial, institutional, residential, and 

vacant/undeveloped. Proceeding northwest along the corridor, land uses within the corridor 

vary in type and intensity between the east and west sides of I-10 due to the proximity of the 

Santa Cruz River west of I-10. The eastern side of I-10 is densely developed with residential and 

industrial uses, while the immediate area on the west side is dominated by undeveloped land 

and land zoned as open space (typically land set aside for conservation or recreation). Leaving 

northern Tucson, land uses within the study corridor common to both the Orange and Yellow 

corridor alternatives transition to predominantly open space to the east of I-10 and agricultural 

to the west of I-10. 
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International

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Existing Conditions and Environmental Consequences

Figure 5-1. Land Ownership and Jurisdiction between Tucson and Eloy

5

Final Tier 1 Environmental Impact Statement 5-9

e

Airport

Interstate

State or US Highway

Railroad

Major Drainage

Yellow Corridor

Alternative

Orange Corridor

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Bureau of Land Managment

City, County, State Park

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National Park Service

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Game and Fish

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Sources: Esri 2014; Arizona Department of Transportation 2013; Arizona Land Resource Information System 2013

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 Indian Community

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5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-10

Figure 5-2. Land Ownership and Jurisdiction between Eloy and Phoenix

Interstate

State or US Highway

Railroad

Major Drainage

Yellow Corridor

Alternative

Orange Corridor

Alternative

Bureau of Land Managment

City, County, State Park

US Forest Service

National Park Service

Tribal Land

Military Reservation

Bureau of Reclamation

County Land

Game and Fish

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City Boundary

Le g e nd

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Sources: Esri 2014; Arizona Department of Transportation 2013; Arizona Land Resource Information System 2013

N
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-11

Sensitive designated land uses are scattered along the study corridor from the southern hub to 

Eloy. In Tucson, both sides of the I-10 corridor are designated as residential land use. Land 

designated as open space and small amounts of designated institutional land are scattered 

within the residential areas. At the boundary of Tucson and Marana, the corridor contains 

designated open space, transitioning into institutional land uses (i.e., churches, schools). 

Traveling north through Marana, residential land is scattered throughout the corridor, with 

open space designated along the southwestern edge. A small amount of agricultural land and 

rangeland is located in Marana east of I-10, as well as just north of the city boundaries in 

unincorporated Pinal County. In the community of Picacho, both sides of the I-10 corridor are 

predominantly undeveloped, with inclusions of agricultural lands near the I-10 and SR 87 

interchange. As the study corridor travels through the narrow Picacho Pass, the west side 

encroaches on Picacho Peak State Park. Small amounts of open space are also designated west 

of I-10 just north of the city boundary. The common study corridor ends near the City of Eloy.

Residential land dominates the future land use designations from southern Pinal County north 

to Eloy, with a few scattered open space areas. 

Eloy to Northern Hub

Advancing north from Eloy, land use in the Yellow Corridor Alternative consists primarily of 

agricultural and vacant/undeveloped parcels until approaching the City of Coolidge. Residential 

subdivisions are located throughout the corridor through Coolidge, with additional subdivisions 

under development at both the south and north ends of the city. As the corridor proceeds 

north, it traverses the western portion of the City of Florence and skirts the eastern edge of the 

Gila River Indian Community. Land uses in this area transition from chiefly residential to 

agricultural and vacant/undeveloped. The corridor passes near Heritage Park in the northern 

portion of Florence before crossing the Gila River, where land use returns to primarily 

agricultural before the corridor alternative turns northwest in the vicinity of the Town of Queen 

Creek and enters Maricopa County.

Continuing northwest through Queen Creek, land use in the Yellow Corridor Alternative 

becomes much more developed, consisting primarily of residential land uses, some 

neighborhood commercial areas, and numerous parks, with areas of vacant/undeveloped and 

agricultural land north of East Queen Creek Road. As the Yellow Corridor Alternative crosses 

into the southeastern corner of Mesa and continues heading northwest into the Town of 

Gilbert, land use patterns intensify. The historic centers of Gilbert and Mesa are within the 

Yellow Corridor Alternative; these areas are characterized by residential development with 

inclusions of commercial, industrial, and institutional uses located adjacent to most major 

intersections, and recreational uses interspersed throughout the residential areas. Turning due 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-12

west in the vicinity of downtown Mesa, the Yellow Corridor Alternative crosses into the City of 

Tempe. Residential uses predominate within the corridor alternative while industrial uses and 

part of the main campus of Arizona State University, a large institutional use, also exist within 

the corridor. Turning north, the Yellow Corridor Alternative would cross to the north bank of 

Tempe Town Lake. Here the Yellow and Orange corridor alternatives converge and continue 

west through primarily industrial and undeveloped areas in the vicinity of Sky Harbor 

International Airport. The corridor continues west through a predominantly heavy industrial 

area, approaching a district containing sports venues; nearby warehouses, many of which have 

been repurposed into mixed uses including restaurants; and residential uses before reaching 

the northern hub.

Between Eloy and Phoenix, 66 percent of the future land uses allocated within the Yellow 

Corridor Alternative are for residential and mixed uses. Industrial, transportation, and utility 

uses account for an additional 15 percent of the uses. No agriculture or rangeland is designated 

in this corridor.

Orange Corridor Alternative

Southern Hub to Eloy

Land use from the southern hub to Eloy would be the same as described for the Yellow Corridor 

Alternative.

Eloy to Northern Hub

Between Eloy and San Tan Valley, the Orange Corridor Alternative heads generally north, 

passing through predominantly agricultural and vacant/undeveloped land before entering

Maricopa County near southeast Mesa. Within Pinal County, the northern portion of this 

segment of the Orange Corridor Alternative passes through the Superstition Vistas Planning 

Area, a proposed master planned community of approximately 175,000 acres, which at 

buildout is proposed to expand the Phoenix metropolitan area to the southeast toward 

Florence.

As the Orange Corridor Alternative enters Maricopa County, land uses north of Queen Creek 

primarily include vacant/undeveloped and residential categories. As the corridor enters Mesa, it 

turns sharply north and then west in an area where residential subdivisions and masterplanned communities dominate. The Orange Corridor Alternative then continues west toward 

Tempe. Residential and commercial land uses, as well as some recreational uses, are contained 

within the corridor in this part of Mesa. The Orange Corridor Alternative then turns sharply 

north again in the vicinity of the Mesa-Tempe border. Land use remains relatively unchanged 

for 2 miles but transitions to predominantly light industrial and eventually recreational and 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-13

undeveloped as the corridor approaches Tempe Town Lake, an impoundment of the Salt River. 

After the Orange Corridor Alternative crosses to the north bank of Tempe Town Lake it turns 

west again, paralleling the bed of the Salt River. Open space dominates the land uses in this 

area, transitioning into industrial just past its convergence with the Yellow Corridor Alternative. 

The corridor continues west to the northern hub, as described earlier for the Yellow Corridor 

Alternative.

5.2.3 Environmental Consequences

To accommodate a passenger rail system, areas may need to be rezoned through the local 

development process. This would depend on the corridor selected, the specific alignment and 

station locations, current zoning, and the locations and size of layover and maintenance 

facilities. These would be considerations addressed during the Tier 2 analysis, but rezoning is an 

effect that can be anticipated in association with either corridor alternative.

Yellow Corridor Alternative

Southern Hub to Eloy

The project horizon date is 2035; therefore, future land use designations were analyzed to 

quantify potential impacts on land use at the time of buildout. Between Tucson and Eloy, 

58 percent of the future land use is projected to consist of residential and mixed uses. Industrial 

uses account for an additional 15 percent. Due to the width of the study corridor, which land 

uses could be affected and to what extent cannot be determined at this time. The effects of 

building and operating a passenger rail system within the Yellow and Orange corridor 

alternatives are presumed to be similar from the southern hub to Eloy. 

Physical Impacts 

Physical impacts include potential construction of rail stations, reconfiguration of existing or 

creation of new rail facilities, and potential ROW acquisition, which may require the conversion 

of non-transportation land to a transportation use. The specific alignment developed in later 

project phases would determine the extent to which land use conversions occur. If the 

alignment is within the ROW of or closely parallel to an existing transportation corridor such as 

the UP Railroad, the extent of land use conversion may be minimal. The farther an alignment 

departs from an existing transportation feature, however, the greater the likelihood for land 

use conversion, ranging from building on vacant/undeveloped land to potential displacement of 

existing structures. 

Construction and operation of a passenger rail system could influence future growth and land 

values as developments consider the perceived assets and drawbacks of proximity to a rail line. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-14

Because land within the corridor includes residential, commercial, and industrial uses, the 

potential for displacement exists and would be addressed in Tier 2 analysis, if applicable.

Operational Impacts

Operational impacts of a passenger rail system could include potential incompatibilities with 

future land uses (i.e., rail facilities adjacent to open space, residences, and/or schools); 

however, operation of passenger rail may also create opportunities, such as increased business 

for commercial establishments near rail stations or increased exposure to businesses along the 

rail facilities.

Construction Impacts

Construction impacts on land use would be temporary in nature, such as those associated with 

temporary construction easements.

Eloy to Northern Hub

If a passenger rail system is constructed and operated within the UP ROW, relatively few ROW 

acquisitions would be required; however, the mile wide corridor allows a future alignment to 

be located beyond the limits of the UP ROW, which would require acquisition of land not 

designated for transportation. Which land uses would be affected by the future construction 

and operation of a passenger rail system, and to what extent, cannot be determined at this 

time. Detailed analysis of ROW acquisition impacts would be completed in a subsequent Tier 2 

analysis.

Physical, operational, and construction impacts would be the same as described for the 

southern hub to Eloy segment of the corridor alternative.

Orange Corridor Alternative

Southern Hub to Eloy

The Orange Corridor Alternative is identical to the Yellow Corridor Alternative from the Tucson 

hub to just south of Eloy. Therefore, the potential impacts to land uses are considered the same 

as the Yellow Corridor Alternative in this section.

Eloy to Northern Hub

The Orange Corridor Alternative continues north of Eloy, centered along the proposed future 

North-South Corridor; however, the proposed highway is not an approved project, and ROW 

has not been acquired. Therefore, construction of a passenger rail system within the Orange 

Corridor Alternative could require acquisition of currently undeveloped private lands, possibly 

conflicting with future land use designations. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-15

Physical, operational, and construction impacts would be similar to those described for the 

Yellow Corridor Alternative; however, the Orange Corridor Alternative offers fewer 

opportunities for a future passenger rail alignment to coincide with an existing transportation 

use. Therefore, the potential for displacing non-transportation land uses would be greater with 

the Orange Corridor Alternative. In addition, the Orange Corridor Alternative is approximately 

8.0 miles longer than the Yellow Corridor Alternative, meaning that more acres of land likely 

would be allocated to the rail facilities rather than other land uses. The size and location of 

other rail facilities, such as rail stations, could also influence the total acreage affected the 

passenger rail system, which would be determined during Tier 2 studies.

Consistency with State, Regional, and Local Plans and Programs

The Yellow and Orange corridor alternatives primarily fall within the jurisdictions of the Arizona 

State Land Department; Pima, Pinal and Maricopa counties; and the cities/towns of Tucson, 

Marana, Eloy, Coolidge, Florence, Queen Creek, Gilbert, Mesa, Tempe, and Phoenix. Each 

jurisdiction’s general plan was reviewed at a Tier 1 level for general consistency with land use 

goals and circulation/transportation goals, as summarized in Table L-4 in the Land Use 

Appendix. As studies advance to a Tier 2 analysis, detailed and specific evaluation of land use 

compatibility with plans and programs would be completed for one or more project-specific 

alignments. Based on a Tier 1 level of analysis, the corridor alternatives are consistent with the 

jurisdictional land use and transportation goals outlined in the general plans, comprehensive 

plans, and transportation plans listed in Table L-4 of the Land Use Appendix. One exception is 

the Master Plan for Coolidge Municipal Airport, located between East Randolph Road and East 

Bartlett Road (Coolidge 2010 Coolidge, Arizona 2010. Coolidge Municipal Airport Master Plan). 

While the Orange Corridor Alternative is located more than 1 mile west of the airport, future 

development of the airport could limit the alignment options for a passenger rail system in the 

Orange Corridor Alternative. 

Land use elements vary greatly among different jurisdictions’ general plans. Typically, land use 

goals relate to economic growth that promotes alternative transportation methods, infill 

development, maintaining buffers between urban and rural land use, and sensitivity to the 

natural environment. In general, the transportation elements include goals relating to 

improving circulation, enhancing public transit, supporting commuter rail service, and creating 

alternatives to automobile transportation.

The Bureau of Reclamation, Bureau of Land Management, National Park Service, Arizona 

Department of Recreation, and the Gila River and Salt River Pima-Maricopa Indian communities 

have jurisdiction over small amounts of land within the corridor alternatives. Compatibility with 
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Final Tier 1 Environmental Impact Statement 5-16

agency plans depends on the specific alignment of a passenger rail system within a corridor and 

cannot be definitively determined at this time. 

No Build Alternative

Under the No Build Alternative, passenger rail service between Tucson and Phoenix would not 

be established, and land would not be allocated for rail facilities. This may prevent potential 

displacements of existing and planned land uses but would increase the likelihood for displacing 

land uses adjacent to existing highways such as I-10, which would likely need to be widened to 

accommodate the projected demand for capacity as population in the region increases. Land 

uses adjacent to major highway corridors would likely be affected by increased traffic 

congestion, which may include time delays, and increased exposure to noise and vehicle 

emissions. Because adding travel lanes for vehicles takes more land than rail facilities to move 

the same volume of people, more land in the region would need to be allocated to 

transportation facilities, precluding other land uses. 

5.2.4 Potential Mitigation Measures

Future construction and operation of a passenger rail system would result in physical impacts 

that could require mitigation. At this stage in project development, potential mitigation 

measures to apply, when the acquisition and conversion of adjacent land within the corridor 

alternatives cannot be avoided, can only be identified in general terms. For example, if property 

acquisition is necessary, the provisions of the Uniform Relocation Assistance and Real Property 

Acquisition Policies Act of 1970, as amended, and the Civil Rights Act of 1964 would be 

followed. During the Tier 2 review, specific locations for rail facilities, such as rail stations, 

would be planned in coordination with local government entities and with public input to 

minimize the potential for land use conflicts and develop appropriate mitigation specific to 

each location.

5.2.5 Tier 2 Considerations

The Tier 2 analysis would be conducted once the selected corridor alternative is refined into 

one or more project segments. The Tier 2 analysis would consider specific effects on land use of 

a passenger rail corridor and rail stations, the potential need to rezone areas along the rail line, 

and consistency with established land use plans and policies. During Tier 2 analyses, the extent 

of land use, zoning, and property acquisition impacts would be analyzed at a project level; and 

potential mitigation issues and measures would be identified through agency coordination and 

the public involvement process. Phoenix is currently updating their general plan, and a draft 

was released for public comment in Fall 2014 (City of Phoenix 2014). In any Tier 2 analysis, the 

general plan update should be reviewed for changes to the policies and goals applicable to land 

use within or adjacent to the Phoenix portions of the corridor alternative. Pima County is 
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Final Tier 1 Environmental Impact Statement 5-17

currently updating their comprehensive plan, and a draft was released for public comment in 

Fall 2014 (Pima County 2014). In any Tier 2 analysis, the comprehensive plan update should be 

reviewed for changes to the policies and goals applicable to land use within or adjacent to the 

Pima County portions of the corridor alternative.

5.3 Socioeconomic Conditions

The evaluation of the social and economic environment considers population; employment; 

demographic shifts; community disruption and cohesion; effects on commerce; and general 

state, regional, and local economies. In addition to assessing potential adverse effects from 

community disruption, the assessment considers likely benefits resulting in any potential 

increase in economic activity in and near a rail corridor. 

5.3.1 Methodology and Regulatory Requirements

This EIS complies with FRA's Procedures for Considering Environmental Impacts (Environmental 

Procedures) (64 FR 28545, May 26, 1999) and FTA’s Environmental Impact and Related 

Procedures (23 CFR Part 771). Impacts to the socioeconomic and human environment were 

evaluated in accordance with FRA’s Procedures for Considering Environmental Impacts Section 

14(n)(16) (FRA 1999a).

Social and economic characteristics were gathered from the US Census Bureau including the 

2010 decennial US Census and the 2007-2011 American Community Survey (ACS). Population, 

households, and employment characteristics were gathered to describe the past, current, and 

future demographic trends. The description of the socioeconomic environment also includes 

identification of community services such as schools, emergency services, and utilities as well as 

communities and economic centers. Major communities and economic centers within each of 

the corridor alternatives were identified from GIS data. 

Demographic data were collected at the county level within rural areas and at the city level 

within urban areas (that is, communities with population greater than 50,000).

Assessment Area

Two corridor alternatives that would connect the metropolitan areas of Tucson and Phoenix, 

Arizona, were evaluated for a future passenger rail system. The two alternatives traverse 

portions of Pima, Pinal, and Maricopa counties and several cities and towns. From south to

north, the cities and towns include Tucson, Marana, Eloy, Coolidge, Florence, Queen Creek, 

Gilbert, Mesa, Tempe, and Phoenix. Due to the regional nature of the study, demographic data 

were collected for an assessment area that extends beyond the 1-mile-wide alternative 

corridors. This area includes the above-mentioned counties, cities, and towns traversed by each 
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Final Tier 1 Environmental Impact Statement 5-18

corridor alternative. The demographic data were used to compare the characteristics of the 

populations that live and/or work within and near each corridor alternative within potentially 

affected communities and the region.

Because socioeconomic effects extend beyond the local level, the influence of an action on 

population, employment, or the tax base would be analyzed at a community scale rather than a 

corridor scale. Conversely, potential business relocations and displacements and disruptions to 

community cohesion resulting from the placement of new infrastructure tend to be location 

specific. The analysis of socioeconomic effects, both at the macroeconomic scale and the 

microeconomic scale, cannot be quantified until specific alignments are identified. 

Consequently, existing socioeconomic conditions within the tri-county region surrounding the 

corridor alternatives are described quantitatively, while potential effects of a passenger rail 

system within the one-mile-wide corridor alternatives can only be described on a qualitative 

level in this analysis.

5.3.2 Existing Conditions

Historical and Projected Population

Between 1970 and 2010 the tri-county region of Pima, Pinal, and Maricopa counties (which 

corresponds to the APRCS Study Area) grew by more than 3.78 million people. In 2010, the 

region was home to approximately 81 percent of the population in the state of Arizona. The 

metropolitan area of Phoenix (Maricopa County) is the dominant population center in the tricounty region (accounting for more than 3.8 million people in 2010) followed by Tucson (Pima 

County), which was home to nearly one million people. Historical growth patterns show that 

the metropolitan regions surrounding Tucson and Phoenix have sprawled, while population 

growth in the urban cores has slowed. Between 1970 and 2010, Marana (northwest of Tucson) 

grew at an average annual rate of 10.7 percent, while Tucson grew by 1.7 percent annually. In 

the Phoenix area, Queen Creek and Gilbert (southeast of Phoenix) grew at an annual rate of 

12.1 percent and 12.4 percent, respectively, while Phoenix grew by 2.3 percent per year. 

Coolidge and Eloy, communities in Pinal County, are relatively small compared to the other 

cities in the assessment area and have grown at a slower pace. In 1970, the nearby town of 

Florence was smaller than these other two Pinal County communities along the corridor 

alternatives, but it has grown more than 1,000 percent between 1970 and 2010 and is now the 

largest of the three communities (see Table S-1 in the Socioeconomic Conditions Appendix).

According to population projections produced in 2012, the population within the state and tricounty region will continue to grow over the next 40 years; however, the annual growth rate is 

anticipated to slow (Arizona Department of Administration, Office of Employment and 

Population Statistics 2012). By 2050, Arizona is projected to be home to more than 11.5 million 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-19

people; which represents an approximately 78-percent increase over December 2012 estimates 

and a 1.6 percent annual growth rate. The tri-county region is projected to grow approximately 

84 percent overall at a 1.7 percent annual growth rate for almost 9.7 million people in 2050. By 

then, the tri-county region will account for almost 84 percent of the state population. Between 

December 2012 and 2050, it is anticipated that Maricopa County and Pima County’s share of 

the total regional population will decrease (from 74 percent to 71 percent and from 19 percent 

to 16 percent, respectively), and that Pinal County’s share will grow (from 7 percent to 13 

percent) (see Table S-2 in the Socioeconomic Conditions Appendix). These growth trends 

suggest that the corridor between Tucson and Phoenix will become a megaregion with growing 

population centers in between these cities.

Employment

According to the US Census Bureau, the largest employment sectors in Arizona in 2012 included 

education, health care, and social services, followed by retail trade and then professional, 

scientific, management, administrative, and waste management services. The employment 

characteristics of the assessment area, particularly in the urban centers of Tucson and Phoenix, 

mirror those of the state. In the tri-county area, education, health care, and social services 

account for 21.5 percent of the employment; retail trade accounts for 12.2 percent; and 

professional, scientific, management, administrative, and waste management services account 

for 12.1 percent. Some of the economies outside the urban centers differ somewhat from the 

regional trends. For example, employment in the agriculture, forestry, fishing, hunting, and 

mining sector; education; and public administration accounts for a larger share in the smaller 

communities in Pinal County. Relative to other communities along the corridor alternatives, the 

share of work-aged people in the labor force in Florence and Eloy is substantially less; this 

economic characteristic is largely due to presence of correctional facilities and the share of 

unemployed and incarcerated population (see Table S-3 in the Socioeconomic Conditions 

Appendix).

The Census statistics are consistent with the largest employers in each community. Within the 

educational services, health care, and social assistance sector, major employers in the 

assessment area include Banner Health (health care), Apollo Group, Inc. (educational services), 

the University of Arizona and Arizona State University (education), as well as local school 

districts (education). According to The Arizona Republic’s 2014 Arizona’s 100 Largest Employers, 

Walmart Stores, Inc. is the largest employer in the state and is a major contributor to the retail 

employment sector in the assessment area. Several large employers within the state are 

headquartered in the study corridor. University of Arizona Health Network (health care) is 

headquartered in Tucson; and Banner Health, Apollo Group, Inc. (educational services), 

Freeport-McMoRan Copper & Gold Inc. (mining), and the Salt River Project (utility provider) are 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-20

headquartered in Phoenix (The Arizona Republic 2014). In the smaller, more rural communities 

of Eloy, Coolidge, and Florence, the local economies are driven more by government 

employment, as well as agriculture and corrections in Eloy and Florence.

The Public Works and Economic Development Act of 1965, as amended, considers an area 

economically distressed if it has an unemployment rate that is at least 1.0 percent greater than 

the national unemployment rate. Unemployment statistics for the three-county Study Area are 

available from the US Census Bureau based on a sample survey from the American Community 

Survey 2008-2012. The estimated 2012 unemployment rate in the US was 6.0 percent. In 

comparison, the overall rate was 6.0 percent in Arizona and 5.9 percent in the three-county 

Study Area (see Table S-3 in the Socioeconomic Conditions Appendix). Several communities in

the assessment area, however, have an unemployment rate that is higher than the nation, the 

state, and the three-county Study Area. Eloy had a 2011 unemployment rate of 16.3 percent, 

and Tucson had a rate of 9.9 percent. Because they exceed the 1.0 percent threshold, these two 

communities are considered to be economically distressed areas. Tempe had an unemployment 

rate of 9.2 percent, higher than the national average but not exceeding the threshold. Historical 

data provided by the US Bureau of Labor Statistics indicate that unemployment in Arizona has 

been consistently above the national rate since June 2008. The April 2013 assessment showed a 

decline in unemployment in both the nation and the state (7.5 percent in the US and 

7.9 percent in Arizona). While these more recent datasets are not available at the assessment 

area level, it is likely that unemployment in the tri-county region has generally followed the 

national and state trend.

Community Facilities

Community facilities, including schools, libraries, places of worship, parks, community centers, 

hospitals, emergency services, and other public buildings, are located throughout the corridors 

in proportion to the intensity of development and density of the local population, as shown in 

Maps 1 through 91 of the Corridor Aerial Atlas Appendix. While most community facilities are 

tailored to serve local neighborhoods, Tucson, Florence, and Phoenix are the county seats of 

each of the Study Area counties; and Phoenix is the state capital. For this reason, each of these 

locations houses state and county offices offering additional services to a larger public.

Community facilities such as police, fire department, and ambulance provide emergency 

services and must share the roadway network with private and commercial vehicles. 
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Final Tier 1 Environmental Impact Statement 5-21

Native American Communities

The corridor alternatives intersect two Native American reservations: the Gila River Indian 

Community and the Salt River Pima-Maricopa Indian Community (see Maps 31, 32, 33, 86, and 

87 of the Corridor Aerial Atlas Appendix).

Gila River Indian Community

The Gila River Indian Community is just south of the City of Phoenix and extends through parts 

of Pinal and Maricopa counties. The Yellow Corridor Alternative intersects the eastern extent of 

the Gila River Indian Community just north of Coolidge where the corridor crosses the Gila 

River. The seven districts in the community cover approximately 584 square miles and are 

home to over 11,000 people from the Akimel O’odham (Pima) and Pee Posh (Maricopa) people. 

Approximately 40,000 acres (10.7 percent) of the reservation is agricultural land. The 

Community owns and operates several business enterprises including three casino resorts, a 

resort hotel, an equestrian center, two golf courses, arts and museum centers, and Firebird 

International Raceway. Valley METRO transit services connect the reservation to Phoenix and 

other communities in the metropolitan area.

Salt River Pima-Maricopa Indian Community

The Salt River Pima-Maricopa Indian Community is located just east of Scottsdale in the Phoenix 

metropolitan area. The Orange Corridor Alternative intersects the southwestern corner of the 

Salt River Pima-Maricopa Indian Community just north of Tempe Marketplace where the 

corridor crosses the Salt River. The reservation covers approximately 112 square miles and is 

surrounded by the cities of Scottsdale, Tempe, Mesa, and Fountain Hills. This community is 

home to a group of over 9,000 Pima and Maricopa people. Almost 12,000 acres of the 

reservation (16.7 percent) are designated for agricultural use. Numerous commercial uses are 

located along the western border of the community. Valley METRO transit services connect the 

reservation to Phoenix and other communities in the metropolitan area.

5.3.3 Environmental Consequences

A passenger rail system’s potential impacts on the socioeconomic environment would depend 

on its specific location and alignment within a corridor alternative. Potential impacts to the 

socioeconomic environment vary between corridor alternatives and among future alignments 

but could include business relocations and displacements, disruptions to community cohesion, 

noise and vibration impacts, concerns of safety and public health, and changes to regional 

travel patterns. 

Because no specific alignment locations have been identified in this Final Tier 1 EIS, ranges of 

potential socioeconomic impacts are described that could apply throughout the length of the 
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Final Tier 1 Environmental Impact Statement 5-22

corridor alternatives, with the intensity of the impact at any given location dependent on the 

existing conditions at that location. For this reason, the environmental consequences for 

socioeconomic conditions address the Yellow and Orange corridor alternatives in their entirety, 

rather than separating the impact descriptions into corridor segments. 

Yellow Corridor Alternative

Physical Impacts

A passenger rail system within the Yellow Corridor Alternative could have potential impacts on 

community cohesion, depending on the characteristics of a given community. Some businesses, 

residential properties, and community facilities within the Yellow Corridor Alternative might be 

displaced to accommodate passenger rail due to the need for new railroad ROW, stations, and 

ancillary facilities such as storage and maintenance yards. Unless similar properties can be 

obtained for relocation, such displacements could result in changes to community character 

and cohesion and potentially result in job losses. The Yellow Corridor Alternative offers 

opportunities for a rail alignment adjacent and parallel to existing transportation infrastructure, 

which could mitigate the potential impacts to community cohesion if such an alignment were 

considered.

The one-mile-wide Yellow Corridor Alternative intersects Arizona State University’s main 

campus (see Maps 50 and 51 of the Corridor Aerial Atlas Appendix). A passenger rail system 

within this area would be designed to preserve the cohesive nature of this campus. Relocation 

of any of the university’s specialized buildings could be particularly challenging and would 

interfere with university operations and students’ ability to access university facilities. 

Phoenix Sky Harbor International Airport’s north runway 8/26 is located within the one-milewide Yellow Corridor Alternative (see Maps 53 and 54 of the Corridor Aerial Atlas Appendix). A 

passenger rail system within this area would be designed to avoid any potential conflict with 

airport activities that could result in adverse socioeconomic impacts at both local and regional 

levels. UP Railroad’s Phoenix Yard, also located within the Yellow Corridor Alternative between 

7

th and 16th Streets (see Maps 54 and 55 of the Corridor Aerial Atlas Appendix), would be 

avoided to preclude the need for any relocations or displacements that could potentially 

disrupt freight operations.

The conversion of property from taxable commercial or residential uses to a tax-exempt 

transportation use could potentially decrease local tax revenues. On the other hand, potential 

new development around future station areas could benefit a community by generating 

economic activity and creating new sources of tax revenue. The effects on local real estate 

markets would vary based on availability of comparable properties within existing 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-23

neighborhoods, zoning, and local planning and economic development objectives. Dynamics 

such as these would be analyzed in more detail during Tier 2 evaluation. 

Automobile, pedestrian, and bicycle access to adjacent neighborhoods and community facilities 

could be altered by the introduction of new rail infrastructure, thereby affecting community 

cohesion. Changes in access could also introduce challenges to emergency service providers. 

Depending on the extent of safety mitigation, potential changes in or additions to highway/rail 

crossings could also introduce safety risks. 

Operational Impacts

Implementation of a passenger rail system within the Yellow Corridor Alternative would likely 

increase the potential for economic development and land use changes, such as transitoriented development around future station locations. Transit-oriented development could be 

designed to support new employment and housing options with associated tax revenue 

benefits for the communities with passenger rail stations. Other potential impacts to land use 

within the corridor alternatives, as described in Section 5.2, could result in additional 

socioeconomic impacts.

Jurisdictions within the Yellow Corridor Alternative would experience changes in socioeconomic 

conditions, as described below, if passenger rail service were implemented within the corridor. 

A rail system in the Yellow Corridor Alternative would bypass some communities within the 

three-county Study Area, which would not afford them the direct economic effects experienced 

by communities with passenger rail stations; however, the bypassed communities may still 

experience indirect benefits of a regional transit option.

Long-term socioeconomic benefits along the Yellow Corridor Alternative would accrue to the 

tri-county Study Area as well as communities intersecting the corridor. Passenger rail service 

within this corridor would provide connections to major economic generators within the 

assessment area, including downtown Tucson and Phoenix. The improved access would likely 

result in increased economic activity within cities and towns directly served by the new 

passenger line, particularly near stations. Connecting urban areas and communities by 

improving access and mobility would likely expand employment opportunities over the larger 

geographic area, benefiting both employers (by expanding the labor pool) and employees (by 

offering more choices regarding where to live and work). Improved access to job and 

educational opportunities within the region, to cultural and recreational activities and events, 

and to shops and services adjacent to future station areas would enhance socioeconomic 

conditions throughout the region. 
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Final Tier 1 Environmental Impact Statement 5-24

Passenger rail service within the Yellow Corridor Alternative could offer travel time savings for 

transit patrons and regional commuters. If the preference for rail transit increased, it could help 

bolster economic development and housing demand in the areas surrounding stations. 

Reductions in vehicular traffic could also result from increased ridership on a passenger rail 

system.

A passenger system within the Yellow Corridor Alternative would bring socioeconomic benefits 

in terms of improving regional mobility and connections between economic and employment 

centers, education centers, and other cultural and recreational activity centers. The improved 

access could increase economic activity in the communities served by the Yellow Corridor 

Alternative and could expand regional employment opportunities and offer more flexibility in 

terms of where to live and work. 

Construction Impacts

Constructing a passenger rail facility within the Yellow Corridor Alternative would result in 

temporary disruption of access to existing businesses and community facilities and temporary 

noise, vibration, and air quality impacts. This may affect businesses if patrons avoided the 

construction zone because of these disruptions. 

Depending on the alignment, construction of a passenger rail facility within the Yellow Corridor 

Alternative could temporarily disrupt freight rail traffic along the UP line that runs within the 

corridor. Although passenger rail service would run on a separate track from freight, existing 

freight customers could experience temporary limits on available service during construction. 

Construction of a passenger rail system along or adjacent to the UP line could temporarily 

affect businesses that rely on the UP for shipping or receiving goods.

Constructing a passenger rail system within the Yellow Corridor Alternative would generate 

short-term economic benefits associated with construction of the rail infrastructure itself, as 

well as construction activities associated with any associated transit-oriented development, 

other development near station locations, and services to support the influx of construction 

workers. If local materials were used during construction, businesses that manufactured and 

sold the materials would experience positive effects, and the communities would receive an 

economic boost from the tax revenues.

Orange Corridor Alternative

Physical Impacts 

As would be the case with the Yellow Corridor Alternative, a passenger rail system within the 

Orange Corridor Alternative could require some properties to be displaced, resulting in 
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Final Tier 1 Environmental Impact Statement 5-25

disruptions to community cohesion and potential loss of employment and taxable property. 

Potential decreases in local tax revenues from the conversion of taxable property to a taxexempt transportation use may be offset by the potential creation of new sources of tax 

revenue through new development around future station areas. Effects on tax revenues, local 

real estate markets, zoning, and related economic issues would be analyzed in more detail 

during the Tier 2 evaluation. 

The Orange Corridor Alternative parallels and, in some locations, is intersected by the Central 

Arizona Project (CAP) Canal (see Maps 66 through 72 of the Corridor Aerial Atlas Appendix). A 

passenger rail system would need to avoid any modifications to or displacement of this vital 

element of Arizona’s water supply system. 

Where the Orange Corridor Alternative converges with the Yellow Corridor Alternative, it 

intersects Phoenix Sky Harbor International Airport and UP Railroad’s Phoenix Yard in the 

manner previously described in the Physical Impacts section of the Yellow Corridor Alternative 

(see Maps 53 through 55 of the Corridor Aerial Atlas Appendix). New infrastructure associated 

with a passenger rail system within the Orange Corridor Alternative could have fewer 

opportunities to locate along or within an existing transportation corridor than a system within 

the Yellow Corridor Alternative and would be more likely to affect community cohesion by 

creating a linear barrier where it intersects established communities, disrupting access from 

one side of the railroad to the other. This community disruption could be lessened by including 

highway-railroad grade crossings; however, these would present safety hazards to a community 

by creating potential accidents involving trains and cross traffic, including pedestrian and 

bicycle traffic. Additional detail concerning Public Health and Safety can be found in 

Section 5.5. 

Grade-separated crossings could minimize impacts to community cohesion by retaining existing 

vehicle and pedestrian access or providing new overpasses or underpasses; however, grade 

separation of rail crossings through construction of an overpass or underpass could result in 

changes in access and possibly community cohesion impacts beyond the specific intersection 

through disruption of views, new drainage patterns, and other effects. 

Operational Impacts 

Operation of passenger rail service within the Orange Corridor Alternative would have both 

beneficial and negative impacts on socioeconomic conditions throughout the corridor similar to 

those described for the Yellow Corridor Alternative, albeit in different locations where the two 

corridor alternatives diverge. 
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Final Tier 1 Environmental Impact Statement 5-26

Both the Orange and Yellow corridor alternatives would accrue travel time benefits to the 

respective communities served by each. The anticipated travel time savings of a passenger rail 

system within the Orange Corridor Alternative between Tucson and Phoenix would provide a 

larger benefit than that anticipated from a system within the Yellow Corridor Alternative.

Overall, the implementation of passenger rail service would provide an alternative form of 

transit that would support persons in the corridor alternative communities that do not have a 

vehicle or the ability to drive. This would be a long-term benefit to community services within 

the selected corridor alternative.

Construction Impacts 

Impacts of construction of a passenger rail system within the Orange Corridor Alternative 

would be similar to those described for the Yellow Corridor Alternative, including potential 

disruption and/or detours of vehicular traffic; temporary access changes; and constructionrelated noise, vibration, and air quality impacts. These impacts are most likely to occur near 

stations where construction intensity is likely to be greatest, although station locations have 

not yet been identified and would be assessed further as part of the Tier 2 analysis.

Short-term economic benefits could result from jobs created to support construction of a 

passenger rail project, as well as the purchase of goods and services. 

No Build Alternative

Under the No Build Alternative, no passenger rail system would be constructed or 

implemented. The Tucson and Phoenix metropolitan areas and the communities between them 

would continue to grow, which would increase regional transportation demand. The ability to 

respond to additional stress on the existing transportation system under the No Build 

Alternative would be limited to the existing transportation infrastructure’s capacity and 

capacity increases resulting from other approved transportation projects in the region. 

The economic drivers of the communities within the three-county Study Area are both 

synergistic and complementary and are dependent on adequate transportation infrastructure 

for localized and regional economic growth potential. Under the No Build Alternative, the 

economies of these communities would experience deficiencies in transportation capacity, 

thereby affecting socioeconomic conditions.

5.3.4 Potential Mitigation Measures

Short-term construction-related impacts could be mitigated using construction best 

management practices (BMPs) such as providing clearly marked detour routes for vehicles and 

pedestrians such that access to adjacent land use is maintained during construction. Other 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-27

construction BMPs include minimizing fugitive dust; reducing idling of construction vehicles; 

and communicating the construction schedule to public officials, emergency service providers, 

and other affected stakeholders. 

All displacements would occur in accordance with the Uniform Relocation Assistance and Real 

Property Acquisition Policies Act of 1970 (Uniform Relocation Act), as amended (42 U.S.C. § 

4601 et seq. and implemented by 49 CFR Part 24). Coordination with local job placement 

agencies would occur to help mitigate the impacts of potential job loss associated with the 

displacement of places of employment. 

New and/or additional rail traffic at existing grade crossings may pose safety hazards for 

pedestrians and vehicles. Additional safety measures may be needed depending on the 

projected rail and vehicle traffic at these intersections. Additional cross-access points (e.g., 

pedestrian bridges or underpasses, or improved vehicle capacity at existing grade crossings) or 

four-quadrant gate crossings (with gates on both sides of the tracks for both directions of 

automotive traffic) may be required to mitigate the effects of closing an existing crossing.

Public involvement and agency coordination activities would help inform the identification of

potential mitigation strategies. Specific mitigation measures would be identified and discussed 

during Tier 2 analysis after design details are known and specific impacts are identified.

5.3.5 Tier 2 Considerations

As design details are further defined and delineated in Tier 2 analysis, more details about the 

potential impacts on socioeconomic conditions would be identified along with strategies to 

avoid or mitigate these impacts.

The Tier 2 NEPA analysis would include a detailed quantitative analysis of the socioeconomic 

impacts of the corridor alternatives. The analysis would focus on the elements of the human 

environment that may be affected by potential actions taken as a result of the development of 

a passenger rail project. Existing resources that may be studied further include population 

changes, labor force changes, business establishments, community characteristics, municipal 

fiscal conditions, and economic development initiatives. Applicable livability principles from the 

Partnership for Sustainable Communities–a joint initiative from the US Department of Housing 

and Urban Development, USDOT, and the US Environmental Protection Agency (EPA)–should 

also be considered. (http://www.sustainablecommunities.gov/)

Design details, such as station locations and need for additional ROW, would be described in 

the Tier 2 analysis, which would allow a more precise understanding of the socioeconomic 
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Final Tier 1 Environmental Impact Statement 5-28

impacts and benefits. Specific mitigation measures would be developed, with coordination of 

local communities and agencies, as part of the Tier 2 analysis.

5.4 Title VI and Environmental Justice

5.4.1 Methodology and Regulatory Requirements

Environmental Justice (EJ) is partially based in Title VI of the Civil Rights Act of 1964 (Title VI), 

one of the laws integrated into the procedures of NEPA. Title VI prohibits discrimination on the 

grounds of race, color, or national origin; and it protects these classes of people from being 

denied the benefits of or being excluded from participation in any program or activity receiving 

federal assistance (Title VI, 42 U.S.C. § 2000[d]). NEPA requires federal agencies to serve as 

trustees of the environment for succeeding generations and assure that all Americans have 

“safe, healthful, productive, and aesthetically and culturally pleasing surroundings” (42 U.S.C. § 

4331(b)(2)).

EO 12898, Federal Action to Address Environmental Justice in Minority Populations and LowIncome Populations, was issued by President Clinton on February 4, 1994, and requires each 

federal agency “to make achieving environmental justice part of its mission by identifying and 

addressing, as appropriate, disproportionately high and adverse human health or 

environmental effects of its programs, policies, and activities on minority and low-income 

populations” (FR 59, No. 32, 7629-7633, February 16, 1994). In the memorandum to agency 

department heads that accompanied the EO, President Clinton specifically recognized the 

importance of NEPA procedures for identifying and addressing environmental justice concerns.

The memorandum states, “each federal agency shall analyze the environmental effects, 

including human health, economic, and social effects, of federal actions including effects on 

minority and low-income communities, when such analysis is required by NEPA.” The 

memorandum also calls out the importance of NEPA’s public participation process, by directing 

each federal agency to “provide opportunities for community input in the NEPA process” and to

“identify potential effects and mitigation measures in consultation with affected communities, 

and improve the accessibility of meetings, crucial documents, and notices” (CEQ 1997).

On May 2, 2012, USDOT issued Order 5610.2(a), Order to Address Environmental Justice in 

Minority Populations and Low-Income Populations which updates USDOT Order 5610.2 and 

describes how USDOT operating administrations comply with EO 12898. The update reaffirms 

USDOT’s commitment to EJ’s guiding principles:

 To avoid, minimize, and mitigate disproportionately high and adverse effects

 To ensure the full and fair participation by all potentially affected communities
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-29

 To prevent the denial of, reduction in, or significant delay in receipt of benefits by 

minority and low-income populations

The order also directs federal agencies to identify and address, as appropriate, 

disproportionately high and adverse human health or environmental effects of agency actions 

to promote the principles of environmental justice in all USDOT programs, policies and 

activities. It requires that EJ principles be fully considered throughout planning and decisionmaking processes using the “principles of NEPA; Title VI; the Uniform Relocation Assistance and 

Real Property Acquisition Policies Act of 1970, as amended; the Intermodal Surface 

Transportation Efficiency Act of 1991; and other USDOT statutes, regulations, and guidance that 

address or affect infrastructure planning and decision making; social, economic, or 

environmental matters; public health; and public involvement.”

The methodology for conducting the review and evaluation of minority and low-income 

populations is in accordance with federal regulations and guidelines, including Title VI, FRA’s 

Environmental Procedures Section 14(n)(20) (FRA 1999a), FTA’s Environmental Justice Policy 

Guidance for Federal Transit Administration Recipients (FTA 2012), and CEQ’s Environmental 

Justice: Guidance Under the National Environmental Policy Act (CEQ 1997a).

Population and demographic data are reported in the decennial US Census; income and 

language proficiency are reported through the American Community Survey (ACS), an ongoing 

Census Bureau survey that samples a small percentage of the population every year. The area 

assessed for this EJ analysis includes all Census block groups that intersect each of the corridor 

alternatives. Demographic data from the 2010 Census and 2008-2012 ACS were gathered at the 

state, county, and Census block group level and included race, ethnicity, median household 

income, and ability to speak English. GIS mapping was used to identify where majority EJ 

populations are located relative to the corridor alternatives.

Because EJ and Title VI impacts are location specific, calculating an estimated effect for a 200-

foot-wide corridor within the one-mile-wide corridor alternatives will not yield meaningful 

information until a specific alignment is identified. The tables used in this analysis disclose 

percentages of the population within the mile-wide corridor alternatives that fall under various 

government acts and regulations protecting them from discrimination and exclusion with 

regard to federally funded projects.

Definition of Terms

This analysis relies on the following definitions of terms. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-30

Minority

Minority and low-income populations are collectively referred herein as EJ populations. 

Minority is defined by USDOT Order 5610.2 as a person who is: 

 Black (a person having origins in any of the black racial groups of Africa)

 Hispanic (a person of Mexican, Puerto Rican, Cuban, Central or South American, or other 

Spanish culture or origin, regardless of race)

 Asian American (a person having origins in any of the original peoples of the Far East, 

Southeast Asia, the Indian subcontinent, or the Pacific Islands)

 American Indian and Alaskan Native (a person having origins in any of the original 

people of the Americas and who maintains cultural identification through tribal 

affiliation or community recognition)

A minority population is defined as:

 Any readily identifiable group of persons and/or a community who lives in geographic 

proximity and, if circumstances warrant, geographically dispersed/transient persons 

(such as migrant workers or Native Americans) who experience common conditions of 

exposure or impact, and

 One that consists of persons classified by the US Census Bureau as minority, including 

those persons of two or more races

Low-Income

Low-income refers to a median household income at or below the US Department of Health 

and Human Services (DHHS) poverty guidelines (USDOT Order 5610.2[a]). The analysis was 

based on the poverty guidelines issued in January 2013. Median household income data in the 

2006-2010 ACS is reported in 2010 dollars. In order to compare the 2013 poverty guidelines 

with data in 2010 dollars, the 2013 guidelines were adjusted to 2010 dollars using the 

Consumer Price Index Inflation Calculator provided by the US Department of Labor, Bureau of 

Labor Statistics. The following steps are necessary to determine low-Income households for an 

EJ analysis:

1. Determine the average household size for each Census block group in the corridor 

alternatives; round up to the next whole number to be more inclusive.

2. Select the appropriate DHHS poverty guideline, as adjusted to 2010 dollars.

3. Collect median household income data for the corridor alternatives from the ACS at the 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-31

block group level.

4. Determine if any block groups with a median household income less than the adjusted 

poverty guideline, as identified in Step 2 above, are present in the corridor alternatives.

Limited English Proficiency

Persons with Limited English Proficiency are defined as individuals for whom English is not their 

primary language and who have a limited ability to read, write, speak, or understand English. It 

includes people who reported to the US Census Bureau that they speak English less than very 

well, not well, or not at all.

Assessed Populations

Based on existing CEQ and EPA guidance, a minority population may be present where “either 

(a) the minority population of the affected area exceeds 50 percent or (b) the minority 

population percentage in the affected area is meaningfully greater than the minority population 

percentage in the general population or other appropriate unit of geographic analysis” 

(CEQ 1997a). The 50 percent threshold was applied to the analysis of Census data to identify 

distinct minority populations. Low-income populations were identified where the median 

household income of each Census block group was below the poverty guideline, as established 

by DHHS, for the household size of each respective Census block group. 

The purpose of identifying distinct EJ communities is to compare the adverse effects and 

benefits of developing a passenger rail system within one of the corridor alternatives as well as 

the mitigation strategies for EJ populations versus non-EJ populations. Population size of EJ 

communities alone does not determine whether disproportionately high and adverse effects 

occur. The comparative impact (adverse and beneficial) of an action on EJ populations and nonEJ populations is the determining factor. Disproportionate impacts could occur even in areas 

with a low statistical concentration of EJ populations. Non-traditional data-gathering 

techniques are proposed for the Tier 2 NEPA analysis to identify the presence of distinct EJ 

populations within close proximity of the corridor alternatives or those EJ populations who are 

dependent upon potentially affected natural resources. Nontraditional data-gathering 

techniques could include, but are not limited to, conducting informal group meetings, using 

digital media, developing partnerships with community groups, participating in community-led 

events, and using direct mail.

Limited English Proficiency

On August 11, 2000, President Clinton issued EO 13166, Improving Access to Services for 

Persons with Limited English Proficiency, to help ensure that all people have access to 

meaningful communications about and participation in any program or activity receiving 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-32

federal assistance. It requires federal agencies to examine the services they provide for persons 

who, because of national origin, have limited English proficiency (LEP). It calls for agencies to 

identify if LEP populations are in need of their services and to develop and implement a system 

to provide those services so LEP persons can have meaningful access to them.

The US Census Bureau collects information about the ability of people to speak English, as well 

as about those living in linguistically isolated households. The Census Bureau defines a 

linguistically isolated household as one in which no member 14 years of age or older speaks 

English at least very well. Members of a linguistically isolated household 14 years old and over 

have at least some difficulty with English. Although they are not considered EJ populations, data 

on LEP populations within the study corridor are included in this Tier 1 analysis.

The impact analysis for LEP populations is not dependent upon a concentration. Instead, it must 

consider the most commonly spoken language(s) other than English and locations where 

residents reported to the US Census Bureau that they speak English “less than very well.” 

Therefore, the impact analysis is directly related to an analysis of US Census data of LEP 

populations in the three-county Study Area who are considered “linguistically isolated.” 

5.4.2 Existing Conditions

Table 5-2 summarizes the percentage of protected populations in the three-county Study Area 

as well as within the corridor alternatives, where data are available. Because data for English 

proficiency and disability are not tabulated at the Census Block level, specific percentages for 

the Yellow and Orange Corridor Alternatives could not be calculated. More specific information 

about the protected populations is discussed under the subheadings that follow. 

Table 5-2. Protected Populations in the Study Area and Corridor Alternatives

Minority Population

Low Income 

Population

Limited English 

Proficiency Population

Arizona 42.2% 12.1% 10.5%

Three-County Study Area 42.0%a 11.2% 10.1%

Yellow Corridor Alternative 46.2% 16.3% not available

Orange Corridor Alternative 43.5% 16.0% not available

Source: US Census Bureau

Notes:

aAs a percentage of the total population.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-33

Minority Populations

The racial and ethnic composition of the population in the three-county Study Area (Pima, 

Pinal, and Maricopa counties) is very similar to the state; however, several communities in the 

three-county Study Area have a larger share of minority population when compared to the 

region. Table 5-3 shows the percent minority population for the state, Study Area, Census block 

groups within the corridor alternatives, and communities with high minority populations. 

The corridor alternatives comprise 424 Census block groups. In comparison to Arizona and the 

three-county Study Area, both corridor alternatives have a slightly larger share of minority 

populations. Figure 5-3, Figure 5-4, and Figure 5-5 highlight the location of the EJ Block Groups 

based on race and ethnicity in and around the corridor alternatives.

Table 5-3. Percent Minority for Selected Geographies

Location

NonHispanic 

White

Other Races

Hispanic or 

Latino

American 

Indian or 

Alaskan Native

Total Minority

Arizona 57.8% 37.6% 29.6% 4.6% 42.2%

Three-County

Study Area

58.0% 40.1% 30.4% 1.9% 42.0%

Yellow Corridor 

Alternativea

53.8% 44.0% 32.3% 2.2% 46.2%

Orange Corridor 

Alternativea

56.5% 41.3% 32.4% 2.0% 43.5%

Coolidge 43.6% 54.5% 42.0% 1.9% 56.4%

Eloy 18.9% 79.9% 58.0% 1.2% 81.1%

Florence 46.6% 53.0% 31.2% 0.4% 53.4%

Phoenix 46.5% 52.9% 40.8% 0.6% 53.5%

Tucson 47.2% 51.8% 41.6% 1.0% 52.8%

Source: US Census 2010

a based on Census block groups that intersect with the corridor alternatives

Low-Income Households

The median household income in the state of Arizona was $50,448 in 2010. Of the more than 

2.3 million households in the state, 12.1 percent earned a household income less than $15,000 

per year. In comparison, the median household incomes in the three-county Study Area ranged 

between $45,521 and $55,054; and 11.2 percent of the households earned less than $15,000 

per year.
Florence

Marana

Eloy

Coolidge

Casa

Grande

Maricopa

Oro 

Valley

PINAL COUNTY

PIMA COUNTY

MARICOPA COUNTY

PINAL COUNTY

GILA COUNTY

PINAL COUNTY

Tohono O'odham Nation

!"a

!"`

)e

Q?Á

Q?¿

Q?É

Q?Æ

UAõ UAú

UAÖ

!"c Q? ̈

!"a

)e

!"a

Q?Ê

Q?É

!"a

!"d

Q?È

)e

Santa Cruz River

Salt River

Gila River

Queen Creek

Superior

Glendale

Scottsdale

Apache

Junction

UAÛ

See Phoenix 

Metropolitan Area

Figure 5-5

See Tucson

Metropolitan Area

Figure 5-4

Ak-Chin

Indian 

Community

Gila River

Indian 

Community Sacaton

San

Tan

Valley

5 Existing Conditions and Environmental Consequences

Figure 5-3. Threshold Minority Populations in the Study Area

Final Tier 1 Environmental Impact Statement 5-34

Interstate

State or US Highway

Railroad

Major Drainage

Yellow Corridor Alternative

Orange Corridor Alternative

Federal Land

National Forest

State Trust Land

City Boundary

Block Groups Intersected

by the Corridor Alternatives

with 50% or Higher

Minority Populations

Block Groups Not Intersected

by the Corridor Alternatives

with 50% or Higher

Minority Populations

Block Groups on Tribal

Land with 50% or Higher

Minority Populations

Le g e nd

0 5 10

Miles

Sources: Census 2010 Summary File 1; Esri 2014; Arizona Department of Transportation 2013;

Arizona Land Resource Information System 2013

N
5 Existing Conditions and Environmental Consequences

Figure 5-4. Threshold Minority Populations in the Tucson Metropolitan Area

Final Tier 1 Environmental Impact Statement 5-35

Prince Rd

La Canada Dr

Speedway Blvd

Silverbell Rd

Swan Rd

Country Club Rd

Silverlake Rd

Golf Links Rd

Broadway Blvd

Grant Rd

1st Ave

Fort Lowell Rd

Alvernon Wy

5th St

22nd St

Campbell Ave

Greasewood Rd

Anklam Rd La Cholla Blvd

Orange Grove Rd

Barraza Aviation Hwy

Ajo Way

Irvington Rd

Drexel Rd

Valencia Rd

Nogales Hwy

Los Reales Rd

Tucson

Q?¿

!"a

!"a

South

Tucson

Davis

Monthan

Air Force

Base

Marana

Santa Cruz River

Catalina Foothills

e

Q?È

Tucson

International

Airport

e

Airport

Interstate

State or US Highway

Local Road

Railroad

Major Drainage

Federal Land

State Trust Land

Yellow and Orange

Corridor Alternatives

Block Groups Intersected

by the Corridor Alternatives

with 50% or Higher

Minority Populations

Block Groups Not Intersected

by the Corridor Alternatives

with 50% or Higher

Minority Populations

Block Groups on Tribal

Land with 50% or Higher

Minority Populations

Le g e nd

0 1 2

Miles

Sources: Census 2010 Summary File 1; Esri 2014; Arizona Department of

Transportation 2013; Arizona Land Resource Information System 2013

N

e
Tempe

Mesa

Gilbert

Phoenix

!"a

AåU

AÖU

Q? ̈

AåU

Q?É

Salt River 

Pima-Maricopa

 Indian Community

Chandler

Scottsdale

Tonto

National Forest

Paradise

Valley

AÖU

AåU

!"a!"c

Queen

Creek

Salt River

Final Tier 1 Environmental Impact Statement 5-36

Existing Conditions and Environmental Consequences

Figure 5-5. Threshold Minority Populations in the Phoenix Metropolitan Area

5

InterstateState or US HighwayLocal RoadRailroadMajor DrainageFederal LandNational ForestTribal LandState Trust Land

Yellow Corridor AlternativeOrange Corridor AlternativeBlock Groups Intersectedby the Corridor Alternativeswith 50% or HigherMinority PopulationsBlock Groups Not Intersectedby the Corridor Alternativeswith 50% or HigherMinority PopulationsBlock Groups on TribalLand with 50% or HigherMinority Populations

Le g e nd

0 1 2

Miles

N

Sources: Census 2010 Summary File 1; Esri 2014; Arizona Department ofTransportation 2013; Arizona Land Resource Information System 2013
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-37

Several communities had a higher share of households that earn less than $15,000 per year 

compared to the three-county Study Area, including; Eloy (26.2 percent of all households), 

Tucson (18.8 percent), Tempe (14.8 percent), Coolidge (14.7 percent), and Phoenix 

(13.2 percent) (Table T-2 in the Title VI and Environmental Justice Appendix). Figure 5-6, 

Figure 5-7, and Figure 5-8 highlight the location of the EJ Block Groups based on income in and 

around the corridor alternatives.

Limited English Proficiency

According to the 2008-2012 American Community Survey, 73.4 percent of the population aged 

five years and older living within the corridor alternatives speak English only. Of those that 

speak a language other than English, almost 1 million people (21.0 percent) speak Spanish; and 

8.7 percent speak Spanish and speak English “less than very well.” The next most commonly 

spoken languages in the three-county Study Area include Chinese (0.5 percent), Vietnamese 

(0.4 percent), and German (0.4 percent). In Pinal County, the most commonly spoken languages 

are, in descending order, Spanish (19.3 percent), other Native North American languages 

(0.7 percent), Navajo (0.4 percent), and German (0.4 percent). In Pima County, commonly 

spoken languages are Spanish (23.5 percent), Chinese (0.6 percent), other Native North 

American languages (0.5 percent), and German (0.5 percent). In Maricopa County, commonly 

spoken languages are Spanish (20.6 percent), Chinese (0.5 percent), Tagalog (0.4 percent), and 

German (0.4 percent). Table T-3 in the Title VI and Environmental Justice Appendix highlights 

the languages spoken in the Study Area and number of people who speak English “less than 

very well.”

In order to provide meaningful communication to the people living in the Study Area, project 

materials would be made available in the dominant languages spoken (English and Spanish); 

and interpretation services should be made available for Spanish speakers and speakers of 

other languages upon request. Different language interpretation may be needed depending on 

where within the Study Area public outreach activities occur. 
Florence

Marana

Eloy

Coolidge

Casa

Grande

Maricopa

Oro 

Valley

PINAL COUNTY

PIMA COUNTY

MARICOPA COUNTY

PINAL COUNTY

GILA COUNTY

PINAL COUNTY

Tohono O'odham Nation

!"a

!"`

)e

Q?Á

Q?¿

Q?É

Q?Æ

UAõ UAú

UAÖ

!"c Q? ̈

!"a

)e

!"a

Q?Ê

Q?É

!"a

!"d

Q?È

)e

Santa Cruz River

Salt River

Gila River

Queen Creek

Superior

Glendale

Scottsdale

Apache

Junction

UAÛ

See Phoenix 

Metropolitan Area

Figure 5-8

See Tucson

Metropolitan Area

Figure 5-7

Ak-Chin

Indian 

Community

Gila River

Indian 

Community Sacaton

San

Tan

Valley

5 Existing Conditions and Environmental Consequences

Figure 5-6. Concentrations of Low-Income Populations in the Study Area

Final Tier 1 Environmental Impact Statement 5-38

Interstate

State or US Highway

Railroad

Major Drainage

Yellow Corridor Alternative

Orange Corridor Alternative

Federal Land

National Forest

State Trust Land

City Boundary

Block Groups Intersected

by the Corridor Alternatives

with Concentrations of

Low-Income Populations

Block Groups Not Intersected

by the Corridor Alternatives

with Concentrations of

Low-Income Populations

Block Groups on Tribal Land

with Concentrations of

Low-Income Populations

Le g e nd

0 5 10

Miles

Sources: Census ACS 2008-2012; Esri 2014; Arizona Department of Transportation 2013;

Arizona Land Resource Information System 2013

N
5 Existing Conditions and Environmental Consequences

Figure 5-7. Concentrations of Low-Income Populations in the Tucson Metropolitan Area

Final Tier 1 Environmental Impact Statement 5-39

Prince Rd

La Canada Dr

Speedway Blvd

Silverbell Rd

Swan Rd

Country Club Rd

Silverlake Rd

Golf Links Rd

Broadway Blvd

Grant Rd

1st Ave

Fort Lowell Rd

Alvernon Wy

5th St

22nd St

Campbell Ave

Greasewood Rd

Anklam Rd La Cholla Blvd

Orange Grove Rd

Barraza Aviation Hwy

Ajo Way

Irvington Rd

Drexel Rd

Valencia Rd

Nogales Hwy

Los Reales Rd

Tucson

Q?¿

!"a

!"a

South

Tucson

Davis

Monthan

Air Force

Base

Marana

Santa Cruz River

Catalina Foothills

e

Q?È

Tucson

International

Airport

e

Airport

Interstate

State or US Highway

Local Road

Railroad

Major Drainage

Federal Land

State Trust Land

Yellow and Orange

Corridor Alternatives

Block Groups Intersected

by the Corridor Alternatives

with Concentrations of

Low-Income Populations

Block Groups Not Intersected

by the Corridor Alternatives

with Concentrations of

Low-Income Populations

Le g e nd

0 1 2

Miles

Sources: Census ACS 2008-2012; Esri 2014; Arizona Department of

Transportation 2013; Arizona Land Resource Information System 2013

N

e
Tempe

Mesa

Gilbert

Phoenix

!"a

AåU

AÖU

Q? ̈

AåU

Q?É

Salt River 

Pima-Maricopa

 Indian Community

Chandler

Scottsdale

Tonto

National Forest

Paradise

Valley

AÖU

AåU

!"a!"c

Queen

Creek

Salt River

Guadalupe

Final Tier 1 Environmental Impact Statement 5-40

Existing Conditions and Environmental Consequences

Figure 5-8. Concentrations of Low-Income Populations in the Phoenix Metropolitan Area

5

InterstateState or US HighwayLocal RoadRailroadMajor DrainageFederal LandNational ForestTribal LandState Trust Land

Yellow Corridor AlternativeOrange Corridor AlternativeBlock Groups Intersectedby the Corridor Alternativeswith Concentrations of Low-Income PopulationsBlock Groups Not Intersectedby the Corridor Alternativeswith Concentrations of Low-Income Populations

Le g e nd

0 1 2

Miles

N

Sources: Census ACS 2008-2012; Esri 2014; Arizona Department of Transportation 2013;Arizona Land Resource Information System 2013
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-41

5.4.3 Environmental Consequences

As explained in the methodology, Census block groups containing a minority population greater 

than 50 percent were identified as EJ Block Groups for the purposes of evaluating potential 

impacts. Table 5-4 shows the number of Census block groups intersected by the Yellow and 

Orange corridor alternatives and, of those, the number of block groups with high 

concentrations of EJ and other protected populations as of the 2010 Census, which is the latest 

year for which actual counts are available. Effects of a passenger rail system on EJ and 

vulnerable populations would vary depending on the exact alignment within a corridor 

alternative; however, for this Tier 1 analysis, corridor-wide percentages of EJ and sensitive 

population Block Groups represent approximate percentages throughout the corridor.

Table 5-4. Environmental Justice Block Groups Intersected by the Corridor Alternatives

Total Block 

Groups

Total EJ Block Groups 

based on Race & 

Ethnicity

Total EJ Block Groups 

based on Household 

Income

Yellow Corridor Alternative 230

94 16

40.9% 7.0%

Orange Corridor Alternative 194

72 14

37.1% 7.2%

Yellow Corridor Alternative

A passenger rail system within the Yellow Corridor Alternative could have direct impacts on 

minority and low-income populations. Potential property displacements, depending on specific 

facility locations, would be determined during Tier 2 studies. Additional impacts to protected 

populations from a passenger rail system within the Yellow Corridor Alternative could include

those related to public health and safety and community cohesion, such as tracks creating a 

barrier to access within a neighborhood, displacing a community center or church, or 

prompting a change in the demographic composition of a neighborhood near rail stations. 

Indirect and temporary impacts on EJ and other protected populations may include increased 

traffic congestion, delays, noise, and vibrations during construction. Due to the location specific 

nature of an environmental justice analysis, a determination of the effects on EJ and other 

protected populations cannot be made until design details are further developed. A full 

determination of impacts would continue in Tier 2. 

Passenger rail would provide economic and quality-of-life benefits to minority and low-income 

populations through improved mobility and access to alternative transportation modes serving 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-42

a variety of destinations throughout the region. Benefits would be greatest near station areas, 

but benefits would also occur where public transit service offers access to rail stations. 

If a passenger rail system within the Yellow Corridor Alternative is built within or along an 

existing railroad alignment, increased traffic within the existing rail ROW could increase noise, 

as addressed in Section 5.9, Noise and Vibration. The potential for additional grade crossings 

can introduce a greater amount of safety concerns for communities, as addressed in 

Section 5.5, Public Health and Safety. 

Minimal temporary impacts on existing public transportation routes could occur as a result of 

detours and delays during construction. If built along or within an existing railroad ROW, a 

passenger rail system could provide beneficial impacts by improving or developing highwayrailroad grade crossings, potentially with additional safety features. 

Potential impacts on EJ populations would be further addressed, along with those for the 

general population, in the Tier 2 analysis. 

Orange Corridor Alternative

Potential impacts of a passenger rail system to EJ and other protected populations within the 

Orange Corridor Alternative would be the same as those described above for the Yellow 

Corridor Alternative, albeit in different locations where the two corridor alternatives diverge. 

Due to the location-specific nature of an environmental justice analysis, a determination of the 

effects on EJ and other protected populations cannot be made until design details are further 

developed. A full determination of impacts would continue in the Tier 2 analysis. 

Passenger rail could provide economic and quality-of-life benefits to minority and low-income 

populations through improved mobility and access to alternative transportation modes serving 

a variety of destinations throughout the region, particularly for populations near rail stations or 

with access to public transit service connecting to rail stations. 

No Build Alternative

Under the No Build Alternative, a new passenger rail system would not be built; and impacts on 

EJ and sensitive populations are not anticipated beyond those that could occur due to other 

approved projects. With the No Build Alternative, minority and low-income populations in the 

assessment area would not realize the mobility and economic benefits provided through access 

to new passenger rail service. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-43

5.4.4 Potential Mitigation Measures

The potential for disproportionate EJ impacts cannot be determine until Tier 2 analysis on a 

specific alignment is conducted. However, if the analysis identifies the potential for 

disproportionate EJ impacts, ADOT would develop an outreach program to engage the 

protected populations in planning, programming, and implementing alternatives that could 

affect them. ADOT also would commit to the other requirements outlined in EO 12898, Federal 

Actions to Address Environmental Justice in Minority Populations and Low-Income Populations.

5.4.5 Tier 2 Considerations

Tier 2 analysis can result in refinements in design that would minimize potential areas of 

impact. In compliance with EO 13166, public involvement activities and communications for the 

study would be conducted to ensure full and fair participation. An LEP investigation would 

inform the Tier 2 public outreach process to ensure specific approaches are available to provide 

access to services and for public involvement. Project communication should be made available 

in Spanish and other languages upon request. 

A Tier 2 NEPA document would include a full analysis of the impacts to EJ and sensitive

populations from construction and operation of a selected alternative at the project level. 

Resources that may need to be studied further during Tier 2 would include displacements and 

relocation; access to employment and business; community characteristics; and affordable 

housing initiatives for protected populations. The Tier 2 NEPA analysis would include a full 

determination of the impacts to EJ and other protected populations of a specific passenger rail 

system. The following strategy, as established by FTA Circular 4703.1 – Environmental Justice 

Policy Guidance for Federal Transit Administration Recipients, August 15, 2012, would be 

addressed in Tier 2: 

 Determine the effects of the activity on the identified EJ populations and compare those 

effects with the effects on the non-EJ population within the area of the activity

 Determine whether the activity creates an adverse effect and then determine whether 

that effect is disproportionate and high by comparing the effects experienced by EJ

populations and non-EJ populations

 Whether the adverse effects on EJ populations exceed those borne by non-EJ 

populations

 Whether cumulative or indirect effects would adversely affect an EJ population

 Whether mitigation and enhancement measures would be taken for EJ and non-EJ 

populations
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-44

 Whether there are offsetting benefits to EJ populations as compared to non-EJ 

populations

 Determine whether it is possible to avoid, minimize, or mitigate any disproportionately 

high and adverse human health or environmental effects on EJ populations

Design details such as station locations, rail alignments, and the need for additional ROW would 

be described in the Tier 2 analysis, resulting in a more precise understanding of the specific 

impacts to EJ populations. Specific mitigation measures would be identified and discussed 

during the Tier 2 analysis after design details are finalized, recorded in NEPA documents as 

specific impacts are identified, and implemented prior to construction. Identification of EJ 

populations would be verified and updated, and public outreach activities would be designed to 

engage EJ populations. Evaluation of disproportionately high and adverse impacts on EJ 

populations would require a detailed analysis of impacts as well as input from public outreach 

to affected communities.

5.5 Public Health and Safety

Public health and safety concerns regarding a potential rail system comprise a number of issues 

including, but not limited to, vehicular traffic and pedestrian conflicts at highway-railroad grade 

crossings, safety of rail passengers on trains and at stations, rail worker health and safety during 

construction and operations, maintaining safe construction zones well separated from public 

areas, and providing cost-effective as well as adequate warning systems for train operations.

This evaluation assesses the potential effects of a passenger rail system on the health and 

safety of residents and communities in the Yellow and Orange corridor alternatives, and the 

types of protection that could be provided during construction and long‐term rail operations to 

help mitigate health and safety concerns.

5.5.1 Methodology and Regulatory Requirements

This EIS complies with FRA's Procedures for Considering Environmental Impacts (Environmental 

Procedures) (64 FR 28545, May 26, 1999) and FTA’s Environmental Impact and Related 

Procedures (23 CFR Part 771). The regulatory framework pertaining to public health and safety 

includes ADA, the Resource Conservation and Recovery Act of 1976 (RCRA) and its 

amendments, and the Occupational Health and Safety Act of 1970. Public health and safety 

considerations were evaluated in accordance with FRA Environmental Procedures Section 

14(n)(17) and (18) (FRA 1999a).

Publications and resource materials from FRA and other USDOT agencies were also reviewed 

for general safety requirements including, but not limited to, the ADA, High-Speed Passenger 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-45

Rail Safety Strategy (FRA 2009), the Rail Safety Improvement Act of 2008 (Public Law 110-432), 

and the Federal Railroad Safety Act (FRSA) (49 U.S.C. § 20101 et seq.). During Tier 2 NEPA 

analysis, ADOT, in coordination with FRA and/or FTA, would coordinate with UP to obtain 

information regarding the level of protection afforded the public concerning health and safety 

issues.

The potential for collisions between trains and vehicles or pedestrians is greatest at 

highway/rail and pedestrian/rail crossings. Locations where a roadway, sidewalk, or pedestrian 

trail/bikeway crosses the track at the same elevation are called “grade” crossings. Crossings 

where a roadway, sidewalk, or pedestrian trail/bikeway passes over the tracks via an overpass 

bridge structure or passes under a railroad track via an underpass bridge structure are referred 

to as “grade separated.” An understanding of the potential number and type of crossings 

contributes to an understanding of the degree of risk for collisions within each corridor 

alternative. Because the greatest potential risk to public health and safety is at rail crossings 

and rail stations, the public health and safety analysis focuses on the number of potential 

crossings, recognizing that these may change during more detailed design.

Existing roadway/rail grade and grade-separated crossings and existing rail station information 

was verified against recent aerial photography and ADOT’s rail crossing database. Additional 

information associated with the UP was collected from the ADOT UP database and recent aerial 

photography (ADOT 2012). Where existing UP track is located within the Yellow and Orange 

corridor alternatives, UP crossing information was collected. Existing crossing data were used to 

formulate a reasonable number of crossings for possible passenger rail alignments within the 

corridor alternatives. Information regarding potential grade and grade-separated crossings was 

drawn from aerial photography with inferences based on the ADOT UP crossing database.

Because the number of potential crossings would vary depending on the future alignment 

within a corridor, densely urbanized areas were assumed to have one grade-separated crossing 

per mile, while a range of potential crossings was given in other areas where the number of 

crossings was highly variable depending on the location of a future alignment within a corridor 

alternative. Aerial photographs illustrating locations where roads are intersected by the 

corridor alternatives, i.e., potential locations for grade crossings, are shown in the Corridor 

Aerial Atlas Appendix, Maps 1 through 91.

A distinction was made between urban and rural crossings, because different safety elements 

need to be considered. For example, urban crossings may include higher volumes of cross 

traffic and warrant the cost of grade-separated crossings and/or additional physical barriers 

such as railroad crossing gates and signals. Slow-moving vehicles, such as agricultural 

equipment, may frequently use rural crossings and may need earlier audio warning systems.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-46

Because the analysis estimated crossings for the length of the proposed corridors regardless of 

the ultimate alignment within each corridor, it was not necessary to apply the ratio for a 

narrower corridor. The estimated number of railroad crossings used in the analysis is the same 

regardless of the corridor width.

Future Tier 2 documentation would evaluate a passenger rail system in detail, including sitespecific identification of grade crossings and stations and information from additional sources 

regarding topics such as unusually busy grade crossings or farm crossings. If a future alignment 

proposes to use existing UP track or rail facilities, ADOT, in coordination with FRA and/or FTA,

would coordinate with UP during Tier 2 documentation to obtain information regarding public 

health and safety issues and associated coordination in protecting the public and rail workers.

5.5.2 Existing Conditions

According to data from the USDOT Bureau of Transportation Statistics, between 2003 and 2012, 

an annual average of 7 passenger fatalities occurred and 1,172 persons were injured traveling 

by rail in nearly 100 million passenger train miles traveled (USDOT, Research and Innovative 

Technology Administration, Bureau of Transportation Statistics 2013). Compared to vehicular 

highway travel, passenger rail service is statistically safer. According to the National Safety 

Council data for 2010, based on miles traveled, personal motor vehicle travel was 

approximately 25 times more likely to result in a fatality than passenger rail travel. In 2010, the 

passenger death rate in light-duty vehicles was 0.50 per 100 million (1 in 200 million) passenger 

miles, compared to a passenger death rate in trains of 0.02 per 100 million (1 in 5 billion) 

passenger miles (National Safety Council 2013).

Numerous public and private roads, state and US highways, and an interstate highway intersect 

the approximately 120-mile-long Yellow and Orange corridor alternatives. 

Table 5-5 summarizes the anticipated number of crossings and stations for the Yellow and 

Orange corridor alternatives. The locations of these rail system facilities are estimated based on 

the communities that intersect the corridors. The anticipated number and types of crossings 

are based on existing UP crossings and aerial photography showing roads that intersect with 

the corridors. Rural grade-separated crossings are not included because none currently exist, 

and traffic volumes on rural roads intersecting the corridor alternatives do not likely warrant 

constructing grade-separated crossings. Actual numbers of crossings and stations would be 

established during Tier 2 studies in consideration of factors such as more detailed engineering 

analysis, utility studies, ridership modeling results, and public input.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-47

Table 5-5. Potential At-Grade and Grade-Separated Crossings and Stations by Alternative 

Segment

Urban Atgrade 

Crossings a

Rural Atgrade 

Crossings

Urban Gradeseparated 

Crossings

Urban Stations Rural Stations

Total Number 

of Anticipated 

Crossings and 

Stations

Southern Hub to Eloy – Yellow and Orange Corridor Alternativesb

16 5 8 8 0 37

Eloy to Northern Hub – Yellow Corridor Alternativeb

78 13 23 6 1 121

Eloy to Northern Hub – Orange Corridor Alternativec

29 5 31 4 3 72

Notes:

a Urban and rural areas identified by location inside (urban) or outside (rural) city boundaries (ALRIS 2013).

b Crossings and stations identified by ADOT UP crossings database and aerial photography.

c Crossings and stations identified by aerial photography and inference based on ADOT UP crossings database

The existing UP at-grade crossings have various forms of warning devices ranging from active 

gates and flashing signals to passive protective lights and bells to simple cross-buck warning 

signs at rural crossings.

Some communities have established Quiet Zones in which the sounding of train horns is 

prohibited except in emergencies. In these areas, FRA requires the use of upgraded crossing 

gates and curbs to prohibit vehicle egress across train tracks from cross streets when a train 

approaches the crossing.

Assuming the Quiet Zones that apply to the UP are extended to the passenger rail system, two 

sections of the Yellow Corridor Alternative would be subject to existing Quiet Zones. The UP is 

currently subject to a Quiet Zone in Tempe, north of Broadway Road from the City of Mesa to 

the City of Phoenix boundaries. The Yellow Corridor Alternative also may be subject to the 

Phoenix Downtown Quiet Zone in effect on the UP between 4th Street and 3

rd Avenue. 

One section of the Orange Corridor Alternative may be subject to the Phoenix Downtown Quiet 

Zone described above.

5.5.3 Environmental Consequences

At the Tier 1 analysis level, project construction and operations in the Yellow or Orange corridor

alternatives do not appear to present major obstacles associated with public health and safety 

challenges.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-48

Yellow Corridor Alternative

Physical Impacts 

A passenger rail system within the Yellow Corridor Alternative would likely have more grade 

crossings than a system within the Orange Corridor Alternative because the road and street 

network in the Yellow Corridor Alternative is more robust. The opportunity exists in the Yellow 

Corridor Alternative to locate part of the passenger rail system within or closely parallel to an 

existing freight railroad. Where railroad crossings for the freight line coincide with the 

passenger rail systems, fewer new grade crossings may be needed; and persons who habitually 

travel across the existing tracks would be accustomed to exercising safety precautions at these 

crossings. Because the alignment of a passenger rail system within this corridor alternative has 

not been determined, the extent of physical impacts to public health and safety cannot be fully 

determined.

Operational Impacts 

Operation of passenger rail service within the Yellow Corridor Alternative would introduce train 

traffic or increase the frequency, number, and average speed of trains along or adjacent to the 

existing freight railroad. In either case, the change in traffic conditions associated with 

passenger rail system operations would increase the public’s risk of misjudging the time 

available to cross the tracks. During the operational phase, moving trains and maintenance of 

the rail facilities would be the primary worker and public health and safety concerns. New 

passenger service at speeds up to 110 mph may require upgrading of safety systems, in 

accordance with applicable design standards and FRA safety regulations (49 CFR Parts 200 to 

299), to help ensure that the most sophisticated warning devices appropriate for the area are 

available for the higher-speed service.

Direct effects on public health and safety could arise from passengers interacting with the rail 

system at stations, on platforms, and within passenger trains. These facilities are susceptible to 

a range of safety and security threats ranging from personal accidents (e.g., slips or trips) to 

criminal activity (e.g., theft or terrorism in passenger areas). Platform areas add risks associated 

with moving trains and train boarding. Passengers on the train are at risk for these same 

incidents. 

An indirect benefit of a passenger rail system would be a relief in some of the volume of 

vehicular traffic using I-10 and other area roadways. Reduced volumes of vehicular traffic would

improve the level of service of the highways, improving traffic flow and thereby reducing the 

potential for vehicular collisions. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-49

In 2012, 87 fatal crashes occurred in the rural segments of Arizona’s interstate highway system 

and killed 104 persons. In the urban segments of Arizona’s interstate highways, 44 fatal crashes 

accounted for 47 deaths (NHTSA 2015). While the 2012 U.S. fatality rate for motor vehicles is 

1.14 per 100 million miles traveled, the Arizona rate during this same year was 1.37 fatalities 

per 100 million miles traveled; this reflects the historical trends from 2008 through 2011 where 

Arizona experienced an average of approximately 0.23 more fatalities per 100 million miles 

traveled than the national average. Additionally, while rural crashes in Arizona accounted for 

19.39 percent of all crashes, they accounted for 49.05 percent of all fatal crashes occurring in 

2012 (ADOT 2013). With passenger rail statistically resulting in 25 times fewer fatalities per 100 

million miles traveled than passenger vehicle (0.02 vs. 0.50), fatality statistics for Arizona may 

start to align closer to national statistics, which includes states with passenger rail service.

Construction Impacts 

Construction of passenger rail system infrastructure and associated safety systems, as well as 

improvements to adjacent transportation modes, would result in temporary impacts along the 

rail ROW and at station locations. During the construction phase, health and safety risks could 

increase. Work crews would be subject to the types of hazards commonly associated with 

construction sites, including working in an environment with heavy equipment, power tools, 

open trenches, and other types of potential hazards. 

Environmental hazards for work crews could include working in extreme temperatures and 

potential exposure to venomous insects and wildlife. Workers also may be working with 

materials that are potentially hazardous if not used, stored, and disposed of properly.

Effects on public health and safety during construction would generally be short-term and 

temporary. These effects may include localized increases in air pollutants, noise, and vibration, 

as well as traffic accidents associated with reductions in travel lanes (particularly in urban 

environments), greater potential exposure to heavy equipment in operation or open trenches, 

and increases in noise. Soil-disturbing activities associated with construction could increase 

exposure to dust, which could reduce visibility in nearby travel corridors. Dust may also 

increase the potential for aggravating pulmonary disorders such as asthma or increasing 

exposure to the fungi found in some soils that can cause valley fever (Coccidioidomycosis) when 

inhaled.

Orange Corridor Alternative

Physical Impacts 

Direct effects on public health and safety from a passenger rail system within the Orange 

Corridor Alternative would be similar to those associated with a system in the Yellow Corridor 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-50

Alternative. Implementing passenger rail service within the Orange Corridor Alternative would 

require approximately 120 miles of new track to be built within new ROW or within the ROW of 

adjacent transportation facilities, including existing and proposed facilities. The introduction of 

a railroad in a new location would present potential public health and safety hazards to the 

area. People within the Orange Corridor Alternative unaccustomed to grade railroad crossings 

and new traffic patterns would need time to become familiar with the presence of these 

elements in their surroundings and be aware of the safety issues and precautions needed for 

their protection.

Operational Impacts 

Operation of passenger rail service within the Orange Corridor Alternative would introduce 

public health and safety concerns similar to those associated with a passenger system in the 

Yellow Corridor Alternative. 

Construction Impacts 

Impacts from constructing passenger rail system infrastructure and associated safety systems in 

the Orange Corridor Alternative would be similar to those associated with a system in the 

Yellow Corridor Alternative. 

No Build Alternative

Under the No Build Alternative, a passenger rail system would not be constructed or 

implemented. Traffic volumes on I-10 between Tucson and Phoenix and other area roadways 

would likely continue to increase, contributing to a likely increase in traffic accidents. In 

addition, with increases in traffic volume, the potential for crossing conflicts on existing rail 

lines could increase without the addition of upgraded warning or traffic control devices.

5.5.4 Potential Mitigation Measures

Site-specific mitigation measures would be identified during Tier 2 documentation, based on 

preliminary design, and implemented with construction of a project. Due to the anticipated 

maximum train speed, a number of safety measures and strategies would be considered for the 

rail system being evaluated in this study to protect the health and safety of passengers as well 

as motorists and pedestrians at existing or new crossings and stations. Several of the following 

safety measures and strategies are recommendations from FRA guidance in the High Speed 

Passenger Rail Safety Strategy (FRA, Office of Railroad Safety and Office of Railroad 

Development 2009). While the rail system being evaluated in this study is not included in the 

FRA’s High Speed Intercity Passenger Rail Program (FRA 2013a), the safety measures identified 

in this program’s safety strategy should be considered for implementation, as necessary and 

practicable.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-51

 Prior to the start of construction, develop a Health, Safety, Security, and Environment 

Plan to address health and safety risks and requirements, safe work practices, worker 

training, dust control, use and storage of potentially hazardous materials, emergency 

response, implementation of safety procedures, incident investigation and reporting, 

and related topics.

 Where practical, consolidate public and private grade crossings along the route.

Eliminate redundant and/or unsafe crossings (due to proximity of exiting road 

intersections, skewed geometry, etc.) where alternate access can be reasonably 

provided.

 For at-grade crossings, especially within and on the fringe of populated areas, install the 

most sophisticated traffic control/warning device appropriate for the location, such as 

median barriers, special signage, flashing lights, four-quadrant gates, etc. In general, 

private crossings should be treated the same as public crossings.

 When feasible, close private crossings within industrial developments and rural areas 

with a prevalence of heavy trucks and farm equipment. If private crossings cannot be 

closed, consider provision of a locking device when not in use.

 Upgrade existing train traffic control systems to ensure safe interactions between 

existing rail facilities and traffic and between new rail facilities and traffic. 

 Clear trees and brush, as needed, to provide necessary sight distances for safe operation 

of the rail system.

 Implement measures to suppress fugitive dust during construction.

 Whenever possible, take measures to minimize noise related to construction.

 Use active warning systems for pedestrians where rail lines cross existing sidewalks, 

trails, and bike routes, particularly when crossings are near parks, schools, and other 

activity centers.

 Prepare road users for the challenges inherent at future crossings through educational 

and public outreach programs. Inform the public that passenger trains travel at 

significantly higher speeds than the freight trains currently operating in portions of the 

corridor alternatives and that relying exclusively on visual and/or audible cues to judge 

the arrival of trains can be extremely dangerous.

 Evaluate if Quiet Zones applicable to UP freight operations should be extended to 

passenger rail operations where the Yellow Corridor Alternative intersects the Tempe 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-52

Quiet Zone and where both corridor alternatives pass through the existing Phoenix 

Downtown Quiet Zone. 

 Evaluate the need for and, where warranted, install additional security improvements 

such as extra lighting, surveillance cameras, and other security measures at train 

stations.

 Ensure that any future construction, operations, and maintenance of a passenger rail 

system meet the Occupational Health and Safety Act of 1970, FRA, ADA, RCRA, and 

other requirements to help protect the safety and health of workers and the public.

5.5.5 Tier 2 Considerations

Temporary and permanent impacts to public health and safety resulting from construction and 

operation of a rail system would be evaluated in detail during Tier 2 documentation. Projectlevel analysis under Tier 2 would also evaluate new and existing crossing locations, as needed, 

to ensure safety issues and standards are addressed. Safety at stations would also be evaluated, 

with upgrades to existing safety equipment proposed as warranted. 

FRA has established train control requirements for train movements above 79 mph 

(49 CFR Part 236). For train speeds between 80 to 110 mph, the highest speed being considered 

for this study, FRA recommends the installation of the most sophisticated warning or traffic 

control devices that fit the location. Examples include dispatcher-controlled electrically locked 

gates, bells, flashing lights, constant warning time devices, and Positive Train Control systems, 

which include designs to prevent train-to-train collisions, derailments caused by excessive 

speed, unauthorized incursion by trains onto sections of track undergoing maintenance, and 

movement of a train through a track switch left in the wrong position. Sophisticated crossing 

facilities would be particularly necessary and/or required within Quiet Zones where train horns 

are not used at crossings unless a hazard is present. Quiet Zones currently exist along certain 

sections of the UP in Tempe and Phoenix. These would be examined in detail in Tier 2

documentation.

5.6 Parklands and Recreation Areas

Parks are defined as lands that have been officially designated as such by a federal, state, or 

local agency. Parks may contain recreational resources (such as trails, ball fields, and swimming 

pools), and recreational resources can also exist independently. For this Tier 1 EIS, federal, 

state, and local parks and recreational resources were identified and assessed for potential 

impacts. Publicly owned parks and recreation areas are also addressed in the separate 

discussion of Section 4(f) and 6(f) resources in Section 5.7.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-53

5.6.1 Methodology and Regulatory Requirements

This EIS complies with FRA's Procedures for Considering Environmental Impacts (Environmental 

Procedures) (64 FR 28545, May 26, 1999) and FTA’s Environmental Impact and Related 

Procedures (23 CFR Part 771). Potential impacts on parks and recreational resources (as defined 

in the introduction to this section) were evaluated in accordance with CEQ regulations

implementing NEPA and FRA’s Environmental Procedures (Section 14(n)(19) (FRA 1999a)).

Data from several sources were used to inventory parks and recreational resources within the

corridor alternatives and adjacent lands. These sources included federal, state, and county

websites and associated GIS data and aerial photography mapping programs such as Google

Maps and ArcGIS. A GIS database of parklands and recreation areas was compiled with input 

from state agencies, local jurisdictions, Councils of Government, and MPOs. The name, 

location, type, and size of the park, recreational resource, or natural area were identified and 

are compiled in the Section 4(f) and 6(f) Resources Appendix. Federal, state, and local sites were

also mapped on the Corridor Aerial Atlas Appendix.

Private parks associated with master planned developments and residential subdivisions are 

also an important resource; however, different local government agencies handle data on 

location and size of these private parks differently, making data gathering and comparisons 

among alternatives problematic. For this reason, the analysis of privately owned parks is better 

suited to be covered in the Tier 2 NEPA analysis. The private parks and recreation areas 

presented below in Table 5-6 consist mostly of recreation areas (golf courses).

This Tier 1 EIS focuses on identifying the public parks and recreational resources located within 

the corridor alternatives and identifying the types of activities having the potential to affect 

those resources. Because a specific alignment within each alternative has not been determined, 

the number, rather than the acreage, of potentially affected parklands was estimated. A scan of 

the 200-foot-wide center swath of each corridor alternative provided a clearer whole-number 

estimate than applying the 200-foot to one-mile ratio (0.0379) to the total number of parklands 

obtained from GIS data for each corridor alternative. 

5.6.2 Existing Conditions

Public parks, recreational resources, and natural areas within the corridor alternatives are

shown in the Corridor Aerial Atlas Appendix, Maps 1 through 91. Within the mile wide corridor 

alternatives, a total of 147 parks (city, county, and state), 67 recreational areas (trails, athletic

fields, public and private golf courses, stadiums, and swimming pools), and 26 privately owned 

parks/recreation areas were identified. The Section 4(f) and 6(f) Resources Appendix includes a

table of the public parks and recreational resources located within the mile-wide corridor
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-54

alternatives, plus a 0.25-mile buffer around them to account for proximity effects such as 

increased noise. Table 5-6 presents summary data for each corridor alternative, and includes 

privately owned parks and recreation areas.

Table 5-6. Summary of Parks, Natural Areas, and Recreation Areas in the Study Corridors

Public Parksa Public Recreation Areasb

Private Parks and Recreation 

Areasb

Southern Hub to Eloy – Yellow and Orange Corridor Alternatives

43 12 2

Eloy to Northern Hub – Yellow Corridor Alternative

56 33 5

Eloy to Northern Hub – Orange Corridor Alternative

48 22 19

Notes: 

a Park jurisdictions include city, county, state, and the National Park Service.

b Recreation areas include schools, athletic fields, trails, recreation centers, golf courses, stadiums, and swimming pools.

Additionally, the southern portion of both corridor alternatives coincides in places with the 

Juan Bautista de Anza National Historic Trail designated historic corridor, auto tour route, and 

recreation retracement route. As defined by the National Trails System Act (16 U.S.C. §§ 1241-

1251), a National Historic Trail is an extended trail which follows as closely as possible and 

practicable the original trail or route of travel of national historical significance. While outside 

of the Santa Cruz River Park the historic corridor is not within a public park or recreation area, 

the Historic Trail designation is intended to identify and protect the remains of this overland 

route for public use and enjoyment. The Anza Trail Corridor appears on Maps 1-11 and 21-27 of 

the Corridor Aerial Atlas Appendix.

5.6.3 Environmental Consequences

Activities having the potential to affect public parks and recreational resources include 

upgrading existing and building new rail infrastructure, as well as constructing new passenger 

stations. Impacts could take the form of physical use of and modifications to the land, or the

indirect effects of increased noise levels and visibility. 

Impacts to parks and recreation areas would depend on the alignment. Parks and recreational 

resources potentially affected by a future passenger rail system would be further identified in 

Tier 2. Specific types and degrees of impacts on individual resources (such as ROW acquisition 

and impacts on characteristics of a resource) would not be known until further design of rail 

facilities takes place. These would be evaluated in Tier 2 NEPA documents.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-55

Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts

Physical impacts to parklands and recreation areas would occur if a resource, or a portion of a 

resource, were permanently incorporated into the passenger rail system. This mile-wide 

corridor segment includes 43 public parks and 13 public recreational areas, as listed in Tables F2 and F-3 of the Section 4(f) and 6(f) Resources Appendix, and 2 private recreational areas. 

Many of these resources are densely clustered in specific areas, including around downtown 

Tucson, the Santa Cruz River Park, and north into Marana. Multiple trails, river parks, and linear 

parks also traverse the corridor, increasing the potential for physical impacts. Physical impacts 

to some resources that serve both a recreational and a flood control purpose (e.g., golf courses) 

would also be subject to floodplain regulation. As shown on Maps 1 through 22 of the Corridor 

Aerial Atlas Appendix, approximately six parks and recreational areas could potentially be 

affected within the 200-foot center of this corridor alternative segment. This number could 

change, depending on the location of a passenger rail system alignment within this segment. 

Operational Impacts

Operational impacts to parks and recreation areas could range from temporary or permanent 

access restrictions to visual, noise, and vibration impacts to nearby resources that would not be 

permanently incorporated into a future rail line. These impacts would also more likely occur in 

the Tucson-Marana area, where the parklands within the corridor are concentrated. Baseline 

noise levels, particularly in areas along Sky Harbor flight paths, should be considered when 

assessing noise impacts to parks along the Salt River in Mesa and Tempe.

Construction Impacts 

Construction impacts to parks or recreation areas would occur if the resources were near a rail 

line or station being constructed. Impacts of this type might include increases in dust from 

ground disturbance, views of and noise from construction equipment, access restrictions, and 

temporary construction staging. These impacts would be short-term and temporary, as they 

would occur during construction or until ground disturbance is stabilized. Like physical and 

operational impacts, construction impacts would be more likely around cities and populated 

areas where parks or other resources are concentrated.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-56

Eloy to Northern Hub

Physical Impacts

Physical impacts to parklands and recreation areas would occur if a resource, or a portion of a 

resource, were permanently incorporated into the rail line. This corridor segment includes

56 public parks and 33 public recreational areas, as listed in Tables F-2 and F-3 in the Section 

4(f) and 6(f) Resources Appendix. In addition, five private recreational areas are located within 

this corridor. Many of these resources are densely clustered in Coolidge, Queen Creek, Gilbert, 

Mesa, Tempe, and Phoenix; and multiple trails also traverse the corridor alternative, increasing 

the potential for physical impacts. As shown on Maps 23 through 55 of the Corridor Aerial Atlas 

Appendix, 15 parks and recreational areas could potentially be affected within the 200-foot 

center of this corridor alternative segment. This number could change depending on the 

location of a passenger rail system alignment within this segment.

Operational Impacts

Operational impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis. 

Construction Impacts

Construction impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

Orange Corridor Alternative

Southern Hub to Eloy

Physical, operational, and construction impacts in this segment of the Orange Corridor 

Alternative would be the same as those described in the Yellow Corridor Alternative southern 

hub to Eloy analysis.

Eloy to Northern Hub

Physical Impacts

Physical impacts to parklands and recreation areas would occur if a resource, or a portion of a 

resource, were permanently incorporated into the rail line. This segment includes 48 public

parks and 22 public recreational resources, as listed in Tables F-2 and F-3 of the Section 4(f) and 

6(f) Resources Appendix. An additional 19 private recreational resources were identified 

within the Orange Corridor Alternative. Many of these resources are densely clustered in 

Florence, Mesa, Tempe, and Phoenix; and multiple trails also traverse the corridor, increasing 

the potential for physical impacts. As shown on Maps 21 and 56 through 91 of the Corridor 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-57

Aerial Atlas Appendix, 14 parks and recreational areas could potentially be affected within the 

200-foot center of this corridor alternative segment. This number could change depending on 

the location of a passenger rail system alignment within this segment.

Operational Impacts

Operational impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

Construction Impacts

Construction impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

No Build Alternative

Under the No Build Alternative, a passenger rail system would not be constructed, and no 

impacts to parks or recreation areas would be anticipated beyond those that could occur due to 

other reasonably foreseeable projects.

5.6.4 Potential Mitigation Measures

Specific mitigation measures, to the extent required, would be identified and discussed during 

Tier 2 analysis after design details are known and specific impacts are identified and recorded in 

NEPA documents. Potential mitigation measures would be developed in consultation with the 

official with jurisdiction over the resource and might include avoiding Section 4(f) and 6(f) 

resources or minimizing the acreage of a physical take of these properties during alignment 

planning and design, selecting rail station locations that avoid public parks, moving equipment 

and facilities to another location within existing parkland, purchasing similar properties, and 

planting vegetation to offset removed vegetation or to establish visual and auditory screening. 

5.6.5 Tier 2 Considerations

Future alignments could be located anywhere within the selected corridor and would need to 

undergo a Tier 2 analysis for potential impacts on the parks and recreation areas affected by 

future alignment alternatives. Private parks associated with master planned developments and 

residential subdivision characteristics are inconsistently documented by various government 

agencies, so field review may be needed to verify data. This exercise is better suited for the 

Tier 2 analysis of specific alignments, when the number of private parks likely to be affected 

could be more readily identified.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-58

5.7 Section 4(f) and 6(f) Resources

Section 4(f) of the Department of Transportation Act of 1966 (49 U.S.C. § 303[c]) is intended to 

protect public parks; recreation areas; wildlife/waterfowl refuges of national, state, or local 

significance; and publicly or privately owned historic sites from being used for a transportation

projects. Protected properties must be of national, state, or local significance as determined by 

the federal, state, or local officials having jurisdiction over the park, recreation area, refuge, or 

historic site.

Section 6(f) lands are defined as parkland or recreation land that was acquired or developed with 

funding authorized under Section 6(f) of the Land and Water Conservation Fund (LWCF) Act of 

1965 (Public Law 88-578). These lands cannot be converted to a non-park or non-recreational use 

without the approval of the National Park Service (NPS). 

5.7.1 Methodology and Regulatory Requirements

Section 4(f) stipulates that FRA, FTA, and other USDOT agencies cannot approve the use of land 

from publicly owned parks, recreational areas, wildlife and waterfowl refuges, or public and 

private historic sites unless there is no feasible and prudent alternative to the use of that land and 

the proposed action includes all possible planning to minimize harm to the property resulting 

from such use.

A “use” of a Section 4(f) resource, as defined in 23 CFR 774.17, occurs:

 When land is permanently incorporated into a transportation facility,

 When temporary occupancy of land is adverse in terms of the statute’s preservation 

purpose, or

 When a constructive use of a Section 4(f) property occurs.

A constructive use of a Section 4(f) resource occurs when the transportation project does not 

incorporate land from the Section 4(f) resource but the project’s proximity impacts are so 

severe that the activities, features, or attributes that qualify a resource for protection under 

Section 4(f) are substantially impaired. For example, a constructive use can occur as a result of 

an increase in noise levels or restrictions in access or from other impacts that substantially 

impair the aesthetic features or attributes of the resource.

A historic site typically is considered a Section 4(f) resource if it is eligible for the National 

Register of Historic Places (NRHP) under Criterion A, B, or C as noted in Section 5.19, Cultural 

Resources. Information on determining NRHP-eligible properties can be found on the National 

Park Service website at www.nps.gov/nr/. Historic properties eligible for the NRHP only under 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-59

Criterion D are protected under Section 4(f) if they warrant protection in place or derive 

significance from being preserved in place.

Section 4(f) allows a direct use of a Section 4(f) resource if it has a de minimis impact (23 CFR § 

774.3[b]). In determining de minimis impacts, FRA considers any avoidance, minimization, and 

mitigation or enhancement measures included in the proposed project to address the impacts 

and adverse effects to the Section 4(f) resource. Use of a Section 4(f) resource may be 

determined to be de minimis if it does not adversely affect the activities, features, and 

attributes that qualify the resource for protection under Section 4(f). This is evidenced by a “no 

adverse effect” determination during the Section 106 process for historic properties and 

through coordination with the officials with jurisdiction over parks, recreational areas, or 

refuges. Use of a Section 4(f) resource is allowed when a de minimis impact finding can be 

supported by FRA with the written concurrence of the officials with jurisdiction over the Section 

4(f) resource. Where the resource is a publicly owned park, recreational area, or wildlife and 

waterfowl refuge, FRA must also provide the public an opportunity review and comment.

Section 6(f) of the LWCF Act is administered by the agency responsible for 6(f) compliance in 

each state, and NPS. This statute pertains to projects that would affect, or result in the 

permanent conversion of, outdoor recreational property acquired with LWCF assistance. The 

LWCF Act established the fund as a matching assistance program to provide grants for the 

acquisition and development cost of outdoor recreational sites and facilities. Section 6(f) 

prohibits the conversion of property acquired or developed with these grants to a nonrecreational purpose without approval from the applicable state agency and NPS. NPS can 

approve a land conversion only if replacement lands of equal value, location, and usefulness are 

provided (16 U.S.C. §§ 4601-4 through 4601-11 and 36 CFR § 59.3).

Potential impacts on Section 4(f) and 6(f) resources have been evaluated in accordance with 

FRA’s Procedures for Considering Environmental Impacts (Section 14[n][19] [FRA 1999a]), the 

requirements set forth in 49 U.S.C. § 303 for Section 4(f) lands, the requirements set forth in 23 

CFR Part 774 (Parks, Recreation Areas, Wildlife and Waterfowl Refuges, and Historic Sites 

[Section 4(f)]), and 36 CFR 59 (LWCF Program of Assistance to States).

The study area for this Tier 1 Section 4(f) evaluation is defined as the corridor alternatives plus a 

0.25-mile buffer around each corridor carried forward for further study. The 0.25-mile buffer is 

included to account for Section 4(f) resources for the Tier 1 environmental analysis that could 

be subject to potential constructive use impacts (e.g., noise and visual impacts) that may 

extend beyond the corridor boundaries. Therefore, data for potential Section 4(f) resources for 

a 1.5-mile corridor (1.0 mile plus 0.25 mile on each side, or 7,920 feet) were collected for this 

analysis. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-60

Because the area potentially affected by a 200-foot ROW corridor also includes a 0.25-mile 

buffer, the total impact width for a Section 4(f) resource analysis is 200 feet + 0.25 mile + 

0.25 mile, or 2,840 feet. To estimate the number of resources potentially affected, the ratio of 

these corridor widths (2,840:7,920, or 0.359) is multiplied by the total number of potentially 

affected Section 4(f) resources identified for each corridor alternative. The effects on protected 

resources will be analyzed further during Tier 2 NEPA analysis. 

5.7.2 Existing Conditions

Based on a review of readily available data – 2012 aerial photography, GIS data, and municipal 

planning documents – the study area contains all of the types of Section 4(f) resources: wildlife 

management areas, preserves, or open space that functions primarily as a refuge, parks, 

recreation areas, and historic properties. The Corridor Aerial Atlas Appendix, Maps 1 through 91

show the refuges, parks, recreational resources, and historic sites of national, state, or local

significance that qualify as Section 4(f) protected properties, as well as trails and schools that 

may potentially qualify for Section 4(f) protection.

The Section 4(f) and 6(f) Resources Appendix includes one table listing the Section 6(f) resources

and four tables that list the Section 4(f) refuges, parks and recreational resources, historic 

properties, and potential Section 4(f) schools within the mile-wide corridor alternatives and 

0.25-mile buffer.

5.7.3 Environmental Consequences

Identification of potential Section 4(f) resources in this Tier 1 EIS does not constitute a final 4(f) 

determination. That determination will not be made until Tier 2 project-level analysis, when a 

specific alignment is under consideration. Impacts to Section 4(f) resources would vary based 

on the future placement of the rail line within a given corridor. Resources identified within a 

0.25-mile buffer around a future alignment would be evaluated for constructive use, while 

resources directly affected by a future alignment would be evaluated for direct use, 

constructive use, and temporary occupancy. Avoidance of Section 4(f) resources is required 

unless there are no feasible and prudent alternatives. Therefore, examining avoidance 

alternatives, as necessary, would be a key criterion in the identification of Tier 2 alignment 

alternatives and design options. If a future alignment were to result in the potential use of a 

Section 4(f) resource, FRA would conduct the appropriate Section 4(f) evaluation. 

Consultation with the officials with jurisdiction over potentially affected resources is key to 

these options. 

With respect to potentially affected Section 6(f) resources, coordination would occur during 

Tier 2 with the administering agencies to confirm which parks and recreation areas were 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-61

acquired and/or developed with LWCF funding. If any areas are identified as LWCF lands, 

potential impacts would be addressed during Tier 2.

Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts

Physical impacts to Section 4(f) resources would constitute a use if the resource, or a portion of 

the resource, is permanently incorporated into the passenger rail system. Applying the 0.359 

multiplier for a ROW corridor as explained in Section 5.1.2, this segment could hypothetically 

include approximately 6 Section 6(f) resources, 3 refuges, 20 public parks and recreational 

resources, 17 private and public historic properties, and 7 schools with potentially public 

recreational resources that would be protected by Section 4(f), based on the resources listed 

in Tables F-1 through F-5 in the Section 4(f) and 6(f) Resources Appendix. Many of these

resources are densely clustered across the corridor alternatives around downtown Tucson, the 

Santa Cruz River Park, and north into Marana; and multiple trails, river parks, and linear parks 

traverse the corridor alternatives. Spanning some of the linear parks and trails that are 

perpendicular to the corridor is an option, but other parks are too large to span and therefore 

avoiding conversion of parkland may not be feasible. Therefore, impacts to Section 4(f) 

properties are likely to occur for any future alignment in the Yellow Corridor Alternative.

Santa Cruz River Park and Picacho Peak State Park have Section 6(f) status and are expansive 

enough to intersect with large portions of the corridor width (see the Corridor Aerial Atlas 

Appendix). If these parks cannot be avoided, the acreage converted for the passenger rail could 

be substantial compared to some of the smaller parks interspersed through the corridor.

Identifying and acquiring replacement properties that would be equally useful to such 

significant regional and state recreational resources could prove problematic and financially 

infeasible. Orna Mae Harn District Park in Marana should also be considered for avoidance 

during Tier 2. While Marana does have other parks, this district park is the primary recreational 

facility; and its current location helps it to serve as a focal point for the town. Ultimately, given 

the wide distribution of Section 6(f) resources along this segment, it is likely that a future 

alignment could result in the conversion of Section 6(f) resources requiring the identification 

and acquisition of replacement property.

Operational Impacts

Operational impacts to Section 4(f) resources could include permanent access restrictions, 

visual impacts, and noise and vibration impacts to resources that are in proximity to a future 

alignment but that would not be permanently incorporated into the passenger rail system. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-62

Nevertheless, because Section 4(f) considers proximity impacts in the determination of 

constructive use, such operational impacts would be evaluated in concert with the analysis of 

physical impacts.

Construction Impacts

Depending on the proximity of Section 4(f) resources to construction of the passenger rail

system, it is possible that such resources could be subject to temporary occupancy. Temporary 

occupancy occurs when any part of a Section 4(f) property is required for construction-related 

activities. The property may not be permanently incorporated into a transportation facility, but 

the activity might be considered adverse in terms of the preservation purpose of Section 4(f). If 

the following five requirements are met, then the temporary occupancy would not be 

considered a use (23 CFR § 774.13[d]):

1. Duration must be temporary and less than the time needed to construct the passenger 

rail system, with no change in ownership.

2. Changes to the Section 4(f) property must be minimal.

3. Physical impacts cannot be permanent or adverse or interfere with the protected 

activities, features, or attributes of the property.

4. Land being used must be fully restored.

5. FRA must obtain concurrence from the official(s) with jurisdiction that the first four 

conditions have been met. 

If these requirements cannot be met, then the construction impacts would be considered a use 

and would be subject to a Section 4(f) evaluation.

Eloy to Northern Hub

Physical Impacts

Physical impacts to Section 4(f) resources would constitute a direct use if the resource or 

portion of the resource is permanently incorporated into the passenger rail system. Applying 

the 0.359 multiplier for a ROW corridor as explained in Section 5.1.2, this segment could 

hypothetically include approximately 5 Section 6(f) resources, 2 refuges, 32 public parks and

recreational resources, 43 private and public historic properties, and 18 schools with 

potentially public recreational resources, based on Tables F-1 through F-5 in the Section 4(f) 

and 6(f) Resources Appendix. Many of these resources are densely clustered across the Yellow 

Corridor Alternative in Coolidge, Queen Creek, Gilbert, Mesa, Tempe, and Phoenix; and multiple 

trails traverse the corridor alternative. Therefore, substantial impacts to Section 4(f) properties 

are likely to occur from any future alignment in the Yellow Corridor Alternative.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-63

Casa Grande Ruins National Monument is one of the most prominent Section 4(f) resources 

within either corridor alternative. Potential impacts include direct conversion of land for 

passenger rail ROW and constructive use effects from noise, vibrations, or visual intrusions. 

Tier 2 studies to identify alignment alternatives should focus on avoidance of the monument. 

The Riparian Preserve at Neely Ranch is notable as the only bird sanctuary in either study 

corridor but is not currently accessible to the public; access to the public would be confirmed 

during Tier 2 to verify the preserve does not qualify for Section 4(f) protection. Woodland 

Parkway, a linear park in downtown Phoenix, is currently closed; however, its status would also 

be confirmed during Tier 2. 

Papago Park and Papago Municipal Golf Course have Section 6(f) status. Identifying and 

acquiring replacement properties that would be equally useful to such significant local 

recreational resources could prove problematic and financially infeasible, so avoidance may be 

required. Ultimately, given the wide distribution of Section 6(f) resources along this segment it 

is likely that a future alignment could result in Section 6(f) impacts requiring the identification 

and acquisition of replacement property.

Operational Impacts

During the agency scoping process, NPS requested consulting party status under Section 106 of 

the National Historic Preservation Act based on the potential for adverse impacts to Casa 

Grande National Monument resources (see the letter appended to the Scoping Report in the 

Public and Agency Coordination Appendix). Primary issues of concern for NPS are impacts to 

cultural and natural resources, viewsheds, and natural soundscapes within the monument 

boundary. Particularly, NPS is concerned about the potential for vibrations from rail traffic to 

affect the Great House and impacts to cultural and natural resources in areas considered for 

expansion of the monument boundary. In June 2013, US Representative Ann Kirkpatrick from 

Arizona introduced a bill (HR 2497) to expand the monument by 10 acres, based on a 2003 NPS 

study of additional prehistoric sites in the area. The boundary expansion would likely be a 

screening criterion for future alternatives, and the boundaries should be confirmed during 

Tier 2. Close coordination with NPS would continue during Tier 2 to avoid the monument and to 

determine a sufficient buffer between the rail line and monument boundary.

Operational impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis. Baseline noise levels, particularly in areas along Sky Harbor flight 

paths, should be considered as part of the constructive use evaluation when assessing noise 

impacts to parks along the Salt River in Mesa and Tempe.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-64

Construction Impacts

Construction impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

Orange Corridor Alternative

Southern Hub to Eloy

Physical, operational, and construction impacts would be the same as those described in the 

Yellow Corridor Alternative southern hub to Eloy analysis.

Eloy to Northern Hub

Physical Impacts

Physical impacts to Section 4(f) resources would constitute a direct use if the resource or 

portion of the resource is permanently incorporated into the rail line. Applying the 0.359 

multiplier for a ROW corridor as explained in Section 5.1.2, this segment could hypothetically 

include approximately 5 Section 6(f) resources, 1 refuge, 26 public parks and recreational 

resources, 29 private and public historic properties, and 16 schools with potentially public 

recreational resources, based on Tables F-1 through F-5 in the Section 4(f) and 6(f) Resources 

Appendix. Many of these resources are densely clustered across the Orange Corridor 

Alternative in Florence, Mesa, Tempe, and Phoenix; and multiple trails traverse the corridor 

alternative. Therefore, substantial Section 4(f) impacts can be anticipated from any future 

alignment in the Orange Corridor Alternative.

Woodland Parkway, a linear park in downtown Phoenix, is currently closed; however, its status 

would be confirmed during Tier 2 analysis. 

Riverview Softball Complex, Papago Park, and Papago Municipal Golf Course would likely 

require avoidance because of their Section 6(f) status. Identifying and acquiring replacement 

properties that would be equally useful to such significant local recreational resources could 

prove problematic and financially infeasible. Ultimately, given the wide distribution of 

Section 6(f) resources along this segment, it is likely that a future alignment could result in 

Section 6(f) impacts requiring the identification and acquisition of replacement property.

Operational Impacts

Operational impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-65

Construction Impacts

Construction impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

No Build Alternative

Under the No Build Alternative, construction would not occur, and no impacts to Section 4(f) 

and 6(f) resources would be anticipated beyond those that could occur due to other, 

reasonably foreseeable projects. A passenger rail line would not operate within either of the 

corridor alternatives. 

5.7.4 Potential Mitigation Measures

In conjunction with the Tier 2 NEPA documents, Section 4(f) resources would be confirmed 

within 0.25 mile of the project footprint. Additionally, the project team would evaluate the 

design to determine where it is possible and practical to avoid or minimize impacts.

Unless exceptions for de minimis impact findings are applicable, a feasible and prudent

alternative that avoids resources protected under Section 4(f) must be selected. If two or more 

alternatives affect Section 4(f) lands, the one causing the least relative harm to Section 4(f) 

resources must be selected.

Where impacts on Section 4(f) resources cannot be avoided, all possible planning must be 

completed to minimize impacts. Minimization of harm includes both alternative design that 

lessens the impact on Section 4(f) resources and mitigation measures that compensate for 

residual impacts. Minimization and mitigation measures should be determined through 

consultation with the official(s) having jurisdiction over the resource. Potential mitigation 

measures for recreational resources could include replacement of equipment and facilities in 

another location within existing parkland, purchase of similar properties, and/or construction 

outreach or other public involvement to apprise the public of access changes or temporary use 

restrictions. Measures to minimize harm to historic resources and cultural resources warranting 

preservation in place would be identified through the National Historic Preservation Act Section 

106 process. 

Section 6(f) lands would be avoided to the extent practicable. If LWCF lands cannot be avoided, 

the land proposed to be taken must be replaced in kind with a replacement property of at least 

equal fair market value and of reasonably equivalent usefulness for recreation purposes. Any 

conversion would have to be approved by Arizona State Parks and NPS.

Specific mitigation measures, to the extent required, would be identified and discussed during 

Tier 2 analysis after design details are known; recorded in NEPA documents as specific impacts 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-66

are identified; and implemented prior to and, as appropriate for temporary occupancy 

determinations, during construction.

5.7.5 Tier 2 Considerations

It is important to note that the data limitations of this Tier 1 EIS would require additional 

confirmation and/or data gathering during subsequent tiers, mostly likely as part of

coordinating with the official(s) with jurisdiction over Section 4(f) resources. Because the future 

alignments could be located anywhere in the corridor alternatives, the specific alignments

would need to be reviewed in Tier 2 for potential impacts to Section 4(f) and Section 6(f) 

resources and potential constructive use to affect properties beyond the alignments.

Potential refuges based on species protection would need to be confirmed during Tier 2. Trails 

would be protected by Section 4(f) only if they traverse publicly owned property and if they are 

open to public use; verification of the land ownership of the trails listed in Table F-3, Parks and 

Recreation Areas in the Study Corridors, in the Section 4(f) and 6(f) Resources Appendix would 

be required during Tier 2 studies. Additional elements that would need to be evaluated and/or 

confirmed in Tier 2 studies include:

 Land ownership of affected trail segments

 Whether affected school recreational facilities meet the criteria for protection under 

Section 4(f)

 The ownership status and availability for public use of parks in master-planned 

developments and residential areas 

 Whether affected historic properties are eligible for protection under Section 4(f)

 Boundary expansion status of Casa Grande National Monument and, in coordination

with NPS, a sufficient buffer between the rail line and monument boundary

 Public availability of the Riparian Preserve at Neely Ranch bird sanctuary 

 Closure status of Woodland Parkway, a linear park in downtown Phoenix

Activities having the potential to affect public parks, recreational resources, and natural areas 

include upgrading existing and building new rail infrastructure and constructing new passenger 

stations. Impacts could take the form of physical modifications to the land or the effects of 

increased noise levels and visibility. Specific types and degrees of impacts on individual 

resources (such as ROW acquisition and impacts on characteristics of a resource) would not be 

known until further design of rail facilities takes place and would be evaluated in Tier 2 NEPA 

documents.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-67

5.8 Air Quality

An air quality assessment was conducted to identify potential changes in vehicle emissions as a 

result of implementing passenger rail service from Tucson to Phoenix, compared to the No 

Build Alternative. A passenger rail system within the corridor alternatives would primarily be 

beneficial to air quality and would be expected to contribute to the region’s long-term 

attainment of air quality goals by reducing vehicle miles traveled, which in turn would reduce 

vehicle emissions. Since this study was conducted at a Tier 1 level and because the passenger 

rail system would primarily result in beneficial air quality effects, the following analysis is only 

qualitative and does not include a detailed quantitative evaluation of project-level air quality 

emissions.

5.8.1 Methodology and Regulatory Requirements

This EIS complies with FRA's Procedures for Considering Environmental Impacts (Environmental 

Procedures) (64 FR 28545, May 26, 1999) and FTA’s Environmental Impact and Related 

Procedures (23 CFR Part 771). Potential impacts on air quality were evaluated in accordance

with FRA’s Procedures for Considering Environmental Impacts, Section 14(n)(1) (FRA 1999a).

Federal

The Clean Air Act (CAA) of 1970, which was amended in 1990, is the federal law that governs air 

quality. EPA is responsible for establishing national ambient air quality standards (NAAQS) for 

the following six criteria pollutants: carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), 

sulfur dioxide (SO2), coarse and fine particulate matter (less than or equal to 10 microns [PM10]

and less than or equal to 2.5 microns [PM2.5], respectively), and lead (Pb). The state of Arizona 

has adopted the NAAQS for these criteria pollutants, which are summarized in Table 5-7. Refer 

to Section 5.17, Energy Use and Climate Change, for a discussion on greenhouse gases.

Geographic areas that violate a NAAQS for a particular criteria pollutant are considered 

“nonattainment” areas for that pollutant. Conversely, areas that are below a criteria pollutant 

standard are considered “attainment” areas. Maintenance areas are defined as having 

previously violated the NAAQS for a criteria pollutant (nonattainment) but are currently 

attaining that standard. Maintenance areas are required to develop a maintenance plan 

outlining steps for continued attainment over the maintenance period.

In addition to the NAAQS for criteria air pollutants, EPA also regulates air toxics under 

section 202 of the CAA. Mobile source air toxics (MSATs) are a subset of the 188 air toxics 

(pollutants known or suspected to cause cancer) defined by the CAA. MSATs denote 

compounds emitted from on-road mobile sources (vehicles), non-road mobile sources (such as 

airplanes and locomotives), and stationary sources (such as factories and refineries). In 2001, 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-68

EPA issued a Final Rule (66 FR 17230) on controlling emissions of hazardous air pollutants.

General information regarding emissions of MSATs is included in the Air Quality Appendix.

Clean Air Act Conformity

The corridor alternatives would require approval by FRA under the General Conformity 

requirements; however, if the corridor alternatives were to be funded or require approval 

under Title 23 U.S.C. or the Federal Transit Act, 49 U.S.C § 1601 et seq., then Transportation 

Conformity requirements would also apply, requiring an analysis of criteria pollutant 

concentrations and comparison to the NAAQS.

FRA, as lead agency, in coordination with EPA, must make a determination that a federal action 

conforms to the applicable state air quality implementation plan to achieve attainment of the

NAAQS. In general, conformity rules are designed to ensure that projects using federal funds or 

requiring federal approval would not:

 Cause or contribute to any new violation of a NAAQS

 Increase the frequency or severity of any existing violation

 Delay the timely attainment of any standard, interim emission reduction, or other 

milestone

Table 5-7. National Ambient Air Quality Standards for Criteria Pollutants

Pollutant/Averaging Time Primary StandardaSecondary Standarda

Carbon monoxide (CO)

8-hour 9 ppmb--

1-hour 35ppm --

Lead (Pb)

Rolling 3-Month Averagec 0.15 μg/m3 0.15 μg/m3

Nitrogen dioxide (NO2)

1-hour 100 ppb --

Annual Arithmetic Meand 53 ppb 53 ppb

Ozone (O3)

8-houre 0.075ppm 0.075ppm

Particulate matter less than 2.5 microns (PM2.5)

Annual 12 μg/m3 15 μg/m3

24-hour 35 μg/m3 35 μg/m3

Particulate matter less than 10 microns (PM10)

24-hour 150 μg/m3 150 μg/m3
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-69

Table 5-7. National Ambient Air Quality Standards for Criteria Pollutants

Pollutant/Averaging Time Primary StandardaSecondary Standarda

Sulfur dioxide (SO2)

1-hourf 75 ppb --

3-hour -- 0.5 ppm

Source: EPA 2013a.

Notes: ppm = parts per million; μg/m3= micrograms per cubic meter; ppb = parts per billion

a Primary standards set limits to protect public health, including the health of “sensitive” populations such as asthmatics, 

children, and the elderly. Secondary standards set limits to protect public welfare, including protection against visibility 

impairment and damage to animals, crops, vegetation, and buildings.

b Due to mathematical rounding, a measured value of 9.5 ppm or greater is necessary to exceed the standard.

c Final rule signed October 15, 2008. The 1978 lead standard (1.5 μg/m3 as a quarterly average) remains in effect until one 

year after an area is designated for the 2008 standard, except that in areas designated nonattainment for the 1978 

standard, where the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard are 

approved.

d 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.

e Final rule signed March 12, 2008. The 1997 ozone standard (0.08 ppm, annual fourth-highest daily maximum 8-hour 

concentration, averaged over 3 years) and related implementation rules remain in place. In 1997, EPA revoked the 1-hour 

ozone standard (0.12 ppm, not to be exceeded more than once per year) in all areas, although some areas have continued 

obligations under that standard (“anti-backsliding”). The 1-hour ozone standard is attained when the expected number of 

days per calendar year with maximum hourly average concentrations above 0.12 ppm is less than or equal to 1.

f Final rule signed June 2, 2010. The 1971 annual and 24-hour SO2 standards were revoked in that same rulemaking; however, 

these standards remain in effect until one year after an area is designated for the 2010 standard, except in areas designated

nonattainment for the 1971 standards, where the 1971 standards remain in effect until implementation plans to attain or 

maintain the 2010 standard are approved.

Under the General Conformity rule (CAA Section 176[c][4]), determinations are made based on de 

minimislevels. These de minimislevels can be found in 40 CFR 93.153(b) and vary according to the 

type of pollutant and severity of the nonattainment area. Table 5-8 summarizes pollutant de 

minimislevels. These levels were established to focus on those federal actions likely to have a 

significant effect on air quality. If the emissions of a future passenger rail system within one of the 

corridor alternatives are projected to be below the de minimislevels, then it is assumed the project 

would not result in any significant air quality impacts and no further analysis would be required. 

Conversely, if a future passenger rail system’s emissions exceeded de minimis levels, then the 

project would require a conformity determination requiring a “hot-spot” analysis of criteria 

pollutants relative to the NAAQS. The federal lead agency would be able to make changes to the 

design of the project to reduce emissions below de minimislevelsto achieve a General Conformity 

determination required by FRA and, if receiving funding from FTA, meet FTA’s Transportation 

Conformity requirements, i.e., ensure that the project would not cause new air quality violations, 

worsen existing violations, or delay timely attainment of the NAAQS
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-70

Table 5-8. De Minimis Levels by Type of Pollutant

Criteria Pollutant

Tons/Year

Nonattainment 

Area

Maintenance 

Area

Ozone (volatile organic compounds or nitrogen oxides) 50 (serious)

25 (severe)

10 (extreme)

100

Ozone (inside transport region – volatile organic compounds) 50 50

Ozone (inside transport region - nitrogen oxides) 100 (marginal and 

moderate)

100

Ozone (outside transport region) 100 100

Carbon Monoxide 100 100

PM10 70 (serious)

100 (moderate)

100

PM2.5 100 100

Lead (Pb) 25 25

Source: EPA 2015

State and Local

The corridor alternatives are under the jurisdiction of ADEQ, CAG, PAG, Pima County 

Department of Environmental Quality, Pinal County Air Quality Control District (PCAQCD), and 

Maricopa County Air Quality Department. These agencies regulate air pollution and operate air 

monitors throughout the state.

A transportation project implemented pursuant to this study would need to adhere to the 

following:

 ADEQ, Title 18. Environmental Quality, Chapter 2 – Air Pollution Control 

 Arizona Statutes, Title 49. The Environment, Chapter 3 – Air Quality

 Pima County, Title 17. Air Quality Control

 Pinal County, Article 2. Fugitive Dust

 PCAQCD Code of Regulations

 Maricopa County rules concerning fugitive dust, the federal hazardous air pollutants

program, and the Maricopa County hazardous air pollutants program
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-71

5.8.2 Existing Conditions

The corridor alternatives are located in portions of Pima, Pinal, and Maricopa counties. With 

regard to air quality, areas within counties can be classified as nonattainment, attainment, 

maintenance, or unclassified. Table 5-9 summarizes the status of those areas traversed by the 

corridor alternatives. 

Table 5-9. Attainment Status within the Corridor Alternatives

Criteria Pollutant County Areas Status

Ozone 8-hr Pinal Phoenix-Mesa Nonattainment

Maricopa Phoenix-Mesa Nonattainment

Carbon Monoxide Pima Tucson Maintenance

Maricopa Phoenix Maintenance

Particulate Matter less than 

10 microns in diameter (PM10)

Pima Rillito Nonattainment

Pinal Phoenix, West Pinal Nonattainment

Maricopa Phoenix Nonattainment

Particulate Matter less than 

2.5 microns in diameter (PM2.5)

Pinal West Central Pinal Nonattainment

Source: EPA 2013a

ADEQ and local air districts maintain a statewide network of monitoring stations that routinely 

measure pollutant concentrations in the ambient air. These stations provide data to assess 

compliance with the NAAQS and to evaluate the effectiveness of pollution control strategies. 

Table A-1 in the Air Quality Appendix summarizes the ambient air quality conditions at 

monitoring stations nearest to the corridor alternatives. 

The elevation of the corridor alternatives ranges from approximately 2,500 feet above sea level 

(amsl) near Tucson to approximately 1,000 feet amsl near Phoenix; and they are located in a 

desert climate characterized by extremely hot summers, mild winters, and minimal 

precipitation. Average daily maximum temperatures during the summer in Tucson and Phoenix 

are in the low 100s (degrees Fahrenheit [oF]). In Phoenix, the average minimum daily 

temperature during the winter is in the mid 40s (oF); however, Tucson experiences cooler 

temperatures in the winter, ranging from the high 30s to low 40s (oF). In addition, Tucson 

receives more precipitation than Phoenix, with an average of 10 inches compared to 6.5 inches

per year, respectively. This precipitation is in the form of rain; snowfall is rare. In addition, this 

precipitation is associated with afternoon showers or thunderstorms during the late summer

and storms that originate in the Pacific Ocean in the winter and move eastward through the 

corridor alternatives. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-72

Fugitive Dust

Fugitive dust is particulate matter from unstable or disturbed soil surfaces that becomes 

airborne due to mechanical disturbance and has the potential to adversely affect human health 

or the environment. The most common forms of particulate matter are known as PM10 and 

PM2.5. Fugitive dust originates from agricultural, mining, construction, and manufacturing 

activities, among others. This study is concerned mostly with fugitive dust generated from 

construction activities such as earth moving, paved road trackout, driving on haul roads, and 

disturbing surface areas, since such activities would likely be required during construction of a 

future passenger rail system. 

Class I Areas

Rail service contributes to visibility concerns in nonattainment and maintenance areas through 

primary PM2.5, SO2, and nitrogen oxide diesel emissions, which contribute to the formation of 

secondary PM2.5. 

Under the provisions of the CAA, EPA has designated a number of areas in the state of Arizona, 

including national parks and wilderness areas, as mandatory Class I Areas where visibility is an 

important value. These mandatory Class I areas are listed in 40 CFR 81.403. Under the EPA 

Regional Haze Rule, states must establish goals to improve visibility in Class I areas and develop 

long-term strategies to reduce emissions of air pollutants that cause visibility impairment. 

These goals are outlined in the state implementation plans. 

Of the mandatory Class I areas in Arizona, Saguaro National Park and the Superstition 

Wilderness are the closest to the corridor alternatives. The nearest boundary of the Saguaro 

National Park is approximately 1.5 miles west of the Orange and Yellow corridor alternatives 

near Tucson (see Figure A-1 in the Air Quality Appendix). The nearest boundary of the 

Superstition Wilderness area is approximately 10 miles east to northeast of the Orange Corridor 

Alternative near Mesa.

5.8.3 Environmental Consequences

Corridor Alternatives

The following assessment would apply to both the Yellow and Orange corridor alternatives.

Physical Impacts 

While construction and operation could result in air quality impacts, the tracks, rail stations, 

and associated infrastructure itself would not result in air emissions Therefore, the physical 

infrastructure associated with a passenger rail system would not be expected to affect air 

quality.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-73

Operational Impacts

Local air quality effects of a passenger rail system within either of the corridor alternatives are 

not expected to be adverse because implementation is expected to increase transit ridership 

within the corridors, which could reduce vehicle miles traveled (VMT). Because overall 

automobile congestion and VMT could be reduced, associated emissions could also be reduced. 

The forecasting model indicates that implementation of a passenger rail system within the 

corridor alternative with the higher ridership is expected to result in a greater reduction in VMT 

and air pollutant emissions. A quantitative air quality analysis would be performed during Tier 2

analysis to determine air pollutant effects from a future passenger rail system operating on a 

specific alignment. 

It is possible that locations adjacent to station-related commuter parking lots could experience 

increases in localized pollutant concentrations, since traffic would now be concentrated in 

these areas. As a result, a quantitative air quality analysis would be undertaken at 

representative locations during the Tier 2 NEPA process. 

Implementation of a passenger rail system within either of the corridor alternatives is not 

expected to have any measurable air quality effects on Federal Class I areas, including the 

Saguaro National Park and Superstition Wilderness; however, since the nearest boundary of the 

Saguaro National Park is approximately 1.5 miles west of the study corridors near Tucson,

further analysis to assess visibility concerns, such as regional haze, may be required during 

Tier 2. 

Construction Impacts

Temporary construction emissions are expected from implementation of a passenger rail 

system within either the Orange or the Yellow corridor alternatives; however, pollutant 

emissions would vary daily depending on the level of activity, specific operations, and prevailing 

weather. These potential effects would be addressed during Tier 2 studies. 

Temporary dust emissions would also be expected from construction activities; however, 

fugitive dust generated from construction activities would be controlled in accordance with the 

Arizona Department of Transportation Standard Specifications for Road and Bridge Construction

(2008) and local rules or ordinances. An activity permit for construction in Pima County would

be required from the Pima County Department of Environmental Quality under Title 17 of the 

Pima County Code, and a dust permit would be required from PCAQCD. Any portion of a 

transportation project implemented pursuant to this study in Maricopa County would also be 

subject to the Maricopa County Rule 310 (fugitive dust).
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-74

No Build Alternative

Under the No Build Alternative, a new passenger rail system would not be built, and impacts on 

air quality are not anticipated beyond those that could occur due to other approved projects. 

The No Build Alternative assumes completion of those reasonably foreseeable transportation, 

development, and infrastructure projects that are already in progress; are programmed; or are 

included in the fiscally constrained Regional Transportation Plan or State Transportation 

Improvement Program. Under the No Build Alternative, planned transportation and transit 

maintenance, modifications, and additions would occur; but a passenger rail system between 

Tucson and Phoenix would not be built. An increase in traffic and VMT is expected with the No 

Build Alternative because more cars would be on the roadways compared to what would occur

with implementation of passenger rail service along a future alignment. Therefore, traffic 

congestion is likely to worsen with the No Build Alternative, resulting in adverse air quality 

impacts. 

5.8.4 Potential Mitigation Measures

Air quality modeling may be required for the Tier 2 NEPA document to quantify potential 

emissions for alternatives studied in detail. Mitigation measures would also be identified at that 

time for any potential air quality effects. In addition, temporary construction effects may be 

quantified, and temporary control measures would be recommended. Typical construction 

mitigation measures include:

 Minimize idling time to save fuel and reduce emissions.

 Use the cleanest fuels available at the time for construction equipment and vehicles to 

reduce exhaust emissions.

 Keep construction equipment well maintained to ensure that exhaust systems are in 

good working order.

 Control fugitive dust through a fugitive dust control plan, including watering disturbed 

areas.

 To minimize wind-blown dust from blasting, particularly near community areas, control 

blasting and avoid blasting on days with high winds.

 Develop a traffic plan to minimize traffic flow interference from construction equipment 

movement and activities. 

5.8.5 Tier 2 Considerations

If a future passenger rail project receives funding from FTA, it would require a Transportation 

Conformity analysis due to the nonattainment status of the areas surrounding the corridor 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-75

alternatives. During Tier 2 NEPA analysis, a detailed air quality analysis would be conducted 

once a future alignment or alternative alignments have been selected and station layout 

designs have been advanced for further environmental evaluation. The passenger rail system

would need to conform to the NAAQS before it is implemented, requiring an assessment of rail 

vehicle emissions within the region. Modeling of CO and PM emissions would be conducted 

during Tier 2 to determine potential local air quality effects from the future construction and 

operation of a passenger rail system. While general information regarding emissions of MSATs 

is included in the Air Quality Appendix, Tier 2 would likely entail quantifying MSAT emissions. 

The potential effects of project-related motor vehicle emissions on local roadways in the 

vicinity of stations would be assessed at Tier 2. Detailed mitigation measures would also be 

developed and refined during Tier 2. Emissions of PM2.5 and nitrogen oxides (NOx) from diesel 

locomotive engines currently contribute to the nonattainment of the NAAQS for PM2.5 and 

ozone. EPA has established emission standards for these pollutants for newly manufactured 

and remanufactured locomotives (see 73 FR 25098, Locomotive and Commercial Marine Rule). 

EPA is projecting that PM2.5 and NOx emissions will drop as a result of these standards. For any 

future alignment selected, the amount of MSATs emitted would be proportional to the 

resulting VMTs, assuming that other variables, such as fleet mix, are the same for each corridor.

5.9 Noise and Vibration

Sound is created when an object vibrates and radiates part of its energy as acoustic pressure or 

waves through a medium, such as air, water, or a solid object. Noise is generally defined as any 

loud or undesired sound. Noise is measured in terms of sound pressure and is expressed in 

decibels (dB). Since the human ear does not respond equally to all frequencies (or pitches), 

measured noise levels (in dB at standard frequency bands) are often adjusted or weighted to 

correspond to the frequency of human hearing and the human perception of loudness. The 

weighted noise level is designated as the A-weighted noise level in decibels (dBA).

Noise levels that correlate with human perception are expressed in such descriptors as Leq, Ldn, 

and Lmax. While sound levels often change over time, Leq (or equivalent noise level) is the 

“equivalent” constant sound level in dBA, which, in a given situation and time period, has the 

same sound energy as does the fluctuating sound level over the same time period. One-hour 

equivalent noise levels measured every hour over a continuous 24-hour period are sometimes 

used to calculate a composite 24-hour noise exposure measure called the day-night noise level 

(Ldn), which adds 10 dBA to nighttime levels between the hours of 10:00 p.m. and 7:00 a.m. to 

account for the increased noise-sensitivity of people during sleeping hours. Lmax is the maximum 

pass-by sound level.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-76

Use of Leq and Ldn is appropriate for transportation noise analysis because these levels are 

sensitive to both the frequency of occurrence and duration of noise events, including freight 

and commuter rail operations that may be characterized by infrequent noise. Typical Ldn noise 

levels range from 50 to 80 dBA for non-transit background sources and 55 to 75 dBA for transit 

sources.

The ability of an average individual to perceive changes in noise levels is well documented. 

Generally, changes in noise levels of 3 dBA would be barely perceived by most listeners, 

whereas a 10-dBA change normally is perceived as a doubling of noise levels. Typical sound 

levels experienced by people range from about 40 dBA, the daytime level in a typical quiet 

living room, to 85 dBA, the approximate level near the sidewalk adjacent to heavy traffic.

In addition to airborne noise, the operation of transportation facilities is a potential source of 

ground-borne vibration (GBV). GBV is defined as rapid fluctuating motions through the ground. 

In contrast to airborne noise, GBV is not a phenomenon experienced by most people on a daily 

basis. Ground-borne noise (GBN) results from the vibration of the floors, walls, etc. of buildings 

affected by GBV. Vibration is measured in terms of root-mean-squared velocity levels in 

decibels, with the abbreviation VdB used to distinguish it from airborne noise. A typical 

background vibration velocity level in residential areas is 50 VdB or lower, well below the 

threshold of perception for humans, which is around 65 VdB. Typical outdoor sources of 

perceptible GBV are construction equipment, steel-wheeled trains, and traffic on rough roads. 

This analysis evaluates airborne noise, GBV, and GBN of a passenger rail system consistent with 

federal guidance for Tier 1 studies. Noise and vibration receptors—or locations potentially 

affected by airborne noise, GBV, and GBN—include residences, businesses, parks, schools, 

recreation areas, churches, libraries, and hospitals.

5.9.1 Methodology and Regulatory Requirements

Noise and Vibration Impact Standards

Title 49 CFR Part 210 contains the Railroad Noise Emission Compliance Regulations 

implemented by FRA to comply with USEPA Noise Emission Standards for Interstate Rail 

Carriers. FRA has established criteria for noise and vibration impacts that are identical to those 

established by FTA, which first published the “Transit Noise and Vibration Impact Assessment” 

guidance document in 1995 with subsequent revisions (FTA 2006).

The FTA/FRA noise criteria are based on a comparison of the noise generated by a transit (or 

rail) system with the outdoor ambient noise from other sources in the community. They 

incorporate both absolute criteria, which consider annoyance due to noise generated by the 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-77

system alone, and relative criteria, which consider annoyance from the change in the 

surrounding noise environment caused by the system. The criteria are used to evaluate noise 

impacts on the basis of cumulative, A-weighted noise exposure, in terms of either Leq or Ldn. Ldn

is applied to residences and other buildings where people normally sleep; and Leq is applied to 

all other noise-sensitive land use categories, such as churches, other institutions, and quiet 

offices. The FTA/FRA noise impact criteria are established by two curves, representing severe 

and moderate noise impacts as shown on Figure 5-9. In its guidance document, High-Speed 

Ground Transportation Noise and Vibration Impact Assessment, FRA (2012) adopts vibration 

impact criteria established by FTA (FTA 2006). Impact criteria are defined by three land use 

categories which vary slightly from those considered for noise impacts. The categories are 

defined as follows:

Vibration Category 1 – High Sensitivity: Buildings where vibration would interfere with the 

operations taking place there, including levels well below those of normal human annoyance. 

These include vibration-sensitive research and manufacturing, hospitals with vibration-sensitive 

equipment, and university research operations.

Moderate Impact: The threshold at which the percentage of people highly annoyed by noise 

related to the proposed action becomes measurable. The magnitude of the proposed action’s 

impact and need for mitigation depends upon other factors such as existing noise levels, the 

predicted future increase in noise levels, and the types and number of land uses affected.

Severe Impact: The threshold at which the percentage of people highly annoyed by the 

proposed action’s noise increases substantially. Noise mitigation must be considered if it is not 

practical to change the location of the proposed project, unless extenuating circumstances 

prevent the incorporation of mitigation measures into the proposed project (i.e., a practical 

mitigation method does not exist).

Exposure to potential future project noise impacts is determined by three land use categories 

identified by the FTA/FRA. Category 3 land uses comprise institutional activities such as schools, 

libraries, and churches. Category 2 land uses include residential areas; and Category 1 land uses 

include amphitheaters, concert pavilions, and National Historic Landmarks. Taken from the FTA 

guidance manual Transit Noise and Vibration Impact Assessment (FTA 2006), 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-78

Figure 5-9. FTA/FRA Noise Impact Criteria

Figure 5-9 illustrates the “moderate” and “severe” noise impact criteria curves and their 

relationship to each land category and existing ambient noise levels (without the potential 

future project). The figure illustrates that persons in a Category 1 or 2 setting would be affected 

by the introduction of future project-related noise at a lower day-night average decibel level 

than persons in a Category 3 setting. Additionally, the figure shows that persons who have 

habituated to louder background noise levels are more tolerant of increases from an added 

source of noise.

The criteria for acceptable ground-borne vibration are measured in VdB micro-inches of 

movement per second, and the criteria for acceptable ground-borne noise are measured in dBA 

micro Pascals of pressure. Table 5-10 identifies the relevant impact criteria for each land use 

category.

Source: FTA 2006
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-79

Table 5-10. Groundborne Vibration and Groundborne Noise Impact Criteria

Land Use Category

GBV Impact Levels

VdB (1 micro-inch/sec)

GBN Impact Levels

dBA (20 micro Pascals)

Frequent 

Events

a

Occasional 

Eventsb

Infrequent 

Eventsc

Frequent 

Eventsa

Occasional 

Eventsb

Infrequent 

Eventsc

Category 1:

Buildings where 

vibration would 

interfere with interior 

operations

65d 65d 65d N/Ae N/Ae N/Ae

Category 2:

Residences and 

buildings where 

people normally sleep

72 75 80 35 38 43

Category 3:

Institutional land uses 

with primarily daytime 

use

75 78 83 40 43 48

Source: Transit Noise and Vibration Impact Assessment (FTA 2006)

Notes:

a “Frequent Events” is defined as more than 70 vibration events of the same source per day. Most rapid transit (e.g., light rail)

projects fall into this category.

b “Occasional Events” is defined as between 30 and 70 vibration events of the same source per day. Most commuter trunk 

lines (e.g., railroads carrying more than one line) have this many operations.

c “Infrequent Events” is defined as fewer than 30 vibration events of the same kind per day. This category includes most 

commuter rail branch lines (e.g., shorter distance railroads branching off a trunk line).

d This criterion limit is based on levels that are acceptable for most moderately sensitive equipment such as optical 

microscopes. Vibration-sensitive manufacturing or research activities would require detailed evaluation to define the 

acceptable vibration levels. Ensuring lower vibration levels in a building often requires special design of the HVAC systems 

and stiffened floors. 

e Vibration-sensitive equipment is generally not sensitive to ground-borne noise.

General Assessment Methodology

For this Tier 1 EIS, a general assessment for noise and vibration impacts is an appropriate level 

of analysis for choosing among corridor alternatives (FRA 2012). Completion of a general noise 

and vibration assessment per FRA/FTA guidelines requires information more appropriate for a 

Tier 2 analysis, such as the identification of a rail alignment as well as vehicle types (train 

engines and number of cars), train schedules and speeds, and the location of future grade 

crossings, to provide a level of detail for determining potential project impacts. The corridor 

alternatives for this Tier 1 EIS have been defined without specific alignment, operational, and 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-80

vehicle parameters; therefore, only the basic noise and vibration screening and impact 

assessment guidelines have been applied to draw distinctions between the No Build Alternative 

and corridor alternatives.

The assessment of the affected environment considered the mile-wide corridor alternatives but 

was based on a hypothetical representative alignment to provide a more valuable and useful 

result, where propagated noise effects would not extend beyond the corridor; in Tier 2 studies, 

an analysis area extending beyond the corridor may need to be considered, depending on the 

position of the alignment within the corridor, to account for rail system noise such as warning 

horns.

Noise Methodology

The FRA and FTA general noise assessment guidance outlines procedures for establishing study 

boundaries through a screening process, estimating noise levels within the boundaries under 

current and future conditions, determining the maximum distance to potential impacts, 

tabulating the number of noise-sensitive areas affected, and estimating the achievable noise 

reduction through mitigation measures. For this Tier 1 analysis, only the screening process and 

estimates of noise levels based on existing facilities and land use density have been applied in 

the analysis of potential noise impacts associated with each corridor alternative. The noise 

screening is designed to identify locations where noise impacts may occur, including where 

horns and warning bells may be heard. The analysis focuses on Category 2 (residential) land 

uses as defined by FTA/FRA, which include places where people sleep. This approach was 

approved by FRA for the Chicago to Council Bluffs-Omaha Regional Passenger Rail System 

Planning Study Tier 1 EIS (FRA 2013b).

The Tier 1 noise analysis examined the Yellow Corridor Alternative, the Orange Corridor 

Alternative, and a No Build Alternative. In order to conduct a noise analysis within the milewide corridor alternatives, hypothetical representative alignments were chosen within each 

corridor alternative to show a general order of magnitude of noise impacts. The data gathered 

for these hypothetical alignments, and the findings of this Tier 1 analysis, may not be relevant 

to a different alignment within the corridor alternatives evaluated during Tier 2. 

Potential future commuter and intercity rail operations from the Alternatives Analysis (AA) as 

required by the FTA, evaluated future UP train operations (where the hypothetical alignments 

coincide with the UP line) to establish a hypothetical level of train frequency and activity for the 

noise analysis. 

The AA is found in the Alternatives Analysis Appendix. Three levels of evaluation and criteria 

used in the AA were designed to compare alternatives using a common measure and advance 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-81

the most feasible alternatives for further study at the next level, consistent with the objectives 

of the FRA Tier 1 EIS process and FTA AA process.

FRA guidance establishes screening distances that are more appropriately applied to trains, 

which generally operate over longer distances with less frequent stops than a commuter rail 

line; therefore, FTA guidelines were applied. 

For commuter rail, FTA has determined a screening distance of between 375 and 750 feet for 

the rail mainline (wayside), depending on the presence of intervening buildings, and between 

1,200 and 1,600 feet for at-grade crossings where the sounding of a horn per FRA “Horns Rule” 

(49 CFR 222 and 229) would occur. 

Screening distances of 750 feet for potential wayside impacts and 1,800 feet for at-grade 

crossings were selected as a worst-case scenario based on a hypothetical daily operation of 26 

commuter and 10 intercity trains for a passenger rail system within each corridor alternative 

(Parsons Brinckerhoff 2013). Where portions of the corridor alternatives are in areas with few 

physical barriers to block train noise, the 1,800-foot screen distance for at-grade crossings was 

used for a more conservative analysis of potential effects.

The FRA and FTA guidance documents also provide methods for calculating noise impact 

contours for a general assessment as well as an alternate method of determining contours to 

define moderate and severe impacts of potential projects using spreadsheet models developed 

by both agencies. Both methods described in the guidance documents are more appropriate for 

a Tier 2, project-level analysis. For this Tier 1 analysis, each alternative was evaluated for its 

potential (with development of a passenger rail system) to substantially increase noise above 

ambient levels, which were estimated, per FTA guidance, based on land use density and existing 

noise sources (trains, highways, airports, etc.) within the identified screening distances. 

Vibration Methodology

The FRA and FTA guidance documents also outline procedures for conducting a general 

vibration assessment. A general vibration assessment also begins with screening. Screening 

distances vary depending on project type and selection of one or more land use categories 

listed in Table 5-10 taken from the FTA guidance manual (FTA 2006). For a conventional 

commuter rail line, an appropriate screening distance for land uses of the type examined in this 

study, Category 2 (residences, hotels, hospitals), is 200 feet. If vibration-sensitive land uses exist 

within the screening distance, a general vibration assessment is performed. A screening 

distance of 320 feet was selected from the representative alignment as a worst-case scenario, 

based on hypothetical daily commuter and intercity operations used in the AA.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-82

The general level of assessment extends from the screening procedure. FTA and FRA have 

developed a general curve of vibration level as a function of distance from the track, based on 

field measurements completed along rail corridors, shown in Figure 5-10 (FTA 2006; FRA 2012). 

Identical to the noise analysis, the vibration analysis examined the Yellow and Orange corridor 

alternatives and a No Build Alternative. The general vibration assessment focuses on Category 2 

land uses, including places where people sleep. For the purposes of the Tier 1 evaluation, the 

appropriate GBV impact criteria shown in Table 5-10 were selected for this land use category;

and hypothetical train frequencies were taken from the AA (Parsons Brinckerhoff 2013).

Figure 5-10. Vibration Level per Distance from Track Centerline

As noted in Table 5-10, frequent vibration events are defined as 70 or more trains daily, 

occasionally between 30 and 70 trains daily, and infrequently less than 30 trains daily. Per FTA 

guidance, GBN levels were estimated assuming a 35-dB correction for typical GBV frequencies 

from the corresponding impact VdB level. These GBV and GBN levels provide an indication of 

potential vibration impacts for Category 2 land uses located within the identified screening

distance.

Source: FTA 2006
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-83

Documenting the number and location of each type of sensitive land use is better suited for a Tier 2 

analysis, but this Tier 1 analysis uses a representative alignment to estimate an order of magnitude 

of the potential impacts. Because Category 2 land uses are far more predominant in the corridor 

alternatives than Category 1 and 3 land uses, the comparison of alternatives for this Tier 1 analysis 

focuses on existing Category 2 land uses and areas zoned for residences and buildings where people 

sleep. The number of Category 2 land uses was estimated based on zoned acreage for residential, 

medical nursing/home, and motel/hotel/resort uses multiplied by the average number of dwelling 

units per acre reported in the GIS database or estimated from county zoning district guidelines. 

Zoned acreage was provided by PAG, CAG, and MAG. Category 2 land uses are zoned for different 

densities of development, as shown in Table 5-11. The zoned acreage was weighted to account for 

the appropriate development density allowed in a given area. The assessment does not account for 

residences that may be unoccupied or areas less developed than the zoned allowances. The 

assessment also assumes that zoned residential areas would be developed, which may or may not 

occur. Consequently, the actual number of potential Category 2 properties (or receptors sensitive 

to noise or vibrations) may be overestimated but provides for a standard method of comparison. By 

using the same approach to estimate the number of Category 2 land uses, the number of noisesensitive and vibration-sensitive land uses within each corridor is the same.

Table 5-11. Zoned Acreage Data for Category 2 Land Uses

Land Use Descriptor Square Footage Range1 Dwelling Units per Acre

Rural residential (SF) 21,7795 to 43,5590 0.13

Estate residential (SF) 43,559 to 217,795 0.33

Large lot residential (SF) 14,500 to 43,559 1.50

Single-family low density 43,559 to 70,000 0.77

Single-family (SF) medium density 10,000 to 43,559 2.00

Medium lot residential (SF) 10,000 to 18,000 3.00

Single-family high density 7,500 to 10,000 5.00

Developing residential 6,000 to 70,000 1.00

Small lot residential (SF) 6,000 to 8,000 6.00

Very small lot residential (SF) 6,000 7.00

Medium density residential (MF) n/a 8.00

Mixed Use (MF) n/a 10.00

Multi Family - Apartment/Condo n/a 20.00

Residential (SF and MF) n/a 9.00

Medical/Nursing Home n/a 30.00

Motel/Hotel/Resort n/a 40.00

Source: Maricopa County Planning and Development Department, Maricopa County Zoning Ordinance, July 2013. 

Note: Zoned acreages shown are for Maricopa County, but Pima and Pinal counties use similar acreages for zone categories.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-84

5.9.2 Existing Conditions

Land uses representing all three noise and vibration categories of impact are found within both 

the Yellow and Orange corridor alternatives, and portions of each corridor are undeveloped 

with no sensitive receptors. 

Sensitive Land Uses

The number of Category 2 land uses within the mile-wide corridor alternatives was estimated 

based on zoned acreage for residential, medical nursing/home, and motel/hotel/resort uses 

multiplied by the average number of dwelling units per acre reported in the GIS database or 

estimated from county zoning district guidelines. Zoned acreage was provided by PAG, CAG, 

and MAG. Table 5-12 shows the estimated number of FTA/FRA Category 2 land uses for each 

corridor alternative. To obtain an approximate number of potentially affected Category 2 land 

uses, an 1,800-foot buffer (the sensitivity distance adopted by FRA/FTA) was added to each side 

of a hypothetical rail line, and divided into the mile-wide corridor. For this analysis, an impact 

corridor of 3,600 feet (1,800 feet on each side of the rail line) was used to obtain the ratio for 

estimating the approximate number of land uses affected by rail noise, as explained on 

Page 5—3: 

3,600′ − wide impact corridor

5,280′ − wide corridor alternative = 0.682

0.682 x Land Uses in the mile-wide corridor = Land Uses in the 3,600-foot Sensitivity Area

The representative numbers for a 3,600-foot corridor are listed in the column next to the 

GIS-derived totals for the mile-wide corridors:

Table 5-12. Noise and Vibration-Sensitive Land Uses within the Corridor Alternatives

Corridor Alternative Number of FTA/FRA Category 2 Land Usesa

Mile-Wide Corridor 1,800-foot Sensitivity Area

Yellow Corridor Alternative 51,260 39,450

Orange Corridor Alternative 50,094 34,155

a The number of Category 2 land uses is estimated based on zoned residential densities.

Existing Transportation Facilities

Table 5-13 summarizes conceptual operational characteristics of rail operations based on the 

AA and information from cooperating agencies. Existing freight operations are a contributing 

factor to the existing noise and vibration environment. For freight train operations, the number 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-85

of train trips shown is an average of the range listed in Table 5-13. Trips are apportioned 

between daytime (7 a.m. – 10 p.m.) and nighttime (10 p.m. – 7 a.m.) periods based on a 24-

hourly average. These data and details about future commuter and intercity operations would

be used to complete the general noise and vibration assessment for the Tier 2 analysis. 

Table 5-13. Train Characteristics

Train Description

Assumed 

Engine

Type

No. of 

Locomotives

No. of Train 

Cars

Maximum 

Speeds

Trains per Day

Phoenix to 

Eloy

Eloy to 

Tucson

Existing FreightaFossil Fuel 2 10 60 mph 5 - 10 26 - 60

Future FreightaFossil Fuel 2 10 80 mph 5 - 10 26 - 60

Commuter Railb Diesel-Electric 

DMU

1

c 4 125 mph 26

Intercity Railb Diesel-Electric 

DMU

1

c 4 125 mph 10

a Train data on existing Union Pacific Railroad provided by Arizona Department of Transportation Multimodal Planning Division.

b Commuter and Intercity rail data provided by Parsons Brinckerhoff (2013).

c Each passenger rail car has its own power so it can run individually or linked.

Existing Noise and Vibration Levels

As discussed in the methodology, existing noise levels were estimated based on FTA guidance, 

which imputes ambient noise levels based on development density descriptors and proximity to 

transportation noise sources such as roads, highways, and trains. Table 5-14 lists reference 

ambient noise levels for four development densities and transportation noise sources that exist 

within the study corridor.

Table 5-14. Estimated Existing Noise Levels within the Corridor Alternatives

Development Density

Estimated 

Ambient 

Level (dBA)

UP Highwaya

Phoenix Sky 

Harbor Airportb

Phoenix Mesa 

Gateway 

Airportc

Rural (300-1,000 

persons/square mile)

45 

60 dBA 62 – 64 dBA 70 dBA 50 dBA Suburban (1,000-3,000 

persons/square mile)

50 

Suburban/Urban (3,000-

10,000 persons/square 

mile)

55 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-86

Table 5-14. Estimated Existing Noise Levels within the Corridor Alternatives

Urban (10,000+ 

persons/square mile)

60 

a Existing noise levels based on typical ambient mitigated noise levels for residential areas located near Arizona Department of 

Transportation facilities including I-10, US 60, SR 202L, SR 101L, and SR 143.

b Existing noise levels are based on noise contours for Phoenix Sky Harbor Airport 2004 Noise Exposure Map (City of Phoenix 

2013).

c Existing noise levels are based on noise contours for Phoenix Mesa Gateway Airport 2004 Noise Exposure Map (City of 

Phoenix 2013).

The typical background vibration velocity level for residential areas is 50 VdB or less. For the 

general vibration assessment, the FTA impact criteria were used to further describe the existing 

vibration environment. The frequency of existing UP freight operations was referenced to 

characterize the GBV and GBN environment for Category 2 land uses. For the rail segments 

between Tucson and Eloy, occasional (30 to 70) trips translate to a reduced tolerance to GBV 

with the 75-VdB impact criterion being more appropriate at the 320-foot screening distance. 

Between Eloy and Phoenix, infrequent (fewer than 30) freight train trips result in a greater 

tolerance to GBV; therefore, the 80-VdB impact criterion is appropriate at the 320-foot 

screening distance. Appropriate GBN impact criteria at the screening distance are 40 dBA and 

45 dBA, respectively, based on the assumption that a 35-dB correction for GBV frequencies is 

typical.

5.9.3 Environmental Consequences

Corridor Alternatives

Implementation of a passenger rail system would affect the future noise environment within 

the corridor alternatives. The following assessment would apply to both the Yellow and Orange 

corridor alternatives except where differences are noted.

Physical Impacts 

The physical infrastructure associated with a passenger rail system would not be expected to 

have notable effects on the noise environment and no effect on the potential for vibrations. 

Passenger vehicles crossing tracks may generate minor quantities of noise compared with those 

operating on smooth pavement.

Operational Impacts

Operational effects may include both noise and vibration impacts.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-87

Noise Impacts

Table 5-15 lists the estimated number of Category 2 land uses (existing and zoned) located 

within the 750- to 1,800-foot screening distance of the hypothetical representative alignment 

for each corridor alternative. Per FRA/FTA assessment methods, potential impacts are partly a 

function of existing noise levels. The existing noise level ranges listed for each of the corridor 

alternatives are a function of typical ambient noise levels by land use density combined with 

other noise sources that exist within each corridor. For instance, the hypothetical alignment for 

the Yellow Corridor Alternative generally follows I-10 and the UP, which would increase the 

upper range of ambient noise levels in rural and suburban areas compared to areas of similar 

land use density elsewhere within the Yellow Corridor Alternative or within the portions of the 

Orange Corridor Alternative. Although the hypothetical alignment for the Orange Corridor 

Alternative encompasses fewer Category 2 land uses within the designated screening distance, 

the potential noise impact of a passenger rail system in an area that generally experiences 

lower existing ambient noise levels is greater.

Table 5-15. Potential Noise Impacts within the Corridor Alternatives

Yellow Orange

Category 2 Land Usesa 25,350 16,925

Land Use Density Existing Noise Levelsb

Rural 45 – 64 dBA 45 – 50 dBA

Suburban 50 – 64 dBA 50 dBA

Suburban/Urban 55 – 64 dBA 55 – 64 dBA

Urban 60 – 70 dBA 60 – 70 dBA

Impact Potential ( per FTA/FRA Noise Impact Criteria shown in Figure 5-12)

None Low Medium

Moderate Medium High

Severe High High

a Residential land uses per FTA/FRA guidelines located within 750 to 1,800-foot screening distance.

b Based on typical ambient noise levels by land use density. Upper end of range is defined by existing noise sources (e.g., 

rail, highway, airport, etc.). See Table 5-15.

Overall, the highest number of future noise impacts would occur in the vicinity of grade 

crossings, where locomotives sound their horns as they approach. Notable exceptions are the 

section of the Yellow Corridor Alternative in Tempe, where train horns would not be used at 

grade crossings due to the Tempe Quiet Zone ordinance that is in force (City of Tempe 2012), 

and the section common to both corridor alternatives between 4th Street and 3rd Avenue in 

Phoenix, which is also a Quiet Zone. Using the hypothetical representative alignments chosen 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-88

for this Tier 1 noise analysis, a passenger rail system within the Yellow Corridor Alternative 

would have the potential to affect more Category 2 land uses than a system within the Orange 

Corridor Alternative near grade crossings, primarily because it would traverse more populous 

areas and would include more grade crossings, and therefore would produce more horn noise, 

than the Orange Corridor Alternative. 

Vibration Impacts

Table 5-16 lists the estimated number of Category 2 land uses (based on zoned acreage data) 

that are located within a vibration screening distance of 320 feet on either side of the assumed 

alignments within the Yellow and Orange corridor alternatives. For high-speed rail traveling 

between 100 and 150 mph or more, three operational regimes define the potential vibration 

impacts. At lower speeds (Regime I), propulsion sources that provide motive power to the train 

are the predominant source of vibration. At higher speeds, mechanical/structural (bridges) and 

aerodynamic sources (Regimes II and III, respectively) become the dominant source (FRA 2012). 

Commuter rail lines generally operate at or below 100 mph, or within Regimes I and II; 

therefore, propulsion and mechanical forces would be the predominant sources of vibration for 

the Yellow and Orange corridor alternatives.

If a passenger rail system were developed within one of the corridor alternatives, the potential 

for vibration impacts would largely be a function of the number of sensitive land uses located 

within the 320-foot screening distance around a future alignment. In comparison to the Yellow 

Corridor Alternative, the number of potential GBV impacts could potentially be much lower 

within the Orange Corridor Alternative because zoned development densities are considerably 

lower within this corridor. 

Table 5-16. Potential Vibration Impacts within the Corridor Alternatives

Yellow Orange

Category 2 Land Usesa 4,925 2,325

Train Activity

Frequent Events Yes Yes

Occasional Events No No

Infrequent Events No No

Impact Potential GBV/GBN Levelsb

GBV Impact Threshold 72 VdB 72 VdB

GBNb at Impact 37 dBA 37 dBA

a Residential land uses per FTA/FRA guidelines located within 320-foot screening distance

b Represents minimum ground borne noise level (GBN) at impact zone limit to be determined by Tier 2 analysis
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-89

The GBN threshold, which is 35 dBA for the planned commuter and intercity rail operations that 

would be categorized by FTA as “frequent,” would be exceeded for the Yellow and Orange 

corridor alternatives where vibration impacts are predicted to occur. While Quiet Zones would 

serve to minimize train horn noise, GBN would not be mitigated by this policy.

Construction Impacts 

At this stage of the study, the duration, schedule, and specific construction equipment that 

would be used are unknown. Details about project construction would be more appropriately 

evaluated during Tier 2. Analysis of construction noise and mitigation would include:

 Duration of construction (overall and at specific locations)

 Equipment expected to be used, e.g., noisiest operations

 Schedule with limits on times of operation, e.g., daytime use only

 Noise monitoring

 Forum for communicating with the public

 Commitments to limit noise to specified levels, including compliance with applicable 

local ordinances 

 Consideration of the application of noise control treatments used successfully in other 

projects 

Similarly, potential impacts from construction vibration would occur only if a passenger rail 

system were constructed within the Yellow or Orange corridor alternatives. Details about 

project construction that are more appropriately examined under a Tier 2 analysis of 

construction vibration and mitigation include the duration and the type of equipment to be 

used during the construction and an explanation of how the GBV would be maintained at an 

acceptable level. If the equipment is of the type that generates little or no ground vibration –

air compressors, light trucks, hydraulic loaders, etc. – a qualitative explanation would suffice 

without the need for a quantitative analysis.

No Build Alternative

Under the No Build Alternative, a passenger rail system would not be built, and no noise and 

vibration impacts would occur. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-90

5.9.4 Potential Mitigation Measures

Noise Mitigation

FRA’s traditional approach to abatement of noise sources from high-speed train systems is 

embodied in its Railroad Noise Emission Compliance Regulation (49 CFR § 210). The compliance 

regulation is intended to enforce the “Noise Emission Standards for Transportation Equipment: 

Interstate Rail Carriers” to limit the amount of noise emitted from power cars and rail cars 

under stationary and moving conditions (FRA 2012). FTA’s noise analysis guidelines are 

contained in its Transit Noise and Vibration Impact Assessment (report number FTA-VA-90-

1003-06).

The need for noise mitigation is determined based on the magnitude of the impacts and 

consideration of other factors such as feasibility, cost-effectiveness, and community views. 

Safety concerns that must be mitigated through project engineering include maintaining 

sufficient lines-of-sight around noise barriers for pedestrians, cyclists, and motorists and 

maintaining sufficient warning devices (i.e., audible and visual devices) at grade crossings. 

Recommended mitigation should be practical, prudent, and safe.

The magnitude of impacts is the first noise abatement consideration. A new passenger rail 

system with noise impacts predicted to stay within the “No Impact” curve per the FTA/FRA 

standards defined on Figure 5-9 would not be considered for mitigation. Severe noise impacts 

present the strongest case for providing mitigation, and moderate noise impacts may also 

require consideration for implementing abatement measures. FRA and FTA require that project 

sponsors prepare a mitigation policy that clearly defines an approach to mitigating moderate 

and severe noise impacts. The policy should address the following items:

 The number of noise-sensitive sites affected – rows and clusters of homes vs. isolated 

properties

 The increase over existing noise levels – predicted levels just below the severe impact 

threshold would take precedence over those just above the moderate threshold

 Noise sensitivity of affected land uses – parks and certain institutional uses vs. 

residential uses

 Minimum effectiveness of noise abatement measures – can a sufficient reduction in 

noise be achieved?

 Community views - NEPA provides a framework for seeking public and agency 

stakeholder input regarding mitigation measures
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-91

 Cost benefit analysis – guidelines should be established regarding cost per benefited 

sensitive land use similar to well-established FHWA guidelines

 Design limitations – limits on engineering design and physical construction of mitigation 

should be considered

 Wayside mitigation vs. building sound insulation – for second story and above locations, 

building insulation may be more appropriate than wayside noise barriers

 Indoor land use activities – indoor impact standards such as those established by the US 

Department of Housing and Urban Development may be more appropriate for multistory locations such as apartment buildings

The most effective mitigation for noise is to adhere to established design specifications for rail 

vehicles and infrastructure because the specifications were developed to minimize the 

potential for added noise. For passenger rail, design parameters and other mitigation measures 

may include: 1) vehicle and equipment design standards, 2) resilient or damped wheels, 3) 

wheel truing and rail grinding, 4) track turning radii greater than 1,000 feet, 5) rail lubrication, 

6) sound barriers, 7) acquisition of buffer zones, 8) ballast on at-grade and aerial guideways, 

9) acquisition of impacted properties, and 10) building insulation, among others.

Vibration Mitigation

Mitigation approaches to GBV are not as well defined because it is not as common a problem as 

environmental noise, and innovative approaches to control the impact are sometimes 

necessary. Examples include the floating slab systems that were developed for rail systems in 

Washington, D.C. and Toronto, Canada, and the use of wheel-flat detectors to identify vehicles 

in need of maintenance (FRA 2012). Maintenance of wheels and tracks is the single most 

important consideration for controlling GBV. Rough wheels and rails can increase vibration 

levels by up to 20 VdB, negating other measures designed to mitigate impacts. Grinding rough 

rails and truing wheels on a routine basis is often the best vibration mitigation strategy (FRA 

2012).

Options to further reduce GBV include: 1) general mechanical maintenance procedures;

2) location and design of special track work such as turnouts and crossovers; 3) vehicle 

modifications to provide a soft primary suspension, minimum metal-to-metal contact of moving 

parts, and perfectly round smooth wheels; 4) track support system modifications that soften 

the connection between tracks and their support structure; 5) modifications to affected 

buildings to reduce vibration levels; 6) vibration transmission path adjustments such as 

trenches that act like barriers to environmental noise; and 7) operational changes such as 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-92

reduced trains speeds, use of lowest vibration equipment at night, and minimizing train 

operations at night.

5.9.5 Tier 2 Considerations

A Tier 2 NEPA assessment of a specific alignment could include noise and vibration analyses for 

a location within the selected corridor different from that chosen for this Tier 1 EIS. A general 

noise assessment would entail the use of more precise project data including a specific 

alignment for the tracks; curvature of the alignment and potential for wheel squeal noise; 

details about train types, schedules, grade crossing locations and types, station locations, and 

maintenance requirements. With the definition of a specific alignment, the Tier 2 analysis 

would include specific locations of sensitive land use types, including Category 1 and Category 3 

uses, where they exist. 

Similarly, a general vibration assessment would require analysis of project-specific data

gathered for the noise analysis, including land use. In addition, the vibration frequency 

generated during operation of the passenger rail system would need to be analyzed.

Based on the results of the Tier 2 noise and vibration analyses, mitigation measures could be 

developed and tested in an iterative process to determine their effectiveness, feasibility, and 

reasonableness.

5.10 Hazardous Materials

Hazardous materials could be encountered during the construction of a passenger rail system; 

therefore, it is important to identify properties that may contain contamination before ROW

acquisition and construction. Hazardous materials are defined as any waste product that is 

considered flammable, corrosive, reactive, or toxic (40 CFR § 261.3). Hazardous materials can 

be found in various forms and can originate from a variety of sources. Examples of potential 

sites that may contain hazardous waste include landfills, service stations, industrial areas, and 

railroad corridors. The presence of soil and/or groundwater contamination, or the existence of 

hazardous materials within existing or proposed ROW, can adversely affect the cost and 

schedule of completing a passenger rail system. Early identification of potentially contaminated

sites provides valuable information for the alternatives analysis, design, ROW acquisition, and 

engineering because it may be possible to design future alignments to avoid these sites or, if 

they cannot be avoided, determine the additional work required to remediate these sites 

before ROW acquisition and the start of construction. 

5.10.1 Methodology and Regulatory Requirements

The regulations governing hazardous materials and waste sites include:
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-93

 Toxic Substances Control Act (TSCA) (15 U.S.C. §§ 2601-2692)

 Comprehensive Environmental Response, Compensation, and Liability Act of 1980 

(CERCLA) as amended (42 U.S.C § 9601 et seq.)

 Resource Conservation and Recovery Act (RCRA) (42 U.S.C § 6901 et seq.)

 Superfund Amendments and Reauthorization Act (42 U.S.C § 9601 et seq.)

USEPA is the federal agency responsible for overseeing hazardous waste management. In 

addition, under RCRA and state statutes and codes modeled on the federal law, ADEQ has the 

authority to monitor and direct industries that may generate, transport, or dispose of 

hazardous waste in Arizona. The following is a list of applicable state statutes and codes:

 Arizona Administrative Code, Title 18 – Environmental Quality, Chapter 8: Hazardous 

Waste Management, Chapter 12: Underground Storage Tanks, and Chapter 13: Solid 

Waste Management 

 Arizona State Legislature, Title 49 – The Environment, Chapter 4: Solid Waste 

Management, Chapter 5: Hazardous Waste Disposal, and Chapter 6: Underground 

Storage Tank Regulation

Title IV of TSCA, as well as other authorities in the Residential Lead-Based Paint Hazard 

Reduction Act of 1992, directs EPA to regulate lead-based paint hazards. 

Under Section 112 of CAA, EPA is responsible for enforcing regulations relating to asbestos and 

demolition activities. Asbestos is regulated by 40 CFR Part 61, subpart M – National Emission 

Standards for Hazardous Air Pollutants. The CAA allows EPA to delegate this authority to state 

and local agencies. The following is a list of National Emission Standards for Hazardous Air 

Pollutants programs for controlling asbestos within Pima, Pinal, and Maricopa counties: 

 Pima County, Title 17, Air Quality Control (Asbestos National Emission Standards for 

Hazardous Air Pollutants)

 Maricopa County rule 370, section 301.8 – subpart M

 Pinal County Air Quality Control District (PCAQCD) Code of Regulations, Chapter 7, 

Hazardous Air Pollutant Standards, Article 1. Federal Hazardous Air Pollutant Program

The assessment methodology began with identifying the area of potential effect for regulated 

materials, which varies depending on the typical extent of exposure. Larger or more 

contaminated sites, such as Superfund sites, often include a broad area, while hazardous spill 

sites are usually cleaned up quickly and are more limited in extent. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-94

The data used to identify potential hazardous material and waste sites within the study 

corridors came from ADEQ and from one of EPA’s online databases (EPA 2013b). The data were 

analyzed by overlaying the study corridors with the identified potential hazardous material and 

waste sites on an aerial background; however, data from EPA could only be viewed online and 

could not be overlaid onto the corridor alternatives. Therefore, the number of potential 

hazardous material and waste sites identified from EPA were estimated. The search distances 

used to identify potential hazardous material and waste sites were based on the American 

Society for Testing and Materials (ASTM) E1527-05 Standard Practice for Environmental Site 

Assessments.

The following federal and state environmental records were reviewed to identify incidents and 

regulated material sites within the study corridors:

 Federal brownfield sites. Brownfields are real property whose expansion, 

redevelopment, or reuse may be complicated by the presence or potential presence of a 

hazardous substance, pollutant, or contaminant. FTA supports the use of brownfields in 

certain circumstances. The US Department of Transportation (USDOT) encourages

participation in transportation projects that include the use and redevelopment of 

contaminated sites, when appropriate (FTA 2015). 

 Federal National Priorities List and Comprehensive Environmental Response, 

Compensation, and Liability Information System (CERCLIS) sites. The National Priorities 

List includes the known releases or threatened releases of hazardous substances, 

pollutants, or contaminants that are considered the highest priority hazardous materials

sites throughout the US and its territories. CERCLIS sites are also referred to as 

“Superfund” sites. Superfund is the federal government program to clean up the 

nation’s uncontrolled hazardous waste sites. Arizona’s state equivalent to a Superfund 

site is a Water Quality Assurance Revolving Fund (WQARF) site.

 Federal RCRA generator sites. RCRA was established for sites that treat, store, and 

dispose of hazardous waste. 

 Federal toxic releases to land – The toxic release inventory (TRI) contains information 

on toxic chemical releases and waste management activities reported annually by 

certain industries as well as federal facilities. 

 Federal TSCA sites. The TSCA authorizes EPA to require reporting, record-keeping, and 

testing requirements and restrictions relating to chemical substances and/or mixtures. 

TSCA addresses the production, importing, use, and disposal of specific chemicals 

including polychlorinated biphenyls, asbestos, radon, and lead-based paint. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-95

 State landfill sites. The state holds records of permitted solid waste disposal facilities or 

landfills in Arizona. 

 State Large Quantity Generator (LQG) sites. Large quantity generator sites generate 

over 1,000 kilograms (kg) of hazardous waste, or over 1 kg of acutely hazardous waste, 

per month. 

 State Leaking Underground Storage Tank (LUST)/underground storage tank (UST) 

sites. The state maintains records for all regulated storage tanks and ensures that tanks 

meet requirements for release detection, spill and overflow prevention, and corrosion 

protection and ensures that tanks not meeting these requirements are closed. Leaking 

USTs are defined as regulated USTs that contain regulated substances including 

petroleum and hazardous substances, such as those typically found at gasoline stations, 

fleet fueling facilities, and industrial sites, that are suspected or confirmed of having a 

leak. 

 State treatment, storage, and disposal facility (TSDF) sites. This includes treatment, 

storage, and disposal facilities of hazardous waste. 

5.10.2 Existing Conditions

The hazardous materials sites of most concern, in general order of magnitude, are Superfund, 

Brownfields, and LUST, since they often encompass a broad area compared to other listed sites. 

Table 5-17 gives an inventory of Superfund and other hazardous material sites based on ASTM 

standard search distances, measured from hypothetical centerline alignments within each 

Corridor Alternative. 

Table 5-17. Regulatory Database Summary

Database

Search Distancea

(mile)

Number of Facilities Identifiedb

Yellow Corridor 

Alternative

Orange Corridor 

Alternative

ADEQ

Landfills 1.00 1 1

LQG 0.25 11 24

LUST 0.50 552 428

UST 0.25 276 172

Superfund 0.50 10 7

TSDF 0.50 1 0

EPA

Brownfields 0.50 95 95
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-96

Table 5-17. Regulatory Database Summary

Database

Search Distancea

(mile)

Number of Facilities Identifiedb

Yellow Corridor 

Alternative

Orange Corridor 

Alternative

CERCLIS 0.50 22 23

RCRA 0.25 501 358

TRI 0.25 31 23

TSCA corridor 10 9

Total 1,511 1,142

a Search distances based on ASTM standards.

b The number of facilities is only an estimate. The same site could be listed in both databases. 

As indicated in Table 5-17, a database search for the Yellow Corridor Alternative discloses up to 

1,511 hazardous material and waste sites, although some of the same sites may be duplicated 

on more than one database, so this may be an overestimated count. The database search for 

the Orange Corridor Alternative indicates almost 25 percent fewer hazardous material and 

waste sites (a total of 1,142 sites) than that for the Yellow Corridor Alternative. Most of these 

sites are located within the more urbanized portions of the corridor, where hazardous waste 

generators are more likely to occur, chiefly in the Eloy to northern hub segment of the corridor 

alternatives, through parts of Mesa, Tempe, and Phoenix.

Superfund Sites

Figure 5-11, Figure 5-12, and Figure 5-13 depict the location of CERCLIS sites, landfills, LUST 

sites, TRI sites, and plumes associated with Superfund and WQARF sites in and around the 

corridor alternatives. The following is a list of Superfund sites intersected by the corridor 

alternatives that have ongoing monitoring and remediation activities.

EPA National Priority List Sites

 Motorola 52nd Street (OU2 and OU3) – This site is located near the Phoenix Sky Harbor 

International Airport. This site was divided into three operating units (OU). South Indian 

Bend Wash – This site represents the southern portion of the Indian Bend Wash 

Superfund site. The site encompasses approximately 4 square miles in Tempe. 

 Williams Air Force Base – This site represents the former Williams Air Force Base, now 

Phoenix-Mesa Gateway Airport. The site encompasses approximately 4,127 acres 

(6.45 square miles).
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5 Existing Conditions and Environmental Consequences

Figure 5-11. Hazardous Waste and Materials Sites in the Study Area

Final Tier 1 Environmental Impact Statement 5-97

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Storage Tank 

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Figure 5-15

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5 Existing Conditions and Environmental Consequences

Figure 5-12. Hazardous Waste and Materials Sites in the Tucson Metropolitan Area

Final Tier 1 Environmental Impact Statement 5-98

Prince Rd

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Final Tier 1 Environmental Impact Statement 5-99

Existing Conditions and Environmental Consequences

Figure 5-13. Hazardous Waste and Materials Sites in the Phoenix Metropolitan Area

5

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#* EPA CERCLIS

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!( Leaking Underground

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5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-100

ADEQ Water Quality Assurance Revolving Fund Sites

 7

th Street and Arizona Avenue – A contaminant plume associated with dry cleaning 

industries lies north of the corridor alternatives’ southern hub.

 Cooper and Commerce – This site consists of a contaminated groundwater plume 

located in the vicinity of Commerce Avenue near Cooper Road in Gilbert.

 Miracle Mile – This contaminated groundwater plume is located in Tucson’s Flowing 

Wells neighborhood north of I-10 between Prince and Wetmore Roads. A portion of the 

plume falls within the Orange and Yellow corridor alternatives, which run in common in 

the southern portion of the study area. 

 Shannon Road El Camino Del Cerro – This site is located in northwest Tucson. 

 Silverbell Landfill – This site is a contaminated groundwater plume in northeast Tucson 

between Silverbell Road and I-10, originating at a landfill underneath the Silverbell Golf 

Course. 

 South Mesa – This site is located in south Mesa. The plume associated with this site 

could be directly affected by a rail system in the Orange Corridor Alternative.

Brownfield Sites

A number of known brownfield sites are located in both corridor alternatives. Current and 

former agricultural land has the potential to be determined a brownfield site due to the 

presence of pesticides and herbicides in the soil.

UST/LUST Sites

UST and LUST sites are located in both corridor alternatives. Approximately 60 percent more 

UST and 29 percent more LUST sites occur within the Yellow Corridor Alternative than within 

the Orange Corridor Alternative, most likely because the Yellow Corridor Alternative covers a 

greater amount of developed areas than the Orange Corridor Alternative.

5.10.3 Environmental Consequences

In general, a greater potential for hazardous material effects exists within urban areas, where 

hazardous materials and waste sites are typically located. Both the Yellow and Orange corridor

alternatives are centered along the same transportation corridor from Tucson to Eloy; thus, 

potential hazardous material effects are the same for both corridor alternatives from Tucson to 

Eloy. From Eloy to Phoenix, the Yellow Corridor Alternative incorporates more developed, 

urban areas than the Orange Corridor Alternative. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-101

Yellow Corridor Alternative

Physical Impacts 

Acquiring ROW within potentially contaminated areas is a concern because contaminated land 

can be a liability, particularly if the landowner becomes responsible for cleanup costs. Although 

potentially contaminated sites were identified within the Yellow Corridor Alternative, specific 

effects at each location were not determined in this Tier 1 analysis; that information would be 

provided once a future alignment has been determined.

As mentioned above, Superfund sites would be of most concern because their contaminant 

plumes often encompass a broad area compared to other listed sites. The Cooper and 

Commerce site contaminant plume in Gilbert would affect or be affected by a passenger rail 

system within the Yellow Corridor Alternative. The plumes associated with the 7th Street and 

Arizona Avenue, Miracle Mile, Shannon Road El Camino del Cerro, and Silverbell Landfill are all 

in Tucson; and Motorola 52nd Street OUs 2 and 3 are in Phoenix. 

A passenger rail system within the Yellow Corridor Alternative would likely be affected by more 

UST and LUST sites than a passenger rail system within the Orange Corridor Alternative, 

because of the greater number of UST and LUST sites.

Operational Impacts 

The potential exists for exposing rail system equipment and passengers to contaminants from 

hazardous materials sites as well as those generated by the operation of the passenger rail 

system itself. While petroleum, oils, and lubricants may be used in rail operations or 

maintenance, proper use, storage, and disposal practices would minimize the potential for 

accidental releases. In selecting locations for rail stations, avoiding contaminated sites during 

design could reduce the risk of passenger exposure to contaminants. 

Hazardous material sites would have minimal effect on the operations of a passenger rail 

system. Work within contaminated areas seldom goes beyond maintenance activities, which 

would be unlikely to increase workers’ exposure to contaminants.

Similarly, operating a passenger rail system would not be expected to result in releases of 

hazardous materials and waste. 

Construction Impacts 

Construction activities involving excavation increase the likelihood for encountering existing 

and unknown regulated materials. Hazardous material sites pose a safety risk to workers who 

might be exposed to contaminated soil, water, and vapors; and it is an additional cost to 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-102

provide workers with personal protective equipment. Vehicles and equipment used during 

construction activities, such as fuel storage tanks, have the potential to release hazardous 

materials, mainly petroleum products. Appropriate construction safety procedures and 

equipment stockpiling methods would be used to minimize the potential for unintended 

releases. All releases would be reported and addressed under appropriate regulatory guidance. 

Heavy truck traffic may also increase with an intensification of construction activities, which has 

the potential to increase the risk of material spills. Dewatering activities during construction 

could potentially alter existing groundwater contamination plumes and potentially affect 

additional properties. Should contamination be encountered, construction activities would be 

temporarily halted until characterization, storage, disposal, and cleanup requirements were 

met. 

In addition, construction activities would be expected to generate waste material. All 

construction debris would be recycled or properly disposed of in a permitted landfill or 

appropriate facility in compliance with federal, state, and local regulations. 

Orange Corridor Alternative

Physical, operational, and construction impacts within the Orange Corridor Alternative would 

be similar to those described for the Yellow Corridor Alternative. A passenger rail system in the 

Orange Corridor Alternative, however, could have a greater potential to be affected by 

brownfield sites because the Orange Corridor Alternative has more current and former 

agricultural land than the Yellow Corridor Alternative. The contaminant plumes associated with 

the Williams Air Force Base and South Mesa sites could affect or be affected by a rail system 

within the Orange Corridor Alternative. The contaminant plume associated with the South 

Indian Bend Wash site would directly affect a rail system in the Orange Corridor Alternative.

No Build Alternative

Under the No Build Alternative, a passenger rail system would not built, and no hazardous 

materials or hazardous waste sites would be affected. The No Build Alternative would not 

preclude the potential for ongoing or future releases, as evidenced by the past regulated 

material releases that have been identified within the corridor alternatives. Cleanup of these 

conditions would continue under regulatory programs, and some sites may be fully remediated 

over time. 

If a passenger rail system is not developed, vehicle use of the existing and reasonably 

foreseeable future transportation system would likely increase. The added congestion may 

cause a higher incidence of accidents than currently occurs. Spills resulting from traffic 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-103

accidents and crashes could influence the amount of hazardous material exposure in these 

travel corridors. 

5.10.4 Potential Mitigation Measures

This Tier 1 review does not identify the nature and severity of contamination at specific sites; 

this level of detail would be conducted if the study advances to Tier 2. It is expected, however,

that appropriate cleanup of hazardous materials and/or removal of USTs may be required. FRA 

and FTA would coordinate with the appropriate agencies to ensure proper cleanup of any 

contaminated sites. In addition, a site management plan would be prepared before 

construction to address known or potential hazardous material issues, including but not limited 

to:

 Measures to identify and address potentially contaminated soil and groundwater, as 

necessary or required

 Measures to identify and address lead-based paint and asbestos-containing materials 

including handling and disposal, as necessary or required 

 A site-specific health and safety plan, including measures to protect construction 

workers and general public 

 Procedures to protect workers and the general public in the event that unknown 

contamination or buried hazards are encountered 

5.10.5 Tier 2 Considerations

During Tier 2, Phase I Environmental Site Assessments would be conducted prior to acquiring 

property or commencing with construction activities, to identify known or suspected hazardous 

material and waste sites, and to characterize the extent of possible contamination from all 

known or suspected sites in accordance with ASTM E 1527-13 standard practice. 

More detailed analysis, such as the status of cleanup and remediation activities at Superfund or 

other sites of concern, would also be more fully evaluated during any Tier 2 analysis.

The identification, handling, and remediation of all known or suspected hazardous or solid 

wastes, such as asbestos-containing materials and lead-based paint, would be addressed during 

Tier 2 studies in accordance with applicable local, state, and federal laws and regulations. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-104

5.11 Geology, Topography, Soils, and Prime and Unique Farmlands

This section describes the study corridor’s geologic resources, topography, soils, and prime and 

unique farmlands and evaluates potential effects to these resources resulting from 

implementing a passenger rail system within each of the corridor alternatives.

Geologic features include rock outcrops, unique rock formations, soils, topography, and mineral 

and energy resources such as mineral ores, petroleum, natural gas, and sand and gravel. 

Geologic features that may affect construction include formations and soils that are unstable or 

erode easily, bedrock outcrops, extreme topography, faults, fissures, and areas of seismic 

activity. Soil features that may affect construction include soil erodibility, shrink/swell 

characteristics, and permeability. Furthermore, soils comprising certain chemical and physical 

properties, in combination with certain current and planned uses, could be subject to 

regulation under the Farmland Protection and Policy Act (FPPA).

5.11.1 Methodology and Regulatory Requirements

This evaluation assesses the potential effects of a future passenger rail system constructed and 

operating within the Yellow or Orange corridor alternatives on geology, soils, and prime 

farmlands. Data sources identifying geology and topography include sources cited under the 

Land Use (Section 5.2) as well as published data from the Arizona Geological Survey (AZGS) and 

US Geological Survey (USGS). Soils and prime and unique farmlands (as defined under FPPA) 

within the corridor alternatives were identified using Natural Resources Conservation Service 

(NRCS) GIS data.

The impact analysis presents a general description of the types of potential effects that could 

occur in the two corridor alternatives. The effects of the No Build Alternative are also discussed. 

General mitigation measures to reduce or avoid effects are identified to inform more detailed, 

future Tier 2 and project-level analyses. No field verification was conducted for this analysis.

Geology and Topography

Geology and topography are discussed in close association because geologic conditions strongly 

influence topography. The primary issues regarding geology and topography are associated 

with the potential costs of construction in areas of relatively high topographic relief 

(i.e., relatively steep slopes), particularly where relatively hard geologic formations 

(i.e., bedrock) are present. Preliminary information regarding fissures, faults, unstable slopes, 

and unsuitable soils is also provided because those conditions may present issues for 

construction. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-105

No state or federal laws were identified that apply specifically to geologic resources in the 

corridor alternatives, although some local agencies may have restrictions regarding building on 

certain types of soils, such as expanding soils.

Soils

Soils are identified using NRCS GIS data and data from the NRCS web soil survey (NRCS 2013c). 

Prime and Unique Farmlands

Soils comprising certain chemical and physical properties, in combination with certain current 

and planned uses, are designated as prime and unique farmlands and farmland of unique 

importance, which may be subject to FPPA. Prime and unique farmlands and farmland of 

unique importance are identified to provide a preliminary, informal assessment of potential 

effects on those resources. Areas of current and planned urban land and water bodies are not 

included and are deducted from mapped areas of prime farmlands and farmland of unique 

importance.

FPPA was established in 1981 in response to concerns about the declining acreages in the US 

being actively farmed. The purpose of FPPA is to minimize the extent to which federal programs 

contribute to the unnecessary and irreversible conversion of farmland to non-agricultural uses. 

FPPA states, “Federal programs shall be administered in a manner that, as practicable, would 

be compatible with state and local government and private programs and policies to protect 

farmland.”

Prime farmland and agricultural land are not necessarily the same. The agricultural land use 

designation is a product of local community planning efforts, while the designation of Prime or 

Unique Farmland is a product of NRCS criteria. Additionally, farmland subject to FPPA 

requirements does not have to be currently used for cropland. It can be forest land, 

pastureland, cropland, or other land, but not water or urban built-up land. Definitions of Prime 

and Unique Farmland, which determine the existing conditions and environmental concerns 

related to farmlands in the corridor alternatives, are as follows. 

 Prime Farmland – Land that has the best combination of physical and chemical 

characteristics for producing food, feed, fiber, forage, oilseed, and other agricultural 

crops with minimum inputs of fuel, fertilizer, pesticides, and labor and without 

intolerable soil erosion. Prime Farmland includes land that possesses the above 

characteristics but is being used to produce livestock and timber. It does not include 

land already in or committed to urban development or water storage (7 CFR 658.2).
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-106

 Unique Farmland – Land other than Prime Farmland that is used for production of 

specific high-value food and fiber crops. Its characteristics include the special 

combination of soil quality, location, growing season, and moisture supply needed to 

economically produce sustained high quality or high yields of specific crops when 

treated and managed according to acceptable farming methods. Examples of such crops 

include citrus, tree nuts, olives, cranberries, fruits, and vegetables (7 CFR 658.2).

The Prime farmland soils are categorized with qualifiers, as follows:

 Prime farmland if irrigated

 Prime farmland if irrigated and either protected from flooding or not frequently flooded 

during the growing season

Farmlands, and areas other than farmlands, are further defined, as follows:

 Farmland of unique importance

 Not prime farmland

Prime farmland and farmland of unique importance are aggregated and are referred to as 

prime and unique farmlands for the purposes of this evaluation.

5.11.2 Existing Conditions

The study corridor occurs in the Sonoran Desert, one of the largest and hottest deserts in North 

America. It also lies within the Basin and Range Geologic Province, characterized by generally 

north-south running mountain ranges (and large, normal faults) separated by broad, relatively 

flat valley floors (USGS 2004). Soils in the study corridors comprise many units that can be 

described generally as clay, silt, and/or sand loams and gravels.

Subsidence Areas

Land subsidence in Arizona is generally caused by lowering of the water table resulting from 

groundwater withdrawals. When land settles evenly, subsidence occurs gradually and is usually 

imperceptible. Several active land subsidence areas exist within the study corridor, one in the 

vicinity of Picacho and Coolidge, and one further north in Mesa and Gilbert. The subsidence 

rate in these areas averages approximately 1 centimeter per year (ADWR 2015).

Fissures and Faults

Fissures and faults are geologic features that may affect infrastructure, including railroads. 

Fissures are typically associated with land subsidence, a phenomenon that has been identified 

in several locations in south-central Arizona, including the study corridor (AZGS 1993). 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-107

Subsidence can take place when water is removed from underground reservoirs and the weight 

of the overlying material compresses the underlying, formerly saturated material, causing the 

land to settle. When the land settles unevenly, cracks in the earth—fissures—may result. 

Fissures may be more than 1.0 mile in length, up to 15 feet wide, and hundreds of feet deep. 

During torrential rains, these fissures can erode rapidly and present substantial hazards to 

people, animals, and infrastructure (Maricopa Association of Governments 2009). According to 

AZGS, fissures are present between Eloy and Picacho Peak. Because fissures can form and/or 

increase in size rapidly, available mapping may not identify all fissures within the corridor. 

USGS defines faults as “fractures or zones of fractures along which there has been displacement 

of the adjacent [bedrock] blocks relative to one another” (USGS 2012). Faults are often 

associated with earthquakes; however, the presence or absence of surface faults is not a 

reliable indicator of earthquake risk. Earthquake hazard levels are low to moderate in most of 

Arizona; and the faults that are known to exist throughout southeast and central Arizona, 

including much of the Phoenix and Tucson areas, have low slip rates, long intervals between 

rupture, and little historic activity (AZGS 2000). Preliminary information regarding the identified 

resources in each of the corridor alternatives is summarized in Table 5-18 and discussed below. 

Approximate acreages of Subsidence and Prime and Unique Farmlands within 200-foot ROW 

corridors are shown in parentheses, based on the 200-foot to 1-mile ratio (0.0379) explained in 

Section 5.1.2. 

Table 5-18. Geologic, Topographic, and Prime/Unique Farmland Resources in the Corridor 

Alternatives

Subsidence (acres) Fissures (number) Prime and Unique Farmlands (acres)

Southern Hub to Eloy – Yellow and Orange Corridor Alternatives (and 200-foot ROW corridor)

2,473 (94) 207 28,437 (1,078)

Eloy to Northern Hub – Yellow Corridor Alternative (and 200-foot ROW corridor)

14,641 (555) 28 48,714 (1,846)

Eloy to Northern Hub – Orange Corridor Alternative (and 200-foot ROW corridor)

17,820 (675) 39 54,324 (2,059)

Sources: ADWR 2013, AZGS GIS 2013, NRCS 2013 Soil Survey data
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-108

Yellow Corridor Alternative

Southern Hub to Eloy

Geology and Topography

Geologic formations in the southern half of the Yellow Corridor Alternative are characterized by 

relatively recent deposits of alluvium as well as relatively older deposits of volcanic and 

sedimentary rocks that comprise the rocky outcrops and mountains (i.e., bedrock) found in the 

study corridor. The significance of the relatively old volcanic and sedimentary bedrock is that it 

may be harder, and more resistant to cutting, than the alluvial deposits. The bedrock's higher 

resistance to erosion generally results in the formation of relatively steep slopes. 

Picacho Peak, located approximately 11 miles southeast of Eloy (see Figure 5-14), comprises 

volcanic rock approximately 38 million years old, the oldest deposit in the southern half of the 

corridor and the only deposit of volcanic rock at the surface in this corridor segment (AZGS

1988). As shown in Figure 5-14, no faults are mapped in the southern half of the Yellow 

Corridor Alternative; however, faults are mapped in four locations in nearby areas. 

The topography reflects the geologic characteristics described above, comprising primarily 

broad, flat, low-lying desert valleys with isolated bedrock outcrops and mountain ranges of 

relatively low relief. Elevations in the southern half of the Yellow Corridor Alternative range 

from approximately 2,400 feet amsl at the southern hub in Pima County down to approximately 

1,650 feet amsl near Eloy in Pinal County, with the steepest slopes occurring adjacent to 

Picacho Peak. 

Soils

Soils in the southern half of the Yellow Corridor Alternative comprise many units that can be 

described generally as clay, silt, and/or sand loams and gravels (NRCS 2013c). The majority of 

these soil units comprise prime and unique farmland, as discussed below.

Prime and Unique Farmlands

Prime farmlands and farmland of unique importance comprise large segments of the area 

traversed by the corridor alternatives, particularly in Pinal County. Prime and unique farmland 

comprises approximately 28 percent of the total area of the southern half of the Yellow 

Corridor Alternative. 
Marana

Tucson

Eloy

Oro 

Valley

PINAL COUNTY

PIMA COUNTY

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Se e Fi g ur e 5- 18

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S a n t a 

C a t a l i n a

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To rt o l i ta

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International

Airport

2750'

2500'

2500'

2000'

2250'

4000'

3000'

3000'

2750'

3250'

3000'

2750'

2750'

2500'

3500'

2500'

2750'

2750'

3000'

2500'

3250'

3750'

3000'

3000'

2750'

2000'

3500'

3250'

3000'

2500'

2250'

2000'

2000'

1750'

1500'

4250'

3500'

3500'

2500'

2250'

2000'

4500'

4000'

3750'

3750'

3250'

2750'

3500'

3250'

2750'

3000'

2500'

2250'

1750'

5000' 4500'

4000'

3750'

4000'

3250'

3500'

2000'

2000'

Existing Conditions and Environmental Consequences

Figure 5-14. Geologic Features and Prime and Unique Farmlands between Tucson and Eloy

5

Final Tier 1 Environmental Impact Statement 5-109

e

Airport

Interstate

State or US Highway

Railroad

Major Drainage

Yellow Corridor Alternative

Orange Corridor Alternative

Fault Line

Fissure

250' Contour

Active Land Subsidence Area

Farmland of unique importance

Prime farmland

Le g e nd

0 5 10

Miles

Sources: Arizona Department of Transportation 2013; Arizona Department of Water Resources 2010;

Arizona Geological Survey 2013; Arizona Land Resource Information System 2013; Esri 2014;

Natural Resources Conservation Service 2013

N

e
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-110

Eloy to Northern Hub

Geology and Topography

Geologic formations in the northern half of the Yellow Corridor Alternative are characterized by 

recent deposits of alluvium as well as older deposits of sedimentary and volcanic bedrock. The 

oldest deposit in the Yellow Corridor Alternative is approximately 1.1 billion years old, located 

approximately 9 miles northwest of Florence, adjacent to Twin Buttes, a feature of the Santan

Mountains (see Figure 5-15). A second deposit of granitoid rock associated with the Santan

Mountains is located within the Yellow Corridor Alternative, approximately 7.6 miles west of 

Florence. Near the northern hub, the Yellow Corridor Alternative comprises approximately 15-

to 38-million-year-old volcanic and sedimentary bedrock associated with Hayden Butte (Tempe) 

and the hills in Papago Park (Phoenix).

Elevations in the northern half of the Yellow Corridor Alternative range from approximately 

1,650 feet amsl near Eloy in Pinal County down to approximately 1,100 feet amsl at the 

northern hub in Maricopa County. The topography of the northern half of the Yellow Corridor 

Alternative also comprises primarily broad, flat, low-lying desert valleys with isolated mountain 

ranges of relatively low relief (such as the Santan Mountains, South Mountain, the Superstition 

Mountains, the hills in Papago Park, and Hayden Butte). The steepest slopes found in the 

northern half of the Yellow Corridor Alternative are adjacent to the Santan Mountains, where 

volcanic bedrock is mapped at the surface, and in Phoenix, north of Hayden Butte and south of 

Papago Park.

According to AZGS, one fault is in the Yellow Corridor Alternative, running roughly northwest to 

southeast for approximately 1.5 miles, located approximately 0.25 mile southwest of Papago 

Park in Phoenix. At least six additional faults are located nearby, as shown in Figure 5-15. The 

Yellow Corridor Alternative intersects an active subsidence area from a point just west of 

Picacho Peak north to the Gila River.

Soils

Soils in the northern half of the Yellow Corridor Alternative comprise many units that can be 

described generally as clay, silt, and/or sand loams and gravels (NRCS 2013c). The majority of 

these soil units comprise Prime and Unique Farmland, as discussed below. 

Prime and Unique Farmlands

Prime and unique farmland comprises approximately 24 percent of the total area of the 

northern half of the Yellow Corridor Alternative, primarily in Pinal County between Eloy and 

Coolidge, and southeast of Queen Creek. 
Eloy

Coolidge

Casa

Grande

Maricopa

Tempe

Mesa

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Queen Creek

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Queen

Creek

Paradise

Valley

MARICOPA COUNTY

PINAL COUNTY

S a c a t o n M o u n t a i n s

S a n t a n

M o u n t a i n s

S u p e r s t i t i o n

M o u n t a i n s

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Hayden

Butte

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San

Tan

Valley

Tw i n

B u t t e s

2000'

1750'

1500'

2250'

1750'

1500'

1250'

1500'

1250'

1250'

3000'

2000'

2750'

1750'

2000'

2750'

2500'

2500'

2500'

1750'

2500'

2250'

2250'

3250'

2250'

2250'

2250'

2000'

2250'

1750' 1500' 1500'

1250'

2750'

3250'

2250'

1500'

2250'

1500'

1500'

1250'

1750'

1500'

2000'

1750'

3000'

2500'

1750'

1500'

1750'

2000'

1750'

2000'

2500' 2750'

2250'

1750'

Existing Conditions and Environmental Consequences

Figure 5-15. Geologic Features and Prime and Unique Farmlands between Eloy and Phoenix

5

Final Tier 1 Environmental Impact Statement 5-111

Interstate

State or US Highway

Railroad

Major Drainage

Yellow Corridor Alternative

Orange Corridor Alternative

Fault Line

Fissure

250' Contour

Active Land Subsidence Area

Farmland of unique importance

Prime farmland

Le g e nd

0 5 10

Miles

Sources: Arizona Department of Transportation 2013; Arizona Department of Water Resources 2010;

Arizona Geological Survey 2013; Arizona Land Resource Information System 2013; Esri 2014;

Natural Resources Conservation Service 2013

N
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-112

Orange Corridor Alternative 

Southern Hub to Eloy

The affected environment for the southern portion of the Orange Corridor Alternative would be 

the same as that described for the Yellow Corridor Alternative from the southern hub to Eloy.

Eloy to Northern Hub

Geology and Topography

Geologic formations in the northern half of the Orange Corridor Alternative have characteristics 

similar to those in the northern half of the Yellow Corridor Alternative. 

The oldest deposits in the northern half of the Orange Corridor Alternative comprise 

approximately 15- to 38-million-year-old volcanic and sedimentary rocks associated with 

Hayden Butte (Tempe) and the hills in Papago Park (Phoenix). 

Elevations in the northern half of the Orange Corridor Alternative range from approximately 

1,600 feet amsl near Eloy in Pinal County down to approximately 1,100 feet at the northern hub 

in Maricopa County. The topography of the northern half of the corridor vicinity also comprises

primarily broad, flat, low-lying desert valleys with isolated mountain ranges of relatively low 

relief (such as the Santan Mountains, South Mountain, the Superstition Mountains, the hills in 

Papago Park, and Hayden Butte). The steepest slopes found in the northern half of the Orange 

Corridor Alternative occur in Phoenix, north of Hayden Butte and south of Papago Park. 

According to AZGS, fissures in the Orange Corridor Alternative are mostly concentrated from 

Eloy to approximately 11 miles north of Eloy. Because fissures can form and/or increase in size 

rapidly, current mapping may not identify all fissures within the corridor and nearby areas.

AZGS indicates one fault in the Orange Corridor Alternative, running roughly northwest to 

southeast for approximately 1.5 miles, located approximately 0.25 mile southwest of Papago 

Park in Phoenix. At least six additional faults are located in the vicinity of the corridor, as shown 

in relatively low relief. Elevations in the southern half of the Yellow Corridor Alternative range 

from approximately 2,400 feet amsl at the southern hub in Pima County down to approximately 

1,650 feet amsl near Eloy in Pinal County, with the steepest slopes occurring adjacent to 

Picacho Peak. 

Soils

Soils in the southern half of the Yellow Corridor Alternative comprise many units that can be 

described generally as clay, silt, and/or sand loams and gravels (NRCS 2013c). The majority of 

these soil units comprise prime and unique farmland, as discussed below. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-113

Prime and Unique Farmlands

Prime farmlands and farmland of unique importance comprise large segments of the area 

traversed by the corridor alternatives, particularly in Pinal County. Prime and unique farmland 

comprises approximately 28 percent of the total area of the southern half of the Yellow 

Corridor Alternative. 

Eloy to Northern Hub

Geology and Topography

Geologic formations in the northern half of the Yellow Corridor Alternative are characterized by 

recent deposits of alluvium as well as older deposits of sedimentary and volcanic bedrock. The 

oldest deposit in the Yellow Corridor Alternative is approximately 1.1 billion years old, located 

approximately 9 miles northwest of Florence, adjacent to Twin Buttes, a feature of the Santan 

Mountains (see Figure 5 15). A second deposit of granitoid rock associated with the Santan 

Mountains is located within the Yellow Corridor Alternative, approximately 7.6 miles west of 

Florence. Near the northern hub, the Yellow Corridor Alternative comprises approximately 15-

to 38-million-year-old volcanic and sedimentary bedrock associated with Hayden Butte (Tempe) 

and the hills in Papago Park (Phoenix).

Elevations in the northern half of the Yellow Corridor Alternative range from approximately 

1,650 feet amsl near Eloy in Pinal County down to approximately 1,100 feet amsl at the 

northern hub in Maricopa County. The topography of the northern half of the Yellow Corridor 

Alternative also comprises primarily broad, flat, low-lying desert valleys with isolated mountain 

ranges of relatively low relief (such as the Santan Mountains, South Mountain, the Superstition 

Mountains, the hills in Papago Park, and Hayden Butte). The steepest slopes found in the 

northern half of the Yellow Corridor Alternative are adjacent to the Santan Mountains, where 

volcanic bedrock is mapped at the surface, and in Phoenix, north of Hayden Butte and south of 

Papago Park.

Soils

Soils in the northern half of the Orange Corridor Alternative comprise many units that can be 

described generally as clay, silt, and/or sand loams and gravels (NRCS 2013c).

Prime and Unique Farmlands

Prime and unique farmland comprises approximately 21 percent of the total area of the 

northern half of the Orange Corridor Alternative and is located mostly between Eloy and 

Florence. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-114

5.11.3 Environmental Consequences

Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts 

An alignment for a passenger rail system within the Yellow Corridor Alternative from the 

southern hub to Eloy would need to avoid bedrock outcrops and steep slopes to minimize cut 

and fill areas. Physical impacts of a passenger rail system within the Yellow Corridor Alternative 

on geologic or topographic resources could be moderated by focusing the design on areas with 

minimal variation in terrain. Faults existing within the corridor alternative should also be 

considered in the design and placement of a rail system. Subsidence areas and fissures within 

the corridor alternative, which are most notable in the vicinity of Eloy, should also be 

considered during design.

Because areas of prime and unique farmland occupy the entire 1-mile width within this 

segment of the Yellow Corridor Alternative, they cannot be entirely avoided. The actual acreage 

of prime and unique farmland that may be affected would depend on track alignment, rail 

station locations, and proximity to existing ROW that may pass through prime and unique 

farmland. An alignment within or near existing linear transportation features, or within existing 

or planned urban areas, may minimize the loss of prime and unique farmlands. 

Operational Impacts 

Operation and maintenance of a passenger rail system generally within this segment of the 

Yellow Corridor Alternative would not be expected to affect geology, topography, soils, or 

prime and unique farmland. Because petroleum, oils, and lubricants would be used to operate 

and maintain the trains, potential for soil contamination exists; however, best management 

practices (BMPs) and routine maintenance of trains to prevent spills would minimize the 

potential risk.

Construction Impacts 

Construction of a future passenger rail system in the Yellow Corridor Alternative from the 

southern hub to Eloy would require ground disturbance to clear construction areas of 

vegetation, to grade the land to appropriate levels of slope, and to establish staging and storage 

areas. The extent of ground disturbance would be identified in Tier 2 studies. The potential for 

soil erosion would increase in areas disturbed for construction from the time soil grading and 

vegetation removal is initiated until disturbed areas are reclaimed through the installation of 

long-term stabilizing features (such as building foundations or covering areas with gravel or 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-115

crushed rock) or reestablishment of vegetation. While construction methods would not be 

identified until later phases, it is not anticipated that development of a passenger rail system 

would require pumping of groundwater or other activities that might result in new or expanded 

subsidence or fissure activity.

The potential for soils to erode by water and wind is influenced by the physical characteristics 

of the soil, slope gradient, vegetative cover, soil surface roughness, and proximity to shelters 

such as windbreaks, as well as rainfall or wind intensity. These factors would need to be 

examined in more detail in Tier 2 studies for a specific rail alignment.

Eloy to Northern Hub

Physical Impacts

Physical impacts of a passenger rail system in the Yellow Corridor Alternative from Eloy to the 

northern hub would be similar to those described above for the segment from the southern 

hub to Eloy. Subsidence areas and fissures to be avoided within the corridor alternative are 

most notable in this segment of the Yellow Corridor Alternative from Eloy to approximately 

11 miles north of Eloy.

Operational Impacts

Operational impacts of a passenger rail system in the Yellow Corridor Alternative from Eloy to 

the northern hub would be similar to those described above for the segment from the southern 

hub to Eloy.

Construction Impacts

Construction impacts of a passenger rail system in the Yellow Corridor Alternative from Eloy to 

the northern hub would be similar to those described above for the segment from the southern 

hub to Eloy.

Orange Corridor Alternative

Southern Hub to Eloy

The physical, operational, and construction impacts of a passenger rail system in the Orange 

Corridor Alternative from the southern hub to Eloy would be the same as those described 

above for the Yellow Corridor Alternative from the southern hub to Eloy.

Eloy to Northern Hub

Physical impacts of a passenger rail system in the Orange Corridor Alternative from Eloy to the 

northern hub would be similar to those described above for the Yellow Corridor Alternative 

from Eloy to the northern hub. Operational and construction impacts in the Orange Corridor 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-116

Alternative from Eloy to the northern hub would be the same as those described above for the 

Yellow Corridor Alternative from the southern hub to Eloy.

No Build Alternative

Under the No Build Alternative, a new passenger rail system would not be built; and effects to 

geologic, topographic, soils, or farmland resources would not be anticipated beyond those that 

could occur due to other projects.

5.11.4 Potential Mitigation Measures

Mitigation for specific effects on geology, topography, soils, and Prime and Unique Farmlands 

would be identified based on the assessment conducted during Tier 2 analysis; however, a 

number of BMPs and other measures to mitigate for effects can be anticipated. These include:

 Avoid steep slopes and known bedrock outcrops 

 Minimize areas of new ground disturbance for access to construction areas by using

existing roads where possible

 Avoid areas of known ground subsidence and fissures, when feasible

 Develop and implement dust control and erosion control strategies

 Stockpile topsoil for use in reclamation

 Develop and implement a reclamation and revegetation plan to minimize soil losses

5.11.5 Tier 2 Considerations

Tier 2 analyses would consider project-level effects on geology, topography, soil, and prime and 

unique farmland. Design considerations would include the potential to avoid areas with greater 

degrees of slope, bedrock outcrops, known faults, subsidence areas, fissures, and prime and 

unique farmland. Environmental considerations would include a more detailed assessment of 

the amount of ground disturbance required and the erosion potential for disturbed soils. 

Because portions of the corridor alternatives consist entirely of prime or unique farmlands, a 

US Department of Agriculture (USDA) Form AD 1006 (Farmland Conversion Impact Rating form) 

would not be submitted to NRCS until Tier 2 documentation when the specific effects of a 

proposed project on prime and unique farmland are identified.

5.12 Biological Resources

Biological resources include general wildlife; plant and animal species that have received special 

designations by a federal, state, or local governmental agency; and the vegetative communities 

that provide habitat for these species. This chapter is intended to provide an overview of the 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-117

biological resources in the vicinity of the corridor alternatives for a passenger rail system from 

Tucson to Phoenix and serves as a foundation for the analysis of potential effects on biological 

resources. 

This EIS complies with FRA's Procedures for Considering Environmental Impacts (Environmental 

Procedures) (64 FR 28545, May 26, 1999) and FTA’s Environmental Impact and Related 

Procedures (23 CFR Part 771). This evaluation follows FRA’s Environmental Procedures Section 

14(n)(5) for evaluation of potential impacts to natural ecological systems and Section 14(n)(7) 

for evaluation of potential impacts to endangered species (FRA 1999a).

5.12.1 Methodology and Regulatory Requirements

Primary jurisdiction for resident wildlife management is implemented on behalf of the State by 

the Arizona Game and Fish Department (AGFD), except where pre-empted by federal law (e.g., 

Endangered Species Act [ESA] listed species). Protected species are species of plants or animals 

that, because of their scarcity or documented declining population numbers in the state or 

nation, have been designated by a federal, state, or local governmental agency as having 

special status for protection and/or management. Regulatory compliance requirements vary 

based on the authorities under which the species has received designation. The regulatory

framework pertaining to natural habitats and wildlife includes the following key federal and 

state statutes, executive orders, and agency and local government policies:

Federal

Endangered Species Act

The Endangered Species Act of 1973 (ESA), as amended (16 U.S.C. § 1531 et seq.) provides a 

means whereby the ecosystems upon which endangered and threatened species depend may 

be conserved and provides a program for the conservation of such endangered and threatened 

species (Section 1531[b], Purposes). All federal agencies are to seek to conserve endangered 

and threatened species and utilize applicable authorities in furtherance of the purposes of the 

ESA (Section 1531[c][1], Policy). The U.S. Fish and Wildlife Service (USFWS) has primary 

administrative responsibility under the ESA for terrestrial and freshwater organisms, and is 

responsible for the listing of plant and animal species under the ESA on the basis of the best 

scientific and commercial data available on the species’ biological status and threats to its 

existence. Species listed as threatened or endangered, or proposed for such listing, have 

specific protections under the ESA. All federal agencies are required to consult (or confer) with 

USFWS (and/or the National Marine Fisheries Service for marine species) in accordance with 

Section 7 of the ESA if the agency determines that any proposed action may affect a listed 

species. Each agency must ensure that any federal action or activity is not likely to jeopardize 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-118

the continued existence of any species listed or proposed to be listed under the ESA, or result in 

the destruction or adverse modification of designated or proposed critical habitat 

(Section1536[a], Interagency Cooperation, and 50 CFR 402). Section 9 of the ESA prohibits any 

“take” (as defined in the ESA: to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or 

collect, or to attempt to engage in any such conduct) of a listed species. Section 10 of the ESA 

allows for exemptions to the take prohibition, based on incidental take statements issued in 

accordance with Biological Opinions issued under Section 7 consultation or other authorized 

permits. 

Categories of species listed under the ESA are as follows:

 Endangered: Species of plants or animals that have been identified by USFWS or NMFS 

as being in danger of extinction throughout all or a significant portion of its range.

 Threatened: Species of plants or animals that have been identified by USFWS or NMFS 

as being likely to become an endangered species within the foreseeable future 

throughout all or a significant portion of its range.

 Proposed: Species identified by USFWS under the ESA that are proposed in the Federal 

Register to be listed as threatened or endangered.

 Candidate: Species for which USFWS has sufficient information on biological 

vulnerability and threats to support proposals to list them as endangered or threatened.

 Critical Habitat: Specific geographic areas (whether occupied by listed species or not) 

that are determined to be essential for the conservation and management of some 

threatened or endangered species.

 Conservation Agreement: Though not an official listing category, conservation 

agreement species have special management plans that obligate land and resource 

management agencies or other entities to certain conservation actions. The 

implementation of these plans often provides the basis upon which USFWS has 

precluded listing under the ESA.

 Petitioned: Plant or animal species that have been formally requested to be listed by 

the USFWS or National Marine Fisheries Service under the ESA. 

Migratory Bird Treaty Act

The Migratory Bird Treaty Act of 1918 (MBTA), as amended (16 U.S.C. § 703-712), is the 

domestic law that affirms, or implements, the United States’ commitment to four international 

conventions (with Canada, Japan, Mexico, and Russia) for the protection of a shared migratory 

bird resource. Each of the conventions protects selected species of birds that occur in both 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-119

countries at some point during their annual life cycle. The MBTA protects migratory birds and 

their nests, eggs, young, and parts from possession, sale, purchase, barter, transport, import, 

export, and take. For purposes of the MBTA, take is defined as “to pursue, hunt, shoot, wound, 

kill, trap, capture, or collect, or attempt to pursue, hunt, shoot, wound, kill, trap, capture, or 

collect” (50 CFR 10.12). The MBTA applies to migratory birds identified in 50 CFR 10.13. 

Generally speaking, the MBTA protects all birds occurring in the United States except for 

several nonnative species (e.g., house sparrow, European starlings, and rock pigeons), and nonmigratory upland game birds. The USFWS implements and enforces the MBTA; is the lead 

federal agency for managing and conserving migratory birds in the United States; regulates the 

take of migratory birds for educational, scientific, and recreational purposes; and requires that 

harvests be limited to levels that prevent overutilization. Special Purpose Permits under 50 CFR 

2I.27 of the MBTA are required in the event that an action would take, possess, or involve the 

sale or transport of birds protected by the MBTA. 

Executive Order 13186 

Executive Order 13186, Responsibilities of Federal Agencies to Protect Migratory Birds

(10 January 2001) directs federal agencies taking actions that have, or are likely to have, a 

measurable negative effect on migratory bird populations to develop and implement a 

Memorandum of Understanding with USFWS that promotes the conservation of migratory bird 

populations within two years of the date of the order. The order outlines specific requirements 

of the Memorandum of Understanding and 15 conservation measures that agencies are 

encouraged to immediately begin implementing, as appropriate and practicable.

Bald and Golden Eagle Protection Act 

The Bald and Golden Eagle Protection Act of 1940 (BGEPA), and as amended (16 U.S.C. § 668–

668d), prohibits anyone without a permit issued by USFWS from “taking” bald or golden eagles 

including their parts, nests, or eggs. The BGEPA defines “take” as “pursue, shoot, shoot at, 

poison, wound, kill, capture, trap, collect, molest or disturb.” For purposes of these guidelines, 

“disturb” means “to agitate or bother a bald or golden eagle to a degree that causes, or is likely 

to cause, based on the best scientific information available, 1) injury to an eagle, 2) a decrease 

in its productivity, by substantially interfering with normal breeding, feeding, or sheltering 

behavior, or 3) nest abandonment, by substantially interfering with normal breeding, feeding, 

or sheltering behavior.”

Bureau of Land Management Special Status Species Policy

Under the authorities of the Federal Land Policy Management Act of 1976 (43 U.S.C. § 1701

et seq.), the Bureau of Land Management (BLM) manages BLM-administered lands in 

accordance with the regulatory framework of the “multiple use” mandate. Special status 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-120

species are managed in accordance with Manual 6840, Special Status Species Management. The 

manual establishes policy to manage species listed or proposed for listing pursuant to the ESA 

and BLM sensitive species which are found on BLM-administered lands. The BLM special status 

species policy aims to conserve and/or recover listed species and their habitats and to initiate 

proactive conservation measures that reduce or eliminate threats to BLM sensitive species to 

prevent them from requiring listing in the future. The BLM Handbook 6840 defines special

status species as: 1) species listed or proposed for listing under the ESA; and 2) species 

requiring special management consideration to promote their conservation and reduce the 

likelihood and need for future listing under the ESA, which are designated as BLM sensitive by 

the BLM State Director(s).

Executive Order 13112

Executive Order 13112, Invasive Species (64 FR 6183 et seq.) requires federal agencies to 

identify actions that may affect invasive species, use relevant programs to prevent introduction 

of invasive species; detect, respond, and control such species; monitor invasive species 

populations; provide for restoration of native species; conduct research on invasive species; 

and promote public education.

State of Arizona

Title 17 of the Arizona Revised Statutes, Game and Fish

The responsibility for maintenance and management of the state’s wildlife resources lies with 

the Arizona Game and Fish Commission and AGFD. Arizona Revised Statutes (ARS) 17-102 

establishes that most wildlife in Arizona is the property of the state. ARS 17-231 establishes 

that through the Commission, that the AGFD may establish policies and programs for the 

management, preservation, and harvest of wildlife; establish hunting, trapping, and fishing 

rules and prescribe the manner and methods which may be used in taking wildlife; enforce laws 

for the protection of wildlife; and develop and distribute information about wildlife and 

activities of the AGFD. Under the authority of ARS 17-201 et seq., AGFD establishes detailed

rules for licenses and permits, taking and handling of wildlife, possession of live wildlife, 

heritage grants, and wildlife areas among others.

Based on the authorities granted by ARS 17, AGFD maintains lists of wildlife species of concern 

(AGFD 1996). The 1996 list of Wildlife of Special Concern in Arizona remains in draft form and is 

pending approval from the Arizona Game and Fish Commission. This list identifies species in 

Arizona that may be in jeopardy due to known or perceived threats or population declines. The 

listing of wildlife as Wildlife of Special Concern in Arizona is intended to indicate to land 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-121

management agencies those species that should be emphasized in habitat management from 

AGFD’s perspective. 

Arizona has developed a proactive State Wildlife Action Plan (comprehensive wildlife action 

strategy) to assess the health of wildlife and determine strategies to conserve the state’s 

numerous wildlife species, including the full array of wildlife as well as those in greatest need of

conservation, and their associated habitats. A component of the State Wildlife Action Plan

identified Species of Greatest Conservation Need as well as Species of Economic and Recreation 

Importance, and the need for strategies to minimize and offset potential impacts to these 

species. 

Arizona Native Plant Law

The Arizona Native Plant Law of 1993 (ARS 7, 3-901 et seq.) is administered by the Plant 

Industries Division of the Arizona Department of Agriculture. The law identifies protected plants 

belonging to the following four categories: 

 Highly Safeguarded: Those Arizona native plants whose prospects for survival in the 

state are in jeopardy or that are in danger of extinction throughout all or a significant 

portion of their ranges, or are likely to become so in the foreseeable future, including 

federally listed species.

 Salvage Restricted: Those Arizona native plants that are not included in the highly 

safeguarded category but are subject to damage by theft or vandalism.

 Salvage Assessed: Those Arizona native plants that are not included in either the highly 

safeguarded or salvage restricted category but have a sufficient value if salvaged to 

support the cost of salvage.

 Harvest Restricted: Those Arizona native plants that are not included in the highly 

safeguarded category but are subject to excessive harvesting or overcutting because of 

their intrinsic value.

The most protective category, and the category most directly parallel to the protection afforded 

wildlife species, is highly safeguarded. Species falling into the salvage restricted, salvage 

assessed, or harvest restricted categories pertain to the commercial salvage; removal for sale;

and harvest of certain plant species that are vulnerable to theft, vandalism, or over-utilization. 

Protection for these native species is through a process of notification to the Arizona 

Department of Agriculture prior to destruction of the plants.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-122

Arizona Executive Order 13112

Arizona Invasive Species Executive Order 13112, dated February 3, 1999, establishes that all 

projects will, “subject to the availability of appropriations, and within Administration budgetary 

limits, use relevant programs and authorities to: 1) prevent the introduction of invasive species; 

2) detect and respond rapidly to, and control, populations of such species in a cost-effective 

and environmentally sound manner; 3) monitor invasive species populations accurately and 

reliably; and 4) provide for restoration of native species and habitat conditions in ecosystems 

that have been invaded.” In Arizona, an invasive species is one that is not native to the 

ecosystem under consideration and whose introduction causes, or is likely to cause, economic 

or environmental harm or harm to human health (AGFD 2013c). 

Pima County

Pima County Native Plant Ordinance 

The Pima County Native Plant Ordinance (Pima County Zoning Code §§ 18.72.500-508)

establishes that when natural lands are to be developed, a Native Plant Preservation Plan may 

be required for the conservation of native species and setting aside lands as open space.

Pima County Sonoran Desert Conservation Plan

The Pima County Sonoran Desert Conservation Plan (SDCP), passed in 1998 (Pima County 

Resolution 1998-250), is part of a land management plan for the County that incorporates 

conservation and protection of natural and cultural resources with community development. 

The plan, which entered into an agreement with the Department of the Interior (USFWS), 

considered the following elements: critical habitats and biological corridors, riparian areas, 

mountain parks, historical and cultural preservation, and ranch conservation. The land-use 

policies and conservation principles developed from the SDCP were incorporated into the 2001 

Pima County Comprehensive Land Use Plan. A Multi Species Conservation Plan, a component of 

the SDCP, manages compliance with the ESA. Primary Conservation Areas are established for 

individual species to maintain sufficient habitat and guide development in those areas. The 

Conservation Lands System (CLS), also a result of the SDCP, identifies lands for conserving open 

space and habitat for native species in relation to those lands suitable for development. The CLS 

established Special Species Management Areas, Multiple Use Management Areas, and 

Important Riparian Areas with guidelines for maintaining natural open space within these areas. 

Pima County conservation of native wildlife and plant species and land management are guided 

by these plans.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-123

Methodology

For the analysis of potential impacts of a passenger rail system to biological resources, 

GIS-based data were used to evaluate the corridor alternatives from a landscape perspective by 

overlaying the corridor alternatives with biological resource data, such as vegetation 

communities, wildlife corridors and habitat linkage zones, special land management 

designations that preserve natural habitat, unfragmented habitat blocks, riparian and wetland 

areas, waterways, special status species occurrences, and the degree to which adjacent land 

uses may have modified natural habitat. Online data sources available from USFWS and AGFD 

were used to acquire relevant site-specific data. The assessment considered the sensitivity of 

each of these resource categories and their associated wildlife, wildlife habitat, and each of 

their special status species to disturbances and habitat loss. 

As a result of ADOT’s coordination with agency stakeholders, AGFD provided an independent 

analysis of the corridor alternatives (see the Natural Habitats and Wildlife Appendix). 

5.12.2 Existing Conditions

The three-county study corridor crosses a large geographic area within the Sonoran Desert 

region of Arizona, spanning a distance of approximately 115 miles from Tucson north to 

Phoenix. The corridor alternatives include some lands that are in mostly natural condition, as 

well as lands that have been highly modified for urban and agricultural purposes. Generally, as 

the corridor alternatives approach the vicinity of Tucson and Phoenix, natural habitats become 

increasingly degraded, giving way to agricultural and urban development. Transportation 

facilities such as an interstate highway, state highways, local roadways, and existing railroads 

are included within portions of the corridor alternatives. The Central Arizona Project (CAP) 

canal runs adjacent to segments of the corridor alternatives. This section of the Tier 1 EIS 

describes in general the biotic communities, wildlife and their associated movement corridors, 

and habitat for special status plant and animal species expected in the vicinity of the corridor 

alternatives.

Biotic Communities

The two corridor alternatives being evaluated in this Tier 1 EIS are within the Sonoran Desert, 

one of the largest and hottest deserts in North America. The corridor alternatives range in 

elevation from approximately 2,400 feet elevation in Pima County (Tucson area) down to 

approximately 1,100 feet elevation in Maricopa County (Phoenix area). The topography crossed 

by the corridor alternatives consists primarily of broad, flat, low-lying desert valleys and bajadas

(i.e., alluvial fans) within the general vicinity of various isolated mountain ranges (e.g., the 

Tortolita Mountains, Picacho Peak, Picacho Mountains, Superstition Mountains, Sierra Estrella 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-124

Mountains, and South Mountain) and dry river systems (e.g., Santa Cruz, Gila, and Salt rivers, 

and Queen Creek Wash).

Natural habitats of the Sonoran Desert biotic community in the vicinity of the corridor 

alternatives are primarily represented by two major vegetation subdivisions (also referred to as 

vegetation series): 1) the Lower Colorado River Valley Sonoran Desertscrub; and 2) the Arizona 

Upland Sonoran Desertscrub (Turner 1982). In addition, Desert Wash Mixed Scrub communities 

follow wash channels crossing both subdivisions, and remnant stands of Sonoran Riparian 

Deciduous Forests and mesquite bosques (i.e., woodlands) are scattered along the major 

drainage systems in the region. Precipitation, though unreliable and uneven, follows a bimodal 

pattern, with rains primarily in the summer and winter (see Figure 5-16).

Past and ongoing development activities between Tucson and Phoenix have resulted in the loss 

of vast areas of native plants and extensive conversion of desert habitats to agricultural fields, 

irrigation canals, housing developments, golf courses, transportation ROW, and abandoned 

lands. Roads, railroads, and property and ROW fencing have influenced wildlife movement

patterns and denied wildlife access to many areas. High-speed traffic and human activities have 

resulted in the deaths of many animals.

Sonoran Desert Lower Colorado River Valley Subdivision 

The Lower Colorado River Valley Subdivision occurs mostly on the valley floors and is 

represented by creosote bush and white bursage associations, often with or replaced by several 

species of saltbush. The various creosote bush desertscrub associations typically occur where 

soil composition is proportionately high in silt and clay. Other plant species that may be 

present, often on rocky slopes, in gravelly soils, or along dry washes, include various species of 

shrubs (e.g., jojoba, cholla, ocotillo, and brittlebush) and scattered trees (e.g., foothill palo

verde, mesquite, ironwood, and saguaro) (Turner and Brown 1982). 

The presence of wildlife species is often in response to soil conditions that influence vegetative 

diversity, density, and structure. At the base of plants in creosote bush habitats where the soils 

are friable (i.e., not compacted or hardpan), many rodent burrows are often found that may 

also be used by many species of lizards and snakes. In areas where the shrubs provide a 

relatively dense canopy cover, species such as pocket mice, deer mice, and side-blotched lizards 

may be found; open areas and where canopy cover is sparse provide habitat for species such as 

kangaroo rats, burrowing owls, and zebra-tailed lizards. Creosote bush habitats are notably

lacking in breeding bird diversity, due in part to the limited vegetative structural diversity

(Turner and Brown 1982). Birds commonly breeding in these habitats include black-throated 

sparrow, common poorwill, and lesser nighthawk. The abundance of rodents inhabiting these
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Existing Conditions and Environmental Consequences

Figure 5-16. Vegetation Communities throughout the Study Area

5

Final Tier 1 Environmental Impact Statement 5-125

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5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-126

areas attracts a variety of predators such as coyote, kit fox, American badger, and, seasonally, 

various avian birds of prey such as red-tail hawk and American kestrel.

The two corridor alternatives intersect four major desert river systems—the Salt, Gila, and 

Santa Cruz rivers and Queen Creek Wash. These rivers are largely dewatered, have limited flows 

associated with storm events or effluent runoff (e.g., the Santa Cruz River near Marana), or 

include managed waters in urban settings (e.g., Tempe Town Lake). Remnant stands of riparian 

vegetation occur where subsurface flows rise and are available to cottonwood, willow, and salt 

cedar trees. In addition, mesquite bosques, greatly reduced in extent from historic times, are

associated with floodplains of major river systems. No permanent natural aquatic habitats or 

flowing streams are present within the corridor alternatives.

Sonoran Desert Arizona Upland Subdivision 

Arizona Upland Subdivision habitat is characterized by greater diversity of vegetation and more 

complex vertical structure (Turner and Brown 1982). It is primarily found on mountains, hills, 

bajadas, and rocky slopes and consists primarily of the palo verde-mixed cacti-mixed scrub 

associations. The Arizona Upland Subdivision comprises a variety of trees, shrubs, and cacti, as 

well as those species represented in the Lower Colorado River Valley Subdivision. This 

community is often dominated by palo verde, saguaro, and various shrubs, including triangleleaf bursage. Along the two corridor alternatives, the Arizona Upland Subdivision reaches its 

greatest development on the bajadas in the Picacho Pass vicinity but is still largely transitional 

with the Lower Colorado River Valley Subdivision. 

Arizona Upland habitats support a diverse wildlife community which includes desert bighorn 

sheep, mule deer, javelina, coyote, black-tailed jackrabbit, desert tortoise, numerous species of 

lizards and snakes (e.g., western whiptail lizard, collared lizard, common kingsnake, long-nosed 

snake, and western diamondback rattlesnake) and a variety of desert-adapted amphibians (e.g., 

Sonoran desert toad, Great Plains toad, and Couch’s spadefoot toad). Caves, crevices, 

abandoned mineshafts found in the nearby mountains, and highway bridges and box culverts 

associated with transportation corridors provide roosting and nursery colony sites for many bat 

species. Many species of breeding birds also occur in these habitats including Gambel’s quail, 

turkey vulture, Harris hawk, Gila woodpecker, Say’s phoebe, and curved-billed thrasher. Many 

other bird species commonly migrate through or winter in Arizona Upland habitats. The Arizona 

Upland community includes most of the species within the Lower Colorado River Valley 

community but often at higher densities; however, many of the species from the Arizona 

Upland community are not found within the hotter and drier Lower Colorado River Valley 

community.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-127

Desert Wash Mixed Scrub and Remnant Riparian Habitats

Often referred to as xeroriparian communities, desert washes generally include many of the 

same plant species found in upland areas, achieving more lush growth and greater densities 

due to the increased availability of surface and/or subsurface water. Blue palo verde, ironwood, 

and mesquite are important trees along these washes. Also, big galleta, a drought-tolerant 

native grass, is often found along washes and drainage channels. Its dense, clumped growth 

form captures soils and reduces the potential for soil erosion and provides cover for small 

mammals, reptiles, and birds.

Desert washes and riparian vegetation provide diverse wildlife habitats. Wildlife, especially 

birds, large mammals, and invertebrates, make disproportionate use of desert washes and 

riparian habitat in comparison to surrounding communities. The increased diversity and density 

of vegetation along the washes provide more seeds and vegetation for herbivores, prey for 

predators, a variety of nest and perch sites, hiding and thermal cover, movement corridors, and 

moisture for wildlife than is available in surrounding habitats. Organic material composed of 

leaf litter and other vegetative debris that is present within the xeroriparian and riparian 

communities provides an important source of nutrients for plants and animals, as well as 

providing cover and nesting material for some animals.

Xeroriparian and riparian habitats support a diverse array of nesting bird species and represent 

an important stop-over habitat for migrating birds. Representative breeding species include 

western screech-owl, verdin, black-tailed gnatcatcher, and Lucy’s warbler. Where deciduous 

riparian trees are present, numerous other birds may be found, including summer tanager, 

kingbirds, and vermillion flycatcher; the larger the stand of riparian trees, the greater the 

diversity of the bird community. Neotropical migrants such as western tanager, MacGillivray’s 

warbler, Swainson’s thrush, ruby-crowned kinglet, and tree swallow pass through the 

Southwest deserts during the flowering periods of palo verde, mesquite, and ironwood. These 

flowering events support a rich insect fauna which provides forage for a variety of migrating 

and resident birds and bats.

Large mammalian species, such as mule deer, depend on xeroriparian and riparian habitats for 

forage, shade, cover, and secluded areas for fawning. Habitat complexity along rivers, washes, 

and drainage channels due to their associated bordering vegetation represent very important 

movement corridors for wildlife. Small mammals forage on the seeds and/or other vegetation 

from the relatively rich flora associated with the xeroriparian and riparian communities. The 

insectivorous California leaf-nosed bat, which does not hibernate or migrate, forages yearround along these dry washes. Many reptile species also occur in xeroriparian habitats where 

lizards forage on a diversity of insects, and rodents and lizards are available for snakes.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-128

Wildlife Linkages

Large mammals, such as mule deer, desert bighorn sheep, javelina, bobcat, and mountain lion 

may range widely across the landscape in search of food and water or in response to changing 

environmental factors, often following seasonal movement patterns. Drainage channels lined 

with dense vegetation are often used as corridors for wildlife movement, providing both cover 

and forage. Natural and man-made barriers to wildlife movement may prevent animals from 

reaching important resources and/or limit the availability of habitats that may otherwise 

become occupied.

Man-made features such as highways, fences, railroads, and irrigation canals found throughout 

the vicinity of the corridor alternatives may become partial or complete barriers to movement 

of some wildlife species. Major transportation corridors in the vicinity of the corridor 

alternatives include I-10, SR 87, and the UP railroad. The effect of highways as barriers to large 

mammal movements may be attributed to ROW fencing, traffic volume, noise, human 

presence, and possibly the speed of traffic. Additionally, surrounding land uses may reduce 

wildlife access to traditional movement corridors. Animal movements may be restricted by 

areas of sparse vegetation cover, especially in areas of human activity. Though most animals 

would typically move across the landscape using natural corridors such as washes, some 

individuals are also likely to cross open roadways, increasing the potential for vehicle-wildlife 

collisions.

The Arizona Wildlife Linkages Workgroup (AWLW) is a cooperative effort among ADOT, USFWS, 

BLM, AGFD, and other federal and state agencies, academic institutions, and conservation 

organizations. This workgroup identified 152 potential habitat linkage zones in Arizona that are 

important to wildlife, 28 of which were recognized as high priority (AWLW 2006). Linkages 

address habitat fragmentation and connectivity among habitat blocks used by wildlife. The 

corridor alternatives intersect four wildlife linkage zones; the lengths of these intersections are 

shown in Table 5-19. These numbers are a function of the corridor alternatives’ length; 

changing the corridor width would have no effect on the numbers. None of the linkage zones 

intersected was ranked as high priority from a statewide perspective. Wildlife linkage zones are 

continually refined through county-level habitat connectivity assessments and have been 

expanded to recognize diffuse movement areas for wildlife, riparian corridor movement areas, 

and landscape level movement areas (Figure 5-17). Various wildlife movement corridors 

intersect with the two corridor alternatives.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-129

Table 5-19. Wildlife Linkage Zones Intersecting the Yellow and Orange Corridor Alternatives

Linkage

Yellow Corridor 

Alternative (miles)

Orange Corridor 

Alternative (miles)

Saguaro-Tortolita 55.98 5.98

Ironwood-Tortolita 4.08 4.08 

Central Arizona Project Canal 8.15 21.77a

Queen Creek-Gila River Indian Community 2.09 1.10 

Source: AWLW 2006

aThe Orange Corridor Alternative parallels and encompasses more than 20 miles of CAP Canal ROW

AWLW has also identified habitat fracture zones, which are areas of reduced wildlife 

movement. Fracture zones occur in Arizona State Trust Land, private holdings, and 

transportation corridors. Within these zones, roads, railroads, border security operations, and 

other built features and human activity limit or prevent animal movement or threaten to do so 

in the foreseeable future. Washes, streams, and rivers in these fracture zones may continue to 

serve in some capacity as wildlife movement corridors. Certain types of improvements to 

culverts and bridges can help to promote wildlife movement (AWLW 2006). A passenger rail 

system may present opportunities to improve wildlife connectivity by siting the corridors to 

minimize habitat and connectivity fragmentation, identifying current and potential important 

wildlife movement areas, and designing facilities to provide maximum permeability for safe 

wildlife movement.

While most lands within the corridor alternatives are privately owned, other land owners in the 

corridor alternatives include Bureau of Reclamation, BLM, National Park Service, tribal lands (Gila 

River Indian Reservation and Salt River Pima-Maricopa Indian Reservation), ADOT, Arizona State 

Parks, and Arizona State Land Department (ASLD) (see Table L-3 in the Land Use Appendix). Public 

lands within the corridor alternatives administered by BLM are managed for multiple use, such as 

habitat management, grazing by livestock, and recreation. No USFWS-managed national wildlife 

refuges, national forests managed by the US Forest Service, or designated wilderness areas are 

located within the corridor alternatives; however, some lands in close proximity to the corridor 

alternatives are minimally developed and may serve as habitat for wildlife.
Florence

Marana

Tucson

Eloy

Coolidge

Casa

Grande

Maricopa

Tempe Gilbert

Phoenix

Oro 

Valley

PINAL COUNTY

PIMA COUNTY

MARICOPA COUNTY

PINAL COUNTY

GILA COUNTY

PINAL COUNTY

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Sacaton

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Pima-Maricopa

 Indian Community

Santa Cruz River

Salt River

Gila River

Queen Creek

Chandler

Superior

Glendale

Scottsdale

Apache

Junction

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Tucson

Mountain

Park

Tortolita

Mountains Santa Catalina

Mountains

Pusch

Ridge

Wilderness

Saguaro 

National

Park

Ironwood

Forest

National

Monument

Picacho Peak

State Park

San Tan

Park

T o n t o

N a t i o n a l F o r e s t

Lost Dutchman

State Park

South

Mountain Park

S u p e r s t i t i o n

W i l d e r n e s s

F o u r P e a k s

W i l d e r n e s s

San

Tan

Valley

Catalina

Foothills

Guadalupe

eTucson

International

Airport

Existing Conditions and Environmental Consequences

Figure 5-17. Wildlife Linkages within the Study Corridor

5

Final Tier 1 Environmental Impact Statement 5-130

e

Airport

Interstate

State or US Highway

Railroad

Major Drainage

Movement Areas

Diffuse Movement Area (Wildlife

Movement Within a Habitat Block)

Landscape Movement Area (Wildlife

Movement Between Wildland Blocks)

Riparian Movement Area (Wildlife

Movement Through Riparian Habitat)

Land Management

Federal Land

National Forest or Park

State Trust Land

Tribal Land

Open Space or State Park

Habitat Block

City Boundary

Le g e nd

0 5 10

Miles

Sources: Arizona Game and Fish Department 2013;

Arizona Department of Transportation 2013;

Esri 2014; Arizona State Resource Information System 2013

N

e
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-131

Table 5-20 identifies land ownership and specially designated land management areas near the 

corridor alternatives and the nearest distance to the identified lands. 

Table 5-20. Proximity of the Yellow and Orange Corridor Alternatives to Specially Designated 

Lands

Special Land Management Designation

(listed from south to north)

Nearest Distance to the Yellow 

Corridor Alternative

Saguaro National Park 1.19 miles

Pusch Ridge Wilderness 5.23 miles 

Coronado National Forest 5.14 miles

Ironwood Forest National Monument 4.53 miles

San Tan Mountain Regional Park 2.46 miles

Tonto National Forest 9.96 miles

Papago Park 1.25 miles

The Corridor Alternatives encroach within the borders of Picacho Peak State Park, administered 

by Arizona State Parks, between Marana and Eloy. The corridor is located along the edge of the 

park, so that portions of its 1-mile width encroach within the park boundary while other parts 

of the corridor lie outside the park. 

Special Status Species

Special status species include plant and animal species that have received special designations 

by a federal, state, or local governmental agency due to concerns of rarity and/or a species’ 

sensitivity to perturbations in the environment. 

ESA Species

Species lists and information available online from the USFWS Information, Planning, and 

Conservation system (IPAC) (accessed November 4, 2014; species status designations updated 

February 2015) on ESA-threatened, endangered, proposed, candidate, petitioned, and 

conservation agreement species potentially occurring in Pima, Pinal, and Maricopa counties 

were reviewed to determine if any of these species could potentially occur in the vicinity of the 

corridor alternatives. Each ESA species included on the USFWS IPAC list is addressed in

Table 5-21, providing information on habitat and distribution to determine the likelihood that 

habitat for the species may be present in the vicinity of the corridor alternative.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-132

Table 5-21. Endangered Species Act Species occurring in Pima, Pinal, and Maricopa Counties, Arizona, and Their Potential to Occur 

in the Vicinity of the Yellow and Orange Corridor Alternatives

Common Name Scientific Name Status Habitat Requirement Potential to Occur

Birds

cactus ferruginous 

pygmy-owl

Glaucidium 

brasilianum 

cactorum

Petitioned

(Pima)

Areas of desert woodlands with tall canopy cover. 

Primarily found in Sonoran desertscrub and 

occasionally in riparian drainages and woodlands 

within semi-desert grassland communities. Prefers to 

nest in cavities in saguaro cacti but has been found in 

low-density suburban developments that include 

natural open spaces. Elevation less than 4,000 feet

Suitable habitat may occur 

throughout the vicinity of the 

corridor alternatives. A special 

species management area has been 

identified by Pima County east of I-10 

between Tucson north to the county 

line.

California least tern Sterna antillarum 

browni

E Open, bare, or sparsely vegetated sand, sandbars, 

gravel pits, or exposed flats along shorelines of inland 

rivers, lakes, reservoirs, or drainage systems. 

Elevation less than 2,000 feet

If present, most likely to occur as 

migrants; occasional breeding 

documented in Arizona. Though not 

documented in the vicinity of the 

corridor alternatives, habitat may 

possibly occur at Picacho Reservoir in 

some years.

Mexican spotted owl Strix occidentalis 

lucida

T Nests in canyons and dense forests with multilayered 

foliage structure. Elevation ranges between 4,100 

and 9,000 feet

No suitable habitat within the vicinity 

of the corridor alternatives.

southwestern willow

flycatcher

Empidonax trailii 

extimus

E

(Pima)

Cottonwood/willow and tamarisk vegetation 

communities along rivers and streams. Elevation less 

than 8,500 feet

Though not documented along the 

Salt River, suitable habitat may occur 

in the vicinity of the corridor 

alternatives upstream of Tempe 

Town Lake. A special species 

management area has been 

identified by Pima County east of I-10 

between Tucson north to the county 

line.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-133

Table 5-21. Endangered Species Act Species occurring in Pima, Pinal, and Maricopa Counties, Arizona, and Their Potential to Occur 

in the Vicinity of the Yellow and Orange Corridor Alternatives

Common Name Scientific Name Status Habitat Requirement Potential to Occur

Sprague's pipit Anthus spragueii C Strong preference to native grasslands with 

vegetation of intermediate height and lacking woody 

shrubs. Elevation less than 5,000 feet

Species current geographic range is 

outside the vicinity of the corridor 

alternatives.

western yellow-billed 

cuckoo

Coccyzus americanus T

PCH

(WSC, Pima)

Large blocks of riparian woodlands; cottonwood, 

willow, or tamarisk galleries. Proposed Critical 

Habitat includes Picacho Reservoir. Elevation less 

than 6,500 feet

Proposed critical habitat in the 

vicinity of the corridor alternatives

includes Picacho Reservoir. 

Additionally, suitable habitat may 

occur in association with Santa Cruz, 

Gila, and Salt rivers in the vicinity of 

the corridor alternative. 

Yuma clapper rail Rallus longirostris 

yumanensis

E Freshwater and brackish marshes. Elevation less than 

4,500 feet

Old occurrence records at Picacho 

Reservoir, with potentially suitable 

habitat associated with the Gila and 

Salt rivers in the vicinity of the 

corridor alternatives. 

Fish

roundtail chub Gila robusta C Cool to warm waters of rivers and streams; occupies 

deepest pools and eddies of large streams. Elevation 

ranges between 1,000 and 7,500 feet

Species geographic range is outside

the vicinity of the corridor 

alternatives.

Mammals

jaguar Panthera onca E Found in Sonoran desertscrub up through subalpine 

conifer forest. Elevation ranges between 1,600 and 

9,000 feet

Species current geographic range is 

outside the vicinity of the corridor 

alternatives.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-134

Table 5-21. Endangered Species Act Species occurring in Pima, Pinal, and Maricopa Counties, Arizona, and Their Potential to Occur 

in the Vicinity of the Yellow and Orange Corridor Alternatives

Common Name Scientific Name Status Habitat Requirement Potential to Occur

lesser long-nosed bat Leptonycteris 

curasoae 

yerbabuenae

E

(WSC, Pima)

Desertscrub habitat with agave and columnar cacti 

present as food plants. Day roosts in caves and 

abandoned tunnels. Forages at night on nectar, 

pollen, and fruit of paniculate agaves and columnar 

cacti. Species is migratory and present in Arizona 

usually April to September. Elevation ranges between 

1,600 and 7,500 feet

Known occurrences within the 

vicinity of the corridor alternatives

south of the Gila River. Foraging 

habitat may occur in association with 

stands of saguaro or agave.

Sonoran pronghorn Antilocapra 

americana 

sonoriensis

E Broad intermountain alluvial valleys with creosotebursage and palo verde-mixed cacti associations. 

Elevation ranges between 2,000 and 4,000 feet

Species current geographic range is 

outside the vicinity of the corridor 

alternatives.

Reptiles

northern Mexican 

gartersnake

Thamnophis eques 

megalops

T

PCH

(WSC)

Cienegas, stock tanks, large-river riparian woodlands 

and forests, streamside gallery forests. Elevation 

ranges between 130 and 8,500 feet

Suitable habitat in Pima County 

associated with the Santa Cruz River 

system in the vicinity of the corridor 

alternatives. 

Sonoran desert 

tortoise

Gopherus morafkai C*

(WSC)

Primarily rocky hillsides (often steep) and bajadas of 

Mohave and Sonoran desertscrub; but may encroach 

into desert grassland, juniper woodland, interior 

chaparral habitats, and even pine communities. 

Washes and valley bottoms may be used in dispersal.

Elevation less than 7,800 feet

Suitable habitat exists throughout 

desert habitats in the vicinity of the 

corridor alternatives.

Sonoyta mud turtle Kinosternon 

sonoriense 

longifemorale

C

(WSC)

Ponds and streams. Found only in Quitobaquito

Springs in Organ Pipe Cactus National Monument, 

Arizona. Species also occurs in Rio Sonoyta, Sonora, 

Mexico. Elevation less than 1,100 feet

Species geographic range is outside

the vicinity of the corridor 

alternatives.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-135

Table 5-21. Endangered Species Act Species occurring in Pima, Pinal, and Maricopa Counties, Arizona, and Their Potential to Occur 

in the Vicinity of the Yellow and Orange Corridor Alternatives

Common Name Scientific Name Status Habitat Requirement Potential to Occur

Plants

Pima pineapple 

cactus

Coryphantha scheeri 

var. robustispina

E

(HS, Pima)

Sonoran desertscrub or semidesert grassland 

communities. Elevation ranges between 2,300 and 

5,000 feet

Species geographic range is outside

the vicinity of the corridor 

alternatives.

Source: USFWS IPAC 2014. 

E = Listed as Endangered under the ESA; 

T = Listed as Threatened; 

PT = Proposed for Listing as Threatened; 

C = Candidate species for listing; 

*Sonoran desert tortoise was removed from the ESA-listed species, and a Candidate 

Conservation Agreement was signed between USFWS, ADOT, AGFD, and several 

federal agencies in May 2015. 

Petitioned = Petitioned for Listing; 

PCH= Proposed Critical Habitat 

WSC = Wildlife of Special Concern in Arizona

HS = Highly Safeguarded under Arizona Native Plant Law

Pima = Species of Special Concern in Pima County
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-136

State Designated Species of Special Concern and Protected Native Plants; BLM 

Sensitive Species; and Pima County Species of Special Concern

The AGFD Environmental Review Online Tool was accessed July 2013 (Online Tool receipt AGFD 

2013b). Table 5-22 lists special status species with occurrence records within 3.0 miles of the 

corridor alternatives as recorded in AGFD’s Heritage Data Management System, the most 

comprehensive listing of rare species data for the state. This table includes AGFD Species of 

Special Concern in Arizona, plants listed by the Arizona Department of Agriculture as highly 

safeguarded under the Arizona Native Plant Law, BLM designated sensitive species, and Pima 

County Species of Special Concern. Table 5-22 includes information on species habitat and 

distribution to determine the likelihood that habitat for these species may be present in either 

of the two corridor alternatives. Species previously noted in Table 5-21 based on their ESA 

status that also hold special status on the state or BLM lists are referenced only in Table 5-21

and not repeated in Table 5-22.

State Designated Species of Greatest Conservation Need and Species of Economic and 

Recreation Importance 

The AGFD Environmental Review Online Tool lists species of high conservation need and species 

of economic importance. Species that the State identified as most in need of conservation 

actions are evaluated through the distribution and abundance of the species, including low and 

declining populations that are indicative of the diversity and health of the State’s wildlife. These 

species are ranked based on vulnerability criteria, including whether still present in Arizona, 

their federal or state status, their numbers and concentration, and their distribution, 

demographics, and extent of fragmentation. They are then tiered with those that are 

vulnerable designated a 1A, and those being vulnerable but not falling within other 

conservation criteria designated a 1B species.

Species that generate revenue, provide spending opportunities, or support jobs within the 

State’s economy include those that are hunted, fished, and/or are valued for watchable wildlife 

recreation opportunities. Table 5-23 includes Species of Greatest Conservation Need and 

Species of Economic and Recreation Importance that would have potential to occur along a 

passenger rail system within the selected corridor.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-137

Table 5-22. Arizona Species of Special Concern, Highly Safeguarded Native Plants, BLM-Designated Senitive Species, and Pima 

County-Designated Species of Special Concern Potentially Occuring in or near the Yellow and Orange Corridor Alternatives.

Common Name Scientific Name Status Habitat Requirements Potential to Occur

Amphibians

lowland leopard frog Rana yavapaiensis BLM

WSC

Sonoran Desert, grassland, oak and oak-pine 

woodland in rivers, streams, cienegas, springs, 

stock tanks, canals, irrigation sloughs, and 

backyard ponds/pools. Elevation ranges 

between 480 and 6,200 feet

Suitable habitat is present in the 

vicinity of the corridor alternatives;

frogs may occur where suitable 

water sources are present. 

western narrowmouthed toadGastrophryne olivacea BLM

WSC

Pima

Mesquite semi-desert grassland to oak 

woodland near streams, springs, or rain pools. 

Elevation less than 4,700 feet

Suitable habitat is present in Pima 

County primarily associated with 

the Santa Cruz River system; 

individuals documented from the 

vicinity of the corridor alternatives.

Birds

Abert’s towhee Melozone aberti Pima Associated with brushy understory of 

cottonwood-willow riparian habitat and 

mesquite bosques along stream sides in the 

lower Colorado River and Gila River valleys. 

Elevation range less than 4,000 feet 

Suitable habitat is present in the 

vicinity of the corridor alternatives 

in Pima County.

bald eagle Haliaeetus 

leucocephalus

BLM

WSC

Large trees or cliffs near water (reservoirs, 

rivers, and streams) with abundant prey; varies 

in elevation.

Species known to nest and forage 

along Salt River within the vicinity 

of the corridor alternatives.

Bell’s vireo Vireo bellii Pima Dense, low, shrubby vegetation associated with 

willows, streamside thickets, chaparral, 

woodland edges and riparian areas.

Suitable habitat is present in the 

vicinity of the corridor alternatives 

in Pima County primarily associated 

with riparian areas.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-138

Table 5-22. Arizona Species of Special Concern, Highly Safeguarded Native Plants, BLM-Designated Senitive Species, and Pima 

County-Designated Species of Special Concern Potentially Occuring in or near the Yellow and Orange Corridor Alternatives.

Common Name Scientific Name Status Habitat Requirements Potential to Occur

black-bellied whistlingduckDendrocygna 

autumnalis

WSC Ponds, stock tanks, rivers, marshes; nests in 

dense thickets, tree cavities, and on the ground 

near water. Elevation ranges between 985 and 

4,200 feet

Suitable habitat is present 

throughout the vicinity of the 

corridor alternatives; may occur in 

association with rivers, stock tanks, 

and irrigation ponds. 

golden eagle Aquila chrysaetos BGEPA

BLM

Mountainous areas; often migrates after 

breeding in some desert areas. Territories up to 

25 square miles. Elevation ranges between 

4,000 and 10,000 feet

No suitable nesting habitat occurs 

within the vicinity of the corridor 

alternatives.

great egret Ardea alba WSC Marshes, streams, lakes, rivers, ponds, fields, 

and meadows. Elevation less than 1,500 feet 

Suitable habitat exists throughout 

the vicinity of the corridor 

alternatives.

least bittern Ixobrychus exilis WSC Dense cattail/bulrush marshes interspersed

with open water. Elevation ranges between 850

and 1,500 feet 

Old occurrence records in the 

vicinity of the corridor alternatives

from Picacho Reservoir where 

suitable habitat may be present in 

some years.

rufous winged sparrow Peucaea carpalis Pima Desert grasslands scattered with thorn bushes, 

bunch grasses, mesquite, or cholla. Also occurs 

in washes with sandy bottoms and vegetated 

slopes, brushy irrigation ditches, and creeks 

bordered by broad-leaved trees, mesquite, 

grasses, and weeds. 

Suitable habitat is present in the 

vicinity of the corridor alternatives 

in Pima County.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-139

Table 5-22. Arizona Species of Special Concern, Highly Safeguarded Native Plants, BLM-Designated Senitive Species, and Pima 

County-Designated Species of Special Concern Potentially Occuring in or near the Yellow and Orange Corridor Alternatives.

Common Name Scientific Name Status Habitat Requirements Potential to Occur

Swainson’s hawk Buteo swainsoni Pima Open habitats for foraging including plains, dry 

grassland and agricultural lands. Uses scattered 

stands of trees near agricultural fields and

grasslands for nesting sites.

Suitable foraging habitat is present

throughout the vicinity of the 

corridor alternatives in Pima 

County.

tropical kingbird Tyrannus 

melancholicus

WSC Scattered trees, open woodland, residential 

areas and agricultural lands, and in lowlands 

near water of southeast Arizona. Elevation 

ranges between 1,070 and 4,100 feet

Species geographic range is outside

the vicinity of the corridor 

alternatives.

western burrowing owl Athene cunicularia 

hypugaea

BLM

Pima

Open, well-drained grasslands, deserts, 

agricultural lands, golf courses, and airports;

often associated with burrowing mammals.

Elevation ranges between 650 and 6,140 feet

Suitable habitat is present, and 

occurrences have been 

documented throughout the 

vicinity of the corridor alternatives, 

especially associated with 

agricultural lands north of Eloy.

Fish

desert sucker Catostomus clarkii BLM Found in rapids of flowing streams and rivers,

primarily over gravel-rubble with sandy silt

substrate. Occurs in the Salt and Gila river 

drainages. Elevation ranges between 480 and 

8,840 feet

Known occurrence along Salt River 

within the vicinity of the corridor 

alternatives.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-140

Table 5-22. Arizona Species of Special Concern, Highly Safeguarded Native Plants, BLM-Designated Senitive Species, and Pima 

County-Designated Species of Special Concern Potentially Occuring in or near the Yellow and Orange Corridor Alternatives.

Common Name Scientific Name Status Habitat Requirements Potential to Occur

Mammals

Allen’s big-eared bat Idionycteris phyllotis Pima Ponderosa pine, pinyon-juniper, pine-oak 

woodland, and riparian habitats of sycamores, 

cottonwoods and willows; roosts in mines, 

caves, and rock shelters. Elevation ranges 

between 2,600 to 9,800 feet

Species geographic range is outside

the vicinity of the corridor 

alternatives within Pima County.

Arizona shrew Sorex arizonae WSC,

Pima

Found primarily in rocky, narrow canyons with 

riparian areas bordered by pine-oak forests, 

usually near surface water. Found in the 

mountains of southeastern Arizona (Huachuca, 

Santa Rita, and Chiricahua mountains).

Species geographic range is outside

the vicinity of the corridor 

alternatives within Pima County.

California leaf-nosed bat Macrotus californicus BLM

WSC

Sonoran desertscrub; roosts in mines, caves, 

and rock shelters. Elevation less than 4,000 feet 

Species occurs across desert 

habitats of Arizona, including the 

vicinity of the corridor alternatives.

cave myotis Myotis velifer BLM Sonoran desertscrub; roosts in caves, tunnels, 

and mines, as well as under bridges. Elevation 

ranges between 300 and 5,000 feet

Known occurrences throughout the 

vicinity of the corridor alternatives.

Merriam’s mouse Peromyscus merriami WSC,

Pima

Found in mesquite bosques, and dense brush in 

the low desert associated with mesquite. The 

mouse has been found in areas of Organ Pipe 

National Monument, Sabino Canyon, Arivaca, 

Baboquivari Mountains, San Xavier, and Fort 

Lowell.

Suitable habitat is present in the 

vicinity of the corridor alternatives 

in Pima County.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-141

Table 5-22. Arizona Species of Special Concern, Highly Safeguarded Native Plants, BLM-Designated Senitive Species, and Pima 

County-Designated Species of Special Concern Potentially Occuring in or near the Yellow and Orange Corridor Alternatives.

Common Name Scientific Name Status Habitat Requirements Potential to Occur

Mexican long-tongued 

bat

Choeronycteris 

mexicana

Pima Lower edge of oak zone through pine-oak 

woodland to pine-fir; foraging habitat includes 

desert areas. Forages on pollen and nectar from 

columnar cacti and agaves; may eat insects. 

Roosts in caves, tunnels, and mines, as well as 

buildings. Generally roost sites are at elevation 

ranges between 4,000 to 6,000 feet.

Suitable foraging habitat is present 

in the vicinity of the corridor 

alternatives in Pima County.

pale Townsend’s bigeared batCorynorhinus 

townsendii pallescens

Pima Roost sites restricted to caves, mines, and lava 

tubes with suitable microclimates. In Pima 

County, the bat has been recorded from Tucson 

Mountain Park and Saguaro National Park.

Known occurrences within the 

vicinity of the corridor alternatives

in Pima County.

western red bat Lasiurus blossevillii WSC,

Pima

Riparian areas dominated by cottonwoods, 

willows, or oaks in the central and southeastern 

portions of the state. Roosts in tree foliage, 2 to 

40 feet above ground. Elevation range between

1,900 to 7,200 feet.

Species occurs across riparian 

habitats of central and 

southeastern Arizona, including the 

vicinity of the corridor alternatives.

western yellow bat Lasiurus xanthinus WSC

Pima

Known from scattered locations across 

southern Arizona, primarily associated with 

dense palm tree stands in urban areas; also 

low- to mid-elevation riparian habitats with 

broad-leaf trees; roosts in leaf skirts of palm 

trees. Elevation range less than 6,000 feet 

May be found in the vicinity of the 

corridor alternatives, primarily in 

the Tucson area where there are 

stands of palm trees.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-142

Table 5-22. Arizona Species of Special Concern, Highly Safeguarded Native Plants, BLM-Designated Senitive Species, and Pima 

County-Designated Species of Special Concern Potentially Occuring in or near the Yellow and Orange Corridor Alternatives.

Common Name Scientific Name Status Habitat Requirements Potential to Occur

Reptiles

desert box turtle Terrapene ornata 

luteola

Pima Sonoran and Chihuahuan desertscrub, 

semidesert grassland; associated with loose soil 

for burrowing. Elevation range less than 7,100 

feet

Species geographic range is outside

the vicinity of the corridor 

alternatives within Pima County.

giant spotted whiptail Aspidoscelis

[Cnemidophorus] 

burti stictogrammus

WSC

Pima

Occur among dense, shrubby vegetation near 

the banks of semi-arid permanent streams and 

intermittent streams. Found in the Santa Cruz 

River floodplain. In 2001, a population of giant 

spotted whiptails was found near the west 

branch of the Santa Cruz River. 

Suitable habitat is present in the 

vicinity of the corridor alternatives 

between Tucson and Marana in 

Pima County.

ground snake Sonora semiannulata Pima Sagebrush and creosote bush in arid and 

semiarid lands; desert grasslands; and mesquite 

and willow thickets. In Pima County, two or 

more forms of uncertain taxonomy. Elevation 

range less than 6,000 feet

Suitable habitat is present in the 

vicinity of the corridor alternatives 

in Pima County. A population of 

interest is located near Marana.

Tucson shovel-nosed 

snake

Chionactis occipitalis 

klauberi

WSC

Pima

Sonoran desertscrub; associated with soft, 

sandy soils having sparse gravel. Elevation 

ranges between 785 and 1,662 feet

Suitable habitat occurs throughout 

the vicinity of the corridor 

alternatives.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-143

Table 5-22. Arizona Species of Special Concern, Highly Safeguarded Native Plants, BLM-Designated Senitive Species, and Pima 

County-Designated Species of Special Concern Potentially Occuring in or near the Yellow and Orange Corridor Alternatives.

Common Name Scientific Name Status Habitat Requirements Potential to Occur

Plants

Pima Indian mallow Abutilon parishii BLM Higher elevation Sonoran desertscrub on rocky 

hillsides, cliff bases, canyon bottoms, lower side 

slopes, and ledges of canyons among rocks and 

boulders. Elevation ranges between 1,720 and 

4,900 feet

No suitable habitat occurs within 

the vicinity of the corridor 

alternatives.

Source: Arizona Game and Fish Department Heritage Data Management System, Environmental Online Tool. Accessed July 2013.

BGEPA = Bald and Golden Eagle Protection Act

BLM=Bureau of Land Management Sensitive Species

WSC = Wildlife of Special Concern in Arizona

Pima = Species of Special Concern in Pima County
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-144

Table 5-23. Arizona Species of Greatest Conservation Need and Species of Economic and 

Recreation Importance Potentially Occuring in or near the Yellow and Orange Corridor 

Alternatives.

Common Name Scientific Name Status

Amphibians

lowland leopard frog Lithobates yavapaiensis 1A

Sonoran desert toad Inciliu alvarius 1B

Birds

Abert’s towhee Melozone aberti 1B

American bittern Botaurus lentiginosus 1B

American peregrine falcon Falco perigrinus anatum 1A

bald eagle Haliaeetus leucocephalus 1A

Bell’s vireo Vireo bellii arizonae 1B

broad-billed hummingbird Cynanthus latirostris 1B

desert purple martin Progne subis hesperia 1B

ferruginous hawk Buteo regalis 1B

Gambel’s quail Callipepla gambelii E

Gila woodpecker Melanerpes uropygialis 1B

gilded flicker Colaptes chrysoides 1B

golden eagle Aquila chrysaetos 1B

Le Conte’s thrasher Toxostoma lecontei 1B

Lincoln’s sparrow Melospiza lincolnii 1B

Pacific wren Troglodytes pacificus 1B

Savannah sparrow Passerculus sandwichensis 1B

Sprague’s pipit Anthus spragueii 1A

scaled quail Callipepla squamata E

western burrowing owl Athene cunicularia hypugaea 1B

white-winged dove Zenaida asiatica E

wood duck Aix sponsa 1B

yellow-billed cuckoo (Western District 

Population Segment)

Coccyzus americanus 1A

yellow warbler Setophaga petechia 1B

Yuma clapper rail Rallus longirostris yumanensis 1A
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-145

Table 5-23. Arizona Species of Greatest Conservation Need and Species of Economic and 

Recreation Importance Potentially Occuring in or near the Yellow and Orange Corridor 

Alternatives.

Common Name Scientific Name Status

Fish

bonytail Gila elegans 1A

Colorado pikeminnow Ptychocheilus lucius 1A

desert pupfish Cyprinodon macularius 1A

desert sucker Catostomus clarkii 1B

flannelmouth sucker Catostomus latipinnis 1A

Gila topminnow Poeciliopsis occidentalis occidentalis 1A

little Colorado sucker Catostomus sp. 3 1A

longfin dace Agosia chrysogaster 1B

Quitobaquito pupfish Cyprinodon eremus 1A

razorback sucker Xyrauchen texanus 1A

roundtail chub Gila robusta 1A

Sonora sucker Catostomus insignis 1B

Mammals

American beaver Castor canadensis 1B

antelope Jackrabbit Lepus alleni 1B

Arizona myotis Myotis occultus 1B

Arizona pocket mouse Perognathus amplus 1B

Brazilian free-tailed bat Tadarida brasiliensis 1B

California leaf-nosed bat Macrotus californicus 1B

cave myotis Myotis velifer 1B

greater western bonneted bat Eumops perotis californicus 1B

Harris's antelope squirrel Ammospermophilus harrisii 1B

jaguar Panthera onca 1A

javelina Pecari tajacu E

kit fox Vulpes macrotis 1B

lesser long-nosed bat Leptonycteris curasoae Yerbabuenae 1A

mountain lion Puma concolor E

mule deer Odocoileus hemionus E

ocelot Leopardus pardalis 1A

pale Townsend’s big-eared bat Corynorhinus townsendii pallescens 1B

pocketed free-tailed bat Nyctinomops femorosaccus 1B
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-146

Table 5-23. Arizona Species of Greatest Conservation Need and Species of Economic and 

Recreation Importance Potentially Occuring in or near the Yellow and Orange Corridor 

Alternatives.

Common Name Scientific Name Status

spotted bat Euderma maculatum 1B

Yuma myotis Myotis yumanensis 1B

western red bat Lasiurus blossevillii 1B

western yellow bat Lasiurus xanthinus 1B

Reptiles

desert mud turtle Kinosternon sonoriense sonoriense 1B

Gila monster Heloderma suspectum 1A

Goode’s horned lizard Phrynosoma goodei 1B

regal horned lizard Phrynosoma solare 1B

saddled leaf-nosed snake Phyllorhynchus browni 1B

Sonoran coralsnake Micruroides euryxanthus 1B

Sonoran desert tortoise Gopherus morafkai 1A

Sonoran whipsnake Coluber bilineatus 1B

tiger rattlesnake Crotalus tigris 1B

Tucson shovel-nosed snake Chionactis occipitalis klauberi 1A

variable sandsnake Chilomeniscus stramineus 1B

Source: Arizona Game and Fish Department Heritage Data Management System, Environmental Online Tool. Accessed 

January 2016.

1A = vulnerable and also meet any of the following: federally listed as endangered or threatened under the ESA; Candidate 

species under ESA; is specifically covered under a signed candidate conservation agreement (CCA) or a signed candidate 

conservation agreement with assurances (CCAA); recently removed from ESA and currently requires post-delisting monitoring; 

closed season species (i.e., no take permitted) as identified in Arizona Game and Fish Commission Orders 40, 41, 42 or 43

1B= Scored “1” for Vulnerability in at least one of the eight categories, but match none of the above criteria.

E = economic and recreational value associated with the species

Of the 43 special status species evaluated as possibly occurring in the vicinity of the corridor 

alternatives, suitable habitat may be present for 27 species (Table 5-24). Critical habitat has 

been proposed for the western yellow-billed cuckoo and includes Picacho Reservoir, within 

approximately 0.1 mile and 0.5 mile of the Yellow and Orange corridor alternatives, 

respectively. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-147

Table 5-24. Special Status Species with Potentially Suitable Habitat in the Vicinity of the 

Yellow and Orange Corridor Alternatives

Common Name Status

bald eagle BLM, WSC

Bell’s vireo Pima

black-bellied whistling-duck WSC

cactus ferruginous pygmy-owl ESA-Petitioned BLM, WSC, Pima

California leaf-nosed bat BLM, WSC, Pima

California least tern E

cave myotis BLM

desert sucker BLM

giant spotted whiptail Pima

great egret WSC

ground snake Pima

least bittern WSC

lesser long-nosed bat E, WSC, Pima

lowland leopard frog BLM, WSC

northern Mexican gartersnake T, PCH, WSC

pale Townsend’s big-eared bat Pima

rufous winged sparrow Pima

Sonoran desert tortoise CCA, WSC

southwestern willow flycatcher E, Pima

Swainson’s hawk Pima

Tucson shovel-nosed snake WSC, Pima

western burrowing owl BLM, Pima

western narrow-mouthed toad BLM, WSC, Pima

western red bat Pima

western yellow bat WSC, Pima

western yellow-billed cuckoo T, PCH, WSC, Pima

Yuma clapper rail E, WSC

Source: USFWS IPaC 2014. 

E = Listed as Endangered under the ESA

T = Listed as Threatened

PT = Proposed for Listing as Threatened 

C = Candidate species for listing

CCA = Candidate Conservation Agreement 

Petitioned = Petitioned for Listing 

PCH= Proposed Critical Habitat 

WSC = Wildlife of Special Concern in Arizona

HS = Highly Safeguarded under Arizona Native Plant Law

Pima = Species of Special Concern in Pima County

Of the 71 species listed as species of high conservation need and species of economic 

importance, 16 are also included in Table 5-24 as special status species. Many of the species, 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-148

including bats, birds, and mammals are migratory or could disperse through the area and have 

the potential to occur in the vicinity of the corridor alternatives. Strategies to minimize and 

offset potential impacts for these species would be developed in conjunction with AGFD during 

the Tier 2 analysis.

5.12.3 Environmental Consequences

This section analyzes the potential impacts to plant and wildlife resources of constructing and 

operating a passenger rail system within the Yellow and Orange corridor alternatives, as well as 

the No Build alternative. The analysis provides a general overview, as no project specific details 

are available (e.g., where the passenger rail system would be placed within the 1-mile wide 

corridor alternatives, where and what type of structures would be used to cross drainage 

channels, and how wide the construction disturbance zone would be). The direct impacts and 

indirect impacts (potential project effects that may occur off site or later in time associated 

with the long-term physical presence and operation of a passenger rail system on the 

landscape, and the temporary disturbance associated with construction activities) are 

addressed.

Effects Common to All Corridor Alternatives

Both the Yellow and Orange corridor alternatives include lands that have been fully converted 

to agricultural and urban uses and generally parallel existing transportation corridors, including 

portions of I-10 and the UP railroad. Due to the proximity of the corridor alternatives to human 

development and activities, remaining native habitat within portions of the corridor 

alternatives has been degraded, and wildlife species diversity and abundance reduced; 

however, wildlife habitat remains throughout the two corridor alternatives. Wildlife habitat 

values are generally greater in areas of denser native vegetation, such as along major and 

minor washes. These washes also provide important corridors for wildlife movement across the 

landscape. In areas of limited or scattered human development, habitats are used by a wide 

array of species. 

Physical Impacts

In both corridor alternatives, the presence of a passenger rail system would result in the direct 

loss of native vegetation and wildlife habitats, increase habitat fragmentation, and impede the 

movement of wildlife across the landscape. Some of these impacts can be reduced by locating 

the rail system as close as possible to existing transportation corridors and other facilities 

where habitats are already fragmented. Habitat that may remain between parallel developed 

corridors would be isolated from larger habitat blocks and would be of less value to wildlife. 

Animals would be in close proximity to potential disturbances, and the size of the area may 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-149

limit access to, and the availability of, seasonally variable sources of food, water, and shelter. A 

loss of species diversity and abundance would occur within these fragmented habitat areas. 

A passenger rail system within either corridor alternative would result in a formidable barrier to 

wildlife movement by both large and small species. Details regarding the elevation of the 

railroad bed above surrounding terrain and how drainage channels would be crossed are not 

available. Retaining as much vegetation as possible within and adjacent to the rail ROW and 

along washes that cross the passenger rail system would reduce the impacts to wildlife. 

Providing under-crossing structures at as many wash crossings as possible would benefit 

wildlife, although the location of these structures would need to be coordinated with wildlife 

crossings in other nearby barriers to wildlife movement. 

A passenger rail system in either corridor alternative would bisect large intact habitat blocks. 

The AGFD wildlife linkages assessment could be used as a guide for locating crossing structures 

based on current wildlife movement patterns. In addition, crossing structures that are large 

enough to accommodate mule deer passage, and that include natural bottom surfaces, would 

facilitate use by a greater variety of species.

Operational Impacts

The corridor alternatives generally parallel existing transportation infrastructure, including I-10 

and the UP railroad. Freight trains traveling on existing UP tracks make approximately 43 trips 

per day through the rural areas between Tucson and Eloy and approximately 8 trips per day 

from Eloy to Phoenix. Existing freight train traffic does not exceed 80 mph. Wildlife that may be 

present in the vicinity of the existing highway and rail lines have been exposed, to some extent, 

to disturbances associated with railroad operations. 

While habituation to transportation noise, such as at airports, highways, and urban centers, is 

commonly seen in some species and individuals of wildlife, the effect of train noise and 

associated vibration on wildlife is unclear. The passage of a train may not cause habitat 

degradation; but wildlife, especially larger mammals such as mule deer and bighorn sheep, may 

have behavioral and physiological responses to this type of disturbance. The magnitude of 

these effects to wildlife is not always clear and reflects individual animals’ experiences and 

habituation to similar events. Krausman et al. (1986) concluded that desert mule deer 

habituated to low-flying, fixed-wing, single-engine aircraft, but found that female desert 

bighorn sheep with lambs were more sensitive to these disturbances (Krausman et al. 1998). 

Noise may affect different animals in different ways. The roar of a dune-buggy engine was 

reported by Immel (1995, in Radle 2007) to temporarily disable the reflexive defense of the 

desert kangaroo rat against the sidewinder rattlesnake by interfering with the rat’s defensive 

hearing. The diversity of effects that noise may have among and between species complicates 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-150

the interpretation of the effects of noise on wildlife as a whole (Radle 2007). Some animal 

species that live near active railroad tracks may become accustomed to noise and vibration 

from trains. Migratory species and species that do not consistently inhabit the rail corridor may 

be more affected by trains (Hanson 2008). High levels of vibration or repeated exposure to 

vibrations may cause the collapse of small mammal dens and reptile burrows. The addition of a 

passenger rail system could further cause wildlife to avoid the expanded transportation 

corridor, particularly if animals are frightened by faster passenger trains (up to 110 mph). 

Higher speed trains could also increase mortality rates of animals crossing the tracks. 

Consequently, with development of a passenger rail system in either corridor alternative, some 

animal species may become accustomed to train noise and vibration, while others may avoid 

the rail system. 

The number of structural features, such as culverts, bridges, and switchyards, may influence the 

frequency and nature of maintenance activities, the removal of vegetation from the ROW, and 

disturbances due to the presence of maintenance crews and heavy equipment. Ground 

disturbance associated with the maintenance of roadways and tracks provides additional 

opportunities for establishment and/or spread of nonnative species. Soil erosion, 

sedimentation, runoff of oils and lubricants from railroad grades, and the potential for spills 

during maintenance activities, could result in these substances entering adjacent drainage 

channels and exposing wildlife to toxic chemicals.

Construction Impacts

Construction activities associated with development of a passenger rail system—including

vegetation removal; ground clearing; placement of fill material for track; new, replaced, or 

extended culverts and bridges; and station facility development—could potentially result in 

disturbance to, and mortality of, local wildlife. Staging areas, access roads, and development of 

other facilities needed to support construction activities could result in permanent loss of 

habitat or reduction of habitat values. Disturbance during construction, and later reclamation 

of such areas, would result in a temporary loss of habitat; although in desert systems, 

restoration of disturbed sites to previous conditions may take decades. Until disturbed areas 

are stabilized, the potential exists for increased sediment transport during storm events and an 

increased potential for the introduction or spread nonnative and invasive species. 

In accordance with the Arizona Native Plant Law (A.R.S. §§ 3-901 et seq.), the Arizona 

Department of Agriculture is to be notified at least 60 days prior to ground-clearing activities to 

determine the disposition of protected native plants.

The removal of vegetation from late winter through spring could result in the loss of active bird 

nests. Projects with the potential to result in take of birds protected under the MBTA require 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-151

the issuance of Special Purpose permits from USFWS. Construction activities, such as land 

clearing or bridge construction during the nesting season could result in a “take” of migratory 

birds. A wide range of migratory birds are expected to occur within and adjacent to the corridor

alternatives; however, the need for a permit may be reduced or eliminated if all vegetation 

removal were completed during the non-breeding season.

Yellow Corridor Alternative

AGFD, in its independent assessment of the passenger rail corridor alternatives (see the 

Biological Resources Appendix), found that the overall impact of a passenger rail system within 

the Yellow Corridor Alternative would be medium, indicating a “moderate to significant effect 

to resources with the potential to minimize or mitigate impacts.” A passenger rail system within 

the Yellow Corridor Alternative would be situated closer to existing development than a 

passenger rail system within the Orange Corridor Alternative, so it would affect less native 

habitat for wildlife and generally expand existing barriers rather than create new ones.

Southern Hub to Eloy

Physical Impacts 

The Yellow Corridor Alternative between the southern hub and Eloy generally parallels the 

existing interstate highway transportation corridor. Within and adjacent to the southernmost 

segment, the Santa Cruz River runs roughly parallel to I-10 on the west side. This river and its 

tributary, the Rillito River, are highly degraded and do not provide perennial flow in this area. 

Scattered patches of riparian vegetation, including deciduous riparian trees, are used by 

numerous neotropical migrant bird species. In addition, records of ESA-listed threatened 

Mexican gartersnake and the Pima County Sensitive Species western burrowing owl are 

associated with the Santa Cruz drainage. The City of Tucson and Pima County have undertaken 

efforts to restore portions of the river corridor. If a passenger rail system were constructed on 

the west side of the corridor alternative, to the west of I-10, it could result in the loss of 

developing riparian habitats along the river and possibly limit opportunities for additional 

restoration. 

North of Tucson, within and adjacent to the corridor alternative, are large expanses of open 

native habitats with braided washes and high species diversity. The presence of a passenger rail 

system could result in the direct loss of up to an estimated 10,950 acres of vacant/undeveloped 

land, much of which would be Arizona Upland Subdivision habitat that includes suitable habitat 

for the ESA-listed endangered lesser long-nosed bat, Sonoran desert tortoise (candidate 

conservation agreement [CCA] species), Tucson shovel-nosed snake (AGFD Wildlife of Special 

Concern, Pima County Sensitive Species), ground snake (Pima County Sensitive Species), 

western burrowing owl (Pima County Sensitive Species), possibly the cactus ferruginous pygmy-
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-152

owl (ESA-listed petitioned); and the special management area identified by Pima County. The 

lesser long-nosed bat feeds on the flowers and fruits of saguaro and agaves. Tortoise habitat is 

typically associated with rocky slopes and outcrops, and the quality of this habitat increases 

closer to Picacho Peak and the Picacho Mountains, the location of an AGFD long-term 

population monitoring plot. The effects of reducing or fragmenting tortoise home ranges and 

possibly cutting off access of tortoises to important resources (e.g., burrows, water collection 

sites, and feeding areas) by the presence of a passenger rail system is unknown. ADOT has 

entered into a conservation partnership with land management agencies and USFWS to address 

desert tortoise conservation issues. The Tucson shovel-nosed snake is found in sandy washes; 

the ground snake occupies desert flats, rocky hillsides, and river bottoms with harder 

substrates; the pygmy-owl is generally associated with dense stands of ironwood, palo verde, 

and mesquite; and the burrowing owl is found in open, sparsely vegetated areas with mammal 

burrows for nesting as well as along river/wash banks. Burrowing owls tend to be tolerant of 

human presence, and will nest in human-modified landscapes, thereby encountering human 

activity and potential loss to burrows or habitat. This would include clearing habitat and grading 

banks for a railroad system. In addition, depending on the alignment, protected desert habitat 

within Picacho Peak State Park could be acquired as ROW for a passenger rail system. 

Due to the presence of the existing interstate highway and railroad within the corridor 

alternative, landscape-level movement corridors for local wildlife have already been affected. 

I-10 is currently a substantial barrier to wildlife movement and habitat connectivity between 

the Picacho Mountains and Ironwood Forest National Monument (AGFD 2014); however, three 

recognized wildlife linkage areas/movement corridors of major (i.e., statewide) importance 

have been identified along I-10 between Marana and Picacho Pass (see Table 5-19 and 

Figure 5-17), with various other wildlife movement areas (see Figure 5-18). The presence of a 

passenger rail system would expand the existing barriers rather than create new barriers to 

animal movements, minimizing habitat fragmentation. In addressing the possibility of a new 

transportation corridor compounding impacts to wildlife movement, an opportunity exists to 

improve wildlife movement and habitat connectivity across the I-10 corridor. Improved 

understanding of the distribution and movement patterns for species like the desert tortoise 

and Tucson shovel-nosed snake, as well as large mammals like the mule deer and big horn 

sheep, is necessary to fully assess the potential impacts of a passenger rail system in this area 

and develop the most effective mitigation measures. The Picacho Peak area is critical to the 

movement of wildlife across the I-10 corridor and especially important to mule deer and 

bighorn sheep movements. AGFD considers this habitat linkage area to be of critical concern 

(AGFD 2014). 
Florence

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Existing Conditions and Environmental Consequences

Figure 5-18. Wildlife Movement Areas within the Study Corridor

5

Final Tier 1 Environmental Impact Statement 5-153

e

Airport

Interstate

State or US Highway

Railroad

Major Drainage

Movement Areas

Diffuse Movement Area 

(Wildlife Movement 

Within a Habitat Block)

Landscape Movement Area 

(Wildlife Movement 

Between Wildland Blocks)

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(Wildlife Movement 

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5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-154

Operational Impacts

Due to the presence of the existing interstate highway and railroad within this segment of the 

corridor alternative, local wildlife are likely familiar with noise and vibrations associated with 

existing transportation facilities. The addition of a passenger rail system may further deter 

wildlife from the area, though it is unclear how wildlife may react to an intensification of an 

already present stimulus/disturbance. 

Construction Impacts

Construction activities would include vegetation removal and ground disturbance by heavy 

equipment. Potential impacts to nesting behavior of protected bird species, native plants, 

plants that provide forage for protected bat species, and desert tortoise should be taken into 

considerations and mitigated, to the extent possible. 

Eloy to Northern Hub

Physical Impacts 

The Yellow Corridor Alternative from Eloy to the northern hub generally parallels an existing 

railroad for its entire length. From the Eloy area the corridor alternative proceeds north to 

Coolidge, passing through agricultural fields interspersed with areas of native habitat consisting 

primarily of Lower Colorado Subdivision vegetation associations. Development of a passenger 

rail system in this corridor alternative segment would result in the loss of Sonoran desert 

tortoise and Tucson shovel-nosed snake habitat. Burrowing owls are also observed throughout 

this area. The corridor alternative passes adjacent to Picacho Reservoir. When filled with water 

from agricultural runoff, this reservoir provides habitat for waterfowl and several special status 

species; past records (over 10 years old) document observations of the ESA-listed endangered 

Yuma clapper rail at the reservoir. From Coolidge, the corridor alternative crosses the Gila River 

(an identified wildlife movement corridor), and circles the east side of the San Tan Mountains 

(desert tortoise habitat), reducing the size of a large, intact block of natural habitat and 

effectively isolating the mountains. Due to existing development, wildlife movements between 

the San Tan and Superstition mountains are already impeded; a passenger rail system may 

present opportunities to improve wildlife connectivity by siting the corridors to minimize habitat 

and connectivity fragmentation, identifying current and potential important wildlife movement 

areas, and designing facilities to provide maximum permeability for safe wildlife movement. The 

corridor alternative continues into the greater Phoenix metropolitan area, crossing Queen Creek 

and the Salt River, both important wildlife movement corridors within an otherwise urban 

setting. The Phoenix Mountains-Salt River-Papago Park habitat block could also be affected. 

Riparian vegetation associated with the Salt and Gila rivers and the Queen Creek Wash, which 

may include suitable habitat for the ESA-listed threatened western yellow-billed cuckoo, and the 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-155

dense stands of xeroriparian vegetation in the vicinity of the San Tan Mountains could be lost to 

provide ROW for a passenger rail system. 

Operational Impacts 

Due to the presence of existing state highways, local roadways, and the railroad within this 

segment of the corridor alternative, local wildlife are likely familiar with noise and vibration 

associated with transportation facilities. The addition of a passenger rail system may further 

deter wildlife from the area, although it is unclear how wildlife may react to an intensification 

of an already present stimulus/disturbance. Bald eagles are known to nest along the Salt River 

upstream of Tempe Town Lake. A passenger rail system through this area could disrupt nesting 

or foraging eagles, as they are known to be sensitive to human-caused disturbance. 

Construction Impacts 

The additional noise and human activity associated with construction of a passenger rail system 

in the vicinity of the Salt River may be a particular concern for disturbance to foraging and 

nesting bald eagles. 

Orange Corridor Alternative

AGFD, in its independent assessment of the corridor alternatives (AGFD 2014), found that the 

overall impact of a passenger rail system within the Orange Corridor Alternative would be 

medium through most of the corridor length (“moderate to significant effect to resources with 

the potential to minimize or mitigate impacts”), but high in the area from a few miles north of 

Eloy to a few miles south of Apache Junction. A high rating indicates “potential significant 

impacts to resources.” Because the Orange Corridor Alternative deviates from existing 

transportation corridors and extends into undeveloped native habitats, it would contribute to 

extensive habitat fragmentation and could create a new barrier to wildlife movement between 

the San Tan and Superstition mountains, resulting in greater effects to wildlife resources, 

wildlife habitat, and wildlife-related recreation than a passenger rail system within the Yellow 

Corridor Alternative. 

Southern Hub to Eloy

The physical, operational, and construction impacts of a passenger rail system within the 

Orange Corridor Alternative for this segment would be the same as those described for this 

segment of the Yellow Corridor Alternative, as they share the same route over this corridor 

segment. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-156

Eloy to Northern Hub

Physical Impacts 

North of Eloy, the Orange Corridor Alternative closely parallels the Yellow Corridor Alternative 

until just north of Picacho Reservoir, where the Orange Corridor Alternative begins to veer to 

the east away from existing transportation corridors, crossing a combination of agricultural 

fields and natural habitats primarily composed of Lower Colorado River Subdivision vegetation 

associations. North of the Gila River, the Orange Corridor Alternative follows the CAP canal, 

which includes dense stands of Desert Wash Mixed Scrub vegetation, mesquite bosque, and 

some riparian vegetation. AGFD has identified the CAP ROW as a wildlife linkage corridor having 

regional importance as it provides opportunities for wildlife movements from Tucson north to 

Phoenix and beyond. The Orange Corridor Alternative crosses the Queen Creek wildlife 

movement corridor and turns to the west, entering the greater Phoenix metropolitan area. The 

Orange Corridor Alternative crosses the Salt River, intersecting the Salt River and Indian Bend 

Wash wildlife movement corridors. Though many of the impacts of a passenger rail system 

within the Orange Corridor Alternative would be consistent with those of a passenger rail 

system within the Yellow Corridor Alternative, the Orange Corridor Alternative could result in a 

greater amount of undeveloped land being acquired to provide ROW. The additional land lost 

to provide ROW for a passenger rail system with the Orange Corridor Alternative could have 

impacts on native desert, xeroriparian, and riparian habitats used by a diverse array of plant 

and animals species, including the Sonoran desert tortoise (a CCA species) and the Tucson 

shovel-nosed snake. Construction of a passenger rail system within the Orange Corridor 

Alternative could fragment large blocks of native habitat between Picacho Reservoir and the 

Town of Queen Creek, disrupt the function of the wildlife linkage corridor associated with the 

CAP ROW, and effectively isolate the San Tan Mountains from the Superstition Mountains. 

Operational Impacts 

Effects from operations and maintenance of a passenger rail system within the Orange Corridor 

Alternative would be generally similar to those described for a passenger rail system within the 

Yellow Corridor Alternative, including the potential disturbance to nesting and foraging bald 

eagles along the Salt River upstream of Tempe Town Lake. Because the Orange Corridor 

Alternative deviates from existing transportation corridors, wildlife in the vicinity of a passenger 

rail system within the Orange Corridor Alternative would be less habituated to transportationrelated noise and vibration.

Construction Impacts 

Effects on natural habitats and wildlife from construction of a passenger rail system within the 

Orange Corridor Alternative would also be similar to the construction impacts described for a 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-157

passenger rail system within the Yellow Corridor Alternative. Since a passenger rail system 

within the Orange Corridor Alternative would affect more land of generally better quality native 

habitat (e.g., dense vegetation farther from human activities) than a passenger rail system 

within the Yellow Corridor Alternative, ground clearing could result in the short- and long-term 

loss of many protected native plants and disruption to many wildlife species. 

5.12.4 No Build Alternative

Under the No Build Alternative, no passenger rail system would be developed; and impacts to 

natural habitats and wildlife would not occur beyond those that could occur due to other

current and proposed projects. Under the No Build Alternative, potential opportunities to 

improve wildlife crossings associated with a passenger rail system within the existing 

transportation corridor would not be realized. 

5.12.5 Potential Mitigation Measures

This Tier 1 analysis provides an overview of potential impacts from the development of a 

passenger rail system within either of the corridor alternatives. Specific project design, 

construction methods, and corridor alignment have not been determined. Therefore, specific 

methods to avoid, minimize, or mitigate project-related impacts cannot be developed. 

However, the general application of these types of measures, consistent with state and federal 

regulations, is outlined below.

 Avoid impacts, when possible, particularly to protected and sensitive species and their 

associated habitat, and to wildlife corridors

 Minimize loss of natural habitats

o Provide construction workers with environmental awareness training, including 

measures to be taken to minimize impacts to the natural environment

o Where options are available, align the corridor to maximize the use of disturbed 

lands and minimize habitat fragmentation

o Minimize construction impacts by limiting the disturbance zone as much as 

possible; use previously disturbed areas for staging and equipment storage

o Flag or fence sensitive habitats such as riparian areas or wetlands to preclude 

construction impacts from occurring within the area 

o Transplant displaced vegetation to adjacent lands, when feasible

 Replace lost habitat 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-158

 Address and minimize edge effects through: the use of existing infrastructure; 

monitoring of adjacent habitats for change; and the development of adaptive 

management strategies for toxins, invasive species, and habitat conversion

 Minimize impacts to plant and animal species 

o Provide notification to Arizona Department of Agriculture of the removal of 

protected native plants so plants may be salvaged

o Implement seasonal restrictions on the removal of vegetation to protect nesting 

birds

o Implement seasonal restrictions on the disturbance of sensitive wildlife areas

o Conduct preconstruction surveys for nesting birds prior to the removal of 

vegetation if ground clearing occurs during the nesting season

o Conduct preconstruction surveys for removal and translocation of Sonoran 

desert tortoise and western burrowing owl

o Provide wildlife escape options in open trenches and inspect trenches to remove 

wildlife prior to filling

o Check under vehicles for wildlife seeking shade (especially reptiles, including the 

desert tortoise) before driving

 Minimize impacts to wildlife movement corridors

o Refine identified wildlife linkage corridors, movement corridors, and habitat 

blocks to reflect current state of knowledge

o Support studies to better understand the movement of mule deer and bighorn 

sheep in association with a passenger rail system within the corridor alternatives

o Support studies to better understand the movement and habitat use of Sonoran 

desert tortoise and Tucson shovel-nosed snake in association with a passenger 

rail system within the corridor alternatives

o Do not compromise the function of existing wildlife movement corridors or large 

habitat blocks

o Design sufficient wildlife crossing structures to facilitate movement of large and 

small species of wildlife across the landscape, including appropriate funnel 

fencing associated with crossing areas, and appropriate ROW fencing to allow 

for, or restrict as necessary, wildlife movement
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-159

o Locate crossing structures to enhance wildlife crossing of the existing 

transportation corridors associated with a passenger rail system 

o Provide for follow-through studies to assess the effectiveness of the wildlife 

crossing structures

 Control the spread of nonnative and invasive species

o Develop a Habitat Restoration Plan for all temporary impacts to native 

vegetation and provide it to land management/resource agencies for review 

prior to project construction

o Address and minimize edge effects through: the use of existing infrastructure; 

monitoring of adjacent habitats for change; and the development of adaptive 

management strategies for toxins, invasive species, and habitat conversion

o Prepare a site restoration plan identifying techniques, timing, and success 

criteria

o Wash vehicles and equipment to avoid potential transport of nonnative seed to 

construction areas

o Rehabilitate disturbed ground as soon as possible following construction 

activities to minimize exposure of bare ground susceptible to colonization by 

nonnative plants 

o Use chemical or mechanical treatments on existing infestation areas within 

construction zones to prevent additional spread

o Restore sites with native seed mixes certified as “weed free” 

5.12.6 Tier 2 Considerations

For the detailed analyses provided in a Tier 2 NEPA document, site-specific data on biological 

resources potentially affected by the project would be required including special status species 

and wildlife movement studies/surveys to inform the NEPA process. Continued coordination 

with land and resource management agencies may reveal new sources of data as well as 

identify additional issues to be addressed in the Tier 2 analysis. Technical studies, including field 

surveys and research programs, can be implemented as part of the Tier 2 analysis. These data 

can be gathered, analyzed, and applied in an iterative manner with the development of project 

design and location of project facilities. Additional data may support a more detailed analysis of 

potential project-specific impacts, including the effects of noise and vibration on various species 

of wildlife, the effects of interrupting or enhancing specific wildlife movement corridors, and 

the evaluation of potential adverse effects to ESA-listed and other special status species. The 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-160

Sonoran desert tortoise occurs over a large portion of the corridor alternatives. Western 

burrowing owls also have the potential to occur throughout a large portion of the corridor 

alternatives, especially inhabiting agricultural lands such as those that occur along both the 

Yellow and Orange corridor alternatives. Surveys for the owl should be conducted in a timely 

manner to allow for the proper accommodation or mitigation for owls, including plans for 

seasonal restrictions to implement in a future construction phase. FRA would coordinate closely 

with USFWS under the ESA consultation requirements of Section 7 to facilitate meeting 

regulatory requirements for planning the alignment of a passenger rail system prior to project 

construction and implementation at Tier 2. The ESA directs all Federal agencies to work to 

conserve endangered and threatened species as well as habitats, and forms the basis of 

biodiversity and endangered species protection in the US. In addition, close coordination with 

AGFD could facilitate resolution of concerns regarding impacts to wildlife, especially wildlife 

movement corridors and habitat loss.

5.13 Waters of the US

5.13.1 Methodology and Regulatory Requirements

The legal framework pertaining to Waters of the US, also referred to as jurisdictional waters, is 

the Clean Water Act of 1972 (as amended) (CWA) and its implementing regulations. Waters of 

the US include traditional navigable waters (TNW), perennial streams, lakes, ponds, and 

wetlands, as well as intermittent streams and ephemeral washes that have a significant nexus 

with a jurisdictional water.

The principal goal of the CWA is to establish water quality standards to restore and maintain 

the chemical, physical, and biological integrity of the nation’s jurisdictional waters by 

preventing pollution sources. The fundamental rationale of the program is that no discharge of 

dredged or fill material should be permitted if a practicable alternative is available that would

be less damaging to aquatic resources or if significant degradation would occur to the nation’s 

waters. Section 404 of the CWA regulates the discharge of earthen fill, concrete, and other 

construction materials into Waters of the US and authorizes the US Army Corps of Engineers 

(Corps) to issue permits regulating such discharges. Permit review and issuance follows a 

sequential process that encourages avoidance of impacts, followed by minimizing impacts, and 

finally, requiring mitigation for unavoidable impacts to the aquatic environment. More details 

on the regulatory framework are available in the Waters of the US Appendix.

The corridor alternatives are located in the Interior Deserts land resource region, and Clean 

Water Act investigation and permitting would be conducted in accordance with the Corps’
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-161

guidance. Refer to Section 5.14 for more information on wetlands within the corridor 

alternatives.

In addition to the 404 permit, a future passenger rail system would require a state water quality 

certification issued by ADEQ to comply with Section 401(a) of the CWA. Impacts to tribal waters 

would trigger a Section 401 water quality certification from EPA. Section 401 certification, 

which can cover both construction and operational phases, includes mitigation measures to 

indicate how a project would comply with surface water quality standards.

Locations of possible Waters of the US were identified through a review of GIS data compiled 

by the Environmental Systems Research Institute (ESRI) and the Nationwide Rivers Inventory,

and a review of USGS maps showing perennial and intermittent streams, lakes, and ponds. A list 

of possible Waters of the US within the corridor alternatives is included in the Waters of the US 

Appendix.

5.13.2 Existing Conditions

As part of the Basin and Range physiography in the study corridor, ephemeral desert washes 

carry stormwater flows and can create intricate, braided drainage systems across the valleys 

between mountains, buttes, and other landforms. The corridor alternatives traverse the Santa 

Cruz and Middle Gila watersheds, where watercourses generally flow toward the Santa Cruz 

and Gila rivers. These two primary rivers run south to north and generally east to west, 

respectively. Named rivers and streams and some of the unnamed washes in the corridor 

alternatives are shown in the Corridor Aerial Atlas Appendix, Maps 1 through 91. No navigable

rivers, as adjudicated by the Arizona Navigable Stream Adjudication Commission, intersect or 

flow through the corridor alternatives (ANSAC 2012). 

The Santa Cruz River, 24 named ephemeral washes, and 4 lakes are located within the southern 

hub to Eloy segment of the Yellow Corridor Alternative. Numerous unnamed ephemeral washes 

also traverse this segment. The Santa Cruz River flows south to north through this segment for 

approximately 18 miles, while the ephemeral washes flow predominantly east to west across 

the corridor toward the Santa Cruz River. A few of the washes flow west to east toward the 

river. The lakes are associated with golf courses and a park; avoidance is recommended. The 

Gila River, Queen Creek, East Maricopa Floodway, Salt River, nine lakes, and numerous 

unnamed washes are located within the Eloy to northern hub portion of the Yellow Corridor 

Alternative.

One segment of the Santa Cruz River flows perennially from discharges from the Roger Road 

wastewater treatment plant. The Corps has determined that the Santa Cruz River from the 

wastewater treatment plant to the Pima County/Pinal County border is a TNW, and this 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-162

segment flows through the southern portion of the corridor alternatives (Corps 2008) (see the 

Corridor Aerial Atlas Appendix, Maps 3-9). Therefore, tributaries flowing into that segment of 

the Santa Cruz River have a connection to a TNW and would likely be determined jurisdictional.

The Corps has determined two segments of the Gila River totaling approximately 37 miles as a 

TNW (Corps 2008). These segments are not located within the corridor alternatives; however, it 

is reasonable to expect that other segments of the Gila River would also be jurisdictional due to 

a direct connection to the Colorado River (Arizona's only adjudicated navigable river). The East 

Maricopa Floodway flows directly into the Salt River and is regulated by the Corps as a 

jurisdictional water.

Several irrigation canals cross the corridor alternatives and are also shown in the Corridor Aerial 

Atlas Appendix. The Corps typically does not have jurisdiction over irrigation canals unless the 

water can be shown to come from and return to a Water of the US. Individual jurisdiction 

determinations would occur during Tier 2, including whether irrigation ditches should be 

considered Waters of the US. 

Several lakes and ponds are also located within the corridor alternatives; most are associated 

with golf courses or parks. The 43 named watercourses and water bodies in the corridor

alternatives are listed in the Waters of the US Appendix by corridor segment, with information 

on the type of resource and, if available, current jurisdictional status. A review of aerial 

photography indicates numerous other unnamed washes. As discussed above, the jurisdictional 

status of possible Waters of the US would be determined and confirmed during Tier 2.

5.13.3 Environmental Consequences

5.13.3.1Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts 

Impacts within Waters of the US would vary based on the placement of a passenger rail system

within a given corridor alternative, and would be unavoidable given the number of washes that

traverse each corridor alternative. Impacts to waters that run perpendicular to a rail line would

likely be less than impacts to waters that parallel a rail line. Perpendicular segments would be 

affected for the length of the culvert(s) required to allow flows to pass beneath the rail line, 

plus any erosion or scour control constructed within the ordinary high water mark (OHWM). In 

some locations, impacts could be further minimized by using a bridge to clear-span the 

watercourse. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-163

Parallel waters, such as the Santa Cruz River, could be affected by longer stretches of cuts, fills, 

or diversions required to construct ballast, embankments, drainage slopes, or other railway

components. Parallel waters may also be relocated or even truncated to accommodate the new 

infrastructure, resulting in additional impacts. Finally, the placement of fill required for major 

structures such as sidings, spurs, yards, and stations could further increase impacts within 

Waters of the US.

As noted in the Tier 2 considerations discussed later in this section, it is likely that at least a 

preconstruction notification of the Corps would be required for construction, especially if it 

results in impacts to the perennial stretch of the Santa Cruz River. Impacts to wetlands would

trigger a Section 404 Individual Permit, as discussed in Section 5.15.

Operational Impacts 

Minimal impacts to Waters of the US would be expected during operation of a rail line. Impacts 

likely would be limited to maintenance of culverts or bridges, which may be covered by 

Nationwide Permit No. 3, Maintenance, or possibly the Clean Water Act Section 404 

maintenance exemption.

Construction Impacts 

Although construction impacts on Waters of the US would occur as a result of soil erosion and 

potential construction pollutant loading of stormwater runoff, they would be temporary and 

would cease after construction is completed and disturbed areas become re-stabilized. In 

addition, requirements associated with the Arizona Pollutant Discharge Elimination System 

(AZPDES) and Stormwater Pollution Prevention Plan (SWPPP) would minimize impacts from 

stormwater and associated pollutants.

Eloy to Northern Hub

Physical Impacts 

The types of potential physical impacts would be similar to those discussed under the southern 

hub to Eloy segment of the Yellow Corridor Alternative. It is possible for future alignments to 

avoid the lakes in the corridor alternative, but a passenger rail system intersecting the four 

major Waters of the US that cross the corridor alternative (Gila River, Queen Creek, East Mesa 

Floodway, and Salt River) would likely trigger one of the permitting scenarios presented in 

Table 5-25 in the discussion of Tier 2 considerations. The use of bridges is recommended to 

reduce impacts within the OHWM and simplify permitting requirements.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-164

Operational Impacts 

Operational impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

Construction Impacts 

Construction impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

5.13.3.2Orange Corridor Alternative

Southern Hub to Eloy

Physical, operational, and construction impacts would be the same as those described in the

Yellow Corridor Alternative southern hub to Eloy analysis.

Eloy to Northern Hub

Physical Impacts 

The types of potential physical impacts would be similar to those discussed under the Eloy to 

northern hub segment of the Yellow Corridor Alternative. The Gila River, Queen Creek, Salt 

River, two named washes, 34 lakes, and numerous unnamed washes are located within the Eloy 

to northern hub portion of the Orange Corridor Alternative. The Superstition Springs Lakes 

comprise a chain of 21 lakes that stretch across the study corridor. A passenger rail system 

intersecting the three major Waters of the US that cross the corridor alternative (Gila River, 

Queen Creek, and Salt River) would likely trigger one of the permitting scenarios presented in 

Table 5-25 in the discussion of Tier 2 considerations. The use of bridges is recommended to 

reduce impacts within the OHWM and simplify permitting requirements.

Operational Impacts 

Operational impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

Construction Impacts 

Construction impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

5.13.3.3No Build Alternative

Under the No Build Alternative, construction would not occur; and no impacts to Waters of the 

US are anticipated beyond those that could occur due to other reasonably foreseeable projects. 

For example, the Clean Water Act Section 404 maintenance exemption permits maintenance
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-165

along existing UP lines, such as modifying or replacing culverts or bridges, with the 

understanding that impacts to the exempt activity would be minimal, in compliance with the 

requirements of Nationwide Permit (NWP) No. 3 for maintenance. In addition, minor impacts to 

Waters of the US from potential culvert replacements/extensions and bridge 

replacements/additions elsewhere in the corridor alternatives may also occur.

5.13.4 Potential Mitigation Measures

In conjunction with the Tier 2 NEPA documents, possible Waters of the US would be evaluated 

during a jurisdictional delineation. In addition, the project team would evaluate the design to 

determine where it is possible and practical to avoid or minimize impacts. Continued 

coordination with the Corps may be necessary to determine the Least Environmentally 

Damaging Practicable Alternative, if necessary.

Mitigation options available for unavoidable impacts to jurisdictional waters would be 

discussed in more detail during the Tier 2 NEPA documentation. Mitigation measures could 

include in-lieu fees and on-site or off-site permittee-responsible mitigation such as vegetation 

or habitat restoration. During the design process, coordination would take place with the Corps

and appropriate state resource agencies to develop mitigation strategies. Specific mitigation 

measures, to the extent required, would be identified and discussed during Tier 2 analysis after 

design details are known, recorded in NEPA documents as specific impacts are identified, and 

implemented prior to construction. In addition, the permit issued by the Corps and their permit 

verification letter(s) must be included as part of the construction documents.

5.13.5 Tier 2 Considerations

A jurisdictional delineation would be undertaken during Tier 2 to identify which washes would

be recommended as Waters of the US and thus subject to Section 404 permitting and 

Section 401 certification. Quantification of new, permanent impacts to Waters of the US and 

permit materials would be completed based on final design of the rail line, major structures, 

utility work, and other associated construction. Any mitigation measures included by the Corps

in their permit verification letter(s) must be included in the construction documents. 

Construction may proceed under the NWP program if impacts conform to the requirements 

and thresholds set forth in each permit. Table 5-25 below presents the likely permitting 

scenarios that may be encountered during Tier 2. The criteria in the first column include

triggers and thresholds that construction must meet to proceed under a given permit. For 

example, construction would not be able to proceed under a non-notifying NWP No. 14 unless

all of the criteria listed in the second column are met.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-166

Table 5-25. Likely Clean Water Act Permitting Scenarios During Tier 2

Permit Criteria

Non-notifying NWP 

No. 14

NWP No. 14 with a 

Preconstruction 

Notification

Individual Permit

Acreage of 

Impacts to Waters 

of the US

Impacts <0.10 acre Impacts between 0.10 acre 

and 0.50 acre

Impacts >0.50 acre

Biology No adverse impacts to 

biological resources

Adverse impacts to 

biological resources with 

complete Section 7 

consultation

Jeopardizes the 

continued existence of a 

threatened, endangered, 

or proposed species

Cultural Resources No effects to cultural 

resources

May affect cultural 

resources with sufficient 

Section 106 consultation

N/A

Perennial Rivers or 

Special Aquatic 

Sites

No impacts to perennial 

rivers or special aquatic 

sites

May affect perennial 

rivers; no impacts to 

special aquatic sites

Impacts to special 

aquatic sites

General/Regional 

Conditions

Complies with all general 

and regional conditions

Complies with all general 

and regional conditions

Does not comply with at 

least one general or 

regional condition

Threshold for 

Meeting Permit 

Requirements

Must meet all the above 

criteria

Any one of the above 

criteria triggers a 

preconstruction 

notification 

Any one of the above 

criteria triggers an 

individual permit

Additional 

Section 404 

Permitting 

Requirement(s)

Would require separate 

permit for impacts from 

stations, other non-linear 

features, or utilities

Would require separate 

permit for impacts from 

stations, other non-linear 

features, or utilities

Could cover all impacts 

from all construction

5.14 Wetlands

To administer the Corps’ Section 404 permit program, the EPA (EPA, May 11, 2012) and the 

Corps define wetlands as “those areas that are inundated or saturated by surface or 

groundwater at a frequency and duration sufficient to support, and that under normal 

circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil 

conditions. Wetlands generally include swamps, marshes, bogs and similar areas” (USEPA, 40 

CFR 239.2 and Corps, 33 CFR 328.3). For this analysis, this resource includes potential wetland 

areas as designated on the USFWS National Wetland Inventory (NWI) maps.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-167

5.14.1 Methodology and Regulatory Requirements

The regulatory framework pertaining to wetlands includes Section 404 of the Clean Water Act 

of 1972 (as amended), and Executive Order 11990, Protection of Wetlands (USDOT Order 

5660.1A). For permitting purposes, the corridor alternatives lie within the Corps’ Los Angeles 

regulatory district. 

The USFWS NWI database was used to identify locations of potential wetland areas within the 

corridor alternatives. The NWI maps are based on a classification system known as the 

Cowardin System, which classifies the types of ecosystems related to water resources 

(USFWS 1979). Typical wetland classifications in the Arid West include riverine, freshwater 

pond, and freshwater forested/shrub.

The regulatory definition of wetlands emphasizes that wetlands must possess three essential 

characteristics before a positive determination of a wetland can be made: hydric soils, a 

prevalence of hydrophytic vegetation, and a persistent wetland hydrology. Jurisdictional 

wetlands in Arizona are regulated as special aquatic sites pursuant to 40 CFR Part 230.41, and, 

per NWP Regional Condition No. 2, very few of the Corps’ NWPs can be used to authorize 

construction that would result in the loss of wetlands in Arizona. Therefore, in Arizona, impacts 

to a wetland are likely to result in a Section 404 Individual Permit. When impacts to wetlands 

trigger a Section 404 Individual Permit, a Section 401 Individual Water Quality Certification is 

also required.

In conjunction with the Tier 2 NEPA documents, a wetland delineation and more detailed 

impact analysis of potential wetland areas would be conducted, including field surveys, to 

determine which areas meet the USEPA and Corps regulatory criteria and definition of a 

wetland, and to determine the types and boundaries of those wetland areas. The potential also 

exists for additional wetlands to be found in the course of those surveys. Coordination would 

take place with the Corps to determine which wetland areas are jurisdictional or nonjurisdictional for Section 404 permitting purposes and mitigation requirements.

5.14.2 Existing Conditions

The Corridor Aerial Atlas Appendix, Maps 1 through 91, show the NWI-mapped wetlands within 

and adjacent to the corridor alternatives. Table 5-26 shows the approximate acreage of 

different wetland types within the 1-mile-wide Yellow and Orange corridor alternatives, and 

based on those numbers, the potential acreage of different wetland types within a 200-foot 

ROW corridor.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-168

Most of the NWI-identified wetlands can be characterized by the following:

 Various channels of the Santa Cruz, Rillito, Gila, and Salt rivers

 Areas within the associated floodplains of the rivers named in the previous bullet 

(including Sweetwater Wetlands Park)

 Ponding areas in or adjacent to ephemeral washes

 Canals that receive water throughout the year

 Freshwater ponds associated with sand and gravel operations, golf courses, and parks

 Retention basins, stock tanks, or other water storage and management areas for 

agricultural, industrial, and residential purposes

Table 5-26. Potential Wetland Areas within the Yellow and Orange Corridor Alternatives

Wetland Type

Wetland 

Abbreviationa

Acres

(1-Mile Corridor)

Acres 

(200' ROW)

Yellow and Orange Corridor Alternatives–Southern Hub to Eloy 465 17.6

Freshwater Emergent Wetland PEM 0.00 0.00

Freshwater Forested/Shrub Wetland PFO, PSS 15 0.57

Freshwater Pond PUB 150 5.69

Lake L2UB 45 1.71

Riverine R2UB, R2US, R4SB, 

R4SBAx, R4SBJ

255 9.66

Associated with river channels and 

ephemeral washes

(percent of total acreage)

- 310

(67%)

11.75

(67%)

Yellow Corridor Alternative–Eloy to Northern Hub 565 21.4

Freshwater Emergent Wetland PEM <1 <0.04

Freshwater Forested/Shrub Wetland PFO <1 <0.04

Freshwater Pond PUB 90 3.41

Lake L2UB 60 2.27

Riverine R4SB 415 15.73

Associated with river channels and 

ephemeral washes

(percent of total acreage)

- 290

(51%)

10.99

(51%)

Orange Corridor Alternative–Eloy to Northern Hub 1,010 38.3

Freshwater Emergent Wetland PEM 2 0.08
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-169

Table 5-26. Potential Wetland Areas within the Yellow and Orange Corridor Alternatives

Wetland Type

Wetland 

Abbreviationa

Acres

(1-Mile Corridor)

Acres 

(200' ROW)

Freshwater Forested/Shrub Wetland PFO, PSS 20 0.76

Freshwater Pond PUB 130 4.93

Lake L1UB, L2UB 50 1.90

Riverine R4SB 810 30.70

Associated with river channels and 

ephemeral washes

(percent of total acreage)

- 590

(58%)

22.36

(58%)

Source: NWI 2014

a L1UB: Lacustrine Limnetic Unconsolidated Bottom

L2UB: Palustrine Littoral Unconsolidated Bottom

PEM: Palustrine Emergent

PFO: Palustrine Forested

PSS: Palustrine Scrub-shrub 

PUB: Palustrine Unconsolidated Bottom

R2UB: Riverine Lower Perennial Unconsolidated Bottom

R2US: Riverine Lower Perennial Unconsolidated Shore

R4SB: Riverine Intermittent Streambed

R4SBAx: Riverine Intermittent Streambed Temporarily Flooded 

Excavated

R4SBJ: Riverine Intermittent Streambed Intermittently Flooded

Based on a review of aerial photos, it is likely that jurisdictional wetlands would only be 

determined along or near the banks of the named rivers, and potentially in ponding areas along 

ephemeral washes. These areas represent almost 60 percent of the NWI-identified potential 

wetlands. As discussed in Section 5.13, Waters of the US, the CAP canal, and the various 

irrigation canals are likely to be considered utilities and determined not jurisdictional. The 

majority of ponds, retention basins, stock tanks, and other water storage and management 

areas appear to be isolated waters without an upstream and/or a downstream connection to a 

possible Water of the US. Therefore, it is likely they would not be considered jurisdictional.

5.14.3 Environmental Consequences

Based on the types of construction typically associated with new rail infrastructure, it is likely 

that a Section 404 Individual Permit would be required if construction were to result in 

permanent impacts to jurisdictional wetlands. If preliminary geotechnical activities within 

jurisdictional wetlands were designed to conform to Nationwide Permit No. 6 (Survey 

Activities), a preconstruction notification to the Corps would be required rather than an 

Individual Permit.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-170

Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts

Impacts to possible jurisdictional wetlands would vary depending on the placement of the 

passenger rail system within the corridor. Acquisition of ROW to construct a passenger rail 

system could have unavoidable impacts to wetlands within the corridor alternative. The 

majority of wetlands likely to be recommended as jurisdictional (approximately 270 acres) are 

associated with the Santa Cruz and Rillito rivers between Tucson and Marana; another 40 acres 

of NWI-identified wetlands are associated with ephemeral washes. Direct physical impacts to 

wetlands would increase if a passenger rail system is constructed southwest of the existing UP

railway, closer to the Santa Cruz River. North of Marana, most of the NWI-identified wetlands 

are associated with stock tanks and water storage; and, if they are found to lack a direct 

connection to a designated Water of the US, impacts to them would not require a Section 404 

permit. Wetland areas could be affected by cuts, fills, or diversions required to construct 

ballast, embankments, drainage slopes, or other railway components.

Impacts to jurisdictional wetlands could occur as a result of construction activities including 

placement of fill material for track and siding, culvert replacement or extensions, and bridge 

replacement or additions. Some construction impacts, like placement of fill, would be 

considered permanent and subject to permitting by the Corps.

Operational Impacts

Impacts to jurisdictional wetlands from the operation of a passenger rail system are likely 

limited to those associated with the maintenance of culverts or bridges. Efforts during the 

design phase to avoid wetlands would help to minimize potential impacts from maintenance 

because fewer wetlands may be in close proximity to a future rail line. Currently, a Nationwide 

Permit No. 3 (Maintenance) cannot be used in jurisdictional wetlands in Arizona. However, 

ADOT would make an effort to avoid and/or minimize permanent impacts to wetlands, and 

would work with the Corps to evaluate alternative permitting scenarios.

Construction Impacts

Temporary construction impacts may occur as a result of soil disturbance and potential 

construction pollutant loading of stormwater runoff; however, they would be temporary and 

would cease after construction is completed. In addition, the AZPDES and SWPPP requirements 

would minimize impacts from stormwater and associated pollutants.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-171

Eloy to Northern Hub

Physical Impacts

Impacts on jurisdictional wetlands would vary based on the placement of the passenger rail 

system within the corridor. Acquisition of ROW to construct new railroad infrastructure could 

have unavoidable impacts to wetlands within the corridor alternative. The majority of wetlands 

likely to be recommended as jurisdictional (approximately 280 acres) are associated with the 

Gila and Salt rivers north of Coolidge and Tempe, respectively. Another 10 acres of NWIidentified wetlands are associated with ephemeral washes. Direct physical impacts to wetlands 

could be minimized to the Gila River because the passenger rail system would likely be placed 

perpendicular to the river. Impacts to the Salt River may increase if the passenger rail system is 

placed south of the SR 202L. The remaining NWI-identified wetlands in this corridor are 

associated with irrigation canals, water storage, and constructed lakes. If they are found to lack 

a direct connection to a designated Water of the US, these resources would not require a 

Section 404 permit. Wetland areas could be affected by impacts to cuts, fills, or diversions 

required to construct ballast, embankments, drainage slopes, or other railway components.

Operational Impacts

Operational impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

Construction Impacts

Construction impacts would be similar to those described in the Yellow Corridor Alternative

southern hub to Eloy analysis.

Orange Corridor Alternative

Southern Hub to Eloy

Physical, operational, and construction impacts would be the same as those described in the 

Yellow Corridor Alternative southern hub to Eloy analysis.

Eloy to Northern Hub

Physical Impacts

Physical impacts would be similar to those described in the Yellow Corridor Alternative-Eloy to 

northern hub analysis; however, the acreage of potential wetlands associated with the Gila and 

Salt rivers (approximately 580 acres) in the Orange Corridor Alternative Eloy to northern hub is 

more than double the acreage in the Yellow Corridor Alternative Eloy to northern hub because 

of an additional 315 acres of Salt River-associated potential wetlands. Another 10 acres of NWI-
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-172

identified wetlands are associated with ephemeral washes. The Gila River-associated wetlands 

decrease by approximately 10 acres in this study corridor. The additional acreage presents 

increased challenges for avoiding and minimizing impacts to wetlands as required by the Corps.

Operational Impacts

Operational impacts would be similar to those described in the Yellow Corridor Alternativesouthern hub to Eloy analysis.

Construction Impacts

Construction impacts would be similar to those described in the Yellow Corridor Alternativesouthern hub to Eloy analysis.

No Build Alternative

Under the No Build Alternative, construction would not occur, and no impacts to wetlands 

would occur beyond those that could occur due to other reasonably foreseeable projects.

5.14.4 Potential Mitigation Measures

In conjunction with the Tier 2 NEPA documents, wetlands would be reviewed to determine 

where it is possible and practical to avoid or minimize impacts. If a Section 404 Individual 

Permit is required, the permit application must include documentation of an alternatives 

selection process and attempts to avoid and minimize impacts to wetlands. The use of pilings or 

bridges to minimize fill is one example of how impacts to wetlands could be minimized. 

Mitigation options available for unavoidable impacts to jurisdictional wetlands would be 

discussed in more detail during Tier 2 NEPA documentation and could include in-lieu fees and 

on-site or off-site permittee-responsible mitigation. Arizona does not have mitigation banking. 

During the design process, coordination would take place with the Corps and appropriate 

resource agencies to develop appropriate mitigation strategies. FRA, as the lead agency, would 

be required to document which alternative would be the Least Environmentally Damaging 

Practicable Alternative; this would be the Corps’ preferred alternative during the Section 404 

Individual Permit process. Specific mitigation measures, to the extent required, would be 

identified and discussed during Tier 2 analysis after design details are known, recorded in NEPA 

documents as specific impacts are identified, and implemented prior to or during construction.

5.15 Water Quality

This water quality assessment addresses the potential effects of sediment erosion and chemical 

pollution on surface water resources (e.g., streams, lakes, ponds, wetlands) as well as 

groundwater. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-173

5.15.1 Methodology and Regulatory Requirements

The CWA is the primary federal statute governing discharge of pollutants into Waters of the US, 

which, in Arizona, include perennial and ephemeral watercourses and their tributaries and 

adjacent wetlands. The principal goal of the CWA is to establish water quality standards to 

restore and maintain the chemical, physical, and biological integrity of the nation’s Waters by 

preventing point (concentrated output) and nonpoint (widely scattered output) pollution 

sources. While effects on Waters of the US are addressed in Section 5.13, CWA compliance is 

mentioned here for its role in preventing deterioration of water quality.

Section 401 of the CWA requires that the activities covered by the Section 404 permit are 

certified according to the state’s applicable effluent limitations and water quality standards. In 

Arizona, Section 401 certification is directly related to the Section 404 permit and certification is 

applied for concurrently with the Section 404 permit approval. Section 401 certification is 

administered by the Arizona Department of Environmental Quality (ADEQ) if the action is 

entirely on non-Tribal lands. If any portion of the action occurred within or affected Tribal 

Waters of the US, the Section 401 certification would be obtained from either the EPA or the 

respective Tribe.

Section 402 of the CWA formed the National Pollutant Discharge Elimination System (NPDES), 

which regulates pollutant discharges, including stormwater, into Waters of the US. An NPDES 

permit sets specific discharge limits for point-source pollutants and outlines special conditions 

and requirements for a particular project to reduce impacts to water quality. In 2002, the EPA 

authorized the ADEQ to administer the NPDES program at the state level, called the Arizona 

Pollutant Discharge Elimination System (AZPDES). AZPDES permits require that projects be 

designed to protect Waters of the US, that erosion control Best Management Practices (BMP)

be implemented, and that a Stormwater Pollution Prevention Plan (SWPPP) be prepared for 

construction activities exceeding 1.0 acre of ground disturbance.

Other regulatory terms used in describing water quality include impaired waters and notattaining waters.

Impaired waters are bodies of water that fail to meet water quality standards (based on a 

bi-annual assessment of surface water chemistry) and are not supporting designated beneficial 

uses (such as supporting aquatic life, fish consumption, and recreation). 

The assessments are submitted to EPA in the Integrated 305(b) Assessment and 303(d) Listing 

Report, named after the two sections of the CWA that established these requirements. The 

303(d) list identifies those waters that are impaired and lists the pollutant causing the 

impairment. States identify waters where required pollution controls are not sufficient to attain 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-174

or maintain applicable water quality standards, and establish priorities for development of 

Total Maximum Daily Load (TMDL) based on the severity of the pollution and the sensitivity of 

how the water body is used. A TMDL is a calculation of the maximum amount of a pollutant

that a waterbody can receive and still meet water quality standards (EPA 2012a). Pollutant 

loading can originate from either point or non-point sources. 

Once a TMDL has been developed, the surface water is removed from the 303(d) list and is 

classified as “not attaining,” which means the TMDL study is complete, but the waterbody is not 

yet in attainment with water quality standards for the designated uses of the waterbody. 

Corrective actions are developed in a TMDL Implementation Plan, and timeframes are 

established to comply with the applicable water quality standards.

Under the Federal Water Pollution Control Act, Section 303(d), each state is required to identify 

water resources that do not meet the state’s water quality standards. In addition to the Water 

Pollution Control Act and Sections 401 and 402 of the CWA (1972, as amended), other 

regulations pertaining to water quality include EO 12088, Federal Compliance with Pollution 

Control Standards (43 FR 47707)(1978).

The sole source aquifer protection program, authorized by Section 1424(e) of the Safe Drinking 

Water Act of 1974 (42 U.S.C. § 300 et seq.) is intended to protect drinking water supplies in 

areas where there are few or no alternatives sources to the groundwater resource and where, 

if contamination occurred, using an alternative source would be extremely expensive (EPA 

2012b).

This evaluation assesses the effects on water quality from a future passenger rail system in one 

of the corridor alternatives. GIS and other data were obtained to evaluate the existing 

conditions and potential effects. Data from ADEQ were used to determine the presence of 

impaired waters and waters not attaining Arizona’s water quality standards. Arizona 

Department of Water Resources data provided information on registered wells. Sole source 

aquifer data were obtained from EPA, and wetland data were obtained from USFWS. Sub-basin 

and watershed boundaries were derived from United States Bureau of Reclamation and NRCS 

data.

5.15.2 Existing Conditions

The Yellow and Orange corridor alternatives are located within the Bureau of Reclamation’s 

Lower Colorado Region and encompass portions of 14 watersheds (USBR 2013; NRCS 2013a,

2013b).
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-175

Yellow Corridor Alternative 

Southern Hub to Eloy

Water resources in the southern half of the Yellow Corridor Alternative comprise an extensive 

network of perennial and ephemeral watercourses, wetlands, and other surface water 

resources that generally flow toward the Santa Cruz River (generally flowing south to north) 

and Gila River (generally flowing east to west). The largest watercourse in the corridor 

alternative is the Santa Cruz River, which extends from the City of Tucson, northwest toward 

the City of Eloy, and on to the Gila River. Most of the ephemeral watercourses in the area, 

including Rillito River, Cañada del Oro, and Julian Wash, are tributaries to the Santa Cruz River. 

At least one small lake is in this portion of the Yellow Corridor Alternative; Silverbell Lake is 

located adjacent to Christopher Columbus Park, at 4600 North Silverbell Road in Tucson. The 

water resources within the corridor alternative are shown in the Corridor Aerial Atlas Appendix. 

Due to ammonia content, a portion of the Santa Cruz River in the vicinity of the City of Marana,

and apparently within the southern half of the Yellow Corridor Alternative, is identified as an 

EPA 303(d) not attaining water (ADEQ 2010a, 2013a).

The southern portion of the Yellow Corridor Alternative passes through the Tucson and Pinal 

Active Management Areas (AMAs), which are areas regulated by Arizona’s Groundwater Code 

to manage the state’s finite groundwater resources. The management goal for the Tucson AMA 

is to establish a safe yield by 2025 so that no more groundwater is being withdrawn than is 

being annually replaced. In the Pinal AMA, the goal is to preserve the agricultural economy for 

as long as is feasible while considering the need to preserve groundwater for future nonirrigation uses.

Key features pertinent to water quality in the southern half of the Yellow Corridor Alternative 

include:

 A designated area of the Upper Santa Cruz & Avra Basin Sole Source Aquifer (EPA 2008a)

 One wastewater treatment plant (Tres Rios Water Reclamation Facility, located near 

I-10 and Ina Road in Tucson)

 Approximately 24 named ephemeral washes and numerous unnamed ephemeral 

washes 

 Approximately 465 acres of wetlands (see Section 5.14)

 Approximately 656 water wells (ADWR 2013) 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-176

Eloy to Northern Hub

The northern half of the Yellow Corridor Alternative also comprises ephemeral watercourses, 

wetlands, and other surface water resources that generally flow from southeast to northwest 

(draining into the Gila River) in areas south of the Gila River. North of the Gila River, water 

generally flows from the northeast to southwest and drains into the Salt River. In the Phoenix 

Metropolitan area, the Yellow Corridor Alternative also includes portions of the Salt River. The 

flow patterns of natural watercourses are generally less well defined in the Phoenix 

Metropolitan area than in outlying areas because the watercourses have been disturbed by 

agricultural activities and development. 

The northern portion of the Yellow Corridor Alternative passes through the Pinal and Phoenix 

AMAs. In the Pinal AMA, the goal is to preserve the agricultural economy for as long as is 

feasible while considering the need to preserve groundwater for future non-irrigation uses. The 

management goal for the Phoenix AMA is to establish a safe yield by 2025 so that no more 

groundwater is being withdrawn than is being annually replaced.

Key features pertinent to water quality in the northern half of the Yellow Corridor Alternative 

include:

 Tempe Town Lake

 Approximately five canals, all in the Phoenix metropolitan area

 Numerous unnamed washes 

 Approximately 565 acres of wetlands (see Section 5.14)

 Approximately 1,135 well sites (ADWR 2013) 

Orange Corridor Alternative

Southern Hub to Eloy

Water resource features in the Orange Corridor Alternative from the southern hub to Eloy are 

the same as those described for Yellow Corridor Alternative from the southern hub to Eloy.

Eloy to Northern Hub

The northern half of the Orange Corridor Alternative also comprises ephemeral watercourses, 

wetlands, and other surface water resources that generally match those described in the Yellow 

Corridor Alternative study, including the presence of the Salt River.

Like the Yellow Corridor Alternative, the northern portion of the Orange Corridor Alternative 

also passes through the Pinal and Phoenix AMAs.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-177

Key features pertinent to water quality in the northern half of the Orange Corridor Alternative 

include:

 Tempe Town Lake

 Approximately five canals, all in the Phoenix metropolitan area

 Approximately 1,010 acres of wetlands (see Section 5.14)

 Two named washes and numerous unnamed washes 

 Approximately 991 well sites (ADWR 2013) 

5.15.3 Environmental Consequences

Yellow and Orange Corridor Alternatives

In general, the potential environmental consequences are similar for all segments of the Yellow 

and Orange corridor alternatives. While the Yellow Corridor Alternative encompasses more 

wells and the Orange Corridor Alternative encompasses more wetlands, the specific effects on 

these resources would not be determined until a Tier 2 analysis is prepared for a specific 

alignment. Additionally, conditions within the corridor alternatives change over time. 

Therefore, updated data would need to be obtained when the Tier 2 analysis is undertaken.

Physical Impacts

A passenger rail system has the potential to affect groundwater due to the large number of 

wells and the presence of the Upper Santa Cruz & Avra Basin Sole Source Aquifer. Wells provide 

a more direct pathway for runoff to flow to groundwater, so the number of wells contributes to 

the understanding of the potential for groundwater contamination and the types of mitigation 

measures that may be required. Additionally, the large number of wells within the study 

corridors suggests that well relocations would be likely with development of a passenger rail 

system in either corridor alternative.

New rail infrastructure would increase the amount of impervious surface (pavement), which 

influences surface water flow and may contribute to flooding because the natural surface is no 

longer exposed and able to absorb water during a storm; however, the potential increase 

represents a very minor fraction of the surfaces in the surrounding area, and potential flooding 

could be mitigated through drainage design. A passenger rail system also could influence 

drainage patterns, which could potentially affect water resources such as wetlands. The effects 

could cut off flows to some areas or increase the amount of flows to other areas. Compliance 

with Section 401 Water Quality Certification and Section 402 AZPDES permit requirements 

would be necessary, but the permit requirements cannot be fully be determined until Tier 2 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-178

studies define a rail alignment and design parameters. Disturbance of 1 contiguous acre or 

more from construction activity (which is reasonably foreseeable) would require a construction 

general permit, which in turn requires an SWPPP. In addition, the corridor’s proximity to the 

not-attaining segment of the Santa Cruz River would trigger a water quality monitoring program 

as part of the SWPPP, and an Individual Section 401 Water Quality Certification.

Operational Impacts

Operational effects on water quality are mainly associated with stormwater runoff and may be 

influenced by operation and maintenance of the rail facilities, while potentially removing some 

volume of vehicle traffic from I-10 and other roadways in the area. Operation of a passenger 

rail system could result in a minor increase the volume of pollutants (e.g., fuel and oils) within 

the corridor that could potentially enter into surface waterways or groundwater (through well 

sites) via stormwater runoff. Stormwater runoff may contain sediment, nutrients (e.g., 

phosphorus and nitrogen), pesticides, petroleum derivatives, solid wastes, or other chemicals 

and metals. 

Construction Impacts

Ground disturbance associated with construction activities would be expected to increase the 

volume of sediment in stormwater. If soils in construction areas were previously contaminated, 

such as by agricultural use of pesticides or petroleum derivatives leaked from vehicles, the soil 

disturbance may potentially increase pollutant loading in the runoff. Construction activities 

would minimize erosion and sediment discharges to the extent practicable using control 

measures.

Water for dust control may be required during construction. This short-term use of water 

would not be expected to affect the goals of the AMAs, but specific water needs and water 

sources would be identified and analyzed during Tier 2 documentation. The southern segment 

of both corridor alternatives is within the Upper Santa Cruz & Avra Basin Sole Source Aquifer. 

Therefore, protection of the aquifer from sources of contamination would be particularly 

important during construction.

Development of a passenger rail system would result in ground disturbance greater than 

1.0 acre and would require an AZPDES permit and the implementation of erosion-control BMPs 

and a SWPPP to ensure water quality is protected during construction activities. Short-term 

effects on water quality include those associated with stormwater runoff from construction 

activities. Most of the effects from construction runoff would remain only for the duration of 

the construction activities; however, construction activities could potentially result in long-term 

effects from pollutant discharge into the groundwater system. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-179

No Build Alternative

Under the No Build Alternative, a new passenger rail system would not be built, so no projectrelated effects on water quality would occur. Operational pollutants such as oils and lubricants 

would not be generated and would not influence the amount of contaminants in stormwater 

runoff; however, traffic volumes along I-10 between the cities of Tucson and Phoenix would 

continue to increase, which would likely raise pollutant levels in stormwater runoff originating 

on the highway. 

5.15.4 Potential Mitigation Measures

An AZPDES Construction General Permit (NPDES permit for tribal or other federal land) would

need to be obtained as part of future Tier 2 activities to authorize any stormwater discharges 

associated with construction of a future passenger rail system.

Specific mitigation measures are anticipated as follows, but future Tier 2 analysis would confirm 

these measures: 

 The contractor will obtain the most current copy of the BMPs for incorporation in the 

SWPPP.

 Upon completion and ADOT Engineer approval of the SWPPP, the ADOT Engineer and 

contractor will each file a Notice of Intent to ADEQ. Upon final acceptance of a project 

by the ADOT Engineer, the ADOT Engineer and the contractor will each file a Notice of 

Termination for a project to ADEQ. The contractor will provide copies of the completed

final SWPPP, Stormwater Monitoring Plan, if needed, and contractor Notice of Intent 

and Notice of Termination to the ADOT Engineer.

 The ADOT Engineer will submit the contractor’s AZPDES Notice of Intent and the Notice 

of Termination to the ADOT Environmental Coordinator.

 No work shall occur within jurisdictional Waters of the US until the appropriate Clean 

Water Act Section 401 certification and 404 permits are obtained.

 Consider secondary containment at rail maintenance yards where petroleum-based 

products may be stored or used and at rail station parking lots to control stormwater 

runoff to minimize the risk of contaminating surface and groundwater, particularly 

within the boundaries of the sole source aquifer.

The following standard specifications also may be included as mitigation measures: 

 According to ADOT’s Standard Specifications for Road and Bridge Construction, 

Section 104 Scope of Work, Subsection 09 Prevention of Landscape Defacement; 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-180

Protection of Streams, Lakes, and Reservoirs (2008 Edition) ― The contractor shall take 

sufficient precautions, considering various conditions, to prevent pollution of streams, 

lakes, and reservoirs with fuels, oils, bitumens, calcium chloride, fresh Portland cement, 

fresh Portland cement concrete, raw sewage, muddy water, chemicals or other harmful 

materials. None of these materials shall be discharged into any channels leading to such 

streams, lakes, or reservoirs.

 According to ADOT’s Standard Specifications for Road and Bridge Construction, 

Section 104 Scope of Work, Subsection 09 Prevention of Landscape Defacement; 

Protection of Streams, Lakes, and Reservoirs (2008 Edition) ― The contractor shall give 

special attention to the effect of its operations upon the landscape and shall take special 

care to maintain natural surroundings undamaged.

5.15.5 Tier 2 Considerations

The quantities of ephemeral watercourses, wetlands, wells, and other water resources 

identified in the affected environment are based on 1-mile-wide corridors rather than specific 

alignments. Many of the resources would be avoided simply by narrowing the width of the 

affected area, but the specific resources affected by a future alignment would warrant careful 

analysis during Tier 2 studies because some water resources may be more sensitive than 

others. Also, because conditions change over time, data would need to be updated when Tier 2

analysis is undertaken. 

Water would be needed for construction and operation of a passenger rail facility. Water is 

typically used to control dust in areas disturbed by construction. Rail stations would require 

water for passenger drinking water and sanitation. Quantities and sources of water have not 

yet been defined and would need to be identified and analyzed in Tier 2 documentation, with 

particular consideration given to the portion of the corridor alternatives within a sole source 

aquifer.

5.16 Floodplains

The analysis for this resource includes 100-year floodplains (areas with a 1-percent annual 

chance of flooding) as defined by the Federal Emergency Management Agency (FEMA) in 

accordance with 44 CFR 59.1. Floodplains are the areas adjoining a river or stream that has 

been or may be covered by the 100-year flood.

Floodways are the channel of a river or stream and the part of the floodplain adjoining the 

channel that serve as the natural conduit for floodwaters. Floodways must remain open to 

allow floodwaters to pass because obstructions in the floodway would result in flooding of an 

even greater area.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-181

5.16.1 Methodology and Regulatory Requirements

The regulatory framework pertaining to floodplains is EO 11988, Floodplain Management (as 

amended), which states that federal agencies are required “... to avoid, to the extent possible, 

the long- and short-term adverse impacts associated with the occupancy and modification of 

floodplains, and to avoid direct and indirect support of floodplain development wherever there 

is a practicable alternative.” 

Flood control districts with jurisdiction within portions of the corridor alternatives include the 

Pima County Flood Control District, City of Tucson, Pinal County Flood Control District, and the 

Flood Control District of Maricopa County. 

The data collection and analysis for this Tier 1 EIS were undertaken prior to the 2015 adoption 

of EO 13690, which changed the approach for establishing the flood hazard area. Digital 100-

year floodplain data, based on FEMA’s Flood Insurance Rate Maps of Special Flood Hazard 

Areas, were compiled from the FEMA website. Special Flood Hazard Areas (or 100-year 

floodplains) are the areas subject to flooding by the 1-percent annual chance flood. Special 

Flood Hazard Area Zone A is designated as having no base flood elevations determined;

whereas, in Special Flood Hazard Area Zone AE, base flood elevations have been determined. 

Zone AH designates areas with a 1-percent chance of shallow flooding with a constant water 

surface elevation, that is, areas of ponding. Zone AO designates areas with a 1-percent annual 

chance of flooding that results in sheet flow on sloping terrain. 

Areas of flood Zone D were not included in readily available data and would be investigated in 

Tier 2 studies.

Potential avoidance and minimization of impacts on 100-year floodplains would be further 

evaluated in the Tier 2 NEPA documents. Per EO 13690, the Tier 2 analysis would either utilize a 

climate-informed science approach, add 2 to 3 feet of elevation to the mapped 100-year 

floodplain, or use the 500-year floodplain. Any proposed encroachments in a 100-year 

floodplain area would require coordination with local floodplain administrators to discuss 

floodplain development permitting and potential mitigation measures.

5.16.2 Existing Conditions

Flooding is common in the desert Southwest where large amounts of precipitation can fall in a 

short period of time. Because of the arid climate, vegetation is often sparse, and soils tend to 

be thin and discontinuous. With little soil to absorb water and little vegetation to hold it back, 

precipitation runs off quickly and can result in floods. The potential for flooding is higher in 

urban areas, where most of the land is covered with buildings and pavement. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-182

Major flooding occurred as recently as 1980 in the Phoenix area and 1983 in southern Arizona. 

The 1980 storm caused severe flooding on the Gila and Salt rivers. The greatest damage 

occurred along the Salt River, where 11 of 13 bridges were destroyed or damaged (Maricopa 

County Flood Control District 2013). The UP bridge over the Salt River survived this storm and 

was even used for a few weeks by a temporary commuter train between Mesa/Tempe and 

Phoenix, as most other routes were closed (Arizona Rail Passenger Association 2013). The 

existing railroad bridge has been in use since 1912 on a site where three previous railroad 

bridges were destroyed by flooding.

In 1983, Tropical Storm Octave brought 10 days of heavy rain to Arizona. The Tucson area was 

hit especially hard, as the Santa Cruz River, Rillito River, and Pantano Wash all overflowed their 

banks. Property damage was estimated at $370 million (Maricopa County Flood Control District 

2013). The effects of the storm were felt throughout the state; for example, the Santa Fe 

Railway serving the city of Prescott was washed out in several places and eventually 

abandoned, leaving Prescott with no rail service.

Floodplains present in the corridor alternatives are associated with:

 Santa Cruz River

 Rillito River

 Gila River

 Queen Creek

 Salt River

 Indian Bend Wash

 Numerous canals (including Eastern, Grand, Roosevelt, and Tempe canals)

 At least 24 named washes and numerous unnamed washes

Most major rivers and washes and some smaller washes within the study corridor have

100-year floodplains mapped by FEMA. Maps 1 through 91 in the Corridor Aerial Atlas Appendix

show the floodplains near or within the corridor alternatives. Early railroads were located along

valley floodplains of rivers and washes wherever possible to take advantage of the level or

nearly level terrain and minimize cut and fill construction operations. As such, portions of the

corridor alternatives run parallel to several waterways and their adjoining floodplains (Santa 

Cruz River, Salt River), in addition to crossing several floodplains at a perpendicular or skewed 

angle (Gila River, Indian Bend Wash, Rillito River). 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-183

Approximately 13,344 acres of 100-year floodplains are within the corridor alternatives, as 

shown in Table 5-27. ROW corridors 200 feet in width would incorporate approximately 506 

100-year floodplain acres.

Table 5-27. Floodplain Acreage in the Corridor Alternatives

Approximate Acres in 

the 1-Mile (and 200') 

Corridor Segment

Acreage within the 

100-year Floodplain for 

1-Mile (and 200’) 

Corridor

Percent of Total 

Corridor Acres in the 

100-year Floodplain

1-Mile (and 200') 

Corridor Acres within 

Floodway

Southern Hub to Eloy – Yellow and Orange Corridor Alternatives

28,400 (1,076) 5,860 (222) 20.6% 0 (0)

Eloy to Northern Hub – Yellow Corridor Alternative

48,700 (1,846) 3,470 (132) 7.1% 230 (8.7) [Salt River]

Eloy to Northern Hub – Orange Corridor Alternative

53,900 (2,043) 4,016 (152) 7.5% 49 (1.9) [Indian Bend 

Wash]

595 (22.6) [Salt River]

5.16.3 Environmental Consequences

Because some stretches of the corridor alternatives run along and across several 100-year 

floodplains, it is unlikely that floodplain impacts from constructing a passenger rail system could 

be avoided. New rail infrastructure would likely cross and permanently encroach on several 

100-year floodplains. Depending on how close a passenger rail line might be to the existing UP 

freight line, this could include adding track and sidings, widening or replacing bridges, and 

replacing or extending culverts. 

Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts

Physical impacts to floodplains could occur through dredging within the floodplain; placement 

of track and sidings; construction of new, widened, or replaced bridges or culverts; or 

placement of rail stations, if these activities occurred within a 100-year floodplain. The 1-milewide Yellow Corridor Alternative from the southern hub to Eloy encompasses approximately 

5,860 acres of floodplain, as summarized in Table 5-27 above. No regulatory floodways are 

located in this corridor segment. Until Tier 2 studies define alignments within the corridor, the 

amount of floodplain affected cannot be determined, but the fact that more than 20 percent of 

the corridor is within the 100-year floodplain suggests there would be effects. Floodplains and 

floodways that could potentially be affected include the following hydrologic features: Arroyo 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-184

Chico Wash, Bronx Wash, Cañada del Oro, El Rio Wash, Flowing Wells Wash, Prospect Wash, 

Rillito River, Santa Cruz River, as well as unnamed washes.

Operational Impacts

Operation of a passenger rail system within the corridor would have no impacts on floodplains, 

although maintenance activities could have an effect, depending on the nature of the work.

Construction Impacts

Construction of a passenger rail system could have temporary impacts associated with 

construction activities in or adjacent to floodplains. This could include parking vehicles or 

storing equipment or materials in a floodplain or having construction equipment in the 

floodplain for short periods of time. These temporary impacts would occur only during the 

construction phase, and would comply with all local, state, and federal floodplain regulations.

Eloy to Northern Hub

Physical Impacts

Physical impacts to floodplains could occur through dredging within the floodplain; placement 

of track and sidings; construction of new, widened, or replaced bridges or culverts; or 

placement of rail stations, if these activities occurred within a 100-year floodplain. 

Approximately 3,470 acres of floodplain are located within this corridor segment; depending on 

the placement of passenger rail system infrastructure, floodplains and floodways could 

potentially be affected, Including those associated with the following hydrologic features: 

Consolidated Canal East Branch, Eastern Canal, Gila River, Grand Canal, Queen Creek, Roosevelt 

Canal, Salt River, Tempe Canal, as well as unnamed washes. 

Operational Impacts

Operation of a passenger rail system within the corridor would be similar to those for the 

southern hub to Eloy corridor segment.

Construction Impacts

Construction impacts would be similar to those for the southern hub to Eloy corridor segment.

Orange Corridor Alternative

Southern Hub to Eloy

Physical, operational, and construction impacts in this segment of the Orange Corridor 

Alternative would be the same as those in the Yellow Corridor Alternative southern hub to Eloy 

segment.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-185

Eloy to Northern Hub

Physical Impacts

Physical impacts to floodplains would occur from dredging within the floodplain or the 

placement of track and sidings, bridges, culverts, or rail stations, if the infrastructure is within a 

100-year floodplain. Depending on the placement of the passenger rail and stations, portions of 

the approximately 4,016 acres of floodplain in this corridor segment could potentially be 

affected, including those associated with the following hydrologic features: Consolidated Canal 

East Branch, Eastern Canal, Gila River, Grand Canal, Indian Bend Wash, Queen Creek, Roosevelt 

Canal, Salt River, Tempe Canal, as well as unnamed washes.

Operational Impacts

Operation of a passenger rail system within the corridor would be similar to those for the 

Yellow Corridor Alternative southern hub to Eloy corridor segment.

Construction Impacts

Construction impacts would be similar to those described for the Yellow Corridor Alternative

southern hub to Eloy corridor segment.

No Build Alternative

Under the No Build Alternative, a passenger rail line would not be constructed within either of 

the corridor alternatives. No impacts to floodplains would be anticipated beyond those that 

could occur due to other reasonably foreseeable future projects and the natural forces of 

deposition and erosion via flows within nearby rivers and washes. Floodplains and floodways 

would continue to be managed by county and local flood control districts.

5.16.4 Potential Mitigation Measures

If the APRCS advances to a design phase, flood control districts with jurisdiction would be 

provided the opportunity to review and comment on the design plans for passenger rail system 

structures within floodplains to ensure flood control district requirements are met and that 

structures would not cause flood-related erosion hazards or aggravate existing flood hazards.

Once construction activities within a floodplain are complete, all construction sites and fills 

(such as crane pads, temporary brides, cofferdams, etc.) would be removed in their entirety 

and the affected areas returned to preconstruction elevations. Structures or other 

modifications to the floodplain may require the filing of a Letter of Map Change to FEMA to 

account changes to the area that may be subject to floods.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-186

Other potential mitigation measures may include restoring natural and beneficial floodplain 

values by seeding with native vegetation and proper design of bridges and culverts so as not to 

restrict flood flows. 

Specific mitigation measures, to the extent required, would be identified and discussed during 

Tier 2 analysis after design details are known, recorded in NEPA documents as specific impacts 

are identified, and implemented prior to construction.

5.16.5 Tier 2 Considerations

Impacts on the 100-year floodplains and Zone D areas (where data were not readily available) 

would be assessed during Tier 2 analysis. Discussions in Tier 2 documents would include 

potential impacts on floodplain elevation, potential impacts on the natural and beneficial 

floodplain values, significant changes in flooding risks or damage, and the potential for 

incompatible floodplain development. Additional hydraulic studies and assessments would be 

required during the final design process to ensure floodplain encroachments would be 

minimized to the extent practicable. Coordination with FEMA and local floodplain 

administrators would be initiated to discuss floodplain development permitting and potential 

mitigation measures.

5.17 Energy Use and Climate Change

This section describes and compares relative energy use for various modes of transportation. 

Because greenhouse gas (GHG) emissions are potentially linked to climate change, expected 

changes in GHG emissions are used to give a general sense of whether impacts to climate 

change from different modes of transportation are beneficial or detrimental. This section 

includes: 

 an examination of current conditions associated with energy use (fuel consumption) for 

light vehicles and rail in the nation

 a discussion of GHG emissions associated with light vehicles and rail in the nation

 an explanation of fuel usage as a proxy for energy use and GHG emissions

 a description of relative fuel usage associated with a passenger rail system (including 

construction and operation of the rail system and expected displacement of vehicles 

anticipated as a result of implementation)

 a discussion of the relative changes in GHG emissions that could be expected from 

development of a future passenger rail system within one of the corridor alternatives or 

from the No Build Alternative
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-187

5.17.1 Methodology and Regulatory Requirements

This assessment evaluates potential commitments of energy resources likely to be involved in a 

passenger rail system and the potential impact that energy usage or conservation may have on 

GHG emissions and, in turn, climate change.

Under EO 12185, Conservation of Petroleum and Natural Gas, agencies are encouraged to 

conserve petroleum and natural gas whenever financial assistance is contemplated as part of a 

federal action.

Transportation modeling and energy use data were collected from the Transportation Energy 

Data Book, Edition 31 (Davis, et al. 2012). The FTA publication Public Transportation’s Role in 

Responding to Climate Change (FTA 2010) was used for information associated with 

transportation-related GHG emissions.

Consideration of the effects of GHG emissions in this analysis is intended to be consistent with 

the CEQ’s Revised Draft NEPA Guidance for Federal Departments and Agencies on 

Consideration of Greenhouse Gas Emissions and the Effects of Climate Change in NEPA Reviews

(CEQ 2014). This guidance advises that when a proposed federal action analyzed in an 

Environmental Assessment or an EIS is anticipated to emit GHGs to the atmosphere in 

quantities that an agency finds may be meaningful, it is appropriate to quantify and disclose an 

estimate of the expected annual direct and indirect GHG emissions in the document. CEQ’s 

revised draft guidance, issued in December 2014, recommends that the effects of climate 

change on a proposed project be taken into consideration.

A review of relevant transportation data collected for this study yielded the following general 

discussion on the relative efficiencies of transportation modes used between Tucson and 

Phoenix in relation to energy consumption and GHG emissions. A more detailed discussion of 

transportation analysis factors is provided in Chapter 4, Transportation Impacts.

5.17.2 Existing Conditions

Energy

All transportation modes, including passenger vehicles and rail transit, generate their motive 

power through the use of some form of energy resources. According to the US Department of 

Energy, transportation accounts for 28 percent of total energy use in the US (Davis et al. 2012). 

Around 59 percent of total energy associated with transportation is expended by light vehicles, 

which include passenger cars, motorcycles, and light trucks.

In 2011, over 12 million light trucks and cars were sold in the US (52 percent of these in the 

light truck category, 48 percent in passenger cars), and over 230 million light vehicles were in 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-188

use. Average fuel economy of all light vehicles on the road in 2010 was about 23.7 miles per 

gallon (mpg) for short-wheelbase vehicles and 17.2 mpg for long-wheelbase vehicles. Average 

new car fuel efficiency for the 2012 model year under Corporate Average Fuel Economy (CAFE) 

standards show passenger car averages at 35.6 mpg and light trucks at 25.0 mpg. Over time, 

increasingly stringent CAFE standards would likely result in increased vehicle efficiencies. 

Table 5-28 provides an overview of the amount of energy expended per vehicle mile and per 

passenger mile for selected modes of transportation. Overall, light vehicles on the road today 

expend an average of approximately 3,600 British thermal units (BTUs) per passenger mile. 

Depending on the type of train travel, average energy expenditures for rail range from under 

2,300 to nearly 2,900 BTUs per passenger mile. Solo drivers of passenger cars and light trucks 

consume from 5,342 to 7,080 BTUs per passenger mile.

Greenhouse Gas Emissions

GHGs associated with various rail technologies, including heavy rail, light rail, and commuter 

rail, include primarily carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated 

gas emissions. The transportation sector, and in particular the personal automobile, has been 

identified as a major and growing contributor to increased GHG emissions. Because they 

represent the bulk of GHG emissions, and because they are used as a standard in the literature, 

CO2 and CO2 equivalents (CO2e) are used interchangeably for GHG emissions in this analysis.

Table 5-28. US Passenger Travel and Energy Use, Selected Travel Modes, 2010

Mode

Vehicle 

Miles 

(millions)

Energy 

Expended 

(BTU/vehicle 

mile)a

Load Factor 

(passengers 

/ vehicle)

Passenger 

Miles 

(millions)

Energy 

Expended (BTU/ 

passenger mile)

Light Vehicles 2,494,475 4,127,357 3,607c

Passenger cars 1,551,457 5,342 1.55 2,404,758 3,447

Light trucks 924,556 7,225 1.84 1,701,183 3,848

Motorcycles 18,462 2,881 1.16 21,416 2,484

Demand 

Responseb

1,529 15,111 1.00 1,477 15,645

Buses 2,425 35,953 8.7 21,172 4,118

Transit Buses 2,425 35,953 8.7 21,172 4,118

Air 5,499 276,329 101.0 555,653 2,735

Certificated 

Route

5,499 276,329 101.0 555,653 2,735

Passenger Rail 1,400 66,378 25.6 35,874 2,590
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-189

Table 5-28. US Passenger Travel and Energy Use, Selected Travel Modes, 2010

Mode

Vehicle 

Miles 

(millions)

Energy 

Expended 

(BTU/vehicle 

mile)a

Load Factor 

(passengers 

/ vehicle)

Passenger 

Miles 

(millions)

Energy 

Expended (BTU/ 

passenger mile)

Intercity Rail 295 49,508 21.8 6,420 2,271

Transit Rail 760 61,740 24.5 18,580 2,520

Commuter Rail 345 91,256 31.5 10,874 2,897

Source: Adapted from Davis, et al. 2012 

Notes:

(a) Represents solo vehicle efficiency

(b) Demand response vehicles include dispatched vehicles (e.g., taxis)

(c) Calculated average of light vehicles

5.17.3 Environmental Consequences

Corridor Alternatives

Analysis of relative energy efficiencies and corresponding GHG emission generation associated 

with different travel modes requires many assumptions. Generally, there is an increase of GHG 

during construction of a passenger rail system that, over time, results in a net reduction as 

displacement of vehicle traffic offsets construction-related emissions. Taken from a purely 

operational perspective, the information presented in Table 5-28 and Table 5-29 suggests that 

displacing ridership from automobiles to rail could potentially produce positive benefits for 

energy usage and GHG emissions. 

These data suggest that reductions in energy use and GHG emissions are achieved when 

vehicles are taken off the road and drivers put into existing transit. Beneficial effects would 

result from:

 avoided car trips due to mode shift from automobile to public transit

 relief of traffic congestion and improved operating efficiency of public highways from 

reduced VMT

 the indirect effect known as the land use multiplier that enables denser land use 

patterns, which in turn promote shorter trips, walking and cycling, and reduced car use 

and ownership (American Public Transportation Association 2009) 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-190

Table 5-29. Average Greenhouse Gas Emissions from Light Vehicles and Rail

Mode

CO2 Emissions 

(average)

(lbs. per passenger 

mile)

CO2 Emissions (low)

(lbs. per passenger 

mile)

CO2 Emissions (high) 

(lbs. per passenger 

mile)

Light Vehicles

Single occupancy 0.96a N/A N/A

Average occupancy 

(1.55 passengers per vehicle)

0.62b N/A N/A

4-person carpool 0.24a N/A N/A

Buses

Transit Buses 0.64 N/A N/A

Air

Airline travelc 0.50 0.41 0.61

Passenger Rail

Heavy rail 0.22d 0.085e 0.919f

Light rail 0.36d 0.146g 4.266h

Commuter rail 0.33d 0.013i 1.524j

Sources: FTA 2010; Davis et al. 2012; and EPA 2008b.

Notes:

a National average for single occupancy light vehicle (FTA 2010).

b Weighted single occupancy emissions based on 1.55 load factor (from Davis, et al. 2012) 

c EPA 2008b, Table 4. Represents medium-haul (300-700 miles), long-haul (>700 miles), and short-haul (<300 mile) CO2 emission 

rates

d FTA 2010. National averages for 14 heavy rail, 29 light rail, and 18 commuter rail systems from across the US

e San Francisco Bay Area Rapid Transit (FTA 2010)

f Baltimore Metro

g San Diego Metropolitan Transit System

h Kenosha Transit, Wisconsin

i Maryland Transit Authority

j Regional Transportation Authority, Tennessee

N/A = Not Available

Taken in a broader context, rail transit has more mixed results when compared with 

automobile, bus, or air travel. Researchers have attempted to consider energy used and GHG 

emissions generated through the life cycle of different travel modes. One such study (Chester 

and Horvath 2009) posited that analysis of passenger transportation should account for more 

than just the active operational elements of a given travel mode. The study included the active 

(e.g., running, take off, cruising, landing) and inactive (e.g., idling, auxiliaries, taxiing) 

operational components of automobile/bus, rail, or air travel in the analysis. Energy 

expenditures and GHG emissions for infrastructure development (e.g., rail bed and train station 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-191

infrastructure, roadway, runway, and other airport infrastructure) necessary for a given mode 

could also be measured and compared. The type of fuel used, including its life cycle attributes 

(extraction, generation, refining, and distribution) could also be included in the analysis. The 

Tier 1 analysis undertaken for the APRCS does not quantify these elements, but such an analysis 

is appropriate for Tier 2 studies. 

Chester and Horvath (2009) reviewed some 79 components across the different travel modes 

to evaluate life-cycle energy usage. Figure 5-19 from the Chester and Horvath study shows the 

relative cost, in terms of energy use and GHG emissions per passenger-kilometer travelled, of 

several transportation modes. The data shown in the figure reflect certain assumptions, 

including the average occupancies used for each travel mode. While the data used in 

Figure 5-19 were based on passenger-kilometers traveled rather than passenger-miles traveled, 

the figure shows that on a relative scale, life cycle energy expenditures and GHG emissions 

generated are lowest for urban buses during peak occupancy periods. For intercity travel, 

commuter rail proves to be relatively efficient. Lowest in terms of efficiencies are passenger 

vehicles and empty buses. Implementation of a passenger rail system within one of the corridor 

alternatives has the potential to provide energy savings and reduce the transportation system’s 

impact on climate change.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-192

Figure 5-19. Energy Use and Greenhouse Gas Emissions per Passenger-Kilometer Traveled 

(PKT)

Note: The vehicle operation components are shown with gray patterns. Other vehicle components are shown in shades of blue. 

Infrastructure components are shown in shades of red and orange. The fuel production component is shown in green. All 

components appear in the order they are shown in the legend (from Chester and Horvath 2009).

Yellow Corridor Alternative

Implementation of a passenger rail system within the Yellow Corridor Alternative has the 

potential to provide energy savings and reduce the transportation system’s impact on climate 

change. Based on ridership forecasts, passenger rail within the Yellow Corridor Alternative 

would decrease vehicle miles traveled by approximately 142 million per year. CO2, the main 

GHG emission, would decrease by approximately 66,710 tons per year. Fuel consumption would

decrease by approximately 3.04 million gallons per year. Construction equipment and vehicles 

operated during project construction would result in a temporary increase in fuel consumption 

which would cease at the end of the construction activity.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-193

Orange Corridor Alternative

Implementation of a passenger rail system within the Orange Corridor Alternative has the 

potential to provide energy savings and would reduce the transportation system’s impact on 

climate change. Based on ridership forecasts, a rail system within the Orange Corridor 

Alternative would decrease vehicle miles traveled by approximately 143 million per year. CO2, 

the main GHG emission, would decrease by approximately 67,104 tons per year. Fuel 

consumption would decrease by approximately 3.06 million gallons per year. Construction 

equipment and vehicles operated during project construction would result in a temporary 

increase in fuel consumption which would cease at the end of the construction activity.

No Build Alternative

Under the No Build Alternative, no passenger rail system would be built, and no changes in 

effects on energy use and climate change would occur beyond those that could occur due to 

other reasonably foreseeable projects, such as the UP’s ongoing operation and maintenance. 

Under the No Build Alternative, passenger train service would not be available to the public 

between Tucson and Phoenix, resulting in the continued reliance on automobiles, buses, and 

planes for transportation between communities in the study corridor. With the continued trend 

in substantial increases in VMT within the three-county study area, energy consumption and 

GHG emissions would be likely to increase steadily under the No Build Alternative. This 

assessment does not, however, take into account other influences, including changes in CAFE 

standards, bus and aircraft efficiency, fuel compositions, and other factors.

5.17.4 Potential Mitigation Measures

Mitigation may not be required for energy use and climate change because of the net benefits 

expected from reduced energy use and displaced emissions due to a model shift to transit, 

reduced congestion, and land use effects. It is expected that once a break-even point is 

reached, increased ridership would result in reduced overall GHG emissions in the study 

corridor. Further reduction of GHG emissions could be expected by employing BMPs associated 

with construction (e.g., conserving fuel and reducing GHG emissions during construction 

activities) and/or operations (e.g., improving fuel efficiency of locomotives, fueling with lowcarbon footprint sources, etc.). Any efforts to increase displacement of riders from light 

vehicles to rail (e.g., advertising, incentives) could be developed into project design or set up as 

additional mitigation. Specific measures that could be incorporated into project design or 

developed as mitigation measures include:

 Operations

o Identifying state-of-the-art locomotives to maximize fuel efficiency
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-194

o Target-marketing to drivers of single-occupancy vehicles to maximize the effects 

of rail modal use on energy conservation and reduction of GHG emissions

o Concentrating bus-service routes to feed passengers to train stations

o Bringing dispersed riders to train stations through other methods (e.g., demand 

response systems [paratransit, taxi, shuttle, call-and-ride]) 

 Construction

o Limiting construction and operational equipment idling

o Encouraging workers to carpool

o Locating staging areas near work sites

o Scheduling material deliveries during off-peak hours to minimize highway 

congestion

5.17.5 Tier 2 Considerations

It is anticipated that ridership data could change before Tier 2 analysis is initiated for many

reasons, including that population trends may not follow projections, growth may occur in 

different communities than anticipated, and cultural values for different modes of 

transportation may change. In addition, engineering design, site-specific alignment decisions, 

and modeling programs are also expected to be more refined. Depending on the availability of 

data and public concerns regarding energy use and climate change, it may be appropriate to 

refine the analysis during Tier 2 studies. 

5.18 Visual and Aesthetic Scenic Resources

This section summarizes the regulatory setting, affected environment, environmental 

consequences, and measures to avoid or mitigate impacts to natural and built visual and 

aesthetic scenic resources (VASR) within and adjacent to the corridor alternatives. 

5.18.1 Methodology and Regulatory Requirements

This section of the Tier 1 EIS was prepared in accordance with FTA’s Environmental Impact and 

Related Procedures (23 CFR Part 771) and FRA’s Procedures for Considering Environmental 

Impacts, (64 FR 28545, May 26, 1999) Section 14(n)(12) (FRA 1999a). The procedures outline 

FRA’s compliance with NEPA and related environmental and historic preservation laws and 

regulations. 

Two distinct categories of views are considered in discussing the visual environment: 1) views 

from the train, which are views of visual/scenic resources; and 2) views by people in adjacent 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-195

areas who see components of a passenger rail system (sidings and track, trains, maintenance 

facilities, and stations) and who are sensitive to those views. Visual/scenic resources include 

historic properties, public parks, recreational areas, and natural areas within the study corridor.

To assess the existing visual environment and identify potential visual impacts, five steps were 

followed:

1. Define the existing visual environment and quality of existing visual resources.

2. Identify the viewing audience and their sensitivity to visual changes.

3. Define the nature of the visual change by the project.

4. Assess potential visual impacts of a passenger rail system within the corridor 

alternatives.

5. Propose methods to mitigate adverse visual impacts.

Land under the jurisdiction of BLM or NPS is subject to a visual resource management (VRM) 

system that assesses the scenic value of an area and then establishes management objectives 

based on an acceptable level of visual preservation or disturbance. The overall goal of BLM's 

VRM system is to minimize visual impacts wherever they occur on public land. See the Visual 

and Aesthetic Scenic Resources Appendix for more information on the VRM system as 

administered by BLM’s Lower Sonoran Field Office.

5.18.2 Existing Conditions

The potential VASR within or adjacent to the corridor alternatives are displayed in Figure 5-20, 

Figure 5-21, and Figure 5-22, and are divided into the following categories: 

 Parks and Recreation Areas – This category includes city, county, state, and federal

parks, as well as designated open space and recreational areas.

 Natural Scenic Areas – This category includes natural areas with scenic qualities such as 

mountain ranges, waterbodies, open vistas, and native desert landscapes, as shown in

Figure 5-23. These areas are informally defined for this Tier 1 EIS and include many 

unique and individually scenic resources that should be analyzed further in a Tier 2

environmental document. 

 Historic Districts and Sites – This category includes sites in the corridor alternatives 

listed on the National Register of Historic Places (NRHP).

 Landmarks – Landmarks include prominent or well-known natural landforms or built

structures within the corridor alternatives. While no National Natural Landmarks are 
Florence

Marana

Eloy

Coolidge

Casa

Grande

Maricopa

Oro 

Valley

PINAL COUNTY

PIMA COUNTY

MARICOPA COUNTY

PINAL COUNTY

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PINAL COUNTY

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Figure 5-25

See Tucson

Metropolitan Area

Figure 5-24

Ak-Chin

Indian 

Community

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Indian 

Community

Tucson

Mountains

Tortolita

Mountains Santa Catalina

Mountains

Pusch

Ridge

Wilderness

Saguaro 

National

Park

Ironwood

Forest

National

Monument

Picacho Peak

State Park

San Tan

Park

Picacho

Reservoir

T o n t o

N a t i o n a l

F o r e s t

Lost Dutchman

State Park

Newman

Peak

Sacaton

Mountains

Silver Reef

Mountains

Slate

Mountains

Sawtooth

Mountains

Suizo

Mountains

Casa Grande

Mountains Table Top

Mountains

Vekol

Mountains

Sierra Estrella

Mountains

Superstition

Mountains

Wassen

Peak

Mount

Lemmon

5 Existing Conditions and Environmental Consequences

Figure 5-20. Visual Resources in the Study Area

Final Tier 1 Environmental Impact Statement 5-196

Le g e nd

Sources: US National Park Service 2013; Maricopa County Flood Control District 2013; Pima Department of Transportation 2013;

Esri 2014; Arizona Department of Transportation 2013; Arizona State Land Resource Information System 2013; Bureau of

Land Management 2011

N

Interstate

State or US Highway

Railroad

Major Drainage

!( National Register of 

Historic Places

National Register

Historic District

" " " " " "

" " " " " "

" " " " " "

" " " " " "

Anza Trail Corridor

Undeveloped Desert

River Bed

Arizona Waterbody

Federal Land

National Forest or Park

Open Space or State Park

State Trust Land

Tribal Land

City Boundary

0 5 10

Miles
5 Existing Conditions and Environmental Consequences

Figure 5-21. Visual Resources in the Tucson Metropolitan Area

Final Tier 1 Environmental Impact Statement 5-197

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Prince Rd

La Canada Dr

Speedway Blvd

Silverbell Rd

Swan Rd

Country Club Rd

Golf Links Rd

Broadway Blvd

Grant Rd

1st Ave

Fort Lowell Rd

Alvernon Wy

5th St

22nd St

Campbell Ave

Greasewood Rd

Anklam Rd La Cholla Blvd

Orange Grove Rd

Barraza Aviation Hwy

Ajo Way

Irvington Rd

Drexel Rd

Valencia Rd

Nogales Hwy

Los Reales Rd

Tucson

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Tucson

Davis

Monthan

Air Force

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Sweetwater

Preserve

Tu cso n M o un ta i n Par k

Greasewood 

Park

Santa Cruz River Park

Sentinel 

Peak Park

Tumamoc

Hill

Christopher 

Columbus Park

Armory

Park

Barrio

Anita

Dunbar

Springs

El Presidio Iron

Horse

Warehouse Historic

District

e

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Q?È

Tucson

International

Airport

e

Airport

Interstate

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Local Road

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!( National Register of 

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Historic District

" " " " " "

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" " " " " " Anza Trail Corridor

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Open Space or State Park

State Trust Land

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Sources: US National Park Service 2013; Pima Department of Transportation 2013; Esri 2014; Arizona Department of

Tansportation 2013; Arizona Land Resource Information System 2013; Bureau of Land Management 2011

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Regional

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Mountain

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Tempe Butte

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International Airport

Arizona

State

University

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Gateway Airport

Final Tier 1 Environmental Impact Statement 5-198

Existing Conditions and Environmental Consequences

Figure 5-22. Visual Resources in the Phoenix Metropolitan Area

InterstateState or US HighwayLocal RoadRailroadMajor Drainage

!( National Register of 

Historic PlacesNational RegisterHistoric DIstrictRiver BedArizona Waterbody

Federal LandNational Forest or ParkOpen Space or State ParkState Trust LandTribal Land

Le g e nd

0 1 2

Miles

NSources: US National Park Service 2013; Maricopa County Flood Control District 2013; Pima Department of Transportation 2013; Esri 2014; Arizona Department of Transportation 2013; Arizona State Land Resource Information System 2013

5
Florence

Marana

Tucson

Eloy

Coolidge

Casa

Grande

Maricopa

Tempe

Mesa

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Valley

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W i l d e r n e s s

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San

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eTucson

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5 Existing Conditions and Environmental Consequences

Figure 5-23. Landscape Characteristics in the Study Area

Final Tier 1 Environmental Impact Statement 5-199

e

Airport

Interstate

State or US Highway

Railroad

Major Drainage

Yellow Corridor Alternative

Orange Corridor Alternative

Federal Land

National Forest or Park

Open Space or State Park

State Trust Land

Tribal Land

Agricultural

Undeveloped Desert

Urban/Suburban

City Boundary

Le g e nd

0 5 10

Miles

Sources: US National Park Service 2013; Maricopa County Flood Control District 2013;

Pima Department of Transportation 2013 ;Esri 2014; Arizona Department of

Transportation 2013; Arizona Land Resource Information System 2013

N

e
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-200

located in the study corridors (National Park Service 2012), a number of natural and 

built features are visible from the corridor alternatives.

Within the two corridor alternatives and a 0.25-mile buffer, 126 parks (city, county, and state), 

67 recreational areas (trails, athletic fields, golf courses, stadiums, and swimming pools),

9 natural areas (including refuges and designated open space), 26 privately owned 

parks/recreation areas, 160 sites or districts listed or eligible for listing on the NRHP, and 

approximately 14 landmarks were identified. No wilderness or conservation areas and no local, 

state, or federal scenic highways have been designated within the corridor alternatives (Arizona 

Office of Tourism 2013).

The southern portion of both corridor alternatives coincides in places with the Juan Bautista de 

Anza National Historic Trail designated historic corridor, auto tour route, and recreation 

retracement route. As defined by the National Trails System Act (16 U.S.C. §§ 1241-1251), a 

National Historic Trail is an extended trail which follows as closely as possible and practicable 

the original trail or route of travel of national historical significance. While the historic corridor 

is not necessarily subject to BLM’s VRM system, Historic Trail designation is intended to identify 

and protect the remains of this overland route for public use and enjoyment. The 

Comprehensive Management and Use Plan/Final Environmental Impact Statement NPS 

completed in response to congressional designation of the Anza Trail envisions a traveler being 

“able to...experience landscapes similar to those the expedition saw....” The Anza Trail corridor 

appears on Figure 5-20 and Figure 5-21 and on Maps 1-11 and 21-27 of the Corridor Aerial Atlas 

Appendix.

Visual Quality of the Study Corridor

Because of the Yellow and Orange corridor alternatives’ close proximity relative to the 

expansive nature of many of the VASR in this Tier 1 EIS, visual quality and character are 

described once for the entire study corridor (see Figure 1-1) and pertain generally to both the 

Yellow and Orange corridor alternatives.

Southern Hub to Eloy

Elements of the urban and suburban landscape character dominate the visual environment 

within the Tucson metropolitan area. Tucson’s skyline features three skyscrapers exceeding 

200 feet, and eight more buildings ranging from 6 to 14 stories, all exceeding 100 feet in height. 

The UP /I-10 corridor, which carries high volumes of rail and automobile traffic, is a prominent 

visual element in the urban fabric that becomes a dominant visual feature as the study corridor 

extends northwest from Tucson. Visible elements of the existing railroad include moving trains 

and railroad infrastructure. Visible features of I-10 include noise and retaining walls, elevated 

sections of road, and on- and off-ramps. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-201

Outside the Tucson metropolitan area the visual environment transitions from an urban and 

suburban landscape character into a mix of undeveloped desert and agricultural landscape 

characters. Views of the UP line and I-10 are interspersed with views of agricultural and 

undisturbed desert landscape character elements. 

Throughout the entire southern study corridor, distant views of the surrounding mountain 

ranges can be seen, including the Santa Catalina Mountains and the Tortolita Mountains to the 

north, the Santa Rita Mountains to the south, the Rincon Mountains to the east, and the Tucson 

Mountains to the west. Landmarks visible from the southern corridor alternative include Mount 

Lemmon, Mount Wrightson, Sentinel Peak, Brown Mountain, Wassen Peak, Saguaro National 

Park, Picacho Peak State Park, and the bed of the Santa Cruz River. Within the City of Tucson, 

the historic neighborhoods of Armory Park, Barrio Anita, El Presidio, Dunbar Springs, Iron 

Horse, and the Warehouse Historic District are also visible from the corridor. Views of Picacho 

and Newman peaks are memorable and can be seen for miles by approaching viewers.

Sensitive viewers in the southern portion of the study corridor include residents and 

recreationists within the Tucson metropolitan area, some of whom live adjacent to I-10 within 

the study corridor. These viewers, as well as automobile drivers and passengers who may be 

less sensitive to visual changes, primarily experience views of the existing railroad, operating 

trains, and I-10. Existing railroad track and sidings are low-profile visual elements, while rail 

signals and signs, and the intermittent views of trains, are vertical elements against the 

landscape. Visual elements of I-10 include the at-grade or above-grade road surface, on- and off 

ramps, noise and retaining walls, above-grade structures, and moving vehicles. Moving to the 

outer extent of the study corridor, the generally flat topography and existing urban and 

suburban development minimize direct views of ground-level features within this portion of the 

corridor. Further northwest of Tucson, where land is less developed and views are more open, 

more expansive views of the landscape, including undeveloped land, suburban development, 

agricultural and industrial complexes, freight trains, and the interstate can be seen from greater 

distances and for longer durations. For less sensitive viewers, including automobile drivers and 

passengers along I-10, views of freight trains, while intermittent, are commonplace. 

Overall, the southern portion of the corridor alternatives features relatively few VASR, including

mountains or historic neighborhoods) in the urban, suburban, and natural landscapes. Urban 

development and built elements in the foreground vary in visual quality and interrupt views of 

the distant natural landscapes. Therefore, the overall visual quality of the southern corridor is

moderately low.
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Final Tier 1 Environmental Impact Statement 5-202

Eloy to Northern Hub

The study corridor continues generally north-northwest into two distinctly different landscape 

types of similar size – the undeveloped desert and agricultural landscape character within Pinal 

County, and the more developed suburban and urban landscape character within Maricopa 

County and the Phoenix metropolitan area. Within Pinal County, views of the agricultural 

landscape character are interspersed with views of undeveloped desert landscape and, along 

the Yellow Corridor Alternative, small rural communities. Views of the undeveloped desert 

landscape dominate the Orange Corridor Alternative from Eloy all the way to the 

Maricopa/Pinal County line. 

Due to the flat topography of the corridor alternatives, views of the existing railroad and freight 

train operations within the Yellow Corridor Alternative are frequent. This portion of the Orange 

Corridor Alternative, on the other hand, travels through a sparsely populated area that does 

not feature a major transportation corridor.

Vast, unconstrained middleground and background views of undeveloped desert and distant 

mountains are visible throughout the Pinal County portion of both the Yellow and Orange 

corridor alternatives. These mountains include the San Tan and Sacaton mountains in the 

north; the Silver Reef, Slate, and Sawtooth mountains in the south; the Suizo Mountains in the 

east; and the Casa Grande, Table Top, and Vekol mountains in the west. Other landmarks that 

train passengers might view in the northern study corridor within Pinal County include the 

Coolidge water tower and the dry riverbed of the Gila River.

Within Maricopa County, the dominant landscape character transitions from undeveloped 

desert and agricultural land to suburban and urban land uses. The Yellow Corridor Alternative 

continues through an urban landscape setting to the northern system hub in Phoenix. The 

Orange Corridor Alternative continues within an agricultural landscape setting that transitions 

gradually to suburban and then urban landscape settings as it progresses toward the northern 

system hub in Phoenix.

The expansive urban and suburban landscape of the Phoenix metropolitan area dominates 

foreground views from within Maricopa County. In the suburban areas on the outskirts of the 

metropolitan area, views are relatively uniform with a predictable pattern of similar-sized

residential structures located in subdivisions, with little variation in aesthetic architectural style. 

Intermittent middleground and background views of distant mountain ranges are constrained 

by the suburban development. Sporadic views of mountain ranges in this portion of the 

northern study corridor include the Phoenix Mountains to the north, South Mountain and the 

Sierra Estrella Mountains to the south and southwest, Usery Mountain and the Superstition

Mountains to the east, and the White Tank Mountains to the west.
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Final Tier 1 Environmental Impact Statement 5-203

Train passengers in this portion of the northern study corridor would view natural and manmade landmarks and other VASR including the downtown Phoenix skyline, South Mountain 

Park, Papago Park, Sunnyslope Mountain, Camelback Mountain, Piestewa Peak, Arizona State 

University, Tempe Butte, the Salt River, Tempe Town Lake, and Phoenix Sky Harbor 

International Airport.

Existing rail alignments and numerous vehicle transportation corridors are common visual 

components within portions of the Maricopa County segment of the study corridor. Visible rail 

infrastructure in this area includes track, sidings, and trains. Views of freight trains, light rail 

vehicles, and motor vehicles occur frequently in the Phoenix metropolitan area. Elements of 

motor vehicle infrastructure include linear features such as highways and interstates, on- and 

off-ramps, noise and retaining walls, and above-grade structures such as overpasses. The level 

topography and vertical urban and suburban development, however, minimize the number of 

direct views of the existing railroad and transportation corridors for many sensitive viewers 

within Maricopa County. 

Sensitive viewers within the northern study corridor may include residents, recreationists, 

tourists, automobile passengers, and agricultural workers. Depending on their travel, these 

individuals, along with less sensitive viewers including daily commuters, business owners, 

employees, patrons of local commercial establishments, and students, may experience 

intermittent views of the railroad in the northern study corridor. 

The northern study corridor within Pinal County provides memorable views of VASR in natural 

landscapes with agricultural and undisturbed desert landscape characteristics. Generally, 

development and urban elements have not interrupted these views, leaving them open,

unconstrained, and memorable. Overall visual quality of the Pinal County portion of the 

northern study corridor is high.

The northern study corridor within Maricopa County provides few memorable views of VASR in 

urban, suburban, and natural landscapes. Urban and suburban development dominates the 

visual landscape. Therefore, the overall visual quality of the northern study corridor is low.

5.18.3 Environmental Consequences

This section analyzes corridor-level changes to VASR, landscape characters within the study 

corridor, and views of VASR that would result from the construction and operation of a 

passenger rail system within the Orange and Yellow corridor alternatives, as well as the No 

Build Alternative.
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Final Tier 1 Environmental Impact Statement 5-204

Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts

Permanent visual changes (physical elements) that could result from introducing a passenger 

rail system to the landscape could include the presence of new railroad track, bridges, tunnel 

portals, grade crossings, train stations, parking facilities, noise walls, open cuts, cut-and-fill 

areas, retaining walls, removed vegetation, and night lighting. The precise location, quantity, 

and design of these physical elements, and the visual changes associated with them, are not 

known at this time. Preliminary project planning, however, indicates that a passenger rail 

system within the southern Yellow Corridor Alternative would be built predominantly at grade 

except for grade-separated crossings and train stations. 

Within the Tucson metropolitan area, the permanent visual changes associated with a

passenger rail system would have a negligible impact on Tucson’s visual quality and landscape 

character. The physical elements of a passenger rail system within this southern portion of the 

Yellow Corridor Alternative would have features similar to the existing transportation facilities 

in this urban setting. Sensitive viewers, including residents and recreationists in this portion of 

the corridor alternative, would be most affected by the physical impacts of a passenger rail 

system.

Outside the Tucson metropolitan area, the visual impacts of a passenger rail system within the 

Yellow Corridor Alternative would have a moderate impact on the existing visual quality and 

landscape character. While the physical elements of a passenger rail system would be similar to 

the existing transportation facilities, it could contrast with the rural agricultural and 

undeveloped desert landscape characters. A new railroad with above-grade elements in this 

location could also affect views of the prominent Picacho and Newman peaks. 

While a passenger rail system within the southern Yellow Corridor Alternative would be built 

predominantly at grade, a few grade separations and train stations are proposed. Physical 

project elements such as bridges, stations, and other elevated structures could visually intrude 

on views of nearby and distant VASR, such as Tucson’s historic neighborhoods adjacent to or 

within the corridor alternative, or distant mountain ranges. Overall, the permanent visual 

changes that could result from a passenger rail system are anticipated to result in minimal to 

moderate adverse impacts to the existing urban-suburban visual character of the southern

portion of the corridor alternative; and views of VASR within the southern portion of the 

corridor alternative would generally remain the same for sensitive viewers. 
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Final Tier 1 Environmental Impact Statement 5-205

Operational Impacts 

Visual changes would occur within the Yellow Corridor Alternative from the operation of 

passenger rail trains after construction is completed. These visual changes would be 

intermittent and would include views of moving passenger trains and moving train lights. These 

operational impacts would mostly affect adjacent residents, who could consider the 

intermittent interruptions of nearby and distant VASR, increased nighttime views of passing 

train lights, and night lighting to be visually intrusive. Views of passenger trains would generally 

be compatible with the existing views of freight trains, and the overall impacts of operating a 

passenger rail system in the Yellow Corridor Alternative to the existing visual character of the 

southern corridor alternative are anticipated to be minimal. Views of VASR from or within the 

southern corridor alternative would generally remain intact.

Construction Impacts 

Temporary visual changes would occur during construction within the Yellow Corridor 

Alternative. These changes include views of construction equipment operation, dust, material 

stockpiling, nighttime construction lighting and glare, construction and operation of temporary 

access roads, increased traffic in construction areas and along detour routes, and construction 

and detour signage. 

The temporary visual changes that occur during construction would minimally affect views of 

the southern corridor alternative by sensitive viewers. The temporary visual changes would

have negligible permanent impacts on the visual quality within the southern corridor

alternative. Any temporary incompatible visual intrusion would not permanently obstruct views 

of the landscape character or VASR or degrade the existing visual quality. Therefore, the 

temporary visual impacts associated with construction within the southern Yellow Corridor 

Alternative are anticipated to be minimal.

Eloy to Northern Hub

Physical Impacts 

Permanent visual changes that could result from a passenger rail system include the 

introduction of physical elements, such as railroad track, bridges, tunnel portals, grade 

crossings, train stations, parking facilities, noise walls, cut-and-fill areas, retaining walls, 

vegetation removal, and night lighting. The precise location, quantity, and design of these 

physical elements, and the visual changes associated with them, are not known at this time. 

Preliminary project planning indicates that a new rail system within the northern Yellow 

Corridor Alternative would be built predominantly at grade, except for passenger stations and 

grade-separated crossings.
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Final Tier 1 Environmental Impact Statement 5-206

Within Pinal County, the physical elements of a passenger rail system could contrast with the 

agricultural and undeveloped desert character, and views could be moderately affected by a 

passenger rail system. Within Maricopa County, the physical changes of a passenger rail system 

within the Yellow Corridor Alternative are similar to those listed in the Metropolitan Tucson 

portion of the southern corridor. The northern Yellow Corridor Alternative within Maricopa 

County contains numerous linear transportation features and corridors, including highways, 

expressways, and railroads in a dense suburban and urban landscape. Residents and other 

sensitive viewers along the passenger rail corridor alternative are accustomed to views of linear 

transportation corridors, retaining and noise walls, overpasses, and access ramps. Views of 

passenger rail infrastructure elements such as bridges, stations, and other elevated rail 

structures in this part of the corridor alternative would be compatible with and similar in nature 

to the existing transportation features and corridors. 

The physical elements of a rail system within the Yellow Corridor Alternative could intrude 

visually on sporadic views of distant VASR, including the Phoenix Mountains, South Mountain, 

and the White Tank Mountains. Views of local landmarks within or adjacent to the corridor 

alternative may be obscured by above-grade rail corridor elements. Impacts to these viewsheds 

would be studied during the Tier 2 NEPA analysis. Overall, the visual changes associated with a 

passenger rail system in the Yellow Corridor Alternative would vary depending on the location 

of a future alternative within the corridor.

Operational Impacts 

The visual changes associated with operation of a passenger railroad system within the Eloy to 

northern hub portion of the Yellow Corridor Alternative are the same as those described for the 

southern hub to Eloy portion of the Yellow Corridor Alternative and include intermittent views 

of moving passenger trains and moving train lights. 

In Pinal County, the operational impacts of a passenger railroad would have a moderate 

adverse impact on the visual quality and character of the landscape. For sensitive viewers 

(including the residents, recreationists, automobile passengers, and agricultural workers within 

the corridor alternative), intermittent views of passenger trains would contrast with the 

existing agricultural and undeveloped desert visual character and could momentarily intrude on 

views of VASR. In addition, nighttime views of passing train lights and night lighting could 

increase.

In Maricopa County, the operational impacts of a passenger railroad would be similar to the 

operational visual impacts in the Metropolitan Tucson portion of the southern portion of the 

Yellow Corridor Alternative. Residents and other sensitive viewers along a passenger rail system 
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Final Tier 1 Environmental Impact Statement 5-207

are accustomed to views of existing transportation facilities, so the views in the Metropolitan 

Phoenix area would be compatible with the existing views of vehicular and train traffic. 

Therefore, the operational visual changes are anticipated to be minimal given the existing 

urban and suburban character and sporadic views of VASR.

Overall, the operational visual changes within the northern Yellow Corridor Alternative are 

anticipated to result in minimal-to-moderate adverse impacts to the existing landscape 

character and visual quality. Views of VASR for sensitive viewers would remain the same.

Construction Impacts 

The temporary visual changes that occur during the construction of a passenger railroad system 

in the northern portion of the Yellow Corridor Alternative would be the same as those listed in

the southern portion of the corridor alternative. In Pinal County, the temporary visual changes 

that occur during construction would introduce views of urban-based elements and intrude on

foreground views of the landscape character and VASR; however, any temporary incompatible 

visual intrusion would not permanently obstruct views of the landscape character or VASR. In 

the more urban and suburban Maricopa County, the temporary construction impacts of a

passenger railroad system would have minimal impacts on the visual quality and landscape 

character, given the short duration. Overall, the temporary visual changes during construction 

would minimally affect views in the northern portion of the Yellow Corridor Alternative by 

sensitive viewers.

Orange Corridor Alternative

Southern Hub to Eloy

The physical, operational, and construction impacts for the southern portion of the Orange 

Corridor Alternative would be the same as those described for the Yellow Corridor Alternative 

from the southern hub to Eloy.

Eloy to Northern Hub

Physical Impacts 

The permanent visual changes (physical elements) of a passenger rail system within the

northern portion of the Orange Corridor Alternative would be similar to those described for the 

northern Yellow Corridor Alternative. Preliminary project planning indicates that within the

Orange Corridor Alternative extensive above-grade sections with elevated structures and 

bridges may be required.

Within Pinal County, a passenger rail system within the northern Orange Corridor Alternative 

would be constructed on a new rail alignment through undeveloped desert landscape. The 
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Final Tier 1 Environmental Impact Statement 5-208

physical elements introduced by a rail system would contrast with the existing visual landscape 

character. The sensitive viewers within and adjacent to the corridor alternative include clusters 

of small residential areas located near the intersections of East Randolph Road and North 

Wheeler Road; North Clemans Road and East Vah Ki Inn Road; North Sierra Vista Drive and East 

Ocotillo Road; and South Mountain Road and East Williams Field Road (see Maps 59, 61, 70, 

and 74 of the Corridor Aerial Atlas Appendix). A new railroad through these areas would impose

a visual intrusion and would represent a substantial change in the areas’ visual character. In 

addition, a new railroad with above-grade features could potentially affect the vast, 

unconstrained background views of distant mountains, including San Tan Mountain, Casa 

Grande Mountain, and the Pinal Mountains. 

Like the northern Yellow Corridor Alternative, a passenger rail system within the northern 

Orange Corridor Alternative within Maricopa County would be visually similar to the numerous 

existing linear transportation features and corridors, including highways, expressways, and

railroads in a dense suburban and urban landscape. Residents and other sensitive viewers 

within and along the corridor alternative are accustomed to views of linear transportation 

corridors, retaining and noise walls, overpasses, and access ramps. Due to the anticipated 

extensive number of above-grade features, however, a passenger rail system could visually

intrude upon views of distant VASR, such as the Phoenix Mountains, South Mountain, and the 

White Tank Mountains, as well as VASR within or adjacent to the northern Yellow Corridor 

Alternative. 

Overall, the visual changes associated with a passenger rail system in the Orange Corridor 

Alternative are anticipated to result in moderate-to-high adverse impacts to sensitive viewers, 

the existing visual character, views of VASR, and visual quality of this portion of the northern

study corridor.

Operational Impacts

In Pinal County, the operational impacts of a passenger railroad would have a moderate 

adverse impact on the visual quality and landscape character. For sensitive viewers near the 

corridor alternative, intermittent views of passenger trains would contrast with the existing 

visual character of the undeveloped desert and could momentarily intrude on views of VASR. In 

addition, nighttime views of passing train lights and night lighting could increase.

In Maricopa County, the operational impacts of a passenger railroad would be the same as 

those described for the Maricopa County portion of the Yellow Corridor Alternative. 
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Final Tier 1 Environmental Impact Statement 5-209

Overall, the visual changes from operation of a rail system within the Orange Corridor 

Alternative are anticipated to result in moderate adverse impacts to the existing landscape 

character, visual quality, and sensitive viewers; views of VASR would remain the same.

Construction Impacts

The temporary visual changes and impacts that would occur during construction activities 

within the northern portion of the Orange Corridor Alternative would be the same as those 

described for the northern Yellow Corridor Alternative.

No Build Alternative

Under the No Build Alternative, a passenger rail system would not be built; and no impacts to 

VASR would occur beyond those that could occur due to other reasonably foreseeable projects. 

5.18.4 Potential Mitigation Measures

Measures to minimize and/or avoid adverse visual impacts would be developed during the 

Tier 2 NEPA analysis as project design details were identified. The mitigation would not only 

address adverse visual impacts identified from the design but would also address concerns from 

the viewing audience identified during the public involvement process.

The following potential mitigation measures could be considered during later phases of project 

development to minimize adverse impacts to the study area’s existing visual quality and its 

surroundings:

 Restore vegetation on areas disturbed during project construction.

 Screen objectionable views of railroad facilities next to sensitive viewers such as 

residents or next to landmarks, cultural resources, or recreation areas.

 Apply context-sensitive design to new or reconstructed rail stations that respects scenic 

resources in adjacent urban or natural surroundings.

 Develop structure aesthetics to soften adverse visual changes for adjacent residents and 

other sensitive viewers.

 Where appropriate, apply landscape design to blend new rail facilities into their 

surroundings.

 Where the project would change the visual quality of existing landforms, shape cut-andfill slopes and revegetate to blend into the surrounding landscape.

 Design new lighting to direct light to focus on where it is needed, minimize light 

intruding onto adjacent properties, and reduce light pollution of the night sky. 
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Final Tier 1 Environmental Impact Statement 5-210

 Where appropriate, provide light screening to shield adjacent sensitive viewers from the 

headlights of passing trains and rail facility lighting.

 Minimize nighttime construction lighting next to residents and other sensitive viewers.

 Screen staging areas where construction equipment and materials are stored.

5.18.5 Tier 2 Considerations

A more detailed analysis of visual impacts, including the degree of visual change to the existing 

views and site-specific VASR, and an analysis of predicted sensitive viewer responses, would be 

provided in a Tier 2 NEPA document. 

Some or all of the parks and recreation areas, historic sites or districts listed or eligible for 

listing on the NRHP, natural scenic areas, and landmarks may be considered Section 4(f) 

resources. As such, views of new rail facilities from these resources and impact avoidance or 

minimization measures would be considered and analyzed in a Tier 2 NEPA analysis.

If a future rail alignment were to traverse BLM or NPS land, a visual impact assessment in 

accordance with the requirements of BLM’s Visual Resource Management system (adopted by 

NPS as well) would be undertaken during Tier 2 and submitted to BLM/NPS for review, 

comment, and concurrence. BLM and/or NPS would be involved in the mitigation plan to 

minimize visual impacts within their jurisdictional boundaries. 

Phoenix is currently updating the general plan and a draft was released for public comment in 

Fall 2014 (City of Phoenix 2014). As the study advances to Tier 2, the general plan update 

should be reviewed for changes to the policies and goals applicable to VASR within or adjacent 

to the Phoenix portions of the corridor alternatives. 

Pima County is currently updating the comprehensive plan, and a draft was released for public 

comment in Fall 2014 (Pima County 2014). As the study advances to Tier 2, the comprehensive 

plan update should be reviewed for changes to the policies and goals applicable to VASR within 

or adjacent to the Pima County portions of the corridor alternatives.

Site-specific mitigation measures would be developed during the Tier 2 NEPA analysis once 

project design details and public concerns are known.

5.19 Cultural Resources

Cultural resources are evidence of past human activity that includes objects, structures, sites, 

and other articles of historical, archaeological, or architectural significance. They are present 

throughout Arizona as a result of millennia of human history. Historic properties are cultural 
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Final Tier 1 Environmental Impact Statement 5-211

resources that are included in, or are eligible for inclusion in, the NRHP maintained by the 

Secretary of the Interior. This term, according to the National Historic Preservation Act (NHPA) 

(54 U.S.C. § 300101), as amended, includes prehistoric or historic districts, sites, buildings, 

structures, and objects significant in American history, architecture, archaeology, engineering, 

and culture. The term also includes artifacts, records, and remains that are related to and 

located within such properties, and properties of traditional religious and cultural importance 

to an Indian tribe or Native Hawaiian organization. Historic properties are afforded certain 

protections in accordance with state and federal legislation. 

5.19.1 Methodology and Regulatory Requirements

The consideration of impacts on cultural resources is subject to several federal laws, 

regulations, and guidelines. The lead federal agencies must comply with NEPA and NHPA, as 

amended. NEPA requires that agencies consider the effects of their actions on all aspects of the 

natural and physical environment and the relationship of people with that environment, 

including historic properties.

Section 106 of NHPA requires federal agencies to take into account the effects of their 

undertakings on historic properties, following regulations issued by the Advisory Council on 

Historic Preservation (Council). The regulations, in part, afford the Council, the State Historic 

Preservation Office (SHPO), Tribal Historic Preservation Offices (THPOs), and other parties with 

a demonstrated interest a reasonable opportunity to comment on proposed undertakings. 

NHPA defines historic properties as any prehistoric or historic district, site, building, structure, 

or object included in, or eligible for inclusion in, the NRHP, including artifacts, records, and 

material remains related to such a property or resource. These properties reflect many kinds of 

significance in architecture, history, archaeology, engineering, and culture. “The term includes 

properties of traditional religious and cultural importance to an Indian tribe or Native Hawaiian 

organization and that meet the NRHP criteria,” as stated in 36CFR § 800.16 (l).

To be considered eligible for listing in the NRHP, a property must be at least 50 years old (with 

rare exception); must retain integrity of location, design, setting, material, workmanship, 

feeling, and association; and must also meet at least one of the following criteria:

 Criterion A – Associated with events that have made a significant contribution to the 

broad patterns of our history; or

 Criterion B – Associated with the lives of persons significant in our past;

 Criterion C – Embodies 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, 
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Final Tier 1 Environmental Impact Statement 5-212

or that represent a significant and distinguishable entity whose components may lack 

individual distinction; or

 Criterion D – Has yielded, or may be likely to yield, information important in prehistory 

or history. 

Amendments to NHPA in 1980 resulted in NRHP Bulletin 38, Guidelines for Evaluating and 

Documenting Traditional Cultural Properties (TCPs). TCPs are properties that have heritage 

value for contemporary communities and are eligible for the NRHP because of their association 

with historic cultural practices or beliefs of a living community that are rooted in that 

community’s history and are important in maintaining the continuing cultural identity of that

community. This category of resources can encompass archaeological resources, structures, 

neighborhoods, prominent topographic features, habitat, plants, animals, and minerals that 

people consider essential for the preservation of a traditional culture. A TCP is ascribed an 

intangible cultural element or value that is linked to a specific geographic location.

Section 106 consultation should be coordinated with the American Indian Religious Freedom 

Act (Public Law No. 95-341), which was enacted in 1978 to protect and preserve the traditional 

religious rights and cultural practices of American Indians, Eskimos, Aleuts, and Native 

Hawaiians. The American Indian Religious Freedom Act affirms the right of Native Americans to 

have access to their sacred places and promotes consultation with Native American religious 

practitioners. Consultation should also be coordinated with NEPA, the Native American Graves 

Protection and Repatriation Act of 1990 (25 U.S.C. §§ 3001 et seq.), the Archaeological 

Resources Protection Act of 1979 (16 U.S.C. §§ 470aa et seq.), and agency-specific legislation.

In addition to other federal laws (e.g., Archaeological Resources Protection Act of 1979, Native 

American Graves Protection and Repatriation Act of 1990), a project may also need to comply 

with state preservation laws including the State Historic Preservation Act of 1982 (A.R.S. §§ 41-

861 and 41-864) and the Arizona Antiquities Act (A.R.S. §§ 41-841 through 41-847). The State 

Historic Preservation Act stipulates that state agencies work to identify and preserve historic 

properties and states that the chief administrator of each state agency is responsible for the 

preservation of historic properties which are owned or controlled by the agency. It also states 

that each state agency shall establish a program to locate, inventory, and nominate to the 

Arizona Register of Historic Places all properties that are under the agency's ownership or 

control and that appear to meet the criteria for inclusion on the register, and provide the 

Arizona SHPO an opportunity to comment on any agency plans that affect properties listed or 

that may qualify for inclusion on the Arizona Register of Historic Places. The Arizona Antiquities 

Act prohibits excavation of historic or prehistoric sites on lands owned or controlled by the 

State of Arizona, any agency or institution of the state, or any county or municipal corporations 
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Final Tier 1 Environmental Impact Statement 5-213

within the state without obtaining the written permission of the director of the Arizona State 

Museum, and directs those in charge of activities on such lands to notify the director of the 

Arizona State Museum of the discovery of any archaeological sites, historical resources, and 

human remains (ASM 2014) in coordination with the SHPO. 

FRA, as the lead federal agency, is responsible for compliance with these and other federal and 

state statutes and is undertaking a phased approach to consultation under Section 106. During 

this Tier 1 analysis, consultation was initiated with tribes having a potential interest in this 

study, identified using a compiled list of federally recognized tribes with ancestral ties or an 

interest within the area on or near the corridor alternatives. Input from the tribes, including 

their THPOs, and the SHPO is helping FRA to identify cultural resource issues of concern to be 

addressed through continuing consultation in future Tier 2 NEPA documents.

Because a specific alignment for a passenger rail system has not been selected, no Area of 

Potential Effects was delineated, nor were specific effect findings made, during Tier 1 analysis.

However, a limited Class I records search was completed for the Tier 1 NEPA analysis to 

summarize and provide an overview of cultural resources within each mile-wide corridor

alternative. The records search was conducted using AZSITE, a GIS-based tool that serves as a 

consolidated informational network of recorded cultural resources and surface surveys within 

Arizona. In addition, site records housed on the NRHP website (http://www.nps.gov/nr/) were 

reviewed and added historic buildings and districts to the inventory of cultural resources that 

were not included in the AZSITE database (see Table C-1 in the Cultural Resources Appendix). 

The objective during the Tier 1 evaluation is to identify the known historic properties and 

cultural and historic resources within the corridor alternatives and to assess the potential for 

impacts on those properties. 

5.19.2 Existing Conditions

The corridor alternatives intersect several large prehistoric sites that have previously 

undergone some archaeological testing and data recovery. As the study proceeds into a projectlevel Tier 2 NEPA process, site information would be obtained from other agencies and/or tribal 

communities and would be added to the site table (see the Cultural Resources Appendix) to 

assist with identification of cultural resources during project development.

As previously mentioned, a limited Class I records search was completed for the Tier 1 NEPA 

process to summarize and provide an overview of resources within each corridor alternative. As 

a result of the AZSITE and NRHP records search, numerous site types, both historic and 

prehistoric in age, were identified. Most of the sites are affiliated with prehistoric Archaic and 

Hohokam cultural traditions or historic American cultures (see Table 1 and Table 2 in the 

Cultural Resources Appendix). Site types include, but are not limited to, villages, habitations, 
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artifact scatters, canals, roads, bridges, petroglyphs, structures, railroads, transmission lines, 

pipelines, roasting pits, and trash dumps. Several of the sites have been evaluated for inclusion 

in the NRHP. The evaluated sites were identified during completion of cultural resources 

surveys associated with an array of previous undertakings (see Table 2 in the Cultural Resources 

Appendix).

The southern portion of both corridor alternatives coincides in places with the Juan Bautista de 

Anza National Historic Trail designated historic corridor, auto tour route, and recreation 

retracement route. As defined by the National Trails System Act (16 U.S.C. §§ 1241-1251), a 

National Historic Trail is an extended trail which follows as closely as possible and practicable 

the original trail or route of travel of national historical significance. While the historic corridor 

is not afforded protection under the NHPA, the Historic Trail designation is intended to identify 

and protect the remains of this overland route for public use and enjoyment. The Anza Trail 

corridor appears on Maps 1-11 and 21-27 of the Corridor Aerial Atlas Appendix.

The AZSITE records search identified approximately 730 previous cultural resource surveys that 

have been conducted within the corridor alternatives (see Table 2 in the Cultural Resources 

Appendix). In total, more than 500 cultural resources were identified within the corridor 

alternative as a result of the records search on AZSITE. Site records on the NRHP website 

indicated that approximately 160 NRHP-listed properties are located within the corridor

alternatives. Most of these are buildings, bridges, or historic districts; but a few properties, such 

as El Tiradito Shrine, Pascua Cultural Plaza, Picacho Peak Skirmish Site, and the Tempe Beach 

Stadium, fall outside these categories. TCPs have not been identified thus far, but further 

research and identification efforts would occur during the Tier 2 analysis.

The areas affected by the Yellow and Orange corridor alternatives are very similar from the 

southern hub to Eloy; therefore, the number of sites in each is also similar. Approximately 

220 cultural resources were identified in the Yellow Corridor Alternative and 225 in the Orange 

Corridor Alternative. The NRHP website indicates more than 40 listed properties south of Eloy; 

10 of these also appear in the AZSITE. South of Eloy, large prehistoric sites include, but are not 

limited to, Sunset Mesa Ruin, Los Morteros, Los Pozos, El Taller, Las Capas, and Stone Pipe Site. 

Within the Yellow Corridor Alternative, the NRHP website indicates nearly 120 listed properties 

north of Eloy; 20 of these also appear in the AZSITE. North of Eloy, large prehistoric sites 

include, but are not limited to, the following: Grewe Site, La Ciudad, Pueblo Patricio, La Villa, 

Pueblo Grande, Las Acequias, and Germann Site. One of the listed properties within the Yellow 

Corridor Alternative is the Casa Grande Ruins National Monument, at the northern end of 

Coolidge in Pinal County. Casa Grande Ruins National Monument includes a four-story structure 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-215

that is part of one of the largest Hohokam settlements and one of the longest occupied 

settlements in the Southwest.

According to the AZSITE and NRHP records search, the segment of the Orange Corridor 

Alternative north of Eloy includes approximately 50 sites that have been determined NRHPeligible, more than 30 sites that have been recommended eligible, and at least 35 sites that 

may require further assessment for potential NRHP inclusion. The NRHP website indicates more 

than 110 listed properties north of Eloy.

According to the AZSITE and NRHP records search, the segment of the corridor alternatives 

south of Eloy includes more than 75 sites that have been determined NRHP-eligible, more than 

35 sites that have been recommended eligible, and at least 65 sites that may require further 

assessment for potential NRHP inclusion. The NRHP website indicates more than 40 properties 

south of Eloy are listed.

North of Eloy, approximately 150 sites were identified in the Yellow Corridor Alternative, and

more than 190 sites were identified in the Orange Corridor Alternative. Overall, AZSITE 

indicates approximately 370 sites are in the Yellow Corridor Alternative; and more than 415 are

in the Orange Corridor Alternative.

5.19.3 Environmental Consequences

This evaluation assesses the potential effects on cultural resources of a passenger rail system in 

the Yellow and Orange corridor alternatives. The corridor alternatives are each 1.0 mile wide.

An adverse effect is found when an undertaking may alter, directly or indirectly, any of the 

characteristics of a historic property that qualify the property for inclusion in the NRHP in a 

manner that would diminish the integrity of the property's location, design, setting, materials, 

workmanship, feeling, or association. Consideration shall be given to all qualifying 

characteristics of a historic property, including those that may have been identified subsequent 

to the original evaluation of the property's eligibility for the NRHP. Adverse effects may include 

reasonably foreseeable effects caused by the undertaking that may occur later in time, be 

farther removed in distance, or be cumulative.

Impacts to cultural resources would vary depending on the future location of a passenger rail 

system within the selected corridor. Avoidance is the preferred way to address cultural 

resources, and decisions on avoidance methods would be reached through Section 106 

Consultation during Tier 2 when more details on the design and operation are known.
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Yellow Corridor Alternative

Southern Hub to Eloy

Physical Impacts

Physical impacts to cultural resources may include direct damage or destruction of cultural 

resources within the footprint of the passenger rail system, including any needed nearby 

staging areas and material sources.

Operational Impacts

Operational impacts to cultural resources could include permanent access restrictions, visual 

impacts, and noise and vibration impacts to properties that are in proximity to a future 

alignment of a passenger rail system. In addition, direct damage to or destruction of cultural 

resources (e.g., pot hunting) due to increased accessibility to previously isolated areas is 

possible. Permanent loss or temporary changes in the viewshed of potential TCPs and 

permanent loss or temporary change of potential TCP access and usage could result.

Construction Impacts

Construction impacts to cultural resources may include direct damage or destruction of cultural 

resources and noise and vibration impacts to properties that are in proximity to a future 

alignment (including material sources and staging areas) but that would not be permanently 

incorporated into the passenger rail system. Indirect damage may be caused through vibrations 

caused by geotechnical testing, use of heavy equipment, or any earth-moving activities. 

Construction impacts may also include unanticipated discovery of previously unknown cultural 

resources (including human burials), permanent loss or temporary changes in viewshed of

potential TCPs, permanent loss or temporary change of potential TCP access and usage, and 

increased noise and dust. The increased noise and dust during construction could disturb 

visitors or adversely affect visitation to structures or potential TCPs.

Eloy to Northern Hub

Physical Impacts

Physical impacts to cultural resources would result if a resource or portion of a resource were

permanently incorporated into the passenger rail system. 

One of the listed properties within the Yellow Corridor Alternative is the Casa Grande Ruins 

National Monument at the northern end of Coolidge in Pinal County. Casa Grande Ruins 

National Monument includes a four-story structure that is part of one of the largest Hohokam 

settlements and one of the longest occupied settlements in the Southwest. 
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Final Tier 1 Environmental Impact Statement 5-217

Operational Impacts

Operational impacts to cultural resources within this segment of the Yellow Corridor Alternative 

would be similar to those described for the segment from the southern hub to Eloy.

Construction Impacts

Construction impacts to cultural resources within this segment of the Yellow Corridor

Alternative would be similar to those described for the segment from the southern hub to Eloy.

Orange Corridor Alternative

Southern Hub to Eloy

Physical, operational, and construction impacts within this segment of the Orange Corridor 

Alternative would be similar to those described for this segment of the Yellow Corridor 

Alternative.

Eloy to Northern Hub

Physical Impacts

Physical impacts to cultural resources would result if a resource or portion of a resource were

permanently incorporated into the rail line. 

Legislation (H.R. 1077) was introduced in the U.S. House of Representatives in February 2015 to 

expand the boundaries of the Casa Grande Ruins National Monument. The 1-mile-wide Orange

Corridor Alternative would encroach upon the proposed expanded boundaries of the national 

monument. This bill was originally introduced to the 113th Congress in July 2013 as H.R. 2497. 

Operational Impacts

Operational impacts to cultural resources within this segment of the Orange Corridor 

Alternative would be similar to those described for the Yellow Corridor Alternative from the 

southern hub to Eloy.

Construction Impacts

Construction impacts to cultural resources within this segment of the Orange Corridor 

Alternative would be similar to those described for the Yellow Corridor Alternative from the 

southern hub to Eloy.

No Build Alternative

Under the No Build Alternative, a passenger rail system would not be built; and no impacts to 

cultural resources are projected to occur beyond those that could occur due to other projects.
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Final Tier 1 Environmental Impact Statement 5-218

5.19.4 Potential Mitigation Measures

Municipalities or counties north of Eloy may require avoidance of certain archaeological sites 

because of established conservation or land use plans (e.g., Historic Homes of Phoenix: An 

Architecture & Preservation Guide, Pinal County Comprehensive Land Use Plan).

Casa Grande Ruins National Monument is one of the most prominent cultural resources within 

the state. It is recommended that the monument be avoided and close coordination with tribal 

communities and NPS occur with regard to proximity of the passenger rail system and 

monument boundaries.

If the alignment of a future passenger rail system resulted in an adverse effect to a property 

that is listed, eligible, or potentially eligible for listing on the NRHP, potential mitigation 

measures could include additional research to recover data or exhaust the information 

potential of a site, changes in project design, development of a Memorandum of Agreement 

(MOA), and other options that may result from Section 106 consultation.

Specific mitigation measures could include a programmatic agreement (PA), a memorandum of 

agreement (MOA) with a public involvement component, archaeological data recovery, 

archaeological treatment plans, historic buildings surveys, and historic engineering record 

documentation.

Consultation with all consulting parties over potentially affected properties would be key to 

developing a passenger rail system in either the Orange or the Yellow corridor alternatives. As 

the study proceeds to a Tier 2 project-level NEPA process, avoidance of these properties and 

mitigation of potential visual and audible impacts would be considered. 

5.19.5 Tier 2 Considerations

During Tier 2 NEPA evaluations, as more detailed information is gathered for review of the 

preferred corridor and specific service alternatives are identified, effect findings on historic 

properties would be proposed to SHPOs and Tribal Historic Preservation Offices (THPOs). The 

SHPO, THPOs, tribes with interest in the area, and other officials with jurisdiction should be 

formally consulted throughout the project. The Section 106 process should be followed: 

establish undertaking, identify consulting parties, identify scope of work and APE, identify 

historic properties, finding of project effect, and assessment and resolution of adverse effects,

as necessary. If any adverse effects are identified during the Tier 2 NEPA process, they would be 

addressed through SHPO/THPO consultation and would be in compliance with 36 CFR 800.5 

(Assessment of adverse effects) and 36 CFR 800.6 (Resolution of adverse effects).
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Final Tier 1 Environmental Impact Statement 5-219

Specific mitigation measures, to the extent required, would be identified and discussed during 

Tier 2 analysis after design details are known. Tier 2 analyses would include data gathered from 

other agencies including ADOT, the Arizona SHPO, and BLM, as well as any information 

gathered from tribal organizations and other land managing agencies (e.g., counties, 

municipalities) and an appropriate level of field investigation. In part, land jurisdiction would

help determine what information is sought and obtained during the Tier 2 analyses. 

Mitigation measures may be developed in accordance with the terms of a programmatic 

agreement (PA) pursuant to 36 CFR Section 800.14 between FRA and consulting parties 

including the Council, SHPO, THPOs, and other officials with jurisdiction. A PA is a formal, legally 

binding agreement that establishes a process for consultation and review and compliance with 

federal laws and regulations. A project-specific PA is tailored to the nature and requirements of 

a specific undertaking. It establishes time frames, procedures for review, dispute resolution, 

discoveries, etc. A PA would focus on describing the actions that would be taken by parties to 

meet their environmental compliance responsibilities and establish a process through which 

the parties would meet these responsibilities. In other words, the PA would focus on study 

commitments, documentation of the qualities that contribute to the historic significance of 

resources, review procedures, and products to be produced during the preparation of Tier 2

NEPA documents for mitigating adverse effects. 

It is recommended that close coordination with NPS continue during Tier 2 to determine a 

sufficient buffer between the passenger rail system and the Casa Grande Ruins National 

Monument boundary.

5.20 Unavoidable Adverse Impacts / Irreversible and Irretrievable 

Commitment of Resources

Irreversible commitments involve the use or destruction of a specific resource (for example, 

energy and natural resources such as water, minerals, or timber) that cannot be replaced within 

a reasonable timeframe. Irretrievable resource commitments involve the loss in value of an 

affected resource that cannot be restored as a result of the action (for example, disturbance of 

a cultural site or extinction of a threatened or endangered species).

5.20.1 Methodology and Regulatory Requirements

Irreversible and irretrievable commitments of resources directly relate to the trade-offs of 

implementing a project versus not implementing a project. Irreversible and irretrievable 

impacts were evaluated in accordance with NEPA (42 U.S.C. § 4321-4347), regulations

published by CEQ on implementing NEPA (40 CFR 1502.16), FTA’s Environmental Impact and 
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Final Tier 1 Environmental Impact Statement 5-220

Related Procedures (23 CFR Part 771), and FRA’s Procedures for Considering Environmental 

Impacts (64 FR 28545, May 26, 1999) Section 14(n)(11) (FRA 1999a).

Data gathered from the review of all applicable resources analyzed in the Tier 1 EIS were used, 

especially the consumption of energy (as derived from the estimated reduction in VMT

generated from the operation of passenger trains between Tucson and Phoenix) cultural 

resources, natural resources (as derived from the assessment of water resources; topography, 

geology, and soils; biotic communities; wetlands; and special status species), and visual and 

scenic resources. Additionally, land that would be committed to a transportation use was 

addressed. Specific government agency coordination is not typically conducted for this resource 

evaluation and was not performed for this Tier 1 EIS.

The potential use of existing resources and land was assessed. In a Tier 1 analysis, the change in 

the use of resources can only be assessed qualitatively. The analysis considered resources on 

which a passenger rail system could have a direct or indirect effect; however, specific 

unavoidable adverse impacts and irreversible and irretrievable commitments of resources 

cannot be identified until future alignments are developed for a Tier 2 analysis.

5.20.2 Existing Conditions

Appendix 4.6, Figures 1 through 91, show various resources within the corridor alternatives, 

portions of which may be disturbed or eliminated to implement a passenger rail system, such as 

farmland, parkland, wetlands, wildlife habitat, and cultural resources. 

5.20.3 Environmental Consequences

Yellow Corridor Alternative

Physical Impacts

Construction of a passenger rail system within the Yellow Corridor Alternative would result in 

the irreversible and irretrievable commitment of land, at least for the life of the project, where 

additional ROW is needed. The land would be converted from its current condition to a railroad 

grade and track, maintenance yards and facilities, and station areas with associated parking 

lots. In the non-urban areas, much of this land is prime and unique farmlands and farmland of 

unique importance, and impacts would be considered an irreversible and irretrievable 

commitment of resources. 

Operational Impacts

Operation of a passenger rail system within the Yellow Corridor Alternative would require the 

commitment of several energy resources, which could include petroleum, electricity, and 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-221

manpower expenditures, for operation and maintenance. Use of these resources would be 

irreversible and irretrievable.

Construction Impacts

Construction materials for building a passenger rail system within the Yellow Corridor 

Alternative would consist largely of steel, concrete, ballast rock, and wood, although water 

would also be consumed for mixing concrete, washing equipment, and controlling dust. 

Maintenance yards would incorporate these materials as well, in addition to building materials 

and equipment usually associated with a rail maintenance plant. Materials for station buildings 

and station areas would include concrete, steel, and various building materials, depending upon 

the station type. Parking lot construction would require asphalt and additional concrete. The 

use of these materials would be largely irretrievable; however, these resources are not in short 

supply, and many of the materials could be recycled for other projects if they were no longer 

required for passenger rail service. Construction would also require the commitment of energy 

resources including petroleum, electricity, and manpower expenditures.

Orange Corridor Alternative

Physical Impacts

Construction of a passenger rail system within the Orange Corridor Alternative would result in 

the irreversible and irretrievable commitment of land similar to that of the Yellow Corridor

Alternative. In the non-urban areas, much of this land is prime and unique farmlands and 

farmland of unique importance. While the nature of the irreversible and irretrievable 

commitments of land would be similar to those described for the Yellow Corridor Alternative, 

the northern section of the Orange Corridor Alternative is approximately 12 miles longer than 

the northern section of the Yellow Corridor so the impact to land use could be expected to be 

somewhat greater than with the Yellow Corridor Alternative.

Operational Impacts

Operating a passenger rail system in the Orange Corridor Alternative would result in an 

irreversible and irretrievable commitment of energy resources similar to that required in the 

Yellow Corridor Alternative; however, the northern section of the Orange Corridor Alternative is 

approximately 12 miles longer than the northern section of the Yellow Corridor Alternative, so 

the quantity of resources required could be expected to be somewhat greater than with the 

Yellow Corridor Alternative.

Construction Impacts

Constructing a passenger rail system in the Orange Corridor Alternative would result in an 

irreversible and irretrievable commitment of resources similar to that required in the Yellow 
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Final Tier 1 Environmental Impact Statement 5-222

Corridor Alternative with regard to materials and energy resources. The exception is that from 

the southern hub in Tucson to the northern hub in Phoenix, the Yellow Corridor Alternative is 

approximately 120 miles in length, while the Orange Corridor Alternative is approximately 

132 miles long. Therefore, the full extent of irreversible and irretrievable commitment of 

physical materials, energy resources, and manpower expenditures associated with construction 

could be expected to be approximately 10 percent greater for a railroad within the Orange 

Corridor Alternative, compared to the Yellow Corridor Alternative. This 10-percent difference 

would also be realized in energy expenditure with regard to Tucson-to-Phoenix operations over 

the respective alternative corridors.

Phased Implementation of a Future Build Alternative

With phased implementation in either corridor alternative, the commitment of resources 

required to implement a single operable segment of a passenger rail system from Tucson to 

Phoenix would be less than that required for a complete Tucson-to-Phoenix rail system. The 

initial implementation would likely require less ROW than a system spanning the entire 

corridor. As additional phases are constructed, resources would be committed in stages, within 

respective segments of the corridor. The full extent of irreversible and irretrievable impacts 

over the entire length of the Tucson-to-Phoenix corridor might eventually be realized, but those 

impacts would occur gradually over the years of implementation as federal and state funds 

were allocated to such a project. Conversely, phased implementation may require more energy 

resources for construction because multiple mobilization and demobilization events may have 

to occur, including transporting heavy equipment. Irreplaceable resources may become scarcer 

over time, which could affect construction costs. 

No Build Alternative

Under the No Build Alternative, a passenger rail system would not be built; and new 

commitments of resources would not occur beyond those that could occur in relation to other 

projects. In addition, energy resources would continue to be consumed by automobile travel 

between Tucson and Phoenix at a slightly higher rate than would be the case with commuter 

and intercity passenger rail service in one of the corridor alternatives.

5.20.4 Tier 2 Considerations

In addition to the above resources commitments, federal and state financial resources would 

be irreversibly and irretrievably committed for the development of Tier 2 NEPA documentation, 

project design, construction, operation, and maintenance. These financial resources would no 

longer be available for other federal or state projects.
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Final Tier 1 Environmental Impact Statement 5-223

During Tier 2 analyses, a more complete review of the design and the specific alignment for a 

passenger rail system would be conducted, which may further refine the nature of or potential 

quantity of resources that may be irreversibly and irretrievably be committed for 

implementation of a passenger rail system.

5.21 Short-Term Uses vs. Long-Term Productivity

Balancing the relationship between short-term impacts and long-term productivity is an 

important consideration in determining project feasibility. The following section discusses 

short-term impacts to and use of resources, and long-term effects and benefits and/or losses 

that could be expected under the Yellow and Orange corridor alternatives and the No Build 

Alternative.

5.21.1 Methodology and Regulatory Requirements

Short-term impacts to and use of resources in relation to long-term productivity were 

evaluated in accordance with NEPA, guidelines published by CEQ on implementing NEPA, FTA’s 

Environmental Impact and Related Procedures (23 CFR Part 771),and FRA’s Environmental 

Procedures (64 FR 28545, May 26, 1999) Section 14(p).

A review of construction impacts for all applicable resource sections included in this Tier 1 EIS 

provided the data for this analysis, which discusses the relationship between short-term 

impacts to and use of resources and the long-term benefits and productivity of the 

environment in qualitative terms.

5.21.2 Existing Conditions

Maps 1 through 91 of the Corridor Aerial Atlas Appendix show various resources within the 

corridor alternatives.

5.21.3 Environmental Consequences

Implementing passenger rail service within one of the corridor alternatives would result in the 

short-term impacts and use of resources described below, while increasing the long-term 

benefits and productivity of passenger rail transportation and economic systems.

Yellow Corridor Alternative

Short-Term Impacts

Construction of a passenger rail system within the Yellow Corridor Alternative could contribute 

to short-term construction impacts related to the following:

 Hazardous materials and waste disposal
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Final Tier 1 Environmental Impact Statement 5-224

 Water quality degradation from erosion and sedimentation, and/or potential fuel and 

lubricant spills

 Air quality degradation from equipment emissions and fugitive dust

 Noise and vibration from construction equipment 

 Changes in property access

 Traffic and pedestrian delays and detours

Short-term employment, use of materials to construct the system, and local purchases of goods 

and services generated by construction activity could create a short-term increase in local 

economic activity that would end once the construction phase is completed. A passenger rail 

system within the Yellow Corridor might be able to utilize existing UP ROW or be built directly 

adjacent to it; in this case, these short-term impacts and resources required for construction 

might be reduced.

Short-term construction impacts such as noise, ground-borne vibration, and air pollutant 

emissions would occur regardless of the new passenger rail system’s proximity to the existing 

railroad.

Long-Term Benefits

In the region between Tucson and Phoenix, the addition of passenger rail service within the 

Yellow Corridor Alternative would contribute to a more robust transportation network and 

access within the region by providing reliable passenger rail service to meet the needs of 

increased future travel demand and more efficient travel between major urban centers. A 

reduction in air pollutant emissions would likely occur as a result of passenger rail service 

replacing automobile, bus, and plane trips, as well as decreased congestion on local streets and 

highways. Improved accessibility within the region would also result in economic benefits 

through employment opportunities, potential for transit-oriented development, and increased 

economic activity. Other long-term benefits include providing an accessible alternative mode of 

transportation for minority and low-income populations.

Long-Term Losses/Effects

Although constructing a passenger rail system along the Yellow Corridor Alternative would 

result in permanent impacts to waterways, waterbodies, wetlands, floodplains, plant 

communities, natural habitat, and wildlife, coordination with resource agencies would be 

conducted to minimize impacts through appropriate mitigation measures. Other long-term 

losses/effects on the productivity of the environment would include the following:
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Final Tier 1 Environmental Impact Statement 5-225

 Removal of existing farmland from cultivation

 Potential economic impacts on other modes of public transportation

 Potential acquisition of park land, recreation land, and natural areas

 Noise and vibration impacts on sensitive receptors from train operations

 Conflicts with wildlife

Orange Corridor Alternative

Short-Term Impacts

Construction and operation of a passenger rail system within the Orange Corridor Alternative 

would contribute to short-term construction impacts related to the same components of the 

natural, social, and built environment as a system within the Yellow Corridor Alternative.

A short-term increase in the local economy similar to that resulting from construction within 

the Yellow Corridor Alternative could also result from a new rail system within the Orange 

Corridor Alternative. A greater degree of construction activity could occur in the Orange 

Corridor Alternative, as compared with the Yellow Corridor Alternative, from the longer length 

of the corridor as well as development in a corridor with more currently undeveloped land, 

resulting in a greater degree of short-term impacts and use of more resources required for 

construction. Short-term impacts connected with construction such as noise, ground-borne 

vibration, and air pollutant emissions would be similar to those impacts resulting from 

constructing a new passenger rail system within the Yellow Corridor Alternative.

Long-Term Benefits

In the region between Tucson and Phoenix, the addition of passenger rail service within the 

Orange Corridor Alternative would result in long-term benefits similar to those resulting from 

construction of a passenger rail system within the Yellow Corridor Alternative. 

Long-Term Losses/Effects

Constructing a passenger rail system within the Orange Corridor Alternative would result in 

permanent impacts to waterways, waterbodies, wetlands, floodplains, plant communities, 

natural habitat, and wildlife. Coordination with resource agencies would be conducted to 

minimize impacts through appropriate mitigation measures. Other long-term losses or effects 

on the productivity of the environment would be similar to those resulting from constructing a 

passenger system within the Yellow Corridor Alternative, including the following:

 Removal of existing farmland from cultivation
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Final Tier 1 Environmental Impact Statement 5-226

 Potential economic impacts on other modes of public transportation

 Potential acquisition of park land, recreation land, and natural areas

 Noise and vibration impacts on sensitive receptors from train operations

 Conflicts with wildlife

A greater number of operational impacts would likely occur on a new passenger system within 

the Orange Corridor Alternative because a future alignment within this corridor has a greater 

potential for traversing areas of undeveloped land; however, the same long-term benefits and 

productivity would be realized with a new rail system within the Orange Corridor Alternative as 

would occur within the Yellow Corridor Alternative.

No Build Alternative

Under the No Build Alternative, no passenger rail system would be built, and no impacts would 

be anticipated beyond those that occurred as the result of other projects.

Short-Term Impacts

The potential construction of other projects within the study corridor could contribute to 

potential short-term construction impacts similar to those of the corridor alternatives discussed 

above. Other projects that may contribute to short-term impacts may include improvements to 

UP train facilities (such as bridge replacements or new warning systems at roadway crossings) 

widening of I-10 to accommodate more automobile traffic, or development of the North-South 

Corridor. The potential short-term construction impacts for these types of projects would be 

similar to the impacts associated with a passenger rail system, but the additive effects would be 

less because a new rail corridor would not be constructed. Construction of other reasonably 

foreseeable projects could create a short-term increase in the local economy resulting from 

short-term employment, use of construction materials, and purchases of ancillary goods and 

services that would end once the construction phases of these other projects were completed, 

as further discussed in Section 5.22, Indirect and Cumulative Effects.

Long-Term Benefits

In the region between Tucson and Phoenix, construction of other planned transportation 

projects would contribute in some degree to the transportation network and facilitate 

improved socioeconomic conditions. With the No Build Alternative, the socioeconomic changes 

from building the passenger rail system would not occur.
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Final Tier 1 Environmental Impact Statement 5-227

Long-Term Losses/Effects

Under the No Build Alternative, long-term productivity could be adversely affected by increases 

in highway congestion and traffic delays, and increased vehicle collisions. As traffic congestion 

increases, energy resources to fuel transportation modes between Tucson and Phoenix would 

be consumed at a higher rate than would occur with implementation of a future rail system 

within one of the corridor alternatives. This, in turn, could result in increased pollutant 

emissions and degraded air quality.

5.21.4 Potential Mitigation Measures

The potential mitigation measures for short-term and long-term impacts are discussed in the 

previous sections for each respective resource in this chapter. 

5.21.5 Tier 2 Considerations

Tier 2 analysis would include evaluation of specific alignments, additional public input, and 

more detailed modeling of the number of persons likely to ride the passenger train and 

between which communities. The Tier 2 analysis of short-term use versus long-term 

productivity would be better able to account for specific types of impacts and benefits. For 

example, the assessment might include the amount of natural habitat removed, the number of 

low-income populations that may benefit from an additional transit option, the projected 

reduction in air pollutant emissions from providing an alternative as compared to automobile 

travel, and the extent of the economic benefits by community.

Public values and persons potentially affected may change by the time Tier 2 studies are 

initiated. Therefore, additional public outreach and scoping would be conducted during Tier 2, 

and the values, issues, and concerns identified at that time may contribute to the analysis of 

short-term uses versus long-term productivity.

5.22 Indirect and Cumulative Effects

5.22.1 Methodology and Regulatory Environment

CEQ regulations implementing NEPA define indirect impacts as those that are caused by the 

action and are later in time or farther removed in distance but are still reasonably foreseeable. 

Indirect effects may include growth-inducing effects and other effects related to induced 

changes in the pattern of land use; population density or growth rate; and related effects on 

air, water, and other natural systems, including ecosystems (40 CFR 1508.8[b]). 

CEQ regulations define cumulative effects as “the impact on the environment which results

from the incremental impact of the action when added to other past, present, and reasonably 

foreseeable future actions regardless of what agency (federal or non-federal) or person 
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Final Tier 1 Environmental Impact Statement 5-228

undertakes such other actions. Cumulative impacts can result from individually minor but 

collectively significant actions taking place over a period of time” (40 CFR 1508.7). Thus, 

cumulative effects include the direct and indirect impacts of a project together with the 

impacts from reasonably foreseeable future actions.

The CEQ handbook for considering cumulative effects advises that focusing the cumulative 

effects analysis on meaningful cumulative impact issues, rather than on all conceivable impact 

relationships, is critical to the success of the analysis and to supporting more informed 

decisions about a proposed action and alternatives (CEQ 1997b). The handbook also advises 

that cumulative effects need to be analyzed in terms of the specific resources, ecosystem, and 

human community that may be affected by a proposed action or alternatives. The analysis must 

consider how cumulative effects may be manifested over short and long time frames and how 

they may cause meaningful impacts that extend over areas that may exceed political or 

administrative boundaries. Each affected resource, ecosystem, and human community must be 

analyzed in terms of its own capacity to accommodate additional effects, based on its own time 

and space parameters.

The methodology for conducting the review and evaluation of indirect and cumulative effects is 

in accordance with federal regulations and guidelines, including NEPA and the CEQ guidelines 

implementing NEPA.

Indirect impacts were evaluated in accordance with 40 CFR 1508.8(b), FTA’s Environmental 

Impact and Related Procedures (23 CFR Part 771), and FRA’s Environmental Procedures (64 FR 

28545, May 26, 1999) Section 14(n). The cumulative effects were evaluated in accordance with 

40 CFR 1508.7 and CEQ guidance on assessing cumulative effects (CEQ 1997b). Data from the 

following sources were used during review of the potential indirect and cumulative impacts on 

the human and natural environment as a result of the study:

 Identification of other major transportation projects within the study corridor through 

planning documents, including state transportation improvement plans, state longrange transportation plans, and comprehensive plans developed by regional 

metropolitan planning organizations and councils of governments

 Land use information

 Internet sources, such as agency or news websites

 Input from Tribal governments and government agencies as part of the scoping process
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Final Tier 1 Environmental Impact Statement 5-229

5.22.2 Existing Conditions

Public documents were reviewed to identify present and reasonably foreseeable future actions, 

other federal actions, and non-federal actions. In accordance with CEQ guidance, analysis was 

performed using available or reasonably obtainable information. To be commensurate with the 

level of detail associated with a Tier 1 EIS regarding project effects, the list of past, present, and 

reasonably foreseeable future actions includes broader categories of actions and projects 

rather than site-specific projects. Table 5-30 outlines the actions considered in this analysis.
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Final Tier 1 Environmental Impact Statement 5-230

Table 5-30. Past, Present, and Reasonably Foreseeable Future Actions

Action/Project Description Location

Past 

Actions/Projects

Community 

Population Growth

Population growth within the study corridor has led to land

use changes over the last century, expending the size of 

urban development and the associated demand for 

services. The table-within-a-table on the following page 

provides some reference to the extent of change that was 

occurred in the three counties and representative cities.

As noted.

Place

Year 1900

Except where 

noted

Year 2010

Pima County 14,689 980,263

 Tucson 7,531 520,116

Pinal County 7,779 375,770

 Eloy 5,381b 16,631

 Florence 2,173b 25,536

Maricopa Co. 20,457 3,817,117

 Mesa 722 439,041

 Chandler 1,378a 388,838

 Tempe 885 161,719

 Phoenix 5,544 1,445,632

Sources: Arizona Geographic Alliance 2014a; Pima Association of 

Governments 2014; US Census Bureau 1995: US Census Bureau 

2010a

Notes:

a 1930 data – earliest identified

b 1970 data
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-231

Table 5-30. Past, Present, and Reasonably Foreseeable Future Actions

Action/Project Description Location

Tribal Settlements The Gila River Indian Reservation was established in 1859, 

the Walt River Pima-Maricopa Indian Community was 

established in 1879, and the Ak-Chin Reservation was 

established in 1912 (Arizona Geographic Alliance 2014b).

South and east of 

Phoenix

Agricultural 

Production

Arizona data from the Census of Agriculture indicate that 

the quantity of land in cultivation grew in the early 1900s, 

peaked in the mid-1950s, and then gradually declined. For 

example, about 14 million acres of Arizona land was in 

cultivation in 1935. In 1954 the figure approached 42 

million acres, but dropped to about 38 million acres by 1969 

and to about 36 million acres by 1987 (U.S Department of 

Agriculture 2014).

Arizona statewide

Southern Pacific 

Railroad; now 

Union Pacific 

Railroad

The Southern Pacific Railroad was extended from Yuma 

reaching Tucson in 1880; the line between Tucson and 

Phoenix was established in the late 1800s. In 1996, the UP 

and Southern Pacific Railroad merged. 

From Nogales 

through Tucson to 

west of Phoenix; a 

rail line also passes 

through Tucson 

and crosses the 

southern part of 

the state 

Interstate 10 I-10 in Arizona was laid out by the Arizona Highway 

Department (as ADOT was called at the time) in 1956-1958, 

and the segment between Tucson and Phoenix was built in 

1967 with two travel lanes in each direction. In more recent 

years, portions of the highway have been widened to 

include up to three travel lanes in each direction in between 

the Tucson and Phoenix metropolitan areas, with additional 

travel lanes within Tucson and Phoenix.

South-central 

Arizona

Highway and Road 

System

While roads and highways are not abundant between 

Tucson and Phoenix, a system of transportation routes 

connects various communities in the Sun Corridor. Of 

particular note are the segments of Old US 80 (now State 

Route 77, State Route 79, and US 60) that collectively 

provide an alternative route from Tucson to Phoenix and 

the suburban communities east of Phoenix.

South-central 

Arizona
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-232

Table 5-30. Past, Present, and Reasonably Foreseeable Future Actions

Action/Project Description Location

Utility Corridors The Central Arizona Project was constructed between 1973 

and 1993, bringing water from Lake Havasu on the Colorado 

River over a distance of 336 miles to Tucson, and is a major 

water supply source (Central Arizona Project 2014).

The Palo Verde Nuclear Power Plant went into commercial 

operation in 1986 and became fully operational in 1988. It is 

a major source of electric power, generating approximately 

4,000 megawatts annually for the Tucson, Phoenix, Los 

Angeles, and San Diego metropolitan areas (Arizona Public 

Service Company 2014). Various transmission lines extend 

from the power plant as well as from other power 

generation facilities, including Roosevelt Dam, located east 

of Phoenix.

South-central 

Arizona

South-central 

Arizona; Southern 

California

Present 

Actions/Projects

Agricultural 

Production

While declining from historic levels, agricultural production 

remains an important component of land use in the threecounty study area. The 2007 Census of Agriculture (US 

Department of Agricultural 2007) reports:

 Pima County: 622 farms; acreage of land in 

cultivation not disclosed

 Pinal County: 785 farms and 1,047,112 acres of land 

in cultivation

 Maricopa County: 1,793 farms and 485,469 acres of 

land in cultivation

While county statistics are not necessarily a reflection of the 

corridor alternatives, the corridors intersect with land in 

agricultural production in each county. The majority of the 

farmland crossed, however, is in Pinal County.

Pima, Pinal, and 

Maricopa counties

Rangeland/ Grazing 

Allotments

Ranching has been an historic land use in Arizona, and 

grazing allotments remain active within the three-county 

study area, particularly in Pinal County.

Generally east of I10 from about 

Marana north to 

State Route (SR) 87 

(Coolidge area)
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-233

Table 5-30. Past, Present, and Reasonably Foreseeable Future Actions

Action/Project Description Location

Union Pacific 

Railroad

In 2012, UP employed more than 1,300 persons in Arizona, 

with nearly 2,100 rail cars originating and more than 96,000 

rail cars terminating in Arizona (UP 2013).

From Nogales 

through Tucson to 

west of Phoenix; a 

rail line also 

crosses the 

southern part of 

the state and 

passes through 

Tucson

UP Sunset Route UP is in the process of upgrading the Sunset Route to 

double tracks. Work has been occurring in the Tucson area 

since 2012. UP’s 2013 capital plan summary indicates that a 

total of 30 miles of a second mainline on the Sunset Route 

was scheduled in Arizona and California in 2013.

Los Angeles to New 

Orleans, including 

the Tucson area

Transportation 

Facilities/ Highways

The major transportation features in the study corridor 

include I-10, SR 77, SR 79, SR 87, SR 287, SR387, and US 60. 

The metropolitan areas of Tucson and Phoenix also have a 

system of major and minor arterial streets contributing to 

the transportation system.

Urban and Rural 

Development

Approximately 20 to 25 percent of the corridor alternatives 

pass through currently developed areas, including 

residential, industrial, and commercial/business land uses. 

Major planned developments that are currently in a buildout phase include, but are not limited to: Gladden Farms, 

Rancho Marana, San Lucas, Continental Ranch, Continental 

Reserve, and Dove Mountain. More than 10,000 lots in 

these subdivisions alone have been built, with more lots 

and commercial space in development.

Study corridor
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-234

Table 5-30. Past, Present, and Reasonably Foreseeable Future Actions

Action/Project Description Location

Reasonably Foreseeable Future Actions/Projects

Major Planned 

Developments

Some of the major planned subdivision developments 

partially or fully within the study corridor include 

Superstition Vistas, Eastmark, The Villages at Tortolita

Mountain Ranch, Saguaro Springs, Sherwood Park, 

Magma Ranch, and Tangerine Crossing. These 

developments collectively include tens of thousands 

of platted and proposed lots for homes as well as land 

allocations for commercial development.

Study corridor

Expansion of Casa 

Grande Ruins National 

Monument

In June 2013, four members of the House of 

Representatives introduced legislation to expand the 

boundaries of Casa Grande Ruins National 

Monument. Similar legislation was introduced in 

February 2015. The bill (H.R. 1077) remains with the 

Subcommittee on Federal Land.

Coolidge

Interstate 10 Between Tucson and Phoenix, ADOT plans to widen 

I-10 to five travel lanes in each direction, where 

feasible.

South-central 

Arizona

North-South Corridor ADOT and FHWA are studying a proposed highcapacity transportation facility between US 60 in 

Apache Junction and I-10 near Eloy and Picacho.

Pinal County

Loop 202-South 

Mountain Freeway

ADOT proposes to complete the Loop 202 highway 

system with a freeway running east and west along 

Pecos Road and then turning north between 55th and 

63rd avenues, connecting with I-10 on each end.

Involves a corridor 

passing through 

portions of 

Phoenix, Tolleson, 

Avondale, 

Chandler, Glendale, 

and Goodyear

Phoenix-Mesa Gateway 

Airport

Phoenix-Mesa Gateway Airport plans a major 

expansion in the next 10 to 20 years, moving the 

terminal across the runways and adding substantial 

airline capacity.

Mesa area

Phoenix Sky Harbor 

Airport

The City of Phoenix plans to modernize and increase 

the capacity of Terminal 3 and eventually close 

Terminal 2.

Phoenix
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-235

Table 5-30. Past, Present, and Reasonably Foreseeable Future Actions

Action/Project Description Location

Ak-Chin Regional Airport The Ak-Chin Indian Community has been renovating 

the former Phoenix Regional Airport and, with 

completion of ongoing additions, will be able to 

accommodate more of the single-engine and multiengine piston aircraft that the airport predominantly 

serves.

Between the cities 

of Maricopa and 

Casa Grande; 33 

miles southsoutheast of 

Phoenix

UP Red Rock 

Classification Yard

UP has submitted an application to purchase 

approximately 1,873 acres of land from the Arizona 

State Land Department to construct a classification 

yard where rail cars would be separated and classified 

and trains assembled to improve operations efficiency 

(RBF 2012).

Southeast of 

Picacho Peak State 

Park on the east 

side of I-10 

between the 

railroad’s Sunset 

mainline and the 

CAP canal

UP Sunset Route Union Pacific Railroad proposes to double-track the 

Sunset Route over the next 20 to 30 years. 

Los Angeles to New 

Orleans, including 

rail within the 

corridor 

alternatives

UP Track Upgrades and 

Increased Train Speeds

UP freight trains using tracks within the corridor 

alternatives currently operate at a maximum speed of 

60 mph, but UP proposes to upgrade the track to 

increase the maximum speed to 80 mph. This 

proposal would not change the number of trains that 

operate, which is currently an average of 26 to 60 

trains per day from Tucson to Eloy and 5 to 10 trains 

per day from Eloy to Phoenix.

UP tracks between 

Tucson and 

Phoenix

Passenger Rail Future 

Connections

The corridor is anticipated to connect to TUS in the 

south and to Surprise and Buckeye in the north.

Tucson and 

Phoenix 

metropolitan areas
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-236

5.22.3 Environmental Consequences

Corridor Alternatives

At the level of analysis conducted for this Tier 1 EIS, the indirect effects and cumulative impact 

analysis of the Yellow Corridor Alternative and Orange Corridor Alternative would be essentially 

the same.

Indirect Effects

Construction and operation associated with any phase of a passenger rail system have the 

potential to cause indirect impacts. The following is a list of potential indirect impacts identified 

through evaluation of various environmental resources; these could occur to varying degrees 

regardless of which corridor alternative might be selected.

 Operation of passenger trains at speeds up to 110 miles per hour would result in 

increased noise and ground vibration, as well as air emissions and visual and aesthetic 

impacts. These direct impacts could potentially result in indirect impacts of reduced use 

of nearby parks, recreation areas, and natural areas. Section 4(f) resources could be 

indirectly affected by noise, ground vibration, aesthetics, and access issues. Wildlife, 

including threatened or endangered species, could potentially be indirectly affected by 

noise, vibration, air emissions, and water quality impacts affecting habitat. 

 Noise and vibration from passenger rail traffic could cause indirect impacts to cultural 

resources by affecting the visitor experience within a historic setting or a TCP. Also, 

induced transit-oriented development in the vicinity of station areas has the potential to 

occur, which may indirectly affect nearby cultural resources. 

 Passenger train service could have the indirect effect of reducing ridership on current 

transportation services, such as intercity bus and flight service, by offering a competitive 

alternative to these modes. Diverted trips from these modes to passenger rail service 

may have implications for the viability of these modes in the future. Conversely, 

passenger train service also could have an indirect effect of increased ridership. For 

example, Central Arizona Regional Transit (CART) travels between Florence, Coolidge, 

Central Arizona College, and Casa Grande. If a station for a Tucson-to-Phoenix train were 

located along the CART route, passenger service would extend beyond the localized 

connection and might draw additional passengers that need to travel beyond the CART 

service area.

 Potential indirect positive effects include anticipated reductions in traffic volumes on 

I-10, potentially reducing congestion and accidents. This could have positive impacts on 

air quality and safety and could reduce future delays due to congestion. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-237

 As a result of train traffic, as well as activities at stations and maintenance facilities, a 

hazardous material incident has an increased chance of occurring in these locations. 

Potential indirect impacts could also occur to water quality as railway contaminants or 

accidental chemical/fuel spills from operations and maintenance activities could reach 

water resources adjacent to, or downstream of, the passenger rail system 

infrastructure. With appropriate BMPs in place, however, water quality impacts from 

hazardous materials could be avoided or minimized. 

 Potential indirect impacts to downstream waterbodies and wetlands could occur from 

culvert and/or bridge replacements. 

 Transit-oriented development could indirectly result from the construction of stations 

and use of surrounding areas. 

 Adjacent land uses could be indirectly affected from changes in traffic flow at rail 

crossings and near future station sites. Temporary indirect impacts to traffic would

occur through closings during construction, which would lead to rerouting traffic 

through adjacent neighborhoods and business areas. Lack of convenient access can 

cause increased travel time and delay for local residents and potential economic 

impacts to businesses that depend on convenient accessibility, such as auto-oriented 

retail and services, drive-through restaurants, etc. Long-term indirect impacts could 

occur through potential increased congestion and traffic delays near crossings with new 

passenger rail service. 

 A temporary increase in greenhouse gas emissions would occur from construction 

activities by onsite equipment as well as increased automobile and bus traffic delays and 

congestion from construction-related changes in access or street lane closures. 

 Indirect positive impacts on air quality would be anticipated from the development of a 

multimodal transportation system within the three-county study area, including planned 

expansion of the passenger rail system, potential changes in long-term travel behavior,

and advocacy for more energy-efficient modes of transport that improve air quality. 

 Upgrades to rail infrastructure may indirectly benefit existing freight service. 

 Transportation projects that create new or substantially improved access to areas that 

are relatively undeveloped indirectly induce commercial, residential, and/or business 

development. Construction of a future passenger rail system within one of the corridor 

alternatives would have the greatest potential to induce development near station stops 

in Pinal County where privately owned land is less developed. Even in the portions of 

the corridors in the developed areas of Tucson and Phoenix, a passenger rail system 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-238

could indirectly influence the type and density of development both near the rail line 

and beyond into areas where passenger service would extend from station stops. Station 

locations would be selected through coordinated efforts with local city/ county/ 

metropolitan area planners to help ensure that the sites and opportunities presented for 

development are suitable to handle increased traffic and other demands that accompany 

such growth, while minimizing the potential for adverse indirect and cumulative impacts.

 Induced growth would be expected in communities with passenger rail stations based 

on the availability of the train for transportation and the opportunities for business by 

concentrating a potential customer base near the stations. Because rail stations have 

not been identified in this stage of study, the effects of induced growth would be 

examined in greater detail in Tier 2 analyses. At a Tier 1 level of evaluation, the other 

identified impacts are not anticipated to be substantial.

Cumulative Effects

Each of the resources evaluated in this Tier 1 EIS has the potential for cumulative effects. The 

analysis below is in the same order as the resources were discussed earlier in this chapter.

Land Use

Land use in the corridor alternatives has been changing from undeveloped desert over the 

decades. While some land remains undeveloped, the land in the region has been generally used 

for agricultural or ranching purposes first and then converted to urban uses, including 

residential, commercial, and industrial. The transportation network has contributed to the 

pattern of land use development in some cases, and followed land use changes in others. For 

example, the UP was transformative in bringing people to Arizona and the West. Development 

is often induced by new or improved transportation systems, but rapid development and 

demand for access also contributes to widening of existing streets and highways, as well as the 

need to establish public transportation systems. The cumulative impact of passenger rail on 

land use within the Yellow and Orange corridors would include continued displacement of 

activities and land uses, and changes in future use patterns influenced by the passenger rail 

system and the associated transportation network. Land use development may continue in the 

I-10 corridor, but some of the development would also be expected to divert to follow a future 

alignment, particularly near future passenger stations. If passenger rail service were to extend 

further, the system could have farther-reaching influences on land development patterns.

Socioeconomics 

Cumulative effects on socioeconomic conditions would be similar to trends in land use 

development influenced by the transportation network. Evolving transportation systems bring 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-239

economic growth through construction jobs as well as operations and maintenance, but the 

greater economic influence is from the induced growth that typically follows new and enhanced 

transportation developments. Quality of life may be influenced positively or negatively, 

depending on one’s perspective. Those who value a more rural lifestyle may view the changes 

negatively, while those who value the opportunities associated with growth or who directly 

benefit by having a passenger rail system nearby may view an enhanced transportation 

network as improving quality of life.

Environmental Justice 

Several communities in the three-county study area have a larger share of minorities within the 

population when compared to the region. Certain areas also have greater concentrations of 

low-income populations when compared to the regional population; consequently, protected 

populations may be affected by actions in the study corridor. While Environmental Justice is 

particularly focused on actions that may adversely and disproportionately affect low-income 

and minority populations, the addition of passenger rail service would generally help these 

populations by providing transit options. Actions that include adverse consequences, such as 

displacements, changes in access, or noise and air pollution, could have adverse effects on 

protected populations.

Public Health and Safety 

The cumulative effect of expanding the transportation network and providing multimodal 

options is generally beneficial to public health and safety. Alternate forms of transportation 

disperse the demand on any single route and system, which in turn may reduce congestion, 

lower the potential for accidents, and minimize exposure to noise and emissions that 

contribute to air pollution. Where multimodal facilities intersect, accident potential may be

somewhat elevated because some modes of transportation are faster, their approach more 

difficult to detect, or their equipment slower to react. Traffic controls such as signalized 

intersections, education programs, and other BMPs can help to minimize the safety risks 

associated with passenger rail and associated traffic, as well as other factors that might 

complicate the health and safety environment, such as nearby utilities or land uses that may 

contribute to congestion or crime.

Parklands and Recreation Areas/Section 4(f) and 6(f) Resources 

Public parks and recreation areas are provided extra protection by Section 4(f) of the USDOT

Act of 1966, which helps to minimize the loss of parks and recreation areas as well as access 

disruptions from transportation projects. This reduces the potential for cumulative effects on 

parks and recreation areas; however, audio and visual intrusions from traffic or trains near 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-240

recreational facilities may be a concern, depending on the proximity of the transportation 

facility and the other actions that may contribute to man-made sights and sounds. 

Because of the protection provided to public parks, recreation areas, wildlife and waterfowl 

refuges, historic sites, and lands acquired or developed with Land and Water Conservation 

Funds, a passenger rail system would not be expected to contribute to adverse cumulative 

impacts on Section 4(f) and 6(f) resources when such impacts can be avoided. A more detailed 

analysis would be undertaken during Tier 2 studies that evaluate specific alignments, rail 

stations, and related facilities.

Air Quality 

Ground-disturbing activities that occur concurrently with passenger rail system construction 

may contribute to temporary and cumulative increases in fugitive dust, including PM10 and 

PM2.5, until soils are stabilized through restoration activities and revegetation. Grounddisturbing activities may include construction of transportation facilities and residential 

development as well as plowing of agricultural land. Contributors of many other types of air 

pollutants include emissions associated with vehicle exhaust, some industrial activities, and 

certain residential activities such as burning wood in fireplaces. Air quality analyses typically are 

cumulative by nature because the baseline air quality condition accounts for current activities 

that may degrade the air. 

If passenger rail facilities effectively reduce the number of passenger miles traveled by 

automobiles, the quality of the air in the region would be expected to improve because the 

reduction in automobile emissions should be greater than any introduction of emissions from 

train operations. The planned connection to Tucson International Airport and other proposed 

connections beyond the hubs identified in this EIS would further reduce the volume of 

automobile traffic, resulting in greater beneficial effects on air quality than development of a 

passenger rail system from downtown Tucson to Phoenix alone.

Noise and Vibration 

Actions that contribute to the cumulative effect of noise and vibration tend to be localized. 

Sound is a vibration that propagates as a wave through a medium such as air; however, the 

intensity of the vibration is affected by surfaces that the sound wave encounters, such as 

vegetation or buildings, so that the noise and vibration diminish with distance. In the areas 

nearest to new passenger rail facilities, multiple sources of noise or vibration would accumulate 

and have a greater effect than any one source alone. If the passenger rail were aligned near the 

UP or near a highway corridor, the cumulative noise and vibration effects would be greater if 

the noise sources occurred at the same time. In addition, the faster that a train travels, the 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-241

more noise and vibrations would increase. UP’s proposal to increase the maximum speed of 

their freight trains by 20 mph would contribute an additive effect, particularly if a passenger rail 

system were operated within the Yellow Corridor Alternative. Similarly, if proposed 

development that involves new construction occurred at the same time and in near proximity 

to construction activities related to a passenger rail system, the effect would be additional 

noise, although construction noise would be short-term.

While the Tier 1 analysis acknowledges that a new passenger rail system would add noise and 

vibration near the tracks, the degree of effect cannot be determined without a more precise 

understanding of the other projects that are likely to occur concurrently that may contribute 

sources of noise and vibration. The Tier 2 analysis would identify the baseline quantity of noise 

and vibrations within the area of potential effect, which may include sources such as farm 

equipment, traffic in nearby transportation corridors, train operations on the UP tracks, 

construction activities, and other sources. The noise and vibrations associated with each 

alternative would be modeled and added to the baseline to identify the degree of the 

cumulative effect.

Hazardous Materials 

Potential key sources of hazardous or toxic materials in the area include past and present use of 

pesticides for agricultural production; petroleum, oils, and lubricants used by trains and 

automobiles in transportation corridors including the UP track and nearby streets and 

highways; chemicals used for industrial or commercial processes; and accidental spills from 

vessels using the transportation system to haul hazardous materials. Typically, proper use, 

storage, and disposal of hazardous materials in accordance with manufacturers’ directions and 

per regulatory requirements keep hazardous materials from accumulating to levels that fail to 

comply with public health and safety standards. However, because a passenger rail system 

would require the use of materials with the potential to be hazardous, the system may 

contribute to local cumulative effects.

Geology, Topography, Soils and Prime Farmland 

Localized ground disturbance during passenger rail construction would contribute to the 

cumulative effects on soils and geological features. Other sources of ground disturbance may 

include ongoing agricultural production as well as other construction for urban development or 

transportation facilities. Until soils are re-stabilized, ground disturbance from construction may 

contribute to soil erosion and downstream sedimentation. Urbanization and transportation 

projects that result in development of prime or unique farmlands would contribute to 

continued loss of such farmland. A passenger rail system would likely remove some farmland 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-242

from production, and could indirectly induce growth that also removes larger areas of prime or 

unique farmland from production.

Natural Ecological Systems 

Many of the natural ecological systems in the study corridor have been heavily affected by past 

actions, including extensive development in the Tucson and Phoenix metropolitan areas, 

population growth and development in Pinal County communities, and agricultural production. 

Historic and ongoing livestock grazing has also influenced the quality of the natural habitat so 

that native wildlife competes with livestock for forage in some areas, and plant quality and 

density may be diminished from the stress of historic overgrazing or drought in certain areas. 

Invasive species and noxious weeds have been introduced within some natural systems through 

development, recreational access, grazing, and other activities that contributed to dispersal of 

nonnative seeds. Such invasions have choked out native species in some areas and further limit 

the native habitat available to wildlife populations. 

Barriers to wildlife movement have been introduced by features such as railroads, highways, 

and fences; this has fragmented habitat and, in some cases, cut off access to historically used 

water and foraging areas. Stronger environmental regulations in the past several decades have

encouraged greater use of mitigating features such as culverts and bridges that are designed 

specifically to retain wildlife connectivity. A passenger rail system would contribute to the 

ongoing loss of natural habitat and increases in wildlife barriers. While the rail facilities would 

contribute to the ongoing loss of native habitat and the potential for direct mortalities on the 

tracks when a train passes, the effects are expected to mostly affect individual animals rather 

than influence the diversity or size of populations, both for common and protected wildlife. 

Waters of the US 

Ongoing and reasonably foreseeable future development in the corridor is likely to encroach on 

Waters of the US and contribute to their loss. A passenger rail line may contribute to the loss of 

Waters of the US along with other construction and development projects including new or 

widened highways and urban development, including residential growth. Past conversion of 

native land to agricultural uses and urban development has also contributed to the loss of 

Waters of the US. Cumulative effects on Waters of the US may be anticipated; however, the 

permits that are required when Waters of the US are adversely affected would include specific 

measures to help mitigate for the losses. The extent of the cumulative effects on Waters of the 

US would be better quantified in Tier 2 analyses.
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-243

Wetlands 

Ongoing and reasonably foreseeable future development in the corridor has the potential to 

result in impacts to wetlands and contribute to their loss. A new passenger rail line, along with 

new or widened highways, urban development and residential growth, and other construction 

projects could contribute to adverse wetland impacts. Past conversion of native land to urban 

development has also adversely affected wetlands associated with river areas. Cumulative 

effects on wetlands may be anticipated, but permits would be required when adverse effects 

were anticipated. Alternatives analysis is required for all work in wetlands and the Corps must 

choose the least environmentally damaging practicable alternative, which should help to 

minimize cumulative impacts. The extent of the cumulative effects on wetlands would be better 

quantified in Tier 2 analyses.

Water Quality 

During the construction phase and until disturbed ground has been stabilized, new passenger 

rail facilities may contribute to increased sediment in adjacent and downstream waterbodies. 

This effect is expected to be localized and temporary but may be intensified if other reasonably 

foreseeable future actions in close proximity, such as the North-South Corridor, are under 

construction at the same time. Inadvertent spills of petroleum, oils, lubricants, or chemicals 

from a passenger rail system or other actions occurring in the same general vicinity could 

contaminate surface water or groundwater if not promptly contained and cleaned up. ADOT 

implements controls to minimize pollution due to sediment and spills using control measures. 

ADOT’s pollution prevention and hazardous materials response protocols are such that spills 

are addressed through prevention and timely response, if needed.

Floodplains 

Actions that modify floodplains may interfere with natural flows, increasing the potential risk of 

flood damage to the infrastructure within the floodplain. Features constructed in floodplains 

also may contribute to higher floodwater beyond the floodplain, increasing the potential for 

flooding of nearby land and property. While long linear features such as a passenger rail 

system, the existing UP railroad, and existing and proposed highways may not be able to avoid 

passing through floodplains, proper design can minimize adverse effects on natural flows and 

reduce the potential for cumulative effects.

Energy Use and Climate Change 

Construction of a passenger rail system as well as other ongoing and planned construction 

projects would result in the consumption of energy. Fuel is needed for construction equipment 

as well as to operate the trains; however, a passenger rail system is expected to reduce overall 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-244

energy consumption in the context of the cumulative effects of the existing and a new 

transportation system because, for the foreseeable future, trains can transport large volumes 

of people more fuel-efficiently than passenger vehicles or buses traveling the same distances 

(Davis et al. 2012). Similarly, while consumption of fuel to construct and operate a passenger 

rail system would generate greenhouse gases that may contribute to climate change, the rail 

system would reduce the cumulative amount of fuel burned to transport the same volume of 

people over the same distance compared with the alternative options of more reliance on 

vehicular travel on highways. A connection to Tucson International Airport would have an 

additive effect to energy use associated with the Tucson-Phoenix passenger rail system 

assessed in this Tier 1 EIS. None of the past, present, or reasonably foreseeable future actions 

identified for this Tier 1 cumulative effects analysis would contribute to energy production, so 

the cumulative effect would be neither positive nor adverse.

Visual and Scenic Resources 

Most planning documents applicable to the study corridor support the preservation of scenic 

views of natural features and community landmarks. In general, few natural features or 

community landmarks would potentially be affected; however, particularly in less developed 

areas, landscape views are expansive. Intrusions from existing and planned development would 

gradually erode the views of distant mountain ranges, native desert, and other notable features 

within the landscape. With a passenger rail system, the rails would be low profile and barely 

visible from distant views, rail stations would be dispersed, and the trains would pass quickly, 

minimizing the duration of their intrusion on the visual environment. In contrast, widening 

existing highways or building new highways would leave a more substantial visual scar.

Cultural Resources 

All actions involving ground disturbance have the potential to adversely affect archaeological

resources, historic properties, and/or places with cultural values. Such disturbance contributes 

to the cumulative and ongoing loss of cultural resources. Federal actions would be 

accomplished in compliance with Section 106 of NHPA; thus, affected cultural resources would 

be treated properly, which may include avoidance, data collection, or other mitigative 

strategies. Private developments on lands where cultural resources are unprotected pose the 

greatest threat to the loss of cultural resources. Cumulative effects can result in the loss of 

cultural resources to a point where important research questions about an area’s prehistory or 

history can never be answered. 
5 Existing Conditions and Environmental Consequences

Final Tier 1 Environmental Impact Statement 5-245

No Build Alternative

Under the No Build Alternative, a passenger rail system between Tucson and Phoenix would not 

be built. New direct, indirect, or cumulative impacts would not be anticipated beyond those 

that could occur due to other projects. The primary transportation system between these cities 

would continue to be I-10, although the proposed North-South Corridor, if approved and 

constructed, could carry some traffic in addition to other regional roadways. Traffic congestion 

on existing routes, potential increases in traffic accidents, and increases in vehicular emissions 

and the associated degradation of air quality associated with congested roadways would be 

expected.

5.22.4 Potential Mitigation Measures

Actions with a federal nexus undergo compliance with NEPA, including the application of 

mitigation measures. Actions undertaken on private land are not subject to these same types of 

regulations and may have impacts that are not mitigated because it is not required. No 

mitigation measures are proposed to address cumulative effects because those are already 

defined and implemented for the actions that require mitigation.

5.22.5 Tier 2 Considerations

Further evaluation of potential indirect impacts would be addressed during Tier 2 analysis when 

more design and operational details are known. For example, the increased noise and vibration 

from passenger train operations would be evaluated for potential constructive use of 

Section 4(f) facilities during Tier 2 analysis. Specific mitigation measures, to the extent required, 

would be identified and discussed during Tier 2 analysis after design details are known, 

recorded in NEPA documents as specific impacts are identified, and implemented prior to 

construction.