Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-1

3.5 Air Quality and Greenhouse Gases

3.5.1 Introduction

This section provides an evaluation of air quality, health risk, GHGs, and global climate 

change-related effects associated with implementing the No Build Alternative and Build Alternative

Options. Information contained in this section is summarized from the Air Quality and Greenhouse 

Gas Technical Memorandum (Appendix E of this Tier 1/Program EIS/EIR).

3.5.2 Regulatory Framework

In accordance with NEPA (42 USC Section 4321 et seq.), CEQ regulations implementing NEPA 

(40 CFR Parts 1501-1508), FRA’s Procedures for Considering Environmental Impacts (64 FR

28545, May 26, 1999) and CEQA, FRA identified sensitive receptors within the Tier 1/Program 

EIS/EIR Study Area and evaluated the potential air quality, health risk, GHGs, and global climate 

change-related impacts that could occur from implementation of the Build Alternative Options.

Federal

The Federal Clean Air Act (FCAA), as amended, is the primary federal law that governs air quality, 

while the California Clean Air Act (CCAA) is its companion state law. These laws and related 

regulations by the U.S. Environmental Protection Agency (EPA) and California Air Resources Board 

(ARB) set standards for the concentration of air pollutants. 

United States Environmental Protection Agency General Conformity Rule

The U.S. EPA General Conformity Rule (40 CFR 93 Subpart B) applies to federal actions, other than 

those related to highway and transit planning, that result in emissions of non-attainment or 

maintenance pollutants, or their precursors, in federally designated non-attainment or maintenance 

areas. The U.S. EPA General Conformity Rule establishes a process to demonstrate that federal 

actions would be consistent with applicable state implementation plans and would not cause or 

contribute to new violations of the National Ambient Air Quality Standards (NAAQS), increase the 

frequency or severity of existing violations of the NAAQS, or delay the timely attainment of the 

NAAQS.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-2

Federal Clean Air Act

The FCAA, enacted in 1963, established federal air quality standards, known as NAAQS, and 

defines non-attainment areas as geographic regions designated as not meeting one or more of the 

NAAQS. Attainment areas are areas with concentrations of criteria pollutants that are below the 

levels established by the NAAQS. The FCAA also requires that a state implementation plan be 

prepared for local areas not meeting these standards (non-attainment area) and a maintenance plan 

be prepared for each former non-attainment area that subsequently demonstrated compliance with 

the standards. 

NAAQS have been established for transportation-related criteria pollutants that are linked to 

potential health concerns: carbon monoxide (CO); nitrogen dioxide (NO2); ozone (O3); particulate 

matter 10 microns or less (PM10); particulate matter 2.5 microns or less (PM2.5); sulfur dioxide (SO2); 

and lead (Pb). The FCAA requires U.S. EPA to designate areas as attainment, non-attainment, or 

maintenance for each criteria pollutant based on whether the NAAQS have been achieved.

Greenhouse Gas Reporting Program 

On September 22, 2009, U.S. EPA published the final rule that requires mandatory reporting of GHG 

emissions from large sources in the U.S. The gases covered by the final rule are carbon dioxide,

methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and other 

fluorinated gases, including nitrogen trifluoride and hydrofluorinated ethers. Currently, this is not a 

transportation-related regulation and, therefore, the final rule does not apply to the Tier 1/Program 

EIS/EIR. However, the methodology developed as part of this regulation is helpful in identifying 

potential GHG emissions.

On December 7, 2009, the Final Endangerment and Cause or Contribute Findings for Greenhouse 

Gases, under Section 202(a) of the FCAA, was signed by the U.S. EPA administrator. The 

endangerment finding states that current and projected concentrations of the seven final rule GHGs 

in the atmosphere threaten public health and welfare. Furthermore, combined emissions of these 

well-mixed GHGs from new motor vehicles and new motor vehicle engines contribute to the GHG 

pollution.

On April 5, 2017, CEQ withdrew its Final Guidance for Federal Departments and Agencies on 

Consideration of Greenhouse Gas Emissions and the Effects of Climate Change in National 

Environmental Policy Act Reviews. As such, California’s laws and CEQA considerations were used 

to satisfy the NEPA considerations for GHGs.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-3

State

California Clean Air Act

The CCAA designates air districts as lead air quality planning agencies, requires air districts to 

prepare air quality plans, and grants air districts explicit authority to implement transportation control 

measures and regulate indirect sources of air pollution. The CCAA focuses on attainment of the 

California Ambient Air Quality Standards (CAAQS), which for certain pollutants and averaging 

periods are more stringent than the comparable federal standards. The following are criteria 

pollutants, which the California ARB and U.S. EPA regulate: CO, NO2, SO2, O3, PM10, PM2.5, and 

Pb. CAAQS are generally more stringent than the NAAQS and incorporate additional standards for 

sulfates, hydrogen sulfide, and vinyl chloride, and visibility-reducing particles. Additional information 

on CAAQS and NAAQS is provided in the Air Quality and Greenhouse Gas Technical Memorandum 

(Appendix E of this Tier 1/Program EIS/EIR).

Assembly Bill 1493

Assembly Bill (AB) 1493, enacted in 2002, requires the California ARB to develop and implement 

regulations to reduce automobile and light-truck GHG emissions. 

Assembly Bill 32

AB 32, known as the Global Warming Solutions Act of 2006 and enacted in 2006, requires the state 

to reduce GHG emissions to 1990 levels by 2020, mandating the California ARB create a plan that 

includes market mechanisms and implement rules to achieve “real, quantifiable, cost-effective 

reductions of GHGs.” The required scoping plan includes the implementation of the high-speed rail 

system as a GHG reduction measure, estimating a 2020 reduction of 1 million metric tons of carbon 

dioxide equivalent.

Executive Order S-3-05

Executive Order (EO) S-3-05, enacted in 2005, establishes targets to reduce California’s GHG 

emissions to 2000 levels by 2010, 1990 levels by 2020, and 80 percent below the 1990 levels by 

2050.

Governor’s Executive Order S-01-07

Under EO S-01-07, enacted in 2007, the carbon intensity of California’s transportation fuels is to be 

reduced by at least 10 percent by 2020.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-4

Governor’s Executive Order S-13-08

EO S-13-08, enacted in 2008, addresses the risk of sea level rise resulting from global climate 

change. It requires all state agencies that are planning construction projects in the areas vulnerable 

to sea level rise consider a range of sea level rise scenarios to assess project vulnerability and, to 

the extent feasible, reduce expected risks, and increase resiliency to sea level rise.

Governor’s Executive Order B-30-15

EO B-30-15, enacted in 2015, established a California GHG reduction target of 40 percent below 

1990 levels by 2030. This is intended to make it possible to reach the state’s goal of reducing 

emissions 80 percent under 1990 levels by 2050.

Senate Bill 375

SB 375, known as the Sustainable Communities and Climate Protection Act of 2008, requires the 

California ARB to develop regional reduction targets for GHG emissions and prompts the creation of 

regional land use and transportation plans to reduce emissions from passenger vehicle use 

throughout the state. The law was enacted in 2008 and became effective on January 1, 2009. The 

targets apply to the regions in the state covered by California’s 18 MPOs. The 18 MPOs have been 

tasked with creating the regional land use and transportation plans called SCSs. The MPOs are 

required to develop the SCSs through integrated land use and transportation planning and 

demonstrate an ability to attain the proposed reduction targets by 2020 and 2035.

Senate Bill 32

SB 32, which was signed into law on September 8, 2016, expands upon AB 32 to reduce GHG 

emissions and mandates the reduction target in GHG emissions as written into EO B-30-15.

Regional

Southern California Association of Governments

Through the FCAA amendments, California’s 18 MPOs are responsible for the planning,

programming, and coordination of federal highway and transit investments in urbanized areas. As 

part of this work, MPOs help to ensure that the transportation and air quality plans of the region are 

consistent with goals established in the state implementation plans. The MPO responsible for air 

quality within the Tier 1/Program EIS/EIR Study Area is the SCAG. The SCAG region encompasses

6 counties (Imperial, Los Angeles, Orange, Riverside, San Bernardino, and Ventura) and 191 cities 

in an area covering more than 38,000 square miles. On April 7, 2016, SCAG’s Regional Council 

adopted the 2016-2040 RTP/SCS. The RTP/SCS is a long-range visioning plan that balances future 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-5

mobility and housing needs with economic, environmental, and public health goals. The RTP/SCS 

charts a course for closely integrating land use and transportation, so that the region can grow 

smartly and sustainably.

South Coast Air Quality Management District Regulations

The South Coast Air Quality Management District (SCAQMD) has jurisdiction over the South Coast 

Air Basin (SCAB) and the Salton Sea Air Basin (SSAB), of which the Program is located within. To 

ensure continued progress toward clean air and comply with state and federal requirements, the 

SCAQMD, in conjunction with the California ARB, SCAG, and U.S. EPA, generally updates its air 

quality management plans every 3 years. The 2016 Air Quality Management Plan was adopted by 

the SCAQMD Governing Board on March 3, 2017 (SCAQMD 2016). The SCAQMD implements the 

following rules:

• SCAQMD Rule 402 – Nuisance: This rule prohibits discharge or air contaminants or other 

materials that cause injury, detriment, nuisance, or annoyance to any considerable number 

of persons or the public; endanger the comfort, repose, health, or safety of any such persons 

or the public; or cause, or have a natural tendency to cause injury or damage to businesses 

or property.

• SCAQMD Rule 403 – Fugitive Dust: This rule prohibits emissions of fugitive dust from any 

active operation, open storage pile, or disturbed surface area that remains visible beyond the 

emission source property line. Additional requirements apply to construction projects on 

property with 50 or more acres of disturbed surface area, or for any earth-moving operation 

with a daily earth-moving or throughput volume of 5,000 cubic yards or more three times 

during the most recent 365-day period. These requirements include submittal of a dust 

control plan, maintaining dust control records, and designating a SCAQMD-certified dust 

control supervisor.

• SCAQMD Rule 1108 – Cutback Asphalt: This rule prohibits the sale or use of any cutback 

asphalt containing more than 0.5 percent by volume organic compounds which evaporate at 

260°C (500°F) or lower within the SCAQMD.

• SCAQMD Rule 1113 – Architectural Coatings: This rule is intended to limit the volatile 

organic compounds (VOC) content of architectural coatings used in the SCAQMD.

Local and Tribal Governments

Regulations from cities, local agencies, and tribal governments would be identified in the Tier 

2/Project-level analysis once site-specific rail infrastructure improvements and station facilities are 

known.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-6

3.5.3 Methods for Evaluating Environmental Effects

The methodology for this Tier 1/Program service-level evaluation identifies existing conditions for air 

quality and GHGs and provides the approach and assumptions for analyzing air quality and GHG 

environmental consequences associated with implementation of the Build Alternative Options. The 

methodology considers the change in travel conditions for the proposed transportation 

improvements by comparing the Build Alternative Options with the No Build Alternative during the 

identified horizon years.

Given that the details of the needed rail infrastructure and station locations are unknown at this time, 

direct and indirect effects on air quality and GHG emissions were evaluated qualitatively for the 

following: 1) evaluation of construction-related emissions; 2) identification and evaluation of 

operation-related emissions sources; 3) evaluation of GHG emissions; and 4) discussions of likely 

Tier 2/Project-level analyses. Quantitative emissions estimates were provided for locomotive and 

VMT emissions reductions during operation of the Build Alternative Options. 

Horizon Years

For the purpose of comparison between the No Build Alternative and Build Alternative Options, three 

horizon years were analyzed:

• Existing Year (2018): Under this scenario, Program-related transportation impacts were 

analyzed for the surrounding roadways and rail (passenger and freight) systems under 

existing conditions. This scenario was analyzed to fulfill CEQA requirements for establishing 

a baseline environmental setting. 

• Opening Year (2024): Under this scenario, Program-related transportation impacts were 

analyzed for the surrounding roadways and rail (passenger and freight) systems on the first 

day the Program is operational.

• Future Year (2044): Under this scenario, Program-related transportation impacts were 

analyzed for the surrounding roadways and rail (passenger and freight) systems under full 

build-out conditions. 

Air Quality Assumptions

Potential regional air quality effects from the Program were evaluated based on a comparison of 

their effects on overall air quality emissions. In addition, the effect of these changes on maintenance 

and non-attainment areas, as classified by U.S. EPA at the time of analysis, is discussed. 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-7

To examine the Program’s potential effects on local air quality, a quantitative analysis was 

conducted based on potential changes in VMT as a result of estimated changes in local traffic at 

stations, changes in rail service, and location of parking facilities. Regional VMT estimates and 

EMFAC2017 emissions factors were used to estimate criteria pollutant emissions for the Build 

Alternative Options and No Build Alternative. Locomotive emissions were estimated using rail miles 

traveled estimates and U.S. EPA locomotive emissions factors. Potential local health risks 

associated with construction and locomotive diesel particulate matter emissions were evaluated 

qualitatively. 

The emissions thresholds that trigger requirements of the General Conformity Rule for federal 

actions emitting criteria pollutants in non-attainment or maintenance areas, or their precursors, are 

called de minimis levels. If a project’s emissions are projected to be below the de minimis levels, 

then the FCAA assumes the project would not result in any substantial air quality effects, and no 

further analysis would be required.

Conversely, if the Build Alternative Options emissions exceed de minimis levels, then the Project

would require an air quality conformity determination relative to the NAAQS. Site-specific information 

is required to assess the need for a conformity determination. This information would be available in 

a Tier 2/Project-level analysis. 

This Tier 1/Program-level analysis was prepared by comparing the net increase in air quality criteria 

pollutant emissions estimated to occur under the No Build Alternative and Build Alternative Options 

against the General Conformity de minimis levels shown in Table 3.5-1. Because the Program would 

be located partially in the SCAB and partially in the SSAB, net criteria pollutant emissions occurring 

in each air basin would be compared with applicable de minimis levels (i.e., emissions occurring 

within the SCAB would be compared with SCAB de minimis levels).

Table 3.5-1. General Conformity De Minimis Thresholds

Criteria Pollutant

SCAB

(tons per year)

SSAB

(tons per year)

O3 10 25

CO 100 100

PM10 100 100

PM2.5 100 100

Pb 25 25

Source: U.S. EPA 2018b

Notes: 

CO=carbon monoxide; O3=ozone; Pb=lead; PM2.5=particulate matter 2.5 microns or less; PM10=particulate matter 

10 microns or less; SCAB=South Coast Air Basin; SSAB=Salton Sea Air Basin
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-8

Greenhouse Gas Emission Assumptions

GHG emissions were evaluated on a statewide level, as emissions released as a result of 

implementing the Build Alternative Options would not be localized or regional due to their rapid 

dispersion into the global atmosphere. For the GHG emissions evaluation, passenger VMT and 

locomotive operations were evaluated as the main source of energy consumption under the Build 

Alternative Options. Regional VMT estimates and EMFAC2017 emissions factors were used to 

estimate GHG emissions for the No Build Alternative and Build Alternative Options. Locomotive 

emissions were estimated using rail miles traveled estimates and U.S. EPA locomotive emissions 

factors. 

Tier 1/Program EIS/EIR Study Area

The Tier 1/Program EIS/EIR Study Area for air quality includes the affected air basins: SCAB for the 

Western Section and the Eastern Section west of Cabazon and the SSAB for the Eastern Section 

east of Cabazon. The Tier 1/Program EIS/EIR Study Area for GHGs includes the state of California. 

Data Sources

The data sources used to establish the existing conditions include information from the California 

ARB, U.S. EPA, and air quality management districts. Existing ambient air quality and GHG 

emissions data from the California ARB and U.S. EPA were collected and summarized. The current 

status of MPO-administered areas within the Program Corridor were described with regard to 

ambient air quality standards and the final conformity rule. GHG emissions were compiled from the 

California ARB for the affected environment. The California ARB GHG emissions information is 

available on a statewide basis. 

Related Resources

This evaluation incorporates data and evaluation from related resources to contribute to the air 

quality and GHG assessment, as applicable. These related resources are identified in Table 3.5-2. 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-9

Table 3.5-2. Related Resource Inputs for Air Quality and Greenhouse Gas Assessment

Resource Input for Air Quality and GHG Assessment

Transportation

(Section 3.3)

Potential changes in VMT were identified, including those resulting from local

traffic, as an input to air quality and GHG emissions.

Public Utilities and Energy

(Section 3.12)

Net changes in energy consumption within the affected environment as a result of 

the Build Alternative Options and the potential effects on regional air quality

would be evaluated during Tier 2/Project-level analysis when specific Project

details are available.

Notes:

GHG=greenhouse gas; VMT=vehicle miles traveled

3.5.4 Affected Environment

Air Quality

The Program Corridor crosses a large geographic area within Southern California, spanning 

approximately 144 miles from its western terminus in Los Angeles to its eastern terminus in 

Coachella. As shown on Figure 3.5-1, the entire Western Section and a portion of the Eastern 

Section (west of Cabazon) of Program Corridor is located within the SCAB. The Eastern Section 

(east of Cabazon) of the Program Corridor is located within the SSAB. 

Build Alternative Option 1 (Coachella Terminus)

Table 3.5-3 summarizes the federal (under NAAQS) and state (under CAAQS) attainment status for 

the SCAB and SSAB. The two air basins are in federal and state non-attainment status for several of 

the air quality criteria pollutants.

Table 3.5-3. Federal and State Attainment Status of the South Coast Air Basin and Salton 

Sea Air Basin

Pollutant

Federal Attainment 

Status: SCAB

State Attainment 

Status: SCAB

Federal Attainment 

Status: SSAB

State Attainment 

Status: SSAB

O3 (1-hour

standard)

— Non-attainment — Non-attainment

O3 (8-hour

standard)

Non-attainment/ 

Extreme

Non-attainment Non-attainment/ 

Severe 15

Non-attainment

PM10 Attainment/ 

Maintenance

Non-attainment Non-attainment/ 

Serious

Non-attainment
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-10

Pollutant

Federal Attainment 

Status: SCAB

State Attainment 

Status: SCAB

Federal Attainment 

Status: SSAB

State Attainment 

Status: SSAB

PM2.5 Non-attainment/ 

Moderate

Non-attainment Attainment/ 

Unclassifiable

Attainment

CO Attainment/ 

Maintenance

Attainment Attainment/ 

Unclassifiable

Attainment

NO2 (1-hour

standard)

Attainment/ 

Unclassifiable 

Attainment Attainment/ 

Unclassifiable

Attainment

NO2 (annual

standard)

Attainment/ 

Maintenance

Attainment Attainment/ 

Unclassifiable

Attainment

SO2 Attainment/ 

Unclassifiable

Attainment Attainment/ 

Unclassifiable

Attainment

Pb Non-attainment 

(partial Los Angeles

County 

only)/Attainment (rest 

of the SCAB) 

Attainment Attainment/ 

Unclassifiable

Attainment

All others — Attainment — Attainment/ 

Unclassifiable

Source: California ARB 2018; U.S. EPA 2018a

Notes:

CO=carbon monoxide; NO2=nitrogen dioxide; O3=ozone; Pb=lead; PM2.5=particulate matter 2.5 microns or less;

PM10=particulate matter 10 microns or less; SCAB=South Coast Air Basin; SO2=sulfur dioxide; SSAB=Salton Sea Air 

Basin

Emissions of PM2.5 and nitrogen oxide (NOx) from diesel locomotive engines currently contribute to 

the non-attainment of the NAAQS for PM2.5 and O3. U.S. EPA has established emission standards 

for these pollutants for newly manufactured and remanufactured locomotives (73 FR

25098, Locomotive and Commercial Marine Rule). U.S. EPA is projecting that PM2.5 and NOx

emissions will drop as a result of these standards.

Rail service can also contribute to visibility concerns in non-attainment and maintenance areas 

through primary and secondary PM2.5, SO2, and NOx diesel emissions. Under the provisions of the 

FCAA, U.S. EPA has designated a number of areas in California, including national parks and 

wilderness areas, as Mandatory Class I Federal Areas, where visibility is an important value. Under 

the U.S. EPA Regional Haze Rule, states must establish goals to improve visibility in Mandatory 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-11

Class I Federal Areas and develop long-term strategies to reduce emissions of air pollutants that 

cause visibility impairment. Of the Mandatory Class I Federal Areas in the region, the San Jacinto 

Wilderness and San Gorgonio Wilderness are located nearest to the Tier 1/Program EIS/EIR Study 

Area; however, no Mandatory Class I Federal Areas are located within the Tier 1/Program EIS/EIR 

Study Area (U.S. EPA 2019).

Build Alternative Option 2 (Indio Terminus)

Existing air quality data and information within Build Alternative Option 2 is the same as Build 

Alternative Option 1. 

Build Alternative Option 3 (Indio Terminus with Limited Third Track)

Existing air quality data and information within Build Alternative Option 3 is the same as Build 

Alternative Option 1. 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-12

This page is intentionally blank. 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-13

Figure 3.5-1. Air Basins Traversed by the Program Corridor
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-14

This page is intentionally blank.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-15

Greenhouse Gas Emissions

Build Alternative Option 1 (Coachella Terminus)

GHGs are inventoried on a statewide basis because their effects are not localized or regional. A 

summary of the 2018 statewide GHG emissions inventory is provided in Table 3.5-4. Transportation 

is the largest contributor of GHGs in California, accounting for 39.8 percent of the total statewide 

GHG emissions. Contributions from the transportation sector include emissions from on-road and 

off-road vehicles, aviation, rail, and water-borne vehicles, as well as a few other smaller sources.

Table 3.5-4. California Greenhouse Gas Inventory

GHG Emission Category

2018 Emissions 

(million metric tons

carbon dioxide

equivalent)

Percentage of Total

(%)

Transportation 169.5 38.8

Electric power 63.1 14.4

Commercial and residential 41.4 9.5

Industrial 89.2 20.4

Agriculture and forestry 32.6 7.5

High global warming potential gases 20.5 4.7

Recycling and waste 20.5 4.7

Total California emissions 436.8 100.0

Source: California ARB 2020

Notes:

GHG=greenhouse gas

Build Alternative Option 2 (Indio Terminus)

Existing GHG data and information within Build Alternative Option 2 is the same as Build Alternative 

Option 1. 

Build Alternative Option 3 (Indio Terminus with Limited Third Track)

Existing GHG data and information within Build Alternative Option 3 is the same as Build Alternative 

Option 1. 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-16

3.5.5 Environmental Consequences

Overview

Effects as a result of implementing the Build Alternative Options can be broadly classified into 

construction and operational effects. Both short-term or temporary effects and long-term or 

permanent air quality and GHG-related effects would be anticipated as a result of constructing any of 

the Build Alternative Options. 

Construction effects on air quality are generally short term and are due to the emissions from 

construction equipment; fugitive dust from ground-level disturbances; on-site materials processing 

and handling, such as concrete plants; and vehicle emissions from increases in local traffic 

congestion. The potential construction effects on air quality are evaluated based on the intensity of 

the construction activities and construction duration of the Program. The longer the construction 

period and the more non-road construction equipment used (such as cranes, bulldozers, heavy duty

trucks, and concrete batch plants), the greater the potential for construction effects on air quality.

Effects could also result from operation of any of the Build Alternative Options, as the addition of two 

daily round trips would result in the increased consumption of fossil fuels and resultant release of 

emissions. However, while implementation of any of the Build Alternative Options would increase 

emissions from locomotives, those emissions would be partially offset by automobile emissions 

reduction that would occur due to the travel mode shift from automobile to rail transport within the 

Program Corridor. Any of the Build Alternative Options would be largely beneficial to air quality in the 

region and anticipated to contribute to the region’s long-term attainment of air quality goals by 

reducing VMT and vehicle emissions.

Site-specific sensitive land uses potentially affected by the Program would be further identified as 

part of the Tier 2/Project-level environmental review process. Specific types and degrees of impacts 

on sensitive receptors would not be known until further design and construction information is 

known.

No Build Alternative

The No Build Alternative, as described in Chapter 2, Program Alternatives, of this Tier 1/Program 

EIS/EIR, is used as the baseline for comparison. The No Build Alternative would not implement the 

Program associated with this service-level evaluation. Existing air quality, compared with future air 

quality without the Program, would be affected by two key factors: regional growth and air quality 

and GHG regulatory actions. Regional growth, such as increased residential development and 

density, along with additional industry, results in more and greater sources of air and GHG 

emissions. These increases in air emissions are offset by transportation projects, which generally
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-17

reduce traffic congestion, thus minimizing local effects for emission hot spots, as well as vehicle

regulatory programs that control the level of emissions from on-road and non-road vehicles.

While regional program efforts and changes in transportation technology (e.g., use of electrified and 

Tier IV equipment) would reduce future pollutant burdens for air quality criteria pollutants such as 

VOC, CO, NOx, PM2.5, and PM10, and GHG emissions within the Program Corridor, several existing 

and committed transportation projects would occur in the Program Corridor under the No Build 

Alternative. These future projects would result in an increase in passenger and freight services 

resulting in more and greater sources of air quality and GHG emissions within the Program Corridor 

under the No Build Alternative. 

As summarized in Table 3.5-5, projected future growth in the Program Corridor would result in a 

corresponding increase in traffic and VMT, as more cars would be on the roadways. Therefore, 

traffic congestion is likely to worsen with the No Build Alternative, resulting in air quality effects. With 

the continued trend in increases of VMT within the Program Corridor, energy consumption and GHG 

emissions would likely increase under the No Build Alternative. This assessment does not, however, 

consider other influences, including changes in Corporate Average Fuel Economy, standards, bus 

and aircraft efficiency, fuel compositions, and other factors.

Table 3.5-5. Annual Vehicle Miles Traveled Estimates (No Build Alternative)

Horizon Year VMT Estimate 

Existing Year (2018) 3,195,227,280 

Opening Year (2024) 3,475,105,216 

Future Year (2044) 4,335,611,649 

Notes:

VMT=vehicle miles traveled

Build Alternative Options 1, 2, and 3

Air Quality Effects

CONSTRUCTION

Western Section. The Build Alternative Options would not require construction of additional rail or 

station infrastructure in the Western Section because the existing railroad infrastructure and stations 

from LAUS to Colton would be used. When compared with the No Build Alternative, 

short-term/temporary air quality effects would be negligible because no additional construction 

activities are planned within the Western Section under Build Alternative Options 1, 2, and 3.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-18

Eastern Section. Construction activities required for infrastructure improvements (such as sidings, 

additional main line track, wayside signals, drainage, grade-separation structures) and station 

facilities would result in short-term increases in dust and equipment-related emissions in and around 

the construction site. Exhaust emissions during construction would be generated by fuel combustion 

in motor vehicles and construction equipment, and particulate emissions would result from soil 

disturbance, earthwork, and other construction activities. Construction vehicle activity and disruption 

of normal traffic flow may also result in increased motor vehicle emissions within the construction 

area.

The air quality emissions that could be generated would vary depending on the length of the 

construction period, specific construction activity (e.g., grading, paving, pile driving), types of 

equipment, and number of personnel.

Construction of any of the Build Alternative Options would have the potential to cause temporary air 

quality effects. In general, the degree of adverse construction effects is proportional to the length of 

new rail proposed to be constructed, number of grade separations, number and size of new facilities, 

relationship of the improvements and facilities to populated areas, and the duration of construction at 

each site. 

Potential air quality impacts from each construction project would be short term, occurring at a 

location only while construction work is in progress. Construction activities would be required to 

comply with applicable local, state, and federal regulations, in addition to the implementation of 

identified best management practices (BMP), to minimize emissions and construction effects. 

Design specifics and locations of the rail infrastructure improvements and station facilities are not 

known at this time, so the air quality emissions that could be generated and potential sensitive 

receptors that could be affected during specific construction activities cannot be quantified at the Tier 

1/Program-level evaluation. Once detailed construction information for the site-specific rail 

infrastructure improvement or station facility is available, a quantitative estimate of the total air 

quality emissions during construction would be conducted and impacts on sensitive receptors would 

be evaluated during the Tier 2/Project-level analysis. 

Although construction of site-specific rail infrastructure and station facilities would be subject to 

applicable regulations and BMPs, when compared with the No Build Alternative, short-term localized 

construction air quality effects could be substantial within the Program Corridor under Build 

Alternative Option 1 if the implementation of BMPs would not bring construction emissions to below 

identified SCAQMD construction emission thresholds. The Tier 2/Project-level analysis would 

also evaluate mobile source air toxics emissions to assess construction period effects and 

SCAQMD regional and local daily significance thresholds. When compared with Build Alternative 

Option 1, Build Alternative Option 2 would have slightly reduced effects due to a shorter route 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-19

alignment and reduced station options. However, the magnitude of effects would be similar for Build 

Alternative Option 2 and would be considered substantial when compared with the No Build 

Alternative. When compared with Build Alternative Options 1 or 2, Build Alternative Option 3 may 

have slightly reduced effects due to a smaller footprint associated with a shorter route alignment, 

reduced station options, and reduced third rail track infrastructure. However, the magnitude of 

effects would be similar for Build Alternative Option 3 and would be considered substantial when 

compared with the No Build Alternative.

OPERATION

Western and Eastern Section. During operation, passenger train frequencies proposed as part of the 

Program would consist of the addition of two daily, round-trip intercity diesel-powered passenger 

trains operating the entire length of the Program Corridor between Los Angeles and Coachella.

Operational activities are anticipated to be limited to maintenance of culverts, bridges, 

embankments, and station areas. Operation of any of the Build Alternative Options would generally 

result in a long-term net benefit to air quality by reducing emissions of criteria pollutants, air toxics, 

and GHG. There are several factors that would contribute to the extent to which the operation any of 

the Build Alternative Options have a long-term effect on air quality. These include the operation of 

the stations and other supporting facilities, the forecast ridership of the rail system, and the 

subsequent vehicle and airplane emission change due to the shift of travel mode.

Build Alternative Options with higher ridership would have the potential to shift more passengers 

from driving to riding the trains, thus decreasing the regional VMT and associated vehicle emissions. 

In addition, longer route segments would provide access to more locations and would likely have a 

greater reduction in regional VMT.

The estimated annual railroad emissions for operation of the Build Alternative Options for the horizon 

years are provided in Table 3.5-6 and Table 3.5-7. These estimates do not consider future emission 

reductions associated with new emission standards or changes in transportation technology (e.g.,

U.S. EPA Tier IV equipment). As summarized in Table 3.5-6 and Table 3.5-7, the estimated Build 

Alternative Options locomotive emissions would not exceed General Conformity de minimis levels in 

the SCAB or SSAB.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-20

Table 3.5-6. Locomotive Emission Estimates (Build Alternative Option 1)

Air Basin

NOx

(tons per year)

VOC

(tons per year)

PM10

(tons per year)

PM2.5

(tons per year)

CO

(tons per year)

Estimated Rail Emissions

SCAB 5.0166 0.2007 0.0008 0.0007 6.4213

SSAB 1.7984 0.0719 0.0003 0.0003 2.3020

Total 6.8150 0.2726 0.0011 0.0010 8.7233

General Conformity De Minimis Level

SCAB 10 10 100 100 100

SSAB 25 25 100 100 100

Source: Appendix E of this Tier 1/Program EIS/EIR

Notes:

CO=carbon monoxide; NOx=nitrogen oxide; PM2.5=particulate matter 2.5 microns or less; PM10=particulate matter 

10 microns or less; SCAB=South Coast Air Basin; SSAB=Salton Sea Air Basin; VOC=volatile organic compound

Table 3.5-7. Locomotive Emission Estimates (Build Alternative Options 2 and 3)

Air Basin

NOx

(tons per year)

VOC

(tons per year)

PM10

(tons per year)

PM2.5

(tons per year)

CO

(tons per year)

Estimated Rail Emissions

SCAB 4.9279 0.1971 0.0007 0.0007 6.3077

SSAB 1.7097 0.0684 0.0003 0.0003 2.1884

Total 6.6376 0.2655 0.0010 0.0010 8.4961

General Conformity De Minimis Level

SCAB 10 10 100 100 100

SSAB 25 25 100 100 100

Source: Appendix E of this Tier 1/Program EIS/EIR

Notes:

CO=carbon monoxide; NOx=nitrogen oxide; PM2.5=particulate matter 2.5 microns or less; PM10=particulate matter 

10 microns or less; SCAB=South Coast Air Basin; SSAB=Salton Sea Air Basin; VOC=volatile organic compound
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-21

While operation of the Build Alternative Options would increase emissions from locomotives, those 

emissions would be offset by automobile emissions reduction that would occur due to the travel 

mode shift from automobile to rail transport within the travel corridor. A projection of ridership and 

VMT reductions is provided in Table 3.5-8 and Table 3.5-9 for the Build Alternative Options.

Table 3.5-8. Annual Ridership and Annual Vehicle Miles Traveled by Horizon Year (Build 

Alternative Option 1)

Alternative Scenarios

Annual Ridership 

(one-way trips) VMT (million)

Existing Year (2018)a

2018 baseline/existing conditions — 3,200.0

Opening Year (2024)

No Build Alternative — 3,500.0

Build Alternative Option 1 204,107 3,489.5

Change in VMTs from No Build Alternative — 10.5 

Future Year (2044)

No Build Alternative — 4,300.0

Build Alternative Option 1 338,540 4,282.6

Change in VMTs from No Build Alternative — 17.4 

Source: Appendix C of this Tier 1/Program EIS/EIR

Notes:

a Existing Year (2018) assumes no reductions from emissions, as the Program would not be in operation. 

VMT=vehicle miles traveled

Table 3.5-9. Annual Ridership and Annual Vehicle Miles Traveled by Horizon Year (Build 

Alternative Options 2 and 3)

Alternative Scenarios

Annual Ridership 

(one-way trips) VMT (million)

Existing Year (2018)a

2018 baseline/existing conditions — 3,200.0

Opening Year (2024)

No Build Alternative — 3,500.0
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-22

Alternative Scenarios

Annual Ridership 

(one-way trips) VMT (million)

Build Alternatives Options 2 and 3 188,290 3,490.3

Change in VMTs from No Build Alternative — 9.7

Future Year (2044)

No Build Alternative — 4,300.0

Build Alternative Options 2 and 3 312,306 4,283.9

Change in VMTs from No Build Alternative — 16.1

Source: Appendix C of this Tier 1/Program EIS/EIR

Notes:

a Existing Year (2018) assumes no reductions from emissions, as the Program would not be in operation. 

VMT=vehicle miles traveled

Operation of the Build Alternative Options would be largely beneficial to air quality in the region and 

anticipated to contribute to the region’s long-term attainment of air quality goals by reducing VMT 

and vehicle emissions. A conservative estimate of regional air quality criteria pollutants and the 

corresponding reductions related to the VMT reduction estimates is provided in Table 3.5-10 and 

Table 3.5-11 for the Build Alternative Options. The VMT emissions reduction estimates provided in 

Table 3.5-10 and Table 3.5-11 would be partially offset by locomotive and station operations 

emissions. 

Table 3.5-10. Regional Air Quality Criteria Pollutant Estimates by Horizon Year (Build 

Alternative Option 1)

Alternative Scenarios

VOC

(tons 

per 

year)

NOX

(tons 

per 

year)

CO

(tons 

per 

year)

SOx

(tons 

per 

year)

PM10

(tons 

per 

year)

PM2.5

(tons 

per 

year)

Existing Year (2018)a

2018 baseline/existing emissions 96.3 349.3 4,282.4 11.2 164.8 69.1 

Opening Year (2024)

No Build Alternative 40.9 163.0 2,637.7 10.1 177.5 73.5 

Build Alternative Option 1 40.7 162.0 2,621.8 10.0 176.4 73.1

Change in emissions from No Build Alternative -0.2 -1.0 -15.9 -0.1 -1.1 -0.4
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-23

Alternative Scenarios

VOC

(tons 

per 

year)

NOX

(tons 

per 

year)

CO

(tons 

per 

year)

SOx

(tons 

per 

year)

PM10

(tons 

per 

year)

PM2.5

(tons 

per 

year)

Future Year (2044)

No Build Alternative 10.1 79.4 1,918.8 9.4 216.7 87.4 

Build Alternative Option 1 10.0 78.8 1,903.4 9.3 215.0 86.7

Change in emissions from No Build Alternative -0.1 -0.6 -15.4 -0.1 -1.7 -0.7

Source: Appendix E of this Tier 1/Program EIS/EIR

Notes: 

a Existing Year (2018) assumes no reductions from emissions, as the Program would not be in operation. 

CO=carbon monoxide; NOx=nitrogen oxide; PM2.5=particulate matter 2.5 microns or less; PM10=particulate matter 

10 microns or less; SOx=sulfur oxide; VOC=volatile organic compounds

Table 3.5-11. Regional Air Quality Criteria Pollutant Estimates by Horizon Year (Build 

Alternative Options 2 and 3)

Alternative Scenarios

VOC

(tons per 

year)

NOX

(tons per 

year)

CO

(tons 

per 

year)

SOx

(tons per 

year)

PM10

(tons per 

year)

PM2.5

(tons per 

year)

Existing Year (2018)a

2018 baseline/existing 

emissions

96.3 349.3 4,282.4 11.2 164.8 69.1 

Opening Year (2024)

No Build Alternative 40.9 163.0 2,637.7 10.1 177.5 73.5 

Build Alternatives

Options 2 and 3

40.7 162.1 2,623.0 10.0 176.5 73.1

Change in emissions 

from No Build Alternative 

-0.2 -0.9 -14.7 -0.1 -1.0 -0.4
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-24

Alternative Scenarios

VOC

(tons per 

year)

NOX

(tons per 

year)

CO

(tons 

per 

year)

SOx

(tons per 

year)

PM10

(tons per 

year)

PM2.5

(tons per 

year)

Future Year (2044)

No Build Alternative 10.1 79.4 1,918.8 9.4 216.7 87.4 

Build Alternative Options

2 and 3

10.0 78.8 1,904.6 9.3 215.1 86.8

Change in emissions 

from No Build Alternative 

-0.1 -0.6 -14.2 -0.1 -1.6 -0.6

Source: Appendix E of this Tier 1/Program EIS/EIR

Notes: 

a Existing Year (2018) assumes no reductions from emissions, as the Program would not be in operation. 

CO=carbon monoxide; NOx=nitrogen oxide; PM2.5=particulate matter 2.5 microns or less; PM10=particulate matter 

10 microns or less; SOx=sulfur oxide; VOC=volatile organic compounds 

Localized activities, including locomotive idling and vehicular queuing in and around commuter 

parking lots, have the potential to result in air quality effects. Locations adjacent to station-related 

commuter parking lots could potentially experience increases in localized air quality pollutant 

concentrations, as additional traffic could be concentrated in these areas in addition to increased 

train idling at the station. The generation of localized CO, PM2.5, and PM10 emissions tend to occur at 

locations with a large number of vehicles idling, such as at congested intersections. Implementation 

of the Program under any of the Build Alternative Options could result in beneficial localized air 

quality effects through relieving traffic congestion in a local area. 

Implementation of the Program could add new at-grade rail crossings that would increase localized 

vehicle emissions at those locations, other rail infrastructure improvements, such as 

grade-separated crossings, could also be implemented, which could also relieve traffic congestion at 

the local level. 

Localized air quality emissions from Program operation would have the potential to expose nearby 

population to air pollutants such as diesel particulate matter. Potential localized air quality emissions 

associated with Program operation would be mostly from diesel locomotives idling. However, 

localized air quality emissions from diesel train travel are expected to be limited due to the low 

number of diesel locomotives that would idle at particular locations. Localized air quality effects 

would be higher in urban or populated areas due to the exposure of sensitive receptors. Facilities 

located mostly in suburban or rural areas, such as those in the Eastern Section, would likely have 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-25

lower potential to cause localized air quality emission exposure than facilities in the Western Section, 

where there are more densely populated areas.

Similar to construction activities, operational activities would be subject to applicable local, state, and 

federal regulations, and operational BMPs would be implemented to minimize emissions and 

operational effects. Although operation of site-specific rail infrastructure and station facilities would 

be subject to applicable regulations and BMPs, when compared with the No Build Alternative, 

localized operational air quality effects could be substantial within the Program Corridor under Build 

Alternative Option 1 if the implementation of BMPs would not bring operational emissions to below 

identified localized SCAQMD operational emission thresholds. The Tier 2/Project-level analysis 

would also evaluate mobile source air toxics emissions to assess operational effects and SCAQMD 

regional and local daily significance thresholds. As shown in Table 3.5-10 and Table 3.5-11, when 

compared with Build Alternative Option 1, Build Alternative Options 2 and 3 could have nominally 

greater operational emissions of NOx, sulfur oxide (SOx), PM10, and PM2.5. However, the magnitude 

of effects would be similar for Build Alternative Option 2 and 3 and could be considered substantial 

when compared with the No Build Alternative.

Final conclusions of localized effects would depend on design details and information on affected 

locations and the corresponding traffic data that are not available as part of this Tier 1/Program 

service-level evaluation. Therefore, localized effects of the Program would be evaluated during Tier 

2/Project-level analysis to determine air pollutant effects and quantify on-road mobile-source 

emissions reductions, as well as locomotive operations and train station operations area-source 

emissions. 

Implementation of any of the Build Alternative Options would not be anticipated to have any 

measurable air quality effects on Mandatory Class I Federal Areas, including the San Gorgonio 

Wilderness and San Jacinto Wilderness. When compared with the No Build Alternative, effects on 

Mandatory Class I Federal Areas would be negligible under Build Alternative Option 1. When 

compared with Build Alternative Option 1, Build Alternative Options 2 and 3 would have the same 

magnitude of effect and would be considered negligible when compared with the No Build 

Alternative. Further site-specific analysis to assess visibility concerns, such as regional haze, would 

be considered during Tier 2/Project-level analysis.

According to the SCAQMD CEQA Air Quality Handbook, land uses associated with odor complaints 

typically include agricultural uses, wastewater treatment plants, food processing plants, chemical 

plants, composting, refineries, landfills, dairies, and fiberglass molding. Implementation of any of the 

Build Alternative Options would not be anticipated to have any measurable odor effects, as the 

Program does not include any uses identified by SCAQMD as being associated with odor

complaints. When compared with the No Build Alternative, odor effects would be negligible under 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-26

Build Alternative Option 1. When compared with Build Alternative Option 1, Build Alternative Options 

2 and 3 would have the same magnitude of effect and would be considered negligible when 

compared with the No Build Alternative. 

Greenhouse Gas Effects

CONSTRUCTION

Western Section. The Build Alternative Options would not require construction of additional rail or

station infrastructure in the Western Section because the existing railroad infrastructure and stations 

from LAUS to Colton would be used. Therefore, no GHG emissions would be generated, as no 

additional construction activities are planned within the Western Section under Build Alternative 

Options 1, 2, and 3. When compared with the No Build Alternative, short-term/temporary GHG 

effects would be negligible.

Eastern Section. Construction activities required for infrastructure improvements (such as sidings, 

additional main line track, wayside signals, drainage, grade-separation structures) and station 

facilities would result in short-term increases GHG emissions in and around the construction site.

GHG emissions would be generated from the use of equipment to conduct vegetation clearing, 

grading and excavation, and transport of materials and waste. The GHG emissions that could be 

generated would vary depending on the length of the construction period, specific construction 

activity (e.g., grading, paving, pile driving), types of equipment, and number of personnel. In some 

situations, construction GHG emissions associated from a project may be orders of magnitude lower 

than the operational emissions from the project due to construction emissions generally being short 

in duration compared with the project’s overall lifetime. However, there are instances when projects 

have long construction periods (e.g., 10 years) and may result in a large amount of emissions. 

The generation of GHG emissions from each construction project would be short term. Construction 

activities would be required to comply with applicable local, state, and federal regulations, in addition 

to the implementation of identified BMPs, to minimize GHG emissions and construction effects. 

Design specifics and locations of the rail infrastructure improvements and station facilities are not 

known at this time, so the GHG emissions that could be generated during specific construction 

activities cannot be quantified at the Tier 1/Program-level evaluation. Once detailed construction 

information for the site-specific rail infrastructure improvement or station facility is available, a 

quantitative estimate of the total GHG emissions during construction would be conducted and 

impacts would be evaluated during the Tier 2/Project-level analysis. 

Although construction of site-specific rail infrastructure and station facilities would be subject to 

applicable regulations and BMPs, when compared with the No Build Alternative, short-term 

construction GHG effects could be moderate within the Program Corridor under Build Alternative 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-27

Option 1. When compared with Build Alternative Option 1, Build Alternative Option 2 would have 

slightly reduced effects due to a shorter route alignment and reduced station options. However, the 

magnitude of effects would be similar for Build Alternative Option 2 and would be considered 

moderate when compared with the No Build Alternative. When compared with Build Alternative 

Option 1 or Build Alternative Option 2, Build Alternative Option 3 may have slightly reduced effects 

due to a smaller footprint associated with a shorter route alignment, reduced station options, and 

reduced third rail track infrastructure. However, the magnitude of effects would be similar for Build 

Alternative Option 3 and would be considered moderate when compared with the No Build 

Alternative.

OPERATION 

Western and Eastern Section. Implementation of any of the Build Alternative Options has the 

potential to provide energy savings and reduce the transportation system’s effect on climate change. 

Based on projected ridership and VMT reductions, passenger rail use within the Program Corridor 

would decrease VMT and related mobile-source emissions. Emission reductions of GHG would 

mainly be attributed to the reduced travel time and resulting reduced fuel usage that would occur 

with operation of the Build Alternative Options. Table 3.5-12 and Table 3.5-13 provide a summary of

mobile-source emissions for Opening Year (2024) and Future Year (2044) for each of the Build 

Alternative Options. 

Table 3.5-12. Greenhouse Gas Emission Estimates (Build Alternative Option 1) 

Emissions

No Build Alternative

(metric tons per year)

Build Alternative 

Option 1

(metric tons per year)

Existing Year (2018)a

Automobile emissions 1,033,792 1,033,792

Passenger rail emissions — —

Total GHG emissions 1,033,792 1,033,792

Change in GHG emissions from No Build Alternative — —

Opening Year (2024) 

Automobile emissions 934,560 928,913

Passenger rail emissions — 3,017

Total GHG emissions 934,560 931,930
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-28

Emissions

No Build Alternative

(metric tons per year)

Build Alternative 

Option 1

(metric tons per year)

Change in GHG emissions from No Build Alternative — -2,630

Change in GHG emissions from Existing Year (2018) -99,232 -101,862

Future Year (2044)

Automobile emissions 862,289 855,363

Passenger rail emissions — 3,017

Total GHG emissions 862,289 858,380

Change in GHG emissions from No Build Alternative — -3,909

Change in GHG emissions from Existing Year (2018) -171,503 -175,412

Source: Appendix E of this Tier 1/Program EIS/EIR

Notes: 

a Existing Year (2018) assumes no reductions from emissions, as the Program would not be in operation. 

GHG=greenhouse gas

Table 3.5-13. Greenhouse Gas Emission Estimates (Build Alternative Options 2 and 3) 

Emissions

No Build Alternative 

(metric tons per year)

Build Alternative 

Options 2 and 3 

(metric tons per year)

Existing Year (2018)a

Automobile emissions 1,033,792 1,033,792

Passenger rail emissions — Not Applicable

Total GHG emissions 1,033,792 1,033,792

Change in GHG emissions from No Build Alternative — —

Opening Year (2024) 

Automobile emissions 934,560 929,352

Passenger rail emissions — 3,017

Total GHG emissions 934,560 932,369

Change in GHG emissions from No Build Alternative — -2,191
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-29

Emissions

No Build Alternative 

(metric tons per year)

Build Alternative 

Options 2 and 3 

(metric tons per year)

Change in GHG emissions from Existing Year (2018) -99,232 -101,423

Future Year (2044) 

Automobile emissions 862,289 855,901

Passenger rail emissions — 3,017

Total GHG emissions 862,289 858,918

Change in GHG emissions from No Build Alternative — -3,371

Change in GHG emissions from Existing Year (2018) -171,503 -174,874

Source: Appendix E of this Tier 1/Program EIS/EIR

Notes: 

a Existing Year (2018) assumes no reductions from emissions, as the Program would not be in operation. 

GHG=greenhouse gas

As shown in Table 3.5-12 and Table 3.5-13, when compared with the No Build Alternative, GHG 

effects would be beneficial within the Program Corridor under Build Alternative Option 1. When 

compared with Build Alternative Option 1, Build Alternative Options 2 and 3 would have slightly 

reduced beneficial effects due to a shorter route alignment and reduced station options. However, 

the magnitude of effects would be similar for Build Alternative Option 2 and 3 and would be 

considered beneficial when compared with the No Build Alternative. A comprehensive quantitative 

GHG analysis would be performed during Tier 2/Project-level analysis to determine GHG effects and 

quantify on-road mobile-source emissions reductions, as well as locomotive operations and train 

station operations area-source emissions. 

3.5.6 NEPA Summary of Potential Effects

Table 3.5-14 through Table 3.5-16 summarize the qualitative assessment of potential effects 

(negligible, moderate, or substantial) under NEPA for each of the Build Alternative Options. This 

service-level evaluation uses the Tier 1/Program EIS/EIR Study Area to determine the relative 

magnitude of the air quality- and GHG-related effects of the Build Alternative Options when 

compared with the No Build Alternative. Specific mitigation measures to reduce effects would be 

identified during the Tier 2/Project-level environmental process.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-30

Table 3.5-14. NEPA Summary of Effects on Air Quality Emissions

Alternative Option

Potential Intensity of Effect: 

Western Section

Potential Intensity of Effect: 

Eastern Section

No Build Alternativea Construction: Negligible

Operation: Substantial

Construction: Negligible

Operation: Substantial

Build Alternative Option 1 

(Coachella Terminus)

Construction: Negligible 

Operation: Beneficial (regional), 

substantial (localized)

Construction: Substantial 

Operation: Beneficial (regional), 

substantial (localized)

Build Alternative Option 2 

(Indio Terminus)

Construction: Negligible 

Operation: Beneficial (regional), 

substantial (localized)

Construction: Substantial 

Operation: Beneficial (regional), 

substantial (localized)

Build Alternative Option 3 

(Indio Terminus with Limited Third 

Track)

Construction: Negligible 

Operation: Beneficial (regional), 

substantial (localized)

Construction: Substantial 

Operation: Beneficial (regional), 

substantial (localized)

Notes:

a The No Build Alternative, as identified, includes existing and potential expansion of roadway, passenger rail, and 

air travel facilities within the Tier 1/Program EIS/EIR Study Area; however, for the service-level evaluation, 

identifying levels of effect from potential expansion of those facilities is speculative and would be dependent on 

Project-level analysis.

Table 3.5-15. NEPA Summary of Effects on Regional Haze and Odors

Alternative Option

Potential Intensity of Effect: 

Western Section

Potential Intensity of Effect: 

Eastern Section

No Build Alternativea Construction: Negligible

Operation: Negligible

Construction: Negligible

Operation: Negligible

Build Alternative Option 1 

(Coachella Terminus)

Construction: Negligible 

Operation: Negligible

Construction: Negligible

Operation: Negligible

Build Alternative Option 2 

(Indio Terminus)

Construction: Negligible 

Operation: Negligible

Construction: Negligible 

Operation: Negligible
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-31

Alternative Option

Potential Intensity of Effect: 

Western Section

Potential Intensity of Effect: 

Eastern Section

Build Alternative Option 3 

(Indio Terminus with Limited Third 

Track)

Construction: Negligible 

Operation: Negligible

Construction: Negligible 

Operation: Negligible

Notes:

a The No Build Alternative, as identified, includes existing and potential expansion of roadway, passenger rail, and 

air travel facilities within the Tier 1/Program EIS/EIR Study Area; however, for the service-level evaluation, 

identifying levels of effect from potential expansion of those facilities is speculative and would be dependent on 

Project-level analysis.

Table 3.5-16. NEPA Summary of Effects on Greenhouse Gases

Alternative Option

Potential Intensity of Effect: 

Western Section

Potential Intensity of Effect: 

Eastern Section

No Build Alternativea Construction: Negligible

Operation: Substantial

Construction: Negligible

Operation: Substantial

Build Alternative Option 1 

(Coachella Terminus)

Construction: Negligible 

Operation: Beneficial 

Construction: Moderate

Operation: Beneficial

Build Alternative Option 2 

(Indio Terminus)

Construction: Negligible 

Operation: Beneficial

Construction: Moderate

Operation: Beneficial

Build Alternative Option 3 

(Indio Terminus with Limited Third 

Track)

Construction: Negligible 

Operation: Beneficial

Construction: Moderate

Operation: Beneficial

Notes:

a The No Build Alternative, as identified, includes existing and potential expansion of roadway, passenger rail, and 

air travel facilities within the Tier 1/Program EIS/EIR Study Area; however, for the service-level evaluation, 

identifying levels of effect from potential expansion of those facilities is speculative and would be dependent on 

Project-level analysis.

3.5.7 CEQA Summary of Potential Impacts

Based on the information provided in Sections 3.5.4 and 3.5.5, and considering the CEQA 

Guidelines Appendix G Checklist questions for air quality and GHGs, the Build Alternative Options 

would have potentially significant impacts on air quality and GHGs when reviewed on a 

Program-wide basis. Placing the infrastructure improvements and new stations largely within or 

along the existing ROW would reduce the potential for significant impacts associated with air quality 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-32

and GHG. However, because the infrastructure and station sites have not been selected, some 

areas that may contain sensitive land uses may be significantly impacted. At the Tier 1/Program 

analysis level, it is not possible to know the location, extent, and particular characteristics of impacts 

on these areas. Proposed programmatic mitigation measures strategies discussed in Section 

3.5.8 would be applied to reduce potential impacts.

Table 3.5-17 summarizes the CEQA significance conclusions for the Build Alternative Options; the 

proposed programmatic mitigation strategies that could be applied to minimize, reduce, or avoid the 

potential impact, and the significance determination after mitigation strategies are applied. The 

identification and implementation of site-specific mitigation measures necessary for Project 

implementation would occur as part of the Tier 2/Project-level analysis. 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-33

Table 3.5-17. CEQA Summary of Impacts on Air Quality and Greenhouse Gases

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

Would the Program conflict with or obstruct implementation of the applicable air quality plan?

Construction 

Western Section – No Impact. No construction impacts are anticipated during at the Tier 

1/Program EIS/EIR evaluation level because no physical improvements are proposed or 

required in the Western Section under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable

Eastern Section – Less Than Significant. The SCAQMD Air Quality Management Plan is a 

regional blueprint for achieving air quality standards and healthful air through various 

measures, such as trip reduction strategies, vehicle substitution, VMT reduction, and 

technological improvements. While construction activities may generate localized air quality 

emissions, construction of the Program under Build Alternative Options 1, 2, and 3 would 

result in the operation of an enhanced passenger rail system within the Eastern Section of the 

Program Corridor. Impacts are anticipated to be less than significant at the Tier 1/Program 

EIS/EIR evaluation level under Build Alternative Options 1, 2, and 3. 

Not applicable Not applicable

Operation

Western Section – Less Than Significant. The SCAQMD Air Quality Management Plan is a 

regional blueprint for achieving air quality standards and healthful air through various 

measures, such as trip reduction strategies, vehicle substitution, VMT reduction, and 

technological improvements. Operation of an enhanced passenger rail system within the 

Western Section of the Program Corridor would reduce VMTs within the region, which would 

have a corresponding reduction in air quality emissions generated. Since the Program would 

improve regional air quality through VMT reductions and technological improvements, the 

Project would not conflict with or obstruct implementation of the SCAQMD Air Quality 

Management Plan. Impacts are anticipated to be less than significant at the Tier 1/Program 

EIS/EIR evaluation level under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-34

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

Eastern Section – Less Than Significant. Operation of an enhanced passenger rail system 

within the Eastern Section of the Program Corridor would reduce VMTs within the region,

which would have a corresponding reduction in air quality emissions generated. Since the 

Program would improve regional air quality through VMT reductions and technological 

improvements, the Project would not conflict with or obstruct implementation of the SCAQMD 

Air Quality Management Plan. Impacts are anticipated to be less than significant at the Tier 

1/Program EIS/EIR evaluation level under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable

Would the Program result in cumulatively considerable net increase of any criteria pollutant for which the region is non-attainment under an 

applicable federal or state ambient air quality standard?

Construction

Western Section – No Impact. No construction impacts are anticipated during at the Tier 

1/Program EIS/EIR evaluation level because no physical improvements are proposed or 

required in the Western Section under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable

Eastern Section – Potentially Significant. Potential impacts associated with air quality 

construction emissions depend of the location of new stations and other rail infrastructure 

improvements, which are currently unknown. Construction of these improvements could 

require large scale construction activities over an extended period of time. A detailed air 

quality construction analysis cannot be considered at the Tier 1/Program EIS/EIR level 

because such an analysis at this stage would be too speculative, given the exact location and 

duration of construction associated with station facilities and other rail infrastructure 

improvements is unknown at this time. Therefore, potentially significant impacts are 

anticipated at the Tier 1/Program EIS/EIR evaluation level under Build Alternative Options 1, 2, 

and 3. Site-specific impacts would be determined during the Tier 2/Project-level analysis.

AQ-1

LU-2

Potentially Significant. AQ-1 and LU-2 

would minimize, reduce, or avoid potential 

impacts associated with net increases of 

criteria pollutants; however, impacts may 

remain significant after mitigation.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-35

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

Operation

Western Section – Potentially Significant. Potential impacts associated with air quality 

pollutant emissions would vary depending on the traffic generated in and around the existing 

stations as a result of operation associated with the enhanced passenger rail system. 

Therefore, there is potential for the Build Alternative Options to result in the generation of 

operational air quality pollutants at a localized level. However, it is anticipated that at the 

regional level, operation of the Program within the Western Section of the Program Corridor 

would result in a reduction of VMTs, which would result in a corresponding reduction in 

regional air quality pollutants generated. Therefore, potentially significant impacts associated 

with localized air quality emissions are anticipated at the Tier 1/Program EIS/EIR evaluation

level under Build Alternative Options 1, 2, and 3. Once Tier 2/Project-level details are known, a 

quantitative air quality analysis would be prepared to identify and evaluate air quality 

emissions during operation.

AQ-1 Potentially Significant. AQ-1 would 

minimize, reduce, or avoid potential 

impacts from air quality emissions; 

however, impacts may remain significant 

at the localized level after mitigation. 

Eastern Section – Potentially Significant. Potential impacts associated with air quality 

pollutant emissions would vary depending on the location of proposed infrastructure, level of 

activity, specific operations, and number of new stations. However, these details are currently 

unknown; therefore, there is potential for the Build Alternative Options to result in an increase 

in air quality emissions at the localized level. However, it is anticipated that at the regional 

level, operation of the Program within the Eastern Section of the Program Corridor would 

result in a reduction of VMTs, which would result in a corresponding reduction in regional air 

quality pollutants generated. Therefore, potentially significant impacts associated with 

localized air quality emissions are anticipated at the Tier 1/Program EIS/EIR evaluation level

under Build Alternative Options 1, 2, and 3. Once Tier 2/Project-level details are known, a 

quantitative air quality analysis would be prepared to identify and evaluate air quality 

emissions during operation.

AQ-1 Potentially Significant. AQ-1 would 

minimize, reduce, or avoid potential 

impacts from air quality emissions; 

however, impacts may remain significant 

at the localized level after mitigation.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-36

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

Would the Program expose sensitive receptors to substantial pollutant concentrations?

Construction

Western Section – No Impact. No construction impacts are anticipated during at the Tier 

1/Program EIS/EIR evaluation level because no physical improvements are proposed or 

required in the Western Section under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable

Eastern Section – Potentially Significant. Potential impacts associated with construction air 

quality emissions depend of the location of new stations and other rail infrastructure 

improvements and their proximity to sensitive receptors, which are currently unknown. A

detailed construction air quality analysis cannot be considered at the Tier 1/Program EIS/EIR 

level because such an analysis at this stage would be too speculative, given the exact location 

and duration of construction associated with station facilities and other rail infrastructure 

improvements is unknown at this time. Therefore, potentially significant impacts are 

anticipated at the Tier 1/Program EIS/EIR evaluation level under Build Alternative Options 1, 2, 

and 3. Site-specific air quality construction impacts would be identified and evaluated during 

the Tier 2/Project-level analysis.

AQ-1

LU-2

Potentially Significant. AQ-1 and LU-2 

would minimize, reduce, or avoid potential 

impacts associated with net increases of 

criteria pollutants; however, impacts may 

remain significant after mitigation. 

Operation

Western Section – Potentially Significant. The increase in train service (two additional 

round-trip daily trains within the Program Corridor) would not change existing land use and is 

anticipated to result in a decrease in regional and local VMTs. Operation of the Program within 

the Western Corridor would enhance passenger rail services within an existing high-quality 

transit corridor. However, there is the potential for generation of air quality criteria pollutants 

associated with increases in vehicles accessing the existing stations to use the enhanced 

passenger rail service. Therefore, potentially significant impacts are anticipated at the Tier 

1/Program EIS/EIR evaluation level under Build Alternative Options 1, 2, and 3. Site-specific 

air quality impacts on sensitive receptors would be identified and evaluated during the Tier 

2/Project-level analysis.

AQ-1 Potentially Significant. Operation of the 

Program is anticipated to result in a 

beneficial air quality impact at the regional 

level, as VMTs would be reduced. AQ-1 

would minimize, reduce, or avoid potential 

impacts associated with cumulatively 

considerable net increases of criteria 

pollutants at the localized level; however, 

impacts at the local level may remain 

significant after mitigation. 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-37

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

Eastern Section – Potentially Significant. Potential impacts are dependent on the location 

of infrastructure improvements and station locations. Temporary emissions would be 

generated during construction, and permanent emissions would be generated by vehicles and 

locomotives at the stations; however, pollutant emissions would vary daily depending on the 

level of activity, specific operations, number of new stations, and prevailing weather. 

Therefore, potentially significant impacts are anticipated at the Tier 1/Program EIS/EIR 

evaluation level under Build Alternative Options 1, 2, and 3. Site-specific air quality impacts on

sensitive receptors would be identified and evaluated during the Tier 2/Project-level analysis. 

AQ-1 Potentially Significant. Operation of the 

Program is anticipated to result in a 

beneficial air quality impact at the regional 

level, as VMTs would be reduced. AQ-1 

would minimize, reduce, or avoid potential 

impacts associated with cumulatively 

considerable net increases of criteria 

pollutants at the localized level; however, 

impacts at the local level may remain 

significant after mitigation.

Would the Program result in other emissions (such as those leading to odors) adversely affecting a substantial number of people?

Construction

Western Section – No Impact. No construction impacts are anticipated at the Tier 1/Program 

EIS/EIR evaluation level because no physical improvements are proposed or required in the 

Western Section under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable

Eastern Section – Less than Significant. Construction activities may generate odors from 

construction equipment and vehicles (e.g., diesel exhaust). However, these impacts would be 

short term and limited in extent at any given time and range. Therefore, less than significant 

impacts are anticipated at the Tier 1/Program EIS/EIR evaluation level under Build Alternative 

Options 1, 2, and 3.

Not applicable Not applicable
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-38

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

Operation

Western Section – Less than Significant. Operation of the Program would generate odors 

from the operation of the additional passenger rail trains and the continued operation of the 

existing station facilities. However, these types of uses and generation of odors already occur 

within the Western Section of the Program Corridor. The types of uses are not within a 

category of land uses that are associated with objectionable odors. Therefore, less than 

significant impacts are anticipated at the Tier 1/Program EIS/EIR evaluation level under Build 

Alternative Options 1, 2, and 3.

Not applicable Not applicable

Eastern Section – Less than Significant. Operation of the Program in the Eastern Section of 

the Program Corridor would not result in objectionable odors because the Build Alternative 

Options do not include any land uses identified by SCAQMD as being associated with 

objectionable odor generation. Therefore, less than significant impacts are anticipated at the 

Tier 1/Program EIS/EIR evaluation level under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable

Would the Program generate GHG emissions, either directly, or indirectly, that may have a significant impact on the environment?

Construction

Western Section – No Impact. No construction impacts are anticipated during at the Tier 

1/Program EIS/EIR evaluation level because no physical improvements are proposed or 

required in the Western Section under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-39

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

Eastern Section – Potentially Significant. Construction of the Build Alternative Options 

would generate GHG emissions. Construction of these improvements could require large 

scale construction activities over an extended period of time. A detailed construction GHG 

analysis cannot be considered at the Tier 1/Program EIS/EIR level because such an analysis 

at this stage would be too speculative, given the exact location and duration of construction 

associated with station facilities and other rail infrastructure improvements is unknown at this 

time. Therefore, potentially significant impacts are anticipated at the Tier 1/Program EIS/EIR 

evaluation level under Build Alternative Options 1, 2, and 3. Site-specific impacts would be 

identified and evaluated during the Tier 2/Project-level analysis. 

GHG-1

LU-2

Less than Significant. GHG-1 and LU-2 

would minimize, reduce, or avoid potential 

impacts through design and further 

analysis. 

Operation

Western Section – Potentially Significant. Operation of the Build Alternative Options would 

generate GHG emissions. However, the Build Alternative Options would result in overall 

energy savings and reduce the transportation system’s impact on climate change because rail 

transit, and public transportation more generally, produces significantly lower GHG emissions 

per passenger mile than private single-occupancy vehicles. Based on projected ridership and 

VMT reductions, passenger rail use within the Program Corridor would decrease VMT and 

related mobile-source emissions. This would be offset somewhat by locomotive operations 

and train station facility operations that would generate GHG emissions. Therefore, potentially 

significant impacts are anticipated at the Tier 1/Program EIS/EIR evaluation level under Build 

Alternative Options 1, 2, and 3. Further analysis would be conducted during Tier 

2/Project-level evaluation.

GHG-2 

LU-3

Less than Significant. GHG-2 and LU-3 

would minimize, reduce, or avoid potential 

impacts through design and further 

analysis. While operation of the Program 

would generate GHG emissions, the 

Program is also anticipated to result in 

regional GHG reduction benefits.

Eastern Section – Potentially Significant. Operation of the Build Alternative Options would 

generate GHG emissions. However, the Build Alternative Options would result in overall 

energy savings and reduce the transportation system’s impact on climate change because rail 

transit, and public transportation more generally, produces significantly lower GHG emissions 

per passenger mile than private single-occupancy vehicles. Based on projected ridership and 

GHG-2 

LU-3

Less than Significant. GHG-2 and LU-3 

would minimize, reduce, or avoid potential 

impacts through design and further 

analysis. While operation of the Program 

would generate GHG emissions, the 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-40

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

VMT reductions, passenger rail use within the Program Corridor would decrease VMT and

related mobile-source emissions. This would be offset somewhat by locomotive operations 

and train station facility operations that would generate GHG emissions. However, the specific 

Tier 2/Project-level details necessary to determine impacts are unavailable at this time 

because station locations and infrastructure components are unknown. Therefore, further 

analysis would be considered during Tier 2/Project-level analysis.

Program is also anticipated to result in 

regional GHG reduction benefits.

Would the Program conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing the emissions of greenhouse 

gases?

Construction

Western Section – No Impact. No construction impacts are anticipated during at the Tier 

1/Program EIS/EIR evaluation level because no physical improvements are proposed or 

required in the Western Section under Build Alternative Options 1, 2, and 3.

Not applicable Not applicable

Eastern Section – Less Than Significant. While construction activities may generate GHG 

emissions, construction of the Program under the Build Alternative Options would result in the 

operation of an enhanced passenger rail system within the Eastern Section of the Program 

Corridor. The operation of the enhanced passenger rail system would reduce VMTs within the 

region, which would have a corresponding reduction in GHG emissions generated. Since the 

Program is anticipated to result in beneficial GHG emission reductions through VMT 

reductions and technological improvements, the Program would not conflict with or obstruct 

implementation of the plans, policies, or programs associated with GHG reduction efforts.

Less than significant impacts are anticipated at the Tier 1/Program EIS/EIR evaluation level 

under Build Alternative Options 1, 2, and 3. 

Not applicable Not applicable

Operation

Western Section – Less Than Significant. Operation of an enhanced passenger rail system 

within the Western Section of the Program Corridor would reduce VMTs within the region,

Not applicable Not applicable
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-41

Impact Summary

Mitigation 

Strategy Significance with Mitigation Strategy

which would have a corresponding reduction in GHG emissions generated. Since the Program 

is anticipated to result in reductions of regional GHG emissions through VMT reductions and 

technological improvements, the Program would not conflict with or obstruct implementation of 

the plans, policies, or programs associated with GHG reduction efforts. Less than significant 

impacts are anticipated at the Tier 1/Program EIS/EIR evaluation level under Build Alternative 

Options 1, 2, and 3.

Eastern Section – Less Than Significant. Operation of an enhanced passenger rail system 

within the Eastern Section of the Program Corridor would reduce VMTs within the region,

which would have a corresponding reduction in GHG emissions generated. Since the Program 

is anticipated to result in reductions of regional GHG emissions through VMT reductions and 

technological improvements, the Program would not conflict with or obstruct implementation of 

the plans, policies, or programs associated with GHG reduction efforts. Less than significant 

impacts are anticipated at the Tier 1/Program EIS/EIR evaluation level under Build Alternative 

Options 1, 2, and 3.

Not applicable Not applicable

Notes:

EIR=environmental impact report; EIS=environmental impact statement; FRA=Federal Railroad Administration; GHG=greenhouse gas; SCAQMD=South Coast Air 

Quality Management District; VMT=vehicle miles traveled
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-42

This page is intentionally blank.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-43

3.5.8 Avoidance, Minimization, and Mitigation Strategies

Identified below are proposed programmatic mitigation strategies for further consideration in the Tier 

2/Project-level analysis. During the Tier 2/Project-level analysis, construction and operational

impacts would be quantified, and BMPs and site-specific mitigation measures would be 

recommended. Proposed programmatic mitigation strategies or design considerations, consistent 

with state and federal regulations may include, but are not limited to, the following: 

Mitigation Strategy AQ-1: During Tier 2/Project-level analysis, a site-specific air quality analysis 

shall be required for the specific rail infrastructure or station facilities proposed. If an air quality 

analysis is warranted at the Tier 2/Project level, the air quality analysis shall be prepared using the 

standards and procedures of the South Coast Air Quality Management District and applicable local 

jurisdiction(s) in which the Project is located. The air quality analysis shall include analysis of 

construction and operational air quality impacts, including identification and analysis of:

• Construction equipment to be used and corresponding air quality emissions that could be 

generated from construction activities.

• Construction and operational traffic impacts analysis, including quantification of construction 

emissions and comparison with South Coast Air Quality Management District significance 

thresholds.

• Sensitive receptors and exposure of those sensitive receptors to air quality emissions during 

construction and operational activities. If sensitive receptors are located within or adjacent to 

the Project site, a health risk assessment to assess cancer risks and non-carcinogenic 

hazards for sensitive receptors may be required.

• Best management practices to be implemented during construction activities such as 

practices to limit idling and construction emissions, the use of ozone precursor emission 

controls, implementation of diesel emission reduction plans, and use of California Air 

Resources Board-certified equipment for pose combustion controls 

• If a Project is located within an area designated as non-attainment for federal particulate 

matter 10 microns or less and particulate matter 2.5 microns or less standards, a particulate 

matter 10 microns or less and particulate matter 2.5 microns or less hot spot analysis shall 

be prepared based on guidance provided in Transportation Conformity Guidance for 

Qualitative Hot Spot Analyses in Particulate Matter 2.5 Microns or Less and Particulate 

Matter 10 Microns or Less Non-attainment and Maintenance Areas (United States

Environmental Protection Agency 2006). As part of the hot-spot analyses, a project-level 
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-44

conformity determination shall include a finding of whether the Project is a Project of Air 

Quality Concern.

Mitigation Strategy GHG-1: During Tier 2/Project-level analysis, a construction energy conservation 

plan to avoid excess energy consumption shall be required for the specific rail infrastructure or 

station facility proposed. The construction energy conservation plan shall identify best management 

practices including, but not limited to, the following:

• Identification of opportunities to use newer, more energy efficient construction equipment, 

vehicles, and materials

• Limit construction equipment idling

• Develop and implement a program encouraging construction workers to carpool or use 

public transportation for travel to and from construction sites

• Locate construction materials production facilities onsite or in proximity to project work sites

• Schedule material deliveries during off-peak hours to minimize highway congestion

Mitigation Strategy GHG-2: During Tier 2/Project-level analysis, an operational energy 

conservation plan shall be required for the specific rail infrastructure or station facility proposed. The 

operational energy conservation plan shall identify best management practices, including, but not 

limited to, the following:

• Limit operational idling at stations

• Identify state-of-the-art locomotives to maximize fuel efficiency

• Target market to drivers of single-occupancy vehicles to maximize the effects of rail modal 

use on energy conservation and reduction of greenhouse gas emissions

• Concentrate bus-service routes to feed passengers to train stations

• Bring dispersed riders to train stations through other methods (e.g., demand response 

systems [paratransit, taxi, shuttle, call-and-ride])
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-45

Mitigation Strategy LU-2: Based on the results of a subsequent Tier 2/Project-level analysis and 

recommendations, the identified lead agency or agencies shall determine if a construction 

management plan is required for construction activities of the Tier 2/Project-level improvement being 

proposed. If required, a construction management plan shall be developed by the contractor and 

reviewed by the lead agency or agencies prior to construction and implemented during construction 

activities. The construction management plan shall include, but not be limited to, the following: 

• Measures that minimize effects on populations and communities within the Tier 2/Project 

Study Area 

• Measures pertaining to visual protection, air quality, safety controls, noise controls, and 

traffic controls to minimize effects on populations and communities within the Tier 2/Project 

Study Area

• Measures to ensure property access is maintained for local businesses, residences, and 

community and emergency services

• Measures to consult with local transit providers to minimize effects on local and regional bus 

routes in affected communities

• Measures to consult with local jurisdictions and utility providers to minimize effects on utilities 

in affected communities

Mitigation Strategy LU-3: During a subsequent Tier 2/Project-level analysis, a land use consistency 

analysis shall be conducted by the identified lead agency or agencies to determine consistency of 

the Tier 2/Project-level improvement being proposed with the applicable local jurisdictional general 

plans or programs. If the land use consistency analysis identifies sensitive land uses or 

environmental resources within the Tier 2/Project-level Study Area, design or siting strategies shall 

be identified by the lead agency or agencies to avoid or minimize conflicts with sensitive land uses or 

environmental resources.
Coachella Valley-San Gorgonio Pass Rail Corridor Service Program – Draft EIS/EIR

3.5 Air Quality and Greenhouse Gases

May 2021 | 3.5-46

This page is intentionally blank.