TIER 1 DRAFT ENVIRONMENTAL IMPACT STATEMENT

7.13 Air Quality

7. Affected Environment, Environmental Consequences, and Mitigation Strategies

Tier 1 Draft EIS Page | 7.13-1

7.13 AIR QUALITY

7.13.1 Introduction

Air quality describes the level of contaminants in the air. Air pollution is a general term that refers 

to one or more chemical substances that degrade the quality of the atmosphere. Individual air 

pollutants degrade the atmosphere by reducing visibility, damaging property, reducing the 

productivity or vigor of crops or natural vegetation, and/or harming human or animal health.

7.13.1.1 Definition of Resource

Human activity affects ambient air quality via production of air pollutants, including emissions by 

mobile and stationary sources. Mobile-source emissions refer to emissions from transportation 

sources. Stationary source emissions refer to emissions from fixed facilities. The No Action 

Alternative and Action Alternatives could affect air emissions and greenhouse gas (GHG)

emissions—and thus air quality—via operational changes in the following:

4 Vehicle-miles traveled (VMT) – regional traffic (potential mode shift from autos to rail)

4 Train-miles traveled (potential changes in power and fuel requirements) 

4 Local traffic (potential shifts in traffic, particularly near station locations)

4 Bus and air travel (potential mode shift from buses and planes to rail)

The summation of these changes will reflect the overall impact of the Action Alternatives on the 

following:

4 Criteria air quality pollutants

4 Mobile-source air toxics

4 GHG emissions

7.13.1.2 Effects-Assessment Methodology 

The Clean Air Act (CAA), as amended, is the basis for most federal air pollution control programs. 

The U.S. Environmental Protection Agency (EPA), under the CAA, regulates air quality nationally. 

Under the authority of the CAA, the EPA established a set of National Ambient Air Quality Standards 

(NAAQS) for various “criteria” air pollutants.

The CAA requires states to develop a general plan to attain and maintain the NAAQS in all areas of 

the country and a specific plan (State Implementation Plan or SIP) to attain the standards for each 

area that the EPA has designated nonattainment for an NAAQS. State and local air quality 

management agencies develop these SIPs and then submitted them to the EPA for approval.

The SIPs serve two main purposes:

4 Demonstrate that the state has the basic air quality management program components in place 

to implement a new or revised NAAQS.

4 Identify the emissions control requirements the state will rely upon to attain and/or maintain 

the primary and secondary NAAQS.
7.13. Air Quality

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In addition, Congress recognized in the Clean Air Act Amendments of 1990 (CAAA) that the more 

densely populated Northeast states share the same airshed, as well as emissions sources and 

commuting patterns. To regionally address air quality in the Northeast, Congress created the Ozone 

Transport Region (OTR)—an area from Maine to Northern Virginia. States in the OTR are required to 

implement additional control measures that apply across the region, whether an area in the OTR is 

attainment or nonattainment.

This air quality analysis follows guidance from the Federal Railroad Administration (FRA) and the 

EPA, as well as applicable state agencies. The analysis considers existing conditions in the Study 

Area, as well as the potential negative and positive impacts of the program on regional air quality.

This analysis calculates potential regional pollutant burdens caused by changes in regional 

passenger VMT and train-miles traveled under the the Action Alternatives. The FRA calculated 

vehicle emission factors using the EPA’s MOVES2010b mobile-source emissions modeling program, 

which estimates emissions and GHGs for mobile sources. MOVES2010b was run using state-specific 

national level runs of EPA’s MOVES2010b, as the VMT data were generated on a statewide basis. It 

should be noted that the EPA has recently released MOVES2014. There is a two-year grace period 

before MOVES2014 is required to be used in a transporation conformity analysis. This grace period 

began on October 7, 2014. Any Tier 2 studies requiring transportation conformity analysis 

conducted after October 7, 2016, would be required to use MOVES2014.

The FRA calculated potential regional pollutant burdens of the trains based on changes in train 

vehicle-miles (average energy requirements of passenger trains) as detailed in the Transportation 

Energy Data Book (Edition 33), and pollutant emission rates for the project area (as detailed in the 

EPA’s egrid database and state-specific regulations and goals pertaining to future energy mixes).

The FRA analyzed the changes in emission burdens caused by the Action Alternatives relative to the 

No Action Alternative, rather than separate baseline emissions burdens associated with each 

Alternative (the No Action and Action Alternatives). This variation in how emission burdens were 

calculated was a result of the service data being presented as changes between the No Action and 

Action Alternatives rather than separate service data for the No Action and Action Alternatives.

The FRA assumed that the emissions generated to supply power to the Action Alternatives occur in 

the same state as the portion of the Action Alternatives being studied. Since the electrical system is 

a grid, there is a chance that the power supplier could be out of state and that the emissions are not 

actually occurring in the state that requires the power. However, for this study the FRA assumed 

that the emissions are generated in the state that requires the power since the eGRID emission 

factors are available on a state-by-state basis. The FRA has qualitatively analyzed the air quality 

impacts caused by changes in local traffic, bus and air travel, and construction. Table 7.13-1

summarizes key factors associated with the methodologies for each air quality resource evaluated.

The FRA did not make any conformity determinations as part of this Tier 1 Draft EIS; conformity 

determinationswould be made as part subsequent Tier 2 analysis as appropriate.
7. Affected Environment, Environmental Consequences, and Mitigation Strategies

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Table 7.13-1: Effects-Assessment Methodology Summary: Air Quality

Resource Affected Environment

Type of 

Assessment Outcome

Criteria Pollutants Ambient air monitoring data 

by counties along the 

Representative Route of 

each Action Alternative

Quantitative:

μg/m3

and/or 

parts per million

Identification of air quality monitoring 

locations along the Representative 

Route of each Action Alternative.

Sources of pollutants in the 

area along the 

Representative Route of 

each Action Alternative

Qualitative:

Major source of 

pollutant

Identification of major source of 

criteria pollutant by county.

Attainment Status –

Counties along the 

Representative Route of 

each Action Alternative

Qualitative:

Designation as 

attainment, 

nonattainment or 

maintenance

Identification of nonattainment and 

maintenance areas along the 

Representative Route of each Action 

Alternative.

Criteria pollutants, 

greenhouse gases

Train VMT – Rail lines within 

the Northeast Corridor

Quantitative:

Tons of 

pollutants

Criteria pollutant changes caused by 

rail operations.

Criteria pollutants, 

mobile-source air 

toxics

Areas around station 

locations

Qualitative:

discussion

Qualitative assessment of potential 

local impacts.

Criteria pollutants, 

mobile-source air 

toxics, greenhouse 

gases

Regional traffic along the 

Representative Route of 

each Action Alternative

Quantitative:

Tons of 

pollutants

Criteria pollutant and greenhouse gas 

pollutant changes due to passenger 

car vehicle mile travel changes.

Bus and air travel within NEC 

region

Qualitative:

discussion

Qualitative assessment of potential 

changes in bus and air travel.

Construction Activities Qualitative:

discussion

Qualitative discussion of air quality 

impacts during construction.

Source: NEC FUTURE team, Air Quality Effects-Assessment Methodology, Appendix E, Section E.13, 2014
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7.13.2 Resource Overview 

The EPA is responsible for establishing the NAAQS and enforcing the CAA. The agency also regulates 

emission sources—such as aircraft, ships, and certain types of locomotives—under the exclusive 

authority of the federal government. The CAA directs the EPA to implement environmental policies 

and regulations that will ensure acceptable levels of air quality. Under the CAA, a project cannot do 

the following:

4 Cause or contribute to any new violation of any NAAQS in any area; 

4 Increase the frequency or severity of any existing violation of any NAAQS in any area; or

4 Delay timely attainment of any NAAQS or any required interim emission reductions or other 

milestones in any area. 

As required by the CAA, the EPA has established NAAQS for six major air pollutants: carbon 

monoxide (CO), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM), sulfur dioxide (SO2), 

and lead (Pb). NO2 is one of a group of highly reactive gases known as “oxides of nitrogen,” or 

“nitrogen oxides (NOx).” Other NOx include nitrous acid and nitric acid. The EPA’s NAAQS uses 

NO2 as the indicator for the larger group of NOx. For this study, a 100 percent conversion rate of 

NOx to NO2 was conservatively assumed, and all NOx emissions are referred to as NO2 emissions.

Table 7.13-2 summarizes these standards, and further information about these “criteria pollutants”

is given later in this section. The EPA established “primary” standards to protect the public health

and “secondary” standards to protect the nation’s welfare and account for air pollutant effects on 

soil, water, visibility, materials, vegetation and other aspects of the general welfare.

Pollutants traced principally to mobile sources and power generation are relevant to the evaluation 

of the each Action Alternative’s impacts. These pollutants include CO, hydrocarbons (HC), NOx, O3, 

PM less than 10 microns (PM10) and less than 2.5 microns (PM2.5), SOx, and mobile-source air toxics 

(MSAT). HC and NOx emissions are a concern primarily because they are precursors in the formation 

of O3 and PM. O3 forms through a series of reactions that occur in the atmosphere in the presence 

of sunlight. Since the reactions are slow and occur as the pollutants are diffusing downwind, 

elevated O3 levels often occur many miles from the sources of the precursor pollutants. Therefore, 

the effects of HC and NOx emissions are generally examined on a regional or “mesoscale” basis. 

PM10 and PM2.5 impacts are both regional and local. CO impacts are generally localized. Even under 

the worst meteorological conditions and most congested traffic conditions, high concentrations are 

limited to a relatively short distance (300 to 600 feet) of heavily traveled roadways.

1 Vehicle 

emissions are the major sources of CO. 

 

1 U.S. Environmental Protection Agency - Office of Transportation and Air Quality. (2015). Near Roadway Air 

Pollution and Health. Retrieved May 28, 2015, from Transportation and Air Quality: 

http://www.epa.gov/otaq/nearroadway.htm
7. Affected Environment, Environmental Consequences, and Mitigation Strategies

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Table 7.13-2: National Ambient Air Quality Standards

Pollutant

Primary/

Secondary Averaging Time Level Form

Carbon Monoxide Primary 8 hours 9 ppm Not to be exceeded more than 

1 hours 35 ppm once per year

Lead Primary and 

Secondary

Rolling 3-month 

average 0.15 μg/m3 (1) Not to be exceeded

Nitrogen Dioxide

Primary 1 hour 100 ppb 98th percentile, averaged over 3 

years

Primary and

Secondary Annual 53 ppb (2) Annual Mean

Ozone Primary and

Secondary 8 hours 0.075 ppm (3)

Annual fourth-highest daily 

maximum 8-hr concentration, 

averaged over 3 years

Particle 

Pollution

PM2.5

Primary Annual 12 μg/m3 Annual mean, averaged over 

3 years

Secondary Annual 15 μg/m3 Annual mean, averaged over 

3 years

Primary and

secondary 24 hours 35 μg/m3 98th percentile, averaged over 3 years

PM10

Primary and

Secondary 24 hours 150 μg/m3

Not to be exceeded more than 

once per year on average over 

3 years

Sulfur Dioxide

Primary 1-hour 75 ppb (4)

99th percentile of 1-hour daily 

maximum concentrations, 

averaged over 3 years

Secondary 3 hours 0.5 ppm Not to be exceeded more than 

once per year

Source: EPA Office of Air and Radiation. Accessed August 2015 at http://www.epa.gov/air/criteria.html

(1) Final rule signed October 15, 2008. The 1978 lead standard (1.5 μg/m3 as a quarterly average) remains in effect until one year after an area 

is designated for the 2008 standard, except that in areas designated nonattainment for the 1978, the 1978 standard remains in effect until 

implementation plans to attain or maintain the 2008 standard are approved.

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

the 1-hour standard.

(3) Final rule signed March 12, 2008. The 1997 ozone standard (0.08 ppm, annual fourth-highest daily maximum 8-hour concentration, 

averaged over 3 years) and related implementation rules remain in place. In 1997, the EPA revoked the 1-hour ozone standard (0.12 ppm, not 

to be exceeded more than once per year) in all areas, although some areas have continued obligations under that standard (“anti-backsliding”).

The 1-hour ozone standard is attained when the expected number of days per calendar year with maximum hourly average concentrations 

above 0.12 ppm is less than or equal to 1.

(4) Final rule signed June 2, 2010. The 1971 annual and 24-hour SO2 standards were revoked in that same rulemaking. However, these 

standards remain in effect until one year after an area is designated for the 2010 standard, except in areas designated nonattainment for the 

1971 standards, where the 1971 standards remain in effect until implementation plans to attain or maintain the 2010 standard are approved.

ppm = parts per million

ppb = parts per billion
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MSAT impacts are both regional and local. Through the issuance of the EPA’s Final Rule regarding 

emission Control of Hazardous Air Pollutants from Mobile Sources [66 FR 17229], it was determined 

that many existing and newly promulgated mobile-source emission control programs would reduce 

MSATs. The EPA examined the impacts of existing and newly promulgated mobile-source control 

programs, including its reformulated gasoline program, its national low-emission-vehicle standards, 

its Tier 2 motor-vehicle emissions standards, and gasoline sulfur control requirements, its proposed 

heavy-duty engine and vehicle standards, and its on-highway diesel-fuel requirements. Future 

emissions would likely be lower than present levels as a result of the EPA’s national control 

programs, which are projected to reduce MSAT emissions by 83 percent from 2010 to 2050, even if 

VMT increases by 102 percent. 

The FRA analyzed greenhouse gases (GHG) on a regional scale. CO2 makes up the largest 

anthropogenic component of GHG emissions. Other prominent transportation GHGs include 

methane (CH4) and NOx. To date, no national standards have been established regarding GHGs, nor 

has the EPA established criteria or thresholds for ambient GHG emissions pursuant to its authority 

to establish motor-vehicle emission standards for CO2 under the CAA. 

As noted earlier, pollutants that have established national standards are referred to as “criteria 

pollutants.” The sources of these pollutants, their effects on human health and the nation’s welfare, 

and their final deposition in the atmosphere vary considerably. A brief description of each pollutant 

is provided below.

Ozone (O3) is a colorless toxic gas. O3 is found in both the Earth’s upper and lower atmospheric 

levels. In the upper- atmosphere, O3 is a naturally occurring gas that helps to prevent the sun’s 

harmful ultraviolet rays from reaching the Earth. In the lower layer of the atmosphere, O3 forms 

mostly through human activity. O3 is not directly emitted into the atmosphere; it forms in the lower 

atmosphere through a chemical reaction between HC—also referred to as volatile organic 

compounds (VOC)—and NOx. O3 is the main ingredient of smog. O3 enters the bloodstream through 

the respiratory system and interferes with the transfer of oxygen, depriving sensitive tissues in the 

heart and brain of oxygen. O3 also damages

vegetation by inhibiting its growth.

Particulate Matter (PM) pollution is a complex 

mixture of extremely small particles and liquid 

droplets. Particle pollution is made up of a 

number of components, including acids (such as 

nitrates and sulfates), organic chemicals, metals, 

and soil or dust particles. The size of particles is 

directly linked to their potential for causing 

health problems. The EPA is concerned about 

particles that are 10 microns (PM10), 2.5 microns 

(PM2.5), or smaller in diameter (Figure 7.13-1. 

because those are the particles that generally 

pass through the throat and nose and enter the 

lungs. Once inhaled, these particles can affect the 

Figure 7.13-1: Relative Particulate Matter 

Size

Source: U.S. Environmental Protection Agency, 2013
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heart and lungs and cause serious health effects. PM can penetrate the human respiratory system’s 

natural defenses and damage the respiratory tract when inhaled. Whereas particles 2.5 to 10 

microns in diameter tend to collect in the upper portion of the respiratory system, particles 2.5 

microns or less are so tiny that they can penetrate deeper into the lungs and damage lung tissues.

CO, a colorless gas, interferes with the transfer of oxygen to the brain. CO is emitted almost 

exclusively from the incomplete combustion of fossil fuels. Prolonged exposure to high levels of CO 

can cause headaches, drowsiness, loss of equilibrium, or heart disease. CO concentrations can vary 

greatly over relatively short distances. Relatively high concentrations of CO are typically found near 

congested intersections, along heavily used roadways carrying slow-moving traffic, and in areas 

where atmospheric dispersion is inhibited by urban “street canyon” conditions. 

NO2, a brownish gas, irritates the lungs. It can cause breathing difficulties at high concentrations. 

Like O3, NO2 is not directly emitted, but is formed through a reaction between nitric oxide (NO) and 

atmospheric oxygen. NO and NO2 are collectively referred to as NOx and are major contributors to 

O3 formation. NO2 also contributes to the formation of PM10. Other NOx include nitrous acid and 

nitric acid. The EPA’s NAAQS uses NO2 as the indicator for the larger group of NOx.

Pb is a stable element that persists and accumulates both in the environment and in animals. Its 

principal effects in humans are on the blood-forming, nervous, and renal systems. Lead levels in the 

urban environment from mobile sources have significantly decreased because of the federally 

mandated switch to lead-free gasoline.

SO2 is a product of high-sulfur fuel combustion. The main sources of SO2 are coal and oil used in 

power stations and industry, as well as domestic heating. Industrial chemical manufacturing is 

another source of SO2, which is an irritant gas that attacks the throat and lungs. It can cause acute 

respiratory symptoms and diminished ventilator function in children. SO2 can also yellow plant 

leaves and erode iron and steel. SO2 is also a precursor to particulate formation. SO2 is the 

component of greatest concern and is used as the indicator for the larger group of gaseous sulfur 

oxides (SOx). Other gaseous sulfur oxides (e.g. SO3) are found in the atmosphere at concentrations 

much lower than SO2.

7.13.3 Criteria Pollutants

7.13.3.1 Affected Environment

As required by the CAA, the EPA publishes a list of all geographic areas in compliance and not 

attaining the NAAQS (nonattainment areas) for each criteria pollutant. Areas that have insufficient 

data to make a determination are deemed unclassified, and are treated as being attainment areas 

until proven otherwise. Maintenance areas were previously designated as nonattainment for a 

particular pollutant but have since demonstrated compliance with the NAAQS for that pollutant. An 

area’s designation is based on the data collected by the state monitoring network on a pollutant-bypollutant basis. Table 7.13-3 lists all counties within the Affected Environment and identifies those 

that are nonattainment or maintenance for at least one pollutant. Table 7.13-4 lists the major 

sources of these pollutants. Appendix E, Section E.13, contains detailed ambient air quality 

monitoring data for the Study Area and attainment status information as well as current and future 

energy profiles.
7.13. Air Quality

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Table 7.13-3: Affected Environment: Air Quality Attainment Status by State and County

Geography County

Attainment Status:

Nonattainment or Maintenance for at least one criteria pollutant?

Existing NEC Alternative 1 Alternative 2 Alternative 3

D.C. Yes Yes Yes Yes

MD

Prince George’s Yes Yes Yes Yes

Anne Arundel Yes Yes Yes Yes

Baltimore City Yes Yes Yes Yes

Baltimore County Yes Yes Yes Yes

Harford Yes Yes Yes Yes

Cecil Yes Yes Yes Yes

DE New Castle Yes Yes Yes Yes

PA

Delaware Yes Yes Yes Yes

Philadelphia Yes Yes Yes Yes

Bucks Yes Yes Yes Yes

NJ

Mercer Yes Yes Yes Yes

Middlesex Yes Yes Yes Yes

Union Yes Yes Yes Yes

Essex Yes Yes Yes Yes

Hudson Yes Yes Yes Yes

NY

New York Yes Yes Yes Yes

Queens Yes Yes Yes Yes

Kings — — Yes Yes

Nassau — — — Yes

Suffolk — — — Yes

Bronx Yes Yes Yes Yes

Putnam — — — No

Westchester Yes Yes Yes Yes

CT

Fairfield Yes Yes Yes Yes

New Haven Yes Yes Yes Yes

Middlesex Yes Yes Yes Yes

New London Yes Yes Yes Yes

Hartford — — Yes Yes

Tolland — — Yes Yes

Windham — — Yes Yes

RI

Washington No No No No

Kent No No No No

Providence No No No No

MA

Bristol No No — No

Norfolk Yes Yes Yes Yes

Suffolk Yes Yes Yes Yes

Source: U.S. Environmental Protection Agency, December 2014

— = County is not in the Affected Environment for the alternative.
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Table 7.13-4: Affected Environment: Primary Source of Air Pollutants (2011) 

Geography County CO VOC NOx PM10 PM2.5 SO2

D.C. Mobile Solvent Mobile Dust Fuel 

combustion

Fuel 

combustion 

MD

Prince George’s

Mobile

Biogenics

Mobile Dust

Fuel 

combustion Fuel 

combustion

Anne Arundel

Baltimore City Solvent

Baltimore County Mobile

Harford Biogenics Mobile Cecil

DE New Castle Mobile Mobile Mobile Dust Fuel 

combustion

Fuel 

combustion

PA

Delaware

Mobile

Mobile

Mobile Dust Fuel 

combustion

Fuel 

combustion Philadelphia Solvent

Bucks Mobile

NJ

Mercer

Mobile

Biogenics

Mobile

Dust Fuel 

combustion

Fuel 

Middlesex combustion Mobile Union Mobile

Essex

Solvent Fuel 

Hudson combustion Fuel 

combustion

NY

New York

Mobile

Solvent

Mobile

Fuel 

combustion

Fuel 

combustion

Fuel 

combustion

Queens

Kings

Dust

Mobile

Nassau Mobile Fuel 

Suffolk combustion

Bronx Solvent Mobile

Putnam Biogenics Dust

Westchester Mobile Fuel 

combustion

CT

Fairfield

Mobile

Mobile

Mobile Dust Fuel 

combustion

Fuel 

combustion

New Haven

Middlesex Biogenics New London

Hartford Mobile

Tolland Biogenics Windham

RI

Washington

Mobile Biogenics Mobile Dust Fuel 

combustion

Fuel 

combustion Kent

Providence

MA

Bristol

Mobile

Biogenics

Mobile Dust

Dust Fuel 

combustion Norfolk Mobile Fuel 

Suffolk Solvent combustion

Source: U.S. Environmental Protection Agency, 2015
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Existing NEC

As shown in Table 7.13-3, almost every county within the Affected Environment of the existing NEC

is nonattainment or maintenance for at least one pollutant. However, all counties in Rhode Island 

are in attainment for all criteria pollutants. 

Alternative 1

Since there are no new counties within the Affected Environment of Alternative 1 as compared to 

the Affected Environment of the existing NEC, the nonattainment and maintenance areas are the 

same for counties within the Affected Environment of the existing NEC and Alternative 1. 

Alternative 2

Almost every county within the Affected Environment of Alternative 2 is nonattainment or 

maintenance for at least one pollutant. However, all counties in Rhode Island are attainment for all 

criteria pollutants.

Alternative 3

Washington, D.C., to New York City

Every county within the Affected Environment for Alternative 3 between Washington, D.C., and 

New York City is nonattainment or maintenance for at least one criteria pollutant. 

New York City to Hartford

Via Central Connecticut

This route includes Putnam County, NY, which is not nonattainment or maintenance for at least one 

pollutant (and therefore attainment for all criteria pollutants).

Via Long Island

This route includes Nassau and Suffolk Counties, NY, both of which are nonattainment or 

maintenance for at least one criteria pollutant. 

Hartford to Boston

Via Providence

Most counties in Connecticut and Massachusetts within the Affected Environment for Alternative 3 

are designated as nonattainment or maintenance areas for at least one criteria pollutant. Counties 

in Rhode Island are in attainment for all criteria pollutants.

Via Worcester

Most counties in Connecticut and Massachusetts within the Affected Environment for Alternative 3 

are designated as nonattainment or maintenance areas for at least one criteria pollutant. Counties 

in Rhode Island are in attainment for all criteria pollutants.
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7.13.3.2 Environmental Consequences

The FRA’s modeling predicts a decrease in regional pollutant burdens from roadways due to the 

expected decrease in roadway VMT (autos) and an increase in regional pollutant burdens from 

power sources (diesel fuel and electric) because of increased train service under the Action 

Alternatives. As shown in Table 7.13-5, the combined (net) effect of these elements is a predicted 

decrease in all criteria pollutant burdens, with the exception of NOx under Alternative 3 (via Central 

Connecticut/Providence, and via Long Island/Providence and Worcester) and SO2 under all Action 

Alternatives.

Table 7.13-5: 2040 Changes in Criteria Pollutant Burdens (tons/year) –

Existing Energy Profile

Pollutant

Project 

Element Alternative 1 Alternative 2

Alternative 3

via Central 

CT/Providence

via Long 

Island/

Providence 

via Long 

Island/

Worcester 

via Central 

CT/Worcester 

CO

Roadways -2,495 -3,375 -3,725 -3,520 -3,850 -3,635

Diesel Trains -1 -25 0 1 1 1

Electric Trains 15 30 50 55 55 35

TOTAL -2,480 -3,375 -3,675 -3,465 -3,800 -3,605

VOC

Roadways -35 -45 -50 -45 -50 -50

Diesel Trains -1 -1 0 1 1 1

Electric Trains 2 3 5 5 5 3

TOTAL -30 -45 -45 -40 -45 -45

NOx

Roadways -165 -225 -250 -235 -255 -240

Diesel Trains -1 -30 0 1 1 1

Electric Trains 90 170 270 275 285 180

TOTAL -75 -80 20 40 30 -60

PM10

Roadways -40 -50 -60 -55 -60 -55

Diesel Trains -1 -1 0 1 1 1

Electric Trains 10 15 25 25 25 15

TOTAL -30 -35 -30 -30 -35 -40

PM2.5

Roadways -15 -25 -25 -25 -25 -25

Diesel Trains 0 -1 0 1 1 1

Electric Trains 5 15 20 20 20 15

TOTAL -10 -10 -4 -3 -4 -10

SO2

Roadways -5 -10 -10 -10 -10 -10

Diesel Trains -1 -1 0 1 1 1

Electric Trains 180 350 555 565 600 385

TOTAL 170 340 545 555 590 375

Source: NEC FUTURE team, 2015

The primary reason for the increases in NOx and SO2 is the increased electrical power requirements 

resulting from additional trains under the Action Alternatives. The predicted increases in NOx and 

SO2 would account for less than 0.02 percent of NOx and 0.1 percent of SO2 emission burdens 

currently generated in the Study Area. These relatively small changes are expected to have little 

impact on overall ambient pollutant concentrations. In addition the vast majority of the Study Area 

is classified as attainment for SO2 and NO2. However, these estimates for emission burdens 
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generated by future power use are conservative since they are based on current emission profile 

information obtained from the EPA’s egrid and national emission inventory databases; in actuality, 

a cleaner energy profile will likely exist in the future due to the adoption or increase of renewable 

portfolio standards by the states within the Study Area. As shown in Table 7.13-6, all states within 

the Study Area have adopted renewable energy goals. For all states, achievement of these 

renewable energy targets are expected by 2040.

Table 7.13-6: Renewable Energy Targets by Geography

Geography

Current Percentage of 

Renewable Energy

Percentage Renewable Energy 

Target

Percentage Increase Applied to 

Current Profile

D.C. 0% 20% 20%

MD 5% 20% 15%

DE 0% 25% 25%

PA 2% 18% 16%

NJ 0% 25% 25%

NY 20% 50% 30%

CT 1% 27% 26%

RI 0% 16% 16%

MA 3% 20% 17%

Sources: Egrid http://www.epa.gov/cleanenergy/documents/egridzips/eGRID_9th_edition_V1-

0_year_2010_Summary_Tables.pdf; National Conference of State Legislatures, State Renewable Portfolio Standards and Goals –

http://www.ncsl.org/research/energy/renewable-portfolio-standards.aspx

To account for the future renewable energy targets of each state, a future energy profile analysis 

was conducted. This analysis was done by taking the difference between the current and future

target renewable energy profile percentages (Table 7.13-6). The resulting percentage was then 

directly applied to the current emission rates to account for the increased future renewable energy 

percentage of each area’s energy profile. Future renewables were assumed to have a zero emission 

profile. The results presented in Table 7.13-7 reflect the impacts of the Action Alternatives based 

upon this future emission profile for electrical generation. As shown in this table, the Action 

Alternatives would have smaller absolute air quality impacts under a predicted future energy 

profile, as compared to the impacts expected if the energy profile were to remain the same as that 

exists today. The reduced air quality impacts would result in an overall reduction in all criteria 

pollutant burdens, with the exception of SO2, under all Action Alternatives. The predicted increase 

in SO2 would account for less than 0.1 percent of SO2 emission burdens currently generated in the 

Study Area.
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Table 7.13-7: 2040 Changes in Criteria Pollutant Burdens (tons/year) – Future Energy 

Profile

Pollutant

Project 

Element Alt. 1 Alt. 2

Alternative 3

via Central 

CT/Providence

via Long 

Island/

Providence 

via Long 

Island/

Worcester 

via Central 

CT/Worcester 

CO

Roadways -2,495 -3,375 -3,725 -3,520 -3,850 -3,635

Diesel Trains -1 -25 0 1 1 1

Electric Trains 15 25 40 45 40 25

TOTAL -2,480 -3,380 -3,685 -3,475 -3,810 -3,610

VOC

Roadways -35 -45 -50 -45 -50 -50

Diesel Trains -1 -1 0 1 1 1

Electric Trains 1 2 4 4 4 2

TOTAL -30 -45 -45 -45 -45 -45

NOx

Roadways -165 -225 -250 -235 -255 -240

Diesel Trains -1 -30 0 1 1 1

Electric Trains 75 135 215 220 225 145

TOTAL -95 -115 -35 -15 -30 -95

PM10

Roadways -40 -50 -60 -55 -60 -55

Diesel Trains -1 -1 0 1 1 1

Electric Trains 5 15 20 20 20 15

TOTAL -30 -40 -35 -35 -40 -45

PM2.5

Roadways -15 -25 -25 -25 -25 -25

Diesel Trains 0 -1 0 1 1 1

Electric Trains 5 10 15 15 20 10

TOTAL -10 -15 -10 -5 -10 -15

SO2

Roadways -5 -10 -10 -10 -10 -10

Diesel Trains -1 -1 0 1 1 1

Electric Trains 145 280 445 450 480 310

TOTAL 135 270 435 445 475 300

Source: NEC FUTURE team, 2015

Several other items suggest that future energy profiles will continue to improve and result in fewer 

emissions:

4 The EPA’s proposed Clean Power Plan2 proposes reducing PM2.5, SO2, and NO2 by over 

25 percent by 2030. The EPA is currently issuing final rules, and implementation is expected to 

start in the summer of 2020. States, including those in the Study Area, that have already 

invested in energy efficiency programs will be able to build on these programs during the 

compliance period to help make progress toward meeting their targets.

4 The use of regenerative braking would reduce the energy use, and resulting power plant 

emissions, from the electric trains. Regenerative braking is the process during which the train’s 

electric traction motors are utilized as generators during a brake application. This regenerated 

electricity can be used to power other trains drawing power within the network. The 

regenerated power can also be returned to the electrical utility grid using bi-directional traction 

 

2 http://www2.epa.gov/carbon-pollution-standards/clean-power-plan-proposed-rule
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Page | 7.13-14 Tier 1 Draft EIS

power substations. Trains with high brake duty cycles can recover upwards of 15 percent of the 

total consumed electricity. High-speed trains can recover approximately 5-10 percent of the 

total electricity consumed, a value that is reduced by the longer distances between stations and 

fewer station stops.

4 Today, Amtrak directly receives a portion of their electrical requirements from the hydroelectric 

generators operating at the Safe Harbor Dam in Pennsylvania. The Safe Harbor Dam has two 

28 megawatt turbines that are dedicated to generating power for Amtrak’s use. Due to the 

nature of the power grid and the Action Alternatives, it is not possible to reliably determine 

what percentage of the Action Alternatives’ power requirements would come from the Safe 

Harbor Dam system. As such, emission estimates from electrical usage are conservative because 

they are based on statewide values, which assume only a percentage of renewable power 

generation rather than a direct portion of electrical usage coming from a renewable source.

4 As discussed in Chapter 5, Transportation Effects, investment in the NEC FUTURE passenger rail

infrastructure would create a shift in demand from aircraft and bus trips servicing the corridor 

to rail trips, when comparing the Action Alternatives to the No Action Alternative. As such, the 

shift in travel mode choice is likely to result in a decrease in criteria pollutant emissions from 

aircraft and buses under all Action Alternatives; however, it is not within the scope of this 

analysis to make quantitative predictions regarding the level of decrease in emissions. 

The FRA did not conduct a quantitative analysis of the impacts to air quality from constructionof the 

Action Alternatives, as a detailed construction schedule, along with estimates of construction 

equipment and activities, are not developed as part of NEC FUTURE. However, construction of the 

Action Alternatives would result in temporary emissions of criteria pollutants associated with 

construction equipment and activities. Local levels of criteria pollutants could also increase near 

station locations and parking facilities caused by vehicles queuing at these locations.

7.13.4 Mobile-Source Air Toxics

7.13.4.1 Affected Environment

In addition to the criteria pollutants for which there are NAAQS, the EPA also regulates air toxics. 

Toxic air pollutants are those pollutants known or suspected to cause cancer or other serious health 

effects. Most air toxics originate from human-made sources, including on-road mobile sources, 

non-road mobile sources (e.g., airplanes), area sources (e.g., dry cleaners), and stationary sources 

(e.g., factories or refineries). 

Controlling air toxic emissions became a national priority with the passage of the CAA, whereby 

Congress mandated that the EPA regulate 188 air toxics, also known as hazardous air pollutants. 

The EPA has assessed this expansive list in their latest rule on the Control of Hazardous Air 

Pollutants from Mobile Sources and identified a group of 93 compounds emitted from mobile 

sources that are listed in their Integrated Risk Information System.

3 In addition, the EPA identified 

seven compounds with significant contributions from mobile sources that are among the nationaland regional-scale cancer risk drivers from their 1999 National Air Toxics Assessment. These are 

acrolein, benzene, 1,3-butadiene, diesel particulate matter plus diesel exhaust organic gases, 

 

3 EPA, Integrated Risk Information System (IRIS), http://www.epa.gov/iris/
7. Affected Environment, Environmental Consequences, and Mitigation Strategies

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formaldehyde, naphthalene, and polycyclic organic matter. While the Federal Highway 

Administration (FHWA) considers these the priority MSATs, the list is subject to change and may be 

adjusted in consideration of future EPA rules. The 2007 EPA rule mentioned previously requires 

controls that will dramatically decrease MSAT emissions through cleaner fuels and cleaner engines. 

According to an FHWA analysis using the EPA’s MOVES2010b model, even if vehicle activity (VMT) 

increases by 102 percent as assumed it will from 2010 to 2050, a combined reduction of 83 percent

in the total annual emissions for the priority MSAT is projected for the same period.

The seven priority MSATs are briefly described below:

4 Acrolein is a water-white or yellow liquid that burns easily, is readily volatilized, and has a 

disagreeable odor. It is considered to have high acute toxicity, and it causes upper respiratory 

tract irritation and congestion in humans. 

4 Benzene is a volatile, colorless, highly flammable liquid with a sweet odor. Most of the benzene 

in ambient air is from incomplete combustion of fossil fuels and evaporation from gasoline 

service stations. Acute inhalation exposure to benzene causes neurological symptoms, such as 

drowsiness, dizziness, headaches, and unconsciousness in humans. Chronic inhalation of certain 

levels of benzene causes blood disorders in humans. 

4 1,3-Butadiene is a colorless gas with a mild gasoline-like odor. Sources of 1,3-butadiene 

released into the air include motor-vehicle exhaust, manufacturing and processing facilities, 

forest fires or other combustion, and cigarette smoke. Acute exposure to 1,3-butadiene by 

inhalation in humans results in irritation of the eyes, nasal passages, throat, and lungs. 

Neurological effects, such as blurred vision, fatigue, headache, and vertigo, have also been 

reported at very high exposure levels. 

4 Diesel Particulate Matter/Diesel Exhaust Organic Gases (DPM) are a complex mixture of 

hundreds of constituents in either a gaseous or particle form. Gaseous components of diesel 

exhaust include CO2, O3, nitrogen, water vapor, CO, nitrogen compounds, sulfur compounds, 

and numerous low-molecular-weight HCs. DPM is directly emitted from diesel-powered engines 

(primary particulate matter) and can be formed from the gaseous compounds emitted by diesel 

engines (secondary PM). Acute or short-term (e.g., episodic) exposure to diesel exhaust can 

cause acute irritation (e.g., eye, throat, bronchial), neurophysiological symptoms (e.g., 

lightheadedness, nausea), and respiratory symptoms (e.g., cough, phlegm). 

4 Formaldehyde is a colorless gas with a pungent, suffocating odor at room temperature. The 

major emission sources of formaldehyde appear to be power plants, manufacturing facilities, 

incinerators, and automobile exhaust. However, most of the formaldehyde in ambient air is a 

result of secondary formation through photochemical reaction of VOC and NOX. The major toxic 

effects caused by acute formaldehyde exposure via inhalation are eye, nose, and throat 

irritation, and it affects the nasal cavity. 

4 Naphthalene is used in the production of phthalic anhydride; it is also used in mothballs. Acute 

(short-term) exposure of humans to naphthalene by inhalation, ingestion, and dermal contact is 

associated with hemolytic anemia, damage to the liver, and neurological damage. Cataracts 

have also been reported in workers acutely exposed to naphthalene by inhalation and 

ingestion. 
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Page | 7.13-16 Tier 1 Draft EIS

4 Polycyclic Organic Matter (POM) defines a broad class of compounds that includes the 

polycyclic aromatic hydrocarbon compounds, of which benzo[a]pyrene is a member. POM 

compounds are formed primarily from combustion and are present in the atmosphere in 

particulate form. Sources of air emissions are diverse and include cigarette smoke, vehicle 

exhaust, home heating, laying tar, and grilling meat. Cancer is the major concern from exposure 

to POM. 

7.13.4.2 Environmental Consequences

Reduction in roadway VMT results in an overall beneficial effect on MSAT. All Action Alternatives

would reduce roadway VMT; therefore, a reduction in MSAT would occur within the Affected 

Environment. Although the No Action Alternative will not affect VMT in the Affected Environment, 

MSAT emissions will likely be lower than present levels in the design year regardless of the 

alternative chosen; this reduction will be due to EPA’s national control programs, which are 

projected to reduce annual MSAT emissions by over 80 percent from 2010 to 2050.

4

Construction of the Action Alternatives could result in temporary, localized emissions of MSAT 

associated with construction equipment and activities. Local levels of MSAT could also increase near 

station locations and parking facilities. 

7.13.5 Greenhouse Gas Emissions

7.13.5.1 Affected Environment

Climate change is an important national and global concern. While the Earth has gone through 

many natural changes in climate in its history, there is scientific consensus that the Earth’s climate 

is currently changing at an accelerated rate and will continue to do so for the foreseeable future. 

Anthropogenic (human-caused) GHG emissions contribute to this rapid change. CO2 makes up the 

largest component of these GHG emissions. Other prominent transportation GHGs include CH4 and 

N2O.

Many GHGs occur naturally. Water vapor is the most abundant GHG and makes up approximately 

two-thirds of the natural greenhouse effect. However, the burning of fossil fuels and other human 

activities are adding to the concentration of GHGs in the atmosphere. Many GHGs remain in the 

atmosphere for time periods ranging from decades to centuries. GHGs trap heat in the Earth’s 

atmosphere. Because atmospheric concentration of GHGs continues to climb, our planet will 

continue to experience climate-related phenomena. For example, warmer global temperatures can 

cause changes in precipitation and sea levels. 

GHGs differ in their ability to trap heat. For example, 1 ton of emissions of CO2 has a different effect 

than 1 ton of emissions of CH4. To compare emissions of different GHGs, inventory compilers use a 

weighting factor called Global Warming Potential (GWP). To use a GWP, the heat-trapping ability of 

1 metric ton (1,000 kilograms) of CO2 is taken as the standard, and emissions are expressed in terms 

 

4 Federal Highway Administration. (2013, February 2). Interim Guidance Update on Mobile Source Air Toxic Analysis 

in NEPA - Appendix B. Retrieved from Air Quality: Transportation and Toxic Air Pollutants: 

http://www.fhwa.dot.gov/environment/air_quality/air_toxics/policy_and_guidance/aqintguidapb.cfm
7. Affected Environment, Environmental Consequences, and Mitigation Strategies

Tier 1 Draft EIS Page | 7.13-17

of CO2-equivalent (CO2e). The CO2e for a gas is derived by multiplying the tons of the gas by the 

associated GWP. The GWP of CO2 is 1. The GWP of CH4 is 21, whereas the GWP of N2O is 310.

To date, no national standards have been established regarding GHGs, nor has the EPA established 

criteria or thresholds for ambient GHG emissions pursuant to its authority to establish motorvehicle emission standards for CO2 under the CAA. However, there is a considerable body of 

scientific literature addressing the sources of GHG emissions and their adverse effects on climate, 

including reports from the Intergovernmental Panel on Climate Change, the U.S. Global Change 

Research Program, the U.S. National Academy of Sciences, and the EPA as well as other federal 

agencies. GHGs are different from other air pollutants evaluated in federal environmental reviews 

because their impacts are not localized or regional due to their rapid dispersion into the global 

atmosphere, which is characteristic of these gases. GHG emissions affect the entire planet.

Table 7.13-8 highlights the total GHG emissions from the commercial, electric power, residential, 

industrial and transportation sectors within the Study Area.

Table 7.13-8: Greenhouse Gas Emissions by Geography (2012)

Geography

Greenhouse Gas Emissions

(million metric tons)

D.C. 3

MD 59

DE 13

PA 233

NJ 99

NY 154

CT 32

RI 10

MA 59

Source: U.S. Energy Information Administration, August 2015.

7.13.5.2 Environmental Consequences

Table 7.13-9 presents the changes in GHGs in the Study Area, in terms of CO2e, in the year 2040.

The changes in CO2e are presented for roadways, diesel trains, and electric trains.

Table 7.13-9: 2040 Changes in CO2e (tons/year) – Existing Energy Profile

Project Element Alt. 1 Alt. 2

Alternative 3

via Central 

CT/Providence

via Long Island/

Providence 

via Long Island/

Worcester 

via Central 

CT/Worcester 

Roadways -403,330 -545,875 -602,530 -568,705 -622,645 -587,905

Diesel Trains 0 -10,540 0 1 1 1

Electric Trains 128,685 229,235 367,365 378,115 384,920 241,545

TOTAL -274,650 -327,180 -235,165 -190,590 -237,730 -346,360

Source: NEC FUTURE team, 2015

As shown in Table 7.13-9, CO2e from roadways would decrease with all Action Alternatives, whereas 

the CO2e from electric trains would increase with all Action Alternatives. Overall, the net total GHGs 
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Page | 7.13-18 Tier 1 Draft EIS

would decrease under all Action Alternatives. For the No Action Alternative, changes in CO2e will 

reflect future regulations and VMT growth. As shown in Table 7.13-10, the CO2e reductions would 

be even greater assuming the future energy profile.

Table 7.13-10: 2040 Changes in CO2e (tons/year) – Future Energy Profile

Project Element Alternative 1 Alternative 2

Alternative 3

via Central 

CT/Providence

via Long Island/

Providence 

via Long Island/

Worcester 

via Central 

CT/Worcester 

Roadways -403,330 -545,875 -602,530 -568,705 -622,645 -587,905

Diesel Trains 0 -10,540 0 1 1 1

Electric Trains 101,805 181,230 291,730 299,405 305,440 192,315

TOTAl -301,525 -375,185 -310,800 -269,300 -317,210 -395,590

Source: NEC FUTURE team, 2015

Additionally, the EPA’s proposed Clean Power Plan5 would reduce carbon pollution by 30 percent by 

2030. The EPA is currently issuing final rules, and implementation is expected to start in the 

summer of 2020. States, including those in the Study Area, that have already invested in energy 

efficiency programs will be able to build on these programs during the compliance period to help 

make progress toward meeting their targets.

The use of regenerative braking, as described in Section 7.13.3.2 , would reduce the energy use, and 

resulting power plant CO2e emissions, from the electric trains.

As discussed in Chapter 5, Transportation Effects, investment in the NEC FUTURE passenger rail

infrastructure would create a shift in demand from aircraft and bus trips servicing the corridor to 

rail trips, when comparing the the No Action Alternative to the Action Alternatives. This mode shift 

from aircraft and bus trips to rail trips would remove some aircraft and buses from the NEC. As 

such, CO2e from aircraft and buses would decrease under all Action Alternatives. 

The FRA did not conduct a quantitative analysis of the construction impacts to air quality of the 

Action Alternatives , since a detailed construction schedule, along with estimates of construction 

equipment and activities, are unknown at the Tier 1 level. However, construction of the Action 

Alternatives would result in temporary CO2e emissions associated with construction equipment and 

activities.

7.13.6 Potential Mitigation Strategies 

Examples of programmatic mitigation measures for air quality include the incorporation of 

Environmental Performance Measures in Tier 2 alternatives, including solar panels on stations and 

other buildings, as well as the use of renewable energy. With regards to construction activities, 

potential mitigation could involve voluntary emission reduction agreements, as well as the use of 

electric, energy efficient or low-emissions equipment. Specific mitigation concerning air quality 

impacts during construction, such as fugitive dust from earth moving and pollutants from 

 

5 http://www2.epa.gov/carbon-pollution-standards/clean-power-plan-proposed-rule
7. Affected Environment, Environmental Consequences, and Mitigation Strategies

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construction equipment, would also be investigated. The following are examples of potential 

mitigation measures:

4 Site Preparation

– Minimize land disturbance.

– Water site a minimum of three times per day.

– Cover trucks when hauling dirt.

– Stabilize the surface of dirt piles if they are not removed immediately.

– Use windbreaks to prevent accidental dust pollution.

– Limit vehicular paths and stabilize temporary roads.

– Pave all unpaved construction roads and parking areas to road grade for a length of no less 

than 50 feet from where such roads and parking areas exit the construction site to prevent 

dirt from washing onto paved roadways.

4 Construction

– Equip applicable construction equipment with emission control devices such as diesel 

particulate filters.

– Cover trucks when transferring materials.

– Use dust suppressants on unpaved traveled paths.

– Minimize unnecessary vehicular and machinery activities.

– Minimize dirt track-out by washing or cleaning trucks before leaving the construction site. 

An alternative to this strategy is to pave a few hundred feet of the exit road just before 

entering the public road.

– Use ultra-low sulfur diesel fuel for all diesel equipment.

– Use cleanest available (Tier 4) equipment.

4 Post-Construction

– Re-vegetate any disturbed land not used.

– Remove unused material.

– Remove dirt piles.

– Re-vegetate all vehicular paths created during construction to avoid future off-road 

vehicular activities.

7.13.7 Subsequent Tier 2 Analysis 

Project-level Tier 2 analyses would include more detailed evaluation of site-specific air quality 

impacts, where appropriate, as well as updated and refined regional and GHG analyses, as 

appropriate. Subsequent Tier 2 analyses would determine the benefits at the individual project 

level. Part of the Tier 2 analyses would include the following:

4 Regional Analysis – A refined regional air quality analysis would be conducted to demonstrate 

the proposed project’s impact on regional air quality levels. The analysis would be conducted 

for the No Action and Action Alternatives and would be based on daily VMT and associated 

average network speeds. Emission factors would be calculated using the EPA’s most current 
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Page | 7.13-20 Tier 1 Draft EIS

approved emission factor program (assumed to be MOVES2014) with the appropriate local area 

parameters. If the project is predicted to affect plane traffic or power generation, the air quality 

impact of these elements would also be quantitatively evaluated.

4 SIP Conformity – Energy requirements of the fleet would be refined along with future emission 

factors from electrical generation. It would be determined if the project conforms with the 

applicable SIPs.

4 MSAT Analysis – An MSAT analysis would be conducted according to the FHWA’s most current 

MSAT guidance at the time of the analysis. This would most likely include a regional MSAT 

analysis.

4 Greenhouse Gas Analysis – The changes the proposed project has on GHG emissions would be 

refined using the recommended FHWA and/or EPA guidance at the time of analysis. The 

analysis would be conducted for the No Action and Action Alternatives and would be based on 

daily VMT and associated average network speeds. Emission factors would be calculated using 

the EPA’s most current approved emission factor program (assumed to be MOVES2014) with 

the appropriate local area parameters. If the project is predicted to affect plane traffic or power 

generation, the GHG impact of these elements would also be quantitatively evaluated.

4 Local Analysis – Based on the area’s attainment status and the project’s proposed traffic 

impacts, particularly near station locations, a CO and PM2.5/PM10 hot-spot analysis would be 

conducted following the latest local, state, and federal guidance. For particulate matter, the 

latest EPA guidance is the Transportation Conformity Guidance for Quantitative Hot-Spot 

Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas.

6 For CO, the latest guidance 

is Using MOVES in Project-Level Carbon Monoxide Analyses.

7 Microscale CO and PM2.5/PM10

would be compared to the applicable NAAQS to determine if the project causes or exacerbates 

a violation of the applicable NAAQS.

4 Construction Analysis – Based on the location of construction sites, staging areas, sensitive 

receptors, and the construction schedule, an analysis of local construction-related air quality 

impacts would be conducted. Emission burdens from construction equipment and activities

would be generated using project-specific operating parameters and emission rates derived 

from the EPA’s NONROAD Model8 and AP-42.

9 Local air quality concentrations would be 

predicted at appropriate sensitive receptors using the EPA’s AERMOD10 program along with 

location and project-specific parameters.

 

6 U.S. Environmental Protection Agency. (2013). Transportation Conformity Guidance for Quantitative Hot-Spot 

Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas. Retrieved from

http://www.epa.gov/otaq/stateresources/transconf/policy/420b13053-sec.pdf 7 U.S. Environmental Protection Agency. (2010). Using MOVES in Project-Level Carbon Monoxide Analyses. 

Retrieved from http://www.epa.gov/otaq/stateresources/transconf/policy/420b10041.pdf 8 U.S. Environmental Protection Agency. NONROAD Model. Retrieved from

http://www.epa.gov/oms/nonrdmdl.htm

9 U.S. Environmental Protection Agency. Compilation of Air Pollutant Emission Factors. Retrieved from

http://www.epa.gov/oms/ap42.htm 10 U.S. Environmental Protection Agency. Preferred/Recommended Models. Retrieved from 

http://www.epa.gov/scram001/dispersion_prefrec.htm
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4 Conformity – Required transportation or general conformity analyses and any necessary 

determinations would be completed for the project. In November 1993, EPA promulgated two 

sets of regulations to implement Section 176(c) of the Clean Air Act. First, on November 24, the 

EPA promulgated the Transportation Conformity Regulations, which apply to highways and 

mass transit. Transportation conformity is required by the Clean Air Act section 176(c) (42 U.S.C. 

7506(c)) to ensure that federal funding and approval are given to highway and transit projects 

that are consistent with (“conform to”) the air quality goals established by a state air quality 

implementation plan (SIP). Conformity, to the purpose of the SIP, means that transportation 

activities will not cause new air quality violations, worsen existing violations, or delay timely 

attainment of the national ambient air quality standards.

On November 30, the EPA promulgated a second set of regulations, known as the General 

Conformity Regulations, which apply to all other federal actions. These regulations ensured that 

other federal actions also conformed to the SIPs (58 FR 63214). The purpose of the General 

Conformity Rule is to:

– Ensure that federal activities do not cause or contribute to new violation of NAAQS.

– Ensure that actions do not cause additional or worsen existing violations of or contribute to 

new violations the NAAQS.

– Ensure that attainment of the NAAQSs is not delayed.