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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE:

SUBJECT:

July 2, 2013 

 

Technical Support Document for the Review of the Clean Data Motor Vehicle 

Emissions Budgets (MVEBs) for Fine Particulate Matter (PM2.5) and Nitrogen 

Oxide (NOx) for the Determination of Attainment of the 2006 24-hour Fine 

Particulate Matter Standard for the Pittsburgh-Beaver Valley Nonattainment Area

FROM: Gregory Becoat /s/

Office of Air Program Planning (3AP30)

TO: Administrative Record of the U.S. Environmental Protection Agency’s Review of 

the Clean Data Motor Vehicle Emissions Budgets (MVEBs) for Fine Particulate 

Matter (PM2.5) and Nitrogen Oxide (NOx) for the Determination of Attainment of 

the 2006 24-hour Fine Particulate Matter Standard for the Pittsburgh-Beaver 

Valley Nonattainment Area

THRU: Cristina Fernandez, Associate Director /s/

Office of Air Program Planning (3AP30)

I. Background

On January 17, 2013, the U.S. Environmental Protection Agency (EPA) Region 3 received a 

request for the approval and establishment of MVEBs for PM2.5 and NOx for the Pittsburgh-Beaver 

Valley Area from the Pennsylvania Department of Environmental Protection (PADEP) for the year 

2011. The establishment of MVEBs for PM2.5 and NOx is based on EPA’s determination of clean 

data for the Pittsburgh-Beaver Valley Area for meeting the 2006 24-hour PM2.5 national ambient 

air quality standard (NAAQS). The Pittsburgh-Beaver Valley Area consists of Allegheny County 

(not including the townships part of the Liberty-Clairton nonattainment area); Beaver, Butler, and 

Westmoreland Counties; and portions of Armstrong, Greene, and Lawrence Counties. The 

Pittsburgh-Beaver Valley Area was designated nonattainment for the 1997 annual (70 FR 944) and 

2006 24-hour PM2.5 NAAQS (74 FR 58688). EPA has already determined that the PittsburghBeaver Valley Area attained the 1997 annual PM2.5 NAAQS (77 FR 62147) and that the monitors 

in the Pittsburgh-Beaver Valley Area have shown compliance with the 2006 24-hour PM2.5 

standard based on ambient air monitoring data for 2010, 2011, and 2012.

II. Transportation Conformity Requirements

Under section 176(c) of the Clean Air Act (CAA), new transportation plans, programs, and 
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projects, such as the construction of new highways, must “conform” to (i.e., be consistent with) the 

part of the state’s air quality plan that addresses pollution from cars and trucks. The CAA requires 

federal actions in nonattainment and maintenance areas to “conform to” the goals of State 

Implementation Plan (SIP). This means that such actions will not cause or contribute to violations 

of NAAQS; worsen the severity of an existing violation; or delay timely attainment of any NAAQS

or any interim milestone. 

To meet emission inventory requirements of section 172(c)(3) of the CAA, a regional mobile 

source highway inventory must be prepared for direct and precursor PM2.5 emissions, which 

includes PM2.5 and the precursor emissions of volatile organic compounds (VOC), NOx, sulfur 

dioxide (SO2), and ammonia (NH3). PADEP provided an emission inventory for the 2011 analysis 

year using the Motor Vehicle Emissions Simulator emissions model (MOVES2010a). The 

MOVES model is EPA’s state-of-the-art tool for estimating highway emissions that incorporates 

the latest emissions data. EPA announced the release of MOVES2010 in March 2010 (75 FR 

9411). EPA subsequently released two minor model revisions: MOVES2010a in September 2010 

and MOVES2010b in April 2012. Both of these minor revisions enhance model performance and 

do not significantly affect the criteria pollutant emissions results from MOVES2010. Upon the 

release of MOVES2010, EPA established a two-year grace period before MOVES is required to be 

used for regional conformity analyses (75 FR 9411). EPA subsequently promulgated a final rule 

on February 27, 2012 to provide an additional year before MOVES was required for these analyses 

(77 FR 11394). The MOVES grace period for regional conformity analyses applied to both the use 

of MOVES2010 and approved minor revisions (e.g., MOVES2010a and MOVES2010b). The 

grace period ended on March 2, 2013; therefore, the MOVES model is now required for new 

regional emissions analyses for transportation conformity determinations (“regional conformity 

analyses”) outside of California. For more information, see EPA’s “Policy Guidance on the Use of 

MOVES2010 and Subsequent Minor Model Revisions for State Implementation Plan 

Development, Transportation Conformity, and Other Purposes” (April 2012).

For MVEBs to be approvable, they must meet, at a minimum, EPA’s adequacy criteria found at 40 

CFR 93.118(e)(4). EPA’s adequacy criteria are: (1) the submitted control strategy implementation 

plan was endorsed by the Governor or designee and was subject to a State public hearing; (2) 

consultation among Federal, State, and local agencies occurred; full implementation plan 

documentation was provided to EPA; and EPA's stated concerns, if any, were addressed before the 

control strategy implementation plan was submitted; (3) the MVEBs are clearly identified and 

precisely quantified; (4) the MVEBs, when considered together with all other emissions sources, 

are consistent with applicable requirements for maintenance; (5) the MVEBs are consistent with 

and clearly related to the emissions inventory and the control measures in the submitted control 

strategy implementation plan; and (6) revisions to previously submitted maintenance plans explain 

and document any changes to previously submitted budgets and control measures; impacts on point 

and area source emissions; any changes to established safety margins; and reasons for the changes 

(including the basis for any changes related to emission factors or estimates of vehicle miles 

traveled).
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As described in 40 CFR 93.109(c)(5) of the transportation conformity rule and the preamble of 

the Transportation Conformity Restructuring Amendments (77 FR 14982, March 14, 2012), any 

nonattainment area that EPA determines has air quality monitoring data that meet the 

requirements of 40 CFR parts 50 and 58 and that show attainment of a NAAQS (clean data),

must satisfy one of the following requirements: (1) the budget test and/or interim emissions tests 

as required by section 93.118 and 93.119; (2) the budget test as required by section 93.118, using 

the adequate or approved motor vehicle emissions budgets in the submitted or applicable control 

strategy implementation plan for the NAAQS for which the area is designated nonattainment; or 

(3) the budget test as required by section 93.118, using the motor vehicle emissions in the most 

recent year of attainment as motor vehicle emissions budgets, if the state or local air quality 

agency requests that the motor vehicle emissions in the most recent year of attainment be used as 

budgets, and EPA approves the request in the rulemaking that determines that the area has 

attained the NAAQS for which the area is designated nonattainment. The Pittsburgh-Beaver 

Valley Area may establish clean data MVEBs under 40 CFR 93.109(c)(5)(iii) because the 

following criteria were met: (1) the state requested that budgets be established in conjunction 

with EPA's determination of attainment (Clean Data) rulemaking for the 2006 24-hour PM2.5 

NAAQS, and EPA approved the request; and, (2) the Pittsburgh-Beaver Valley Area has not 

submitted a maintenance plan for the 2006 24-hour PM2.5 NAAQS and EPA has determined that 

the Area is not subject to the CAA reasonable further progress and attainment demonstration 

requirements for the 2006 24-hour PM2.5 NAAQS. Table 1 below demonstrates how the 

document prepared by PADEP satisfies the requirements for clean data MVEBs.

TABLE 1. EPA’S EVALUATION OF THE CLEAN DATA MOTOR VEHICLE EMISSIONS 

BUDGETS SUBMITTED BY THE PENNSYLVANIA DEPARTMENT OF 

ENVIRONMENTAL PROTECTION FOR THE PITTSBURGH-BEAVER VALLEY AREA TO 

EPA ON JANUARY 17, 2013

CRITERIA APPLICABLE TO CLEAN DATA BUDGETS

SECTION

OF 

40 CFR PART 

93

CRITERIA Y/N COMMENTS

93.110 Are the budgets based upon 

the latest planning 

assumptions?

Y

All planning assumptions used were the 

latest available. The highway mobile source 

emission inventory was developed using 

available travel data and EPA’s

MOVES2010a emission model. A mix of 

local data and national default data was 

used for this analysis (based on EPA’s 

MOVES technical guidance). Local data 

was used for the primary data items that 

have a significant impact on emissions. 
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These include the following: vehicle miles 

of travel (VMT) by vehicle type, average 

speed distribution, vehicle type mixes, 

source type population (for light-duty 

vehicles), vehicle age distribution, hourly 

distributions, meteorology data, 

Inspection/Maintenance program, and fuel 

supply. Most local data inputs to the 

analysis process reflect the latest planning 

assumptions based on 2008 data obtained 

from the Pennsylvania Department of

Transportation (PennDOT), the Bureau of 

Motor Vehicles, and other local/national 

sources. Newer data was available and was 

used for control strategies (e.g. InspectionMaintenance programs), vehicle age 

distributions and fuel characteristics. 

PPSUITE was used to calculate hourly 

congested speeds for each roadway link, 

apply vehicle type fractions, aggregate 

VMT, prepare MOVES2010a trafficrelated input files, and process 

MOVES2010a outputs. CENTRAL was 

used to execute the PPSUITE and 

MOVES2010a processes in order to allow 

users to execute runs for a variety of input 

options and integrates custom MYSQL 

steps into the process.

93.111 Are the budgets based upon 

the latest emissions model?

Y The inventory reflects the highway mobile 

source emission estimations using EPA’s 

MOVES2010a emission model. EPA’s 

MOVES model was officially released on 

March 2, 2010 and was followed with a 

revised version (MOVES2010a) in August 

2010. MOVES2010a has been integrated 

with local traffic, vehicle fleet, 

environmental, fuel, and control strategy 

data to estimate emissions. The 

MOVES2010a inputs that were prepared by 

PPSUITE included vehicle type VMT, 

vehicle population, VMT fractions, average 

speed distributions, road type distribution 
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and ramp fractions. These files were input 

into the MOVES2010a county data 

importer. Additional non-PPSUITE inputs 

included fuel and vehicle ages, as well as 

temperatures and I/M programs. 

93.118

93.118(e)(4)(i)

93.118(e)(4)(ii)

Did the state or local air 

quality agency request that 

the motor vehicle emissions 

in the most recent year of 

attainment be used as 

budgets, and did EPA 

approve the request in the 

rulemaking that determines 

that the area has attained 

the NAAQS for which the 

area is designated 

nonattainment?

Was the request for the 

establishment of the clean 

data budgets endorsed by 

the Governor (or his or her 

designee)?

Before the request that 

clean data budgets be 

established was submitted 

to EPA, consultation 

among federal, State, and 

local agencies occurred; 

full implementation plan 

documentation was 

provided to EPA; and 

Y

Y

Y

PADEP requested for approval and 

establishment of MVEBs for PM2.5 and 

NOx for the Pittsburgh-Beaver Valley Area 

for the attainment year 2011. EPA has 

determined that the Pittsburgh-Beaver 

Valley Area has clean data for the 2006 24-

hour PM2.5 NAAQS. MOVES2010a was 

executed to provide a highway mobile 

source emission inventory. For the 1997 

annual (70 FR 944) and 2006 24-hour (74 

FR 58688) PM2.5 NAAQS for the 

Pittsburgh-Beaver Valley Nonattainment 

Area, the highway vehicle emissions of 

direct PM2.5 and NOx for the analysis year 

2011 are as follows (short tons/year): 

2011 Analysis Year Budget

28,973.05 (NOx)

961.71 (PM2.5)

Letter addressed to Shawn M. Garvin, 

Regional Administrator, EPA Region III 

from Michael L. Krancer, Secretary, 

Pennsylvania DEP

This conformity analysis does not 

accompany a control strategy 

implementation plan or maintenance plan; 

therefore, documentation of consultation is 

not applicable for a clean data budget 

request. However, consultation has 

occurred among all required Federal, State, 

and local agencies to discuss the PM2.5 

clean data budgets before submittal of the 
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93.118(e)(4)(iii)

93.118(e)(4)(iv)

93.118(e)(4)(v)

93.118(e)(4)(vi)

EPA's stated concerns, if 

any, were addressed;

Were the motor vehicle 

emissions budget(s) 

(MVEBs) clearly identified 

and precisely quantified?

Are the motor vehicle 

emissions budget(s), when 

considered together with all 

other emissions sources, 

consistent with applicable 

requirements for 

attainment?

Are the motor vehicle 

emissions budget(s) 

consistent with and clearly 

related to the emissions 

inventory and the control 

measures in the submitted 

conformity analysis?

Revisions to previously 

submitted maintenance 

plan: explain and document

any changes to previously 

submitted budgets and 

control measures; impacts 

on point and area source 

emissions; any changes to 

Y

Y

Y

N/A

request.

Appendix A-2 of the submittal provides 

detailed emission summary tables for the 

Pittsburgh-Beaver Valley Area for analysis 

year 2011.

EPA believes that the MVEBs are 

consistent with the applicable requirements 

for attainment because the budgets are 

based on the motor vehicle emissions in the 

most recent year of attainment and EPA has 

made a determination of clean data for the 

Pittsburgh-Beaver Valley Area for meeting 

the 2006 24-hour PM2.5 NAAQS. EPA has 

determined that the monitors in the 

Pittsburgh-Beaver Valley Area have shown 

compliance with the 2006 24-hour PM2.5 

standard based on ambient air monitoring 

data for 2009, 2010, and 2011.

EPA believes that the motor vehicle 

emissions are clearly related to the 

emissions inventory and none of the control 

measures have changed.

This section does not apply because the 

budgets are not being established through 

an attainment demonstration or 

maintenance plan. The newly established 

MVEBs are clean data budgets and are not 

required to be submitted with an attainment 

demonstration or a maintenance plan.
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established safety margins 

(see Sec. 93.101 for 

definition); and reasons for 

the changes (including the 

basis for any changes 

related to emission factors 

or estimates of vehicle 

miles traveled).

CONCLUSION

Based upon our review and evaluation of the clean data MVEBs estimated in the PittsburghBeaver Valley Area conformity analysis, EPA finds that the conformity analysis meets the 

requirements of the CAA and the applicable regulations promulgated at 40 CFR part 93. 

Therefore, EPA is proposing to approve the establishment of the clean data MVEBs for the year 

2011 for the Pittsburgh-Beaver Valley Area. EPA can conclude that the development methodology 

of the MVEBs is consistent with applicable guidance documents intended for the development of 

on-road inventories and MVEBs. EPA has also reviewed the ambient air monitoring data for 

2010, 2011, and 2012 and has determined clean data for the Pittsburgh-Beaver Valley Area for 

meeting the 2006 24-hour PM2.5 NAAQS. As a result, the Pittsburgh-Beaver Valley Area may 

establish MVEBs under 40 CFR 93.109(c)(5)(iii). By establishing clean data MVEBs, the 

Southwestern Pennsylvania Commission, the Metropolitan Planning Organization for the 

Pittsburgh-Beaver Valley Area, can compare emissions estimated for future transportation planning 

to the 2011 clean data MVEBs that were developed using MOVES2010a.