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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

 

SUBJECT:

 June 5, 2012

Technical Support Document (TSD) - Insignificance Findings for the Motor 

Vehicle Emissions for the Redesignation Request and Maintenance Plan for the 

West Virginia Portion of the Wheeling, WV-OH 1997 Fine Particulate Matter

(PM2.5) Nonattainment Area 

FROM:

 /s/

Gregory Becoat

Environmental Scientist (3AP30)

TO: Administrative Record for the Insignificance Findings for the Motor Vehicle 

Emissions for the Redesignation Request and Maintenance Plan for West Virginia 

Portion of the Wheeling, WV-OH 1997 PM2.5 Nonattainment Area 

THRU:

 /s/

Donna Mastro, Acting Associate Director

Office of Air Program Planning (3AP30)

I. Background

The Clean Air Act (CAA) requires federal actions in nonattainment and maintenance areas to 

“conform to” the goals of State Implementation Plans (SIP). See, e.g., CAA section 176. This 

means that such actions will not cause or contribute to violations of a national ambient air quality

standard (NAAQS); worsen the severity of an existing violation; or delay timely attainment of 

any NAAQS or any interim milestone. Actions involving Federal Highway Administration 

(FHWA) or Federal Transit Administration (FTA) funding or approval are subject to the 

transportation conformity rule (40 CFR part 93, subpart A). Under this rule, metropolitan 

planning organizations (MPOs) in nonattainment and maintenance areas coordinate with state air 

quality and transportation agencies, Environmental Protection Agency (EPA), FHWA, and FTA 

to demonstrate that their metropolitan transportation plans and transportation improvement 

programs (TIP) conform to applicable SIPs. This is typically determined by showing that 

estimated emissions from existing and planned highway and transit systems are less than or equal 

to the motor vehicle emissions budgets (MVEBs) contained in a SIP.

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

40 CFR 93.118(e)(4). In certain instances, the Transportation Conformity Rule allows areas to 
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forgo establishment of a MVEB where it is demonstrated that the regional motor vehicle 

emissions for a particular pollutant or precursor are an insignificant contributor to the air quality

problem in an area. The general criteria for insignificance determinations can be found in 40 

CFR 93.109(f). Insignificance determinations are based on a number of factors, including the 

percentage of motor vehicle emissions in context of the total SIP inventory; the current state of 

air quality as determined by monitoring data for the relevant NAAQS; the absence of SIP motor 

vehicle control measures; and the historical trends and future projections of the growth of motor 

vehicle emissions. EPA’s rationale for providing for insignificance determinations is described 

in the July 1, 2004, revision to the Transportation Conformity Rule at 69 FR 40004. Specifically, 

the rationale is explained on page 40061 under the subsection XXIII.B. entitled, “Areas With 

Insignificant Motor Vehicle Emissions.” Any insignificance determination under review of EPA 

is subject to the adequacy and approval process for EPA's action on the SIP.

II. Administrative Requirements for Making Insignificance Findings 

EPA has followed the process for reviewing the submitted SIP and determining if an

insignificance finding for Motor Vehicle Emissions is warranted in accordance with the 

procedures listed in the January 2008 Conformity Regulations contained in 40 CFR 93.102(b) -

“Geographical applicability” and 40 CFR 93.118(f) - “Adequacy review process for 

implementation plan submissions.”

On March 8, 2012, the State of West Virginia formally submitted a Redesignation Request and 

Maintenance Plan for West Virginia Portion of the Wheeling, WV-OH 1997 PM2.5

Nonattainment Area (hereafter the Redesignation Request and Maintenance Plan). The SIP 

included a request for a finding of insignificance by EPA for motor vehicle emissions for 

nitrogen oxides (NOx), direct particulate matter (PM), and sulfur dioxide (SO2).

III. Evaluation of the Request for an Insignificance Finding for Motor Vehicle Emissions 

in the Redesignation Request and Maintenance Plan for the West Virginia Portion of the 

Wheeling, WV-OH 1997 PM2.5 Nonattainment Area Submitted By The West Virginia

Department of Environmental Protection

In this TSD, EPA is evaluating the West Virginia Department of Environmental Protection’s 

request for an insignificance finding for motor vehicle emissions associated with the 

Redesignation Request and Maintenance Plan contained in the submittal. EPA is using the 

evaluation criteria detailed in the Transportation Conformity Rule, 40 CFR 93.102(b)(2)(iv),

93.102(b)(2)(v), 93.102(b)(3), and 93.118(e)4 through 93.118(e)5. The evaluation is presented 

below.
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Review of the Request for Insignificance Finding of Motor Vehicle Emissions in the

Redesignation Request and Maintenance Plan for the West Virginia Portion of the 

Wheeling, WV-OH PM2.5 Nonattainment Area 

Transportation Conformity Rule

40 CFR Part 93, 93.118

Review Criteria Was the Criterion Satisfied? If 

Yes, How was this Criteria 

Satisfied?

93.102(b)(2)(iv) Has the EPA and the State 

made a finding that NOx is 

an insignificant contributor 

to the direct mobile PM 

emissions or does the

implementation plan fail to 

establish a NOx budget as 

part of the PM 2.5

maintenance strategy?

The State has requested that NOx 

be found an insignificant 

contributor to the mobile PM 

emissions. This request is based 

on the fact that Onroad mobile 

source NOx constitutes less than 

twelve and a half percent of the 

area’s total NOx emission in the 

2015 and 2022 horizon years due 

to continuing fleet turnover even 

with future vehicle miles traveled 

(VMT) growth included in the 

emission projections.

93.102(b)(2)(v) Has the EPA or State made a 

finding that Volatile Organic 

Compounds (VOCs), Sulfur 

Dioxide (SO2) or Ammonia 

(NH(3)) as precursors to be a 

significant contributor to the 

mobile PM emissions or does

the implementation plan 

submission establish a 

budget for VOCs, SOx or 

NH(3) as part of a PM 2.5 

maintenance strategy?

Neither EPA nor the State has

made any findings that VOCs, 

SO2, or NH(3) is a significant 

contributor to the PM2.5 mobile 

emissions, and therefore, it has 

not been included in the SIP. 

Onroad mobile source SO2

constitutes less than 0.1% of the 

area’s total SO2 emissions in the 

2015 and 2022 horizon years.

93.102(b)(3) Has the EPA or the State 

made a finding that direct 

PM is a significant 

contributor to the PM mobile 

emissions or does the 

implementation plan 

establish a budget that 

includes direct PM as part of 

a PM 2.5 maintenance 

strategy?

The State has requested that direct 

PM be found an insignificant 

contributor to the mobile PM 

emissions. This request is based 

on the fact that Onroad mobile 

source PM2.5 constitutes less than 

two and a half percent of the 

area’s total PM2.5 emissions in the 

2015 and 2022 horizon years due 

to continuing fleet turnover even 

with future VMT growth included 

in the emission projections. 
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Sec. 93.118(e)(4)(i) Was the submitted revised 

plan endorsed by the 

Governor (or his or her 

designee) and subject to a 

State public hearing?

Yes. The submitted 

Redesignation Request and 

Maintenance Plan was endorsed 

and submitted as a SIP revision by

the Governor’s designee, the 

Secretary of the West Virginia

Department of Environmental 

Protection. A public hearing on 

the SIP proposal was held. 

Sec. 93.118(e)(4)(ii) Before the maintenance plan

was submitted to EPA, did 

consultation between federal, 

State and local agencies 

occur; was full 

implementation plan 

documentation provided to 

EPA, and was EPA’s stated 

concerns, if any, addressed?

Yes. Consultation has occurred 

among all required Federal, State,

and local agencies.

Sec. 93.118(e)(4)(iii) Were the MVEBs clearly

identified and precisely

quantified?

As there was a request for an 

insignificance finding, no MVEBs

were identified in the SIP. 

Sec. 93.118(e)(4)(iv) Are the motor vehicle 

emissions, when considered 

together with all other 

emission reductions, 

consistent with applicable 

requirements for 

maintenance strategies?

EPA believes that motor vehicle 

emissions can be declared 

insignificant contributors because 

in comparing the motor vehicle

emissions to the overall emissions 

inventory, the motor vehicle

emissions comprise only a small 

portion of the over PM2.5

emissions for the nonattainment 

area and are projected to continue 

to significantly decline due to fleet 

turnover.

Sec. 93.118(e)(4)(v) Is the motor vehicle 

emissions consistent with 

and clearly related to the 

emissions inventory and the 

control measures in the Plan?

EPA believes that the motor 

vehicle emissions have clearly

related to the emissions inventory

in the SIP submittal.

Sec. 93.118(e)(4)(vi) Revisions to previously N/A 
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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 

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).

This is a new NAAQS that the 

area was designated as 

nonattainment for and this is the 

initial control strategy SIP 

submitted by the state to address 

the new NAAQS.

Sec. 93.118(e)(5) Did they provide and we 

review public comments and 

the State’s responses to those 

comments with the submitted 

control strategy SIP?

There were no comments on the 

SIP related to the proposed 

insignificance finding request.

IV. Findings

Based upon our review and evaluation of the motor vehicle emissions contained in the

Redesignation Request and Maintenance Plan for the West Virginia Portion of the Wheeling, 

WV-OH 1997 PM2.5 Nonattainment Area, EPA finds that the SIP submittal meets the criteria in 

the transportation conformity rules for an insignificance finding for NOx, PM2.5, and SO2

contribution from motor vehicles. Weighing all the factors for an insignificance finding, 

particularly the minor contribution of mobile source PM2.5, and SO2, EPA has determined that 

the PM2.5 and SO2 contribution from motor vehicles emissions to the Annual PM2.5 pollution for 

the West Virginia portion of the Nonattainment Area are insignificant. With respect to 

transportation conformity, the larger NOx contribution of less than twelve and a half percent of 

the area’s total NOx emission in the 2015 and 2022 horizon years requires further justification to 

request an insignificant finding. 40 CFR 93.109(f) bases insignificance on emission percentages, 

emission trends, and the effectiveness of the pollutant in forming PM. For the Wheeling area, 

there is a significant emission decrease projected for the highway sector and total emissions 

inventory in years 2008, 2015, and 2022. Given the relatively small contribution of the highway

emissions to the total SIP inventory, highway emissions are not likely to contribute significantly

to local PM2.5. Additionally, NOx reductions are significantly less effective in reducing PM 

concentrations than are reductions in direct PM and SO2. Consequently, NOx percent emission 

contribution may be higher than direct PM and SO2 without adversely affecting air quality. 

Based on the analysis of local historical trends and growth patterns in order to develop the long 

range transportation plan and transportation improvement program for transportation conformity

purposes, there is no reason to expect highway motor vehicle emissions growth that would lead 
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to a violation of the PM2.5 standard. Although vehicle miles traveled increases, NOx emissions 

decrease dramatically from 4505.4 tons/year in 2002 to 665.7 tons/year in 2030. This 

demonstrates that highway emissions will remain insignificant in the future. Upon review of the 

further justification for requesting an insignificant finding for NOx, EPA has determined that 

NOx contribution from motor vehicles emissions to the Annual PM2.5 pollution for the West 

Virginia portion of the Nonattainment Area is insignificant.