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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

DATE: September 21, 2011

SUBJECT: Technical Support Document for Virginia’s Regulations for 

Transportation Conformity

FROM: Gregory Becoat, Environmental Scientist /s/

Office of Air Program Planning 

TO: File

THRU: Cristina Fernandez, Associate Director /s/

Office of Air Program Planning

A. BACKGROUND 

On June 13, 2011, the Virginia Department of Environmental Quality (VADEQ) 

submitted a revision to the Virginia State Implementation Plan (SIP). The SIP revision 

amends existing regulation 9VAC5-151 (Transportation Conformity) in order to 

incorporate federal revisions to transportation conformity requirements. The effective 

date of this regulation is March 17, 2010.

Transportation conformity is required under the Clean Air Act (CAA) section 176(c) (42 

U.S.C. 7506(c)) to ensure that transportation plans, transportation improvement programs 

(TIPs) and federally supported highway and transit project activities are consistent with 

the purpose of the SIP. Metropolitan planning organizations and the United States 

Department of Transportation must demonstrate that such plans, programs, and projects 

conform to Virginia’s 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 relevant national ambient air quality 

standards (NAAQS) or any interim milestones. Transportation conformity applies to 

areas that are designated nonattainment and those areas redesignated to attainment for 

transportation-related criteria pollutants: carbon monoxide (CO), ozone, nitrogen dioxide 

(NO2) and particulate matter (PM2.5 and PM10).

On October 17, 2006, Environmental Protection Agency (EPA) promulgated a final rule 

that strengthened the 24-hour PM2.5 NAAQS and revoked the annual PM10 NAAQS (71 

FR 61144). As a result of this rulemaking, EPA promulgated amendments to the 

transportation conformity rule in order to provide regulations for implementing 
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conformity for the revisions to the PM2.5 and PM10 NAAQS and to address hot-spot 

analyses as a result of a remand from the Court of Appeals for the District of Columbia 

Circuit (March 24, 2010, 75 FR 14260). 

Under 40 CFR 51.390, the Commonwealth of Virginia is required to submit a SIP 

revision to EPA in order to establish conformity criteria and procedures consistent with 

the transportation conformity regulation promulgated by EPA at 40 CFR part 93. In 

order to implement the federal transportation conformity requirements, Virginia’s 

regulation must reflect the most recent rulemaking promulgated by EPA.

B. STATE SUBMITTAL:

Amendments to 9VAC5-151-40 – General

The revision amends 9VAC5-151-40 administratively in order to change the date of the 

specific version of the provisions incorporated by reference from CFR (2008) in effect 

July 1, 2008 to CFR (2010) in effect July 1, 2010.

Amendments to 9VAC5-151-70 – Consultation

Section 9VAC5-151-70 specifies how various government agencies, federal, state and 

local, interacts and consults with the public and each other in developing transportation 

plans and projects. The revision amends 9VAC5-151-70 in order to change conformity 

tests and methodologies for isolated rural nonattainment and maintenance areas as 

required by 40 CFR 93.109(1)(2)(iii) to as required by 40 CFR 93.109(n)(2)(iii).

C. CONCLUSIONS AND RECOMMENDED AGENCY ACTION:

This SIP revision satisfies all requirements for an acceptable SIP. EPA evaluates that 

amendments to 9VAC5-151 (Transportation Conformity) contains the required elements 

for a federally enforceable rule. The amendments incorporate federal revisions to 

transportation conformity requirements and establish conformity criteria and procedures 

consistent with the transportation conformity regulation promulgated at 40 CFR part 93.

EPA approval of the SIP revision is recommended.