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Adequacy Status of Motor Vehicle Budgets in Submitted Eight-Hour Ozone Attainment Plan for the Phoenix-Mesa Nonattainment Area for Transportation Conformity Purposes; Arizona

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Environmental Protection Agency (EPA).


Notice of adequacy.


In this notice, EPA is notifying the public that the Agency has found that the motor vehicle emissions budgets in the submitted Eight-Hour Ozone Plan for the Maricopa Nonattainment Area (June 2007) (“2007 MAG Eight-Hour Ozone Plan”) are adequate for transportation conformity purposes. The 2007 MAG Eight-Hour Ozone Plan was submitted to EPA on June 15, 2007 by the Arizona Department of Environmental Quality as a revision to the Arizona state implementation plan. As a result of our finding, the Maricopa Association of Governments (MAG) and the Federal Highway Administration must use the motor vehicle emissions budgets from the submitted eight-hour ozone attainment plan for future conformity determinations.


This finding is effective November 9, 2007.

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Wienke Tax, U.S. EPA, Region IX, Air Division AIR-2, 75 Hawthorne Street, San Francisco, CA 94105-3901; (520) 622-1622 or

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Throughout this document, whenever “we,” “us,” or “our” is used, we mean EPA.

Today's notice is simply an announcement of a finding that we have already made. EPA Region IX sent a letter, dated October 4, 2007, to the Arizona Department of Environmental Quality on October 10, 2007 stating that the motor vehicle emissions budgets for volatile organic compounds (VOC) and oxides of nitrogen (NOX) in the submitted 2007 MAG Eight-Hour Ozone Plan for 2008 are adequate. The budgets correspond to the Phoenix-Mesa 8-hour ozone nonattainment area, which encompasses roughly half of Maricopa County, including the cities of Phoenix and Mesa, and also the Apache Junction area of Pinal County, in central Arizona. The finding is available at EPA's conformity Web site:​otaq/​stateresources/​transconf/​adequacy.htm. The adequate motor vehicle emissions budgets (calculated for a Thursday in 2008) are provided in the following table:

Adequate Motor Vehicle Emissions Budgets

[In metric tons per day]

Budget yearVOC motor vehicle emissions budgetNOX motor vehicle emissions budget

Transportation conformity is required by Clean Air Act section 176(c). EPA's conformity rule requires that transportation plans, transportation improvement programs, and projects conform to state air quality implementation plans (SIPs) and establishes the criteria and procedures for determining whether or not they do. Conformity to a SIP means that transportation activities will not produce new air quality violations, worsen existing violations, or delay timely attainment of the national ambient air quality standards.

The criteria by which we determine whether a SIP's motor vehicle emission budgets are adequate for conformity purposes are outlined in 40 CFR 93.118(e)(4). The process for determining the adequacy of such budgets is set forth at 40 CFR 93.118(f). Please note that an adequacy review is separate from EPA's completeness review, and should not be used to prejudge EPA's ultimate approval action for the SIP. Even if we find a budget adequate, the SIP could later be disapproved.

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Authority: 42 U.S.C. 7401 et seq.

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Dated: October 16, 2007.

Nancy Lindsay,

Acting Regional Administrator, Region IX.

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[FR Doc. E7-21073 Filed 10-24-07; 8:45 am]