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Adequacy Status of Motor Vehicle Budget in Submitted Subsequent NO2

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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 nitrogen dioxide (NO2) motor vehicle emissions budgets in the subsequent NO2 maintenance plan portion of the 2007 South Coast State Implementation Plan (SIP) are adequate for transportation conformity purposes. The 2007 South Coast SIP was submitted to EPA on November 28, 2007 by the California Air Resources Board as a revision to the California state implementation plan. CARB corrected the NO2 motor vehicle emissions budgets from the 2007 South Coast SIP by letter dated May 1, 2009. As a result of our finding, the Southern California Association of Governments and the U.S. Department of Transportation must use the NO2 motor vehicle emissions budgets from the submitted subsequent NO2 maintenance plan for future transportation conformity determinations.


This finding is effective January 4, 2010.

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Wienke Tax, U.S. EPA, Region IX, Air Division AIR-2, 75 Hawthorne Street, San Francisco, CA 94105-3901; (415) 947-4192 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 to the California Air Resources Board on November 20, 2009 stating that the 2002 and 2020 motor vehicle emissions budgets for NO2 in the submitted 2007 AQMP are adequate. The budgets correspond to the South Coast NO2 maintenance area, which generally includes Orange County, the southwestern two-thirds of Los Angeles County, southwestern San Bernardino County, and western Riverside County. Receipt of these motor vehicle emissions budgets was announced on EPA's transportation conformity Web site, and no comments were submitted. The finding is available at EPA's conformity Web site:​otaq/​stateresources/​transconf/​adequacy.htm.

The adequate 2002 and 2020 motor vehicle emissions budgets (calculated for a winter season day) are provided in the following table:

Adequate Motor Vehicle Emissions Budget

(In tons per day)

Budget YearNO2 motor vehicle emissions budgets
2002 and 2020680 tons per day (winter season)

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 conform. 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 emissions budgets are adequate for conformity purposes are outlined in 40 CFR 93.118(e)(4). We have described our process for determining the adequacy of submitted SIP budgets in our July 1, 2004, preamble starting at 69 FR 40038, and we used the information in these resources while making our adequacy determination. 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: December 2, 2009.

Laura Yoshii,

Acting Regional Administrator, Region IX.

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[FR Doc. E9-30048 Filed 12-16-09; 8:45 am]