Adequacy Status of the South Coast and Coachella Valley, CA; Attainment and Maintenance Plans for Transportation Conformity Purposes

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of adequacy determination.

SUMMARY:

In this notice, EPA is notifying the public that we have found that the motor vehicle emissions budgets contained in California plans for attainment of the 1-hour ozone, PM10, and carbon monoxide (CO) National Ambient Air Quality Standards (NAAQS) and maintenance of the nitrogen dioxide (NO2) NAAQS in the South Coast, and attainment of the PM10 NAAQS in the Coachella Valley, are adequate for transportation conformity purposes. As a result of our finding, the Southern California Association of Governments, the Federal Highway Administration, and the Federal Transit Authority must use the motor vehicle emissions budgets from the submitted plan for future conformity determinations.

DATES:

This determination is effective April 9, 2004.

FOR FURTHER INFORMATION CONTACT:

The finding is available at EPA's conformity Web site: http://www.epa.gov/otaq/transp/conform/reg9sips.htm. You may also contact Dave Jesson, U.S. EPA, Region IX, Air Division, AIR-2, 75 Hawthorne Street, San Francisco, CA 94105-3901; (415) 972-3957 or jesson.david@epa.gov.

SUPPLEMENTARY INFORMATION:

This notice announces our finding that the following emissions budgets contained in the 2003 South Coast Air Quality Management Plan and the 2003 Coachella Valley PM10 State Implementation Plan, submitted by the California Air Resources Board (CARB) on January 9, 2004, are adequate for transportation conformity purposes: 1-hour ozone budgets for volatile organic compounds (VOC) and nitrogen oxides (NO_X) for the years 2005, 2008, and 2010, as part of the 1-hour ozone attainment plan for the South Coast Air Basin; PM10 budgets for VOC, NO_X, and PM10 for the years 2003 and 2006, as part of the PM10 attainment plan for the South Coast; CO budget for CO for the year 2002, as part of the CO attainment plan for the South Coast; NO2 budget for NO_X for the year 2003, as part of the NO2 maintenance plan for the South Coast Air Basin; and PM10 budgets for PM10 for the years 2003 and 2006, as part of the PM10 attainment plan for the Coachella Valley. EPA Region IX made these findings in letters to CARB on March 11, 2004. We are also announcing these findings on our conformity Web site: http://www.epa.gov/otaq/transp/conform/reg9sips.htm.

The methodology for estimating paved road dust emissions in the South Coast and Coachella Valley PM10 plans and budgets is consistent with EPA's AP-42 emissions factors, with one exception: California did not use correction factor C in the current version of AP-42, which subtracts out MOBILE6.2 1980's fleet exhaust emissions, brake wear, and tire wear. California-specific roadway silt loading inputs to the emission factor equation were derived from measurements by Midwest Research Institute. The unpaved road dust emissions factor was based on measurements performed by the University of California, Davis, and the Desert Research Institute. We are specifically approving the State's reentrained dust methodologies for paved and unpaved roads for use in future conformity analyses.

Transportation conformity is required by section 176(c) of the Clean Air Act. Our conformity rule requires that transportation plans, programs, and projects conform to state air quality implementation plans (SIPs) and establishes the criteria and procedures for determining whether or not they 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). One of these criteria is that the plan provide for attainment or maintenance (as appropriate) of the relevant ambient air quality standard. We have preliminarily determined that the South Coast SIP submittal provides for progress and attainment of the 1-hour ozone, PM10, and CO NAAQS, and maintenance of the nitrogen dioxide (NO2) NAAQS, and that the budgets associated with the plans are consistent with the plan and, therefore, can be found adequate. Similarly, we have preliminarily determined that the Coachella Valley SIP submittal provides for progress and attainment of the PM10 NAAQS, and that the budgets associated with the plan are consistent with the plan and, therefore, can be found adequate.

We have described our process for determining the adequacy of submitted SIP budgets in guidance (May 14, 1999 memo titled “Conformity Guidance on Implementation of March 2, 1999 Conformity Court Decision”). We followed this guidance in making our adequacy determination on the budgets in the South Coast and Coachella Valley SIP submittals.

Authority: 42 U.S.C. 7401-7671q.