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Adequacy Status of the Clark County, Nevada Submitted CO Attainment Plan for Transportation Conformity Purposes

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Environmental Protection Agency (EPA).


Notice of inadequacy determination.


In this document, EPA is notifying the public that we have found that the submitted Clark County (Las Vegas, NV) serious area carbon monoxide (CO) attainment plan is inadequate for transportation conformity purposes. As a result of our finding, the Regional Transportation Commission and the Federal Highway Administration cannot use the CO motor vehicle emissions budgets from the submitted plan for future conformity determinations.


This determination is effective February 17, 2000.

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The finding is available at EPA's conformity website:​oms/​traq, (once there, click on the “Conformity” button, then look for “Adequacy Review of SIP Submissions for Conformity”). You may also contact Karina O'Connor, U.S. EPA, Region IX, Air Division AIR-2, 75 Hawthorne Street, San Francisco, CA 94105; (415) 744-1247 or

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This document announces our finding that the Carbon Monoxide Air Quality Implementation Plan for the Clark County Non-Attainment Area, submitted by Nevada on October 6, 1999, is inadequate for transportation conformity purposes. EPA Region IX made this finding in a letter to the Nevada Division of Environmental Protection on January 12, 2000. We are also announcing this finding on our conformity website:​oms/​traq, (once there, click on the “Conformity” button, then look for “Adequacy Review of SIP Submissions for Conformity”). 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 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). One of these criterion is that the plan provide for attainment of the relevant ambient air quality standard by the applicable Clean Air Act attainment date. We have Start Printed Page 4966preliminarily determined that the Clark County CO plan does not provide for attainment of the CO standards and therefore, cannot 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 inadequacy determination on the Clark County CO plan.

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

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Dated: January 18, 2000.

Laura Yoshii,

Acting Regional Administrator, Region IX.

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[FR Doc. 00-2181 Filed 2-1-00; 8:45 am]