Skip to Content


Adequacy Status of Motor Vehicle Emissions Budgets in Submitted Early Progress Plan Imperial County 8-Hour Ozone for Transportation Conformity Purposes; California

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


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 for 8-hour ozone in the Imperial County 8-hour Ozone Early Progress Plan are adequate for transportation conformity purposes. The Imperial County 8-hour Ozone Early Progress Plan was submitted to EPA on March 24, 2008 by the California Air Resources Board as a revision to the California State Implementation Plan (SIP). As a result of our adequacy findings, the Southern California Association of Governments and the U.S. Department of Transportation must use these budgets in future conformity analyses once the finding becomes effective.


This finding is effective May 20, 2008.

Start Further Info


Adrienne Priselac, U.S. EPA, Region IX, Air Division AIR-2, 75 Hawthorne Street, San Francisco, CA 94105-3901; (415) 972-3285 or

End Further Info End Preamble Start Supplemental Information


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 April 16, 2008 stating that the motor vehicle emissions budgets in the submitted Imperial County 8-hour Ozone Early Progress Plan for 2009 are adequate. The finding is available at EPA's conformity Web site:​otaq/​stateresources/​transconf/​adequacy.htm. The adequate motor vehicle emissions budgets are provided in the following table:

Motor Vehicle Emissions Budgets

Budget yearVolatile organic compounds 1 (tons per day)Nitrogen oxides (tons per day)
1 The plan uses a comparable State term, reactive organic gases (ROG).

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). 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 in 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.

Start Authority

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

End Authority Start Signature

Dated: April 16, 2008.

Laura Yoshii,

Deputy Regional Administrator, Region IX.

End Signature End Supplemental Information

[FR Doc. E8-9821 Filed 5-2-08; 8:45 am]