This site provides most of the information relevant to areas that have been designated nonattainment for the 2008 Ozone National Ambient Air Quality Standards (NAAQS). Information on other pages may also be relevant for conformity in individual areas.You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.

Transportation Conformity Guidance

• Baseline Year for the Baseline Year Test (in 40 CFR 93.119)
  This page provides a table showing the baseline year to be used for each NAAQS and the regulatory provision where it is found.
• Transportation Conformity Guidance for 2008 Ozone NAAQS Nonattainment Areas (PDF) (24pp, 180K, EPA-420-B-12-045, July 2012)
  This document provides guidance for meeting transportation conformity requirements in areas designated nonattainment for the 2008 ozone national ambient air quality standards (“2008 ozone NAAQS”). Note:  On December 23, 2014, the DC Circuit Court vacated EPA’s revocation of the 1997 ozone NAAQS for transportation conformity purposes only in NRDC v. EPA (12/23/2014).  On March 6, 2015 EPA published a final rule revoking the 1997 ozone NAAQS for all purposes.  (80 FR 12264) The final rule will be effective on April 6, 2015.
• Guidance for Transportation Conformity Implementation in Multi-Jurisdictional Nonattainment and Maintenance Areas (PDF) (54pp, 589K, EPA-420-B-12-046, July 2012)
  This guidance describes how transportation conformity determinations are done in areas where multiple metropolitan planning organizations (MPOs), states and/or other agencies have jurisdiction in a nonattainment or maintenance area. This guidance updates and supersedes the July 2004 “Companion Guidance for the July 1, 2004 Final Transportation Conformity Rule: Conformity Implementation in Multi-Jurisdictional Nonattainment and Maintenance Areas for Existing and New Air Quality Standards” .
  Contact:  Laura Berry at 734-214-4858 or berry.laura@epa.gov
• Policy Guidance on the Use of MOVES2010 and Subsequent Minor Revisions for State Implementation Plan Development, Transportation Conformity, and Other Purposes (PDF) ( 19 pp, 290K, EPA-420-B-12-010, April 2012)
  This document describes how and when to use the MOVES2010 (and subsequent minor revisions like MOVES2010b) for SIP development, transportation conformity, general conformity, and other purposes.

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Transportation Conformity Regulations

• Transportation Conformity:  Restructuring Amendments.
  This final rule restructures several sections of the existing transportation conformity rule so that the rule applies to any new or revised NAAQS EPA establishes, including the 2008 ozone NAAQS (77 FR 14979).
  • Final Rule (PDF) (10 pp, 489K published March 14, 2012)
  • Fact Sheet (PDF) (2 pp, 555K, EPA-420-F-12-009, February 2012)
  • Proposed Rule (PDF) (7 pp, 182K, published October 13, 2011)

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Other Regulations for the 2008 Ozone NAAQS

• Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area Classifications Approach, Attainment Deadlines and Revocation of the 1997 Ozone Standards for Transportation Conformity Purposes (77 FR 30160):
  • Final Rule (PDF)(12 pp, 278K, published May 21, 2012)
  Note: The portions of this final rule involving revoking the 1997 NAAQS for purposes of transportation conformity and attainment dates were vacated by the D.C. Circuit Court in NRDC v. EPA (12/23/2014). However, on March 6, 2015 EPA published a final rule revoking the 1997 ozone NAAQS for all purposes. (80 FR 12264) The final rule will be effective on April 6, 2015.
• Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards (77 FR 30088):
  • Final Rule (PDF)(74 pp, 609K, published May 21, 2012)
  This final rule establishes initial air quality designations for most areas in the United States, including areas of Indian country, for the 2008 primary and secondary ozone NAAQS.
• Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards for Several Counties in Illinois, Indiana, and Wisconsin; Corrections to Inadvertent Errors in Prior Designations (77 FR 34221):
  • Final Rule (PDF)(8 pp, 241K, published June 11, 2012)
  This rule completes the initial air quality designations for the 2008 primary and secondary NAAQS for ozone.
• EPA's 2008 Ozone NAAQS Regulatory Actions page contains a chronological listing of regulatory actions related to designations for the 2008 ozone NAAQS.

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For more information, contact Meg Patulski at 734-214-4842 or patulski.meg@epa.gov.

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