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July 1, 2004, Transportation Conformity Final Rule

This Web page provides access to the July 1, 2004, conformity final rule that addresses the new ozone and PM2.5 air quality standards and the March 2, 1999, conformity court decision. This page also includes a complete collection of support and reference documents for this rulemaking, as well as EPA's June 30, 2003, and November 5, 2003, proposals to the final rule.

July 1, 2004 Final Rule:

  • Transportation Conformity Rule Amendments for the New 8-hour Ozone and PM2.5 National Ambient Air Quality Standards and Miscellaneous Revisions for Existing Areas: Transportation Conformity Rule Amendments - Response to Court Decision and Additional Rule Changes (PDF) (78 pp, 523K, July 1, 2004). The final rule amends the transportation conformity regulations to include criteria and procedures for the new 8-hour ozone and fine particulate matter (PM2.5) national ambient air quality standards (NAAQS). Specifically, the rule describes the general requirements for conducting conformity determinations for the new NAAQS, such as the conformity test(s) that apply in new standard areas. In addition, the rule includes PM2.5 as a criteria pollutant subject to transportation conformity and outlines the specific conformity requirements that would apply in PM2.5 nonattainment areas. The rule also incorporates existing guidance issued by EPA and the U.S. Department of Transportation that implements the March 2, 1999, court decision. Finally, the rule also includes a few miscellaneous revisions to clarify the existing regulation and improve implementation. Of particular interest are the streamlining of the number of triggers that require a new conformity determination and allowing transportation planners to base regional emission analyses on assumptions available at the beginning of the conformity process.
  • Federal Register Notice: Corrects two errors in the preamble to the July 1, 2004 Final Rule (PDF)(4 pp, 66 K, July 20, 2004) This notice contains the correct version of the table "What Parts of the Final Rule Apply to Me?" which replaces the table found in Section II. D. of the final rule. This notice also inserts a paragraph at the end of Section XXIII. G., "Use of Adequate and Approved Budgets", which was omitted when the final rule was published.
  • Reference Document: Detailed Summary of the July 1, 2004, Published Final Rule (PDF)(6 pp, 119 K,  EPA420-S-04-007, October 2004) The summary descriptions included in this document correspond with the individual preamble sections included in the final rule.
  • Reference Document: What Parts of the Final Rule Apply to Me? This document includes a table which lists the issues addressed in the final rule and where they are addressed in the preamble and in the regulation.
  • Fact Sheet: Transportation Conformity Final Rule: Conformity Amendments for the New 8-hour Ozone and PM2.5 National Ambient Air Quality Standards, Response to March 1999 Court Decision, and Additional Rule Changes (PDF) (EPA-420-F-04-043, 5 pp, 138K, June 2004) This document provides general information about the final rule.
  • Reference Document: Comparison Table for Provisions for Conformity under the New Ozone and PM2.5 Standards This table comparing the proposed rule to the final rule.
  • Reference Document: Boundary Scenarios for 8-hour Ozone Nonattainment Areas Previously Designated as Nonattainment or Maintenance for the 1-hour Ozone Standard (PDF) (EPA-420-F-04-007, 2 pp, 181 K, June 2004) Description of boundary scenarios for 8-hour nonattainment areas previously designated nonattainment or maintenance for the 1-hour ozone standard.
  • Federal Register Notice: Proposed Rulemaking - Transportation Conformity Rule Amendments for the New 8-hour Ozone and PM2.5 National Ambient Air Quality Standards and Miscellaneous Revisions for Existing Areas (PDF)(40 pp, 343K, November 5, 2003) 
  • Federal Register Notice: Proposed Rulemaking - Transportation Conformity Rule Amendments: Response to March 2, 1999, Court Decision and Additional Rule Changes (PDF)(25 pp, 260K, June 30, 2003)
  • Minor Correction for Transportation Conformity Rule Amendments: Response to Court Decision and Additional Rule Changes, NPRM This document corrects citations for the sections of the June 30, 2003 rulemaking preamble that describe EPA's Proposed Adequacy Process.

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