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

Today we (EPA) are amending the transportation conformity rule to finalize several provisions that were proposed last year. First, today's final rule includes criteria and procedures for the new 8-hour ozone and fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS or "standards"). Transportation conformity is required under Clean Air Act section 176(c) to ensure that federally supported highway and transit project activities are consistent with ("conform to") the purpose of a state air quality implementation plan (SIP). We are conducting this rulemaking in part to revise the conformity regulation in the context of EPA's broader strategies for implementing the new ozone and PM<INF>2.5</INF> standards. The final rule also addresses a March 2, 1999 ruling by the U.S. Court of Appeals for the District of Columbia Circuit (Environmental Defense Fund v. EPA, et al., 167 F. 3d 641, D.C. Cir. 1999). This final rule incorporates into the transportation conformity rule the EPA and Department of Transportation (DOT) guidance that has been used in place of certain regulatory provisions of the rule since the court decision. DOT is EPA's federal partner in implementing the transportation conformity regulation. We have consulted with DOT on the development of this rulemaking, and DOT concurs with this final rule. EPA notes that a supplemental notice of proposed rulemaking will be published in the near future to request additional comment on options related to PM<INF>2.5</INF> and PM<INF>10</INF> hot-spot requirements. EPA is also not finalizing at this time any requirements for addressing PM<INF>2.5</INF> precursors in transportation conformity determinations for PM<INF>2.5</INF> nonattainment and maintenance areas. EPA is considering the transportation conformity rule's PM<INF>2.5</INF> precursor requirements in the context of EPA's broader PM<INF>2.5</INF> implementation strategy. All of these issues will be addressed in a separate final rule