ELR Citation: 41 ELR 20331
No(s). 10-1105 (D.C. Cir. Oct 28, 2011)

The D.C. Circuit upheld an EPA rule issued in 2010 that amends and clarifies transportation conformity regulations as they pertain to hot spot analyses in particulate matter (PM) nonattainment and maintenance areas. Transportation conformity is required under the CAA to ensure that new federally supported highway and transit projects are consistent with SIPs. Under CAA §176(c)(1)(B), the project must not: (i) cause or contribute to any new violation of any standard in any area; (ii) increase the frequency or severity of any existing violation of any standard in any area; or (iii) delay timely attainment of any standard or any required interim emission reductions or milestones in any area. The Agency's 2006 transportation conformity rule addressed the requirements set forth in §176(c)(1)(B)(i) and (ii), but it failed to consider subsection (iii). The rule was therefore remanded. In the 2010 rule that responds to that remand, EPA clarified that all three requirements under §176(c)(1)(B) must be met in hot spot conformity determinations, but petitioners argued that the 2010 rule still fails to embody (B)(iii)'s requirement that the project not cause any delay in attainment. The court disagreed. EPA's interpretation of that provision—that "delay" is evaluated relative to what would otherwise have occurred—is entirely reasonable. Accordingly, given EPA's clarification that (B)(iii) applies to local transportation projects and its explanation of how the "delay" condition is met, the court upheld the 2010 rule.