ELR Citation: 55 ELR 20059
No(s). 17-60088 (5th Cir. May 16, 2025)

The Fifth Circuit agreed to rehear a petition for review that it previously denied concerning EPA's designation of two counties in Texas as nonattainment for the 2010 sulfur dioxide NAAQS. The state of Texas and a power plant operator argued EPA violated the CAA by ignoring monitoring data that purportedly showed the two counties in attainment, that the Agency unlawfully treated similarly situated counties in other states differently from the two counties, and that it misconceived the law in issuing the designation and denying petitions for reconsideration because EPA erroneously believed it did not have authority to delay classification until the state gathered monitoring data. The court found EPA's failure to reconcile inconsistencies between predictions of the model on which it based its designation and monitoring data that showed actual sulfur dioxide concentrations below NAAQS created an unexplained inconsistency, and that it could not "excuse the Agency's reliance upon a methodology that generate[d] apparently arbitrary results." It remanded for further proceedings.