ELR Citation: 45 ELR 20051
No(s). 13-70544 (9th Cir. Mar 11, 2015)

The Ninth Circuit denied an environmental group's petition challenging EPA's approval of a revision to California's SIP. The revision provided alternative "not less stringent" controls to what is required in CAA §185's antibacksliding measures, which require that major stationary sources of pollution in severely polluted areas pay fees for their emissions. EPA approved the revision under CAA §172(e) after finding that the pollution controls it imposed were "not less stringent" than CAA §185. The environmental group challenged EPA's approval, arguing that §172(e) applies only when air quality standards are relaxed, not when they are tightened. But CAA §172(e) is ambiguous. In addition, EPA's interpretation of that ambiguity—that the CAA's antibacksliding provisions, allowing for not less stringent alternative controls, applied when air quality standards have been strengthened as well as when they have been relaxed—was reasonable. The court, therefore, denied the petition.