On Thursday, the U.S. Court of Appeals for the Ninth Circuit granted a petition for review of the Environmental Protection Agency (EPA) final rule approving the State of California’s plan for meeting the ozone air quality standard in the San Joaquin Valley and remanded the plan to EPA for further consideration. EPA approved the plan in 2019, which included a single contingency measure that would be activated if the plan did not achieve reasonable further progress toward meeting the ozone standard. A local environmental group, the Association of Irritated Residents (AIR), challenged the approval and argued that the single contingency measure was arbitrary and capricious because it provided for only nominal emissions reductions.
The court agreed, finding that EPA failed to provide a reasoned explanation for approving the contingency measure. Because EPA had previously concluded that contingency measures must be tied to “reasonable further progress” in reducing emissions, the court stated that it could not now take an alternative policy position by adopting a contingency plan that would achieve only nominal reductions without providing a reasoned explanation. The court further explained that EPA impermissibly assumed that robust contingency measures were not necessary by relying on surplus emissions reductions projected to occur separate and apart from the contingency measure. As explained by the court, “the reason the [Clean Air Act] requires contingency measures is to have a backup that can be put in place immediately in case already implemented measures in a plan fail to achieve reasonable further progress.”