The Clean Air Act (CAA) requires each state to prepare and regularly update its State Implementation Plan (SIP). The SIP describes how the state will attain and maintain compliance with CAA requirements. States must submit their SIP updates to EPA for approval. The CAA allows those affected by EPA’s approval or disapproval of a SIP to appeal.

DC Circuit or Appropriate Regional Circuit
The CAA has a somewhat unusual venue provision for appeals of EPA actions. When the EPA action is “nationally applicable,” the District of Columbia Circuit Court hears the appeal. The appropriate regional circuit court hears the appeal when the action is “locally or regionally applicable.”

Disapproval of a Group of SIPs
EPA recently disapproved SIPs from several states as a group, using what EPA claims is a consistent methodology. EPA asserts that these SIP disapprovals are a single national action that must be challenged only in the D.C. Circuit. A recent decision by the 10th Circuit agreed with EPA and transferred the case to the DC Circuit.

Several other circuit courts considering the same issue have disagreed, holding that SIPs are quintessentially “locally or regionally applicable” actions because they are state-specific in nature, regardless of how EPA packages or how allegedly consistent EPA acts in evaluating those SIPs.

US Supreme Court Will Clarify
On October 21, the US Supreme Court agreed to hear appeals of cases from the 10th and 5th Circuits that considered the same issue but arrived at different conclusions. In addition to resolving the split between the circuit courts on the specific issue, the Supreme Court’s decision will probably provide guidance as to what EPA actions courts should view as “nationally applicable.”