Pat Murphy//June 23, 2025//
The U.S. Environmental Protection Agency’s denial of air quality implementation plans submitted by Oklahoma and Utah in response to the Clean Air Act‘s “good neighbor” provision are subject to review in the regional circuit court of appeals rather than the D.C. Circuit, the U.S. Supreme Court has ruled in reversing a decision from the 10th Circuit.
The Clean Air Act provides that challenges to EPA actions are heard within the regional circuit when the case is “locally or regionally applicable” and in the D. C. Circuit if the disputed actions are “nationally applicable.” The CAA also contains an exception under 42 U. S. C. §7607(b)(1) for certain “locally or regionally applicable” actions “based on a determination of nationwide scope or effect,” which also must be brought in the D. C. Circuit.
In 2015, EPA revised the national ambient air quality standards for ozone, prompting states to file implementation plans detailing how they would comply with the new standards in accordance with the CAA’s “Good Neighbor” provision. In this regard, the CAA requires “state implementation plans” include “adequate” provisions” to prevent in-state emissions activity that would interfere the air quality compliance efforts of other states.
In the case before the court, Oklahoma and Utah were among the 21 states that had their SIPs denied by the EPA.
The 10th Circuit transferred to the D.C. Circuit challenges to SIP denials brought by Oklahoma and Utah.
In deciding the case, the majority applied the interpretation of §7607(b)(1) outlined in another environmental case decided the same day, EPA v. Calumet Shreveport Refining.
Click here to read the full text of the June 18 decision in Oklahoma v. EPA.
BULLET POINTS: “EPA undertakes SIP disapprovals pursuant to the same CAA authority underlying its SIP approvals. Namely, §7410 directs ‘[e]ach State’ to ‘adopt and submit [to EPA] … a plan’ for [national ambient air quality standards] implementation, and in turn directs EPA to either ‘approve such submittal’ or ‘disapprove’ it. Thus, EPA’s approvals and disapprovals are opposite sides of the same coin. As §7410’s SIP-specific focus makes clear, and §7607(b)(1)’s enumeration confirms, the CAA treats both individual SIP approvals and individual SIP disapprovals as discrete actions. Thus, we have before us two EPA actions — EPA’s disapprovals of the Oklahoma and Utah SIPs.
“These two disapprovals are undisputedly locally or regionally applicable actions. A SIP is a state-specific plan, so an EPA disapproval on its face applies only to the State that proposed the SIP. And, the CAA recognizes this limited scope in enumerating a SIP approval as a locally or regionally applicable action. §7607(b)(1). If anything, EPA’s decision on an individual SIP ‘is the prototypical “locally or regionally applicable” action,’ as courts have recognized and even EPA acknowledges.”
—Justice Clarence Thomas, opinion of the court (Justice Samuel A. Alito Jr. took no part in the decision)
“The Court holds that the proper venue for this litigation lies in an appropriate regional circuit, not in the D.C. Circuit. I agree. As I explain in today’s companion case [EPA v. Calumet Shreveport Refining], however, the Court and I arrive at that conclusion by different paths.”
— Justices Neil M. Gorsuch, joined by Chief Justice John Roberts Jr., concurring in judgment