The Ninth Circuit Court of Appeals ruled on August 5, 2026, regarding the United States Environmental Protection Agency's (EPA) air quality measures for California's San Joaquin Valley. The court determined that the EPA exceeded its authority by including a feasibility exemption in its contingency measures for air quality improvement. This decision affects environmental groups and residents in the San Joaquin Valley, an area known for its poor air quality.
The case, known as Committee for a Better Arvin v. United States Environmental Protection Agency (docket number 24-7270), involved multiple nonprofit organizations, including the Committee for a Better Arvin, Medical Advocates for Healthy Air, the National Parks Conservation Association, and the Sierra Club. These groups challenged a final rule issued by the EPA that approved state implementation plans (SIPs) designed to meet air quality standards in the Valley. They argued that the contingency measures proposed were inadequate and did not meet the necessary standards set by the Clean Air Act.
The Clean Air Act, enacted in 1963, aims to improve air quality across the United States. It allows the EPA to set national ambient air quality standards (NAAQS) and requires states to develop SIPs to meet these standards. Areas that do not meet the NAAQS are designated as “nonattainment” regions, and states must include contingency measures in their SIPs to address any shortfalls in progress towards meeting air quality standards. Section 172(c)(9) of the Act specifically mandates that these contingency measures be “specific” and take effect automatically if the area fails to make reasonable further progress.
The petitioners contended that the contingency measures approved by the EPA fell short of what was necessary to improve air quality in the San Joaquin Valley. They argued that the EPA's approval of a feasibility exemption effectively weakened the requirements of Section 172(c)(9), allowing for less stringent measures to be adopted. The EPA had previously allowed states to provide feasibility analyses to justify their proposed contingency measures, which the petitioners claimed contradicted the intent of the Clean Air Act.
The Ninth Circuit's ruling, delivered by Judge Salvador Mendoza, Jr., found that the EPA had indeed exceeded its authority by introducing a feasibility exemption into Section 172(c)(9). The court stated, "The EPA erred by plucking a feasibility exemption out of thin air and reading it into Section 172(c)(9) when the language of the provision does not provide for one." The court emphasized that the Clean Air Act's language is clear and does not allow for such exemptions. It further stated that allowing a feasibility exemption undermines the purpose of the Act, which is to ensure that states take effective measures to improve air quality.
The court decided to remand the case without vacatur, meaning that the EPA's previous approval of the contingency measures would remain in effect while the agency reconsiders its decision. The ruling acknowledged the potential disruption that could occur if the Valley were to lack contingency measures during this reconsideration period. The court noted, "Given the potential disruptive consequences of the Valley lacking contingency measures while the EPA reconsiders the rule, we find that remand without vacatur was the appropriate remedy." This decision allows the EPA to continue its work while ensuring that the air quality measures are adequately reviewed.
The impact of this ruling is significant for the San Joaquin Valley, which has struggled with some of the worst air quality in the United States. The court's decision reinforces the importance of strict adherence to the Clean Air Act's requirements and may lead to more rigorous air quality measures in the future. Environmental groups and residents in the Valley are hopeful that this ruling will lead to stronger actions to combat air pollution and protect public health.
Looking ahead, the EPA may appeal the ruling or seek to modify its approach to developing contingency measures. The court's decision may also influence other cases related to air quality standards and environmental regulations across the country. As the situation develops, stakeholders will be watching closely to see how the EPA responds to this significant ruling and what it means for air quality efforts in California and beyond.