Ninth Circuit judges say EPA overstepped in San Joaquin Valley air plan

A three-judge panel of the Ninth Circuit concluded the EPA improperly inserted a feasibility exemption into a California air-quality plan for the San Joaquin Valley and sent the matter back to the agency.

In a split ruling, a Ninth Circuit three-judge panel found that the Environmental Protection Agency exceeded its authority by adding a feasibility exemption to a California plan aimed at improving air quality in the heavily polluted San Joaquin Valley. Writing for the majority, Judge Salvador Mendoza Jr. determined that Section 172(c)(9) of the Clean Air Act does not allow such an exemption, and the panel remanded the rule to the EPA for reconsideration.

Judge Daniel Bress dissented, asserting that the agency’s feasibility analysis was within legal bounds. The Committee for a Better Arvin argued the EPA’s contingency measures—stricter wood-burning limits, tighter dust controls, and expanded smog checks—provided only a year’s progress, falling short of the traditional “reasonable further progress” standard. The decision references the Supreme Court’s 2024 Loper Bright ruling, emphasizing that courts must interpret ambiguous statutory language rather than defer to agency preferences. The outcome highlights ongoing tension between federal regulators and state officials over the implementation of air-quality standards.