EPA Must Re-Evaluate Clean Air Requirements in California’s San Joaquin Valley

The Ninth Circuit Court of Appeals ruled yesterday that the Environmental Protection Agency cannot create a loophole for state officials looking to avoid Clean Air Act requirements in highly polluted regions. The decision emphasizes that this bedrock environmental law requires states to employ meaningful “contingency measures”–or backup pollution-control rules–to reduce air pollution when Clean Air Act standards are not being met. This statutory requirement still applies even if a state argues that stronger measures are difficult to implement

Community and conservation groups filed the lawsuit to hold the EPA accountable for faithfully implementing the Clean Air Act’s requirements to reduce air pollution, especially harmful fine particulate matter (PM2.5), in the San Joaquin Valley. This region has some of the worst air quality in the United States that contributes to higher rates of asthma, heart attacks, and premature death. Committee for a Better Arvin, Medical Advocates for Healthy Air, National Parks Conservation Association, and the Sierra Club, filed the suit in 2025 and were represented by co-counsel Law Office of Brent J. Newell and Earthjustice. 

“We are grateful the court decided that the Environmental Protection Agency and California must follow the Clean Air Act as Congress intended, which is to ensure states do their part to improve air quality and protect public health,” said Colin O’Brien, a Deputy Managing Attorney with Earthjustice who argued the case.  

“This is the third time the Ninth Circuit has rejected the Environmental Protection Agency’s attempts to gut Clean Air Act rules designed by Congress to serve as a backup plan when states fail to deliver healthy air. This decision ensures that the EPA can’t invent a loophole to excuse state officials from adopting meaningful measures to improve air quality. San Joaquin Valley residents should soon enjoy the benefits of more significant pollution reductions,” said co-counsel Brent J. Newell, an attorney with the Law Office of Brent J. Newell.

“This decision is welcome news for residents of the San Joaquin Valley and nearby national parks like Yosemite, Sequoia, and Kings Canyon,” said Mark Rose, Sierra Nevada and Clean Air Senior Program Manager with National Parks Conservation Association. “For decades, these parks and communities have faced some of the nation’s most polluted air. It’s long past time for California and EPA to stop playing games with the air we breathe and get to work developing measures that will achieve actual results.”

“This decision comes at a pivotal moment when even more sources of pollution are popping up and being proposed across the Valley, further endangering the health of our communities,” said Lori Pesante, Director of Sierra Club Kern-Kaweah Chapter. “California and EPA must step up and actually enforce laws to hold polluters accountable and protect our lungs.”