Medical Advocates for Healthy Air, Latinos United for Clean Air, the Sierra Club, the National Parks Conservation Association, and the Natural Resources Defense Council filed a lawsuit October 19 in the U.S. Court of Appeals for the Ninth Circuit challenging the Environmental Protection Agency’s approval of the Ozone Nonattainment Mandate Alternative. Air quality officials in California’s San Joaquin Valley adopted the rule as an alternative to a Clean Air Act provision mandating that major stationary sources pay significant penalties in certain ozone nonattainment areas that miss attainment deadlines.