On July 17, 2018, the U.S. EPA signed a notice for the final ozone designations of the 8 counties comprising the San Antonio area. The U.S. EPA finalized a marginal nonattainment designation for San Antonio (Bexar County), which became effective on September 24, 2018 (60 days from the publication of the final designation in the federal register on July 25, 2018). The surrounding counties of San Antonio (Atascosa, Bandera, Comal, Guadalupe, Kendall, Medina, and Wilson) were designated as attainment or unclassifiable for ozone. With this action, EPA completed the initial designations for the 2015 ozone NAAQS for all areas of Texas.
On August 28, 2018, Texas filed a petition against the U.S. EPA for review by the U.S. Court of Appeals for the Fifth Circuit of the U.S. EPA's final action. “The ozone rule will force costly regulations on a number of Texas counties,” Attorney General Paxton said. “We are continually and successfully reducing ambient ozone concentrations without stifling economic or population growth, and we will continue to do so without the EPA's overreaching regulations.” Meanwhile, San Antonio is conducting an air quality study that will be complete in September 2018 to understand the causes of ozone formation in the city. “Preliminary findings of this analysis show that there is a lot we can do here in San Antonio to lower our ozone by decreasing the sources of chemicals that combine to create ozone,” said Dr. Colleen Bridger, Director of the City's Metropolitan Health District.