EPA approves Texas’ clean air plan for ozone

DALLAS - The U.S. Environmental Protection Agency recently approved the state of Texas’ plan for administering programs related to the National Ambient Air Quality Standards (NAAQS) for ozone. Texas’ state implementation plan (SIP) demonstrates that it meets the Clean Air Act infrastructure requirements for the 2015 ozone NAAQS.

“Texas understands how to run an effective air quality program,” said EPA Regional Administrator Ken McQueen. “This plan shows the state’s continued commitment to protecting communities throughout the state by meeting federal air quality requirements.”

This type of SIP is commonly referred to as an infrastructure SIP because it addresses the basic requirements of state air quality management programs, such as air quality monitoring and enforcement. By meeting EPA’s guidelines for these programs, states help protect public health through air quality management. States are required to submit a SIP within three years after a new or revised NAAQS to ensure the state meets its responsibilities under the federal Clean Air Act.

EPA approved Texas’ infrastructure SIP except for certain portions relating to interstate transport of air pollutants. The remaining parts of the plan will be addressed in future, separate actions. EPA proposed approval of the Texas state plan on April 30, 2019, and held a 30-day public comment period. The final rule was published in the Federal Register on Sept. 23, 2019.

Nationally, the concentration of ground level ozone has decreased 17% from 2000 to 2017. All other air pollutants regulated under NAAQS–carbon monoxide, lead, nitrogen dioxide, particulate matter and sulfur dioxide–have also significantly decreased thanks to the various air quality management and control strategies developed and implemented at the local, state, regional, and national level.

Ground level ozone is not emitted directly into the air but is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOCs. Breathing ozone can trigger a variety of health problems, including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema and asthma. Ground level ozone also can reduce lung function and inflame the linings of the lungs. Children are at increased risk from exposure to ozone because their lungs are still developing.