Clean Wisconsin and Sierra Club filed motions to intervene and for summary disposition on Thursday in a case at the U.S. Court of Appeals for the Seventh Circuit to defend a pollution cleanup rule designed to protect families from dangerous ozone, also known as smog. This rule is especially critical for people in southeastern Wisconsin, who repeatedly breathe air with unsafe levels of ozone.
“This is about protecting families along the lakeshore—in places like Kenosha, Milwaukee and Sheboygan—who are being harmed by the air they breathe. Ozone damages our lungs, triggers asthma attacks, increases hospital visits, and contributes to premature death,” says Clean Wisconsin Energy and Air Manager, Dr. Ciaran Gallagher. “We know stronger pollution controls are necessary to protect public health. That’s what this pollution rule calls for, and it’s what Wisconsin families deserve.”
When ozone pollution in an area reaches unsafe levels, the Environmental Protection Agency (EPA) designates that area as being in “nonattainment” for ozone under the Clean Air Act. Nonattainment areas are then classified as Marginal, Moderate, Serious, Severe, or Extreme. In much of southeastern Wisconsin, ozone pollution has worsened over the last decade, triggering an automatic reclassification from Moderate to Serious. The reclassification means polluters in those areas, like fossil fuel-burning power plants, are required to implement stronger pollution controls.
Yet in early 2025, the Department of Natural Resources asked the court to block the EPA’s action reclassifying those areas. Then this July, the EPA abruptly abandoned its defense of its own Reclassification Action.
“We shouldn’t have to negotiate for clean air,” says Elizabeth Ward, Sierra Club Wisconsin Chapter Director. “The state is looking to avoid its compliance obligations under the Clean Air Act, putting the health and safety of Wisconsinites at risk. Southeastern Wisconsinites already struggle with some of the worst smog pollution in the country. Our state officials should be doing everything they can to keep residents safe and healthy, not put them at greater risk for more asthma attacks, hospital visits, and higher medical costs.”
The public health consequences of these actions by the State of Wisconsin and EPA are real: smog pollution above the national standard contributes to an estimated 2 to 4 excess deaths every year in Wisconsin and between $88 million and $112 million in annual health harms.
The graph below shows the worsening severity of ozone pollution for communities in southeastern Wisconsin compared with the federal ozone standard (red line).
About Clean Wisconsin
Founded in 1970, Clean Wisconsin is the state’s oldest and largest environmental group. On behalf of its more than 20,000 members and supporters, Clean Wisconsin works to combat climate change and pollution in our air, water and land to ensure a healthy future for every Wisconsin community. For more information, visit cleanwisconsin.org.
About the Sierra Club
The Sierra Club is America’s largest and most influential grassroots environmental organization, with millions of members and supporters. In addition to protecting every person’s right to get outdoors and access the healing power of nature, the Sierra Club works to promote clean energy, safeguard the health of our communities, protect wildlife, and preserve our remaining wild places through grassroots activism, public education, lobbying, and legal action. For more information, visit sierraclub.org.
