Enviro groups ask court to find U.S. Steel liable for more than 12,000 Clean Air Act violations

Media Contacts
Ashleigh Deemer

Former Deputy Director, PennEnvironment

Air pollution occurred at nation’s largest coke plant, two steel mills


PITTSBURGH – U.S. Steel violated the Clean Air Act more than 12,000 times at its three Pittsburgh-area plants, including Clairton Coke Works, the largest coke oven facility in North America, according to a motion filed in federal court Thursday by PennEnvironment and Clean Air Council. The violations, which the groups say are proven by U.S. Steel’s own statements and compliance reports, occurred when the company operated Mon Valley Works for more than three months in 2018 and 2019 while required pollution control equipment was out of commission.

“The proof is in the pudding — and in this case, the pudding is U.S. Steel’s own official statements and monitoring records. These documents prove the company violated its Clean Air Act permits many thousands of times when it decided to run its plants without essential pollution controls required by its permits,” said Ashleigh Deemer, the deputy director for PennEnvironment. 

The lawsuit alleges that U.S. Steel’s Clairton Coke Works and Irvin and Edgar Thomson steel mills, all located in the Mon Valley south of Pittsburgh, showered residents with unlawful pollution, including emissions of sulfur dioxide (a respiratory irritant) at levels many times higher than permits allow, after a massive fire knocked out pollution controls for all three plants.  Published health studies have documented an increase in asthma symptoms, hospital visits and outpatient visits for asthma during the time U.S. Steel’s pollution controls were down.  

“For more than 100 consecutive days, U.S. Steel used dirty coke oven gas that wasn’t properly treated as fuel for its steelmaking operations, and burned extraordinary amounts of that dirty gas in open flares,” explained Matt Walker, Advocacy Director with Clean Air Council.  “These documented activities violated  a number of Clean Air Act requirements and released excessive amounts of harmful pollution into Mon Valley communities.”

The environmental groups’ motion seeks “summary judgment,” a ruling before trial that U.S. Steel committed more than 12,000 separate violations of numerous permit requirements that are designed to protect public health. At trial, the groups will pursue a remedy for these violations, which they say includes a court-appointed outside monitor to oversee environmental compliance and payment of a substantial civil penalty.  


PennEnvironment is a citizen-funded environmental advocacy organization working to promote clean air, clean water, and protect Pennsylvania’s great natural heritage. For more information about this and PennEnvironment’s other work, visit www.PennEnvironment.org.

Clean Air Council is a member-supported, nonprofit environmental organization dedicated to protecting everyone’s right to a healthy environment. For more information, please visit www.cleanair.org.