Clairton Coke Works. Photo courtesy of Breathe Project. Photo by Mark Dixon / Blue Lens.

U.S. Steel’s Clairton Coke Works plant won dubious honors in the PennEnvironment Research & Policy Center’s “Toxic Ten” report as the worst air polluter in Allegheny County. 

In response, U.S. Steel issued a statement:

“In 2021, U.S. Steel’s Clairton Plant continued its relentless pursuit of environmental excellence. In a year where the Clairton Plant ramped up production to meet increased coke/steel demand, the plant continued to maintain its excellent environmental performance in terms of combustion stack and fugitive compliance. Furthermore, based on 2021 data, the nearby Liberty monitor was in attainment with National Ambient Air Quality Standards (NAAQS) for all criteria pollutants.

“These achievements, as well as other environmental progress demonstrate U.S. Steel’s commitment to Environmental Stewardship. U.S. Steel values our shared environment, employees and the communities in which we operate. Safety and environmental performance remain our top priorities, now and into the future.”

More information can be found in the “2021 Mon Valley Works Clairton Plant Operations and Environmental Report.”

In collaboration with researchers from Frontier Group, the “Toxic Ten” study reveals that the 10 most severe industrial polluters in Allegheny County discharged 1.4 million pounds of harmful air pollutants in 2021. 

U.S. Steel’s Clairton Coke Works plant overtakes ATI Flat Rolled Products Holdings in Brackenridge as the county’s worst polluter. The Clairton plant is the largest manufacturer of refined coal (coke) in North America. The ranking comes as U.S. Steel recently announced it would begin closing three of the 10 remaining coke batteries at the plant. It is expected that this move will reduce emissions

Allegheny County is in the top 1% of U.S. counties for cancer risk from point-source air pollution, according to the Breathe Project. And with frequent temperature inversions overnight or in the early morning, pollutants can linger in the air, causing frequent dosing of pollutants.

Clairton Coke Works was identified as the worst polluter due to its escalated discharge of hydrogen sulfide, benzene and hydrogen cyanide, which can cause respiratory irritation particularly for residents of the Mon Valley community. 

“If our local leaders rein in the Toxic Ten, we could make significant headway in reducing unhealthy air pollution in the Pittsburgh region,” says Zachary Barber, a clean air advocate with PennEnvironment.  

Clairton Coke Works. Photo courtesy of Wikimedia Commons.

Barber says the report shows that the county’s leading 10 air polluting industries are responsible for 80% of the entire toxic air pollution measured in Allegheny County.

According to a study published in the Journal of Asthma, children in the city of Clairton have a 34% risk of developing asthma compared to the national rate of 8% and the state and county rates of 10-13%. In 2022, the Allegheny County Health Department fined the plant $1.8 million for hydrogen sulfide leaks. The plant was also fined $4.5 million for 831 emissions violations between 2020 and 2022.

“I love this great city, and it’s not acceptable that a handful of industrial polluters are making it less healthy and less attractive to businesses and new residents,” says Pennsylvania House Rep. Dan Frankel. “Under-regulation of polluters is a health issue, a workers’ issue and an economic issue.”

The top 10 air polluters in Allegheny County are: 

  1. USS – Clairton Plant, Clairton
  2. ATI Flat Rolled Products Holdings LLC, Brackenridge
  3. Thermal Transfer Corp., Duquesne
  4. PPG Industries Inc. – Springdale Complex, Springdale
  5. Universal Stainless & Alloy Products Inc., Bridgeville
  6. TMS International LLC, Braddock
  7. Holtec Manufacturing, East Pittsburgh
  8. Neville Chemical Co, Pittsburgh
  9. USS Mon Valley Works – Edgar Thomson Plant, Braddock
  10. McConway & Torley LLC, Lawrenceville

The list was compiled using industry-reported data from the U.S. Environmental Protection Agency’s Toxic Release Inventory for facilities in Allegheny County in 2021. Researchers weighed pollution releases for toxicity using the EPA’s Risk-Screening Environmental Indicators (RSEI) Hazard model.

PennEnvironment and other area groups are urging more action from the Allegheny County Health Department to take action against the heaviest polluters. One group is Allegheny County Clean Air Now, which advocates for cleaner air in areas around Neville Island. 

Neville Chemical was fined $62,000 in 2021 for a chemical leak that resulted in the release of 25,000 pounds of volatile organic compounds.

Karen Grzywinski is the president of Allegheny County Clean Air Now’s board.

“The air pollution from Neville Chemical has harmed residents in the ACCAN air shed for decades,” Grzywinski says. “The Health Department has referred to Neville Island as Allegheny County’s ‘Second Pollution Hotspot’ — second only to the Mon Valley. We have petitioned the Health Department for years to monitor and identify the toxins from Neville Chemical and other area industries so that they can be held accountable and forced to stop harming the health of our communities.”

The chemicals emitted by the Toxic Ten are linked to significant health effects. Benzene and chromium are linked to cancer. Hydrogen sulfide, which smells like rotten eggs, can impact the respiratory and nervous systems. Lead is a neurotoxicant.

“These facilities churned out a whopping 80% of all toxic air pollution reported by facilities in Allegheny County,” says Barber in a press release. “If our local leaders rein in the Toxic Ten, we could make significant headway in reducing unhealthy air pollution in the Pittsburgh region.”

“Polluting facilities in the Mon Valley are linked to our region’s poor cancer statistics as well as the many voices frequently heard in the Mon Valley about family and community disruptions to ongoing acute pollution episodes there. This situation needs to stop,” says Matthew Mehalik, Executive Director of the Breathe Project.  

“Our region’s leadership can enforce air quality standards to hold polluters accountable with required changes to their operations in order to stop ongoing pollution events. Imposing fines in a pay-to-pollute relationship with polluting companies and facilities does not serve our region well.”

Jason Phox contributed to this report.

Jason Phox

General Assignment Reporter

Jason Phox is a journalist in the Pittsburgh area sharing important information with the people of the Steel City. He enjoys writing, photography, and mostly comic books. More by Jason Phox

Ethan Woodfill

A Pittsburgh native, Ethan is a freelance journalist interested in telling the stories of people doing great things to build community and sustainability. Ethan served as Editor-in-Chief of Allegheny College's newspaper, The Campus.