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News Story
Two large air pollution sources will soon be offline. Will Allegheny County’s air quality future be as clean as it can be?

The Clairton Coke Works in Clairton, Pa. (Pittsburgh City Paper photo)
By Ryan Deto
PITTSBURGH — The American Lung Association provides yearly air quality rankings for metro areas across the country, and every year, the Pittsburgh region receives failing grades. Though Pittsburgh shed its “smoky city” moniker decades ago, and the air quality in the region has vastly improved compared to what it once was, there is still a lot to be desired.
Pittsburgh consistently ranks as one of the worst regions for air quality in the U.S., usually matching the smoggy cities of California’s central valley.
However, recent announcements from two heavy-industry facilities in Allegheny County could play a large role in improving Pittsburgh’s air quality. In April, U.S. Steel canceled plans for $1 billion in upgrades to its Mon Valley Works facilities, which includes Edgar Thomson Works in Braddock, Irvin Plant in West Mifflin, and the Clairton Coke Works.
As part of those cancellations, U.S. Steel will be idling three of the oldest batteries at the Clairton Coke Works, a coal-processing facility that is arguably the most significant air polluter by volume in the region.
In June, the Cheswick coal-fired power plant also announced it will shut down completely in September. Zachary Barber, a clean air advocate at statewide environmental group PennEnvironment, says pollution from the Clairton Coke Works and the Cheswick Power Plant has had an outsized role in Pittsburgh’s air pollution and the health problems they cause for residents.
“For years, some of the biggest polluters have been the Clairton Coke Works. By quantity, that’s the biggest. And the Cheswick Power Plant, which in our previous report, was one of the most toxic,” Barber said, referring to PennEnvironment’s Toxic Ten Report, which ranks Allegheny County’s worst polluters. “When we get to the point when Clairton closes three of their most polluting batteries, which is a third of their pollution, that is going to be a pretty substantial reduction in pollution.”
Despite the significant air quality improvements following these closures and reductions, messages were mixed after the announcements, and there wasn’t a collective celebration.
Labor and political leaders didn’t weigh in on the air quality effects of the U.S. Steel decision, but did call out the company for canceling their planned investment and the potential job losses the decision will cause. Environmentalists applauded the air quality benefits, but are only cautiously optimistic, citing concerns about future battles over natural gas and petrochemical facilities. And the county’s health department is trying to find a middle ground.
It all leads to uncertainty of how competing factions of environmentalists, fossil-fuel labor unions, and economic forces influence Southwestern Pennsylvania moving into the future, and what that means for the air Pittsburghers breathe.

Failing grades
In April, the American Lung Association released its 2021 “State of the Air” report cards, and Allegheny County received F grades for ozone and particle pollution over a 24-hour test, and failed its annual particle pollution test.
These F grades weren’t a new development. Allegheny County has been failing the ALA air quality report cards for years.
The persistence of Allegheny County’s poor air quality is caused by a combination of industrial facilities and vehicles in the region releasing pollutants into the air, as well as the region’s proclivity for inversions, a weather phenomenon occurring when the air on the ground is quite warm, but cold air masses above it in the atmosphere trap pollutants near the surface. Inversions occur about 157 days a year on average in Allegheny County, according to the Allegheny County Health Department.
Environmentalists cite the poor air quality grades as a reason for more regulations against industrial facilities, and their advocacy appears to be working, to an extent. Actions from the county’s health department concerning air quality have been growing in frequency over the years, including more communication about poor air quality days and more fines against facilities violating air quality standards. In January, Allegheny County saw its first-ever days in compliance with all federal air quality guidelines under the National Ambient Air Quality Standards.
Regardless of what air quality ranking the Pittsburgh region receives, the recent announcements concerning the Clairton Coke Works and the Cheswick Power Plant should have a significant impact.
In June, PennEnvironment released its Toxic Ten report, which ranks the top 10 worst polluters in Allegheny County. Both the Clairton Coke Works and the Cheswick Power Plant were ranked in the top 10, with the Coke Works ranking third and Cheswick ranking seventh.
Clairton is set to idle three of its oldest coke batteries, which produce the most pollution, by 2022. And Cheswick is set to shut down completely by September.
Barber acknowledges the air quality benefits that will follow these closures and reductions, but cautions that there is still a way to go “until residents have clean air to breathe every day of the year.”
“Closing the coal plant in Rachel Carson’s hometown will make the region’s air cleaner, as will retiring the most-polluting batteries at Clairton Coke Works,” Barber said in a statement, referencing the famed Silent Spring author and environmentalist. “But we aren’t out of the smoggy haze yet. Even with the closure of these batteries, Clairton Coke Works will still likely be one of the largest and most-toxic polluters in Allegheny County.”

Economic forces
Cheswick mentioned environmental regulations as a reason for its decision to shut down, but U.S. Steel didn’t blame regulations for its decision to cancel upgrade plans. In a statement, U.S. Steel CEO David Burritt instead mentioned the company’s goal to move towards zero carbon emissions by 2050.
“In the wake of the 2020 pandemic and the increased urgency of the climate crises, we are reviewing all projects and facilities with an even greater focus on their implications for our carbon footprint,” Burritt said.
It appears to be a passive acknowledgement that coal and coal-related facilities don’t have a future in Pittsburgh or the country. Economists have noted this for some time, as the market has largely put coal out of business, especially as natural gas has emerged as an energy provider.
University of Pittsburgh economist Chris Briem said the Pittsburgh region has not been a competitive place for steel for a long time. Southwestern Pennsylvania steelmaking is reliant on coke, a coal by-product, which benefits from river transportation. For the first part of the 20th century, this helped Pittsburgh maintain a stranglehold on steel production, along with powerful political lobbying on the part of the steel industry and allies, according to Briem.
But by the 1970s, steel production gains had shifted from coke and coal-related facilities towards electric arc minimills, which don’t need coke for production. Instead, they rely on scrap metal, which can be found many places outside of coal country. Instead of Pittsburgh remaining the steel capital of the world, U.S. production of steel has largely shifted to the South, where labor unions are weaker. U.S. Steel was also slower to start investing in minimills, instead relying on legacy facilities like the Mon Valley Coke Works. Now, the company is shifting gears. In 2020, it acquired a minimill in Arkansas.
“U.S. Steel has made a lot of decisions to invest in minimills, but they wouldn’t have done it here,” Briem said.
Coal facilities have also faced an uphill battle to remain open in the region. The same day that Cheswick announced it was closing, a coal mine in Greene County announced it was shutting down. Both facilities had seen declines in production before announcing the respective closures. Cheswick’s production decline actually helped lower its ranking on PennEnvironment’s Toxic Ten report. It was No. 1 in the previous report, which used 2016 data.
Briem says the loss of Cheswick shouldn’t have an impact on the region’s electricity supply, since the region is already a net exporter of electricity. In both the U.S. Steel and Cheswick decisions, Briem said they failed to compete in a changing market.
“Market forces have really cleaned the air,” Briem said.
This leaves the region’s biggest polluters as smaller, more specialized facilities, such as the ATI Flat Rolled Products Holdings in Brackenridge, which ranked first on the most recent Toxic Ten report.
Luckily for air quality advocates, there are positive signs in regulating those facilities without the loss of production that leads to job losses, like the ones that will occur when Cheswick shuts down and Clairton idles its batteries.
The McConway & Torley Foundry in Lawrenceville was previously ranked in the top 10 for the most polluting facilities in Allegheny County.
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