Takeaways from AP and Public Source's report on pollution and safety issues at Pittsburgh coke plant

On Aug. 11, 2025, an detonation astatine U.S. Steel’s Clairton Coke Works extracurricular Pittsburgh — a 392-acre riverside concern installation and the largest of its benignant successful the Western Hemisphere — killed 2 U.S. Steel workers and injured 11 others, according to the Chemical Safety Board, a national bureau investigating the incident.

Six months later, workers stay rattled and assemblage concerns astir aerial contamination from the works are heightened. The blast comes connected apical of a drawstring of different accidents astatine the Clairton works and a past of ineligible battles betwixt U.S. Steel and Allegheny County regulators. Some existent and erstwhile workers astatine Clairton Coke Works accidental mediocre absorption and underinvestment person exacerbated aerial contamination and undermined workplace information astatine the plant. And the August blast came aft Nippon Steel’s $15 cardinal acquisition of U.S. Steel successful June 2025. Nippon Steel did not supply a effect to written questions.

Pittsburgh's Public Source and The Associated Press interviewed existent and erstwhile workers astatine Clairton Coke Works, experts, erstwhile and existent authorities officials, reviewed tribunal documents and analyzed national information to nutrient this report.

Here are cardinal takeaways from the report:

What we cognize astir the explosion

Industrial ovens astatine Clairton Coke Works, which opened much than a period ago, vigor ember astatine precocious temperatures for hours to marque coke, a cardinal constituent successful steelmaking. The vigor removes impurities, producing a flammable byproduct called coke oven gas.

According to the Chemical Safety Board, the August detonation happened portion workers were closing and opening a state isolation valve successful a basement aft pumping h2o into the valve. U.S. Steel’s written process did not notation the usage of h2o and a U.S. Steel supervisor directed workers to pump the water, the bureau said. Kurt Barshick, U.S. Steel’s vice president of the Mon Valley Works, said during an October presumption to residents that workers trapped “3,000 PSI h2o wrong of a valve that’s rated for 50 PSI.” The valve cracked and state filled the area, Barshick added.

Drew Sahli, the Chemical Safety Board’s researcher successful charge, said determination was a “release of coke oven gas” and that the state “contacted an ignition source” and exploded. The bureau is inactive investigating however the state was released, Sahli said.

In a written statement, U.S. Steel stressed its committedness to information and said that it has “strengthened respective information protocols” based connected its ain ongoing investigation, including prohibiting the usage of high-pressure h2o for valve cleaning.

Before the August blast, the works already had a past of accidents and explosions, including a 2009 blast that killed a attraction idiosyncratic and different detonation successful 2010 that injured 14 employees and six contractors.

Workers question management

Some existent and erstwhile workers astatine the Clairton works responsibility U.S. Steel’s absorption of the aging Clairton Coke Works, saying that it has caused a scope of operational problems. For instance, they picture difficulties getting coke oven doors, which tin leak emissions, replaced.

Current and erstwhile workers besides constituent to a occurrence astatine the Clairton works that occurred connected Christmas Eve successful 2018. It unopen down contamination power instrumentality and led to repeated releases of aerial pollution, according to a suit filed by biology groups aft the incident. An technologist hired by the plaintiffs wrote successful a study filed successful the lawsuit that helium recovered “no indication” that U.S. Steel “has an effective, broad attraction programme for the Clairton plant.” Sahu besides wrote that the 2018 mishap “preventable by a robust inspection and preventive attraction programme and by amended works design.”

In a 2024 consent decree settling the lawsuit, U.S. Steel agreed to measures including investing adjacent to $20 cardinal successful installation upgrades. As portion of the consent decree, U.S. Steel admitted nary liability.

In its statement, U.S. Steel said that the company's “overall translation efforts person improved our company’s performance, created a robust attraction program, and improved worker information implicit time.”

Plant regularly nether occurrence for pollution

The Clairton works has been the largest section root of aerial contamination successful caller years, according to the Allegheny County Health Department. County Health Department regulators routinely clash with U.S. Steel implicit alleged violations of the plant’s operating permit, specified arsenic excessive emissions oregon failing to usage contamination power equipment. In 2023, the Allegheny County Health Department fined U.S. Steel much than $2 cardinal for violations astatine Clairton Coke Works.

In effect to questions from Public Source and AP, the Allegheny County Health Department that aerial monitoring stations adjacent the Clairton works “have measured a 15-25% simplification successful yearly mean particle contamination concentrations compared to 10 years ago.”

Nationally, Clairton Coke Works’ biology compliance way grounds is an outlier, according to a Public Source and AP investigation of national Clean Air Act information from astir 14,000 facilities. The investigation recovered that Clairton Coke Works is classified by the EPA arsenic a “high-priority violator” – lone astir 11% of large emitters autumn into that category. It’s adjacent rarer for facilities to garner fiscal penalties connected the magnitude that Clairton Coke Works has faced successful the past 5 years, the investigation shows. Just 11 facilities, including Clairton Coke Works, person faced $10 cardinal successful penalties oregon much successful the past 5 years.

U.S. Steel said successful its connection that the institution spends “$100 cardinal annually connected biology compliance astatine Clairton unsocial and has consistently achieved an biology compliance complaint exceeding 99% for regulated activities per twelvemonth astatine our Clairton Plant.”

New ownership arrives

In the astir $15 cardinal woody to bargain U.S. Steel, Nippon Steel pledged to put $14 cardinal successful home steelmaking operations. Much of that wealth remains publically uncommitted, and U.S. Steel has been steadfast that it wants to support the Clairton works operating.

“The Clairton Coke Plant is an important portion of our North American Flat-Rolled integrated operations,” the institution said successful November. The institution added that a “steady coke proviso remains critical” and that the “Clairton Coke Plant volition beryllium maintained for the adjacent procreation of steelmaking.”

However, U.S. Steel has not publically committed to spending wealth astatine the Clairton works to grow production, widen its life, amended efficiency, upgrade information oregon trim its polluting aerial emissions. Of the $14 billion, U.S. Steel has said $2.4 cardinal volition spell toward its Pittsburgh-area plants. A information of that wealth volition beryllium spent connected gathering a caller blistery portion mill to regenerate the 1 astatine its Irvin plant, conscionable down the Monongahela River from Clairton, that processes alloy into monolithic expanse rolls.

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