[1][2] The 392-acre facility has operated since the beginning of the 20th century[3] and is capable of producing 4.7 million tons of coke annually in its nine batteries.

[6] The broader region was the epicenter of steelmaking in the United States, largely because of the Pittsburgh seam, an extensive deposit of high-quality coal.

These more advanced ovens capture a variety of industrially useful chemicals released by the coking process, like coal tar, ammonium sulfate and benzole.

[11] By the 1920s, U.S. Steel had abandoned the use of beehive ovens on-site at mines, instead centralizing its coke production at the Clairton works.

The work stoppage was denounced by leads of the national unions, who feared that they would undo the progress they had made with President Roosevelt and others.

[13] In the 1960s, it started to be understood that the gases from the coke operation were causing lung cancer and other health problems in workers, but it had not been demonstrated clearly in scientific studies.

Since different areas of the coking operation had substantially different racial makeup, the authors believed that specific environments in the plant were causing cancer.

In 1970, new county air quality regulations meant that process water, which was too contaminated to be released into the Monogahela river even with pretreatment, could no longer be used to quench coke.

[18] The company tried to acquire a variance to violate the regulation, arguing that it was technologically impossible to comply, ceasing operations would harm the local economy, and that there was no evidence that the released gases posed a health hazard.

After 33 separate violations in October 1971 alone, the Allegheny County Air Pollution Appeals Board was convinced that U.S. Steel "will delay cleaning up the Clairton Coke Works until it is forced to take action.

"[19] In September 1972, U.S. Steel and Allegheny County entered a legal agreement (a consent decree) to come into compliance with air pollution regulations within 10 years, and to meet weaker standards in the meantime.

[21] Days later, the Environmental Protection Agency conducted a surprise inspection of Clairton Coke Works with news media.

The EPA argued that the consent decree effectively offered the company immunity from new antipollution laws for ten years.

[23] Only months later, in March 1973, the Department of Environmental Resources and Allegheny County sued U.S. Steel for 241 violations[24] of the interim standards they had agreed to.

Assistant Attorney General Marvin Fein said "U.S. Steel has violated every provision of the consent decree under which they agreed to undertake a cleanup at the coke works.

DER Secretary Maurice K. Goddard called Clairton Coke Works a "national disgrace," and "probably the worst pollution source in the country.

U.S. Steel argued that it was impossible to comply as 16 of its officials were subpoenaed to appear before a grand jury initiated by the Justice Department at the behest of the EPA.

The city shut off street lights, laid off all 14 of its police officers and its 10 fire fighters (the firefighters continued to work without pay).

A 1986 amendment to U.S. Superfund laws added "right-to-know" provisions, requiring companies to publish data on releases of toxic pollutants even if the substances are not federally regulated.