The fine came just weeks after the health department fined U.S. Steel nearly 2 million dollars for gas leaks at the Clairton Coke Works.
An Allegheny County study pinned hydrogen sulfide levels on the Clairton plant. The company disputes the findings.
Clairton coke works is the county’s largest single emitter of particle pollution.
The plaintiffs are asking a judge to find the company guilty of committing over 12,000 violations of the Clean Air Act, and to order US Steel to ensure the plant will never again go without air pollution controls.
A clean-air group criticized the county for limiting its own ability to regulate the company.
A report by U.S. Steel investigators found that multiple equipment failures made the fire bigger and more destructive.
The network of physicians, researchers, activists and cancer survivors says research shows rates for six types of cancer that have strong links to toxic chemicals are elevated in seven Southwestern Pennsylvania counties compared with national rates.
The Christmas Eve fire destroyed the pollution controls at the Clairton Coke Works, knocking them offline for three months.
A company spokesperson said the purpose of putting in new pollution controls is to improve the efficiency of the pollution collection system, not to increase coke production