The county found the company’s Clairton coke works caused hydrogen sulfide levels at the nearby air monitor to surpass standards 159 times between March 2022 and November 2023.
About 30 people attended a rally organized by local environmental groups to protest outside of a conference about metallurgical coal co-sponsored by Norfolk Southern.
When a warning is in effect, industrial facilities in the Mon Valley must limit their activities, and residents, especially vulnerable ones, are discouraged from spending time outdoors.
The federal lawsuit had asked for $42 million fine for U.S. Steel under the Clean Air Act. The fire knocked out pollution controls for more than 100 days.
