U.S. Steel has agreed to pay a $135,000 fine in a settlement with the Pennsylvania Department of Environmental Protection for pollution into the Monongahela River from its Irvin Works facility near Pittsburgh.
The plant in West Mifflin is a steel finishing plant that rolls and treats steel slabs produced at the company’s Edgar Thomson Plant in nearby Braddock. According to the settlement, the plant “stores and utilizes substantial amounts of lubricating oils and greases” on-site and has been releasing oil from wastewater pipes into the river over the past few years.
The wastewater pipes are permitted to release treated plant wastewater and stormwater from the site.
The DEP first observed an oil-like sheen in 2022 after receiving a complaint. It determined the plant was releasing “wastewater contaminated with oil” to the river. In 2023, DEP issued a notice of violation to U.S. Steel, mandating the plant put “hard booms” around its discharge pipes to prevent contamination from reaching the river.
In total, the DEP determined the plant released oil-contaminated water on nine separate occasions, from August 2022 through April 2025. Once, according to the settlement, the DEP observed that the sheen traveled as far as 1.5 miles downriver.
In 2023, the company reported to the agency that some of the spills could have been linked to an equipment failure.
As part of the settlement, U.S. Steel agreed to find out where the oil is coming from and fix the problem. The company will also install cameras to monitor its discharge into the river. The settlement also sets a maximum $7,500-per-day fine for subsequent infractions.
“This agreement ensures that U.S. Steel takes concrete, enforceable steps to prevent further pollution of the Monongahela River,” said DEP Secretary Jessica Shirley in a statement.
Heather Hulton VanTassel, executive director of Three Rivers Waterkeeper, a local water pollution watchdog, says her group first started hearing about the releases from residents.
“Community members who live just downstream from this area – they have docks on the water – and that is where we first started hearing about the issues,” VanTassel said. “They can’t fish, they would have grandchildren over and aren’t able to let them actually enjoy the Mon River.”
VanTassel said the oily sheen hurts aquatic wildlife, like insects, birds and fish. It also affects downstream drinking water treatment plants, which must clean the water to ensure it meets federal drinking water standards.
On top of that, the oily slicks affect how people in the region view the rivers.
“When we’re talking about oil on our rivers and reducing the ability to recreate, it also really drastically impacts people’s perspectives of our rivers,” she said. “If we always believe that our rivers are polluted, then we’re going to have a hard time fighting for clean water if we accept that as the status quo.”
VanTassel hopes the settlement means the company will finally keep the discharge out of the river.
“These are old facilities, they need maintenance,” she said. “They need constant care and attention. Without doing that, these are the types of things that will just go on and get worse.
In a statement, U.S. Steel spokesman Andrew Fulton said the company is “dedicated to the actions contained within” the agreement. “These actions include the installation of live video feeds, daily and weekly inspections, and a comprehensive facility review to further map areas where lubricants are used. U. S. Steel remains committed to environmental excellence and to ensuring compliance with applicable laws and regulations.”
