2 hours ago
Three Rivers Waterkeeper has issued a notice of intention to sue U.S. Steel for releasing oil into the Monongahela River from its Irvin Works facility near Pittsburgh.
The group claims that it has observed an oily sheen on the Monongahela River “emanating from the Irvin Plant on at least 36 occasions” since December 2021.
The sheens ranged from two to 18 miles long “and can remain on the River for days,” the group said in its notice. The group claimed that the company is violating state environmental laws.
Pennsylvania Department of Environmental Protection
“Pennsylvania’s Clean Streams Law and the accompanying regulations are clear: Discharges that create a sheen on our rivers are illegal. Full stop,” said Heather Hulton VanTassel, Three Rivers Waterkeeper’s executive director, in a statement. “Decades of research has shown that a visible sheen is a telltale sign that oil discharges are harming the aquatic ecosystem.”
In November, U.S. Steel signed a consent order with the Pennsylvania Department of Environmental Protection, agreeing to identify and fix the cause of the oil releases into the river and pay a $135,000 fine.
But the group’s legal filing states the releases continued even after the order was signed.
“The Waterkeeper most recently observed a sheen on January 9, 2026, and further documented sheen on at least 4 days in December,” the notice said.
Laina Aquiline, a DEP spokeswoman, said that the agency “has observed (either physically or via submitted video evidence) a total of three sheening events at the Irvin Works site” since the consent order was signed, which would result in a $750 fine each.
In response, U.S. Steel spokesman Andrew Fulton said in a statement that “[c]onditions on the Monongahela River are impacted by multiple environmental factors and dischargers.” He said the company monitors and samples its discharges to the river regularly, as required by its state-administered pollution discharge permit. “U.S. Steel maintains that it is in compliance with our permit requirements and the requirements of the DEP consent order.”
The Irvin Works, 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 November 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.
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.
Aquiline said the consent order requires the company “to undertake a comprehensive evaluation of the Irvin Works site to identify and ultimately eliminate the source of the sheens.”
So far, the company has installed hard booms at two of its outfalls to collect oil sheens discharged from the outfalls, Aquiline said.
In addition, according to the DEP, the company has installed a live video feed, conducts daily inspections and is required to collect samples and clean up sheens when they’re observed. The company submitted a comprehensive study of its oil releases in February to the DEP and is required to study the feasibility of installing an “oil and grease separator” at its Mon River outfalls as part of its efforts to eliminate oil sheens.
Read more from our partners, The Allegheny Front.
