Federal regulators recently sued the operators of an East Chicago oil re-refinery plant for violating its wastewater permits by discharging excess pollutants — including cyanide, mercury, oil and grease — from its facility toward the Grand Calumet River.

In a 34-page complaint filed April 10, they also accused Wisconsin-based Safety-Kleen Systems, Inc., of repeatedly failing to notify the East Chicago Sanitary District of violations as required by law — a domino effect that caused the Sanitary District to violate its own permits.

The plant — located at 601 Riley Rd. — is the world’s largest oil re-refinery, wrote lawyers for the Department of Justice, on behalf of the EPA. The court filing detailed multiple federal Clean Water Act violations dating back to at least April 2017.

Among violations cited, EPA inspectors flagged “petroleum odors” and “oil sheens” in the river in January 2024.

A man who answered the phone at Safety-Kleen after hours on Friday said representatives were not immediately available.

The company is required to “pretreat” contaminated wastewater in its own treatment plant, before it gets discharged into the city’s municipal water system. The city sends the water to its municipal treatment plant to get partially treated before it is discharged into the Grand Cal, filings show.

“Since April 10, 2017, Safety-Kleen has violated discharge limits … on multiple occasions, including the limits for ammonia, bis (2-ethylhexyl) phthalate, copper, cyanide, fluoride, lead, mercury, n-octadecane, oil and grease, phenols, pH, and zinc,” lawyers wrote.

The government is asking a federal judge to order the company to “take all steps” to ensure compliance with the Clean Water Act — including up to a $68,000 daily fine per violation and other potential financial penalties down the road.

The EPA designated the Grand Calumet River — a 22-mile waterway from Gary to Illinois — as a highly-polluted “area of concern” in 1987.

Prior to the 1972 Clean Water Act, industries discharged waste that included toxic chemicals such as polychlorinated biphenyls or PCBs, polycyclic aromatic hydrocarbons or PAHs, mercury, cadmium, chromium and lead along with oil and grease.

The toxics killed fish and wildlife, closed beaches, and endangered environmentally sensitive areas.

Some of the toxic sediment has been dredged, including in the Indiana Harbor and Ship Canal, and other sediment has been capped.

Post-Tribune archives contributed.

mcolias@post-trib.com