City firefighters deployed these three containment booms in the Susquehanna River after an undetermined amount of an oily substance from Eureka Resources polluted the water at the Hepburn Street pump station, according to investigators. PHILIP HOLMES/Sun-Gazette

A major hazardous material cleanup operation was underway Monday at the former Eureka Resources facility on Second Street after upwards of 10,000 to 15,000 gallons of an oily substance leaked from a storage tank inside the building, according to Williamsport Fire Chief Sam Aungst.

The substance leaked out of the building and into storm drains of Williamsport Sanitary Authority before entering the Susquehanna River at the pump station at the foot of Hepburn Street, Aungst said. The substance came from a tank that holds upwards 26,000 gallons of the oily substance, he said.

It was unclear how much of the substance actually entered the storm drains or the river, he added. City firefighters were called to the pump station about 10:45 p.m. Sunday after a fisherman notified authorities that there was evidence of pollutants in the water. Aungst said it was his understanding that Eureka pulled out of the facility 419 Second St. sometime last year. It was unknown how many storage tanks are still on site, and it was unclear what exactly were in the tanks, he said.

Beside the fire department, a member of the state Department of Environmental Protection (DEP) emergency response team as well as the Williamsport Sanitary Authority and the county’s director of public safety responded to the pump station.

“We got notified of a discharge into the river just before midnight. The Hepburn Street pump station was immediately turned off to prevent further discharge into the West Branch of the river,” Michael D. Miller , executive director of both the Williamsport Sanitary Authority and Williamsport Municipal Water Authority, said.

A vacuum truck from Eagle Hazmat Response arrives Monday morning at the former Eureka Resources facility to assist with the cleanup of an extensive spill of "reclaimed oil." PHILIP HOLMES/Sun-Gazette

“An investigation by the authority and DEP staff determined that the discharge was coming from the Eureka Resources facility” on Second Street, just west of Hepburn Street, he said. The substance, which the authority termed “reclaimed oil,” leaked “from a door and was flowing across the Eureka property to a stormwater inlet which discharges into the stormwater system at Second Street,” Miller explained.

In addition to shutting off the pump station, “the gates to the river at the pump station were also closed so no more of the oily substance could enter the river,” he added. “Steps were immediately taken to isolate the spill and prevent further discharge into the stormwater system,” Miller said, adding that a giant plug was put in place at the inlet at the Eureka property.

The sanitary authority has contracted with Eagle Response Services of Milesburg to flush and clean all the remaining oily residue from the stormwater system, Miller said, calling it “a significant” cleanup operation.

Aungst said the county has also contracted with Eagle to clean up the former Eureka plant site, which he expected to be completed by mid-week. The city’s Bureau of Codes is also conducting an investigation.

DEP as well as the Pennsylvania Fish and Boat Commission are leading the investigation into the cause of the tank leak, which left an oily sheen that extended at least a mile in the river.