The former Westinghouse building in Sharon.

SHARON – Testing at the former Westinghouse Electric Corp. electrical transformer plant in Sharon has discovered the presence of the chemical polychlorinated biphenyls, PCBs, in the soil on an open section of land.

The contaminants are leaching into the nearby Shenango River, the U.S. Environmental Protection Agency said.

In the report, known as an “explanation of significant differences,’’ the EPA said, “…additional soil sampling conducted in 2019 in an unpaved area identified concentration of PCBs in surface soil at unacceptable risk-based levels.’’

Property of the sprawling plant was found to have PCBs in its soil and was placed on the federal Superfund site. It was removed from the Superfund list in 1999 after a cleanup but continues to undergo constant monitoring.

It isn’t unusual to discover hazardous materials seeping from a former Superfund site that requires additional cleaning measures, said Aaron Mroz, an EPA remedial project manager overseeing the Sharon site.

“It’s actually quite common,’’ Mroz said.

Recent tests of fish in the Shenango River near the site showed increased levels of PCBs.

“The most recent test found PCB levels in fish were going up, not down,’’ Mroz said. “We needed additional investigation in place to find out what was going on. We want to know why those levels have gone up.’’

The state Department of Environmental Protection issued a “do not eat’’ advisory in 2017 for any fish caught in the river.

Mroz said the findings don’t show imminent danger to humans.

PCBs were used in transformer coolant oil until use of the chemical was banned in 1979 in the United States.

The site with PCBs is along the south side of Clark Street in Sharon and covers less than an acre.

That section of the 58-acre complex wasn’t included in the initial environmental cleanup. Mitigation options could involve excavating to remove contaminated soil and place it in a licensed landfill or capping the site to prevent further leaching, the report said.

Testing hasn’t revealed any other new PCB sites in the complex, Mroz said. The mitigation project won’t interrupt operations at any businesses in the plant area.

Aqua Pennsylvania, which supplies drinking water to much of the Shenango Valley, takes in water from the Shenango River for its Sharon water plant roughly a half mile from the former Westinghouse site. Jim Willard, Aqua’s area manager, said all of the treated water is safe.

“We continually test our water, and in every test we have never found any detectible PCBs,’’ Willard said.

Several years ago the EPA had talked about dredging a portion of the river to remove PCBs, he said.

“We talked to them about coordinating that with them,’’ Willard said.

But when the agency found the new contaminated area, they canceled the dredging project, he said. While Aqua isn’t involved with the cleanup, Willard said EPA and DEP have always been good in informing the company about any projects involving the Shenango River. 

While not offering a specific cleanup schedule, Mroz said it won’t be prolonged.

“It will certainly be taken care of in a timely basis,’’ he said. “I don’t think it will take years.’’

All future studies and remedies for the site will need EPA approval. The cleanup will also involve DEP.

Mroz said, paying for the work fall upon the three past and current owners:

• ViacomCBS. – The successor company after CBS Corp. merged with Westinghouse in 1995.

• AK Steel Corp. – A steel company that operated Sawhill Tube in part of the complex. Sawhill was sold, then closed. 

• Winner Development LLC – The Sharon-based company that is now developing the site.

Mroz said there is an agreement among the three companies that lays out who pays for environmental cleanups, but he didn’t know the details.

Sharon-based Winner Development owns dormant sections of the factory and office building. The company has given a master lease to Valley Shenango Economic Development Corp., a nonprofit company with its own board of directors.

Winner Development is developing the former Westinghouse office for multi-purpose commercial and retail uses, including artisans and crafts people.

Jack Campbell, vice president of Winner Development, said he didn’t know the exact structure of the agreement with the other two companies.

“From our standpoint, most of the liability lies with CBS,’’ Campbell said.

The former Westinghouse plant is a major asset for attracting business to Mercer County, said Randy Seitz, CEO of Penn-Northwest Development Corp. which is the county’s lead economic development agency.

“These two properties are the tools we need to attract new and expanding industries,’’ Seitz said. “We have to pay attention to that. These properties offer us a distinct advantage because there are not many of these in the eight-county area around us.’’