WILLIAMS BAY — Four Walworth County wastewater treatment facilities have received letters from the Wisconsin Department of Natural Resources asking for assistance in tracking a potentially dangerous industrial chemical that may be reaching their treatment facilities.

Two of the facilities are the Lake Geneva municipal utility and Walworth County Metropolitan, which serves several other communities, including Williams Bay.

The other two are in East Troy and Whitewater.

The DNR does not know whether local water contains the pollutant, but it is trying to locate any potential sources.

The toxic chemicals created concern when large concentrations were found in the land and groundwater near a company that makes fire extinguishers in Marinette County.

According to the DNR, concentrations of the chemicals in the drinking water for nearby communities pose no health risks.

The chemicals are a group of man-made compounds that were widely used in industrial and consumer products starting in the 1940s.

The compounds are known by the names of perfluoroalkyl and polyfluoroalkyl, while the specific complex chemicals the DNR is seeking are named perfluorooctanesulfonic acid and perfluorooctanoic acid.

The chemicals are commonly known by the abbreviated term PFAS.

Common products containing these compounds include nonstick coatings, paper and packaging materials, certain firefighting foams, and metal plating materials.

High levels of the chemicals in the water can cause thyroid disease, high blood pressure and low birth weight in infants, said Dr. Sarah Yang of the Wisconsin Department of Health Services.

Yang said health services is working with the DNR to track down possible sources of the chemical.

She said the chemicals are persistent and do not break down in nature. Even though use of the chemical has declined over the years, residue from as long as 70 years ago remains in the soil and sometimes in the linings of storage facilities.

It also accumulates in human beings, Yang said.

“It is correct that WalCoMet was one of approximately 126 wastewater treatment plants that received correspondence from the Department of Natural Resources,” said Neal Kolb, administrator of the Walworth County Metropolitan agency.

In addition to Williams Bay, members of WalCoMet include the city of Elkhorn, city of Delavan, village of Darien, town of Darien, the Delavan Lake Sanitary District, Walworth County institutions, the Veolia ES Mallard Ridge Landfill, Inspiration Ministries, Geneva National and the Lake Como Sanitary District.

Kolb said the WalCoMet board of directors has not decided whether to commit to testing for the chemicals.

“We are in the process of evaluating the request,” Kolb said. “We will continue to work with the department on a long-term response to this issue.”

WalCoMet serves six communities and five special districts with a population of more than 28,000 that cover 16 square miles.

Josh Gajewski, utilities director for the Lake Geneva Utility Commission, which oversees the city’s water and wastewater operations, has not decided, either, whether the participate in the DNR’s testing program.

He said the DNR is generally aware of where the compounds might come from.

The Lake Geneva utility has two customers who do industrial pretreatment of wastewater and who have DNR permits. The DNR might consider those potential sources.

Gajewski said that should the utility department agree to do testing, those tests would be at the pretreatment sites and also at the city treatment plant.

However, neither the U.S. Environmental Protection Agency nor the DNR have an approved testing method for the chemicals.

No health effect limits have been established, either, Gajewski said.

At this point, neither Lake Geneva nor WalCoMet test for the chemical and have no idea how much, if any, is present in the local water.

Adrian Stocks, DNR water quality program director, said industry and the EPA agreed to limit use of PFAS chemicals in 2002, which cut back on manufacture and importation of products that use the chemical.

But the chemical is still used in some manufacturing and some imported goods contain it. And some companies still have inventories of the chemical as well, Stocks said.

The EPA has not ignored the chemical, but the agency is relying on the states to take the lead in controlling PFAS, Stocks said.

The state DNR wants to work with companies still using the chemicals to replace them with alternative substances that are not as persistent or dangerous.

Possible sources of the chemicals as: plating and metal finishers; paper and packaging manufacturers; tanneries and leather, fabric and carpet treaters; and makers or users of Teflon-type chemicals.

Places where the persistent chemical may have accumulated include dairy processing plants and cheesemakers where milk comes from livestock grazing on fields that have received PFAS-contaminated fertilizers.

Time-tested treatments exist to take the PFAS chemicals out of the water.

“This isn’t some sort of experimental process,” Stocks said. “It’s a common treatment process.”

But the larger the flow of water, the higher the cost of the treatment.

The DNR would prefer to remove the contaminants from the water at a pretreatment facility near the source, where the costs would be lower, Stocks said.

Chris Schultz has been a reporter for more than 40 years. He has been with the Lake Geneva Regional since 2010. He covers the Lake Geneva City Council and the Lake Geneva area schools.