Amid growing concern about the safety of groundwater near an old Wolverine Worldwide dumpsite in Plainfield Township, there are differing ideas over what level of contamination should be of concern.

“I am saying any detection in the groundwater, in a person’s groundwater well for drinking, I would recommend at this time not to use it for drinking or cooking,’’ said Christina Bush, a toxicologist with the Michigan Department of Health and Human Services.

The federal government, however, is more forgiving. Its health advisory level is set at 70 parts per trillion and does not make a distinction between private wells and municipal water.

It all has to do with a chemical once used in Scotchgard to waterproof shoes and boots made by Rockford-based Wolverine. It showed up in well water around Wolverine's old dump site on House Street NE.

The fluorinated organic chemical is part of a larger group of chemicals referred to as perfluoroalkyl substances, or PFAS.

Even though the EPA says levels below 70 parts per trillion are acceptable, Bush says when it comes to well water, “we are not relying on that number.’’

“We are relying on whether there is a presence to make our recommendation,’’ she said. “For this investigation, until we know better, we want to recommend, to be safe, not to use the water if there is something present - any presence.’’

Bush makes the distinction for well water, especially well water near known dump sites. Municipal supplies that test positive for low levels of PFAS are less of a concern, she said.

On Wednesday, Rockford Public Schools announced that well water at three of its elementary schools tested positive for trace amounts of PFAS. Levels at Cannonsburg, Crestwood and Lakes elementary schools in Cannon Township ranged from 0.891 to 1.25 parts per trillion – well below the EPA advisory level.

"I consider it to be statistically insignificant,'' Rockford Superintendent Dr. Michael Shibler said. "I still have a concern only because of the fact that it's there. But in trying to put it in perspective, everybody somewhere along the line has some of that in their body.’’

He says he will have water tested at the three elementary schools and at East Rockford Middle School each May. The four Cannon Township schools draw water from wells.

Steve Kelso, a spokesman for the Kent County Health Department, said there are no known dump sites near the three elementary schools.

Plainfield Township is in the process of bringing municipal water to homes near the mothballed Wolverine dumpsite. The initial cost is expected to be about $4 million.

“We’re willing to hook up whoever needs clean, fresh water,’’ township Superintendent Cameron Van Wyngarden said. “At this point, until we receive results on the well testing, we don’t know exactly how many homes that will be.’’

The township’s municipal water, which serves about 35,000 customers, has consistently tested positive for low levels of PFAS, Plainfield Township Public Works Director Rick Solle said. Recent tests showed levels at 8.1 parts per trillion, he said.

“A municipal system is going to be much easier to control as far as blending of water or putting in other types of controls,’’ Bush said. “I am concerned about the chemicals showing up in people’s private wells from dumps that they’ve had no control over and no understanding of.’’

The Michigan Department of Environmental Quality has not returned numerous phone calls and emails seeking comment.

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