Private drinking water wells at some homes near an old tannery dump site are polluted with fluorinated chemicals, Kent County health officials said Wednesday.

Wolverine Worldwide, a Rockford footwear manufacturer, dumped sludge from tanning pigskin on the 76-acre plot before the 1970s. Nearly 50 years later, a citizen group in Rockford alerted officials about problems with the water.

"They didn't foresee a groundwater issue at the time," said David O'Donnell, the field operations supervisor for the Michigan Department of Environmental Quality's Grand Rapids District (MDEQ).

Wolverine worked with MDEQ to test the water and found the presence of per/polyfluoroalkyl substances, called PFAS, in 21 residences. Seven of those tests were above the EPA's advisory requirements.

"Theres an advisory level set for that at 70 parts per trillion," O'Donnell said. "That's trillion with a T -- very small quantities."

This is like finding the needle in the hay field, and the effects are largely unknown, said Steve Kelso, communications manager for the Kent County Health Department.

""We see some things with thyroid," Kelso said. "We know that it does bioaccumulate, which means you don't flush it out. It just keeps building and building in your system."

The chemicals are everywhere, often found in products like cosmetics and Teflon, O'Donnell said.

Part of a Wolverine Worldwide statement released Wednesday:

"The Company developed and submitted to the Department of Environmental Quality a proposed plan to voluntarily sample this site...In addition, Wolverine has taken the initiative to assist homeowners in the House Street area by providing bottled water and water filtration systems certified for these substances."

Wolverine and officials are planning to test more homes and told people in homes that were already tested to only drink and brush their teeth with bottled water.

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