LA CROSSE, Wis. (AP) — Health officials in a west-central Wisconsin county are finding increased levels of nitrates in private wells.
The La Crosse County Health Department told 2,000 households last month their private wells may be contaminated, Wisconsin Public Radio reported. Contaminated wells have been found in Onalaska, Holland and Holmen.
More than 450 wells have since been tested for nitrates, and 29 percent show levels over the permissible 10 parts per million.
Carol Drury is the environmental health and lab manager at the health department. She said most of the 130 wells that tested positive were between 10 and 14 parts per million, but some were over 20 parts per million.
“When you think one out of three people have dangerously high levels of nitrates in their drinking water, that is of great concern,” said Monica Kruse, a County Board member.
Kruse said the county began worrying about possible contamination after a state audit last year found issues with the Wisconsin Department of Natural Resources’ regulation of a concentrated animal feeding operation in the area.
“We didn’t realize that that was going on and that La Crosse County was affected,” Kruse said.
She said determining the direct cause of the contamination isn’t easy.
“It’s hard to really pin all the blame on some of the more obvious entities that could be causing some of this pollution,” Kruse said. “Farmers are dumping raw manure on their fields in that area. There are a lot of residential areas that are probably fertilizing their lawns, putting product on their lawns that are leeching into the groundwater.”
A department spokesman declined the newspaper’s request for comment, but said it’s is working with the county on the issue.