New results from a study on the contamination of private wells in Kewaunee County leaves stakeholders hopeful for stronger rules to protect drinking water.
They also include an estimate of how many people are getting sick from their well water, a result that activists such as Amber Meyer Smith, of Clean Wisconsin, said should help people “realize the magnitude of the problem.”
The study, done in collaboration with UW-Oshkosh and the USGS Wisconsin Water Science Center, centered on the dairy-farm intensive northeastern county, where residents have long been raising concerns over groundwater pollution. Its results were presented last night in Luxemburg.
Among the new findings are an estimate that 140 people and 1,700 cattle are getting sick from private wells contaminated with cryptosporidium in Kewaunee County every year.
“Are people getting sick? Yes they are,” said Mark Borchardt, a microbiologist with the U.S. Department of Agriculture and one of the researchers who participated in the DNR-funded study.
He said those who get infected would experience severe diarrhea, and it could be fatal to people with already weak immune systems.
In order to calculate those numbers, Borchardt said he performed a risk assessment, taking the number of wells contaminated with cryptosporidium, and then determining the contamination rate and the number of people exposed to those wells, before ultimately calculating the total number of infections per year.
Overall, Borchardt said it was “really surprising” to see cryptosporidium in the groundwater to begin with.
He said prior to the study’s release, there had been a debate across the county over whether manure or septic systems were behind the well pollution.
While one of the team’s research objectives was to solve that debate, Borchardt said they were “amazed” by the results.
They show that the source of well contamination changes depending on the season; in the spring and fall, private wells were largely contaminated with manure, but at other times, the contamination came from humans.
That’s because during a groundwater recharge, a time when groundwater levels rise due to rain or melting snow, for example, water from the surface carries manure downward. But in the summer, Borchardt said, much of the well contamination comes from septic systems, as the groundwater levels fall.
In all, researchers tested 131 wells over five sampling periods ranging from April 2016 to March 2017, and found that 40 of them had evidence of bovine manure, 29 had evidence of human wastewater and seven wells registered both.
While faulty septic systems have been a source of blame in the well contamination debate, Davina Bonness, who heads the Kewaunee County Land & Water Conservation Department, said the county’s zoning department has been working to update the septic systems countywide. As of March, she said 80 percent of the county’s approximately 4,800 systems were in compliance.
Rep. Joel Kitchens, R-Sturgeon Bay, whose district includes Kewaunee County, called the results showing the presence of human waste in contaminated wells “a little bit eye opening.”
“There is a lot more contamination from bad septic systems than people previously thought,” he said.
Still, Clean Wisconsin’s Smith cautioned against losing sight of “the main part of the problem that is really making people sick,” manure.
On that front, Don Niles, a dairy farmer in Kewaunee County who leads a nonprofit group called Peninsula Pride Farms that’s working to lessen the impact of manure on both groundwater and surface water, said Borchardt’s research would help inform what initiatives the group will undertake.
“As farmers, it’s our job to control what we can control, which is farming practices,” Niles said.
He pointed to a few key findings, including the recharge times, that could help give the group direction to keep water safe while fostering a strong agricultural community in the county.
Niles said farmers largely applied manure when there weren’t crops growing, in the fall and spring. But he said the group was looking at and experimenting with new techniques, including one to apply liquid manure to growing crops that could help reduce the contamination.