Study: Most private wells in rural SW Wisconsin are polluted

The majority of private wells in southwestern Wisconsin are substantially polluted with fecal matter as concerns intensify over pollution of rural drinking water, according to a new study.

Results from the independent study released Aug. 1 indicated that 32 of 35 wells — or 91 percent — contained fecal matter from humans or livestock, the Milwaukee Journal Sentinel reported.

"As a researcher of groundwater for 25 years now, I continue to be amazed by the level of fecal contamination in Wisconsin groundwater," said Mark Borchardt, a research microbiologist for the U.S. Agricultural Research Service.

The work was led by Borchardt, others in his agency and the Wisconsin Geological and Natural History Survey. Monetary backing came from the counties, the agencies and other local groups. Additional testing in the counties is likely, with the next round set for early August.

Create a More Connected Minnesota

MPR News is your trusted resource for the news you need. With your support, MPR News brings accessible, courageous journalism and authentic conversation to everyone - free of paywalls and barriers. Your gift makes a difference.

During testing in April, it was discovered that some of the wells contained illness-causing pathogens such as salmonella, rotavirus and cryptosporidium.

The results from Grant, Iowa and Lafayette counties are the latest in a series of examinations showing an assortment of problems with well water in the three counties.

These conclusions, and other test results, underscore the possible vulnerability of Wisconsin groundwater from agricultural practices and faulty septic systems.

Wisconsin figures indicate about one-quarter of the state's people get their water from more than 800,000 private wells.

On July 31, Democratic Gov. Tony Evers proposed new rules aimed at farmers and their use of manure and fertilizer. The regulations would focus on the regions vulnerable to nitrates, another source of groundwater pollution.

But those measures will require authorization by the Republican-controlled Legislature.

In the meantime, Assembly Speaker Robin Vos created a water quality task force in February to highlight the heightened attention to groundwater. Vos has since been holding hearings across Wisconsin.

Vos created the legislative task force after Borchardt's group released the results from an early round of testing in the three counties.

In that first round, 42 percent of 301 wells had evidence of total coliform or nitrate that surpassed the state's health standard. In a second round, 27 percent of 539 wells subsequently turned up total coliform or nitrate exceeding the state standard.