Wisconsinites Drink Water Contaminated With High Levels of Nitrates and Coliform Bacteria, Study Says
WISCONSIN – January 10, 2019
A survey of private wells in southwestern Wisconsin found almost half had unsafe contamination levels.
Researchers randomly selected 301 wells for testing in Iowa, Grant and Lafayette counties in November 2018. 42% of the wells exceeded standards for bacteria or nitrate, a compound linked to a variety of health problems.
The research team sent landowners instructions and equipment to collect the samples, which were analyzed in a lab at the University of Wisconsin-Stevens Point.
Katie Abbott, Iowa County conservationist, said 34% tested positive for coliform bacteria.
"Coliform is not an illness-causing bacteria on its own," Abbott said. "It's an indication that there could be other things in the water as well."
"Actually my own house was one that was by chance randomly selected. So I was able to do it and experience the well testing myself and the instructions were easy to do," Abbot said.
She said her well tested positive for coliform bacteria, so she plans to get a second test to confirm the results. If the presence of the bacteria is confirmed, Abbott said residents should stop drinking their water until they can have their well disinfected.
4% of the wells had E. coli, a bacteria that can cause illness. 16% of the wells had nitrate levels above the state standard of 10 parts per million.
The sampling is part of a two-year study on groundwater quality commissioned by the three counties, called the Southwest Wisconsin Groundwater and Geology study, or SWIGG.
Around 44% of residents in Grant, Iowa and Lafayette counties get their water from private wells. Ken Bradbury, state geologist and a principal investigator on the study, said there are more than 10,800 private wells in the region.
"It's probably the largest synoptic, which means all taken at the same time, water quality sample that's ever been done in those three counties," Bradbury said.
Bradbury said the results of the survey weren't surprising. He said previous sampling indicated similar trends in bacteria and nitrate levels and the region's soil and bedrock makes the groundwater susceptible to contamination.
The region's geology is similar to northeastern counties like Kewaunee County, which has seen increased concern and regulation around groundwater contamination in recent years.
Another study in Kewaunee County in northeastern Wisconsin in 2017 showed well contamination was linked to both cattle — especially during wet conditions — as well as ineffective septic systems.
But Abbott said there are also important differences between the two regions.
"They were having brown water events — we’re not having any of those. They have a much more concentrated amount of people and cattle," Abbott said. "Those two main differences are enough for us to say that we need our own data, we need to know what's going on out here. We can't again make assumptions based on a completely different part of the state."
The SWIGG study will use the water quality data to identify the likely factors of contamination.
Under pressure from residents and environmental groups, the administration of Republican Gov. Scott Walker advanced stricter rules for the spreading of manure in 15 eastern Wisconsin counties in 2018.
But Walker’s Department of Natural Resource balked at expanding the rules to other parts of the state, and some agriculture interests pushed to keep the limits from applying elsewhere.
In a statement released last Thursday, Assembly Speaker Robert J. Vos, R-Rochester, said Republican Reps. Travis Tranel, of Cuba City, and Todd Novak, of Dodgeville, asked him to form a water quality task force.
“I agree that the recent reports of water contamination in private wells in southwestern Wisconsin are disturbing. Every Wisconsinite should have access to safe, clean drinking water. Unfortunately, there are other areas of Wisconsin facing a similar issue. I have had numerous conversations with Rep. Joel Kitchens about water quality concerns in his area as well… I have decided to move forward on the creation of a Speaker’s Task Force on Water Quality. An official announcement that will include committee membership will be made in the coming weeks,” the statement reads.
Bradbury said another round of well tests will take place this spring. Researchers will then determine possible causes of the contamination.
Novak said he understands the research in southwestern Wisconsin is in a preliminary stage. He said he hopes the task force will offer a proactive response when contamination problems are confirmed.
"It would be premature to say, 'We need to put rules here, we need to put rules there.' I think what we need to do is sit down, start from scratch and see what needs to be done," Novak said, according to Wisconsin Public Radio.
Wells considered unsafe showed the presence of total coliform, which is a measure of bacteria, or nitrates.
No amount of total coliform is allowable in drinking water. In the case of nitrates, some of the wells exceeded the state’s limit of 10 parts per million. High nitrate levels have been associated with blue baby syndrome, colorectal cancer, thyroid disease and some birth defects affecting the central nervous system.