Despite State Efforts, Arsenic Continues to Poison Many Private Wells in Wisconsin
Special regulations to reduce exposure to the ancient poison have helped, but high-capacity wells can exacerbate the problem.
By the time Bradley Burmeister met his high school science teacher more than a decade ago, concerns had already surfaced about an ancient poison that was appearing in drinking water around their Fox River Valley community. Burmeister never suspected, though, that his family’s well would provide some of the scariest data.
High levels of arsenic, a substance used as a poison since the Middle Ages, had been detected in 1989 in several counties in the Fox Valley region of northeastern Wisconsin. In 2003, Seymour High School science teacher Dennis Rohr and his students began a study of private well water samples from the area that would continue for the next five years.
The arsenic level the students detected in the Burmeister family’s well was off the charts: 1,650 parts per billion (ppb), or 165 times the federal health standard of 10 ppb. Burmeister — whose experience in the study sparked an interest in science that culminated in medical school — recalls it being the highest level found in the study.
To this day, Burmeister’s parents regularly buy a case of gallon-sized water jugs at the grocery store to use for drinking and cooking. Despite the inconvenience, Burmeister said his parents feel it is a more affordable way to address their arsenic problem than drilling a new well or purchasing a water treatment system.
The Burmeisters are not the only family having to find alternatives to turning on the tap; arsenic is a major concern in Outagamie and Winnebago counties. The Wisconsin Department of Natural Resources designated an arsenic advisory area in these counties in 1993 and implemented stricter regulations for testing and well construction in 2004 and 2014.
But arsenic problems are not confined to northeastern Wisconsin. Levels above the federal standard have been detected in 51 of Wisconsin’s 72 counties, according to a 2006 Wisconsin Groundwater Coordinating Council report.
The most serious health effects from arsenic exposure include a variety of cancers, nerve damage, diabetes and cardiovascular disease. Chronic low-level exposure during childhood has also been linked to decreased intelligence.
In a 2014 study, researchers studying schoolchildren in Maine found regular consumption of drinking water containing 5 ppb of arsenic or more was associated with a significant IQ reduction in students in grades three to five.
"The magnitude of the association ... raises the possibility that levels (of arsenic in drinking water) that are not uncommon in the United States pose a threat to child development,” the researchers wrote.
Human activity can mobilize arsenic
In 2001, the U.S. Environmental Protection Agency lowered the federal health standard, or maximum contaminant level, for arsenic in public drinking water from 50 to 10 ppb. This step reflected the increasing scientific evidence for the dangers of arsenic exposure to human health and matched the World Health Organization’s global drinking water standard.
The highest level ever detected in the state was found in a private well in northeastern Wisconsin. The well tested at 15,000 ppb — 1,500 times the new federal threshold.
“We have an arsenic hot spot in Wisconsin,” said John Luczaj, a geoscience associate professor at the University of Wisconsin-Green Bay.
Madeline Gotkowitz, a hydrogeologist at the Wisconsin Geological and Natural History Survey, agreed. “Arsenic is a big problem in Wisconsin, and I don’t think many realize that,” she said.
In 1987, the DNR discovered that the St. Peter Sandstone aquifer in northeastern Wisconsin contains a high concentration of sulfide minerals which, when exposed to oxygen, can break down into arsenic. Knowing that it was the water source of more than 20,000 private wells, agency officials knew this might spell trouble.
“Seymour High School rests directly above the St. Peter Sandstone formation,” science teacher Rohr said. “So arsenic was the main focus (of our water study) as it impacted our local community the most.”
The oxygen that sets off the breakdown of sulfide minerals can be introduced by well drilling and disinfection methods, or when the water table — the level below which the ground is saturated with water — is drawn down. This may occur during periods of drought, or be triggered by human use, such as the operation of high-capacity wells.
Because of this interplay between geology and human activity, Luczaj said, private wells whose water previously tested fine for arsenic may lose their integrity.
Patrick Laughrin is all too familiar with the effect of high-capacity wells in his part of the state. He lives in Hilbert in Calumet County, just east of Winnebago County.
“The arsenic in our well showed up for the first time when the high-capacity wells came in and dropped the water table,” Laughrin said. “It makes sense. If you drop the water table, you get more oxygen and that releases more arsenic into your water.”
State steps up regulation
In 2004, the DNR introduced tougher arsenic laws in Winnebago and Outagamie counties. With 20 percent of the private well samples there analyzed in 1992-93 exceeding the EPA’s new health standard of 10 ppb, this area was thought to pose the greatest exposure threat to the largest number of residents. The new regulation required all drilling and disinfection methods to minimize the exposure of sulfide rocks to oxygen.
For Luczaj, of UW-Green Bay, this was a step in the right direction, but he said it may not go far enough.
“The geology doesn’t stop at political boundaries,” Luczaj said. “The area definitely extends into the neighboring counties. It’s pretty likely that we’ll see increasing problems as aquifers get drawn down.”
A 2013 study of 3,868 private wells from across the state found 2.4 percent of them exceeded arsenic levels of 10 ppb. If that proportion was applied to all of the estimated 940,000 households on private wells in Wisconsin — a calculation endorsed by the study’s lead author — residents of 22,560 homes may be consuming unsafe levels of the chemical.
Testing, grants rarely used
The DNR has a well compensation grant program that makes residents whose well water exceeds 50 ppb of arsenic — five times the federal standard — eligible for up to $9,000 to drill a new well. The program can be used to address other types of contamination as well.
However, during the past five years, only 10 or fewer grants were awarded per year. Households whose water contains up to 49 ppb — almost 10 times the amount of arsenic shown to impact a child’s intellectual development — have to cover the cost of a new well on their own, or pay for other options that will make their water safe to drink.
To reduce arsenic exposure, people must be aware of its presence in their drinking water in the first place. But with a mere 16 percent of private well owners in Wisconsin estimated to test their water annually, the number of residents who are unaware is large.
Raising that awareness was part of Rohr’s goals when he began his water study in 2003. In 2014 — 11 years after Rohr’s study — the DNR revised its arsenic regulation yet again, recognizing the persistent nature of Wisconsin’s arsenic problem.
This time, the new state law required that arsenic, in addition to coliform bacteria and nitrate, be tested at the time of a property transfer, but only if the buyer requests a well inspection. The same three contaminants also have to be tested after the completion of certain well repair work, such as fixing a broken water pump.
Bad wells replaced by city water
Some communities in Wisconsin have addressed their arsenic problem by offering citizens a switch from private to municipal water. City water is required by law to be tested regularly for arsenic, which takes the burden of monitoring water quality off the homeowners’ shoulders.
The Stilson family in Oshkosh took advantage of the opportunity to switch in 2000, following several years of having bottled water delivered to their home after the level of arsenic in their well rose to 999 ppb, or nearly 100 times the health standard.
“We said, ‘Let’s just get city water and get it over with,’ ” Lynn Stilson said.
When drilling a new well is too expensive, a switch to city water not possible, or purchasing bottled water too big a hassle, another remediation option is to install an in-home water treatment system. The most cost-effective method is called a reverse osmosis system, which removes 95 percent of arsenic, as well as other contaminants.
Luczaj said vigilance is the key to avoiding arsenic, since human activity can increase the amount of the naturally occurring contaminant in well water. “A one-time test for arsenic is not at all sufficient,” he said.
Gabrielle Menard and Elise Bayer, students in the University of Wisconsin-Madison School of Journalism and Mass Communication, contributed to this story. This report was produced as part of journalism classes participating in The Confluence, a collaborative project involving the Wisconsin Center for Investigative Journalism and UW-Madison School of Journalism and Mass Communication. The nonprofit Center (www.WisconsinWatch.org) collaborates with Wisconsin Public Radio, Wisconsin Public Television, other news media and the UW-Madison School of Journalism and Mass Communication. All works created, published, posted or disseminated by the Center do not necessarily reflect the views or opinions of UW-Madison or any of its affiliates.