The greatest risk is found in aquifers running from Green Bay to Illinois. The DNR estimates that 90 municipal water systems exceed the safety standard of 5 pCi/L (pico Curies per liter).
While radium is more often found in shale, which occurs less in northeast Wisconsin than in the southeast part of the state, it is also found in the granite of the Wolf River Batholith. This formation, according to the UWGB natural sciences department, runs from Oshkosh to Wausau, though Shawano County up to Oconto County.
Dave Johnson, water specialist for the DNR, said that isolated high concentrations of radium have been found in Winnebago County and in wells near Ashwaubenon in Brown County.
“It’s typically a deep well problem,” said Johnson of radium. “Private wells tend not to have much trouble with it – one exception, is the Town of Algoma,” located in Winnebago County.
It’s important to remember, he added, that “radium behaves like calcium and is readily removed by a water softener.”
The EPA reports that studies show radium exposure can cause increased risk of bone cancer, leukemia and lymphoma. The Centers for Disease Control notes that exposure to high levels of radium also increases incidences of liver and breast cancer. However, cancer deaths directly related to radium exposure are low – the EPA estimates an additional 44 deaths per one million people each year.
“If you notice a change in taste, odor, color of your water,” said Johnson, who recently provided a workshop on groundwater at St. John Neumann School in Oshkosh, “that’s a good indicator that something is going on.”
Then it’s a good idea to contact the DNR, or the county health department.
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Another colorless, odorless element contaminating drinking water in our area is arsenic. The risk was only recently discovered by the state’s Department of Health and Human Services, in 1987, when groundwater contamination was discovered at a proposed landfill in Winnebago County.
Since then, the DNR has found that St. Peter sandstone and Galena dolomite combination in Outagamie, Winnebago and Brown counties contain elevated levels of arsenic. More than 20,000 private wells and 434 public water systems draw water from these rock formations. Studies have shown increased risk of skin, bladder, colon and prostate cancer related to arsenic intake.
However, increased rates of cancer in northeast Wisconsin have not been proven, according Dr. Lynda Knobeloch, senior toxicologist for Wisconsin’s Department of Health Services. The department did a 2000-2002 study of wells in Outagamie and Winnebago counties. While increased cancer rates were not found, Knobeloch cautioned that this may be because many of those studied had not lived in the contaminated areas for very long.
“Skin cancer rates (excluding melanoma) were higher among adults who consumed arsenic contaminated water for 10 years or longer,” she said.
Additionally, she said that people who smoke and are exposed to arsenic, are more at risk.
“Among residents over the age of 50 years,” she said, “those who smoked cigarettes and drank water that had an arsenic level greater than 5 ug/L (ppb) were three times as likely to report a diagnosis of skin cancer than non-smokers who drank water that was low in arsenic.”
DNR reports show that arsenic in wells is highly variable, ranging from none detected up to 15,000 parts per billion (ppb). U.S. health standards of safe levels of arsenic in drinking water were lowered to 10 ppb in 2001, and further studies show that there are still safety concerns at this level.
According to Liz Heinen, a drinking water specialist for the DNR based in Appleton, the Fox River Valley has the highest of levels of naturally occurring arsenic in groundwater anywhere in the world. And those levels are rising, due to the groundwater tables dropping in the region.
Increased water usage due to development of housing and manufacturing in the 1980s and 1990s lowered water tables into the layers of the rock that carry uranium and leached out radium and arsenic.
“Pumping water from aquifers changed the geochemistry underground,” Heinen said. “There are (healthy) people who say, ‘I’ve been drinking this well water all my life and look at me.’ No, they haven’t been drinking that same water their whole life. This is a new phenomenon.”
She knows of one family that had such an increase of arsenic in their well that they washed their clothes and the garments fell apart from contamination.
Johnson noted that arsenic risk increases with depleted water levels because bedrock is exposed to oxygen. He said this causes a chemical reaction called Acid Mine Drainage and is the same reaction people were concerned about with the Crandon zinc mine. And it’s an increasing problem in areas of development.
Johnson said that, in the 1970s, the U.S. Department of Energy conducted studies of the sediments, stream and ground water around Wisconsin.
“The highest arsenic we found (in NE Wisconsin well water) was 19 ppb in Outagamie County and 17 ppb in Winnebago,” he said.
Then, in 1993, another study was done. That was when the DNR found area wells containing elevated arsenic – 5,900 ppb in a well in Outagamie County, and a well in Winnebago County with 15,000 ppb.
“Development and sewer construction were cutting off infiltration,” Johnson said. “The water table had dropped 20 feet in that area (Winnebago County, Town of Algoma).
Heinen said research has shown increased risk of skin and bladed cancer from arsenic – as well as increased kidney problems, hair loss, and possible ties with cardiovascular and adult onset diabetes. Knobloch agreed that diabetes and heart disease occur more
often in adults “who consumed water that contained arsenic” but the reasons why are not yet known.
While bathing or showering in arsenic contaminated water appears to be safe, there may be some skin risks. Johnson noted that, along with arsenic, the leaching of pyrite and sulfide minerals in the rocks releases other chemicals including nickel. We know nickel as “the cheap jewelry rash” metal, he said, “but it is also a known carcinogen.”
Health departments in affected counties are required by law to constantly monitor arsenic levels in city wells. The EPA requires that if levels rise above 10 micrograms per liter (µg/L), residents must be informed. However, owners of private wells should be aware of the risk and have their water tested.
“You should sample your well,” said Heinen. “And sample it every year, because it can change over time. When you put a well in, you change everything. That’s an open hole that exposes the arsenic to oxygen.”