As Wells Go Deeper, Radium Levels Rise in Wisconsin's Tap Water
In 2014, the village of Sussex in southeast Wisconsin made a dismaying discovery. The radioactive element radium, a contaminant that occurs naturally in bedrockthroughout the region, had seeped into two of its seven water wells.
It was not exactly a surprise. Radium has long been a problem in drinking water for dozens of Wisconsin communities from Green Bay to the Illinois border.
The city of Waukesha has proposed replacing its radium-tainted groundwater with Lake Michigan water. If approved, the controversial plan would mark the first test of a provision in a 2008 international compact that allows Great Lakes water diversions only when a county — such as Waukesha County — straddles the basin that feeds water into the Great Lakes.
Another factor fueling Wisconsin’s radium problem is the lack of regulation of high-capacity wells, which can lead to depletion of groundwater.
As communities such as Sussex drill wells deeper into a diminishing aquifer to meet growing water demands, they are pulling up more radium contamination and creating a public health challenge.
“It is certainly a concern for everyone in southeast Wisconsin that more radium will turn up,” said Melissa Weiss, assistant administrator for Sussex.
About 25 Wisconsin water systemshave exceeded the U.S. Environmental Protection Agency’s maximum contaminant level over the previous two years, which means radium levels remained over the limit of 5 picocuries per liter for more than a year. Some other communities, such as Madison, have seen spikes in individual wells above 5 pCi/L but are not in violation because the levels were elevated for less than a year.
Because of high radium levels in deep groundwater, communities surrounding Green Bay over the past decade have begun receiving water from Manitowoc, which draws most of its drinking water from Lake Michigan.
The extent of radium contamination in private wells is considered minimal because most are not drilled into deep geologic formations. There is no requirement to test for radium in private wells.
In addition, “We don’t know the radium concentration in private wells because the test is expensive (about $200), so hardly anybody tests for it,” said John Luczaj, a University of Wisconsin-Green Bay professor of geoscience who has studied radium in Wisconsin’s water.
The city of Waukesha has been struggling with radium contamination in its water for more than two decades. The request to tap into Lake Michigan, which has beenendorsed by the state Department of Natural Resources, is opposed by many environmentalists. Waukesha has proposed replacing the full amount of its withdrawal to Lake Michigan with treated wastewater piped through the Root River.
Critics fear the request by Waukesha, which lies just outside the Great Lakes basin that drains into Lake Michigan, could open the door for additional requests to tap into the Great Lakes. The size of Waukesha’s water service area, which stretches beyond the city limits, also has been a criticized by opponents who fear the water will be used to fuel sprawl.
The proposal must be ratified by governors from all eight Great Lakes states. If the request is approved, Waukesha will spend an estimated $206 million to solve its radium problem.
Health risks of radium
According to the federal Centers for Disease Control and Prevention, radium is a known carcinogen at high levels, causing bone, breast and liver cancer. But there islittle research evaluating low-dose, long-term exposure in drinking water.
Small amounts of radium can accumulate in the human skeleton over time, damaging bones and tissues, according to the U.S. Geological Survey.
A person who drinks two liters of water containing 5 pCi/L of radium every day for 70 years has a 1 in 10,000 risk for developing fatal cancer, according to the geological survey. Other harms of drinking radium-tainted water include anemia, cataracts and fractured teeth, according to the CDC.
The EPA began regulating radium in water in 1977. The rule is based largely on studies of occupational health risk such as the “radium girls” of the 1920s who ingested deadly amounts of radium as they licked their brushes while painting glow-in-the-dark watch faces. By 1927, more than 50 women had died.
“The relationship between the amount of radium that you are exposed to and the amount of time necessary to produce these effects is not known,” the CDC cautions. “Although there is some uncertainty ... the greater the total amount of your exposure to radium, the more likely you are to develop one of these diseases.”
Given that uncertainty, some have argued that the current regulations are too strict.
But that question was decided 12 years ago in a nationally watched lawsuit in which Waukesha and Sussex tried but failed to block updates to radium rules in 2000. The communities charged, among other things, that the EPA used flawed science in determining the dangers of radium.
Geology, pumping tied to radium
A naturally occurring element, radium is found throughout the environment. Overpumping of the sandstone aquifer where radium resides is largely to blame for the high radium levels, experts say.
“Water moves through that aquifer slower than it does in other areas that also contain sandstone aquifers,” according to Timothy Grundl, UW-Milwaukee professor of geosciences. “This can cause bigger problems because the water has more time to pick up contaminants.”
Growing populations and increased demand for water have caused the aquifer to become one of the most depleted in the country, according to Ezra Meyer, a water resource specialist at the Madison-based environmental group, Clean Wisconsin.
Although groundwater levels have rebounded some in the last decade, communities have had to drill deeper wells to tap into an aquifer that researchers say has dropped by nearly 500 feet since the late 1800s. In the process, communities run into more radium because contamination tends to increase the deeper the well is drilled, said Steve Elmore, the state DNR’s public water supply section chief.
Overpumping of the aquifer also can alter the water’s natural flow.
“Water that used to flow to Lake Michigan is now flowing west,” said U.S. Geological Survey hydrologist Daniel Feinstein. “Part of the reason we are seeing high levels of radium is that the flow field was energized by overpumping.”
There are a variety of ways radium levels can be brought into compliance, at varying costs. Municipalities can use expensive methods such as water treatment or diluting water from deep wells with water from shallower ones; Waukesha is using both strategies. Homeowners with private wells also can use water softeners to remove radium.
Waukesha is counting on diversion of Lake Michigan water, saying it is the only reasonable alternative to provide safe drinking water for its residents.
Depending on how much funding the federal government kicks in, average water bills would rise from $27 a month to between $50 and $90 a month, said Daniel Duchniak, general manager of the Waukesha Water Utility. Even if Waukesha gets federal funding for up to 25 percent of the cost, he said, “We expect that water bills will at least double and potentially triple.”
Reporters Silke Schmidt and Dee J. Hall contributed to this report. The story was produced as part of journalism classes participating in The Confluence, a collaborative project involving the Wisconsin Center for Investigative Journalism and University of Wisconsin-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.