Radium creates challenges for clean drinking water
Genoa City is among several municipalities battling radium levels greater than the amount allowed by the U.S. Environmental Protection Agency. A narrow band in the deep sandstone aquifer stretching from the southeastern corner of the state up to Green Bay contains high concentrations of radium.
The National Academy of Sciences said long exposure to radium puts people at greater risk of bone cancer. Others question whether the threat is real and if the EPA’s standards are too strict, forcing communities to unnecessarily spend thousands to stay in compliance.
“We’re nowhere near the ‘get-nervous’ stage,” said Todd Schiller, Genoa City’s public works superintendent. “The limits are so tight, but you don’t have any choice (but to comply).”
The state Department of Natural Resources is required by federal law to submit a water quality report to Congress every two years. Last year’s report indicated radionuclides—uranium, radium and radon—are “becoming an increasing concern for groundwater quality, especially in the … aquifer system in eastern Wisconsin.”
Federal law keeps radium limits at 5 picocuries per liter of water, and results from the DNR show single samples in a handful of communities in Rock and Walworth counties came close to that level. A sample in Elkhorn was as high as 5.4 picocuries, but the EPA uses a composite average to determine a water district’s compliance.
Genoa City is the only community in either county required to make changes. While the village is among the latest to have radium problems, it’s not the first, and it likely won’t be the last.
The EPA estimates that water containing the maximum allowed radium contamination will cause 44 cancer deaths for every 1 million people exposed. That number doubles for every 5 picocuries over the limit.
Opponents argue that the estimate makes the unlikely assumption that the same person is drinking two liters of radium-contaminated water every day for 70 years. The DNR characterizes that risk as similar to dying from a lightning strike.
“You can’t stand up and say to the national health experts that you’re wrong,” said Daniel Lynch, Janesville’s utilities director. “They’re going to come up with numbers, and we’re going to have to deal with it.”
Janesville’s radium count was as high as 4.1 picocuries found in a well drilled in 2006. Water Utility Superintendent Katie Karow said radium initially wasn’t detected, but it began to show up after about a year.
The city mixes water from that well with water from a nearby shallow well to dilute the radium. That also dilutes nitrates from the shallow well.
Janesville is in better shape than most communities in the eastern portion of the state. The city pumps about 10 million gallons of water daily, and just 4 million of that comes from deeps wells, where radium is mostly found.
Communities can take a variety of measures to lower radionuclide counts in their water, but some are tedious and costly. More expensive, however, is abandoning a well that can cost hundreds of thousands of dollars to drill.
Janesville’s solution—blending with water from another well—is among the most common. Radium usually is drawn from deep wells, so mixing it with shallower wells can significantly deplete the mineral’s presence, said Mark Nelson, water supply specialist with the DNR.
Schiller said Genoa City did that, too, but it required him to reduce the output of the deep well. That can burn out the pump over time.
“It’s like having a Corvette and only being able to push the pedal down a quarter of an inch,” he said.
The village plans to spend $30,000 to $40,000 to install a filtering system, which could be installed by winter. The system will cost about $4,000 annually to operate.
Communities that don’t take steps to reduce radium can be fined.
The city of Waukesha in 2009 paid $55,000 to settle a state lawsuit over its drinking water violations. The settlement put the city on a strict monitoring and reporting program that forces it to become compliant with radium standards by 2018.
Waukesha joined other communities in challenging the EPA’s strict regulations, arguing the standards violated the federal Safe Drinking Water Act. The U.S. Court of Appeals in 2003 rejected their claim.
“This is mandated by the DNR so either do it or shut the wells off,” Schiller said. “It’s not a choice we can give to the public.”