More than 50 homes near the Twin Cities have lost their drinking water after dozens of wells were found to be contaminated with a powerful industrial chemical.
The Minnesota Pollution Control Agency (MPCA) found the contamination this summer while it was monitoring the groundwater near two sites with known pollution problems — the now-closed Waste Disposal Engineering (WDE) Landfill in Andover and the Water Gremlin plant near the city of Gem Lake.
The agency found unsafe levels of 1,4 dioxane, a potential carcinogen that has been used for decades in solvents and adhesives, in the wells of 47 homes next to the WDE landfill and in 15 homes in Gem Lake. The unrelated contaminations likely came from two separate sources. The state has been providing affected homes with bottled water since the contamination was discovered in July.
"The first goal is always to limit exposure to the contamination," said Kirk Koudelka, an assistant commissioner for the MPCA. "Then we move forward to long-term solutions and finally clean up the contamination as much as possible."
It's unclear if the homeowners will ever be able to use their wells for drinking water again. The agency doesn't know how long the contamination has been there, where it came from or exactly how far it has spread. Investigations are underway, Koudelka said.
While 1,4 dioxane is hardly new, health and pollution control officials have only begun testing for it recently. No studies have linked the chemical to a case of cancer in humans, but tests on laboratory animals have shown that prolonged exposure can cause cancer as well as liver, kidney and respiratory problems, said Jim Kelly, manager of environmental surveillance and assessment for the Minnesota Department of Health.
"We know it has the potential to cause cancer in people," he said.
The Health Department set safety standards calling for no more than one part per billion of the chemical in drinking water. That's believed to be the threshold that could cause cancer after a lifetime — or 70 years — of exposure, Kelly said.
Most of the homes with the contaminated wells tested between three to four times that threshold.
Monika Dipert's home in Andover tested nearly 2,000 times higher, at close to 2,000 parts per billion.
"I thought it had to be a mistake," Dipert said. "So they came back and took a second sample and it was actually higher than the first. The last scientist actually held up their hands and said, 'We are slightly freaking out.' That level is so absurd."
The higher the exposure the quicker the chemical can cause health problems.
According to the Health Department, regularly drinking water contaminated with more than 300 parts per billion of 1,4 dioxane for longer than a month could cause kidney, liver or respiratory problems.
In Andover, one long-term solution could mean hooking the homes up to city water and sewer. The city's drinking water system was tested for the chemical and was found to be clean, Koudelka said.
But the big question is who would pay for the hookups, which could cost as much as $20,000 per home.
Gem Lake does not have a municipal water system, so homes would have to be hooked up to a neighboring water supply or new private wells may need to be dug deeper to find clean groundwater.
Investigating the source
While the MPCA hasn't found the source for the two contaminations, both neighborhoods are close to sites with a long list of pollution violations.
The WDE Landfill has long been one of the most toxic and polluted former landfills in Minnesota. It's been closed since the early 1980s, and the state took over management of the cleanup in 1995. The landfill once accepted hazardous materials such as barrels of solvents, plating sludge and cyanides. In 2019, the state removed roughly 6,600 rotting drums and barrels of toxic waste that had been buried in a one-third-acre pit at the site.
"The pit is leaking and contaminating the groundwater below with polychlorinated biphenyls (PCBs), paint wastes, heavy metals, solvents, and other volatile organic compounds," the MPCA said at the time.
Koudelka said the agency is working to trace the 1,4 dioxane contamination to see if it came from the landfill, which borders the neighborhood, or some other source.
"The results we're seeing are not typical for what we'd expect if it's coming from the landfill," he said. "There is the potential that there is another source. More sampling may tie down where it may be coming from."
In Gem Lake, the agency found the contamination as part of its heightened groundwater monitoring in the area after a host of issues were discovered at the nearby Water Gremlin plant, which makes lead terminals for batteries.
The company had to pay more than $7 million in fines and clean up projects after the MPCA discovered it emitted high levels of trichloroethylene, or TCE, into the air for years, and violated its air permit. The plant was shut down for a week that year after finding that children of employees had been poisoned by the lead dust carried home from the factory.
The source of the Gem Lake contamination is still under investigation, Koudelka said.
"We will follow the data," he said. "We will continue to move forward and if a responsible party is found and we can link it to a facility we will go after those companies to seek cost recovery."
Greg Stanley • 612-673-4882