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.
Worrisome levels
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.