A former 3M chemical that has contaminated municipal wells in six east-metro communities has also been detected in nearly 100 private wells, state health officials said Wednesday.
Minnesota experts do not know the potential long-term health risks from drinking water that contains PFBA, the chemical in question, but the latest findings are higher than the state's guideline of 1 part per billion.
Virginia Yingling, hydrogeologist for the Minnesota Department of Health, said the wells were among 350 sampled during the past three months after the state found the chemical early this year in the public drinking water of Woodbury, Cottage Grove, St. Paul Park, Hastings, South St. Paul and Newport.
Yingling said that the private well results were not surprising and that the source appears to be a 3M disposal in Woodbury that the company used decades ago to bury wastes.
"A fairly substantial area of [private wells in] Cottage Grove, St. Paul Park and southwestern Woodbury are showing levels at or above 1 part per billion," Yingling said.
Levels of PFBA measured in public water early this year ranged up to 2.3 parts per billion, but she said concentrations in private wells reached as high as 5.8 parts per billion.
There is no official state or federal standard for PFBA, one of several compounds known as perfluorochemicals. Health officials have said citizens with the chemical in their well water may want to buy bottled water or install granular carbon filters if they're concerned.
Yingling said that well owners have been notified of the results and that more private wells will be sampled where contamination levels are highest.
Officials discuss the issue
The research was mentioned only briefly during a half-day discussion in St. Paul that brought together about 100 local, state and federal officials, industry representatives and others.
Mary Dominiak, perfluorochemical coordinator for the federal Environmental Protection Agency, said the compounds are of concern because they do not break down in the environment and they accumulate in human blood.
"These chemicals don't behave like anything else on the planet," Dominiak said. "That makes them very difficult to study."
She said it may be a few years before the EPA can determine what concentrations of the chemicals might be risky for human health.
However, local officials said they don't have the luxury of waiting that long, when frustrated and concerned residents ask whether their water is safe to drink.
"We're answering the phone every day trying to provide information and guidance to people," said Cindy Weckwerth, a program specialist for public health and the environment in Washington County.
Cottage Grove Mayor Sandy Shiely said the concern also goes beyond health to uncertainty about property values, and attracting new businesses and residential development.
"All these issues affect the sense of well-being in our communities," said Rep. Julie Bunn, DFL-Lake Elmo.
About the chemicals
PFBA was used in photographic film and other products. It is part of a larger family of compounds, including PFOS and PFOA, formerly manufactured by 3M for use in Scotchgard, Teflon and dozens of other products.
Perfluorochemicals have also contaminated drinking water in Oakdale and Lake Elmo, and have been found in fish in the Mississippi River near 3M's Cottage Grove plant and in Lake Calhoun in Minneapolis.
3M officials have said that at concentrations found in the environment, the compounds have never shown any adverse health effects, even to company workers who were exposed to much higher levels.
Tom Sinks, deputy director of the National Center for Environmental Health, said that it's reassuring that studies done so far have not shown problems, but that it's premature to conclude that exposure to the compounds is risk-free.
"We haven't done the number of health studies that we need to conclude that they're safe," he said.