Minnesota health officials are ordering bottled water for 80 homes in southern Washington County after determining perfluorochemical levels in the well water of those homes now exceeds a new federal health advisory level.
Residents were told this week about the contamination and will receive the bottled water at no cost until carbon filter systems can be installed in their homes, the Minnesota Department of Health said Tuesday.
The department said it's reviewing the studies and methods used by the federal Environmental Protection Agency to determine whether Minnesota should alter its safety levels for those chemicals.
"While we believe the immediate health risks for most people exposed to PFCs are low, the latest information from EPA indicates a risk for developing fetuses and infants. This additional information prompted us to take action now to reduce the risk of exposure from drinking water," Minnesota Health Commissioner Dr. Ed Ehlinger said in a statement. "People are exposed to PFCs ... from a wide variety of substances and consumer products in our everyday lives," he added. "Eliminating a significant source over which we have some control makes good public health sense."
• MPR News archive: Toxic traces
Perfluorochemicals were used extensively by 3M for years at a plant in Cottage Grove in southern Washington County. The chemicals were used to make 3M products including Scotchgard anti-stain spray.
The company said in 2000 it was phasing out the use of the chemicals because they were toxic to lab animals. They also turned up in the blood of 3M workers, although the company said its employees were not harmed.
However, tens of thousands of east metro residents were exposed to trace amounts of the chemicals once used in 3M's manufacturing process and later disposed of in east metro waste sites.
Groundwater contaminated with PFCs was first discovered in the area in 2002. State pollution officials believe the chemicals got into the water supply from underground movement of water toward wells.
In 2005, an investigation by Minnesota Public Radio and American RadioWorks found that even after 3M said it would no longer make the toxic chemicals, the Minnesota Pollution Control Agency let two years pass before it began any inquiries.
On Tuesday, state health officials said EPA set the new health advisory levels based on recent studies in laboratory animals that indicated a value lower than their previous interim advisory value of 200 parts per trillion for perfluorooctane sulfonate and 400 ppt for perfluoro-octanoic acid would better protect developing fetuses and infants.
Minnesota's existing health risk limit of 300 ppt for PFOA and PFOS is likely to be protective for most people, said Jim Kelly, the state Health Department's manager of environmental surveillance and assessment.
State officials intend to sample 400 to 500 wells within the area of contamination in the coming months and will issue additional drinking water advisories as needed. More than 1,500 private wells in affected areas of Washington County are being monitored.
For most people, the concern is long-term, lifetime exposure to the chemicals, although "evidence indicates shorter-term exposure can present heightened concern for fetuses and infants," the department added.
Eighty-one Washington County homes currently have filters in place to remove contaminants to acceptable levels.
Four community public water supply wells in Oakdale have groundwater PFC contamination above the EPA advisory level, but that water is treated so that "no finished water in the distribution system is above the EPA level," the Health Department said, adding, "a similar situation occurred in Bemidji, where groundwater in two city wells is above the EPA advisory level. Bemidji is also blending its water so that no finished water in its system is above the EPA level."
Water with PFC levels above health advisory levels is safe for bathing, showering or washing clothes and cleaning, but should not be used for drinking or cooking. Residents in the affected area can call the Health Department at (651) 201-4897. A public meeting for the community is expected in coming weeks.