August 23, 2016
Health officials move to protect more well owners in east metro from exposure to PFOS, PFOA
Eighty homes in southern Washington County will begin receiving bottled water soon because their well water exceeds an updated federal health advisory level for perfluorooctane sulfonate (PFOS) and perfluoro-octanoic acid (PFOA) – two types of man-made pollutants in a category known as perfluorochemicals (PFCs). If they so choose, the residents will receive bottled water until carbon filter systems can be installed in their homes.
The Minnesota Department of Health (MDH) this week sent letters to the 80 Washington County residents whose wells are known to have one or both of the man-made chemicals at levels above the new federal Environmental Protection Agency (EPA) lifetime health advisory level of 70 parts per trillion (ppt) and who were not previously provided water treatment.
In addition, the Minnesota Pollution Control Agency (MPCA) and MDH will continue sampling nearby residential wells to see if they have water with PFCs above 70 ppt and will inform residents of their results. A map of the potentially affected areas can be found on the special page for the PFOS-PFOA advisory on the MDH website. Those residents with well water above the advisory level will be offered bottled water until filters can be installed.
The 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 (PFOS) and 400 (PFOA) ppt would better protect developing fetuses and infants. Studies indicate exposure to PFOA and PFOS at high levels may result in an increased risk of adverse health effects, including developmental effects (such as low birth weight, accelerated puberty, skeletal variations); some cancers (testicular, kidney); liver damage, interference with immune system function; thyroid effects; or cholesterol changes.
MDH is reviewing the studies and methods used by EPA to determine whether its own health-based values for the chemicals need to be lowered and if so, what the values should be. This review is expected to be completed in the next several months.
“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,” said Minnesota Health Commissioner Dr. Ed Ehlinger. “This additional information prompted us to take action now to reduce the risk of exposure from drinking water. People are exposed to PFCs, including PFOA and PFOS, from a wide variety of substances and consumer products in our everyday lives. Eliminating a significant source over which we have some control makes good public health sense.”
MDH’s existing Health Risk Limit (HRL) of 300 ppt for PFOA and PFOS is likely to be protective for most people, said Jim Kelly, manager of environmental surveillance and assessment for MDH. The concern with PFCs for most people is with long-term, lifetime exposure;however, evidence indicates shorter-term exposure can present heightened concern for fetuses and infants.
“Our review of the EPA guidance was far enough along to tell us that it would be prudent to notify the public now rather than waiting until our review was completed,” Kelly said.
MDH and MPCA expect to sample approximately 400 to 500 wells within the area of contamination in the coming months and will issue additional drinking water advisories as needed. Until their wells are tested, residents who have concerns about their health can take steps to reduce their potential exposure to PFCs. Information on inexpensive, point-of-use filters and other steps people can take in their homes can be found on the MDH website.
The Minnesota Pollution Control Agency will provide the bottled water to affected residents until granular-activated carbon (GAC) filters can be installed in homes at no cost to homeowners.
From the late 1940s until as recently as the 1970s, the 3M Company disposed of products containing PFCs, including PFOA and PFOS, in a landfill and three dump sites in Washington County. Groundwater contaminated with PFCs was first discovered in the area in 2002. PFOA and PFOS have been used to make carpets, clothing, fabrics or furniture, paper packaging for food and other materials, such as cookware that resists water, grease or stains. They are also in some products used for firefighting at airfields and in a number of industrial processes.
According to MDH data, there are currently 81 homes in Washington County that already have GAC filters in place to remove contaminants to acceptable levels; several other homes have been provided bottled water instead of filters, at the homeowners’ requests. The GAC filters were installed beginning in the mid-2000s following initial investigations and well sampling, based on MDH health recommendations at the time. MDH and MPCA have been monitoring PFC concentrations in more than 1,500 private wells in affected areas of Washington County.
While there are now four community public water supply wells in the City of Oakdale with groundwater that is above the EPA advisory level, that water is blended with other PFC-free water or treated so that no finished water in the distribution system is above the EPA level. 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 plume area who have questions or concerns about their health or their water can find information on the PFCs page on the MDH website or may call 651-201-4897. MDH and MPCA are planning a public meeting for the community in the next few weeks and will be providing residents with more details about date, time and location in the days ahead.