Minnesota Department of Health

News Release

January 19, 2007

Contact information

Low levels of PFBA found in six cities’ wells in southeast metropolitan area
Levels pose no immediate health risk to residents; source of contamination under investigation

The Minnesota Department of Health has detected low levels of the chemical perfluorobutanoic acid (PFBA) in municipal wells in Woodbury, Cottage Grove, Newport, St. Paul Park, South St. Paul and Hastings. The contamination in all of these cities, except Woodbury, appears to be occurring in an area of groundwater that is separate from the one in Lake Elmo and Oakdale. The source of this new area of contamination is under investigation.

PFBA is one of a family of chemicals known as perfluorochemicals or PFCs. They were made and used by several companies around the world in household and industrial products such as stain repellents, lubricants, fire retardants and suppressants, pesticides, surfactants, and emulsifiers. PFBA was made by the 3M Company at its Cottage Grove facility.

Studies in laboratory animals have shown that PFCs may cause health problems if consumed in large enough quantities over long periods of time, or consumed at a sensitive time during development. Studies by 3M of workers exposed to PFCs during manufacturing show no apparent impact on their health.

“Finding this chemical at low levels does not pose an immediate health risk for residents,” said John Linc Stine, director of the Environmental Health Division for MDH. “It does mean we need to proceed cautiously, investigate further and, if necessary, take steps to reduce people’s exposure for the long term. Our toxicologists are currently evaluating the limited scientific information available on PFBA.”

Staff from MDH and the Minnesota Pollution Control Agency will be conducting extensive testing, including private wells, to determine the extent of the groundwater contamination. City wells will be monitored monthly for levels of PFCs.

The PFBA was found as part of MDH’s ongoing investigation into groundwater contamination in southern Washington County. The investigation began several years ago when health officials learned 3M disposed of PFC wastes at three sites in Washington County: the former Washington County Sanitary Landfill, the former Abresch dump in Oakdale, the 3M Cottage Grove facility and another disposal site on the border of Woodbury and Cottage Grove.

In 2004, MDH staff began collecting samples from private wells in the City of Lake Elmo to look for two PFCs, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). Low levels of PFOA were found in a few private wells near the Washington County Landfill. In 2005 more testing detected PFOS and PFOA in a larger group of private wells in Lake Elmo and several city wells in Oakdale. Tests in several other nearby municipal water supplies, including Cottage Grove, Woodbury, and Hastings did not find PFOA or PFOS.

In spring 2006, the MDH Public Health Laboratory developed methods to detect five more types of PFCs. Analysis of the water samples revealed that one of these, PFBA, is widespread. PFBA seems to move very freely in the groundwater; more so than PFOS or PFOA. It does not break down or degrade. PFBA has now been found in two distinct areas of southern Washington County.

One area of groundwater contamination appears to originate from the former Washington County Landfill in Lake Elmo and the former Abresch Dump in Oakdale. This area extends into the City of Woodbury. In drinking water near the disposal sites, multiple PFCs, including PFOA and PFOS, are found. Only PFBA has been detected in the Woodbury municipal wells.

A second area of groundwater contamination is located further south and is primarily PFBA, with no detections of PFOA or PFOS. PFBA has been detected in all of the city wells in Cottage Grove, St. Paul Park and Newport and in some city wells in South St. Paul and Hastings. This area of contamination may originate from the disposal site on the border of Woodbury and Cottage Grove.

So far, PFCs have not been found in limited testing of groundwater done elsewhere in the metropolitan area.

“Learning about chemical contamination in groundwater is a step-by-step process,” Stine said. “Though the discovery of PFCs in the southeast metro is relatively new, testing information from the last couple of years suggests that the levels of PFCs in the groundwater are stable and not increasing. The testing information also suggests that PFCs have been present for some time. Our testing for these chemicals has improved since we began.”

MDH has been using the well advisory guideline for PFOA, 1 ppb, as a temporary guideline for PFBA. “It’s important to note that these are guidelines and there is not a bright line of health risk for findings just above or below the number of 1,” Stine said. “The levels of PFBA in each of the four cities is still very low. Some wells in Cottage Grove and St. Paul Park slightly exceed the MDH guidelines. The initial sampling results for South St. Paul and Hastings still need to be confirmed.”

Scientific understanding of the relative toxicity of PFBA, along with the other PFCs is evolving. “Looking at new studies and some underway, we anticipate that PFBA should be less toxic to people than PFOA based on its chemical characteristics and on preliminary data from animal studies,” Stine said. “In contrast to PFOA and PFOS, PFBA does not appear to accumulate in animals or people.” Once the studies are completed and reviewed, MDH will develop specific advice for PFBA as well as revised values for PFOS and PFOA. 

MDH will meet with officials from the affected cities next week to further discuss the test results and their implications. MDH will continue to provide technical support to cities for managing their drinking water systems.

While there is no immediate concern for drinking water, residents who have PFBA in their drinking water and wish to reduce their exposure can take some simple steps. They can use bottled water for part or all of their drinking or cooking needs. Also, filters containing granular activated carbon (GAC) remove PFCs, including PFBA. Many common water filters contain GAC.
Residents in the affected areas who want further information can contact the Minnesota Department of Health Environmental Health Division at 651-201-4897 or visit MDH's Drinking Water Protection Web page at http://www.health.state.mn.us/divs/eh/water/index.html.

-MDH-

Map of PFC plumes in S. Washington Co. (PDF: 74KB/1 page)

PFBA in the Groundwater of the South East Metro Area

For more information, contact:

Doug Schultz
MDH Communications
(651) 201-4993

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