MDH Response to EPA Health Advisory for PFOS and PFOA
The U.S. Environmental Protection Agency released health advisory values in 2016 to reflect the latest scientific evidence about the risk posed by PFCs. MDH staff have reviewed the studies and methods used by EPA to determine whether our health-based values for these chemicals need to be lowered, and if so, what the values should be.
In May 2017, MDH released updated guidance values for PFOA and PFOS. The values apply to short periods of time (i.e., weeks to months) during pregnancy and breastfeeding, as well as over a lifetime of exposure. The revision is based on the understanding that PFOA and PFOS stay in the human body for years and can increase with additional exposures, and can cross the placenta and are secreted in breastmilk.
The updated values are health recommendations to local officials operating public water supplies and to private well owners in the areas with PFCs in groundwater. In addition, these values are used by the Minnesota Pollution Control Agency (MPCA) and other agencies to take action to ensure responsible parties are held accountable for clean-up and remediation of contaminated sites.
The updated values are 35 parts per trillion for PFOA and 27 parts per trillion for PFOS. These values are more protective than the Environmental Protection Agency (EPA) value of 70 parts per trillion. While the EPA value is protective for most people, the updated MDH values reflect new state-level analysis of the potential for mothers to pass along the chemicals to fetuses and nursing infants.
MDH recommends that women in the affected communities who are currently breastfeeding, and pregnant women who plan to breastfeed, should continue to do so. Breastfeeding is important for the short and long-term health of both a mother and infant. Pregnant or nursing women using water from affected groundwater sources to prepare infant formula may consider using filtration or bottled water to reduce PFC exposure until the contamination of their water supply has been remedied.
Residents of south Washington County who live in or near areas where groundwater has been contaminated with perfluorochemicals (PFCs) had an opportunity to ask questions about PFCs and discuss this issue one-on-one with staff from the Minnesota Department of Health (MDH), the Minnesota Pollution Control Agency (MPCA) and Washington County. The meetings took place on June 6, 2017 in Lake Elmo and on June 7, 2017 in Cottage Grove. Cottage Grove recorded the presentation and has it available on the Cottage Grove Watering Ban: City Water is Safe to Drink webpage.
Information for affected Minnesotans
- Over 550 private wells have been sampled (see map of PFCs - Private Well Sampling Areas - East Metro (PDF)), primarily in portions of Lake Elmo, West Lakeland Township (see map of PFCs - Private Well Sampling Areas - North (PDF)), Cottage Grove, and Grey Cloud Island Township (see map of PFCs - Private Well Sampling Areas - South (PDF)).
- Over 340 new drinking water advisories [see map of Private Well Drinking Water Advisories (PDF)) have been issued.
- Approximately 240 additional wells have been identified for sampling in spring 2017. More wells will be added as needed, based on sample results.
- If a well is selected to be sampled, MDH will contact the well owner by mail with more information and to get their permission.
- Sampling will continue until the areas that exceed levels of health concern have been defined.
- MPCA has an interactive version of the map which you can use to locate your address and determine if you are within an area of concern.
- There are currently five community public water supplies that have individual wells above the new MDH health-based guidance: Oakdale, Woodbury, Cottage Grove, St. Paul Park, and Bemidji. All of these cities have put in place interim measures to manage their public water supply systems to provide drinking water at or below the new MDH health-based guidance. These measures include shutting off the most highly contaminated wells and relying on wells that are clean or have lower levels of PFCs.
- In some cities, watering restrictions may be needed to reduce demand so the wells in use can supply enough water for homes, schools, churches, and businesses. In some cases, this may mean the city has to declare a "State of Emergency". This is not a public health emergency. Cities may need to make this declaration in order to be able to issue watering restrictions.
- MDH continues to monitor water quality at all the affected communities to ensure that the finished drinking water meets the new EPA health advisory values and combined PFCs do not exceed the health index value.
- PFC concentrations in most city wells have remained stable or decreased slightly over time.
Other Public Wells
- MDH is also sampling non-community, public wells (businesses, schools, churches, etc.) and providing drinking water advice as needed.
- Sampling detected PFCs above the health based drinking water values in the stormwater drainage system. The system helps to control flooding in the Lake Elmo area.
- Sampling near this drainage system indicates that PFC-contaminated water has infiltrated from the surface water to groundwater and affected nearby wells, many of which exceed EPA and MDH health based values.
- Most of the private well sampling in spring 2017 will focus on defining the extent of groundwater contamination along the course of the stormwater drainage system.
- MDH and MPCA plan to do additional surface water sampling in 2017.
Public meetings were held in September and November in Lake Elmo and Cottage Grove.There will be more opportunities to meet with MDH and MPCA staff in the future when we have new information available.
- MDH's existing Health Risk Limit (HRL) of 300 ppt for PFOA and PFOS in drinking water is likely to be protective for most people – for whom the concern with PFCs is with long-term exposure.
- While we believe the immediate health risks for most people exposed to PFCs are low, the latest information from EPA identifies a possible risk for developing fetuses and infants.
Until their wells are tested, residents who have concerns about their health can take steps to reduce their potential exposure to PFCs. Filters containing activated carbon or reverse osmosis membranes have been shown to be effective at removing PFCs from water supplies. Other types of common water treatment systems, such as water softeners, are not likely to remove PFCs. Boiling water will not remove PFCs.
Information on inexpensive, point-of-use filters and other steps people can take in their homes can be found on the MDH website on the Home Water Treatment Units: Point-of-Use Devices webpage.
- Water with PFC levels above health concern is safe for bathing, showering or washing clothes and cleaning, but should not be used for drinking or cooking.
An Evaluation of Perfluorochemical Removal by a Small, Point-of-Use Filter (PDF) was finalized by MPCA, MDH and West Central Environmental Consulting in September 2016. This evaluation provides information about an inexpensive, easily installed, point -of-use carbon filter option for filtering drinking water at a sink faucet.
For more information about how to lower your exposure to PFCs and the EPA Health Advisory for PFOA and PFOS, visit the PFCs and Health webpage.
For Health Care Providers:
Information to help answer questions patients may bring to a visit.
About Perfluorochemicals (PFCs) in Drinking Water - for Health Professionals
- Fish Consumption Guidance
MDH and MPCA are evaluating whether to do any additional fish sampling in the affected surface waters. Fish sampling between 2006-2013 resulted in fish consumption advisories for Lake Elmo, the St. Croix River, and several other surface waters in the East Metro.
- Gardening and PFCs (PDF)
MDH conducted a study of PFC levels in homegrown produce, garden soil, and outdoor tap water from the eastern Twin Cities area in 2010. MDH concluded that no health risks of concern were found for anyone living in these communitieis when considering combined risk from all exposure pathways. MDH determined that the health benefits provided by growing and eating homegrown produce greatly outweigh any potential risk from low levels of PFBA or other PFCs in produce.
- Minnesota Cancer Surveillance System Information
DATA UPDATE: CANCER INCIDENCE IN DAKOTA AND WASHINGTON COUNTIES (PDF) (MCSS Epidemiology Report 2015:1; May 13, 2015)
The cancer surveillance methods applied in this report did not find the cancer experience of Dakota and Washington County residents to be unusual, compared with the State of Minnesota as a whole. For most cancer types the number of cancers occurring in the two counties did not differ from the numbers expected.
- PFC Biomonitoring: East Metro
MDH conducted three rounds of biomonitoring between 2008 and 2014, looking at the concentrations of PFCs in the blood of East Metro residents who were exposed to PFCs in their water supplies. Levels of PFCs declined measurably over that time, although they remain above national averages. This indicates that providing a water supply that is treated or free of PFCs is an effective public health intervention.
- For questions about GAC Filter Installation, contact Gary Krueger (MPCA). 651-757-2509 or firstname.lastname@example.org.
- For questions about Water Sample Results, contact Ginny Yingling (MDH). 651-201-4930 or email@example.com.
- For questions about Health Concerns or more information about PFCs, contact the Site Assessment and Consultation Unit (MDH) at 651-201-4897 or firstname.lastname@example.org.