MDH Current Activites: Perflurochemicals (PFCs) in Minnesota
Also referred to as Perfluoroalkyl Substances (PFAS)
Update on Lake Elmo's water supply
The municipal water in Lake Elmo is safe to drink and use for all household purposes. The Minnesota Department of Health (MDH) has been monitoring city water for many years and found low levels of PFOA in one well, slightly above MDH’s Health Based Value (HBV). This well has been shut down and PFOA is no longer in the city water at any concentration.
Last May, MDH recommended setting an HBV of 0.035 ppb for PFOA. MDH bases their guidance values on long-term, higher than average water consumption to protect highly exposed individuals. Most individuals are exposed for a shorter period of time and have lower water consumption. The PFOA value is based not only on highly exposed individuals drinking the water, but includes extra protection against passing accumulated levels onto babies during pregnancy and breast feeding.
PFOA first appeared at low levels (0.048 ppb) in one city well (well #1) in 2013. Concentrations increased slightly in 2014 to 0.086 ppb and have been on a decreasing trend ever since; decreasing to 0.023 ppb by 2016. In May 2017, the concentration in well #1 had fluctuated up slightly to 0.052 ppb. This is typical of groundwater contaminants – even if concentrations are trending downward, there is usually a bit of fluctuation. Although the PFOA concentrations are continuing to decrease, the average over the period from April 2017 – Feb 2018 was slightly above 0.035 ppb, so MDH issued an advisory to the city and the city shut off well #1. The concentrations of PFOA have not been high enough or present long enough to pose a potential health risk. Well #1 was shut off to eliminate PFOA from the city water.
According to the city, well #1 supplied water only to those residents on municipal services south of the railroad tracks and along Lake Elmo Ave. south to 5th St. Other areas of the city are served by the other wells that were not affected.
The U.S. Environmental Protection Agency (EPA) released health advisory values in 2016 to reflect the latest scientific evidence about the risk posed by PFCs. MDH staff reviewed the studies and methods used by EPA, to determine whether our health-based values for these chemicals needed 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, can increase with additional exposures, cross the placenta, and are secreted in breastmilk.
The updated values are health recommendations to local officials operating public water supplies and private well owners in 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 EPA value of 70 parts per trillion for either chemical or whenn added together. 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 at meetings on June 6, 2017 in Lake Elmo and on June 7, 2017 in Cottage Grove.
Information for affected Minnesotans
- Over 1000 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 440 new drinking water advisories [see map of Private Well Drinking Water Advisories (PDF)) have been issued.
- Approximately 100 additional wells have been identified for sampling in fall 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 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 included shutting off the most highly contaminated wells and relying on wells that are clean or have lower levels of PFCs.
- The city of Cottage Grove instituted a watering ban at the beginning of the summer in response to shutting off several wells until treatment systems could be installed and tested. The ban was lifted on August 1, after MDH sampling proved the treated water meets the new Health Based Values for PFOS and PFOA, and the combined PFC concentrations meet MDH health based guidance.
- 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 in 2016 and 2017 detected PFCs above the health based drinking water values in the “Project 1007” stormwater drainage system that helps to control flooding in the Lake Elmo and West Lakeland Township 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.
- M Most of the private well sampling in fall 2017 will continue to focus on defining the extent of groundwater contamination downgradient of the stormwater drainage system.
Public meetings were held June 2017 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.
Our understanding of and ability to detect PFCs in the environment has evolved since Minnesota Pollution Control Agency (MPCA) and Minnesota Department of Health (MDH) began investigating them in 2002. Laboratories at that time could not detect very low concentrations of PFCs and the science suggested that exposure to very small amounts of PFCs was not a health concern. We now are able to measure PFCs in extremely small amounts (parts per trillion in water) and newer studies suggest long-term exposure in this range might affect the health of the most vulnerable members of the population.
See the Perfluorochemicals (PFCs) and Health webpage for more information about guidance values for PFCs.
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.
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.