Perfluoroalkyl Substances (PFAS) - EH: Minnesota Department of Health

Perfluoroalkyl Substances (PFAS)

Perfluoroalkyl Substances (PFAS) are also referred to as Perfluorochemicals (PFCs)

PFAS are a family of manmade chemicals that were used for decades. PFAS are extremely stable and do not breakdown in the environment. Common uses of PFAS include:

  1. Nonstick cookware, stain-resistant carpets and fabrics,
  2. Coatings on some food packaging (especially microwave popcorn bags and fast food wrappers),
  3. Components of fire-fighting foam, and
  4. Many industrial applications.

PFAS have been found in the groundwater in Minnesota. PFAS are emerging contaminants. Emerging contaminants are contaminants about which we have a new awareness or understanding about how they move in the environment or affect public health. PFAS, like other emerging contaminants, are the focus of active research and study, which means that new information is released occasionally.

Private Drinking Water Well Sampling Request Form

MDH can help you with well testing if you are in the East Metro sampling area. The Minnesota Pollution Control Agency's Interactive Map to the best way to see if you are in the sampling area.

We are working through the sampling lists as we are able based on current resources. We are experiencing a high volume of requests at this time. We will address your request as soon as we are able. You will be contacted based on your location compared to the current sampling area as we work through the sampling list.

Please use the MDH Well Sampling Request Form to submit your request.

Information about Private Drinking Water Well Sampling
in South Washington County

Download the PFAS Sampling in South Washington County map from the video above.

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PFAS Activities In Minnesota

Current Activities

MDH is applying for funds to establish a study site in the East Metro area of the Twin Cities. While MDH has been working with other state agencies, local agencies, and water operators to reduce PFAS drinking water exposures in East Metro communities since the contamination was first discovered, MDH recognizes that there is still more to learn about the potential health effects of exposures to these chemicals.

By participating in this research, MDH hopes to provide some answers to East Metro communities about potential health impacts. This research is also an important opportunity to contribute to scientific knowledge on these chemicals that may lead to additional public health actions to reduce exposures and any identified health risks in other communities impacted by PFAS-contaminated drinking water.

For more information, please contact:

Jim Kelly, Manager: 651-201-4910 or

Deanna Scher, Epidemiologist: 651-201-4922 or

For more information about the study proposal, see Health Implications of Exposure to PFAS-Contaminated Drinking Water: Proposal for a Multi-Site Study (PDF)

Minnesota Department of Health (MDH) officials issued new health-based values for two chemicals associated with groundwater contamination in the eastern Twin Cities on April 3, 2019. MDH set the new values after reviewing the latest scientific data on the two chemicals.

The two chemicals PFOS and PFHxS are in the family of chemicals known as perfluoroalkyl substances, or perfluorochemicals. The new PFOS value of 15 parts per trillion (ppt) replaces the previous value of 27 ppt. The new health-based value for PFHxS is 47 ppt. Until now, the state had used the 27 ppt PFOS health-based value as a “surrogate” for PFHxS due to a lack of available data specific to PFHxS.

For more information about the values, see Safe Levels of PFAS in Drinking Water on this page.

Private Wells

Over 2700 private wells have been sampled in the East Metro. Recent sampling has focused mainly on portions of Lake Elmo, West Lakeland Township, north Afton, Lakeland, Lakeland Shores, Cottage Grove, Grey Cloud Island Township, south Woodbury, and south Maplewood. See Washington County Maps on the MDH website.

  • Over 1,100 drinking water advisories have been issued. See map of Private Well Drinking Water Advisories (PDF)
  • Approximately 300 additional wells have been identified for sampling in spring 2019. 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 the health-based guidance values have been defined.
  • MPCA has an interactive PFCs - Private Well Sampling Areas map that you can use to locate your address and find out if your property is in an area where sampling shows the groundwater is above or below the health-based guidance values or where the state is currently sampling. If you have a private drinking water well and would like to have your water tested, you can also use this interactive map to find out if your property is inside the area where the state will test private well water for PFAS. If it is, you can request sampling using the MDH Well Sampling Request form.
    • If your well has already been sampled, you do not need to request additional sampling – it will be placed on a regular monitoring schedule.How often your well is sampled will be based on your past sample results and how close your property is to areas that exceed health-based guidance levels. MDH will contact you regarding re-sampling.

City Wells

  • There are currently five community public water supplies in the East Metro that have individual wells above the MDH health-based guidance values: Oakdale, Lake Elmo, Woodbury, Cottage Grove, and St. Paul Park. All of these cities put in place interim measures to manage their public water supply systems to provide drinking water at or below the MDH health-based guidance values. These measures included shutting off the most highly contaminated wells and relying on wells that are clean or have lower levels of PFAS.
  • In 2017, the city of Cottage Grove installed treatment systems for two city wells. MDH sampling shows the treated water meets the health-based guidance values for PFOS and PFOA, and the combined PFAS concentrations meet MDH health-based guidance values.
  • Since 2006, the city of Oakdale has treated the water from their two primary production wells and in 2010 added another well to their system that is located outside the PFAS area (in addition to a pre-existing well outside the PFAS area).
  • In 2018, one city well in Lake Elmo exceeded the health-based guidance values. It was shut off and the city is exploring options for replacing it.MDH continues to monitor water quality at all the affected communities to ensure that the finished drinking water meets the EPA health advisory values and combined PFAS do not exceed the guidance values.
  • PFAS 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.

Surface Water

  • Sampling in 2016-2018 detected PFAS 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 PFAS-contaminated water infiltrated from the surface water to groundwater in south West Lakeland Township and affected nearby wells, many of which exceed EPA and MDH health-based guidance values.
  • Sampling of nearby surface waters not connected to the “Project 1007” drainage system did not detect PFAS, except for trace levels of PFBA typical of surface waters in the US.
For questions about GAC Filter Installation:

Contact Gary Krueger (MPCA). 651-757-2509 or

For questions about Water Sample Results:

Contact Ginny Yingling (MDH). 651-201-4930 or

For questions about health concerns or more information about PFAS:

Contact the Site Assessment and Consultation Unit (MDH) at 651-201-4897 or


The Minnesota Department of Health (MDH) and Minnesota Pollution Control Agency (MPCA) have investigated a number sites across the state where PFAS were released to the environment. View the MDH webpage Perfluoroalkyl Substances (PFAS) Sites in Minnesota.

History of PFAS in Minnesota

Since 2002, the MDH has partnered with the MPCA to investigate PFAS in Minnesota. This work began with drinking water investigations near the 3M Cottage Grove plant and related legacy waste disposal sites in Washington County (east of St. Paul). Read more about the History of Perfluoroalkyl Substances (PFAS) in Minnesota.

PFAS and Health

Our understanding and ability to detect PFAS in the environment has evolved since the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Health (MDH) began investigating them in 2002. Laboratories at that time only identified a few PFAS and could not detect very low concentrations. The science in the past also suggested that exposure to very small amounts of PFAS were not a health concern. We are now able to measure extremely small amounts (parts per trillion in water) of a number of PFAS and newer studies suggest that long-term exposure to PFAS in this range might affect the most vulnerable members of the population. MDH continues to monitor the growing body of science about PFAS and we will adjust our health advice as needed.

  • In the environment: Because PFAS are so stable, they may be found in soil, sediments, water or other places. Studies show some PFAS travel through soil and easily enter groundwater, where they may move long distances. Some experts suggest PFAS also travel long distances in air. PFAS have been released to the environment through spills and disposal in the past. For information about where PFAS have been found in Minnesota, see the MPCA Perfluorochemicals webpage.
  • In wildlife: PFAS have been found in many species of wildlife around the world, including fish, bald eagles, and mink in the mid-western U. S.
  • In fish: PFOS is a specific PFAS that accumulates to levels of concern in fish. Most fish have low levels of PFOS. However, fish in some Minnesota lakes have levels of PFOS that require restrictive fish consumption advice. Information about PFAS in fish and site-specific meal advice are available on the MDH webpage Site-Specific Meal Advice for Tested Lakes and Rivers.
  • In Minnesota lakes and rivers: PFAS may be present in lakes and rivers at very low levels. MDH has determined that exposure to PFAS through swimming is not of concern. PFAS are poorly absorbed through skin and swallowing small amounts of water while swimming will not result in significant exposure. Also, because there is little evaporation of PFAS from water into the air, breathing them in while swimming or bathing is not a health concern.
  • In people: Studies show nearly all people have some PFAS in their blood, regardless of their age. The PFAS most commonly found in human blood are PFOS, PFOA, PFHxS, and PFNA. People are exposed through food, water, dust or consumer products. Some PFAS can build up and stay in the human body for many years. They can also slowly decline if the exposure stops. MDH has conducted three studies that measured PFAS in the blood of East Metro residents. Results showed that PFAS levels in the blood of longer-term residents dropped between 2008 and 2014 after public health interventions were put in place to reduce drinking water exposures. For information about the studies, see the MDH webpage PFAS Biomonitoring in the East Metro.

Scientists are actively studying whether PFAS cause health problems in people. Researchers have found links between PFAS and some human health outcomes. In some studies, higher levels of PFAS in a person’s body were associated with higher cholesterol, changes to liver function, reduced immune response, thyroid disease, and increased kidney and testicular cancer. More work needs to be done to determine if PFAS or other factors caused the health outcomes.

There are several different PFAS and health effects are slightly different for each PFAS. For specific information about PFAS with MDH health-based values, use the links in the table below. Studies in animals have shown some health effects such as changes in development, liver and thyroid function, immune response, and increased kidney weight and cellular changes. Increased tumors were also observed in certain organs in animals exposed to very high doses of PFOA. Research continues on PFAS and health effects such as birth outcomes, hormone balance, cholesterol levels, immune response, and carcinogenicity.

  • While we believe the immediate health risks for people exposed to PFAS are low, the latest information indicates that fetuses and infants are more vulnerable. Long term exposure to PFOA, PFOS, and PFHxS leads to a buildup of these chemicals in women of child bearing age that results in more exposure to the fetus and breastfed infants. Breastfeeding provides many health benefits to both a mother and infant. MDH recommends that women currently breastfeeding, and pregnant women who plan to breastfeed, continue to do so. For information about breastfeeding, see the MDH Breastfeeding webpage.
  • Bottle-fed infants are also of concern because they drink more water per body weight than adults. If you are concerned about exposure through bottle feeding, consider using bottled water as your water source until you have filtered drinking water. This can lower exposure to PFAS for your infant.

Water with PFAS levels above the health-based guidance values is safe for bathing, showering or washing clothes and cleaning, but should not be used for drinking or cooking.

MDH is responsible for ensuring safe drinking water for all Minnesotans. One way we do this is through regular testing of public water supplies for contaminants. MDH also works with the MPCA to investigate situations where groundwater contaminants may affect private drinking water wells.

MDH has developed health-based guidance values to represent levels for various PFAS in drinking water that MDH considers safe for people, including sensitive populations. The guidance values apply to short periods of time as well as over a lifetime of exposure. The table below shows the PFAS that the MDH Public Health Laboratory can test for and the health-based drinking water guidance values (in parts per billion, or ppb) MDH uses to evaluate drinking water samples. More information can be found on the MDH Guidance Values and Standards for Contaminants in Drinking Water webpage.

Table of Health-based Values for PFAS

PFAS Detected in Minnesota

Drinking Water Guidance Value
pb or µg/L)

perfluorobutane sulfonate (PFBS)

PFBS and Drinking Water (PDF)


perfluorohexane sulfonate (PFHxS)


perfluorooctane sulfonate (PFOS)

PFOS and Groundwater(PDF)


perfluorobutanoic acid (PFBA)

PFBA and Drinking Water (PDF)


perfluoropentanoic acid (PFPeA)

Not established

perfluorohexanoic acid (PFHxA)

Not established

perfluorooctanoic acid (PFOA)

PFOA and Drinking Water (PDF)


Water samples often contain multiple chemicals. Chemicals in combination may cause effects that would not be predicted based on separate exposures to the individual concentrations of each chemical present. When more than one PFAS for which guidance values are available are present in drinking water, MDH evaluates their “additive” risk. For more information, visit the MDH webpage: Evaluating Concurrent Exposures to Multiple Chemicals.

Completely stopping exposure to PFAS is not practical, because they are so common and present throughout the world.

If you live where drinking water sources are contaminated, you can take the steps below to lower your exposure to PFAS.

PFOS may also be present in the fish people catch and eat. The MDH website provides Site-Specific Meal Advice for Tested Lakes and Rivers for eating fish, including fish caught in areas affected by PFOS.

Ingestion of household dust can also be a significant route of exposure, especially for infants and young children. Dust household surfaces regularly to lower the amount of dust in the house.

Printable Information Sheets

PFAS and Home Treatment of Water

Until their wells are tested, residents who have concerns about their health can take steps to reduce their potential exposure to PFAS. Filters containing activated carbon or reverse osmosis membranes have been shown to be effective at removing PFAS from water supplies. Other types of common water treatment systems, such as water softeners, are not likely to remove PFAS. Boiling water will not remove PFAS.

The evaluation below 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.

The activated carbon and reverse osmosis treatment technologies described in the following reports are expected to perform as described. At this point, Minnesota Department of Health has not evaluated other technologies for PFAS removal. You should contact a water treatment specialist to make sure the filter model you choose meets your needs.

A filter with granular activated carbon (GAC) is a proven option to remove certain chemicals, particularly organic chemicals, from water. GAC filters also can be used to remove chemicals that give objectionable odors or tastes to water such as hydrogen sulfide (rotten eggs odor) or chlorine.

For more information, visit Water Treatment Using Carbon Filters: GAC Filter Information.

PFAS and Fish

PFOS is a specific PFAS that accumulates to in fish. Most fish have low levels of PFOS. However, fish in some Minnesota lakes have levels of PFOS that require restrictive fish consumption advice. Information about PFAS in fish and Site-Specific Meal Advice for Tested Lakes and Rivers are available on the MDH webpage Contaminants and Minnesota Fish.

Minnesota Pollution Control Agency (MPCA) is investigating the sources of PFAS in fish. See the MPCA PFC investigation and clean up webpages for more information.

Additional Resources

  • Perfluorochemicals in Homes and Gardens Study (PDF)

    MDH conducted a study of PFAS 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 communities 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 PFAS in produce.

  • Brief Update on Cancer Occurrence in East Metro Communities (PDF), February 2018

    The cancer experience of Dakota and Washington County residents is not unusual compared with the State of Minnesota as a whole. For many cancer types, the number of cancers occurring in the two counties did not differ from the numbers expected.

    While these analyses are instructive, the department only examined data for two potential health outcomes: birth outcomes and cancer. MDH has not collected public health data on other types of potential health effects reported in the scientific literature, such as liver and kidney effects, thyroid disease, or immune system changes. While MDH’s water guidance values protect against all of these effects, data on their occurrence in people are not available.

  • Data Update: Cancer Incidence in Dakota and Washington Counties (PDF), 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.

  • Cancer Incidence in Dakota and Washington Counties, June 7, 2007

    If you would like a copy of this archived report, please send an email to

  • PFAS Biomonitoring: East Metro

    MDH conducted three rounds of biomonitoring between 2008 and 2014, looking at the concentrations of PFAS in the blood of East Metro residents who were exposed to PFAS in their water supplies. Levels of PFAS declined measurably over that time, although they remain above national averages. This indicates that providing a water supply that is treated or free of PFAS is an effective public health intervention.

Updated Tuesday, 01-Oct-2019 12:41:31 CDT