Per- and Polyfluoroalkyl Substances (PFAS) and Private Wells
PFAS are a family of human-made chemicals that have been widely used for decades. PFAS are extremely stable and do not breakdown in the environment.
PFAS have been found in the groundwater and surface water 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 frequently.
At this time, Minnesota Department of Health (MDH) does not recommend that every private well is tested for PFAS. If you use a private well for drinking water that is included in an existing environmental investigation near a known source of contamination, the Minnesota Pollution Control Agency (MPCA) will notify you if your well might be affected. If you want to test your private well for PFAS and are not a part of an MPCA environmental investigation, see the Testing your private well for PFAS section.
Health-Based Guidance Values
MDH has developed health-based guidance values to represent levels for several PFAS in drinking water. The guidance values are levels that MDH considers safe for all people to consume, including sensitive populations. The guidance values apply to short time periods as well as a lifetime of exposure. The table below shows the health-based guidance values (in parts per billion, or ppb) for six PFAS that MDH uses to evaluate sample results.
|PFAS||Drinking Water Guidance Value (ppb)|
|perfluorobutane sulfonate (PFBS)||0.1|
|perfluorohexane sulfonate (PFHxS)||0.047|
|perfluorooctane sulfonate (PFOS)||0.015|
|perfluorobutanoic acid (PFBA)||7|
|perfluorohexanoic acid (PFHxA)||0.2|
|perfluorooctanoic acid (PFOA)||0.035|
Scientists are actively studying PFAS exposures and human health impacts. Numerous studies have shown that higher levels of exposure to PFAS are associated with a wide range of human health effects. These include higher cholesterol, changes to liver function, reduced immune response, thyroid disease, and, in the case of PFOA, increased kidney and testicular cancer. However, more work needs to be done to determine if PFAS, or other factors, caused the effects. Research continues on PFAS to determine effects on birth outcomes, hormone balance, cholesterol levels, immune response, and cancer. There are many different PFAS and each may have varying roles for different effects. Learn more about health risks at PFAS and Health.
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Testing Your Private Well for PFAS
The science about PFAS continues to change as new data and information become available. EPA has issued interim health-based guidance values for two PFAS (PFOA and PFOS) and final guidance values for PFBS and GenX chemicals. At this time, MDH is not recommending that you test your well for PFAS based on these new values. Currently, laboratories cannot test water down to the level of the new EPA health-based guidance values. After EPA has released the documents supporting the new values, MDH will review those and share recommendations on how Minnesotans using private wells can take actions to reduce their exposures to PFAS through drinking water.
Here is where you can look to see if your private well may be near a known source of PFAS contamination:
- Minnesota Groundwater Contamination Atlas
- What's in My Neighborhood
- Interactive Dashboard for PFAS Testing in Drinking Water
How to get your private well tested for PFAS depends on whether your well is part of a MPCA environmental investigation.
Private wells that are part of an MPCA environmental investigation
If you use a private well for drinking water that is included in an existing environmental investigation near a known source of contamination, the MPCA will notify you if your well might be affected. MDH works with MPCA during environmental investigations to issue private well advisories. MPCA and MDH staff are available to answer questions about private well testing results.
MDH does not issue well advisory letters based on third party results (i.e., those not provided by the state or its contractors). If you test your well on your own, and the well is a part of an environmental investigation, MPCA would still need to resample the well and provide results to MDH before a well advisory would be issued.
Private wells that are not part of an MPCA environmental investigation
The Minnesota Environmental Laboratory Accreditation Program (MNELAP) accredits seven laboratories that test for PFAS and say they will accept samples from homeowners. Contact the laboratory to make sure they will accept samples from homeowners and to get sample collection information and costs.
Accredited Laboratories – PFAS Testing
|Eurofins Test America Denver||Arvada||CO||303-736-0100|
|Enthalpy Analytical LLC||El Dorado Hills||CA||916-673-1520|
|Eurofins Lancaster Laboratories Environment Testing, LLC||Lancaster||PA||717-656-2300|
|Michigan Department of Environment, Great Lakes, and Energy Laboratory Services||Lansing||MI||517-335-9800|
|Pace Analytical Services, LLC||Minneapolis||MN||612-607-1700|
|SGS North America, Inc.||Wilmington||NC||910-350-1903|
The list of laboratories is current as of June 2022. You can confirm the list above at Search for Accredited Laboratories.
Do not be put off by the fact that some are not in Minnesota – they will mail/overnight bottles and instructions. Some accredited laboratories may not accept samples from homeowners, and sometimes they are not very responsive to such requests (likely when they have more than enough work and do not have capacity for a one-time, one sample project).
If you cannot find a laboratory willing to take your sample, you could also try contacting an environmental consulting firm here in Minnesota and request that they collect the sample. They will either have their own laboratory or contract with a local laboratory. This can avoid problems that private homeowners have in finding a laboratory to run the sample.
Interpreting your well test results
If you would like help interpreting your sample results and how they relate to MDH health-based guidance values, please contact the Site Assessment and Consultation Unit at 651-201-4897 or email firstname.lastname@example.org.
Protect Your Family
Eliminating all exposure to PFAS is unlikely, however, you can take the following steps to reduce your exposure to PFAS:
- Consider home water treatment if you live near sources of drinking water that is contaminated with PFAS, know there is PFAS in your drinking water, or are concerned about PFAS. (See PFAS and Home Treatment of Water).
- Prepare infant formula with filtered tap water or bottled water if your private well has not been tested for PFAS.
- PFOS may also be present in the fish people catch and eat. Fish Consumption Guidance for fish caught in areas affected by PFOS is available at Fish Consumption Guidance.
- Learn additional tips at PFAS and Health.
PFAS and Home Treatment of Water
There are both point-of-use (water is treated at one faucet or location) and point-of-entry (all the water in your home is treated) treatment options to reduce PFAS in drinking water. See PFAS and Home Treatment of Water.
PFAS in Minnesota Water
Since PFAS is an emerging contaminant, we are still learning about how often PFAS is found in groundwater, at what levels, and where. 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 (see Per- and Polyfluoroalkyl Substances (PFAS) Sites in Minnesota). MDH is also sampling drinking water in public water systems and is finding very few water systems have a detectable level of PFAS (see PFAS Testing of Public Water Systems).
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Should I test my well water for anything besides PFAS?
Yes. Both natural sources and human activities can contaminate well water and cause short- or long-term health effects. Testing your well water is the only way to detect most of the common contaminants in Minnesota groundwater; you cannot taste, see, or smell most contaminants. Minnesota Department of Health recommends testing for:
- Coliform bacteria every year and any time the water changes in taste, odor, or appearance. Coliform bacteria can indicate that disease-causing microorganisms may be in your water. See Bacterial Safety of Well Water.
- Nitrate every other year. Bottle-fed infants under six months old are at the highest risk of being affected by levels of nitrate higher than 10 milligrams per liter in drinking water. See Nitrate in Well Water.
- Arsenic at least once. About 40 percent of wells in Minnesota have arsenic in the water. Drinking water with arsenic in it for a long time can contribute to reduced intelligence in children and increased risks of cancer, diabetes, heart disease, and skin problems. See Arsenic in Well Water.
- Lead at least once. The well and water system may have parts that have lead in them, and that lead can get into drinking water. Lead can damage the brain, kidneys, and nervous system. Lead can also slow development or cause learning, behavior, and hearing problems. See Lead in Well Water Systems.
- Manganese before a baby drinks the water. High levels of manganese can cause problems with memory, attention, and motor skills. It can also cause learning and behavior problems in infants and children. See Manganese in Drinking Water.
Other contaminants sometimes occur in private water systems, but less often than the contaminants listed above. Consider testing for:
- Volatile organic chemicals if the well is near fuel tanks or a commercial or industrial area.
- Agricultural chemicals commonly used in the area if the well is shallow and is near cropped fields or handling areas for agricultural chemicals or is in an area of geologic sensitivity (such as fractured limestone).
- Fluoride if children or teenagers drink the water.
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