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PFAS stands for per- and polyfluoroalkyl substances. These "forever chemicals" are a group of man-made chemicals that have been widely used in various industries due to their water and grease-resistant properties. PFAS compounds are found in many everyday products such as non-stick cookware, waterproof clothing, food packaging, and firefighting foam. These chemicals are of concern because they are persistent in the environment and can accumulate in the human body over time. Exposure to PFAS has been associated with potential health effects, including liver damage, immune system dysfunction, and an increased risk of certain cancers.
PFAS chemicals are used in thousands of products, and they are found everywhere-in the air, water, soil, clothing, and even our bodies. Despite their widespread use, we still lack a comprehensive understanding of their health effects. The breakdown products of PFAS and their movement in the environment still is not fully understood. Not all PFAS compounds behave the same way, so researchers are actively working to unravel these complexities and provide answers to the questions we still have surrounding PFAS.
When should I test for PFAS in my well water?
USEPA released standards for six PFAS. PFOA, PFOS, PFHxS, PFNA, and HFPO-DA are listed as contaminants with individual maximum contaminant levels (MCLs). PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS use a Hazard Index MCL.
Compound | Final MCLG | Final MCL (enforceable levels) |
PFOA | Zero | 4.0 parts per trillion (ppt) (also expressed as ng/L) |
PFOS | Zero | 4.0 ppt |
PFHxS | 10 ppt | 10 ppt |
PFNA | 10 ppt | 10 ppt |
HFPO-DA (commonly known as GenX Chemicals) | 10 ppt | 10 ppt |
Mixtures containing two or more of PFHxS, PFNA, HFPO-DA, and PFBS | 1 (unitless) Hazard Index | 1 (unitless) Hazard Index |
Figure 1: PFAS MCLs as set by the United States Environmental Protection Agency
Even though testing for PFAS is expensive, it is worth it if you live near a known source (airport, chemical plant, etc.). To ensure you are protecting your family’s health, we have developed a set of recommendations for testing that are provided in our article, "What do I need to know about sampling my well water?". When testing your well water you will very rarely be testing for only one thing — like PFAS — and instead testing for a suite of constituents that are important to identify if in your drinking water.
What treatment should I use if there is PFAS in my well water?/ How do I remove PFAS from my water?
The encouraging news is that PFAS chemicals are treatable. Once you test and have decided to treat your water to remove PFAS, the Minnesota Department of Health has developed a Home Water Treatment Guide that covers treatment for any common constituent in well water. The most important advice we can provide you is if you are going to add treatment to your home water system, be sure the treatment device has been certified to remove PFAS by an independent third-party certification.
Where can I get local help and information about PFAS chemicals in my well water?
Contact your local health department — They can help you interpret your sample results and may have information on the best treatment options for your situation. If they personally aren’t able to answer your questions, they will know who to contact who will be able to help you, likely at your state health department.
Contact a water treatment professional — We would recommend contacting a water treatment professional who has been certified through the Water Quality Association’s Professional Certification Program.
Research online — You should be inquisitive; it will help you significantly because there can be great information available online. Since new information is constantly emerging about PFAS, check frequently for any updates. Use search terms like “my state (CA, ME, IL, etc.) PFAS,” “my state groundwater quality,” or “my state well water quality.”
Contact us directly — If these other local sources don’t work out for you, we may be able to help. We may be able to provide direct assistance, and/or direct you to a technical assistance provider in your area who can help answer your questions. (This is a free service funded by USEPA).
Want to learn more?
Check out our webinar "What Private Well Owners and Well Professionals Need to know about PFAS-May 29 2025" featuring our guest PFAS experts, Jacqueline MacDonald Gibson from North Carolina State University and Jennifer Hoponick Redmon from RTI International.
Additional Resources:
Per- and Polyfluoroalkyl Substances. EPA Treatability Database. US Environmental Protection Agency.
Reducing PFAS in Drinking Water with Treatment Technologies. 2018. US Environmental Protection Agency.
Want to learn more about your private well and how to care for it?
Sign up for the free 10-week email course from PrivateWellClass.org. The class is a project of RCAP and the University of Illinois, with funding from USEPA.
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