Quick answer: PFAS in well water are “forever chemicals” from sources like firefighting foam, factories, landfills and sludge spread on fields. The EPA’s 2024 limit of 4.0 parts per trillion each for PFOA and PFOS still stands in 2026. Private wells are unregulated, so test at a certified lab if you live near a source. Boiling does not remove PFAS. Reverse osmosis, activated carbon or ion exchange filters certified for PFOA/PFOS can reduce them.
You cannot tell by looking at, smelling or tasting your water. A lab test is the only way to know.
What are PFAS?
PFAS (per- and polyfluoroalkyl substances) are a group of thousands of manufactured chemicals, according to the EPA. They have been used since the 1940s in products that resist water, grease and stains, and in firefighting foam.
The Pennsylvania Department of Health explains the nickname: they are called “forever chemicals” because some PFAS take a very long time to break down in the environment and in the human body. Once they reach groundwater, they can travel with it and stay for years.
The two best-studied PFAS are PFOA and PFOS. Others you may see on a lab report include PFHxS, PFNA, PFBS and HFPO-DA (often called GenX).
Where PFAS in well water come from
All PFAS are human-made, as Connecticut’s Department of Energy and Environmental Protection (DEEP) points out, so unlike arsenic or manganese they do not come from the rock. They reach wells from nearby sources, including:
| Likely source near your well | Why it matters |
|---|---|
| Airports and military bases | Firefighting foam used in training and emergencies soaks into soil and groundwater (Pennsylvania DOH, Virginia DOH) |
| Factories and industrial sites | Facilities that made or used PFAS can release them to air, soil or water (EPA) |
| Landfills, active or closed | Discarded PFAS products can leach into groundwater (Pennsylvania DOH, Virginia DOH) |
| Fields spread with biosolids or sludge | Wastewater treatment concentrates PFAS in sludge, which was spread as fertilizer (Maine DEP, EPA) |
| Septic systems | Household products can carry PFAS into septic effluent (Virginia DOH, Pennsylvania DOH) |
Maine is a well-known example. Maine DEP says sludge and septage were often spread on farmland from the late 1970s, and that PFAS levels in sludge were not considered until 2019. Maine became the first state to ban land application of sludge, effective August 8, 2022.
Health effects
According to the CDC’s Agency for Toxic Substances and Disease Registry (ATSDR), studies link higher PFAS exposure to:
- Higher cholesterol levels
- Lower antibody response to some vaccines
- Changes in liver enzymes
- High blood pressure during pregnancy and preeclampsia
- Small decreases in birth weight
- Kidney and testicular cancer (PFOA)
The EPA notes that drinking water above the federal limit does not necessarily mean health effects will occur. Risk depends on how much, for how long, and on individual factors. If you have been drinking water with PFAS, discuss it with your doctor.
EPA PFAS limits: where things stand in 2026
Here is the timeline, based on EPA announcements:
| Date | What happened |
|---|---|
| April 10, 2024 | EPA finalized the first national PFAS drinking water standards for public water systems, with compliance due by 2029 |
| May 14, 2025 | EPA announced it would keep the PFOA and PFOS limits, extend the deadline to 2031, and rescind the limits for PFHxS, PFNA, GenX and the mixture “Hazard Index” |
| May 20, 2026 | Two proposed rules were published: one to extend PFOA/PFOS compliance to April 2031, one to rescind the other four limits. Comments closed July 20, 2026 |
| September 2026 | Both are still proposals, not final. A federal appeals court heard arguments on the 2024 rule on September 18, 2026 and had not ruled as of this writing |
The limits set in 2024 were:
| PFAS | Limit (MCL) | Status in 2026 |
|---|---|---|
| PFOA | 4.0 ppt | EPA keeping it; deadline extension proposed |
| PFOS | 4.0 ppt | EPA keeping it; deadline extension proposed |
| PFHxS | 10 ppt | Proposed for rescission |
| PFNA | 10 ppt | Proposed for rescission |
| HFPO-DA (GenX) | 10 ppt | Proposed for rescission |
| Mixture of PFHxS, PFNA, GenX and PFBS | Hazard Index of 1 | Proposed for rescission |
For PFOA and PFOS, the EPA’s health goal is zero.
These rules apply to public water systems, not private wells. Many states use their own standards or action levels, which may differ from the federal numbers. Connecticut, for example, has action levels for 10 PFAS. Ask your state health or environmental agency which numbers it uses to interpret well results.
PFAS testing for private wells
Not every well needs a PFAS test. The Minnesota Department of Health, for example, does not recommend testing every private well, but it does recommend it near known contamination. Consider testing if your well is near any source in the table above.
- Call your state health or environmental agency first. Some states test wells near known sites for free or maintain lists of affected areas.
- Use a certified lab running EPA Method 533 or 537.1. These are the EPA drinking water methods for PFAS. Connecticut DEEP recommends Method 533 because it covers more PFAS; Method 537.1 is acceptable but misses some.
- Follow the lab’s sampling instructions exactly. PFAS are measured in parts per trillion, so tiny amounts of outside contamination can skew results. Some labs include a “field blank” bottle to check for this, and Connecticut DEEP notes it may be billed separately.
- Budget for it. Connecticut DEEP says a PFAS test typically costs $300 or more per sample, and results usually take 2 to 3 weeks.
PFAS are not part of a standard well test package. See our well water testing guide for what else to include.
Treatment: filters that reduce PFAS
The EPA lists three home treatment types that can reduce PFAS. Look for certification to NSF/ANSI 53 or NSF/ANSI 58 for PFOA and PFOS reduction, from an accredited body such as NSF, WQA, UL, CSA Group or IAPMO.
| Treatment | Where installed | Cost range (Pennsylvania DOH) | Notes |
|---|---|---|---|
| Reverse osmosis (RO) | Point of use, usually the kitchen sink | $350 to $950, plus $100 to $200 a year | Certified under NSF/ANSI 58. See reverse osmosis for well water. |
| Granular activated carbon (GAC) | Point of use or whole house | $300 to $1,000 | Media lasts about 6 to 12 months, per Pennsylvania DOH |
| Ion exchange resin | Point of use or whole house | $500 to $6,000, plus $100 to $200 a year | Resin lasts about 10 to 15 years, per Pennsylvania DOH |
The EPA says home filters range from about $20 to over $1,000, not counting maintenance. It also cautions that, as of April 2024, certification standards did not yet show that a filter reduces PFAS all the way down to the new EPA limits. Test your treated water after installation to confirm it works.
Point of use or whole house? Connecticut DEEP lists both whole-house GAC and under-sink RO as options. Since the main risk is drinking and cooking (Virginia DOH notes little PFAS gets through skin), a point-of-use system is often enough. A general whole-house water filter will not remove PFAS unless it is certified for them.
Boiling does not remove PFAS. Connecticut DEEP and Virginia DOH both state this. Until treatment is installed, use bottled water for drinking, cooking and infant formula if your results are above your state’s guidance.
State programs for PFAS in wells
Help varies a lot by state. A few examples:
- Maine: Maine DEP samples wells near licensed sludge and septage sites and has installed and maintained treatment systems at more than 500 homes where PFAS exceeded the state’s interim standard.
- Connecticut: DEEP’s Potable Water Program handles PFAS contamination in private wells, since PFAS are human-made.
- Pennsylvania: The Department of Health and Penn State Extension have offered limited free well testing funded by the CDC.
- Minnesota: MDH and the Pollution Control Agency track contaminated sites and advise nearby well owners.
Start with your state health department or environmental agency, and ask whether any testing or treatment help is available near you.
Frequently asked questions
Does boiling water remove PFAS?
No. Connecticut DEEP and Virginia DOH both say PFAS cannot be removed by boiling. Use a certified filter or bottled water instead.
Is it safe to shower in well water with PFAS?
Generally yes. The Virginia and Pennsylvania health departments say only a small amount of PFAS gets through the skin. The main exposure is from drinking water and cooking.
What is the EPA limit for PFAS in drinking water?
The EPA’s 2024 limit for PFOA and PFOS is 4.0 parts per trillion each, and the EPA said in 2025 it will keep it. Limits for four other PFAS are proposed for rescission, and none of these rules apply to private wells.
Does a reverse osmosis system remove PFAS?
RO is one of the three treatment types the EPA lists for PFAS. Choose a system certified to NSF/ANSI 58 for PFOA and PFOS, pre-treat for hardness and iron if needed, and test the treated water.
How much does it cost to test well water for PFAS?
Connecticut DEEP says it is typically $300 or more per sample. Check with your state first; some programs test wells near known sites at no cost.
Related guides
- Well water testing: what to test for and how often
- Reverse osmosis for well water
- Buying a home with a well
Sources
- EPA – PFAS in Private Wells
- EPA – Proposed PFOA and PFOS Compliance Extension Rule
- Connecticut DEEP – Private Wells and PFAS
- ATSDR – How PFAS Impacts Your Health
This guide is for general information. Federal PFAS rules are changing; check with your state health or environmental agency for current guidance, and have your water tested by a certified lab.
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