PFAS “Forever Chemicals” in Private Wells: Why You Should Test
In 2024, the U.S. Environmental Protection Agency set the first national drinking-water limits for several PFAS — the so-called “forever chemicals.” Those rules apply to public water systems. If your home runs on a private well, nobody is required to test your water for you.
What are PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a large family of human-made chemicals used for decades in nonstick coatings, stain-resistant fabrics, firefighting foams, and many industrial processes. They are called “forever chemicals” because many of them break down extremely slowly in the environment and can build up in people and wildlife.
In April 2024, EPA finalized National Primary Drinking Water Regulations for six PFAS. The enforceable Maximum Contaminant Levels (MCLs) include:
- PFOA: 4.0 parts per trillion (ppt)
- PFOS: 4.0 ppt
- PFHxS, PFNA, and HFPO-DA (GenX): 10 ppt each
- Mixtures of certain PFAS: a Hazard Index of 1
EPA also set the health-based goal (MCLG) for PFOA and PFOS at zero — meaning any exposure is considered to carry some risk, even though the enforceable limit is set higher for practical reasons.
Who is at risk?
Higher-risk situations for private wells
- You live near a military base, airport, industrial site, landfill, or fire-training area where PFAS-containing foams or wastes may have been used
- Your community has documented PFAS in groundwater or in a nearby public system
- Your state or county health department has issued PFAS advisories for private wells
- You rely on well water for infant formula, cooking, and drinking every day
EPA estimates that more than 23 million U.S. households rely on private wells. Those wells are not regulated under the Safe Drinking Water Act the way public systems are. National PFAS rules for public systems do not force anyone to sample your private well.
You can’t taste or smell PFAS
PFAS do not usually change the color, smell, or taste of water. Waiting for a warning sign means waiting for something that may never appear. By the time a public system nearby finds PFAS, private wells in the same aquifer may already have been exposed for years — with no monitoring required.
That is why EPA’s private-well guidance is blunt: contact your state environmental or health agency for advice, use a state-certified lab that can run EPA-developed PFAS methods, and consider treatment or an alternate water source if levels are high.
What to do if you’re worried
- Find a certified lab. Not every drinking-water lab runs PFAS. Ask whether they use EPA-approved methods for the compounds you care about, and whether they accept private-well samples.
- Follow the sampling instructions exactly. PFAS sampling is easy to contaminate with everyday products (some waterproof clothing, certain bottles). Use only the kit and instructions the lab provides.
- Compare results to EPA’s MCLs as a reference. Those limits are written for public systems, but they are the clearest national health benchmarks available. If your result is above them, talk to your health department about next steps.
- Reduce exposure while you plan. EPA notes that certified point-of-use filters or an alternate water source for drinking, cooking, and formula can lower exposure while you decide on longer-term treatment.
Find a certified lab near you
We turn each state’s official certified-lab list into a phone-friendly page — with sources and the date we last checked.
Disclaimer: This page is for general information only. It is not medical advice, diagnosis, or treatment guidance. For health questions, talk to a clinician. For test results and local risks, contact your state or county health department.
Sources
- U.S. EPA — Per- and Polyfluoroalkyl Substances (PFAS) drinking water rule
- Federal Register — PFAS National Primary Drinking Water Regulation (April 26, 2024)
- U.S. EPA — PFAS in Private Wells
- U.S. EPA — Addressing Emerging Contaminants in Private Wells (fact sheet)
- U.S. EPA — Private Drinking Water Wells
Free well water safety checklist
15 family-friendly steps based on CDC and EPA guidance. Print it, keep it on the fridge, and know when to call a certified lab.
More guides
- Nitrates in Well Water and Blue Baby Syndrome: Who Must TestNitrate in well water can cause blue baby syndrome in infants. Learn who is at risk, when to test, and how to find a certified lab.
- Arsenic in Private Well Water: The Invisible Risk UndergroundArsenic in groundwater is often naturally occurring and invisible. USGS research shows millions of private-well users may be above the EPA drinking-water standard.
- Lead in Well Water: Old Pumps, Plumbing, and Why Taste Won’t Warn YouLead doesn’t change how water looks or tastes. If your home has older plumbing or well equipment, testing is the only way to know your exposure.
- Coliform Bacteria in Well Water After a Flood: Test Before You DrinkFloodwater, septic systems, and runoff can push bacteria into private wells. Don’t drink until a certified lab clears your water.