PFAS in Private Wells: Testing and Treatment

What’s the current federal standard?

In April 2024, EPA set enforceable limits for six PFAS in public drinking water (EPA):

What’s changing. On May 18, 2026, EPA proposed two rules. One would keep the PFOA and PFOS limits but let water systems request two more years, to 2031, to comply. The other would rescind the limits for PFHxS, PFNA, GenX and the Hazard Index mixture (EPA). These are proposals open for public comment, not final rules. We’ll update this page as they change.

None of these limits apply legally to private wells, but they’re the standard yardstick. Some states set their own rules. New Jersey, for example, requires PFOA, PFOS and PFNA testing when a home with a private well is sold.

Should you test?

PFAS testing is specialized and measured in parts per trillion, so it isn’t part of a basic annual panel. Ask your state environmental or health agency whether PFAS has been found near you. Start with EPA’s PFAS in Private Wells page, which links to state resources.

• Use a lab test, not a strip. Detecting PFAS at these levels requires a lab. Find one through EPA’s certified lab directory or your state’s PFAS program.
• “Mail-in option: Tap Score: PFAS water test →. Before you buy, make sure any mail-in kit uses a state-certified laboratory or one recognized by your state’s PFAS program, check which specific PFAS compounds the kit reports, and confirm it covers the ones your state regulates.”

Treatment: what EPA says works

EPA names three home filter types that can be effective at reducing PFAS:

• Activated carbon (GAC): traps chemicals as water passes through.
• Reverse osmosis (RO): forces water through a very thin membrane. EPA notes RO typically wastes about one gallon of water for each gallon treated and needs cartridge and membrane changes (EPA).
• Ion exchange resins.

EPA research found that the GAC, ion exchange and RO point-of-use systems it studied “can greatly reduce PFAS levels.” Filters only work if they’re maintained on the manufacturer’s replacement schedule (EPA). EPA estimates filters cost from about $20 to over $1,000, not counting maintenance.

How to choose a certified filter

From EPA:

1. Check the packaging for NSF/ANSI 53 or NSF/ANSI 58 certification for PFAS reduction.
2. Confirm the exact model in the certifier’s online directory, such as NSF’s listings.
3. Make sure it covers the PFAS you’re trying to remove. EPA notes that as of April 2024, filter certifications focus on PFOA and PFOS.

One important limit: EPA says it hasn’t designated home point-of-use or point-of-entry devices as compliance options for public water systems. That’s because the PFAS limits are lower than current NSF/ANSI certification standards for these devices (EPA fact sheet). A certified filter reduces PFOA and PFOS, but certification alone doesn’t prove your treated water meets the 4.0 ppt limit. “Retest your treated water with a state‑certified lab or a lab recognized by your state PFAS program.“

Options to compare. Confirm each model’s PFAS certification before buying: SpringWell: reverse osmosis systems → · Aquasana: RO systems → · iSpring: RO systems → · US Water Systems: RO systems →

Whole-house PFAS treatment is a bigger project. Have your test results reviewed by a water treatment professional and your state program first.