Every private well owner has had the same experience: a PFAS story breaks, a city announces it is treating its water, and you go looking for what it means for your well. The answer is uncomfortable. In 2024 the EPA set the first enforceable national limits for PFAS in drinking water — and private wells were left out of the rule entirely.
That is not an oversight specific to PFAS. Federal drinking-water regulation has never covered private wells. No one tests yours, no one notifies you, and no one funds your treatment. The difference with PFAS is that these are chemicals designed not to break down, at limits measured in parts per trillion, and most well owners have never tested for them once.
What the Numbers Actually Are
The EPA limits apply to public systems, but they are the yardstick worth holding your own water to.
| Compound | Limit |
|---|---|
| PFOA | 4 parts per trillion |
| PFOS | 4 parts per trillion |
| PFHxS | 10 parts per trillion |
| PFNA | 10 parts per trillion |
| HFPO-DA (GenX) | 10 parts per trillion |
| Mixtures of the above | Hazard index of 1 |
Parts per trillion is not a typo, and it is worth pausing on. One part per trillion is roughly a single drop in twenty Olympic swimming pools. These are the lowest limits the EPA has ever set for a drinking-water contaminant, close to the level at which laboratories can reliably measure at all.
PFAS are often called "forever chemicals" because the carbon-fluorine bond is among the strongest in organic chemistry. They do not meaningfully degrade in soil, in water, or in you. That is what makes small numbers matter.
Where It Comes From, and Whether You Are at Risk
Most well owners picture a chemical plant. The more common rural pathway is firefighting foam.
- Aqueous film-forming foam (AFFF) used at airports, military installations, refineries, and fire training grounds. This is the single most documented source of well contamination, and plumes travel with groundwater far beyond the fence line.
- Land-applied biosolids — treated sewage sludge spread as fertilizer, which concentrates PFAS from everything upstream of the treatment plant.
- Landfills, where decades of consumer products leach into groundwater.
- Manufacturing of textiles, paper coatings, plating, and non-stick or waterproof goods.
Distance and groundwater direction matter more than the presence of any single facility. A well two miles downgradient of a fire training site is at more risk than one half a mile upgradient of it.
How to Test — and Why Sampling Is Different
A standard well panel does not include PFAS. You need a laboratory offering analysis by EPA Method 533 or 537.1, and it costs meaningfully more than a routine panel.
The unusual part is the sampling. PFAS is in so many everyday products that you can contaminate your own sample without trying:
- Use only the bottles the lab sends. Do not rinse them.
- Avoid contact with anything waterproof, stain-resistant, or non-stick — including some rain jackets, food wrappers, and plumber's tape.
- Wash your hands with plain soap, not anything labelled water-resistant.
- Follow the lab's flush instructions exactly, and record the date and tap.
Any result comes back as a list of individual compounds. Log each one and keep the report itself — PFAS science and limits are still moving, and a dated baseline is worth far more than a remembered impression.
What Actually Removes It
Two technologies have solid evidence behind them, and both have the same failure mode.
Reverse osmosis at the kitchen tap is the most reliable option for drinking and cooking water. Look for NSF/ANSI 58 certification that specifically names PFOA and PFOS reduction — general certification is not the same claim. Membranes last two to three years; pre- and post-filters are annual.
Granular activated carbon, properly sized, works whole-house and is the usual choice when the whole supply is affected. Sizing and contact time are everything, and a system built for taste and odor is not built for PFAS.
The shared danger: carbon media stops working before anything changes at the tap. There is no taste, no smell, no pressure drop to warn you. An exhausted filter can even release accumulated contaminant. The only way to know a treatment system is still doing its job is to test the treated water on a schedule and log the result against the date you changed the media.
Boiling, softening, and standard sediment filtration do nothing for PFAS. Boiling makes it marginally worse by evaporating water and leaving the chemicals behind — the same trap as nitrate.
A Sensible Order of Operations
PFAS testing is expensive, and it is not the first thing to spend money on if you have never tested at all. Do it in this order:
- Bacteria and nitrate first, every year. They are cheap, common, and can hurt you this month rather than this decade.
- Check your surroundings for the known PFAS pathways above — airport, military site, fire training ground, biosolid application, landfill.
- Ask your state. Many state environmental agencies have run private-well PFAS sampling programs in affected areas, sometimes free. Your county health department will know.
- Then test, if the exposure map or your own peace of mind says so.
- Log the result with its date, whatever it says. A non-detect today is the baseline that makes a future result meaningful.
The uncomfortable truth about being your own water utility is that nobody sends you a report. The upside is that nothing stops you writing one.
Frequently Asked Questions
Are private wells covered by the EPA PFAS rules? No. The 2024 PFAS drinking water rule applies to public water systems only. Private wells are outside every federal drinking-water regulation, which means nobody will test your well, notify you, or pay for treatment. The limits are still the right yardstick to hold your own water to — you are simply the one who has to do the measuring.
What PFAS level is considered safe in well water? The EPA set enforceable limits of 4 parts per trillion for PFOA and PFOS individually, with limits for PFHxS, PFNA and HFPO-DA (GenX) and a hazard index for mixtures. Parts per trillion is not a typo — these are the lowest drinking-water limits EPA has ever set, and they are near the level labs can reliably detect.
How do I test my well for PFAS? Use a lab that specifically offers PFAS analysis by EPA Method 533 or 537.1 — a standard well panel does not include it. Sampling matters more than usual: PFAS is in many consumer products, so follow the lab's instructions exactly, avoid contact with anything waterproof or non-stick, and never use the fast-food container in your truck as a rinse cup.
Does boiling or a carbon pitcher remove PFAS? Boiling does nothing — like nitrate, it concentrates PFAS as water evaporates. A basic carbon pitcher is unreliable. Reverse osmosis and properly sized granular activated carbon both work when maintained; the failure mode with carbon is a spent filter that quietly stops adsorbing while the water still looks and tastes fine.
Should I test for PFAS if there is no factory near me? Firefighting foam is the most common rural source, so proximity to an airport, military installation, or fire training site matters more than heavy industry. Land-applied biosolids and some agricultural uses are also documented pathways. If none of those apply, PFAS is a lower priority than your annual bacteria and nitrate tests.