PFAS in Well Water
PFAS are the forever chemicals from firefighting foam, some factories and consumer products. They do not come from your rock and they cannot be seen or tasted, so the question is whether a source is nearby and whether your state will test for free.
Likely causes
- Firefighting foam use at airports and military bases
- Industrial discharge
- Landfill leachate
- Biosolids spread on farmland
Tests to order
- PFAS panel by EPA Method 533 or 537.1
- State-sponsored PFAS testing where offered
Treatment options
- Reverse osmosis at the tap
- Granular activated carbon whole-house system
- Ion exchange resin
- Bottled water while testing
Start with a map, not a lab
PFAS travel in groundwater from specific sources: airports and fire training sites where foam was used, military bases, plating and textile plants, landfills and fields treated with sludge. Every state keeps a map of known PFAS sites, and several, including Colorado and Michigan, test private wells near them for free. Check the map and the free program first. A private PFAS test costs $250 to $400.
What the numbers mean
The federal limits set in 2024 are 4 parts per trillion for PFOA and PFOS individually, with limits for four others. Those are tiny numbers, and lab reports list a dozen compounds. Look at PFOA, PFOS, PFHxS, PFNA and GenX first. Long-term exposure is linked to cholesterol changes, immune effects, some cancers and developmental effects, which is why infants and pregnant women are the priority.
Treatment that is proven
Reverse osmosis at the kitchen tap removes more than 90% of the regulated PFAS from drinking and cooking water, $300 to $800, and is what most health departments recommend first. For whole-house treatment, granular activated carbon in large tanks or ion exchange resin work, $2,000 to $6,000, with media changes every one to two years. Pitcher filters certified under NSF 53 for PFAS are a stopgap. Boiling does nothing.
Is it safe to bathe in PFAS water?
Yes. PFAS are not absorbed through skin in meaningful amounts and do not vaporize. Drinking and cooking are the exposure routes.
Will PFAS go away on their own?
No. They do not break down in groundwater on any human timescale, which is the point of the name.