PFAS in Well Water: The "Forever Chemical" Crisis

PFAS are a class of approximately 12,000 synthetic chemicals containing carbon-fluorine bonds, which are among the strongest in chemistry. The carbon-fluorine bond makes PFAS extremely stable — they resist water, oil, heat, and biological breakdown.

Common PFAS uses:

• Non-stick cookware (PTFE, Teflon)
• Stain-resistant fabrics and carpet (Scotchgard)
• Water-resistant clothing (Gore-Tex)
• Food packaging (greaseproof paper, fast food wrappers)
• Firefighting foam (AFFF — aqueous film forming foam) — the largest source of environmental contamination
• Industrial coatings and lubricants
• Personal care products

The two most-studied PFAS compounds are PFOA (perfluorooctanoic acid) and PFOS (perfluorooctanesulfonic acid). Both were phased out of US production by 2015 but persist in the environment indefinitely. They've been found in the blood of nearly all Americans tested.

Sources of PFAS in well water:

• Military bases and airports where AFFF firefighting foam was used
• Fire training facilities
• Industrial sites manufacturing or using PFAS
• Wastewater treatment plants and biosolid application areas
• Landfills containing PFAS-treated products
• Agricultural areas where contaminated biosolids were applied as fertilizer

In April 2024, EPA finalized the first-ever national legally enforceable drinking water standards for six PFAS compounds. The Maximum Contaminant Levels (MCLs):

• PFOA: 4 parts per trillion (ppt) — extraordinarily low
• PFOS: 4 ppt
• PFHxS: 10 ppt
• PFNA: 10 ppt
• HFPO-DA (GenX): 10 ppt
• Mixtures of PFHxS, PFNA, GenX, and PFBS: hazard index of 1

For context, "parts per trillion" means 4 PFOA molecules per 1 trillion water molecules. This is roughly 1,000 times more sensitive than typical drinking water standards. EPA chose these levels because animal studies show health effects at extremely low doses for some PFAS compounds.

Public water systems must comply by 2027 (initial monitoring) and 2029 (full compliance). Cost estimates: tens of billions of dollars for the US water infrastructure.

Critical caveat: these standards apply only to public water systems regulated under the Safe Drinking Water Act. Private wells are NOT covered. Private well owners with PFAS contamination receive no federal protection, no required testing, and no government assistance.

Three risk factors that warrant PFAS testing on a private well:

1. Proximity to a known PFAS source. Within 1-3 miles of:
   • Military bases (especially Air Force, Army, Navy with AFFF use)
   • Civilian airports with fire training
   • Industrial manufacturing sites
   • Landfills
   • Wastewater treatment plants with biosolid application
   • Areas where PFAS-treated biosolids were applied as fertilizer
2. Living in a state with known PFAS contamination. Worst-affected states include Michigan, North Carolina, New Jersey, New Hampshire, Massachusetts, Vermont, Pennsylvania, and parts of California, Texas, and Colorado.
3. Living near other contaminated wells. If neighbors have tested positive, contamination is likely groundwater-wide and you should test.

The Environmental Working Group maintains a database of known PFAS contamination sites at ewg.org/interactive-maps/pfas_contamination/. The Department of Defense publishes a list of military installations where AFFF was used. State environmental agencies often have additional contamination maps.

PFAS testing is more difficult and expensive than typical water testing:

• Cost: $250-$600 per test, depending on which compounds are included. Comprehensive panels covering 20+ PFAS compounds are at the high end.
• Specialized labs: not all certified drinking water labs have PFAS testing capability. Search for "PFAS water testing" + your state. Tasmanian Tiger Labs, Eurofins, and several others offer mail-in PFAS testing kits.
• Sample collection: requires specific bottles and procedures. The lab provides them. Avoid plastic bottles or anything that might contain trace PFAS — must use glass or specific HDPE.
• Detection limits: good labs can detect down to 1-2 ppt, well below the EPA MCLs. Cheaper tests with higher detection limits may miss low-level contamination.

EPA Method 537.1 is the standard analytical method for drinking water PFAS testing. Make sure your lab uses this method or equivalent.

Three treatment technologies effectively remove PFAS:

1. Granular Activated Carbon (GAC). The most common and affordable PFAS treatment. Whole-house GAC systems cost $1,500-$3,500 installed. Effectiveness: 80-95% for long-chain PFAS like PFOA and PFOS, less effective for short-chain compounds. Filter media must be replaced every 6-24 months depending on water volume and contamination level.
2. Ion exchange (specifically anion exchange resins designed for PFAS). More effective than GAC, especially for short-chain PFAS. 90-99% removal. Cost: $2,500-$5,000 installed. Specialty resins are more expensive than standard ion exchange.
3. Reverse osmosis (RO). 90-99% removal of nearly all PFAS compounds. Most effective single technology. Under-sink point-of-use RO systems: $200-$600. Whole-house RO is much more expensive and wastes substantial water.

Treatments that do NOT work:

• Boiling: doesn't remove PFAS (and may concentrate them as water evaporates)
• Standard pitcher filters (Brita): not effective for PFAS removal at the EPA MCL levels
• UV disinfection: no effect on PFAS
• Water softeners: no effect on PFAS
• Aeration: no effect

For private well owners with PFAS contamination, the practical recommendation is: under-sink reverse osmosis at the kitchen tap for drinking water (~$300-$500). If contamination is severe (well above EPA MCLs) or if you want whole-house treatment, install a whole-house GAC or ion exchange system ($1,500-$5,000).

Five-step response:

1. Stop drinking the water immediately. Switch to bottled water or filtered water for drinking and cooking until treatment is in place. The lower the PFAS levels in your blood, the better — and exposure reduction is the only way to lower blood levels (PFAS half-life is 4-8 years for major compounds).
2. Install treatment. Under-sink RO at the kitchen tap is the cheapest effective option. Whole-house treatment is more comprehensive but more expensive.
3. Re-test after treatment. Verify the treatment system is working by testing the treated water output.
4. Notify neighbors with private wells. If contamination came from a known source, others nearby may be affected. Group testing can reduce per-well costs.
5. Report to state environmental agency. They may help identify the source and (in some states) offer assistance with treatment costs. Some states have PFAS funds for affected homeowners.

Some states (especially in the Northeast) have set up PFAS assistance programs for private well owners. New Hampshire, Vermont, Massachusetts, and Maine have especially proactive programs. Check your state environmental department for details.