The EPA's 2024 PFAS rule is a landmark regulation, but it applies only to public water systems serving 25 or more people. If your home is on a private well, you are not covered. No federal agency tests your water. No utility sends you an annual report. No one is monitoring for PFAS contamination on your behalf.
Approximately 43 million Americans rely on private wells, according to the U.S. Geological Survey. A 2023 USGS study found that PFAS was detected in nearly half of all tap water samples tested nationwide, with private wells in certain areas showing contamination levels comparable to or exceeding those found in public systems.
The difference is that public water systems are now required to test, report, and treat for PFAS. Well owners must do all of this themselves.
Check your water quality to see if PFAS contamination has been reported in your area. Even though your well is not in the database, nearby public water data can indicate whether PFAS is present in your region's groundwater.
Not all wells face the same PFAS risk. Your risk level depends on proximity to contamination sources. The most common sources of PFAS in groundwater include:
AFFF (aqueous film-forming foam) used in fire training is the largest single contributor to PFAS groundwater contamination in the U.S. If your well is within 10 miles of a current or former military base, National Guard facility, or airport where AFFF was used, your risk is elevated.
Manufacturers of PFAS-containing products (textiles, nonstick coatings, electronics) have contaminated groundwater in many communities. Check the EPA's PFAS Analytic Tools website for known industrial sources near your property.
Treated wastewater and landfill leachate can contain PFAS that seeps into groundwater. Wells near these facilities may be affected.
Sewage sludge (biosolids) used as fertilizer on farmland can contain PFAS. If your well is near agricultural land where biosolids have been applied, PFAS may have migrated into your aquifer.
Even small municipal fire departments that used AFFF for training can be local PFAS sources.
The most important decision is choosing a laboratory accredited to run EPA Method 533 or 537.1 for PFAS in drinking water. These methods can detect individual PFAS compounds at concentrations as low as 2 parts per trillion (ppt).
Recommended labs for residential well testing:
Avoid cheap test strips marketed for PFAS screening. Their detection thresholds (typically 20 to 70 ppt) are far above the EPA MCL of 4 ppt for PFOA and PFOS. A test strip showing "not detected" could still mean your water has 15 ppt of PFAS, which is nearly four times the federal limit.
PFAS sample collection requires more care than standard water testing because PFAS is so ubiquitous that contamination of the sample itself is a real risk.
Follow these rules: 1. Use only the container provided by the lab. It is certified PFAS-free. 2. Do not use any personal care products (hand lotion, sunscreen, cosmetics) before collecting. Many contain PFAS that can transfer to the sample. 3. Remove waterproof or stain-resistant clothing before collecting. Gore-Tex, Scotchgard-treated fabrics, and similar materials can shed PFAS. 4. Run the cold water tap nearest to where your well water enters the house for 2 to 3 minutes before collecting. 5. Do not collect from a tap with any attached filter (you want to test the raw well water). 6. Fill to the line, cap immediately, and do not touch the inside of the bottle or cap. 7. Label with date, time, and the specific tap used. 8. Ship within 24 hours using the lab's provided packaging.
A comprehensive well water PFAS panel should include at minimum the six EPA-regulated compounds:
| Compound | EPA MCL | Notes | |---|---|---| | PFOA | 4 ppt | Most studied PFAS compound | | PFOS | 4 ppt | Primary component of AFFF firefighting foam | | PFHxS | Hazard Index | Part of mixture standard | | PFNA | Hazard Index | Part of mixture standard | | HFPO-DA (GenX) | Hazard Index | PFOA replacement chemical | | PFBS | Hazard Index | Short-chain PFAS |
Many labs test for 30 or more PFAS compounds, which is valuable because well water contamination often involves a complex mixture. The broader panel can help identify the likely source of contamination (e.g., AFFF produces a different PFAS profile than industrial discharge).
This is the best outcome. Your well water is below the lab's detection limits for PFAS (typically around 2 ppt). Retest in 12 months and after any significant changes in nearby land use.
Your water is below the federal MCL but PFAS is present. The EPA's health goal (MCLG) for PFOA and PFOS is zero, meaning any detectable amount carries some theoretical risk. Consider installing a certified filter, especially if you have infants, pregnant household members, or immunocompromised individuals.
Your water exceeds the federal standard (which would apply if you were on a public system). Take immediate action:
This indicates a significant contamination source near your well. In addition to immediate filtration:
Where: Under the kitchen sink Removes: 90% to 99% of PFAS Cost: $150 to $500 plus $50 to $150/year for filter replacements Best for: Addressing drinking and cooking water
Where: Point of entry, treats all water Removes: 60% to 90% of PFAS (varies by carbon type and contact time) Cost: $1,000 to $3,000 plus ongoing carbon replacement Best for: Moderate contamination, reducing whole-house exposure
Where: Point of entry Removes: 90%+ of PFAS, including short-chain compounds Cost: $2,000 to $5,000 plus resin replacement Best for: High contamination levels, comprehensive treatment
Many well water professionals recommend combining a whole-house GAC or ion exchange system with a point-of-use RO at the kitchen sink. This provides baseline treatment for the entire home plus the highest level of protection for drinking water.
Check your water quality regularly to stay informed about contamination trends in your region.
Check your water now. Enter your zip code at KnowYourExposure.com to see what contaminants have been detected in your local water supply, including PFAS, lead, and other regulated compounds.