PFAS (per- and polyfluoroalkyl substances) are in an estimated 45%+ of US tap water, according to USGS research. But most water systems haven't been required to test for them until recently. So how do you find out if your water has PFAS?
Step 1: Check existing data
Before spending money on a test, check what's already available. Search your ZIP code on ClearWater to see if your water system was tested under the EPA's UCMR5 program (which tested roughly 3,500 systems nationwide for 29 PFAS compounds between 2023 and 2025). If your system was tested, you'll see exactly which PFAS compounds were detected and at what levels.
You can also check the EPA's PFAS enforcement data and your state's environmental agency website, as some states have conducted their own testing programs independent of the federal requirement.
Step 2: If no data exists, test yourself
If your system wasn't included in UCMR5 testing - or if you're on a private well - you'll need to arrange testing yourself.
Certified laboratory testing ($200–$500)
The most reliable option is sending a water sample to an EPA-certified lab that uses EPA Method 533 or 537.1. These methods can detect PFAS at concentrations as low as 2 parts per trillion - well below the new EPA MCLs of 4 ppt for PFOA and PFOS.
You'll receive a sample collection kit with specific instructions (PFAS can contaminate samples easily - no Teflon-coated containers, avoid wearing water-resistant clothing while collecting). Results typically take 2–4 weeks.
Reputable labs include Eurofins, SGS, and state university extension programs. Your state health department may offer discounted or free PFAS testing for private well owners - check before paying full price.
Home PFAS test kits ($100–$250)
Several companies now offer mail-in PFAS test kits. These work the same way - you collect a sample and mail it to a certified lab - but the packaging and instructions are more consumer-friendly. Companies like Cyclopure, SimpleLab (Tap Score), and 4Water Health offer kits specifically for PFAS.
Make sure any kit you buy uses an EPA-approved testing method. Some cheaper "screening" tests provide less reliable results.
Do instant/DIY test strips work for PFAS?
No. As of 2026, there are no reliable instant test strips or home test kits for PFAS. The compounds exist at parts-per-trillion levels - far below what any dip-and-read strip can detect. Any product claiming to instantly detect PFAS at home should be viewed skeptically.
Understanding your results
If your results come back showing PFAS, here's how to interpret the numbers:
PFOA or PFOS above 4 ppt: Exceeds the EPA MCL. Consider a filter certified for PFAS removal
PFHxS, PFNA, or HFPO-DA above 10 ppt: Exceeds the EPA MCL for these individual compounds
Combined PFAS (mixture) above 30 ppt Hazard Index: Exceeds the EPA MCL for combined PFAS
Any PFAS detected below MCLs: Below regulatory limits, but some health researchers suggest minimizing exposure where practical
If you're on a public water system that exceeds the new MCLs, your utility is required to notify you and take corrective action (they have until 2029 to comply). If you're on a private well, the responsibility is yours - the EPA MCLs don't apply to private wells, but the health science is the same.