How to Test Your Water for PFAS: A Step-by-Step Guide
Before you spend hundreds on a water filter, find out if you actually have a PFAS problem. Here are three ways to check — from free to lab-grade accurate.
Why You Should Test Before You Buy
Not every home has a PFAS problem. A 2023 USGS study found PFAS in about 45% of US tap water. That means roughly half of homes tested positive — and half did not.
If your water is clean, you may not need a $90 pitcher or a $450 under-sink system. But if your water has PFAS above EPA limits, you need to know exactly what you are dealing with so you can pick the right filter.
Testing also gives you a baseline. After you install a filter, you can test again to see if it is working. Without a before-and-after comparison, you are guessing.
Three Ways to Check Your Water
1EWG Tap Water Database (Free)
2Tap Score PFAS Water Test ($299)
3SimpleLab PFAS Test ($299)
What Does NOT Work for PFAS Testing
Some products claim to test water quality at home. Here is what does not work for PFAS:
TDS Meters ($10-$25)
Total Dissolved Solids meters measure minerals, salts, and ions. They cannot detect PFAS. A reading of 000 tells you nothing about forever chemicals. Do not rely on these for PFAS peace of mind.
Basic Water Test Strips ($10-$30)
Test strips check for chlorine, pH, hardness, nitrates, and a few metals. None of them test for PFAS. The chemistry is completely different, and PFAS levels are measured in parts per trillion — far below what test strips can detect.
"Multi-Contaminant" Home Kits ($20-$50)
Cheap home test kits that claim to test for "dozens of contaminants" do not include PFAS. PFAS testing requires specialized lab equipment (LC-MS/MS) that costs tens of thousands of dollars. No $20 kit can do it.
Understanding Your PFAS Test Results
When your lab results come back, here is what the numbers mean:
| Compound | EPA Limit (2024) | What It Means |
|---|---|---|
| PFOA | 4 parts per trillion (ppt) | Above 4 ppt = exceeds federal limit. Filter or find a new source. |
| PFOS | 4 parts per trillion (ppt) | Above 4 ppt = exceeds federal limit. Same as PFOA. |
| PFHxS | 10 ppt | Found near military bases. Related to firefighting foam. |
| PFNA | 10 ppt | Industrial PFAS. Less common in residential water. |
| HFPO-DA (GenX) | 10 ppt | Replacement chemical for PFOA. Found near specific factories. |
| Combined PFAS mix | 25 ppt (Hazard Index) | If multiple PFAS compounds are found, the EPA uses a combined calculation. |
If any result is above the EPA limit, do not panic. The health effects of PFAS exposure are long-term, not immediate. But you should act. Get a PFAS water filter and start using it for all drinking and cooking water.
If your results show "non-detect" or "below detection limit" for all PFAS compounds, your water is likely fine. No filter needed for PFAS (though you might still want one for other reasons).
When Should You Test?
You do not need to test every month. Here are the situations where PFAS testing makes sense:
You just moved into a new home
Especially if you do not know the water history. Test once to get a baseline.
You live near a military base or airport
AFFF firefighting foam used at military bases and airports is a major PFAS source. Groundwater contamination can spread for miles.
You live near an industrial site
Chemical plants, semiconductor factories, paper mills, and chrome plating facilities have all been linked to PFAS contamination.
You have a private well
Private wells are not monitored by the EPA or your water utility. You are responsible for your own water quality. Test at least once.
You installed a PFAS filter and want to verify it works
Test 6 months after installation. Compare the new results to your baseline. If PFAS levels dropped below detection limits, the filter is working.
Frequently Asked Questions
How much does a PFAS water test cost?
A comprehensive PFAS lab test costs about $299 from Tap Score or SimpleLab. This covers 30+ PFAS compounds with results in about two weeks. The EWG Tap Water Database is free but uses older public utility data rather than testing your specific tap.
Can I test for PFAS at home with a kit?
There are no reliable at-home instant test kits for PFAS. TDS meters do not detect PFAS. Test strips do not detect PFAS. You need to send a water sample to a certified laboratory for accurate results.
How often should I test my water for PFAS?
Test once when you move into a new home. If your area has known contamination, test annually. If you install a PFAS filter, test again after 6 months to make sure the filter is working. And test any time your water source changes.
What PFAS level is safe in drinking water?
The EPA set enforceable limits of 4 parts per trillion (ppt) for PFOA and 4 ppt for PFOS in 2024. For other PFAS, the limits range from 10 to 25 ppt depending on the compound. Any amount above these limits means your water does not meet federal standards.
Does the EWG Tap Water Database show PFAS?
The EWG database shows publicly reported PFAS data by zip code. It is a good starting point, but it relies on utility-reported data which may be outdated. It also does not cover private wells. For precise, current results, you need a lab test.
Should I test my well water for PFAS?
Yes. Private wells are not covered by EPA regulations and are not tested by utilities. If you have a well near a military base, airport, industrial site, or fire training facility, PFAS testing is strongly recommended.
Found PFAS in Your Water?
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