Quick answer: PFAS contamination varies widely by U.S. state. Michigan, California, Colorado, Texas, and Pennsylvania are frequently cited among the most affected, though this partly reflects which states test most aggressively. The EPA’s 2024 rule now requires every state’s public water systems to monitor six PFAS compounds. To check your area, use the EWG PFAS map, your utility’s Consumer Confidence Report, and your state health department — and test your own tap with a certified mail-in kit for a definitive answer.
PFAS in tap water by state is not a uniform picture — these “forever chemicals” have been detected in thousands of U.S. water systems, but some states have widespread known contamination while others simply haven’t tested as much. Here’s how to understand PFAS where you live and what to do about it.
The states most affected
Based on identified contamination sites, several states come up repeatedly: Michigan (often ranked highest, partly because it tests aggressively), California, Colorado, Texas, and Pennsylvania. The Environmental Working Group (EWG) has mapped thousands of contaminated locations across all 50 states, and USGS research estimates that at least 45% of U.S. tap water contains detectable PFAS.
An important caveat: a state ranking “high” often means it tests thoroughly, while a “low” state may simply have gaps in testing. Absence of data is not proof of clean water.
Why it varies so much
PFAS contamination clusters around specific sources: military bases and airports (firefighting foam), industrial plants, landfills, and manufacturing sites. If you live near any of these, your risk is higher regardless of statewide averages.
How to check your state and your tap
- EWG PFAS map — a free interactive map of known contamination sites nationwide.
- Consumer Confidence Report (CCR) — your utility’s annual water-quality report; under the EPA’s 2024 rule it should include PFAS monitoring.
- State health department — many publish PFAS data and some offer free testing for wells.
- A mail-in lab test — the only way to know exactly what’s in your specific tap. Learn how to test your water for PFAS at home.
What to do if your state is high-risk
Test first, then filter if needed. The proven removal methods are reverse osmosis and certified activated carbon — see the best water filters for PFAS and our guide to under-sink PFAS filters. Boiling does not remove PFAS, and bottled water isn’t a guaranteed fix.
Frequently asked questions
Which states have the worst PFAS contamination?
Michigan is often cited as having the highest number of identified contamination sites, followed by California, Colorado, Texas, and Pennsylvania. However, testing coverage varies widely by state, so ‘worst’ partly reflects which states test most thoroughly.
How do I find out if my state has PFAS in the water?
Check the Environmental Working Group (EWG) interactive PFAS map, your water utility’s annual Consumer Confidence Report, and your state health department’s website. For your specific tap, a mail-in lab test is the most accurate.
Does the EPA regulate PFAS in all states?
Yes. The EPA set the first nationwide enforceable PFAS limits in 2024, requiring public water systems in every state to monitor six PFAS compounds and act if levels exceed the limits.
Are some states offering free PFAS testing?
Yes. States including New York, Colorado, and New Hampshire have offered free PFAS testing programs for private well owners. Contact your state health department to check current availability.
Is bottled water safer in high-PFAS states?
Not reliably. PFAS have been detected in some bottled water brands, so bottled water is not a guaranteed way to avoid them. A certified filter is more dependable.
Reviewed by the Complete Water Guide team. This article is for general information and is not a substitute for professional water-quality or medical advice. We may earn a commission from some links on this page.
