The EPA's Unregulated Contaminant Monitoring Rule (UCMR 5) has produced the most comprehensive picture of PFAS contamination in American drinking water ever assembled. Over 31,000 public water systems have been tested, and the results paint a sobering picture: PFAS contamination is not limited to a few hotspots – it's a nationwide crisis.
This article ranks states by contamination severity, identifies key contamination sources in each region, and explains what state governments are doing to address the problem.
Want to check your specific water system? Use our free ZIP code lookup for data specific to your address.
Our rankings consider multiple factors:
New Jersey has some of the most extensive PFAS contamination in the country, driven by decades of industrial manufacturing and military activity.
Key facts: - Over 300 water systems with PFAS detections - Multiple Superfund sites with PFAS contamination - State has enacted some of the strictest PFAS limits in the nation (13 ppt for PFNA, 14 ppt for PFOA, 13 ppt for PFOS) - Major sources: Industrial manufacturing (Solvay, Chemours), military installations
What NJ is doing: New Jersey led the nation by setting enforceable PFAS limits before the federal government acted. The state has allocated hundreds of millions for water treatment upgrades and is pursuing litigation against manufacturers.
Michigan's PFAS crisis gained national attention through contamination events in communities like Oscoda, Kalamazoo, and Kent County.
Key facts: - 190+ sites with known PFAS contamination - Former Wurtsmith Air Force Base is one of the most contaminated sites in the country - 3M's manufacturing operations contributed significantly - State has invested over $400 million in response efforts
What MI is doing: Michigan created a dedicated PFAS Action Response Team and set state-level MCLs (8 ppt for PFOA, 16 ppt for PFOS) that are stricter than federal standards for some compounds.
North Carolina's PFAS crisis centers on the Cape Fear River region, where Chemours' Fayetteville Works plant discharged GenX and other novel PFAS compounds.
Key facts: - GenX contamination discovered in 2017 affecting 350,000+ residents - Cape Fear River supplies drinking water to Wilmington and surrounding communities - The Chemours facility is the largest known source of GenX in the world - Contamination extends 100+ miles downstream
What NC is doing: North Carolina ordered Chemours to reduce air emissions by 99% and is requiring the company to provide alternative water supplies to affected communities. The state has set a health goal of 140 ppt for GenX.
Despite its small size, New Hampshire has disproportionately high PFAS contamination, largely due to the former Pease Air Force Base and Saint-Gobain manufacturing facilities.
Key facts: - Pease Air Force Base had PFOS levels exceeding 2,200 ppt (550x the EPA limit) - Saint-Gobain Performance Plastics contaminated wells in Merrimack and Litchfield - State enacted some of the strictest PFAS limits in the nation (12 ppt for PFOA, 15 ppt for PFOS)
What NH is doing: New Hampshire is actively litigating against 3M, DuPont, and Saint-Gobain. The state's PFAS Investigation Fund has allocated millions for water treatment and alternative water supplies.
California's vast size and diverse contamination sources make it one of the most broadly affected states.
Key facts: - Hundreds of water systems with PFAS detections statewide - Military bases (Camp Pendleton, Edwards AFB, March ARB) are major sources - Industrial contamination in Los Angeles, Orange County, and the Bay Area - State is pursuing the nation's strictest notification levels
What CA is doing: California has set notification levels as low as 5.1 ppt for PFOA and 6.5 ppt for PFOS – among the strictest in the nation. The state is also investigating PFAS in food packaging and cosmetics.
Industrial legacy and military installations drive contamination, particularly near Joint Base Cape Cod and in the Merrimack Valley.
Contamination clusters near military bases (Willow Grove, Horsham), industrial sites, and the Delaware River Valley.
Widespread contamination from Hoosick Falls (industrial PFOA) to Long Island (firefighting foam) and multiple upstate communities.
DuPont's Washington Works plant in Parkersburg, WV contaminated communities across the Ohio River in southeastern Ohio. Dayton, Columbus, and Cleveland metro areas also show detections.
Extensive military presence (NAS Jacksonville, Tyndall AFB, Patrick SFB) and firefighting training facilities have contaminated groundwater across the state.
States including Illinois, Virginia, Minnesota, Connecticut, Colorado, Georgia, Texas, Washington, Wisconsin, and Maryland all have significant numbers of water systems with PFAS detections. Contamination sources vary but typically include military bases, airports, and industrial facilities.
Several states have enacted PFAS regulations that are stricter than federal standards:
### Maine - Banned PFAS in all products by 2030 – the most aggressive product ban in the nation - Required testing of agricultural land that received biosolids - Set drinking water standards at 20 ppt for the sum of six PFAS
### Vermont - Requires manufacturers to disclose PFAS in products - Set drinking water standard at 20 ppt (sum of five PFAS) - Banned PFAS in food packaging and firefighting foam
### Minnesota - Home state of 3M – the state has pursued aggressive litigation - Set health-based guidance values for multiple PFAS compounds - Required 3M to fund groundwater treatment in the eastern metro area
State-level data provides important context, but your personal exposure depends on your specific water system. Two neighbors in the same city might be served by different water systems with very different PFAS levels.
The most important step you can take is to check your specific ZIP code against EPA testing data. Our free lookup tool shows you:
New Jersey and Michigan consistently rank as the most contaminated states based on number of affected water systems, maximum contamination levels, and variety of PFAS compounds detected. However, severe contamination exists in every state.
Under the EPA's UCMR 5 program, water systems serving 3,300+ people were required to test for PFAS between 2023 and 2025. Smaller systems are being tested through 2026. Use our ZIP code checker to see if your specific system has been tested.
States can set PFAS limits that are stricter than federal standards, and several have done so. If your state has a stricter limit, your water utility must comply with the stricter standard. However, states cannot set limits that are weaker than federal MCLs once those take effect in 2029.
Having fewer detections doesn't mean your water is safe. PFAS contamination is highly localized – a single military base or industrial site can contaminate water systems in an otherwise "clean" state. Always check your specific ZIP code rather than relying on state-level averages.
No. The EPA's UCMR 5 program only covers public water systems. If you rely on a private well, especially near a military base, airport, or industrial site, you should consider private testing through labs like Tap Score ($149) or SimpleLab ($225).
You can Check your water quality by zip code to see if your area is affected. If you're looking for solutions, Find water filters that remove PFAS certified for removal. Check your state's water quality to compare contamination levels across the country.
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.