Is there PFAS in your
tap water?
PFAS "forever chemicals" have been detected in water systems serving millions of Americans. Enter your ZIP code for free results from EPA's most recent national testing data.
Free. No account needed. Data from EPA UCMR 5 (updated Jan 2026).
"Forever chemicals" that don't break down in your body or the environment
Per- and polyfluoroalkyl substances (PFAS) are a group of over 12,000 synthetic chemicals used in non-stick cookware, firefighting foam, food packaging, and countless industrial processes since the 1940s.
They're called "forever chemicals" because they resist breaking down. Once in water, they persist indefinitely. Studies link PFAS exposure to kidney cancer, thyroid disease, immune suppression, and developmental harm in children.
Learn about each PFAS compound →Documented Health Effects of PFAS Exposure
Decades of peer-reviewed research link PFAS to serious health conditions. Effects are cumulative — PFAS builds up in the body over years of low-level exposure through drinking water.
Cancer Risk
- Kidney cancer
- Testicular cancer
- Bladder cancer
Thyroid & Hormones
- Thyroid disease
- Hormone disruption
- Metabolic disorders
Immune Suppression
- Weakened vaccine response
- Increased infections
- Autoimmune conditions
Child Development
- Low birth weight
- Developmental delays
- Earlier puberty onset
Sources: EPA, NIH National Toxicology Program, ATSDR, peer-reviewed studies in Environmental Health Perspectives
How PFAS Gets Into Drinking Water
PFAS contamination follows predictable patterns. Understanding the sources helps explain why some communities face much higher risk than others.
Industrial Manufacturing
Major SourceFacilities producing non-stick coatings, semiconductors, and fluoropolymers discharge PFAS into nearby waterways and groundwater. Major contamination hotspots exist around legacy manufacturing plants in states like NC, WV, and MN.
Military Bases & Airports
Major SourceAqueous film-forming foam (AFFF) used in fire training exercises and emergencies has saturated groundwater at hundreds of military installations and civilian airports. The DoD has identified over 700 contaminated sites.
Consumer Products & Landfills
Diffuse SourcePFAS from stain-resistant carpets, waterproof clothing, food packaging, and cookware accumulates in landfills. Leachate from these landfills can migrate into groundwater over time, especially in older, unlined sites.
Sewage Sludge (Biosolids)
Emerging ConcernPFAS-laden biosolids (treated sewage) spread on farmland as fertilizer have contaminated soil and groundwater across rural America, impacting private wells and small water systems far from any industrial site.
Most Affected States
How CheckPFAS Works
EPA Source Data
All data comes directly from EPA's UCMR 5 — the most comprehensive PFAS testing ever conducted on US public water systems.
ZIP → Water System Mapping
We map every US ZIP code to its corresponding public water utility using official EPA service area data.
Plain-English Results
Chemical acronyms translated to plain language — with EPA limit comparisons and certified filter recommendations. Glossary of terms →
What Do These Terms Mean?
Water quality reports are full of acronyms. Here are the four you'll see most often on CheckPFAS.
The EPA's legal limit for a contaminant in tap water. Water utilities must act — and tell you — if this level is exceeded.
How PFAS concentration is measured. 4 ppt = 4 drops of water in 250 Olympic swimming pools — tiny amounts with real health effects.
"Forever chemicals" — 12,000+ synthetic compounds that don't break down in water, soil, or the human body.
The 2023–2025 program that tested 10,000+ water systems for 29 PFAS compounds. Every result on this site comes from UCMR 5.
Find out what's in your water
Free. Takes 5 seconds. Data from 10,000+ water utilities nationwide.