PFAS in Drinking Water: Forever Chemicals Complete Guide
Everything about PFAS contamination in US drinking water. 29 compounds tested, 4,920+ water systems analyzed, 49% national detection rate.
Reviewed by Dr. Marcus Reilly, PhD – PFAS & Drinking Water Scientist
Quick Answer
PFAS (per- and polyfluoroalkyl substances) are 12,000+ synthetic forever chemicals that don't break down in the environment or the human body. EPA UCMR5 testing (2023-2025) detected PFAS in 49% of US public water systems. The 2024 EPA rule sets enforceable limits at 4 parts per trillion (ppt) for PFOA and PFOS each. Reverse osmosis (NSF/ANSI 58) removes 90-99% of PFAS from drinking water.
Key facts
- Compounds tracked by EPA UCMR5
- 29
- EPA-regulated PFAS compounds (2024 rule)
- 6
- EPA limit for PFOA + PFOS
- 4 parts per trillion each
- US public water systems with detected PFAS
- approximately 49%
- Most effective home filter
- Reverse osmosis (NSF/ANSI 58), 90-99% removal
Frequently asked questions
What are PFAS forever chemicals?
PFAS (per- and polyfluoroalkyl substances) are synthetic chemicals used since the 1940s in products like non-stick cookware, food packaging, and firefighting foam. They are called forever chemicals because they do not break down in the environment or the human body.
What is the EPA limit for PFAS in drinking water?
In 2024 the EPA set enforceable limits of 4 parts per trillion (ppt) for PFOA and PFOS individually, and hazard-index limits for four other PFAS compounds. Water systems must comply by April 2029.
How can I check if my water has PFAS?
Enter your ZIP code on KnowYourExposure for a free instant check using EPA UCMR5 data. You can also order a certified lab test for $200-$400 for comprehensive results.