Contaminants
PFAS in Drinking Water: What You Need to Know
PFAS — "forever chemicals" — are in the drinking water of an estimated 200+ million Americans. In 2024, the EPA set the first-ever enforceable limits. Here is what PFAS are, how they got into your water, what the science says about health effects, and how to protect yourself.
What Are PFAS?
PFAS (per- and polyfluoroalkyl substances) are a class of over 12,000 synthetic chemicals that share a common feature: carbon-fluorine bonds that are virtually indestructible. This chemical stability makes PFAS useful in products that need to repel water, oil, and heat — but it also means PFAS persist in the environment and accumulate in living organisms indefinitely.
The two most studied PFAS compounds are PFOA (used in Teflon manufacturing) and PFOS (used in Scotchgard and firefighting foam). Both have been linked to multiple cancers, immune system damage, thyroid disease, and developmental effects.
How PFAS Got Into Drinking Water
PFAS enter water supplies through several pathways:
- Firefighting foam (AFFF): Military bases and airports used PFAS-containing foam for decades during training exercises, contaminating groundwater near hundreds of installations
- Manufacturing: Facilities that made or used PFAS released the chemicals into waterways and soil
- Landfills: PFAS-containing products in landfills leach into groundwater
- Wastewater treatment: Conventional treatment doesn't remove PFAS — treated wastewater discharged into rivers carries PFAS downstream to drinking water intakes
- Biosolids: Treated sewage sludge applied to farmland as fertilizer can contain PFAS, which leaches into groundwater
The 2024 EPA PFAS Standards
In April 2024, the EPA established the first-ever maximum contaminant levels for PFAS in drinking water:
Near the limit of analytical detection. Associated with kidney cancer, testicular cancer, thyroid disease.
Same stringent limit. Associated with cancer, immune suppression, developmental effects.
Newer PFAS compounds with emerging health evidence.
Water systems must begin monitoring by 2027 and achieve compliance by 2029. The EPA has allocated $9 billion in funding to help systems install treatment.
How to Remove PFAS From Your Water
Not all filters remove PFAS. Here's what works:
- Reverse Osmosis (RO): The most effective home treatment, removing 95%+ of all PFAS compounds. Under-sink RO systems cost $200-500 and treat water at a single tap
- Granular Activated Carbon (GAC): Effective for some PFAS, particularly longer-chain compounds like PFOA and PFOS. Less effective for shorter-chain PFAS. Must be replaced regularly
- Ion Exchange: Highly effective for PFAS removal. Some whole-house systems use ion exchange media specifically designed for PFAS
- Standard pitcher filters: Limited PFAS removal. Some newer models with specialized media (like carbon block) perform better — look for NSF P473 certification
Important: Boiling water does NOT remove PFAS. It actually concentrates them by evaporating water while the PFAS remain.
Related Resources
Frequently Asked Questions
PFAS (per- and polyfluoroalkyl substances) are a class of thousands of synthetic chemicals used since the 1940s in nonstick coatings, food packaging, and firefighting foam. They're called "forever chemicals" because their carbon-fluorine bonds — the strongest in organic chemistry — don't break down in the environment or the human body. PFAS accumulate over time, and virtually all Americans have detectable levels in their blood.
Possibly. PFAS have been detected in the water supplies of an estimated 200+ million Americans. Communities near military bases, airports, and manufacturing facilities are at highest risk. Search your water system on IsWaterSafe, and check if your system has tested for PFAS. Note that many systems have not yet tested for PFAS, so absence of data doesn't mean absence of PFAS.
Reverse osmosis (RO) systems are the most effective, removing 95%+ of PFAS. Activated carbon filters (including granular activated carbon and carbon block) can remove some PFAS, but effectiveness varies by filter type and PFAS compound. Standard pitcher filters have limited PFAS removal capability. Ion exchange filters are also effective. Look for NSF/ANSI 53 or P473 certification for PFAS removal.
In April 2024, the EPA set the first-ever enforceable limits for six PFAS compounds in drinking water: 4 ppt (parts per trillion) each for PFOA and PFOS, and 10 ppt each for PFHxS, PFNA, and HFPO-DA (GenX). A hazard index approach covers mixtures of these compounds. Water systems must comply by 2029. These are among the most stringent drinking water standards ever set.