PFAS in Drinking Water — What It Is, Where It Is, and What Removes It
PFAS — per- and polyfluoroalkyl substances — are a group of over 12,000 synthetic chemicals that don't break down in the environment or your body. They've been manufactured since the 1940s and are now found in the drinking water of an estimated 200 million Americans. In 2023 the USGS found PFAS in 45% of US tap water samples. In 2024 the EPA set the first-ever legally enforceable limits.
Why they're called "forever chemicals"
PFAS stands for per- and polyfluoroalkyl substances. The name comes from the carbon-fluorine bond — the strongest bond in organic chemistry. That bond is why PFAS don't break down. Not in soil. Not in water. Not in your body. They accumulate over a lifetime of exposure.
They were invented in the 1940s and put into everything: nonstick cookware, waterproof clothing, food packaging, firefighting foam, stain-resistant carpet, and hundreds of industrial processes. Decades of production and disposal have put PFAS into groundwater, rivers, and tap water across every state.
The EPA regulates 6 PFAS compounds. Over 12,000 exist. Most have never been tested in drinking water. The 45% contamination figure only covers the ones we know to look for.
How PFAS gets into drinking water
What PFAS does to your body
PFAS accumulate in blood and organs over time. Health effects are linked to long-term low-level exposure, not single acute events. The science has strengthened considerably since 2015.
The first legally enforceable PFAS limits in US history
In April 2024, the EPA finalized the first-ever legally enforceable Maximum Contaminant Levels (MCLs) for PFAS in drinking water:
Water systems have until 2027 to comply. Many systems that currently exceed these limits are still legally operating. Enter your ZIP to see if your system has PFAS detected above the new MCLs.
Where PFAS contamination is most documented
PFAS contamination has been found in all 50 states, but these states have the highest documented levels based on EPA monitoring data and state testing programs:
Risk is especially elevated near military bases, airports, chemical plants, and industrial manufacturing sites regardless of state.
The only filters proven to remove PFAS
Not all filters remove PFAS. Standard carbon pitcher filters (Brita, PUR) do not remove PFAS effectively. Reverse osmosis and certified activated carbon block filters are the only residential technologies with documented PFAS removal.
Reverse osmosis is the gold standard for PFAS removal — the only residential technology proven to remove PFAS at >99%. The G3P800 is NSF 58 certified, tankless, 800 GPD, and removes PFOA, PFOS, GenX, and all 6 EPA-regulated PFAS compounds.
WQA Gold Seal plus NSF 42, 53, 58, and 401 — the most certifications of any under-sink RO on the market. Removes PFAS, microplastics, and 90+ contaminants.
The only pitcher certified to remove PFAS at 99.9%. NSF certified against 365+ contaminants. Best option for renters or anyone who can't install an under-sink system.
Is PFAS in your tap water?
Enter your ZIP to see the EPA PFAS testing results for your exact water system — from the 2023-2025 federal monitoring program covering 6,151 systems nationwide.
Check My Water Free →No. Boiling does not remove PFAS — it actually concentrates them by evaporating water while leaving the chemicals behind. The only way to remove PFAS from drinking water is through reverse osmosis, activated carbon block filtration (certified NSF P473), or distillation.
Standard Brita pitchers with basic carbon filters do not remove PFAS effectively. Brita's Longlast+ filter claims some PFAS reduction but is not independently certified to NSF P473. For confirmed PFAS removal, use a filter certified to NSF/ANSI 58 (RO) or NSF/ANSI P473.
The EPA's 2024 MCL is 4 parts per trillion (ppt) for PFOA and PFOS individually. However, the EPA's own Maximum Contaminant Level Goal (MCLG) — the health-ideal level — is zero for both. There is no established safe level of PFAS exposure. EWG recommends 1 ppt as a health guideline.
Enter your ZIP code at watercheckup.com to see the federal PFAS testing results for your specific water system. The EPA tested 6,151 systems in 2023-2025 under the UCMR5 monitoring program. If your system was tested and PFAS was detected, it will show in your report. Well water owners need a certified lab test — well water is not included in the federal monitoring.
Yes. Studies have found PFAS in bottled water brands including several major national brands. Bottled water is regulated as a food product under the FDA, which has not yet set PFAS limits for bottled water. A reverse osmosis system at home produces water that is generally cleaner and cheaper than bottled water.
Yes. NSF/ANSI 58–certified reverse osmosis systems are designed to reduce a wide range of contaminants, including PFAS, by forcing water through a semipermeable membrane. Performance depends on the specific system and maintenance — replace prefilters and the RO membrane on the schedule the manufacturer recommends.
Most OEM refrigerator filters and basic faucet-mount filters target taste, odor, and chlorine. They are not a substitute for NSF/ANSI 58 (RO) or certified carbon-block systems tested for PFAS. Check the label for explicit NSF standards (58, 53 with lead/PFAS claims, or P473) — marketing language like “reduces contaminants” is not enough.
PFOA and PFOS are two of the best-studied “long-chain” PFAS historically used in nonstick coatings and firefighting foam. GenX (HFPO-DA) is a newer replacement chemistry. The EPA now regulates six PFAS in drinking water, including PFOA, PFOS, and GenX, because each has distinct chemistry but similar persistence in water and the environment.
Drinking water is the main exposure route regulators focus on for municipal systems. Dermal absorption from short showers is thought to be minor compared with ingestion, but hot showers aerosolize water — if you have elevated PFAS, a whole-house or shower filter may reduce exposure for sensitive groups. For drinking and cooking, treat at the point of use with certified filtration.
No. Ion-exchange water softeners swap calcium and magnesium for sodium (or potassium) to reduce hardness. They are not designed to remove PFAS. Some whole-house systems combine softening with other media — only components certified for PFAS or RO at the kitchen tap should be relied on for drinking water.
Not automatically. Wells can be contaminated by septic systems, landfills, firefighting training sites, biosolids on farmland, or industrial plumes — all documented PFAS sources. City water is tested under federal programs; private wells are not. If you use a well near a known contamination corridor, lab testing (EPA Method 533 or 537.1) is the only way to know.
Elimination half-lives vary by compound — on the order of years for some legacy PFAS in blood. That is why they are called “forever chemicals”: they clear slowly and can accumulate with ongoing exposure. Reducing intake from water and dust helps; the science on reversing long-term body burden is still evolving.
NSF/ANSI 58 certifies reverse osmosis systems for structural integrity and contaminant reduction claims the certifier validates. NSF/ANSI P473 specifically covers PFOA and PFOS reduction in drinking water treatment devices. Always read which standard applies — a pitcher certified to P473 is not the same as an under-sink RO certified to 58.
Distillation can remove many non-volatile contaminants, including PFAS, because they are left behind when water vapor condenses. Practical downsides include energy use, maintenance, and taste. If you choose distillation, use equipment designed for drinking water and follow cleaning instructions so residues do not build up.
Legal compliance means your system meets EPA enforceable limits on the schedule the rule requires — it does not mean zero PFAS. Many systems show detections below the new MCLs, or were not yet in violation when data were published. Your ZIP-level report shows what was measured, not just pass/fail language from a brochure.