Updated:
18.9 Million Californians in PFAS-Contaminated Water
Forever chemicals (PFAS) including GenX entered California tap water through industrial discharge and firefighting foam. California law does not require utilities to remove them. The EPA just rolled back federal protections. Find out what is in your water.
California has no enforceable state maximum contaminant level for any PFAS compound, despite 18.9 million Californians living in water systems that detected PFAS above state notification levels between 2023 and 2025. Per and polyfluoroalkyl substances, commonly called forever chemicals, are synthetic fluorinated compounds that persist indefinitely in the environment and accumulate in human blood. GenX (HFPO-DA), PFOA, and PFOS have been found in California drinking water supplies. The federal EPA set limits for PFOA and PFOS at 4 parts per trillion in 2024 but proposed removing protections for GenX and three other PFAS in May 2026. If that rollback is finalized in late 2026 or early 2027, California utilities will have no federal mandate to monitor or treat for those compounds. The state has notification levels and response levels but no enforceable MCLs. Until lawmakers act, a NSF/ANSI 58 certified reverse osmosis system is the only home filtration method independently validated to remove 90 to 99 percent of PFAS. Purest Water Solutions provides free in-home testing across California and Phoenix metro to identify your specific water quality risks.
Does California Have a PFAS Limit for Drinking Water?
No state maximum contaminant level exists for any PFAS compound in California. The state has established notification levels and response levels for certain PFAS, which require utilities to notify customers and take responsive action if detected. However, notification levels are not the same as enforceable limits, and California law does not mandate treatment.
California depends on federal EPA standards under the Safe Drinking Water Act. In April 2024, the EPA set the first federal maximum contaminant levels for PFAS: PFOA and PFOS at 4 parts per trillion, and three additional compounds at 10 ppt each. A hazard index for mixtures was also established. Compliance was set for April 2029.
In May 2026, the EPA proposed rescinding the limits for GenX, PFHxS, PFNA, and the hazard index on procedural grounds. The public comment period closed July 20, 2026. If the rollback is finalized, California utilities will not be required by federal law to monitor or treat for those four compounds, leaving families to rely solely on state notification (non-mandatory) levels and private home filtration.
For current California standards, verify at the State Water Board: waterboards.ca.gov/pfas
Where Has PFAS Been Detected in California and Phoenix Water?
PFAS contamination in California and Phoenix metro water systems comes from three primary sources: industrial manufacturing discharge, military and civilian firefighting foam (AFFF), and land application of PFAS-contaminated sewage sludge on agricultural fields. Below are documented PFAS detections affecting major California and Phoenix utilities.
California Systems with Documented PFAS
- San Francisco Bay Area — Multiple systems detected PFOA, PFOS, and GenX above state notification levels. East Bay Municipal Utility District, Santa Clara Valley Water District, and San Jose Water have all issued PFAS notifications since 2023.
- Los Angeles metro — PFAS detected in multiple supplies. Los Angeles Department of Water and Power and several regional systems serving millions.
- San Diego County — Documented PFAS detections in multiple water systems serving coastal communities.
- Central Valley — Widespread PFAS from agricultural land application of biosolids. Affects communities from Sacramento to Kern County.
Phoenix Metro
- Luke Air Force Base contamination — AFFF (aqueous film forming foam) used in military training and emergency exercises has contaminated groundwater and surface water near Luke AFB. Phoenix metro communities and agricultural areas affected.
- Phoenix municipal supplies — Several Phoenix-area utilities have detected PFAS above notification levels and issued public advisories.
For your specific utility, search the EWG Tap Water Database at ewg.org/tapwater (free, no login required).
Which Home Water Filter Actually Removes Forever Chemicals?
Not all filters remove PFAS. Water softeners do not work. Many activated carbon filters are ineffective against newer, shorter-chain PFAS compounds like GenX. The only home filtration method independently certified to remove 90 to 99 percent of all PFAS is reverse osmosis certified to NSF/ANSI Standard 58.
Reverse Osmosis (NSF/ANSI 58)
Removes 90-99% of PFOA, PFOS, GenX, and shorter-chain variants. This is the gold standard for PFAS removal. Always verify NSF/ANSI 58 certification before purchasing.
Activated Carbon (NSF/ANSI 53)
Reduces some long-chain PFAS but is less effective for GenX and shorter-chain compounds. Do not rely on carbon alone for PFAS concerns.
Water Softeners
Remove hardness minerals only. Zero PFAS removal capability. If you have soft water and PFAS concerns, you still need reverse osmosis.
Know What is in Your Tap Water
Purest Water Solutions provides free in-home water testing across California and Phoenix metro. We test for PFAS, PFOA, PFOS, GenX, and 25+ other contaminants. No obligation.
Schedule Your Free TestFrequently Asked Questions About PFAS and Forever Chemicals
Does California have a PFAS limit for drinking water?
No state MCL, but California has notification levels. See the section above for details on federal and state standards.
What are forever chemicals and why GenX?
PFAS (per and polyfluoroalkyl substances) do not break down in nature or the human body. GenX was introduced as a replacement for older banned PFAS and has been found in California water. See the section above for toxicity details.
18.9 million Californians — what does this mean?
The Environmental Working Group reports that 18.9 million Californians live in water systems that detected PFAS above state notification levels between 2023-2025. This is not a current safety alert but reflects the scale of PFAS presence.
Does a water softener remove PFAS?
No. Softeners only remove hardness minerals. You need reverse osmosis (NSF/ANSI 58) to remove PFAS.
Which filter removes forever chemicals?
Only reverse osmosis certified to NSF/ANSI Standard 58 removes 90-99% of PFAS. See the section above for details.