PFAS (Per- and Polyfluoroalkyl Substances) in California Drinking Water
California has a 34.6% PFAS detection rate with 56 systems exceeding the EPA 4 ppt MCL.
Total Systems
20,579
Systems Tested
760
Detection Rate
34.6%
Population Served
42.7M
PFAS (Per- and Polyfluoroalkyl Substances) in California: Key Facts
Detection Rate
34.6%
Systems Exceeding MCL
56
Max Level Detected
110 ppt
EPA MCL
4 ppt
EPA Standard
0.000004 mg/L
MCLG (goal): 0 mg/L
Water Systems with Violations in California
| System | Population | Violations |
|---|---|---|
| Grindstone Rancheria | 150 | 1214 |
| Tule River Reservation Main | 3K | 662 |
| Yurok - Weitchpec | 120 | 622 |
| Arizona Village | 3K | 607 |
| Oasis Mobile Home Park | 1K | 564 |
| ROHNERT PARK, CITY OF | 44K | 561 |
| Yurok - Kepel | 76 | 561 |
| Yurok - Wautec | 96 | 525 |
Health Effects of PFAS (Per- and Polyfluoroalkyl Substances) Exposure
Cancer risk
PFOA and PFOS linked to kidney and testicular cancers
Immune disruption
Reduced vaccine response and immune function
Thyroid and hormonal effects
Disrupts thyroid and reproductive hormones
Developmental harm
Fetal and child development impacts
Increased risk of certain cancers, immune system effects, thyroid hormone disruption, high cholesterol, reproductive effects.
Frequently Asked Questions
Is there pfas (per- and polyfluoroalkyl substances) in California water?
Yes. California has a 34.6% PFAS detection rate across 760 tested water systems. 56 systems exceed the EPA 4 ppt MCL for PFOA/PFOS.
How can I check my California water for pfas (per- and polyfluoroalkyl substances)?
Search for your water system using the WaterCheck system lookup, or contact your utility and request a copy of your Consumer Confidence Report (CCR). The CCR is published annually and lists all detected contaminants, their levels, and the EPA MCLs. For private wells, contact a state-certified lab for independent testing.
What is the EPA limit for pfas (per- and polyfluoroalkyl substances)?
The EPA Maximum Contaminant Level (MCL) for pfas (per- and polyfluoroalkyl substances) is 0.000004 mg/L. Systems that exceed MCLs are required to notify customers and take corrective action.
PFAS (Per- and Polyfluoroalkyl Substances) at a Glance
Source
Industrial discharges, firefighting foam (AFFF), non-stick cookware coatings, water-resistant fabrics
How to Filter PFAS (Per- and Polyfluoroalkyl Substances)
- +Reverse osmosis is most effective against PFAS (90-95% removal)
- +Granular activated carbon (GAC) filters reduce some PFAS
- +Look for NSF/ANSI 58 or 62 certified systems
- +Standard pitcher filters offer limited protection