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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Analysis of fluoride contamination levels across California cities
Complete list of cities where fluoride has been detected, sorted by level
| City | Level | EPA Limit | % of Limit | Status |
|---|---|---|---|---|
| Lake ForestGrade C+ | 1.49 mg/L | 4.00 mg/L | 37.3% | Safe |
| CarlsbadGrade C+ | 1.48 mg/L | 4.00 mg/L | 37.1% | Safe |
| LancasterGrade C- | 1.46 mg/L | 4.00 mg/L | 36.5% | Safe |
| Garden GroveGrade D | 1.42 mg/L | 4.00 mg/L | 35.6% | Safe |
| WoodlandGrade D | 1.38 mg/L | 4.00 mg/L | 34.6% | Safe |
| WatsonvilleGrade C+ | 1.30 mg/L | 4.00 mg/L | 32.6% | Safe |
| San MarcosGrade F | 1.25 mg/L | 4.00 mg/L | 31.4% | Safe |
| MaderaGrade C+ | 1.23 mg/L | 4.00 mg/L | 30.6% | Safe |
| Santa ClaraGrade D | 1.21 mg/L | 4.00 mg/L | 30.3% | Safe |
| Moreno ValleyGrade C+ | 1.15 mg/L | 4.00 mg/L | 28.7% | Safe |
| San BernardinoGrade F | 1.15 mg/L | 4.00 mg/L | 28.6% | Safe |
| EncinitasGrade C- | 1.11 mg/L | 4.00 mg/L | 27.8% | Safe |
| Santa AnaGrade C+ | 1.11 mg/L | 4.00 mg/L | 27.6% | Safe |
| RocklinGrade B- | 1.10 mg/L | 4.00 mg/L | 27.5% | Safe |
| MantecaGrade B- | 1.09 mg/L | 4.00 mg/L | 27.3% | Safe |
| OrangeGrade C+ | 1.09 mg/L | 4.00 mg/L | 27.3% | Safe |
| AlamedaGrade F | 1.08 mg/L | 4.00 mg/L | 27.0% | Safe |
| PleasantonGrade C+ | 1.07 mg/L | 4.00 mg/L | 26.8% | Safe |
| NapaGrade A- | 1.07 mg/L | 4.00 mg/L | 26.6% | Safe |
| SalinasGrade B+ | 1.06 mg/L | 4.00 mg/L | 26.6% | Safe |
| VisaliaGrade A- | 1.06 mg/L | 4.00 mg/L | 26.4% | Safe |
| Buena ParkGrade A- | 1.06 mg/L | 4.00 mg/L | 26.4% | Safe |
| Santa CruzGrade C+ | 1.05 mg/L | 4.00 mg/L | 26.3% | Safe |
| SanteeGrade B+ | 1.04 mg/L | 4.00 mg/L | 26.1% | Safe |
| DelanoGrade C+ | 1.04 mg/L | 4.00 mg/L | 26.0% | Safe |
Showing 25 of 173 cities. View individual city pages for detailed reports.
While fluoride at low levels is added to prevent tooth decay, excessive exposure can cause problems. Dental fluorosis causes white spots on teeth in children. Skeletal fluorosis from long-term exposure to very high levels can cause joint stiffness and bone damage. Studies have suggested potential links between high fluoride levels and thyroid function issues.
Water additive for dental health; erosion of natural deposits; discharge from fertilizer factories
Based on our analysis of EPA Safe Drinking Water Information System (SDWIS) data and local water utility reports,fluoride has been detected in 173 California water systems. The average level across all tested cities is 19% of the EPA Maximum Contaminant Level (MCL), with the highest detection at 37.3% of the limit.
The EPA MCL for fluoride is 4.0 mg/L, with a secondary standard of 2.0 mg/L. The EPA MCL for fluoride is 4 mg/L. This limit is set to protect public health based on available scientific evidence about the contaminant's health effects.
173 California cities have fluoride detected in their water supply. All tested cities are within EPA safety limits.
Dental fluorosis (tooth discoloration), skeletal problems at high levels, potential thyroid effects. The most vulnerable groups include children during tooth development and people with kidney disease.
The most effective methods for removing fluoride include Reverse Osmosis, Distillation, Activated Alumina. Look for filters certified by NSF/ANSI for fluoride reduction.
The EPA Maximum Contaminant Level (MCL) for fluoride is 4 mg/L.The EPA MCL for fluoride is 4.0 mg/L, with a secondary standard of 2.0 mg/L.
Recommended filtration methods for fluoride removal:
Removes 90-95% of fluoride
Very effective
Specifically designed for fluoride