Fluoride in California Drinking Water — 34 ZIPs Tested
EPA data analysis for fluoride in California drinking water systems
Fluoride Contamination in California
ZipCheckup analyzed drinking water data across 2,630 ZIP codes in California for fluoride contamination. 34 ZIP codes have reported fluoride detections, and 2 have EPA violations on record.
The violation rate for fluoride in California is 0.1% of all ZIP codes — lower than the national average.
EPA Standard for Fluoride
The EPA maximum contaminant level (MCL) for fluoride is 4.0 mg/L (MCL) / 2.0 mg/L (SMCL), governed by the National Primary Drinking Water Regulations. Water systems that exceed this limit must take corrective action and notify consumers.
Worst ZIP Codes for Fluoride in California
These ZIP codes reported the highest fluoride levels in California based on CCR reports and EPA data:
Lowest Fluoride Levels in California
These ZIP codes had the lowest reported fluoride detections in California:
Health Effects of Fluoride
At levels above the EPA MCL of 4 mg/L, fluoride can cause skeletal fluorosis (bone pain, joint stiffness). The secondary standard of 2 mg/L is set to prevent dental fluorosis in children. At levels used in water fluoridation (0.7 mg/L), fluoride helps prevent tooth decay.
How to Remove Fluoride From Drinking Water
The most effective treatment for fluoride removal is Reverse Osmosis or Activated Alumina. Look for filters certified under NSF 58 standards.
Check Your ZIP Code
Use the ZipCheckup water quality search to see fluoride data for your specific water system in California.
Worst ZIP Codes for Fluoride in California
Ranked by highest fluoride detection level.
| Rank | ZIP Code | City | Level Detected | EPA Limit | Status |
|---|---|---|---|---|---|
| 1 | 95005 | Ben Lomond | 485 ppm | 2 ppm | Exceeds |
| 2 | 95006 | Boulder Creek | 485 ppm | 2 ppm | Exceeds |
| 3 | 95007 | Brookdale | 485 ppm | 2 ppm | Exceeds |
| 4 | 95017 | Davenport | 485 ppm | 2 ppm | Exceeds |
| 5 | 93261 | Richgrove | 17.5 mg/L | 2 mg/L | Exceeds |
| 6 | 92239 | Desert Center | 7.8 ppm | 2 ppm | Exceeds |
| 7 | 93306 | Bakersfield | 6.1 ppm | 2 ppm | Exceeds |
| 8 | 92365 | Newberry Springs | 5.5 ppm | 2 ppm | Exceeds |
| 9 | 92860 | Norco | 2.4 mg/L | 4 mg/L | Within Limit |
| 10 | 93243 | Lebec | 2.3 mg/L | 2 mg/L | Exceeds |
| 11 | 92307 | Apple Valley | 1.85 ppm | 2 ppm | Within Limit |
| 12 | 92384 | Shoshone | 1.75 MG/L | 2 MG/L | Within Limit |
| 13 | 92389 | Tecopa | 1.75 MG/L | 2 MG/L | Within Limit |
| 14 | 92236 | Coachella | 1.7 mg/L | 2 mg/L | Within Limit |
| 15 | 92304 | Amboy | 1.7 ppm | 2 ppm | Within Limit |
| 16 | 92332 | Essex | 1.7 ppm | 2 ppm | Within Limit |
| 17 | 92338 | Ludlow | 1.7 ppm | 2 ppm | Within Limit |
| 18 | 93225 | Frazier Park | 1.7 ppm | 2 ppm | Within Limit |
| 19 | 92356 | Lucerne Valley | 1.5 ppm | 2 ppm | Within Limit |
| 20 | 92277 | Twentynine Palms | 1.46 ppm | 2 ppm | Within Limit |
Lowest Fluoride Levels in California
Cities with Fluoride Data in California
27 cities in California have fluoride testing data available.
+ 7 more cities