PFAS · California

PFAS in California Drinking Water — 21 ZIPs Tested

EPA data analysis for pfas in California drinking water systems

21
ZIPs with Detections
1
ZIPs with Violations
4 ppt (PFOA/PFOS)
EPA Limit
High
Health Risk
Reverse Osmosis or Granular Activated Carbon
Best Filter Method

PFAS Contamination in California

ZipCheckup analyzed drinking water data across 2,630 ZIP codes in California for pfas contamination. 21 ZIP codes have reported pfas detections, and 1 have EPA violations on record.

EPA Standard for PFAS

The EPA maximum contaminant level (MCL) for pfas is 4 ppt (PFOA/PFOS), governed by the PFAS NPDWR (2024). Water systems that exceed this limit must take corrective action and notify consumers.

Worst ZIP Codes for PFAS in California

These ZIP codes reported the highest pfas levels in California based on CCR reports and EPA data:

Lowest PFAS Levels in California

These ZIP codes had the lowest reported pfas detections in California:

Health Effects of PFAS

PFAS (per- and polyfluoroalkyl substances) are linked to cancer (kidney, testicular), thyroid disease, immune system suppression, reproductive problems, and elevated cholesterol. These "forever chemicals" persist in the body for years.

How to Remove PFAS From Drinking Water

The most effective treatment for pfas removal is Reverse Osmosis or Granular Activated Carbon. Look for filters certified under NSF 53 / NSF 58 standards.

Check Your ZIP Code

Use the ZipCheckup water quality search to see pfas data for your specific water system in California.

Worst ZIP Codes for PFAS in California

Ranked by highest pfas detection level.

Rank ZIP Code City Level Detected EPA Limit Status
1 90630 Cypress 9.9 ppt 3 ppt Exceeds
2 90680 Stanton 9.9 ppt 3 ppt Exceeds
3 90721 Los Alamitos 9.9 ppt 3 ppt Exceeds
4 92840 Garden Grove 9.9 ppt 3 ppt Exceeds
5 92841 Garden Grove 9.9 ppt 3 ppt Exceeds
6 92842 Garden Grove 9.9 ppt 3 ppt Exceeds
7 92843 Garden Grove 9.9 ppt 3 ppt Exceeds
8 92844 Garden Grove 9.9 ppt 3 ppt Exceeds
9 92845 Garden Grove 9.9 ppt 3 ppt Exceeds
10 92846 Garden Grove 9.9 ppt 3 ppt Exceeds
11 95721 Echo Lake 4 ppt 4 ppt Within Limit
12 95735 Twin Bridges 4 ppt 4 ppt Within Limit
13 96150 South Lake Tahoe 4 ppt 4 ppt Within Limit
14 96151 South Lake Tahoe 4 ppt 4 ppt Within Limit
15 96152 South Lake Tahoe 4 ppt 4 ppt Within Limit
16 96154 South Lake Tahoe 4 ppt 4 ppt Within Limit
17 96155 South Lake Tahoe 4 ppt 4 ppt Within Limit
18 96156 South Lake Tahoe 4 ppt 4 ppt Within Limit
19 96157 South Lake Tahoe 4 ppt 4 ppt Within Limit
20 96158 South Lake Tahoe 4 ppt 4 ppt Within Limit

Lowest PFAS Levels in California

ZIP Code City Level Detected
96158 South Lake Tahoe 4 ppt
96157 South Lake Tahoe 4 ppt
96156 South Lake Tahoe 4 ppt
96155 South Lake Tahoe 4 ppt
96154 South Lake Tahoe 4 ppt
96152 South Lake Tahoe 4 ppt
96151 South Lake Tahoe 4 ppt
96150 South Lake Tahoe 4 ppt
95735 Twin Bridges 4 ppt
95721 Echo Lake 4 ppt

Cities with PFAS Data in California

294 cities in California have pfas testing data available.

+ 274 more cities

California Water Quality Overview: See statewide water quality rankings on the California water quality page.
Learn more about PFAS: Read the full guide on PFAS in drinking water.
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