Chromium-6 in drinking water
Also called hexavalent chromium.
The 'Erin Brockovich' chemical. Occurs naturally and from industrial pollution. No federal limit for chromium-6 alone, and the total chromium limit is 100 ppb.
Health: California set a 10 ppb limit for chromium-6 in 2024. EPA's IRIS assessment considers it likely carcinogenic by ingestion.
Across the US
From EPA's earlier unregulated contaminant testing (UCMR 3). These results are older, so ask your utility for current data.
Highest results
| Water system | People | Highest result |
|---|---|---|
| Norman Utilities Authority | 104,868 | 97.4 ppb |
| Kingman Municipal Water | 45,000 | 79 ppb |
| EPCOR – Agua Fria | 128,040 | 62 ppb |
| City of Phoenix | 1.7 million | 54 ppb |
| Moore Public Works Authority | 55,083 | 54 ppb |
| Edmond Public Works Authority | 79,408 | 50.9 ppb |
| Uc – Davis Water System | 13,177 | 47 ppb |
| City of Los Banos | 48,896 | 42 ppb |
| City of Davis | 67,826 | 41 ppb |
| City of Surprise – Mountain Vista | 40,007 | 39 ppb |
| Arizona Water Company – Pinal Valley | 134,432 | 37 ppb |
| City of Scottsdale | 241,361 | 36 ppb |
| City of Peoria | 187,676 | 36 ppb |
| Soquel Creek Water District | 40,962 | 35 ppb |
| City of Buckeye Sonora – Sundance | 21,405 | 33 ppb |
| City of Kerman | 17,256 | 31 ppb |
| EPCOR – Paradise Valley/Scottsdale | 14,107 | 30.1 ppb |
| City of Mustang | 18,576 | 29.9 ppb |
| Goodyear Water Department | 50,001 | 27 ppb |
| PRASA – Guanica Urbano | 6,881 | 26.3 ppb |
| City of Glendale | 234,766 | 26 ppb |
| Guam Waterworks Authority – Northern Water System | 139,207 | 26 ppb |
| City of Woodland | 61,462 | 26 ppb |
| City of Patterson | 24,977 | 26 ppb |
| Vaya Chin Intertie Water System | 1,151 | 25.1 ppb |
States with the most detections
- California: 442
- Texas: 320
- Florida: 219
- Illinois: 216
- Pennsylvania: 160
- New York: 157
- New Jersey: 153
- Massachusetts: 152
- Ohio: 152
- Michigan: 141
- North Carolina: 138
- Tennessee: 131
Sources
The limits, health goals and health effects on this page come from these EPA sources. The results come from EPA's monitoring data for each water system.
- EPA: UCMR occurrence data (the test results)
- EPA: National Primary Drinking Water Regulations (limits and health effects table)
This page summarizes public regulatory information. It is not medical advice. How we source and check this site.
Questions
How do I remove Chromium-6 from tap water?
See the filter guidance on this page: look for a product certified for Chromium-6 specifically, and check the claim in NSF's certified product listings.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.