42 cities covered
California water quality and radon, by city
26 of 42 covered California cities use chloramine in at least part of the system, and 19 have hard water. 2 of California's 58 counties are EPA radon zone 1.
| City | Disinfectant | Hardness | Lead | PFAS | Radon |
|---|---|---|---|---|---|
| Los Angeles | Chloramine | 7.1 gpg | 3.9 ppb | Not detected | Zone 2 |
| San Diego | Chloramine | 13.2 gpg | Not detected | Not detected | Zone 3 |
| San Jose | Mixed | 10.8 gpg | Not detected | PFOS | Zone 2 |
| San Francisco | Chloramine | 1.5 gpg | Not detected | Not detected | Zone 2 |
| Fresno | Chlorine | 0.7 gpg | Not detected | PFOA, PFOS | Zone 2 |
| Sacramento | Chlorine | 2.6 gpg | Not detected | PFOS, PFOA | Zone 3 |
| Long Beach | Chloramine | 10.0 gpg | 1 ppb | Not detected | Zone 2 |
| Oakland | Chloramine | 2.0 gpg | Not detected | Not detected | Zone 2 |
| Bakersfield | Chlorine | 2.0 gpg | 1.3 ppb | PFOS | Zone 2 |
| Anaheim | Mixed | 16.0 gpg | Not detected | PFOS, PFOA | Zone 3 |
| Stockton | Chloramine | 0.6 gpg | Not detected | PFOS, PFOA | Zone 3 |
| Riverside | Chlorine | 6.5 gpg | 1 ppb | Detected | Zone 2 |
| Irvine | Chloramine | 5.8 gpg | Not detected | Not detected | Zone 3 |
| Santa Ana | Mixed | 8.8 gpg | Not detected | PFOA, PFOS | Zone 3 |
| Chula Vista | Chloramine | 12.6 gpg | Not detected | PFOA, PFOS | Zone 3 |
| Santa Clarita | Chloramine | 13.4 gpg | Not detected | PFOA, PFOS | Zone 2 |
| Fremont | Chloramine | 3.8 gpg | Not detected | Not detected | Zone 2 |
| San Bernardino | Chlorine | 4.6 gpg | Not detected | Detected | Zone 2 |
| Modesto | Chlorine | 2.6 gpg | 12 ppb | PFOS, PFOA | Zone 3 |
| Fontana | Chlorine | 5.4 gpg | Not detected | Not detected | Zone 2 |
| Moreno Valley | Chloramine | 7.2 gpg | 2.8 ppb | Not detected | Zone 2 |
| Oxnard | Chloramine | 16.3 gpg | Not detected | Not detected | Zone 1 |
| Huntington Beach | Mixed | 7.5 gpg | Not detected | PFOS | Zone 3 |
| Glendale | Mixed | 5.0 gpg | Not detected | PFOS, PFOA | Zone 2 |
| Ontario | Mixed | 6.1 gpg | 0.6 ppb | PFOA, PFOS | Zone 2 |
| Santa Rosa | Chlorine | 7.1 gpg | 1.3 ppb | Not detected | Zone 3 |
| Rancho Cucamonga | Chlorine | 4.0 gpg | Not detected | Not detected | Zone 2 |
| Garden Grove | Chloramine | 16.6 gpg | Not detected | PFOA, PFOS | Zone 3 |
| Oceanside | Chloramine | 10.1 gpg | Not detected | Not detected | Zone 3 |
| Lancaster | Chlorine | 4.7 gpg | 1.8 ppb | Not detected | Zone 2 |
| Roseville | Chlorine | 1.1 gpg | Not detected | Not detected | Zone 2 |
| Palmdale | Chlorine | 3.6 gpg | Not detected | Detected | Zone 2 |
| Corona | Chloramine | 9.0 gpg | 3.7 ppb | Detected | Zone 2 |
| Salinas | Chlorine | 6.2 gpg | 1.2 ppb | Not detected | Zone 2 |
| Hayward | Chloramine | 2.6 gpg | Not detected | Not detected | Zone 2 |
| Sunnyvale | Chloramine | 17.4 gpg | Not detected | Not detected | Zone 2 |
| Escondido | Chloramine | 10.0 gpg | 1.1 ppb | Not detected | Zone 3 |
| Pomona | Chlorine | 8.1 gpg | 2.1 ppb | PFOA, PFOS | Zone 2 |
| Visalia | Chlorine | 4.3 gpg | Not detected | PFOA, PFOS | Zone 2 |
| Victorville | Chlorine | 1.0 gpg | Not detected | Not detected | Zone 2 |
| Fullerton | Chloramine | 10.2 gpg | 1.5 ppb | PFOA, PFOS | Zone 3 |
| Torrance | Chloramine | 6.5 gpg | Not detected | Not detected | Zone 2 |
California radon zones
Zone 1 (highest)2 counties
Zone 229 counties
Zone 3 (lowest)27 counties