California Water Quality
Health violation data for 3,077 community water systems in California. Based on EPA Safe Drinking Water Information System (SDWIS) data.
Water Systems
3,077
Total Violations
17,550
Systems with Violations
50
Cities with Issues
592
Water Systems with Most Violations
| # | Water System | Violations | Health |
|---|---|---|---|
| 1 | CAL AM - OAKHURST Sacramento | 368 | Yes |
| 2 | CAL AM - RAYMOND Sacramento | 364 | Yes |
| 3 | CSA 70 W-4 PIONEERTOWN San Bernardino | 284 | Yes |
| 4 | Grindstone Rancheria Elk Creek | 234 | Yes |
| 5 | NORTH EDWARDS WD North Edwards | 203 | Yes |
| 6 | US ARMY FORT IRWIN Fort Irwin | 180 | Yes |
| 7 | PAPPAS & CO (MENDOTA) Fresno | 176 | Yes |
| 8 | DEL ORO RIVER ISLAND SERV TERR #1 Chico | 176 | Yes |
| 9 | HARRIS FARMS HEADQUARTERS Coalinga | 174 | Yes |
| 10 | LINDSAY, CITY OF Linsday | 173 | Yes |
| 11 | COLUSA CO. WWD #1 - GRIMES Grimes | 135 | Yes |
| 12 | IRONWOOD CAMP Newberry Springs | 134 | Yes |
| 13 | ARVIN COMMUNITY SERVICES DIST Arvin | 133 | Yes |
| 14 | LANARE COMMUNITY SERVICES DIST Coalinga | 120 | Yes |
| 15 | CARUTHERS COMM SERV DIST Caruthers | 120 | Yes |
| 16 | KETTLEMAN CITY CSD Kettleman City | 120 | Yes |
| 17 | LEMOORE, CITY OF Lemoore | 119 | Yes |
| 18 | KNOLL ENTERPRISES Ludlow | 119 | Yes |
| 19 | LAND PROJECTS MUTUAL WATER CO. Lancaster | 117 | Yes |
| 20 | BAR-LEN MWC Barstow | 114 | Yes |
| 21 | PAUMA VALLEY WATER COMPANY Pauma Valley | 111 | Yes |
| 22 | KEYES COMMUNITY SERVICES DIST. Keyes | 110 | Yes |
| 23 | FOREST SPRINGS Boulder Creek | 109 | Yes |
| 24 | HARRIS FEEDING COMPANY Coalinga | 108 | Yes |
| 25 | VALLEY FORD WATER ASSOCIATION Valley Ford | 108 | Yes |
| 26 | LAS CUMBRES MUTUAL WATER CO Los Gatos | 107 | Yes |
| 27 | NPS-WOLVERTON Three Rivers | 107 | Yes |
| 28 | RIVERDALE PUBLIC UTILITY DISTRICT Riverdale | 104 | Yes |
| 29 | QUIET OAKS MOBILE HOME PARK Stockton | 101 | Yes |
| 30 | MAHER MUTUAL WATER COMPANY Bakersfield | 98 | Yes |
| 31 | MADERA CO MD1-HIDDEN LAKE ESTATES Madera | 98 | Yes |
| 32 | SIERRA LINDA MUTUAL WATER CO North Fork | 97 | Yes |
| 33 | ALPAUGH COMMUNITY SERVICES DISTRICT Alpaugh | 96 | Yes |
| 34 | BRIDGEPORT PUD Bridgeport | 93 | Yes |
| 35 | RAINBIRD VALLEY MWC Weldon | 90 | Yes |
| 36 | LSID - TONYVILLE Lindsay | 90 | Yes |
| 37 | MCKEE BRIDGE MOBILE HOME PARK Encinitas | 88 | Yes |
| 38 | MD 42 STILL MEADOW Madera | 87 | Yes |
| 39 | SURFWOOD MUTUAL WATER CORPORATION Mendocino | 87 | Yes |
| 40 | R.S. MUTUAL WATER COMPANY Wofford Heights | 86 | Yes |
| 41 | INDIAN OAKS TRAILER PARK Murrieta | 86 | Yes |
| 42 | CSA 70 W-3 HACIENDA San Bernardino | 85 | Yes |
| 43 | CSA 70-F MORONGO San Bernardino | 84 | Yes |
| 44 | UC DESERT RESEARCH AND EXTENSION CENTER Holtville | 83 | Yes |
| 45 | ENCINAL RD WS #01 Salinas | 83 | Yes |
| 46 | SONOMA COUNTY MUTUAL WATER COMPANY San Francisco | 83 | Yes |
| 47 | HARRIS FARMS SOUTH 101-144 Coalinga | 82 | Yes |
| 48 | SIERRA VISTA ASSOCIATION Clovis | 82 | Yes |
| 49 | BORON CSD Boron | 80 | Yes |
| 50 | MORO RD WS #09 Salinas | 78 | Yes |
Most Common Contaminants in California
| Contaminant | Violations | Systems Affected |
|---|---|---|
| Barium | 5,421 | 145 |
| Nitrate | 2,428 | 136 |
| Total Trihalomethanes (TTHM) | 2,016 | 120 |
| Lead (Action Level) | 1,664 | 55 |
| Arsenic | 1,249 | 162 |
| Haloacetic Acids (HAA5) | 1,183 | 91 |
| Total Coliform (RTCR) | 887 | 236 |
| Gross Alpha | 516 | 514 |
| Manganese | 453 | 17 |
| Fluoride | 364 | 58 |
| E. coli | 295 | 116 |
| PFOA + PFOS | 139 | 16 |
| Turbidity | 124 | 29 |
| Thallium | 102 | 8 |
| Nitrite | 85 | 15 |
Cities with Water Quality Issues
Los Angeles West Hollywood Compton Downey Hawthorne Buena Park Artesia Victorville Long Beach Signal Hill Bakersfield Arcadia Pasadena Valencia Santa Clarita Azusa Chino Corona Rancho Cucamonga El Monte Lemoore Mira Loma Pomona Rosemead Upland West Covina Boulevard Campo Escondido Camp Pendleton San Marcos Santee Valley Center Vista San Diego Coachella El Centro Twentynine Palms Adelanto Fort Irwin +552 more
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About This Data
Water quality data is from the EPA Safe Drinking Water Information System (SDWIS). Health-based violations include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations. Only community water systems (CWS) in California are included.
Source: U.S. Environmental Protection Agency, SDWIS Federal Reporting Services U.S. Environmental Protection Agency, SDWIS Federal Reporting Services
Read our methodology - how this data is sourced, computed, and verified.