Public Water Systems
7,249 active public water systems in CA, tracked from EPA's Safe Drinking Water Information System (SDWIS) across all 50 states. See our methodology.
| System Name | Location | Population | Violations | PFAS |
|---|---|---|---|---|
| Gswc-South San Gabriel | San Dimas, CA | 26,240 | 1 | Detected |
| Big Bear Lake Dwp - Big Bear System | Big Bear Lake, CA | 26,132 | 3 | Detected |
| Reedley, City Of | Reedley, CA | 26,076 | 26 | Clean |
| Hollister, City Of | Hollister, CA | 26,017 | 35 | Clean |
| Windsor, Town Of | Windsor, CA | 25,561 | 6 | Clean |
| City of South Pasadena | South Pasadena, CA | 25,329 | 10 | Clean |
| Sunny Slope Water Co. | Pasadena, CA | 25,252 | 1 | Clean |
| Loma Linda, City Of | Loma Linda, CA | 25,129 | 9 | Clean |
| Dhs Border Patrol Hwy 94 Checkpoint | San Diego, CA | 25,083 | 39 | - |
| Norco, City Of | Norco, CA | 25,068 | 144 | Detected |
| Auerbach Farms | Ramona, CA | 25,068 | 0 | - |
| Antelope Valley Poppy Reserve State Park | Lancaster, CA | 25,007 | 0 | - |
| Orchard Dale Water District | Whittier, CA | 25,000 | 10 | Detected |
| Sunnyslope County Water Dist | Hollister, CA | 24,954 | 11 | Detected |
| City of Mountain House | Mountain House, CA | 24,948 | 3 | Clean |
| City of Seal Beach | Seal Beach, CA | 24,937 | 4 | Clean |
| Riverbank, City Of | Riverbank, CA | 24,834 | 34 | Clean |
| Cal-Am Water Company - Duarte | Rosemead, CA | 24,773 | 0 | Detected |
| Liberty Utilities - Lynwood | Downey, CA | 24,701 | 0 | Detected |
| Calico Ghost Town | San Bernardino, CA | 24,623 | 131 | - |
| La Cocina | Aguanga, CA | 24,524 | 12 | - |
| Phelan Pinon Hills Csd | Phelan, CA | 24,285 | 3 | Clean |
| San Fernando-City, Water Dept. | San Fernando, CA | 23,946 | 2 | Clean |
| Golden State Water Company - Bay Point | Rancho Cordova, CA | 23,731 | 7 | Clean |
| Rainbow Municipal WD | Fallbrook, CA | 23,536 | 14 | Clean |
| Patterson, City Of | Patterson, CA | 23,304 | 8 | Clean |
| Oakdale, City Of | Oakdale, CA | 23,235 | 19 | Clean |
| Valley of the Moon Water District | El Verano, CA | 23,107 | 9 | Detected |
| El Monte-City, Water Dept. | El Monte, CA | 22,968 | 21 | Detected |
| Corcoran, City Of | Corcoran, CA | 22,808 | 18 | Clean |
| City of Millbrae | Millbrae, CA | 22,795 | 0 | Clean |
| Cws - North Garden | San Jose, CA | 22,762 | 0 | Detected |
| Wasco, City Of | Wasco, CA | 22,757 | 30 | Clean |
| South Feather W&p - Miners Ranch | Oroville, CA | 22,664 | 0 | Clean |
| Menlo Park Municipal Water | Menlo Park, CA | 22,362 | 3 | Clean |
| Pico WD | Pico Rivera, CA | 22,051 | 50 | Detected |
| Temescal Valley Water District | Temescal Valley, CA | 21,971 | 16 | Clean |
| Shafter, City Of | Shafter, CA | 21,915 | 39 | Clean |
| Linda County Water District | Marysville, CA | 21,654 | 25 | Clean |
| Imperial, City Of | Imperial, CA | 21,591 | 39 | Clean |
| Santa Fe I.D. | Rancho Santa Fe, CA | 21,578 | 1 | Detected |
| American Canyon, City Of | American Canyon, CA | 21,437 | 33 | Clean |
| Port Hueneme City Water Dept | Port Hueneme, CA | 21,407 | 16 | Clean |
| San Lorenzo Valley Water Dist | Boulder Creek, CA | 21,145 | 20 | Detected |
| Arcata, City Of | Arcata, CA | 20,875 | 2 | Clean |
| Cal/Am Water Company - Baldwin Hills | Rosemead, CA | 20,724 | 4 | Clean |
| West Kern Water District | Taft, CA | 20,500 | 6 | Clean |
| Norwalk - City, Water Dept. | Norwalk, CA | 20,283 | 2 | Detected |
| Dhs Boulevard Border Patrol | San Diego, CA | 20,270 | 3 | - |
| Lomita-City, Water Dept. | Lomita, CA | 20,256 | 4 | Detected |