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 |
| Coarsegold School | Mariposa, CA | 441 | 13 | - |
| Fcsa 49 - Five Points | Fresno, CA | 440 | 89 | - |
| Convict Lake Campground | Bishop, CA | 440 | 31 | - |
| Cypress Center WS | Salinas, CA | 440 | 46 | - |
| Garden Farms C.w.d. | Atascadero, CA | 440 | 13 | - |
| Whiskeytown Nra-Oak Bottom | Whiskeytown, CA | 440 | 2 | - |
| Hayward Flat Campground | Redding, CA | 440 | 0 | - |
| Bennett Ridge Mutual Water Company | Santa Rosa, CA | 439 | 9 | - |
| Son Shine Properties | Edison, CA | 438 | 92 | - |
| Psmcsd - Vega RD WS #01 | Royal Oaks, CA | 438 | 18 | - |
| Sunnyside Farms Mutual Water Company | Palmdale, CA | 436 | 9 | - |
| Wp&a-Firebaugh Water System | Lost Hills, CA | 435 | 0 | - |
| Sereno del Mar Water Company (Puc) | Forestville, CA | 435 | 19 | - |
| El Rio Estates | Anderson, CA | 434 | 16 | - |
| Stockdale Annex Mutual Water | Bakersfield, CA | 433 | 22 | - |
| Yolo Co Housing Authority-El Rio Villa | Woodland, CA | 432 | 14 | - |
| Csp-Pt. Cabrillo Light Station Shp | Duncans Mills, CA | 430 | 2 | - |
| Sierra Enterprise Elementary School | Sacramento, CA | 430 | 2 | - |
| Delicato Vineyards | Manteca, CA | 430 | 39 | - |
| Strickland Mutual Water Company | Oxnard, CA | 429 | 78 | - |
| Tomales High School | Tomales, CA | 427 | 7 | - |
| Sonoma County CSA 41-Salmon Creek | Santa Rosa, CA | 427 | 15 | - |
| Morada Estates N PWS #46 | Stockton, CA | 426 | 1 | - |
| Albion River Campground | San Francisco, CA | 425 | 17 | - |
| Ward Well Water Company | Tahoe City, CA | 425 | 5 | - |
| Dp&r - Castle Crags Sp | Oroville, CA | 425 | 0 | - |
| Usmc - Housing Coleville | Bridgeport, CA | 424 | 3 | - |
| East Orosi Community Services District | Visalia, CA | 423 | 190 | - |
| Wente Scout Reservation | Pleasant Hill, CA | 422 | 15 | - |
| Redwood Maint. & Oper. | Crescent City, CA | 421 | 15 | - |
| Yosemite West Water System | Mariposa, CA | 420 | 28 | - |
| Csp-Manchester State Park | Duncans Mills, CA | 420 | 7 | - |
| Los Robles Mobile Home Estates | Templeton, CA | 420 | 4 | - |
| Santa Rosa Mobile Estates | San Leandro, CA | 420 | 9 | - |
| Sun Valley Packing | Reedley, CA | 420 | 2 | - |
| Villa del Monte MWC | Los Gatos, CA | 419 | 30 | - |
| Shasta CSA - French Gulch, #11 | Redding, CA | 419 | 20 | - |
| Alliance Redwoods Conference Grounds | Occidental, CA | 418 | 46 | - |
| Fcsa 05 - Wildwood Island | Fresno, CA | 417 | 25 | - |
| Sutter Home Winery | St. Helena, CA | 417 | 0 | - |
| Shingletown Store Water System | Shingletown, CA | 417 | 2 | - |
| Slide Inn Snowbowl Water Co | Sonora, CA | 417 | 10 | - |
| Island Union School | Lemoore, CA | 416 | 41 | - |
| Post Ranch Inn WS | Big Sur, CA | 416 | 23 | - |
| Rancho Oso | Santa Barbara, CA | 416 | 12 | - |
| Country Hills RV Park | Beaumont, CA | 415 | 23 | - |
| Fess Parker Winery | Los Olivos, CA | 415 | 2 | - |
| White Oak Mutual Water Company | Cottonwood, CA | 415 | 10 | - |
| Yolo Fliers Club | Woodland, CA | 415 | 30 | - |
| Sanborn-Skyline County Park | San Jose, CA | 414 | 28 | - |