All water systems in California
7,380 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Acorn Ridge Casino County |
3,640 | 2 | 1 | |
|
Brooktrails Township Csd Mendocino County |
3,632 | 0 | 0 | |
|
Blm-Briceburg Water System Mariposa County |
3,609 | 1 | 0 | |
|
Grosso Kresser Winery San Simeon · San Luis Obispo County |
3,606 | 0 | 0 | |
|
Mission Hills Csd Santa Barbara County |
3,600 | 0 | 0 | |
|
Commerce-City, Water Dept. Montebello · Los Angeles County |
3,598 | 0 | 0 | |
|
Esparto C.s.d. Yolo County |
3,572 | 0 | 0 | |
|
Lockeford Community Serv. Dist. San Joaquin County |
3,572 | 0 | 0 | |
|
Cdcr Sierra Conservation Center Tuolumne County |
3,571 | 0 | 0 | |
|
Bandy Canyon Ranch Corp San Diego County |
3,564 | 0 | 0 | |
|
Crowley Lake Campground (blm) Mono County |
3,562 | 0 | 0 | |
|
Big River Development Big River · County |
3,550 | 9 | 4 | |
|
Sweetwater Springs Cwd Monte Rio Sonoma County |
3,531 | 0 | 0 | |
|
Cobb Area County Water District Lake County |
3,515 | 2 | 2 | |
|
Csp-Salt Point State Park Sonoma County |
3,513 | 0 | 0 | |
|
North Gualala Water Company Mendocino County |
3,508 | 0 | 0 | |
|
Csp-Fort Ross State Park Sonoma County |
3,501 | 0 | 0 | |
|
Bear Valley Mountain Resort Alpine County |
3,500 | 0 | 0 | |
|
Caltrans-Lakehead Srra Shasta County |
3,500 | 0 | 0 | |
|
Hoopa Valley-Wide System Hoopa · County |
3,500 | 0 | 0 | |
|
Mount Laguna Water System San Diego County |
3,500 | 0 | 0 | |
|
Mt. Shasta Ski Park Siskiyou County |
3,500 | 0 | 0 | |
|
Naval Base Ventura County, Port Hueneme Ventura County |
3,500 | 0 | 0 | |
|
Palisades Tahoe 8200 Water System Placer County |
3,500 | 0 | 0 | |
|
Presidio of San Francisco San Francisco County |
3,500 | 0 | 0 | |
|
Psmcsd Pajaro Monterey County |
3,500 | 0 | 0 | |
|
Yosemite Nps-Mariposa Grove Madera County |
3,500 | 0 | 0 | |
|
Colusa Southern System County |
3,474 | 0 | 0 | |
|
East Orange County WD RZ Orange County |
3,464 | 0 | 0 | |
|
San Antonio Water Company San Bernardino County |
3,441 | 0 | 0 | |
|
City of Brisbane Brisbane · San Mateo County |
3,434 | 0 | 0 | |
|
Borrego WD San Diego County |
3,429 | 1 | 0 | |
|
Groveland Community Serv Dist Tuolumne County |
3,400 | 2 | 1 | |
|
Box Springs Mutual WC Riverside County |
3,382 | 1 | 0 | |
|
Rio Alto Water District Tehama County |
3,377 | 0 | 0 | |
|
Cottonwood Water District Shasta County |
3,316 | 2 | 0 | |
|
San Benito High School San Benito County |
3,310 | 0 | 0 | |
|
Folsom, City of Ashland Folsom · Sacramento County |
3,300 | 0 | 0 | |
|
Gibson Ranch County Park Sacramento County |
3,300 | 0 | 0 | |
|
Rio Dell, City of Rio Dell · Humboldt County |
3,300 | 0 | 0 | |
|
Lukins Brothers Water Company El Dorado County |
3,277 | 0 | 0 | |
|
Arbuckle Public Utility District Colusa County |
3,251 | 2 | 1 | |
|
Cwsc Oak Hills Monterey County |
3,214 | 0 | 0 | |
|
Providence Mtns Sra San Bernardino County |
3,203 | 0 | 0 | |
|
Rancho los Amigos Hospital Los Angeles County |
3,200 | 0 | 0 | |
|
Applewhite Campground San Bernardino County |
3,177 | 1 | 0 | |
|
Northstar C.s.d. Placer County |
3,165 | 0 | 0 | |
|
Marygold Mwc San Bernardino County |
3,155 | 1 | 0 | |
|
Valley State Prison Madera County |
3,151 | 0 | 0 | |
|
Buena Vue Casino County |
3,150 | 1 | 0 |
About this data
Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules currently in violation at EPA's latest data refresh.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The California records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.