All water systems in California
7,380 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Nevada ID North Auburn Placer County |
6,870 | 0 | 0 | |
|
Foresthill Public Utility Dist Placer County |
6,811 | 0 | 0 | |
|
Ojai Water System Ventura County |
6,801 | 0 | 0 | |
|
Caltrans, Cactus City Rest Area Indio · Riverside County |
6,800 | 0 | 0 | |
|
Nuevo Water Company Riverside County |
6,733 | 0 | 0 | |
|
Los Angeles Cwwd 36-Val Verde Los Angeles County |
6,712 | 0 | 0 | |
|
City of Colusa Colusa · Colusa County |
6,675 | 0 | 0 | |
|
Rubio Canon Land & Water Association Los Angeles County |
6,646 | 0 | 0 | |
|
Madera Valley Water Company Madera County |
6,524 | 0 | 0 | |
|
Lake of the Springs Yuba County |
6,500 | 0 | 0 | |
|
Joshua Basin Water District San Bernardino County |
6,489 | 0 | 0 | |
|
Santa Ana River Water Company Riverside County |
6,475 | 0 | 0 | |
|
Tahoe City Pud Main Tahoe City · Placer County |
6,411 | 0 | 0 | |
|
Holtville, City of Holtville · Imperial County |
6,355 | 0 | 0 | |
|
Maywood Mutual Water Co. #2 Los Angeles County |
6,349 | 0 | 0 | |
|
Helendale Community Service District San Bernardino County |
6,347 | 0 | 0 | |
|
North Tahoe Pud Main Placer County |
6,321 | 0 | 0 | |
|
Calaveras Pud Calaveras County |
6,286 | 0 | 0 | |
|
Purissima Hills Water District Santa Clara County |
6,252 | 1 | 0 | |
|
Golden State Water CO Apple Vly South San Bernardino County |
6,247 | 0 | 0 | |
|
Hidden Valley Lake Csd Lake County |
6,235 | 0 | 0 | |
|
Cutler Pud Tulare County |
6,200 | 2 | 1 | |
|
Willits, City of Willits · Mendocino County |
6,175 | 0 | 0 | |
|
City of Industry Waterworks Systems La Puente · Los Angeles County |
6,151 | 0 | 0 | |
|
Cal Trans Erreca Rest Area Merced County |
6,150 | 0 | 0 | |
|
City of Gustine Gustine · Merced County |
6,138 | 1 | 1 | |
|
Jackson Rancheria Casino & Hotel County |
6,120 | 1 | 0 | |
|
IV Desert Museum Society Inc. Imperial County |
6,110 | 1 | 0 | |
|
Ventura River Water District Ventura County |
6,100 | 1 | 0 | |
|
Montara Water and Sanitary District San Mateo County |
6,088 | 0 | 0 | |
|
Maywood Mutual Water Co. #3 Los Angeles County |
6,059 | 0 | 0 | |
|
Cambria Comm Services Dist San Luis Obispo County |
6,038 | 0 | 0 | |
|
Bellflower Municipal Water System Los Angeles County |
6,032 | 0 | 0 | |
|
Barona Barona · County |
6,000 | 1 | 0 | |
|
Caltrans, Whitewater Rest Area Riverside County |
6,000 | 1 | 0 | |
|
Lemoore Naval Air Station Kings County |
6,000 | 0 | 0 | |
|
Soledad Mission WS Monterey County |
6,000 | 0 | 0 | |
|
Solvang Water Division Santa Barbara County |
5,980 | 0 | 0 | |
|
Golden State Water Company los Osos San Luis Obispo County |
5,942 | 0 | 0 | |
|
Konocti County Water District Lake County |
5,928 | 0 | 0 | |
|
Glen Helen Water System San Bernardino County |
5,900 | 0 | 0 | |
|
San Joaquin County Lincoln Village San Joaquin County |
5,841 | 0 | 0 | |
|
Northrop Grumman Corp. Los Angeles County |
5,764 | 1 | 0 | |
|
Rancho Murieta Community Servi Sacramento County |
5,728 | 1 | 0 | |
|
Cal AM Meadowbrook Merced County |
5,723 | 0 | 0 | |
|
Pauma County |
5,700 | 1 | 1 | |
|
LA Habra Heights Cwd Los Angeles County |
5,682 | 0 | 0 | |
|
Golden State Water CO Arden Water Serv Sacramento County |
5,679 | 0 | 0 | |
|
Keyes Community Services Dist. Stanislaus County |
5,672 | 0 | 0 | |
|
Serrano Water District Orange County |
5,659 | 0 | 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.