All water systems in California
7,380 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Calistoga, City of Calistoga · Napa County |
5,610 | 2 | 1 | |
|
Camp Fresno Water System Fresno County |
5,600 | 0 | 0 | |
|
Bear Valley Csd Kern County |
5,592 | 1 | 0 | |
|
City of Williams Williams · Colusa County |
5,538 | 0 | 0 | |
|
Palm Ranch Irrigation Dist. Los Angeles County |
5,507 | 0 | 0 | |
|
Hilmar County Water District Merced County |
5,504 | 1 | 0 | |
|
Millview County Water District Mendocino County |
5,500 | 0 | 0 | |
|
Tud Columbia Water System Tuolumne County |
5,482 | 1 | 0 | |
|
Gavilan Joint Community College District Santa Clara County |
5,400 | 0 | 0 | |
|
St. Helena, City of St. Helena · Napa County |
5,386 | 2 | 1 | |
|
Pleasant Valley Mutual Water CO Ventura County |
5,306 | 1 | 0 | |
|
Suburban Water Systems-Glendora Los Angeles County |
5,301 | 0 | 0 | |
|
Yosemite Spring Park Util CO Madera County |
5,300 | 3 | 3 | |
|
Running Springs Water District San Bernardino County |
5,268 | 1 | 0 | |
|
Wasco St. Prison Reception Ctr Kern County |
5,217 | 0 | 0 | |
|
Valley Auto Water Riverside County |
5,215 | 0 | 0 | |
|
San Gabriel Valley Water Co-Montebello 1 Los Angeles County |
5,205 | 0 | 0 | |
|
Redwood Valley County Water District Mendocino County |
5,200 | 0 | 0 | |
|
Ccwd Copper Cove Calaveras County |
5,187 | 0 | 0 | |
|
Sweetwater Springs Cwd Guerneville Sonoma County |
5,156 | 0 | 0 | |
|
Hope Valley CG Alpine County |
5,128 | 0 | 0 | |
|
Denair Community Services District Stanislaus County |
5,093 | 0 | 0 | |
|
City of Buellton Water Division Santa Barbara County |
5,091 | 0 | 0 | |
|
City of Jackson Jackson · Amador County |
5,079 | 0 | 0 | |
|
Willow Springs Raceway Kern County |
5,022 | 0 | 0 | |
|
Rincon del Diablo Mwd (id-A) San Diego County |
5,016 | 0 | 0 | |
|
Channel Islands Beach Csd Ventura County |
5,011 | 0 | 0 | |
|
Chukchansi Gold Resort Chukchansi Gold Resort & Casino · County |
5,000 | 0 | 0 | |
|
Famoso Raceway, Smokers Inc. Kern County |
5,000 | 0 | 0 | |
|
Kern Valley State Prison Kern County |
5,000 | 0 | 0 | |
|
City of Grass Valley Grass Valley · Nevada County |
4,947 | 0 | 0 | |
|
Awa, Tanner Amador County |
4,940 | 1 | 0 | |
|
Stallion Springs Csd Kern County |
4,910 | 2 | 1 | |
|
Needles, City of Needles · San Bernardino County |
4,872 | 1 | 0 | |
|
LA Cumbre Mutual Water CO Santa Barbara County |
4,861 | 0 | 0 | |
|
Trumbull Lake Campground Mono County |
4,859 | 0 | 0 | |
|
Sswd del Paso Manor Service Area Sacramento County |
4,854 | 0 | 0 | |
|
Hanna Flats Campground San Bernardino County |
4,850 | 0 | 0 | |
|
Bishop Creek System Inyo County |
4,839 | 0 | 0 | |
|
Blue Lake Springs Mut Wtr Calaveras County |
4,822 | 0 | 0 | |
|
Calipatria State Prison Imperial County |
4,800 | 0 | 0 | |
|
Los Angeles Cwwd 37-Acton Los Angeles County |
4,782 | 0 | 0 | |
|
Rolling Hills Casino County |
4,782 | 0 | 0 | |
|
Union Public Utility District Calaveras County |
4,774 | 0 | 0 | |
|
Lakeport, City of Lakeport · Lake County |
4,762 | 0 | 0 | |
|
Coachella Vwd: I.d. No. 8 Riverside County |
4,700 | 0 | 0 | |
|
Mojave Pud Kern County |
4,699 | 0 | 0 | |
|
Tesoro Viejo Master Mwc, Inc. Madera County |
4,660 | 0 | 0 | |
|
Golden State Water Co.-Clearlake System Lake County |
4,623 | 0 | 0 | |
|
Valley View Mutual Water Co. Los Angeles County |
4,613 | 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.