All water systems in California
7,380 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
City of Sunnyvale Sunnyvale · Santa Clara County |
157,566 | 5 | 0 | |
|
Cws Visalia Tulare County |
153,522 | 0 | 0 | |
|
Pomona City, Water Dept. Pomona · Los Angeles County |
151,713 | 0 | 0 | |
|
California Water Service Co. Dominguez Los Angeles County |
149,490 | 0 | 0 | |
|
Rancho California Water District Riverside County |
146,147 | 0 | 0 | |
|
California Water Service Co. Ela Los Angeles County |
142,140 | 0 | 0 | |
|
Victorville Water District San Bernardino County |
140,721 | 0 | 0 | |
|
City of Fullerton Fullerton · Orange County |
140,054 | 0 | 0 | |
|
Escondido, City of Escondido · San Diego County |
137,044 | 0 | 0 | |
|
Jurupa Community SD Riverside County |
134,638 | 0 | 0 | |
|
City of Santa Clara Santa Clara · Santa Clara County |
134,587 | 0 | 0 | |
|
Vista Irrigation District San Diego County |
134,501 | 0 | 0 | |
|
City of Clovis Clovis · Fresno County |
133,118 | 0 | 0 | |
|
Cal AM Water Company Monterey Monterey County |
128,928 | 0 | 0 | |
|
EL Dorado ID Main El Dorado County |
128,408 | 0 | 0 | |
|
Palmdale Water Dist. Los Angeles County |
126,804 | 0 | 0 | |
|
City of Vallejo Vallejo · Solano County |
121,420 | 0 | 0 | |
|
City of Orange Orange · Orange County |
120,770 | 0 | 0 | |
|
City of Fairfield Fairfield · Solano County |
120,720 | 1 | 1 | |
|
Jalama Beach Park Santa Barbara County |
120,017 | 1 | 0 | |
|
City of Antioch Antioch · Contra Costa County |
116,781 | 0 | 0 | |
|
Vallecitos WD San Diego County |
114,700 | 1 | 1 | |
|
Golden State WC West Orange County Orange County |
114,693 | 0 | 0 | |
|
Cwsc Salinas Monterey County |
114,286 | 0 | 0 | |
|
Great Oaks WC INC Santa Clara County |
112,582 | 0 | 0 | |
|
Ventura Water Department Ventura County |
112,285 | 0 | 0 | |
|
City of Santa Maria Utilities Department Santa Barbara County |
112,208 | 0 | 0 | |
|
Downey City, Water Dept. Downey · Los Angeles County |
110,556 | 0 | 0 | |
|
Cal-Water Service Co.-Chico Butte County |
110,473 | 0 | 0 | |
|
Azusa Light and Water Los Angeles County |
110,044 | 0 | 0 | |
|
Mesa Water District Orange County |
110,000 | 0 | 0 | |
|
San Bernardino Valley WD San Bernardino County |
109,608 | 0 | 0 | |
|
East Valley Water District San Bernardino County |
108,600 | 0 | 0 | |
|
Torrance-City, Water Dept. Torrance · Los Angeles County |
106,183 | 0 | 0 | |
|
Burbank-City, Water Dept. Burbank · Los Angeles County |
106,146 | 0 | 0 | |
|
Cal-Am Water Coronado San Diego County |
106,000 | 1 | 0 | |
|
California Water Service San Mateo San Mateo County |
103,536 | 0 | 0 | |
|
City of Daly City Daly City · San Mateo County |
102,593 | 0 | 0 | |
|
Hesperia WD San Bernardino County |
101,836 | 0 | 0 | |
|
Walnut Valley Water District Los Angeles County |
100,941 | 0 | 0 | |
|
California Water Service Co. Herm/redo Los Angeles County |
100,072 | 0 | 0 | |
|
City of San Jose Evg/edv/coy San Jose · Santa Clara County |
99,783 | 0 | 0 | |
|
City of Vacaville Vacaville · Solano County |
99,650 | 0 | 0 | |
|
Dublin San Ramon Services District Alameda County |
98,776 | 0 | 0 | |
|
Tracy, City of Tracy · San Joaquin County |
98,215 | 0 | 0 | |
|
Carlsbad Mwd San Diego County |
96,371 | 0 | 0 | |
|
West Valley Water District San Bernardino County |
96,123 | 0 | 0 | |
|
City of Merced Merced · Merced County |
96,073 | 0 | 0 | |
|
Ventura Wwd No. 8 Simi Valley Ventura County |
94,736 | 0 | 0 | |
|
Santa Cruz Water Department Santa Cruz County |
94,626 | 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 still 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. Retrieved from ECHO on Oct 11, 2026.