All water systems in California
7,380 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Los Angeles-City, Dept. of Water & Power Los Angeles · Los Angeles County |
3,875,566 | 0 | 0 | |
|
East Bay MUD Alameda County |
1,468,000 | 0 | 0 | |
|
San Diego, City of San Diego · San Diego County |
1,408,937 | 0 | 0 | |
|
San Jose Water Santa Clara County |
1,039,920 | 0 | 0 | |
|
Sfpuc City Distribution Division San Francisco County |
848,019 | 0 | 0 | |
|
Eastern Municipal WD Riverside County |
659,923 | 0 | 0 | |
|
City of Fresno Fresno · Fresno County |
545,970 | 0 | 0 | |
|
City of Sacramento Main Sacramento · Sacramento County |
527,979 | 0 | 0 | |
|
Long Beach Utilities Department Long Beach · Los Angeles County |
466,772 | 0 | 0 | |
|
Irvine Ranch Water District Orange County |
450,323 | 0 | 0 | |
|
City of Anaheim Anaheim · Orange County |
350,254 | 1 | 0 | |
|
Alameda County Water District Alameda County |
344,000 | 0 | 0 | |
|
City of Santa Ana Santa Ana · Orange County |
316,184 | 0 | 0 | |
|
Riverside, City of Riverside · Riverside County |
302,776 | 0 | 0 | |
|
Santa Clarita Valley Water Agency Los Angeles County |
292,014 | 0 | 0 | |
|
Helix Water District San Diego County |
277,918 | 0 | 0 | |
|
Gswc Southwest Los Angeles County |
277,740 | 0 | 0 | |
|
Coachella Vwd: Cove Community Riverside County |
270,000 | 0 | 0 | |
|
Cws Bakersfield Kern County |
268,129 | 0 | 0 | |
|
Otay Water District San Diego County |
242,155 | 0 | 0 | |
|
San Gabriel Valley Water Co.-El Monte Los Angeles County |
240,000 | 0 | 0 | |
|
San Gabriel Valley WC Fontana San Bernardino County |
228,270 | 0 | 0 | |
|
Modesto, City of Modesto · Stanislaus County |
218,915 | 0 | 0 | |
|
San Bernardino City San Bernardin0 · San Bernardino County |
214,665 | 0 | 0 | |
|
Cucamonga Valley Water District San Bernardino County |
213,375 | 0 | 0 | |
|
Contra Costa Water District Contra Costa County |
210,500 | 0 | 0 | |
|
Los Angeles Cwwd 40 Reg 4 & 34 Lancaster Los Angeles County |
208,129 | 0 | 0 | |
|
City of Huntington Beach Huntington Beach · Orange County |
201,000 | 0 | 0 | |
|
Oxnard Water Dept Ventura County |
200,232 | 0 | 0 | |
|
Sacramento Suburban Water District Sacramento County |
194,444 | 0 | 0 | |
|
City of Stockton Stockton · San Joaquin County |
192,702 | 2 | 0 | |
|
Glendale-City, Water Dept. Glendale · Los Angeles County |
192,212 | 0 | 0 | |
|
Scwa Laguna/vineyard Sacramento County |
188,417 | 1 | 1 | |
|
Marin Municipal Water District Marin County |
188,116 | 0 | 0 | |
|
Terribles #412 County |
185,181 | 0 | 0 | |
|
Ontario Municipal Utilities Company Ontario · San Bernardino County |
185,010 | 0 | 0 | |
|
Sweetwater Authority San Diego County |
184,915 | 0 | 0 | |
|
California Water Service Stockton San Joaquin County |
182,775 | 0 | 0 | |
|
Santa Rosa, City of Santa Rosa · Sonoma County |
178,452 | 0 | 0 | |
|
Oceanside, City of Oceanside · San Diego County |
174,340 | 0 | 0 | |
|
City of Garden Grove Garden Grove · Orange County |
174,226 | 0 | 0 | |
|
Bakersfield, City of Bakersfield · Kern County |
171,108 | 0 | 0 | |
|
Suburban Water Systems-San Jose Los Angeles County |
170,523 | 0 | 0 | |
|
Elsinore Valley Mwd Riverside County |
169,455 | 0 | 0 | |
|
Corona, City of Corona · Riverside County |
169,380 | 6 | 0 | |
|
Moulton Niguel Water District Orange County |
168,315 | 0 | 0 | |
|
City of Roseville Roseville · Placer County |
165,736 | 0 | 0 | |
|
Pasadena Water and Power Pasadena · Los Angeles County |
165,448 | 0 | 0 | |
|
Santa Margarita Water District Orange County |
165,275 | 0 | 0 | |
|
City of Hayward Hayward · Alameda County |
162,954 | 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.