All water systems in California
7,380 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Padre Dam Mwd San Diego County |
93,980 | 0 | 0 | |
|
City of Westminster Westminster · Orange County |
93,591 | 0 | 0 | |
|
Placer Cwa Foothill Placer County |
93,417 | 0 | 0 | |
|
City of Santa Barbara Water Department Santa Barbara · Santa Barbara County |
93,334 | 0 | 0 | |
|
Compton-City, Water Dept. Compton · Los Angeles County |
90,986 | 0 | 0 | |
|
Santa Monica-City, Water Division Santa Monica · Los Angeles County |
90,729 | 0 | 0 | |
|
City of Redding Redding · Shasta County |
90,254 | 0 | 0 | |
|
Chino, City of Chino · San Bernardino County |
90,187 | 0 | 0 | |
|
City of Redwood City Redwood City · San Mateo County |
90,043 | 0 | 0 | |
|
Indio Water Authority Riverside County |
89,137 | 1 | 0 | |
|
South Gate-City, Water Dept. South Gate · Los Angeles County |
88,544 | 0 | 0 | |
|
Western Mwd Riverside County |
87,955 | 0 | 0 | |
|
Olivenhain Mwd San Diego County |
86,458 | 0 | 0 | |
|
Goleta Water District Santa Barbara County |
85,535 | 0 | 0 | |
|
Manteca, City of Manteca · San Joaquin County |
84,928 | 1 | 0 | |
|
Napa, City of Napa · Napa County |
84,804 | 0 | 0 | |
|
Yorba Linda Water District Orange County |
84,292 | 0 | 0 | |
|
City of Buena Park Buena Park · Orange County |
82,667 | 0 | 0 | |
|
City of Milpitas Milpitas · Santa Clara County |
81,915 | 1 | 0 | |
|
City of Mountain View Mountain View · Santa Clara County |
81,340 | 0 | 0 | |
|
Inglewood City, Water Dept. Inglewood · Los Angeles County |
81,191 | 0 | 0 | |
|
Folsom, City of Main Folsom · Sacramento County |
80,969 | 0 | 0 | |
|
City of Alhambra Alhambra · Los Angeles County |
80,279 | 0 | 0 | |
|
Upland, City of Upland · San Bernardino County |
78,376 | 0 | 0 | |
|
Redlands City Mud-Water Div Redlands · San Bernardino County |
78,025 | 0 | 0 | |
|
Las Virgenes Mwd Los Angeles County |
77,562 | 0 | 0 | |
|
City of Pleasanton Pleasanton · Alameda County |
76,689 | 0 | 0 | |
|
Chino Hills, City of Chino Hills · San Bernardino County |
76,314 | 0 | 0 | |
|
Desert Water Agency Riverside County |
75,588 | 0 | 0 | |
|
Snow Summit San Bernardino County |
75,500 | 3 | 1 | |
|
Turlock, City of Turlock · Stanislaus County |
72,888 | 0 | 0 | |
|
Liberty Utilities Bellflower-Norwalk Los Angeles County |
72,472 | 0 | 0 | |
|
Tulare, City of Tulare · Tulare County |
72,241 | 0 | 0 | |
|
California Water Service Co. Palos Ver Los Angeles County |
70,830 | 0 | 0 | |
|
City of Yuba City Yuba City · Sutter County |
70,256 | 0 | 0 | |
|
City of Newport Beach Newport Beach · Orange County |
69,520 | 0 | 0 | |
|
Valley County Water Dist. Los Angeles County |
68,871 | 0 | 0 | |
|
City of Davis Davis · Yolo County |
67,826 | 0 | 0 | |
|
Citrus Heights Water District Sacramento County |
67,818 | 0 | 0 | |
|
City of Palo Alto Palo Alto · Santa Clara County |
67,658 | 0 | 0 | |
|
Lodi, City of Lodi · San Joaquin County |
67,093 | 0 | 0 | |
|
Lynwood-City, Water Dept. Lynwood · Los Angeles County |
66,967 | 0 | 0 | |
|
Beaumont Cherry Valley WD Riverside County |
66,841 | 0 | 0 | |
|
Cal American Water CO Ventura County |
66,809 | 0 | 0 | |
|
Suburban Water Systems-Whittier Los Angeles County |
66,565 | 0 | 0 | |
|
City of Madera Madera · Madera County |
66,560 | 0 | 0 | |
|
Lakewood City, Water Dept. Lakewood · Los Angeles County |
66,356 | 0 | 0 | |
|
Watsonville, City of Watsonville · Santa Cruz County |
65,231 | 0 | 0 | |
|
City of Tustin Tustin · Orange County |
65,143 | 0 | 0 | |
|
Brentwood Brentwood · Contra Costa County |
64,513 | 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.