California Drinking Water Violations

8,328Water Systems
73,699Total Violations
26,750Health-Based

California has 8,328 active public water systems regulated under the EPA's Safe Drinking Water Act. Across these systems, there have been 26,750 health-based violations out of 73,699 total violations recorded. Currently, 863 water systems have unresolved health-based violations.

The most frequently cited health-based contaminants in California are Unknown, Unknown, and Unknown. Health-based violations mean a water system exceeded an EPA maximum contaminant level (MCL) or failed required treatment standards.

Browse the counties below to find specific water systems, or search by address or ZIP code to find your water provider.

Counties

CountyWater SystemsTotal ViolationsHealth-Based
Kings County 5 350 299
Tulare County 12 227 191
Stanislaus County 22 161 118
Fresno County 24 186 95
Napa County 14 98 85
Imperial County 8 110 69
Merced County 13 72 58
Kern County 17 140 57
San Joaquin County 8 64 37
Siskiyou County 10 65 33
Yolo County 13 40 30
Los Angeles County 48 202 29
San Benito County 3 34 23
Sutter County 2 28 20
Mendocino County 7 35 17
Santa Clara County 10 248 16
Amador County 5 47 16
Trinity County 1 15 11
San Mateo County 8 12 9
Sacramento County 7 11 9
Solano County 10 20 6
Riverside County 11 151 5
Inyo County 5 11 4
Calaveras County 1 6 4
Alameda County 6 4 4
Orange County 19 54 3
Humboldt County 7 8 3
Nevada County 4 5 3
Santa Cruz County 2 4 3
Sonoma County 16 1,080 2
Butte County 2 15 2
Contra Costa County 6 14 2
Tehama County 3 7 2
Madera County 7 18 1
Glenn County 6 16 1
Monterey County 5 7 1
Lake County 5 5 1
Shasta County 6 5 1
Ventura County 2 3 1
Modoc County 1 2 1
Lassen County 3 1 1
San Diego County 8 44 0
San Bernardino County 14 43 0
Placer County 6 12 0
Colusa County 3 11 0
Del Norte County 2 6 0
Santa Barbara County 6 6 0
Fall River County 1 4 0
Sierra County 2 4 0
Yuba County 1 4 0
Tuolumne County 3 2 0
San Luis Obispo County 14 1 0
El Dorado County 2 0 0
Plumas County 2 0 0