2382 water systems in California have at least one health-based violation on record. The system with the most health-based violations is Cal Am - Oakhurst in Sacramento with 368 health-based violations. Health-based violations mean a system exceeded an EPA maximum contaminant level or failed required treatment standards.
| Water System | City | Population | Health Violations | Total Violations |
|---|
| Cal Am - Oakhurst |
Sacramento | 3,693 |
368 | 369 |
| Cal Am - Raymond |
Sacramento | 343 |
364 | 365 |
| Csa 70 W-4 Pioneertown |
San Bernardino | 470 |
284 | 296 |
| Grindstone Rancheria |
Elk Creek | 150 |
234 | 1,142 |
| Calico Ghost Town |
San Bernardino | 24,623 |
224 | 229 |
| Saucelito Elementary School |
Terra Bella | 87 |
222 | 262 |
| North Edwards Wd |
North Edwards | 1,105 |
203 | 224 |
| US Army Fort Irwin |
Fort Irwin | 15,701 |
180 | 183 |
| Del Oro River Island Serv Terr #1 |
Chico | 1,280 |
176 | 212 |
| Pappas & Co (Mendota) |
Fresno | 36 |
176 | 179 |
| Harris Farms Headquarters |
Coalinga | 140 |
174 | 180 |
| City of Lindsay |
Linsday | 12,659 |
173 | 175 |
| Colusa Co. Wwd #1 - Grimes |
Grimes | 512 |
135 | 152 |
| Ironwood Camp |
Newberry Springs | 210 |
134 | 150 |
| Arvin Community Services Dist |
Arvin | 19,669 |
133 | 254 |
| Waukena Elementary School |
Tulare | 220 |
132 | 153 |
| Lone Pine Oasis |
Valley Center | 49 |
124 | 175 |
| Kettleman City Csd |
Kettleman City | 1,242 |
120 | 133 |
| Caruthers Comm Serv Dist |
Caruthers | 2,613 |
120 | 129 |
| Lanare Community Services Dist |
Coalinga | 540 |
120 | 125 |
| City of Lemoore |
Lemoore | 27,185 |
119 | 136 |
| Knoll Enterprises |
Ludlow | 500 |
119 | 129 |
| Land Projects Mutual Water Co. |
Lancaster | 2,800 |
117 | 368 |
| California Citrus Association |
Exeter | 96 |
115 | 137 |
| Bar-Len Mwc |
Barstow | 126 |
114 | 118 |
| Pauma Valley Water Company |
Pauma Valley | 185 |
111 | 146 |
| Keyes Community Services Dist. |
Keyes | 5,672 |
110 | 110 |
| Forest Springs |
Boulder Creek | 385 |
109 | 118 |
| Harris Feeding Company |
Coalinga | 203 |
108 | 114 |
| Valley Ford Water Association |
Valley Ford | 88 |
108 | 114 |
| Kings Inn Motel |
Glendora | 129 |
108 | 111 |
| Nps-Wolverton |
Three Rivers | 2,940 |
107 | 117 |
| Las Cumbres Mutual Water Co |
Los Gatos | 402 |
107 | 111 |
| Riverdale Public Utility District |
Riverdale | 2,756 |
104 | 112 |
| Mcwane Plant and Industrial, LLC |
Exeter | 105 |
102 | 108 |
| Quiet Oaks Mobile Home Park |
Stockton | 120 |
101 | 107 |
| Caillier Water System |
Boron | 1,008 |
99 | 102 |
| Maher Mutual Water Company |
Bakersfield | 140 |
98 | 116 |
| Madera Co Md1-Hidden Lake Estates |
Madera | 162 |
98 | 99 |
| Sierra Linda Mutual Water Co |
North Fork | 200 |
97 | 98 |
| Alpaugh Community Services District |
Alpaugh | 871 |
96 | 110 |
| Western Valley Meat Company |
Fresno | 815 |
95 | 100 |
| Bridgeport Pud |
Bridgeport | 524 |
93 | 158 |
| Frazier Nut Farms, Inc. |
Waterford | 64 |
92 | 92 |
| Lsid - Tonyville |
Lindsay | 500 |
90 | 97 |
| Rainbird Valley Mwc |
Weldon | 238 |
90 | 94 |
| Mckee Bridge Mobile Home Park |
Encinitas | 40 |
88 | 203 |
| Md 42 Still Meadow |
Madera | 100 |
87 | 92 |
| Surfwood Mutual Water Corporation |
Mendocino | 160 |
87 | 87 |
| Grange Hall Ws |
Salinas | 25 |
87 | 87 |
| R.S. Mutual Water Company |
Wofford Heights | 67 |
86 | 93 |
| Indian Oaks Trailer Park |
Murrieta | 70 |
86 | 92 |
| Csa 70 W-3 Hacienda |
San Bernardino | 611 |
85 | 86 |
| Jireh Packing Company-Orange Cove |
Orange Cove | 120 |
84 | 86 |
| Csa 70-F Morongo |
San Bernardino | 300 |
84 | 84 |
| Uc Desert Research and Extension Center |
Holtville | 30 |
83 | 88 |
| Encinal Rd Ws #01 |
Salinas | 91 |
83 | 86 |
| Sonoma County Mutual Water Company |
San Francisco | 40 |
83 | 83 |
| Dollar General Store 14889 |
San Diego | 250 |
82 | 128 |
| Sierra Vista Association |
Clovis | 43 |
82 | 90 |
| Harris Farms South 101-144 |
Coalinga | 182 |
82 | 86 |
| Boron Csd |
Boron | 2,086 |
80 | 114 |
| Moro Rd Ws #09 |
Salinas | 210 |
78 | 78 |
| Washington School Ws |
Salinas | 250 |
77 | 94 |
| Kern Mobile Estates LLC |
Los Angeles | 73 |
76 | 90 |
| Md 07 Marina View Heights |
Madera | 200 |
76 | 81 |
| Laguna Seca Recreation Ws |
Salinas | 1,248 |
76 | 80 |
| City of Hughson |
Hughson | 7,481 |
75 | 77 |
| Madera Co Sa16 Sumner Hill |
Madera | 135 |
75 | 77 |
| Greenfield County Wd |
Bakersfield | 11,590 |
74 | 87 |
| Hope Elementary School |
Porterville | 255 |
74 | 80 |
| Rim Rock Water Company |
Grover Beach | 55 |
74 | 78 |
| Twin Lakes Resort |
Potrero | 400 |
72 | 89 |
| Golden State Water Co. - Robbins |
Rancho Cordova | 205 |
72 | 81 |
| Harris Farms/Horse Barn |
Coalinga | 98 |
72 | 78 |
| Mettler Valley Mutual |
Lancaster | 160 |
72 | 75 |
| Armona Community Services Dist |
Armona | 4,143 |
71 | 77 |
| Md 06 Lake Shore Park |
Madera | 148 |
71 | 76 |
| Seeley Cwd |
Seeley | 1,729 |
69 | 76 |
| Sierra Lodge |
Three Rivers | 52 |
67 | 71 |
| Round Mountain Water Company |
Bakersfield | 50 |
66 | 84 |
| Sierra Mutual Water Company |
Porterville | 43 |
66 | 84 |
| Akal Travel Plaza |
Delano | 88 |
66 | 78 |
| South Bay Rod & Gun Club Inc. |
San Diego | 18,900 |
66 | 66 |
| Nacimiento Water Company |
Bradley | 2,181 |
65 | 104 |
| Howell Mountain Mutual Water Company |
Angwin | 1,240 |
65 | 78 |
| Foster Farms Delhi Feedmill Collier Road |
Delhi | 244 |
64 | 68 |
| Los Gatos Tomato Products |
Huron | 219 |
64 | 66 |
| Lake Isabella Koa Campground |
Templeton | 280 |
64 | 64 |
| Lhoist North America Ws |
Salinas | 44 |
64 | 64 |
| Live Oak Child Care Center |
Live Oak | 108 |
63 | 70 |
| Stockton Baptist Church |
Stockton | 78 |
62 | 66 |
| Lemoore Naval Air Station |
Lemoore | 15,000 |
62 | 62 |
| Two Twenty Four Mobile Home Pk |
Clovis | 35 |
61 | 87 |
| Rand Communities Water District |
Johanesburg | 303 |
61 | 74 |
| Del Oro Grandview Gardens District |
Chico | 323 |
61 | 62 |
| Aptco LLC |
Delano | 50 |
60 | 76 |
| Panoche Water District |
Firebaugh | 220 |
60 | 68 |
| El Camino Wc Inc |
Salinas | 133 |
60 | 66 |
| Lancaster Park Mobile Home Park |
Lancaster | 60 |
60 | 66 |