All water systems in California
7,380 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
City of Orland Orland · Glenn County |
8,298 | 1 | 1 | |
|
LA Puente Valley Cwd Los Angeles County |
8,276 | 0 | 0 | |
|
City of Corning Corning · Tehama County |
8,244 | 1 | 1 | |
|
Mammoth Cwd Mono County |
8,234 | 1 | 0 | |
|
Gswc Hollydale Los Angeles County |
8,099 | 0 | 0 | |
|
Templeton Csd San Luis Obispo County |
8,041 | 0 | 0 | |
|
Gray Lodge Check Station Butte County |
8,000 | 0 | 0 | |
|
Hughson, City of Hughson · Stanislaus County |
7,977 | 2 | 1 | |
|
Pismo Beach Water Department San Luis Obispo County |
7,944 | 2 | 0 | |
|
Woodlake, City of Woodlake · Tulare County |
7,918 | 0 | 0 | |
|
California-American Larkfield (puc) Sonoma County |
7,911 | 0 | 0 | |
|
Yreka, City of Yreka · Siskiyou County |
7,879 | 1 | 1 | |
|
Florin County Water District Sacramento County |
7,831 | 1 | 1 | |
|
City of Susanville Susanville · Lassen County |
7,811 | 0 | 0 | |
|
US Army Fort Irwin San Bernardino County |
7,800 | 0 | 0 | |
|
Delhi Cwd Merced County |
7,784 | 1 | 1 | |
|
North Fork Mono Casino Water System County |
7,780 | 0 | 0 | |
|
Valencia Heights Water Co. Los Angeles County |
7,775 | 0 | 0 | |
|
Highlands Mutual Water Company Lake County |
7,772 | 0 | 0 | |
|
Western Heights Water Company San Bernardino County |
7,735 | 0 | 0 | |
|
Cwsc Salinas Hills Monterey County |
7,733 | 0 | 0 | |
|
Earlimart Pud Tulare County |
7,679 | 1 | 1 | |
|
Imperial Valley College Imperial County |
7,650 | 1 | 0 | |
|
Oceano Comm Services Dist. San Luis Obispo County |
7,598 | 0 | 0 | |
|
Sebastopol, City of Sebastopol · Sonoma County |
7,522 | 0 | 0 | |
|
Castroville Community Services District Monterey County |
7,515 | 2 | 0 | |
|
Caltrans-Willows Reststop-Nb Glenn County |
7,500 | 0 | 0 | |
|
Caltrans-Willows Reststop-Sb Glenn County |
7,500 | 0 | 0 | |
|
Gswc Calipatria Imperial County |
7,475 | 0 | 0 | |
|
City of Dos Palos Dos Palos · Merced County |
7,452 | 2 | 1 | |
|
City of Fowler Fowler · Fresno County |
7,448 | 1 | 0 | |
|
Folsom State Prison Sacramento County |
7,399 | 1 | 1 | |
|
Heber Public Utility District Imperial County |
7,312 | 1 | 0 | |
|
Vandenberg Village Comm. Serv. Dist. Santa Barbara County |
7,308 | 0 | 0 | |
|
Huron, City of Huron · Fresno County |
7,306 | 1 | 0 | |
|
Cotati, City of Cotati · Sonoma County |
7,290 | 0 | 0 | |
|
City of Gridley Gridley · Butte County |
7,269 | 1 | 1 | |
|
Escalon, City of Escalon · San Joaquin County |
7,232 | 0 | 0 | |
|
Awa, Ione Jackson · Amador County |
7,227 | 1 | 0 | |
|
Fort Bragg, City of Fort Bragg · Mendocino County |
7,117 | 1 | 1 | |
|
City of Winters Winters · Yolo County |
7,115 | 0 | 0 | |
|
Cal-Water Service Co.-Willows Glenn County |
7,107 | 0 | 0 | |
|
Los Osos Community Services District San Luis Obispo County |
7,086 | 0 | 0 | |
|
Lake Arrowhead Csd San Bernardino County |
7,038 | 0 | 0 | |
|
Santa Ynez River Water Cons. Dist. Id#1 Santa Barbara County |
7,022 | 0 | 0 | |
|
Golden State WC Cowan Heights Orange County |
7,006 | 0 | 0 | |
|
Rincon Northern County |
7,003 | 0 | 0 | |
|
Cherry Auction Fresno County |
7,000 | 0 | 0 | |
|
Peter Pitchess Honor Rancho Detn. Ctr Los Angeles County |
7,000 | 0 | 0 | |
|
Nevada ID Lake of Pines Nevada County |
6,870 | 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 currently 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.