Water quality for ZIP code 91320
ZIP 91320 covers Thousand Oaks and Casa Conejo in Ventura County, California, one of 29 ZIP codes in the county. 95 active public water systems serve the county; 37 had an EPA violation in the past three years.
Most likely your provider
Your location is within the outer bounds of this system's EPA service area.
Other community water systems in Ventura County
67 systems, nearest firstNon-community systems in Ventura County (27: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Ventura Farms |
100 | 0 | 0 | |
|
Foxfield Riding School |
120 | 0 | 0 | |
|
The Ranch at Live Oak |
82 | 1 | 1 | |
|
Glass House Camarillo Cultivation, LLC |
450 | 0 | 0 | |
|
Laguna Vista School/oceanview School Dis |
377 | 0 | 0 | |
|
Oxnard Pallet Company |
38 | 1 | 0 | |
|
GP Anacapa Foods, Llc. |
50 | 0 | 0 | |
|
Bouquet Multimedia |
100 | 0 | 0 | |
|
Nishi Quality Flowers, Inc. |
92 | 1 | 1 | |
|
Rio School Dist/rio del Valle School |
820 | 0 | 0 | |
|
Rio Mesa High School/oxnard Uhs |
2,600 | 1 | 1 | |
|
State Ready Mix, Inc. Ventura |
25 | 1 | 1 | |
|
Rio School Dist/ Rio Real School |
550 | 0 | 0 | |
|
Vulcan Materials Company Cal Mat |
30 | 1 | 1 | |
|
Beedy Water Company, LLC |
35 | 0 | 0 | |
|
Vineyard Mutual Water Company/industrial |
259 | 0 | 0 | |
|
Santa Clara School |
39 | 0 | 0 | |
|
Pyramid Flowers |
30 | 1 | 0 | |
|
Thomas Aquinas College |
382 | 1 | 0 | |
|
Dennison Park |
102 | 1 | 0 | |
|
Lake Piru Park Uwcd |
960 | 0 | 0 | |
|
Usfs Wheeler Gorge Campground |
500 | 0 | 0 | |
|
Smith Forks Water System |
3,000 | 1 | 0 | |
|
Camp Scheideck |
33 | 1 | 1 | |
|
Usfs Chuchupate Ranger Station |
26 | 1 | 1 | |
|
Channel Islands National Park |
30 | 0 | 0 | |
|
Santa Clara Resources |
30 | 1 | 0 |
About this data
Water systems are matched to Ventura County, the county this ZIP code lies in, nearest to the ZIP code's centre first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system.
ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.
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.