Water quality for ZIP code 92121
ZIP 92121 covers San Diego in San Diego County, California, one of 115 ZIP codes in the county. 198 active public water systems serve the county; 83 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 San Diego County
81 systems, nearest first| System | Serves | Status | Rules violated, 3 yr | Distance |
|---|---|---|---|---|
| Del Mar, City of Del Mar |
3,950 | 0 | 5.7 mi | |
| Santa FE I.d. |
21,539 | 0 | 7.9 mi | |
| Olivenhain Mwd |
86,458 | 0 | 10.2 mi | |
| San Diego County Water Authority |
0 | 0 | 10.8 mi | |
| Poway, City of Poway |
49,888 | 0 | 11.4 mi | |
| San Dieguito WD |
40,405 | 1 | 11.4 mi | |
| Del Dios Mutual Water Company |
330 | 3 | 12.9 mi | |
| Nas North Island & Nab Coronado |
421 | 0 | 13.8 mi | |
| Rincon del Diablo Mwd (id-A) |
5,016 | 0 | 15.3 mi | |
| Rincon del Diablo Mwd (id-1) |
28,427 | 0 | 15.5 mi | |
| Helix Water District |
277,918 | 0 | 15.6 mi | |
| Lakeside WD |
35,500 | 1 | 16.1 mi | |
| Carlsbad Mwd |
96,371 | 0 | 17.0 mi | |
| Vallecitos WD |
114,700 | 1 | 17.8 mi | |
| Escondido, City of Escondido |
137,044 | 0 | 18.0 mi | |
| Sweetwater Authority |
184,915 | 0 | 19.0 mi | |
| San Pasqual Academy |
298 | 0 | 19.4 mi | |
| Padre Dam Mwd |
93,980 | 0 | 19.7 mi | |
| Ramona Municipal WD |
36,455 | 0 | 19.8 mi | |
| Vista Irrigation District |
134,501 | 0 | 20.3 mi | |
| Cal-Am Water Coronado |
106,000 | 1 | 21.0 mi | |
| Oakvale Park |
260 | 3 | 22.0 mi | |
| Lake Wohlford Resort |
250 | 0 | 22.5 mi | |
| Otay Water District |
242,155 | 0 | 22.6 mi | |
| Oceanside, City of Oceanside |
174,340 | 0 | 23.3 mi |
Non-community systems in San Diego County (116: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
About this data
Water systems are matched to San Diego 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.