Tapcensus

Water quality for ZIP code 92078

ZIP 92078 covers San Marcos, Lake San Marcos, Harmony Grove, Carlsbad, and Vista 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

Vallecitos WD CA3710002 · Community water system · Surface water purchased
Serves 114,700 people Rules violated, past 3 years 1 Unresolved 1 Last sanitary survey Mar 17, 2022 Distance 2.8 mi

Your location is within the outer bounds of this system's EPA service area.

View system details EPA facility report

Other community water systems in San Diego County

81 systems, nearest first
SystemServesStatusRules violated, 3 yrDistance
Rincon del Diablo Mwd (id-1)
 28,427 0 4.0 mi
Del Dios Mutual Water Company
 330 3 4.7 mi
Olivenhain Mwd
 86,458 0 4.9 mi
Vista Irrigation District
 134,501 0 5.8 mi
Carlsbad Mwd
 96,371 0 6.6 mi
Escondido, City of
Escondido		 137,044 0 7.2 mi
San Dieguito WD
 40,405 1 7.5 mi
Santa FE I.d.
 21,539 0 7.6 mi
Rincon del Diablo Mwd (id-A)
 5,016 0 8.4 mi
Oceanside, City of
Oceanside		 174,340 0 10.5 mi
Oakvale Park
 260 3 11.3 mi
Lake Wohlford Resort
 250 0 11.4 mi
Valley Center Mwd
 30,166 0 11.5 mi
Del Mar, City of
Del Mar		 3,950 0 11.6 mi
Poway, City of
Poway		 49,888 0 12.5 mi
San Pasqual Academy
 298 0 13.6 mi
Rainbow Municipal WD
 23,536 0 15.6 mi
Rancho Pauma Mutual WC
 899 1 16.9 mi
Lazy H Mutual Water Company
 117 0 17.1 mi
Camp Pendleton (south)
 44,555 0 17.4 mi
Ramona Municipal WD
 36,455 0 18.0 mi
Yuima Municipal Water District Ida
 693 0 18.2 mi
Yuima Municipal Water District
 360 0 18.2 mi
Rancho Estates Mutual Water Co.
 200 0 18.8 mi
Pauma Valley Water Company
 185 5 19.0 mi
All 82 community water systems in San Diego County
Non-community systems in San Diego County (116: schools, campgrounds, workplaces, restaurants)

These systems serve places you visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Questhaven Municipal Water District
 81 2 0
Hodges Reservoir Recreation Area
 200 0 0
Daley Ranch
 200 0 0
San Pasqual Battlefield State Park
 44 0 0
Bandy Canyon Ranch Corp
 3,564 0 0
Sycamore Canyon / Goodan Ranch
 50 0 0
Santa Margarita County Preserve
 75 0 0
Oak Knoll Village
 66 1 0
Palomar Mtn. SP Silvercrest
 143 0 0
Palomar Mtn. SP Doane Valley
 131 0 0
Ramona Oaks RV Resort
 250 4 0
Oakoasis Open Space Preserve
 25 1 0
Yoga Center Mother's Kitchen
 101 0 0
Sutherland Reservoir Recreation Area
 300 1 0
Rey River Ranch Corp.
 12 0 0
Yoga Center Retreat
 201 0 0
Fry Creek / Observatory
 660 0 0
Camp Denver Fox
 86 1 1
EL Monte County Park
 100 0 0
Fallbrook Kamp Retreat
 24 0 0
The Oaks Venture, LLC
 220 0 0
San Diego Mountain Lodge
 26,641 3 0
City of San Diego EL Capitan Reservoir
 300 0 0
Auerbach Farms
 68 0 0
Oak Grove Complex
 68 0 0
Santa Ysabel Nature Center
San Diego 		248 0 0
Spencer Valley School District
 40 2 0
Apple Water IS Good
 25 1 0
Mataguay Scout Reservation
 4,000 1 0
Calvary Chapel Julian
 101 1 0
Camp Winacka
 250 0 0
Alpine American Legion
 100 1 0
Warner Unified School District
 250 1 0
Warner Springs Ranch Resort LLC
 32 2 1
Sacred Mountain Inn
 30 1 0
Camp Cedar Glen
 65 1 0
Julian Oaks Camp
 72 0 0
Jess Martin County Park
 150 1 0
William Heise County Park
 850 1 0
Nickel Beer Water Company
San Diego 		100 0 0
Diamond Jack's RV Ranch
 115 1 1
Skyline Ranch RV Park & Campground
 45 0 0
Pinecrest
 70 0 0
Whispering Winds Catholic Conference Cen
 164 0 0
Pinezanita Inc.
 400 0 0
Cuyamaca SP Paso Picacho
 691 0 0
KQ Ranch Resort
 400 0 0
Descanso Fire Station
 34 0 0
Dhs Border Patrol Hwy 94 Checkpoint
 83 2 1
All Saints Retreat and Formation Center
 72 2 1
All non-community systems
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.