Tapcensus

Water quality for ZIP code 91978

ZIP 91978 covers Spring Valley and Jamul 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

Helix Water District CA3710010 · Community water system · Surface water
Serves 277,918 people Rules violated, past 3 years 0 Last sanitary survey Feb 25, 2026 Distance 4.5 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
Otay Water District
 242,155 0 3.9 mi
MHC TT Inc. (dba Pio Pico)
 23 0 7.0 mi
San Diego County Water Authority
 0 0 8.9 mi
Padre Dam Mwd
 93,980 0 8.9 mi
Sweetwater Authority
 184,915 0 9.0 mi
Lakeside WD
 35,500 1 10.7 mi
Cal-Am Water Coronado
 106,000 1 13.2 mi
Alpine Oaks Estates LLC
 185 0 13.9 mi
San Diego, City of
San Diego		 1,408,937 0 13.9 mi
Sunrise Estates Mutual Water Company
 150 2 14.5 mi
Willowside Terrace Water Association
 100 2 14.9 mi
Nas North Island & Nab Coronado
 421 0 15.6 mi
Barrett Lake MH and RV LLC
 300 1 16.1 mi
Poway, City of
Poway		 49,888 0 18.8 mi
Twin Lakes Resort
 400 5 20.4 mi
Ramona Municipal WD
 36,455 0 20.7 mi
Descanso Community Water District
 870 3 21.1 mi
Heavenly Oaks
 300 1 23.3 mi
Pine Valley Trailer Park
 200 0 23.9 mi
Guatay Mutual Benefit Corporation
 100 4 24.6 mi
San Pasqual Academy
 298 0 24.9 mi
Del Mar, City of
Del Mar		 3,950 0 25.0 mi
Lake Morena's Oak Shores Mwc
 670 2 25.0 mi
Pine Valley Mutual WC
 2,574 1 25.0 mi
Rincon del Diablo Mwd (id-A)
 5,016 0 25.1 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
Diamond Jack's RV Ranch
 115 1 1
Dhs Border Patrol Hwy 94 Checkpoint
 83 2 1
Skyline Ranch RV Park & Campground
 45 0 0
South Bay Rod & Gun Club Inc.
 18,900 1 0
EL Monte County Park
 100 0 0
Oakoasis Open Space Preserve
 25 1 0
East County Transitional Living Center
 50 1 0
City of San Diego EL Capitan Reservoir
 300 0 0
Alpine American Legion
 100 1 0
Sycamore Canyon / Goodan Ranch
 50 0 0
ND Daniel's Investment LLC
 106 0 0
Descanso Fire Station
 34 0 0
Descanso Junction
 100 1 0
Potrero Elementary School
 300 0 0
Tecate Vista Mutual Water Company
 204 1 1
Muir Industries Inc.
 70 0 0
Tecate Supermarket
 25 0 0
All Saints Retreat and Formation Center
 72 2 1
Gsa Tecate Port of Entry
 70 1 0
Potrero General Store
 75 0 0
Potrero County Park
 100 1 0
Thousand Trails Oakzanita Inc.
 404 0 0
Lake Morena County Park
 300 0 0
Bandy Canyon Ranch Corp
 3,564 0 0
City of San Diego, Camp Morena
 200 0 0
San Pasqual Battlefield State Park
 44 0 0
Cuyamaca SP Green Valley
 455 0 0
Hodges Reservoir Recreation Area
 200 0 0
Ramona Oaks RV Resort
 250 4 0
Mountain Empire High School
 1,000 0 0
Mountain Empire R.v. Park and Campground
 23 0 0
Cuyamaca Outdoor School
 20 0 0
Caltrans, Buckman Springs Rest Area
 25 1 0
Cuyamaca SP Paso Picacho
 691 0 0
Freedom Ranch
 235 0 0
Campo Elementary School
 300 3 0
The Oaks Venture, LLC
 220 0 0
Sutherland Reservoir Recreation Area
 300 1 0
Camp Winacka
 250 0 0
Camp Lockett Middle School
 34 1 1
San Ysidro Health Mhfm
 30 1 0
Cameron Corners
 50 0 0
Campo Group LLC
 50 0 0
Questhaven Municipal Water District
 81 2 0
Cibbetts Flats Campground
 25 0 0
Pine Valley Border Patrol Station
 54 0 0
Mount Laguna Water System
 3,500 0 0
William Heise County Park
 850 1 0
Usn Camp Michael Monsoor
San Diego 		159 0 0
Whispering Winds Catholic Conference Cen
 164 0 0
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.