Tapcensus

Water quality for ZIP code 91941

ZIP 91941 covers Casa de Oro-Mount Helix, La Mesa, Rancho San Diego, Spring Valley, El Cajon, and Lemon Grove 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 2.3 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
San Diego County Water Authority
 0 0 4.9 mi
Otay Water District
 242,155 0 7.5 mi
Sweetwater Authority
 184,915 0 8.6 mi
Padre Dam Mwd
 93,980 0 9.2 mi
Lakeside WD
 35,500 1 9.3 mi
San Diego, City of
San Diego		 1,408,937 0 9.8 mi
MHC TT Inc. (dba Pio Pico)
 23 0 11.1 mi
Cal-Am Water Coronado
 106,000 1 12.8 mi
Nas North Island & Nab Coronado
 421 0 12.8 mi
Poway, City of
Poway		 49,888 0 15.7 mi
Alpine Oaks Estates LLC
 185 0 15.8 mi
Willowside Terrace Water Association
 100 2 16.8 mi
Sunrise Estates Mutual Water Company
 150 2 18.4 mi
Ramona Municipal WD
 36,455 0 19.1 mi
Barrett Lake MH and RV LLC
 300 1 20.1 mi
Del Mar, City of
Del Mar		 3,950 0 20.9 mi
Santa FE I.d.
 21,539 0 21.8 mi
Rincon del Diablo Mwd (id-A)
 5,016 0 22.1 mi
Olivenhain Mwd
 86,458 0 22.7 mi
San Pasqual Academy
 298 0 22.7 mi
Del Dios Mutual Water Company
 330 3 22.8 mi
Descanso Community Water District
 870 3 23.2 mi
Twin Lakes Resort
 400 5 24.3 mi
Rancho Santa Teresa MW Co.
 102 2 24.8 mi
Rincon del Diablo Mwd (id-1)
 28,427 0 25.2 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
Sycamore Canyon / Goodan Ranch
 50 0 0
Dhs Border Patrol Hwy 94 Checkpoint
 83 2 1
Oakoasis Open Space Preserve
 25 1 0
EL Monte County Park
 100 0 0
Skyline Ranch RV Park & Campground
 45 0 0
City of San Diego EL Capitan Reservoir
 300 0 0
Alpine American Legion
 100 1 0
South Bay Rod & Gun Club Inc.
 18,900 1 0
East County Transitional Living Center
 50 1 0
ND Daniel's Investment LLC
 106 0 0
Bandy Canyon Ranch Corp
 3,564 0 0
Hodges Reservoir Recreation Area
 200 0 0
Descanso Fire Station
 34 0 0
San Pasqual Battlefield State Park
 44 0 0
Descanso Junction
 100 1 0
All Saints Retreat and Formation Center
 72 2 1
Potrero Elementary School
 300 0 0
Questhaven Municipal Water District
 81 2 0
Ramona Oaks RV Resort
 250 4 0
Tecate Vista Mutual Water Company
 204 1 1
Muir Industries Inc.
 70 0 0
Tecate Supermarket
 25 0 0
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
Sutherland Reservoir Recreation Area
 300 1 0
Cuyamaca SP Green Valley
 455 0 0
The Oaks Venture, LLC
 220 0 0
Lake Morena County Park
 300 0 0
Cuyamaca Outdoor School
 20 0 0
Cuyamaca SP Paso Picacho
 691 0 0
City of San Diego, Camp Morena
 200 0 0
Camp Winacka
 250 0 0
Daley Ranch
 200 0 0
Mountain Empire High School
 1,000 0 0
Caltrans, Buckman Springs Rest Area
 25 1 0
Mountain Empire R.v. Park and Campground
 23 0 0
William Heise County Park
 850 1 0
Auerbach Farms
 68 0 0
Freedom Ranch
 235 0 0
Campo Elementary School
 300 3 0
Santa Ysabel Nature Center
San Diego 		248 0 0
Apple Water IS Good
 25 1 0
Calvary Chapel Julian
 101 1 0
Spencer Valley School District
 40 2 0
Whispering Winds Catholic Conference Cen
 164 0 0
Cibbetts Flats Campground
 25 0 0
Pinezanita Inc.
 400 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.