Tapcensus

California

San Diego County drinking water quality

198 active public water systems serve 3,535,829 people in San Diego County. 115 are compliant, 83 had at least one EPA violation in the past three years, 1 is a designated serious violator, and 11 carry a health flag.

Active systems 198 82 community systems
People served 3.5M by public water systems
Systems with violations 83 42% of active systems, past 3 years
Serious violators 1 11 systems carry a health flag

Needs attention

Twin Lakes Resort CA3701793 · Community water system · Serves 400 5 rules violated in the past three years. Unresolved: Lead and Copper Rule and Public Notice Rule and Revised PN Rule.
Majestic Pines Community SD CA3710041 · Community water system · Serves 1,768 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Lake Morena's Oak Shores Mwc CA3700923 · Community water system · Serves 670 2 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Julian Community Services District CA3700909 · Community water system · Serves 617 3 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions and Consumer Confidence Rule.
Butterfield Ranch CA3701184 · Community water system · Serves 350 2 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Pauma Valley Water Company CA3700934 · Community water system · Serves 185 5 rules violated in the past three years. Unresolved: Interim and Long Term 1 Enhanced Surface Water Treatment Rule and Long Term 2 Enhanced Surface Water Treatment Rule.
Diamond Jack's RV Ranch CA3700174 · Non-Transient non-community system · Serves 115 1 rule violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Willowside Terrace Water Association CA3701995 · Community water system · Serves 100 2 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions.
Dhs Border Patrol Hwy 94 Checkpoint CA3710053 · Non-Transient non-community system · Serves 83 2 rules violated in the past three years. Unresolved: Surface Water Treatment Rule.
Dhs Border Patrol I-8 Checkpoint CA3710052 · Non-Transient non-community system · Serves 50 2 rules violated in the past three years. Unresolved: Surface Water Treatment Rule.

2 more systems with a serious violator or health flag designation are in the lists below.

Community water systems

82 systems, largest first
SystemServesStatusRules violated, 3 yrUnresolved
San Diego, City of
San Diego 		1,408,937 0 0
Helix Water District
 277,918 0 0
Otay Water District
 242,155 0 0
Sweetwater Authority
 184,915 0 0
Oceanside, City of
Oceanside 		174,340 0 0
Escondido, City of
Escondido 		137,044 0 0
Vista Irrigation District
 134,501 0 0
Vallecitos WD
 114,700 1 1
Cal-Am Water Coronado
 106,000 1 0
Carlsbad Mwd
 96,371 0 0
Padre Dam Mwd
 93,980 0 0
Olivenhain Mwd
 86,458 0 0
Poway, City of
Poway 		49,888 0 0
Camp Pendleton (south)
 44,555 0 0
San Dieguito WD
 40,405 1 0
Ramona Municipal WD
 36,455 0 0
Lakeside WD
 35,500 1 0
Fallbrook Pud
 35,237 0 0
Valley Center Mwd
 30,166 0 0
Rincon del Diablo Mwd (id-1)
 28,427 0 0
Rainbow Municipal WD
 23,536 0 0
Santa FE I.d.
 21,539 0 0
Camp Pendleton (north)
 11,576 0 0
Rincon del Diablo Mwd (id-A)
 5,016 0 0
Del Mar, City of
Del Mar 		3,950 0 0
Borrego WD
 3,429 1 0
Naval Medical Center San Diego
 2,981 0 0
Pine Valley Mutual WC
 2,574 1 0
Majestic Pines Community SD
 1,768 1 1
Rancho Pauma Mutual WC
 899 1 0
Descanso Community Water District
 870 3 1
Yuima Municipal Water District Ida
 693 0 0
Lake Morena's Oak Shores Mwc
 670 2 1
Julian Community Services District
 617 3 2
Jacumba Community SD
 561 1 0
Campo Hills-County Public Works Wastewtr
 500 0 0
Warner Springs Estates
 448 0 0
Nas North Island & Nab Coronado
 421 0 0
Twin Lakes Resort
 400 5 2
Pine Hills Mutual Water Company
 380 2 0
Lake Morena Views Mwc
 360 1 0
Yuima Municipal Water District
 360 0 0
Butterfield Ranch
 350 2 1
Del Dios Mutual Water Company
 330 3 0
Live Oak Springs Water System
 317 1 1
Barrett Lake MH and RV LLC
 300 1 0
Heavenly Oaks
 300 1 1
San Pasqual Academy
 298 0 0
North Peak Mutual Water Company
 294 0 0
Rancho del Campo Water System
 290 0 0
Non-community systems (116: schools, campgrounds, workplaces, restaurants)

These systems serve places people visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
San Diego Mountain Lodge
 26,641 3 0
South Bay Rod & Gun Club Inc.
 18,900 1 0
Jacumba Chevron and Shell
 4,520 0 0
Jacumba Valley Ranch Water Company
 4,520 1 0
Mataguay Scout Reservation
 4,000 1 0
Bandy Canyon Ranch Corp
 3,564 0 0
Mount Laguna Water System
 3,500 0 0
Schoepe Scout Reservation at Lost Valley
 2,500 0 0
Mobiland Camper Park
 2,000 1 0
DE Anza Springs Resort
 1,000 0 0
Mountain Empire High School
 1,000 0 0
William Heise County Park
 850 1 0
Cuyamaca SP Paso Picacho
 691 0 0
Fry Creek / Observatory
 660 0 0
Stagecoach Trails RV Resort
 600 2 0
Mount Laguna Improvement Assn.
 580 1 1
Anza Borrego SP Palm Canyon
 507 0 0
Rough Acres Foundation
 495 1 0
Cuyamaca SP Green Valley
 455 0 0
Thousand Trails Oakzanita Inc.
 404 0 0
Agua Caliente County Park
 400 0 0
KQ Ranch Resort
 400 0 0
Pinezanita Inc.
 400 0 0
Campo Elementary School
 300 3 0
City of San Diego EL Capitan Reservoir
 300 0 0
Lake Morena County Park
 300 0 0
Potrero Elementary School
 300 0 0
Sutherland Reservoir Recreation Area
 300 1 0
Whispering Oaks Program Center
 260 0 0
Camp Winacka
 250 0 0
DG Campo
 250 1 0
Ramona Oaks RV Resort
 250 4 0
Warner Unified School District
 250 1 0
Santa Ysabel Nature Center
San Diego 		248 0 0
Freedom Ranch
 235 0 0
The Oaks Venture, LLC
 220 0 0
Tecate Vista Mutual Water Company
 204 1 1
Yoga Center Retreat
 201 0 0
City of San Diego, Camp Morena
 200 0 0
Daley Ranch
 200 0 0
Hodges Reservoir Recreation Area
 200 0 0
Louis A. Stelzer County Park
 200 0 0
Usn San Clemente Island
 200 3 0
Banner Small Water Company
 175 1 0
Whispering Winds Catholic Conference Cen
 164 0 0
Clover Flat Elementary School
 160 0 0
Usn Camp Michael Monsoor
San Diego 		159 0 0
Dhs Boulevard Border Patrol
 155 0 0
Jess Martin County Park
 150 1 0
Vallecito County Park
 145 1 0
Palomar Mtn. SP Silvercrest
 143 0 0
Palomar Mtn. SP Doane Valley
 131 0 0
Diamond Jack's RV Ranch
 115 1 1
ND Daniel's Investment LLC
 106 0 0
Calvary Chapel Julian
 101 1 0
Yoga Center Mother's Kitchen
 101 0 0
Alpine American Legion
 100 1 0
Canebrake County Water District
 100 0 0
Descanso Junction
 100 1 0
EL Monte County Park
 100 0 0
Nickel Beer Water Company
San Diego 		100 0 0
Potrero County Park
 100 1 0
Camp Denver Fox
 86 1 1
Wynola Farms Water District
 84 0 0
Dhs Border Patrol Hwy 94 Checkpoint
 83 2 1
Questhaven Municipal Water District
 81 2 0
Potrero General Store
 75 0 0
Santa Margarita County Preserve
 75 0 0
All Saints Retreat and Formation Center
 72 2 1
Julian Oaks Camp
 72 0 0
Gsa Tecate Port of Entry
 70 1 0
Leapin' Lizard RV Ranch
 70 0 0
Muir Industries Inc.
 70 0 0
Pinecrest
 70 0 0
Auerbach Farms
 68 0 0
Oak Grove Complex
 68 0 0
Oak Knoll Village
 66 1 0
Camp Cedar Glen
 65 1 0
Usn Sere Camp Warner Springs
 65 0 0
Pine Valley Border Patrol Station
 54 0 0
Anza Borrego SP Tamarisk Grove
 52 0 0
Boulevard KOA Drinking Water
 50 0 0
Cameron Corners
 50 0 0
Campo Group LLC
 50 0 0
Dhs Border Patrol I-8 Checkpoint
 50 2 1
East County Transitional Living Center
 50 1 0
Ocotillo Wells Svra HQ
 50 1 0
Sycamore Canyon / Goodan Ranch
 50 0 0
Calexico Lodge
 49 0 0
Back Country Inn
 47 1 0
Rancho Corta Madera
 46 0 0
Skyline Ranch RV Park & Campground
 45 0 0
Ocotillo Wells RV Park & Store
 44 0 0
San Pasqual Battlefield State Park
 44 0 0
Pine Hill Egg Ranch
 40 3 1
Spencer Valley School District
 40 2 0
Camp Lockett Middle School
 34 1 1
Descanso Fire Station
 34 0 0
Warner Springs Ranch Resort LLC
 32 2 1
Anza Borrego SP Vallecito
 31 0 0
All 116 in the systems table
Inactive systems (234, no longer operating or reporting)

Kept for the record and excluded from the county totals above. Browse inactive systems.

About this data

Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.

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.