County · California
San Diego County, California: drinking water records
Explore EPA records for 84 community water systems across 115 ZIP codes in San Diego County, then find water-testing resources and available recent monitoring-station readings.
Data as of EPA UCMR 5 final release, August 2026 (file dated Aug 28, 2026) · EPA SDWIS 2026Q2 (file dated Jul 9, 2026). How we build these pages
Drinking-water records
EPA survey and compliance records are historical reports. UCMR 5 results are available for 27 of the 84 listed systems in this snapshot. A system with no reported PFAS detection is not a test of every tap or every contaminant.
System population figures are summed from EPA registry records and can overlap where wholesalers and retail systems serve the same people. They are not a Census county-population estimate.
Water systems in this county
All 84 active community systems in the available county records, sorted by record completeness. Scroll the table to explore more systems.
| Water system | People served | PFAS survey results | PFAS found | Health-based violations | Lead, 9 in 10 homes at or below |
|---|---|---|---|---|---|
| Cal-Am Water Coronado CA3710001 | 106,000 | 95 | 0 | 1 | 0 ppbbelow the action level |
| Camp Pendleton (South) CA3710702 | 42,219 | 120 | 2 | 2 | 0.5 ppbbelow the action level |
| Camp Pendleton (North) CA3710700 | 12,651 | 55 | 1 | 1 | 0.1 ppbbelow the action level |
| San Diego, City of CA3710020 | 1,385,379 | 480 | 0 | 0 | 0 ppbbelow the action level |
| Helix Water District CA3710010 | 277,668 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Otay Water District CA3710034 | 238,008 | 240 | 0 | 0 | 0 ppbbelow the action level |
| Sweetwater Authority CA3710025 | 191,282 | 240 | 8 | 0 | 0 ppbbelow the action level |
| Oceanside, City of CA3710014 | 171,483 | 180 | 0 | 0 | 0 ppbbelow the action level |
| Escondido, City of CA3710006 | 137,044 | 70 | 0 | 0 | 1.1 ppbbelow the action level |
| Vista Irrigation District CA3710027 | 132,430 | 240 | 0 | 0 | 0 ppbbelow the action level |
| Vallecitos WD CA3710002 | 113,500 | 236 | 0 | 0 | 0 ppbbelow the action level |
| Carlsbad MWD CA3710005 | 95,158 | 480 | 0 | 0 | 0 ppbbelow the action level |
| Padre Dam MWD CA3710037 | 93,980 | 240 | 1 | 0 | 1.1 ppbbelow the action level |
| Olivenhain MWD CA3710029 | 86,458 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Poway, City of CA3710015 | 49,888 | 120 | 0 | 0 | 0 ppbbelow the action level |
| San Dieguito WD CA3710021 | 40,405 | 120 | 4 | 0 | 1.1 ppbbelow the action level |
| Ramona Municipal WD CA3710019 | 37,047 | 120 | 0 | 0 | 1.7 ppbbelow the action level |
| Nas North Island & Nab Coronado CA3710750 | 36,990 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Lakeside WD CA3710013 | 35,500 | 176 | 3 | 0 | 0 ppbbelow the action level |
| Fallbrook PUD CA3710008 | 35,237 | 335 | 0 | 0 | 1 ppbbelow the action level |
| Rincon del Diablo MWD (Id-1) CA3710018 | 30,757 | 120 | 1 | 0 | 0 ppbbelow the action level |
| Valley Center MWD CA3710026 | 29,938 | 120 | 0 | 0 | 4 ppbbelow the action level |
| Rainbow Municipal WD CA3710016 | 23,536 | 95 | 0 | 0 | 2.7 ppbbelow the action level |
| Santa Fe I.D. CA3710023 | 21,578 | 120 | 2 | 0 | 1.7 ppbbelow the action level |
| Indian Hills Camp CA3701476 | 13,032 | 0 | 0 | 11 | 0 ppbbelow the action level |
| Lake Henshaw Resort INC. CA3700900 | 9,913 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Viejas Community System 090600158 | 9,600 | 120 | 1 | 0 | 0.8 ppbbelow the action level |
| Del Mar, City of CA3710004 | 3,919 | 120 | 0 | 0 | 2.6 ppbbelow the action level |
| Borrego WD CA3710036 | 3,429 | 540 | 0 | 0 | 0 ppbbelow the action level |
| Cuyamaca Water District CA3700074 | 2,923 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Pine Valley Mutual Wc CA3710039 | 2,645 | 0 | 0 | 8 | 0 ppbbelow the action level |
| Majestic Pines Community Sd CA3710041 | 1,768 | 0 | 0 | 1 | 6.1 ppbbelow the action level |
| Julian Community Services District CA3700909 | 1,517 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Descanso Community Water District CA3710009 | 870 | 0 | 0 | 20 | 0 ppbbelow the action level |
| Pine Hills Mutual Water Company CA3700905 | 760 | 0 | 0 | 2 | 3.5 ppbbelow the action level |
| Lake Morena'S Oak Shores Mwc CA3700923 | 670 | 0 | 0 | 1 | 8.6 ppbbelow the action level |
| Twin Lakes Resort CA3701793 | 400 | 0 | 0 | 30 | 0 ppbbelow the action level |
| Lake Morena Views Mwc CA3700924 | 360 | 0 | 0 | 21 | 2.6 ppbbelow the action level |
| Yuima Municipal Water District CA3701408 | 360 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Butterfield Ranch CA3701184 | 353 | 0 | 0 | 4 | 10.7 ppbbelow the action level |
| Ymca Camp Marston/Raintree CA3700912 | 338 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Del Dios Mutual Water Company CA3700866 | 330 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Barrett Lake Mh and RV LLC CA3700041 | 300 | 0 | 0 | 4 | 0 ppbbelow the action level |
| Oakvale Park CA3700962 | 260 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Lake Wohlford Resort CA3700919 | 250 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Rancho Estates Mutual Water Co. CA3700936 | 200 | 0 | 0 | 6 | 0 ppbbelow the action level |
| Pauma Valley Water Company CA3700934 | 185 | 0 | 0 | 51 | 2.7 ppbbelow the action level |
| Quiet Oaks Mobile Home Park CA3701341 | 120 | 0 | 0 | 37 | 3.1 ppbbelow the action level |
| Rancho Santa Teresa Mw Co. CA3700918 | 102 | 0 | 0 | 17 | 3.7 ppbbelow the action level |
| Guatay Mutual Benefit Corporation CA3700897 | 100 | 0 | 0 | 46 | 35 ppbat or above the action level |
| Willowside Terrace Water Association CA3701995 | 100 | 0 | 0 | 9 | 0 ppbbelow the action level |
| Ocotillo Oasis, LLC CA3700291 | 96 | 0 | 0 | 12 | 0 ppbbelow the action level |
| Palomar Christian Conference Center CA3701982 | 13,050 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Palomar Observatory CA3702236 | 4,416 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rincon del Diablo MWD (Id-A) CA3710044 | 3,275 | 0 | 0 | 0 | 5.9 ppbbelow the action level |
| Rancho Pauma Mutual Wc CA3710012 | 899 | 0 | 0 | 0 | 1.3 ppbbelow the action level |
| MHC Tt INC. (Dba Pio Pico) CA3702104 | 828 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Yuima Municipal Water District Ida CA3700938 | 769 | 0 | 0 | 0 | 0.6 ppbbelow the action level |
| Jacumba Community Sd CA3710011 | 561 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Campo Hills-County Public Works Wastewtr CA3710047 | 500 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Warner Springs Estates CA3702354 | 448 | 0 | 0 | 0 | 2.8 ppbbelow the action level |
| Live Oak Springs Water System CA3700922 | 317 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Heavenly Oaks CA3700071 | 300 | 0 | 0 | 0 | 6.3 ppbbelow the action level |
| North Peak Mutual Water Company CA3701747 | 298 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Pasqual Academy CA3700968 | 298 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rancho del Campo Water System CA3700859 | 290 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Pine Valley Bible Conference Center CA3701934 | 255 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Los Tules Mutual Water Company CA3700958 | 238 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Pine Valley Trailer Park CA3701961 | 200 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Palomar Mountain Mutual Water Co. CA3700933 | 193 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Alpine Oaks Estates LLC CA3701988 | 185 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sunrise Estates Mutual Water Company CA3700277 | 150 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lazy H Mutual Water Company CA3700937 | 142 | 0 | 0 | 0 | 2.5 ppbbelow the action level |
| Wynola Water District CA3701837 | 140 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Old Campo 090600057 | 102 | 0 | 0 | 0 | 1.8 ppbbelow the action level |
| Laguna Mountain Mutual Water Co. CA3700422 | 100 | 0 | 0 | 0 | 0 ppbbelow the action level |
| H & J Water Company CA3700073 | 86 | 0 | 0 | 0 | 70 ppbat or above the action level |
| Camp Stevens CA3700906 | 78 | 0 | 0 | 0 | 12 ppbbelow the action level |
| La Cima Fire Center CA3710802 | 60 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Richardson Beardsley Park INC. CA3701780 | 28 | 0 | 0 | 0 | 5 ppbbelow the action level |
| Puerta la Cruz Cc #14 CA3710800 | 27 | 0 | 0 | 0 | 3.3 ppbbelow the action level |
| San Diego County Water Authority CA3710042 | 0 | 0 | 0 | 1 | not reported |
| Naval Medical Center San Diego CA3710710 | 2,981 | 0 | 0 | 0 | not reported |
| Carlsbad Desalination Plant CA3710045 | 0 | 0 | 0 | 0 | not reported |
Shaded rows report lead at or above the 15 ppb action level in their latest monitoring period. EPA sets that level for the value 9 in 10 sampled homes fall at or below; reaching it requires the utility to act, and it is not a measurement of any single tap. 2 systems in this table are at or above it. What an action level means
USGS · Monitoring stations
The water, more recently.
Available station readings in San Diego County, California. Each measurement keeps its time, unit and original source.
These readings describe water at a monitoring station. They do not test your tap, measure PFAS or lead, or determine whether water is safe to drink or swim in.
Recent observations load when this section comes into view.
How these readings update
We check for updates every 10 minutes while this section is visible and show supported observations from the last 48 hours. The time beside a reading is when USGS measured it; the checked time is when our service retrieved the response. We mark a reading more than 6 hours old as older. Provisional observations can change after USGS review. A missing reading does not mean zero or clean water.
Temperature, pH, dissolved oxygen, turbidity, conductivity, streamflow and water level are shown only where a station reports them. Different measurements have different units and sampling intervals. USGS data and documentation.
Your next step
Water testing, reports & local help.
Use these official directories to find your drinking-water agency, a certified laboratory and public water records. We have not yet added an individually reviewed local resource list for this county.
Official national directories
Water testing
Find your state’s private-well program
EPA’s state directory points well owners to local program information. Services and eligibility vary by state and county.
Water testing
Find a certified drinking-water laboratory
Use EPA’s directory to reach your state’s laboratory certification program. EPA does not provide on-request testing of residential drinking water.
Public records
Find your utility’s Consumer Confidence Report
EPA links to community water-system reports and explains how to read them. Look for your actual supplier rather than assuming every address in a county shares one system.
Public records
Explore USGS water observations
Find current and historical observations from USGS monitoring locations, including available stream, lake, and groundwater data. Measurements vary by station and do not replace a test of your household water.
A county overview cannot identify every property’s water provider. If you use a public water system, confirm its name on your bill and request its annual Consumer Confidence Report. Private wells need their own testing; public-system records do not describe a private well.
Understand water testing and laboratory reportsResource descriptions are compiled by Tap Water Lookup. Review dates describe our source check, not a new water sample. How we review sources · Suggest a correction
Explore your area
Local coverage in San Diego County
115ZIP areas in this overview
Explore the water-system records, recent station readings and testing resources on this county page. They describe the systems and stations identified in each section; they are not a separate water test for every community.
Towns and communities
- Alpine
- Bonita
- Bonsall
- Borrego Springs
- Boulevard
- Camp Pendleton Mainside
- Campo
- Carlsbad
- Casa de Oro-Mount Helix
- Chula Vista
- Coronado
- Descanso
- El Cajon
- Encinitas
- Escondido
- Fallbrook
- Harbison Canyon
- Imperial Beach
- Jacumba
- Jamul
- Julian
- La Mesa
- La Presa
- Lakeside
- Lemon Grove
- Mount Laguna
- National City
- Oceanside
- Pala
- Pine Valley
- Potrero
- Poway
- Ramona
- Rancho San Diego
- Rancho Santa Fe
- San Clemente
- San Diego
- San Marcos
- Santee
- Solana Beach
- Spring Valley
- Valley Center
- Vista
View ZIP areas and understand coverage
- 91901Alpine
- 91902Bonita
- 91905Boulevard
- 91906Campo
- 91910Chula Vista
- 91911Chula Vista
- 91913Chula Vista
- 91914Chula Vista
- 91915Chula Vista
- 91916Descanso
- 91917
- 91931
- 91932Imperial Beach
- 91934Jacumba
- 91935Jamul
- 91941Casa de Oro-Mount Helix
- 91942La Mesa
- 91945Lemon Grove
- 91948Mount Laguna
- 91950National City
- 91962Pine Valley
- 91963Potrero
- 91977La Presa
- 91978Spring Valley
- 91980
- 92003Bonsall
- 92004Borrego Springs
- 92007Encinitas
- 92008Carlsbad
- 92009Carlsbad
- 92010Carlsbad
- 92011Carlsbad
- 92014San Diego
- 92019Rancho San Diego
- 92020El Cajon
- 92021Harbison Canyon
- 92024Encinitas
- 92025Escondido
- 92026Escondido
- 92027Escondido
- 92028Fallbrook
- 92029Escondido
- 92036Julian
- 92037San Diego
- 92040Lakeside
- 92054Oceanside
- 92055Camp Pendleton Mainside
- 92056Oceanside
- 92057Oceanside
- 92058Camp Pendleton Mainside
- 92059Pala
- 92060
- 92061
- 92064Poway
- 92065Ramona
- 92066
- 92067Rancho Santa Fe
- 92069San Marcos
- 92070
- 92071Santee
- 92075Solana Beach
- 92078San Marcos
- 92081Vista
- 92082Valley Center
- 92083Vista
- 92084Vista
- 92086
- 92091Encinitas
- 92092San Diego
- 92093San Diego
- 92096San Marcos
- 92101San Diego
- 92102San Diego
- 92103San Diego
- 92104San Diego
- 92105San Diego
- 92106San Diego
- 92107San Diego
- 92108San Diego
- 92109San Diego
- 92110San Diego
- 92111San Diego
- 92113San Diego
- 92114San Diego
- 92115San Diego
- 92116San Diego
- 92117San Diego
- 92118Coronado
- 92119San Diego
- 92120San Diego
- 92121San Diego
- 92122San Diego
- 92123San Diego
- 92124San Diego
- 92126San Diego
- 92127San Diego
- 92128San Diego
- 92129San Diego
- 92130San Diego
- 92131San Diego
- 92132San Diego
- 92134San Diego
- 92135Coronado
- 92136San Diego
- 92139San Diego
- 92140San Diego
- 92145San Diego
- 92147San Diego
- 92154San Diego
- 92155Coronado
- 92161San Diego
- 92173San Diego
- 92179
- 92182San Diego
- 92672San Clemente
These Census ZIP Code Tabulation Areas are grouped here by their largest county overlap. A ZIP area can cross county lines and contain several water suppliers or private wells. Place labels reflect Census geography, not verified postal city names or utility service boundaries.
Records for these areas are currently presented in this county overview rather than individual ZIP reports. An unpublished report does not mean there are no water records. Confirm your supplier on your water bill; if you use a private well, testing your own well is the relevant next step.
Sources and scope
EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Database prepared 2026-09-03.
Counts cover the systems that report this county to EPA. A water system may cross county lines. "Found" means at least one result at or above the laboratory reporting level; it is not a compliance finding.
Compiled by Tap Water Lookup from the sources identified on this page. Read the methodology and review process.