County · California
San Joaquin County, California: drinking water records
Explore EPA records for 94 community water systems across 30 ZIP codes in San Joaquin 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 13 of the 94 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 94 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 |
|---|---|---|---|---|---|
| City of Stockton CA3910012 | 191,302 | 1,140 | 3 | 2 | 0 ppbbelow the action level |
| California Water Service - Stockton CA3910001 | 176,266 | 840 | 1 | 0 | 0 ppbbelow the action level |
| Tracy, City of CA3910011 | 96,609 | 480 | 0 | 0 | 0 ppbbelow the action level |
| Manteca, City of CA3910005 | 84,928 | 720 | 4 | 0 | 0.4 ppbbelow the action level |
| Lodi, City of CA3910004 | 68,272 | 1,500 | 7 | 0 | 0 ppbbelow the action level |
| City of Lathrop CA3910015 | 35,080 | 180 | 3 | 0 | 0 ppbbelow the action level |
| City of Mountain House CA3910027 | 24,948 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Ripon, City of CA3910007 | 15,741 | 300 | 3 | 0 | 0 ppbbelow the action level |
| Escalon, City of CA3910003 | 7,429 | 180 | 0 | 0 | 0 ppbbelow the action level |
| San Joaquin County - Lincoln Village CA3910010 | 5,841 | 120 | 0 | 0 | 0 ppbbelow the action level |
| Cdcr California Health Care Facility CA3910803 | 5,551 | 0 | 0 | 3 | 0 ppbbelow the action level |
| San Joaquin County-Mokelumne Acres CA3910017 | 3,802 | 300 | 6 | 0 | 0 ppbbelow the action level |
| Little Potato Slough Mutual CA3910022 | 1,510 | 0 | 0 | 4 | 0 ppbbelow the action level |
| San Joaquin County-Raymus Village CA3910014 | 1,086 | 0 | 0 | 9 | 0 ppbbelow the action level |
| San Joaquin River Club INC CA3910018 | 600 | 60 | 0 | 0 | 0 ppbbelow the action level |
| 132 Investments Water System CA3901031 | 252 | 0 | 0 | 1 | 4.7 ppbbelow the action level |
| Big Wheel Mobile Home Park CA3900637 | 120 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Glenwood Mobile Home Park CA3900649 | 100 | 0 | 0 | 2 | 0 ppbbelow the action level |
| A1 Winstons Mobile Home Park CA3900606 | 75 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Mokelumne Mobile Senior Park CA3900719 | 55 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Riverside Mobile Home Park CA3900762 | 55 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Century Mobile Home Park CA3900579 | 50 | 0 | 0 | 34 | 0 ppbbelow the action level |
| Haynes Board & Care Home CA3901217 | 41 | 0 | 0 | 1 | 0 ppbbelow the action level |
| La Torres Park CA3900991 | 40 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Wine Country Apartments CA3900559 | 40 | 60 | 0 | 0 | 0 ppbbelow the action level |
| Fremont One CA3901474 | 39 | 0 | 0 | 16 | 5 ppbbelow the action level |
| V & P Trailer Court Water System CA3900732 | 35 | 0 | 0 | 6 | 0 ppbbelow the action level |
| Sunny Road Water System CA3901213 | 34 | 0 | 0 | 36 | 0 ppbbelow the action level |
| Cardoza Villa Corp CA3900921 | 30 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Martinez Apartments CA3900751 | 26 | 0 | 0 | 25 | 0 ppbbelow the action level |
| Lockeford Community Serv. Dist. CA3910008 | 3,572 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Joaquin County - Colonial Heights CA3910002 | 1,841 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Linden County Water District CA3910019 | 1,784 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oakwood Lake Water District-Subdivision CA3910023 | 1,479 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Fairoaks PWS #44 CA3901348 | 1,172 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Joaquin County - Thornton CA3910009 | 964 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Joaquin County - Wilkinson Manor CA3910024 | 851 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Stockton Verde Mobile Home Park CA3910020 | 711 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Morada Estates N PWS #46 CA3901337 | 426 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Arbor Mobile Home Park Ws CA3900831 | 340 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Bel Air Mobile Estate CA3900907 | 325 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Double L Mobile Estates CA3900842 | 320 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Santos Ranch PWS #5-Csa #35 CA3901216 | 320 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Joaquin Water Works #2 CA3901092 | 310 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Morehead Park CA3900805 | 300 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sahara Mobile Court CA3900964 | 300 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Morada Estates PWS CA3900722 | 290 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mapache Trailer Park CA3900661 | 275 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Farmington Water Company CA3900505 | 270 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Clements Water Works #43 CA3900504 | 264 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Shaded Terrace PWS CA3900720 | 238 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Twin Oaks Mobile Park CA3901074 | 238 | 0 | 0 | 0 | 0 ppbbelow the action level |
| King Island Trailer Park Water System CA3901114 | 236 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Elkhorn Estates Water System CA3900724 | 234 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Acampo Water System CA3901303 | 231 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Juan Vista CA3901215 | 201 | 0 | 0 | 0 | 2.6 ppbbelow the action level |
| Tahama Village Mobile Home Park CA3900602 | 200 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Villa Cerezos CA3900596 | 200 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Caribou Mobile Park PWS CA3900568 | 180 | 0 | 0 | 0 | 9.3 ppbbelow the action level |
| Gayla Manor PWS CA3900563 | 178 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Par Country Estates Csa-16 CA3901172 | 178 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rancho San Joaquin Water Sys CA3900558 | 172 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Il Vineto CA3900624 | 160 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Islander Marina CA3900653 | 150 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Shady Rest Trailer Court CA3900755 | 150 | 0 | 0 | 0 | 8 ppbbelow the action level |
| Fairway Estates PWS Csa-18 CA3901075 | 149 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Currier Estates Water Corp CA3900701 | 148 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Corral Hollow PWS CA3900702 | 145 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Country Squire Mobile Estates & Water Sy CA3900607 | 131 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mobile Villas Trailer Park CA3901081 | 130 | 0 | 0 | 0 | 3 ppbbelow the action level |
| New Hope Landing General Store CA3900664 | 125 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Wilkinson Manor A-Zone PWS CA3901159 | 125 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lockeford Mobile Home Park Wtr Sys CA3900682 | 123 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Spring Creek Estates PWS CA3900927 | 119 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Morada Manor Water System CA3900523 | 112 | 0 | 0 | 0 | 11 ppbbelow the action level |
| Walnut Acres CA3901113 | 106 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Morada Acres Water System CA3900512 | 105 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lodi Lake Mobile Home Park CA3900561 | 104 | 0 | 0 | 0 | 8 ppbbelow the action level |
| Cherry Lane Trailer Park CA3900983 | 100 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Haven Acres River Club INC CA3900813 | 100 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Maurland Manor Water System CA3900543 | 92 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Country Club Vista Mutual Water Co CA3900733 | 75 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Country Manor MHP CA3900844 | 75 | 0 | 0 | 0 | 0.6 ppbbelow the action level |
| Wayside Motel Apartments Wtr Sys CA3900835 | 70 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Sunnyside Estates Water System CA3900714 | 69 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Almond Park Water System CA3900517 | 60 | 0 | 0 | 0 | 0 ppbbelow the action level |
| El Rio Mobile Home Park CA3900569 | 60 | 0 | 0 | 0 | 13 ppbbelow the action level |
| Finnlees Trailer Park CA3900705 | 55 | 0 | 0 | 0 | 0 ppbbelow the action level |
| B&g Mobile Home Park LLC Ws CA3900586 | 50 | 0 | 0 | 0 | 7 ppbbelow the action level |
| Enclave at the Delta CA3901304 | 39 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Lodi Homes CA3900837 | 39 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Hanot Foundation INC CA3901276 | 38 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Stockton East Water District CA3910006 | 50 | 0 | 0 | 0 | not reported |
| Thomas Shaft Wholesale CA3810008 | 1 | 0 | 0 | 0 | not reported |
USGS · Monitoring stations
The water, more recently.
Available station readings in San Joaquin 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 Joaquin County
30ZIP 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
- Dogtown
- Escalon
- French Camp
- Lathrop
- Linden
- Lockeford
- Lodi
- Manteca
- Ripon
- Stockton
- Thornton
- Tracy
- Victor
- Waterloo
- Woodbridge
View ZIP areas and understand coverage
- 95202Stockton
- 95203Stockton
- 95204Stockton
- 95205Stockton
- 95206Stockton
- 95207Stockton
- 95209Stockton
- 95210Stockton
- 95211Stockton
- 95212Stockton
- 95215Waterloo
- 95219Stockton
- 95220Dogtown
- 95227
- 95231French Camp
- 95236Linden
- 95237Lockeford
- 95240Lodi
- 95242Lodi
- 95253Victor
- 95258Woodbridge
- 95304Tracy
- 95320Escalon
- 95330Lathrop
- 95336Manteca
- 95337Manteca
- 95366Ripon
- 95376Tracy
- 95377Tracy
- 95686Thornton
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.