County · California
San Joaquin County, California: drinking water records
This overview covers 30 ZIP codes and 95 community water systems in San Joaquin County. It also stands in for 1 ZIP codes whose utility has too little EPA data for a page of its own.
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 with the most complete records
| 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 ppb |
| California Water Service - Stockton CA3910001 | 176,266 | 840 | 1 | 0 | 0 ppb |
| Tracy, City of CA3910011 | 96,609 | 480 | 0 | 0 | 0 ppb |
| Manteca, City of CA3910005 | 84,928 | 720 | 4 | 0 | 0.4 ppb |
| Lodi, City of CA3910004 | 68,272 | 1,500 | 7 | 0 | 0 ppb |
| City of Lathrop CA3910015 | 35,080 | 180 | 3 | 0 | 0 ppb |
| City of Mountain House CA3910027 | 24,948 | 120 | 0 | 0 | 0 ppb |
| Ripon, City of CA3910007 | 15,741 | 300 | 3 | 0 | 0 ppb |
| Escalon, City of CA3910003 | 7,429 | 180 | 0 | 0 | 0 ppb |
| San Joaquin County - Lincoln Village CA3910010 | 5,841 | 120 | 0 | 0 | 0 ppb |
| Cdcr California Health Care Facility CA3910803 | 5,551 | 0 | 0 | 3 | 0 ppb |
| San Joaquin County-Mokelumne Acres CA3910017 | 3,802 | 300 | 6 | 0 | 0 ppb |
| Little Potato Slough Mutual CA3910022 | 1,510 | 0 | 0 | 4 | 0 ppb |
| San Joaquin County-Raymus Village CA3910014 | 1,086 | 0 | 0 | 9 | 0 ppb |
| San Joaquin River Club INC CA3910018 | 600 | 60 | 0 | 0 | 0 ppb |
| 132 Investments Water System CA3901031 | 252 | 0 | 0 | 1 | 4.7 ppb |
| Big Wheel Mobile Home Park CA3900637 | 120 | 0 | 0 | 1 | 0 ppb |
| Glenwood Mobile Home Park CA3900649 | 100 | 0 | 0 | 2 | 0 ppb |
| A1 Winstons Mobile Home Park CA3900606 | 75 | 0 | 0 | 2 | 0 ppb |
| Mokelumne Mobile Senior Park CA3900719 | 55 | 0 | 0 | 1 | 0 ppb |
| Riverside Mobile Home Park CA3900762 | 55 | 0 | 0 | 2 | 0 ppb |
| Century Mobile Home Park CA3900579 | 50 | 0 | 0 | 34 | 0 ppb |
| Haynes Board & Care Home CA3901217 | 41 | 0 | 0 | 1 | 0 ppb |
| La Torres Park CA3900991 | 40 | 0 | 0 | 1 | 0 ppb |
| Wine Country Apartments CA3900559 | 40 | 60 | 0 | 0 | 0 ppb |
ZIP reports in San Joaquin County
No ZIP report in this county is published yet.
These ZIP codes are covered by this overview because their utility has too little EPA data for a separate page: 95253.
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. Page generated 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.