San Joaquin County, California — public water systems
At a glance
302 active public water systems are filed under San Joaquin County, California in EPA's SDWIS records, together reporting 776,334 people served. The largest is City of Stockton, which reports serving 191,302 people. 94 are community water systems serving people where they live; the other 208 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.
Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.
Active systems
302
Population served
776.3K
Community systems
94
Groundwater share
94.7%
How does San Joaquin County compare with other California counties?
San Joaquin County has the 6th-most active public water systems among the 201 counties listed for active California systems in EPA records; among the 72 with 3 or more systems, the median has 73. Its systems report 776,334 people served in total, the 14th-largest county figure in the state and 1.8% of the statewide total. The average system here reports serving 2,571 people, about half of the California average of 5,706. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.
Where does San Joaquin County's drinking water come from?
By primary water source, San Joaquin County's active systems draw on groundwater (283, 94%), purchased surface water (10, 3.3%), surface water (6, 2%) and purchased groundwater (3, 1%). Overall, 95% rely mainly on groundwater (including purchased groundwater) and 5.3% on surface water, compared with 85% and 15% across California. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, City of Stockton, draws primarily on surface water.
What kinds of water systems operate in San Joaquin County?
San Joaquin County's active systems break down as 94 community systems (31%), 95 non-transient non-community systems (31%) and 113 transient non-community systems (37%). A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (75%), local government (23%), federal government (1.3%) and state government (1.3%).
The 50 largest water systems in San Joaquin County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | City of Stockton | San Joaquin | 191,302 | Community | Surface water |
| 2 | California Water Service - Stockton | San Joaquin | 176,266 | Community | Purchased surface water |
| 3 | Tracy, City of | San Joaquin | 96,609 | Community | Surface water |
| 4 | Manteca, City of | San Joaquin | 84,928 | Community | Purchased surface water |
| 5 | Lodi, City of | San Joaquin | 68,272 | Community | Surface water |
| 6 | City of Lathrop | San Joaquin | 35,080 | Community | Purchased surface water |
| 7 | City of Mountain House | San Joaquin | 24,948 | Community | Surface water |
| 8 | Ripon, City of | San Joaquin | 15,741 | Community | Groundwater |
| 9 | Escalon, City of | San Joaquin | 7,429 | Community | Groundwater |
| 10 | San Joaquin County - Lincoln Village | San Joaquin | 5,841 | Community | Purchased surface water |
| 11 | Cdcr California Health Care Facility | San Joaquin | 5,551 | Community | Purchased surface water |
| 12 | San Joaquin County-Mokelumne Acres | San Joaquin | 3,802 | Community | Groundwater |
| 13 | Lockeford Community Serv. Dist. | San Joaquin | 3,572 | Community | Groundwater |
| 14 | Jimmys One Stop | San Joaquin | 2,505 | Transient non-community | Groundwater |
| 15 | San Joaquin County - Colonial Heights | San Joaquin | 1,841 | Community | Purchased surface water |
| 16 | Linden County Water District | San Joaquin | 1,784 | Community | Groundwater |
| 17 | Little Potato Slough Mutual | San Joaquin | 1,510 | Community | Surface water |
| 18 | Oakwood Lake Water District-Subdivision | San Joaquin | 1,479 | Community | Groundwater |
| 19 | Defense Distrib. Depot - Tracy Site | San Joaquin | 1,200 | Non-transient non-community | Groundwater |
| 20 | Starbucks | San Joaquin | 1,200 | Transient non-community | Groundwater |
| 21 | Fairoaks Pws #44 | San Joaquin | 1,172 | Community | Groundwater |
| 22 | Family Market Water System | San Joaquin | 1,105 | Transient non-community | Groundwater |
| 23 | San Joaquin County-Raymus Village | San Joaquin | 1,086 | Community | Groundwater |
| 24 | Sjc Micke Grove Park | San Joaquin | 1,025 | Non-transient non-community | Groundwater |
| 25 | Escalon Golf Course Ws | San Joaquin | 1,010 | Transient non-community | Groundwater |
| 26 | Horizon Christian Fellowship | San Joaquin | 1,000 | Transient non-community | Groundwater |
| 27 | Jahant Food N Fuel Stop | San Joaquin | 1,000 | Transient non-community | Groundwater |
| 28 | King Island Resort Pws | San Joaquin | 1,000 | Transient non-community | Groundwater |
| 29 | Smk Chevron | San Joaquin | 1,000 | Transient non-community | Groundwater |
| 30 | San Joaquin County - Thornton | San Joaquin | 964 | Community | Groundwater |
| 31 | St Marys High School | San Joaquin | 950 | Non-transient non-community | Groundwater |
| 32 | San Joaquin County - Wilkinson Manor | San Joaquin | 851 | Community | Groundwater |
| 33 | Navarra Water System | San Joaquin | 730 | Transient non-community | Groundwater |
| 34 | Stockton Verde Mobile Home Park | San Joaquin | 711 | Community | Groundwater |
| 35 | Lodi Usd-Davis School | San Joaquin | 630 | Non-transient non-community | Groundwater |
| 36 | San Joaquin River Club Inc. | San Joaquin | 600 | Community | Groundwater |
| 37 | Musd-New Haven School | San Joaquin | 600 | Non-transient non-community | Groundwater |
| 38 | Rodeway Inn | San Joaquin | 600 | Transient non-community | Groundwater |
| 39 | Central Valley Baptist Church Ws | San Joaquin | 556 | Non-transient non-community | Groundwater |
| 40 | Harney Lane Migrant Center Ws | San Joaquin | 500 | Non-transient non-community | Groundwater |
| 41 | Defense Distrib. Depot, Sharpe Site | San Joaquin | 500 | Non-transient non-community | Groundwater |
| 42 | Jefferson Esd-Jefferson School | San Joaquin | 483 | Non-transient non-community | Groundwater |
| 43 | Ripon Usd-Colony Oak School | San Joaquin | 465 | Non-transient non-community | Groundwater |
| 44 | Sutter Home Winery Inc.. | San Joaquin | 463 | Non-transient non-community | Groundwater |
| 45 | Delicato Vineyards | San Joaquin | 430 | Non-transient non-community | Groundwater |
| 46 | Morada Estates N Pws #46 | San Joaquin | 426 | Community | Groundwater |
| 47 | Lodi Usd-Houston School | San Joaquin | 405 | Non-transient non-community | Groundwater |
| 48 | Wienerschnitzel | San Joaquin | 400 | Transient non-community | Groundwater |
| 49 | Oak View Union Elementary Sch | San Joaquin | 350 | Non-transient non-community | Groundwater |
| 50 | Musco Family Olive Co | San Joaquin | 348 | Non-transient non-community | Groundwater |
All other water systems in San Joaquin County (252)
The remaining active systems filed under San Joaquin County, largest first, with the population each reports serving.
- Arbor Mobile Home Park Ws340
- Phillips Farms330
- French Camp Golf Course327
- Bel Air Mobile Estate325
- Santos Ranch Pws #5-Csa #35320
- Double L Mobile Estates320
- San Joaquin Water Works #2310
- Deshmesh Darbar Lodi/Stk Water Sys305
- Morehead Park300
- Sahara Mobile Court300
- Cherokee Memorial Park Inc. Water System300
- Escalon Premier Brands300
- Franks One/Stop Food Mart Water Sys300
- Denny Boys Water System300
- Morada Estates Pws290
- Owens-Brockway Glass Container Inc.280
- Mapache Trailer Park275
- Alpine Meats Inc.270
- Farmington Water Company270
- Clements Water Works #43264
- Lawrence Livermore National Lab-Site 300261
- 132 Investments Water System252
- Franzia Winery250
- Shaded Terrace Pws238
- Twin Oaks Mobile Park238
- King Island Trailer Park Water System236
- Elkhorn Estates Water System234
- Acampo Water System231
- Linden Usd-Waterloo Elementary225
- Zinc House Farm Winery220
- Fc Tracy Holdings, LLC219
- New Jerusalem School210
- Boething Treeland Farms Inc.203
- San Juan Vista201
- Villa Cerezos200
- Normans Nursery200
- Paradise Point Marina200
- Banta Elementary School200
- Eusd-Van Allen School200
- Tahama Village Mobile Home Park200
- Morada Chevron Fast N Easy #60*200
- Csp Caswell State Park186
- Kellogg Garden Products185
- Caribou Mobile Park Pws180
- Gayla Manor Pws178
- Par Country Estates Csa-16178
- Rancho San Joaquin Water Sys172
- Lodi Usd-Turner Academy at Tokay Colony166
- Viejo Ltd163
- Il Vineto160
- Islander Marina150
- Cbuso Dba Woodbridge Winery150
- Collegeville Market & Cafe150
- St Josephs Hospital150
- Shady Rest Trailer Court150
- Fairway Estates Pws Csa-18149
- Currier Estates Water Corp148
- Carnegie Svra145
- Corral Hollow Pws145
- Flag City Water System135
- Country Squire Mobile Estates & Water Sy131
- Mobile Villas Trailer Park130
- Wilkinson Manor A-Zone Pws125
- Arp Minimart Corp Ws125
- New Hope Landing General Store125
- Lockeford Mobile Home Park Wtr Sys123
- Corti Water System120
- Lodi Usd-Turner Academy120
- Big Wheel Mobile Home Park120
- Spring Creek Estates Pws119
- Jahant Woods Cellars115
- Morada Manor Water System112
- Fresh Innovations LLC111
- San Joaquin Fair - 2nd District110
- Btqc-Escalon110
- Podesta Packing Water System109
- Walnut Acres106
- Morada Acres Water System105
- Lodi Lake Mobile Home Park104
- Escalon Livestock Mkt100
- Darrigos Water System100
- Escalon Usd- Collegeville Sch100
- Cherry Lane Trailer Park100
- Haven Acres River Club Inc.100
- J M Eagle (Ws)100
- Valpico Industrial Park100
- Oasis Marina-Resort100
- Ranch Coffee Shop100
- Turner Cut Resort100
- New 99 Speedway Water System100
- Plug Connection Lodi100
- West Kingdom Hall of Jehovah'S Witnesses100
- Countryside Liquors & Gas100
- Linden Usd-Glenwood School100
- Oakmoore Congre of Jehovah Wit100
- Mcmanis Family Vineyards Inc..100
- Holiday Harbor Marina100
- Glassfab Tempering Services Inc..100
- Sjc Sports Complex100
- Lodi Usd-Live Oak School100
- Church of Jesus Christ of LDS100
- St Francis Yacht Club100
- Berea Baptist Church Stockton Ca100
- Glenwood Mobile Home Park100
- Maurland Manor Water System92
- Cozad Water System85
- Sj County-Redwood School83
- Northwest Pipe Company82
- Turner Road Vintners (East)80
- Stockton Baptist Church78
- Marions Ranch House Motel78
- El Rancho Motel76
- Manteca Industrial Prk Csa-3076
- Country Manor MHP75
- A1 Winstons Mobile Home Park75
- Country Club Vista Mutual Water Co75
- Wayside Motel Apartments Wtr Sys70
- Sunnyside Estates Water System69
- Bethany Temple Water System65
- Dan R Costa Inc. (Ws)62
- 88 Market & Grill62
- Lodi Wine & Business Center61
- El Rio Mobile Home Park60
- Western Pallet Supply & Logistics60
- Gico Management60
- Almond Park Water System60
- Raudel Delgado Water System56
- Riverside Mobile Home Park55
- Town & Country Inn55
- Mokelumne Mobile Senior Park55
- Finnlees Trailer Park55
- Banta Inn Water System54
- Italian Athletic Club50
- Century Mobile Home Park50
- Waterloo Gun & Bocce Club50
- Pastor St Bernard Chrch Wtr Sys50
- B&G Mobile Home Park LLC Ws50
- Oak Ridge Winery, LLC50
- Chargin-Sossamon Water System50
- Victor Service Center50
- Tiki Lagoon Resort & Marina50
- Calva Products Co Inc.50
- Two Rivers Rv Park50
- Om Scott & Sons/Hyponex Corp50
- Bay Valley Estates Pws50
- Frank C Alegre Trucking Inc. Ws50
- Enviroplex, Inc.50
- Windmill Cove Resort/Marina LLC50
- Lodi Airport Cafe50
- Petes Place LLC50
- Zapien Market50
- Stockton East Water District50
- Valimet Inc.48
- Haynes Board & Care Home41
- La Torres Park40
- St Francis Motel40
- Linden Usd-Chartville School40
- Knapheide Truck Equipment Company40
- Wine Country Apartments40
- Dynatect Ro-Lab, Inc..40
- Fremont One39
- Tulare Farms Lllp Water System39
- Lodi Homes39
- Enclave at the Delta39
- Hanot Foundation Inc.38
- North Valley School Pws35
- V & P Trailer Court Water System35
- Country Mart Diesel & Gas Water Sys35
- Sunny Road Water System34
- Burlington Northern Santa Fe31
- Durham Ferry Community School31
- Gaf Materials Co30
- Mokelumne Beach Rv Park30
- P G & E-Turner Cut Water System30
- Carmelo Industrial Park30
- Yongs Bar & Grill Water System30
- Cardoza Villa Corp30
- S M S Briners Inc.30
- River Road Produce Water System30
- Larsen Ranch 39-40/Water System30
- Zuckerman, Roscoe 39-31630
- German Guys29
- Haven of Peace28
- Idle Wild Market28
- Tarditi Rentals Water27
- Bullfrog Landing Marina27
- Star Motel27
- Kingdom Hall of Jehovahs Witnesses26
- Martinez Apartments26
- Van Ruiten Family Winery26
- Gurdawara, Gur Nanak Parkash Water Syste26
- Jessies Grove Winery26
- Eusd-Gateway Charter25
- Finleys25
- Diede Trucking Water System25
- Oasis Market & Produce25
- West 11th Street Chevron Water System25
- Old River Golf Course25
- Lower Sac Plaza25
- Bear Creek Community Church25
- Delrio Market & Deli25
- Valley Landscaping & Maint Inc.25
- Viaggio Winery Water System25
- Lockeford Springs Golf Course25
- Investors of King Island Water Sys25
- Lockeford Holdings Water District LLC25
- River Mill, the25
- Faith Community Church of the Nazarene25
- Morada Produce25
- Tracy Islamic Center Water System25
- Country Market25
- Van Groningen & Sons Inc. Water System25
- Gico Valley Farms25
- Stevens Motel Water System25
- Pnp Stockton #8025
- Westgate Landing Park Water System25
- Lovelace Transfer Station25
- O-G Packing Co25
- Victoria Island Farms25
- Waterloo California Restaurant25
- Prima Frutta Packing25
- A Sambado & Son 39-32125
- Korean Presbyterian Church25
- Schulte Road Warehouse 3, LLC Wtr Sys25
- Basalite - Tracy25
- Devil Mountain Wholesale Nursery25
- California Islamic Center25
- Ripon Church of Christ25
- Turner Road Vintners (West)25
- St Patrick Catholic Church Wtr Sys25
- Moose Outdoor Sportsman Club25
- Austin Industrial Park Water System25
- Home Church, the25
- St Michaels Water System25
- Mclaughlin Waste Equipment Inc.25
- Down River An Itw Company25
- Southwinds Church of Tracy25
- Ripon Vfw Post 1051 Water System25
- Woodbridge Pizza Water System25
- Park Green Houses Water System25
- Zuckerman Heritage-Mcdonald25
- Clements Ridge Produce25
- Biglieri Farm Market25
- Mchenry Ave Recreation Area25
- Jacobs Terminous Market25
- Tracy Matrl Recvry/Sld Waste Ws25
- California Fruit Processors25
- Bear Creek Winery25
- Tracy Wildlife Assoc25
- San-I-Pak Inc.25
- Olde Towne25
- Thomas Shaft Wholesale1
San Joaquin County water systems: frequently asked questions
How many public water systems are in San Joaquin County, California?
EPA's SDWIS records file 302 active public water systems under San Joaquin County, California: 94 community systems (31%), 95 non-transient non-community systems (31%) and 113 transient non-community systems (37%).
Who supplies drinking water in San Joaquin County, CA?
The largest community water systems filed under San Joaquin County are City of Stockton (191,302 people served), California Water Service - Stockton (176,266 people served) and City of Tracy (96,609 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.
Does San Joaquin County's drinking water come from groundwater or surface water?
Of the 302 active public water systems in San Joaquin County, 95% draw mainly on groundwater and 5.3% on surface water, counting purchased supplies. The largest system, City of Stockton, uses surface water.
Where can I find a water quality report for San Joaquin County?
Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 94 community systems are filed under San Joaquin County, so the report to look for is the one from the system that supplies your address.
How can I check violations for a water system in San Joaquin County?
Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.
More California water systems
- All California public water systems· 7,479 active
- Fresno County· 328 systems
- Kern County· 327 systems
- Monterey County· 307 systems
- San Bernardino County· 306 systems
- Los Angeles County· 275 systems
- Tulare County· 274 systems
- How to find out who supplies your drinking water
- How to find and read your annual water quality report
About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Public water systems in San Joaquin County, California”, https://aquacensus.com/water-systems/california/san-joaquin (data as of October 1, 2026).