County · California
Stanislaus County, California: drinking water records
Explore EPA records for 61 community water systems across 25 ZIP codes in Stanislaus 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 12 of the 61 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 61 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 |
|---|---|---|---|---|---|
| Turlock, City of CA5010019 | 72,682 | 300 | 0 | 1 | 0 ppbbelow the action level |
| Ceres, City of CA5010028 | 54,513 | 480 | 7 | 1 | 0 ppbbelow the action level |
| Riverbank, City of CA5010018 | 24,834 | 540 | 0 | 1 | 0 ppbbelow the action level |
| Oakdale, City of CA5010014 | 23,235 | 420 | 0 | 1 | 0 ppbbelow the action level |
| City of Newman-Water Department CA5010013 | 12,207 | 300 | 0 | 1 | 0 ppbbelow the action level |
| Hughson, City of CA5010008 | 7,481 | 180 | 0 | 36 | 0 ppbbelow the action level |
| Keyes Community Services Dist. CA5010009 | 5,672 | 60 | 0 | 14 | 0 ppbbelow the action level |
| Modesto, City of CA5010010 | 218,771 | 2,580 | 7 | 0 | 0 ppbbelow the action level |
| Patterson, City of CA5010017 | 24,977 | 360 | 0 | 0 | 0 ppbbelow the action level |
| City of Modesto - Salida CA5010005 | 14,537 | 120 | 0 | 0 | 0 ppbbelow the action level |
| City of Waterford CA5010006 | 8,788 | 240 | 0 | 0 | 0.6 ppbbelow the action level |
| Denair Community Services District CA5010021 | 5,090 | 240 | 0 | 0 | 0 ppbbelow the action level |
| Western Hills Water District/Diablo Gran CA5010039 | 2,000 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Riverdale Park Tract CSD CA5000019 | 610 | 0 | 0 | 1 | 5 ppbbelow the action level |
| Riverview Mobile Home Estates CA5000090 | 540 | 0 | 0 | 23 | 0 ppbbelow the action level |
| Crows Landing Comm Svc District CA5000005 | 500 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Sunrise Village MHP CA5000095 | 353 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Knights Ferry Comm. Svc. Dist. CA5000008 | 168 | 0 | 0 | 5 | 9.6 ppbbelow the action level |
| Lazy B Mobilehome Park CA5000048 | 125 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Westley CSD CA5000408 | 70 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Country Villa Apts CA5000218 | 60 | 0 | 0 | 37 | 0 ppbbelow the action level |
| Martin'S Mobile Home Court CA5000061 | 60 | 0 | 0 | 24 | 0 ppbbelow the action level |
| Cobles Corner CA5000033 | 50 | 0 | 0 | 33 | 0 ppbbelow the action level |
| Oid-Oakdale Rural Water System #1 CA5000433 | 1,570 | 0 | 0 | 0 | 0 ppbbelow the action level |
| City of Modesto - del Rio CA5010029 | 1,327 | 0 | 0 | 0 | 0 ppbbelow the action level |
| City of Modesto - South Turlock CA5010023 | 1,099 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Waterford-River Pointe CA5010042 | 1,079 | 0 | 0 | 0 | 0 ppbbelow the action level |
| City of Modesto - Grayson CA5010033 | 914 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Hillsview Homes CA5010007 | 887 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Waterford - Hickman CA5010026 | 597 | 0 | 0 | 0 | 2.3 ppbbelow the action level |
| Oid #51 - Sunset Oaks #10 CA5000317 | 287 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oid #46 - Sunset Oaks CA5000014 | 269 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Park Heights Mutual Water Co CA5000017 | 250 | 0 | 0 | 0 | 0 ppbbelow the action level |
| North Oaks Mutual Water Co CA5000237 | 234 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Casa de Amigos Manufactured Housing Comm CA5000060 | 204 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Tid/ la Grange Water System CA5000010 | 195 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Monterey Park Tract CSD CA5000389 | 186 | 0 | 0 | 0 | 0 ppbbelow the action level |
| City of Modesto - Walnut Manor CA5010031 | 175 | 0 | 0 | 0 | 0 ppbbelow the action level |
| City of Modesto - North Turlock CA5010034 | 172 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Olive Lane Mobilehome Park CA5000055 | 153 | 0 | 0 | 0 | 8 ppbbelow the action level |
| Buehner Water System CA5000313 | 150 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oid #22 - Williams Tract CA5000015 | 150 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mulberry MHP CA5000072 | 148 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oid #45 CA5000013 | 144 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Fisherman'S Bend MHP CA5000058 | 120 | 0 | 0 | 0 | 0 ppbbelow the action level |
| City of Modesto - Central Turlock CA5010035 | 119 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Twin Cypress Mobile Home Park CA5000071 | 112 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Del Rio East HOA Water System CA5000099 | 110 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oasis Investments CA5000263 | 75 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Morningside Mobilehome Park CA5000054 | 67 | 0 | 0 | 0 | 0 ppbbelow the action level |
| 4n Mobilehome Park CA5000082 | 65 | 0 | 0 | 0 | 4.2 ppbbelow the action level |
| Lone Pine MHP CA5000049 | 64 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Tully Mobile Estates CA5000067 | 56 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Country Western Mhrv CA5000080 | 55 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Maze Blvd Mobilehome Park CA5000041 | 36 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Foster Farms #5 CA5000579 | 26 | 0 | 0 | 0 | 0 ppbbelow the action level |
| River Road Mutual Water Company CA5000020 | 26 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Buehner Houses CA5000297 | 25 | 0 | 0 | 0 | 0 ppbbelow the action level |
| South San Joaquin Irrigation District CA5010040 | 25 | 0 | 0 | 0 | not reported |
| Modesto Irrigation District CA5010038 | 23 | 0 | 0 | 0 | not reported |
| Stanislaus Regional Water Authority CA5010043 | 0 | 0 | 0 | 0 | not reported |
USGS · Monitoring stations
The water, more recently.
Available station readings in Stanislaus 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 Stanislaus County
25ZIP 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
- Ceres
- Denair
- Empire
- Farmington
- Hickman
- Hughson
- Keyes
- Modesto
- Newman
- Oakdale
- Patterson
- Riverbank
- Salida
- Turlock
- Waterford
- Westley
View ZIP areas and understand coverage
- 95230Farmington
- 95307Ceres
- 95313Modesto
- 95316Denair
- 95319Empire
- 95323Hickman
- 95326Hughson
- 95328Keyes
- 95350Modesto
- 95351Modesto
- 95354Modesto
- 95355Modesto
- 95356Modesto
- 95357Modesto
- 95358Modesto
- 95360Newman
- 95361Oakdale
- 95363Patterson
- 95367Riverbank
- 95368Salida
- 95380Turlock
- 95382Turlock
- 95385
- 95386Waterford
- 95387Westley
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.