County · California
Santa Clara County, California: drinking water records
Explore EPA records for 74 community water systems across 58 ZIP codes in Santa Clara 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 16 of the 74 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 74 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 |
|---|---|---|---|---|---|
| San Jose Water CA4310011 | 1,039,920 | 1,125 | 2 | 1 | 0 ppbbelow the action level |
| City of Gilroy CA4310004 | 59,203 | 420 | 7 | 1 | 2 ppbbelow the action level |
| Stanford University CA4310013 | 35,853 | 120 | 0 | 1 | 0 ppbbelow the action level |
| City of Sunnyvale CA4310014 | 157,566 | 600 | 0 | 0 | 0 ppbbelow the action level |
| City of Santa Clara CA4310012 | 130,746 | 1,190 | 0 | 0 | 2.7 ppbbelow the action level |
| Great Oaks Wc INC CA4310022 | 110,088 | 1,140 | 4 | 0 | 0 ppbbelow the action level |
| City of San Jose - Evg/Edv/Coy CA4310020 | 101,265 | 275 | 0 | 0 | 0 ppbbelow the action level |
| City of Milpitas CA4310005 | 81,773 | 240 | 0 | 0 | 2.5 ppbbelow the action level |
| City of Mountain View CA4310007 | 81,501 | 430 | 0 | 0 | 0 ppbbelow the action level |
| Cwsc Los Altos Suburban CA4310001 | 69,973 | 1,080 | 1 | 0 | 1.5 ppbbelow the action level |
| City of Palo Alto CA4310009 | 67,231 | 120 | 0 | 0 | 0 ppbbelow the action level |
| City of Morgan Hill CA4310006 | 47,374 | 960 | 3 | 0 | 0 ppbbelow the action level |
| City of San Jose - Nsj/Alviso CA4310019 | 45,559 | 215 | 0 | 0 | 0 ppbbelow the action level |
| City of Cupertino CA4310018 | 16,336 | 155 | 0 | 0 | 0 ppbbelow the action level |
| Nasa Ames Research Center CA4300997 | 16,273 | 120 | 0 | 0 | 10.4 ppbbelow the action level |
| Purissima Hills Water District CA4310021 | 6,245 | 120 | 0 | 0 | 6 ppbbelow the action level |
| Cal Am - West San Martin CA4300543 | 1,173 | 0 | 0 | 1 | 3 ppbbelow the action level |
| Coyote Valley RV Resort CA4300994 | 500 | 0 | 0 | 1 | 4.6 ppbbelow the action level |
| Chemeketa Park Mutual Water Company CA4300517 | 346 | 0 | 0 | 1 | 18.2 ppbat or above the action level |
| Twin Valley INC CA4300575 | 317 | 0 | 0 | 54 | 3.9 ppbbelow the action level |
| Lupin Lodge CA4300716 | 300 | 0 | 0 | 3 | 0.2 ppbbelow the action level |
| Casa de Fruta Water System CA4300611 | 250 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Mt. Eden Mutual Water Company CA4300831 | 165 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Lake Canyon Mutual Water Company CA4300522 | 156 | 0 | 0 | 1 | 6 ppbbelow the action level |
| Roseview Heights Mutual Water Company CA4300562 | 148 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Raineri Mutual Water Company CA4300520 | 145 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Kennon Water Company CA4300521 | 142 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Brush and Old Well Mutual Water Company CA4300978 | 70 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Los Ranchos de Uvas Water Company CA4300637 | 58 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Green Acres Mutual Water CA4300573 | 53 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Sullivan Mutual Water CA4300571 | 53 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Valley View Ranches CA4300996 | 45 | 0 | 0 | 1 | 0.6 ppbbelow the action level |
| Chiri Sweet Water Company CA4300757 | 40 | 0 | 0 | 1 | 0 ppbbelow the action level |
| Foothill Mutual Water Company CA4300630 | 36 | 0 | 0 | 2 | 0 ppbbelow the action level |
| Live Oak Creek Mutual Water Company CA4300829 | 30 | 0 | 0 | 2 | 6 ppbbelow the action level |
| San Martin County Water District CA4300542 | 627 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Thousand Trails - Morgan Hill CA4300615 | 413 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Aldercroft Heights County Water District CA4300516 | 338 | 0 | 0 | 0 | 0 ppbbelow the action level |
| New Avenue Mutual Water Company CA4300771 | 305 | 0 | 0 | 0 | 3.9 ppbbelow the action level |
| Mt. Pleasant Water Users Association CA4300563 | 300 | 0 | 0 | 0 | 0.7 ppbbelow the action level |
| Lick Observatory-Ucsc CA4300909 | 284 | 0 | 0 | 0 | 3.2 ppbbelow the action level |
| Saratoga Heights Mutual Water Company CA4300545 | 258 | 0 | 0 | 0 | 0.7 ppbbelow the action level |
| Parkway Lakes RV Park CA4300924 | 250 | 0 | 0 | 0 | 19.9 ppbat or above the action level |
| Happy Acres Mwc CA4300551 | 220 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Melody Woods Water Company CA4300525 | 168 | 0 | 0 | 0 | 0 ppbbelow the action level |
| San Martin Foothills Water Company CA4300638 | 145 | 0 | 0 | 0 | 60 ppbat or above the action level |
| Three Springs Ranch Mutual Water Company CA4300770 | 110 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mecchi Water Company CA4300912 | 104 | 0 | 0 | 0 | 1.6 ppbbelow the action level |
| Oak Dell Park CA4300603 | 104 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rancho Robles Mutual Water Company CA4300577 | 103 | 0 | 0 | 0 | 1.4 ppbbelow the action level |
| Green Mountain Water Company CA4300560 | 80 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Vista Grande Water Users Association CA4300550 | 79 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Santa Teresa Meadows Water Company CA4300760 | 68 | 0 | 0 | 0 | 2.9 ppbbelow the action level |
| Golden Heights Mutual Water Company CA4300992 | 66 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Spring Valley Heights Association INC CA4300856 | 66 | 0 | 0 | 0 | 2.9 ppbbelow the action level |
| Burchell Road Water Association CA4300567 | 65 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Uvas Pines RV Park CA4300999 | 65 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Oakmont Water System CA4300526 | 61 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mireval Improvement Association CA4300741 | 60 | 0 | 0 | 0 | 6 ppbbelow the action level |
| Quail Creek Estates Mutual Water Company CA4300979 | 55 | 0 | 0 | 0 | 0.7 ppbbelow the action level |
| South County Retirement Home CA4300832 | 46 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Aborn Heights Water Mutual Association CA4300792 | 45 | 0 | 0 | 0 | 7.6 ppbbelow the action level |
| Emerald Valley Mutual Water Company CA4301004 | 43 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Angelo Lane Water Company CA4300578 | 41 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Mountain Springs Mutual Water Company CA4300740 | 40 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Deer Hill Mutual Water Co CA4300842 | 36 | 0 | 0 | 0 | 3.6 ppbbelow the action level |
| Rancho de Lomas Mutual Water Company CA4300848 | 35 | 0 | 0 | 1 | not reported |
| Rockwood Estates Mutual Water Company CA4301013 | 30 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Rucker Avenue Mutual Water Co CA4301410 | 25 | 0 | 0 | 0 | 0 ppbbelow the action level |
| Camp Saratoga CA4300834 | 450 | 0 | 0 | 0 | not reported |
| Maria Lane Mutual Water Company CA4300752 | 42 | 0 | 0 | 0 | not reported |
| Stonebridge Mutual Water Co CA4300787 | 38 | 0 | 0 | 0 | not reported |
| Lee'S Orchard Owners Association CA4301062 | 35 | 0 | 0 | 0 | not reported |
| Santa Clara Valley Water District CA4310027 | 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. 3 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 Santa Clara 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 Santa Clara County
58ZIP 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
- Campbell
- Cupertino
- Gilroy
- Los Altos
- Los Altos Hills
- Los Gatos
- Milpitas
- Mountain View
- Palo Alto
- San Jose
- San Martin
- Santa Clara
- Saratoga
- Stanford
- Sunnyvale
View ZIP areas and understand coverage
- 94022Los Altos Hills
- 94024Los Altos
- 94040Mountain View
- 94041Mountain View
- 94043Mountain View
- 94085Sunnyvale
- 94086Sunnyvale
- 94087Sunnyvale
- 94089Sunnyvale
- 94301Palo Alto
- 94303Palo Alto
- 94304Palo Alto
- 94305Stanford
- 94306Palo Alto
- 95002San Jose
- 95008Campbell
- 95013San Jose
- 95014Cupertino
- 95020Gilroy
- 95030Los Gatos
- 95032Los Gatos
- 95035Milpitas
- 95037San Jose
- 95046San Martin
- 95050Santa Clara
- 95051Santa Clara
- 95053Santa Clara
- 95054Santa Clara
- 95070Saratoga
- 95110San Jose
- 95111San Jose
- 95112San Jose
- 95113San Jose
- 95116San Jose
- 95117San Jose
- 95118San Jose
- 95119San Jose
- 95120San Jose
- 95121San Jose
- 95122San Jose
- 95123San Jose
- 95124San Jose
- 95125San Jose
- 95126San Jose
- 95127San Jose
- 95128San Jose
- 95129San Jose
- 95130San Jose
- 95131San Jose
- 95132San Jose
- 95133San Jose
- 95134San Jose
- 95135San Jose
- 95136San Jose
- 95138San Jose
- 95139San Jose
- 95140
- 95148San Jose
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.