Local lookup
Peninsula Drinking Water by Town
Every water supplier publishes an annual water quality report, called a Consumer Confidence Report, listing what was found in the water and how it compares with legal limits. Choose your town to see who supplies your tap water, where it comes from, and the link to the latest report.
Reviewed October 24, 2026 · Free to use · No sign-up, no tracking of your town
- 27towns covered
- 21water suppliers
- 1 reportper supplier, every year
- NSF/ANSI 53 or 58filters certified for PFAS
Choose Your Town
Every Town at a Glance
Suppliers as of October 24, 2026. Most of the Peninsula drinks water from the Hetch Hetchy system run by the San Francisco Public Utilities Commission, delivered by a local supplier.
| Town | Supplier | Main sources |
|---|---|---|
| Atherton | California Water Service, Bear Gulch district | SFPUC Hetch Hetchy water plus local Bear Gulch surface water |
| West Menlo Park | California Water Service, Bear Gulch district | SFPUC Hetch Hetchy water plus local Bear Gulch surface water |
| Menlo Park | Menlo Park Municipal Water California Water Service, Bear Gulch district O'Connor Tract Co-operative Water Company |
SFPUC Hetch Hetchy system |
| Palo Alto | City of Palo Alto Utilities | SFPUC Hetch Hetchy system |
| North Fair Oaks | City of Redwood City | SFPUC Hetch Hetchy system |
| Redwood City | City of Redwood City | SFPUC Hetch Hetchy system |
| East Palo Alto | City of East Palo Alto water system Palo Alto Park Mutual Water Company O'Connor Tract Co-operative Water Company |
SFPUC Hetch Hetchy system |
| Ladera | California Water Service, Bear Gulch district | SFPUC Hetch Hetchy water plus local Bear Gulch surface water |
| Woodside | California Water Service, Bear Gulch district | SFPUC Hetch Hetchy water plus local Bear Gulch surface water |
| San Carlos | California Water Service, Bayshore district (San Carlos system) | SFPUC Hetch Hetchy system |
| Portola Valley | California Water Service, Bear Gulch district | SFPUC Hetch Hetchy water plus local Bear Gulch surface water |
| Los Altos | California Water Service, Los Altos Suburban district | Valley Water treated water plus local groundwater |
| Los Altos Hills | Purissima Hills Water District California Water Service, Los Altos Suburban district |
SFPUC Hetch Hetchy system |
| Mountain View | City of Mountain View California Water Service, Los Altos Suburban district |
SFPUC Hetch Hetchy water, Valley Water treated water and some groundwater |
| Foster City | Estero Municipal Improvement District (City of Foster City) | SFPUC Hetch Hetchy system |
| Belmont | Mid-Peninsula Water District | SFPUC Hetch Hetchy system |
| San Mateo | California Water Service, Bayshore district (San Mateo system) | SFPUC Hetch Hetchy system |
| Burlingame | City of Burlingame | SFPUC Hetch Hetchy system |
| Hillsborough | Town of Hillsborough | SFPUC Hetch Hetchy system |
| Millbrae | City of Millbrae | SFPUC Hetch Hetchy system |
| Sunnyvale | City of Sunnyvale California Water Service, Los Altos Suburban district |
SFPUC Hetch Hetchy water, Valley Water treated water and groundwater |
| Cupertino | San Jose Water California Water Service, Los Altos Suburban district |
Valley Water treated water, groundwater and local mountain surface water |
| Saratoga | San Jose Water | Valley Water treated water, groundwater and local mountain surface water |
| Milpitas | City of Milpitas | SFPUC Hetch Hetchy water and Valley Water treated water |
| Newark | Alameda County Water District | A blend of local groundwater, State Water Project water and SFPUC water |
| Union City | Alameda County Water District | A blend of local groundwater, State Water Project water and SFPUC water |
| Fremont | Alameda County Water District | A blend of local groundwater, State Water Project water and SFPUC water |
Reading Your Water Report
MCL
The legal limit
The maximum contaminant level is the enforceable limit. A result below it means the supplier met the standard.
PHG or MCLG
The health goal
California's public health goal and the EPA's goal are levels with no known health risk. They are not enforceable, and some are set at zero.
Filters
Choose certified ones
The EPA advises filters certified to NSF/ANSI Standard 53 or 58 for PFAS reduction, and checking the certification for any other contaminant of concern.
Common Questions
How do I know which supplier serves my home?
The supplier's name is printed on the water bill. Renters can ask the landlord or property manager. Several towns, including Menlo Park, East Palo Alto and Mountain View, have more than one supplier, so the bill is the surest check.
Is Peninsula tap water safe to drink?
Public water systems must meet federal and California drinking water standards, and each annual report shows whether the supplier met them. Meeting legal limits is not the same as zero exposure, which is why some people choose a certified filter for specific contaminants such as PFAS or lead.
What are PFAS, and are they in my water?
PFAS are long-lasting industrial chemicals found in many products. In 2024 the EPA set the first national limits for some PFAS in drinking water, including 4 parts per trillion for PFOA and PFOS. Each supplier's report lists any PFAS detected.
Does my home's plumbing matter?
Yes. Lead usually comes from household plumbing, fixtures or service lines rather than the water supply. Homes built before 1986 are more likely to have lead solder. Running the cold tap for a minute or two before drinking and using cold water for cooking lowers exposure.
Sources and How This Tool Works
Suppliers were matched to towns from each supplier's service area information and city utility pages, checked October 2026. Where a town has more than one supplier, all are listed and the water bill decides. Source descriptions are summaries; each report gives the full detail. Links go to the supplier's report or water quality page; when a supplier posts a new report, the link sometimes changes, so the supplier's home page is the fallback. Filter guidance comes from the EPA.
- EPA. Consumer Confidence Reports: information for consumers
- EPA. Understanding your annual water quality report
- EPA. Identifying drinking water filters certified to reduce PFAS
- EPA. Per- and polyfluoroalkyl substances (PFAS) national primary drinking water regulation
- California Water Service. Find your district
General health information, reviewed October 24, 2026. This tool informs; it does not diagnose, treat or replace care from a licensed clinician, and the linked sources' current versions control. Water that suddenly changes in color, smell or taste should be reported to the supplier listed on your bill. If something feels urgent, call 911 or your doctor.
Curious how everyday exposures affect your health? Start with a free discovery call.
Book a Discovery Call