Is Los Altos, CA Tap Water Safe to Drink?
Los Altos, CA tap water currently meets EPA health guidelines across all monitored ZIP codes in this dataset. Contaminants including lithium have been detected at or below guideline thresholds.
Where Does Los Altos Get Its Water?
Water in Los Altos, CA is provided by 2 public water systems: CWSC LOS ALTOS SUBURBAN and CITY OF CUPERTINO.
How Is Los Altos Tap Water Treated?
Treated water is disinfected using free chlorine and calcium hypochlorite. Treatment includes conventional treatment (coagulation, flocculation, and filtration), groundwater disinfection and post-ozone biofiltration.
What's in Los Altos Tap Water?
The following contaminants were detected most frequently in Los Altos public water systems. All detected levels fall at or below EPA health guidelines in this dataset.
| Contaminant | Peak detected | EPA guideline | ZIPs detected | Status |
|---|---|---|---|---|
| lithium | 9 µg/L | — | 0 ZIPs | Within guideline |
| PFTrDA | 0.007 µg/L | 0.007 µg/L | 1 ZIP | Within guideline |
| 11Cl-PF3OUdS | 0.005 µg/L | — | 0 ZIPs | Within guideline |
| 8:2 FTS | 0.005 µg/L | — | 0 ZIPs | Within guideline |
| 6:2 FTS | 0.005 µg/L | — | 0 ZIPs | Within guideline |
Health Risk Profile for Los Altos
Current EPA monitoring data for Los Altos shows contaminant levels within guideline thresholds across all ZIP codes in this dataset. As with all public water systems, sensitive populations may choose to use a certified filter for additional peace of mind.
Best Broad-Spectrum Filters for This Water Profile
This city profile includes PFAS detections, chlorine disinfection, and other dissolved contaminants. Reverse osmosis (RO) systems certified under NSF/ANSI 58 provide broad reduction coverage; for PFAS specifically, confirm NSF/ANSI P473 or equivalent PFAS reduction certification.
8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.
See recommendations matched to your exact address: choose your ZIP code below.
Frequently Asked Questions about Los Altos Tap Water
Is Los Altos tap water safe to drink?
Los Altos tap water currently meets EPA health guidelines across all monitored ZIP codes in this dataset. Sensitive populations may still choose to use a certified filter as a precaution.
What contaminants are in Los Altos tap water?
The most commonly detected contaminants in Los Altos water systems include: lithium, PFTrDA, 11Cl-PF3OUdS. See the ZIP-level reports for exact measurements and EPA guideline comparisons.
Where does Los Altos get its drinking water?
Los Altos receives water from 2 public water systems, including CWSC LOS ALTOS SUBURBAN.
Do I need a water filter in Los Altos?
Current data does not show guideline exceedances in Los Altos. A certified filter can still reduce trace contaminants and improve taste for households that prefer filtered water.
How often is Los Altos tap water tested?
Public water systems in Los Altos are required by the EPA to test for regulated contaminants on schedules ranging from daily (for microbials and disinfectants) to annual or triennial (for many chemical contaminants). Results are published in annual Consumer Confidence Reports (CCRs). The data on this page reflects the most recent available EPA monitoring results, with the latest sample date of 2025-03-25.
Tap water reports by ZIP in Los Altos
- 94024 - Los Altos tap water report Some concern
Water utilities serving Los Altos, CA
Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.
- CWSC LOS ALTOS SUBURBANSome concern
- SANTA CLARA VALLEY WATER DISTRICTNo recent federal sampling
Also covers / overlaps with
- Los Altos Hills, CA
- Loyola, CA · CDP
- San Jose CCD, CA · Township
- West Santa Clara CCD, CA · Township