Is Half Moon Bay, CA Tap Water Safe to Drink?
Half Moon Bay, 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 Half Moon Bay Get Its Water?
Water in Half Moon Bay, CA is provided by 2 public water systems: CALIFORNIA WATER SERVICE - BEAR GULCH and COASTSIDE COUNTY WATER DISTRICT.
How Is Half Moon Bay Tap Water Treated?
Treated water is disinfected using calcium hypochlorite. Treatment includes conventional treatment (coagulation, flocculation, and filtration) and direct filtration.
What's in Half Moon Bay Tap Water?
The following contaminants were detected most frequently in Half Moon Bay 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 Half Moon Bay
Current EPA monitoring data for Half Moon Bay 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 Filters for PFAS Water Profile
PFAS compounds are detected in this water supply. A reverse osmosis (RO) system or an activated-carbon filter specifically certified under NSF/ANSI P473 is required for reliable PFAS reduction. Standard pitcher and faucet filters without P473 certification do not remove PFAS.
8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.
NSF-certified dual-layer filtration reduces 70+ contaminants including PFAS, lead, chlorine, microplastics, and bacteria.
See recommendations matched to your exact address: choose your ZIP code below.
Frequently Asked Questions about Half Moon Bay Tap Water
Is Half Moon Bay tap water safe to drink?
Half Moon Bay 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 Half Moon Bay tap water?
The most commonly detected contaminants in Half Moon Bay water systems include: lithium, PFTrDA, 11Cl-PF3OUdS. See the ZIP-level reports for exact measurements and EPA guideline comparisons.
Where does Half Moon Bay get its drinking water?
Half Moon Bay receives water from 2 public water systems, including CALIFORNIA WATER SERVICE - BEAR GULCH.
Do I need a water filter in Half Moon Bay?
Current data does not show guideline exceedances in Half Moon Bay. A certified filter can still reduce trace contaminants and improve taste for households that prefer filtered water.
How often is Half Moon Bay tap water tested?
Public water systems in Half Moon Bay 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 2025-04-02.
Tap water reports by ZIP in Half Moon Bay
- 94019 - Half Moon Bay tap water report Some concern
Water utilities serving Half Moon Bay, 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.
- COASTSIDE COUNTY WATER DISTRICTSome concern
Also covers / overlaps with
- El Granada, CA · CDP
- Half Moon Bay CCD, CA · Township