Tap Water Results

Is Menlo Park, CA tap water safe?

Data: U.S. EPA · How we read the data · How we check it

Summary

No federal limits exceeded in EPA data for California Water Service – Bear Gulch.

2 public water systems serve parts of Menlo Park. The largest, California Water Service – Bear Gulch, serves 60,382 people. Your water bill names your system.

Largest system

California Water Service – Bear Gulch

60,382 people · Surface water · EPA ID CA4110006

Buys treated water from San Francisco Regional Water System.

PFASHighest averageLimitStatus
PFOA
Not detected
–4 pptNot detected
PFOS
Not detected
–4 pptNot detected
PFHxS
Not detected
–10 pptNot detected
PFNA
Not detected
–10 pptNot detected
HFPO-DA (GenX)
Not detected
–10 pptNot detected

ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.

Lead: 4 ppb at the 90th percentile (Dec 2024, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0

Full California Water Service – Bear Gulch results

Across California, 129 of 691 water systems EPA tested had PFAS above a 2024 federal limit, and 26 systems were above the lead action level in results from the last five years. California results.

Menlo Park homes and lead pipes

70%
of homes built before 1980 (California 56%, US 50%)
21%
built before 1950 (California 14%)
46%
of households rent (California 44%)

Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. Renting? Ask your landlord what the service line is made of, because it's their pipe to replace. How to check your own line.

Housing: Census American Community Survey 2020–2024 5-year estimates for Menlo Park city (tables B25034, B25003). Estimates for small places have a margin of error.

Other water systems serving Menlo Park

  • Menlo Park Municipal Water
    22,362 people · Purchased surface water · California · lists this city
    No PFAS above limits

How nearby cities compare

CityMain water systemPFASLead (90th pct.)
East Palo Alto 1 mi
City of East Palo Alto
City of East Palo AltoNone above limits0 ppb
Redwood City 4 mi
City of Redwood City
City of Redwood CityNone above limits0 ppb
Palo Alto 6 mi
City of Palo Alto
City of Palo AltoNone above limits0 ppb
Newark 7 mi
Alameda County Water District
Alameda County Water DistrictNone above limits0 ppb
San Carlos 7 mi
California Water Service – San Carlos
California Water Service – San CarlosNone above limits5.8 ppb
Mountain View 7 mi
City of Mountain View
City of Mountain ViewNone above limits0 ppb
Menlo Park ZIP codes (1)
  • 94025

Questions

Is Menlo Park tap water safe to drink?

California Water Service – Bear Gulch has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.

Who supplies water in Menlo Park, CA?

2 public water systems serve parts of Menlo Park. The largest is California Water Service – Bear Gulch (60,382 people). Your water bill names your system. The EPA ID is also on your utility's Consumer Confidence Report.

Does Menlo Park tap water have PFAS?

None detected above EPA's reporting limits. California Water Service – Bear Gulch had no PFAS detected in EPA's 2023–2025 testing. "Not detected" means below the reporting limit (about 2 to 20 ppt), not proven zero.

Do Menlo Park homes have lead pipes?

Census estimates put 70% of Menlo Park homes as built before 1980 (California: 56%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. California Water Service – Bear Gulch's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.

Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.