Menlo Park, CA water hardness

Tap water hardness
46mg/L
2.7gpg
Soft

Reported by City of East Palo Alto · May 2025

CA typical
121 mg/L
EPA health violations since 2016
0
Data
Utility report

Menlo Park water measures 46 mg/L (2.7 gpg) of hardness, soft by USGS standards. The number comes from City of East Palo Alto, dated May 2025.

Menlo Park on the hardness scale, with nearby cities
060120180240300360+CA typical 121Palo Alto: 29 mg/LPalo Alto 29North Fair Oaks: 32 mg/LNorth Fair Oaks 32Redwood City: 32 mg/LRedwood City 32Woodside: 32 mg/LWoodside 32San Carlos: 33 mg/LSan Carlos 33Foster City: 33 mg/LFoster City 33Newark: 65 mg/LNewark 65Mountain View: 134 mg/LMountain View 134Stanford: 146 mg/LStanford 146Los Altos Hills: 274 mg/LLos Altos Hills 274Menlo Park 46mg/L as calcium carbonate060120180240300360+CA 121Palo Alto: 29 mg/LPalo Alto 29North Fair Oaks: 32 mg/LNorth Fair. 32Redwood City: 32 mg/LRedwood Ci. 32San Carlos: 33 mg/LSan Carlos 33Newark: 65 mg/LNewark 65Stanford: 146 mg/LStanford 14646 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 46 mg/L, Menlo Park is 75 mg/L below the typical California figure of 121. Of the 10 nearest cities we track, 6 have softer water and 4 have harder. The range nearby runs from 29 mg/L in Palo Alto to 274 in Los Altos Hills.

What 46 mg/L means at home

Soap and shampoo lather with very little product. Kettles and showerheads stay mostly free of white crust.

Some people notice that soap feels slow to rinse off in soft water. That slippery feel is normal and harmless.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

Nothing, as far as hardness goes. At 46 mg/L a softener would have almost nothing to remove.

Carbon filter

If the water tastes of chlorine, a pitcher or faucet carbon filter takes care of that. It does not change hardness.

EPA record for Menlo Park's water system

Menlo Park Municipal Water · PWSID CA4110017

No health-based violations since 2016

Serves about 22,362 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

EPA lists Menlo Park Municipal Water as the system serving Menlo Park. The hardness figure above comes from a different system's report, which TapWaterData uses for Menlo Park.

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Menlo Park water hard?

No. It measures about 46 mg/L (2.7 grains per gallon), which the USGS classes as soft.

What is the water hardness in Menlo Park in grains per gallon?

About 2.7 gpg. One grain per gallon equals 17.1 mg/L, so 46 mg/L divided by 17.1 gives 2.7.

Has the Menlo Park water system had EPA violations?

EPA records show no health-based violations for Menlo Park Municipal Water since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, May 27, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.