Santa Monica, CA water hardness

Tap water hardness
57mg/L
3.4gpg
Soft

Reported by Santa Monica-City, Water Division · September 2025

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

Tap water in Santa Monica has about 57 mg/L of hardness, which is 3.4 grains per gallon. On the USGS scale that counts as soft. The number comes from Santa Monica-City, Water Division, dated September 2025.

Santa Monica on the hardness scale, with nearby cities
060120180240300360+CA typical 121Topanga: 77 mg/LTopanga 77Marina del Rey: 121 mg/LMarina del Rey 121Los Angeles: 121 mg/LLos Angeles 121Beverly Hills: 121 mg/LBeverly Hills 121West Hollywood: 121 mg/LWest Hollywood 121Culver City: 122 mg/LCulver City 122Ladera Heights: 122 mg/LLadera Heights 122View Park-Windsor Hills: 122 mg/LView Park-Windsor Hills 122El Segundo: 172 mg/LEl Segundo 172Manhattan Beach: 215 mg/LManhattan Beach 215Santa Monica 57mg/L as calcium carbonate060120180240300360+CA 121Marina del Rey: 121 mg/LMarina del. 121Los Angeles: 121 mg/LLos Angeles 121Beverly Hills: 121 mg/LBeverly Hi. 121Culver City: 122 mg/LCulver City 122Ladera Heights: 122 mg/LLadera Hei. 122El Segundo: 172 mg/LEl Segundo 17257 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 57 mg/L, Santa Monica is 64 mg/L below the typical California figure of 121. None of the 10 nearest cities we track has softer water. The range nearby runs from 77 mg/L in Topanga to 215 in Manhattan Beach.

What 57 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 57 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 Santa Monica's water system

Santa Monica-City, Water Division · PWSID CA1910146

No health-based violations since 2016

Serves about 90,729 people from surface water.

Health-based
0
Monitoring or reporting
0
Open now
0

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 Santa Monica water hard?

No. It measures about 57 mg/L (3.4 grains per gallon), which the USGS classes as soft.

What is the water hardness in Santa Monica in grains per gallon?

About 3.4 gpg. One grain per gallon equals 17.1 mg/L, so 57 mg/L divided by 17.1 gives 3.4.

Has the Santa Monica water system had EPA violations?

EPA records show no health-based violations for Santa Monica-City, Water Division since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, September 24, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.