Hard water in Alhambra, CA
Reported by City of Alhambra · September 2025
- CA typical
- 121 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in Alhambra carries roughly 137 mg/L of dissolved calcium and magnesium, or 8.0 grains per gallon. That is hard water. The number comes from City of Alhambra, dated September 2025.
Alhambra sits 16 mg/L above the typical California figure of 121. Of the 10 nearest cities we track, 7 have softer water and 3 have harder. The range nearby runs from 34 mg/L in South San Gabriel to 230 in Pasadena.
What 137 mg/L means at home
Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.
Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.
Soap and detergent need a little more to lather, and soap scum shows up in the tub.
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
At 137 mg/L most of the trouble is scale, and only a few things deal with it.
Ion-exchange water softener
The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.
Salt-free conditioner
No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.
Reverse osmosis or carbon filter
Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.
3 people × 75 gallons a day × 8.0 gpg = 1,798 grains a day. A 24,000-grain unit regenerates about every 13 days.
EPA record for Alhambra's water system
No health-based violations since 2016
Serves about 80,279 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 Alhambra water hard?
Yes. It measures about 137 mg/L (8.0 grains per gallon), which the USGS classes as hard.
What is the water hardness in Alhambra in grains per gallon?
About 8.0 gpg. One grain per gallon equals 17.1 mg/L, so 137 mg/L divided by 17.1 gives 8.0.
What size water softener do I need in Alhambra?
For 3 people using 75 gallons each per day, 8.0 gpg works out to about 1,798 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.
Has the Alhambra water system had EPA violations?
EPA records show no health-based violations for City of Alhambra since 2016.
Nearby cities
- South Pasadena128 mg/LHard
- San Gabriel116 mg/LModerately hard
- San Marino116 mg/LModerately hard
- Rosemead46 mg/LSoft
- South San Gabriel34 mg/LSoft
- East San Gabriel192 mg/LVery hard
- East Los Angeles123 mg/LHard
- Temple City113 mg/LModerately hard
- East Pasadena192 mg/LVery hard
- Pasadena230 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, September 9, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.