Hard water in La Verne, CA
Reported by GSWC-San Dimas · September 2025
- CA typical
- 121 mg/L
- EPA health violations since 2016
- 1
- Softener for 3 people
- 24k grain
- Data
- Utility report
Tap water in La Verne has about 231 mg/L of hardness, which is 13.5 grains per gallon. On the USGS scale that counts as very hard. The number comes from GSWC-San Dimas, dated September 2025. Reports for this system disagree, with values from 231 to 275 mg/L.
La Verne sits 110 mg/L above the typical California figure of 121. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 112 mg/L in Citrus to 275 in San Dimas.
What 231 mg/L means at home
Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.
Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.
Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.
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 231 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 × 13.5 gpg = 3,035 grains a day. A 24,000-grain unit regenerates about every 7 days.
EPA record for La Verne's water system
1 health-based violation since 2016
Serves about 31,334 people from surface water.
- Health-based
- 1
- Monitoring or reporting
- 0
- Open now
- 0
EPA lists La Verne, City WD as the system serving La Verne. The hardness figure above comes from a different system's report, which TapWaterData uses for La Verne.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Nitrateoften from fertilizer or septic systems | 1 | 2017 | Resolved |
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 La Verne water hard?
Yes. It measures about 231 mg/L (13.5 grains per gallon), which the USGS classes as very hard.
What is the water hardness in La Verne in grains per gallon?
About 13.5 gpg. One grain per gallon equals 17.1 mg/L, so 231 mg/L divided by 17.1 gives 13.5.
What size water softener do I need in La Verne?
For 3 people using 75 gallons each per day, 13.5 gpg works out to about 3,035 grains a day. A 24,000-grain softener covers that with a regeneration about every 7 days.
Has the La Verne water system had EPA violations?
EPA records show 1 health-based violation for La Verne, City WD since 2016, involving Nitrate.
Nearby cities
- San Dimas275 mg/LVery hard
- Claremont157 mg/LHard
- Pomona138 mg/LHard
- Glendora122 mg/LHard
- Charter Oak275 mg/LVery hard
- Montclair166 mg/LHard
- Upland126 mg/LHard
- Covina167 mg/LHard
- Citrus112 mg/LModerately hard
- Walnut210 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, September 29, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.