How hard is the water in West Puente Valley, CA?
Reported by San Gabriel Valley Water CO.-El Monte · August 2025
- CA typical
- 121 mg/L
- EPA health violations since 2016
- 2
- Softener for 3 people
- 24k grain
- Data
- Utility report
Tap water in West Puente Valley has about 109 mg/L of hardness, which is 6.4 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from San Gabriel Valley Water CO.-El Monte, dated August 2025.
At 109 mg/L, West Puente Valley is 12 mg/L below the typical California figure of 121. Of the 10 nearest cities we track, 4 have softer water and 6 have harder. The range nearby runs from 34 mg/L in Avocado Heights to 223 in Valinda.
What 109 mg/L means at home
You may see faint white spots on glasses and shower doors after the water dries.
Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.
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
Optional. Plenty of households at this level live with it and descale the kettle now and then.
Water softener
Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.
Carbon filter
Improves taste and removes chlorine. It leaves calcium and magnesium in place.
3 people × 75 gallons a day × 6.4 gpg = 1,438 grains a day. A 24,000-grain unit regenerates about every 16 days.
EPA record for West Puente Valley's water system
2 health-based violations since 2016
Serves about 240,000 people from groundwater.
- Health-based
- 2
- Monitoring or reporting
- 0
- Open now
- 0
TapWaterData ties West Puente Valley to this system. EPA's service-area records do not name West Puente Valley, so check the utility printed on your water bill.
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Groundwater Ruletreatment of well water | 2 | 2018–2019 | 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 West Puente Valley water hard?
Somewhat. It measures about 109 mg/L (6.4 grains per gallon), which the USGS classes as moderately hard.
What is the water hardness in West Puente Valley in grains per gallon?
About 6.4 gpg. One grain per gallon equals 17.1 mg/L, so 109 mg/L divided by 17.1 gives 6.4.
What size water softener do I need in West Puente Valley?
For 3 people using 75 gallons each per day, 6.4 gpg works out to about 1,438 grains a day. A 24,000-grain softener covers that with a regeneration about every 16 days.
Has the West Puente Valley water system had EPA violations?
EPA records show 2 health-based violations for San Gabriel Valley Water CO.-El Monte since 2016, involving Groundwater Rule.
Nearby cities
- Avocado Heights34 mg/LSoft
- Valinda223 mg/LVery hard
- West Covina170 mg/LHard
- El Monte48 mg/LSoft
- Hacienda Heights117 mg/LModerately hard
- Vincent112 mg/LModerately hard
- South San Jose Hills208 mg/LVery hard
- South El Monte34 mg/LSoft
- Mayflower Village135 mg/LHard
- South Monrovia Island75 mg/LModerately hard
Hardness data: TapWaterData US Water Hardness (utility report, August 18, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.