Hard water in La Cañada Flintridge, CA
Reported by Pasadena Water and Power · October 2025
- CA typical
- 121 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in La Cañada Flintridge carries roughly 218 mg/L of dissolved calcium and magnesium, or 12.8 grains per gallon. That is very hard water. The number comes from Pasadena Water and Power, dated October 2025.
At 218 mg/L, La Cañada Flintridge is 97 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 3 mg/L in La Crescenta-Montrose to 234 in Altadena.
What 218 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 218 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 × 12.8 gpg = 2,873 grains a day. A 24,000-grain unit regenerates about every 8 days.
EPA record for La Cañada Flintridge's water system
No health-based violations since 2016
Serves about 165,448 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
TapWaterData ties La Cañada Flintridge to this system. EPA's service-area records do not name La Cañada Flintridge, so check the utility printed on your water bill.
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 Cañada Flintridge water hard?
Yes. It measures about 218 mg/L (12.8 grains per gallon), which the USGS classes as very hard.
What is the water hardness in La Cañada Flintridge in grains per gallon?
About 12.8 gpg. One grain per gallon equals 17.1 mg/L, so 218 mg/L divided by 17.1 gives 12.8.
What size water softener do I need in La Cañada Flintridge?
For 3 people using 75 gallons each per day, 12.8 gpg works out to about 2,873 grains a day. A 24,000-grain softener covers that with a regeneration about every 8 days.
Has the La Cañada Flintridge water system had EPA violations?
EPA records show no health-based violations for Pasadena Water and Power since 2016.
Nearby cities
- La Crescenta-Montrose3 mg/LSoft
- Glendale86 mg/LModerately hard
- Altadena234 mg/LVery hard
- Pasadena230 mg/LVery hard
- Burbank133 mg/LHard
- South Pasadena128 mg/LHard
- San Marino116 mg/LModerately hard
- East Pasadena192 mg/LVery hard
- Sierra Madre161 mg/LHard
- East San Gabriel192 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, October 14, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.