Lake Arrowhead, CA water hardness

Tap water hardness
56mg/L
3.3gpg
Soft

Reported by Lake Arrowhead CSD · September 2025

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

Tap water in Lake Arrowhead has about 56 mg/L of hardness, which is 3.3 grains per gallon. On the USGS scale that counts as soft. The number comes from Lake Arrowhead CSD, dated September 2025.

Lake Arrowhead on the hardness scale, with nearby cities
060120180240300360+CA typical 121Running Springs: 36 mg/LRunning Springs 36Crestline: 51 mg/LCrestline 51Muscoy: 72 mg/LMuscoy 72San Bernardino: 79 mg/LSan Bernardino 79Rialto: 89 mg/LRialto 89Loma Linda: 99 mg/LLoma Linda 99Hesperia: 108 mg/LHesperia 108Mentone: 111 mg/LMentone 111Redlands: 111 mg/LRedlands 111Highland: 123 mg/LHighland 123Lake Arrowhead 56mg/L as calcium carbonate060120180240300360+CA 121Running Springs: 36 mg/LRunning Sp. 36Crestline: 51 mg/LCrestline 51Muscoy: 72 mg/LMuscoy 72San Bernardino: 79 mg/LSan Bernar. 79Hesperia: 108 mg/LHesperia 108Highland: 123 mg/LHighland 12356 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Lake Arrowhead sits 65 mg/L below the typical California figure of 121. Of the 10 nearest cities we track, 2 have softer water and 8 have harder. The range nearby runs from 36 mg/L in Running Springs to 123 in Highland.

What 56 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 56 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 Lake Arrowhead's water system

Lake Arrowhead CSD · PWSID CA3610005

No health-based violations since 2016

Serves about 7,038 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 Lake Arrowhead water hard?

No. It measures about 56 mg/L (3.3 grains per gallon), which the USGS classes as soft.

What is the water hardness in Lake Arrowhead in grains per gallon?

About 3.3 gpg. One grain per gallon equals 17.1 mg/L, so 56 mg/L divided by 17.1 gives 3.3.

Has the Lake Arrowhead water system had EPA violations?

EPA records show no health-based violations for Lake Arrowhead CSD since 2016.

Nearby cities

All 515 cities in California

Hardness data: TapWaterData US Water Hardness (utility report, September 10, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.