How hard is the water in Kalispell, MT?

Tap water hardness
73mg/L
4.3gpg
Moderately hardCounty estimate

County estimate from 963 water samples in Flathead County · July 2026

MT typical
116 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
County estimate

Water samples from around Kalispell put hardness at about 73 mg/L (4.3 gpg), which would be moderately hard on the USGS scale. Treat this as a rough guide: it is the median of 963 samples taken across Flathead County, mostly wells and streams, not a test of Kalispell's treated tap water.

Kalispell on the hardness scale, with nearby cities
060120180240300360+MT typical 116Bozeman: 92 mg/LBozeman 92Butte: 97 mg/LButte 97Missoula: 116 mg/LMissoula 116Orchard Homes: 116 mg/LOrchard Homes 116Great Falls: 145 mg/LGreat Falls 145Billings: 159 mg/LBillings 159Belgrade: 226 mg/LBelgrade 226Sidney: 491 mg/LSidney 491Kalispell 73mg/L as calcium carbonate060120180240300360+MT 116Bozeman: 92 mg/LBozeman 92Butte: 97 mg/LButte 97Missoula: 116 mg/LMissoula 116Orchard Homes: 116 mg/LOrchard Ho. 116Great Falls: 145 mg/LGreat Falls 145Belgrade: 226 mg/LBelgrade 22673 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 73 mg/L, Kalispell is 43 mg/L below the typical Montana figure of 116. None of the 8 nearest cities we track has softer water. The range nearby runs from 92 mg/L in Bozeman to 491 in Sidney.

What 73 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.

Softener size for Kalispell

3 people × 75 gallons a day × 4.3 gpg = 961 grains a day. A 24,000-grain unit regenerates about every 24 days.

Size it for your household

EPA record for Kalispell's water system

Kalispell Public Works · PWSID MT0000259

No health-based violations since 2016

Serves about 25,000 people from groundwater.

Health-based
0
Monitoring or reporting
25
Open now
0

EPA lists this system as serving Kalispell.

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 Kalispell water hard?

Somewhat. It measures about 73 mg/L (4.3 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Kalispell in grains per gallon?

About 4.3 gpg. One grain per gallon equals 17.1 mg/L, so 73 mg/L divided by 17.1 gives 4.3.

What size water softener do I need in Kalispell?

For 3 people using 75 gallons each per day, 4.3 gpg works out to about 961 grains a day. A 24,000-grain softener covers that with a regeneration about every 24 days.

Has the Kalispell water system had EPA violations?

EPA records show no health-based violations for Kalispell Public Works since 2016. There were also 25 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 9 cities in Montana

Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.