How hard is the water in Missoula, MT?

Tap water hardness
116mg/L
6.8gpg
Moderately hardReports range 116–168

Reported by Missoula Water · July 2025

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

Tap water in Missoula has about 116 mg/L of hardness, which is 6.8 grains per gallon. On the USGS scale that counts as moderately hard. The number comes from Missoula Water, dated July 2025. Reports for this system disagree, with values from 116 to 168 mg/L.

Missoula on the hardness scale, with nearby cities
060120180240300360+MT typical 116Kalispell: 73 mg/LKalispell 73Bozeman: 92 mg/LBozeman 92Butte: 97 mg/LButte 97Orchard Homes: 116 mg/LOrchard Homes 116Great Falls: 145 mg/LGreat Falls 145Billings: 159 mg/LBillings 159Belgrade: 226 mg/LBelgrade 226Sidney: 491 mg/LSidney 491Missoula 116mg/L as calcium carbonate060120180240300360+MT 116Kalispell: 73 mg/LKalispell 73Bozeman: 92 mg/LBozeman 92Butte: 97 mg/LButte 97Orchard Homes: 116 mg/LOrchard Ho. 116Great Falls: 145 mg/LGreat Falls 145Belgrade: 226 mg/LBelgrade 226116 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

Missoula sits close to the typical Montana figure of 116 mg/L. Of the 8 nearest cities we track, 3 have softer water and 4 have harder. The range nearby runs from 73 mg/L in Kalispell to 491 in Sidney.

What 116 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 Missoula

3 people × 75 gallons a day × 6.8 gpg = 1,526 grains a day. A 24,000-grain unit regenerates about every 15 days.

Size it for your household

EPA record for Missoula's water system

Missoula Water · PWSID MT0000294

No health-based violations since 2016

Serves about 68,200 people from groundwater.

Health-based
0
Monitoring or reporting
25
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 Missoula water hard?

Somewhat. It measures about 116 mg/L (6.8 grains per gallon), which the USGS classes as moderately hard.

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

About 6.8 gpg. One grain per gallon equals 17.1 mg/L, so 116 mg/L divided by 17.1 gives 6.8.

What size water softener do I need in Missoula?

For 3 people using 75 gallons each per day, 6.8 gpg works out to about 1,526 grains a day. A 24,000-grain softener covers that with a regeneration about every 15 days.

Has the Missoula water system had EPA violations?

EPA records show no health-based violations for Missoula Water 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 (utility report, July 22, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.