How hard is the water in Valley County, MT?
14.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Valley County, MT is 243 mg/L as calcium carbonate, which is 14.2 gpg. That is very hard on the USGS scale. It comes from 103 samples at 88 sites between 1990 and 2026, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 11.4 and 23.3 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: high (how it is measured).
What to do next
At 14.2 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water.
More on sizing a softener for your household.
From 1.6 to 112.7 gpg
The softest single sample on record in Valley County was 27.2 mg/L and the hardest 1,930 mg/L, a 71-fold gap. The top quarter of sites read above 23.3 gpg and the bottom quarter below 11.4 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 14.2 gpg, rivers and lakes 13.6 gpg
103 groundwater samples from 88 wells put the median at 243.3 mg/L. 205 surface samples from 48 sites put it at 233 mg/L. In Valley County the wells come out 0.6 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 310 lb of salt a year (8 bags of 40 lb, about $56), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $156 a year.
Sizing at 14.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 852 | 24,000 | 104 lb |
| 2 | 1,704 | 24,000 | 207 lb |
| 4 | 3,408 | 24,000 | 415 lb |
| 6 | 5,112 | 40,000 | 622 lb |
Valley County against the rest of Montana
Among the 56 Montana counties with data, Valley County is number 31 of 56 counting from the hardest. Across the whole country it is harder than 67% of counties.
Softest in Montana: Lincoln County at 3.4 gpg. Hardest: Rosebud County at 138.9 gpg. Closest to Valley County: Meagher County (13.9), Glacier County (13.6), Pondera County (13.6).