How hard is the water in Hill County, MT?
8.7 grains per gallon
A softener is worth it here.
The median hardness measured in Hill County, MT is 149 mg/L as calcium carbonate, which is 8.7 gpg. That is hard on the USGS scale. It comes from 75 samples at 46 sites between 1993 and 2016, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 6.5 and 11 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: high (how it is measured).
What to do next
At 8.7 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below. Because Hill County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
From 4.8 to 24.4 gpg
The softest single sample on record in Hill County was 82.1 mg/L and the hardest 418 mg/L, a 5-fold gap. The top quarter of sites read above 11 gpg and the bottom quarter below 6.5 gpg.
Wells 24.4 gpg, rivers and lakes 8.7 gpg
1 groundwater samples from 1 wells put the median at 418 mg/L. 71 surface samples from 42 sites put it at 149 mg/L. In Hill County the wells come out 15.7 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 190 lb of salt a year (5 bags of 40 lb, about $34), 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 $134 a year.
Sizing at 8.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 522 | 24,000 | 64 lb |
| 2 | 1,044 | 24,000 | 127 lb |
| 4 | 2,088 | 24,000 | 254 lb |
| 6 | 3,132 | 24,000 | 381 lb |
Hill County against the rest of Montana
Among the 56 Montana counties with data, Hill County is number 45 of 56 counting from the hardest. Across the whole country it is harder than 46% of counties.
Softest in Montana: Lincoln County at 3.4 gpg. Hardest: Rosebud County at 138.9 gpg. Closest to Hill County: Missoula County (8.4), Deer Lodge County (8.9), Granite County (9.2).