How hard is the water in Sheridan County, MT?
98.1 grains per gallon
A softener will pay its way here.
The median hardness measured in Sheridan County, MT is 1680 mg/L as calcium carbonate, which is 98.1 gpg. That is very hard on the USGS scale. It comes from 22 samples at 21 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 56.5 and 123.8 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: medium (how it is measured).
What to do next
At 98.1 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 24.2 to 274.6 gpg
The softest single sample on record in Sheridan County was 413.5 mg/L and the hardest 4,700 mg/L, an 11-fold gap. The top quarter of sites read above 123.8 gpg and the bottom quarter below 56.5 gpg.
Wells 98.1 gpg, rivers and lakes 19.4 gpg
22 groundwater samples from 21 wells put the median at 1680 mg/L. 58 surface samples from 20 sites put it at 331.5 mg/L. In Sheridan County the wells come out 78.7 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, the water is harder than a standard single tank handles in a week, so plan on a larger or twin-tank unit. Expect about 2,143 lb of salt a year (54 bags of 40 lb, about $386), 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 $486 a year.
Sizing at 98.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 5,886 | 48,000 | 716 lb |
| 2 | 11,772 | twin tank | 1,432 lb |
| 4 | 23,544 | twin tank | 2,865 lb |
| 6 | 35,316 | twin tank | 4,297 lb |
Sheridan County against the rest of Montana
Among the 56 Montana counties with data, Sheridan County is number 2 of 56 counting from the hardest. Across the whole country it is harder than 99% of counties.
Softest in Montana: Lincoln County at 3.4 gpg. Hardest: Rosebud County at 138.9 gpg. Closest to Sheridan County: Liberty County (67.8), Powder River County (60.8), Cascade County (58.6).