How hard is the water in Toole County, MT?
38.1 grains per gallon
A softener will pay its way here.
The median hardness measured in Toole County, MT is 653 mg/L as calcium carbonate, which is 38.1 gpg. That is very hard on the USGS scale. It comes from 43 samples at 15 sites between 1990 and 2026, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 13.9 and 73.8 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: high (how it is measured).
What to do next
At 38.1 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 8.1 to 115.7 gpg
The softest single sample on record in Toole County was 139 mg/L and the hardest 1,981.4 mg/L, a 14-fold gap. The top quarter of sites read above 73.8 gpg and the bottom quarter below 13.9 gpg.
Wells 15.1 gpg, rivers and lakes 43 gpg
2 groundwater samples from 2 wells put the median at 259 mg/L. 39 surface samples from 11 sites put it at 735.5 mg/L. In Toole County the rivers and lakes come out 27.9 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 64,000-grain unit covers a week between regenerations. Expect about 833 lb of salt a year (21 bags of 40 lb, about $150), 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 $250 a year.
Sizing at 38.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 2,286 | 24,000 | 278 lb |
| 2 | 4,572 | 40,000 | 556 lb |
| 4 | 9,144 | 80,000 | 1,113 lb |
| 6 | 13,716 | twin tank | 1,669 lb |
Toole County against the rest of Montana
Among the 56 Montana counties with data, Toole County is number 8 of 56 counting from the hardest. Across the whole country it is harder than 97% of counties.
Softest in Montana: Lincoln County at 3.4 gpg. Hardest: Rosebud County at 138.9 gpg. Closest to Toole County: Musselshell County (38.1), Golden Valley County (37.7), Big Horn County (32.1).