How hard is the water in Benton County, MN?
8.3 grains per gallon
A softener is worth it here.
The median hardness measured in Benton County, MN is 142 mg/L as calcium carbonate, which is 8.3 gpg. That is hard on the USGS scale. It comes from 105 samples at 10 sites between 1991 and 2024, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 8.2 and 9.6 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 8.3 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.
More on sizing a softener for your household.
From 7.0 to 11.7 gpg
The softest single sample on record in Benton County was 119.3 mg/L and the hardest 200 mg/L, a 2-fold gap. The top quarter of sites read above 9.6 gpg and the bottom quarter below 8.2 gpg.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 181 lb of salt a year (5 bags of 40 lb, about $33), 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 $133 a year.
Sizing at 8.3 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 498 | 24,000 | 61 lb |
| 2 | 996 | 24,000 | 121 lb |
| 4 | 1,992 | 24,000 | 242 lb |
| 6 | 2,988 | 24,000 | 364 lb |
Benton County against the rest of Minnesota
Among the 87 Minnesota counties with data, Benton County is number 79 of 87 counting from the hardest. Across the whole country it is harder than 44% of counties.
Softest in Minnesota: Lake County at 1.3 gpg. Hardest: Traverse County at 42.6 gpg. Closest to Benton County: Chisago County (8.4), Crow Wing County (8), Roseau County (9.5).