How hard is the water in Nobles County, MN?
21.4 grains per gallon
A softener will pay its way here.
The median hardness measured in Nobles County, MN is 367 mg/L as calcium carbonate, which is 21.4 gpg. That is very hard on the USGS scale. It comes from 33 samples at 12 sites between 2014 and 2023, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 14.5 and 24.7 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 21.4 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 11.7 to 25.9 gpg
The softest single sample on record in Nobles County was 200 mg/L and the hardest 444 mg/L, a 2-fold gap. The top quarter of sites read above 24.7 gpg and the bottom quarter below 14.5 gpg.
What a softener would cost to run
For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 468 lb of salt a year (12 bags of 40 lb, about $84), 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 $184 a year.
Sizing at 21.4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,284 | 24,000 | 156 lb |
| 2 | 2,568 | 24,000 | 312 lb |
| 4 | 5,136 | 40,000 | 625 lb |
| 6 | 7,704 | 64,000 | 937 lb |
Nobles County against the rest of Minnesota
Among the 87 Minnesota counties with data, Nobles County is number 20 of 87 counting from the hardest. Across the whole country it is harder than 87% of counties.
Softest in Minnesota: Lake County at 1.3 gpg. Hardest: Traverse County at 42.6 gpg. Closest to Nobles County: Swift County (21.1), Clay County (21), Rice County (20.9).