How hard is the water in Cass County, ND?
21.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Cass County, ND is 363 mg/L as calcium carbonate, which is 21.2 gpg. That is very hard on the USGS scale. It comes from 1,215 samples at 54 sites between 1990 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 16.2 and 25.7 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 21.2 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 3.1 to 39.1 gpg
The softest single sample on record in Cass County was 53 mg/L and the hardest 668.5 mg/L, a 13-fold gap. The top quarter of sites read above 25.7 gpg and the bottom quarter below 16.2 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 16.5 gpg, rivers and lakes 21.4 gpg
9 groundwater samples from 4 wells put the median at 282 mg/L. 1,179 surface samples from 47 sites put it at 366 mg/L. In Cass County the rivers and lakes come out 4.9 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 32,000-grain unit covers a week between regenerations. Expect about 463 lb of salt a year (12 bags of 40 lb, about $83), 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 $183 a year.
Sizing at 21.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,272 | 24,000 | 155 lb |
| 2 | 2,544 | 24,000 | 310 lb |
| 4 | 5,088 | 40,000 | 619 lb |
| 6 | 7,632 | 64,000 | 929 lb |
Cass County against the rest of North Dakota
Among the 53 North Dakota counties with data, Cass County is number 25 of 53 counting from the hardest. Across the whole country it is harder than 87% of counties.
Softest in North Dakota: Hettinger County at 1.1 gpg. Hardest: Walsh County at 54 gpg. Closest to Cass County: Wells County (21.2), Richland County (21.3), Foster County (21.4).