How hard is the water in Oliver County, ND?
24.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Oliver County, ND is 421 mg/L as calcium carbonate, which is 24.6 gpg. That is very hard on the USGS scale. It comes from 109 samples at 6 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 20 and 33.5 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 24.6 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 10.4 to 78.3 gpg
The softest single sample on record in Oliver County was 178 mg/L and the hardest 1,340 mg/L, an 8-fold gap. The top quarter of sites read above 33.5 gpg and the bottom quarter below 20 gpg.
Wells 78.3 gpg, rivers and lakes 24 gpg
1 groundwater samples from 1 wells put the median at 1340 mg/L. 108 surface samples from 5 sites put it at 410 mg/L. In Oliver County the wells come out 54.3 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, a 32,000-grain unit covers a week between regenerations. Expect about 537 lb of salt a year (14 bags of 40 lb, about $97), 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 $197 a year.
Sizing at 24.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,476 | 24,000 | 180 lb |
| 2 | 2,952 | 24,000 | 359 lb |
| 4 | 5,904 | 48,000 | 718 lb |
| 6 | 8,856 | 64,000 | 1,077 lb |
Oliver County against the rest of North Dakota
Among the 53 North Dakota counties with data, Oliver County is number 13 of 53 counting from the hardest. Across the whole country it is harder than 91% of counties.
Softest in North Dakota: Hettinger County at 1.1 gpg. Hardest: Walsh County at 54 gpg. Closest to Oliver County: Kidder County (24.6), Barnes County (24.4), Rolette County (24.9).