How hard is the water in Campbell County, SD?
27.8 grains per gallon
A softener will pay its way here.
The median hardness measured in Campbell County, SD is 476 mg/L as calcium carbonate, which is 27.8 gpg. That is very hard on the USGS scale. It comes from 73 samples at 3 sites between 1999 and 2019, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 26.2 and 28.5 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 27.8 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 24.6 to 29.1 gpg
The softest single sample on record in Campbell County was 421.5 mg/L and the hardest 498.5 mg/L, a 1-fold gap. The top quarter of sites read above 28.5 gpg and the bottom quarter below 26.2 gpg.
Wells 27.8 gpg, rivers and lakes 26.9 gpg
1 groundwater samples from 1 wells put the median at 476 mg/L. 72 surface samples from 2 sites put it at 460 mg/L. In Campbell County the wells come out 0.9 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 40,000-grain unit covers a week between regenerations. Expect about 607 lb of salt a year (16 bags of 40 lb, about $109), 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 $209 a year.
Sizing at 27.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,668 | 24,000 | 203 lb |
| 2 | 3,336 | 24,000 | 406 lb |
| 4 | 6,672 | 48,000 | 812 lb |
| 6 | 10,008 | 80,000 | 1,218 lb |
Campbell County against the rest of South Dakota
Among the 55 South Dakota counties with data, Campbell County is number 22 of 55 counting from the hardest. Across the whole country it is harder than 94% of counties.
Softest in South Dakota: Dewey County at 0.5 gpg. Hardest: Hanson County at 84.7 gpg. Closest to Campbell County: Brookings County (27.9), Moody County (28), Deuel County (28.6).