How hard is the water in Deuel County, SD?
28.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Deuel County, SD is 489 mg/L as calcium carbonate, which is 28.6 gpg. That is very hard on the USGS scale. It comes from 21 samples at 10 sites between 1999 and 2013, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 26.1 and 29.2 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 28.6 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 22.2 to 40.3 gpg
The softest single sample on record in Deuel County was 380 mg/L and the hardest 690 mg/L, a 2-fold gap. The top quarter of sites read above 29.2 gpg and the bottom quarter below 26.1 gpg.
Wells 29.3 gpg, rivers and lakes 28.2 gpg
1 groundwater samples from 1 wells put the median at 502 mg/L. 20 surface samples from 9 sites put it at 482.5 mg/L. In Deuel County the wells come out 1.1 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 624 lb of salt a year (16 bags of 40 lb, about $112), 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 $212 a year.
Sizing at 28.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,716 | 24,000 | 209 lb |
| 2 | 3,432 | 32,000 | 418 lb |
| 4 | 6,864 | 64,000 | 835 lb |
| 6 | 10,296 | 80,000 | 1,253 lb |
Deuel County against the rest of South Dakota
Among the 55 South Dakota counties with data, Deuel County is number 19 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 Deuel County: Moody County (28), Brookings County (27.9), Campbell County (27.8).