How hard is the water in Fall River County, SD?
24.8 grains per gallon
A softener will pay its way here.
The median hardness measured in Fall River County, SD is 425 mg/L as calcium carbonate, which is 24.8 gpg. That is very hard on the USGS scale. It comes from 38 samples at 22 sites between 1990 and 2018, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 17.9 and 36.2 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: high (how it is measured).
What to do next
At 24.8 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 5.8 to 113.3 gpg
The softest single sample on record in Fall River County was 99 mg/L and the hardest 1,940 mg/L, a 20-fold gap. The top quarter of sites read above 36.2 gpg and the bottom quarter below 17.9 gpg.
Wells 24.8 gpg, rivers and lakes 49.9 gpg
38 groundwater samples from 22 wells put the median at 425 mg/L. 121 surface samples from 14 sites put it at 853.7 mg/L. In Fall River County the rivers and lakes come out 25.1 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 542 lb of salt a year (14 bags of 40 lb, about $98), 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 $198 a year.
Sizing at 24.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,488 | 24,000 | 181 lb |
| 2 | 2,976 | 24,000 | 362 lb |
| 4 | 5,952 | 48,000 | 724 lb |
| 6 | 8,928 | 64,000 | 1,086 lb |
Fall River County against the rest of South Dakota
Among the 55 South Dakota counties with data, Fall River County is number 28 of 55 counting from the hardest. Across the whole country it is harder than 91% of counties.
Softest in South Dakota: Dewey County at 0.5 gpg. Hardest: Hanson County at 84.7 gpg. Closest to Fall River County: Aurora County (25.1), Grant County (25.3), Meade County (25.5).