How hard is the water in Tripp County, SD?
9.9 grains per gallon
A softener is worth it here.
The median hardness measured in Tripp County, SD is 170 mg/L as calcium carbonate, which is 9.9 gpg. That is hard on the USGS scale. It comes from 53 samples at 2 sites between 1990 and 2014, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 9.5 and 10.3 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: low (how it is measured).
What to do next
At 9.9 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below.
More on sizing a softener for your household.
From 9.2 to 10.6 gpg
The softest single sample on record in Tripp County was 157 mg/L and the hardest 182 mg/L, a 1-fold gap. The top quarter of sites read above 10.3 gpg and the bottom quarter below 9.5 gpg.
Wells 9.2 gpg, rivers and lakes 10.6 gpg
1 groundwater samples from 1 wells put the median at 157 mg/L. 52 surface samples from 1 sites put it at 182 mg/L. In Tripp County the rivers and lakes come out 1.4 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. 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 24,000-grain unit covers a week between regenerations. Expect about 216 lb of salt a year (6 bags of 40 lb, about $39), 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 $139 a year.
Sizing at 9.9 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 594 | 24,000 | 72 lb |
| 2 | 1,188 | 24,000 | 145 lb |
| 4 | 2,376 | 24,000 | 289 lb |
| 6 | 3,564 | 32,000 | 434 lb |
Tripp County against the rest of South Dakota
Among the 55 South Dakota counties with data, Tripp County is number 48 of 55 counting from the hardest. Across the whole country it is harder than 51% of counties.
Softest in South Dakota: Dewey County at 0.5 gpg. Hardest: Hanson County at 84.7 gpg. Closest to Tripp County: Beadle County (10.5), Brule County (10.8), Gregory County (11.1).