How hard is the water in Jackson County, SD?

2.7 grains per gallon

You do not need a softener here.

The median hardness measured in Jackson County, SD is 46 mg/L as calcium carbonate, which is 2.7 gpg. That is soft on the USGS scale. It comes from 6 samples at 6 sites between 1990 and 2010, 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 1.7 and 4 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: medium (how it is measured).

What to do next

You can skip the softener. At 2.7 gpg the most a softener would fix is the odd water spot. If a salesperson in Jackson County says otherwise, ask to see their reading in grains per gallon and compare it with this one. Because Jackson County straddles a decision line, check your own tap with a $10 test strip before you spend anything.

More on when a softener is not worth it.

From 1.6 to 5.6 gpg

The softest single sample on record in Jackson County was 27.2 mg/L and the hardest 95.2 mg/L, a 4-fold gap. The top quarter of sites read above 4 gpg and the bottom quarter below 1.7 gpg.

Wells 2.7 gpg, rivers and lakes 150.4 gpg

6 groundwater samples from 6 wells put the median at 46.2 mg/L. 164 surface samples from 42 sites put it at 2575 mg/L. In Jackson County the rivers and lakes come out 147.7 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.

Jackson County against the rest of South Dakota

Among the 55 South Dakota counties with data, Jackson County is number 52 of 55 counting from the hardest. Across the whole country it is harder than 20% of counties.

Softest in South Dakota: Dewey County at 0.5 gpg. Hardest: Hanson County at 84.7 gpg. Closest to Jackson County: Corson County (1.2), Dewey County (0.5), Ziebach County (0.5).