How hard is the water in Union County, AR?

0.5 grains per gallon

You do not need a softener here.

The median hardness measured in Union County, AR is 8 mg/L as calcium carbonate, which is 0.5 gpg. That is soft on the USGS scale. It comes from 120 samples at 43 sites between 1990 and 2026, 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 0.2 and 1.6 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

You can skip the softener. At 0.5 gpg the most a softener would fix is the odd water spot. If a salesperson in Union County says otherwise, ask to see their reading in grains per gallon and compare it with this one.

More on when a softener is not worth it.

From 0.1 to 6.2 gpg

The softest single sample on record in Union County was 1.5 mg/L and the hardest 105.5 mg/L, a 70-fold gap. The top quarter of sites read above 1.6 gpg and the bottom quarter below 0.2 gpg.

Wells 0.5 gpg, rivers and lakes 2.2 gpg

120 groundwater samples from 43 wells put the median at 8.4 mg/L. 1,396 surface samples from 27 sites put it at 37 mg/L. In Union County the rivers and lakes come out 1.7 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. The two sources are close, so the county figure should hold whichever one your tap is on.

Union County against the rest of Arkansas

Among the 75 Arkansas counties with data, Union County is number 73 of 75 counting from the hardest. Across the whole country it is harder than 2% of counties.

Softest in Arkansas: Hempstead County at 0.1 gpg. Hardest: Prairie County at 23.9 gpg. Closest to Union County: Desha County (0.4), Calhoun County (0.6), Johnson County (0.6).