How hard is the water in Ouachita County, AR?

2 grains per gallon

You do not need a softener here.

The median hardness measured in Ouachita County, AR is 35 mg/L as calcium carbonate, which is 2 gpg. That is soft on the USGS scale. It comes from 78 samples at 34 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 0.6 and 2.7 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 2 gpg the most a softener would fix is the odd water spot. If a salesperson in Ouachita 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 7.1 gpg

The softest single sample on record in Ouachita County was 2.5 mg/L and the hardest 121 mg/L, a 48-fold gap. The top quarter of sites read above 2.7 gpg and the bottom quarter below 0.6 gpg.

Wells 2 gpg, rivers and lakes 0.8 gpg

78 groundwater samples from 34 wells put the median at 34.5 mg/L. 519 surface samples from 11 sites put it at 13.2 mg/L. In Ouachita County the wells come out 1.2 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.

Ouachita County against the rest of Arkansas

Among the 75 Arkansas counties with data, Ouachita County is number 46 of 75 counting from the hardest. Across the whole country it is harder than 16% of counties.

Softest in Arkansas: Hempstead County at 0.1 gpg. Hardest: Prairie County at 23.9 gpg. Closest to Ouachita County: Saline County (2.1), White County (2.3), Lincoln County (2.3).