How hard is the water in Barnwell County, SC?

1.4 grains per gallon

You do not need a softener here.

The median hardness measured in Barnwell County, SC is 24 mg/L as calcium carbonate, which is 1.4 gpg. That is soft on the USGS scale. It comes from 17 samples at 14 sites between 1993 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 1.9 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: medium (how it is measured).

What to do next

You can skip the softener. At 1.4 gpg the most a softener would fix is the odd water spot. If a salesperson in Barnwell 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 0.3 to 6.7 gpg

The softest single sample on record in Barnwell County was 4.5 mg/L and the hardest 115 mg/L, a 26-fold gap. The top quarter of sites read above 1.9 gpg and the bottom quarter below 0.6 gpg.

Wells 1.4 gpg, rivers and lakes 1.2 gpg

17 groundwater samples from 14 wells put the median at 24 mg/L. 90 surface samples from 20 sites put it at 21.3 mg/L. In Barnwell County the wells come out 0.2 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.

Barnwell County against the rest of South Carolina

Among the 46 South Carolina counties with data, Barnwell County is number 22 of 46 counting from the hardest. Across the whole country it is harder than 11% of counties.

Softest in South Carolina: Aiken County at 0.2 gpg. Hardest: Georgetown County at 15.2 gpg. Closest to Barnwell County: Edgefield County (1.4), Union County (1.5), Williamsburg County (1.2).