How hard is the water in Harrison County, MS?

0.3 grains per gallon

You do not need a softener here.

The median hardness measured in Harrison County, MS is 5 mg/L as calcium carbonate, which is 0.3 gpg. That is soft on the USGS scale. It comes from 33 samples at 33 sites between 1990 and 2019, 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 0.5 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 0.3 gpg the most a softener would fix is the odd water spot. If a salesperson in Harrison 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 0.0 to 43.3 gpg

The softest single sample on record in Harrison County was 0.5 mg/L and the hardest 742 mg/L, a 1,484-fold gap. The top quarter of sites read above 0.5 gpg and the bottom quarter below 0.2 gpg. So even in a soft county, a handful of wells here produce water hard enough to scale a heater.

Wells 0.3 gpg, rivers and lakes 0.5 gpg

33 groundwater samples from 33 wells put the median at 5.3 mg/L. 8 surface samples from 5 sites put it at 8.8 mg/L. In Harrison County the rivers and lakes come out 0.2 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.

Harrison County against the rest of Mississippi

Among the 78 Mississippi counties with data, Harrison County is number 76 of 78 counting from the hardest. Across the whole country it is harder than 0% of counties.

Softest in Mississippi: Issaquena County at 0.1 gpg. Hardest: Franklin County at 60.5 gpg. Closest to Harrison County: Perry County (0.2), Hancock County (0.4), Itawamba County (0.4).