How hard is the water in Hardin County, TN?

1.8 grains per gallon

You do not need a softener here.

The median hardness measured in Hardin County, TN is 31 mg/L as calcium carbonate, which is 1.8 gpg. That is soft on the USGS scale. It comes from 232 samples at 47 sites between 1990 and 2019, drawn from every sampling site in the county, wells and surface water together.

How much it varies here

Half the sites came in between 0.9 and 3.2 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 1.8 gpg the most a softener would fix is the odd water spot. If a salesperson in Hardin 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 23.4 gpg

The softest single sample on record in Hardin County was 5.8 mg/L and the hardest 400 mg/L, a 69-fold gap. The top quarter of sites read above 3.2 gpg and the bottom quarter below 0.9 gpg. So even in a soft county, a handful of wells here produce water hard enough to scale a heater.

Wells 5.9 gpg, rivers and lakes 1.8 gpg

2 groundwater samples from 2 wells put the median at 101.4 mg/L. 230 surface samples from 45 sites put it at 30 mg/L. In Hardin County the wells come out 4.1 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.

Hardin County against the rest of Tennessee

Among the 95 Tennessee counties with data, Hardin County is number 84 of 95 counting from the hardest. Across the whole country it is harder than 15% of counties.

Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Hardin County: Henry County (1.8), Cocke County (1.8), Cumberland County (1.9).