How hard is the water in Benton County, TN?
1.5 grains per gallon
You do not need a softener here.
The median hardness measured in Benton County, TN is 26 mg/L as calcium carbonate, which is 1.5 gpg. That is soft on the USGS scale. It comes from 167 samples at 23 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 1.1 and 3.4 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 1.5 gpg the most a softener would fix is the odd water spot. If a salesperson in Benton 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 11.8 gpg
The softest single sample on record in Benton County was 5.6 mg/L and the hardest 202.5 mg/L, a 36-fold gap. The top quarter of sites read above 3.4 gpg and the bottom quarter below 1.1 gpg. So even in a soft county, a handful of wells here produce water hard enough to scale a heater.
Wells 1.3 gpg, rivers and lakes 1.8 gpg
1 groundwater samples from 1 wells put the median at 22.8 mg/L. 166 surface samples from 22 sites put it at 31.5 mg/L. In Benton County the rivers and lakes come out 0.5 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.
Benton County against the rest of Tennessee
Among the 95 Tennessee counties with data, Benton County is number 86 of 95 counting from the hardest. Across the whole country it is harder than 12% of counties.
Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Benton County: McNairy County (1.3), Cocke County (1.8), Morgan County (1.2).