How hard is the water in Henderson County, TN?
0.9 grains per gallon
You do not need a softener here.
The median hardness measured in Henderson County, TN is 16 mg/L as calcium carbonate, which is 0.9 gpg. That is soft on the USGS scale. It comes from 228 samples at 31 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 0.6 and 1.1 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 0.9 gpg the most a softener would fix is the odd water spot. If a salesperson in Henderson 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 0.2 to 25.7 gpg
The softest single sample on record in Henderson County was 4 mg/L and the hardest 440 mg/L, a 110-fold gap. The top quarter of sites read above 1.1 gpg and the bottom quarter below 0.6 gpg. So even in a soft county, a handful of wells here produce water hard enough to scale a heater.
Wells 9.9 gpg, rivers and lakes 0.9 gpg
1 groundwater samples from 1 wells put the median at 169 mg/L. 227 surface samples from 30 sites put it at 15.5 mg/L. In Henderson County the wells come out 9.0 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.
Henderson County against the rest of Tennessee
Among the 95 Tennessee counties with data, Henderson County is number 93 of 95 counting from the hardest. Across the whole country it is harder than 6% of counties.
Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Henderson County: Weakley County (1), Carroll County (1.1), Gibson County (1.1).