How hard is the water in Lewis County, TN?

1.9 grains per gallon

You do not need a softener here.

The median hardness measured in Lewis County, TN is 33 mg/L as calcium carbonate, which is 1.9 gpg. That is soft on the USGS scale. It comes from 91 samples at 14 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 1.6 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 1.9 gpg the most a softener would fix is the odd water spot. If a salesperson in Lewis 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 0.5 to 8.8 gpg

The softest single sample on record in Lewis County was 8.5 mg/L and the hardest 150 mg/L, an 18-fold gap. The top quarter of sites read above 3.2 gpg and the bottom quarter below 1.6 gpg.

Wells 0.5 gpg, rivers and lakes 2 gpg

2 groundwater samples from 1 wells put the median at 8.5 mg/L. 89 surface samples from 13 sites put it at 34 mg/L. In Lewis County the rivers and lakes come out 1.5 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.

Lewis County against the rest of Tennessee

Among the 95 Tennessee counties with data, Lewis County is number 81 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 Lewis County: Cumberland County (1.9), Hardin County (1.8), Henry County (1.8).