How hard is the water in Stewart County, TN?
7.6 grains per gallon
A softener is worth it here.
The median hardness measured in Stewart County, TN is 130 mg/L as calcium carbonate, which is 7.6 gpg. That is hard on the USGS scale. It comes from 199 samples at 13 sites between 1999 and 2023, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 7 and 8.2 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
At 7.6 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below.
More on sizing a softener for your household.
From 5.7 to 9.7 gpg
The softest single sample on record in Stewart County was 97.4 mg/L and the hardest 166.5 mg/L, a 2-fold gap. The top quarter of sites read above 8.2 gpg and the bottom quarter below 7 gpg.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 166 lb of salt a year (5 bags of 40 lb, about $30), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $130 a year.
Sizing at 7.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 456 | 24,000 | 55 lb |
| 2 | 912 | 24,000 | 111 lb |
| 4 | 1,824 | 24,000 | 222 lb |
| 6 | 2,736 | 24,000 | 333 lb |
Stewart County against the rest of Tennessee
Among the 95 Tennessee counties with data, Stewart County is number 42 of 95 counting from the hardest. Across the whole country it is harder than 41% of counties.
Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Stewart County: Campbell County (7.2), Polk County (8), Roane County (8).