How hard is the water in Cheatham County, TN?
8.2 grains per gallon
A softener is worth it here.
The median hardness measured in Cheatham County, TN is 140 mg/L as calcium carbonate, which is 8.2 gpg. That is hard on the USGS scale. It comes from 545 samples at 26 sites between 1990 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 5.9 and 8.7 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: high (how it is measured).
What to do next
At 8.2 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. Because Cheatham County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
From 4.9 to 12.9 gpg
The softest single sample on record in Cheatham County was 84.7 mg/L and the hardest 220 mg/L, a 3-fold gap. The top quarter of sites read above 8.7 gpg and the bottom quarter below 5.9 gpg.
Wells 5 gpg, rivers and lakes 8.2 gpg
1 groundwater samples from 1 wells put the median at 85.2 mg/L. 544 surface samples from 25 sites put it at 140 mg/L. In Cheatham County the rivers and lakes come out 3.2 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 179 lb of salt a year (5 bags of 40 lb, about $32), 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 $132 a year.
Sizing at 8.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 492 | 24,000 | 60 lb |
| 2 | 984 | 24,000 | 120 lb |
| 4 | 1,968 | 24,000 | 239 lb |
| 6 | 2,952 | 24,000 | 359 lb |
Cheatham County against the rest of Tennessee
Among the 95 Tennessee counties with data, Cheatham County is number 39 of 95 counting from the hardest. Across the whole country it is harder than 43% of counties.
Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Cheatham County: Roane County (8), Polk County (8), Monroe County (8.4).