How hard is the water in Wilson County, TN?
11.9 grains per gallon
A softener will pay its way here.
The median hardness measured in Wilson County, TN is 205 mg/L as calcium carbonate, which is 11.9 gpg. That is very hard on the USGS scale. It comes from 416 samples at 40 sites between 1990 and 2018, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 10.4 and 15.2 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 11.9 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water. Because Wilson 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 19.7 gpg
The softest single sample on record in Wilson County was 84.3 mg/L and the hardest 338 mg/L, a 4-fold gap. The top quarter of sites read above 15.2 gpg and the bottom quarter below 10.4 gpg.
Wells 19 gpg, rivers and lakes 11.9 gpg
1 groundwater samples from 1 wells put the median at 326 mg/L. 415 surface samples from 39 sites put it at 204 mg/L. In Wilson County the wells come out 7.1 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.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 261 lb of salt a year (7 bags of 40 lb, about $47), 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 $147 a year.
Sizing at 11.9 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 714 | 24,000 | 87 lb |
| 2 | 1,428 | 24,000 | 174 lb |
| 4 | 2,856 | 24,000 | 347 lb |
| 6 | 4,284 | 32,000 | 521 lb |
Wilson County against the rest of Tennessee
Among the 95 Tennessee counties with data, Wilson County is number 14 of 95 counting from the hardest. Across the whole country it is harder than 58% of counties.
Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Wilson County: Knox County (12), Rutherford County (11.8), Davidson County (12.2).