How hard is the water in Dickson County, TN?
8.9 grains per gallon
A softener is worth it here.
The median hardness measured in Dickson County, TN is 152 mg/L as calcium carbonate, which is 8.9 gpg. That is hard on the USGS scale. It comes from 402 samples at 37 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 7.6 and 9.9 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 8.9 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 3.9 to 12.9 gpg
The softest single sample on record in Dickson County was 66 mg/L and the hardest 220 mg/L, a 3-fold gap. The top quarter of sites read above 9.9 gpg and the bottom quarter below 7.6 gpg.
Wells 5.9 gpg, rivers and lakes 9 gpg
2 groundwater samples from 1 wells put the median at 101 mg/L. 400 surface samples from 36 sites put it at 153.3 mg/L. In Dickson County the rivers and lakes come out 3.1 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 194 lb of salt a year (5 bags of 40 lb, about $35), 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 $135 a year.
Sizing at 8.9 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 534 | 24,000 | 65 lb |
| 2 | 1,068 | 24,000 | 130 lb |
| 4 | 2,136 | 24,000 | 260 lb |
| 6 | 3,204 | 24,000 | 390 lb |
Dickson County against the rest of Tennessee
Among the 95 Tennessee counties with data, Dickson County is number 30 of 95 counting from the hardest. Across the whole country it is harder than 46% of counties.
Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Dickson County: Bradley County (8.8), Loudon County (8.9), Warren County (8.9).