How hard is the water in Blount County, TN?
8.7 grains per gallon
A softener is worth it here.
The median hardness measured in Blount County, TN is 149 mg/L as calcium carbonate, which is 8.7 gpg. That is hard on the USGS scale. It comes from 9 samples at 8 sites between 1990 and 2023, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 3.2 and 9.9 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: medium (how it is measured).
What to do next
At 8.7 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 Blount 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 0.5 to 11.4 gpg
The softest single sample on record in Blount County was 8.3 mg/L and the hardest 196 mg/L, a 24-fold gap. The top quarter of sites read above 9.9 gpg and the bottom quarter below 3.2 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 8.7 gpg, rivers and lakes 3.8 gpg
9 groundwater samples from 8 wells put the median at 148.5 mg/L. 842 surface samples from 64 sites put it at 64.3 mg/L. In Blount County the wells come out 4.9 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 189 lb of salt a year (5 bags of 40 lb, about $34), 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 $134 a year.
Sizing at 8.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 522 | 24,000 | 64 lb |
| 2 | 1,044 | 24,000 | 127 lb |
| 4 | 2,088 | 24,000 | 254 lb |
| 6 | 3,132 | 24,000 | 381 lb |
Blount County against the rest of Tennessee
Among the 95 Tennessee counties with data, Blount County is number 34 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 Blount County: Cannon County (8.7), Montgomery County (8.6), Overton County (8.6).