How hard is the water in Hamblen County, TN?
14.7 grains per gallon
A softener will pay its way here.
The median hardness measured in Hamblen County, TN is 251 mg/L as calcium carbonate, which is 14.7 gpg. That is very hard on the USGS scale. It comes from 22 samples at 11 sites between 1997 and 2016, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 13.8 and 15.7 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: medium (how it is measured).
What to do next
At 14.7 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.
More on sizing a softener for your household.
From 12.4 to 26.2 gpg
The softest single sample on record in Hamblen County was 212 mg/L and the hardest 448 mg/L, a 2-fold gap. The top quarter of sites read above 15.7 gpg and the bottom quarter below 13.8 gpg.
Wells 16.3 gpg, rivers and lakes 14.7 gpg
4 groundwater samples from 4 wells put the median at 279 mg/L. 18 surface samples from 7 sites put it at 251 mg/L. In Hamblen County the wells come out 1.6 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 320 lb of salt a year (9 bags of 40 lb, about $58), 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 $158 a year.
Sizing at 14.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 882 | 24,000 | 107 lb |
| 2 | 1,764 | 24,000 | 215 lb |
| 4 | 3,528 | 32,000 | 429 lb |
| 6 | 5,292 | 40,000 | 644 lb |
Hamblen County against the rest of Tennessee
Among the 95 Tennessee counties with data, Hamblen County is number 7 of 95 counting from the hardest. Across the whole country it is harder than 68% of counties.
Softest in Tennessee: Fayette County at 0.5 gpg. Hardest: Fentress County at 42.9 gpg. Closest to Hamblen County: Sullivan County (14.5), Washington County (14.5), Greene County (14.3).