How hard is the water in Shannon County, MO?
11.9 grains per gallon
A softener will pay its way here.
The median hardness measured in Shannon County, MO is 204 mg/L as calcium carbonate, which is 11.9 gpg. That is very hard on the USGS scale. It comes from 27 samples at 21 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 10.3 and 13.7 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: medium (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 Shannon 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 7.0 to 17.9 gpg
The softest single sample on record in Shannon County was 119 mg/L and the hardest 307 mg/L, a 3-fold gap. The top quarter of sites read above 13.7 gpg and the bottom quarter below 10.3 gpg.
Wells 11.9 gpg, rivers and lakes 9.1 gpg
27 groundwater samples from 21 wells put the median at 204 mg/L. 205 surface samples from 14 sites put it at 155.5 mg/L. In Shannon County the wells come out 2.8 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 260 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 |
Shannon County against the rest of Missouri
Among the 110 Missouri counties with data, Shannon County is number 53 of 110 counting from the hardest. Across the whole country it is harder than 58% of counties.
Softest in Missouri: Livingston County at 4.1 gpg. Hardest: Reynolds County at 96.7 gpg. Closest to Shannon County: Douglas County (11.9), Saline County (11.9), Butler County (12).