How hard is the water in Lewis County, MO?
11.7 grains per gallon
A softener will pay its way here.
The median hardness measured in Lewis County, MO is 201 mg/L as calcium carbonate, which is 11.7 gpg. That is very hard on the USGS scale. It comes from 103 samples at 8 sites between 1999 and 2026, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 7.5 and 12.4 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 11.7 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. Because Lewis 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 14.0 gpg
The softest single sample on record in Lewis County was 120 mg/L and the hardest 240 mg/L, a 2-fold gap. The top quarter of sites read above 12.4 gpg and the bottom quarter below 7.5 gpg.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 256 lb of salt a year (7 bags of 40 lb, about $46), 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 $146 a year.
Sizing at 11.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 702 | 24,000 | 85 lb |
| 2 | 1,404 | 24,000 | 171 lb |
| 4 | 2,808 | 24,000 | 342 lb |
| 6 | 4,212 | 32,000 | 512 lb |
Lewis County against the rest of Missouri
Among the 110 Missouri counties with data, Lewis County is number 58 of 110 counting from the hardest. Across the whole country it is harder than 57% of counties.
Softest in Missouri: Livingston County at 4.1 gpg. Hardest: Reynolds County at 96.7 gpg. Closest to Lewis County: Dade County (11.7), Johnson County (11.7), Adair County (11.8).