How hard is the water in Cole County, MO?
13.1 grains per gallon
A softener will pay its way here.
The median hardness measured in Cole County, MO is 224 mg/L as calcium carbonate, which is 13.1 gpg. That is very hard on the USGS scale. It comes from 116 samples at 5 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 7.7 and 20.3 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 13.1 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 Cole 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 7.3 to 23.1 gpg
The softest single sample on record in Cole County was 125 mg/L and the hardest 395 mg/L, a 3-fold gap. The top quarter of sites read above 20.3 gpg and the bottom quarter below 7.7 gpg.
Wells 21.7 gpg, rivers and lakes 7.7 gpg
2 groundwater samples from 2 wells put the median at 371 mg/L. 114 surface samples from 3 sites put it at 131 mg/L. In Cole County the wells come out 14.0 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 285 lb of salt a year (8 bags of 40 lb, about $51), 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 $151 a year.
Sizing at 13.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 786 | 24,000 | 96 lb |
| 2 | 1,572 | 24,000 | 191 lb |
| 4 | 3,144 | 24,000 | 383 lb |
| 6 | 4,716 | 40,000 | 574 lb |
Cole County against the rest of Missouri
Among the 110 Missouri counties with data, Cole County is number 33 of 110 counting from the hardest. Across the whole country it is harder than 62% of counties.
Softest in Missouri: Livingston County at 4.1 gpg. Hardest: Reynolds County at 96.7 gpg. Closest to Cole County: Washington County (13), Texas County (13), Osage County (13.2).