How hard is the water in Ste. Genevieve County, MO?
9.6 grains per gallon
A softener is worth it here.
The median hardness measured in Ste. Genevieve County, MO is 164 mg/L as calcium carbonate, which is 9.6 gpg. That is hard on the USGS scale. It comes from 135 samples at 15 sites between 1992 and 2025, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 1.2 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: high (how it is measured).
What to do next
At 9.6 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 Ste. Genevieve 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 0.8 to 15.1 gpg
The softest single sample on record in Ste. Genevieve County was 14 mg/L and the hardest 258 mg/L, an 18-fold gap. The top quarter of sites read above 12.4 gpg and the bottom quarter below 1.2 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 15.1 gpg, rivers and lakes 8.1 gpg
1 groundwater samples from 1 wells put the median at 258 mg/L. 134 surface samples from 14 sites put it at 138.5 mg/L. In Ste. Genevieve County the wells come out 7.0 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 209 lb of salt a year (6 bags of 40 lb, about $38), 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 $138 a year.
Sizing at 9.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 576 | 24,000 | 70 lb |
| 2 | 1,152 | 24,000 | 140 lb |
| 4 | 2,304 | 24,000 | 280 lb |
| 6 | 3,456 | 32,000 | 420 lb |
Ste. Genevieve County against the rest of Missouri
Among the 110 Missouri counties with data, Ste. Genevieve County is number 93 of 110 counting from the hardest. Across the whole country it is harder than 49% of counties.
Softest in Missouri: Livingston County at 4.1 gpg. Hardest: Reynolds County at 96.7 gpg. Closest to Ste. Genevieve County: Newton County (9.4), Stone County (9.5), Bollinger County (9.7).