How hard is the water in Pettis County, MO?
11.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Pettis County, MO is 192 mg/L as calcium carbonate, which is 11.2 gpg. That is very hard on the USGS scale. It comes from 100 samples at 14 sites between 2000 and 2017, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 9.1 and 13.4 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 11.2 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 Pettis 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 6.4 to 16.8 gpg
The softest single sample on record in Pettis County was 110 mg/L and the hardest 288 mg/L, a 3-fold gap. The top quarter of sites read above 13.4 gpg and the bottom quarter below 9.1 gpg.
Wells 16.8 gpg, rivers and lakes 11.1 gpg
1 groundwater samples from 1 wells put the median at 288 mg/L. 99 surface samples from 13 sites put it at 190.5 mg/L. In Pettis County the wells come out 5.7 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 245 lb of salt a year (7 bags of 40 lb, about $44), 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 $144 a year.
Sizing at 11.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 672 | 24,000 | 82 lb |
| 2 | 1,344 | 24,000 | 164 lb |
| 4 | 2,688 | 24,000 | 327 lb |
| 6 | 4,032 | 32,000 | 491 lb |
Pettis County against the rest of Missouri
Among the 110 Missouri counties with data, Pettis County is number 69 of 110 counting from the hardest. Across the whole country it is harder than 55% of counties.
Softest in Missouri: Livingston County at 4.1 gpg. Hardest: Reynolds County at 96.7 gpg. Closest to Pettis County: Cedar County (11.2), Dent County (11.1), New Madrid County (11).