How hard is the water in Louisa County, IA?
13.7 grains per gallon
A softener will pay its way here.
The median hardness measured in Louisa County, IA is 235 mg/L as calcium carbonate, which is 13.7 gpg. That is very hard on the USGS scale. It comes from 61 samples at 24 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 and 16.3 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: high (how it is measured).
What to do next
At 13.7 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 Louisa 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 4.8 to 68.3 gpg
The softest single sample on record in Louisa County was 83 mg/L and the hardest 1,170 mg/L, a 14-fold gap. The top quarter of sites read above 16.3 gpg and the bottom quarter below 10 gpg.
Wells 13.7 gpg, rivers and lakes 13.5 gpg
61 groundwater samples from 24 wells put the median at 235 mg/L. 350 surface samples from 5 sites put it at 231.5 mg/L. In Louisa County the wells come out 0.2 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 300 lb of salt a year (8 bags of 40 lb, about $54), 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 $154 a year.
Sizing at 13.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 822 | 24,000 | 100 lb |
| 2 | 1,644 | 24,000 | 200 lb |
| 4 | 3,288 | 24,000 | 400 lb |
| 6 | 4,932 | 40,000 | 600 lb |
Louisa County against the rest of Iowa
Among the 93 Iowa counties with data, Louisa County is number 85 of 93 counting from the hardest. Across the whole country it is harder than 65% of counties.
Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to Louisa County: Chickasaw County (13.7), Page County (13.4), Butler County (14).