How hard is the water in Mills County, IA?
21.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Mills County, IA is 370 mg/L as calcium carbonate, which is 21.6 gpg. That is very hard on the USGS scale. It comes from 32 samples at 11 sites between 1990 and 2006, 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 19.9 and 26.3 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: high (how it is measured).
What to do next
At 21.6 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.
More on sizing a softener for your household.
From 16.9 to 106.0 gpg
The softest single sample on record in Mills County was 290 mg/L and the hardest 1,815 mg/L, a 6-fold gap. The top quarter of sites read above 26.3 gpg and the bottom quarter below 19.9 gpg.
What a softener would cost to run
For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 472 lb of salt a year (12 bags of 40 lb, about $85), 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 $185 a year.
Sizing at 21.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,296 | 24,000 | 158 lb |
| 2 | 2,592 | 24,000 | 315 lb |
| 4 | 5,184 | 40,000 | 631 lb |
| 6 | 7,776 | 64,000 | 946 lb |
Mills County against the rest of Iowa
Among the 93 Iowa counties with data, Mills County is number 35 of 93 counting from the hardest. Across the whole country it is harder than 87% of counties.
Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to Mills County: Polk County (21.6), Story County (21.6), Marshall County (21.2).