How hard is the water in O'Brien County, IA?
26.1 grains per gallon
A softener will pay its way here.
The median hardness measured in O'Brien County, IA is 448 mg/L as calcium carbonate, which is 26.1 gpg. That is very hard on the USGS scale. It comes from 23 samples at 10 sites between 1990 and 2013, 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 24.2 and 27.4 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: medium (how it is measured).
What to do next
At 26.1 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.
More on sizing a softener for your household.
From 1.4 to 70.1 gpg
The softest single sample on record in O'Brien County was 24 mg/L and the hardest 1,200 mg/L, a 50-fold gap. The top quarter of sites read above 27.4 gpg and the bottom quarter below 24.2 gpg. So even here some sites draw water soft enough to need nothing at all.
What a softener would cost to run
For a household of 3, a 40,000-grain unit covers a week between regenerations. Expect about 571 lb of salt a year (15 bags of 40 lb, about $103), 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 $203 a year.
Sizing at 26.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,566 | 24,000 | 191 lb |
| 2 | 3,132 | 24,000 | 381 lb |
| 4 | 6,264 | 48,000 | 762 lb |
| 6 | 9,396 | 80,000 | 1,143 lb |
O'Brien County against the rest of Iowa
Among the 93 Iowa counties with data, O'Brien County is number 15 of 93 counting from the hardest. Across the whole country it is harder than 92% of counties.
Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to O'Brien County: Harrison County (26.3), Kossuth County (25.7), Woodbury County (25.7).