How hard is the water in Sioux County, IA?
31 grains per gallon
A softener will pay its way here.
The median hardness measured in Sioux County, IA is 530 mg/L as calcium carbonate, which is 31 gpg. That is very hard on the USGS scale. It comes from 29 samples at 13 sites between 1990 and 2014, 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 26.3 and 33.6 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 31 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 19.3 to 111.0 gpg
The softest single sample on record in Sioux County was 330 mg/L and the hardest 1,900 mg/L, a 6-fold gap. The top quarter of sites read above 33.6 gpg and the bottom quarter below 26.3 gpg.
Wells 31 gpg, rivers and lakes 27.7 gpg
29 groundwater samples from 13 wells put the median at 530 mg/L. 127 surface samples from 1 sites put it at 475 mg/L. In Sioux County the wells come out 3.3 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 40,000-grain unit covers a week between regenerations. Expect about 676 lb of salt a year (17 bags of 40 lb, about $122), 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 $222 a year.
Sizing at 31 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,860 | 24,000 | 226 lb |
| 2 | 3,720 | 32,000 | 453 lb |
| 4 | 7,440 | 64,000 | 905 lb |
| 6 | 11,160 | 80,000 | 1,358 lb |
Sioux County against the rest of Iowa
Among the 93 Iowa counties with data, Sioux County is number 9 of 93 counting from the hardest. Across the whole country it is harder than 95% of counties.
Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to Sioux County: Lyon County (31.2), Plymouth County (31.5), Emmet County (31.8).