How hard is the water in Dallas County, IA?
23.4 grains per gallon
A softener will pay its way here.
The median hardness measured in Dallas County, IA is 400 mg/L as calcium carbonate, which is 23.4 gpg. That is very hard on the USGS scale. It comes from 51 samples at 20 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 21 and 25.6 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: high (how it is measured).
What to do next
At 23.4 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 16.4 to 59.6 gpg
The softest single sample on record in Dallas County was 280 mg/L and the hardest 1,020 mg/L, a 4-fold gap. The top quarter of sites read above 25.6 gpg and the bottom quarter below 21 gpg.
Wells 23.4 gpg, rivers and lakes 16.4 gpg
51 groundwater samples from 20 wells put the median at 400 mg/L. 111 surface samples from 3 sites put it at 280.5 mg/L. In Dallas County the wells come out 7.0 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 32,000-grain unit covers a week between regenerations. Expect about 510 lb of salt a year (13 bags of 40 lb, about $92), 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 $192 a year.
Sizing at 23.4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,404 | 24,000 | 171 lb |
| 2 | 2,808 | 24,000 | 342 lb |
| 4 | 5,616 | 40,000 | 683 lb |
| 6 | 8,424 | 64,000 | 1,025 lb |
Dallas County against the rest of Iowa
Among the 93 Iowa counties with data, Dallas County is number 24 of 93 counting from the hardest. Across the whole country it is harder than 90% of counties.
Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to Dallas County: Boone County (23.4), Audubon County (23.4), Ida County (23.7).