How hard is the water in Madison County, IA?
14.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Madison County, IA is 250 mg/L as calcium carbonate, which is 14.6 gpg. That is very hard on the USGS scale. It comes from 3 samples at 3 sites between 1991 and 2004, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 12 and 15.6 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: low (how it is measured).
What to do next
At 14.6 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.
Wells 12 gpg, rivers and lakes 16.5 gpg
2 groundwater samples from 2 wells put the median at 205 mg/L. 1 surface samples from 1 sites put it at 283 mg/L. In Madison County the rivers and lakes come out 4.5 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 319 lb of salt a year (8 bags of 40 lb, about $57), 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 $157 a year.
Sizing at 14.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 876 | 24,000 | 107 lb |
| 2 | 1,752 | 24,000 | 213 lb |
| 4 | 3,504 | 32,000 | 426 lb |
| 6 | 5,256 | 40,000 | 639 lb |
Madison County against the rest of Iowa
Among the 93 Iowa counties with data, Madison County is number 80 of 93 counting from the hardest. Across the whole country it is harder than 68% of counties.
Softest in Iowa: Taylor County at 8.2 gpg. Hardest: Pocahontas County at 45.3 gpg. Closest to Madison County: Warren County (14.6), Clinton County (14.5), Lee County (14.1).