How hard is the water in Clinton County, IA?
14.5 grains per gallon
A softener will pay its way here.
The median hardness measured in Clinton County, IA is 249 mg/L as calcium carbonate, which is 14.5 gpg. That is very hard on the USGS scale. It comes from 39 samples at 13 sites between 1990 and 2023, 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 12.6 and 17.5 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 14.5 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 10.5 to 23.4 gpg
The softest single sample on record in Clinton County was 180 mg/L and the hardest 400 mg/L, a 2-fold gap. The top quarter of sites read above 17.5 gpg and the bottom quarter below 12.6 gpg.
Wells 14.5 gpg, rivers and lakes 10.8 gpg
39 groundwater samples from 13 wells put the median at 249 mg/L. 401 surface samples from 2 sites put it at 184.3 mg/L. In Clinton County the wells come out 3.7 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 24,000-grain unit covers a week between regenerations. Expect about 318 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 14.5 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 870 | 24,000 | 106 lb |
| 2 | 1,740 | 24,000 | 212 lb |
| 4 | 3,480 | 32,000 | 423 lb |
| 6 | 5,220 | 40,000 | 635 lb |
Clinton County against the rest of Iowa
Among the 93 Iowa counties with data, Clinton County is number 81 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 Clinton County: Madison County (14.6), Warren County (14.6), Lee County (14.1).