How hard is the water in Iroquois County, IL?
14.4 grains per gallon
A softener will pay its way here.
The median hardness measured in Iroquois County, IL is 247 mg/L as calcium carbonate, which is 14.4 gpg. That is very hard on the USGS scale. It comes from 14 samples at 6 sites between 1990 and 2021, 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 13.9 and 19 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 14.4 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 5.9 to 36.2 gpg
The softest single sample on record in Iroquois County was 101.6 mg/L and the hardest 620 mg/L, a 6-fold gap. The top quarter of sites read above 19 gpg and the bottom quarter below 13.9 gpg.
Wells 14.4 gpg, rivers and lakes 19.4 gpg
14 groundwater samples from 6 wells put the median at 246.8 mg/L. 263 surface samples from 30 sites put it at 332 mg/L. In Iroquois County the rivers and lakes come out 5.0 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 315 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 14.4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 864 | 24,000 | 105 lb |
| 2 | 1,728 | 24,000 | 210 lb |
| 4 | 3,456 | 32,000 | 420 lb |
| 6 | 5,184 | 40,000 | 631 lb |
Iroquois County against the rest of Illinois
Among the 102 Illinois counties with data, Iroquois County is number 70 of 102 counting from the hardest. Across the whole country it is harder than 68% of counties.
Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Iroquois County: Adams County (14.3), Lawrence County (14.3), Jersey County (13.9).