How hard is the water in Henderson County, IL?
18.4 grains per gallon
A softener will pay its way here.
The median hardness measured in Henderson County, IL is 316 mg/L as calcium carbonate, which is 18.4 gpg. That is very hard on the USGS scale. It comes from 108 samples at 10 sites between 1990 and 2002, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 17.8 and 19.1 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 18.4 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 7.8 to 21.0 gpg
The softest single sample on record in Henderson County was 133 mg/L and the hardest 360 mg/L, a 3-fold gap. The top quarter of sites read above 19.1 gpg and the bottom quarter below 17.8 gpg.
Wells 15.2 gpg, rivers and lakes 18.6 gpg
9 groundwater samples from 3 wells put the median at 260 mg/L. 99 surface samples from 7 sites put it at 318 mg/L. In Henderson County the rivers and lakes come out 3.4 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 403 lb of salt a year (11 bags of 40 lb, about $72), 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 $172 a year.
Sizing at 18.4 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,104 | 24,000 | 134 lb |
| 2 | 2,208 | 24,000 | 269 lb |
| 4 | 4,416 | 32,000 | 537 lb |
| 6 | 6,624 | 48,000 | 806 lb |
Henderson County against the rest of Illinois
Among the 102 Illinois counties with data, Henderson County is number 43 of 102 counting from the hardest. Across the whole country it is harder than 80% of counties.
Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Henderson County: Champaign County (18.4), Hamilton County (18.4), De Witt County (18.5).