How hard is the water in Shelby County, IL?
13.7 grains per gallon
A softener will pay its way here.
The median hardness measured in Shelby County, IL is 235 mg/L as calcium carbonate, which is 13.7 gpg. That is very hard on the USGS scale. It comes from 251 samples at 15 sites between 1990 and 2013, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 12.9 and 16.1 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 13.7 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 10.0 to 17.5 gpg
The softest single sample on record in Shelby County was 172 mg/L and the hardest 300 mg/L, a 2-fold gap. The top quarter of sites read above 16.1 gpg and the bottom quarter below 12.9 gpg.
Wells 15.4 gpg, rivers and lakes 13.7 gpg
2 groundwater samples from 2 wells put the median at 264 mg/L. 249 surface samples from 13 sites put it at 234.5 mg/L. In Shelby County the wells come out 1.7 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 299 lb of salt a year (8 bags of 40 lb, about $54), 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 $154 a year.
Sizing at 13.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 822 | 24,000 | 100 lb |
| 2 | 1,644 | 24,000 | 200 lb |
| 4 | 3,288 | 24,000 | 400 lb |
| 6 | 4,932 | 40,000 | 600 lb |
Shelby County against the rest of Illinois
Among the 102 Illinois counties with data, Shelby County is number 76 of 102 counting from the hardest. Across the whole country it is harder than 65% of counties.
Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Shelby County: Macoupin County (13.6), Effingham County (13.8), Monroe County (13.8).