How hard is the water in Jefferson County, IL?
10.9 grains per gallon
A softener will pay its way here.
The median hardness measured in Jefferson County, IL is 187 mg/L as calcium carbonate, which is 10.9 gpg. That is very hard on the USGS scale. It comes from 258 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 10.3 and 12.8 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: high (how it is measured).
What to do next
At 10.9 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. Because Jefferson County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
From 5.3 to 16.4 gpg
The softest single sample on record in Jefferson County was 90 mg/L and the hardest 280 mg/L, a 3-fold gap. The top quarter of sites read above 12.8 gpg and the bottom quarter below 10.3 gpg.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 238 lb of salt a year (6 bags of 40 lb, about $43), 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 $143 a year.
Sizing at 10.9 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 654 | 24,000 | 80 lb |
| 2 | 1,308 | 24,000 | 159 lb |
| 4 | 2,616 | 24,000 | 318 lb |
| 6 | 3,924 | 32,000 | 477 lb |
Jefferson County against the rest of Illinois
Among the 102 Illinois counties with data, Jefferson County is number 91 of 102 counting from the hardest. Across the whole country it is harder than 54% of counties.
Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Jefferson County: Clay County (10.9), Montgomery County (11), Jackson County (10.5).