How hard is the water in Marion County, IL?
9.9 grains per gallon
A softener is worth it here.
The median hardness measured in Marion County, IL is 170 mg/L as calcium carbonate, which is 9.9 gpg. That is hard on the USGS scale. It comes from 399 samples at 18 sites between 1990 and 2004, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 7.3 and 11.6 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 9.9 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below. Because Marion 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 5.4 to 13.9 gpg
The softest single sample on record in Marion County was 92.5 mg/L and the hardest 238 mg/L, a 3-fold gap. The top quarter of sites read above 11.6 gpg and the bottom quarter below 7.3 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 217 lb of salt a year (6 bags of 40 lb, about $39), 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 $139 a year.
Sizing at 9.9 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 594 | 24,000 | 72 lb |
| 2 | 1,188 | 24,000 | 145 lb |
| 4 | 2,376 | 24,000 | 289 lb |
| 6 | 3,564 | 32,000 | 434 lb |
Marion County against the rest of Illinois
Among the 102 Illinois counties with data, Marion County is number 95 of 102 counting from the hardest. Across the whole country it is harder than 51% of counties.
Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Marion County: Wayne County (10.1), Franklin County (9.4), Jackson County (10.5).