How hard is the water in Cass County, IL?
22.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Cass County, IL is 380 mg/L as calcium carbonate, which is 22.2 gpg. That is very hard on the USGS scale. It comes from 97 samples at 5 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 22 and 25.1 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: medium (how it is measured).
What to do next
At 22.2 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 21.0 to 32.0 gpg
The softest single sample on record in Cass County was 360 mg/L and the hardest 547 mg/L, a 2-fold gap. The top quarter of sites read above 25.1 gpg and the bottom quarter below 22 gpg.
Wells 25.1 gpg, rivers and lakes 22.1 gpg
3 groundwater samples from 3 wells put the median at 430 mg/L. 94 surface samples from 2 sites put it at 378.3 mg/L. In Cass County the wells come out 3.0 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 485 lb of salt a year (13 bags of 40 lb, about $87), 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 $187 a year.
Sizing at 22.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,332 | 24,000 | 162 lb |
| 2 | 2,664 | 24,000 | 324 lb |
| 4 | 5,328 | 40,000 | 648 lb |
| 6 | 7,992 | 64,000 | 972 lb |
Cass County against the rest of Illinois
Among the 102 Illinois counties with data, Cass County is number 15 of 102 counting from the hardest. Across the whole country it is harder than 88% of counties.
Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Cass County: Livingston County (22.2), Marshall County (22.2), Ogle County (22.3).