How hard is the water in Coles County, IL?
17.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Coles County, IL is 302 mg/L as calcium carbonate, which is 17.6 gpg. That is very hard on the USGS scale. It comes from 126 samples at 14 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 14.9 and 19.2 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 17.6 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 10.2 to 22.8 gpg
The softest single sample on record in Coles County was 175 mg/L and the hardest 390 mg/L, a 2-fold gap. The top quarter of sites read above 19.2 gpg and the bottom quarter below 14.9 gpg.
Wells 22.1 gpg, rivers and lakes 16.4 gpg
2 groundwater samples from 2 wells put the median at 379 mg/L. 124 surface samples from 12 sites put it at 281.3 mg/L. In Coles County the wells come out 5.7 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. 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 24,000-grain unit covers a week between regenerations. Expect about 385 lb of salt a year (10 bags of 40 lb, about $69), 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 $169 a year.
Sizing at 17.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,056 | 24,000 | 128 lb |
| 2 | 2,112 | 24,000 | 257 lb |
| 4 | 4,224 | 32,000 | 514 lb |
| 6 | 6,336 | 48,000 | 771 lb |
Coles County against the rest of Illinois
Among the 102 Illinois counties with data, Coles County is number 48 of 102 counting from the hardest. Across the whole country it is harder than 78% of counties.
Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Coles County: DuPage County (17.6), Mason County (17.5), Sangamon County (17.5).