HardnessCheck

How hard is the water in Williamson County, IL?

11.7 grains per gallon

The median hardness measured in Williamson County, IL is 200 mg/L as calcium carbonate, which is 11.7 gpg. That is very hard on the USGS scale. It comes from 383 samples at 29 sites between 1990 and 2003, drawn from every sampling site in the county, wells and surface water together.

How much it varies here

Half the sites came in between 8.4 and 21.5 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 11.7 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. Because Williamson 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 2.9 to 54.2 gpg

The softest single sample on record in Williamson County was 49 mg/L and the hardest 927 mg/L, a 19-fold gap. The top quarter of sites read above 21.5 gpg and the bottom quarter below 8.4 gpg. So even here some sites draw water soft enough to need nothing at all.

What a softener would cost to run

For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 255 lb of salt a year (7 bags of 40 lb, about $46), 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 $146 a year.

Sizing at 11.7 gpg

PeopleGrains a dayUnitSalt a year
170224,00085 lb
21,40424,000171 lb
42,80824,000342 lb
64,21232,000512 lb

Williamson County against the rest of Illinois

Among the 102 Illinois counties with data, Williamson County is number 87 of 102 counting from the hardest. Across the whole country it is harder than 57% of counties.

Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Williamson County: Clinton County (11.6), Washington County (11.7), White County (11.9).