HardnessCheck

How hard is the water in Monroe County, IL?

13.8 grains per gallon

The median hardness measured in Monroe County, IL is 237 mg/L as calcium carbonate, which is 13.8 gpg. That is very hard on the USGS scale. It comes from 24 samples at 7 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 12.9 and 18.1 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 13.8 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 12.4 to 22.2 gpg

The softest single sample on record in Monroe County was 212 mg/L and the hardest 380 mg/L, a 2-fold gap. The top quarter of sites read above 18.1 gpg and the bottom quarter below 12.9 gpg.

Wells 21.3 gpg, rivers and lakes 13.1 gpg

9 groundwater samples from 2 wells put the median at 365 mg/L. 15 surface samples from 5 sites put it at 225 mg/L. In Monroe County the wells come out 8.2 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 302 lb of salt a year (8 bags of 40 lb, about $54), 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 $154 a year.

Sizing at 13.8 gpg

PeopleGrains a dayUnitSalt a year
182824,000101 lb
21,65624,000201 lb
43,31224,000403 lb
64,96840,000604 lb

Monroe County against the rest of Illinois

Among the 102 Illinois counties with data, Monroe County is number 74 of 102 counting from the hardest. Across the whole country it is harder than 65% of counties.

Softest in Illinois: Pope County at 4.3 gpg. Hardest: Cook County at 34.8 gpg. Closest to Monroe County: Effingham County (13.8), Jersey County (13.9), Shelby County (13.7).