How Hard Is the Water in Peoria?

The published numbers

Most homes in Peoria get their water from Illinois American Water. Its Peoria water quality summary lists total hardness of 300 to 600 mg/L as calcium carbonate, which it also states as 19 to 37 grains per gallon. The Pekin system, run by the same utility, lists 470 mg/L, or 28 grains per gallon.

Morton is different. The village treats its own water, and its drinking water FAQ says it softens roughly two thirds of the treated water, with finished hardness of 7 to 8 grains (120 to 137 mg/L). That is softer than Peoria, but it still lands in the hard range on the USGS scale below.

These are utility figures for city water. A private well is its own water source and needs its own test.

How the hardness scale works

Hardness is mostly dissolved calcium and magnesium, measured as calcium carbonate. You will see it written two ways: milligrams per liter (mg/L, the same as parts per million) or grains per gallon (gpg). The Water Quality Association treats 1 grain per gallon as 17.1 mg/L.

The USGS uses four bands:

Where Peoria's hardness comes from

Illinois American Water's Peoria report says the system draws from four sources: the Illinois River and three well sites that pull groundwater from the San Koty Aquifer.

The USGS Ground Water Atlas explains the pattern for this part of the Midwest. It describes water in the region's glacial sand and gravel aquifers as typically hard, with median hardness that generally exceeds 300 mg/L, and notes that slightly acidic groundwater partially dissolves limestone, which adds calcium and magnesium. In plain terms, the ground under Central Illinois loads the water with minerals before it ever reaches a pipe.

What hard water does inside a house

According to the USGS, when hard water is heated, calcium carbonate can form solid deposits. That scale can shorten the life of equipment, raise the cost of heating water, lower the efficiency of electric water heaters and clog pipes. Hard water also means more soap or detergent is needed to get things clean.

It is a nuisance, not a health problem. Illinois American Water says calcium and magnesium pose no health problems, which is why the utility does not remove them. Softening is a choice people make for their fixtures, appliances and laundry.

What this means for your softener

A softener pulls hardness out of the water and then cleans itself with brine made from the salt in your tank. Morton Salt says salt use depends on how hard your water is and how much you use, so water this hard asks more of a softener than water in the moderately hard range. For the numbers, see how much salt a water softener uses.

The part that trips people up is not the chemistry, it is the routine: remembering to check the tank and hauling 40 lb bags to it. That is the job Simply Salt takes over with softener salt delivery in Peoria and the towns around it. A sensor in your brine tank reports the level, and we refill it before you run out. See how it works.