Pictured at left is one of two lime slakers in use at the treatment plant. These units convert lime from its rock-like, calcium oxide state, to liquid, calcium hydroxide.  

The lime that is added to the water is stored in a silo in the form of calcium oxide and looks very much like the limestone rock used on a gravel road. 

Lime is dropped into the lime slaker at a predetermined feed rate. water is added and a great deal of mixing occurs. By the time the lime leaves the lime slaker it is in liquid form and looks similar to milk. Just like farmers apply lime to corn or bean fields to increase the soil pH, adding lime to the water increases its pH. Elevating the pH of the water to about 10.4 precipitates the hardness causing ions, calcium and magnesium, out of the water.