Overview of the Water Purification Process

The purification process begins at the intake tower, where water flows into one of the tower's four gates, passes through a six-foot tunnel, and enters the pump room in the Lakeside Power Station. There, revolving screens remove fish, leaves and other large debris. It is also at this point that powdered activated carbon is added to remove unpleasant tastes and odors, as well as residual agricultural pesticides.

The water is then pumped to the Purification Plant, where it passes through a chemical dosing chamber to receive lime, which softens the water, and ferrous sulfate (iron) and polymer, both of which coagulate the suspended particles in the water. From the dosing chamber, the water passes to one of five upflow clarifiers.

In the clarifiers, 90% of the suspended particles are removed from the water, which is then sent to the filter gallery for the final step in the purification process. On its way to the filter gallery, the clarified water receives a dose of chlorine to kill bacteria and fluoride to prevent tooth decay.

From the filter gallery, the clean water is sent to two underground clearwells for temporary storage prior to distribution. At this point, the purification process is complete. It has taken less than two hours to convert raw lake water into a safe, clean product that consistently meets state water quality standards .