The treatment processes at the Kimball Surface Water Treatment Plant include chemical coagulation, flocculation and sedimentation in a circular clarifier, chlorination, filtration and storage in a 100,000 gallon clearwell.
Raw water from the reservoir to the clarifier is controlled by a modulating valve. This valve opens or closes to maintain a constant water level and flow through the clarifier. Coagulants are injected into the raw water line just upstream of the clarifier. These chemicals are added to assist with the removal of impurities dissolved in the raw water supply. The water then enters the 20 foot diameter center flocculating well, where it is gently mixed. Water then flows from the center well into the main section of the clarifier where sedimentation occurs. This process consists of separating floc particles from the treated water. The heavy floc particles settle to the bottom of the clarifier by the force of gravity. The treated water at the surface is collected through orifices of seven – 6 inch diameter collector pipes radial spaced in the tank. Each of the collector pipes flows into a single 10 inch diameter effluent pipe to continue the water treatment sequence.
Water from the clarifier is injected with a chlorine solution for disinfection purposes. Chlorine is a strong oxidizer and ensures that no harmful bacteria can exist in the water supply. The water then flows through two parallel banks of trimedia pressure filters. There are four filters in a bank, for a total of eight filters. Each filter is 6 feet in diameter and 6 feet in height. This treatment process is necessary to remove any remaining particulates in the finished water. Finally, filtered water flows into the clearwell for storage prior to distribution.
Three finished water pumps supply water from the clearwell to the distribution system. These pumps are responsible for maintaining the level in the Feige 1 million gallon storage tank and the distribution system pressure.