AWWA ACE59921

Water quality modeling is becoming popular with water utilities seeking to better understand the dynamic behavior of their distribution systems. The development of a water quality model often involves intensive data collection efforts, making it difficult for many utilities to undertake. This paper illustrates an application of water quality modeling for small systems. Because of their compact size, water quality modeling can be successfully implemented by small systems with minimal effort, particularly if the modeling goal is a general understanding of water quality dynamics rather than a precise prediction of specific water quality parameters. A water quality model was developed for the Town of Carthage, North Carolina and was used to simulate free chlorine concentrations in summer months, combined chlorine concentrations in winter months, and the movement of constituents throughout the system during a switch in disinfectants. The results of the modeling effort show that tank sizing, pipe material, and residence time all affect the water quality in the distribution system. Includes 3 references, figures.