AWWA JAW61267

Utilities expend significant time, effort, and money to treat water to a high standard. But within the distribution system, that quality water may deteriorate over time if storage tanks are under utilized or have poor mixing characteristics. In this research, computational fluid dynamics (CFD) modeling, water temperature measurements, and chlorine residual measurements were used to determine mixing characteristics within storage tanks, identify tanks with poor mixing (and thus the greatest potential for water quality deterioration), and help modify designs to improve mixing characteristics. Field data demonstrated how modifications improved water mixing in an operating storage tank. Results of this study should boost confidence in the use of CFD modeling and field temperature measurements as efficient methods of assessing and improving water quality within distribution system storage tanks. System managers can use these tools to further their knowledge of how water ages in their own storage systems and ultimately take steps to ensure that the water they supply maintains its high quality from treatment to tap. Includes 11 references, tables, figures.