AWWA JAW41447

Long detention times and improper mixing in tanks and reservoirs may negatively affect water quality. Mathematical and physical models of mixing and water quality dynamics may be used to determine how alternative designs of operational policies affect the quality of water within and leaving the facility. Three models--a systems model that uses a simplified representation of the reservoir emphasizing the input and output from the facility, a computational fluid dynamics model based on mathematical equations, and physical scale models of the reservoir--were applied to the Ed Heck Reservoir, a 4-million-gallon cylindrical reservoir in Azusa, California. Results of the application of each model are presented graphically along with a discussion of each model's advantages, disadvantages, and costs. Includes 4 references, figures.