ABSTRACT
This chapter discusses the process undertaken to set up, calibrate and apply a water quality model to support the combined sewer overflows facility planning process. The calibrated water quality model was used in continuous simulations to evaluate the sensitivity of water quality in Mill Creek to various control alternatives being considered and for the evaluation of the overall facility plan. Land use within the drainage basin is primarily urban, most of it zoned for single and multiple family dwellings. Commercial and industrial areas are generally adjacent to main streets, with open space limited to small parks, one large park on the south side of the Creek, cemeteries, a golf course and a race track. Fecal coliform modeling involves the use of a first-order decay expression to describe bacterial die-off. The coliform levels are a function of initial loading and the disappearance rate. The decay rate in the context of the Mill Creek was not a sensitive parameter during wet weather.
