Development and Application of a Water Quality Management Model of Onondaga Lake, NY

The water quality of Onondaga Lake, a waterbody located in central New York, has been compromised by a 100-year history of municipal and industrial pollution. A water quality model for the Lake was developed to facilitate calculation of a total phosphorus TMDL and to assess the feasibility of diverting WWTP effluent entering the Lake into an adjacent river. The model describes the major water column processes affecting Lake water quality, including nitrification, organic matter decomposition, algal photosynthesis, respiration, and nutrient uptake, and zooplankton and zebra mussel grazing and respiration. The sediment component of the model simulates nutrient and dissolved oxygen fluxes across the sediment-water interface. The Onondaga Lake water quality model was calibrated to ten years of extensive water quality monitoring data. The model reproduces the seasonal water quality and thermal dynamics of the Lake well. Moreover, the model simulates compliance-based measures of important water quality standards and guidance values developed for the Lake.