Multigoal Water Quality Planning Model

A nonlinear programming river basin model is presented which can be solved for the least-cost combination of treatment strategies to meet some predetermined quality goals. The model presented is unique in two respects: (1) the interaction of temperature and dissolved oxygen levels is explicitly modeled; and (2) five alternative treatment strategies are examined. Although both the behavior of thermal and oxygen demanding wastes have been modeled in a river, they are always modeled independently even though it is well known that the level of the temperature affects the rates of oxidation reactions and the saturation level of oxygen. In the model presented these relations are explicitly assumed. The treatment strategies examined simultaneously are on-site treatment, regional treatment, by-pass piping, flow augmentation, and cooling towers.