MODELS FOR WATER REUSE PLANNING.

Mathematical Models to assess various conjunctive water and wastewater system alternatives are developed. The models include important planning aspects such as the economies of scale in treatment and transportation costs, the water quality and quantity requirements for each user individually, the characteristics for each freshwater source (surface or underground) individually, the interactions among users, sources and treatment plants which allow for direct and indirect reuse alternatives. The objective of the research was to develop and solve the mathematical planning models. Application of the models is illustrated by a series of hypothetical examples that were solved using the Large Scale Generalized Reduced code. A real world application is also presented using the San Antonio region as the study area.