Integrated Multiobjective Optimization and Simulation Model Applied to Drinking Water Treatment Placement in the Context of Existing Infrastructure

摘要

Drinking water systems provide consistent and safe supplies of water across urban areas through the use of treatment and distribution infrastructure. Design of drinking water infrastructure requires incorporation of multiple conflicting stakeholder goals, such as cost and water quality. This work expands on a previously developed integrated modeling framework that uses simulation and optimization models for long-term planning of treatment infrastructure in the context of existing distribution systems. The optimization model component is a multi-objective formulation. The expanded model framework is demonstrated on the USEPA Net3 treatment network. The multiobjective optimization includes three objectives-minimizing cost, maximizing systemwide chlorine residual, and minimizing the demand-weighted water age (a proxy for water quality)-to identify the optimal location and capacity of treatment plants. Results show the trade-offs between each pair of objectives. Of a maximum of five possible treatment locations, three treatment plants were optimal for the water quality objectives, whereas one treatment plant was optimal for the cost objective. The capacity allocation and sites selected for treatment differed between the two water quality objectives.