Optimal Design of Regional Wastewater Systems: A Fixed-Charge Network Flow Model

A regional wastewater quality management system was modeled as a fixed-charge network flow problem. The model included alternative trunk-line connections, methods of treatment, and variation in system boundaries. The paper describes the model, development of the input data, the network flow analysis method, simplifications, and results. Particular emphasis is put on modification and simplification of the basic fixed-charge model to produce a fixed-charge network flow model of tractable size.