Optimal Monitoring Sites Based on Water Quality and Quantity in Water Distribution Systems

The optimal monitoring sites of water quality should reflect both the water quantity and quality, and be representatives of the water distribution system. In the previous research, only the water quantity was considered as a factor of monitoring importance. Even if the water quality as well as the water quantity was considered, the retention times in the system was used to estimate the water quality at the network nodes. However the retention times cannot well represent the water quality because of their nonlinear relationship. In this paper, we present a new method of determining the optimal monitoring sites, in which the water quality is incorporated into the optimization model with a different method for water distribution system from the previous researches. In the method, the water quality at the nodes is determined by using a simulation model EPANET rather than retention times. The method of minimal path enumeration with list processing is applied to constructing the coverage matrix and determining all the flow paths. With the coverage matrix, an integer programming problem is formulated and solved. The cases of steady-state simulation is analyzed by the newly developed method. For the extended period simulation, minimal set of covering algorithm is used to locate the optimal monitoring sites. Our method provides more reasonable monitoring sites than those of the previous methods for two sample distribution networks.