Optimizing Locations for Chlorine Booster Stations in Small Water Distribution Networks

Abstract

In this paper, an index-based approach is proposed to locate chlorine booster stations in a water distribution network (DN). Chlorination is a common practice for secondary disinfection, essential for protection against microbiological regrowth and contaminant intrusion. However, higher levels of free residual chlorine (FRC) may lead to unwanted disinfectant by-products (DBPs) and taste and odor complaints. Booster chlorination can be used to maintain minimum levels of FRC. This requires proper selection of booster locations. The approach proposed here uses a generic hydraulic and water quality modeling software programmers’ toolkit to predict FRC and total trihalomethanes (TTHMs) converted, thereafter, into a water quality index (WQI). A heuristic algorithm maximum covering location problem (MCLP) used in optimization maximizes WQI. TTHM is converted into trihalomethane (THM) species using quadratic optimization, then to cancer and noncancer risk potentials. Finally, the required number of booster stations is recommended based on a trade-off analysis of risk potentials, WQI, and the life cycle cost of booster chlorination. For proof of concept, case studies are conducted in a hypothetical and a municipal DN.