Locating satellite booster disinfectant stations

Booster disinfectant is introduced within a distribution system to maintain disinfectant residuals and avoid high dosages near water sources. Assuming that first order reaction kinetics apply to chlorine decay, an integer linear programming optimization problem is posed to determine booster locations and their injection rates. The formulation avoids long water quality simulations by adding constraints requiring the concentrations at the beginning and end of the design period to be the same. The optimization problem is divided into two levels. The upper level selects the booster locations using a genetic algorithm, if more than a few boosters are included, or enumeration, if the number of boosters and/or potential locations is relatively small. Given a set of boosters from the upper level, the lower level minimizes the chlorine mass to be injected to maintain required residuals. The approach is applied to the Brushy Plains system for alternative numbers of allowable boosters.