Comparing Single- and Multi-Species Water Quality Modeling Approaches for Assessing Contamination Exposure in Drinking Water Distribution Systems

New software such as EPANET-MSX enables water quality models that account for multiple reactive species in the distribution system. This allows for a more complete analysis of network water quality, including processes such as adsorption and biological inactivation by a disinfectant. For each of these reaction processes, three models are presented: single-specie conservative, single-specie reactions modeled by wall demand or bulk decay, and multi-species. The implications of model selection on the resulting exposure to contaminants that undergo these reaction processes are investigated for a hypothetical intentional contamination event and a simple single pipe system.