Residual chlorine in the extremities of the drinking water distribution system: The influence of stochastic water demands

An all pipes network model with stochastic drinking water demand patterns (bottom-up) was used to study the difference in residual chlorine predictions compared to a transport model with one demand pattern (top-down). The results showed that the demand model had a small effect in combination with bulk decay at constant temperature. The top-down model results in higher chlorine predictions, but not at all locations and not consistently throughout the day. Including wall decay is important but only at certain locations. The bottom-up approach can help clarify the residence time at the worst locations.