Study of transport of contaminants in a pipe network using the model EPANET

A rural water supply system having two probable water sources, with an elevated tank, required to serve three schools and a hospital, was selected for this study. The model EPANET was used to study the variation of concentrations within the network of conservative and non-conservative substances introduced into the water at the source node and at other nodes. This paper discusses the findings of four scenario analyses undertaken in order to study the behaviour of the contaminants, and to develop strategies for management of some difficult situations encountered in water supply schemes. In the two source supply situation, it was observed that the water quality at the critical points in the system could be maintained below the permissible fluoride concentration, while maintaining the water requirements, by changing the pump operation cycles. When the behaviour of residual chlorine in the system was studied, it was observed that the model can be used to discover the chlorine booster points to maintain the required minimum residual chlorine content at the distribution terminal points. The results need to be verified by field-testing, once the water supply scheme, which is still under construction, is commissioned.