EFFECTS OF PUMPING SCHEDULE ON WATER QUALITY IN A DISTRIBUTION SYSTEM

Abstract

"Effect of Pumping Schedule on Water Quality in a Distribution System" Water conveyance and distribution are similar to large reactors where chemical and biological reaction takes place, both in bulk water supplied and at the point of interaction between water and system components ' such as pipes, fittings and storage tanks. Conventional (chlorination at the treatment plant disinfects the water and residual chlorine is maintained to take care of the future possible contamination in the distribution system. Extended residence times spent in the water distribution network can lead to excessive decay of chlorine residual concentration. In the water distribution network, residual chlorine decay is influenced by a number of factors such as residence time, storage tank permanent volume (i.e. for fire fighting and other emergency cases), pumping schedule, demand pattern etc. In the present study, effect of pumping schedule on the chlorine decay has been discussed. It has been found that the resilience of the system- can be decisive factor in the performance of the pumping schedules. The effect of various pumping schedules and durations has been demonstrated with the help of illustrative example. Different scenarios of a typical water distribution system are simulated using EPANET 2.0, software developed by United States Environmental Protection Agency and results are discussed to identify the optimal pumping schedule from residual chlorine point of view.