DYNAMIC MODELLING OF ESCHERICHIA COLI GROWTH IN WATER DISTRIBUTION SYSTEM (A CASE STUDY: WATER SUPPLY ZONE 3 IN SURABAYA INDONESIA).

Escherichia coli is the biological standard in determining the quality of water in the distribution network. Chlorine residual, distribution distances, and pH are variables which can affect the quality of water distribution system. However, the reality showed that the pipeline leakage was one of the unpredictable existence variables which can also has a significant effect on the Escherichia coli in the distribution network. Therefore, by using STELLA 9.1.3, the dynamic model simulated the PDAM distribution network to modelling Escherichia coli in the nearest consumer from treatment plant based on two main scenarios, extreme scenario and optimum scenario. The simulation results showed that the highest pipeline leakage persentation might cause Escherichia coli growth eventhough it was at the nearest consumer. Thus, in order to reduce public health risk, it is necessary to repair pipes and to inject disinfectant when pipeline leaks have been detected.