Blow off Modeling in District Metering Area THUNGMAHAMEK Brunch Office

Abstract

Metropolitan Waterworks Authority has a regulation to flush a district metering area at least once a year for solving turbidity and substandard chlorine concentration problems.  However, there has been no study of the extent of the clean area and appropriate duration for flushing.  Therefore, the modelling of flushing through a fire hydrant will enable us to understand the hydraulic nature of such process.

This research modelled a flushing process in a district metering area 05-05-05 in Thungmahamek branch office by using EPANET model. We measured pressure at three fire hydrants for 5 days and opened a fire hydrant to simulate a flushing process. The model results showed low pressure affected area from flushing and indicated that flushing duration did not affect chlorine concentration in a long run but rather temporarily induced a new water into the area. The essential factor in effective flushing is fluid velocity that must be higher than 0.91 meter/second according to AWWA standard ANSI/AWWA C651-14 [1] The modelling results showed velocities distribution in the pipe network which can help in assessment of flushing effectiveness. The model can be used for an efficient and appropriate flushing plan.