Background losses reduction by excessive pressure cut off

Abstract

It is one of the greatest challenges water utilities are facing in striving to reduce and control Non Revenue Water (NRW) within an economic level. While supplying the population with sufficient water, the reduction of NRW has been a key issue in judging the performance of all water utilities. Background loss is one component of physical losses which is the most to contribute to NRW. This study aimed on pressure management method conducted at a site to reduce background loss. The pressure management method used is by the installation of a Pressure Reducing Valve (PRV) with timer-based pressure cut-off controller as an on-site verification. The BE59 - Kg. Melayu Pandan, one of the District Meter Area (DMA) in Johor Bahru has been selected as a case study. The Step Tests are carried out to analyse and identify the steps with high background leakage and to find suitable location for the purpose of PRV installation. The DMA meter and a data logger are used to measure and record pressure and flow profiles to determine leakage at each step and to establish leakage baselines, before and after the activation of the PRV. The results indicated a high reduction of background loss and given significant impact on the NRW level in Johor Bahru. In financial terms, volume of water saved and the monthly expenditure shows the return of investment (R.O.I) is in a period of 6 months. This research findings show a higher reduction on background loss can be achieved by optimising the cut-off controller, analysing further excess pressure cutoff based on pressure profiles in the existing or new DMA with a PRV and controller in a large scale. Comparisons with other methods of pipe replacement and Active Leakage Control (ALC), indicate that, the pressure management by excess pressure cut-off is the most feasible, economical and effective method in the NRW reduction.