CCWI2017: F114 'Application of Water Distribution Models in Mains Cleaning- A Case Study'

The main purpose of the project was to remove the biofilms and sediments in the pipe while making sure the network does not experience discolorations. In this project only the preferred material (Plastic, Asbestos Cement, and Ductile Iron) mains were cleaned using two different approaches, namely robust flushing and air scouring. This paper is only concerned with the robust flushing aspect, where mains are cleaned by generating sufficient shear stress. The Prediction of Discolouration in Distribution Systems (PODDS) methodology is used in the flushing design [1]. The main challenge in the design was to clean the mains while maintain the levels of service to the customer and preventing discolouration upstream and maintaining a calm network so that valve operations carried out in the field do not cause pressure surges and isolations in the network. Potential issues faced during the hydraulic design of flushing are highlighted through a case study.