Annotated Summary

Vreeburrg, J.H.G., Boxall, J.B. (2007). Discolouration in potable water distribution systems: A review. Water Research, 41(3), 519-529. Retrieved from https://www.sciencedirect.com/science/article/pii/S0043135406005136

This article is a review done by Vreeburg and Boxall (2007), that explains how Prediction of Discolouration in Distribution Systems (PODDS) is a technique to allow people to foresee the possibilities of discolouration in pipes and eventually to fix the pipes after adequate adjustments. The main issue that causes the discolouration of water in water distribution system are the particles, in the form of loose deposits or trapped in cohesive layers. The authors mention that water supply companies receive complains about the incident of discoloured water from huge number of consumers around the globe. To add on, the article state that companies can reply to discolouration complaints in a reactive approach. Boxall et al (2001) propose that traditional sediment transport theory is not suitable for explaining the generation of discolouration within distribution system. Hence, the authors indicate that by implementing simplified version of PODDS, as an interaction of hydraulic shear stress with the pipe wall with material layer, the excess shear stress will create successively more turbidity. Next, using the formula of shear stress in order to achieve the value to flush the turbidity. Boxall and Prince (2006) estimate that the force requires to hinder accumulation of material through evaluation of imposed shear stress is 1.12N/mm ² for clay driven discolouration problems face in Melbourne, Australia. To sum up, the particles in distribution system are the key to aesthetical water quality, as corrective measures are taken to clean the network once a certain threshold is met. This article relates back to my team research project in a way that discolouration in distribution network is already an existing problem throughout the globe, including Singapore. So countermeasure needs to be taken to solve this issue.