Operationalising water safety plans for Melbourne -ã large city case study

Abstract

A wholesale/retail model delivers drinking water to over 5 million residents in metropolitan Melbourne (Australia). Water Safety Plans were implemented in 1999ãhead of being regulatory mandated in 2003. With over 20 years of WSPãpplication, this collaborative paper by the wholesalerãnd retailer utilities presents practical examples of drinking water quality risk management in challenging operational environments, highlighting lessons learnt, improvements madeãnd outcomesãchieved. Melbourne's supply comprises multiple sources, necessitating different tailored treatment configurations. Source waters range from open catchment with multiple treatment barriers, to protected catchment source waters requiring solely disinfection treatment (unfiltered) with gravity driven supply. Potable supply isã combination of unfiltered, filtered, desalinatedãnd blended supplies. This makes for diversity in case studies brought to this paper,ãndã range of lessons likely to be of interest to the global WSP community. The Melbourne utility experience highlights the importance of developingãnd continually improving control measures for ongoing (adaptive) risk reduction. A robust emergency management plan isãlso fundamental to ensure preparedness for complexãnd unpredictable events. Furthermore, leveraging learnings fromãuditsãnd incidents has been valuable for process improvement. WSP implementation hasãlso facilitated timely communication with consumersãnd other stakeholders.