Operationalising water safety plans for Melbourne – a large city case study

Abstract A wholesale/retail model delivers drinking water to over five million residents in metropolitan Melbourne (Australia). Water safety plans were implemented in 1999 ahead of being mandated in regulations in 2003. With over 20 years of WSP application, this collaborative paper prepared by the wholesaler and retailer utilities presents practical examples of drinking water quality risk management in challenging operational environments, highlighting lessons learnt, improvements made and outcomes achieved. Melbourne's supply systems comprise multiple types of supply sources, necessitating different tailored treatment configurations. Source waters range from an open catchment with multiple treatment barriers to protected catchment source waters requiring solely disinfection treatment (unfiltered) with gravity-driven supply. This makes for a diversity in case studies brought to this paper, and in turn a range of lessons likely to be of interest to the global WSP community. Discussion of the Melbourne utility experience highlights the importance of developing and continually improving control measures for ongoing (adaptive) risk reduction. A robust emergency management plan is also fundamental to ensure preparedness for complex and unpredictable events. Leveraging learnings from audits, incidents and events has also been valuable for process improvement. WSP implementation has also facilitated timely communication with consumer s and other stakeholders.