Water Journal : Water Journal August 2011
technical features 62 AUGUST 2011 water governance Starting then with the dynamic nature of risk, this paper describes Sydney Water's processes for managing risk under the 2006 AGWR. The dynamic nature of risk can be considered from several viewpoints. By way of analogy, these viewpoints are as the windows on the four walls of a single room -- they enable us to see the same reality from different angles and more fully appreciate the whole. For the purposes of this paper we define risk as the combination of an expected consequence and estimated likelihood. Mathematically we express this as Risk = Consequence x Likelihood. This follows the understanding and definition of ISO31000:2009 and of the 2006 AGWR. Risk varies over different time frames. In some cases this is more or less instantaneous, such as the quality characteristics of water entering or exiting a unit process. An example of this is the turbidity of filter effluent, which can vary according to chemical pre-treatment changes, or according to influent quality, which itself can be caused by change in plant influent or process upset in preceding unit processes. One risk mitigation is the control of filter effluent turbidity using plant control systems. This type of control is, or should be, instantaneous. In contrast, other risks can occur over longer time frames. Examples of these include long-term trends in the chemical composition of plant influent, changes to business processes, changes to product quality and emerging chemicals of concern. The source or location of the variation in risk can occur throughout all elements of the supply chain. One may see varying pathogen loads in the production facility's influent. Change in risk can also occur due to process upset or equipment failure. Risks can change in the delivery system, for example, due to insufficient chlorine residual maintenance or on-site plumbing modifications post scheme commissioning. Finally, risk can vary with end users depending on their practices and uses of the product. Again, this can occur over short time frames such as incorrect plumbing modifications, or over longer time periods due to increased product familiarity, resulting in reduced implementation of controls. Risk must also be managed over the different life-cycle stages of a scheme from inception through to ongoing operations and maintenance. Understood in this light, treatment process design, for instance, is a control measure for managing risk. Therefore, risk assessment should be one of the first activities in developing a scheme. In addition, as with any project, regular reviews of the risk register during project delivery ensures that the delivered scheme will produce product that is fit for purpose. Again, an obvious example of this is commissioning of treatment processes to demonstrate that they are operating according to their design intent within the operational limits for which they have been validated. The AGWR account for the dynamic nature of risk in the immediate and over the longer term through various elements. For the short term these include, for instance, the use of Critical Control Points (CCPs), appropriate monitoring and short-term evaluation of data. Over the longer term, some of the aspects of the guidelines that contribute to managing risk include identification of knowledge gaps and measures to address uncertainty, evaluation and audit as well as R&D. Sydney Water's Framework for Managing Risk in Recycled Water With the advent of the 2006 AGWR the challenge for Sydney Water was how to incorporate the new guidelines within its existing management systems across a diverse range of new and imminent schemes, without duplicating the ISO- certified processes and procedures that already incorporate ISO31000:2009. Sydney Water's processes are typically managed along functional lines, not according to product line. For instance, Sydney Water applies the same communications and consultation process to all of its capital projects in a Recycled Water Quality Risk Management Planning Sydney Water STRATEGIC Sydney Water FUNCTIONAL CUSTOMER FUNCTIONAL Wollongong Stage II RWQMP Port Kembla Coal Terminal Customer Agreement Wollongong City Council Customer Agreement Wollongong Golf Course Customer Agreement Wollongong Stage I RWQMP BlueScope Steel Customer Agreement Western Replacement Flows RWQMP 5-Year RWQMP (Five-Year Plan) QMP -- RWS Sydney Water Customer Contract Rouse Hill RWQMP Figure 3: Risk management planning framework.
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