Evaluating reliability and life-cycle cost for decentralized wastewater within the context of asset management

摘要: This paper describes the findings of the initial stages of a project that aims to review and develop tools for asset management of decentralized wastewater systems. The work is being conducted for the NDWRCDP (National Decentralized wastewater Research and Capacity Development Project) in the United States. Here we provide a description of what reliability analysis and an asset management approach mean for decentralized wastewater. The key facets of centralized urban water asset management are first summarized. Strong parallels can be drawn from these, however important differences exist between centralized and decentralized systems and their management. These differences stem from the distinctive characteristics of decentralized wastewater assets and the large spectrum of management, regulatory, and policy scenarios confronting decentralized asset managers. In addition, for decentralized wastewater, we argue that system reliability must be interpreted broadly, and include the analysis and evaluation of technical, ecological, public health, and socio-economic risks. Such differences mean that an adapted asset management framework is necessary for decentralized wastewater. Finally, although some of the necessary tools already exist, our framework and outline of tool groupings shows that potential remains for development of further reliability analysis and life-cycle costing tools to aid asset management of decentralized wastewater systems.