Strategic planning approach for optimising investment at WWTPs

Abstract

From an asset management perspective there is an ongoing challenge to make strategic investment decisions which are based on maintaining asset serviceability, effluent quality requirements and providing for growth. Additionally, individual performance of treatment stages and changes in sewage flows and loads have to be considered to achieve an optimised outcome. Typically, large scale capital projects are required to address the many challenges that face a WWTP. However, significant cost savings can be made if smaller optimisation projects are pursued to maximise the capacity of existing infrastructure and therefore defer high cost capital upgrades. To achieve this end, SA Water started a formal process to review the capacity of each process element of the Bolivar WWTP and found several opportunities to optimise current process performance. Based on these outcomes a future strategy document was developed that enables the next major plant upgrade to be deferred by 8–10 years. This paper summarises SA Water's approach to develop such a documentation to allow a strategic asset management, optimise its capital expenditure and achieve significant cost savings. It also highlights some of the projects that were identified during this process to improve the current treatment plant performance.