Abstract
There is a growing demand for an integrated assessment to identify and select asset management options based on sustainability in the wastewater industry. However, water companies are often not equipped with a rigorous methodology and sufficient resources to perform sustainability assessments. Although many frameworks and tools for sustainability assessment have been developed in academia, practical challenges such as feasibility and usability remain when implementing sustainability assessment methods to support corporate decision-making. This study developed a Multi-Criteria Analysis based framework to evaluate wastewater treatment processes from a sustainability perspective. This study firstly explored the decision and organizational context of a water company with preliminary interviews and then applied the Analytical Hierarchy Process (AHP) with composite scores to evaluate wastewater technologies at a sewage treatment works. The preliminary interviews with stakeholders highlighted that the existing investment decisions were primarily driven by financial cost and compliance whilst calling for a wider consideration of other criteria. A selection of assessment criteria and indicators were then proposed to compare seven treatment technologies at a sewage treatment works. The results of composite scores indicated that the baseline activated sludge process (ASP) was the best option for this study. Experience from the development process highlighted usability, stakeholder engagement and the organizational context should all be considered as part of the design and implementation of the sustainability assessment. The insights from this study provide a valuable practical foundation for applying a multi-criteria approach to perform sustainability assessments and inform asset management decisions in the water company.