Abstract
A decision support system (DSS) is developed to optimise the performance of different operations of small water treatment systems to improve day-to-day decisions. The support system includes a data management system, knowledge-based system, performance assessment of different unit processes, fault tree analyses, preventive and corrective actions and event tree analysis (ETA). Performance assessment identifies the critical events (failures) and fault tree analysis identifies the interrelationships between the critical events and the root causes. Fault trees are developed based on the information obtained from events of waterborne outbreaks, responses to questionnaires by the participating smaller utilities, state-of-the-art literature review and personal communication with the operators. ETA is used to identify the potential health outcomes which are further integrated with the quantitative microbial risk assessment. The developed DSS is advanced to an automated user friendly program that can be used by treatment plant operators to assess system performance.