Legislative and economic stimuli are increasing the pressure for effluent to be treated to a higher quality, with quality levels achieved more consistently. Many older treatment plants may be treating effluent with characteristics that were not considered during the initial design stage. This research project will investigate the feasibility of applying a knowledge-based system to monitoring and controlling an existing system in order to achieve improved quality of treated effluent, quality of product, reduction of pollution and to avoid the risk of incidents to personnel and the environment.