AWWA WQTC64097

In order to perform an integral optimization for operation of a drinking water treatment plant, explicit objectives for optimization have to be identified and defined for operational control. This paper discusses what these objectives should be with respect to water quality, environmental impact and costs. Therefore integral assessments are performed for the drinking water production plant Weesperkarspel of Waternet (formerly Amsterdam Water Supply). It is concluded that the objectives for integral optimization of drinking water treatment plants should be water quality and costs. The management should decide upon the relative weight between water quality and costs keeping in mind that the greatest threat for drinking water companies in The Netherlands is the use of bottled water for drinking, when tap water quality cannot be guaranteed for that purpose or clients do not trust the tap water quality. Therefore, emphasis must be laid on maintaining the high drinking water quality. The environmental impact should not be an objective for operational optimization of drinking water treatment plants because the environmental impact is relatively low and will in general benefit from optimization of cost and from good manufacturing practice, for instance the use of 100% green energy. Assuming that disinfection and removal of suspended solids and particles are sufficient, the water quality parameters for integral optimization are SI for chemical stability, AOC and/or biodegradable DOC and DOC for biological stability and disinfection byproducts and organic micro-pollutants for toxicity. Since the SI, AOC, DOC and pathogen concentration are influenced by many processes and influence many processes an integral approach of these parameters is necessary. Because of the complexity of the relations and effects on these parameters by changes in the operational control, different control strategies can best be evaluated by an integral model. Includes 23 references, tables, figures.