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2Q - Online Biomonitoring (WEP/161) Application of the biological early warning system Musselmonitor® in chlorinated drinking water monitoring. Kramer, Kees J.M.1, Barreto, Sára2, 1 Mermayde, P.O. Box 109, 1860 AC Bergen, Netherlands, Netherlands2 Waterworks of Budapest Co. Ltd., Department of Water Quality and Environment, Váci út 102, 1044 Budapest IV, Hungary, Hungary ABSTRACT- ABSTRACT. The biological early warning system Musselmonitor® has been successfully applied for years in the monitoring of surface waters or, for example, of raw water intake for the drinking water industry. The measurement principle is based on the rapid detection of changes in behaviour of bivalves (e.g. closure of shells) as a result of detected pollution. Since September 2001, monitoring of (chlorinated) drinking water (tap water) for the (non)-accidental presence of contaminants has become an even more important issue. Direct application of any BEWS is, however, often hampered by the presence of chlorine. Due to the sensitivity of mussels to free chlorine and the absence of food (particulate matter) in drinking water, adaptations to the normal working operation of the monitoring system had to be developed. Just before the water inlet to the Musselmonitor, the injection of small amounts of a concentrated sodium thiosulphate solution to the drinking water neutralises the free chlorine present. Further, addition of a continuous flow of a suspension of cultured algae ensures constant feeding of the mussels. This approach was successfully implemented at the Waterworks of Budapest, where thus adapted flow-through Musselmonitor units were installed to monitor the chlorinated drinking water at the company's various water distribution pumping stations. At the prime test location the same set of eight mussels acted as guardians of potable water quality for over 8 months. The results of the experiments related to the addition of thiosulphate, addition of food, and the sensitivity to toxicants and the implementation will be presented. Key words: Toxicity monitoring, Biological early warning, Risk management, Drinking water |
