EARLY WARNING MONITORING TECHNOLOGIES

摘要

Contamination of raw drinking water sources may result from accidental, natural, or intentional (including terrorist) events. Such events pose threats to raw waters in water supply catchments, storages and in some bulk water transfer infrastructure components such as aqueducts. Standard on-line water quality sensors (e.g. turbidity, pH, conductivity) play an important role in detecting water quality changes in raw water inflows to water treatment plants. However these devices cannot detect many types of contaminants such as fuel, oil, surfactants, solvents, biocides, algal toxins and other chemicals nor can they detect pathogens. The public health threat posed by contamination events is significant. Given these challenges, a number of water authorities around the world have invested in biologically based early warning monitoring systems. Biological response sensors operate by using an organism or groups of organisms as sentinels to detect changes in water quality (similar to the use of canaries in coalmines in the past). The systems operate by passing a continuous stream of the water to be monitored past the test organism and monitoring the behaviour of the organism in real time. The sophistication of these on-line toxicity meters has been facilitated by the development of advanced electronics and fast computers. While there are many technologies in development, only a handful of devices are currently in commercial operation. In this paper we review 6 devices. The devices are manufactured in Europe and the USA and involve the use of either fish, Daphnia (a species of zooplankton), algae (phytoplankton) and mussels. All the devices are currently in operation overseas and are commercially available in Australia. A guide to the capital, set up, operation and maintenance costs for each system is also presented.