Standardisation, quality assurance and data evaluation of on-line biological alarm systems

The first on-line biomonitors were developed in the eighties and implemen- ted to monitor the water quality of the river Meuse and the Rhine, both of which were more heavily polluted at the time. However, the water quality of these rivers has improved substantially over the years. During the nineties a strong technological development took place, as well as a growing insight into the implementation of on-line biomonitors for water quality assurance. This made it possible to develop biomonitors that are able to detect toxic substances quickly and at the required lower detection level.
On-line biomonitors are currently being used to monitor the water quality of the surface water at seven locations in the Netherlands. Five of the locations are inflow points of water companies and two are RIZA monitoring stations. The aim of the inflow control of the different water companies is to signal pollution peaks at an early stage and to selectively abstract good quality water to avoid unnecessarily taxing subsequent purification or the purifying capacity of reservoirs.