Investigative monitoring in the context of detecting anthropogenic impact on an epipotamal river.

In the context of an investigative monitoring programme a monitoring system comprising of a water quality monitoring station and a camera station has been installed and operated for more than one year. The monitoring target was to investigate changes of water quality which can be related to a repeated occurrence of foam, observed at a river stretch downstream the monitoring station. The extent and frequency of foam buildup was recorded by means of the camera station. The analysis of the online data clearly showed that some of the measured parameters can be used as indicators for specific discharges, which from additional targeted investigations could be identified as contributors to the foaming problems. The continuous ammonium measurement could be used to detect nitrification problems of WWTPs discharging upstream of the monitoring station. By combining different data sources (emission data, operative and investigative monitoring data) additional information can be gained, which can be used for a comprehensive data assessment as well as a detailed system analysis. Copyright IWA Publishing 2008.