Within the framework of ten research projects, the potential to reduce the input of organic trace pollutants into the river Ruhr by industrial companies will be investigated. Among the identification and the quantification of eco-toxicological and hygienic relevant chemicals, (technical) strategies should be developed to reduce the input in the aquatic environment. Considering the fate of relevant chemicals in waste water treatment plant and in surface water the concentrations within the river Ruhr will be calculated using an existing water quality model. The results of this project lead to a minimisation of eco-toxicological effects of trace organic pollutants on organisms in the aquatic environment and will ensure a sustainable and high quality water supply in the catchment area of the river Ruhr.