Discharge via the municipal waste water system is the dominant emission pathway to water for many micropollutants especially for household chemicals, substances used in commerce and industry (especially in small and medium-sized enterprises), pharmaceuticals and biocides. Against this background, the primary objective of this study was to develop suitable measures or combinations of measures and their framework conditions to reduce the emission of micropollutants to water via the municipal waste water system that are characterized by high cost efficiency. The emission-relevant material flows were analysed for twelve selected micropollutants and to some extent the substance input into the water bodies  were modelled. The results served as basis for the derivation of emission reduction measures. A focal point was the investigation into costs and effectiveness of the introduction of an advanced treatment stage in municipal wastewater treatment plants and the constraints to be considered with this. At the same time, the result have shown that both source-oriented as well as decentralised measures, depending on the substance considered, represent a cost-efficient possibility for the reduction of emission and can make an important contribution to the implementation of the polluter pays principle.