A research and monitoring station has been established as a part of the intercepting sewer from Frejlev, a small town of 2000 inhabitants 7 km Southwest of Aalborg, Denmark. The purpose is to perform continuous high quality time series of flow as well as waste water and runoff water characteristics. Based on these future time series, research will be carried out in order to establish knowledge on dry weather characteristics, and rainfall-runoff relationships including the variability of relevant storm water pollutants. Furthermore, the measurements can form the basis of a better understanding of transport and transformation of pollutants in combined sewers including suspended and bed load characteristics, sedimentation and resuspension.