In consequence of the direct discharge of highly polluted stormwater from roadways runoffs, the surface water pollution loading is increasing. Currently, this non-point source water pollution by contaminants is significantly responsible for the surface water pollution load in Germany. Suitable treatment units for decentralised applications have been developed in recent years, however the state of knowledge in terms of their treatment performance and operation behaviour is still insufficient. For this reason, a research programme for Berlin has been designed to close the knowledge gaps in the fields of design, application and operation of selected decentralised storm water treatment units and to gather information on their future application. Against this background, catchment-related estimating calculations are performed allowing for the direct identification of future environmental relief effects for Berlin resulting from the application of decentralised stormwater treatment schemes. A cost-benefit analysis and a Life Cycle Assessment will complete the project. The possible development of guidelines for the application and the approval procedure of such systems in Berlin is another project component.

KWB supervises the in situ testing and is responsible for the data management. LCA and systems comparison between centralised/decentralised schemes is conducted at KWB as well. The summarising evaluation is supported by all partners.