Model based investigations on the pollution loads of stormwater treatment particle separators Enquêtes modèle basé sur la charge polluante des eaux pluviales de séparateurs de particules traitement

The cleaning efficiency of stormwater sedimentation tanks can be increased significantly with mechanical equipment like downstream placed filters or implemented lamella plates whilst decreasing the required tank volume. (Fuchs and Mayer, 2009) The German guidelines for the layout of stormwater sedimentation tanks do not regard the implementation of mechanical equipment like lamella plates. The present investigation analyses the design criteria and efficiency of stormwater treatment sedimentation tanks with implemented lamella separators. Therefore a hydrologic-deterministic precipitation runoff model is used to analyse and evaluate the hydraulic efficiency and the overflow behaviour of stormwater sedimentation tanks with implemented lamella plates on the basis of long term rain series. Several scenarios with different design inflows were created for a given catchment area. The first results of the present investigation led to a new layout approach for stormwater sedimentation tanks with implemented lamella plates depending on the inflow. (Schaffner et al., 2011) Further investigations evaluated the annual pollution loads of the different scenarios to connected waters. In a final investigation the results were discussed regarding the economic or cost-effective installation of stormwater sedimentation tanks with or without a lamella particle separation system.