In view to a reduction of the discharge from combined water outflow the increase of the influent to a wastewater treatment plant can be an efficient solution. Through bypassing the aeration with combined water and a direct feed of the combined water into the final clarification the specific sludge volume loading, which is significant to the efficiency of the final clarification, will not be raised. But the adsorption capability of the aerated sludge, the sedimentation effect of the final clarification, and the partial recirculation over return-sludge can be used for an elimination of suspended solids, COD, ammonia and phosphate from the combined wastewater. Through the dilution of the bypass, the suspended solids concentration in the inflow section of the final clarifier will be reduced. By this the settling velocity will increase and the influence of the higher hydraulic load will be more than compensated. In large-scale tests in Wilhelmshaven (160,000 PE) removal efficiencies for the elimination in the bypass of 75 % of COD, 60 % of ammonia and 89 % of suspended solids were reached. In comparison with conventional procedures for combined water treatment (e.g. storage volumes, soil filter) the bypass technology has got the possibility to achieve a highly efficient and economical combined water treatment by using the capability of existing clarifiers. In the frame of the presentation the basics for this advanced solution will be explained and the results from the technical application will be demonstrated.