Combined sewer overflow treatment — Knowledge or speculation

Abstract

The stochastic behaviour of rainfall and the uncertainties in land use development as well as the limited knowledge on efficiency of CSO-treatment measures yield the most difficult conditions for design. Therefore less emphasis should be given to regulations for sizing individual structures and more ingenuity must be used for flexible designs and integration of CSO-facilities in the overall system. More emphasis should be paid to observe and monitor the effectiveness of constructed facilities. The greatest potential in achieving more protection for less money is seen in better using the tradeoff potential between decentral and central treatment and between storage and treatment level.