Operational experience with CSO sieving treatment

The first rotary drum type sieve filter has been automatically operating for 4 years now. At low hydraulic loads the device acts as a filter and at high hydraulic loads as a sieve. It is located at a storm overflow tank to treat the overflow of the combined sewage system into the receiving waters and thus avoid visible, unaesthetic pollution by floatables. The paper reports our experience concerning dimensioning, frequency of operation and pollution removal efficiency.