A combined sewer receives sewage and stormwater runoff within a single collection system. Whilst it has the benefit of being lower cost than a separated network, it can cause serious water pollution problems in the event of an overflow situation resulting from large variations in flow between dry and wet weather, and particularly in storm conditions. Overflow points are referred to as Combined Sewer Overflows or CSO’s. They vary considerably in size, frequency of spill and location. Ovivo’s range of CSO screens are specifically designed to suit most CSO applications, and can be categorised as: powered, non-powered self-cleaning, and static.