Testing the Performance of Pressure Sewer Systems to Reduce Wastewater Overflow

Wastewater overflow is one of the major sources of surface water pollution. A pressure sewer system is considered to be effective for reducing wastewater overflow by controlling the operation of pump stations during different storm events. It is a challenge to control pressure sewer systems efficiently and effectively especially in a complex sewer network. In a simple, well-defined sewer network, pressure sewers are highly effective in controlling sewer overflows in the downstream network. But in a complex sewer network pressure sewer systems may, in some cases, even increase the sewage overflows due to complexity in the network and area-wide variation of wet weather response in the network. This paper reviews the pressure sewer systems in post-earthquake Christchurch. The paper examines how reliable a pressure sewer system is in reducing wastewater overflows during different storm events. Hydraulic modelling tools have been used for this research.