Heritage Cases

The project entails the replacement of the Sterkspruit Regional Waste Water Treatment Works (WWTW) and associated bulk infrastructure. The replacement of the sewage bulk connector systems entails division of the systems into three major drainage zones, one for each community. The replacement will aim to maximise the delivery of sewer services to the communities. The sewer connector services will consist out of the following infrastructure: • The construction of 1200 m of 160 mm diameter sewer pump lines. • The construction of 6000 m of 200 mm diameter sewer pipes. • The construction of 12000 m of 250 mm diameter sewer pipes. • The construction of 5000 m of 355 mm diameter sewer pipes. • The construction of 2000 m of 400 mm diameter sewer pipes. • The construction of 350 manholes. The WWTW will be replaced and will have an initial capacity of 4Ml per day. The final effluent will be irrigated onto sports fields and other designated irrigation areas. This 4Ml capacity will be sufficient for 5 years and will accommodate all excess sewage that the current WWTW cannot handle. After the 5-year period the WWTW will be upgraded to handle approximately 7Ml per day. During this upgrade, the re-use of the final effluent will be investigated as well as the installation of an outfall sewer to evaporation dams will be investigated. The WWTW will consist of amongst others: • Inlet works with screening and de-gritting • Flow measurement • Biological reactor • Secondary sedimentation tanks • Maturation rivers A series of lift pump stations will also be constructed to accommodate the bulk connector services where gravitational feeds cannot carry any raw sewage to the WWTW. A total of 7 sewer lift pump stations will be constructed along bulk connector systems. The following specifications will be applicable to the pump stations: • 20hour pumping per day. • Sized for the summer peak demand. • Sized for a minimum of 33% standby capacity. Due to the fact that the existing WWTW is overloaded at present it is of critical importance that the construction of the new WWTW commence.