The Lourens River Sewer Pump Station is one of several facilities across the city to benefit from an improvement to infrastructure recently.
The City of Cape Town’s Water and Sanitation Directorate has installed robust mechanical filtration screens at the Lourens River, Retreat Main, Raapenberg and Muller Street stations to prevent large items from entering the wastewater system.
The initiative aims to reduce the risk of overflows and damage to pump stations.
Ten of Cape Town’s sewer pump stations across various areas have been fitted with the uniquely designed mechanical bar/basket screens at the cost of R8,1 million over the last two years. The screens act like sieves, filtering out large objects such as wet wipes, sanitary towels, disposable nappies, clothes, rags and condoms, which should not be in the sewage system.
This upgrade is part of a collaborative effort between the directorate’s Engineering and Asset Management (EAM) and Reticulation branches. The Design and Contracts team at the EAM branch leads the innovative design and specifications for each screen, considering the existing infrastructure of each pump station.
When sewage pump stations fail to operate optimally it results in a surcharge within the sewer network, triggering overflows from manholes and leading to outflows into residential and environmentally sensitive areas. This poses significant health risks.
Some larger pump stations, such as those at Langa, Raapenberg, and Lourens River, require double screens, either stacked or positioned in separate chambers or channels.
A grapple has been designed to service multiple screens using a single hoist or crawl beam. The grapple, attached to the hoist chain, features a release mechanism on which to latch and release each screen for cleaning.
“These upgrades are essential and will reduce the frequency of pump breakdowns and repair costs,” said Zahid Badroodien, Mayoral Committee member for Water and Sanitation. “With the EAM branch leading the design we can continuously enhance the screens for easier operation.”
Future installations are planned for more pump stations, including Macassar.
