The City of Cape Town says they have put multiple interventions in place to improve operations at the Koeberg Sewer Pump Station.
This after residents were up in arms over the toxic smell, sewage spills and pollution, calling on the City to ramp up the sewage infrastructure.
The City says increased sand and foreign debris have been found in the inflow to the Koeberg Sewer Pump Station, which negatively impacts the pumps, causing frequent failures.
“Although the City has been diligently maintaining the pumps, significant flow surges may periodically cause the system to backwash and overflow via emergency discharge points,” the City said in a recent statement.
TygerBurger reported last week (‘Lagoon crisis deepens’, 21 February) that #RethinkTheStink, an environmental group, shared various videos and photos of the pollution in the Diep River Canal on social media.
One Facebook user says the stench and environmental disasters have plagued the greater Milnerton area for the past 15 years.
“This continuous sewage seepage should be being dealt with long before it flows anywhere near this nature reserve. The pump the City had placed there to help divert some of this sewage to the sewer system was inextricably removed some weeks ago and never brought back, allowing the sewage to once again contaminate the wetland. This is simply inexcusable,” a post reads.
Restoration
The City says despite their strides in restoring the Milnerton Lagoon, pollution has persisted due to a string of unanticipated incidents.
Significant sand intrusion has been caused mainly by the 12 collapses on the 900mm diameter fibre cement pipeline in Montague Gardens, the City says. This is mainly due to ageing infrastructure, which is approximately 50 years old.
Another cause for system failures is high sewage flows, putting pressure on the entire sewer system.
“Additional complexities are presented when the need for repairs arises. Due to the depth of the pipeline excavation, typically measures 5m below the surface. The R470 million Milnerton Bulk Sewer Improvement Project has been instrumental in earmarking the area’s deteriorating sewage infrastructure for phased replacement.
The City says long-term improvements to Koeberg Pump Station will cost R118 million. A sand trap and screening facility will be installed and completed first.
“The goal is to finish this project in 2025. Furthermore, from 2026 to 2028, Koeberg Pump Station will be re-constructed to increase overall capacity,” says the City’s Mayco member for water and sanitation, Zahid Badroodien.
Interim measures
As an interim measure, various interventions are in place to manage overflows during peak times including:
- A diesel-operated mobile pump was installed to alleviate pressure. When necessary, the pump acts as a backup, turned on to manage sewage overflows.
- Completed installation of a 610m-long rising main connected to the mobile pump. This helps to channel excess flow directly from Koeberg Pump Station to Potsdam, reducing the amount of effluent that Koeberg’s four pumps have to process.
- The City has ordered four pump impellers which will reduce redundancy. Four new pumps for Koeberg Pump Station and two for Racecourse Pump Station are due for delivery in May 2024.
The City says the following measures will also help:
- The Montague Bulk Sewer line repairs, which are complete.
- Water and Sanitation is in the process of relooking the design of the berm, to make it more effective in containing spills from the pump station. Progress will be communicated as the matter progresses.
“While every effort is made to upgrade infrastructure and find solutions to the challenges presented, the City is committed to providing regular updates on all developments at Koeberg Pump Station as they unfold,” Badroodien says.
“We apologise for the inconvenience experienced by residents living and working in the surrounding community.”
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