Cape Town - After years of neglect, the multimillion-rand cleaning of maturation ponds at the Potsdam Waste Water Treatment Works (WWTW) is well under way to improve the quality of treated effluent being discharged into the Diep River and being provided to end users in the northern part of Cape Town.
The cleaning began last month and is set to be completed by the end of June, bringing relief and improving the quality of effluent discharged, even before the City’s R5 billion upgrade for Potsdam is completed.
This is a small part of the puzzle to rehabilitate the Diep River and Milnerton lagoon.
Water and sanitation Mayco member Zahid Badroodien visited Potsdam yesterday to assess the progress and explained that the effluent was meant to be retained in these ponds before release.
However, pollution build-up in the pond sediment prevented this and, as a result, the ponds were being bypassed using pumps as far as possible.
The main benefit of this process, which ultimately seeks to naturally disinfect the treated effluent, is that afterwards water test results will show that the combined Total Suspended Solids (TSS) concentrations were within the Department of Water and Sanitation (DWS) limits.
This has been a big challenge for the City for years.
Badroodien said that people will now be able to use this as an alternative water source for their gardening and other uses.
He added that this cleaning was a key component of the bigger, but necessary R5 billion upgrade investment into Potsdam to rehabilitate the Diep River and Milnerton lagoon.
Caroline Marx, director of Rethink The Stink and environmental head of Milnerton Central Residents Association, said: “The completion of the extensive repairs and refurbishments at Potsdam WWTW by June will be welcomed, as these should result in improved quality effluent, even before the R5 billion upgrade is completed.”
If the ammonia, total suspended solids, and chemical oxygen demand levels in the effluent discharged complies with safety standards, Marx said the water quality in the Milnerton Lagoon will start to improve almost immediately.
“Another major pollution source, however, is the contaminated stormwater flow near Milnerton High School which is being pumped into the sewer system with a mobile pump.
While the soon-to-be built permanent low-flow diversion near the high school will provide relief when it is not raining, it is disappointing that the City is still only ‘planning’ to divert the flow further upstream, where it would be more effective,” Marx said.
kristin.engel@inl.co.za