Zeekoevlei sewage spill contained

The City of Cape Town says it has contained a sewage overflow into Zeekoevlei and part of the False Bay Nature Reserve.

Sidney Jacobs, chairman of Friends of Zeekoevlei and Rondevlei, said the City had been doing “urgent repairs even until the early hours of the morning and the weekends”.

And, he said: “They have committed to rehabilitate the damaged areas and we are finalising time-lines.”

However, the closure of the vlei had forced many sporting bodies to halt activities which usually take place on the Zeekoevlei waterways.

Mr Jacobs added that the spill and subsequent operations could have a "possible negative effect on this year's breeding season of the critically endangered Western Leopard Toads found here”.

Inspectors from the Department of Environmental Affairs and Development Planning have ordered the City to explain the cause of the Zeekoevlei spill and what it planned to do to clean it up.

The City confirmed significant damage to the Archimedes screws at the Strandfontein sewerage works. The screws are pumps that lift raw sewage from the inlet sumps, into the sewerage plant.

However, Xanthea Limberg, mayoral committee member for water and waste, said the failure of the Archimedes screws would not have led to spillage in Zeekoevlei because the sewage would spill over the sump and into filtration holding ponds at the treatment plant.

Instead, she said, the “compounding effect” of damaged manholes and high volumes of stormwater entering the system had caused the spill into Zeekoevlei.

The Strandfontein sewer works had been unable to cope with the ingress of stormwater, resulting in a backup in sewer lines across the False Bay Nature Reserve and Cape Flats, causing multiple sewer overflows across several suburbs, including Lotus River, Grassy Park, Phumlani, Pelican Park and New Horizon, with subsequent drainage into Zeekoevlei, she said.

The City had been using temporary pumps to get sewage into the treatment plant, since the incident was reported on Monday July 12.

In a media statement dated August 1, Ms Limberg said: “The sewer overflow was the result of heavy rains leading to significant stormwater ingress, damaged manholes in the vicinity and infrastructure damage due to illegal dumping into the sewer system.

“The spill has now been contained with no further seepage into the vlei. This follows successful efforts to divert most of the seepage away from the vlei and into the nearby cut-off drain and wastewater pond system.

“The City has been conducting regular water tests to monitor the water quality. Due to the high E. coli count, the water quality in Zeekoevlei remains above levels deemed safe for intermediate recreational contact. Water quality monitoring continues.”

A draft rehabilitation and repair plan for Zeekoevlei sets out immediate steps to be taken between now and April 2022 regarding roads and picnic area, the terrestrial ecosystem, banks of the vlei, and the water body. A consultant will be appointed to further develop this plan.

Mr Jacobs said: “We are committed to working with the City to ensure that our environment is protected.”