Work on the City of Cape Town’s R1.5 billion project to upgrade the Zandvliet Wastewater Treatment Works is expected to start in the first half of 2019.

This comes after council approved most of the upgrade work last year. The project, which has been in the pipeline for several years, has been delayed by several issues including five tender appeals, including a high court appeal, and a land claim.

Urban growth

The City has started the process of diverting eight million litres of flow per day away from the Zandvliet Wastewater Treatment Works (WWTW) to the Bellville WWTW with completion of the diversion expected early this year.

The upgrade is being implemented to ensure that the plant can cater to the rapid ongoing development in the Khayelitsha, Delft, Blackheath and Eerste River areas.  According to the City the new plant is set for commissioning by December 2023.

“Soon thereafter, a further expansion will be implemented to cater for continuing urban growth in the area. Work will see construction of a membrane bioreactor (MBR), sludge dewatering facilities, new inlet works, pump stations, primary settling tanks and maturation ponds where effluent is purified before discharge,” the City explains.

Algal bloom controversy

Meanwhile media outlets have speculated that wastewater quality and work at the Zandvliet WWTW may be linked to a recent algal bloom along the False Bay coastline.

The City disputed the claims noting that treated effluent discharged from the City’s wastewater treatment plants achieve a compliance rate of more than 80% with the standards required by the Regulator; and the plants operate in accordance with ISO standards.

“Importantly, it must be noted that the City does not discharge untreated sewage into the river. The plant currently operates within the design capacity in term of flow rates.”