Cape Town to invest $120.4m in WWTWs upgrade project

City of Cape Town in South Africa is set to invest ZAR1.7bn ($120.4m) to upgrade the Zandvliet Wastewater Treatment Works (WWTWs) plant.

The Zandvliet WWTWs treats effluent from the southern parts of Kuils River, Delft, Blackheath, Blackheath Industria, Blue Downs, Eerste River, De Wijnlanden, Thembokwezi, Mxolisi Phetani and Khayelitsha.

The facility currently handles 72 million litres of wastewater per day, and the upgrade is expected to add an additional 18 million litres per day to its processing capacity bringing the total to 90 million litres per day.

As part of the investment, Cape Town will also add a new preliminary treatment process as well as upgrade the existing treatment modules to ensure that the treated effluent being discharged complies with the licence conditions issued by the National Department of Water and Sanitation.

Cape Town Water and Waste Mayoral Committee member and councillor Xanthea Limberg said: “The treatment processes applied at the facility, being biological activated sludge processes, are considered best practice for municipal wastewater treatment.

“Additionally, the existing Membrane Bioreactor Module, which incorporates membrane technology for solid and liquid separation, was the first application of this technology in the municipal sector in South Africa.

“The City of Cape Town is among the highest performers nation-wide, in terms of treated effluent being discharged from WWTWs, within the standards required by the Regulator.”

Additionally, Cape Town will add a membrane bioreactor, sludge dewatering facilities, new inlet works, pump stations, primary settling tanks and disinfection facilities to the facility.

The WWTWs facility is expected to be commissioned by December 2023, following which, further expansion will be implemented to cater to continuing urban growth in the area.

Furthermore, Cape Town will continue to operate and treat wastewater at the existing plant throughout this upgrade period.