Twenty months into the large-scale upgrade of the Potsdam wastewater treatment works (WWTW), the City of Cape Town (CoCT) says the R5.2-billion project is on track to be completed in 2027.

The upgrade is being executed through two construction contracts – one for civil infrastructure and another for providing the mechanical and electrical infrastructure.

It is one of the city’s largest infrastructure projects, designed to more than double the plant's capacity from 47-million litres a day, to 100-million litres a day.

To date, the civil construction of the ultrafiltration plant has been completed.

This plant will allow for advanced treatment processes, such as micro-screening, ultrafiltration membrane technology and UV disinfection.

Also included is a treated effluent reuse pump station, increasing water availability to the city.

Construction of the process control facility is also under way. This will be the operational node for the plant, and will consist of a new control room, with a system to monitor the plant’s operations in real time.

This area will also be the administration block where the operations management team will be based.

The civils portion of the membrane bioreactor facility, inlet works and raw sewage pump station is also under construction.

This is the largest part of the project, and will increase the treatment capacity of the Potsdam WWTW to 100-million litres a day.

Civil construction of the dewatering plant has been completed and has been handed over to the mechanical and electrical contractor for equipment installation.

This includes eight new primary sludge belt presses and eight new secondary sludge belt presses for dewatering of the respective sludges.

This facility will assist the plant in maintaining a consistent sludge age – or, good bacteria levels – ensuring improved treated effluent quality.

The dewatering and ultrafiltration installations are likely to be commissioned in the middle of next year.

This is anticipated to have a positive impact on existing operations, as it may realise improved treated effluent quality at the WWTW at an earlier stage.

CoCT says it aims for the completed treatment works to start operational trials in 2026.

“The city is steadily working towards restoring the environmental health of the Diep river and the Milnerton lagoon through a combination of efforts,” notes CoCT Water and Sanitation MMC Zahid Badroodien.

“The major infrastructure upgrades within the area at Potsdam WWTW are instrumental in achieving this, and we are looking forward to seeing more progress on site over the coming months.”