Construction on the Potsdam wastewater treatment works (WWTW) upgrade, the Western Cape’s second largest infrastructure project, has started.

The R5.2-billion upgrade, which will double the plant’s capacity from 47-million to 100-million litres of treated wastewater a day, is expected to be completed by 2027, with the operational trial starting in 2026.

“The Potsdam upgrade is a critical part of our plan to restore the environmental health of Milnerton Lagoon, which is a non-negotiable for the City of Cape Town,” said Cape Town Mayor Geordin Hill-Lewis, highlighting the aim of steadily closing off pollution sources to the lagoon over time, building up to the ultimate goal of dredging the water body to remove the sediment containing the decades-long build-up of pollution.

“The installation of cutting-edge wastewater treatment tech at Potsdam will be dovetailed with the completion of dredging at the lagoon, in around two years,” he added.

Other major sewerage infrastructure upgrades under way include the R430-million Montague Gardens bulk sewer rehabilitation, the R118-million Koeberg pump station upgrade and long-term pump station and pipe replacement programmes.

This is as Cape Town increased its water and sanitation infrastructure budget over three years by 223%, from R2.3-billion in 2022/23 to R7.8-billion in 2025/26.

The City is planning capital expenditure of R8.6-billion on WWTW upgrades over three years; R1.3-billion for sewer spill responsiveness including the proactive jet-cleaning of 200 km of sewers a year; R1.4-billion in bulk sewer upgrades to the Cape Flats, Milnerton, Philippi and Gordon’s Bay lines; and quadrupling pipe replacement from 25 km in 2021/22 to 100 km a year, worth R850-million total over three years.

Meanwhile, Water and Sanitation MMC Councillor Zahid Badroodien pointed to the City of Cape Town’s range of short-term actions to combat pollution in the Diep River catchment.

“We have just installed over 20 litter nets all along the Diep river, and expanded our waste interception to the Black and Salt rivers as well as the Jakkalsvlei canal. We are also investigating and correcting cross connections created by residents from Stormwater and Sewer pipes, alongside ongoing by-law enforcement operations,” Badroodien highlighted.

Progress is also being made on critical maintenance work to improve treated effluent quality at Potsdam, including major cleaning work to maturation ponds and the re-engineering of natural reed beds to prevent pollution from reaching the Diep river.