The City of Cape Town’s R4-billion capital investment programme to upgrade the Athlone Waste Water Treatment Works (WWTW) is under way, with 25% of the first phase of the programme having been completed and most of the new equipment required delivered.

The city’s Water and Sanitation Directorate initiated the programme in 2022, scheduling the work in phases starting with improvements to the aeration system. It is expected to be concluded by 2026.

The city aims to improve its treated effluent quality and minimise odours emanating from the site.

During the first phase in the 2023/24 financial year, the City of Cape Town invested R202-million towards upgrading the facility.

This phase included the completion of a new blower house to enhance the aeration system, which is critical for maintaining the biological processes that treat wastewater.

Replacing the aeration systems, mixers and recycle pumps is ongoing, while work on Reactor A has been completed, and work on Reactor B is in progress.

The upgrades to the aeration and disinfection systems are also crucial to ensuring that the effluent discharged into the Black river meets environmental standards.

The next series of upgrades under Phase 2, which will see the plant's capacity increased to serve more households, includes enhancing the inflow system to improve the initial treatment of wastewater.

Further, the disinfection facility will be refurbished to improve the final treatment stage, ensuring safer effluent discharge, and new odour control systems will be installed to significantly reduce the emission of gases, which will address the persistent issue of foul odours, which is a primary concern for nearby residents.

In addition, upgrades to the dewatering systems will help manage sludge more effectively, reducing the likelihood of odours and improving overall plant efficiency.

“Steady progress is being made towards completing the multibillion-rand upgrades to Athlone WWTW, while at the same time, ongoing repairs and maintenance continue to keep this vital plant operational,” said Water and Sanitation MMC Councillor Zahid Badroodien.

Once completed, the improved treated effluent quality and new aeration systems will result in better living conditions for residents in close proximity to the plant.

“The city earmarked this facility for upgrades owing to its ageing infrastructure and we are cognisant of the negative impact of the foul odours caused by sludge build-up.”

The combined interventions are designed to ultimately minimise odours through improved sludge management and biological treatment processes, he concluded.