Stellenbosch cleans up its water with new treatment works

Membrane technology and UV disinfection have been deployed to combat pollution of Stellenbosch's downstream water resource and the quality of drinking water, with the launch of a new waste water treatment works.

Mayor Gesie van Deventer said the now fully operational water works is the single biggest capital expenditure item and bulk infrastructure project in the history of the town, known for its agricultural industry, tourism and university.

Van Deventer said in a statement he had prioritised the facility after finding a situation that was “very distressing and bordered on an economic and environmental disaster”.

Before the upgrade, the municipality found the system to be “severely constrained, dilapidated, struggling to meet effluent compliance and a nuisance to the surrounding community and environment”.

The rapid urban expansion of Stellenbosch also placed pressure on the old waste water treatment works, hampering developments and economic growth in the urban edge of the town.

The municipality said: “The new facility has greatly improved our waste water treatment capacity and the incorporation of innovative technology will make any future upgrades easy and cost effective.”

The facility makes use of a membrane biological reactor (MBR) process, an advanced waste water treatment process that uses ultrafiltration membranes for liquid solid separation instead of conventional clarifiers.

“The incorporation of membrane technology has significantly improved the state of the downstream river and the quality of water available for users.”

The municipality also worked with engineers to replace conventional chlorine disinfection methods with more environmentally friendly UV disinfection technology. This technology is also more effective as it kills a wider spectrum of harmful microorganisms, it said. 

Initial construction of the waste water treatment works started in 2015 and the budget for the project was R394m, excluding VAT. The project was funded by Stellenbosch municipality and the department of water & sanitation, through the Regional Bulk Infrastructure Grant.

The Stellenbosch municipality said it is the largest ultrafiltration membrane biological reactor waste water treatment works in SA. The plant is capable of handling up to 35 Mℓ a day and is fully automated.

High odour generation areas at the plant were equipped with an advanced odour treatment system to mitigate any odour nuisances, the municipality added.

Upgrades at several other waste water treatment facilities in the area have begun.