Veolia Water Solutions & Technologies South Africa (Veolia), part of the global Veolia Water Solutions & Technologies group of companies, is currently executing the electrical design and mechanical installation of the new ZAR 125 million Ujams industrial wastewater treatment project near the City of Windhoek's northern industrial zone. The plant is designed to treat up to 5,000 m3/day of industrial wastewater for re-use and irrigation, and is one of the city's key water infrastructure projects aimed at complying with Namibia's updated national water regulations.
The Ujams Wastewater Treatment Company, a Special Purpose Company, contracted Veolia alongside VA Tech in 2012 to design, build, install and commission the wastewater treatment plant. The Ujams Wastewater Treatment Company raised finance for the project and will operate and maintain the plant for 21 years.
"The new Ujams wastewater plant is designed to accommodate additional effluent from future industrial developments in the greater catchment area," explains Veolia's Managing Director, Gunter Rencken. "This new plant will enable reliability, efficiency and compliance with the country's standards for reclaimed water used for irrigation."
The plant's incoming wastewater is screened and de-gritted before entering the latest-generation MBR (membrane bio-reactor) system. Before being released from the plant, the water is disinfected with UV treatment, and the various treatment areas are linked to an odour removal process.
Improved water for the Elisenheim and Brakwater communities
The new wastewater treatment plant replaces the region's older UJAMS wastewater treatment plant, located roughly 20 km north of Windhoek. Originally commissioned in 1966, the plant gradually became overloaded with the northern industrial zone's expansion. With a large tannery, a brewery and an abattoir discharging effluents into the catchment area, peak flows often resulted in poor treatment quality, which caused odours within the nearby Elisenheim and Brakwater communities.
"The new plant features some of the water industry's latest technologies, and we're able to remove high levels of E. coli and other pathogens, grease and salts, which will make the water ideal for re-use as irrigation water. During the rainy season, when the demand for irrigation water is low, the high-grade reclaimed water will be discharged into the Klein Windhoek River, where it will enter the groundwater system or the Swakoppoort Dam as a high-quality water stream," Rencken says.
The city's main drinking water reclamation system at Goreangab is a world-first in water re-use by upgrading municipal sewage for direct re-use in the city's potable water reticulation system. "To protect this system from industrial inflows, Windhoek's wastewater systems have been set up in such a way that effluents coming from industrial areas are kept separate from domestic sewage, and treated separately. This, as well as the fact that the Swakoppoort Dam is a main source of drinking water for the city, makes the Ujams plant a critical part of the city's infrastructure," adds Rencken.
Interim wastewater treatment
An interim wastewater project was kicked off in April 2012, and was completed during October, 2013. During construction of the interim project, Veolia Water Solutions & Technologies South Africa's Namibian subsidiary, ASE (Aqua Services & Engineering) installed two Actiflo® water purification units in an emergency effort to reduce the risk of groundwater contamination from overloading, while simultaneously making recycled water available for irrigation and other non-drinking purposes.
At a construction cost of roughly ZAR 2,96 million, the plants are configured to treat 4,8 megalitres per day. "These portable, fully containerised plants will be re-deployed by the city when the new water reclamation plant has been commissioned. We are already in talks as to where these plants will be utilised in the future," concludes Rencken.