The existing sanitation system for the Kasane and Kazungula villages in northern Botswana only served a minor portion of the communities. The population growth in the region had resulted in the already overloaded treatment works overflowing, causing river contamination and health concerns.
This ecologically-sensitive area on the banks of the Chobe and Zambezi Rivers is very close to Botswana’s Chobe National Park with its approximately 120 000 elephants, and serves as a gateway for tourists intending to visit the Victoria Falls (Zimbabwe), Livingstone (Zambia) and Namibia’s Caprivi Strip.
To address the increasingly critical situation, Zutari was appointed by the Botswana Department of Waste Management and Pollution Control to undertake the Kasane-Kazungula Villages Sanitation Project.
An innovative solution for Africa
With an in-depth understanding of the area’s topography and sanitation problems, Zutari designed a solution incorporating a unique, fully automated, vacuum-based closed sewage collection system. The technology was new on the African continent and the installed system is believed to be the largest of its kind in the world.
A vacuum sewer system works by sucking the wastewater at high velocity through small diameter pipes to a central collection point, from where it is pumped in the conventional way. Designed to eventually serve 30 000 people and accommodate the high volumes of visitors to the area, the scope of the new system included five vacuum pump stations with 20-25 m³ vessels, 110 km of reticulation pipes (of which 50 km were vacuum pipes), and a 5 Ml/d activated sludge plant.
HDPE pipes were selected for the vacuum system and joined using a highly successful, sophisticated computerised electrofusion welding process.
Subsequently, many of the trainees obtained permanent employment to manage and maintain the scheme.
Involving the community
In collaboration with the client, Zutari ensured that the local communities received optimal added value from the project. This included employing local people during project construction, sourcing material from a locally-owned quarry and training men and women from the communities. Subsequently, many of the trainees obtained permanent employment to manage and maintain the scheme.
The success of the innovative project solution was facilitated by Zutari’s holistic, inclusive approach to community-centred projects. The preliminary design report had involved lengthy consultation with stakeholders to motivate community participation.
The project won numerous awards: Winner ‘Best International Project’ category at the 2016 CESA Aon Engineering Excellence Awards; Winner Construction World Best Project Award – South Africa; Commendation in SAICE and SAFCEC Annual Awards.
*The Aurecon Africa business has been officially renamed Zutari as at 21 July 2020. Zutari acquired Aurecon Middle East on 20 November 2020.