Published: 31. May 2024

South Africa gains knowledge on wastewater treatment processes and reduction of water loss


In Denmark, we use approx. 100 liters of water per inhabitant per day – in South Africa the figure is 270 liters. Water loss is the explanation for the large water consumption. Since 2017, Aarhus has cooperated with the city of Tshwane in South Africa transferring knowledge on drinking water and wastewater management.

In a pilot area in Tshwane, we are working to improve wastewater treatment and minimize non-revenue water. The primary goals and knowledge transfer taking place are within:​

  • Reduction of water loss
  • Asset management to prioritize resources in relation to the replacement of water pipes
  • Improved processes and management of wastewater treatment plants​
  • Comprehensive planning for water including climate adaptation
  • Water security vision and strategy enabling a sustainable water cycle

Tackling the issue of water loss

Most of the drinking water consumed in Tshwane comes from 150 km away and around 30-40% is lost on its way to the consumers. Aarhus are contributing with methods to perform leakage search on water pipes and have educated water operators to find leaks and repair them. The mayor of the city, Cilliers Brink, is convinced that active leakage search is a means to reduce water loss: "Leak detection makes good sense and should be performed quarterly."

In South Africa, a lot of our residents don’t have access to clean water, and we are facing a situation where we will become water scarce in the coming years
- Thulani Mlilwana, Water Security, Partnership and Implementation – C40 cities Africa

Furthermore, Aarhus are contributing with asset management and methods to collect data on water pipes. Thereby it is easier to ascertain which pipes have had the most leaks and thus would be smart to replace. Finding new water resources within Tshwane is also on the agenda for the cooperation. A water vision on how to obtain a sustainable water cycle in Tshwane is being developed which should serve as a tool to improve water management in South Africa.

Improvement of wastewater processes

Wastewater treatment also poses challenges. Power outages and theft within the plants give daily challenges and a majority of the Wastewater Treatment plants are dysfunctional. As a result, wastewater is often not treated to an extent where it fulfills national standards before it is discharged into the rivers and dams, which is also the drinking water resource. At the project’s pilot plant in Temba, the aim is to increase the compliance of the effluent demand from 54% to 64%.

Pisystem Sscsouthafrica
Demonstration of the new PI numbering system at Temba WWTW

A team from Aarhus brings in know-how on wastewater processes such as sampling practice and analysis as well as monitoring of incoming wastewater which can lead to better wastewater treatment. Furthermore, Aarhus contribute with operating principles which we transfer through workshops to local operators.

Improving water management feeds into the sustainable development goals. Aarhus can add a lot of value, transferring knowledge regarding all the processes of wastewater treatment which will impact the environment in Tshwane directly.
- Kristoffer Rønde Møller, Sector Advisor - Embassy of Denmark in South Africa

Recognizing the importance of building long-term capacity, the cooperation also aims to address the broader challenges rooted in governance, policies, and political considerations within Tshwane. Through the sector cooperation, the Danish Embassy in Pretoria assists the WWTPs to navigate the intricate political landscape and ensure active participation from all political levels throughout the city's value chain.

Read more about wastewater management i Tshwane


  • Partners: the City of Tshwane, the City of Aarhus, and Aarhus Vand.

  • Duration: 2017 -2027 (prolongation possible)

  • Financed by the Ministry of Foreign Affairs of Denmark

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