Project Aims to Improve Wastewater Ponds for Irrigation
What is a simple way to upgrade wastewater stabilisation pond systems in Africa so that the water can be reused for animal fodder production? Under the direction of Technische Universität Darmstadt, the joint project "EPoNa – upgrading wastewater ponds to generate irrigation water, using the Cuvelai-Etosha basin in Namibia as an example" has been researching into a comprehensive response to this question since the start of September.
The town of Outapi in Northern Namibia operates a 4-step pond system to treat their wastewater. When the ponds were constructed twelve years ago, Outapi had around 4,000 inhabitants, with only a small proportion having access to sewerage services. Project engineer Jochen Sinn from the Wastewater Engineering Research Group at the Institute IWAR of TU Darmstadt estimates that now, more than 5,000 inhabitants in this constantly growing town are already using the sewerage system. The produced wastewater passes through a succession of four ponds. The suspended solids sink to the bottom, where they are broken down by microorganisms, and the sun's ultraviolet light disinfects the water.
But the system is so heavily overburdened and now silted up, that the originally constructed evaporation pond keeps overflowing. At the same time, the community is facing a problem of fodder shortage towards the end of the dry season lasting around nine months. The lack of water means that they can no longer cultivate enough fodder crops, so if the rain does not come, they have to slaughter livestock as a matter of necessity. The Town Council made use of its contact from the earlier CuveWaters wastewater project and approached the Institute IWAR to solve both problems.