Twenty-five years of wastewater reclamation in windhoek, Namibia

Abstract

In 1968, a direct water reclamation system from domestic sewage was pioneered in Windhoek, Namibia, to supplement the potable water supply to the city. This system went through a succession of modifications and improvements over the years, but consistently produced water of acceptable quality, as evidenced a comprehensive chemical, bacteriological, virological, and epidemiological monitoring. Now, in 1995, Windhoek is again facing a shortfall of potable water in the light of a population increase (growing at 6% to 8% per annum) and increasing water demand, and is currently extending the water reclamation system from the previous 4800 to 21000 m3.d−1, the maximum attainable. All the components of the reclamation system are being reviewed and re-analyzed; demand management, diversion of some industrial effluents, wastewater treatment, water reclamation, oxidation and adsorption technologies, blending of reclaimed wastewater with other sources, buildup of salinity, treatment costs, and monitoring and quality control strategies. The practical experience at Windhoek demonstrates that a direct wastewater reclamation system is a practical, responsible way of augmenting potable water supplies in arid regions, but that it requires comprehensive planning, training and on-going commitment for its continued success.