Management of city aquifers from anthropogenic activities: Example of the Windhoek aquifer, Namibia

Should We Be Concerned with Long-Term Health Problems Associated with Pesticides in Namibian Groundwater?

“…This implies a low holding water capacity, and the soils are generally deficient in nutrients such as Mn, Fe, and Zn. This data suggests that natural attenuation factors suggested by Lerner et al (2000) and Mapani and Schreiber (2008) Table 2. Summarized Main soil types in Namibia Fig.…”

“…Once pesticides have entered the hydrological cycle, their elimination is difficult, and in most places impossible, especially so with groundwater. However when pesticides percolate together with surface water, towards the groundwater table, certain quantities may be trapped by clay minerals (Mapani & Schreiber, 2008). The effectiveness of this trapping process (attenuation) depends on the soil types developed in a particular area.…”

“…In zones away from ephemeral rivers and streams, this process of displacement time can take months to years. For example, in Windhoek, the water table occurs at 70-76 m below surface; and the displacement time can tale up to ten (10) years due to the nature of the fractured aquifer (Mapani & Schreiber, 2008). In other aquifers with semi-arid conditions, chemicals used today may take 50 years to reach the groundwater table.…”

Food Security Among Small-Scale Agricultural Producers in Southern Africa

“…While the above mentioned vegetable gardens use tap water from the municipality water distribution system, others outside the reach of the municipality water distribution system depend on independent boreholes. Research carried out during 2008 pointed out the imminent pollution threat to the ground water aquifer from anthropogenic activities in Windhoek area (Mapani and Shreiber 2008 ). More recent research carried out during 2012/2013 on water quality in the Windhoek Green Belt area revealed that the agricultural practitioners in the peri-urban area depend on boreholes whose water quality is threatened by Windhoek's municipal waste water disposal system and small-scale industries within the peri-urban zone.…”

The Potential of Rainwater Harvesting: A Case of the City of Windhoek, Namibia

“…All these sources are delicate and vulnerable to environmental or economic factors. Water recycling, for example, has many economic implications due to the expensive nature of the recycling of waste water to potable quality, whilst the aquifers in Windhoek are said to be very vulnerable to pollution because they are shallow, and unprotected (Murray & Tredoux, 2004;Mapani, 2008).…”