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Development Account Projects

Combating urban pollution of superficial and groundwater aquifers in Africa

Background:

Most of the water supply systems in African mega-cities are based on groundwater. Unplanned and rapid urban expansion has put enormous pressure on this natural resource, which becomes polluted from excessive use of fertilizers, pesticides and herbicides as well as effluents from leaky sewerage systems, septic tanks, leaky fuel tanks, factories or pollutants from solid waste (garbage) dumps. The provision of adequate supplies of water to industry, agriculture and urban residents, especially the urban poor, is becoming one of the biggest challenges facing governments and local authorities. Because of groundwater flow, polluted urban groundwater will spread over large areas in the direction of the flow, even if the contaminants emanate only from discrete point locations.

In the near future, it will be practically impossible to clean up urban aquifers once they became polluted over a large area. Consequently, in the long-term, polluted urban groundwater will lead to acute shortage and require extensive interim systems. It will place public health at risk through exposure to a variety of substances, such as pathogens, carcinogens and nitrates. Nutrient-enriched groundwater discharging to lakes and reservoirs, will induce algae blooms and other symptoms of eutrophication. Trace metals and organic contaminants may enter the food chain.

The project's implementation will result in the establishment of a sub-regional task forces of relevant experts, who will undertake various activities on ground water vulnerability. It will also facilitate technological cooperation among countries in the area; lead to the establishment of a regional network to monitor urban groundwater pollution in West Africa; create a monitoring framework at the national level complemented by a regional database; further knowledge of physical and chemical properties of surface and groundwater; minimise existing or potential contamination at the source; develop attitudes and tools reducing the adverse effects of human activities in the residential areas; facilitate the use of models on groundwater vulnerability in African residential areas; strengthen capacity to design vulnerability maps.

Objective:

To reduce water pollution in urban areas of Africa, including reduction of the risk of exposing the population to a variety of substances, such as pathogens, carcinogens and nitrates

Expected accomplishments:

  • Establishment of a regional network with methodologies developed for the optimal monitoring of the contamination of surficial and groundwater aquifers in African residential areas to serve as an early warning system for possible water supply contamination;
  • Strengthened capacity to design vulnerability maps.

Effects and Impact:

The project has had a measurable impact on stakeholders and interested parties. The distribution of early warning bulletins has had a clear local impact on relevant politicians and water industry managers in each country. Several workshops gathering the major stakeholders in the participating countries lead to a strong awareness about groundwater vulnerability and involved various media. The wider capacity building, together with further publicity and scientific/technical knowledge transfer actions will create a lasting and strategic impact. The real importance of the project should be more actively publicized to key decision-makers on a national scale in order to promote effective legislation and regulation as far as urban groundwater resource management is concerned.