Use of waste water in urban agriculture in the Dakar area, Senegal : an interdisciplinary study towards sustainability

Swiss Coordinator : Hans-Rudolf Pfeifer, Faculty of Geosciences, University of Lausanne
Main Foreign partner : Seydou Niang, University C.A. Diop Dakar
Cooperation with : Senegal
Disciplines : Urban agriculture

Abstract
This project aims to assess two widespread practices used in irrigated agriculture in developing countries : the use of untreated or poorly treated wastewater or mixtures of wastewater with groundwater water in order to supply for the lack of fresh water (during the dry seasons) and the massive use of often prohibited pesticides. The area to be studied is the costal area of Dakar, whose urban agriculture provides more than 60 % of the vegetable production for the 2.3 million inhabitants living there. A group of university teachers, NGOs and local authorities, instead of prohibiting this practice of known high health and environmental risks, but of a high potential to guarantee a certain level of livelihood, collaborates to find optimal, sustainable practices and alleviate poverty among the rapidly growing urban population. By studying the current agronomic practices, testing low cost extensive wastewater treatment methods and by studying in detail the current interaction between water contaminants (micro-organisms, macro- and micro-pollutants), farm products, soils and groundwater, a complete environmental and socio-economic assessment is planned. The used approach will necessarily be interdisciplinary, based on environmental and socio-economic research methods, involving 2 Ph.D. students, several master students and the scientific and technical specialists of their host institutions. The final results will be presented as a Geographical Information System (GIS), including different layers showing not only scientific maps of soil types, ground water level, micro-contaminant degrees of pollution, but also socio-economical date as farmer income, farming practices, identified diseases, etc. This powerful tool will facilitate communication between researchers, stakeholders and local policy makers and will allow an integration of urban agriculture in urban development politics. Besides, it could be easily and regularly updated. Furthermore, GIS will allow authorities to regulate and communicate a sustainable use of wastewater and pesticides in the various local situations and thereby help to alleviate poverty.

Contact Addresses:

Dr. Seydou Niang, Laboratoire d’eaux usées, Institut Fondamentale d’Afrique Noire, University C.A.Diop, 86 Cité Assemblée Ouakam, Dakar, Senegal, e-mail: seyniang@refer.sn

Prof. Hans-Rudolf Pfeifer, IMG- Centre d’Analyse Minérale, Bâtiment Humense, University of Lausanne, CH-1015 Lausanne, Switzerland, e-mail: Hans-Rudolf.Pfeifer@unil.ch

 

Context: Senegal, Dakar area

Urban agriculture in a semi-arid region: use of waste water to avoid too high salinities and fertilizers

Detailed knowledge of agricultural practices is a prerequisite to model their impact