Science et changements planétaires / Sécheresse


Water table contamination problems due to open sewage in Metropolitan areas of black Africa. Case study of the water table in Brazzaville, Congo Volume 12, issue 3, Septembre 2001


See all figures

Unité de recherche sur les écosystèmes aquatiques, BP 125 Brazzaville, Congo.
  • Page(s) : 175-82
  • Published in: 2001

Brazzaville has a population of about 1 million people, and more than two-thirds of these inhabitants live in the suburbs. These areas do not have a supply of clean drinking water, nor an organised sewage disposal system. The residents often use water holes, springs, and rainwater for their water supplies. This situation cannot continue without serious degradation of the public health situation. Diseases linked to fad water quality, such as amoebiasis, typhoid fever, severe diarrhoea are thus the main cause of death. The Brazzaville hydrology laboratory is fully aware of this situation. A study on degradation of the water table was implemented in 1995. Measurements were obtained from 1995 to 1999 with a break in 1997 due to the political situation. Overall, 6,815 chemical quantitative analyses and 612 bacteriological analyses were performed. The results indicated that 34% of the bacteriological analysis samples had traces of faeces contamination. The dissolved matter concentration was in line with standards set out by the World Health Organisation for drinking water.