Well water survey in two districts of Conakry (Republic of Guinea), and comparison with the piped city water

Analyses of water from wide-diameter open wells were carried out in two districts of Conakry (Republic of Guinea) during the dry season of 1994 (April-May) to evaluate its bacteriological and physico-chemical quality and to compare well water to the piped city water. Widespread well water contamination for nitrate and fecal bacteria was found throughout both districts. The other common water-quality parameters, as well as total organic carbon and halogens, oils and greases of general use, and 34 inorganic elements were within the standard norms for safe drinking water. Chromium and, to a lesser extent, lead and mercury could become a threat to health if the situation worsens. Although thorough hydrogeological studies are needed to determine contaminant pathways, insufficient well maintenance appears to be the main factor contributing to the bacteriological contamination, while the nitrate contamination seems more closely linked to infiltration of organic contaminants from the soil surface. Piped city water was found to comply with WHO norms for drinking water and its use should be strongly encouraged to reduce the incidence of water-borne diseases.