Pollution in the water supply wells of Khartoum, Sudan

 The supply of water to Khartoum, Sudan, is from wells tapping aquifers in the Nubian Sandstone Formation. The boreholes are located in residential areas where sewage disposal is by means of a siphon septic tank system draining into the water table in the upper alluvial deposits. The aquifers are leaky to unconfined in nature and as the lower groundwater moves from the Nile towards the residential areas, it is susceptible to pollution from the septic tanks. Evidence that such pollution is occurring was found in three production wells where the presence of E. coli bacteria was identified. Received: 9 July 1998 · Accepted: 20 May 1999