Bacteriological Quality and Possible Health Effects of Gravity-Piped Water in Hohoe District of Ghana

Abstract

A simple technology termed Gravity-Piped Water System (GPWS) has been used in the Hohoe District in the Volta Region of Ghana to provide drinking water without any disinfection treatment. Ten years after the establishment of the GPWS, there were complains about the incidence of diarrhoea diseases, colouration of water and sediment in some of the systems put in place to provide potable water. The paper reports on bacteriological quality and health implications of water at various points (source, reservoir, standpipe and individual homes) of four GPWS in four communities in the Hohoe District over two seasonal regimes for three consecutive years, 2005–2007. Conventional cultural methods, as specified by APHA (1995), were used to detect the resident faecal and total coliform bacteria. Biochemical methods, employing API 20E identification kit and serological tests, were used to confirm the presence of bacteria species and diarrhoeagenic agents, respectively. Structured questionnaires were used to obtain medical information. With the exception of the source at one of the communities, Nyagbo Israel, all points of the GPWS were heavily contaminated with Enterobacteria. Ten gram-negative nonsporing bacteria of possible health consequences belonging to the family  Enterobacteriaceae were isolated from water samples at all points. The presence of diarrhoeagenic agents, enterotoxigenic E. coli (ETEC), enteropathogenic Escherichia coli (EPEC), Salmonella and Shigella species were confirmed. All the systems showed a trend of reduction in parameters from source to tap, with no significant elevations in the homes. Enteric diseases peaked in rainy seasons (August-October). Medical reports support a strong link between diarrhoeal incidence and water used. The practical implications of the findings are discussed.