Use of geographic information system in the assessment of bacteriological quality and sanitary risk factors of household drinking water sources in Ibadan, Nigeria

This study used a combination of Geographic Information System (GIS), bacteriological analysis and sanitary inspections to assess the risk of contamination of drinking water sources in 62 randomly selected households in Ibadan, Nigeria. Findings revealed that the majority of the households used groundwater sources of poor quality. The raw bacteriological data was classified into five water quality Grades A to E (from no risk to very high risk). Majority (82.3%) of the households were grouped as D and E, implying that a large proportion of the households was exposed to high bacterial load in their water supplies thus exposing these households to the risk of water-borne diseases. Results of sanitary inspection also showed that most (62.9%) households have intermediate/high risks associated with physical defects in the water supply facilities which could lead to quality deterioration. A weak positive correlation (Spearman's r = 0.379, p = 0.02) was observed between the E. coli and sanitary risk score grades. The study proposed urgent remedial action by all stakeholders and an extension of the study to cover the rural and urban local government areas in Ibadan.