Spatial Variability of Borehole Water Quality in Saki West Local Government Area of Oyo State, Nigeria

Abstract

Access to water from the State Water Corporation in Saki West Local Government Area (LGA) is a serious challenge and this has forced  inhabitants to concentrate and invest on borehole water for consumption. This study examined the spatial variability of borehole water  quality in Saki West using Geographic Information System (GIS). Global Positioning System (GIS) was used to identify the locations of the  boreholes. The results showed that 298 boreholes were distributed across the landscape of 2,014 km2 . Water samples were collected  from twenty-two boreholes of the eleven wards in the study area. The water samples were analysed for physical, chemical and bacteriological parameters using standard techniques in the laboratory and the results were compared with the World Health  Organisation (WHO) and National Standard for Drinking Water Quality (NSDWQ). Also, geostatistical analysis Kriging method of  interpolation were performed using ArcGIS 10.3 to visualize the spatial variability of the borehole water quality of the parameters in  different wards. The results for pH, temperature, taste, odour, colour, dissolved oxygen, total hardness, chloride, fluoride, sulphate and  nitrate, for all the water samples were within the permissible limits except turbidity, total coliform and faecal coliform which were above the recommended values. The result of the Spatial variability showed that Adabo, Agannmu, Baabo, Iya and Otun are the areas that have  least quality of water which may be as a result of contamination from run-off surface water along with indiscriminate defecations. The  study therefore recommends that borehole water in the area need treatment before consumption and there should be an improvement  in hygiene education at all levels.