Characteristics and Quality Assessment of Drinking Water in Some Major Towns of Osun State, South-Western Nigeria

Abstract

The characteristics and quality of drinking water of four different sources (Borehole, tap, stream and well) in five major towns covering the three senatorial districts of Osun State, Nigeria were analysed in order to determine their potability status. Water samples were collected for a period of six months and analyzed for seven physico-chemical parameters using standard literature methods. The mean values and ranges of the parameters measured were as follows: pH 8.85 ± 0.96 (6.0 -10.70); temperature 26.05 ± 2.27 (22.50- 30.00oC); conductivity 218.74 ± 129.56 (90-560 μS/cm); chloride39.66 ± 24.24 (ND-139.96) mg/L; phosphate 0.61 ± 0.41 (ND-2.60) mg/L; sulphate 4.06 ± 9.31 (0.14-57.05) mg/L; and nitrate 0.79 ± 1.74 (ND-13.14) mg/L. Generally, results compared favourably with the WHO (2008) and Nigerian Standards for Drinking Water Quality (NSDWQ) except temperature which was slightly higher than the ambient temperature. The
pH was also above the specified limit of 6.5 - 8.5 indicating alkaline nature of the water samples. This implies that the water samples may enhance the growth of micro-organisms, hence increase in the problems related to taste, odour, colour and corrosion. Periodical assessment of both physicochemical and microbial analysis of the areas is highly recommended, as this would be helpful in early detection of any future deterioration.