SEASONAL VARIATION OF PHYSICOCHEMICAL AND BACTERIOLOGICAL QUALITY OF BOREHOLE WATER IN OGENGEN, OJU- BENUE STATE

Abstract

An investigative study was carried out to determine the physicochemical and bacteriological quality of borehole water available to residents of Ogengen Phase II and students of College of Education, Oju. The study was carried out in rainy and dry season and the results obtained were compared with the WHO standards for potable water. The range of results obtained for both seasons were: pH (6.60 -7.90), turbidity (0.99-35.1 NTU), total chlorine (0.25-0.50 mg/L), conductivity (410-697 µs/cm), and total dissolved solids (249-426 mg/L). The concentrations of the heavy metals determined were Fe (? 0.10 mg/L), Cu (0.12-0.21 mg/L) and Zn (0.22-1.34 mg/L). The range obtained for DO was 2.4- 6.30 mg/L while that of BOD was 0.5-2.50 mg/L and COD was 1.20-4.80 mg/L. The hardness showed that magnesium hardness (79-120 mg/L), calcium hardness (101-307.8 mg/L) and total hardness (213-427.6 mg/L). The results of the analysis showed that most of the parameters tested including the heavy metals concentrations were within the permissible limit of WHO standard for drinking water, however the hardness was far above the WHO standard. The findings also proved that the concentrations of the parameters measured were slightly higher in the rainy season. The bacteriological analysis showed that all the samples contained coliforms with coliform count of 45-140 cfu/L. The bacteria strains detected and isolated from the water samples were: Escherichia coli, Staphylococcus aureus, Klebsiella species and Lactbacillus species. The presence of microorganisms in the water samples proved that the water is not safe for direct consumption. Therefore proper treatment of water from these boreholes should be carried out before consumption.