Quality determination of groundwater for drinking at Nkawkaw in the eastern region of Ghana

Abstract

The physical, trace element and microbiology of groundwater randomly collected from four boreholes namely (BH3, BH5, BH103 and BH105) at Nkawkaw in the Eastern Region of Ghana were examined by comparing it to the Ghana standards for drinking water using various standard methods of analysis and the results were compared to the Ghana standards in 2011. The microbiological data indicated that the water from all the boreholes surveyed was safe for drinking since no thermotolerant colifom bacteria were detected in them. Although the results revealed evidence of minimum physical variations in terms of colour (0.67 Pt. Co - 61.0 Pt. Co), conductivity (819µs/cm - 1052µs/cm) and turbidity (0.59 NTU - 23.5 NTU), as well as relatively higher manganese (0.038mg/L - 0.638mg/L) and aluminum (0.064 - 0.479mg/L) concentrations in some boreholes, the values obtained were generally acceptable when compared to the Ghana water Company’s Standards and WHO Guideline values. The boreholes with high levels of manganese were all located in the same area which signified a possible rock mineral and groundwater interaction. Additionally, nitrogen concentration was found to be within the acceptable limits according to Ghana Water Company’s Standard even though at p<0.05, both forms of nitrogen (ammonium and nitrate), showed significant difference (p<0.00094) among their corresponding means (0.058, 0.054, 0.072 and 0.060) mg/L in BH3, BH5, BH103 and BH105 respectively. Frequent monitoring programmes and education are recommended to ensure implementation of safe water plans for the Nkawkaw area where tapping of groundwater from richer aquifer reserves appears unavoidable. Keywords: Groundwater, Nkawkaw, Borehole, Ghana Water Company, Bacteria, Physico-chemical, Traced Metal.