Bacteriological quality and metal levels of boreholes and hand-dug well within the Golden Star Wassa mining areas in Ghana

Abstract

This study seeks to assess the bacteriological, physicochemical and some trace metals levels in water samples from seven boreholes and a hand-dug well within communities of Golden Star Wassa Mine Limited in Ghana. Five of the sampling sites were slightly acidic and were below the lower limit of the acceptable World Health Organization (WHO) and Ghana Standard Authority (GSA) permissible guidelines for pH. However, sampling from Kubekro well BH04, Akyempim BH07 and at New Akosombo BH06 reported pH mean of 6.9±0.352, 6.7±0.696 and 6.6±0.283, respectively. Well BH02 and that of BH06, respectively reported True Colour mean values of 36.5±6.097 and 17.4±1.930 true colour units (TCU) which were above the WHO/GSA permissible value of 15 TCU. Electrical conductivity, total dissolved solids (TDS), alkalinity, and total hardness were below their respective WHO/GSA permissible limits in the sampling sites with 100% compliance. Pb, Zn, As, Hg, Cu, and Fe recorded a marginal degree of non-compliance with their respective WHO/GSA guideline values of 0.01 mg/L for Pb, 3.0 mg/L for Zn, 0.01 mg/L for As, 0.006 mg/L for Hg and 0.3 mg/L for Fe in all the sampling sites except Cu. All the boreholes indicated a non-detectable microbial load (total coliforms and Escherichia coli) except the hand-dug well at Kubekro Well (BH02) which showed some amount of total coliform bacteria load of 6±6.594 coliforms forming unit (CFU). The mechanised borehole groundwater sources within the study area, except the well at BH02 is good for drinking, and hence have not been adversely impacted by mining