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The infl uence of large-scale mining operations on groundwater quality was investigated in this study. Trace element concentrations in groundwater samples from the North Mara mining area of northern Tanzania were analyzed. Statistical analyses for
relationships between elemental concentrations in the samples and distance of a sampling site from the mine tailings dam were
also conducted. Eleven trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were determined, and averages of Fe
and Al concentrations were higher than levels accepted by the Tanzanian drinking water guideline. Levels of Pb in three samples were higher than the World Health Organization ( WHO ) and United States Environmental Protection Agency ( USEPA )
drinking water guidelines of 10 and 15 µg/L, respectively. One sample contained a higher As level than the WHO and USEPA
guideline of 10 µg/L. The correlation between element concentrations and distance from the mine tailings dam was examined
using the hierarchical agglomeration cluster analysis method. A signifi cant difference in the elemental concentration existed depending on the distance from the mine tailings dam. Mann–Whitney U -test post hoc analysis confi rmed a relationship between
element concentration and distance of a sampling site from the mine tailings dam. This relationship raises concerns about the
increased risks of trace elements to people and ecosystem health. A metal pollution index also suggested a relationship between
elemental concentrations in the groundwater and the sampling sites’ proximity from the mine tailings dam. |
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