TITLE:
Surface and Groundwater Quality and Flow Dynamics around a Tropical Highland Open Pit Mine, Amid Progressive Ecological Rehabilitation
AUTHORS:
Lefranc Busane Basima, Jean-Berckmans Bahananga Muhigwa, Venant Muderhwa Nshombo, Christian Kalikone, Patrick Vualu
KEYWORDS:
Mining, Water Quality and Quantity, Heavy Metals
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.2,
February
28,
2025
ABSTRACT: It is essential to investigate the impact of tropical highland open pit gold mines on surface and groundwater quality and flow dynamics. Samples from the Twangiza gold mine, with long term mining activities, including small-scale mining were analyzed in an accredited South African Laboratory. Results indicate that TDS and EC were higher in the mine site due the concentration of many metals. DO values were higher downstream. ORP and pH levels were similar at all site positions. Upstream: Fe, Si, K, Mg, Al have the highest concentrations (14.0 - 23.1 mg∙l−1). P, Pb, B, Ti, Sr, Ag, Ni, Ba, and As have concentrations ranging from 0.1 - 0.9 mg∙l−1. Li and Au have the lowest concentrations (0.01 - 0.05 mg∙l−1). Zn was also relatively abundant upstream, most likely airborne by the plant generator smoke. Within the mine site: Si, Al, Mg, Fe are found in higher concentrations (19 - 50 mg∙l−1). These are followed by K, As, and P (1.4 - 4 mg∙l−1). Ni, Ti, Ag, Sr, Ba are also found in lesser concentrations (0.2 - 0.7 mg∙l−1). The groundwater flow remained consistent. This study has the advantage of having continuously followed up a large number of heavy metals during years.