Assessment of heavy metal contamination in surface water near tailings dam

Elevated levels of heavy metals in surface water can lead to the degradation of water quality, especially in mining areas where tailing dams are sources of heavy metal pollution. This study focuses on evaluating the concentrations of heavy metals in surface water near the Legadembi tailings dams. The mean concentrations (in µg/L) of various heavy metals including: arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), molybdenum (Mo), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), thallium (Tl), uranium (U), vanadium (V), tungsten (W), zinc (Zn), and zirconium (Zr) were determined: 79.7, 0.15, 162.3, 0.66, 18.1, 0.01, 22.5, 55.7, 0.30, 3.3, 2.6, 0.01, 0.49, 1.7, 136.1, 5.7, and 0.32, respectively. Moreover, the concentrations of metals in the surface water exhibit a temporal or seasonal variation, which makes the study interesting. Overall, the results indicate that the concentrations of heavy metals generally decrease as the distance from the tailings dam increases, signifying the downstream dilution effect. Nevertheless, it was observed that dams two and three surpassed both national and international standards for certain heavy metals, such as As, Co, and W. These dams, which are accessible to domestic animals, would pose a potential health risk to humans and animals.