The Impact of Open Pit Mine on Nearby Watercourse Mala Rijeka, Vareš

Abstract

Veovača open pit mine, located near Vareš, was used for extraction of ore rich with zinc, lead, and barite from 1982 until 1988, with the floatation processing plant in the near vicinity. Water quality of Mala Rijeka, watercourse passing by the mine and the processing plant, was examined in 2019. This paper analyses the presence of selected heavy metals (Cd, Zn, Fe, Mn, Pb), sulphate anion, and electrical conductivity along the entire length of Mala Rijeka, to determine the nature of impact that the mine and the processing plant have on the watercourse. FAAS/ETAAS techniques were used to determine concentration of the heavy metals in water samples. Concentration of sulphates was determined by gravimetric (with BaSO4) method. Concentrations of Cd (<0.05–2.50 µg/L), Zn (0.119–1.212 mg/L), Fe (0.002–1.313 mg/L), Mn (0.001–0.580 µg/L) and Pb (0.002–0.007 mg/L) were found to be over the limit values prescribed in the national legislation, having decreasing trend toward the downstream watercourse sections. Electrical conductivity results (359–1060 µS/cm) and concentration of sulphates (29.4–319.0 mg/L) followed the same trend. Research work confirmed that watercourse Mala Rijeka was still under the influence of the open pit mine even more than 30 years after the closure of the mine.