Assessment of pollution potential of the Hasangazi chromite pit (Tunceli, Turkey): implications for the natural environment

The Hasangazi chromite pit is an abandoned mine located to the east of the town of Pulumur (Tunceli, Turkey). The surface water that circulates in the pit flows into the Pulumur stream via the Turnadere creek. The quality of the surface water and soil from the region is important regarding the ecosystem in the Tunceli area. The open pit operations in the chromite deposits may be the cause of toxic element enrichments. To understand the effects of such pits, samples from the sediments, soil, waste material, and surface water were collected from the Hasangazi pit and its surrounding area. Samples were mineralogically and geochemically analyzed by XRD, ICP-OES, and ICP-MS methods. Mineralogical analyses showed the presence of chrysotile and plagioclase in the sediment and soil samples. These samples are also enriched in toxic elements, e.g., Cr, Ni, and Co. In particular, the Cr and Ni concentrations exceed the limits of soil pollution regulation of Turkey and the US Environmental Protection Agency. Overall the Cr, Ni, and chrysotile contents demonstrate the impact of the abandoned pit and the ultramafic rocks. Moreover, the surface water samples in the dry season have Zn concentrations above the toxic levels that may have been derived from the volcanic rocks. Environmental remediation precautions should immediately be taken around this inactive pit.