Assessment of the effect of the tailings dam on the quality of surface and underground water in Takht-e-Gonbad copper mining area

Materials in tailings dams that contain major ions and heavy metals lead to the release of toxic metals and acid production with the presence of oxygen, which has a high potential for pollution and has an adverse effect on the quality of surface and underground waters. In this research, the effect of tailings dam on zinc on the changes of manganese, molybdenum and arsenic in surface and underground waters of Takht-e-Gonbad copper mining area has been studied. Number of 11 samples were taken from different parts of the tailings dam area, these studies were carried out on surface and underground water in two dry and wet seasons. The concentration of heavy metals such as manganese, molybdenum, and arsenic were investigated and the related graphs were drawn and interpreted using Arc GIS software. Then the monitoring of underground water pollution in the mining area was investigated. The concentration of manganese in the drainage of the sedimentation dam, tailings dam water No. 3, and mine pit water is slightly higher than the environmental standard. The highest amount of molybdenum is found in the dry season and in mine peat. The concentration of arsenic in the wet season in all samples is below the standard limit, and in the dry season, this amount is more than the drinking standard of Iran. Based on the instructions of the Environmental Protection Organization and according to the existing conditions, it is suggested to dig 17 observation wells with a maximum depth of 50 meters as 1st grade monitoring wells around the tailings dam of Takht-e-Gonbad copper mine.