Contamination of water resources in the mining region

Abstract Mines disturb ecological systems and are major source of environmental contamination at local and regional levels. Mines generate a huge quantity of sulfide rich waste, such as tailings and waste rocks, during the ore extraction and mineral processing. Sulfides on exposure to oxygen and water generates acid mine drainage (AMD) which leads to a decrease in pH and leaching of heavy metals from the waste. The AMD generation capacity of mine waste depends on the chemical composition of waste, extraction, or beneficiation process and climatic factors. The runoff from waste piles enriched with AMD mixes with streams and increases the load of heavy metals. The percolation of heavy metals from waste piles contaminates the groundwater and the impact is more in shallow aquifers. The abandoned mines (surface and underground) left after the extraction of ore are also major source of water contamination. Additionally, the overexploitation of water resources during dewatering and changes in land use and land cover due to mines disturbs the recharge and discharge capacity of aquifers. It leads to the degradation of water quality and changes in hydrogeochemical processes. Thus the implementation of proper waste management and treatment policies are urgently needed to save the quality and quantity of water resources in the mining regions.