Mining coal pollutes the originally good groundwater quality, introducing large amounts of coal dust, rocks, dust, suspended solids, anthropogenic pollutants, and microorganisms into the water. Some mine water has high levels of suspended solids, chemical oxygen demand, sulfides, and total hardness. Therefore, the discharge of excessive wastewater from mines without treatment directly pollutes water quality, damages the groundwater system, and leaves many coal mines without a source of production and domestic water.
