OPEN-PIT MINING

The process of removing mineral deposits that are found close enough to the surface so that the construction of tunnels (underground mining) is not necessary. The soil and strata that cover the deposit are removed to gain access to the mineral deposit. The primary environmental concerns related to this technique are the disposition of spoils removed to gain access to the deposit and the scoring of the landscape that remains following the complete removal of the mineral deposit. Erosion and water pollution are also concerns because runoff from the mining area is frequently rich in sediments and minerals which may pollute receiving streams. Furthermore, when the resulting pit extends below the water table, it may necessitate the removal of groundwater that infiltrates the mining pit, potentially altering the groundwater flow with possible implications on the water table and groundwater characteristics. Also referred to as Strip Mining or Surface Mining. Also see Acid Mine Drainage, Dewater and Dewatering, and Yellowboy.