vegetation. Another reclamation method involves filling in the hole with water to create an artificial lake. Large tailing piles left behind may contain heavy metals which can leach out acids such as lead and copper and enter into water systems. Open-pit mining - One of the world's largest types of mine and the size of these operations leave behind massive landscape scars, destruction to environmental habitats, and substantial clean-up cost. An open-pit mine can yield an enormous quantity of waste rock, sinkholes can form down the road, flooding and similar negative impacts as strip mining. Mountaintop removal mining - Involves the removal of whole mountaintops, the waste rock of which is used to flatten out the surrounding land by infilling rivers and valleys. This is very destructive as it physically permanently alters the landscape and the associated ecosystem. Throughout the Appalachians in states such as Kentucky and Virginia, mountaintop removal is a common mining method where whole forests are cleared and the area becomes vulnerable to possible landslides, with restoration sometimes being too difficult/costly. Dredging - A form of surface mining where the environmental impacts are primarily found underwater. The method of extracting material from the seafloor or any water body leads to the harmful risk of marine life. Overall, the effect are far less compared to the other mining methods. The influx of sediment can bury flora and fauna, change water levels and can alter the oxygen content. Water and noise pollution is a concern that must be monitored because marine life is very sensitive and vulnerable to drastic and harmful changes within their ecosystem. Highwall mining - Has a lower environmental impact than mountaintop removal because of the smaller external surface area present but there is still negative side effects. Air and noise pollution from blasting are common environmental effects along with the large tailing piles, which can leach into waterways and numerous ecosystems. See also Shaft mining Hobet Coal Mine References External links "Why Surface Mine?", an argument in favor of surface mining, by an executive of International Coal Group Surface mining Environmental impact of mining