Mining in the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or (coal) seam.
The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock salt and potash, Mining in a wider sense comprises extraction of any non-renewable resource (e.g., petroleum, natural gas or even water).
The nature of mining processes creates a potential negative impact on the environment both during the mining operations and for years after the mine is closed. Environmental issues can include erosion, formation of sinkholes, loss of biodiversity, and contamination of soil, ground water and surface water by chemicals from mining processes.
In some cases, additional forest logging is done in the vicinity of mines to increase the available room for the storage of the created debris and soil. Contamination resulting from leakage of chemicals can also affect the health of the local population if not property controlled. Extreme examples of pollution from mining activities include coal fires, which can last for years or even decades, causing massive amounts of environmental damage.
Ore mills generate large amounts of waste, called tailings. For example, 99 tons of waste are generated per tons of copper, with even higher ratios in gold mining. These tailings can be toxic and most commonly dumped into ponds, rivers and seas.
Mining companies in most countries are required to follow stringent environmental and rehabilitation codes in order to minimize environmental impact and avoid impacts on human health. These codes and regulations all require the common steps of Environmental management plans.
Certification of mines with good practices occurs through the International Organization for standardization (ISO) such as ISO 9000 and ISO 14001, which certifies an ‘auditable environmental management system’; this certification involves short inspections, although it has been accused for lacking rigor.