OVERVIEW OF THE IMPACT OF MINING ON THE ... - IIED pubs

these substances are often mobilized during rainfall and transported by runoff into nearby watercourses where
they have additional effects on components of the aquatic ecosystem as well as other water users.
2.3.6 Stockpiling and transport of final product
In most mining operations, the stockpiling and eventual transport of final product to markets is seldom
associated with significant impacts on the biophysical environment. However, the exception to this
generalization concerns those mining operations where the ore is transported for beneficiation elsewhere (for
example, coal, manganese and iron). In these cases, the primary impacts on the biophysical environment are
linked to noise disturbance and the emission of dusts and fumes from both the stockpiles and the transportation
system (Fuggle & Rabie, 1996).
• 2.3.7 Mine closure and post-operational waste management
Many mine-related environmental impacts often continue long after the mine has stopped production and has
been closed (see Table 2.2). Amongst the more pronounced post-closure impacts on record are landscape
scarring in the form of unrehabilitated waste rock dumps, mine tailings dams, discard dumps, old shafts and
underground fires. In addition, continuing environmental damage from polluted waters (including acid rock
drainage), wind-blown dusts and the dispersal of contaminated solid waste is a feature of mines throughout the
world (Johnson et al., 1994). Environmental changes that result from these impacts include the following (Carl
Duisberg Gesellschaft, 1999):
• Loss of productive land for alternative uses;
• Loss or degradation of groundwater quality;
• Pollution of surface water by sediments and/or salts, as well as lower pH values and increased metal
concentrations;
• Alterations to river channels by erosion and slumping;
• Changes in river flow regimes with sharper flow peaks and reduced dry season flows;
• Air pollution from dusts, radionuclides and toxic gases; and
• Risks of falls into abandoned shafts and pits that are not adequately protected.
2.4 Specific impacts of mining on water resources
Five key areas of impact that mining may have on water systems are: acid mine drainage (AMD), release of
metals, cyanide, siltation and water use. The set of impacts that any specific mining operation will have on the
environment, and especially the aquatic environment, depends on:
• The type of rock and ore being mined;
• The type of mining operation and the scale of operations;
• The efficiency and effectiveness of any environmental management systems that are deployed by mine
management; and
• The sensitivity of the receiving environment (including scarcity of water).
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