Reducing the Environmental Impacts of Coal
Mining
Overview
 The
Australian coal industry is committed to operating
in an environmentally responsible manner, and
to continuously improving its environmental performance.
The industry is concerned to minimise its impact
on all aspects of the environment - visual landform,
air and water quality, noise levels, native flora
and fauna, soil conditions, and historic and archeological
sites.
Environmentally, coal mining has two important
factors in its favour. It makes only temporary
use of the land and produces no toxic chemical
wastes.
By carefully pre-planning projects, implementing
pollution control measures, monitoring the effects
of mining and rehabilitating mined areas, the
coal industry minimises the impact of its activities
on the neighbouring community, the immediate environment
and on long-term land capability.
Australia's coal mines are required to meet stringent
environmental requirements at all stages of mine
development, from planning through to post-operational
mine site rehabilitation. The industry has responded
by developing and applying more and more effective
and sophisticated pollution control measures supported
by comprehensive monitoring and reporting.
State and Territory Mining Acts and related legislation
are the major laws determining environmental requirements
for the development of coal projects in Australia.
Projects requiring Commonwealth approvals (for
example, approval of foreign investment), may
also be required to satisfy Commonwealth environmental
requirements before approval is given.
Air, Noise and Water
 To
protect workers and communities from air, noise
and water pollution, each mine invests heavily
in specialised equipment and continuously monitors
the effectiveness of its pollution control measures
and researches new methods.
Dust levels are controlled by spraying roads,
stockpiles and conveyor transfer points, drills
are fitted with dust collection and additional
land surrounding the mine may be purchased to
form a buffer zone between the mine and its neighbours.
Water pollution is controlled by carefully separating
the water runoff from undisturbed areas from water
which contains sediments or salt from mine workings.
Clean runoff can be discharged into surrounding
watercourses, while other water is treated and
re-used for dust suppression and in the coal preparation
plant.
Noise is controlled through selection of equipment
and insulation and sound enclosures around machinery
and each site has noise and vibration monitoring
equipment installed.
Mine Rehabilitation
 Since
mining activities represent only a temporary use
of the land, extensive rehabilitation measures
have been adopted to ensure that land capability,
post mining, meets agreed and appropriate standards
which, in some cases, are superior to the land's
pre-mining condition.
Where the mining is underground, the surface area
can be simultaneously used for forests, cattle
grazing and crop raising, even reservoirs and
urban development with little or no disruption
to the existing land use. In all cases, mining
is subject to stringent controls and approvals
processes.
In open-cut operations land rehabilitation measures
generally progress simultaneously with the mine's
development. As core samples are retrieved to
assess the quality and quantity of coal at a site,
they are also analysed to assess the value of
soil or subsoil material to support vegetation.
Computer models are used to simulate mining and
backfilling operations over the operating life
of the mine. Top soils are stripped and stockpiled
prior to mining for subsequent dispersal over
rehabilitated areas.
As mining ceases in one section of the open-cut,
bulldozers and scrapers are used to reshape the
disturbed area. Drainage within and off the site
is carefully designed to make the new land surface
as stable and resistant to soil erosion as the
local environment allows. Often dams are built
to protect the area from erosion and to serve
as permanent sources of water. Based onthe soil
requirements, the land is suitably fertilised
and revegetated.
 Companies
keep a close watch on the progress and usually
prohibit use of the land until the vegetation
is self-supporting. The cost of the rehabilitation
of mined land is factored into the mine's operating
costs.
Mine Subsidence
Some land subsidence is a consequence of underground
mining, if the maximum amount of the coal resource
is to be recovered from each mining lease. However,
efficient resource recovery can be achieved through
careful mine design, involving subsidence control
practices which minimise surface disturbance,
integrated with thoughtful planning of proposed
urban and other surface developments.
Our community is understandably concerned about
any land-use activity that could place private
or public property or valuable landscapes at risk.
However, a thorough understanding of subsidence
patterns in a particular region enables the effects
of underground mining on surface subsidence to
be quantified. This ensures the safe maximum recovery
of our valuable coal reserves, while providing
protection to other competing land uses, structures
and environmental features on the land surface.
The coal mining industry uses a range of engineering
techniques to design the layout and dimensions
of its underground mine workings so that surface
subsidence can be anticipated and controlled.
Further references/links:
For further information on mine site rehabilitation,
mine subsidence and coal-based environmental research
generally, visit the University of Queensland's
Centre for Mined Land Rehabilitation at:
http://www.cmlr.uq.edu.au
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