Mine Rehabilitation Handbook - Mining and Blasting

• Where batters or culverts are required, protect slopes and
discharge points.
6.8.3 Rehabilitation
• Consult landholders to determine whether they require the retention
of roads and tracks for future access.
• Install gates or barriers to prevent unlawful access.
• Properly designed roads and tracks will remain stable. Re-spreading
topsoil and ripping will relieve compaction prior to seeding. It will
also discourage unauthorised access and facilitate revegetation (see
figure 6.7.)
Figure 6.7
• Remove temporary culverts, spoon drains etc and re-instate natural
flow lines.
• Where construction of cut or fill batters has resulted in unstable
slopes, return fill material from the road or track formation to create
a stable slope prior to attempting revegetation.
• Program closure and rehabilitation work so that access for
rehabilitation equipment (hydroseeders etc) is maintained to those
specific locations requiring treatment.
6.9 Power Lines and Telecommunication Installations
• During installation, minimise excavation and clearing of vegetation.
Only limited access is required and leaving rootstock undisturbed will
promote rapid revegetation of the access way.
• Consider helicopters for installation and access for maintenance and
removal at isolated or difficult sites.
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• Remove cables and guys etc when towers are dismantled. Bury or
remove concrete slabs and footings.
• Prevent access and rehabilitate access ways after de-commissioning.
6.10 Final Voids
When open cut mining techniques are employed it is common for an
open pit to remain at the end of mining. The extent of this final void may
be minimised in some cases by progressive direct emplacement of
overburden in the mined out sections of the pit. It is essential that final
voids be left in a safe condition where backfilling is not reasonably
feasible. The location and nature of the pit mainly determine available
options for post mining land-use.
Void options include:
• Water Storage Area.
Depending on the intended use of the stored water, the quality of
water in the pit (both on entry and after storage) will be a
determining factor. Sufficient catchment area should be provided to
fill the pit within a reasonable time and flush the pit storage
periodically to prevent the stored water becoming saline.
• Wetland/Wildlife Habitat.
Depth will be a critical factor. Deep, steep sided voids are generally
not suited. Consideration of the natural movement in the level of
ground water and the consequent effect on any remodeled
landscapes and habitats requires careful investigation.
• Waste Disposal.
The void must be located sufficiently close to the source of waste for
this option to be economical. The type and amount of waste available
is important. Wastes which may be suitable include domestic waste,
industrial wastes, tailings, coal wash rejects and flyash. Investigation
of the ground water regime and the risk of contamination by leachate
from the disposed material will also require investigation.
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