Xstrata Copper North Queensland.pdf - Mount Isa Mines

Environmental performance
Energy
In 2010, the Mount Isa Mines copper
operations had a total energy consumption
of 5.1 petajoules (PJ) compared to 5.3 PJ in
2009. This decrease was primarily due to
reduced consumption of natural gas and coal.
Energy intensity remained stable in 2010 at
24 gigajoules (GJ) per tonne of contained
metal, the same result we reported in 2009.
Water management
Fresh water supply and use
Fresh water consumed at the Mount Isa
Mines copper operations is sourced from
Lake Moondarra and Lake Julius. These two
dams are used in combination to ensure fresh
water supply to Mount Isa Mines as well as
the Mount Isa community. Lake Moondarra
reached 87% capacity in March 2010 and
Lake Julius reached 100% in February 2010.
Of the fresh water consumed in 2010, 100%
was sourced from Lake Moondarra. In 2010,
a total of 4,670 ML of fresh water was
consumed by the Mount Isa Mines copper
operations, including mining, processing
and smelting operations. The water intensity
figure for 2010 was 21.75 kilolitres per tonne
of contained metal.
Surface water
Surface water in the Mount Isa Mines region
flows into the Leichhardt River and then into
Lake Moondarra approximately 15 kilometres
downstream of the major site operations.
Water discharged off site is sampled and
analysed; and results have been provided to
the Department of Environment and Resource
Management.
In 2010, approximately $4 million was spent
on installing a new tailings reclamation line,
enabling water that would otherwise be
lost to evaporation in the tailings dams, to
be reused as process water on site. Refer to
case study on page 95 for more information.
Other improvements to water management
systems on site during 2010 have included
cleaning out antipollution ponds, relining
drains, and increasing stormwater
pumping capabilities.
Significant improvements have been made
across site over the past few years in order to
maximise reuse of stormwater in the process
water circuits. In particular, we have focused
on improving stormwater management
in areas associated with potential off-site
discharge points. In 2010, the final stage of
the Death Adder Gully (DAG) improvements
was completed, including installation of a
pumping system to enable water at the DAG
weir to be pumped back into Barracks Dam,
which forms part of the site-wide water
management strategy.
Biodiversity
The Mount Isa Mines copper operations
manage approximately 30,000 hectares (ha)
of land on mining lease ML8058, for the
copper and zinc businesses, within the Mount
Isa Inlier bioregion and Australia’s tropical
savannas. ML8058 is characterised by rugged,
rocky hills and poor shallow soil. Low open
woodland with Eucalyptus, Corymbia and
Acacia species predominates, with a ground
layer of Triodia species (Spinifex) which
reflects the complex geology, infertile soil and
semi-arid climate.
In 2010, 11 ha of land was disturbed by
our Mount Isa Mines copper operations
(see table below) for the construction
of infrastructure and to support mine
development. Opportunity for rehabilitation
on ML8058 is limited because most areas
currently disturbed are considered ‘active’ and
are not available for rehabilitation. Numerous
rehabilitation studies were progressed in
2010 to develop best practice rehabilitation
techniques specifically tailored to the
local environment.
During the year we continued biodiversity
management planning comprising various
projects and internal systems updates with
outcomes from the ML8058 biodiversity
study, which was finalised early in the year.
Effects on local environment
As part of the biodiversity management
planning in 2010, recommendations from
the ML8058 biodiversity study were
developed and will remain ongoing in 2011.
Biodiversity projects targeted key threatening
processes for biodiversity on the lease and
included development of a fire management
plan, and a pest management plan. No
known effects were identified on the Red
Goshawk, which is listed as ‘vulnerable’
under national legislation and International
Union for Conservation of Nature (IUCN)
Red List. During 2010, areas of conservation
significance were managed by existing land
management systems. No disturbed areas
were identified during the biodiversity study
as being of conservation significance.
Management of sulphur dioxide (SO 2 )
emissions forms part of the biodiversity
strategy as SO 2 fallout from the smelters
can have a localised impact on vegetation.
The introduction of the acid plant in 2000,
owned and operated by Incitec Pivot,
reduced SO 2 emissions from the copper
smelter by 78% during 2010.
Habitats protected or restored
The conservation significance of ML8058
has been interpreted with respect to the
surrounding landscape, the conservation
status of the species present and the
potential and actual threats operating on
the lease. Our copper operations are within
a traditionally grazed area and confined to
a minimal footprint. However there were
some habitats identified during the 2009
biodiversity study which are deemed to be
of conservation significance.
A Conservation Management Plan was
developed in 2009 based on the outcomes
of the study in relation to these regional
ecosystems, and the plan was finalised and
communicated to key stakeholders early
in 2010.
Following the vegetation survey conducted
as part of the biodiversity study, seeds were
collected from a community of Eucalyptus
nudicaulis trees. The conservation status
of this species is being reviewed and
may be classified as vulnerable. Seeds
were propagated and distributed into the
community during various environment
events such as World Environment Day and
Green Week.
During 2010 there were no instances of
stormwater discharging off site from copper
mining or processing areas at the Mount Isa
Mines site.
Land disturbed (ha) – Mount Isa Mines copper operations
2009 2010
Rehabilitation during the year 0 0
Total rehabilitation completed to date 0 0
Area disturbed during the year 23 11
Total area disturbed 1,494 1,505
Sustainability Report 2010 89