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WASTE MANAGEMENT
The two largest waste streams produced at IGO
operations are waste rock and tailings. At the Jaguar
Operation both are produced, whereas the Long
Operation produces only waste rock. The waste rock is
stored and managed in accordance with Department of
Mines and Petroleum guidelines to minimise its potential
to cause environmental impact and ensure the effective
rehabilitation of our mine sites both progressively and at
closure.
In FY2015, a total of 237,862 tonnes of waste rock was
mined from Jaguar Operation’s Bentley Mine. The majority
of waste rock generated at the Bentley mine is stored
before being crushed and processed in the Bentley CAF
plant and then pumped underground. At present, it is
predicted that all waste rock extracted from the Bentley
underground mine will be placed back underground in
the form of CAF prior to mine closure. As mining activities
in the Jaguar underground mine have now ended, no
waste rock has been removed in the reporting period. All
waste rock removed in the past has been formed into
the Jaguar waste rock dump, which has now been partly
rehabilitated (5.40ha).
In FY2015, a total of 110,570 tonnes of waste rock was
mined from the Long Operation. This is stored on a waste
rock dump and will be rehabilitated at mine closure.
During the 2014 calendar year, Tropicana Operation JV
produced 39.84 mega tonnes of waste rock.
At each of the sites, a small quantity of waste rock that is
known to be non-acid forming is crushed for use as road
base, bunding and other operational purposes.
Tailings produced at Jaguar Operation’s Processing
Plant are stored in a TSF to prevent discharge into the
environment. At the Jaguar Operations in FY2015, a total
of 2,479,978 wet tonnes of tailings was discharged into
the active Tailings Storage Facility 2.
The Tropicana Operation JV has a single cell tailings
storage facility where all tailings from the Tropicana
processing plant are deposited. In 2014 calendar year,
Tropicana deposited 13 mega tonnes of tailings into their
storage facility.
All IGO tailings storage facilities undergo an annual audit
to ensure that they are operated in accordance with the
mine’s operating strategy, safety conditions, prescribed
premises conditions and mining tenement conditions
It is noteworthy that the Long Operation uses tailings
from St Ive’s Gold Mine to produce a paste backfill material
that is used to re-fill mined underground voids. In FY2015,
Long Operation used 63,711 dry tonnes of tailings to
produce 86,424 tonnes of paste.
WATER MANAGEMENT
Water is a key consideration in IGO’s mining activities.
Water is used in exploration drilling, in the mining process,
in ore processing, in our camps, for dust suppression
and many other uses. Water is variously extracted
from underground mines and dedicated borefields. The
uncontrolled release of water and process solutions can
have unintended safety and environmental impacts.
Consequently, the management of water is central to the
sustainability of our operations.
JAGUAR OPERATION
The Jaguar Operation is situated in a remote area and
extracts all its required water from groundwater sources.
Groundwater naturally seeps into our underground
mines. The water is extracted from the mines to prevent
them from flooding. Our water needs are supplemented
by production bores situated throughout the mining
tenement.
All groundwater abstraction is controlled under a
groundwater licence issued by the Department of Water.
The licence defines a maximum abstraction volume
from varying sources around the site. A series of flow
meters have been installed to accurately measure the
volume of water used. This ensures we operate within
our licence limits. The standing water level (SWLs) of
each of the production bores and surrounding pastoral
bores are periodically measured to assess the degree to
which the underlying aquifers is affected. Of particular
importance is Jaguar Operation’s effect on the water
table and water quality within the surrounding pastoral
leases. Groundwater monitoring to date has found water
levels are dropping in accord with the modelled outcomes.
However, albeit that water levels in some pastoral bores
have dropped, it has not been to an extent that will have
a detrimental impact on the pastoral lease.
IGO also carries out water chemistry analysis on samples
taken on a quarterly basis at all production bores, pastoral
bores and underground water reservoirs. The monitoring
provides clear insight into the impacts of our activities
on the areas groundwater chemistry. Monitoring to date
has demonstrated that our activities have not caused
any material changes to water chemistry beyond that
predicted.
Communications with pastoralists has confirmed that
they have experienced no adverse outcomes on their
properties.
All volumes, SWLs and chemistry results are reported
in an annual groundwater monitoring summary report,
produced by a specialist hydrogeologist, and then
submitted to the Department of Water for review. This
report highlights any issues or environmental impacts
abstraction may be causing. This year’s report found no
specific concerns relating to groundwater abstraction.