2010
AMBATOVY SUSTAINABILITY REPORT
24
C1. Environmental Performance
C1.3 Water
The mine site extends into seven different watersheds. The
mine’s operational plan is designed to ensure that runoff from
mining excavations in each of the watershed areas flows into
a sediment retention basin. All water, both surface water and
groundwater, will be directed to one of the retention basins.
At the plant site, the principal water source is the water
recovered from dewatering of the ore slurry, which will be
augmented with water from the Ivondro River. A portion of the
effluent discharge from the tailings facility will be utilized in the
process to minimize river water usage. The use of processed
water at the plant is primarily for cooling water and boiler
feed water.
Water management complies with applicable criteria
including Malagasy regulations, World Bank guidelines and
recommendations from the World Health Organization (WHO)
for the supply of drinking water and disposal of wastewater.
Water use is controlled to minimize extraction and discharge.
Use of a pipeline to transport ore to the plant site allows
for balanced extraction from the Mangoro and Ivondro
Rivers. Following its use, water is treated in accordance with
approved operating permits, where applicable, before it is
returned to the environment.
Ambatovy’s Water Management Plan is a living document
that can be adapted according to the Project’s progress and
in response to data analysis. Key components of the Water
Management Plan are:
3
To ensure that works and operations do not adversely
affect surface and groundwater quality, and that any
wastewater complies with environmental standards.
3
To evaluate the flow rate and quality of surface and
groundwater downstream of mining activities to detect
any abnormalities, and to record all information in the
central hydrological database.
3
To ensure that the Torotorofotsy Wetlands is not
adversely affected by the mine’s activities.
3
To monitor water flow and quality and implement the
construction of retention basins to ensure compliance
with environmental standards in force.
3
To communicate with downstream users to ensure
their water needs are met, and to propose solutions if
problems arise.
3
To ensure that water supply and sewage treatment
meet the criteria of applicable water quality regulations
and guidelines.
3
To ensure that structures controlling erosion and
sedimentation are managed in accordance with the
recommendations of the Soil Management Plan.
Ambatovy has a permit to withdraw up to 2,000 m
3
/hr of
water from the Mangoro River. Water is mixed with the ore to
create slurry that will be transported down the pipeline. The
actual water consumption at full production is estimated to be
between 1,400 and 1,800 m
3
/hr, which corresponds to about
0.5% of mean annual flow.
Ambatovy has a permit to withdraw similar volumes from the
lower reaches of the Ivondro River near the plant site as a
carrying medium for reactants in the nickel-extraction process.
Much smaller extractions will be made from the Andranovery
River for human consumption at the mine site. This water
will be processed by a treatment plant. None of the sources
of water withdrawal will be significantly affected. Ambatovy’s
Water Management Plan, coupled with strict environmental
regulations, ensures that no withdrawal will have any impact
on the health of aquatic ecosystems.
Table 2: Estimated Water Withdrawals during Operations
Source
Amount
Mangoro River (mine site)
1,800 m
3
/hr
Andranovery River
N/A
Ivondro River
1,375 m
3
/hr
Total
3,175 m
3
/hr
At the mine site, the most sensitive ecological area of the
Project, there are three large sedimentation ponds, which
ensure the water that flows through impacted land or ore
preparation processes does not release sediments into local
water catchments. Furthermore, regular testing at the mine
site and along the pipeline of such measurements as total
suspended solids (TSS), pH, heavy metals and coliform
bacteria ensure the Project is not adversely impacting water
quality. A sewage treatment plant at the mine site ensures that
treated effluent meets applicable standards before discharge
into the retention ponds and subsequently into the local water
courses.
The tailings facility will collect large volumes of runoff from the
upper reaches of three water basins. During operations, the
tailings material will be disposed into the basins in phases as
the Project progresses. All collected water within each basin
will meet prescribed water quality requirements prior to being
discharged to the ocean through a diffusor system. Water
management at the tailings facility includes a groundwater
interception system to prevent movement of contaminated
groundwater into the downstream reaches of the basins.
Ground and surface water monitoring plays a key role in the
protection of the downstream fresh water systems.
The tailings facility is a long-term construction project
involving continuous raising of the perimeter dams to meet
containment needs. During the course of construction
activities, the development and management of erosion
collection systems to protect the downstream resources are
established.
