Creating Value with the Future in Mind - Anglo American South Africa

arro Alto
water project
Many of our operations are in waterstressed
areas but even when access
to this precious resource is not limited,
we do our best to ensure we use it
responsibly. Our Barro Alto nickel
operation in Brazil embodies this
commitment.
As one of our most recent start-up
operations – first metal was produced
in March 2011 – we designed and built
Barro Alto with an emphasis on best
practice water stewardship. Using
approximately 300,000 m 3 of water each
month, it was important that we could
demonstrate appropriate management
in terms of both quantity and quality.
Water for the operation is sourced
from a fresh water river nine kilometres
from the site. From there, we pump the
water to a lined dam capable of storing
1.8 million m 3 . By lining the dam we
have avoided loss through infiltration,
resulting in a saving of 438,000 m 3 a
year, or 6% of total water requirements.
Water is then pumped from the dam to
the site, where it is used in processes
to cool the furnace and to granulate the
slag and metal. The closed-circuit system
sees the water pumped back to the dam
with no discharge from the operational
processes. The quality of the water is
checked against 71 parameters –
encompassing biological, chemical
and physical conditions – before and
after it has been used, to determine
any changes.
In an effort to mitigate the impact on
the river, the operation also draws
20% of its water requirements from
rainwater. Rain channels around the
plant collect water which then flows
naturally to the dam. This provides
for all the plant’s water requirements
for three to four months of the year,
during which time there is no need
for energy-intensive pumping of
fresh water. Some 800,000 m 3 per
annum of rainwater is captured and
used in this way.
Thanks to these measures,
Barro Alto now re-uses 85–87%
of its water – around 10% higher
than levels achieved at equivalent
older mine operations – and has
been recognised by local
environmental bodies.
Image
Otavio Lopes, an environmental engineering
coordinator, samples water quality at a
Barro Alto pump station.
Total water consumed
2008–2012
(million m 3 )
180
162
144
126
108
90
72
54
36
18
0
2008 2009 2010 2011
Anglo American actual
Business-as-usual (BAU) baseline
2012
externally – though the relevant
authorities are kept informed about
incidents until they are entirely
resolved. During 2012, in relation to
water, we confirmed seven Level 3
environmental incidents, one Level 4
incident and no Level 5 incidents (see
incident definitions on page 78). The
Level 3 incidents involved unplanned
discharges, where immediate remedial
action was taken to mitigate the
impact of each incident. None of
these receiving water bodies was
significantly affected by the incidents.
A number of longer-term interventions
remain in progress to avoid repeat
incidents. The Level 4 incident involved
effluent from our sewage treatment
plant at LLX Minas-Rio at Açu Port
in Brazil exceeding legal standards.
Operational personnel immediately
investigated water sources entering
the plant that could have caused the
issue and have implemented additional
maintenance measures to avoid
repeat incidents.
Anglo American’s exposure to acid
rock drainage (ARD) in southern Africa
is limited to some of our Thermal Coal
mines in the country’s Mpumalanga
province, where the geology is
predisposed to acidity. We have
mitigated the risk of ARD impact
through the development of a water
reclamation plant in eMalahleni and
two mobile water treatment plants.
The water reclamation plant, built in
partnership with BHP Billiton and the
eMalahleni Municipal Council in 2007,
currently treats around 25–30 Ml per
day of acid mine water from four mines.
We are currently expanding the facility
to double its capacity, with a planned
completion date of end-2013. In
addition to addressing ARD at its point
of impact by treating affected water,
we seek to avoid its occurrence in the
first instance through, for example,
designing our new mines differently,
concurrent rehabilitation of open-cut
operations and the effective
rehabilitation of waste facilities.
Managing our impact on the environment
Anglo American plc Sustainable Development Report 2012 59