Sustainability Report - Antofagasta PLC

Water
Our approach
Using water efficiently and recycling it wherever possible is a central concern
for the mining operations. All of our mines have water management plans in
place and they strive to use water efficiently and recycle or reuse it. Our
operations recycle up to 85% of the water used in their processes through a
system of industrial water recirculation. The rest is lost either through
evaporation or from being trapped in tailings or waste ore.
The mining companies monitor the quantity and quality of the water they use
and report on these key performance indicators every month. This is one of
the KPIs that affect each company’s bonus. The mines also ensure that
emissions of wastewater meet quality standards.
To reduce demand on surface and groundwater sources Antofagasta
Minerals has pioneered the use of sea water in the mining process in Chile.
Michilla began using non-desalinated sea water in the 1990s and, on a
much larger scale, Esperanza also operates using non-desalinated seawater.
We have recently approved the Antucoya project to operate using nondesalinated
sea water.
As both water availability and water quality are important social issues, each
mining company engages with local communities to understand their
concerns and evaluates how to reduce its impact on local water demands.
This is most relevant for Los Pelambres, as it is situated within an
agricultural valley. In 2011 it relocated one of its surface water intakes so
that from 2012 it will be able to collect water from the naturally lower quality
upper section of the Pelambres river. This will improve the quality of water
downstream which is used by the local communities. El Tesoro continues to
collaborate with the water authority to collect information to better
understand and manage the Calama wellfield.
Antofagasta Minerals 53
What is the issue?
Water is a key input for mining and mineral
processing. All of our operations are in waterstressed
regions. Three of our mines operate in the
extremely arid conditions of the Atacama desert. The
fourth one is situated at the source of an agricultural
valley.
Antofagasta Minerals’ main challenge is to operate
and to grow sustainably by preventing and controlling
the impact of our activities and being efficient in the
use of natural resources.
When using surface and groundwater, we have
strong water management programmes to recirculate
water and to intensively monitor basin water quality
and quantities (flows and levels). We have also
pioneered the use of alternative water sources.
Michilla has used seawater since the 1990s and our
newest operation, Esperanza, was built to operate
using non-desalinated seawater.
In the longer term, climate change is likely to have an
impact on the freshwater resources in Chile, with
changes in precipitation and increased temperatures,
predicted to reduce the availability of water.
Overview
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