World's largest copper mine indicted for water over-use

Chilean watchdog charges BHP for water misuse at Escondida

Cecilia Jamasmie

mining.com

31 July 2020

Chile’s environmental watchdog said on Friday it would charge BHP’s
Escondida copper mine, the world’s largest, with drawing more water than
its permits allowed for nearly 15 years.

The Superintendence of the Environment (SMA) said the operation has
caused a decrease in the water table levels greater than 25 cm, which is
the allowed limit in the Atacama desert, the world’s driest, where
Escondida is located.

The regulator said the charge against BHP’s copper mine could result in
the revocation of its environmental permit, closure or a fine.

“The company, despite committing to reduce its extraction of water …
exceeded the maximum level permitted since 2005, tripling that level in
2019,” SMA said in a statement.

The news comes on the heels of a top environmental court’s call for a
government-vetted water study. Such a report would help stamp out
lingering questions about mining sustainability in Chile’s north.

This is not the first time Escondida has come under scrutiny. In
February, the country’s Defence Council’s (CDE) filed a lawsuit against
the mine, alleging it had caused “irreparable damage” to the Punta Negra
salt flat in the northern Antofagasta region.

The bone of contention is the mine’s now-abandoned practice of drawing
water from the salt flat. The area is one of the many natural resources
that has been depleted after decades of mining activity in and around
the Atacama desert and nearby salt flats.

Time for sea water

Northern Chile, which hosts some of the planet’s largest copper and
lithium deposits, is occasionally hit by heavy rains and floods.

According to the country’s water authority DGA, however, the area has
become drier over the last decade. This has added an extra layer of
difficulty for mining companies with projects and operations nearby, at
times when the industry’s demand for water is expected to soar as ore
grades decline.

Data from the national mining association, Sonami, shows that about 20%
of the water currently used by major copper miners comes from the sea.
The figure, however, is expected to more than double by 2029.

Chile’s copper commission, Cochilco, in turn, forecasts that ocean water
consumption will represent around 43% of the total used by the local
mining industry in the next 10 years.

BHP already gets more than 40% of the water it needs from the ocean. The
world’s largest miner has vowed to stop using fresh water drawn from the
surface and underground in Chile by 2030.

In 2018, the mining giant spent $3.43 billion on a desalination plant
for the Escondida mine, which includes two pipelines to transport the
water 3,200 meters above sea level.

Other than their high cost, desalination plants also pose worries
related to the waste miners generate.

Lithium producers generated brine, which is usually pumped back into the
reservoir where the water was taken from. This causes an imbalance in
the overall water composition, which is harmful to the environment
within the sourcing body.