BHP’s (ASX, LON, NYSE: BHP) Escondida copper mine in Chile, the world’s largest, won’t continue to draw fresh water from the Atacama salt flat, using instead desalinated water brought from its coastal plants.
The miner’s decision comes as the
country is stepping up protections for a natural resource that has been
depleted after decades of mining activity in and around the Atacama desert, the
driest place on Earth.
The Atacama region, which hosts
some of the planet’s largest copper and lithium mines, is occasionally hit by
heavy rains and floods. According to Chile’s water authority DGA, however, the
area has become drier over the last decade, adding an extra layer of difficulty
to mining companies with projects and operations nearby, at
times when the industry’s demand for water is expected to soar as ore
grades decline.
BHP’s decision to withdraw applications
to renew a permit to pump 428 litres per second of underground water is
expected to reduce pressure on the vast, lithium-rich salt flat. The plain is home
to top lithium miners Albemarle and SQM, which also extract fresh water from
underneath it.
The world’s No. 1 miner already gets more than 40% of the water it needs from the ocean and 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 Escondida mine, which includes two pipelines to transport the water 3,200 meters above sea level.
Antofagasta’s (LON:ANTO) Zaldívar copper
mine is also seeking to renew permits to draw water from the flat.
Unlike Escondida, it has no backup
plan. The mine, which is approaching the end of its productive life, will have
to close down if its water license isn’t renewed, the company has
warned in the past. Even with water use permits in place, Zaldívar will
probably stop producing in 2029.
The current license allows Antofagasta
to pump 500 liters a second through 2025 and the miner is asking for a license
to pump 213 liters a second through 2029.
Other than their high cost,
desalination plants also pose worries related to the waste miners
generate. That product — brine — 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.