Glencore’s controversial McArthur River Mine has overcome one of the final barriers to its plans to keep digging, more than five years after an enormous error caused spontaneous combustion on the mine site and created fears of an environmental catastrophe that could last millennia.

On Thursday, Northern Territory primary industry and resources minister Paul Kirby signed off on changes to the McArthur River Mine’s management plan. It follows a similar approval issued by the federal government in June.



The decision marks the end of a five-year environmental approval process, sparked by dramatic spontaneous combustion and plumes of sulfur dioxide on the mine site.

The burning and smoke were caused by a misclassification of the open-cut lead-zinc-silver mine’s rock, which led to risky, reactive rock being stacked in a waste rock dump without being appropriately quarantined.

The misclassification, and contamination incidents on the mine site, gave rise to fears in the nearby community of Borroloola that the McArthur River was no longer safe to fish in.

It also created a risk that acid mine drainage and toxic leaching from the dump could slowly contaminate the McArthur River, permanently affecting the region’s water system.

Glencore has admitted the area will need to be monitored for 1000 years after digging ceases.

The new authorisation has adopted all thirty recommendations made by the NT’s Environment Protection Authority. These include the establishment of an independent panel of experts to advise on the waste rock dump, monitoring of sulfur dioxide within a kilometre of the dump, and monitoring of contamination in fish in the McArthur River.

The approval means Glencore can now begin works to fix the environmental problems it created.

Mining expert at RMIT university Gavin Mudd told BuzzFeed News the conditions imposed by the government on Glencore were mostly positive, but did not deal with the critical question of how the mine would eventually be closed.

“To me it’s just a formal disappointment,” Mudd said. “It doesn’t require the whole waste rock to be put back in the pit. So much of it is basically saying, just monitor everything, just review everything through independent expert panels.”

Mudd argues that the safest way to deal with the long-term risk is to backfill the open-cut pit with the risky rock, but Glencore has dismissed that option as uneconomic, preferring to seal the dump and leave it on the earth’s surface.

The conditions require Glencore to fund an independent panel of experts to advise on the environmental performance of the waste rock dump and closure planning.

“It’s basically an acknowledgement that you’re dealing with a very difficult site,” Mudd said. “I don’t know of any other mine site, except the Ranger uranium mine, that has this level of detail and review and everything else. It needs it without a doubt.”

Under the new authorisation, Glencore will also have to front up another $33 million for the security bond, which has increased from $487 million to $520 million.

Mudd was concerned by an approval condition that Glencore had to commit to creeks on the mine site showing long-term improving trends in water quality within 20 years of mining wrapping up. He said it was “contradictory” with another condition that the health of the McArthur River along its whole length has to be protected at all times from mine related impacts.

The government approval also means Glencore must conduct all works according to the requirements of the Aboriginal Areas Protection Authority (AAPA) – an independent government agency that oversees the protection of Indigenous sacred sites.



The AAPA is considering whether to issue an authority certificate to allow the waste rock dump to go up to a height of 140 metres, from its current cap of 80. Increasing the height would obscure the view of the Barramundi Dreaming from the highway.