Mine closure planning is standard practice in Australia, where end-of-mine-life plans are part of the initial approvals process.

They cover issues like site rehabilitation, risk assessment, long term monitoring, management of water community interactions.

Mine closure plans are considered just as important as planning to start mining in the first place.

There is also the ongoing environmental management of so-called 'legacy' mines to consider.

They are historic mines that may be up to 100-plus years old, long before the environment was considered.

America is also dealing with legacy mines that may be much older, and is working more on mine closure planning.

Professor Gary Pierzynski, of Kansas State University, has been in Australia to speak on the American experience.

"We're in the position where much of legacy mine issues have been addressed, and we're focused on the mine closure process in terms of beginning that at the very initiation of mining.

"We're learning from our past mistakes, so that when active mines are closed we won't have to deal with those legacy issues.

"Acidity is probably the biggest one and we need to contain those problems in the long term.

"We're probably effectively doing that over five to 10 year periods, but it gets beyond that and we get problems with acidity that we didn't anticipate and they get longer as time goes on."

The problems arise from acid drainage and acid soil runoff from sulphide-bearing minerals that oxidise when they're exposed to oxygen and become acidic.

"Another big issue is getting the community in the surrounding areas involved in the mining from the exploration stage.

"It could be in terms of economic growth. They might experience how that's handled in terms of critical services, like housing, and potentially even what will happen to the mine when operations cease.

"And looking at relocation and retraining of individuals in another area."

 

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