Backflip … Beaconsfield gold mine. Photo: Craig Abraham

One day it was “world’s best practice”, the next it was time to consider an “alternative method”.

The operator of the Tasmania Mine at Beaconsfield has quietly stopped dumping its toxic waste back into the historic gold mine but neither the operator nor the state regulators is willing to explain the reasons for the backflip.

BusinessDay reported in August opposition to a proposal by the operator BCD Resources to dump 300,000 tonnes of tailings – mining leftovers thick with arsenic, cyanide and other toxins – straight back into the underground mine itself.

At the time, BCD chief executive Peter Thompson, West Tamar mayor Barry Easther, Tasmania EPA and the state department, Mineral Resources Tasmania, all denied there was a risk of poisonous seepage into the water table as a result of the waste.

The plan was “world’s best practice”, said Thompson. EPA director Alex Schaap agreed with Thompson’s assessment and the company’s waste proposals.

Fine print

Yet buried in the small print in the latest BCD quarterly release is this: “Removal of tailings from the plastic-lined tailing dam 2 by hydromining (water cannon and suction pumps) has been suspended after the removal of 20 per cent of its contents as this technique was neither effective nor efficient. Alternative, lower cost means for closure of tails dam 2 are under investigation”.

The company has dumped one-fifth of its waste from its main tailings dam back down the mine but stopped, with little explanation. Contacted last week, BCD chief financial officer Rochelle Greenwood declined to elaborate on the decision.

Peter Thompson was unavailable for comment as he had left the company. The EPA’s Alex Schaap issued this statement through a spokeswoman:

“I am considering a proposal from the company for an alternative method of management of tailings at the Beaconsfield site.”

There is no news as to whether the decision to stop dumping the tailings was due to safety reasons, environmental reasons, technical reasons or cost reasons – a mixture of these – or even intervention by other parties.

Tragic past

This Beaconsfield gold mine is no stranger to controversy. Its collapse on Anzac Day in 2005 killed miner Larry Knight and buried two others underground, before a dramatic rescue.

Both before and after that there had been rancorous controversy and a slather of legal actions over the ownership and corporate activity of the mine. Even today, a nine-year battle over a Freedom of Information request relating to the abandoned investigation of the corporate collapse by the regulators remains unresolved.

The Australian Securities and Investments Commission (ASIC) is still refusing to hand over FOI documents despite orders from the Administrative Appeals Tribunal (AAT). It still denies a cover-up.

The dispute over the tailings then, and the latest mysterious volte-face, is darkly befitting of the history of the Tasmania Mine.

The practice of pumping benign tailings underground to backfill mining stopes is common practice in Australia – as BCD had claimed – and it was used previously at the mine itself. But one mining expert told BusinessDay tailings had “never before been used in this country to fill up all the non-stope mine openings (such as ventilation shafts, the main access decline, main levels, drives, cross cuts etc) in an underground mine and therefore resulted in the sterilisation of significant JORC-standard mineral resources”.

Waterlogged slimes

 BCD had claimed, he said, that filling up all the mine openings with toxic tailings would not prevent the mine being reopened. Thompson had told BusinessDay that it would be easy to drill back through the tailings in all the openings even if the slimes were waterlogged.

Critics of the plan disagreed, citing not only environmental risks to the water table but also “economic vandalism” in sterilising a demonstrated gold resource. There is still plenty of gold in this mine, although costly and technically difficult to extract.

The company had declined to discuss the size of the remaining gold resources. It did not dispute the calculation (based on its own announcements before it began to play down the size of the resource this year) that remaining resources were at least 275,000 ounces of gold, worth over $420 million in the ground at the current gold price of about $1530 an ounce

Critics of the tailings proposal also claimed that BCD was seeking to obtain a short-term financial benefit, of the order of $2 million to $3 million, related to environmental bonds. The Tasmanian government, via its department, Mineral Resources Tasmania (MRT), and its regulator, the Environmental Protection Agency (EPA), have approved the BCD proposal.

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