Shree Minerals has come under fire from environmentalists after it was revealed the miner would generate 20 times more rock waste than was approved by regulatory authorities.
Environmental group Save the Tarkine has called for the company to suspend operations at its Nelson Bay River mine pending a public inquiry.
The group says the miner was approved to produce 11,700 bank cubic metres of the rock, but will actually produce 230,000 bank cubic metres, The Advocate reported.
“This is scandalous that this mine has been allowed to proceed despite approvals accounting for only one twentieth of the acid producing waste,'' Save the Tarkine campaign coordinator Scott Jordan said.
“More acid producing waste means greater risks to waterways and aquatic life, and surrounding flora and fauna.''
Jordan said his group was seeking legal advice on the matter.
“Shree Minerals disclosed the discrepancy in a request to relocate the storage of acid producing wastes to an above ground location, despite the original EPA assessment finding that there were no suitable and safe above ground storage solutions.''
He called on Tasmanian government to suspend mining operations until a “proper and public'' assessment could be run”.
EPA director Alex Schaap said he allowed Shree to temporarily store the waste rock outside the open pit.
“That was necessary because the larger than expected amounts of waste rock could not have been stored inside the open pit without extending the pit into areas which could otherwise remain outside the pit footprint,” Schaap said.
"To avoid such an unnecessarily large pit, I required instead that the material be temporarily stored outside the pit on a specially constructed drainage pad for no longer than 30 months.
"The material is to be returned to the pit and securely capped after that time and an additional bond payment has been secured to ensure that this will occur.''
Plans to build the mine were halted in July 2013 after the Federal Court ruled former environmental minister Tony Burke failed to give “genuine consideration'' to conservation advice on the endangered Tasmanian devil.
It was then re-approved by new Environment Minister Mark Butler subject to 30 strict conditions.
The mine was officially opened in November last year.