VANCOUVER - The Canadian Environmental Assessment Agency wants a British Columbia mining company to explain its accusations that an agency panel used incorrect information in when it determined that a gold and copper mine could harm the environment.

The agency panel issued its report a couple of weeks ago, saying it did not believe that Taseko's (TSX:TKO) design for the New Prosperity mine near Williams Lake could avoid contaminating a nearby lake, as the company said.

The mine project was already rejected once by the federal environment minister because the company proposed using the lake as a tailings pond, so preserving the lake was key to the revised proposal.

Taseko issued a news release last week saying Natural Resources Canada and the review panel used the wrong design in their analysis of the new proposal.

"NRCan and the panel have chosen to ignore the Taseko design for the tailings basin that has been developed and reviewed by very experienced reputable tailings dam engineering and construction experts registered in the province of B.C.," Russell Hallbauer, company president, said in a statement issued Nov. 5.

The company said they had advised Environment Minister Leona Aglukkaq and asked her to consider additional information outside the panel report.

Now Yves Leboeuf, vice-president of operations for the federal Environmental Assessment Agency, has asked Taseko to identify the basis for those claims.

"Kindly explain how and why Taseko was, or would have been, prevented from raising its concerns about any differences in the models used by Taseko and by (Natural Resources Canada) through submissions to, and testimony before, the review panel itself as part of the review panel process," Leboeuf wrote in a letter to Brian Battison, the company's vice-president of corporate affairs, and Karl Gustafson, the company's legal representative at the review hearings.

Leboeuf also asked the company to provide the basis for the company's claim that the panel did not take into account the differences in the models used by Taseko and the federal agency in its decision.

The review process for the project has been a contentious one, and after the original plan was rejected the company met with federal Natural Resources Minister Joe Oliver, and wrote to him about the "overzealous individuals in government."

New Prosperity is the 10th largest undeveloped gold deposit in the world, and the company says the open pit mine will generate 550 direct jobs and $11 billion in real gross domestic product over 20 years.

Several local First Nations and environmental groups oppose the development, saying it will irrevocably damage the local ecosystem and disrupt traditional First Nations activities.

The decision is now in the hands of the federal environment minister.

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