The Minto Mine wants to go underground in its next phase of operations beginning next year.

In its current application before the Yukon Environmental and Socio-economic Assessment Board (YESAB), Capstone Mining has applied through its wholly-owned Minto Explorations for approval of a second open pit, along with an underground mining program to run simultaneously.

YESAB issued a notice last week providing interested parties and individuals with an opportunity to comment on the application until Dec. 24.

Steven Quin, president of Capstone Mining Corp., explained Monday while in Whitehorse for a Yukon Water Board hearing the phase-four application would extend mining life for two years.

Additional ore would also result in enough stockpile to keep the mill running into 2015, he pointed out.

In its original application before ramping up production, the mine life was estimated at approximately seven years from the start of commercial operations in 2007.

It's expected the main pit, however, will be mined out by March or April, with enough stockpile to feed the mill for about another year after that.

Quin said the phase-four application will take mining into 2013.

The company, however, fully expects to apply next year for a phase-five extension which would extend operations into 2020 or 2021, he said, adding the continuing exploration program could even push the mine life beyond that.

Quin said the plan is to start stripping the overburden for the new pit next year, along with beginning the underground tunnelling work.

Included in the application before YESAB is a proposal to expand the capacity of the camp from 200 to 300 workers, partly due to the additional 40 to 50 positions which would be onsite at any one time for the underground program.

If there is a need to raise power consumption, it would be minimal because of the changed operational plan, though the company is undertaking an assessment to look at the issue more closely, he said.

The new proposal also calls for the construction of a mechanical shop.

Meanwhile, the water board heard an application this week from the Minto Mine to amend its existing water licence, in light of unexpected volumes of water in the last three years which required emergency discharge orders at the mine site.

Quin pointed out in his opening remarks to the board members and interveners Monday morning, when the potential purchase of Minto Explorations was examined, one of the key issues was the possibility of not having enough water.

But unexpected volumes in the spring melt of 2008, heavy rains later that summer followed by another heavy spring melt in 2009 and the water situation this year have confirmed the need for amendments to the licence, he said.

Quin said the company has worked extensively with the Selkirk First Nation, the Yukon and federal governments and other stakeholders in preparing its application.

"We are pleased to say through this approach, we believe we come to this board on this application in general agreement about almost all of the material issues,” he told members of the board.

"Through this collaborative approach, we believe that we have a better understanding of the concerns of the interveners, and with input, we have been able to develop what we believe is a sustainable water management strategy for the Minto Mine going forward to address the unanticipated water events that have presented such challenges for our operations over the last three years.”

Capstone Mining announced this week Quin will step down as company president at the end of the year to

pursue other opportunities, though he would remain a member of Capstone's board of directors.