The proposal for the Carmacks Copper mine has been given the green light by the Yukon Environmental and Socio-economic Board (YESAB).

The board released its decision late Friday afternoon, recommending a total of 148 measures to mitigate environmental and social impacts.

The YESAB recommends, for instance, that at least $21 million be posted as security to ensure adequate financing to close and reclaim the mine site.

Accommodations for single and transient workers employed by Western Copper during the estimated eight-year life of the mine should be located at the mine site instead of in Carmacks, to minimize social impacts on the community of 450, the board recommends.

"The executive committee believes that the recommendation to proceed is sound and that the terms and conditions within the report will mitigate or eliminate the potentially adverse effects of this project," Steven Mills, a member of the board's executive committee, told reporters during a press conference this morning.

"We are confident that this mine can be safe in the short term and most importantly, safe in the long term, so that Yukoners are not left with an environmental liability."

Mills emphasized that production will not involve the disturbance of any acid-generating rock.

The board's screening report and recommendations will be forwarded for consideration to the Yukon government and Natural Resources Canada.

The two decision bodies in this case have up to 60 days to accept, reject or vary the recommendations.

Mills pointed out any variations put forward by the two decision bodies must be returned to the YESAB for further review.

Rob Moar, director of the lands branch for the Little Salmon-Carmacks First Nation, said this morning he was still reviewing the document and would not be in a position to comment until after he briefed Chief Eddie Skookum this afternoon.

Karen Baltgailis, executive director of the Yukon Conservation Society, said this morning she too would have to go through the document before commenting, with it having just been released late Friday afternoon.

"These are such important recommendations that we really have to look very carefully at the recommended mitigations before we make any comment," Baltgailis said.

"It will take probably a couple of days before we can draw any conclusions about how effective those mitigations will be. This is much too serious for us to speak off the top of our head."

Western Copper is proposing to construct the open-pit mine about 38 kilometres northwest of Carmacks, along the Freegold Road.

It is currently proposing a mine producing 14,000 tonnes of copper annually, with an initial work force of 115 or so on shift work, half of whom would be at the mine site at any given day.

Full-time employment is expected to peak at 181 in years four through six. Employment during construction is expected to peak at more than 300.

Western Copper is expected to take two years to prepare the mine site for production.

"We are glad that the Carmacks Project is moving ahead, and we believe that YESAB completed a thorough and comprehensive analysis of the Carmacks Copper Project's environmental implications," the company's chairman and CEO, Dale Corman, said in a press release issued this morning.

"During the last four years, we have actively collaborated with YEA (Yukon Environmental Assessment) first and then YESAB in the screening of the Carmacks Project. Going forward, it is our intent to operate in an environmentally responsible manner and to act ethically in all aspects of our business practices."

Company spokesman Claire Derome said today the company will wait for the decision documents from the Yukon and federal governments but expects to begin moving through the permitting process soon after it receives them.

In addition to a quartz mining licence and other key permits such as a class A water licence, the company needs to raise the $140 million capital financing required.

Derome, formally a director with the Yukon government's Department of Economic Development, has been hired as the company's vice-president of government and community relations.

Derome said she will be opening a Whitehorse office to be closer to the community.

She doesn't expect production would begin until 2011.

The Little Salmon-Carmacks First Nation and the conservation society, among others, have challenged the soundness of the company's claims that it can successfully detoxify the sulphuric acid heap leach it's proposing to remove the copper from the ore.

Mills said even among those questioning the technology, there is general agreement that the heap pads can be detoxified. Concerns with regards to the heaps, he said, revolved primarily around how long it would take to neutralize the pads.

Instead of the initial four to five years Western Copper was estimating to detoxify the heaps, the board is recommending the Yukon government and Natural Resources Canada consider requiring enough security to treat the heaps for at least 10 years.

There will be a need for the Yukon to consider the provision of additional land for residential development, the report recommends.

The recommendations also suggest that the first of 18-plus individual heaps the company is proposing over the estimated eight years of mine life be used as a test cell to prove up the technology and better refine time estimates for detoxification.

Consideration must be given by the Yukon government to the influx of 10 to 20 new families in the community and the impact they will have on local infrastructure, such as the school, day care and nursing services.

The board also recommends the government, the village of Carmacks and the first nation work together to look at measures to minimize the impact of additional truck traffic, which currently will have to go directly through the community.

Construction of an alternative bypass road and bridge across the Nordenskiold River has been discussed, though the proposal did not form part of the project proposal under review by the board, Mills pointed out.

The YESAB's 148 recommendations cover everything from reclamation, to wildlife, air and water quality, to land use and the risk of oil and chemical spills.

The board recommends the government carefully monitor the test results from the first heap leach pad to get a better idea of what is realistic in terms of timing and cost of reclaiming the pads after the mine closes.

In the end, the company is proposing to detoxify, cover and re-vegetate the heap leach pads.

The open pit, measuring approximately 200 metres by 400 metres, would be fenced and left to fill with water from natural precipitation and groundwater inflow.

It's estimated the pit will take 300 years to fill naturally, Michael Muller, YESAB's project manager, explained this morning.

Yukon Energy has built the possibility of the Carmacks Copper mine going into production into its plan to extend the electrical grid from Carmacks to Stewart Crossing.

Providing a power line to the mine site was not part of the proposal, which currently calls for the use of onsite diesel generators as its source of power.

Yukon Energy has noted, however, the mine has expressed an interest in hooking up to the grid. The publicly-owned power corporation has also stated it would charge the company a certain portion of the cost of phase two of the grid extension, from Pelly Crossing to Stewart Crossing, in the same way it required Sherwood Copper to pay a portion of the main line extension from Carmacks to Pelly.