The Yukon Water Board was right to dig as deep as it did into the Carmacks Copper Project, says the lawyer representing two Yukon First Nations in this week's appeal hearing.

Arthur Pape said Wednesday the greater the complexity of a proposal, the greater the board's task of assuring itself that it understands the project.

The water board not only needed to conduct a thorough examination of the many different aspects of the open pit mining proposal, it was obligated to do so, Pape told Yukon Supreme Court Justice Ron Veale in his opening submissions Wednesday afternoon.

He argued there was no basis for Western Copper's suggestion that the board concerned itself with matters beyond its jurisdiction when it rejected the application for a water licence.

Just as the lawyer for the water board did Wednesday, Pape told Veale the board's roles and responsibilities are well established in several documents, including the Umbrella Final Agreement, which is protected by the Constitution of Canada.

Unlike YESAB, Pape continued this morning, the board was not comfortable going forward with unanswered questions, which is exactly why it rejected the application.

"YESAB said we are going to take an adaptive management approach, and the board said how are we going to adapt,” Pape told Veale.

Western Copper is asking the Yukon Supreme Court to overturn the water board's rejection of a water licence for the Carmacks Copper Project.

The project had already been cleared through YESAB and approved by the Yukon government when the water board rendered its decision last May, some five years after Western Copper entered the environmental screening process.

Veale is being asked to rule on two matters.

First of all, he must decide whether Western Copper has the legal grounds to launch an appeal, given that decisions of the water board can only be appealed on a question of law or jurisdiction.

If the judge agrees to allow the appeal, then he must decide whether the board went too far in rejecting the application for a water licence.

Western Copper is arguing the board did not have to reject the application outright, but could have dealt with its concerns in the terms and conditions of the licence. It's also arguing once the Yukon government issued its decision document accepting YESAB's recommendation for approval, the water board was required by law to issue a licence, though it was still free to impose whatever conditions it felt necessary.

The Yukon Chamber of Mines was in court this week arguing in support of Western Copper. It too argued that once the Yukon government issued a decision approving the project, the water board was obligated to provide a water licence.

The Little Salmon-Carmacks First Nation has spearheaded the opposition to the Carmacks Copper Project, maintaining Western Copper was proposing to use unproven technology that could backfire on the Yukon River watershed. The Selkirk First Nation and the Yukon Conservation Society are also standing in opposition to the project, in agreement with the concerns over unproven technology.

The First Nations and the society also argue the water board is independent in assessing applications for a water licence, and is not obligated to issue a licence under any circumstances.

On the specific issue of whether the water board was under any obligation to issue a licence, the Yukon government says it was not.

As the third days of hearings got underway this morning, Pape continued his assault on Western Copper's case by pointing the judge to a number of areas where there was uncertainty in the technology proposed for the mine.

Even YESAB identified the areas of concern, which is exactly why it recommended Carmacks Copper conduct a large scale field test to prove its theory if the project proceeded, Pape pointed out.

Heap leach technology, he explained briefly to the judge this morning, involves putting a bunch of crushed ore in a big pile and pouring a solution it over to leach the product down into a capture basin.

It took the gold mining industry about 30 to 40 years to establish reliable technology with the use of cyanide to leach gold from heaps of ore, he pointed out.

Pape said evidence before the water board suggested the use of sulphuric acid to leach out copper is whole other ball game that is not even close to the reliability that took the gold industry decades to refine.

YESAB, he said, was satisfied the large scale field testing would provide the answers to any uncertainties.

"The board felt that doing it the way YESAB suggested did not give them the comfort they needed,” said Pape.

"That is where they departed.”

He told the judge that during the seven days of public hearings conducted by the water board earlier this year, there was expert testimony indicating the mine would be well into production before the test cell could start answering any of the uncertainties.

In fact, the board heard it would take nine years for the test cell to proof Western Copper's assertion that it could detoxify the heap pads of all left over sulphuric acid in nine years at the most, and probably a lot sooner, said Pape.

The company, he suggested, wanted the board to accept the trust-us approach, and the board simply couldn't.

"I know the petitioner is unhappy, but the petitioner is the author of his own fate,” Pape told the judge.