Mine committee reviews Echo's '97 concept, tailings

Posted: Friday, March 11, 2011

The AJ Mine Advisory Committee is gearing up to outline what criteria would be needed to reopen the AJ mine and what would be wanted.

The committee met Thursday evening and heard presentations on the 1997 Echo Bay proposal, and what tailings are and methods of disposal.

Committee Chairwoman Donna Pierce warned that the proposal was by no means something they’re considering as a mine proposal, but they were merely using the study to look at the issues from then.

Sam Smith, committee member, was one who helped develop the ‘97 study and previously worked for Greens Creek Mine and Echo Bay.

The initial Echo proposal was mining 15,000 to 22,000 tons of ore per day, he said, but the company also wanted to look at what else was an option. So a study was done for a small mine — 3,500 tons of ore mined per day.

One reason they looked into smaller production was to reduce milling, another was to make the project more easy to get through the permit process.

Then the price of gold was about $375 per ounce, and even a small mine wouldn’t have been profitable. Now, the price is averaging $1,400 an ounce.

Smith warned that the work put into a proposal back then did not include a feasibility study, nor a complete mine study.

He said the major issues at that time were:

• Mining method (long haul open stoking), tailing disposal methods (not studied with the proposal);

• Facilities (keeping many underground);

• Noise (they felt since most operations were underground that noise would be minimal).

• Traffic (would depend upon where the surface facility was, busing was encouraged).

• Employment opportunities (likely 80-90 jobs at all skill levels).

• Financial impact (would likely increase tax revenue, royalty payments would be received, it would potentially increase the number of children in schools and utilize local contractors for detailed work).

• Water quality (careful attention to practices around water source would be required, would still be treated at the wastewater plant and allowable fluids would discharge into the channel).

Smith said all the tailings could be disposed of underground in some method. That project would have milled 2,000 tons of ore per day, produced the same amount in waste rock for sale or project use, have a mine life of 12.8 years, have 12.8 million tons of ore available, an average grade of .074 ounces per ton and would have capacity for 15.8 million tons of tailings.

Smith added that he didn’t know what the city’s intention was if the mine never redevelops, but if the structures inside aren’t stabilized there will be underground collapses and other undesirable effects.

Committee member Gregg Erickson said they need to include in the report to the Assembly why the project was canned. Committee member Frank Bergstrom said it was due to financial reasons.

Smith said there were permitting issues at the time, but that wasn’t the primary concern.

Rorie Watt, CBJ engineering director, said he’s often asked what’s changed and why they’re looking at the project.

“I’ve got it narrowed down to three points,” he said. “Concern for the local and state economy, gold prices ..., and the third really is this small mine concept, somewhat new in the industry and is percolating in peoples minds. It never had any public review or comment. Could this be done a different way?”

Watt said the committee has to narrow down what Juneau needs to have in order for the mine to fly and what it would want to have. That, he said, would have to be spelled out in a lease. Details also would need to be worked out for junior mining companies selling to larger ones.

Smith said the lease also has to be something that is approachable, otherwise they may exclude any development.

“This is really helpful discussion,” said committee member Laurie Ferguson Craig. “It really helps us to try and envision what we would look at as a community.”

Committee member Kurt Fredriksson said the citizens of the state are very environmentally conscious, yet it also is a resource-rich state. He also agreed that protecting the environment, while utilizing resources, would come through in lease form.

“The city has an extra level of protection because it is an owner,” he said. “As an owner, you can insist upon it. You might not get it because somebody walks away. I would like to hear maybe a little bit more about what’s done in leasing mines.”

The committee also heard from Mike Satre, executive director for the Council of Alaska Producers, vice chair of the planning commission and an Echo Bay employee.

Satre said he wasn’t there to take a stand one way or another. Satre provided the committee with information on tailings and how they’re handled at Greens Creek Mine.

He said tailings, which is all the material left over, are one of the most important considerations when developing a mine. He said Greens Creek puts most of the tailings back into the ground with a cement paste process, which leaves on average of 60 percent of the tailings below ground. That material is compacted and pumped into “void” spaces in the mine. This process allows for stability of the mine and the ability to mine above and to the sides of where they have extracted.

Satre explained that mine has more acidic material coming out of it, which means they have a very meticulous system in place for their above-ground dry storage of the remaining tailings. They have to prevent any moisture that falls on the outdoor tailings from getting into the water streams.

Satre said that wouldn’t be a concern with the AJ mine since the material extracted doesn’t have the same acidic properties.

Part of the mine’s long term plan includes managing the dry-storage tailings that eventually gets covered by topsoil and other components, however that must be maintained after the mine closes.

“As miners, we know that our responsibility to our region, to our environment doesn’t end the day you shut the door,” Satre said. “We do have to maintain things long-term. That’s different than how mining was thought of ... even 20 years ago.”

• Contact reporter Sarah Day at 523-2228 or sarah.day@juneauempire.com.

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