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Getting ready for the mine plan PLP has asked stakeholders to hold off judging its project until an official mine plan is released. Timeline • The plan is in production now; the public should receive updates in 2013. Pebble Watch interviewed Mike Heatwole, PLP’s vice president of public affairs, who said that creating the best plan is a complicated process involving engineers from PLP, Northern Dynasty Minerals and Anglo American. Any time a new component is considered, it has a domino effect on the plan. “We’re also spending significant time working our way through closure,” he said. “What does it look like … how will we get land back to chemical, biological and physical stability, what is the plan for long-term monitoring?” Plan rollout • PLP intends to take the plan to communities and get initial feedback from people shortly before permitting begins. “There are physical things you can’t change, like where the ore body is,” said Heatwole. But other aspects of the plan will change through the process. “It’s helpful for folks to understand that the project that gets initially rolled out and put into permitting is not a final. There are always terms and conditions that come out of that process based on public input and technical input.” Understanding technical aspects of the plan • PLP will be making multiple visits to different communities to make sure everyone gets a chance to see the plan presented in person. Staff members are working on explaining complicated terminology and concepts in layman’s terms, as well as possibly having multiple versions of the plan— an in-depth version for those who want details, as well as a “lighter” version that gives more of an overview.

About the proposed Pebble mine

Image: Northern Dynasty Minerals

Mine design & construction Mine developers have considered many mining scenarios with economic and environmental goals in mind. PLP has stated a commitment to environmental stewardship and its intent to employ modern technology to develop a mine that will meet regulatory requirements. A complete mining plan has not yet been published, but developers have provided some details of what will be needed for various aspects of the mine.

Type of mine

According to PLP, the mine will be “modern open pit”; according to Northern Dynasty, it could be open pit, a high-volume underground mine (block caving), or a combination of both.

Milling and processing

Metals in this deposit are distributed throughout the surrounding rock, so need to be ground into powder and then separated. Industry-standard froth flotation will likely be the main method used to accomplish this. Much of the material processed will be waste (tailings) that needs a long-term storage solution so that it does not create acid mine drainage that would adversely affect the environment.

Tailings storage options

The study team is looking at a range of options. What is known is that the tailings facility will be earthen, with waste material covered by a shallow layer of water, which will be constantly monitored.

Transportation, power and related infrastructure

• An 86-mile transportation corridor would be built between the deposit site and a new port planned for Cook Inlet. It would include a two-lane road and four pipelines for copper-gold concentrate, reclaim water, natural gas, and diesel fuel. • A natural gas-generating plant (approximately 400 megawatts) would be built at the mine site. 15

Pebble Watch Guide  

A reference guide to issues and science related to the development of the proposed Pebble mine in Bristol Bay, Alaska.