by some estimates pebble will be three times larger because the gold and copper is spread out, deep and wide. and to get it they have to turn that rock into dust. and to do that they'll need a new explosives factory just to make enough dynamite. that's just to start the project that would take decades and cost billions. >> not only do we have to develop the mine, we've got a build a role between 90 and 100 miles. we've got to build a port and bring in substantial power. and operating costs will be over a billion dollars a year. >> but it's still worth it. it's still so precious -- >> yeah, it's a world class project. >> in addition to gold and copper, this ground also holds millions of tons of sulfur. mixed with air and water, sulfur turns to acid. so pebble would create a giant