With a puff of smoke, a boom and an agonizingly slow 15-second drop, the tallest smokestack ever demolished in North America crashed to the ground Sunday.
Explosives blew out the base of the 715-foot smelter stack on Bunker Hill, and it fell its full length to the ground seconds after 2 p.m. At the same time, three other stacks on the federal Superfund site were demolished.Phil Peterson of Nampa won a raffle to press the plunger signaling the demolition expert to trigger the charge. Peterson said it was an incredible sight.
"Physically, it was not much of a task," Peterson said. "The boom was delayed and then it starts to go down like a Ponderosa pine."
The slender, gray, concrete stacks that dominated the skyline of this narrow mining valley in northern Idaho almost appeared to withstand the initial blast of 240 pounds of dynamite. But then they toppled like trees and raised a huge cloud of dust upon impact.
Thousands of people lined the hillsides and parked their cars wherever they could to watch the symbolic end of the region's former smelting industry.
"With the toppling of these stacks, a new Silver Valley emerges," said Shirley Mix of the Idaho Division of Environmental Quality.
Before the blast, numerous speakers invoked the Silver Valley's production of silver, lead and zinc this century.
"The industry produced new materials to allow our nation to win two world wars," said Tim Olson, director of the Northwest Mining Association, based in Spokane, Wash.
The stacks fell into shallow trenches, where they will be broken up and then buried in place.
Minneapolis-based Engineering Demolitions Inc. handled the project.
The three smaller stacks measured 610 feet, 202 feet and 200 feet.
The stacks, built in the mid-1970s, held little sentimental value in the scenic valley. When the smelter complex closed in 1981, more than 2,000 people were thrown out of work, and the area has never recovered economically.
The stacks towered over a devastated moonscape of rusted metal, weeds and huge mounds of slag at the fenced smelter site.
The stacks no longer served any purpose. They posed an aviation hazard and cost $25,000 a year to keep their aircraft warning lights blinking.
More than 100 buildings have already been demolished at the former zinc and lead smelter, part of one of the nation's largest Superfund sites at 21 square miles.
The site contains lead, arsenic and other hazardous contaminants left behind from decades of mining and smelting. Cleaning it up is expected to take until 1998 and cost an additional $65 million.